The effect of energy weighting on the SNR under the influence of non-ideal detectors in mammographic applications

International Nuclear Information System (INIS)

Patatoukas, G.; Gaitanis, A.; Kalivas, N.; Liaparinos, P.; Nikolopoulos, D.; Konstantinidis, A.; Kandarakis, I.; Cavouras, D.; Panayiotakis, G.

2006-01-01

This work investigates the effect of the energy-weighting technique on the signal to noise ratio (SNR) response of X-ray imaging detectors. So far in the literature all scintillation-detector characteristics (detection efficiency, conversion efficiency, light-attenuation effects, etc) that degrade image quality have been ignored. A theoretical evaluation of the scintillator's SNR output was carried out. An algorithm was produced to describe the variation of the weighting factor, and SNR, with respect to the anode material (Mo or W), in a particular energy range (25-40 keV), typical for mammography, using two different phantoms. Results show that under non-ideal conditions the ratio of the weighted SNR to the original SNR appears to be increasing from values that are close to unity, and under specific conditions, can reach values up to 30. For the further investigation of this method, a more complex, simulated computed tomography breast imaging system was modeled and studied for various parameters such as breast software phantoms, scintillation materials and reconstruction filters

Umweltbildung - Bildung für nachhaltige Entwicklung. Was macht den Unterschied?

OpenAIRE

Rost, Jürgen

2002-01-01

Der vorliegende Beitrag will zeigen, dass Bildung für eine nachhaltige Entwicklung gegenüber herkömmlicher Umweltbildung tatsächlich eine neue Qualität hat. ... Das Konzept der Bildung für eine nachhaltige Entwicklung hat eine weitere Facette neben der Umweltbildung, nämlich das Konzept des globalen Lernens. Zunächst werden die zentralen Probleme dargestellt, die die Umwelterziehung in den vergangenen drei Jahrzehnten nicht lösen konnte und woran sie vielleicht gescheitert ist. Abschnitt 2 be...

A Semi-Empirical SNR Model for Soil Moisture Retrieval Using GNSS SNR Data

Directory of Open Access Journals (Sweden)

Mutian Han

2018-02-01

Full Text Available The Global Navigation Satellite System-Interferometry and Reflectometry (GNSS-IR technique on soil moisture remote sensing was studied. A semi-empirical Signal-to-Noise Ratio (SNR model was proposed as a curve-fitting model for SNR data routinely collected by a GNSS receiver. This model aims at reconstructing the direct and reflected signal from SNR data and at the same time extracting frequency and phase information that is affected by soil moisture as proposed by K. M. Larson et al. This is achieved empirically through approximating the direct and reflected signal by a second-order and fourth-order polynomial, respectively, based on the well-established SNR model. Compared with other models (K. M. Larson et al., T. Yang et al., this model can improve the Quality of Fit (QoF with little prior knowledge needed and can allow soil permittivity to be estimated from the reconstructed signals. In developing this model, we showed how noise affects the receiver SNR estimation and thus the model performance through simulations under the bare soil assumption. Results showed that the reconstructed signals with a grazing angle of 5°–15° were better for soil moisture retrieval. The QoF was improved by around 45%, which resulted in better estimation of the frequency and phase information. However, we found that the improvement on phase estimation could be neglected. Experimental data collected at Lamasquère, France, were also used to validate the proposed model. The results were compared with the simulation and previous works. It was found that the model could ensure good fitting quality even in the case of irregular SNR variation. Additionally, the soil moisture calculated from the reconstructed signals was about 15% closer in relation to the ground truth measurements. A deeper insight into the Larson model and the proposed model was given at this stage, which formed a possible explanation of this fact. Furthermore, frequency and phase information

Gender - Schlüsselthema für Entwicklung sowie Bildung für Nachhaltige Entwicklung

OpenAIRE

von Hagen, Markéta; Willems, Johanna

2011-01-01

Gleichberechtigung der Geschlechter ist international als Schlüssel für Nachhaltige Entwicklung anerkannt. Die internationale und deutsche Entwicklungszusammenarbeit hat zum Ziel, Frauen und Männer gleichermaßen am Entwicklungsprozess zu beteiligen und profitieren zu lassen. Die Integration des Gender-Ansatzes bedeutet, dass Entwicklungsmaßnahmen die Geschlechterverhältnisse berücksichtigen und versuchen diese im Sinne der Gleichberechtigung zu beeinflussen. Der Gender-Ansatz ist einerseits a...

Low-SNR Capacity of MIMO Optical Intensity Channels

KAUST Repository

Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

2017-01-01

The capacity of the multiple-input multiple-output (MIMO) optical intensity channel is studied, under both average and peak intensity constraints. We focus on low SNR, which can be modeled as the scenario where both constraints proportionally vanish, or where the peak constraint is held constant while the average constraint vanishes. A capacity upper bound is derived, and is shown to be tight at low SNR under both scenarios. The capacity achieving input distribution at low SNR is shown to be a maximally-correlated vector-binary input distribution. Consequently, the low-SNR capacity of the channel is characterized. As a byproduct, it is shown that for a channel with peak intensity constraints only, or with peak intensity constraints and individual (per aperture) average intensity constraints, a simple scheme composed of coded on-off keying, spatial repetition, and maximum-ratio combining is optimal at low SNR.

Low-SNR Capacity of MIMO Optical Intensity Channels

KAUST Repository

Chaaban, Anas

2017-09-18

The capacity of the multiple-input multiple-output (MIMO) optical intensity channel is studied, under both average and peak intensity constraints. We focus on low SNR, which can be modeled as the scenario where both constraints proportionally vanish, or where the peak constraint is held constant while the average constraint vanishes. A capacity upper bound is derived, and is shown to be tight at low SNR under both scenarios. The capacity achieving input distribution at low SNR is shown to be a maximally-correlated vector-binary input distribution. Consequently, the low-SNR capacity of the channel is characterized. As a byproduct, it is shown that for a channel with peak intensity constraints only, or with peak intensity constraints and individual (per aperture) average intensity constraints, a simple scheme composed of coded on-off keying, spatial repetition, and maximum-ratio combining is optimal at low SNR.

Safety design of SNR-300

International Nuclear Information System (INIS)

Traube, K.

1976-01-01

The joint German-Belgian-Dutch loop-type 300 MW(e) LMFBR prototype is being constructed at Kalkar on the lower Rhine in Germany. Among the many arguments put forward in defense of SNR-300, that of acquiring licensing exprience has proven to be of major importance to the international breeder scene. The severity of the licensing procedures and of the safety standards imposed are unique in several respects, including timing: generally growing scepticism towards nuclear power increased severity of the licensing practice; organizational features: the procedure and criteria developed for commercial light water reactors have been applied without exemptions. This relates to the commercial-type contract under which SNR-300 is being built for private utilities by a private company; and German nuclear safety standards, known worldwide to be most stringent. The following three important areas are discussed in which SNR-300 decidedly deviates from its forerunners: protection against the hypothetical core disruptive accident (HCDA), protection against external events, and provisions for in-service inspection

Bildung für eine nachhaltige Entwicklung und Fairer Handel

OpenAIRE

Mathar, Reiner

2003-01-01

Im Rahmen des BLK-Programms '21' kann Bildung für nachhaltige Entwicklung im schulischen Rahmen greifbar gemacht werden. Der Beitrag beschreibt einige Umsetzungsmöglichkeiten am Beispiel des Fairen Handels. (DIPF/Orig.)

Perbedaan Tolerabilitas Meloxicam dengan Natrium Diklofenak terhadap Saluran Cerna pada Pasien Rawat Jalan di PoliklinikPenyakit Saraf Rumah Sakit Angkatan Laut Dr. Mintohardjo Jakarta 2011

Directory of Open Access Journals (Sweden)

Lailan Azizah

2013-06-01

Full Text Available Abstrak Obat anti inflamasi non steroid dihubungkan dengan insiden efek samping yang tinggi terhadap saluran cerna. Penghambatan enzim siklooksigenase merupakan dasar efikasi dan toksisitas obat anti inflamasi non steroid. Penelitian ini bertujuan untuk mengevaluasi jenis obat anti inflamasi non steroid yang digunakan di poliklinik penyakit saraf Rumah Sakit Angkatan Laut (Rumkital Dr. Mintohardjo Jakarta dan mengevaluasi tolerabilitas meloxicam 15 mg dengan natrium diklofenak 100 mg terhadap saluran cerna. Metode penelitian ini observasi cross-sectional dan cohortprospektif pada periode Desember 2010–Maret 2011. Pengambilan data mengenai keluhan dispepsia terkait penggunaan obat anti inflamasi non steroid terdiri dari nyeri abdomen atas, mual, muntah, kembung abdomen, dan cepat kenyang dilakukan melalui wawancara berdasarkan kuesioner the porto alegre dyspeptic symptoms questionnaire (PADYQyaitu sebelum, setelah 2 minggu, dan setelah 4 minggu pengobatan. Hasil penelitian menyatakan obat anti inflamasi non steroid paling banyak diresepkan di poliklinik penyakit saraf Rumkital Dr. Mintohardjo adalah meloxicam (48,21%, selanjutnya natrium diklofenak (31,07%, asam mefenamat (15,36%, piroxicam (3,93% dan asetaminofen (1,43%. Meloxicam secara bermakna menunjukkan risiko yang lebih kecil terhadap insiden saluran cerna daripada natrium diklofenak setelah 2 minggu pengobatan dalam hal keluhan nyeri abdomen atas dan kembung abdomen dengannilai kebermaknaan pengujian masing-masing sebesar 0,020 dan 0,037. Berdasarkan hasil penelitian ini diketahui meloxicam memiliki tolerabilitas saluran cerna lebih baik daripada natrium diklofenak setelah 2 minggu pengobatan. AbstractPerbedaan Tolerabilitas Meloxicam dengan Natrium Diklofenak terhadap Saluran Cerna pada Pasien Rawat Jalan di Poliklinik Penyakit Saraf Rumah Sakit Angkatan Laut Dr. Mintohardjo, Jakarta 2011. Non-steroidal anti-inflammatory drugs (NSAIDs are associated with a high incidence of

Indications and technique of fetal magnetic resonance imaging; Indikationen und Technik der fetalen Magnetresonanztomographie

Energy Technology Data Exchange (ETDEWEB)

Asenbaum, U.; Woitek, R.; Furtner, J.; Prayer, D. [Medizinische Universitaet Wien, Abteilung fuer Neuroradiologie und Muskuloskelettale Radiologie, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria); Brugger, P.C. [Medizinische Universitaet Wien, Zentrum fuer Anatomie und Zellbiologie, Wien (Austria)

2013-02-15

Evaluation and confirmation of fetal pathologies previously suspected or diagnosed with ultrasound. Ultrasound and magnetic resonance imaging (MRI). Technique for prenatal fetal examination. Fetal MRI is an established supplementary technique to prenatal ultrasound. Fetal MRI should only be used as an additional method in prenatal diagnostics and not for routine screening. Fetal MRI should only be performed in perinatal medicine centers after a previous level III ultrasound examination. (orig.) [German] Evaluierung und Bestaetigung von im praenatalen Ultraschall entdeckten Pathologien. Ultraschall und Magnetresonanztomographie. Praenatale Untersuchungsmethode. Die fetale MRT ist inzwischen als ergaenzende Methode zum praenatalen Ultraschall anerkannt. Die fetale MRT soll als additive Methode bei klinischer Relevanz, nicht jedoch als Routinescreeningverfahren waehrend der Schwangerschaft angewendet werden. Durchfuehrung ausschliesslich an einem Perinatalzentrum nach vorangegangenem Level-III-Ultraschall. (orig.)

Die Entwicklung von Kindern: eine Einführung

OpenAIRE

Siegler, Robert; DeLoache, Judy; Eisenberg, Nancy

2005-01-01

Das Kapitel behandelt zunächst die Gründe für die Untersuchung der Kindesentwicklung und ihre historischen Wurzeln. Es werden anschließend Leitfragen der Kindesentwicklung sowie Methoden der Untersuchung kindlicher Entwicklung erläutert. Eine Zusammenfassung stellt schließlich die Kernthesen der einzelnen Abschnitte in einer kompakten Übersicht dar.(DIPF/paul)

Assessment of broadband SNR estimation for hearing aid applications

DEFF Research Database (Denmark)

May, Tobias; Kowalewski, Borys; Fereczkowski, Michal

2017-01-01

was systematically investigated. The most accurate approach utilized an estimation of the clean speech power spectral density (PSD) and the noisy speech power across a sliding window of 1280 ms and achieved an total SNR estimation error below 3 dB across a wide variety of background noises and input SNRs......An accurate estimation of the broadband input signal-to-noise ratio (SNR) is a prerequisite for many hearing-aid algorithms. An extensive comparison of three SNR estimation algorithms was performed. Moreover, the influence of the duration of the analysis window on the SNR estimation performance...

Die Entwicklung des Verhaltens bei der Nahrungsaufnahme, der Pflege und dem Spielen bei Kindern im 2. und 3. Lebensjahr in Tageseinrichtungen

OpenAIRE

Sporrer, Tobias

2013-01-01

Die vorliegende Arbeit beschäftigt sich mit einem Teil des Dokumentationsbogens der kindlichen Entwicklung, der im Lóczy-Institut in Budapest unter der Leitung der Kinderärztin Emmi Pikler erarbeitet wurde. Mit ihm können außerhäuslich betreute Kinder in ihrer Entwicklung beobachtet und diese dokumentiert werden. Das Ziel ist, differenzierte Aussagen zur Entwicklung der betreuten Kinder machen zu können. Die Normierung des Bogens erfolgte erstmals in den 1960er Jahren in Ungarn. Wir führen in...

Magnetic resonance imaging in acute intractional tuberculosis; Magnetresonanztomographie bei akuter intrakranieller Tuberkulose

Energy Technology Data Exchange (ETDEWEB)

Venz, S. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Sander, B. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Benndorf, G. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Terstegge, K. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Podrabsky, P. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Cordes, M. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Felix, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

1994-12-31

We reported three cases of acute intracranial tuberculosis including miliary tuberculosis, basal meningitis, tuberculomas and neuritis of cranial nerves. All patients had native and contrast enhanced CT and MRI scans. MRI revealed more granulomas and a better imaging contrast in the detection of basal meningitis. Neuritis was diagnosed only with the MRI. MRI scans should be prefered as the imaging procedure in clinically presumed intracranial tuberculosis. (orig.) [Deutsch] Die Befunde von drei Patienten mit intrakranieller Tuberkulose (intrakranielle Miliartuberkulose, Meningitis tuberculosa, Neuritis und Tuberkulome) in der Magnetresonanztomographie (MRT) wurden mit der Computertomographie (CT) verglichen. Sowohl die MRT als auch die CT wurden nativ und nach Kontrastmittelgabe durchgefuehrt. Die MRT zeigte sich im Nachweis von Granulomen insbesondere im Bereich des Hirnstamms ueberlegen. Ebenso wurde ein hoeherer Bildkontrast bei der Darstellung der Meningitis beobachtet. Eine Neuritis der Hirnnerven war nur mit der MRT nachweisbar. Die kontrastmittelunterstuetzte MRT sollte in der bildgebenden Diagnostik einer intrakraniellen Turberkulose primaer zum Einsatz gelangen. (orig.)

Methods and findings of the SNR study

International Nuclear Information System (INIS)

Koeberlein, K.; Schaefer, H.; Spindler, H.

1983-01-01

A featfinding committee of the German Federal Parliament in July 1980 recommended to perform a ''risk-oriented study'' of the SNR-300, the German 300 MW fast breeder prototype reactor being under construction in Kalkar. The main aim of this study was to allow a comparative safety evaluation between the SNR-300 and a modern PWR, thus to prepare a basis for a political decision on the SNR-300. Methods and main results of the study are presented in this paper. In the first step of the risk analysis six groups of accidents have been identified which may initiate core destruction. These groups comprise all conceivable courses, potentially leading to core destruction. By reliability analyses, expected frequency of each group has been calculated. In the accident analysis potential failure modes of the reactor tank have been investigated. Core destruction may be accompanied by the release of significant amounts of mechanical energy. The primary coolant system of SNR-300 is designed to withstand mechanical energy releases up to 370 MJ. Design features make it possible to cool the molten core inside the reactor tank. (orig./RW) [de

Optimum SNR data compression in hardware using an Eigencoil array.

Science.gov (United States)

King, Scott B; Varosi, Steve M; Duensing, G Randy

2010-05-01

With the number of receivers available on clinical MRI systems now ranging from 8 to 32 channels, data compression methods are being explored to lessen the demands on the computer for data handling and processing. Although software-based methods of compression after reception lessen computational requirements, a hardware-based method before the receiver also reduces the number of receive channels required. An eight-channel Eigencoil array is constructed by placing a hardware radiofrequency signal combiner inline after preamplification, before the receiver system. The Eigencoil array produces signal-to-noise ratio (SNR) of an optimal reconstruction using a standard sum-of-squares reconstruction, with peripheral SNR gains of 30% over the standard array. The concept of "receiver channel reduction" or MRI data compression is demonstrated, with optimal SNR using only four channels, and with a three-channel Eigencoil, superior sum-of-squares SNR was achieved over the standard eight-channel array. A three-channel Eigencoil portion of a product neurovascular array confirms in vivo SNR performance and demonstrates parallel MRI up to R = 3. This SNR-preserving data compression method advantageously allows users of MRI systems with fewer receiver channels to achieve the SNR of higher-channel MRI systems. (c) 2010 Wiley-Liss, Inc.

Low-SNR Capacity of Parallel IM-DD Optical Wireless Channels

KAUST Repository

Chaaban, Anas

2016-11-29

The capacity of parallel intensity-modulation and direct-detection (IM-DD) optical wireless channels with total average intensity and per-channel peak intensity constraints is studied. The optimal intensity allocation at low signal-to-noise ratio (SNR) is derived, leading to the capacity-achieving onoff keying (OOK) distribution. Interestingly, while activating the strongest channel is optimal if (i) the peak intensity is fixed, this is not the case if (ii) the peak intensity is proportional to the average intensity. The minimum average optical intensity per bit is also studied, and is characterized for case (i) where it is achievable at low SNR. However, in case (ii), the average optical intensity per bit grows indefinitely as SNR decreases, indicating that lower optical intensity per bit can be achieved at moderate SNR than at low SNR.

Studi Ketebalan Elektroda Pada Produksi Gas HHO (Hidrogen Hidrogen Oksigen Oleh Generator Hho Tipe Basah Dengan Katalis NaHCO3 (Natrium Bikarbonat

Directory of Open Access Journals (Sweden)

Ihsan Sopandi

2015-12-01

Full Text Available Abstrak. Salah satu energi alternatif yang efektif dikembangkan sekarang ini untuk mengganti bahan bakar minyak yaitu hidrogen. Untuk mendapatkan gas hidrogen dapat  dilakukan melalui proses elektrolisis air dengan memecahkan senyawa H2O menjadi gas HHO (Hidrogen Hidrogen Oksigen dengan bantuan listrik arus searah (Direct Current melalui media elektroda berupa plat stainless steel 304. Pada penelitian ini, akan diteliti hasil produksi gas HHO oleh generator HHO tipe basah dengan metode elektrolisa H2O menggunakan variasi ketebalan elektroda jenis stainless steel 304 yaitu 0,8 mm, 1 mm dan 1,2 mm dengan katalis NaHCO3 (Natrium Bikarbonat pada larutan elektrolitnya. Karakteristik yang diketahui meliputi konsumsi daya listrik yang digunakan oleh generator, volume gas yg dihasilkan,  laju produksi gas HHO yang dihasilkan dan efisiensi generator. Hasil penelitian dan pengujian generator HHO tipe basah ini didapatkan generator terbaik pada ketebalan elektroda 1 mm diperoleh data hasil pengujian dengan daya HHO yang digunakan sebesar 59,11 Watt, laju produksi gas HHO yang dihasilkan sebanyak 0,00054 kg/s dan efisiensi generator HHO sebesar 9,42 %.   Study On The  Electrode Thickness In HHO (Hidrogen Hidrogen Oksigen Gas Production By Wet Type HHO Generator With Catalyst NaHCO3 (Natrium Bikarbonat Abstract. One of the alternative energy that effective and currently being developed to replace fossil fuels is hydrogen. To obtain the hydrogen gas can be done through the process of electrolysis of water by breaking the compound H2O into HHO (Hydrogen Hydrogen Oxygen gas by using an electric direct current through the medium of 304 stainless steel plate  as an electrode. This research will be developing and observing HHO gas production process using HHO generator wet type (wet cell through electrolysis H2O with thickness variation of electrode that used 0.8 mm, 1 mm and 1.2 mm of electrode 304 stainless steel plate with NaHCO3 (Nathrium Bicarbonat

Multiengine Speech Processing Using SNR Estimator in Variable Noisy Environments

Directory of Open Access Journals (Sweden)

Ahmad R. Abu-El-Quran

2012-01-01

Full Text Available We introduce a multiengine speech processing system that can detect the location and the type of audio signal in variable noisy environments. This system detects the location of the audio source using a microphone array; the system examines the audio first, determines if it is speech/nonspeech, then estimates the value of the signal to noise (SNR using a Discrete-Valued SNR Estimator. Using this SNR value, instead of trying to adapt the speech signal to the speech processing system, we adapt the speech processing system to the surrounding environment of the captured speech signal. In this paper, we introduced the Discrete-Valued SNR Estimator and a multiengine classifier, using Multiengine Selection or Multiengine Weighted Fusion. Also we use the SI as example of the speech processing. The Discrete-Valued SNR Estimator achieves an accuracy of 98.4% in characterizing the environment's SNR. Compared to a conventional single engine SI system, the improvement in accuracy was as high as 9.0% and 10.0% for the Multiengine Selection and Multiengine Weighted Fusion, respectively.

Kajian Sifat Fisik Dan Kimia Tepung Labu Kuning (Cucurbita Maxima) Dengan Perlakuan Blanching Dan Perendaman Natrium Metabisulfit (Na2s2o5)

OpenAIRE

Purwanto, Chatrine Chrisandy; Ishartani, Dwi; Muhammad, Dimas Rahadian Aji

2013-01-01

Penelitian ini bertujuan untuk mengetahui sifat fisik dan kimia tepung labu kuning yang diberi perlakuan blanching dan perendaman natrium metabisulfit. Penelitian ini terdiri dari dua tahap utama, yaitu pembuatan tepung labu kuning dan pengujian sifat fisik dan kimia tepung labu kuning. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan dua kali ulangan analisa. Data yang diperoleh dianalisis dengan metode Analysis of Variance (ANOVA). Bila ada perbedaan antar perlakuan maka dilan...

Improved SNR of phased-array PERES coils via simulation study

International Nuclear Information System (INIS)

RodrIguez, Alfredo O; Medina, LucIa

2005-01-01

A computational comparison of signal-to-noise ratio (SNR) was performed between a conventional phased array of two circular-shaped coils and a petal resonator surface array. The quasi-static model and phased-array optimum SNR were combined to derive an SNR formula for each array. Analysis of mutual inductance between coil petals was carried out to compute the optimal coil separation and optimum number of petal coils. Mutual interaction between coil arrays was not included in the model because this does not drastically affect coil performance. Phased arrays of PERES coils show a 114% improvement in SNR over that of the simplest circular configuration. (note)

Radio-continuum study of the supernova remnants in the large Magellanic Cloud: An SNR with a highly polarized breakout region: SNR J0455-6838

Directory of Open Access Journals (Sweden)

Crawford E.J.

2008-01-01

Full Text Available We present the results of new moderate resolution ATCA observations of SNR J0455-6838. We found that this SNR exhibits a mostly typical appearance with rather steep and curved α=-0.81±0.18 and D=43×31±1 pc. Regions of high polarization were detected, including unusually strong (~70% region corresponding to the northern breakout. Such a strong polarization in breakout regions has not been observed in any other SNR.

Development with DMU. Options in the modern product life cycle; Entwicklung mit DMU. Moeglichkeiten im modernen Produktlebenszyklus

Energy Technology Data Exchange (ETDEWEB)

Hoehn, H.; Moser, H. [Competent Engineering GmbH, Graz (Austria)

2005-02-01

In this contribution, the Graz-based development company Competent Engineering outlines the advantages of digital mock-ups for efficient product development. The focus is on a uniform product and data structure that is to ensure early availability of DMU for all stages of the product life cycle. (orig.) [German] Der Grazer Entwicklungsdienstleister Competent Engineering beschreibt in diesem Beitrag anhand der Entwicklung eines Ottomotors, welche Vorteile der Einsatz von Digital Mock-Ups fuer eine effiziente Produktentwicklung hat. Besondere Bedeutung hat dabei eine moeglichst durchgaengige Produkt- und Datenstruktur, um eine fruehe Verfuegbarkeit der DMUs fuer alle Bereiche innerhalb des Produktlebenszyklus zu ermoeglichen. (orig.)

A Family of Maximum SNR Filters for Noise Reduction

DEFF Research Database (Denmark)

Huang, Gongping; Benesty, Jacob; Long, Tao

2014-01-01

significantly increase the SNR but at the expense of tremendous speech distortion. As a consequence, the speech quality improvement, measured by the perceptual evaluation of speech quality (PESQ) algorithm, is marginal if any, regardless of the number of microphones used. In the STFT domain, the maximum SNR...

Politische Bildung für nachhaltige Entwicklung und das Konzept des Globalen Lernens

OpenAIRE

Brunold, Andreas (Prof.)

2009-01-01

Politische Bildung für nachhaltige Entwicklung und das Konzept des Globalen Lernens. - In: Standortbestimmung Politische Bildung / Heinrich Oberreuter (Hrsg.). - Schwalbach/Ts. : Wochenschau-Verl., 2009. - S. 307-333. - (Tutzinger Schriften zur politischen Bildung)

Entwicklung und Anwendung neuer NMR-Methoden: Orientierungsmedien zur Strukturbestimmung mit anisotropen Parametern und Metabonomics

OpenAIRE

Büchler, Silke

2014-01-01

Das Ziel dieser Arbeit war die Entwicklung und Anwendung neuer Orientierungsmedien zur Strukturbestimmung mit anisotropen Parametern, sowie die Etablierung von Metabonomics-Studien an Flüssigzellkulturen und Reispflanzen.

Measuring natrium alginate content of brown algae spesies Padina sp. as the basic matter for making dental impression material (Irreversible hydrocolloid impression material)

OpenAIRE

Nurlindah Hamrun; Suci Amalia Rachman

2016-01-01

One of the most important procedure in denture fabrication and orthodontic treatment is molding the patient’s detail oral cavity to determine the treatment planning. This procedure does by using alginate impression material or irreversible hydrocolloid which is the basic material is natrium alginate which is imported from abroad because it is extracted from brown algae which habitat is not in Indonesia so it is causes the impression material is relative expensive which is impact to high cost ...

Postoperative MRI of the ankle; Postoperative Magnetresonanztomographie des Sprunggelenks

Energy Technology Data Exchange (ETDEWEB)

Sharabianlou Korth, M.; Fritz, L.B. [Rheinlandaerzte, Willich (Germany)

2017-11-15

Postoperative imaging of the ankle can be challenging, even for the experienced radiologist. Pathological and postoperative changes to the primarily complex anatomy of the ankle with its great variety of bone structures, tendons, ligaments, and soft tissue in a very limited space may cause great difficulty in differentiating underlying pathology from expected postoperative changes and artifacts, especially in magnetic resonance imaging (MRI). Selecting the appropriate radiological modality is key to making the correct diagnosis. Therefore, knowledge of the initial and current symptoms is just as important as familiarity with the most frequently performed operations in the ankle. This article aims to give its reader a summary of the most important and frequently performed operation techniques of the ankle and discusses the expected appearance and possible complications in postoperative imaging. (orig.) [German] Die postoperative radiologische Bildgebung des Sprunggelenks kann auch fuer den erfahrenen Radiologen eine besondere Herausforderung darstellen. Die komplex aufgebaute Anatomie des Sprunggelenks, mit seinen multiplen Gelenkflaechen, Sehnen, Baendern und neurovaskulaeren Strukturen auf engstem Raum, kann durch Operationen signifikant veraendert und insbesondere in der Magnetresonanztomographie (MRT) verfaelscht dargestellt werden. Fuer eine fundierte Befundung und Beurteilung der Operationsergebnisse ist die Kenntnis der praeoperativen Diagnose, Zeitpunkt und Technik der durchgefuehrten Operation(en) sowie der aktuellen klinischen Symptomatik von grosser Bedeutung. Dieser Artikel konzentriert sich auf zu erwartende radiologische Veraenderungen und gibt Tipps zur Befundung der postoperativen MRT des Sprunggelenks bei einer Auswahl relevanter operativer Eingriffe. Zudem wird auf moegliche postoperative Komplikationen und ihre radiologische Darstellung hingewiesen. (orig.)

Selective Route Based on SNR with Cross-Layer Scheme in Wireless Ad Hoc Network

Directory of Open Access Journals (Sweden)

Istikmal

2017-01-01

Full Text Available In this study, we developed network and throughput formulation models and proposed new method of the routing protocol algorithm with a cross-layer scheme based on signal-to-noise ratio (SNR. This method is an enhancement of routing protocol ad hoc on-demand distance vector (AODV. This proposed scheme uses selective route based on the SNR threshold in the reverse route mechanism. We developed AODV SNR-selective route (AODV SNR-SR for a mechanism better than AODV SNR, that is, the routing protocol that used average or sum of path SNR, and also better than AODV which is hop-count-based. We also used selective reverse route based on SNR mechanism, replacing the earlier method to avoid routing overhead. The simulation results show that AODV SNR-SR outperforms AODV SNR and AODV in terms of throughput, end-to-end delay, and routing overhead. This proposed method is expected to support Device-to-Device (D2D communications that are concerned with the quality of the channel awareness in the development of the future Fifth Generation (5G.

Indications for fetal magnetic resonance imaging (MRI); Indikationen zur fetalen Magnetresonanztomographie

Energy Technology Data Exchange (ETDEWEB)

Prayer, D. [Medizinische Universitaet Wien (Austria). Klinik fuer Radiodiagnostik; Brugger, P.C. [Zentrum fuer Anatomie und Zellbiologie der Medizinischen Universitaet Wien (Austria). Arbeitsgruppe Integrative Morphologie; Krampl, E. [Medizinische Universitaet Wien (Austria). Klinik fuer Gynaekologie und Geburtshilfe; Prayer, L. [Diagnosezentrum Urania, Wien (Austria)

2006-02-15

Indications to perform fetal magnetic resonance imaging (MRI) are composed of common ones related to methodological problems of ultrasound (US) assessment (such as for instance hydramnios) and special ones. The latter are related to MR capability of high-resolution soft tissue contrast and an extended field of view that allows visualization of the whole fetus, even in later stages of pregnancy. The most important indications include confirmation of US findings, work-up of malformations with respect to individual prognosis and genetic background, differentiation between acquired conditions and malformations, visualization of pathologies that have to be treated surgically immediately after birth, and morphological changes of the placenta. (orig.) [German] Indikationen zur Durchfuehrung einer fetalen Magnetresonanztomographie (MRT) setzen sich aus allgemeinen Fragestellungen zusammen, die auf methodischen Problemen von Ultraschalluntersuchungen (US) beruhen (wie beispielsweise Anhydramnion), und speziellen, bei denen die MR-Eigenschaften der hochaufloesenden Gewebedifferenzierung und eines Untersuchungsfensters, das eine Abbildung des gesamten Fetus auch im fortgeschrittenen Schwangerschaftsalter erlaubt, ausgenuetzt werden. Im Vordergrund stehen dabei die Absicherung von US-Befunden, die Abklaerung von Fehlbildungen in Hinblick auf individuelle Prognose und Vorliegen eines Syndroms mit genetisch determiniertem Hintergrund, und die Differenzierung erworbener Stoerungen von Fehlbildungen, die Abklaerung von Veraenderungen, die einer unmittelbar postnatalen operativen Therapie beduerfen, und morphologischer Veraenderungen der Plazenta. (orig.)

Weighted-SNR-based fair scheduling for uplink OFDMA

KAUST Repository

Ma, Yao

2009-11-01

In this paper, we study the sum rate maximization algorithms with long-term proportional rate fairness (PRF) for uplink orthogonal frequency division multiple access (OFDMA) systems. In contrast to the rate-maximization schemes which used short-term PRF in the literature, we propose to use a selective multiuser diversity (SMuD) scheme to achieve a long-term PRF and improved sum rate performance. This scheme implements weighted channel signal-to-noise ratio (w-SNR)-based ranking for user selection on each subchannel, and then uses either water-filling (WF) or equal power allocation (EPA) along the assigned channels of each user. Both offline and online methods to find the optimal SNR weight factors are designed to achieve the target proportional rates for different users. The offline optimization technique requires to know the channel distribution information (CDI) at the scheduler. The online method uses the weight adaption combined with individual user rate tracking, which avoids the need to know the CDI. Analytical throughput metrics for the proposed w-SNR scheme with WF and EPA over Rayleigh channels are derived, and verified by simulations. Simulation results show that the proposed w-SNR PRF scheme can achieve significantly higher sum rates than the frequency diversity-based short-term and long-term fairness schemes. Besides the improved performance, the proposed schemes have a low complexity which is linear to numbers of users and subchannels.

Present status and further objectives of SNR fuel element development

International Nuclear Information System (INIS)

Karsten, G.

Within the scope of the fuel element development program for the fast breeder reactor SNR 300, 500 fuel pins have been irradiated since 1964, 250 of them in fast flux. Results indicate that the maximum nominal target burnup of 90.000 MWd/t of the SNR 300 Mk Ia possibly can be reached. The main problems, which arise from clad swelling and internal corrosion, can be met by special pretreatments of the austenitic stainless steel 1.4970 and a fuel stoichiometry of 1.97. Beyond this target burnup either material property improvements have to be made or burnup reductions have to be accepted. The remaining questions can be answered by the use of the SNR 300 as a test reactor. A further target is the development of a carbide fuel element, which should be very effective in a high power breeder reactor because of its low fissile inventory and high breeding gain. This development program will also be finalized in the SNR 300. (U.S.)

Influence of range-gated intensifiers on underwater imaging system SNR

Science.gov (United States)

Wang, Xia; Hu, Ling; Zhi, Qiang; Chen, Zhen-yue; Jin, Wei-qi

2013-08-01

Range-gated technology has been a hot research field in recent years due to its high effective back scattering eliminating. As a result, it can enhance the contrast between a target and its background and extent the working distance of the imaging system. The underwater imaging system is required to have the ability to image in low light level conditions, as well as the ability to eliminate the back scattering effect, which means that the receiver has to be high-speed external trigger function, high resolution, high sensitivity, low noise, higher gain dynamic range. When it comes to an intensifier, the noise characteristics directly restrict the observation effect and range of the imaging system. The background noise may decrease the image contrast and sharpness, even covering the signal making it impossible to recognize the target. So it is quite important to investigate the noise characteristics of intensifiers. SNR is an important parameter reflecting the noise features of a system. Through the use of underwater laser range-gated imaging prediction model, and according to the linear SNR system theory, the gated imaging noise performance of the present market adopted super second generation and generation Ⅲ intensifiers were theoretically analyzed. Based on the active laser underwater range-gated imaging model, the effect to the system by gated intensifiers and the relationship between the system SNR and MTF were studied. Through theoretical and simulation analysis to the image intensifier background noise and SNR, the different influence on system SNR by super second generation and generation Ⅲ ICCD was obtained. Range-gated system SNR formula was put forward, and compared the different effect influence on the system by using two kind of ICCDs was compared. According to the matlab simulation, a detailed analysis was carried out theoretically. All the work in this paper lays a theoretical foundation to further eliminating back scattering effect, improving

Magnetic resonance imaging. Density equalizing mapping analysis of global research architecture; Magnetresonanztomographie. Eine Density-equalizing-mapping-Analyse der globalen Forschungsarchitektur

Energy Technology Data Exchange (ETDEWEB)

Ohlendorf, D.; Schwarze, B.; Groneberg, D.A.; Schwarzer, M. [Goethe-Universitaet Frankfurt/M, Institut fuer Arbeitsmedizin, Sozialmedizin und Umweltmedizin, Frankfurt/M (Germany)

2015-09-15

Despite the great medical importance, there is still no comprehensive scientometric analysis regarding the results of magnetic resonance imaging (MRI) and the development of the importance for the healthcare system. This paper evaluated and analyzed the entire research publication results on the topic of MRI for the period 1981-2007 based on scientometric methods and parameters. A scientometric analysis (database: ISI Web of Science 1981-2007, search terms MRI and magnetic resonance imaging) was performed. The following parameters were analyzed: number of publications, countries of publication, number of citations, citation rate and collaborations, using various analytical and display techniques, including density equalizing map projections. Most of the 49,122 publications on MRI could be attributed to the USA (32.5 %), which also has the most cooperative collaborations. Within Europe, Germany (10.3 %) is the country with the highest number of publications followed by the UK (9.3 %). The western industrialized nations dominate over the rest of the world in terms of scientific developments of MRI. The thematic focus of the publications lies in the fields of radiology and neuroscience. In addition to the journal Neurology most scientific articles were published in Magnetic Resonance in Medicine and Circulation. The results show that the current trend is continuing and the scientific interest in MRI is continuously increasing. (orig.) [German] Trotz der grossen medizinischen Bedeutung existiert bis heute keine umfassende szientometrische Analyse bzgl. der Forschungsergebnisse zur Magnetresonanztomographie (MRT) und der Entwicklung ihrer Bedeutung fuer das Gesundheitssystem. Im vorliegenden Beitrag soll anhand szientometrischer Methoden und Parameter das gesamte Forschungsaufkommen zum Thema MRT fuer den Zeitraum 1981-2007 evaluiert und analysiert werden. Es wurde eine szientometrische Analyse (Datenbank: ISI-Web of Science, 1981-2007; Suchterm &apos

The southern molecular environment of SNR G18.8+0.3

OpenAIRE

Paron, S.; Peña, M. Celis; Ortega, M. E.; Petriela, A.; Dubner, G.; Giacina, E.; Rubio, M.

2015-01-01

In a previous paper we have investigated the molecular environment towardsthe eastern border of the SNR G18.8+0.3. Continuing with the study of thesurroundings of this SNR, in this work we focus on its southern border, whichin the radio continuum emission shows a very peculiar morphology with acorrugated corner and a very flattened southern flank. We observed two regionstowards the south of SNR G18.8+0.3 using the Atacama Submillimeter TelescopeExperiment (ASTE) in the 12CO J=3-2. One of thes...

Risk-oriented analysis on the German prototype fast breeder reactor SNR-300

International Nuclear Information System (INIS)

Bayer, A.; Koeberlein, K.; Gesellschaft fuer Reaktorsicherheit, Garching, Germany)

1984-01-01

On request of a fact-finding committee of the German Federal Parliament, a risk-oriented analysis on the SNR-300, the German prototype fast breeder reactor, has been performed to allow a pragmatic safety comparison of the SNR-300 and a modern light-water reactor. Results of the technical plant analysis have been summarized in seven release categories. Accident consequences have been calculated for the actual site at Kalkar/Rhine. The results indicate that for the SNR-300 both the frequency of major accidents and the consequences of accidents are smaller than for the pressurized-water reactor analyzed in the German Risk Study. This article summarizes the methods and main results of the analysis of the SNR-300

Entwicklung von Methoden zur ereignisgesteuerten neurofunktionellen Kernspintomographie für die Messung der Gehirnaktivität bei der Schmerzverarbeitung

OpenAIRE

Meyer, Heiko

2000-01-01

Die ereignisgesteuerte neurofunktionelle Magnetresonanz-Tomographie ermöglicht die Darstellung der aktiven Gehirnareale, indem sie die unterschiedlichen magnetischen Eigenschaften von oxygeniertem und desoxygeniertem Blut ausnutzt. Im Rahmen dieser Arbeit wurden vier ereignisgesteuerte FLASH-Meßsequenzen für die Untersuchung der Schmerzverarbeitung entwickelt und implementiert. Diese Methoden ermöglichen die Abbildung der Gehirnfunktion auf einen äußeren Reiz mit hoher zeitlicher und räum...

Free-space optical communications with peak and average constraints: High SNR capacity approximation

KAUST Repository

Chaaban, Anas

2015-09-07

The capacity of the intensity-modulation direct-detection (IM-DD) free-space optical channel with both average and peak intensity constraints is studied. A new capacity lower bound is derived by using a truncated-Gaussian input distribution. Numerical evaluation shows that this capacity lower bound is nearly tight at high signal-to-noise ratio (SNR), while it is shown analytically that the gap to capacity upper bounds is a small constant at high SNR. In particular, the gap to the high-SNR asymptotic capacity of the channel under either a peak or an average constraint is small. This leads to a simple approximation of the high SNR capacity. Additionally, a new capacity upper bound is derived using sphere-packing arguments. This bound is tight at high SNR for a channel with a dominant peak constraint.

Synchronization of OFDM at low SNR over an AWGN channel

NARCIS (Netherlands)

Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria; Dimitrova, D.C.; Blom, K.C.H.; Meratnia, Nirvana

2011-01-01

This paper is based on Extended Symbol OFDM (ES-OFDM) where symbols are extended in time. This way ES-OFDM can operate at low SNR. Each doubling of the symbol length improves the SNR performance by 3 dB in case of a coherent receiver. One of the basic questions is how to synchronize to signals far

Safety and risk assessments for the SNR 300

International Nuclear Information System (INIS)

Maschek, W.; Froehlich, R.; Jacobs, H.; Schikorr, M.; Heusener, G.; Caldarola, L.; Royl, P.; Struwe, D.

1983-01-01

Under the official inquiry ''Future Nuclear Energy Policies'', KfK have carried out a number of studies concerning the hazards arising from core-destructive accidents at the SNR-300 reactor. Among these, there was the so-called ''Upper Limit Study'' providing a critical evaluation of literature on all research done on core-destructive accidents (Bethe-Tait excursion) with a high mechanic energy release potential; the other one was the so-called ''SAI Study'' (a cooperation of KfK, Science Applications, Inc. (SAI) and Interatom (IA)) which investigated the hazards of an uncontrolled coolant flow rate disturbance occurring in the SNR-300 reactor. KfK also took part in the analysis of hazards comparing the SNR-300 reactor with an LWR-type reactor like the one at Biblis B, ordered by the Federal Ministry of Research and Technology (BMFT). These studies have already been dealt with KfK-Nachrichten, 14th annual set issue 4/1982. The article on hand summarizes and evaluates once more the most important results. (orig./RW) [de

Detection and localisation of leaks in steam generators

Energy Technology Data Exchange (ETDEWEB)

Westenbrugge, J.K. van; Visbach, D M [B.V. NERATOM, The Hague (Netherlands)

1978-10-01

Steam generator experience in Netherlands is concentrated in NERATOM, the company that takes part n the construction of LMFBRs: SNR-300 in Kalkar in the framework of the international company INB (Internationale Natrium Brutreaktor Bau) together with the German company INTERATOM and the Belgian company BelgoNucleaire. Experience consists of designing constructing and testing of prototypes of the SNR-300 plant components, constructing and licensing of the components for SNR-300 proper and in conceptual design of components for larger power plants. Supporting research and testing of the prototypes is carried out by the organization for Industrial Research TNO. The two types studied are the straight tube type and the helical tube type steam generator. Descriptions of both types were published earlier. It should be pointed out here that the construction material is the ferritic 2% Cr 1 Mo 1NiNb-steel (DIN Wnr. 1.6770)

Multifrequency radio observations of a SNR in the LMC: The case of SNR J0527-6549 (DEM l204

Directory of Open Access Journals (Sweden)

Bozzetto L.M.

2010-01-01

Full Text Available We present a detailed study and results of new Australia Telescope Compact Array (ATCA observations of supernova remnant SNR J0527-6549. This Large Magellanic Cloud (LMC object follows a typical supernova remnant (SNR horseshoe morphology with a diameter of D=(66×58±1 pc which is among the largest SNRs in the LMC. Its relatively large size indicates older age while a steeper than expected radio spectral index of α=-0.92±0.11 is more typical of younger and energetic SNRs. Also, we report detections of regions with a high order of polarization at a peak value of ~54%±17% at 6 cm.

Entwicklung eines kontinuierlichen Verfahrens zur enzymkatalysierten Synthese eines strukturierten Triglycerides

OpenAIRE

Stadler, Hans-Gerhard

2005-01-01

Ausgangspunkt für die in der vorliegenden Arbeit durchgeführten Entwicklung eines kontinuierlichen Verfahrens zur Synthese des strukturierten Triglycerides 1,3-Oleyl-2-palmitoylglycerin war die von Schmid [Schmid 1999] entwickelte lipase-katalysierte Zwei-Schritt-Synthese für strukturierte Triglyceride vom Typ ABA [European Patent Application; EP 0 882 797 A2]. In der ersten Reaktionsstufe dieser zweistufigen Umesterung wird in einer Folgereaktion das Substrat Tripalmitin mit Hilfe ein...

Review on Dutch-German steam generator safety activities in the field of SNR-development

International Nuclear Information System (INIS)

Dumm, K.; Westenbrugge, J.K. van

1984-01-01

This paper reviews the results of the experimental and theoretical safety related work for SNR steam generators in brief. A review of the operating experience with SNR-300 sodium-water heat-exchangers and protection philosophy used in SNR-2 is also given

The SNR-300 steam generator small leak detection system

International Nuclear Information System (INIS)

Dumm, K.

1984-01-01

Small leak detection in the SNR-300 steam generator moduls is achieved by hydrogen meters. Development and design of the Nickel membrane - ion getter pump combination are described and sensitivity requests derived. Results of calibration tests by water/steam injections in a sodium loop are presented. The arrangement and interconnection of signals in SNR-300 are given and possibilities for inservice calibrations are discussed, supported by long time operation tests in the KNK-reactor plant. (author)

The effect of SNR structure on non-equilibrium X-ray spectra

International Nuclear Information System (INIS)

Hamilton, A.J.S.; Sarazin, C.L.

1983-01-01

A technique is presented for characterizing the ionization structure and consequent thermal X-ray emission of a SNR when non-equilibrium ionization effects are important. The technique allows different theoretical SNR models to be compared and contrasted rapidly in advance of detailed numerical computations. In particular it is shown that the spectrum of a Sedov remnant can probably be applied satisfactorily in a variety of SNR structures, including the reverse shock model advocated by Chevalier (1982) for Type I SN, the isothermal similarity solution of Solinger, Rappaport and Buff (1975), and various inhomogenous or 'messy' structures. (Auth.)

Entwicklung und Evaluation computerbasierter Trainingsaufgaben für das wissenschaftliche Schreiben

OpenAIRE

Proske, Antje

2006-01-01

Wissenschaftliches Schreiben ist eine sehr komplexe Aufgabe, die eine Vielzahl unterschiedlicher Aktivitäten umfasst. Viele Studierende haben jedoch Schwierigkeiten, die damit verbundenen Anforderungen selbständig zu bewältigen. Im Mittelpunkt des Interesses der vorliegenden Arbeit stand daher die Entwicklung und Evaluation interaktiver computerbasierter Trainingsaufgaben, die Studienanfänger beim Erwerb von Grundkompetenzen des wissenschaftlichen Schreibens unterstützen. Zentrale Anliegen di...

Functional magnetic resonance imaging with ultra-high fields; Funktionelle Magnetresonanztomographie bei ultrahohen Feldern

Energy Technology Data Exchange (ETDEWEB)

Windischberger, C.; Schoepf, V.; Sladky, R.; Moser, E. [Medizinische Universitaet Wien, Exzellenzzentrum Hochfeld-MR, Wien (Austria); Medizinische Universitaet Wien, Zentrum fuer Medizinische Physik und Biomedizinische Technik, Wien (Austria); Fischmeister, F.P.S. [Medizinische Universitaet Wien, Exzellenzzentrum Hochfeld-MR, Wien (Austria); Universitaet Wien, Fakultaet fuer Psychologie, Wien (Austria)

2010-02-15

Functional magnetic resonance imaging (fMRI) is currently the primary method for non-invasive functional localization in the brain. With the emergence of MR systems with field strengths of 4 Tesla and above, neuronal activation may be studied with unprecedented accuracy. In this article we present different approaches to use the improved sensitivity and specificity for expanding current fMRT resolution limits in space and time based on several 7 Tesla studies. In addition to the challenges that arise with ultra-high magnetic fields possible solutions will be discussed. (orig.) [German] Die funktionelle Magnetresonanztomographie (fMRT) stellt zurzeit die wichtigste Methode zur nichtinvasiven Funktionslokalisation im Gehirn dar. Mit der Verfuegbarkeit von MRT-Geraeten mit Magnetfeldstaerken von 4 Tesla (T) und darueber ergeben sich neue Moeglichkeiten, mittels fMRT die neuronale Aktivitaet in bislang unerreichter Genauigkeit zu untersuchen. In diesem Artikel zeigen wir anhand mehrerer Studien bei 7 T, in wieweit die Zugewinne an Sensitivitaet und Spezifitaet verwendet werden koennen, um die bisherigen Grenzen der fMRT-Aufloesung in raeumlicher und zeitlicher Hinsicht auszuweiten. Die neuen Herausforderungen, die mit dem Schritt zu ultrahohen Magnetfeldern einhergehen, werden dabei ebenso diskutiert wie moegliche Ansaetze zu deren Loesung. (orig.)

Detection of local sodium boiling in the nuclear boiling generator in KNK II and in the cores of SNR 300 and SNR 2

International Nuclear Information System (INIS)

Erhardt, J.; Hoppe, P.

1977-03-01

As a basis of a global detection system, the detection of local boiling in sodium cooled reactors via surveillance of the neutron flux background noise is of special importance. With the help of parameter studies it is investigated in the present report, which parts of the core of SNR 300 and SNR 2 could be monitored with such a detection system. As a comparison the detection sensibility of the planned boiling generator in KNK II is determined

3D-Master-Leitungssatz - Konzept zur Entwicklung von Leitungssätzen als 3D-Master in einem realistischen, vollständigen DMU-Modell

OpenAIRE

Neckenich, Jonas

2017-01-01

Die Fokussierung auf eine 3D-orientierte Produktentwicklung und einen durchgängigen 3D-Prozess wird in der heutigen Industrie immer wichtiger. Im Entwicklungsprozess des Kabelbaums trifft dabei die bauraumorientierte 3D-Entwicklung auf die produktorientierte 2D-Entwicklung. Die unsaubere Trennung zwischen bestehenden Definitionssystemen im heutigen Entwicklungsprozess führt dabei zu Datendiskrepanzen, Zeitverzug und Fehlern. Im Digital Mock-Up, welcher zur digitalen Absicherung des Fahrzeugs ...

Multi-reception strategy with improved SNR for multichannel MR imaging.

Directory of Open Access Journals (Sweden)

Bing Wu

Full Text Available A multi-reception strategy with extended GRAPPA is proposed in this work to improve MR imaging performance at ultra-high field MR systems with limited receiver channels. In this method, coil elements are separated to two or more groups under appropriate grouping criteria. Those groups are enabled in sequence for imaging first, and then parallel acquisition is performed to compensate for the redundant scan time caused by the multiple receptions. To efficiently reconstruct the data acquired from elements of each group, a specific extended GRAPPA was developed. This approach was evaluated by using a 16-element head array on a 7 Tesla whole-body MRI scanner with 8 receive channels. The in-vivo experiments demonstrate that with the same scan time, the 16-element array with twice receptions and acceleration rate of 2 can achieve significant SNR gain in the periphery area of the brain and keep nearly the same SNR in the center area over an eight-element array, which indicates the proposed multi-reception strategy and extended GRAPPA are feasible to improve image quality for MRI systems with limited receive channels. This study also suggests that it is advantageous for a MR system with N receiver channels to utilize a coil array with more than N elements if an appropriate acquisition strategy is applied.

Core design aspects of SNR 2

International Nuclear Information System (INIS)

Wehmann, U.K.

1987-01-01

The paper describes in its first part the main characteristics of the core of the SNR 2 fast breeder reactor which is being planned within the European collaboration on fast breeder reactors. In the second part some core design aspects are discussed. The fuel element management with an inwards shuffling after each cycle is illustrated which offers advantages with respect to linear rating, steel damage and average discharge burnup. For this management, the full three-dimensional power and burnup history has been calculated and some typical results are presented. The shutdown requirements and the capabilities of the two shutdown systems of SNR 2 are discussed. The necessity for a reliable surveillance of the power distribution is demonstrated by the pronounced power tilts in case of the unintentional withdrawal of an absorber rod. Finally, a short review of the main nuclear design methods and their validation with help of the evaluation of experiments in zero power facilities and power reactors is given

A CLT on the SNR of Diagonally Loaded MVDR Filters

Science.gov (United States)

Rubio, Francisco; Mestre, Xavier; Hachem, Walid

2012-08-01

This paper studies the fluctuations of the signal-to-noise ratio (SNR) of minimum variance distorsionless response (MVDR) filters implementing diagonal loading in the estimation of the covariance matrix. Previous results in the signal processing literature are generalized and extended by considering both spatially as well as temporarily correlated samples. Specifically, a central limit theorem (CLT) is established for the fluctuations of the SNR of the diagonally loaded MVDR filter, under both supervised and unsupervised training settings in adaptive filtering applications. Our second-order analysis is based on the Nash-Poincar\\'e inequality and the integration by parts formula for Gaussian functionals, as well as classical tools from statistical asymptotic theory. Numerical evaluations validating the accuracy of the CLT confirm the asymptotic Gaussianity of the fluctuations of the SNR of the MVDR filter.

Entwicklung von Cysteinproteaseinhibitoren - ein klassischer und ein kombinatorischer Ansatz zur Inhibitoroptimierung

OpenAIRE

Machon, Uwe Rainer

2009-01-01

Ziel der Dissertation „Entwicklung von Cysteinproteaseinhibitoren – ein klassischer und ein kombinatorischer Ansatz zur Inhibitoroptimierung“ war die Optimierung von neuen Inhibitoren von Falcipain-2 und Rhodesain als neue potentielle Wirkstoffe gegen Malaria bzw. die Schlafkrankheit über zwei verschiedene Methoden. Es handelt sich hierbei um einen klassischen und einen kombinatorischen Ansatz. Der klassische Ansatz basiert auf einer Struktur, deren Aktivität per Zufall entdeckt wurde. In Scr...

Magnetic resonance imaging for early diagnosis of rheumatoid arthritis; Magnetresonanztomographie in der Fruehdiagnostik der rheumatoiden Arthritis

Energy Technology Data Exchange (ETDEWEB)

Uhl, M. [Universitaetsklinik Freiburg (Germany). Abt. fuer Radiologische Diagnostik; Allmann, K.H. [Universitaetsklinik Freiburg (Germany). Abt. fuer Radiologische Diagnostik; Hauer, M.P. [Universitaetsklinik Freiburg (Germany). Abt. fuer Radiologische Diagnostik; Laubenberger, J. [Universitaetsklinik Freiburg (Germany). Abt. fuer Radiologische Diagnostik; Kempis, J. v. [Universitaetsklinik Freiburg (Germany). Abt. fuer Rheumatologie und Klinische Immunologie; Langer, M. [Universitaetsklinik Freiburg (Germany). Abt. fuer Radiologische Diagnostik

1997-06-01

Nuclear magnetic resonance tomography (MRI) represents essential progress in the diagnostic means for evaluation of lesions of the muskuloskeletal system. The imaging of bone joints including material and structures like cartilage, tendons, ligaments, effusions, pannus, cortical bone and marrow offers essential advantages for diagnosis, differential diagnosis, follow-up control and detection of local complications in rheumatics radiology. The review article discusses the achievements of MRI for detection of early signs of rheumatoid arthritis and the current indications for MRI examination for early diagnosis. (Orig./AJ) [Deutsch] Die Magnetresonanztomographie (MRT) ist ein bedeutender Fortschritt in der Diagnostik von Erkrankungen des muskuloskelettalen Systems. Die Darstellung von Gelenkstrukturen einschliesslich Knorpel, Sehnen, Baendern, Erguessen, Pannus, kortikalem Knochen und Mark ist in der Diagnostik, Differentialdiagnostik, Verlaufsbeurteilung und der Aufdeckung von lokalen Komplikationen in der Rheumaradiologie von erheblichem Vorteil. In der Uebersicht werden die Fruehveraenderungen der rheumatoiden Arthritis in der MRT-Bildgebung und die heute aktuellen Indiakationen fuer den Einsatz der MRT in der Fruehdiagnostik diskutiert. (Orig./AJ)

Secure diversity-multiplexing tradeoff of zero-forcing transmit scheme at finite-SNR

KAUST Repository

Rezki, Zouheir

2012-04-01

In this paper, we address the finite Signal-to-Noise Ratio (SNR) Diversity-Multiplexing Tradeoff (DMT) of the Multiple Input Multiple Output (MIMO) wiretap channel, where a Zero-Forcing (ZF) transmit scheme, that intends to send the secret information in the orthogonal space of the eavesdropper channel, is used. First, we introduce the secrecy multiplexing gain at finite-SNR that generalizes the definition at high-SNR. Then, we provide upper and lower bounds on the outage probability under secrecy constraint, from which secrecy diversity gain estimates of ZF are derived. Through asymptotic analysis, we show that the upper bound underestimates the secrecy diversity gain, whereas the lower bound is tight at high-SNR, and thus its related diversity gain estimate is equal to the actual asymptotic secrecy diversity gain of the MIMO wiretap channel. © 2012 IEEE.

The upper limits of the SNR in radiography and CT with polyenergetic x-rays

International Nuclear Information System (INIS)

Shikhaliev, Polad M

2010-01-01

The aim of the study is to determine the upper limits of the signal-to-noise ratio (SNR) in radiography and computed tomography (CT) with polyenergetic x-ray sources. In x-ray imaging, monoenergetic x-rays provide a higher SNR compared to polyenergetic x-rays. However, the SNR in polyenergetic x-ray imaging can be increased when a photon-counting detector is used and x-rays are optimally weighted according to their energies. For a particular contrast/background combination and at a fixed x-ray entrance skin exposure, the SNR in energy-weighting x-ray imaging depends on tube voltage and can be maximized by selecting the optimal tube voltage. The SNR in energy-weighted x-ray images acquired at this optimal tube voltage is the highest SNR that can be achieved with polyenergetic x-ray sources. The optimal tube voltages and the highest SNR were calculated and compared to the SNR of monoenergetic x-ray imaging. Monoenergetic, energy-weighting polyenergetic and energy-integrating polyenergetic x-ray imagings were simulated at a fixed entrance skin exposure of 20 mR. The tube voltages varied in the range of 30-140 kVp with 10 kV steps. Contrast elements of CaCO 3 , iodine, adipose and tumor with thicknesses of 280 mg cm -2 , 15 mg cm -2 , 1 g cm -2 and 1 g cm -2 , respectively, inserted in a soft tissue background with 10 cm and 20 cm thicknesses, were used. The energy weighting also improves the contrast-to-noise ratio (CNR) in CT when monoenergetic CT projections are optimally weighted prior to CT reconstruction (projection-based weighting). Alternatively, monoenergetic CT images are reconstructed, optimally weighted and composed to yield a final CT image (image-based weighting). Both projection-based and image-based weighting methods improve the CNR in CT. An analytical approach was used to determine which of these two weighting methods provides the upper limit of the CNR in CT. The energy-weighting method was generalized and expanded as a weighting method applicable in

Secure diversity-multiplexing tradeoff of zero-forcing transmit scheme at finite-SNR

KAUST Repository

Rezki, Zouheir; Alouini, Mohamed-Slim

2012-01-01

information in the orthogonal space of the eavesdropper channel, is used. First, we introduce the secrecy multiplexing gain at finite-SNR that generalizes the definition at high-SNR. Then, we provide upper and lower bounds on the outage probability under

Recent radio studies of SNR

International Nuclear Information System (INIS)

Dickel, J.R.

1983-01-01

SNR can generally be recognized as extended sources of continuum radio emission with non-thermal spectra located near the galactic plane. The author describes the kinds of observations currently being obtained and what they tell us about the objects. The data include continuum observations which can reach resolutions of about 1 arcsec using aperture synthesis techniques and also spectral line observations of the interstellar matter being encountered by the remnants. (Auth.)

On the low SNR capacity of MIMO fading channels with imperfect channel state information

KAUST Repository

Benkhelifa, Fatma

2014-06-01

The capacity of multiple-input multiple-output (MIMO) Rayleigh fading channels with full knowledge of channel state information (CSI) at both the transmitter and the receiver (CSI-TR) has been shown recently to scale at low signal-to-noise ratio (SNR) essentially as SNR log(1/SNR), independently of the number of transmit and receive antennas. In this paper, we investigate the ergodic capacity of MIMO Rayleigh fading channel with estimated channel state information at the transmitter (CSI-T) and possibly imperfect channel state information at the receiver (CSI-R). Our framework can be seen as a generalization of previous works as it can capture the perfect CSI-TR as a special case when the estimation error variance goes to zero. In this paper, we mainly focus on the low SNR regime, and we show that the capacity scales as (1-α) SNR log(1/SNR), where α is the estimation error variance. This characterization shows the loss of performance due to error estimation over the perfect channel state information at both the transmitter and the receiver. As a by-product of our new analysis, we show that our framework can be also extended to characterize the capacity of MIMO Rician fading channels at low SNR with possibly imperfect CSI-T and CSI-R. © 1972-2012 IEEE.

On the low SNR capacity of MIMO fading channels with imperfect channel state information

KAUST Repository

Benkhelifa, Fatma

2014-05-01

The capacity of Multiple Input Multiple Output (MIMO) Rayleigh fading channels with full knowledge of channel state information (CSI) at both the transmitter and the receiver (CSI-TR) has been shown recently to scale at low Signal-to-Noise Ratio (SNR) essentially as SNR log(1=SNR), independently of the number of transmit and receive antennas. In this paper, we investigate the ergodic capacity of MIMO Rayleigh fading channel with estimated channel state information at the transmitter (CSI-T) and possibly imperfect channel state information at the receiver (CSI-R). Our framework can be seen as a generalization of previous works as it can capture the perfect CSI-TR as a special case when the estimation error variance goes to zero. In our work, we mainly focus on the low SNR regime and we show that the capacity scales as (1-α) SNR log(1=SNR), where α is the estimation error variance. This characterization shows the loss of performance due to error estimation over the perfect channel state information at both the transmitter and the receiver. As a by-product of our new analysis, we show that our framework can also be extended to characterize the capacity of MIMO Rician fading channels at low SNR with possibly imperfect CSI-T and CSI-R. © 2014 IFIP.

Pengaruh Penambahan Garam Natrium Dalam Proses Pengendapan Limbah Pengolahan Gambir Terhadap Rendemen Tanin

Directory of Open Access Journals (Sweden)

Hendri Muchtar

2013-06-01

  natrium bikarbonat dan larutan jenuh air kapur. Tahap pengendapan pH larutan diatur dengan menambahkan  NaHCO3 atau air kapur jenuh sedemikian rupa sampai pH 8.   Penambahan  garam NaCl atau garam dapur pada bahan tersebut di atas dengan konsentrasi antara 50 g/L, 100 g/L,  150 g/L, 200 g/L, 250 g/L, 300 g/L, 350g/L, 400 g/L pada 200 ml limbah cair pengolahan gambir. Dari hasil penelitian diperoleh endapan yang optimal adalah  dengan penambahan NaCl   teknis dengan konsentrasi 300 g/L dengan menggunakan pengatur pH natrium bikarbonat dengan rendemen sebesar 30,05 %. Penambahan NaCl dengan konsentrasi diatas 300 g/L memberikan hasil yang tidak jauh berbeda.  Zat warna tanin dari limbah cair pengolahan gambir berupa  tepung soga berwarna cokelat.

SNR Estimation in Linear Systems with Gaussian Matrices

KAUST Repository

Suliman, Mohamed Abdalla Elhag; Alrashdi, Ayed; Ballal, Tarig; Al-Naffouri, Tareq Y.

2017-01-01

This letter proposes a highly accurate algorithm to estimate the signal-to-noise ratio (SNR) for a linear system from a single realization of the received signal. We assume that the linear system has a Gaussian matrix with one sided left correlation. The unknown entries of the signal and the noise are assumed to be independent and identically distributed with zero mean and can be drawn from any distribution. We use the ridge regression function of this linear model in company with tools and techniques adapted from random matrix theory to achieve, in closed form, accurate estimation of the SNR without prior statistical knowledge on the signal or the noise. Simulation results show that the proposed method is very accurate.

SNR Estimation in Linear Systems with Gaussian Matrices

KAUST Repository

Suliman, Mohamed Abdalla Elhag

2017-09-27

This letter proposes a highly accurate algorithm to estimate the signal-to-noise ratio (SNR) for a linear system from a single realization of the received signal. We assume that the linear system has a Gaussian matrix with one sided left correlation. The unknown entries of the signal and the noise are assumed to be independent and identically distributed with zero mean and can be drawn from any distribution. We use the ridge regression function of this linear model in company with tools and techniques adapted from random matrix theory to achieve, in closed form, accurate estimation of the SNR without prior statistical knowledge on the signal or the noise. Simulation results show that the proposed method is very accurate.

MIMO Intensity-Modulation Channels: Capacity Bounds and High SNR Characterization

KAUST Repository

Chaaban, Anas

2016-10-01

The capacity of MIMO intensity modulation channels is studied. The nonnegativity of the transmit signal (intensity) poses a challenge on the precoding of the transmit signal, which limits the applicability of classical schemes in this type of channels. To resolve this issue, capacity lower bounds are developed by using precoding-free schemes. This is achieved by channel inversion or QR decomposition to convert the MIMO channel to a set of parallel channels. The achievable rate of a DC-offset SVD based scheme is also derived as a benchmark. Then, a capacity upper bound is derived and is shown to coincide with the achievable rate of the QR decomposition based scheme at high SNR, consequently characterizing the high-SNR capacity of the channel. The high-SNR gap between capacity and the achievable rates of the channel inversion and the DC-offset SVD based schemes is also characterized. Finally, the ergodic capacity of the channel is also briefly discussed.

A model of SNR evolution for an O-star in a cloudy ISM

International Nuclear Information System (INIS)

Shull, P. Jr.

1988-01-01

The authors present an analytical model of SNR evolution in a cloudy interstellar medium for a single progenitor star of spectral type 05 V. The model begins with the progenitor on the zero-age main sequence, includes the effects of the star's wind and ionizing photons, and ends with the SNR's assimilation by the ISM. The authors assume that the ISM consists of atomic clouds, molecular clouds, and a hot intercloud phase. The type of SNR that results bears a strong resemblance to N63A in the Large Magellanic Cloud

SNR characteristics of 850-nm OEIC receiver with a silicon avalanche photodetector.

Science.gov (United States)

Youn, Jin-Sung; Lee, Myung-Jae; Park, Kang-Yeob; Rücker, Holger; Choi, Woo-Young

2014-01-13

We investigate signal-to-noise ratio (SNR) characteristics of an 850-nm optoelectronic integrated circuit (OEIC) receiver fabricated with standard 0.25-µm SiGe bipolar complementary metal-oxide-semiconductor (BiCMOS) technology. The OEIC receiver is composed of a Si avalanche photodetector (APD) and BiCMOS analog circuits including a transimpedance amplifier with DC-balanced buffer, a tunable equalizer, a limiting amplifier, and an output buffer with 50-Ω loads. We measure APD SNR characteristics dependence on the reverse bias voltage as well as BiCMOS circuit noise characteristics. From these, we determine the SNR characteristics of the entire OEIC receiver, and finally, the results are verified with bit-error rate measurement.

Prospektive Entwicklung des postoperativen Sprachverstehens nach Tympanoplastik bei chronischer Otitis media

OpenAIRE

Knof, B; Plotz, K; Krack, A; Stumper, J; Schönfeld, R

2013-01-01

Einleitung: Tympanoplastiken I/III bei chron. Otitis media COM (mesotympanalis CMOM und epitympanalis CEOM). In der Literatur werden erfolgreiche operative Behandlungen mit Verringerung der Schallleitungskomponente (air-bone gap) belegt (Gierke et al. 2011). Aus Sicht des Patienten steht die Verbesserung des Hörvermögens und des Sprachverstehens im Alltag im Vordergrund. Das Ziel war die Untersuchung der Entwicklung des Hörvermögens in Ruhe sowie im Störgeräusch.Methoden: An den Hör- und Sp...

Free-space optical communications with peak and average constraints: High SNR capacity approximation

KAUST Repository

Chaaban, Anas; Morvan, Jean-Marie; Alouini, Mohamed-Slim

2015-01-01

. Numerical evaluation shows that this capacity lower bound is nearly tight at high signal-to-noise ratio (SNR), while it is shown analytically that the gap to capacity upper bounds is a small constant at high SNR. In particular, the gap to the high

On the low SNR capacity of log-normal turbulence channels with full CSI

KAUST Repository

Benkhelifa, Fatma; Tall, Abdoulaye; Rezki, Zouheir; Alouini, Mohamed-Slim

2014-01-01

In this paper, we characterize the low signal-To-noise ratio (SNR) capacity of wireless links undergoing the log-normal turbulence when the channel state information (CSI) is perfectly known at both the transmitter and the receiver. We derive a closed form asymptotic expression of the capacity and we show that it scales essentially as λ SNR where λ is the water-filling level satisfying the power constraint. An asymptotically closed-form expression of λ is also provided. Using this framework, we also propose an on-off power control scheme which is capacity-achieving in the low SNR regime.

On the low SNR capacity of log-normal turbulence channels with full CSI

KAUST Repository

Benkhelifa, Fatma

2014-09-01

In this paper, we characterize the low signal-To-noise ratio (SNR) capacity of wireless links undergoing the log-normal turbulence when the channel state information (CSI) is perfectly known at both the transmitter and the receiver. We derive a closed form asymptotic expression of the capacity and we show that it scales essentially as λ SNR where λ is the water-filling level satisfying the power constraint. An asymptotically closed-form expression of λ is also provided. Using this framework, we also propose an on-off power control scheme which is capacity-achieving in the low SNR regime.

Stratification in SNR-300 outlet plenum

International Nuclear Information System (INIS)

Reinders, R.

1983-01-01

In the inner outlet plenum of the SNR-300 under steady state conditions a large toroidal vortex is expected. The main flow passes through the gap between dipplate and shield vessel to the outer annular space. Only 3% of the flow pass the 24 emergency cooling holes, situated in the shield vessel. The sodium leaves the reactor tank through the 3 symmetrically arranged outlet nozzles. For a scram flow rates and temperatures are decreased simultaneously, so it is expected, that stratification occurs in the inner outlet plenum. A measure of stratification effects is the Archimedes Number Ar, which is the relation of buoyancy forces (negative) to kinetic energy. (The Archimedes Number is nearly identical with the Richardson Number). For values Ar>1 stratification can occur. Under the assumption of stratification the code TIRE was developed, which is only applicable for the period of time after some 50 sec after scram. This code serves for long term calculations. As the equations are very simple, it is a very fast code which gives the possibility to calculate transients for some hours real time. This code mainly has to take into account the pressure difference between inner plenum and outlet annulus caused by geodatic pressure. That force is in equilibrium with the pressure drop over the gap and holes in the shield vessel. For more detailed calculations of flow pattern and temperature distribution the code MIX and INKO 2T are applied. MIX was developed and validated at ANL, INKO 2T is a development of INTERATOM. INKO 2T is under validation. Mock up experiments were carried out with water to simulate the transient behavior of the SNR-300 outlet plenum. Calculations obtained by INKO 2T for steady state and the transient are shown for the flow pattern. Results of measurements also prove that stratification begins after about 30 sec. Measurements and detailed calculations show that it is admissible to use the code TIRE for the long term calculations. Calculations for a scram

On the capacity of Rician fading channels with full channel state information at low SNR

KAUST Repository

Rezki, Zouheir

2012-06-01

The capacity of flat Rayleigh fading channels with full channel state information (CSI) at the transmitter and at the receiver at asymptotically low SNR has been recently shown to scale essentially as SNR log (1/SNR). In this paper, we investigate the Rician fading channel capacity with full CSI, and show that the capacity of this channel scales essentially as 1/1+K SNR log (1 /SNR), where K is the Rician factor. This characterization includes perfect CSI at both the transmitter and the receiver or noisy CSI at the transmitter and perfect CSI at the receiver. We also show that one-bit CSI at the transmitter is enough to achieve this asymptotic capacity using an On-Off power control scheme. Our framework may be seen as a generalization of previous works as it captures the Rayleigh fading channel as a special case by letting K goes to zero. © 2012 IEEE.

Aircraft Research Guideline 1999 - 2002: High pressure compressor - preliminary design as a basis for the development of an efficient and environmentally friendly core engine. Final report; Leitlinie Luftfahrtforschung 1999 - 2002: Hochdruckverdichter-Vorauslegung als Grundlagenuntersuchung zur Entwicklung eines Kerntriebwerkes fuer einen effizienten und umweltfreundlichen Antrieb. Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Klinger, H.

2001-08-01

This report completes the documentation for the research project 'High Pressure Compressor - Preliminary Design as Basis for the Development of an Efficient and Environmentally Friendly Core Engine' which was funded by the Ministry of Economics of State Brandenburg. The objective of the project is to deliver a preliminary compressor aerodynamic design as well as design studies for an efficient, weight and cost improved compressor. The increase of stage pressure ratio and improved efficiency, whilst stage and blade count is reduced, has been achieved by advanced 3D methods. Compressor stability also at off-design conditions will be retained. The mechanical design focusses on a cost and weight optimised rotor not only for a conventional bladed discs but also for Blish stages. Various options for split casings have been developed and assessed. Alternative vortex reducers based on different design options have been carried out. The results from this project will be directly exploited in a follow-on project for a new nine-stage compressor. The new high pressure compressor will be a key element of the future two-shaft-engine architecture. (orig.) [German] Der vorliegende Bericht schliesst das vom Land Brandenburg im Rahmen der Leitlinie Luftfahrtforschung gefoerderte Vorhaben 'Hochdruckverdichter - Vorauslegung als Grundlagenuntersuchung zur Entwicklung eines Kerntriebwerkes fuer einen effizienten und umweltfreundlichen Antrieb' ab. Ziel dieses Vorhabens ist es, im Rahmen einer aerodynamischen Vorauslegung sowie Designstudien die notwendigen Technologien zu erarbeiten, um einen hinsichtlich Effizienz, Kosten, Gewicht und Wartungsintervallen verbesserten Hochdruckverdichter auszulegen. Die Erhoehung des Druckverhaeltnisses und des Wirkungsgrads bei verringerter Stufen- und Schaufelzahl sowie ein stabiles Betriebsverhalten auch ausserhalb des Auslegungspunktes wurde dabei durch eine aeusserst fortschrittliche 3D Schaufelauslegung erreicht. Auf der

On the capacity of nakagami-m fading Channels with full channel state information at low SNR

KAUST Repository

Rezki, Zouheir

2012-06-01

The capacity of flat Rayleigh fading channels with full channel state information (CSI) at the transmitter and at the receiver at asymptotically low SNR has been recently shown to scale essentially as SNR log(1/SNR)}. In this paper, we investigate the Nakagami-m fading channel capacity with full CSI, and show that the capacity of this channel scales essentially as m/ Omega SNR log(1/SNR), where m is the Nakagami-m fading parameter and where Ω is the channel mean-square. We also show that one-bit CSI at the transmitter is enough to achieve this asymptotic capacity using an On-Off power control scheme. Our framework may be seen as a generalization of previous works as it captures the Rayleigh fading channel as a special case by taking m=1. © 2012 IEEE.

SNR-steam generator design with respect to large sodium water reactions

International Nuclear Information System (INIS)

Jong, J.J. de; Kellner, A.; Florie, C.J.L.

1984-01-01

This paper deals with the experiences gained during the licensing procedure for the steam generators for the SNR 300 LMFBR regarding large sodium-water reactions. A description is given of the different calculations executed to investigate the effects of large leaks on the 85 MW helical coiled and straight tube steam generators. The investigations on the helical coiled steam generators are divided in the formulations of fluid behaviour, dynamic force calculations, dynamic response calculation and finally stress analyses. Several results are shown. The investigations on the straight tube steam generators are performed using models describing fluid-structure interaction, coupled with stress analyses. Several results are presented. A description is given of the problems and necessary construction changes during the licensing process. Advises are given for future analyses and design concepts for second generation commercial size LMFBR steam generators with respect to large leaks; based on the experience, gained with SNR 300, and using some new calculations for SNR 2. (author)

Detection of plumes at Redoubt and Etna volcanoes using the GPS SNR method

Science.gov (United States)

Larson, Kristine M.; Palo, Scott; Roesler, Carolyn; Mattia, Mario; Bruno, Valentina; Coltelli, Mauro; Fee, David

2017-09-01

Detection and characterization of volcanic eruptions is important both for public health and aircraft safety. A variety of ground sensors are used to monitor volcanic eruptions. Data from these ground sensors are subsequently incorporated into models that predict the movement of ash. Here a method to detect volcanic plumes using GPS signals is described. Rather than carrier phase data used by geodesists, the method takes advantage of attenuations in signal to noise ratio (SNR) data. Two datasets are evaluated: the 2009 Redoubt Volcano eruptions and the 2013/2015 eruptions at Mt. Etna. SNR-based eruption durations are compared with previously published seismic, infrasonic, and radar studies at Redoubt Volcano. SNR-based plume detections from Mt. Etna are compared with L-band radar and tremor observations. To place these SNR observations from Redoubt and Etna in context, a model of the propagation of GPS signals through both water/water vapor and tephra is developed. Neither water nor fine ash particles will produce the observed attenuation of GPS signals, while scattering caused by particles > 1 cm in diameter potentially could.

Steam generator in the SNR-project

International Nuclear Information System (INIS)

van Westenbrugge, J.K.

1979-01-01

The design philosophy of steam generators for 1300 MWe LMFBR's is presented. The basis for this philosophy is the present experience with the licensing of the SNR-300. This experience is reported. The approach for the steam generators for the 1300 MWe LMFBR is elaborated on, both for accident prevention and damage limitation, for the component itself as well as for the system design. Both Design Base Accident and Hypothetical Accidents are discussed. 8 refs

Wie Geschwister sich in ihrer musikalischen Entwicklung beeinflussen. Ergebnisse einer Erhebung mit offenem Fragebogen

OpenAIRE

Olbertz, Franziska

2012-01-01

Die Rolle der Geschwister in der musikalischen Entwicklung sollte anhand empirischer Daten fassbar gemacht und damit eine Forschungslücke der musikalischen Entwicklungspsychologie geschlossen werden. Dazu wurden in der aktuellen Studie zunächst die Formen der musikalischen Beeinflussung unter Geschwistern qualitativ erhoben und kategorisiert. Einfache quantitative Analysen desselben Materials sollten auch Hypothesen über die Bedeutung einiger Variablen ermöglichen, wie z. B. des Altersabstand...

Description of the global fuel element failure detection for SNR 300

International Nuclear Information System (INIS)

Dauk, J.

1985-07-01

For the detection of fission products in the cover gas of SNR 300 a high-resolution gamma-spectrometer with connected mini-computer is applied. The mechanical structure of the two Ge-detectors, which are positioned at two redundant gas lines, the analogous electronic and the structure of the computer with its periphery are described in this report. The concept of the software is presented, which had been developed especially for SNR 300. The start-up of the system and the calibration of the auxiliary measuring points and of the Ge-detectors are described [de

The single SNR fuel assembly container (ESBB) to transport unirradiated SNR 300 fuel assemblies

International Nuclear Information System (INIS)

Hilbert, F.; Hottenrott, G.

1998-01-01

In this paper a new type B(U) package design is presented. The Single SNR Fuel Assembly Container (ESBB) is designed for the transport and storage of a single SNR 300 fuel assembly. This package is the main component for the future interim storage of the fuel assemblies in heavy storage casks. Its benefits are that it is compatible with the Category I transport system of Nuclear Cargo + Service NCS) used in Germany and that it can be easily handled at the current storage locations as well as in an interim storage facility. In total 205 fuel assemblies are currently stored in Hanau, Germany and Dounreay, U.K. Former studies have shown, that heavy transport and storage casks can be handled there only with considerable efforts. But the required category I transport to an interim storage is not reasonably feasible. To overcome these problems the ESBB was designed. It consists of a stainless steel tube with welded bottom, a welded plug as closure system and shock absorbers 26 packages at maximum can be transported in one batch with the NCS security vehicle. The safety analysis shows that the package complies with IAEA 1996. Standard calculations methods and computer codes like HEATING 7.2 (Childs 1993) have been used for the analysis. Criticality safety assessment is based on conservative assumptions as required in IAEA 1996. Drop tests carried out by BAM will be used to verify the design. These tests are scheduled for mid 1998. For the validation of the design prototypes have already been manufactured. Handling tests show that the design complies with the requirements. Preliminary drop tests show that the certification drop tests will be passed positively. (authors)

Evaluation of special safety features of the SNR-300 in view of the Chernobyl accident

International Nuclear Information System (INIS)

Vossebrecker, H.

1987-03-01

A comparison of those characteristics, which decisively influenced the accident in the RMBK-1000 reactor, with the safety features of SNR-300 has been performed. The conclusions of this comparison are presented in the present report. The SNR-300 is characterized by a stable reactivity behaviour and good controllability, whereas RBMK-1000 has an instable behaviour and complex spatial dependencies in the core. Among other points, design deficiencies in the protection and emergency shutdown systems were responsible for the Chernobyl accident. The protection and scram systems of the SNR-300 are unquestionably superior to those of the RBMK-1000 with regard to redundancy, diversity, degree of automation, separation of operational and safety-relevant tasks, protection against inadmissible interventions, effectiveness and safety reserves. Therefore, excursion accidents can be classified as hypothetical for SNR-300. Due to elementary physical properties, possible energy releases during hypothetical excursions are substantially lower for SNR-300 and would be controlled by the design of the primary system and containment systems. No damage limiting measures are provided in the RBMK-100 for excursion accidents. Finally, exothermal processes augmented the consequences of the accident in the RBMK-1000 and the long-lasting graphite fire intensified the release of radioactivity. In the SNR-300, however, inertisation of the containment, the steel plate lining and the floor troughs ensure that activity enclosure inside the containment after leakage or hypothetical excursion accident is not endangered by exothermal reactions. Further safety aspects are presented in the report, which can be linked with the accident in Chernobyl. In summary, it is obvious that the disadvantageous physical and technical features of the RBMK-1000 do either not exist in the SNR-300 or are covered by the safety design

Low SNR Capacity of FSO Links over Gamma-Gamma Atmospheric Turbulence Channels

KAUST Repository

Benkhelifa, Fatma; Alouini, Mohamed-Slim; Rezki, Zouheir

2013-01-01

free space optical communication systems over Gamma-Gamma atmospheric turbulence fading channels with perfect channel state information at both the transmitter and the receiver. In our framework, we mainly focus on the low signal-to-noise ratio range and show that the ergodic capacity scales proportionally to SNR log^4(1/SNR). We show also that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-o ff power control scheme.

On the finite-SNR diversity-multiplexing tradeoff of zero-forcing transmit scheme under secrecy constraint

KAUST Repository

Rezki, Zouheir

2011-06-01

In this paper, we address the finite Signal-to-Noise Ratio (SNR) Diversity-Multiplexing Tradeoff (DMT) of the Multiple Input Multiple Output (MIMO) wiretap channel, where a Zero-Forcing (ZF) transmit scheme, that intends to send the secret information in the orthogonal space of the eavesdropper channel, is used. First, we introduce the secret multiplexing gain at finite-SNR that generalizes the definition at high-SNR. Then, we provide upper and lower bounds on the outage probability under secrecy constraint, from which secret diversity gain estimates of ZF are derived. Through asymptotic analysis, we show that the upper bound underestimates the secret diversity gain, whereas the lower bound is tight at high-SNR, and thus its related diversity gain estimate is equal to the actual asymptotic secret diversity gain of the Multiple-Input Multiple-Output (MIMO) wiretap channel. © 2011 IEEE.

Multipath detection with the combination of SNR measurements - Example from urban environment

Science.gov (United States)

Špánik, Peter; Hefty, Ján

2017-12-01

Multipath is one of the most severe station-dependent error sources in both static and kinematic positioning. Relatively new and simple detection technique using the Signal-to-Noise (SNR) measurements on three frequencies will be presented based on idea of Strode and Groves. Exploitation of SNR measurements is benefi cial especially for their unambiguous character. Method is based on the fact that SNR values are closely linked with estimation of pseudo-ranges and phase measurements during signal correlation processing. Due to this connection, combination of SNR values can be used to detect anomalous behavior in received signal, however some kind of calibration in low multipath environment has to be done previously. In case of multipath, phase measurements on different frequencies will not be affected in the same manner. Specular multipath, e.g. from building wall introduces additional path delay which is interpreted differently on each of the used carrier, due to different wavelengths. Experimental results of multipath detection in urban environment will be presented. Originally proposed method is designed to work with three different frequencies in each epoch, thus only utilization of GPS Block II-F and Galileo satellites is possible. Simplification of detection statistics to use only two frequencies is made and results using GPS and GLONASS systems are presented along with results obtained using original formula.

Optical intensity modulation direct detection versus heterodyne detection: A high-SNR capacity comparison

KAUST Repository

Chaaban, Anas

2016-09-15

An optical wireless communications system which employs either intensity-modulation and direct-detection (IM-DD) or heterodyne detection (HD) is considered. IM-DD has lower complexity and cost than HD, but on the other hand, has lower capacity. It is therefore interesting to investigate the capacity gap between the two systems. The main focus of this paper is to investigate this gap at high SNR. Bounds on this gap are established for two cases: between IM-DD and HD, and between IM-DD and an HD-PAM which is an HD system employing pulse-amplitude modulation (PAM). While the gap between IM-DD and HD increases as the signal-to-noise ratio (SNR) increases, the gap between IM-DD and an HD-PAM is upper bounded by a constant at high SNR. © 2015 IEEE.

Optical intensity modulation direct detection versus heterodyne detection: A high-SNR capacity comparison

KAUST Repository

Chaaban, Anas; Alouini, Mohamed-Slim

2016-01-01

An optical wireless communications system which employs either intensity-modulation and direct-detection (IM-DD) or heterodyne detection (HD) is considered. IM-DD has lower complexity and cost than HD, but on the other hand, has lower capacity. It is therefore interesting to investigate the capacity gap between the two systems. The main focus of this paper is to investigate this gap at high SNR. Bounds on this gap are established for two cases: between IM-DD and HD, and between IM-DD and an HD-PAM which is an HD system employing pulse-amplitude modulation (PAM). While the gap between IM-DD and HD increases as the signal-to-noise ratio (SNR) increases, the gap between IM-DD and an HD-PAM is upper bounded by a constant at high SNR. © 2015 IEEE.

A method to design high SNR nanoscale magnetic sensors using an array of tunnelling magneto-resistance (TMR) devices

International Nuclear Information System (INIS)

Gomez, P; Litvinov, D; Khizroev, S

2007-01-01

This paper presents a systematic method to design and calculate tunnelling magneto-resistance (TMR) sensors with high signal-to-noise ratio (SNR). The sensing module consists of four TMR devices arranged in a Wheatstone-bridge configuration. Closed-form equations were obtained to calculate TMR sensor current, array output voltage, magneto-resistance ratio, overall noise (thermal and shot) and SNR for a given bandwidth. Using this technique we were able to maximize the SNR by tuning the many parameters of the TMR devices. Typical SNR values are in excess of 45 dB

dDYRK2 and Minibrain interact with the chromatin remodelling factors SNR1 and TRX.

Science.gov (United States)

Kinstrie, Ross; Lochhead, Pamela A; Sibbet, Gary; Morrice, Nick; Cleghon, Vaughn

2006-08-15

The DYRKs (dual specificity tyrosine phosphorylation-regulated kinases) are a conserved family of protein kinases that autophosphorylate a tyrosine residue in their activation loop by an intra-molecular mechanism and phosphorylate exogenous substrates on serine/threonine residues. Little is known about the identity of true substrates for DYRK family members and their binding partners. To address this question, we used full-length dDYRK2 (Drosophila DYRK2) as bait in a yeast two-hybrid screen of a Drosophila embryo cDNA library. Of 14 independent dDYRK2 interacting clones identified, three were derived from the chromatin remodelling factor, SNR1 (Snf5-related 1), and three from the essential chromatin component, TRX (trithorax). The association of dDYRK2 with SNR1 and TRX was confirmed by co-immunoprecipitation studies. Deletion analysis showed that the C-terminus of dDYRK2 modulated the interaction with SNR1 and TRX. DYRK family member MNB (Minibrain) was also found to co-precipitate with SNR1 and TRX, associations that did not require the C-terminus of the molecule. dDYRK2 and MNB were also found to phosphorylate SNR1 at Thr102 in vitro and in vivo. This phosphorylation required the highly conserved DH-box (DYRK homology box) of dDYRK2, whereas the DH-box was not essential for phosphorylation by MNB. This is the first instance of phosphorylation of SNR1 or any of its homologues and implicates the DYRK family of kinases with a role in chromatin remodelling.

Low SNR Capacity of FSO Links over Gamma-Gamma Atmospheric Turbulence Channels

KAUST Repository

Benkhelifa, Fatma

2013-01-27

In this paper, we study the ergodic capacity of free space optical communication systems over Gamma-Gamma atmospheric turbulence fading channels with perfect channel state information at both the transmitter and the receiver. In our framework, we mainly focus on the low signal-to-noise ratio range and show that the ergodic capacity scales proportionally to SNR log^4(1/SNR). We show also that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-o ff power control scheme.

Low SNR Capacity of FSO Links over Gamma-Gamma Atmospheric Turbulence Channels

KAUST Repository

Benkhelifa, Fatma

2013-02-23

In this paper, we study the ergodic capacity of free space optical communication systems over Gamma-Gamma atmospheric turbulence fading channels with perfect channel state information at both the transmitter and the receiver. In our framework, we mainly focus on the low signal-to-noise ratio range and show that the ergodic capacity scales proportionally to SNR log^4(1/SNR). We show also that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-off power control scheme.

Low SNR Capacity of FSO Links over Gamma-Gamma Atmospheric Turbulence Channels

KAUST Repository

Benkhelifa, Fatma; Alouini, Mohamed-Slim; Rezki, Zouheir

2013-01-01

In this paper, we study the ergodic capacity of free space optical communication systems over Gamma-Gamma atmospheric turbulence fading channels with perfect channel state information at both the transmitter and the receiver. In our framework, we mainly focus on the low signal-to-noise ratio range and show that the ergodic capacity scales proportionally to SNR log^4(1/SNR). We show also that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-off power control scheme.

High SNR Acquisitions Improve the Repeatability of Liver Fat Quantification Using Confounder-corrected Chemical Shift-encoded MR Imaging

Science.gov (United States)

Motosugi, Utaroh; Hernando, Diego; Wiens, Curtis; Bannas, Peter; Reeder, Scott. B

2017-01-01

Purpose: To determine whether high signal-to-noise ratio (SNR) acquisitions improve the repeatability of liver proton density fat fraction (PDFF) measurements using confounder-corrected chemical shift-encoded magnetic resonance (MR) imaging (CSE-MRI). Materials and Methods: Eleven fat-water phantoms were scanned with 8 different protocols with varying SNR. After repositioning the phantoms, the same scans were repeated to evaluate the test-retest repeatability. Next, an in vivo study was performed with 20 volunteers and 28 patients scheduled for liver magnetic resonance imaging (MRI). Two CSE-MRI protocols with standard- and high-SNR were repeated to assess test-retest repeatability. MR spectroscopy (MRS)-based PDFF was acquired as a standard of reference. The standard deviation (SD) of the difference (Δ) of PDFF measured in the two repeated scans was defined to ascertain repeatability. The correlation between PDFF of CSE-MRI and MRS was calculated to assess accuracy. The SD of Δ and correlation coefficients of the two protocols (standard- and high-SNR) were compared using F-test and t-test, respectively. Two reconstruction algorithms (complex-based and magnitude-based) were used for both the phantom and in vivo experiments. Results: The phantom study demonstrated that higher SNR improved the repeatability for both complex- and magnitude-based reconstruction. Similarly, the in vivo study demonstrated that the repeatability of the high-SNR protocol (SD of Δ = 0.53 for complex- and = 0.85 for magnitude-based fit) was significantly higher than using the standard-SNR protocol (0.77 for complex, P magnitude-based fit, P = 0.003). No significant difference was observed in the accuracy between standard- and high-SNR protocols. Conclusion: Higher SNR improves the repeatability of fat quantification using confounder-corrected CSE-MRI. PMID:28190853

Die Etablierung massenspektrometrischer quantitativer Studien des Herzproteoms während der embryonalen Entwicklung und der Alterung

OpenAIRE

Konzer, Anne

2012-01-01

Neue Erkenntnisse über die physiologischen, molekularen und pathologischen Prozesse im Herzen konnten im letzten Jahrzehnt anhand von Modellorganismen gewonnen werden. Die Entwicklung neuer Techniken ermöglichte außerdem die Etablierung umfangreicher und eindrucksvoller Studien basierend auf den neusten Mikroskopieverfahren, auf globalen Genexpressionsanalysen (Microarray) sowie auf modernen Massenspektrometrie (MS)- basierenden Proteinanalysen anhand von hochauflösenden Tandem-Massenspektrom...

A Ramp Cosine Cepstrum Model for the Parameter Estimation of Autoregressive Systems at Low SNR

Directory of Open Access Journals (Sweden)

Zhu Wei-Ping

2010-01-01

Full Text Available A new cosine cepstrum model-based scheme is presented for the parameter estimation of a minimum-phase autoregressive (AR system under low levels of signal-to-noise ratio (SNR. A ramp cosine cepstrum (RCC model for the one-sided autocorrelation function (OSACF of an AR signal is first proposed by considering both white noise and periodic impulse-train excitations. Using the RCC model, a residue-based least-squares optimization technique that guarantees the stability of the system is then presented in order to estimate the AR parameters from noisy output observations. For the purpose of implementation, the discrete cosine transform, which can efficiently handle the phase unwrapping problem and offer computational advantages as compared to the discrete Fourier transform, is employed. From extensive experimentations on AR systems of different orders, it is shown that the proposed method is capable of estimating parameters accurately and consistently in comparison to some of the existing methods for the SNR levels as low as −5 dB. As a practical application of the proposed technique, simulation results are also provided for the identification of a human vocal tract system using noise-corrupted natural speech signals demonstrating a superior estimation performance in terms of the power spectral density of the synthesized speech signals.

SNR coolant system components

International Nuclear Information System (INIS)

De Haas Van Dorsser, A.H.; Mausbeck, H.

1976-01-01

The DEBENELUX prototype fast reactor power plant SNR 300 at Kalkar has a loop-type heat transfer system similar to that of the prototype LMFBR plants in the USA and Japan. There exist three 257 MW/sub th/ primary sodium loops, each with a hot leg centrifugal pump and three 85.6 MW/sub th/ intermediate heat exchangers in parallel. From there the heat is transferred to the steam generators via three secondary sodium loops with one cold leg sodium circulating pump in each. At a nominal reactor outlet temperature of 819 0 K and a turbine inlet power of 771 MW/sub th/ super heated steam of 166 bar and 733 0 K is produced, giving rise to a plant rating of 327 MW/sub e/ gross. The primary and secondary loops are described in detail

Skalabilitas Signal to Noise Ratio (SNR pada Pengkodean Video dengan Derau Gaussian

Directory of Open Access Journals (Sweden)

Agus Purwadi

2015-04-01

Full Text Available In video transmission, there is a possibility of packet lost an d a large load variation on the bandwidth. These are the source of network congestion, which can interfere the communication data rate. This study discusses a system to overcome the congestion with Signal-to-noise ratio (SNR scalability-based approach, for the video sequence encoding method into two layers, which is a solution to decrease encoding mode for each packet and channel coding rate. The goal is to minimize any distortion from the source to the destination. The coding system used is a video coding standards that is MPEG-2 or H.263 with SNR scalability. The algorithm used for motion compensation, temporal redundancy and spatial redundancy is the Discrete Cosine Transform (DCT and quantization. The transmission error is simulated by adding Gaussian noise (error on motion vectors. From the simulation results, the SNR and Peak Signal to Noise Ratio (PSNR in the noisy video frames decline with averages of 3dB and 4dB respectively.

Best relay selection using SNR and interference quotient for underlay cognitive networks

KAUST Repository

Hussain, Syed Imtiaz

2012-06-01

Cognitive networks in underlay settings operate simultaneously with the primary networks satisfying stringent interference limits. This condition forces them to operate with low transmission powers and confines their area of coverage. In an effort to reach remote destinations, underlay cognitive sources make use of relaying techniques. Selecting the best relay among those who are ready to cooperate is different in underlay settings than traditional non-cognitive networks. In this paper, we present a relay selection scheme which uses the quotient of the relay link signal to noise ratio (SNR) and the interference generated from the relay to the primary user to choose the best relay. The proposed scheme optimizes this quotient in a way to maximize the relay link SNR above a certain value whereas the interference is kept below a defined threshold. We derive closed expressions for the outage probability and bit error probability of the system incorporating this scheme. Simulation results confirm the validity of the analytical results and reveal that the relay selection in cognitive environment is feasible in low SNR regions. © 2012 IEEE.

Multipath detection with the combination of SNR measurements – Example from urban environment

Directory of Open Access Journals (Sweden)

Špánik Peter

2017-12-01

Full Text Available Multipath is one of the most severe station-dependent error sources in both static and kinematic positioning. Relatively new and simple detection technique using the Signal-to-Noise (SNR measurements on three frequencies will be presented based on idea of Strode and Groves. Exploitation of SNR measurements is benefi cial especially for their unambiguous character. Method is based on the fact that SNR values are closely linked with estimation of pseudo-ranges and phase measurements during signal correlation processing. Due to this connection, combination of SNR values can be used to detect anomalous behavior in received signal, however some kind of calibration in low multipath environment has to be done previously. In case of multipath, phase measurements on different frequencies will not be affected in the same manner. Specular multipath, e.g. from building wall introduces additional path delay which is interpreted differently on each of the used carrier, due to different wavelengths. Experimental results of multipath detection in urban environment will be presented. Originally proposed method is designed to work with three different frequencies in each epoch, thus only utilization of GPS Block II-F and Galileo satellites is possible. Simplification of detection statistics to use only two frequencies is made and results using GPS and GLONASS systems are presented along with results obtained using original formula.

Magnetic resonance imaging. Recent studies on biological effects of static magnetic and high-frequency electromagnetic fields; Magnetresonanztomographie. Neuere Studien zur biologischen Wirkung statischer Magnetfelder und hochfrequenter elektromagnetischer Felder

Energy Technology Data Exchange (ETDEWEB)

Pophof, B. [Bundesamt fuer Strahlenschutz, Abteilung fuer Wirkungen und Risiken ionisierender und nichtionisierender Strahlung, Oberschleissheim/Neuherberg (Germany); Brix, G. [Bundesamt fuer Strahlenschutz, Abteilung fuer medizinischen und beruflichen Strahlenschutz, Oberschleissheim/Neuherberg (Germany)

2017-07-15

During the last few years, new studies on biological effects of strong static magnetic fields and on thermal effects of high-frequency electromagnetic fields used in magnetic resonance imaging (MRI) were published. Many of these studies have not yet been included in the current safety recommendations. Scientific publications since 2010 on biological effects of static and electromagnetic fields in MRI were researched and evaluated. New studies confirm older publications that have already described effects of static magnetic fields on sensory organs and the central nervous system, accompanied by sensory perceptions. A new result is the direct effect of Lorentz forces on ionic currents in the semicircular canals of the vestibular system. Recent studies of thermal effects of high-frequency electromagnetic fields were focused on the development of anatomically realistic body models and a more precise simulation of exposure scenarios. Strong static magnetic fields can cause unpleasant sensations, in particular, vertigo. In addition, they can influence the performance of the medical staff and thus potentially endanger the patient's safety. As a precaution, medical personnel should move slowly within the field gradient. High-frequency electromagnetic fields lead to an increase in the temperature of patients' tissues and organs. This should be considered especially in patients with restricted thermoregulation and in pregnant women and neonates; in these cases exposure should be kept as low as possible. (orig.) [German] In den letzten Jahren wurden neue Studien zu biologischen Wirkungen starker statischer Magnetfelder und zu thermischen Effekten hochfrequenter elektromagnetischer Feldern, wie sie bei der Magnetresonanztomographie (MRT) verwendet werden, publiziert. Viele dieser Studien sind noch nicht in aktuelle Sicherheitsempfehlungen eingeflossen. Wissenschaftliche Publikationen ab dem Jahr 2010 zur biologischen Wirkung statischer und elektromagnetischer Felder

Effect of exposure time reduction towards sensitivity and SNR for computed radiography (CR) application in NDT

International Nuclear Information System (INIS)

Sapizah Rahim; Khairul Anuar Mohd Salleh; Noorhazleena Azaman; Shaharudin Sayuti; Siti Madiha Muhammad Amir; Arshad Yassin; Abdul Razak Hamzah

2010-01-01

Signal-to-noise ratio (SNR) and sensitivity study of Computed Radiography (CR) system with reduction of exposure time is presented. The purposes of this research are to determine the behavior of SNR toward three different thicknesses (step wedge; 5, 10 and 15 mm) and the ability of CR system to recognize hole type penetrameter when the exposure time decreased up to 80 % according to the exposure chart (D7; ISOVOLT Titan E). It is shown that the SNR is decreased with decreasing of exposure time percentage but the high quality image is achieved until 80 % reduction of exposure time. (author)

Future development LMFBR-steam generators SNR2

International Nuclear Information System (INIS)

Essebaggers, J.; Pors, J.G.

1975-01-01

The development work for steam generators for large LMFBR plants by Neratoom will be reviewed consisting of: 1. Development engineering information. 2. Concept select studies followed by conceptual designs of selected models. 3. Development manufacturing techniques. 4. Detail design of a prototype unit. 5. Testing of sub-constructions for prototype steam generators. In this presentation item 1 and 2 above will be high lighted, identifying the development work for the SNR-2 steam generators on short term basis. (author)

Energy report for Bavaria, 1996/97. Data on the development of the Bavarian energy industry, with an energy balance; Energiebericht Bayern 1996/97. Daten zur Entwicklung der bayerischen Energiewirtschaft mit Energiebilanz

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-04-01

The report presents the energy balance for Bavaria and provides information on: Bavarian energy industry; structure and development of primary and end-use energy consumption; situation and development of energy sources (electricity, gas, mineral oil, coal, district heating). (orig.) [Deutsch] Der Bericht enthaelt die Energiebilanz Bayern fuer das Berichtsjahr und bietet Informationen zur Energiewirtschaft in Bayern, zur Struktur und Entwicklung des Primaer- und Endenergieverbrauchs und zur Situation und Entwicklung bei den einzelnen Energietraegern (Elektrizitaet, Gas, Mineraloel, Kohle, Fernwaerme). (orig.)

Energy efficiency in Germany - a meta-analysis. Analysis and recommendations; Energieeffizienz in Deutschland - eine Metastudie. Analyse und Empfehlungen

Energy Technology Data Exchange (ETDEWEB)

Bauernhansl, Thomas (ed.) [Stuttgart Univ. (Germany). Inst. fuer Energieeffizienz in der Produktion (EEP)

2014-07-01

The Stuttgart Institute of energy efficiency in production compiled the first meta-analysis ''Energy Efficiency in Germany''.It provides facts and figures on the development atatus and knowledge level of energy efficiency in Germany. The study shows the contribution have been made by individual measures and the potentials which are known, but have not yet been lifted. For this meta-analysis more than 250 items available from research institutions, government departments, professional and industry associations have been identified with the main topic of energy efficiency and evaluated. It provides an overview of the status of development and is an important reference work for industry, associations and politics. [German] Das Stuttgarter Institut fuer Energieeffizienz in der Produktion hat die erste Metastudie ''Energieeffizienz in Deutschland'' erarbeitet. Sie liefert Zahlen, Daten und Fakten zum Entwicklungs- und Kenntnisstand der Energieeffizienz in Deutschland. Die Studie zeigt auf, welchen Beitrag einzelne Massnahmen bisher geleistet haben und welche Potenziale zwar bekannt sind, aber bisher noch nicht gehoben wurden. Fuer diese Metastudie wurden mehr als 250 Veroeffentlichungen von Forschungseinrichtungen, Ministerien, Fach- und Industrieverbaenden mit Themenschwerpunkt Energieeffizienz identifiziert und ausgewertet. Sie bietet einen Ueberblick ueber den Stand der Entwicklung und ist ein wichtiges Nachschlagewerk fuer Industrie, Verbaende und Politik.

Design of planar microcoil-based NMR probe ensuring high SNR

Science.gov (United States)

Ali, Zishan; Poenar, D. P.; Aditya, Sheel

2017-09-01

A microNMR probe for ex vivo applications may consist of at least one microcoil, which can be used as the oscillating magnetic field (MF) generator as well as receiver coil, and a sample holder, with a volume in the range of nanoliters to micro-liters, placed near the microcoil. The Signal-to-Noise ratio (SNR) of such a probe is, however, dependent not only on its design but also on the measurement setup, and the measured sample. This paper introduces a performance factor P independent of both the proton spin density in the sample and the external DC magnetic field, and which can thus assess the performance of the probe alone. First, two of the components of the P factor (inhomogeneity factor K and filling factor η ) are defined and an approach to calculate their values for different probe variants from electromagnetic simulations is devised. A criterion based on dominant component of the magnetic field is then formulated to help designers optimize the sample volume which also affects the performance of the probe, in order to obtain the best SNR for a given planar microcoil. Finally, the P factor values are compared between different planar microcoils with different number of turns and conductor aspect ratios, and planar microcoils are also compared with conventional solenoids. These comparisons highlight which microcoil geometry-sample volume combination will ensure a high SNR under any external setup.

Design of planar microcoil-based NMR probe ensuring high SNR

Directory of Open Access Journals (Sweden)

Zishan Ali

2017-09-01

Full Text Available A microNMR probe for ex vivo applications may consist of at least one microcoil, which can be used as the oscillating magnetic field (MF generator as well as receiver coil, and a sample holder, with a volume in the range of nanoliters to micro-liters, placed near the microcoil. The Signal-to-Noise ratio (SNR of such a probe is, however, dependent not only on its design but also on the measurement setup, and the measured sample. This paper introduces a performance factor P independent of both the proton spin density in the sample and the external DC magnetic field, and which can thus assess the performance of the probe alone. First, two of the components of the P factor (inhomogeneity factor K and filling factor η are defined and an approach to calculate their values for different probe variants from electromagnetic simulations is devised. A criterion based on dominant component of the magnetic field is then formulated to help designers optimize the sample volume which also affects the performance of the probe, in order to obtain the best SNR for a given planar microcoil. Finally, the P factor values are compared between different planar microcoils with different number of turns and conductor aspect ratios, and planar microcoils are also compared with conventional solenoids. These comparisons highlight which microcoil geometry-sample volume combination will ensure a high SNR under any external setup.

Empirical investigation on the dependence of TCP downstream throughput on SNR in an IEEE802.11b WLAN system

Directory of Open Access Journals (Sweden)

Ikponmwosa Oghogho

2017-04-01

Full Text Available The dependence of TCP downstream throughput (TCPdownT on signal to noise ratio (SNR in an IEEE802.11b WLAN system was investigated in various environments and varieties of QoS traffic. TCPdownT was measured for various SNR observed. An Infrastructure based IEEE802.11b WLAN system having networked computers on which measurement software were installed, was set up consecutively in various environments (open corridor, small offices with block walls and plaster boards and free space. Empirical models describing TCPdownT against SNR for different signal ranges (all ranges of signals, strong signals only, grey signals only and weak signals only were statistically generated and validated. As the SNR values changed from high (strong signals through low (grey signals to very low (weak signals, our results show a strong dependence of TCPdownT on the received SNR. Our models showed lower RMS errors when compared with other similar models. We observed RMS errors of 0.6734791 Mbps, 0.472209 Mbps, 0.9111563 Mbps and 0.5764460 Mbps for general (all SNR model, strong signals model, grey signals model and Weak signals model respectively. Our models will provide researchers and WLAN systems users with a tool to estimate the TCP downstream throughput in a real network in various environments by monitoring the received SNR.

Risk oriented analysis of the SNR-300

International Nuclear Information System (INIS)

Koeberlein, K.

1982-01-01

The Fact Finding Committee on 'Future Nuclear Power Policy' established by the 8th German Federal Parliament in its report of June 1980 among other items published the recommendation to commission a 'risk oriented analysis' of the SNR-300 in order to enable a pragmatic comparison to be made of the safety of the German prototype fast breeder reactor and a modern light water reactor (a Biblis B PWR). The Federal Minister for Research and Technology in August 1981 officially commissioned the Gesellschaft fuer Reaktorsicherheit (GRS) to conduct the study. Following a recommendation by the Fact Finding Committee, additional studies were performed also by a group of opponents of the breeder reactor. On the instigation of the group of opponents the delivery date of the study was altered several times and finally set at April 30, 1982. GRS submitted its report by this deadline. However, a joint report by the two groups could not be compiled, as had been requested by the client, because the contributions of the opponents were not made available until mid-May 1982 and then only as an 'interim report'. In summary, the GRS study indicates that the frequency and severity of major accidents is lower for the SNR-300 at the Kalkar site than for a PWR as covered in the German Nuclear Power Plant Risk Study. (orig.) [de

Study of the accidental risk of the German fast breeder prototype reactor SNR-300

International Nuclear Information System (INIS)

Koeberlein, K.

1983-01-01

A fact-finding committee of the German Federal Parliament in July 1980 recommended to perform a 'risk-oriented study' of the SNR-300, the German 300 MWe fast breeder prototype reactor being under construction at Kalkar. The main aim of this study was to allow a comparative safety evaluation between the SNR-300 and a modern PWR, thus to prepare a basis for a political decision on the SNR-300. Methods and main results of the study are presented in this paper. In the first step of the study six groups of accidents have been identified which may initiate core destruction. By reliability analyses, expected frequency of each group has been estimated. Conditional probabilities for conceivable reactor tank failure modes have been analysed. Tank failure after core destruction leads to release of energy and radioactive material into the containment system. Such accident sequences have been pursued further. Based on a number of core destruction initiators and tank failure modes and various combinations of success and failure states of the containment systems, detailed calculations of different containment scenarious were carried out. From the results of the plant systems analysis, five release categories have been defined. Possible effects of external events and releases of radioactivity from the spent fuel storage pool have also been analysed. In order to quantify the degree of uncertainty of the calculated frequencies, subjective probability distributions of fixed, but inaccurately known quantities have been propagated through the calculations. Using the release categories as input, accident consequences were calculated for the site Kalkar. Though the uncertainty bandwidths for the accident frequencies estimated in the SNR-300 analysis are much wider than for the PWR, the analysis indicates that frequencies of severe accidents, and consequences, are smaller for the SNR-300 than for the PWR as analysed in the 'German Risk Study'. (orig.)

Intelligibility for Binaural Speech with Discarded Low-SNR Speech Components.

Science.gov (United States)

Schoenmaker, Esther; van de Par, Steven

2016-01-01

Speech intelligibility in multitalker settings improves when the target speaker is spatially separated from the interfering speakers. A factor that may contribute to this improvement is the improved detectability of target-speech components due to binaural interaction in analogy to the Binaural Masking Level Difference (BMLD). This would allow listeners to hear target speech components within specific time-frequency intervals that have a negative SNR, similar to the improvement in the detectability of a tone in noise when these contain disparate interaural difference cues. To investigate whether these negative-SNR target-speech components indeed contribute to speech intelligibility, a stimulus manipulation was performed where all target components were removed when local SNRs were smaller than a certain criterion value. It can be expected that for sufficiently high criterion values target speech components will be removed that do contribute to speech intelligibility. For spatially separated speakers, assuming that a BMLD-like detection advantage contributes to intelligibility, degradation in intelligibility is expected already at criterion values below 0 dB SNR. However, for collocated speakers it is expected that higher criterion values can be applied without impairing speech intelligibility. Results show that degradation of intelligibility for separated speakers is only seen for criterion values of 0 dB and above, indicating a negligible contribution of a BMLD-like detection advantage in multitalker settings. These results show that the spatial benefit is related to a spatial separation of speech components at positive local SNRs rather than to a BMLD-like detection improvement for speech components at negative local SNRs.

On the origin of the system PSR B 1757-24/SNR G 5.4-1.2

Science.gov (United States)

Gvaramadze, V. V.

2004-03-01

A scenario for the origin of the system PSR B 1757-24/supernova remnant (SNR) G 5.4-1.2 is proposed. It is suggested that both objects are the remnants of a supernova (SN) that exploded within a pre-existing bubble blown-up by a runaway massive star (the SN progenitor) during the final (Wolf-Rayet) phase of its evolution. This suggestion implies that (a) the SN blast centre was significantly offset from the geometric centre of the wind-blown bubble (i.e. from the centre of the future SNR), (b) the bubble was surrounded by a massive wind-driven shell, and (c) the SN blast wave was drastically decelerated by the interaction with the shell. Therefore, one can understand how the relatively young and low-velocity pulsar PSR B 1757-24 was able to escape from the associated SNR G 5.4-1.2 and why the inferred vector of pulsar transverse velocity does not point away from the geometric centre of the SNR. A possible origin of the radio source G 5.27-0.9 (located between PSR B 1757-24 and the SNR G 5.4-1.2) is proposed. It is suggested that G 5.27-0.9 is a lobe of a low Mach number (≃1.7) jet of gas outflowing from the interior of G 5.4-1.2 through the hole bored in the SNR's shell by the escaping pulsar. It is also suggested that the non-thermal emission of the comet-shaped pulsar wind nebula originates in the vicinity of the termination shock and in the cylindric region of subsonically moving shocked pulsar wind. The role of magnetized wind-driven shells (swept-up during the Wolf-Rayet phase from the ambient interstellar medium with the regular magnetic field) in formation of elongated axisymmetric SNRs is discussed.

Magnetic resonance imaging of complex congenital heart disease in aduits; Magnetresonanztomographie komplexer kongenitaler Herzerkrankungen beim Erwachsenen

Energy Technology Data Exchange (ETDEWEB)

Bremerich, J. [San Francisco Univ, CA (United States). Dept. of Radiology]|[Universitaetsklinik Basel (Switzerland). Abt. fuer Medizinische Radiologie; Wyttenbach, R.; Higgins, C.B. [San Francisco Univ, CA (United States). Dept. of Radiology; Buser, P. [Universitaetsklinik Basel (Switzerland). Abt. fuer Kardiologie; Steinbrich, W. [Universitaetsklinik Basel (Switzerland). Abt. fuer Medizinische Radiologie

1999-04-01

An increasing number of patients with complex congenital heart disease reaches adulthood, because treatment and patient outcome have improved considerably in recent years. Monitoring of these patients requires both definition of cardiac anatomy and assessment of function with good reproducibility. Complications after surgical repair such as restenoses of pulmonary arteries after surgical repair of Tetralogy of Fallot, ventricular hypertrophy, stenoses or leakage of baffles, or stenosis and aneurysms of anastomoses have to be detected at an early stage. Magnetic Resonance Imaging (MRI) is an excellent tool to monitor these patients because of its noninvasive nature, its good interstudy and interobserver reproducibility, and because it allows assessment of both cardiac anatomy and function. This paper reviews the current applications of MRI in complex congenital heart disease in adults. (orig.) [Deutsch] Durch Verbesserungen in der Diagnose und Therapie komplexer kongenitaler Herzerkrankungen kann eine zunehmende Anzahl von betroffenen Patienten das Erwachsenenalter erreichen. Diese Patienten benoetigen regelmaessige postoperative Verlaufskontrollen, um Komplikationen wie z.B. Restenosen der grossen Arterien, Stenosen, Lecks und Aneurysmata von Anastomosen, Ventrikelhypertrophie und -dilatation oder Klappendysfunktionen fruehzeitig zu erkennen und zu behandeln. Fuer nichtinvasive regelmaessige Verlaufskontrollen bietet sich die Magnetresonanztomographie (MRT) des Herzens an, da sie eine umfassende Untersuchung sowohl der Morphologie als auch der Funktion des Herzens mit guter Reproduzierbarkeit erlaubt. Die gegenwaertigen klinischen Anwendungen der MRT bei komplexen kongenitalen Herzerkrankungen beim Erwachsenen werden in dieser Uebersicht beschrieben. (orig.)

Energy-Efficient Power Allocation for Fixed-Gain Amplify-and-Forward Relay Networks with Partial Channel State Information

KAUST Repository

Zafar, Ammar

2012-06-01

In this report, energy-efficient transmission and power allocation for fixed-gain amplify-and-forward relay networks with partial channel state information (CSI) are studied. In the energy-efficiency problem, the total power consumed is minimized while keeping the signal-to-noise-ratio (SNR) above a certain threshold. In the dual problem of power allocation, the end-to-end SNR is maximized under individual and global power constraints. Closed-form expressions for the optimal source and relay powers and the Lagrangian multiplier are obtained. Numerical results show that the optimal power allocation with partial CSI provides comparable performance as optimal power allocation with full CSI at low SNR.

Energy-Efficient Power Allocation for Fixed-Gain Amplify-and-Forward Relay Networks with Partial Channel State Information

KAUST Repository

Zafar, Ammar

2012-09-16

In this letter, energy-efficient transmission and power allocation for fixed-gain amplify-and-forward relay networks with partial channel state information (CSI) are studied. In the energy-efficiency problem, the total power consumed is minimized while keeping the signal-to-noise-ratio (SNR) above a certain threshold. In the dual problem of power allocation, the end-to-end SNR is maximized under individual and global power constraints. Closed-form expressions for the optimal source and relay powers and the Lagrangian multiplier are obtained. Numerical results show that the optimal power allocation with partial CSI provides comparable performance as optimal power allocation with full CSI at low SNR. © 2012 IEEE.

A novel method for enhancing the lateral resolution and image SNR in confocal microscopy

Science.gov (United States)

Chen, Youhua; Zhu, Dazhao; Fang, Yue; Kuang, Cuifang; Liu, Xu

2017-12-01

There is always a tradeoff between the resolution and the signal-to-noise ratio (SNR) in confocal microscopy. In particular, the pinhole size is very important for maintaining a balance between them. In this paper, we propose a method for improving the lateral resolution and image SNR in confocal microscopy without making any changes to the hardware. By using the fluorescence emission difference (FED) approach, we divide the images acquired by different pinhole sizes into one image acquired by the central pinhole and several images acquired by ring-shaped pinholes. Then, they are added together with the deconvolution method. Simulation and experimental results for fluorescent particles and cells show that our method can achieve a far better resolution than a large pinhole and a higher SNR than a small pinhole. Moreover, our method can improve the performance of classic confocal laser scanning microscopy (CLSM) to a certain extent, especially CLSM with a continuously variable pinhole.

The SNR 300 fast breeder in the ups and downs of its history

International Nuclear Information System (INIS)

Marth, W.

1994-12-01

The Fast Breeder Project was founded in Karlsruhe in 1960. After an initial period of fundamental research, industry assumed responsibility for designing the SNR 300. Construction of the Kalkar Nuclear Power Station was hampered by a variety of political influences, but finally completed in 1985. As a consequence of the North Rhine-Westphalian party-in-government's opting out of nuclear power, no startup permit was issued for the SNR 300. Consequently, the Kalkar Nuclear Power Station project was discontinued for political reasons in March 1991. The report is the English translation of KFK--4466. (orig./HP) [de

Optimized optical wireless channel for indoor and intra-vehicle communications: power distribution and SNR analysis

Science.gov (United States)

Shaaban, Rana; Faruque, Saleh

2018-01-01

Light emitting diodes - LEDs are modernizing the indoor illumination and replacing current incandescent and fluorescent lamps rapidly. LEDs have multiple advantages such as extremely high energy efficient, longer lifespan, and lower heat generation. Due to the ability to switch to different light intensity at a very fast rate, LED has given rise to a unique communication technology (visible light communication - VLC) used for high speed data transmission. By studying various kinds of commonly used VLC channel analysis: diffuse and line of sight channels, we presented a simply improved indoor and intra-vehicle visible light communication transmission model. Employing optical wireless communications within the vehicle, not only enhance user mobility, but also alleviate radio frequency interference, and increase efficiency by lowering the complexity of copper cabling. Moreover, a solution to eliminate ambient noise caused by environmental conditions is examined by using optical differential receiver. The simulation results show the improved received power distribution and signal to noise ratio - SNR.

PSR B 1706-44 and the SNR G 343.1-2.3 as the remnants of a cavity supernova explosion

Science.gov (United States)

Bock, D. C.-J.; Gvaramadze, V. V.

2002-11-01

The possible association of the supernova remnant (SNR) G 343.1-2.3 with the pulsar PSR B 1706-44 (superposed on the arclike ``shell" of the SNR) has been questioned by some authors on the basis of an inconsistency between the implied and measured (scintillation) transverse velocities of the pulsar, the absence of any apparent interaction between the pulsar and the SNR's ``shell'', and some other indirect arguments. We suggest, however, that this association could be real if both objects are the remnants of a supernova (SN) which exploded within a mushroom-like cavity (created by the SN progenitor wind breaking out of the parent molecular cloud). This suggestion implies that the actual shape of the SNR's shell is similar to that of the well-known SNR VRO 42.05.01 and that the observed bright arc corresponds to the ``half'' of the SNR located inside the cloud. We report the discovery in archival radio data of an extended ragged radio arc to the southeast of the bright arc which we interpret as the ``half'' of the SN blast wave expanding in the intercloud medium.

Improved method for SNR prediction in machine-learning-based test

NARCIS (Netherlands)

Sheng, Xiaoqin; Kerkhoff, Hans G.

2010-01-01

This paper applies an improved method for testing the signal-to-noise ratio (SNR) of Analogue-to-Digital Converters (ADC). In previous work, a noisy and nonlinear pulse signal is exploited as the input stimulus to obtain the signature results of ADC. By applying a machine-learning-based approach,

Magnetic resonance maging of epidural and subdural spinal hematomas; Magnetresonanztomographie bei epiduralen und subduralen spinalen Haematomen

Energy Technology Data Exchange (ETDEWEB)

Felber, S. [Universitaetskliniken Innsbruck (Austria). Klinik fuer Neurologie]|[Universitaetskliniken Innsbruck (Austria). Inst. fuer Magnetresonanz]|[Universitaetskliniken des Saarlandes, Homburg/Saar (Germany). Inst. fuer Neuroradiologie; Langmaier, J. [Universitaetskliniken Innsbruck (Austria). Klinik fuer Neurochirurgie; Judmaier, W. [Universitaetskliniken Innsbruck (Austria). Inst. fuer Magnetresonanz]|[Universitaetskliniken Innsbruck (Austria). Klinik fuer Radiologie; Dessl, A. [Universitaetskliniken Innsbruck (Austria). Klinik fuer Radiologie; Ortler, M. [Universitaetskliniken Innsbruck (Austria). Klinik fuer Neurochirurgie; Birbamer, G. [Universitaetskliniken Innsbruck (Austria). Klinik fuer Neurologie]|[Universitaetskliniken Innsbruck (Austria). Inst. fuer Magnetresonanz; Piepgras, U. [Universitaetskliniken des Saarlandes, Homburg/Saar (Germany). Inst. fuer Neuroradiologie

1994-11-01

wurde. Wir berichten ueber 9 Patienten, die primaer magnetresonanztomographisch diagnostiziert wurden. Bei allen Patienten wurden T1, Spindichte und T2-gewichtete Bilder erzeugt. Zusaetzlich wurden T2*-gewichtete Gradientenechosequenzen angewendet. Die Magnetresonanztomographien wurden mit dem intraoperativen Situs korreliert. Computertomographische Befunde waren bei 4 und myelographische Befunde waren bei 2 Patienten vorhanden. Die Haematome komprimierten in 2 Faellen das Zervikalmark, bei 6 Patienten das Thorakalmark und bei 2 Patienten Konus und Cauda. Die Magnetresonanztomographie ergab 6 epidurale und 3 subdurale Haematome, operativ handelte es sich um 5 epidural und 4 subdurale Blutungen. In einem Fall konnte die Kernspintomographie nicht zwischen epi- und subduraler Lokalisation unterscheiden. Perakute Haematome (<24 h) waren isointens auf T1-gewichteten Bildern und hatten gemischte Signalintensitaet auf T2- und T*-gewichteten Bildern (n=3). Akute Blutungen (24 h bis 3 Tage) waren ebenfalls isointens auf T1 aber hypointens auf T- und T2*-gewichteten Bildern (n=4). Erst nach 7 Tagen fand sich die methaemoglobintypische Hyperintensitaet auf T1- und T2-gewichteten Bildern (n=2). Diese Ergebnisse unterstreichen, dass die Magnetresonanztomographie perakute und akute spinale Blutungen adaequat diagnostizieren kann. Die exakte Beurteilung der kraniokaudalen Ausdehnung verbessert die Operationsplanung. (orig.)

"Bildung für nachhaltige Entwicklung" - die Sicht der Kinder : Ergebnisse aus dem weltweiten OMEP-Projekt

OpenAIRE

Engdahl, Ingrid

2017-01-01

Während der UNESCO Dekade „Bildung für nachhaltige Entwicklung“ (BNE) führte die Weltorganisation für Frühe Bildung (OMEP) zwischen 2009-2014 ein umfangreiches Projekt zum Thema Nachhaltigkeit durch. Das übergeordnete Ziel des Projektes war das Bewußtsein der OMEP Mitglieder und der internationalen Fachgemeinde für die Bildung für nachhaltige Entwicklung (BNE) zu stärken. Dabei wurde ein besonderer Fokus auf die kindorientierte Perspektive gelegt.

The possibilities of application of experimental Kfk results from BR2 on SNR designs

International Nuclear Information System (INIS)

Karsten, G.; Elbel, K.; Dienst, W.; Schaefer, L.

1978-01-01

A review is given of the relevant results of the technological application for the SNR300 reactor, since the BR2 reactor has been used as a test facility for the material development. Special emphasis has been laid on the fuel pin behavior under the aspect of chemical and mechanical fuel-clad interaction and on the specification of the cladding in terms of high temperature mechanical behavior in the SNR 300 reactor. A systematic analysis of urgent research topics in BR2 test facility reactor is presented. (A.F.)

Constellation modulation - an approach to increase spectral efficiency.

Science.gov (United States)

Dash, Soumya Sunder; Pythoud, Frederic; Hillerkuss, David; Baeuerle, Benedikt; Josten, Arne; Leuchtmann, Pascal; Leuthold, Juerg

2017-07-10

Constellation modulation (CM) is introduced as a new degree of freedom to increase the spectral efficiency and to further approach the Shannon limit. Constellation modulation is the art of encoding information not only in the symbols within a constellation but also by encoding information by selecting a constellation from a set of constellations that are switched from time to time. The set of constellations is not limited to sets of partitions from a given constellation but can e.g., be obtained from an existing constellation by applying geometrical transformations such as rotations, translations, scaling, or even more abstract transformations. The architecture of the transmitter and the receiver allows for constellation modulation to be used on top of existing modulations with little penalties on the bit-error ratio (BER) or on the required signal-to-noise ratio (SNR). The spectral bandwidth used by this modulation scheme is identical to the original modulation. Simulations demonstrate a particular advantage of the scheme for low SNR situations. So, for instance, it is demonstrated by simulation that a spectral efficiency increases by up to 33% and 20% can be obtained at a BER of 10 -3 and 2×10 -2 for a regular BPSK modulation format, respectively. Applying constellation modulation, we derive a most power efficient 4D-CM-BPSK modulation format that provides a spectral efficiency of 0.7 bit/s/Hz for an SNR of 0.2 dB at a BER of 2 × 10 -2 .

Small leak detection requirements for SNR-300 steam generator operation

International Nuclear Information System (INIS)

Dumm, K.

1975-01-01

The leak detection philosophy of the SNR-300 steam generators is described. Due to operational demands small leaks have already to be detectable at a stage where secondary tube damage has not yet occurred. The requirements on a leak detection instrument are developed and the instrument itself is described. (author)

Small leak detection requirements for SNR-300 steam generator operation

Energy Technology Data Exchange (ETDEWEB)

Dumm, K

1975-07-01

The leak detection philosophy of the SNR-300 steam generators is described. Due to operational demands small leaks have already to be detectable at a stage where secondary tube damage has not yet occurred. The requirements on a leak detection instrument are developed and the instrument itself is described. (author)

Renewables in figures. National and international trends in 2016; Erneuerbare Energien in Zahlen. Nationale und internationale Entwicklung im Jahr 2016

Energy Technology Data Exchange (ETDEWEB)

NONE

2017-09-15

The expansion of renewable energies is a central pillar of the energy transition. The development is positive: In 2016, renewable energies accounted for 31.7 percent of total gross electricity consumption. The brochure informs about the progress achieved in the further development of renewable energies in Germany, Europe and the world. The data on the development of renewable energies in Germany is based on the results of the Working Group on Renewable Energy Statistics (AGEE-Stat), which compiles the balance sheet of renewable energies for Germany on behalf of the BMWi. The data published here are a snapshot with the editorial deadline of August 2016 - they are still provisional in some places, especially for 2016. At the same time, current time series on the development of renewable energies in Germany since 1990 as well as a variety of graphs are published on the websites of the BMWi. These time series and graphs will be updated at the turn of the year 2017/2018. [German] Der Ausbau der erneuerbaren Energien ist eine zentrale Saeule der Energiewende. Die Entwicklung ist positiv: Im Jahr 2016 hatten die erneuerbare Energien einen Anteil von 31,7 Prozent am gesamten Bruttostromverbrauch. Mit der Broschuere wird ueber den erreichten Fortschritt beim weiteren Ausbau der Erneuerbaren Energien in Deutschland, in Europa und der Welt informiert. Grundlage der Daten zur Entwicklung der erneuerbaren Energien in Deutschland sind die Ergebnisse der Arbeitsgruppe Erneuerbare Energien-Statistik (AGEE-Stat), die im Auftrag des BMWi die Bilanz der erneuerbaren Energien fuer Deutschland erarbeitet. Die hier veroeffentlichten Daten stellen eine Momentaufnahme mit Redaktionsschluss August 2016 dar - sie haben insbesondere fuer das Jahr 2016 an einigen Stellen noch vorlaeufigen Charakter. Parallel werden auf den Internetseiten des BMWi aktuelle Zeitreihen zur Entwicklung der erneuerbaren Energien in Deutschland seit dem Jahr 1990 sowie vielfaeltige Schaubilder veroeffentlicht

Secret-key agreement over spatially correlated multiple-antenna channels in the low-SNR regime

KAUST Repository

Zorgui, Marwen; Rezki, Zouheir; Alomair, Basel; Jorswieck, Eduard A.; Alouini, Mohamed-Slim

2015-01-01

We consider secret-key agreement with public discussion over Rayleigh fast-fading channels with transmit, receive and eavesdropper correlation. The legitimate receiver along with the eavesdropper are assumed to have perfect channel knowledge while the transmitter has only knowledge of the correlation matrices. We analyze the secret-key capacity in the low signal-to-noise ratio (SNR) regime. We derive closed-form expressions for the first and the second derivatives of the secret-key capacity with respect to SNR at SNR= 0, for arbitrary correlation matrices and number of transmit, receive and eavesdropper antennas. Moreover, we identify optimal transmission strategies achieving these derivatives. For instance, we prove that achieving the first and the second derivatives requires a uniform power distribution between the eigenvectors spanning the maximal-eigenvalue eigenspace of the transmit correlation matrix. We also compare the optimal transmission scheme to a simple uniform power allocation. Finally, we express the minimum energy required for sharing a secret-key bit as well as the wideband slope in terms of the system parameters.

Secret-key agreement over spatially correlated multiple-antenna channels in the low-SNR regime

KAUST Repository

Zorgui, Marwen

2015-09-28

We consider secret-key agreement with public discussion over Rayleigh fast-fading channels with transmit, receive and eavesdropper correlation. The legitimate receiver along with the eavesdropper are assumed to have perfect channel knowledge while the transmitter has only knowledge of the correlation matrices. We analyze the secret-key capacity in the low signal-to-noise ratio (SNR) regime. We derive closed-form expressions for the first and the second derivatives of the secret-key capacity with respect to SNR at SNR= 0, for arbitrary correlation matrices and number of transmit, receive and eavesdropper antennas. Moreover, we identify optimal transmission strategies achieving these derivatives. For instance, we prove that achieving the first and the second derivatives requires a uniform power distribution between the eigenvectors spanning the maximal-eigenvalue eigenspace of the transmit correlation matrix. We also compare the optimal transmission scheme to a simple uniform power allocation. Finally, we express the minimum energy required for sharing a secret-key bit as well as the wideband slope in terms of the system parameters.

How to improve a critical performance for an ExoMars 2020 Scientific Instrument (RLS). Raman Laser Spectrometer Signal to Noise Ratio (SNR) Optimization

Science.gov (United States)

Canora, C. P.; Moral, A. G.; Rull, F.; Maurice, S.; Hutchinson, I.; Ramos, G.; López-Reyes, G.; Belenguer, T.; Canchal, R.; Prieto, J. A. R.; Rodriguez, P.; Santamaria, P.; Berrocal, A.; Colombo, M.; Gallago, P.; Seoane, L.; Quintana, C.; Ibarmia, S.; Zafra, J.; Saiz, J.; Santiago, A.; Marin, A.; Gordillo, C.; Escribano, D.; Sanz-Palominoa, M.

2017-09-01

The Raman Laser Spectrometer (RLS) is one of the Pasteur Payload instruments, within the ESA's Aurora Exploration Programme, ExoMars mission. Raman spectroscopy is based on the analysis of spectral fingerprints due to the inelastic scattering of light when interacting with matter. RLS is composed by Units: SPU (Spectrometer Unit), iOH (Internal Optical Head), and ICEU (Instrument Control and Excitation Unit) and the harnesses (EH and OH). The iOH focuses the excitation laser on the samples and collects the Raman emission from the sample via SPU (CCD) and the video data (analog) is received, digitalizing it and transmiting it to the processor module (ICEU). The main sources of noise arise from the sample, the background, and the instrument (Laser, CCD, focuss, acquisition parameters, operation control). In this last case the sources are mainly perturbations from the optics, dark signal and readout noise. Also flicker noise arising from laser emission fluctuations can be considered as instrument noise. In order to evaluate the SNR of a Raman instrument in a practical manner it is useful to perform end-to-end measurements on given standards samples. These measurements have to be compared with radiometric simulations using Raman efficiency values from literature and taking into account the different instrumental contributions to the SNR. The RLS EQM instrument performances results and its functionalities have been demonstrated in accordance with the science expectations. The Instrument obtained SNR performances in the RLS EQM will be compared experimentally and via analysis, with the Instrument Radiometric Model tool. The characterization process for SNR optimization is still on going. The operational parameters and RLS algorithms (fluorescence removal and acquisition parameters estimation) will be improved in future models (EQM-2) until FM Model delivery.

Quasi Cyclic Low Density Parity Check Code for High SNR Data Transfer

Directory of Open Access Journals (Sweden)

M. R. Islam

2010-06-01

Full Text Available An improved Quasi Cyclic Low Density Parity Check code (QC-LDPC is proposed to reduce the complexity of the Low Density Parity Check code (LDPC while obtaining the similar performance. The proposed QC-LDPC presents an improved construction at high SNR with circulant sub-matrices. The proposed construction yields a performance gain of about 1 dB at a 0.0003 bit error rate (BER and it is tested on 4 different decoding algorithms. Proposed QC-LDPC is compared with the existing QC-LDPC and the simulation results show that the proposed approach outperforms the existing one at high SNR. Simulations are also performed varying the number of horizontal sub matrices and the results show that the parity check matrix with smaller horizontal concatenation shows better performance.

Inelastic analysis of SNR-300 piping

International Nuclear Information System (INIS)

Huebel, H.; Di Luna, L.J.; Moy, G.

1983-01-01

This paper investigates plasticity, creep, and elastic follow-up effects on a full size hot primary piping system of the German fast breeder reactor prototype, the SNR-300. A large model (327 elements, 419 nodes) of straight pipe, special elbow and hanger elements of the general purpose finite element program, MARC-CDC, is used to predict piping behavior for a heat-up, sodium loading-unloading-reloading cycle and other significant operating conditions. Included in this work are many time-dependent solution increments for a 5,000 hour creep period. Creep strains and relaxed stress results, after 5,000 hours, for the complete model are used with uniaxial and biaxial models and results to extrapolate conclusions for a 100,000 hour operating life. (author)

Inelastic analysis of SNR-300 piping

Energy Technology Data Exchange (ETDEWEB)

Huebel, H [INTERATOM, Bergisch Gladbach (Germany); Di Luna, L J; Moy, G [Teledyne Engineering Services, Waltham, MA (United States)

1983-05-01

This paper investigates plasticity, creep, and elastic follow-up effects on a full size hot primary piping system of the German fast breeder reactor prototype, the SNR-300. A large model (327 elements, 419 nodes) of straight pipe, special elbow and hanger elements of the general purpose finite element program, MARC-CDC, is used to predict piping behavior for a heat-up, sodium loading-unloading-reloading cycle and other significant operating conditions. Included in this work are many time-dependent solution increments for a 5,000 hour creep period. Creep strains and relaxed stress results, after 5,000 hours, for the complete model are used with uniaxial and biaxial models and results to extrapolate conclusions for a 100,000 hour operating life. (author)

Comparison study on CNR and SNR of thoracic spine lateral radiography

Energy Technology Data Exchange (ETDEWEB)

Kim, Ki Won [Dept. of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Min, Jung Whan; Lyu, Kwang Yeul [Dept. of Radiology, Shingu University, Sungnam (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Science, College of Health Science, Korea University, Seoul (Korea, Republic of); Jeong, Hei Woun [Dept. of Radiological Science, Beakseok Culture University, Cheonan (Korea, Republic of); Lee, Joo Ah [Dept. of Oncology, Catholic University of Korea Incheon St.Mary,s Hospital, Incheon (Korea, Republic of); Jung, Jae Hong [Dept. of Oncology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Sung, Dong Chan [Dept. of Radiology, Dong Guk University Medical Center, Seoul (Korea, Republic of); Park, Soon Cheol [Dept. of Radiology, Kang Dong Kyung Hee University Medical Center, Seoul (Korea, Republic of)

2013-12-15

This study was proven for the T-spine breathing technique in lateral projection, using computer radiography (CR), charge coupled device (CCD), indirect digital radiography (IDR) and direct digital radiography (DDR). All images were evaluated and compared with CNR and SNR measured with the mean pixels and the standard deviation as setting ROI of spinous process, pedicle, vertebral body, intervertebral foramen and intervertebral disk using Image J. In experiment results of 4 type detectors, T-spine breathing technique was indicated as excellent in ROI of spinous process, pedicle, vertebral body, intervertebral foramen and intervertebral disk. As T-spine breathing technique indicated excellent images compared to the existing T-spine lateral radiography, this method would be useful for elderly patients who have difficulty in deep exhalation. This study was indicated the application possibility of T-spine breathing technique by presenting contrast to noise ratio (CNR) and signal to noise ratio (SNR) with quantitative value in 4 type detectors.

Optimizing the night time with dome vents and SNR-QSO at CFHT

Science.gov (United States)

Devost, Daniel; Mahoney, Billy; Moutou, Claire; CFHT QSO Team, CFHT software Group

2017-06-01

Night time is a precious and costly commodity and it is important to get everything we can out of every second of every night of observing. In 2012 the Canada-France-Hawaii Telescope started operating 12 new vent doors installed on the dome over the course of the previous two years. The project was highly successful and seeing measurements show that venting the dome greatly enhances image quality at the focal plane. In order to capitalize on the gains brought by the new vents, the observatory started exploring a new mode of observation called SNR-QSO. This mode consist of a new implementation inside our Queued Service Observation (QSO) system. Exposure times are adjusted for each frame depending on the weather conditions in order to reach a specific depth, Signal to Noise Ratio (SNR) at a certain magnitude. The goal of this new mode is to capitalize on the exquisite seeing provided by Maunakea, complemented by the minimized dome turbulence, to use the least amount of time to reach the depth required by the science programs. Specific implementations were successfully tested on two different instruments, our wide field camera MegaCam and our high resolution spectrograph ESPaDOnS. I will present the methods used for each instrument to achieve SNR observing and the gains produced by these new observing modes in order to reach the scientific goals of accepted programs in a shorter amount of time.

Experimental and theoretical investigations on safety of the SNR - straight-tube design steam generator with sodium-water reactions

International Nuclear Information System (INIS)

Dumm, K.; Sauermann, F.; Schnitker, W.; Welter, A.

A number of large sodium-water reaction tests has been performed in a steam generator model in order to verify the layout criteria of the SNR straight-tube design steam generators under accident conditions. The experimental setup is described. The test results and their applicability to the SNR steam generators are given and discussed. (U.S.)

Möglichkeiten der Umsetzung einer Bildung für nachhaltige Entwicklung unter Verwendung kooperativer Lernformen im Geographieunterricht

OpenAIRE

Stange, Sarah

2016-01-01

„Ohne Nachhaltigkeit gibt es keine gute Zukunft“ betonte die Bildungsstaatssekretärin Cornelia Quennet-Thielen in einem Interview Anfang Oktober (BMBF 2015). Sie erklärte weiter: „Und ohne Bildung bleibt Nachhaltigkeit nur eine Forderung.“ (ebd.) Genau zehn Jahre sind vergangen, seit die Vereinten Nationen die UN-Dekade für Bildung für nachhaltige Entwicklung, kurz BNE, ausriefen. Der Leitgedanken der Nachhaltigkeit sollte über die Bildung Eingang in die Alltagswelten finden. Nun ist die UN-D...

A Meta Analysis of Radiosensitivity on Non-small Cell Lung Cancer 
by Metronidazole Amino Acidum Natrium

Directory of Open Access Journals (Sweden)

Weiwei REN

2012-06-01

Full Text Available Background and objective The efficacy and safety of radiosensitivity on non-small cell lung cancer (NSCLC using metronidazole amino acidum natrium (CMNa are yet to be proven. This study evaluates the efficacy and safety of radiosensitivity on NSCLC by CMNa to provide references for further clinical practice and research. Methods Relevant randomized controlled trials (RCTs were obtained from the Cochrane library, Pubmed, EMbase, CBM, CNKI, VIP, and Wan Fang databases. Dates were searched through other means. RCTs of radiosensitivity on NSCLC by CMNa were included. The data included in the study were evaluated and analyzed using the Cochrane Collaboration's RevMan 5.1 software. Results A total of 21 RCTs were included. The results of the meta-analyses showed that the total effective rate of the test group that received CMNa plus radiotherapy was higher than that of the control group that received radiotherapy alone (OR=3.29, 95%CI: 2.47-4.39, P<0.000,01 or radiotherapy plus placebo (OR=3.65, 95%CI: 2.25-5.92, P<0.000,01, respectively. No significant differences were found in the quality of life between one and two-year survival rates (P>0.05. No significant differences were found among radiation pneumonitis, radiation esophagitis, hematological toxicity, and cardiotoxicity (P>0.05. Conclusion CMNa plus radiotherapy elicit beneficial effects in the treatment of NSCLC and produce fewer adverse effects. Therefore, this technique can be recommended and applied in clinics.

Licensing aspects in the verification of the SNR 300 design concept against hypothetical accidents

International Nuclear Information System (INIS)

Kugler, E.; Wiesner, S.

1976-01-01

The German prototype of a fast breeder reactor, the SNR 300, is being built near Kalkar on the Lower Rhine. It is a loop-type fast sodium-cooled reactor, designed and constructed by Interatom, Bensberg. Experiences gained from the first phase of construction are described. The report is restricted to the aspects of the SNR 300 design against a core disruptive accident (CDA) and its consequences and to the difficulties having arisen in the verification of the design concept so far. Some examples of the detailed design are described and discussed from the licensing authority's point of view showing that the difficulties have been typical for a prototype reactor subjected to a regular licensing procedure

Development of process technology for large-area thin-film solar modules based on compound semiconductors. Final report; Entwicklung der technologischen Grundlagen fuer grosse Photovoltaikmodule auf Basis von Duennschicht-Verbindungshalbleitern. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Maurus, H.; Lechner, P.; Geyer, R.; Ruebel, H.; Schade, H.; Psyk, W.; Frammelsberger, W.; Berthold, W.; Eichner, C.; Heckel, E.; Huber, R.; Labudde-Eibl, H.; Raith, S.; Schenk, B.; Ullrich, H.

1998-06-01

A cooperative effort of the Center for Solar Energy and Hydrogen Research (ZSW) and Phototronics Solartechnik GmbH (PST) aimed at the transfer of highly efficient solar cells developed on a laboratory scale, to large-area thin-film solar modules suitable for production. This work was based on research and development at the Institute for Physical Electronics (IPE) of Stuttgart University and ZSW on one hand, and on the know-how of PST in regard to large-area module fabrication on the other hand. The various thin-film layers of the cells and modules comprize molybdenum as rear contact, copper-indium(gallium)-diselenide (CIGS) as absorber material, the combination of cadmium sulphide (CdS) and ZnO as window layer. To produce these layers on large areas (30x30 cm{sup 2}), equipment was constructed and procedures were developed. Monolithic series connection of cells, used in other thin-film technologies, was studied and optimized by suitable patterning procedures, such as laser-scribing, mechanical scribing or lift-off techniques. Central to the PST efforts was the large-area deposition of Mo followed by patterning for the monolithic series connection, and furthermore important contributions in regard to the ZnO window layer as well as aspects of the module technology. The latter include film removal along the module edges, contacting and cable attachment, lamination, module measurements and temperature/humidity tests. The main goal, namely the basic development of equipment and procedures to fabricate large-area (30x30 cm{sup 2}) modules with an efficiency of 10-12%, was reached (best module with 11.7% efficiency referenced to the aperature area). (orig.) [Deutsch] Um die im Labormassstab entwickelten hocheffizienten Solarzellen in industriell relevante grossflaechige Duennschichtmodule umzusetzen, arbeiteten das Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung (ZSW) Baden-Wuerttemberg und die Phototronics Solartechnik GmbH (PST) zusammen. Ausgangsbasis waren

IVA2 verification: Expansion phase experiment in SNR geometry

International Nuclear Information System (INIS)

Kolev, N.I.

1987-09-01

Using the IVA2/005 computer code the SNR model explosion experiment SGI-09-1 was numerically simulated. The experiment consists of high pressure gas injection into a low pressure liquid pool with a free surface in a cylindrical geometry with internals. Bubble formation and pressure history as a function of time was predicted and compared with the experimental observation. A good agreement between theory and experiment was obtained. Numerical diffusion and its influence on the results are discussed. (orig.) [de

Use of reflected GNSS SNR data to retrieve either soil moisture or vegetation height from a wheat crop

Directory of Open Access Journals (Sweden)

S. Zhang

2017-09-01

Full Text Available This work aims to estimate soil moisture and vegetation height from Global Navigation Satellite System (GNSS Signal to Noise Ratio (SNR data using direct and reflected signals by the land surface surrounding a ground-based antenna. Observations are collected from a rainfed wheat field in southwestern France. Surface soil moisture is retrieved based on SNR phases estimated by the Least Square Estimation method, assuming the relative antenna height is constant. It is found that vegetation growth breaks up the constant relative antenna height assumption. A vegetation-height retrieval algorithm is proposed using the SNR-dominant period (the peak period in the average power spectrum derived from a wavelet analysis of SNR. Soil moisture and vegetation height are retrieved at different time periods (before and after vegetation's significant growth in March. The retrievals are compared with two independent reference data sets: in situ observations of soil moisture and vegetation height, and numerical simulations of soil moisture, vegetation height and above-ground dry biomass from the ISBA (interactions between soil, biosphere and atmosphere land surface model. Results show that changes in soil moisture mainly affect the multipath phase of the SNR data (assuming the relative antenna height is constant with little change in the dominant period of the SNR data, whereas changes in vegetation height are more likely to modulate the SNR-dominant period. Surface volumetric soil moisture can be estimated (R2  =  0.74, RMSE  =  0.009 m3 m−3 when the wheat is smaller than one wavelength (∼ 19 cm. The quality of the estimates markedly decreases when the vegetation height increases. This is because the reflected GNSS signal is less affected by the soil. When vegetation replaces soil as the dominant reflecting surface, a wavelet analysis provides an accurate estimation of the wheat crop height (R2  =  0.98, RMSE  =  6

Gain and offset calibration reduces variation in exposure-dependent SNR among systems with identical digital flat-panel detectors.

Science.gov (United States)

Willis, Charles E; Vinogradskiy, Yevgeniy Y; Lofton, Brad K; White, R Allen

2011-07-01

The conditions under which vendor performance criteria for digital radiography systems are obtained do not adequately simulate the conditions of actual clinical imaging with respect to radiographic technique factors, scatter production, and scatter control. Therefore, the relationship between performance under ideal conditions and performance in clinical practice remains unclear. Using data from a large complement of systems in clinical use, the authors sought to develop a method to establish expected performance criteria for digital flat-panel radiography systems with respect to signal-to-noise ratio (SNR) versus detector exposure under clinical conditions for thoracic imaging. The authors made radiographic exposures of a patient-equivalent chest phantom at 125 kVp and 180 cm source-to-image distance. The mAs value was modified to produce exposures above and below the mAs delivered by automatic exposure control. Exposures measured free-in-air were corrected to the imaging plane by the inverse square law, by the attenuation factor of the phantom, and by the Bucky factor of the grid for the phantom, geometry, and kilovolt peak. SNR was evaluated as the ratio of the mean to the standard deviation (SD) of a region of interest automatically selected in the center of each unprocessed image. Data were acquired from 18 systems, 14 of which were tested both before and after gain and offset calibration. SNR as a function of detector exposure was interpolated using a double logarithmic function to stratify the data into groups of 0.2, 0.5, 1.0, 2.0, and 5.0 mR exposure (1.8, 4.5, 9.0, 18, and 45 microGy air KERMA) to the detector. The mean SNR at each exposure interval after calibration exhibited linear dependence on the mean SNR before calibration (r2=0.9999). The dependence was greater than unity (m = 1.101 +/- 0.006), and the difference from unity was statistically significant (p grid replacement. The nonconformant behavior of the other system was corrected by replacing

SNR-300 steam generator accident philosophy - Assessment due to new understandings in Na/H20-reactions

International Nuclear Information System (INIS)

Ruloff, G.; Huebner, R.

1990-01-01

Recent R+D results in the intermediate leak range (finally confirmed by the PFR steam generator accident) lead to a new assessment for the SNR-300 steam generator accident. This paper discusses the course of such accident which has to be expected under the SNR-300 conditions, starting with an unblocked micro leak and ending with the pressure loads on the secondary system due to overheating failure. Also, enclosed are the possibilities for a leak detection before serious damage has occurred and the discussion of the definition of the DBA. (author). 2 refs, 9 figs

On the origin of the system PSR B1757-24/SNR G5.4-1.2

OpenAIRE

Gvaramadze, V. V.

2003-01-01

A scenario for the origin of the system PSR B1757-24/supernova remnant (SNR) G5.4-1.2 is proposed. It is suggested that both objects are the remnants of a supernova (SN) that exploded within a pre-existing bubble blown-up by a runaway massive star (the SN progenitor) during the final (Wolf-Rayet) phase of its evolution. This suggestion implies that (a) the SN blast centre was significantly offset from the geometric centre of the wind-blown bubble (i.e. from the centre of the future SNR), (b) ...

On the low SNR capacity of maximum ratio combining over rician fading channels with full channel state information

KAUST Repository

Benkhelifa, Fatma; Rezki, Zouheir; Alouini, Mohamed-Slim

2013-01-01

In this letter, we study the ergodic capacity of a maximum ratio combining (MRC) Rician fading channel with full channel state information (CSI) at the transmitter and at the receiver. We focus on the low Signal-to-Noise Ratio (SNR) regime and we show that the capacity scales as L ΩK+L SNRx log(1SNR), where Ω is the expected channel gain per branch, K is the Rician fading factor, and L is the number of diversity branches. We show that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-off power control scheme. Our framework can be seen as a generalization of recently established results regarding the fading-channels capacity characterization in the low-SNR regime. © 2012 IEEE.

On the low SNR capacity of maximum ratio combining over rician fading channels with full channel state information

KAUST Repository

Benkhelifa, Fatma

2013-04-01

In this letter, we study the ergodic capacity of a maximum ratio combining (MRC) Rician fading channel with full channel state information (CSI) at the transmitter and at the receiver. We focus on the low Signal-to-Noise Ratio (SNR) regime and we show that the capacity scales as L ΩK+L SNRx log(1SNR), where Ω is the expected channel gain per branch, K is the Rician fading factor, and L is the number of diversity branches. We show that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-off power control scheme. Our framework can be seen as a generalization of recently established results regarding the fading-channels capacity characterization in the low-SNR regime. © 2012 IEEE.

[St. Petersburg und Livland - und die Entwicklung der estnischen Literatur : Anton Schiefner (1817-1879) und Friedrich R. Kreutzwald (1803-1882) im Briefwechsel (1853-1879)] / Felix Köther

Index Scriptorium Estoniae

Köther, Felix

2015-01-01

Arvustus: St. Petersburg und Livland - und die Entwicklung der estnischen Literatur : Anton Schiefner (1817-1879) und Friedrich R. Kreutzwald (1803-1882) im Briefwechsel (1853-1879) / bearbeitet von Hartmut Walravens. Wiesbaden : Harrassowitz, 2013. (Orientalistik-Bibliographien und Dokumentationen ; Bd. 22)

The split symbol moments SNR estimator in narrow-band channels

Science.gov (United States)

Shah, Biren; Hinedi, Sami

1990-01-01

The split symbol moments estimator is an algorithm that is designed to estimate symbol SNR in the presence of additive white Gaussian noise. The performance of the algorithm in band-limited channels is examined, and the effects of the resulting intersymbol interference are quantified. All results obtained are in closed form and can be easily evaluated numerically for performance-prediction purposes. The results are also validated through digital simulations.

Cavitation problems in mixing devices of SNR-300 fuel elements

International Nuclear Information System (INIS)

Benemann, A.

1976-01-01

Because of a complex flow path within the mixing device developed for the fuel elements of the SNR-300, in order to determine the minimum allowable interval to the beginning of cavitation, experimental tests with the original geometry are necessary. These conclusions show that for cavitation values CV>=1,3 - in the model and prototype - no cavitation zones can form. For reactor conditions a maximum velocity of Vsub(max)=4,7m/sec is therefore allowable in the free annular space of the compensator unit which corresponds to a massflow of M=22,5kg/sec. A cavitation value of CV=1,5 can be figured for the 120% load factor (M=20,4kg/sec,T=560 0 C). The mixing device developed is free of cavitation under the present conditions in the SNR-300. The condition of the fully developed cavitation is evidenced by a white noise with frequencies of at least 2.000 - 300.000cps and a signal/noise ratio S/R>40dB. The pressure amplitudes dependent on frequency are propagated in the streaming fluid and are severely damped by the locally existing two-phase flow. The unstable range at the beginning of cavitation is characterized by frequencies of about f=15.000cps

Natrium dischargement from peripheral blood as a predominant factor influenced by the administration of banana (Musa paradisiaca) on elderly female hypertensive patient

Science.gov (United States)

Pramono, A.; Noriko, N.; Komara, S. B.

2017-04-01

Hypertension is more common in eldery female that triggered by diet and lifestyle changes. Bananas were not only useful for the food, but also for hypertension therapy and preserving life. Administration of bananas decreased blood pressure in hypertensive patients. This study aims to identify of factors that influenced by the administration of banana (Musa paradisiaca) on elderly female hypertensive patient. Twenty of eldery female patient were divided into 2 respondents group: control (11 patients) and treatment (9 patients). The treatment groups received banana twice a day during 2 weeks, but the control group didn’t. Here, we showed the administration of banana significantly decreased blood pressure on elderly female hypertensive patient (p = 0.00) in both systole and diastole. There was a significant decrease in sodium levels (p = 0.037) in the blood, but potassium levels remained the same. Erythrocyte sedimentation level (p = 0.136) and trombocyte count (p = 0.176) in treatment group, were not affected by banana administration. Taken together, banana administration on elderly female hypertensive patient decreased the blood pressure significantly, greatly affected by the natrium dischargement from the blood. Thus, our findings contribute to preliminary comprehension of banana effect on hypertension reduction.

Interventional magnetic resonance imaging - non-invasive imaging for interventions; Interventionelle Magnetresonanztomographie - nichtinvasive Bildgebung fuer Interventionen

Energy Technology Data Exchange (ETDEWEB)

Buecker, A.; Adam, G.; Neuerburg, J.M.; Glowinski, A.; Tacke, J.; Guenther, R.W. [Technische Hochschule Aachen (Germany). Medizinische Fakultaet

2000-02-01

der Bildkontrast noch die raeumliche Aufloesung duerfen unter den erhoehten Anforderungen leiden. Des weiteren sollte der Kernspintomograph einen ausreichend guten Zugang zum Patienten gewaehrleisten. Weder der ideale diese Bedingungen erfuellende Kernspintomograph noch die eine optimale Sequenz existieren. Vor allem ueber Veraenderungen der Echozeit und der Phasenkodierrichtung sowie die Wahl zwischen einer Spin- und Gradientenechosequenz kann die Abbildungsgroesse metallischer Instrumente beeinflusst werden. Die klinische Durchfuehrbarkeit nicht vaskulaerer Interventionen ist an Magneten mit Feldstaerken von 0,064 T bis 1,5 T belegt. Knochen- und Weichteilpunktionen, Drainagen und Kontrollen von interstitiellen Thermo- und Kryotherapien sind beschrieben worden. Verschiedenste MR-Ueberwachungsstrategien fuer vaskulaere Interventionen werden derzeit in Tierversuchen erprobt. Die Entwicklung geeigneter Katheter und Fuehrungsdraehte hat die Machbarkeit von Dilatationen, Stentungen, Vena cava Filter-Plazierungen und TIPS-Anlagen moeglich gemacht. Bedenkt man die rasante Entwicklung und Verbesserung der Bildqualitaet und Vorteile der MRT wie exzellenter Weichteilkontrast, multiplanare Schichtfuehrung, Flussgeschwindigkeitsmessung, hochaufloesende Darstellung der Gefaesswand und fehlende ionisierende Strahlung, so darf man erwarten, dass die Interventionelle MRT sich ueber ein Nischendasein ihren festen Platz hinaus sichern wird. (orig.)

Optimized filtering of regional and teleseismic seismograms: results of maximizing SNR measurements from the wavelet transform and filter banks

Energy Technology Data Exchange (ETDEWEB)

Leach, R.R.; Schultz, C.; Dowla, F.

1997-07-15

Development of a worldwide network to monitor seismic activity requires deployment of seismic sensors in areas which have not been well studied or may have from available recordings. Development and testing of detection and discrimination algorithms requires a robust representative set of calibrated seismic events for a given region. Utilizing events with poor signal-to-noise (SNR) can add significant numbers to usable data sets, but these events must first be adequately filtered. Source and path effects can make this a difficult task as filtering demands are highly varied as a function of distance, event magnitude, bearing, depth etc. For a given region, conventional methods of filter selection can be quite subjective and may require intensive analysis of many events. In addition, filter parameters are often overly generalized or contain complicated switching. We have developed a method to provide an optimized filter for any regional or teleseismically recorded event. Recorded seismic signals contain arrival energy which is localized in frequency and time. Localized temporal signals whose frequency content is different from the frequency content of the pre-arrival record are identified using rms power measurements. The method is based on the decomposition of a time series into a set of time series signals or scales. Each scale represents a time-frequency band with a constant Q. SNR is calculated for a pre-event noise window and for a window estimated to contain the arrival. Scales with high SNR are used to indicate the band pass limits for the optimized filter.The results offer a significant improvement in SNR particularly for low SNR events. Our method provides a straightforward, optimized filter which can be immediately applied to unknown regions as knowledge of the geophysical characteristics is not required. The filtered signals can be used to map the seismic frequency response of a region and may provide improvements in travel-time picking, bearing estimation

New method to extract radial acceleration of target from short-duration signal at low SNR

Institute of Scientific and Technical Information of China (English)

2008-01-01

In order to extract target radial acceleration from radar echo signal at low SNR (signal-to-noise), this paper employed FRFT (fractional Fourier transformation) to analyze short-duration radar echo and studied the relations between signal convergence peaks in matched transformation domain and signal duration and modu- lated frequency of signal. When signal duration is specified, the method of multi- plying sampled signal by the known frequency modulated signal to alter modulated frequency was presented, which generated the new signal with larger convergence peaks than the initial signal in matched transformation domain. Thus, it could successfully estimate the radial acceleration of radar target at low SNR. Simulations were conducted to show the feasibility and effectiveness of the method.

Star Forming Dense Cloud Cores in the TeV -ray SNR RX J1713.7-3946

Energy Technology Data Exchange (ETDEWEB)

Sano, H.; Sato, J.; Yamamoto, H.; Hayakawa, T.; Torii, K.; Moribe, N.; Kawamura, A.; Okuda, T.; Mizuno, N.; Onishi, T.; Maezawa, H.; Inoue, T.; Inutsuka, S.; Tanaka, T.; Mizuno, A.; Ogawa, H.; Stutzki, J.; Bertoldi, F.; Anderl, S.; Bronfman, L.; Koo, B.C.

2010-10-27

RX J1713.7-3946 is one of the TeV {gamma}-ray supernova remnants (SNRs) emitting synchrotron X rays. The SNR is associated with molecular gas located at {approx}1 kpc. We made new molecular observations toward the dense cloud cores, peaks A, C and D, in the SNR in the {sup 12}CO(J=2-1) and {sup 13}CO(J=2-1) transitions at angular resolution of 90 degrees. The most intense core in {sup 13}CO, peak C, was also mapped in the {sup 12}CO(J=4-3) transition at angular resolution of 38 degrees. Peak C shows strong signs of active star formation including bipolar outflow and a far-infrared protostellar source and has a steep gradient with a r{sup -2.2 {+-} 0.4} variation in the average density within radius r. Peak C and the other dense cloud cores are rim-brightened in synchrotron X rays, suggesting that the dense cloud cores are embedded within or on the outer boundary of the SNR shell. This confirms the earlier suggestion that the X rays are physically associated with the molecular gas (Fukui et al. 2003). We present a scenario where the densest molecular core, peak C, survived against the blast wave and is now embedded within the SNR. Numerical simulations of the shock-cloud interaction indicate that a dense clump can indeed survive shock erosion, since shock propagation speed is stalled in the dense clump. Additionally, the shock-cloud interaction induces turbulence and magnetic field amplification around the dense clump that may facilitate particle acceleration in the lower-density inter-clump space leading to the enhanced synchrotron X rays around dense cores.

Magnetic resonance imaging of respiratory movement and lung function; Magnetresonanztomographie der Atembewegung und Lungenfunktion

Energy Technology Data Exchange (ETDEWEB)

Tetzlaff, R. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie (E010), Heidelberg (Germany); Deutsches Krebsforschungszentrum (DKFZ), Abteilung Medizinische und Biologische Informatik, Heidelberg (Germany); Eichinger, M. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie (E010), Heidelberg (Germany)

2009-08-15

Lung function measurements are the domain of spirometry or plethysmography. These methods have proven their value in clinical practice, nevertheless, being global measurements the functional indices only describe the sum of all functional units of the lung. Impairment of only a single component of the respiratory pump or of a small part of lung parenchyma can be compensated by unaffected lung tissue. Dynamic imaging can help to detect such local changes and lead to earlier adapted therapy. Magnetic resonance imaging (MRI) seems to be perfect for this application as it is not hampered by image distortion as is projection radiography and it does not expose the patient to potentially harmful radiation like computed tomography. Unfortunately, lung parenchyma is not easy to image using MRI due to its low signal intensity. For this reason first applications of MRI in lung function measurements concentrated on the movement of the thoracic wall and the diaphragm. Recent technical advances in MRI however might allow measurements of regional dynamics of the lungs. (orig.) [German] Die Lungenfunktion wird bislang hauptsaechlich durch die Spirometrie oder Plethysmographie untersucht. Diese Methoden sind zwar sehr leistungsfaehig zur Diagnostik von Lungenerkrankungen, sind jedoch globale Messmethoden, deren Messparameter immer die Summe aller funktionellen Einheiten der Lunge beschreiben. Veraenderungen, die auf eine Teilkomponente der Atempumpe beschraenkt sind oder kleine Teile des Lungengewebes betreffen, koennen durch gesunde Lungenanteile kompensiert werden. Mit dynamischen bildgebenden Verfahren koennten solche regionalen Veraenderungen erfasst und so eine fruehere Therapie ermoeglicht werden. Die Magnetresonanztomographie (MRT) bietet sich hier ideal an, da sie als Schnittbildverfahren weder die Probleme der Bildverzerrung, der Projektionsverfahren noch die Strahlenbelastung der Computertomographie hat. Allerdings wird die MRT der Lunge durch das geringe Signal des

Reactivity feedback evaluation of material relocations in the CABRI-1 experiments with fuel worth distributions from SNR-300

International Nuclear Information System (INIS)

Royl, P.; Pfrang, W.; Struwe, D.

1991-01-01

The fuel relocations from the CABRI-1 experiments with irradiated fuel that had been evaluated from the hodoscope measurements were used together with fuel reactivity worth distributions from the SNR-300 to estimate the reactivity effect which these motions would have if they occurred in SNR-300 at the same relative distance to the peak power as in CABRI. The procedure for the reactivity evaluation is outlined including the assumptions made for fuel mass conservation. The results show that the initial fuel motion yields always negative reactivities. They also document the mechanism for a temporary reactivity increase by in-pin fuel flow in some transient overpower tests. This mechanism, however, never dominates, because material accumulates always sufficiently above the peak power point. Thus, the late autocatalytic amplifications of voiding induced power excursions by compactive in-pin fuel flow, that had been simulated in bounding loss of flow analyses for SNR-300, have no basis at all when considering the results from the CABRI-1 experiments

Quantitative perfusion imaging in magnetic resonance imaging; Quantitative Perfusionsbildgebung in der Magnetresonanztomographie

Energy Technology Data Exchange (ETDEWEB)

Zoellner, F.G.; Gaa, T.; Zimmer, F. [Universitaet Heidelberg, Computerunterstuetzte Klinische Medizin, Medizinische Fakultaet Mannheim, Mannheim (Germany); Ong, M.M.; Riffel, P.; Hausmann, D.; Schoenberg, S.O.; Weis, M. [Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Universitaetsmedizin Mannheim, Medizinische Fakultaet Mannheim, Mannheim (Germany)

2016-02-15

Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI. While the first method uses magnetically labelled water protons in arterial blood as an endogenous tracer, the latter involves the injection of a contrast agent, usually gadolinium (Gd), as a tracer for calculating hemodynamic parameters. Studies have demonstrated the potential of perfusion MRI for diagnostics and also for therapy monitoring. The utilization and application of perfusion MRI are still restricted to specialized centers, such as university hospitals. A broad application of the technique has not yet been implemented. The MRI perfusion technique is a valuable tool that might come broadly available after implementation of standards on European and international levels. Such efforts are being promoted by the respective professional bodies. (orig.) [German] Die Magnetresonanztomographie (MRT) zeichnet sich durch einen ueberlegenen Gewebekontrast aus, waehrend sie nichtinvasiv und frei von ionisierender Strahlung ist. Sie bietet Zugang zu Gewebe- und Organfunktion. Eine dieser funktionellen bildgebenden Verfahren ist die Perfusionsbildgebung. Mit dieser Technik koennen u. a. Gewebeperfusion und Kapillarpermeabilitaet aus dynamischen Bilddaten bestimmt werden. Perfusionsbildgebung mithilfe der MRT kann durch 2 Ansaetze, naemlich ''arterial spin labeling'' (ASL) und dynamische kontrastverstaerkte (DCE-)MRT durchgefuehrt werden. Waehrend die erste Methode magnetisch

Functional magnetic resonance imaging in the activation of working memory; Funktionelle Magnetresonanztomographie bei Aktivierung des Arbeitsgedaechtnisses

Energy Technology Data Exchange (ETDEWEB)

Spitzer, M. [Sektion Experimentelle Psychopathologie, Psychiatrische Universitaetsklinik, Heidelberg (Germany); Kammer, T. [Sektion Experimentelle Psychopathologie, Psychiatrische Universitaetsklinik, Heidelberg (Germany); Bellemann, M.E. [Forschungsschwerpunkt Radiologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum, Heidelberg (Germany); Gueckel, F. [Inst. fuer Klinische Radiologie, Klinische Fakultaet 2, Univ. Heidelberg, Klinikum Mannheim (Germany); Georgi, M. [Inst. fuer Klinische Radiologie, Klinische Fakultaet 2, Univ. Heidelberg, Klinikum Mannheim (Germany); Gass, A. [Neurologische Klinik, Klinische Fakultaet 2, Univ. Heidelberg, Klinikum Mannheim (Germany); Brix, G. [Forschungsschwerpunkt Radiologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum, Heidelberg (Germany)

1996-07-01

Functional magnetic resonance imaging was used in conjunction with a letter detection task for the study of working memory in 16 normal subjects. Because of movement artifacts, data from only 9 subjects were analysed. In the activation taks, subjects responded by pressing a button whenever any presented letter was the same as the second last in the sequence. In the control condition, the subjects had to respond to a fixed letter. Hence, the activation condition and the control condition differend only subjectively, i.e., regarding the task demand, whereas the stimuli and the type and frequency of response were identical. The activation condition produced significant activation in the dorsolateral prefrontal cortex (Brodmann`s areas 10, 46, and 9). In contrast to experimental tasks previsouly used rather extensively to study the prefrontal cortex, the present paradigm is characterized by its simplicity, interpretability, and its ties to known neurophysiology of the frontal cortex. (orig.) [Deutsch] Unter Verwendung eines Buchstabenerkennungsparadigmas wurde die Funktion des Arbeitsgedaechtnisses mittels funktioneller Magnetresonanztomographie an 16 gesunden Probanden untersucht, von denen 9 ausgewertet werden konnten. Aktivierungsbedingung (Reaktion auf jeden Buchstaben, der identisch ist mit dem jeweils vorletzten Buchstaben) und Kontrollbedingung (Reaktion auf einen bestimmten vorselektierten Buchstaben) unterschieden sich lediglich durch unterschiedliche Instruktionen. Die beiden Bedingungen waren damit subjektiv verschieden, jedoch durch physikalisch identische Reize sowie eine identische Reaktion (Erkennen des zu diskriminierenden Zielreizes und Knopfdruck) charakterisiert. Unter der das Arbeitsgedaechtnis beanspruchenden Aktivierungsbedingung wurde eine umschriebene signifikante Vermehrung der Aktivtaet im dorsolateralen praefrontalen Kortex (Brodmannsche Areale 10, 46 und 9) beobachtet. Im Gegensatz zu anderen experimentellen Paradigmen, die zu funktionellen

Capacity Bounds and High-SNR Capacity of MIMO Intensity-Modulation Optical Channels

KAUST Repository

Chaaban, Anas

2018-02-19

The capacity of the intensity modulation direct detection multiple-input multiple-output channel is studied. Therein, the nonnegativity constraint of the transmit signal limits the applicability of classical schemes, including precoding. Thus, new ways are required for deriving capacity bounds for this channel. To this end, capacity lower bounds are developed in this paper by deriving the achievable rates of two precodingfree schemes: Channel inversion and QR decomposition. The achievable rate of a DC-offset SVD-based scheme is also derived as a benchmark. Then, capacity upper bounds are derived and compared against the lower bounds. As a result, the capacity at high signal-to-noise ratio (SNR) is characterized for the case where the number of transmit apertures is not larger than the number of receive apertures, and is shown to be achievable by the QR decomposition scheme. This is shown for a channel with average intensity or peak intensity constraints. Under both constraints, the high-SNR capacity is approximated within a small gap. Extensions to a channel with more transmit apertures than receive apertures are discussed, and capacity bounds for this case are derived.

Capacity Bounds and High-SNR Capacity of MIMO Intensity-Modulation Optical Channels

KAUST Repository

Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

2018-01-01

The capacity of the intensity modulation direct detection multiple-input multiple-output channel is studied. Therein, the nonnegativity constraint of the transmit signal limits the applicability of classical schemes, including precoding. Thus, new ways are required for deriving capacity bounds for this channel. To this end, capacity lower bounds are developed in this paper by deriving the achievable rates of two precodingfree schemes: Channel inversion and QR decomposition. The achievable rate of a DC-offset SVD-based scheme is also derived as a benchmark. Then, capacity upper bounds are derived and compared against the lower bounds. As a result, the capacity at high signal-to-noise ratio (SNR) is characterized for the case where the number of transmit apertures is not larger than the number of receive apertures, and is shown to be achievable by the QR decomposition scheme. This is shown for a channel with average intensity or peak intensity constraints. Under both constraints, the high-SNR capacity is approximated within a small gap. Extensions to a channel with more transmit apertures than receive apertures are discussed, and capacity bounds for this case are derived.

MIMO channel capacity with full CSI at Low SNR

KAUST Repository

Tall, Abdoulaye

2012-10-01

In this paper, we characterize the ergodic capacity of Multiple Input Multiple Output (MIMO) Rayleigh fading channels with full channel state information (CSI) at both the transmitter (CSI-T) and the receiver (CSI-R) at asymptotically low signal-to-noise ratio (SNR). A simple analytical expression of the capacity is derived for any number of transmit and receive antennas. This characterization clearly shows the substantial gain in terms of capacity over the no CSI-T case and gives a good insight on the effect of the number of antennas used. In addition, an On-Off transmission scheme is proposed and is shown to be asymptotically capacity-achieving. © 2012 IEEE.

Bildung für eine nachhaltige Entwicklung. Bericht der BLK an die Regierungschefs von Bund und Ländern zur Umsetzung des Orientierungsrahmens

OpenAIRE

2001-01-01

Der Orientierungsrahmen "Bildung für eine nachhaltige Entwicklung" wurde 1998 durch die Bund-Länder-Kommission für Bildungsplanung und Forschungsförderung (BLK) beschlossen. In dem vorliegenden Dokument wird auf der Grundlage einer Umfrage der BLK-Geschäftsstelle bei den Kultus- und Wissenschaftsministerien über seine Umsetzung berichtet. Der Bericht gliedert sich wie folgt: 1. Rechtliche und politische Grundlagen sowie landesspezifische Initiativen/Programme einer Bildung für nachhaltige Ent...

Entwicklung der Reglementierung von 10 MEM-Berufen im Kontext von Bildungsreformen und dem Wandel in der Arbeitswelt: Eine Kurzstudie im Auftrag von LIBS: Eine Kurzstudie im Auftrag von LIBS Industrielle Berufslehren Schweiz, Baden

OpenAIRE

Egg, Maria Esther; Renold, Ursula

2015-01-01

Im Auftrag der LIBS Industrielle Berufslehren Schweiz, hat die KOF die Entwicklung von 10 MEM1-Berufsbildern seit dem ersten Berufsbildungsgesetz dargestellt und diese eingebettet in eine kurze Zusammenfassung der wichtigsten Etappenschritte des Schweizer Berufsbildungssystems.

Magnetic resonance tomography and dental radiology (Dental-MRT); Die Magnetresonanztomographie in der Dentalradiologie (Dental-MRT)

Energy Technology Data Exchange (ETDEWEB)

Gahleitner, A. [Wien Univ. (Austria). Abt. fuer Osteologie; Wien Univ. (Austria). Abt. fuer Orale Chirurgie; Solar, P.; Ertl, L. [Wien Univ. (Austria). Abt. fuer Orale Chirurgie; Nasel, C.; Homolka, P. [Wien Univ. (Austria). Inst. fuer Biomedizinische Technik und Physik; Youssefzadeh, S.; Schick, S. [Wien Univ. (Austria). Abt. fuer Osteologie

1999-12-01

Purpose: To demonstrate the usefulness of Dental-MRT for imaging of anatomic and pathologic conditions of the mandible and maxilla. Methods: Seven healthy volunteers, 5 patients with pulpitis, 9 patients with dentigerous cysts, 5 patients after tooth transplantation and 12 patients with atrophic mandibles were evaluated. Studies of the jaws using axial T1- and T2-weighted gradient echo and spin echo sequences in 2D and 3D technique have been to performed. The acquired images were reconstructed with a standard dental software package on a workstation as panoramic and cross sectional views of the mandible or maxilla. Results: The entire maxilla and mandibula, teeth, dental pulp and the content of the mandibular canal were well depicted. Patients with inflammatory disease of the pulp chamber demonstrate bone marrow edema in the periapical region. Dentigerous cysts and their relation to the surrounding structures are clearly shown. After contrast media application marked enhancement of the dental pulp can be found. Conclusion: Dental-MRT provides a valuable tool for visualization and detection of dental diseases. (orig.) [German] Ziel dieses Beitrags ist die Vorstellung der Untersuchungsmoeglichkeiten des Ober- und Unterkiefers mittels Magnetresonanztomographie (Dental-MRT) und ihre Anwendung bei der Diagnose zahnmedizinischer Erkrankungen. Sieben gesunde Probanden, 5 Patienten mit Pulpitis, 9 Patienten mit dentogenen Zysten, 5 Patienten nach Zahntransplantationen und 12 Patienten mit atrophem Unterkiefer wurden untersucht. Axiale T1- und T2-gewichtete Gradientenecho- und Spinecho-Sequenzen in 2D und 3D-Technik wurden durchgefuehrt. Nach der Untersuchung wurden zusaetzliche Panoramaschnitte und orhoradiale Rekonstruktionen des Ober- und Unterkiefers, unter Verwendung einer gebraeuchlichen Dental-Software, angefertigt. Der gesamte Ober- oder Unterkiefer, Zaehne, Pulpa und der Inhalt des Mandibularkanals koennen gut dargestellt werden. Patienten mit einer Entzuendung der

Long-term perspectives of technical and social development in Germany. Visions for research and technology policy; Langfristige Perspektiven technischer und gesellschaftlicher Entwicklung in Deutschland. Visionen fuer die Forschungs- und Technologiepolitik

Energy Technology Data Exchange (ETDEWEB)

Baron, W; Zweck, A

1995-12-01

This publication contains six contributions discussing the medium- and long-term perspectives of technical, social and economic development in Germany. (UA) [Deutsch] Die vorliegende Publikation enthaelt 6 Vortraege, die sich mit mittel- und langfristigen Perspektiven der technischen, sozialen und wirtschaftlichen Entwicklung in Deutschland befassen. (UA)

Use of compensation assemblies in the first core of SNR-300

International Nuclear Information System (INIS)

Billaux, M.; De Wouters, R.; Pilate, S.; Vandenberg, C.

1975-01-01

For the SNR-300 reactor, the use of thin fuel pins was limited to the first core. A direct consequence of changing from the cycle reloading scheme to a complete irradiation without refueling operation is an increase of the initial excess reactivity and plutonium investment. The new system of special assemblies conceived to compensate for the too high reactivity of the first core is described: fixed absorbers, made of B 4 C pins, and sodium diluents, consisting simply of hollow wrapper tubes [fr

An interactive videogame designed to improve respiratory navigator efficiency in children undergoing cardiovascular magnetic resonance.

Science.gov (United States)

Hamlet, Sean M; Haggerty, Christopher M; Suever, Jonathan D; Wehner, Gregory J; Grabau, Jonathan D; Andres, Kristin N; Vandsburger, Moriel H; Powell, David K; Sorrell, Vincent L; Fornwalt, Brandon K

2016-09-06

Advanced cardiovascular magnetic resonance (CMR) acquisitions often require long scan durations that necessitate respiratory navigator gating. The tradeoff of navigator gating is reduced scan efficiency, particularly when the patient's breathing patterns are inconsistent, as is commonly seen in children. We hypothesized that engaging pediatric participants with a navigator-controlled videogame to help control breathing patterns would improve navigator efficiency and maintain image quality. We developed custom software that processed the Siemens respiratory navigator image in real-time during CMR and represented diaphragm position using a cartoon avatar, which was projected to the participant in the scanner as visual feedback. The game incentivized children to breathe such that the avatar was positioned within the navigator acceptance window (±3 mm) throughout image acquisition. Using a 3T Siemens Tim Trio, 50 children (Age: 14 ± 3 years, 48 % female) with no significant past medical history underwent a respiratory navigator-gated 2D spiral cine displacement encoding with stimulated echoes (DENSE) CMR acquisition first with no feedback (NF) and then with the feedback game (FG). Thirty of the 50 children were randomized to undergo extensive off-scanner training with the FG using a MRI simulator, or no off-scanner training. Navigator efficiency, signal-to-noise ratio (SNR), and global left-ventricular strains were determined for each participant and compared. Using the FG improved average navigator efficiency from 33 ± 15 to 58 ± 13 % (p < 0.001) and improved SNR by 5 % (p = 0.01) compared to acquisitions with NF. There was no difference in navigator efficiency (p = 0.90) or SNR (p = 0.77) between untrained and trained participants for FG acquisitions. Circumferential and radial strains derived from FG acquisitions were slightly reduced compared to NF acquisitions (-16 ± 2 % vs -17 ± 2 %, p < 0.001; 40 ± 10�

Main heat transfer components for SNR-300

International Nuclear Information System (INIS)

De Haas Van Dorsser, A.H.

1976-01-01

Early in the joint German-Belgium-Dutch fast breeder programme it was decided that all main components should be tested, if possible at full scale, before fabrication of the actual SNR-300 components. Descriptions are given of the results of testing, and subsequent modifications, of the pumps, intermediate heat exchangers, and steam generators. A full scale model of the primary pump, free surface vertical shaft centrifugal type, was constructed and tested in the 5000 cubic metres per hour pump test facility erected at Bensberg. A 70 MW model of an intermediate heat exchanger, straight tube type with floating head, was tested in the 50 MW steam generator test station at Hengelo. Also tested in the Hengelo facility was an almost full scale straight tube 50 MW steam generator and subsequently a 50 MW helical tube evaporator. The latter tests were of more than 3000 h operation and resulted in minor changes in design and manufacturing operation. (U.K.)

LATE-TIME EVOLUTION OF COMPOSITE SUPERNOVA REMNANTS: DEEP CHANDRA OBSERVATIONS AND HYDRODYNAMICAL MODELING OF A CRUSHED PULSAR WIND NEBULA IN SNR G327.1-1.1

Energy Technology Data Exchange (ETDEWEB)

Temim, Tea [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Slane, Patrick [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kolb, Christopher; Blondin, John [North Carolina State University, 421 Riddick Hall, Raleigh, NC 27695 (United States); Hughes, John P. [Rutgers University, 57 US Highway 1, New Brunswick, NJ 08901 (United States); Bucciantini, Niccoló [INAF Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi, 5, 50125, Firenze Italy (Italy)

2015-07-20

In an effort to better understand the evolution of composite supernova remnants (SNRs) and the eventual fate of relativistic particles injected by their pulsars, we present a multifaceted investigation of the interaction between a pulsar wind nebula (PWN) and its host SNR G327.1-1.1. Our 350 Chandra X-ray observations of SNR G327.1-1.1 reveal a highly complex morphology: a cometary structure resembling a bow shock, prong-like features extending into large arcs in the SNR interior, and thermal emission from the SNR shell. Spectral analysis of the non-thermal emission offers clues about the origin of the PWN structures, while enhanced abundances in the PWN region provide evidence for a mixing of supernova ejecta with PWN material. The overall morphology and spectral properties of the SNR suggest that the PWN has undergone an asymmetric interaction with the SNR reverse shock (RS), whichcan occur as a result of a density gradient in the ambient medium and/or a moving pulsar that displaces the PWN from the center of the remnant. We present hydrodynamical simulations of G327.1-1.1 that show that its morphology and evolution can be described by a ∼17,000-year-old composite SNR that expanded into a density gradient with an orientation perpendicular to the pulsar’s motion. We also show that the RS/PWN interaction scenario can reproduce the broadband spectrum of the PWN from radio to γ-ray wavelengths. The analysis and modeling presented in this work have important implications for our general understanding of the structure and evolution of composite SNRs.

Late-Time Evolution of Composite Supernova Remnants: Deep Chandra Observations and Hydrodynamical Modeling of a Crushed Pulsar Wind Nebula in SNR G327.1-1.1

Science.gov (United States)

Temim, Tea; Slane, Patrick; Kolb, Christopher; Blondin, John; Hughes, John P.; Bucciantini, Niccolo

2015-01-01

In an effort to better understand the evolution of composite supernova remnants (SNRs) and the eventual fate of relativistic particles injected by their pulsars, we present a multifaceted investigation of the interaction between a pulsar wind nebula (PWN) and its host SNR G327.1-1.1. Our 350 ks Chandra X-ray observations of SNR G327.1-1.1 reveal a highly complex morphology; a cometary structure resembling a bow shock, prong-like features extending into large arcs in the SNR interior, and thermal emission from the SNR shell. Spectral analysis of the non-thermal emission offers clues about the origin of the PWN structures, while enhanced abundances in the PWN region provide evidence for mixing of supernova ejecta with PWN material. The overall morphology and spectral properties of the SNR suggest that the PWN has undergone an asymmetric interaction with the SNR reverse shock(RS) that can occur as a result of a density gradient in the ambient medium and or a moving pulsar that displaces the PWN from the center of the remnant. We present hydrodynamical simulations of G327.1-1.1 that show that its morphology and evolution can be described by a approx. 17,000 yr old composite SNR that expanded into a density gradient with an orientation perpendicular to the pulsar's motion. We also show that the RSPWN interaction scenario can reproduce the broadband spectrum of the PWN from radio to gamma-ray wavelengths. The analysis and modeling presented in this work have important implications for our general understanding of the structure and evolution of composite SNRs.

THE NEUTRAL INTERSTELLAR GAS TOWARD SNR W44: CANDIDATES FOR TARGET PROTONS IN HADRONIC {gamma}-RAY PRODUCTION IN A MIDDLE-AGED SUPERNOVA REMNANT

Energy Technology Data Exchange (ETDEWEB)

Yoshiike, S.; Fukuda, T.; Sano, H.; Ohama, A.; Moribe, N.; Torii, K.; Hayakawa, T.; Okuda, T.; Yamamoto, H.; Mizuno, N.; Onishi, T.; Fukui, Y. [Department of Physics and Astrophysics, Nagoya University, Nagoya, Aichi 464-8602 (Japan); Tajima, H.; Maezawa, H.; Mizuno, A. [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, Aichi 464-8601 (Japan); Nishimura, A.; Kimura, K.; Ogawa, H. [Department of Astrophysics, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Giuliani, A. [INAF-IASF Milano, via E. Bassini 15, I-20133 Milano (Italy); Koo, B.-C., E-mail: yoshiike@a.phys.nagoya-u.ac.jp [Seoul National University, Seoul 151-742 (Korea, Republic of)

2013-05-10

We present an analysis of the interstellar medium (ISM) toward the {gamma}-ray supernova remnant (SNR) W44. We used NANTEN2 {sup 12}CO(J = 2-1) and {sup 12}CO(J = 1-0) data and Arecibo H I data in order to identify the molecular and atomic gas in the SNR. We confirmed that the molecular gas is located in the SNR shell with a primary peak toward the eastern edge of the shell. We newly identified high-excitation molecular gas along the eastern shell of the SNR in addition to the high-excitation broad gas previously observed inside the shell; the line intensity ratio between the {sup 12}CO(J = 2-1) and {sup 12}CO(J = 1-0) transitions in these regions is greater than {approx}1.0, suggesting a kinetic temperature of 30 K or higher, which is most likely due to heating by shock interaction. By comparing the ISM with {gamma}-rays, we find that target protons of hadronic origin are dominated by molecular protons of average density around 200 cm{sup -3}, where the possible contribution of atomic protons is 10% or less. This average density is consistent with the recent discovery of the low-energy {gamma}-rays suppressed in 50 MeV-10 GeV as observed with AGILE and Fermi. The {gamma}-ray spectrum differs from place to place in the SNR, suggesting that the cosmic-ray (CR) proton spectrum significantly changes within the middle-aged SNR perhaps due to the energy-dependent escape of CR protons from the acceleration site. We finally derive a total CR proton energy of {approx}10{sup 49} erg, consistent with the SN origin of the majority of the CRs in the Galaxy.

Improvement of stress tolerance and leavening ability under multiple baking-associated stress conditions by overexpression of the SNR84 gene in baker's yeast.

Science.gov (United States)

Lin, Xue; Zhang, Cui-Ying; Bai, Xiao-Wen; Feng, Bing; Xiao, Dong-Guang

2015-03-16

During the bread-making process, industrial baker's yeast cells are exposed to multiple baking-associated stresses, such as elevated high-temperature, high-sucrose and freeze-thaw stresses. There is a high demand for baker's yeast strains that could withstand these stresses with high leavening ability. The SNR84 gene encodes H/ACA snoRNA (small nucleolar RNA), which is known to be involved in pseudouridylation of the large subunit rRNA. However, the function of the SNR84 gene in baker's yeast coping with baking-associated stresses remains unclear. In this study, we explored the effect of SNR84 overexpression on baker's yeast which was exposed to high-temperature, high-sucrose and freeze-thaw stresses. These results suggest that overexpression of the SNR84 gene conferred tolerance of baker's yeast cells to high-temperature, high-sucrose and freeze-thaw stresses and enhanced their leavening ability in high-sucrose and freeze-thaw dough. These findings could provide a valuable insight for breeding of novel stress-resistant baker's yeast strains that are useful for baking. Copyright © 2015 Elsevier B.V. All rights reserved.

Optimize the Power Consumption and SNR of the 3D Photonic High-Radix Switch Architecture Based on Extra Channels and Redundant Rings

Directory of Open Access Journals (Sweden)

Jie Jian

2018-01-01

Full Text Available The demand from exascale computing has made the design of high-radix switch chips an attractive and challenging research field in EHPC (exascale high-performance computing. The static power, due to the thermal sensitivity and process variation of the microresonator rings, and the cross talk noise of the optical network become the main bottlenecks of the network’s scalability. This paper proposes the analyze model of the trimming power, process variation power, and signal-to-noise ratio (SNR for the Graphein-based high-radix optical switch networks and uses the extra channels and the redundant rings to decrease the trimming power and the process variation power. The paper also explores the SNR under different configurations. The simulation result shows that when using 8 extra channels in the 64×64 crossbar optical network, the trimming power reduces almost 80% and the process variation power decreases 65% by adding 16 redundant rings in the 64×64 crossbar optical network. All of these schemes have little influence on the SNR. Meanwhile, the greater channel spacing has great advantages to decrease the static power and increase the SNR of the optical network.

Magnetic resonance imaging findings after shoulder surgery: What the radiologist needs to know; Besonderheiten der Magnetresonanztomographie nach operativer Schulterintervention

Energy Technology Data Exchange (ETDEWEB)

Fahlenkamp, U.L.; Hermann, K.G.A. [Universitaetsklinikum Charite - Campus Mitte, Institut fuer Radiologie, Berlin (Germany); Gerhardt, C. [Universitaetsklinikum Charite - Campus Mitte, Centrum fuer muskuloskeletale Chirurgie, Berlin (Germany)

2017-11-15

Even primary diagnostic evaluation of the shoulder is a challenge for radiologists. Many imaging findings that definitely indicate abnormal findings in the untreated shoulder should be evaluated carefully in postoperative patients. Artifacts caused by implants or metal abrasion pose considerable problems in postoperative magnetic resonance imaging (MRI). Classic approaches to minimizing artifacts caused by foreign bodies include using turbo spin echo sequences, increasing bandwidth, and reducing voxel size. In recent years, several vendors have developed dedicated pulse sequences for reducing metal artifacts. Different postoperative imaging findings will be encountered, depending on the kind of surgery done. This review article describes typical postoperative MRI findings, focusing on subacromial decompression, reconstruction of the rotator cuff, labrum procedures, and biceps tenodesis. (orig.) [German] Das Schultergelenk stellt fuer jeden Radiologen bereits in der primaeren Diagnostik eine Herausforderung dar. Viele Bildbefunde, welche bei einer nicht therapierten Schulter als eindeutig pathologisch zu bewerten sind, muessen im postoperativen Setting als kritisch bewertet werden. Artefakte durch Implantate oder Metallabrieb stellen eine grosse Huerde der postoperativen Magnetresonanztomographie dar. Klassische Methoden, um Artefakte durch Fremdmaterial so gering wie moeglich zu halten, bestehen in der Anwendung von Turbo-Spin-Echo-Sequenzen sowie in der Erhoehung der Bandbreite oder der Reduktion der Voxelgroesse. Mittlerweile haben einige Anbieter jedoch spezielle Sequenzen zur Reduktion von Metallartefakten entwickelt. In Abhaengigkeit von der erfolgten Schulteroperation muessen verschiedene Bildbefunde beruecksichtigt werden. Dieser Uebersichtsartikel geht insbesondere auf die subakromiale Dekompression, die Rekonstruktion der Rotatorenmanschette, Operationen am Labrum sowie Bizepstenodesen ein und beschreibt typische postoperative Befunde. (orig.)

Entwicklung und Evaluierung eines auf dem Stellungsfeldermodell basierenden syntaktischen Annotationsverfahrens für Lernerkorpora innerhalb einer Mehrebenen-Architektur mit Schwerpunkt auf schriftlichen Texten fortgeschrittener Deutschlerner

OpenAIRE

Doolittle, Seanna

2008-01-01

Die Arbeit zeigt exemplarisch die Möglichkeiten, die die Mehrebenen-Korpusarchitektur bei der Annotation von „standard-“ und „nicht standardsprachlichen“ Äußerungen in einem gemeinsamen Korpus bieten. // Konkret beschäftigt sie sich mit der Entwicklung und Evaluierung eines auf dem Stellungsfeldermodell basierenden syntaktischen Annotationsverfahrens für Lernerkorpora, bestehend aus schriftlichen Texten fortgeschrittener Deutschlerner, innerhalb einer Mehrebenen-Architektur. Die Felderannotat...

CORE-COLLAPSE MODEL OF BROADBAND EMISSION FROM SNR RX J1713.7–3946 WITH THERMAL X-RAYS AND GAMMA RAYS FROM ESCAPING COSMIC RAYS

International Nuclear Information System (INIS)

Ellison, Donald C.; Slane, Patrick; Patnaude, Daniel J.; Bykov, Andrei M.

2012-01-01

We present a spherically symmetric, core-collapse model of SNR RX J1713.7–3946 that includes a hydrodynamic simulation of the remnant evolution coupled to the efficient production of cosmic rays (CRs) by nonlinear diffusive shock acceleration. High-energy CRs that escape from the forward shock (FS) are propagated in surrounding dense material that simulates either a swept-up, pre-supernova shell or a nearby molecular cloud. The continuum emission from trapped and escaping CRs, along with the thermal X-ray emission from the shocked heated interstellar medium behind the FS, integrated over the remnant, is compared against broadband observations. Our results show conclusively that, overall, the GeV-TeV emission is dominated by inverse-Compton from CR electrons if the supernova is isolated regardless of its type, i.e., not interacting with a >>100 M ☉ shell or cloud. If the supernova remnant is interacting with a much larger mass ∼> 10 4 M ☉ , pion decay from the escaping CRs may dominate the TeV emission, although a precise fit at high energy will depend on the still uncertain details of how the highest energy CRs are accelerated by, and escape from, the FS. Based on morphological and other constraints, we consider the 10 4 M ☉ pion-decay scenario highly unlikely for SNR RX J1713.7–3946 regardless of the details of CR escape. Importantly, even though CR electrons dominate the GeV-TeV emission, the efficient production of CR ions is an essential part of our leptonic model.

A Study on the Optimal Receiver Impedance for SNR Maximization in Broadband PLC

Directory of Open Access Journals (Sweden)

Massimo Antoniali

2013-01-01

Full Text Available We consider the design of the front-end receiver for broadband power line communications. We focus on the design of the input impedance that maximizes the signal-to-noise ratio (SNR at the receiver. We show that the amplitude, rather than the power, of the received signal is important for communication purposes. Furthermore, we show that the receiver impedance impacts the amplitude of the noise term. We focus on the background noise, and we propose a novel description of the noise experienced at the receiver port of a PLC network. We model the noise as the sum of four uncorrelated contributions, that is, the active, resistive, receiver, and coupled noise components. We study the optimal impedance design problem for real in-home grids that we assessed with experimental measurements. We describe the results of the measurement campaign, and we report the statistics of the optimal impedance. Hence, we study the best attainable performance when the optimal receiver impedance is deployed. We focus on the SNR and the maximum achievable rate, and we show that power matching is suboptimal with respect to the proposed impedance design approach.

Carrier tracking by smoothing filter improves symbol SNR

Science.gov (United States)

Pomalaza-Raez, Carlos A.; Hurd, William J.

1986-01-01

The potential benefit of using a smoothing filter to estimate carrier phase over use of phase locked loops (PLL) is determined. Numerical results are presented for the performance of three possible configurations of the deep space network advanced receiver. These are residual carrier PLL, sideband aided residual carrier PLL, and finally sideband aiding with a Kalman smoother. The average symbol signal to noise ratio (SNR) after losses due to carrier phase estimation error is computed for different total power SNRs, symbol rates and symbol SNRs. It is found that smoothing is most beneficial for low symbol SNRs and low symbol rates. Smoothing gains up to 0.4 dB over a sideband aided residual carrier PLL, and the combined benefit of smoothing and sideband aiding relative to a residual carrier loop is often in excess of 1 dB.

A relationship between SNR G109.1-1.0 and the molecular cloud of Sh2-152

International Nuclear Information System (INIS)

Heydari-Malayeri, M.; Kahane, C.; Lucas, R.

1981-01-01

The possible association of the supernova remnant SNR G109.1 - 1.0 and the x-ray source GF2259 + 586 with the molecular cloud of Sh2 - 152 has been investigated by observing the molecular line 13 CO (J = 1 → 0) of the complex Sh2 - 147/Sh2 - 153. The present results are compared with those of previous workers. It is shown that although the various estimates of distance for the SNR, the x-ray source, the H II region Sh2 - 152 and the molecular cloud are in relatively good agreement, because of the uncertainties of distance evaluation in the Perseus arm this cannot be regarded as conclusive proof of the association of these objects. (U.K.)

Multifrequency radio observations of SNR J0536-6735 (N 59B with associated pulsar

Directory of Open Access Journals (Sweden)

Bozzetto L.M.

2012-01-01

Full Text Available We present a study of new Australian Telescope Compact Array (ATCA observations of supernova remnant, SNR J0536-6735. This remnant appears to follow a shell morphology with a diameter of D=36x29 pc (with 1 pc uncertainty in each direction. There is an embedded HII region on the northern limb of the remnant which made various analysis and measurements (such as flux density, spectral index and polarisation difficult. The radio-continuum emission followed the same structure as the optical emission, allowing for extent and flux density estimates at 20 cm. We estimate the surface brightness at 1 GHz of 2.55x10−21 Wm−2 Hz−1 sr−1 for the SNR. Also, we detect a distinctive radio-continuum point source which confirms the previous suggestion of this remnant being associated with pulsar wind nebula (PWN. The tail of this remnant is not seen in the radio-continuum images and is only seen in the optical and X-ray images.

Concepts on high temperature design analysis for SNR 300

International Nuclear Information System (INIS)

Bieniussa, K.; Zolti, E.

1976-01-01

The paper briefly describes the evolution, the present situation and the next activities on the design of high temperature components of the DEBENELUX prototype fast breeder reactor SNR-300 with particular regard to the design criteria. Elastic structural analyses are performed for the basic design of the components and are supplied by the manufacturer. In agreement with the Safety Experts simplified and/or detailed inelastic analyses of the critical areas are supplied by the prime contractor of the plant. The elastic computations are evaluated on the basis of a set of design rules derived from ASME Code Case Interpretation 1331-4 but with more conservative limits, and the inelastic ones on the basis of the ASME Code Case Interpretation 1592

Nature of the Diffuse Source and Its Central Point-like Source in SNR 0509–67.5

Energy Technology Data Exchange (ETDEWEB)

Litke, Katrina C.; Chu, You-Hua; Holmes, Abigail; Santucci, Robert; Blindauer, Terrence; Gruendl, Robert A.; Ricker, Paul M. [Astronomy Department, University of Illinois, 1002 W. Green Street, Urbana, IL 61801 (United States); Li, Chuan-Jui [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan, R.O.C. (China); Pan, Kuo-Chuan [Departement Physik, Universität Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Weisz, Daniel R., E-mail: kclitke@email.arizona.edu [Department of Astronomy, University of California, 501 Cambell Hall #3411, Berkeley, CA 94720-3411 (United States)

2017-03-10

We examine a diffuse emission region near the center of SNR 0509−67.5 to determine its nature. Within this diffuse region we observe a point-like source that is bright in the near-IR, but is not visible in the B and V bands. We consider an emission line observed at 6766 Å and the possibilities that it is Ly α , H α , and [O ii] λ 3727. We examine the spectral energy distribution (SED) of the source, comprised of Hubble Space Telescope B , V , I , J , and H bands in addition to Spitzer /IRAC 3.6, 4.5, 5.8, and 8 μ m bands. The peak of the SED is consistent with a background galaxy at z ≈ 0.8 ± 0.2 and a possible Balmer jump places the galaxy at z ≈ 0.9 ± 0.3. These SED considerations support the emission line’s identification as [O ii] λ 3727. We conclude that the diffuse source in SNR 0509−67.5 is a background galaxy at z ≈ 0.82. Furthermore, we identify the point-like source superposed near the center of the galaxy as its central bulge. Finally, we find no evidence for a surviving companion star, indicating a double-degenerate origin for SNR 0509−67.5.

Nature of the Diffuse Source and Its Central Point-like Source in SNR 0509–67.5

International Nuclear Information System (INIS)

Litke, Katrina C.; Chu, You-Hua; Holmes, Abigail; Santucci, Robert; Blindauer, Terrence; Gruendl, Robert A.; Ricker, Paul M.; Li, Chuan-Jui; Pan, Kuo-Chuan; Weisz, Daniel R.

2017-01-01

We examine a diffuse emission region near the center of SNR 0509−67.5 to determine its nature. Within this diffuse region we observe a point-like source that is bright in the near-IR, but is not visible in the B and V bands. We consider an emission line observed at 6766 Å and the possibilities that it is Ly α , H α , and [O ii] λ 3727. We examine the spectral energy distribution (SED) of the source, comprised of Hubble Space Telescope B , V , I , J , and H bands in addition to Spitzer /IRAC 3.6, 4.5, 5.8, and 8 μ m bands. The peak of the SED is consistent with a background galaxy at z ≈ 0.8 ± 0.2 and a possible Balmer jump places the galaxy at z ≈ 0.9 ± 0.3. These SED considerations support the emission line’s identification as [O ii] λ 3727. We conclude that the diffuse source in SNR 0509−67.5 is a background galaxy at z ≈ 0.82. Furthermore, we identify the point-like source superposed near the center of the galaxy as its central bulge. Finally, we find no evidence for a surviving companion star, indicating a double-degenerate origin for SNR 0509−67.5.

Radiological imaging in early diagnosis of rheumatoid arthritis. The role of ultrasound and magnetic resonance imaging; Radiologische Fruehdiagnostik der rheumatoiden Arthritis. Stellenwert von Ultraschall und Magnetresonanztomographie

Energy Technology Data Exchange (ETDEWEB)

Platzgummer, H.; Schueller-Weidekamm, C. [AKH, Medizinische Universitaet Wien, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

2012-02-15

For optimal therapy management of patients with rheumatoid arthritis (RA) specific and sensitive diagnostic methods are essential for assessment of disease activity. In addition to projection radiography, imaging techniques, in particular magnetic resonance imaging (MRI) and ultrasound (US) are becoming increasingly more important for the early diagnosis of RA. The MRI and US techniques play a key role in the early imaging diagnostics of RA. Measurement of inflammation activity represents the basis of therapeutic decision-making and can be quantitatively and qualitatively determined with MRI and US. Synovitis and bone marrow edema are predictors of erosion. (orig.) [German] Fuer das optimale Therapiemanagement bei Patienten mit rheumatoider Arthritis (RA) sind spezifische und sensible diagnostische Methoden zur Beurteilung der Krankheitsaktivitaet unerlaesslich. Neben der Projektionsradiographie gewinnen die bildgebenden Methoden zur Fruehdiagnostik der RA, insbesondere die Magnetresonanztomographie (MRT) und der Ultraschall (US), zunehmend an Bedeutung. MRT und US spielen eine Schluesselrolle in der bildgebenden Fruehdiagnostik der RA. Die Messung der Entzuendungsaktivitaet stellt die Basis fuer die Therapieentscheidung dar. Sie kann mit dem US und der MRT quantitativ und semiquantitativ bestimmt werden. Synovialitis und Knochenmarkoedem sind Praediktoren fuer Erosionen. (orig.)

Paleo-oil and gas fields in the red sandstone of the North German Basin: Effects of hydrocarbon migration on storage quality development. Fluid flow, diagenesis and storage quality in the red sandstone strata of northern Germany; Palaeo-Oel- und -Gasfelder im Rotliegenden des Norddeutschen Beckens: Wirkung der KW-Migration auf die Speicherqualitaets-Entwicklung. Fluidfluss, Diagenese und Speicherqualitaet im Rotliegend Norddeutschlands

Energy Technology Data Exchange (ETDEWEB)

Solms, M. [SGC, Lehrte (Germany); Gaupp, R. [Jena Univ. (Germany); Littke, R.; Schwarzer, D. [RWTH Aachen (Germany); Schubarth-Engelschall, J.; Trappe, H. [TEEC, Isernhagen (Germany); Krawczyk, C.; Tanner, D.; Oncken, O. [GFZ, Potsdam (Germany)

2003-07-01

This sub-project was aimed at improving the geological concept of the development of storage quality, at the development of a model for monitoring and reconstruction of the structural development and restructuring of reservoirs, and at obtaining information on hydrocarbon origins, migration pathways and filling chronology. Drill core data were combined with 3D seismic data in order to obtain a deeper understanding of the processes involved. [German] Im Rahmen des DGMK-Forschungsprogrammes ''Tight Gas Reservoirs'' (Projekt 593-8) wurden von der Arbeitsgruppe Sedimentologie 43 Bohrungen aus dem Rotliegend Nordwestdeutschlands untersucht. Die vorgestellten Ergebnisse schliessen sich an den Vortrag ''Einfluss von Fazies und Diagenese auf die Speicher-Qualitaets-Entwicklung von Rotliegendsandsteinen NW Deutschlands'' (SOLMS et al., DGMK-Fruehjahrstagung 2002). Ziel dieses Teilprojektes ist die Verbesserung des geologischen Konzeptes zur Entwicklung der Speicherqualitaet, die Entwicklung eines Modells zur Erfassung und Rekonstruktion der strukturellen Entwicklung und Restrukturierung von Lagerstaetten sowie die Klaerung von KW-Herkunftsgebieten, Migrationswegen und Fuellungschronologien. Durch die Verknuepfung der Kerndaten mit 3D seismischen Daten soll eine verbesserte Einschaetzung der Speicherqualitaeten aus dem 3D seismischen Abbild erreicht werden. (orig.)

Development, design, construction and testing of pumps, intermediate heat exchangers and manipulator systems for in-service inspection of SNR 300

International Nuclear Information System (INIS)

Vroom, J.P.; Heslenfeld, M.W.; Westerweele, W.J.; Willigen, A. van

1978-01-01

The first part of this paper reviews the development, design, construction and testing of sodium pumps and intermediate heat exchangers as carried out by NERATOOM in the Netherlands. Testing of full-size components under operational conditions yielded important information for the design of the components for SNR 300. Information is also given in brief on the manufacture of the components. The second part reviews the work done on manipulator systems for in-service inspection as carried out by INTERATOM in Germany. In this field again experience gained from tests had important consequences for the design of the apparatus for SNR 300. (author)

An 8-channel transceiver 7-channel receive RF coil setup for high SNR ultrahigh-field MRI of the shoulder at 7T.

Science.gov (United States)

Rietsch, Stefan H G; Pfaffenrot, Viktor; Bitz, Andreas K; Orzada, Stephan; Brunheim, Sascha; Lazik-Palm, Andrea; Theysohn, Jens M; Ladd, Mark E; Quick, Harald H; Kraff, Oliver

2017-12-01

In this work, we present an 8-channel transceiver (Tx/Rx) 7-channel receive (Rx) radiofrequency (RF) coil setup for 7 T ultrahigh-field MR imaging of the shoulder. A C-shaped 8-channel Tx/Rx coil was combined with an anatomically close-fitting 7-channel Rx-only coil. The safety and performance parameters of this coil setup were evaluated on the bench and in phantom experiments. The 7 T MR imaging performance of the shoulder RF coil setup was evaluated in in vivo measurements using a 3D DESS, a 2D PD-weighted TSE sequence, and safety supervision based on virtual observation points. Distinct SNR gain and acceleration capabilities provided by the additional 7-channel Rx-only coil were demonstrated in phantom and in vivo measurements. The power efficiency indicated good performance of each channel and a maximum B 1 + of 19 μT if the hardware RF power limits of the MR system were exploited. MR imaging of the shoulder was demonstrated with clinically excellent image quality and submillimeter spatial resolution. The presented 8-channel transceiver 7-channel receive RF coil setup was successfully applied for in vivo 7 T MRI of the shoulder providing a clear SNR gain vs the transceiver array without the additional receive array. Homogeneous images across the shoulder region were obtained using 8-channel subject-specific phase-only RF shimming. © 2017 American Association of Physicists in Medicine.

Design Report for the core design of the first core Mark-Ia of the SNR-300

International Nuclear Information System (INIS)

Stanculescu, A.

1984-05-01

The report describes the first core Mark-Ia of the SNR-300 reactor and its different assembly types with their operational strategy. Methods, criteria and results of the neutron physical, thermal hydraulic and core mechanical design of the whole core and its assemblies are presented

Risk-oriented analysis of the German prototype fast breeder reactor SNR-300: off-site accident consequence model and results of the study

International Nuclear Information System (INIS)

Bayer, A.; Ehrhardt, J.

1984-01-01

Accident off-site consequence calculations and risk assessments performed for the ''risk oriented analysis'' of the German prototype fast breeder reactor SNR-300 were performed with a modified version of the off-site accident consequence model UFOMOD. The modifications mainly relate to the deposition and resuspension processes, the ingestion model, and the dose factors. Consequence calculations at the site of Kalkar on the Rhine River were performed for 115 weather sequences in 36 wind directions. They were based on seven release categories evaluated for the SNR-300 with two different fueling strategies: plutonium from Magnox reactors only and plutonium from light water reactors and Magnox reactors. In parallel, the corresponding frequencies of occurrence are determined. The following results are generated: 1. complementary cumulative frequency distribution functions for collective fatalities and collective doses 2. expected values of the collective fatalities and collective doses as well as distance-dependent expected values of individual fatality 3. contributions of the different exposure pathways to fatalities with respect to the various organs. For comparison with the risk of a PWR-1300, calculations for the PWR-1300 of the ''German Risk Study'' were repeated with the same modified consequence model. Comparison shows that smaller risks result for the SNR-300. However, the confidence interval bandwidths obtained for the frequencies of the release categories for the SNR-300 are larger than those of the PWR-1300

Status of sodium removal and component decontamination technology in the SNR programme

Energy Technology Data Exchange (ETDEWEB)

Haubold, W [INTERATOM GmbH, Bergisch Gladbach (Germany); Smit, C Ch [MT-TNO Dept. 50-MW Sodium Component Test Facility, Hengelo (Netherlands); Stade, K Ch [Kernkraftwerk-Betriebsgesellschaft mbH, Eggenstein-Leopoldshafen (Germany)

1978-08-01

This paper summarizes the experience with sodium removal and component decontamination processes within the framework of the SNR project since the IAEA Specialists Meeting on 'Decontamination of Plant Components from Sodium and Radioactivity' at Dounreay, April 9-12, 1973. The moist nitrogen process has been successfully applied to remove sodium from all 66 fuel elements of the KNK I core. Progress has been obtained in removing sodium from fuel elements and large components by vacuum distillation. Areas where future development is required are identified. (author)

Status of sodium removal and component decontamination technology in the SNR programme

International Nuclear Information System (INIS)

Haubold, W.; Smit, C.Ch.; Stade, K.Ch.

1978-01-01

This paper summarizes the experience with sodium removal and component decontamination processes within the framework of the SNR project since the IAEA Specialists Meeting on 'Decontamination of Plant Components from Sodium and Radioactivity' at Dounreay, April 9-12, 1973. The moist nitrogen process has been successfully applied to remove sodium from all 66 fuel elements of the KNK I core. Progress has been obtained in removing sodium from fuel elements and large components by vacuum distillation. Areas where future development is required are identified. (author)

Off-gas filter system of the SNR-300

International Nuclear Information System (INIS)

Boehm, L.; Jordan, S.; Schikarski, W.

1975-01-01

The Reventing-Exventing-System of the German Liquid Metal Fast Breeder Prototype SNR-300 is described. After an accident with major damage to the core the ventilation valves are quickly closed. At the same time the blower of the reventing system evacuates the reventing gap up to a pressure difference of 2 mbar between the containment and the outer atmosphere. This pressure difference prevents a leakage from the containment to the outside. The revented gas is recirculated into the outer-containment. Leaks from the atmosphere and possibly from the inner containment into the reventing gap increase the pressure in the outer-containment. Therefore depending on the pressure build-up which is determined by the course of the accident, it is necessary to exvent the containment after several days. The exvented gas is filtered by a filter combination consisting of pre-filters, charcoal-filters and HEPA-filters. Because accidental sodium fires produce high concentrations of sodium oxide-aerosols this filter system must resist chemical aggressive aerosols. (U.S.)

Post-irradiation creep properties of four plates and two forgings DIN 1.4948 steel from the SNR-300 permanent primary structures

International Nuclear Information System (INIS)

Schaaf, B. van der.

1987-01-01

The safety authorities, involved in the licensing procedure of the SNR-300, have required the determination of the irradiation effect on the heat-to-heat variation of tensile and creep properties of Werkst. No. DIN 1.4948 austenitic stainless steel. These data are lacking in the present codes and they are necessary for the design and safety considerations of the permanent structures. Results are presented of about 200 tests on irradiated and unirradiated material of 6 heats used in the production of the SNR-300 permanent structures. After irradiation in the HFR-Petten to neutron fluences relevant for the SNR-300 service conditions post-irradiation tensile and creep tests (up to 10,000 hrs rupture time) were performed in the temperature range 723 K to 923 K. All heats are embrittled by irradiation resulting in reduction of rupture times, creep strength and ultimate tensile strength. The considerable reduction is attributed to helium enhanced intergranular creep crack growth, which reduces the ductility and strength, but does not affect the creep rate. The variation of tensile and creep properties is large and independent of irradiation. The minimum derived creep strength in irradiated condition drops below the values expected in the ASME Code and VdTuV Blatt. In design and safety analyses the irradiation effect on creep properties must be accounted for with an appropriate reduction factor. The predictions given, have to be verified with long-term creep tests and parts of the SNR surveillance programme. 172 figs.; 17 refs.; 58 tables

A Method to Optimize Geometric Errors of Machine Tool based on SNR Quality Loss Function and Correlation Analysis

Directory of Open Access Journals (Sweden)

Cai Ligang

2017-01-01

Full Text Available Instead improving the accuracy of machine tool by increasing the precision of key components level blindly in the production process, the method of combination of SNR quality loss function and machine tool geometric error correlation analysis to optimize five-axis machine tool geometric errors will be adopted. Firstly, the homogeneous transformation matrix method will be used to build five-axis machine tool geometric error modeling. Secondly, the SNR quality loss function will be used for cost modeling. And then, machine tool accuracy optimal objective function will be established based on the correlation analysis. Finally, ISIGHT combined with MATLAB will be applied to optimize each error. The results show that this method is reasonable and appropriate to relax the range of tolerance values, so as to reduce the manufacturing cost of machine tools.

A CHANDRA OBSERVATION OF SNR 0540 - 697

International Nuclear Information System (INIS)

Seward, F. D.; Williams, R. M.; Chu, Y.-H.; Gruendl, R. A.; Dickel, J. R.

2010-01-01

This paper describes a Chandra observation of SNR 0540 - 697 within the H II complex N159 in the Large Magellanic Cloud (LMC). Scattering from the nearby bright source LMC X-1, which obscures the western edge of the remnant, has been removed. Larger than previously believed, the 2.'0 x 2.'8 remnant is defined by optical filaments and two lobes of X-ray emission. A band of intervening material absorbs X-rays from the central part of the remnant. The N Lobe of the remnant is relatively bright and well defined, while emission from the S Lobe is much weaker. There is structure within the N Lobe but no clear X-ray emission from an outer shell indicating a shock in the interstellar medium. The X-ray spectrum is thermal with emission lines from Fe, Mg, and Si. The observed temperature and luminosity of the hot gas are 0.6 keV and 6 x 10 35 erg s -1 , respectively. These are consistent with characteristics expected for older remnants. There is also diffuse thermal X-ray emission north of N159 extending into N160, evidence for a larger remnant or bubble.

Steam generators under construction for the SNR-300 power plant

Energy Technology Data Exchange (ETDEWEB)

Essebaggers, J

1975-07-01

The prototype straight tube and the helical coil-steam generator has been designed and fabricated of which the straight tube steam generator has been successfully tested for over 3000 hours at prototypical conditions and is presently being dismantled for detailed examination of critical designed features. The prototype helical coil steam generator is presently under testing in the 50 MWt test facility at TNO-Hengelo with approximately 500 hours of operation at full load conditions. In an earlier presentation the design and fabrication of the prototype steam generators have been presented, while for this presentation the production units for SNR-300 will be discussed. Some preliminary information will be presented at this meeting of the dismantling operations of the prototype straight tube steam generator. (author)

Steam generators under construction for the SNR-300 power plant

International Nuclear Information System (INIS)

Essebaggers, J.

1975-01-01

The prototype straight tube and the helical coil-steam generator has been designed and fabricated of which the straight tube steam generator has been successfully tested for over 3000 hours at prototypical conditions and is presently being dismantled for detailed examination of critical designed features. The prototype helical coil steam generator is presently under testing in the 50 MWt test facility at TNO-Hengelo with approximately 500 hours of operation at full load conditions. In an earlier presentation the design and fabrication of the prototype steam generators have been presented, while for this presentation the production units for SNR-300 will be discussed. Some preliminary information will be presented at this meeting of the dismantling operations of the prototype straight tube steam generator. (author)

Functional magnetic resonance imaging in neuroradiology; Funktionelle Magnetresonanztomographie in der Neuroradiologie

Energy Technology Data Exchange (ETDEWEB)

Essig, M.; Schoenberg, S.O.; Schlemmer, H.P.; Metzner, R.; Kaick, G. van [Deutsches Krebsforschungszentrum, Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie

2000-10-01

Bildgebungssequenzen, optimierter Kontrastmittelapplikationen und spezieller Nachverarbeitungsmethoden wurde es moeglich, physiologische und pathophysiologische Prozesse mittels der Magnetresonanztomographie (MRT) zu beobachten. Mit T1- und T2*-gewichteten kontrastmittelunterstuetzten Bildgebungssequenzen koennen Informationen ueber die Gewebeperfusion, Mikrozirkulation und die Permeabilitaet der Blut-Hirn-Schranke unter Anwendung spezieller, z.T. aus der Nuklearmedizin stammender Modelle erfasst werden. Die Eigendiffusion von Wassermolekuelen im Gewebe ist mit diffusiongewichteter MRT, die Markrovaskulatur, zeitlich aufgeloest, mit MR-angiographischen Techniken darstellbar. Auch eine neuronale Aktivitaet einfacher oder komplexer Natur kann mit funktionellen MR-Techniken visualisiert werden. Mit MR-spektroskopischen Untersuchungen koennen metabolische Verteilungen in normalem und pathologischem Gewebe mehrdimensional erfasst und Stoffwechselvorgaenge im Verlauf beobachtet werden. Vorteile der MRT ist die geringe Invasivitaet, die Moeglichkeit einer dreidimensionalen Darstellung der Daten und eine beliebige Wiederholbarkeit der Untersuchung bei fehlender Strahlenbelastung. Die bereits klinisch einsetzbaren funktionellen Methoden werden beschrieben und ihr Einsatz in der Neuroradiologie auch in Bezug auf die Wertigkeit im Vergleich zu nuklearmedizinischen Methoden diskutiert. Perfusions- und Diffusions-MRT liefern wichtige Zusatzinformationen im akuten und chronischen Stadium der zerebralen Ischaemie und werden bereits routinemaessig bei akutem Schlaganfall eingesetzt. Dynamische MR-Angiographien erlauben eine haemodynamische Einstufung von Gefaessmissbildungen. In der Tumordiagnostik liefern die funktionellen MR-Techniken wichtige Zusatzinformationen fuer die Therapiefindung, Therapieplanung und das Therapiemonitoring. Die Untersuchung psychiatrischen Erkrankungen wurden durch die funktionelle MRT revolutioniert, obwohl der klinische Einsatz noch limitiert ist. Erste Untersuchungen

Soziologische Wissenskulturen zwischen individualisierter Inspiration und prozeduraler Legitimation. Zur Entwicklung qualitativer und interpretativer Sozialforschung in der deutschen und französischen Soziologie seit den 1960er Jahren

Directory of Open Access Journals (Sweden)

Reiner Keller

2016-01-01

Full Text Available Wie wissen Soziologinnen und Soziologen, was sie wissen? Trotz der Internationalisierung der Soziologie bestehen nach wie vor starke sprachräumliche Unterschiede in der soziologischen Wissensproduktion, in eingesetzten Theorien, Methoden und Fragestellungen. Der nachfolgende Beitrag erläutert die Entwicklung und Ausprägung der Unterschiedlichkeit soziologischer Wissenskulturen im Hinblick auf den Einsatz qualitativer bzw. interpretativer Ansätze seit den 1960er Jahren in Deutschland und Frankreich. Er stützt sich auf ein von uns 2012-2014 geleitetes Forschungsprojekt und dessen empirische Grundlagen: Dokumentenanalysen und Interviews. Wissenskulturen werden als die Arten und Weisen der Produktion und Legitimation von (hier: soziologischem Wissen verstanden. Diesbezüglich lässt sich von der Erkenntnisproduktion als dem zentralen Handlungsproblem soziologischen Forschens sprechen. Während für die französischsprachige Soziologie diagnostisch von einer Lösung dieses Erkenntnisproblems durch die den Forschenden zugeschriebenen Kompetenzen und Inspirationen ausgegangen werden kann, schiebt sich im deutschsprachigen Raume eine prozedurale Legitimation durch Verfahren in den Vordergrund. Der Beitrag rekonstruiert exemplarisch die Ausgangssituation dieser Entwicklungen um die Wende zu den 1960er Jahren und bettet sie in die weitere Entfaltung der jeweiligen Soziologien ein. Er will damit zur gegenwärtigen Entwicklung einer reflexiven Soziologie beitragen. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1601145

Signal to noise ratio (SNR) and image uniformity: an estimate of performance of magnetic resonance imaging (MRI) system

International Nuclear Information System (INIS)

Narayan, P.; Suri, S.; Choudhary, S.R.

2001-01-01

In most general definition, noise in an image, is any variation that represents a deviation from truth. Noise sources in MRI can be systematic or random and statistical in nature. Data processing algorithms that smooth and enhance the edges by non-linear intensity assignments among other factors can affect the distribution of statistical noise. The SNR and image uniformity depends on the various parameters of NMR imaging system (viz. General system calibration, Gain coil tuning, AF shielding, coil loading, image processing and scan parameters like TE, TR, interslice distance, slice thickness, pixel size and matrix size). A study on SNR and image uniformity have been performed using standard head AF coil with different TR and the estimates of their variation are presented. A comparison between different techniques has also been evaluated using standard protocol of the Siemens Magnetom Vision Plus MRI system

Der Weg zum Java-Profi Konzepte und Techniken für die professionelle Java-Entwicklung

CERN Document Server

Inden, Michael

2015-01-01

Sie haben bereits Einiges an Erfahrung mit Java und möchten Ihre Entwicklungstätigkeit nun professionalisieren? Oder sind Sie schon auf dem Weg zum Profi, benötigen aber ein Nachschlagewerk, das Ihnen die wichtigen Themen aus der Java-Welt kompakt und kompetent vermittelt? Dieses Buch bietet eine umfassende Einführung in die professionelle Entwicklung und vermittelt Ihnen das notwendige Wissen, um stabile und erweiterbare Softwaresysteme auf Java-SE-Basis zu bauen. Praxisnahe Beispiele helfen dabei, das Gelernte rasch umzusetzen. Neben der Praxis wird viel Wert auf das Verständnis zugrunde liegender Konzepte gelegt. Dabei kommen dem Autor Michael Inden seine umfangreichen Schulungs- und Entwicklererfahrungen zugute - und Ihnen als Leser damit ebenso. Diese Neuauflage wurde durchgehend überarbeitet, aktualisiert und erweitert. Natürlich darf das aktuelle Java 8 nicht fehlen. Verschiedene Kapitel sind Java 8 und seinen Neuerungen gewidmet. Dort wird ein fundierter Einstieg in die umfangreichen Erweit...

Development of renewable energy sources in Germany 2014. Charts and figures based on statistical data from the working group on renewable energy-statistics (AGEE-Stat); Entwicklung der erneuerbaren Energien in Deutschland im Jahr 2014. Grafiken und Diagramme unter Verwendung aktueller Daten der Arbeitsgruppe Erneuerbare Energien-Statistik (AGEE-Stat)

Energy Technology Data Exchange (ETDEWEB)

Nieder, Thomas; Bickel, Peter; Musiol, Frank (comps.) [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany)

2015-12-15

The more than 30 diagrams and graphs describe the development of the importance of renewable energy in Germany by the year 2014. Also, discusses the development of avoided greenhouse emissions through renewable energies, as well as the investments and their economic impulses for Germany. Some technical terms are conclusively explained in a glossary. [German] Die mehr als 30 Diagramme und Graphiken beschreiben die Entwicklung der Bedeutung der erneuerbaren Energien fuer Deutschland bis zum Jahr 2014. Auch wird auf die Entwicklung der vermiedenen Treibhaus-Emissionen durch erneuerbare Energien, sowie die Investitionen und deren wirtschaftlichen Impulse fuer Deutschland eingegangen. Einige Fachbegriffe werden abschliessend in einem Glossar erlaeutert.

SNR in ultrasonic pluse compression using Golay codes

International Nuclear Information System (INIS)

Kim, Young Hwan; Kim, Young Gil; Jeong, Peter

1994-01-01

The conventional ultrasonic flaw detection system uses a large amplitude narrow pulse to excite a transducer, however, these systems are limited in average transmit power. An excessively large amplitude causes a dielectric breakage of the transducer, and an excessively long pulse cuases decrease of the resolution. Using the pulse compression, a long pulse of psudorandom signal can be used without sacrificing resolution by signal correlation. In the present work, the pulse compression technique was utilized to the ultrasonic system. Golay code was used as a psudorandom signal in this system, since pair sum of auto-correlations has not sidelobe. The equivalent input pulse of the Golay code was proposed to analyze the pulse compression system. In experiment, the material type, material thickness and code length were considered. As results, pulse compression system considerably reduced system's white noise, and approximately 30 dB improvement in SNR was obtained over the conventional ultrasonic system. The technique seems to perform particularly well with highly energy-absorbent materials such as polymers, plastics and rubbers.

Study of the containment system of the planned SNR-2 Fast Breeder Reactor

International Nuclear Information System (INIS)

Bunz, H.; Scholle, U.

1979-01-01

Research is presented concerning the behaviour of four possible containment concepts for the planned Fast Breeder Reactor SNR-2 under the conditions of a HCDA. Detailed descriptions and calculations are given dealing with the acceptable leakages and the filter loads reached. The transport of the aerosol-type as well as the gaseous activity through the different compartments into the environment is calculated and from this the resulting accident doses. To cover the uncertainties of the accident course a wide range of accident parameters is examined

Molecular imaging techniques in magnetic resonance imaging and nuclear imaging; Molekulare Bildgebung in der Magnetresonanztomographie und der Nuklearmedizin

Energy Technology Data Exchange (ETDEWEB)

Hoegemann, D.; Basilion, J.P.; Weissleder, R. [Center for Molecular Imaging Research, Massachusetts General Hospital, Charleston, MA (United States)

2001-02-01

The identification of genetic and biochemical changes allows a more conclusive characterization and classification of disease. Up to now this information is mostly obtained through in vitro analysis after resection or biopsy by immunohistopathology and molecular biology. There is a definite need for non-invasive detection and repeated monitoring of such changes in experimental research as well as in clinical trials. Therefore, it is necessary to develop radiological imaging techniques that not only visualize morphologic and physiologic alterations, but track genetic and biochemical processes. This short review reports some of the various ongoing research projects that address this problem and provide some very promising approaches. (orig.) [German] Die Bestimmung genetischer und biochemischer Veraenderungen erlaubt in zunehmendem Masse die eindeutige Charakterisierung und Klassifikation von Erkrankungen. Bisher ist hierzu in der Regel eine gezielte immunohistopathologische oder molekularbiologische In-vitro-Analyse nach Resektion oder Entnahme einer Biopsie erforderlich. In der experimentellen Forschung wie auch in der klinischen Anwendung sind bildgebende Verfahren wuenschenswert, die eine nichtinvasive Detektion und ein wiederholt durchfuehrbares Monitoring gewaehrleisten. Aus diesem Grunde ist die Entwicklung radiologischer Untersuchungsmethoden erforderlich, die ueber die morphologischen und physiologischen Veraenderungen hinaus eine Beurteilung der genetischen und biochemischen Vorgaenge ermoeglichen. In diesem kurzen Uebersichtsartikel werden einige der zahlreichen aktuellen Forschungsprojekte zusammengefasst, die sich mit diesem Problem beschaeftigen und inzwischen aussichtsreiche Techniken zur Verfuegung stellen. (orig.)

Large-area NbN superconducting nanowire avalanche photon detectors with saturated detection efficiency

Science.gov (United States)

Murphy, Ryan P.; Grein, Matthew E.; Gudmundsen, Theodore J.; McCaughan, Adam; Najafi, Faraz; Berggren, Karl K.; Marsili, Francesco; Dauler, Eric A.

2015-05-01

Superconducting circuits comprising SNSPDs placed in parallel—superconducting nanowire avalanche photodetectors, or SNAPs—have previously been demonstrated to improve the output signal-to-noise ratio (SNR) by increasing the critical current. In this work, we employ a 2-SNAP superconducting circuit with narrow (40 nm) niobium nitride (NbN) nanowires to improve the system detection efficiency to near-IR photons while maintaining high SNR. Additionally, while previous 2-SNAP demonstrations have added external choke inductance to stabilize the avalanching photocurrent, we show that the external inductance can be entirely folded into the active area by cascading 2-SNAP devices in series to produce a greatly increased active area. We fabricated series-2-SNAP (s2-SNAP) circuits with a nanowire length of 20 μm with cascades of 2-SNAPs providing the choke inductance necessary for SNAP operation. We observed that (1) the detection efficiency saturated at high bias currents, and (2) the 40 nm 2-SNAP circuit critical current was approximately twice that for a 40 nm non-SNAP configuration.

Wildnisbildung als Möglichkeit zur Professionalisierung zukünftiger Geographielehrer/innen – ein neuer Ansatz zur Bildung für nachhaltige Entwicklung?. GW-Unterricht|GW-Unterricht 142/143|

OpenAIRE

Lindau, Anne-Kathrin; Hottenroth, Daniela; Lindner, Martin

2016-01-01

Der in den deutschen Nationalparken seit mehreren Jahren thematisierte und praktizierte Ansatz der Wildnisbildung stellt möglicherweise einen neuen Zugang zur Bildung für nachhaltige Entwicklung (BNE) in der universitären Lehrer/innenbildung im Fach Geographie dar. Am Beispiel des DBU-geförderten Projektes „Wildnis macht stark“ wird eine Konzeption für die Umsetzung von Wildnisbildung im Rahmen des Geographie-Lehramtsstudiums vorgestellt und mit ersten Forschungsergebnissen zur Wirksamkeit in...

Development of new layer systems for sliding bearings under high mechanical and tribological stress. Final report; Entwicklung neuer Schichtsysteme fuer den Einsatz bei mechanisch-tribologisch hochbeanspruchten Gleitlagern. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Mathias, M.; Herrmann, B.

1995-12-31

The report describes the sputtering technique as a coating method for sliding bearings of high-speed diesel engines. The project aimed at the development of a heavy-duty, wear-resistant sputtered layer on a copper-lead basis for sliding bearings. (HW) [Deutsch] Es wird berichtet ueber die Einfuehrung der Sputtertechnik als Beschichtungsverfahren fuer Gleitlager fuer schnell laufende Dieselmotoren. Ziel des Projektes war die Entwicklung einer hochbelastbaren, verschleissfesten Gleitlager-Sputterschicht auf Kupfer-Blei-Basis. (HW)

The Fast Breeder SNR 300 in the ups and downs of its history

International Nuclear Information System (INIS)

Marth, W.

1992-03-01

The Fast Breeder Project was founded in 1960 at Karlsruhe. After an initial period of basic research, the industry took over the design of SRN 300. Affected by various political influences, the construction of the nuclear power plant Kalkar was disturbed and delayed, but was finally completed in 1985. However, since the governing party of Nordrhein-Westfalen decided to drop out of nuclear energy, the authorisation for starting up the SNR 300 could not be obtained. Therefore, the Kalkar project was cancelled for political reasons in March 1991. (orig.) [de

Combining parallel detection of proton echo planar spectroscopic imaging (PEPSI) measurements with a data-consistency constraint improves SNR.

Science.gov (United States)

Tsai, Shang-Yueh; Hsu, Yi-Cheng; Chu, Ying-Hua; Kuo, Wen-Jui; Lin, Fa-Hsuan

2015-12-01

One major challenge of MRSI is the poor signal-to-noise ratio (SNR), which can be improved by using a surface coil array. Here we propose to exploit the spatial sensitivity of different channels of a coil array to enforce the k-space data consistency (DC) in order to suppress noise and consequently to improve MRSI SNR. MRSI data were collected using a proton echo planar spectroscopic imaging (PEPSI) sequence at 3 T using a 32-channel coil array and were averaged with one, two and eight measurements (avg-1, avg-2 and avg-8). The DC constraint was applied using a regularization parameter λ of 1, 2, 3, 5 or 10. Metabolite concentrations were quantified using LCModel. Our results show that the suppression of noise by applying the DC constraint to PEPSI reconstruction yields up to 32% and 27% SNR gain for avg-1 and avg-2 data with λ = 5, respectively. According to the reported Cramer-Rao lower bounds, the improvement in metabolic fitting was significant (p < 0.01) when the DC constraint was applied with λ ≥ 2. Using the DC constraint with λ = 3 or 5 can minimize both root-mean-square errors and spatial variation for all subjects using the avg-8 data set as reference values. Our results suggest that MRSI reconstructed with a DC constraint can save around 70% of scanning time to obtain images and spectra with similar SNRs using λ = 5. Copyright © 2015 John Wiley & Sons, Ltd.

Activities with regard to research and development of technics for SNR 300 reactor vessel in-service inspection procedures

International Nuclear Information System (INIS)

Hoeller, K.; Kirchner, G.; Menck, J.

1980-01-01

During the development of SNR 300 in-service inspection equipment, several branches were tested by experiment. In this report special steps for testing of manipulation systems and additional engineering equipment for control systems, such as coupling fluid circuit or camera cooling system are considered more in detail

Joint volumetric extraction and enhancement of vasculature from low-SNR 3-D fluorescence microscopy images.

Science.gov (United States)

Almasi, Sepideh; Ben-Zvi, Ayal; Lacoste, Baptiste; Gu, Chenghua; Miller, Eric L; Xu, Xiaoyin

2017-03-01

To simultaneously overcome the challenges imposed by the nature of optical imaging characterized by a range of artifacts including space-varying signal to noise ratio (SNR), scattered light, and non-uniform illumination, we developed a novel method that segments the 3-D vasculature directly from original fluorescence microscopy images eliminating the need for employing pre- and post-processing steps such as noise removal and segmentation refinement as used with the majority of segmentation techniques. Our method comprises two initialization and constrained recovery and enhancement stages. The initialization approach is fully automated using features derived from bi-scale statistical measures and produces seed points robust to non-uniform illumination, low SNR, and local structural variations. This algorithm achieves the goal of segmentation via design of an iterative approach that extracts the structure through voting of feature vectors formed by distance, local intensity gradient, and median measures. Qualitative and quantitative analysis of the experimental results obtained from synthetic and real data prove the effcacy of this method in comparison to the state-of-the-art enhancing-segmenting methods. The algorithmic simplicity, freedom from having a priori probabilistic information about the noise, and structural definition gives this algorithm a wide potential range of applications where i.e. structural complexity significantly complicates the segmentation problem.

FERMI LARGE AREA TELESCOPE DISCOVERY OF GeV GAMMA-RAY EMISSION FROM THE VICINITY OF SNR W44

Energy Technology Data Exchange (ETDEWEB)

Uchiyama, Yasunobu; Funk, Stefan; Katsuta, Junichiro [SLAC National Accelerator Laboratory, 2575 Sand Hill Road M/S 29, Menlo Park, CA 94025 (United States); Katagiri, Hideaki [College of Science, Ibaraki University, 2-1-1, Bunkyo, Mito 310-8512 (Japan); Lemoine-Goumard, Marianne [Centre d' Etudes Nucleaires de Bordeaux Gradignan, Universite Bordeaux 1, CNRS/IN2p3, 33175 Gradignan (France); Tajima, Hiroyasu; Tanaka, Takaaki [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Torres, Diego F., E-mail: uchiyama@slac.stanford.edu [Institut de Ciencies de l' Espai (IEEE-CSIC), Campus UAB, 08193 Barcelona (Spain)

2012-04-20

We report the detection of GeV {gamma}-ray emission from the molecular cloud complex that surrounds the supernova remnant (SNR) W44 using the Large Area Telescope on board Fermi. While the previously reported {gamma}-ray emission from SNR W44 is likely to arise from the dense radio-emitting filaments within the remnant, the {gamma}-ray emission that appears to come from the surrounding molecular cloud complex can be ascribed to the cosmic rays (CRs) that have escaped from W44. The non-detection of synchrotron radio emission associated with the molecular cloud complex suggests the decay of {pi}{sup 0} mesons produced in hadronic collisions as the {gamma}-ray emission mechanism. The total kinetic energy channeled into the escaping CRs is estimated to be W{sub esc} {approx} (0.3-3) Multiplication-Sign 10{sup 50} erg, in broad agreement with the conjecture that SNRs are the main sources of Galactic CRs.

SNR and BER Models and the Simulation for BER Performance of Selected Spectral Amplitude Codes for OCDMA

Directory of Open Access Journals (Sweden)

Abdul Latif Memon

2014-01-01

Full Text Available Many encoding schemes are used in OCDMA (Optical Code Division Multiple Access Network but SAC (Spectral Amplitude Codes is widely used. It is considered an effective arrangement to eliminate dominant noise called MAI (Multi Access Interference. Various codes are studied for evaluation with respect to their performance against three noises namely shot noise, thermal noise and PIIN (Phase Induced Intensity Noise. Various Mathematical models for SNR (Signal to Noise Ratios and BER (Bit Error Rates are discussed where the SNRs are calculated and BERs are computed using Gaussian distribution assumption. After analyzing the results mathematically, it is concluded that ZCC (Zero Cross Correlation Code performs better than the other selected SAC codes and can serve larger number of active users than the other codes do. At various receiver power levels, analysis points out that RDC (Random Diagonal Code also performs better than the other codes. For the power interval between -10 and -20 dBm performance of RDC is better ZCC. Their lowest BER values suggest that these codes should be part of an efficient and cost effective OCDM access network in the future.

Physical characteristic of brown algae (Phaeophyta from madura strait as irreversible hydrocolloid impression material

Directory of Open Access Journals (Sweden)

Prihartini Widiyanti

2012-09-01

Full Text Available Background: Brown algae is a raw material for producing natrium alginates. One type of brown algae is Sargassum sp, a member of Phaeophyta division. Sargassum sp could be found in Madura strait Indonesia. Natrium alginate can be extracted from Sargassum sp. The demand of alginate in Indonesia is mainly fulfilled from abroad, meanwhile Sargassum sp is abundantly available. Purpose: The purpose of study were to explore the potency of brown alga Sargassum sp from Madura strait as hydrocolloid impression material and to examine its physical characteristic. Methods: The methods of research including extraction natrium alginate from Sargassum sp, synthesis of dental impression material and the test of porosity, density, viscosity, and water content of impression material which fulfilled the standard of material used in clinical application in dentistry. Results: Extraction result of Sargassum sp was natrium alginate powder with cream colour, odorless, and water soluble. The water content of natrium alginate was 21.64% and the viscosity was 0.7 cPs. The best porosity result in the sample with the addition of trinatrium phosphate 4% was 3.61%. Density value of impression material was 3 gr/cm3. Conclusion: The research suggested that brown algae Sargassum sp from Madura strait is potential as hydrocolloid impression material, due to its physical properties which close to dental impression material, but still need further research to optimize the physical characteristic.Latar belakang: Alga coklat adalah sumber bahan baku material natrium alginat. Salah satu jenis alga coklat adalah Sargassum sp yang merupakan anggota divisi Phaeophyta. Sargassum sp dapat ditemukan di Selat Madura Indonesia. Natrium alginat dapat diekstraksi dari Sargassum sp. Kebutuhan akan bahan ini di Indonesia sebagian besar dipenuhi dari impor, padahal ketersediaan Sargassum sp di Indonesia sangat melimpah. Tujuan: Penelitian ini bertujuan untuk mengeksplorasi potensi alga coklat

DISCOVERY OF TeV GAMMA-RAY EMISSION TOWARD SUPERNOVA REMNANT SNR G78.2+2.1

Energy Technology Data Exchange (ETDEWEB)

Aliu, E. [Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States); Archambault, S. [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Arlen, T.; Aune, T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Bird, R.; Cannon, A.; Collins-Hughes, E. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Bouvier, A. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Bradbury, S. M. [School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT (United Kingdom); Byrum, K. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Cesarini, A.; Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Cui, W. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Duke, C., E-mail: amandajw@iastate.edu [Department of Physics, Grinnell College, Grinnell, IA 50112-1690 (United States); and others

2013-06-20

We report the discovery of an unidentified, extended source of very-high-energy gamma-ray emission, VER J2019+407, within the radio shell of the supernova remnant SNR G78.2+2.1, using 21.4 hr of data taken by the VERITAS gamma-ray observatory in 2009. These data confirm the preliminary indications of gamma-ray emission previously seen in a two-year (2007-2009) blind survey of the Cygnus region by VERITAS. VER J2019+407, which is detected at a post-trials significance of 7.5 standard deviations in the 2009 data, is localized to the northwestern rim of the remnant in a region of enhanced radio and X-ray emission. It has an intrinsic extent of 0.23 Degree-Sign .23 {+-} 0. Degree-Sign 03{sub stat-0 Degree-Sign .02sys}{sup +0 Degree-Sign .04} and its spectrum is well-characterized by a differential power law (dN/dE = N{sub 0} Multiplication-Sign (E/TeV){sup -{Gamma}}) with a photon index of {Gamma} = 2.37 {+-} 0.14{sub stat} {+-} 0.20{sub sys} and a flux normalization of N{sub 0} = 1.5 {+-} 0.2{sub stat} {+-} 0.4{sub sys} Multiplication-Sign 10{sup -12} photon TeV{sup -1} cm{sup -2} s{sup -1}. This yields an integral flux of 5.2 {+-} 0.8{sub stat} {+-} 1.4{sub sys} Multiplication-Sign 10{sup -12} photon cm{sup -2} s{sup -1} above 320 GeV, corresponding to 3.7% of the Crab Nebula flux. We consider the relationship of the TeV gamma-ray emission with the GeV gamma-ray emission seen from SNR G78.2+2.1 as well as that seen from a nearby cocoon of freshly accelerated cosmic rays. Multiple scenarios are considered as possible origins for the TeV gamma-ray emission, including hadronic particle acceleration at the SNR shock.

Summary of results for the SNEAK-9 series of critical experiments and conclusions for the accuracy of predicted physics parameters of the SNR-300

International Nuclear Information System (INIS)

Helm, F.

1978-08-01

In a series of critical assembles in SNEAK physics parameters of interest for the prototype fast reactor SNR-300 were investigated and compared to the results of calculations. Since a complete mock-up of the SNR-300 was not possible with the material supply available the measurements were performed in three different assemblies, each being adapted to the investigation of a particular set of problems. Work was concentrated on the following quantities: criticality, breeding ratio, Na-void effect, control rod worths and power distribution. The calculation were performed using the diffusion and transport methods available at KFK and as a data basis the KFKINER cross section set. Detailed descriptions of the assemblies, the majority of the results and extensive discussions of the experimental and calculational methods used can be found in separate KFK reports about each assembly which were already published. This report contains a summary of the results for each quantity investigated including a basic account of the methods used, and an evaluation of the significance of these data for the prediction of parameters of the SNR-300. (orig.) 891 RW [de

Comparison of ANL containment codes with SNR-300 simulation experiments

International Nuclear Information System (INIS)

Marchertas, A.H.; Wang, C.Y.; Fistedis, S.H.

1976-01-01

A comparison of REXCO and ICECO code predictions is made with data obtained from experiments of LMFBR excursion models. The comparisons are based on published results of tests conducted for the safety analysis of the SNR-300 fast breeder. The test configurations consist of a centrally located spherical source immersed in a pool of water which is encased in a cylindrical container. The cylinical walls of the container are prestressed by holddown bolts which span the two rigid ends. The space above the surface of the water within the container is occupied by air. Although certain aspects of the tests could not be simulated by the analytical models exactly, the comparison of results shows quite close agreement. The fact that the REXCO and ICECO codes involve different analytical formulations, their own close correspondence of results lends added credence to the value of analytical predictions

Physiological and technical limitations of functional magnetic resonance imaging (fMRI) - consequences for clinical use; Physiologische und technische Grenzen der funktionellen Magnetresonanztomographie und die damit verbundenen Konsequenzen fuer die klinische Anwendung

Energy Technology Data Exchange (ETDEWEB)

Wuestenberg, T. [Neurologische Klinik der Charite, Humboldt-Universitaet Berlin (Germany); Neurologische Klinik der Charite, Humboldt-Universitaet Berlin, Schumannstrasse 20/21, 10117, Berlin (Germany); Jordan, K. [Institut fuer Psychologie II, Otto-von-Guericke-Universitaet Magdeburg (Germany); Giesel, F.L. [Abteilung fuer onkologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum Heidelberg (Germany); Villringer, A. [Neurologische Klinik der Charite, Humboldt-Universitaet Berlin (Germany)

2003-07-01

Functional magnetic resonance imaging (fMRI) is the most common noninvasive technique in functional neuroanatomy. The capabilities and limitations of the method will be discussed based on a short review of the current knowledge about the neurovascular relationship. The focus of this article is on current methodical and technical problems regarding fMRI-based detection and localization of neuronal activity. Main error sources and their influence on the reliability and validity of fMRI-methods are presented. Appropriate solution strategies will be proposed and evaluated. Finally, the clinical relevance of MR-based diagnostic methods are discussed. (orig.) [German] Die funktionelle Magnetresonanztomographie (fMRT) ist eines der wichtigsten Verfahren der funktionellen Neuroanatomie. Aufbauend auf einer kurzen Darstellung des aktuellen Wissensstands bzgl. des Zusammenhangs zwischen lokaler neuronaler Aktivitaet und haemodynamischer Reaktion werden ausgewaehlte Moeglichkeiten und Grenzen des Verfahrens fuer die klinische Anwendung diskutiert. Der Schwerpunkt liegt dabei auf der Darstellung der derzeitigen methodischen und technischen Einschraenkungen hinsichtlich einer fMRT-basierten Detektion und Lokalisierung neuronaler Aktivitaet. Es werden die Hauptfehlerquellen und ihre Auswirkungen auf die Reliabilitaet und Validitaet des Verfahrens erlaeutert und aktuelle Loesungsansaetze diskutiert. Abschliessend erfolgt eine Bewertung der aktuellen klinischen Relevanz funktioneller MR-Diagnosemethoden. (orig.)

Performance of the split-symbol moments SNR estimator in the presence of inter-symbol interference

Science.gov (United States)

Shah, B.; Hinedi, S.

1989-01-01

The Split-Symbol Moments Estimator (SSME) is an algorithm that is designed to estimate symbol signal-to-noise ratio (SNR) in the presence of additive white Gaussian noise (AWGN). The performance of the SSME algorithm in band-limited channels is examined. The effects of the resulting inter-symbol interference (ISI) are quantified. All results obtained are in closed form and can be easily evaluated numerically for performance prediction purposes. Furthermore, they are validated through digital simulations.

The Association of PSR B1757-24 and the SNR G5.4-1.2

Science.gov (United States)

Gvaramadze, V. V.

The association of PSR B1757-24 and the supernova remnant (SNR) G5.4-1.2 was recently questioned by Thorsett et al. (2002) on the basis of proper motion measurements of the pulsar and the "incorrect" orientation of the vector of pulsar transverse velocity (inferred from the orientation of the cometary-shaped pulsar wind nebula). We show, however, that the association could be real if both objects are the remnants of an off-centered cavity supernova explosion.

Corrosion and deposition behaviour of 60Co and 54Mn in the SNR mockup loop for the primary sodium system

International Nuclear Information System (INIS)

Menken, G.; Reichel, H.

1976-01-01

The SNR corrosion mockup loop, simulating the SNR primary system is described. The influence of hydraulic conditions and temperature on the deposition behaviour is studied. γ-spectroscopy measurements at the pipe-work and removable samples allowed to determine the distribution of radioactive corrosion products in the loop and by-pass system. The release rate of Mn 54 could be reduced by a factor of 3 by decreasing the cold trap temperature from 165 0 C to 105 0 C while the Co 60 release rate could be reduced by a factor of 14, respectively. High temperature loop sections (873K) representing 13% of the loop surface absorbed 50-60% of the released Co 60 and only 8 - 18% of the Mn 54. The cold trap absorbed not more than 1% of the Co 60 and 10% of the Mn 54 inventory. (author)

High resolution MR imaging of the anal sphincter using an intravaginal surface coil; Hochaufloesende Magnetresonanztomographie des Analsphinkters mit einer intravaginalen Oberflaechenspule

Energy Technology Data Exchange (ETDEWEB)

Mueller-Schimpfle, M. [Radiologische Klinik, Abt. fuer Radiologische Diagnostik, Tuebingen Univ. (Germany); Franz, H. [Frauenklinik, Tuebingen Univ. (Germany); Lobinger, B. [Radiologische Klinik, Abt. fuer Radiologische Diagnostik, Tuebingen Univ. (Germany); Claussen, C.D. [Radiologische Klinik, Abt. fuer Radiologische Diagnostik, Tuebingen Univ. (Germany)

1995-06-01

MR imaging was performed using a 1.0 T unit. In 10 females (6 nullipara, one primipara without and three primipara with postpartum faecal incontinence) a surface coil, originally designed for endorectal use, was placed into the vagina. Transverse oblique T{sub 1}-weighted spin echo and double echo turbo spin echo sequences with T{sub 2}- and proton density-weighting were acquired parallel to the puborectal, rectococcygeal and anorectal planes. Three readers analysed the images in consensus. The anatomic structures of the external and internal sphincter as well as the mucosa were differentiated in all cases with a good contrast. The best results were yielded by the proton density weighting. In one case of faecal incontinence a sphincter defect after repair of a complete rupture of the anal sphincter was shown. In another case irregularities in the structure of the external sphincter and perineum were visualised. (orig./MG) [Deutsch] Die Magnetresonanztomographie (MRT) wurde an einem 1,0-Tesla-Geraet durchgefuehrt. Bei 10 Frauen (6 Nulliparae, eine Primipara ohne und drei Primiparae mit postpartaler Stuhlinkontinenz) wurde eine Oberflaechenspule, die urspruenglich zur endorektalen Anwendung konzipiert war, intravaginal eingefuehrt. Es wurden T{sub 1}-gewichtete Spin-Echo-Sequenzen sowie Doppel-Echo-Turbo-Spin-Echo-Sequenzen mit T{sub 2}- und Protonendichtegewichtung parallel zur puborektalen, rektokokzygealen und anorektalen Ebene akquiriert. Drei Auswerter analysierten die Aufnahmen im Konsensmodus. Die anatomischen Strukturen des Musculus sphincter ani externus und internus sowie die Mukosa konnten in allen Faellen gut differenziert werden. Das beste Ergebnis wurde mit der Protonendichte-Gewichtung erzielt. In einem Fall von Stuhlinkontinenz zeigte sich ein kombinierter Defekt des M. sphincter ani internus und externus nach Naht eines Dammrisses III. Grades. In einem weiteren Fall waren Irregularitaeten im Perineum und externen Sphinkteranteil darzustellen. (orig./MG)

Bellows for the DEBENE SNR-Project

International Nuclear Information System (INIS)

Warmerdam, C.P.; Lievense, K.

1980-01-01

Liquid Metal cooled Fast Breeder Reactors (LMFBR) are designed to work at temperature levels up to 600 deg C. The components and piping systems are submitted to changing temperature fields varying between room temperature and temperatures in operational, incidental or accidental conditions. Bellows are generally used to introduce a higher flexibility of piping systems and for the leak tight connection of components with relative displacements. The total piping length of a loop type LMFBR is principally determined by thermal expansion requirements. The application of bellows could reduce piping length and building volume. In certain cases a reduction of the nozzle loads can be realized. In cooperation between Neratoom and TNO a feasibility study concerning the applicability of bellows as compensating elements in a primary piping system of a loop type LMFBR has been studied. Different configurations are compared with each other. TNO has performed dimension calculations, with the criteria from the ASME Code Section III and Code Case N-47, as guideline. In this paper a review of the results of these calculations will be given. The development of the expansion bellows, in the shells of the SNR 300 straight tube steam generators to compensate the difference in the thermal expansion between shell and tube bundle, has been concluded by a series of full scale fatigue tests under design conditions, except for the sodium environment. In this paper a summary is given of these tests and of the procedure used to prove that the bellows in the actual steam generators will withstand the design fatigue loads. (This is the LMFBR project of the DEBENE states: Federal Republic of Germany, Belgium and The Netherlands)

Enhancing the efficiency of constrained dual-hop variable-gain AF relaying under nakagami-m fading

KAUST Repository

Zafar, Ammar

2014-07-01

This paper studies power allocation for performance constrained dual-hop variable-gain amplify-and-forward (AF) relay networks in Nakagami- $m$ fading. In this context, the performance constraint is formulated as a constraint on the end-to-end signal-to-noise-ratio (SNR) and the overall power consumed is minimized while maintaining this constraint. This problem is considered under two different assumptions of the available channel state information (CSI) at the relays, namely full CSI at the relays and partial CSI at the relays. In addition to the power minimization problem, we also consider the end-to-end SNR maximization problem under a total power constraint for the partial CSI case. We provide closed-form solutions for all the problems which are easy to implement except in two cases, namely selective relaying with partial CSI for power minimization and SNR maximization, where we give the solution in the form of a one-variable equation which can be solved efficiently. Numerical results are then provided to characterize the performance of the proposed power allocation algorithms considering the effects of channel parameters and CSI availability. © 2014 IEEE.

A Comprehensive Lighting Configuration for Efficient Indoor Visible Light Communication Networks

Directory of Open Access Journals (Sweden)

Thai-Chien Bui

2016-01-01

Full Text Available Design of an efficient indoor visible light communication (VLC system requires careful considerations on both illumination and communication aspects. Besides fundamental factors such as received power and signal-to-noise ratio (SNR level, studies on mobility scenarios and link switching process must be done in order to achieve good communication link quality in such systems. In this paper, a comprehensive lighting configuration for efficient indoor VLC systems for supporting mobility and link switching with constraint on illumination, received power, and SNR is proposed. Full connectivity in mobility scenarios is required to make the system more practical. However, different from other literatures, our work highlights the significance of recognizing the main influences of field of view angle on the connectivity performance in the practical indoor scenarios. A flexible link switching initiation algorithm based on the consideration of relative received power with adaptive hysteresis margin is demonstrated. In this regard, we investigate the effect of the overlap area between two light sources with respect to the point view of the receiver on the link switching performance. The simulation results show that an indoor VLC system with sufficient illumination level and high communication link quality as well as full mobility and support link switching can be achieved using our approach.

Reduction of energy consumption and reduction of galvanisation fluid loss by means of innovative galvanisation drums made of novel materials and with novel geomentries. Final report; Senkung des Energieverbrauches und Verringerung der Galvanisierbadverschleppung durch die Entwicklung von innovativen Galvanisiertrommeln aus neuen Werkstoffen mit neuer Geometrie. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Tscherwitschke, R.

2003-09-01

The project intended to develop a galvanizing drum with higher efficiency (30 percent) without inducing limitations, either by reducing the exposure time at identical energy consumption or by permitting a higher coating rate at higher energy consumption. Developments during the last 50 years have been unsatisfactory in this field. (orig.) [German] Ziel des Projektes war, eine Galvanisiertrommel zu entwickeln, die ohne sonstige Einschraenkung eine signifikante Leistungssteigerung erbringt, konkret bei gleichem Energie-Einsatz (V x A) die Expositionszeit beim Galvanisierprozess reduziert oder bei gleichem Energie-Einsatz ein groesseres Warenvolumen mit der gleichen Schichtdicke, galvanisch beschichtet. Angestrebte Effizienzsteierung war 30%. In der gleichen Groessenordnung sollte eine Energieeinsparung einhergehen. In den letzten 50 Jahren gab es nur eine Entwicklung in diese Richtung, die sich aus einer Reihe von Gruenden nicht dauerhaft durchgesetzt hat. (orig.)

Boosting the SNR by adding a receive-only endorectal monopole to an external antenna array for high-resolution, T2 -weighted imaging of early-stage cervical cancer with 7-T MRI

NARCIS (Netherlands)

van Kalleveen, I.M.L.; Hoogendam, J.P.; Raaijmakers, A.J.E.; Visser, F.; Arteaga de Castro, C.S.; Verheijen, R.H.M.; Luijten, P.R.; Zweemer, R.P.; Veldhuis, W.B.; Klomp, D.W.J.

The aim of this study was to investigate the signal-to-noise ratio (SNR) gain in early-stage cervical cancer at ultrahigh-field MRI (e.g. 7 T) using a combination of multiple external antennas and a single endorectal antenna. In particular, we used an endorectal monopole antenna to increase the SNR

Energy supply with growing energy efficiency - the energy supply companies as driving force for rational energy use?; Energieversorgung bei wachsender Energieeffizienz - die Energieversorgungsunternehmen als Motor rationeller Energieverwendung?

Energy Technology Data Exchange (ETDEWEB)

Grawe, J. [Vereinigung Deutscher Elektrizitaetswerke VDEW e.V., Frankfurt am Main (Germany); Schulz, E. [Vereinigung Deutscher Elektrizitaetswerke VDEW e.V., Frankfurt am Main (Germany)

1996-09-23

The authors explain that growing energy efficiency was and is the positive prerequisite for the development of the electricity supply industry. They show that the business-oriented use of the concept of integrated resource planning by economic enterprises can improve energy efficiency and thus contribute towards mastering future demands and challenges. With the eta-initiative for energy rationalism the German electricity suppliers also intend to continue being motors of energy efficiency. (orig.) [Deutsch] Die Verfasser verdeutlichen, dass wachsende Energie-Effizienz positive Voraussetzung fuer die Entwicklung der Elektrizitaetswirtschaft war und ist. Sie arbeiten heraus, dass die unternehmenswirtschaftliche Nutzung des Konzepts der Integrierten Ressourcen-Planung die Energie-Effizienz verbessern und damit dazu beitragen kann, die kuenftigen Anforderungen und Herausforderungen zu meistern. Mit der eta-Initiative fuer Energievernunft wollen die deutschen Stromversorger auch in Zukunft Motor der Energie-Effizienz bleiben. (orig.)

Final report on the development of a disturbanceless NDE compact cooling device; Abschlussbericht zur Entwicklung einer stoerarmen maschinellen NDE-Kompaktkuehlung

Energy Technology Data Exchange (ETDEWEB)

Kaiser, G.

2002-08-13

The project comprised the following aspects: 1. Development of a disturbance-free, mechanized compact cooling system for a NDE measuring system on the basis of a commercial SL200-10 split stirling cooling system of AEG Infrarotmodule GmbH, Heilbronn; 2. Support of the development work at the HTSL/Hall magnetometer of Friedrich-Schiller University, Jena; 3. Measurements of HTSL/Hall magnetometer samples and thermal characterisation. [German] Im Rahmen dieses Vorhabens wurden die folgenden Aufgabenstellungen behandelt: 1. Entwicklung einer stoerarmen, maschinellen Kompaktkuehlung fuer ein NDE-Messsystem auf der Basis eines kommerziellen Split-Stirlingkuehlers SL200-10 der Firma AEG Infrarotmodule GmbH, Heilbronn, 2. Unterstuetzung der Entwicklungsarbeiten am HTSL/Hall-Magnetometer, die bei der Friedrich-Schiller-Universitaet in Jena durchgefuehrt wurden, 3. Messungen an HTSL/Hall-Magnetometer-Proben zu deren thermischer Charakterisierung. (orig.)

Status reports on the development and application of acoustic emission analysis. Proceedings; Statusberichte zur Entwicklung und Anwendung der Schallemissionsanalyse. Beitraege

Energy Technology Data Exchange (ETDEWEB)

NONE

2017-08-01

The colloquium lectures represent the wide range of applications in acoustic emission analysis and testing in the areas of damage development and damage mechanisms, testing of components, condition monitoring, development of new measuring systems and sensors as well as software development regarding locating methods and signal analysis. One focus of the colloquium is on current hardware and software developments for status monitoring by means of AE monitoring. One of the papers was separately analyzed for this database. [German] Die Vortraege des Kolloquiums repraesentieren das breite Spektrum der Anwendungen der Schallemissionsanalyse und -pruefung in den Bereichen der Schadensentwicklung und Schadensmechanismen, Pruefung von Bauteilen, Zustandsueberwachung, Entwicklung neuer Messsysteme und Sensoren sowie Softwareentwicklung bezueglich Ortungsverfahren und Signalanalyse. Ein Schwerpunkt des Kolloquiums betrifft aktuelle Hard- und Softwareentwicklungen zur Zustandsueberwachung durch AE-Monitoring.

Design and operational behaviour of the SNR-reactor fuel element structure

International Nuclear Information System (INIS)

Dietz, W.; Toebbe, H.

1985-01-01

The fuel element and core concept of a fast breeder reactor is described by the example of the SNR 300 (1st core), and the requirements made on the fuel elements with respect to burnup and neutron dose are listed for existing and projected plants. Irradiation experiments carried out and operational experience gained with fuel elements show that the residence time of the fuel elements is influenced mainly by the stability of shape of the fuel element components. The requirements made with reference to neutron loading for future advanced high-performance fuel elements can not be anticipated from the present state of experience. Besides optimization of fuel element design and checking-out of the limits of operation by PFADFINDERELEMENTE elements, R and D work for the improvement of fuel element materials is also necessary. (orig.) [de

PIC simulations of magnetic field production by cosmic rays drifting upstream of SNR shocks

International Nuclear Information System (INIS)

Pohl, M.

2008-01-01

Turbulent magnetic-field amplification appears to operate near the forward shocks of young shell-type SNR. I review the observational constraints on the spatial distribution and amplitude of amplified magnetic field in this environment. I also present new PIC simulations of magnetic-field growth due to streaming cosmic rays. While the nature of the initial linear instability is largely determined by the choice of simulation parameters, the saturation always involves changing the bulk motion of cosmic rays and background plasma, which limits the field growth to amplitudes of a few times that of the homogeneous magnetic field. (author)

PENGIKATAN GARAM EMPEDU OLEH SUSU KEDELAI TERFERMENTASI DAN STABILITASNYA TERHADAP PEPSIN DAN PANKREATIN [Binding of Bile Salts by Fermented Soymilk and Its Stability Against Pepsin and Pancreatin

Directory of Open Access Journals (Sweden)

Yusmarini1*

2013-06-01

Full Text Available Processed soybean products especially the fermented ones have beneficial health effects since they are capable of reducing the level of plasmacholesterol (hypocholesterolemic effect. One of the mechanisms is by increasing the binding of bile salt. This research was aimed to assess the ability of soymilk, fermented soymilk products and fermented soymilk products combined with enzymatic hydrolysis to bind bile salts. The stability of the binding against hydrolysis by digestive enzymes (pepsin and pancreatin was also evaluated. Fermented soybean products inoculated with isolates of L. plantarum 1 R.11.1.2 was be able to bind 1.40 μmol/100 mg protein (62.26% of natrium taurocholate. This binding ability is slightly higher than that of soymilk to natrium taurocholate, i.e.1.33 μmol/100 mg protein (59.04%. Addition of a protease enzyme specific to hydrophobic amino acid (thermolysin on fermented soymilk products was able to enhance the ability of bind natrium taurocholate. Enzymatic hydrolysis products having a molecular weight of <7 kDa could bind 1.51 μmol/100 mg protein natrium taurocholate (67.4%. There was a significant increase in the binding, i.e. 7.9% by the fermented products or an increase of 13.5% from soymilk. Meanwhile peptides measuring ≥7 kDa showed no binding ability against natrium taurocholate.

Energy efficient cooperation in underlay RFID cognitive networks for a water smart home.

Science.gov (United States)

Nasir, Adnan; Hussain, Syed Imtiaz; Soong, Boon-Hee; Qaraqe, Khalid

2014-09-30

Shrinking water resources all over the world and increasing costs of water consumption have prompted water users and distribution companies to come up with water conserving strategies. We have proposed an energy-efficient smart water monitoring application in [1], using low power RFIDs. In the home environment, there exist many primary interferences within a room, such as cell-phones, Bluetooth devices, TV signals, cordless phones and WiFi devices. In order to reduce the interference from our proposed RFID network for these primary devices, we have proposed a cooperating underlay RFID cognitive network for our smart application on water. These underlay RFIDs should strictly adhere to the interference thresholds to work in parallel with the primary wireless devices [2]. This work is an extension of our previous ventures proposed in [2,3], and we enhanced the previous efforts by introducing a new system model and RFIDs. Our proposed scheme is mutually energy efficient and maximizes the signal-to-noise ratio (SNR) for the RFID link, while keeping the interference levels for the primary network below a certain threshold. A closed form expression for the probability density function (pdf) of the SNR at the destination reader/writer and outage probability are derived. Analytical results are verified through simulations. It is also shown that in comparison to non-cognitive selective cooperation, this scheme performs better in the low SNR region for cognitive networks. Moreover, the hidden Markov model's (HMM) multi-level variant hierarchical hidden Markov model (HHMM) approach is used for pattern recognition and event detection for the data received for this system [4]. Using this model, a feedback and decision algorithm is also developed. This approach has been applied to simulated water pressure data from RFID motes, which were embedded in metallic water pipes.

Influence of detector collimation on SNR in four different MDCT scanners using a reconstructed slice thickness of 5 mm

International Nuclear Information System (INIS)

Verdun, F.R.; Pachoud, M.; Monnin, P.; Valley, J.-F.; Noel, A.; Meuli, R.; Schnyder, P.; Denys, A.

2004-01-01

The purpose of this paper is to compare the influence of detector collimation on the signal-to-noise ratio (SNR) for a 5.0 mm reconstructed slice thickness for four multi-detector row CT (MDCT) units. SNRs were measured on Catphan test phantom images from four MDCT units: a GE LightSpeed QX/I, a Marconi MX 8000, a Toshiba Aquilion and a Siemens Volume Zoom. Five-millimetre-thick reconstructed slices were obtained from acquisitions performed using detector collimations of 2.0-2.5 mm and 5.0 mm, 120 kV, a 360 tube rotation time of 0.5 s, a wide range of mA and pitch values in the range of 0.75-0.85 and 1.25-1.5. For each set of acquisition parameters, a Wiener spectrum was also calculated. Statistical differences in SNR for the different acquisition parameters were evaluated using a Student's t-test (P<0.05). The influence of detector collimation on the SNR for a 5.0-mm reconstructed slice thickness is different for different MDCT scanners. At pitch values lower than unity, the use of a small detector collimation to produce 5.0-mm thick slices is beneficial for one unit and detrimental for another. At pitch values higher than unity, using a small detector collimation is beneficial for two units. One manufacturer uses different reconstruction filters when switching from a 2.5- to a 5.0-mm detector collimation. For a comparable reconstructed slice thickness, using a smaller detector collimation does not always reduce image noise. Thus, the impact of the detector collimation on image noise should be determined by standard deviation calculations, and also by assessing the power spectra of the noise. (orig.)

Erkundungen im Spannungsfeld von Pädagogik, Spielspass und technischer Machbarkeit. Gedanken zur Konzeption und Entwicklung spielbasierter digitaler Lernumgebung

Directory of Open Access Journals (Sweden)

Florian Berger

2009-02-01

Full Text Available Computerspiele sind heute aus der digitalen Medienwelt nicht mehr wegzudenken. Ihre rasante technische Entwicklung sowie ihre hohe Akzeptanz in der Jugendkultur werfen Fragen nach pädagogischer Verwertbarkeit dieses Mediums auf. Auf diesem Gebiet besteht Forschungsbedarf: Für den Einsatz aktueller Spielkonzepte als Lehrmittel existieren keine fundierten Theorien oder Konzepte. Der schöpferische Umgang mit Spielen durch Anwender («Emergent Gameplay» bietet hier durch sein hohes Motivationspotential einen vielversprechenden Ansatz. Die oft wenig beachtete Rolle der digitalen Spielen zugrunde liegenden Softwaretechnik sollte stärkere Berücksichtigung finden: Es existiert einerseits ein für die Akzeptanz beim Anwender notwendiges Minimum, andererseits ist der Einsatz des aktuellen technischen «state of the art» für die Umsetzung pädagogischer und didaktischer Ambitionen durch seine enormen Anforderungen wenig zielführend. Im Ergebnis sind Idee und Spielspass das Mass auch für Anwendungen des Game Based Learn­ing.

Evaluation of the signal-to-noise ratio (SNR) in a CR system and establishment of RQR-M and RQA-M IEC reference radiations in mammography

International Nuclear Information System (INIS)

Rosado, Paulo H.G.; Nogueira, Maria S.; Dantas, Marcelino V.A.; Santana, Priscila do C.

2009-01-01

In this work, the radiation condition RQR-M e RQA-M of IEC were established in the Siemens Mammomat 3000 mammography equipment. The standard radiation condition are described in terms of: emitting target of molybdenum, percentage ripple not more that 4%, total filtration of 0,032 ± 0,002 mm of molybdenum and specific values of first half-value layer. The results show that the values of parameters were in the range that the IEC recommends. Only the RQAM-3 the value of CSR was not in agreement of the value recommend, and was necessary a additions of 0,1 mm Al in the x-ray tube. After this, the signal noise ratio (SNR) of de Computer radiography (CR) system was evaluated in the reference qualities of RQR-M e RQA-M. For SNR the RQR-M mode of exposure was done with both the 20 mAs and automatic one. To RQA-M the exposure was done with 100 mAs. The variations of the values of SNR were approximated 4%. The tests were done with CR model CR850 made from Kodak and 40 mm of PMMA. (author)

Efficient resource allocation scheme for visible-light communication system

Science.gov (United States)

Kim, Woo-Chan; Bae, Chi-Sung; Cho, Dong-Ho; Shin, Hong-Seok; Jung, D. K.; Oh, Y. J.

2009-01-01

A visible-light communication utilizing LED has many advantagies such as visibility of information, high SNR (Signal to Noise Ratio), low installation cost, usage of existing illuminators, and high security. Furthermore, exponentially increasing needs and quality of LED have helped the development of visible-light communication. The visibility is the most attractive property in visible-light communication system, but it is difficult to ensure visibility and transmission efficiency simultaneously during initial access because of the small amount of initial access process signals. In this paper, we propose an efficient resource allocation scheme at initial access for ensuring visibility with high resource utilization rate and low data transmission failure rate. The performance has been evaluated through the numerical analysis and simulation results.

Efficient power allocation for fixed-gain amplify-and-forward relaying in rayleigh fading

KAUST Repository

Zafar, Ammar; Radaydeh, Redha Mahmoud; Chen, Yunfei; Alouini, Mohamed-Slim

2013-01-01

-to-end signal-to-noise ratio (SNR) and 2) minimizing the total consumed power while maintaining the end-to-end SNR over a threshold value. We assume that the relays have knowledge of only the channel statistics of all the links. We show that the SNR maximization

Optimum efficiency lidar sensing of multilayer hydrometeors through a turbid atmosphere

Science.gov (United States)

Evgenieva, Ts T.; Gurdev, L. L.

2018-03-01

The detected lidar return power is a basic factor determining the brightness of the detected lidar images and the signal-to-noise ratio (SNR) of a given measurement. At equal other characteristics, the laser radiation wavelength should influence the lidar return signal and assume an optimum value depending on the specificity of the objects investigated. As such a problem had not been considered systematically, we recently began developing a modeling approach to solving it, based on evaluating the mean and the noisy lidar profiles and the SNR profile of the measurement along the lidar line of sight by using the lidar equation and well known realistic models of the atmospheric objects and background. The main purpose of the present work is to estimate by numerical modeling the detectability of the lidar return from different distances and multilayer cirrus clouds, depending on the laser radiation wavelengths. The results obtained confirm the expectations that at a higher atmospheric turbidity, a relatively higher sensing efficiency (return power) is achievable by longer-wavelength laser radiation, within the NIR range.

Suzaku observation of TeV SNR RX J1713.7-3946

International Nuclear Information System (INIS)

Takahashi, Tadayuki; Tanaka, Takaaki; Uchiyama, Yasunobu

2007-01-01

We report on results from Suzaku broadband X-ray observations of the Galactic supernova remnant (SNR) RX J1713.7-3946 with an energy coverage of 0.4-40 keV. With a sensitive hard X-ray measurement from the HXD PIN on board Suzaku, we determine the hard X-ray spectrum in the 12-40 keV range to be described by a power law with photon index Γ=3.2±0.2, significantly steeper than the soft X-ray index of Γ=2.4±0.05 measured previously with ASCA and other missions. We find that a simple power law fails to describe the full spectral range of 0.4-40 keV and instead a cutoff power law with hard index Γ=1.96±0.05 and high energy cutoff ε c =9±1 keV provides an excellent fit over the full bandpass. (author)

Decay heat removal plan of the SNR-300: a licensed concept

International Nuclear Information System (INIS)

Morgenstern, F.H.; Gyr, W.; Stoetzel, H.; Vossebrecker, H.

1976-01-01

The report describes how the decay heat removal plan of the SNR-300 has been established in 3 essential licensing steps, thus giving a very significant example for the slow but steady progress in the overall licensing process of the plant. (1) Introduction of an ECCS in addition to the 3 main heat transfer chains as a back-up for rather unlikely and undefined occurrences, 1970; (2) Experimental and computational demonstration of a reliable functioning of the in-vessel natural convection of the fluid flow, 1974; and (3) Proof of fulfilling the general safety and specific reliability criteria for the overall decay heat removal plan; i.e., the 3 main heat transfer chains with specific installations on the steam/water system side and the ECCS, 1976. Some special problem areas, for instance the cavity concept provided for the pipe fracture accident, have still to be licensed, but they do not contribute considerably to the overall risk

Magnetic resonance imaging of the hand in rheumatoid arthritis. New scientific insights and practical application; Magnetresonanztomographie der Hand bei rheumatoider Arthritis. Wissenschaftliche Ergebnisse und praktische Anwendung

Energy Technology Data Exchange (ETDEWEB)

Hermann, K.G.A. [Charite - Universitaetsmedizin Berlin, Institut fuer Radiologie am Campus Mitte, Berlin (Germany)

2006-05-15

Magnetic resonance imaging (MRI) is a sensitive diagnostic modality for the detection of inflammatory changes in peripheral joints. Nevertheless, the widespread clinical use of MRI in assessing patients with early rheumatoid arthritis is still hampered by the technical complexity and higher cost of MRI compared with conventional radiography. This overview summarizes the results of recent research and gives practical tips on how to perform MRI of the hands. The authors present an MR protocol for hand imaging, discuss the pros and cons of low-field MR scanners, and outline pitfalls and artifacts. The MRI changes associated with rheumatoid arthritis such as synovitis, tenosynovitis, erosions, and bone marrow edema are described including their prognostic significance. The proven facts on the validation and grading of MR changes in rheumatoid arthritis are summarized. Finally, the role of MRI in the differential diagnosis of arthritis is critically discussed. (orig.) [German] Die Magnetresonanztomographie (MRT) ist ein sensitives Verfahren zur Detektion entzuendlicher Veraenderungen der peripheren Gelenke. Den breiten Einsatz der MRT im Fruehstadium der rheumatoiden Arthritis behindern derzeit jedoch der im Vergleich zur konventionellen Roentgendiagnostik hoehere technische Aufwand und vermehrte Kosten. Diese Uebersichtsarbeit fasst wichtige Studienergebnisse zusammen und gibt praktische Hinweise fuer Hand-MRTs. Ein geeignetes Sequenzprotokoll wird vorgestellt, Vor- und Nachteile von Niederfeld-MRTs werden beruecksichtigt, moegliche Fehlerquellen und Artefakte diskutiert. Magnetresonanztomographische Befunde bei rheumatoider Arthritis wie Synovitis, Tenosynovitis, Erosionen und Knochenmarkoedeme werden beschrieben und deren prognostische Bedeutung dargestellt. Gesicherte Fakten zur Validierung und Moeglichkeiten der Graduierung MR-tomographischer Veraenderungen bei rheumatoider Arthritis werden zusammengefasst. Der Nutzen der MRT zur differenzialdiagnostischen

YOUNG REMNANTS OF TYPE Ia SUPERNOVAE AND THEIR PROGENITORS: A STUDY OF SNR G1.9+0.3

International Nuclear Information System (INIS)

Chakraborti, Sayan; Childs, Francesca; Soderberg, Alicia

2016-01-01

SNe Ia, with their remarkably homogeneous light curves and spectra, have been used as standardizable candles to measure the accelerating expansion of the universe. Yet, their progenitors remain elusive. Common explanations invoke a degenerate star (white dwarf) that explodes upon almost reaching the Chandrasekhar limit, by either steadily accreting mass from a companion star or violently merging with another degenerate star. We show that circumstellar interaction in young Galactic supernova remnants can be used to distinguish between these single and double degenerate (DD) progenitor scenarios. Here we propose a new diagnostic, the surface brightness index, which can be computed from theory and compared with Chandra and Very Large Array (VLA) observations. We use this method to demonstrate that a DD progenitor can explain the decades-long flux rise and size increase of the youngest known galactic supernova remnant (SNR), G1.9+0.3. We disfavor a single degenerate scenario for SNR G1.9+0.3. We attribute the observed properties to the interaction between a steep ejecta profile and a constant density environment. We suggest using the upgraded VLA, ASKAP, and MeerKAT to detect circumstellar interaction in the remnants of historical SNe Ia in the Local Group of galaxies. This may settle the long-standing debate over their progenitors

YOUNG REMNANTS OF TYPE Ia SUPERNOVAE AND THEIR PROGENITORS: A STUDY OF SNR G1.9+0.3

Energy Technology Data Exchange (ETDEWEB)

Chakraborti, Sayan; Childs, Francesca; Soderberg, Alicia, E-mail: schakraborti@post.harvard.edu [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2016-03-01

SNe Ia, with their remarkably homogeneous light curves and spectra, have been used as standardizable candles to measure the accelerating expansion of the universe. Yet, their progenitors remain elusive. Common explanations invoke a degenerate star (white dwarf) that explodes upon almost reaching the Chandrasekhar limit, by either steadily accreting mass from a companion star or violently merging with another degenerate star. We show that circumstellar interaction in young Galactic supernova remnants can be used to distinguish between these single and double degenerate (DD) progenitor scenarios. Here we propose a new diagnostic, the surface brightness index, which can be computed from theory and compared with Chandra and Very Large Array (VLA) observations. We use this method to demonstrate that a DD progenitor can explain the decades-long flux rise and size increase of the youngest known galactic supernova remnant (SNR), G1.9+0.3. We disfavor a single degenerate scenario for SNR G1.9+0.3. We attribute the observed properties to the interaction between a steep ejecta profile and a constant density environment. We suggest using the upgraded VLA, ASKAP, and MeerKAT to detect circumstellar interaction in the remnants of historical SNe Ia in the Local Group of galaxies. This may settle the long-standing debate over their progenitors.

Sustainable development - theory and practice of environmental consulting. Proceedings of a seminar of Zentrale Informationsstelle Umweltberatung Bayern. Vol. 11; Nachhaltige Entwicklung - Theorie und Praxis fuer die Umweltberatung. Seminarband der Zentralen Informationsstelle Umweltberatung Bayern. Bd. 11

Energy Technology Data Exchange (ETDEWEB)

Koller, U.; Behling, G.; Klemmer, A.; Haury, H.J. [comps.

1998-12-31

On 25/26 November, 1997, Zentrale Informationsstelle, Umweltberatung Bayern held its 11th seminar under the title ``Sustainable development - theory and practice of environmental consulting. Subjects related to the Agenda 21 were discussed in lectures and workshops. [Deutsch] Am 25. und 26. November 1997 veranstaltete die Zentrale Informationsstelle, Umweltberatung Bayern ihr elftes Seminar mit dem Thema ``Nachhaltige Entwicklung- Theorie und Praxis fuer die Umweltberatung``. In Fachvortraegen und Workshops wurden Themen zur Agenda 21 behandelt. (ABI)

Measurement and analysis of vibrational behaviour of an SNR-fuel element in sodium flow

International Nuclear Information System (INIS)

Hess, B.F.H.; Ruppert, E.; Schmidt, H.; Vinzens, K.

1975-01-01

Within the framework of SNR-300 fuel element development programme a complete full size fuel element dummy has been tested thoroughly for nearly 3000 hours at 650 0 C system temperature in the AKB sodium loop at Interatom, Bensberg. Investigations of the hydraulic characteristics by measurements of specific pressure losses, flow velocities, leakage flow through the piston rings and investigations of its vibrational behaviour were part of this endurance test at elevated temperatures. The pressure drop versus flow and the leakage measurement are mentioned briefly to confirm the correctness of the test hydraulics. The vibrational behaviour of the element and the approach to analysis is the main object of this report. (Auth.)

Development of plans for retrofitting Russian housing, taking into account European competences for increasing its energy efficiency; Entwicklung von Planungs- und Sanierungskonzepten fuer den russischen Wohnungsbau

Energy Technology Data Exchange (ETDEWEB)

Ezhov, Andrey; Himburg, Stefan [Hochschule fuer Technik Berlin (Germany)

2010-02-15

There are various options for retrofitting Russian prefabricated concrete-slab buildings of the first period of industrial construction, so-called khrushchevki, with the object of bringing them up to European standards of thermal insulation technology. In the given case the basis of calculations was the German EnEV 2007 (Building Energy Conservation Ordinance). The analysis of sample building data opened up a large range of possibilities for increasing its energy efficiency. For instance, calculations ascertained that relatively inexpensive methods of enhancing a buildings thermal insulation can achieve a significant decrease in energy consumption for heating. In addition, this thesis analyzes possible variations of retrofitting and reconstruction using different types of materials and heating systems. The results clearly illustrate that residential houses e.g. type series 1-507 have a future as comfortable and functional housing space. In fact, and in contrast to common prejudices, their fate is far from hopeless. Even the climatic circumstances of a northern city such as St. Petersburg do not preclude the use of alternative energy sources such as solar energy. On the contrary, it is a conceivable method of support for heating systems. In summary, the investigations show that the retrofitting of prefabricated concrete-slab buildings of the first construction period is a sensible project, especially when taking into account the further development of fossil energy prices. In its most sophisticated form (the passive house), retrofitting will result in energy savings of up to 90 %. [German] Fuer russische Wohnhaeuser der ersten Periode des industriellen Bauens, so genannte ''Chruschtschowki'', besteht ein hoher Sanierungsbedarf. Im Rahmen der nachfolgenden Betrachtungen werden moegliche energetische Sanierungsmassnahmen fuer diese typischen russischen Wohngebaeude vorgestellt. Das Ziel ist eine Angleichung an das europaeische Waermeschutzniveau

Review: Gerd Jüttemann (Hrsg. (2013. Die Entwicklung der Psyche in der Geschichte der Menschheit

Directory of Open Access Journals (Sweden)

Uwe Krebs

2015-03-01

Full Text Available Der Vorbereitungsband für die Reihe "Die Psychogenese der Menschheit" – ein Sammelband aus 32 Beiträgen, betitelt "Die Entwicklung der Psyche in der Geschichte der Menschheit" und 2013 herausgegeben von Gerd JÜTTEMANN – wird in dieser Besprechung in mehreren Schritten vorgestellt und bewertet. Zunächst wird kontextuell argumentiert, dass die bewährte, empirisch-experimentelle Methodologie der Psychologie zur Vernachlässigung weiterer Erkenntnisverfahren führte, die bei Themen wie dem hier zu besprechenden Werk allein verbleiben und die kurz angesprochen werden. Sodann wird das Werk im Überblick knapp dargestellt und die außergewöhnliche Heterogenität in Inhalten und Methoden betont. Die Besprechung einzelner Beiträge, die nach dem Gesichtspunkt großer Unterschiedlichkeit ausgewählt wurden, schließt sich an. Die abschließende Gesamtbewertung betont den lückenhaften Forschungsstand, die Notwendigkeit der allein verbleibenden qualitativen Methodik mit ihren verschiedenen Möglichkeiten und nennt Desiderata künftigen Vorgehens für diesen thematisch und methodisch interessanten Auftakt-Band, der insbesondere durch Dichte und Verschiedenheit der Beiträge beeindruckt. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1502219

Design of an adaptive CubeSat transmitter for achieving optimum signal-to-noise ratio (SNR)

Science.gov (United States)

Jaswar, F. D.; Rahman, T. A.; Hindia, M. N.; Ahmad, Y. A.

2017-12-01

CubeSat technology has opened the opportunity to conduct space-related researches at a relatively low cost. Typical approach to maintain an affordable cubeSat mission is to use a simple communication system, which is based on UHF link with fixed-transmit power and data rate. However, CubeSat in the Low Earth Orbit (LEO) does not have relative motion with the earth rotation, resulting in variable propagation path length that affects the transmission signal. A transmitter with adaptive capability to select multiple sets of data rate and radio frequency (RF) transmit power is proposed to improve and optimise the link. This paper presents the adaptive UHF transmitter design as a solution to overcome the variability of the propagation path. The transmitter output power is adjustable from 0.5W to 2W according to the mode of operations and satellite power limitations. The transmitter is designed to have four selectable modes to achieve the optimum signal-to-noise ratio (SNR) and efficient power consumption based on the link budget analysis and satellite requirement. Three prototypes are developed and tested for space-environment conditions such as the radiation test. The Total Ionizing Dose measurements are conducted in the radiation test done at Malaysia Nuclear Agency Laboratory. The results from this test have proven that the adaptive transmitter can perform its operation with estimated more than seven months in orbit. This radiation test using gamma source with 1.5krad exposure is the first one conducted for a satellite program in Malaysia.

A HOS-based blind deconvolution algorithm for the improvement of time resolution of mixed phase low SNR seismic data

International Nuclear Information System (INIS)

Hani, Ahmad Fadzil M; Younis, M Shahzad; Halim, M Firdaus M

2009-01-01

A blind deconvolution technique using a modified higher order statistics (HOS)-based eigenvector algorithm (EVA) is presented in this paper. The main purpose of the technique is to enable the processing of low SNR short length seismograms. In our study, the seismogram is assumed to be the output of a mixed phase source wavelet (system) driven by a non-Gaussian input signal (due to earth) with additive Gaussian noise. Techniques based on second-order statistics are shown to fail when processing non-minimum phase seismic signals because they only rely on the autocorrelation function of the observed signal. In contrast, existing HOS-based blind deconvolution techniques are suitable in the processing of a non-minimum (mixed) phase system; however, most of them are unable to converge and show poor performance whenever noise dominates the actual signal, especially in the cases where the observed data are limited (few samples). The developed blind equalization technique is primarily based on the EVA for blind equalization, initially to deal with mixed phase non-Gaussian seismic signals. In order to deal with the dominant noise issue and small number of available samples, certain modifications are incorporated into the EVA. For determining the deconvolution filter, one of the modifications is to use more than one higher order cumulant slice in the EVA. This overcomes the possibility of non-convergence due to a low signal-to-noise ratio (SNR) of the observed signal. The other modification conditions the cumulant slice by increasing the power of eigenvalues of the cumulant slice, related to actual signal, and rejects the eigenvalues below the threshold representing the noise. This modification reduces the effect of the availability of a small number of samples and strong additive noise on the cumulant slices. These modifications are found to improve the overall deconvolution performance, with approximately a five-fold reduction in a mean square error (MSE) and a six

Development of a CdTe/CdS solar wafer. Final report; Entwicklung einer CdTe/CdS Duennschicht-Solarzelle. Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Koentges, M.; Reineck-Koch, R.

2002-07-01

The focus was on the development and optimisation of the close-spaced sublimation process in an inline coating plant for production of stable high-efficiency CdS/CdTe solar wafers. An inline plant was to be constructed by ANTEC GmbH and ISFH. Film layers were to be optimised, and investigations were to show whether processing of single films is possible without breaking the vacuum, e.g. for etching. The results were to be used directly by ANTEC GmbH. An efficiency of 14 percent and an idle voltage of about 850 V were to be achieved with a film thickness of 2 {mu}m. To achieve these goals, the following project stages were envisaged: 1. Replacement of the expensive window material ITO by a less costly material. 2. Higher stability of the back contact by using appropriate intermediate layers. 3. Alternative activation processes other than the conventional CdCl{sub 2} activation. 4. Investigation of the effects of the activation step on the electric properties of the sample. [German] Die uebergreifende Aufgabenstellung des Projektes war die Entwicklung und Optimierung des Close-spaced-Sublimation verfahrens in einer Inline-Beschichtungsanlage fuer die Herstellung stabiler und hocheffizienter CdS/CdTe Duennschichtsolarzellen. Mit dem Wissen der ANTEC GmbH sollte zusammen mit dem ISFH eine Inline-Anlage konzipiert und gebaut werden. Die fuer die Solarzelle notwendigen Einzelschichten sollten in dem Inline-Prozess optimiert werden. Es sollte ermittelt werden, ob eine Prozessierung der Einzelschichten ohne Brechen des Vakuums, z.B. fuer einen Aetzschritt, moeglich ist. Die erzielten Ergebnisse sollen direkt der ANTEC GmbH zufliessen. In dem Projekt wurde als Endziel ein Wirkungsgrad der CdTe/CdS-Duennschichtsolarzelle von 14% und eine Erhoehung der Leerlaufspannung auf Werte um 850 mV angestrebt. Gleichzeitig sollte die CdTe-Schichtdicke auf 2 {mu}m vermindert werden. Um dieses Gesamtziel zu erreichen, sollen folgende Teilaufgaben bearbeitet werden: 1) Das teuere

Recovery of a broken inspection lance from the reactor vessel of the German sodium cooled fast breeder reactor SNR 300

International Nuclear Information System (INIS)

Menck, J.W.; Hoeft, E.; Kirchner, G.

1988-01-01

An inspection lance for flow and vibration measurements was installed into the SNR-300 rotating plug. Centering and guiding of the lower end of the lance was effected in the central grid plate insert. The lance was torn off due to handling problems. The task consisted in recovering all defective parts from the reactor vessel and re-establishing the intact initial state. (author)

Renewable energies in Germany. Data on the development in 2016; Erneuerbare Energien in Deutschland. Daten zur Entwicklung im Jahr 2016

Energy Technology Data Exchange (ETDEWEB)

NONE

2017-03-15

The Working Group on Renewable Energy Statistics (AGEE-Stat), which regularly evaluates the use of renewable energies on behalf of the German Federal Ministry of Economics and Energy, has made an initial assessment of the development of renewable energies in Germany on the basis of available, mostly provisional data of 2016. The present background paper describes the previous findings for the areas of electricity, heat and transport, supplemented by figures on economic significance as well as on emission reductions through renewable energies. [German] Die Arbeitsgruppe Erneuerbare Energien-Statistik (AGEE-Stat), die im Auftrag des Bundesministeriums fuer Wirtschaft und Energie regelmaessig die Nutzung der erneuerbaren Energien bilanziert, hat auf der Grundlage verfuegbarer, zumeist vorlaeufiger Daten eine erste Abschaetzung zur Entwicklung der erneuerbaren Energien in Deutschland im Jahr 2016 erstellt. Das vorliegende Hintergrundpapier beschreibt die bisherigen Erkenntnisse fuer die Bereiche Strom, Waerme und Verkehr, ergaenzt um Zahlen zur wirtschaftlichen Bedeutung sowie zur Emissionsvermeidung durch erneuerbare Energien.

Energy Efficient Cooperation in Underlay RFID Cognitive Networks for a Water Smart Home

Directory of Open Access Journals (Sweden)

Adnan Nasir

2014-09-01

Full Text Available Shrinking water  resources all over the world and increasing  costs of water consumption  have prompted  water users  and distribution companies  to come up with water conserving strategies. We have proposed an energy-efficient  smart water monitoring application in [1], using low power RFIDs. In the home environment,  there exist many primary interferences within a room, such as cell-phones,  Bluetooth  devices, TV signals, cordless phones and WiFi devices.  In order to reduce the interference  from our proposed RFID network for these primary  devices, we have proposed a cooperating  underlay  RFID cognitive network for our smart application on water.  These underlay  RFIDs should strictly adhere to the interference thresholds to work in parallel with the primary wireless devices [2].  This work is an extension of our previous  ventures proposed in [2,3], and we enhanced the previous efforts by introducing  a new system model and RFIDs.  Our proposed scheme is mutually energy efficient and maximizes the signal-to-noise ratio (SNR for the RFID link, while keeping the interference levels for the primary  network below a certain threshold. A closed form expression for the probability density function (pdf of the SNR at the destination reader/writer and outage probability are derived. Analytical results are verified through simulations. It is also shown that in comparison to non-cognitive selective cooperation,  this scheme performs  better in the low SNR region for cognitive networks. Moreover, the hidden Markov model’s (HMM multi-level variant hierarchical hidden Markov model (HHMM approach is used for pattern recognition and event detection for the data received for this system [4]. Using this model, a feedback and decision algorithm is also developed.  This approach has been applied  to simulated water pressure data from RFID motes, which were embedded in metallic water pipes.

Research parallel to 'Solarthermie 2000'. Development of a standardized acceptance test for industrial-scale solar thermal systems. Final report; Begleitforschung Solarthermie 2000. Entwicklung eines standardisierten Abnahmeverfahrens fuer solarthermische Grossanlagen. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Beikircher, T.; Benz, N.; Gut, M.; Schwenk, C.; Schoelkopf, W.

2000-02-01

First, a simple and efficient tool for projecting solar thermal power systems was to be developed by ITW Stuttgart (see separate ITW Stuttgart report). Parallel to this, a fast and simple method was to be developed for in-situ assessment or the annual yield of such systems, with a maximum error of 5 percent. The following steps were taken: 1. Development of a measuring system for the task; 2. Selection of methods of evaluation for the dynamic in situ short-term test; 3. Development and testing of the method in several industrial-scale systems and validation by comparison with the results of conventional measurements. The dynamic in situ short-term test method developed on this basis consists of six steps which are described in the report. The measuring accuracy depends on the correct function of the plant. [German] Zunaechst sollte fuer solarthermische Grossanlagen ein Katalog standardisierter Anlagenkonfigurationen erstellt und anschliessend in die gaengigen Planungswerkzeuge TRNSYS und TSOL uebertragen werden, um Planern ein einfaches und leistungsfaehiges Werkzeug zur Auslegung und zur Berechnung des GSR zur Verfuegung zu stellen. Damit sollen Planungsfehler aufgrund fehlender Erfahrung mit Solaranlagen vermieden und ein Standard fuer innovative Anlagenkonzepte verbreitet werden. Dieser Arbeitspunkt wurde ausschliesslich durch das ITW Stuttgart bearbeitet, siehe separater Berichtsteil des ITW Stuttgart. Parallel dazu war ein Testverfahren zu entwickeln, mit dem der Jahresertrag grosser thermischer Solaranlagen in situ, d.h. an der installierten Anlage vor Ort, ohne Eingriff in die Anlage, um die Gewaehrleistungspflicht des Anlagenbauers zu erhalten, auf 5% genau, um ein klares juristisches Kriterium fuer die Feststellung einer etwaigen Nachbesserungspflicht des Erbauers zu haben, kostenguenstig und in kurzer Zeit (maximal 6 Wochen) bestimmt werden kann. Hierzu waren folgende Arbeiten notwendig: 1. Entwicklung einer an die Aufgabenstellung angepassten Messtechnik

Fast breeder reactor expected to soon overtake LWRs in terms of economic efficiency

International Nuclear Information System (INIS)

Eitz, A.W.; Theisen, G.; Wolff, U.; Riethmueller, R.

1986-01-01

On the basis of current knowledge, the authors try to comparatively assess the fuel cycle costs of the SNR and the LWR, and to establish a prognosis of the competibility of the SNR in terms of fuel expenditure. The result is that already today, the fast breeder would achieve the economic efficiency of the LWR-type reactor, and in future would offer clear advantages. For their assessments, the authors made a few cost estimates, as e.g. with regard to the fuel reprocessing plant, which deserve close attention, and power discussion. As to the next project to follow, a large-scale European fast breeder reactor power plant, the authors state that the fuel cycle cost will not present a special economic risk, if an option for interim fuel storage is ensured. Determination of the right and adequate time to start construction of a commercial fuel reprocessing plant is no point in current discussions, and should anyhow be made with great care and the least time pressure possible. Cooperation among European states, however, is indispensable for this project. (orig.) [de

Acute disseminated encephalomyelitis; Akute disseminierte Enzephalomyelitis

Energy Technology Data Exchange (ETDEWEB)

Politi, M.; Papanagiotou, P.; Grunwald, I.Q.; Roth, C.; Reith, W. [Universitaetsklinikum des Saarlandes, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Homburg/Saar (Germany)

2008-06-15

Acute disseminated encephalomyelitis (ADEM) is an acute widespread autoimmune demyelinating condition, which principally affects the white matter of the brain and spinal cord. It usually follows an infection or vaccination. The typical presentation is that of multifocal neurologic disturbances accompanied by change in mental status. CSF analysis reveals lymphocytic pleocytosis and elevated protein content, but may also yield normal results. MRI is regarded as the diagnostic imaging modality of choice and typically demonstrates involvement of deep cerebral hemispheric and subcortical white matter as well as lesions in the basal ganglia, gray-white junction, diencephalon, brainstem, cerebellum and spinal cord. Unlike multiple sclerosis (MS), ADEM has a monophasic course and a favorable long-term prognosis. (orig.) [German] Die akute disseminierte Enzephalomyelitis (ADEM) ist eine akut auftretende autoimmune demylinisierende Erkrankung der weissen Substanz, die hauptsaechlich Gehirn und Rueckenmark befaellt. Ueblicherweise tritt sie nach einer Infektion oder Impfung auf. Die Entwicklung einer fokalen oder multifokalen neurologischen Funktionsstoerung ist das Kennzeichen der klinischen Praesentation der ADEM. Lymphozytaere Pleozytose und Eiweisserhoehung sind typische Befunde in der Liquoruntersuchung. Die Magnetresonanztomographie (MRT) ist die Untersuchungsmethode der Wahl. Die ADEM-Laesionen sind typischerweise gross, multipel und asymmetrisch. Sie koennen in den Gross- und Kleinhirnhemisphaeren, im Hirnstamm und im Rueckenmark lokalisiert sein. Die subkortikale und die zentrale weisse Substanz sind am haeufigsten befallen. Weniger haeufig ist die graue Substanz der Thalami und der Basalganglien betroffen. Im Gegensatz zur Multiplen Sklerose (MS) ist die Prognose der ADEM im Allgemeinen guenstig. (orig.)

Conventional angiography in comparison with magnetic resonance tomography and arthroscopy for the diagnosis of knee joint lesion - specific indications?; Die konventionelle Arthrographie im Vergleich zu Magnetresonanztomographie und Arthroskopie bei Kniegelenkbinnenlaesionen: Verbleiben Indikationen?

Energy Technology Data Exchange (ETDEWEB)

Koenig, H. [Universitaetsklinikum Steglitz, Radiologische Klinik, Abt. fuer Roentgendiagnostik und Nuklearmedizin, FU Berlin (Germany); Andresen, R. [Universitaetsklinikum Steglitz, Radiologische Klinik, Abt. fuer Roentgendiagnostik und Nuklearmedizin, FU Berlin (Germany); Radmer, S. [Orthopaedisches Institut, Berlin (Germany); Schmidt, M. [Krankenhaus Moabit, Roentgenabteilung, Berlin (Germany); Wolf, K.J. [Universitaetsklinikum Steglitz, Radiologische Klinik, Abt. fuer Roentgendiagnostik und Nuklearmedizin, FU Berlin (Germany)

1995-03-01

Twenty-one patients with suspected internal knee joint lesions were examined prospectively. In all patients an MRI was carried out first and was followed within two weeks by an arthrography and an arthrocopy. Lesions of the menisci, cruciate ligaments, hyaline cartilage, and synovial tissues were evaluated. Arthroscopy findings were defined as the `gold standard`. MRI achieved an accuracy of 96.4%, a sensitivity of 93.6%, and a specifity of 92.5%, whereas arthrography achieved an accuracy of 67.8%, a sensitivity of 66.6%, and a specifity of 71.4%. These statistical data as well as the single findings revealed no special indications for arthrography in suspected knee joint lesions. (orig.) [Deutsch] In einer prospektiven Studie wurden insgesamt 21 Patienten mit suspekten Kniegelenksbinnenlaesionen untersucht. Bei allen Patienten erfolgte zunaechst eine Magnetresonanztomographie (MRT), anschliessend innerhalb von zwei Wochen eine Arthrographie und Arthroskopie des Kniegelenks. Beurteilt wurden Laesionen der Meniski, der Kreuzbaender, des hyalinen Gelenkknorpels und des Synovialgewebes. Bezogen auf den Arthroskopiebefund als `Gold-Standard` erreichte die MRT eine Treffsicherheit von 96,4%, eine Sensitivitaet von 93,6% und eine Spezifitaet von 92,5%; dagegen die Arthrographie eine Treffsicherheit von 67,8%, eine Sensitivitaet von 66,6% und eine Spezifitaet von 71,4%. Sowohl eine Uebersicht als auch die Auswertung der Einzelbefunde ergaben keine speziellen Indikationen zur Durchfuehrung einer Kniegelenksarthrographie bei suspekten Binnenlaesionen. (orig.)

3 tesla magnetic resonance imaging in children and adults with congenital heart disease; 3-Tesla-Magnetresonanztomographie zur Untersuchung von Kindern und Erwachsenen mit angeborenen Herzfehlern

Energy Technology Data Exchange (ETDEWEB)

Voges, I.; Hart, C.; Kramer, H.H.; Rickers, C. [Universitaetsklinikum Schleswig-Holstein, Klinik fuer angeborene Herzfehler und Kinderkardiologie, Kiel (Germany); Jerosch-Herold, M. [Harvard Medical School, Department of Radiology, Brigham and Women' s Hospital, Boston (United States); Helle, M. [Universitaetsklinikum Schleswig-Holstein, Institut fuer Neuroradiologie, Kiel (Germany)

2010-09-15

Cardiovascular magnetic resonance imaging (CMR) has become a routinely used imaging modality for congenital heart disease. A CMR examination allows the assessment of thoracic anatomy, global and regional cardiac function, blood flow in the great vessels and myocardial viability and perfusion. In the clinical routine cardiovascular MRI is mostly performed at field strengths of 1.5 Tesla (T). Recently, magnetic resonance systems operating at a field strengths of 3 T became clinically available and can also be used for cardiovascular MRI. The main advantage of CMR at 3 T is the gain in the signal-to-noise ratio resulting in improved image quality and/or allowing higher acquisition speed. Several further differences compared to MRI systems with lower field strengths have to be considered for practical applications. This article describes the impact of CMR at 3 T in patients with congenital heart disease by meanings of methodical considerations and case studies. (orig.) [German] Die kardiovaskulaere Magnetresonanztomographie (MRT) hat sich zu einer etablierten bildgebenden Methode zur Untersuchung von Patienten mit angeborenen Herzfehlern entwickelt. Sie erlaubt in einer einzigen Untersuchung die exakte Beurteilung von Anatomie, globaler und regionaler Funktion, Blutfluessen sowie der myokardialen Perfusion und Vitalitaet. In der klinischen Routine erfolgen die Untersuchungen zumeist bei einer Feldstaerke von 1,5 Tesla (T), mittlerweile gibt es jedoch Geraete und Bildgebungstechniken, die die kardiovaskulaere MRT auch bei 3 T ermoeglichen. Der wesentliche Vorteil der MRT bei 3 T ist das hoehere Signal-zu-Rausch-Verhaeltnis, das sowohl zu einer Verbesserung der Bildqualitaet als auch zu einer Verkuerzung der Untersuchungszeit genutzt werden kann. Darueber hinaus bestehen verschiedene andere Unterschiede gegenueber Systemen mit niedriger Feldstaerke, die im praktischen Einsatz beachtet werden muessen. Dieser Artikel beschreibt die Erfahrungen der 3-T-MRT fuer die

Development of a two-phase, two-component jet pump refrigerator for utilization of low-temperature solar heat. Final report; Entwicklung einer Zweiphasen-/Zweikomponenten-Strahlpumpenkaelteanlage zur Nutzung solarer Niedertemperaturwaerme. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Mostofizadeh, C.; Bohne, D.

2001-08-01

A solar refrigerator for air conditioning and cooling was developed. The key component is a two-phase, two-component jet pump with ammonia and water as working fluid. Both the pump flow and the suction flow can be two-phase flows. This way, the advantages of both the absorption and the compression principle will be utilized, and a compact size will be achieved. Upon termination of the calculations, the function of the pump will be investigated in a 0 W pilot plant. For this, various geometries were calculated and tested for their potential efficiencies. A prototype will be constructed on the basis of the results. [German] Das Ziel des Vorhabens besteht in der Entwicklung einer solarbetriebenen Kaelteanlage fuer Klimatisierungs- und Kuehlungszwecke. Die Hauptkomponente der Kaelteanlage ist eine Zweiphasen-/Zweikomponenten-Strahlpumpe, die mit dem Arbeitsgemisch Ammoniak/Wasser betrieben wird. Sowohl der Treib- als auch der Saugstrom koennen zweiphasig sein. Dadurch sollen einerseits die Vorteile des Absorptions- und des Kompressionsprinzips miteinander verknuepft und andererseits ein kompakter Aufbau erreicht werden. Nach Abschluss der thermodynamischen und kinetischen Berechnungen soll die Funktion der Zweiphasen-/Zweikomponenten-Strahlpumpe mit Hilfe einer Pilotanlage mit ca. 20 kW Kaelteleistung untersucht werden. Dazu werden nach Vorausberechnungen verschiedene Geometrien in Bezug auf erzielbare Wirkungsgrade getestet. Die Ergebnisse bilden die Basis fuer den Bau eines Prototyps. (orig.)

Preparation and evaluation of oral multiparticulate formulations of acid-labile drugs

OpenAIRE

Huang, Fang

2017-01-01

Säure-labile Medikamente werden leicht in saurem Medium abgebaut, welche hauptsächlich als enterisch beschichtete Dosierungsformen für die orale Verabreichung formuliert wurden. Das Ziel dieser Studie war es, orale multipartikuläre Formulierungen von säure-labilen Medikamenten, mit Ilaprazol, Lansoprazol und Rabeprazol Natrium als Modellarzneistoffe vorzubereiten. Der Einfluss der Wirkstofflöslichkeit von Lansoprazol und Rabeprazol Natrium und des Kerntyps, wurde auf das Übe...

One decade of functional imaging in schizophrenia research. From visualisation of basic information processing steps to molecular brain imaging; Zehn Jahre funktionelle Magnetresonanztomographie in der Schizophrenieforschung. Von der Abbildung einfacher Informationsverarbeitungsprozesse zur molekulargenetisch orientierten Bildgebung

Energy Technology Data Exchange (ETDEWEB)

Tost, H. [Zentralinstitut fuer Seelische Gesundheit, NMR-Forschung in der Psychiatrie (Germany); Zentralinstitut fuer Seelische Gesundheit, NMR-Forschung in der Psychiatrie, Mannheim (Germany); Meyer-Lindenberg, A. [Genes, Neuroimaging Core Facility and Unit on Integrative Neuroimaging, Cognition and Psychosis Program, National Institute of Mental Health (United States); Ruf, M.; Demirakca, T.; Grimm, O.; Henn, F.A.; Ende, G. [Zentralinstitut fuer Seelische Gesundheit, NMR-Forschung in der Psychiatrie (Germany)

2005-02-01

Modern neuroimaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET) have contributed tremendously to our current understanding of psychiatric disorders in the context of functional, biochemical and microstructural alterations of the brain. Since the mid-nineties, functional MRI has provided major insights into the neurobiological correlates of signs and symptoms in schizophrenia. The current paper reviews important fMRI studies of the past decade in the domains of motor, visual, auditory, attentional and working memory function. Special emphasis is given to new methodological approaches, such as the visualisation of medication effects and the functional characterisation of risk genes. (orig.) [German] Bildgebende Verfahren wie die Magnetresonanz- und Positronenemissionstomographie haben entscheidend dazu beigetragen, dass psychiatrische Erkrankungen heutzutage im Kontext funktioneller, biochemischer und feinstruktureller Veraenderungen des Gehirns verstanden werden. Im Bereich der Schizophrenieforschung gibt insbesondere die funktionelle Magnetresonanztomographie seit Mitte der 90er-Jahre wichtige Einblicke in die neurobiologischen Grundlagen schizophrener Defizitbereiche. Die vorliegende Arbeit stellt die wichtigsten fMRT-Befunde der letzten Dekade in den Bereichen Psychomotorik, visuelle bzw. akustische Informationsverarbeitung, Aufmerksamkeit und Arbeitsgedaechtnis vor. Die Betrachtung erfolgt dabei unter der besonderen Beruecksichtigung aktueller methodischer Ansaetze wie der Darstellung von Therapieeffekten und der funktionellen Charakterisierung psychiatrischer Risikogene. (orig.)

Fabrication of fuel elements interplay between typical SNR Mark Ia specifications and the fuel element fabrication

International Nuclear Information System (INIS)

Biermann, W.K.; Heuvel, H.J.; Pilate, S.; Vanderborck, Y.; Pelckmans, E.; Vanhellemont, G.; Roepenack, H.; Stoll, W.

1987-01-01

The core and fuel were designed for the SNR-300 first core by Interatom GmbH and Belgonucleaire. The fuel was fabricated by Alkem/RBU and Belgonucleaire. Based on the preparation of drawings and specifications and on the results of the prerun fabrication, an extensive interplay took place between design requirements, specifications, and fabrication processes at both fuel plants. During start-up of pellet and pin fabrication, this solved such technical questions as /sup 239/Pu equivalent linear weight, pellet density, stoichiometry of the pellets, and impurity content. Close cooperation of designers and manufacturers has allowed manufacture of 205 fuel assemblies without major problems

Detailed investigation of the gamma-ray emission in the vicinity of SNR W28 with Fermi-LAT

Energy Technology Data Exchange (ETDEWEB)

Hanabata, Y. [Institute for Cosmic-Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan); Katagiri, H. [College of Science, Ibaraki University, 2-1-1, Bunkyo, Mito 310-8512 (Japan); Hewitt, J.W. [CRESST, University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d' Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Fukazawa, Y. [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Fukui, Y.; Hayakawa, T. [Department of Physics and Astrophysics, Nagoya University, Chikusa-ku Nagoya 464-8602 (Japan); Lemoine-Goumard, M. [Centre d' Études Nucléaires de Bordeaux Gradignan, IN2P3/CNRS, Université Bordeaux 1, BP120, F-33175 Gradignan Cedex (France); Pedaletti, G.; Torres, D. F. [Institut de Ciències de l' Espai (IEEE-CSIC), Campus UAB, 08193 Barcelona (Spain); Strong, A. W. [Max-Planck Institut für extraterrestrische Physik, D-85748 Garching (Germany); Yamazaki, R., E-mail: hanabata@icrr.u-tokyo.ac.jp, E-mail: katagiri@mx.ibaraki.ac.jp [Department of Physics and Mathematics, Aoyama Gakuin University, Sagamihara, Kanagawa 252-5258 (Japan)

2014-05-10

We present a detailed investigation of the γ-ray emission in the vicinity of the supernova remnant (SNR) W28 (G6.4–0.1) observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. We detected significant γ-ray emission spatially coincident with TeV sources HESS J1800–240A, B, and C, located outside the radio boundary of the SNR. Their spectra in the 2-100 GeV band are consistent with the extrapolation of the power-law spectra of the TeV sources. We also identified a new source of GeV emission, dubbed Source W, which lies outside the boundary of TeV sources and coincides with radio emission from the western part of W28. All of the GeV γ-ray sources overlap with molecular clouds in the velocity range from 0 to 20 km s{sup –1}. Under the assumption that the γ-ray emission toward HESS J1800–240A, B, and C comes from π{sup 0} decay due to the interaction between the molecular clouds and cosmic rays (CRs) escaping from W28, they can be naturally explained by a single model in which the CR diffusion coefficient is smaller than the theoretical expectation in the interstellar space. The total energy of the CRs escaping from W28 is constrained through the same modeling to be larger than ∼2 × 10{sup 49} erg. The emission from Source W can also be explained with the same CR escape scenario.

Detailed investigation of the gamma-ray emission in the vicinity of SNR W28 with Fermi-LAT

International Nuclear Information System (INIS)

Hanabata, Y.; Katagiri, H.; Hewitt, J.W.; Ballet, J.; Fukazawa, Y.; Fukui, Y.; Hayakawa, T.; Lemoine-Goumard, M.; Pedaletti, G.; Torres, D. F.; Strong, A. W.; Yamazaki, R.

2014-01-01

We present a detailed investigation of the γ-ray emission in the vicinity of the supernova remnant (SNR) W28 (G6.4–0.1) observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. We detected significant γ-ray emission spatially coincident with TeV sources HESS J1800–240A, B, and C, located outside the radio boundary of the SNR. Their spectra in the 2-100 GeV band are consistent with the extrapolation of the power-law spectra of the TeV sources. We also identified a new source of GeV emission, dubbed Source W, which lies outside the boundary of TeV sources and coincides with radio emission from the western part of W28. All of the GeV γ-ray sources overlap with molecular clouds in the velocity range from 0 to 20 km s –1 . Under the assumption that the γ-ray emission toward HESS J1800–240A, B, and C comes from π 0 decay due to the interaction between the molecular clouds and cosmic rays (CRs) escaping from W28, they can be naturally explained by a single model in which the CR diffusion coefficient is smaller than the theoretical expectation in the interstellar space. The total energy of the CRs escaping from W28 is constrained through the same modeling to be larger than ∼2 × 10 49 erg. The emission from Source W can also be explained with the same CR escape scenario.

Silicon solar cells with high efficiencies. Final report; Silicium-Solarzellen mit hoechsten Wirkungsgraden. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Wettling, W.; Knobloch, J.; Glunz, S.W.; Henninger, V.; Kamerewerd, F.J.; Koester, B.; Leimenstoll, A.; Schaeffer, E.; Schumacher, J.; Sterk, S.; Warta, W.

1996-06-01

In this report the basic activities for the development of the silicon high efficiency solar cell technology are described. The project had two main goals: (i) The improvement of efficiencies using a systematic optimization of all cell parameters and technology steps and (ii) the simplification of the technology towards the possibilities of an industrial production, keeping the cell efficiency at a high level. Starting from the LBSF technology, developed at Fraunhofer ISE, the reduction of all loss mechanisms led to efficiencies up to 22.5% on FZ-silicon. Using a modification of this technology efficiencies of up to 21.7% have been reached on Cz-silicon. Even after the reduction of the number of photolithographic steps from six to three efficiencies up to 21.6% on FZ- and 19.5% on Cz-silicon have been obtained. These are best values in an international comparison. (orig.) [Deutsch] In diesem Projektbericht werden grundlegende Arbeiten zur Entwicklung der Silicium-`Highefficiency`-Solarzellentechnologie beschrieben. Das Projekt hatte zwei Hauptziele: (i) Die Erhoehung der Wirkungsgrade durch eine systematische Optimierung aller Zellparameter und aller Technologieschritte und (ii) die Vereinfachung der Technologie unter Beibehaltung sehr hoher Wirkungsgrade mit dem Ziel einer Annaeherung an die Moeglichkeiten der Industriefertigung. Ausgehend von der im Fraunhofer ISE entwickelten LBSF-Technologie gelang es durch Reduzierung aller Verlustmechanismen, Wirkungsgrade bis zu 22.5% auf FZ-Silicium zu erreichen. Nach Anpassung der Technologie wurden auf Cz-Silicium Wirkungsgrade bis 21.7% erzielt. Ein von sechs auf drei Fotomaskenschritte reduzierter Prozess erzielte immerhin noch Werte bis 21.6% auf FZ- und 19.5% auf Cz-Material. Alle dieser Werte stellen im internationalen Vergleich Spitzenleistungen dar. (orig.)

Development of a smartphone-based pulse oximeter with adaptive SNR/power balancing.

Science.gov (United States)

Phelps, Tom; Haowei Jiang; Hall, Drew A

2017-07-01

Millions worldwide suffer from diseases that exhibit early warnings signs that can be detected by standard clinical-grade diagnostic tools. Unfortunately, such tools are often prohibitively expensive to the developing world leading to inadequate healthcare and high mortality rates. To address this problem, a smartphone-based pulse oximeter is presented that interfaces with the phone through the audio jack, enabling point-of-care measurements of heart rate (HR) and oxygen saturation (SpO 2 ). The device is designed to utilize existing phone resources (e.g., the processor, battery, and memory) resulting in a more portable and inexpensive diagnostic tool than standalone equivalents. By adaptively tuning the LED driving signal, the device is less dependent on phone-specific audio jack properties than prior audio jack-based work making it universally compatible with all smartphones. We demonstrate that the pulse oximeter can adaptively optimize the signal-to-noise ratio (SNR) within the power constraints of a mobile phone (<; 10mW) while maintaining high accuracy (HR error <; 3.4% and SpO 2 error <; 3.7%) against a clinical grade instrument.

Revolution by way of technical transfer in the development of locomotive brake systems; Revolutionierung in der Entwicklung von Bremssystemen bei Lokomotiven durch Technologietransfer

Energy Technology Data Exchange (ETDEWEB)

Wright, E.C. [New York Air Brake (United States). Bereich Engineering; Sinn, R. [New York Air Brake (United States). Bereich Elektronik und Software

1997-12-31

With the use of components from other sectors and orientation on the technologies of other fields it has been possible to enhance the standard of electronic braking systems. The reliability of the CCBII is ten times greater than with conventional systems. The physical volume could be reduced by 40 percent and the weight by 30 percent. The CCBII has functional redundancy and the Locotrol Distributed Power System is already integrated. A diagnostics system allows repair times to be reduced to 20 minutes. Production is now commencing and it is planned to make the first deliveries starting from January 1998. (orig.) [Deutsch] Durch das Einbinden von Entwurfsverfahren aus der Luft- und Raumfahrtindustrie sowie der Verwendung von Komponenten aus dem Automobilsektor, hochentwickelter Werkstoffe und Techniken ist es moeglich, neue Wege bei Bremssystemen zu gehen. Der Beitrag beschreibt die Entwicklung einer neuen Generation von computergesteuerten Bremssystemen fuer Lokomotiven. (orig.)

Two potential hookworm DAF-16 target genes, SNR-3 and LPP-1: gene structure, expression profile, and implications of a cis-regulatory element in the regulation of gene expression.

Science.gov (United States)

Gao, Xin; Goggin, Kevin; Dowling, Camille; Qian, Jason; Hawdon, John M

2015-01-08

Hookworms infect nearly 700 million people, causing anemia and developmental stunting in heavy infections. Little is known about the genomic structure or gene regulation in hookworms, although recent publication of draft genome assemblies has allowed the first investigations of these topics to be undertaken. The transcription factor DAF-16 mediates multiple developmental pathways in the free living nematode Caenorhabditis elegans, and is involved in the recovery from the developmentally arrested L3 in hookworms. Identification of downstream targets of DAF-16 will provide a better understanding of the molecular mechanism of hookworm infection. Genomic Fragment 2.23 containing a DAF-16 binding element (DBE) was used to identify overlapping complementary expressed sequence tags (ESTs). These sequences were used to search a draft assembly of the Ancylostoma caninum genome, and identified two neighboring genes, snr-3 and lpp-1, in a tail-to-tail orientation. Expression patterns of both genes during parasitic development were determined by qRT-PCR. DAF-16 dependent cis-regulatory activity of fragment 2.23 was investigated using an in vitro reporter system. The snr-3 gene spans approximately 5.6 kb in the genome and contains 3 exons and 2 introns, and contains the DBE in its 3' untranslated region. Downstream from snr-3 in a tail-to-tail arrangement is the gene lpp-1. The lpp-1 gene spans more than 6 kb and contains 10 exons and 9 introns. The A. caninum genome contains 2 apparent splice variants, but there are 7 splice variants in the A. ceylanicum genome. While the gene order is similar, the gene structures of the hookworm genes differ from their C. elegans orthologs. Both genes show peak expression in the late L4 stage. Using a cell culture based expression system, fragment 2.23 was found to have both DAF-16-dependent promoter and enhancer activity that required an intact DBE. Two putative DAF-16 targets were identified by genome wide screening for DAF-16 binding

Physical characteristic of brown algae (Phaeophyta) from madura strait as irreversible hydrocolloid impression material

OpenAIRE

Prihartini Widiyanti; Siswanto Siswanto

2012-01-01

Background: Brown algae is a raw material for producing natrium alginates. One type of brown algae is Sargassum sp, a member of Phaeophyta division. Sargassum sp could be found in Madura strait Indonesia. Natrium alginate can be extracted from Sargassum sp. The demand of alginate in Indonesia is mainly fulfilled from abroad, meanwhile Sargassum sp is abundantly available. Purpose: The purpose of study were to explore the potency of brown alga Sargassum sp from Madura strait as hydrocolloid im...

The diffuse source at the center of LMC SNR 0509–67.5 is a background galaxy at z = 0.031

International Nuclear Information System (INIS)

Pagnotta, Ashley; Walker, Emma S.; Schaefer, Bradley E.

2014-01-01

Type Ia supernovae (SNe Ia) are well-known for their use in the measurement of cosmological distances, but our continuing lack of concrete knowledge about their progenitor stars is both a matter of debate and a source of systematic error. In our attempts to answer this question, we presented unambiguous evidence that LMC SNR 0509–67.5, the remnant of an SN Ia that exploded in the Large Magellanic Cloud 400 ± 50 yr ago, did not have any point sources (stars) near the site of the original supernova explosion, from which we concluded that this particular supernova must have had a progenitor system consisting of two white dwarfs. There is, however, evidence of nebulosity near the center of the remnant, which could have been left over detritus from the less massive WD, or could have been a background galaxy unrelated to the supernova explosion. We obtained long-slit spectra of the central nebulous region using GMOS on Gemini South to determine which of these two possibilities is correct. The spectra show Hα emission at a redshift of z = 0.031, which implies that the nebulosity in the center of LMC SNR 0509–67.5 is a background galaxy, unrelated to the supernova.

Experimental investigations on scaled models for the SNR-2 decay heat removal by natural convection

International Nuclear Information System (INIS)

Hoffmann, H.; Weinberg, D.; Tschoeke, H.; Frey, H.H.; Pertmer, G.

1986-01-01

Scaled water models are used to prove the mode of function of the decay heat removal by natural convection for the SNR-2. The 2D and 3D models were designed to reach the characteristic numbers (Richardson, Peclet) of the reactor. In the experiments on 2D models the position of the immersed cooler (IC) and the power were varied. Temperature fields and velocities were measured. The IC installed as a separate component in the hot plenum resulted in a very complex flow behavior and low temperatures. Integrating the IC in the IHX showed a very simple circulating flow and high temperatures within the hot plenum. With increasing power only slightly rising temperature differences within the core and IC were detected. Recalculations using the COMMIX 1B code gave qualitatively satisfying results. (author)

Constraining the Single-degenerate Channel of Type Ia Supernovae with Stable Iron-group Elements in SNR 3C 397

Energy Technology Data Exchange (ETDEWEB)

Dave, Pranav; Kashyap, Rahul; Fisher, Robert [Department of Physics, University of Massachusetts Dartmouth, 285 Old Westport Road, North Dartmouth, MA 02740 (United States); Timmes, Frank [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Townsley, Dean [Department of Physics and Astronomy, Box 870324, University of Alabama, Tuscaloosa, AL 35487 (United States); Byrohl, Chris [Institut für Astrophysik, Georg August Universität Göttingen, Friedrich-Hund-Platz 1, D-37077 Göttingen (Germany)

2017-05-20

Recent Suzaku X-ray spectra of supernova remnant (SNR) 3C 397 indicate enhanced stable iron group element abundances of Ni, Mn, Cr, and Fe. Seeking to address key questions about the progenitor and explosion mechanism of 3C 397, we compute nucleosynthetic yields from a suite of multidimensional hydrodynamics models in the near-Chandrasekhar-mass, single-degenerate paradigm for Type Ia supernovae (SNe Ia). Varying the progenitor white dwarf (WD) internal structure, composition, ignition, and explosion mechanism, we find that the best match to the observed iron peak elements of 3C 397 are dense (central density ≥6 × 10{sup 9} g cm{sup −3}), low-carbon WDs that undergo a weak, centrally ignited deflagration, followed by a subsequent detonation. The amount of {sup 56}Ni produced is consistent with a normal or bright normal SNe Ia. A pure deflagration of a centrally ignited, low central density (≃2 × 10{sup 9} g cm{sup −3}) progenitor WD, frequently considered in the literature, is also found to produce good agreement with 3C 397 nucleosynthetic yields, but leads to a subluminous SN Ia event, in conflict with X-ray line width data. Additionally, in contrast to prior work that suggested a large supersolar metallicity for the WD progenitor for SNR 3C 397, we find satisfactory agreement for solar- and subsolar-metallicity progenitors. We discuss a range of implications our results have for the single-degenerate channel.

SYNTHESIS NEW POTENTIAL ANTI-INFLAMMATORY AGENT SODIUM SALT OF PENTAGAMAVUNON-0

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Enade Perdana Istyastono

2010-06-01

Full Text Available Inflammation is the response of living tissues to injury. The process affects physiological changes such as erythema, edema, asthma and fever. Non-steroid Anti-inflammatory Drugs (NSAIDs have been developed since they could inhibit inflammation process because of its ability to inhibit biosynthesis of prostaglandin, one of inflammation mediators, through inhibition of cyclooxigenase (COX enzymes. Molecules, which have been reported having anti-inflammatory activity, for example, are curcumin, some curcumin derivatives and curcumin analogues. One of curcumin analogues that has been  developed is pentagamavunon-0 (PGV-0 whose IUPAC name is 2,5-bis(4'-hidroxy-3'-methoxy-benzylidenecyclo-pentanone. But PGV-0, which is like curcumin, practically insoluble in water, so it causes problems in the development. The aim of this research is to synthesize a derivative of PGV-0, a natrium salt of PGV-0 (natrium pentagamavunonate-0/Na-pentagamavunonate-0, which is hoped to have a better anti-inflammatory activity and solubility in water than PGV-0. PGV-0 was synthesized by reacting vanillin and cyclopentanone catalized by acid. Na-pentagamavunonate-0 was synthesized with PGV-0 as a starting material using an appropriate method. This research was able to synthesize new compound that was estimated as a natrium salt of PGV-0 (natrium pentagamavunonate-0/Na-pentagamavunonate-0.   Keywords: Curcumin, PGV-0, Na-pentagamavunonate-0, anti-inflammation

Interstellar protons in the TeV γ-ray SNR HESS J1731-347: Possible evidence for the coexistence of hadronic and leptonic γ-rays

International Nuclear Information System (INIS)

Fukuda, T.; Yoshiike, S.; Sano, H.; Torii, K.; Yamamoto, H.; Fukui, Y.; Acero, F.

2014-01-01

HESS J1731-347 (G353.6-0.7) is one of the TeV γ-ray supernova remnants (SNRs) that shows the shell-like morphology. We have made a new analysis of the interstellar protons toward the SNR by using both the 12 CO(J = 1-0) and H I data sets. The results indicate that the TeV γ-ray shell shows significant spatial correlation with the interstellar protons at a velocity range from –90 km s –1 to –75 km s –1 . The total mass of the interstellar medium (ISM) protons is estimated to be 6.4 × 10 4 M ☉ , 25% of which is atomic gas, and the distance corresponding to the velocity range is ∼5.2 kpc, a factor of 2 larger than the previous figure, 3 kpc. We have identified the cold H I gas observed as self-absorption which shows significant correspondence with the northeastern γ-ray peak. While the good correspondence between the ISM protons and TeV γ-rays in the north of the SNR lends support to the hadronic scenario for the TeV γ-rays, the southern part of the shell shows a break in the correspondence; in particular, the southwestern rim of the SNR shell shows a significant decrease of the interstellar protons by a factor of two. We argue that this discrepancy can be explained due to leptonic γ-rays because this region coincides well with the bright shell that emits non-thermal radio continuum emission and non-thermal X-rays, suggesting that the γ-rays of HESS J1713-347 consist of both the hadronic and leptonic components. The leptonic contribution corresponds to ∼20% of the total γ-rays.

Magnetic resonance angiography and tomography of vertebrobasilar dissections; Magnetresonanzangiographie und Magnetresonanztomographie bei Dissektionen der A. vertebralis

Energy Technology Data Exchange (ETDEWEB)

Felber, S. [Inst. fuer Magnetresonanztomographie und Spektroskopie, Universitaetskliniken Innsbruck (Austria)]|[Universitaetsklinik fuer Radiologie, Klinische Abt. 2, Universitaetskliniken Innsbruck (Austria); Auer, A. [Inst. fuer Magnetresonanztomographie und Spektroskopie, Universitaetskliniken Innsbruck (Austria); Schmidauer, C. [Universitaetsklinik fuer Neurologie, Universitaetskliniken Innsbruck (Austria); Waldenberger, P. [Universitaetsklinik fuer Radiologie, Klinische Abt. 1, Universitaetskliniken Innsbruck (Austria); Aichner, F. [Inst. fuer Magnetresonanztomographie und Spektroskopie, Universitaetskliniken Innsbruck (Austria)

1996-11-01

wichtige Ursache von Schlaganfaellen bei juengeren Erwachsenen. Wir untersuchten die diagnostischen Moeglichkeiten der Magnetresonanzangiographie (MRA) in Kombination mit der Magnetresonanztomographie (MRT) bei vertebrobasilaeren Dissektionen anhand einer retrospektiven Analyse von 24 Patienten mit einer Vertebralisdissektion und einem Patienten mit einer Basilarisdissektion. Bei 24 von 25 Patienten (95,5%) wurden mit der Magnetresonanzangiographie abnorme Flussverhaeltnisse im disseziierten Gefaess erkannt. Die Sensitivitaet der konventionellen Angiographie war 100% und die des Ultraschalls 77%. In 7 Faellen (30,4%) ergab die Magnetresonanz spezifische Hinweise auf eine Dissektion (Doppellumen n=1, murales Haematom n=4, Pseudoaneurysma n=2). Demgegenueber standen 36,4% spezifische Befunde in der Angiographie. Dabei waren die spezifischen Resultate von MRT/MRA und Angiographie z.T. komplementaer, beide Methoden zusammen erzielten 43,5% Spezifitaet. Die kombinierte MRT und MRA kann bei etwa 1/3 der Patienten bereits die Diagnose einer Vertebralisdissektion stellen. Bei den anderen Patienten kann die Indikation zur konventionellen Angiographie verbessert werden. Dies gilt besonders fuer jene Patienten mit unspezifischen Prodromalsymptomen. Eine negative Magnetresonanzuntersuchung erzetzt bei Patienten mit hinweisenden Symptomen die konventionelle Angiographie allerdings nicht. Die Angiographie wird aufgrund der hoeheren Ortsaufloesung und der sicheren Beurteilbarkeit auch des proximalen V Abschnittes 1 vorerst diagnostischer Standard bleiben. (orig.)

Energy-efficient relay selection and optimal power allocation for performance-constrained dual-hop variable-gain AF relaying

KAUST Repository

Zafar, Ammar

2013-12-01

This paper investigates the energy-efficiency enhancement of a variable-gain dual-hop amplify-and-forward (AF) relay network utilizing selective relaying. The objective is to minimize the total consumed power while keeping the end-to-end signal-to-noise-ratio (SNR) above a certain peak value and satisfying the peak power constraints at the source and relay nodes. To achieve this objective, an optimal relay selection and power allocation strategy is derived by solving the power minimization problem. Numerical results show that the derived optimal strategy enhances the energy-efficiency as compared to a benchmark scheme in which both the source and the selected relay transmit at peak power. © 2013 IEEE.

Unterrichtsentwurf: Die Entwicklung eines nationalen Identitätsbewusstseins in den von Napoleon besetzten Ländern

Directory of Open Access Journals (Sweden)

Natalie Fridrich

2012-05-01

Full Text Available Nathalie Friedrichs proposes the following lesson plan for the senior classes of the German Gymnasium (grammar-school: „Die Entwicklung eines nationalen Identitätsbewusstseins in den von Napoleon besetzten Ländern“ (The Development of a National Sense of Identity in the Countries Occupied by Napeoleon.The central question, however, is whether this new German national consciousness at the dawn of the 19th century can be traced back to Napoleon’s reign in the Rhineland region or whether it emerged during the wars of liberation as a result of a firm rejection of Napoleon.The following materials will be given to the pupils beforhand: A short preparatory text with essential background information, a pithy quote , and two historical sources, namely the appeal of Ludwig Adolf Peter Graf von Sayn-Wittgenstein to support the war of liberation, and another more francophile source by the physician Adolf Kußmaul. The latter source points in the direction of a positive experience during the time of French occupation and therefore relativises the claim of a German patriotism as a direct result of the war against France. From a didactical viewpoint, the lesson aims to develop the prerequisites for a critical analysis of historical source texts and different points of view on the topic. Finally, a table listing the respective pros and cons of the Napoleonic arguments is sketched out, visualising the perspectives of the students and leading to the final discussion, which should produce answers to the questions of the role of Napoleon for the Germans.

A study on evaluating validity of SNR calculation using a conventional two region method in MR images applied a multichannel coil and parallel imaging technique

Energy Technology Data Exchange (ETDEWEB)

Choi, Kwan Woo; Son, Soon Yong [Dept. of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Min, Jung Whan [Dept. of Radiological Technology, Shingu University, Sungnam (Korea, Republic of); Kwon, Kyung Tae [Dept. of Radiological Technology, Dongnam Health University, Suwon (Korea, Republic of); Yoo, Beong Gyu; Lee, Jong Seok [Dept. of Radiotechnology, Wonkwang Health Science University, Iksan (Korea, Republic of)

2015-12-15

The purpose of this study was to investigate the problems of a signal to noise ratio measurement using a two region measurement method that is conventionally used when using a multi-channel coil and a parallel imaging technique. As a research method, after calculating the standard SNR using a single channel head coil of which coil satisfies three preconditions when using a two region measurement method, we made comparisons and evaluations after calculating an SNR by using a two region measurement method of which method is problematic because it is used without considering the methods recommended by reputable organizations and the preconditions at the time of using a multi-channel coil and a parallel imaging technique. We found that a two region measurement method using a multi-channel coil and a parallel imaging technique shows the highest relative standard deviation, and thus shows a low degree of precision. In addition, we found out that the difference of SNR according to ROI location was very high, and thus a spatial noise distribution was not uniform. Also, 95% confidence interval through Blend-Altman plot is the widest, and thus the conformity degree with a two region measurement method using the standard single channel head coil is low. By directly comparing an AAPM method, which serves as a standard of a performance evaluation test of a magnetic resonance imaging device under the same image acquisition conditions, an NEMA method which can accurately determine the noise level in a signal region and the methods recommended by manufacturers of a magnetic resonance imaging device, there is a significance in that we quantitatively verified the inaccurate problems of a signal to noise ratio using a two region measurement method when using a multi-channel coil and a parallel imaging technique of which method does not satisfy the preconditions that researchers could overlook.

Mechatronics in the car: success through efficient methodological development; Mechatronik im Kraftfahrzeug: Erfolg durch effiziente Entwicklungsmethodik

Energy Technology Data Exchange (ETDEWEB)

Dieterle, W.; Dilger, E. [Bosch (R.) GmbH, Gerlingen (Germany). Zentralbereich Forschung und Vorausentwicklung; Buerger, K.G. [Bosch (R.) GmbH (Germany)

2001-04-01

The ever increasing requirements with respect to fuel consumption, emissions as well as safety and comfort necessitate ever increasing complex functionalities in the car. They are realized, as a rule, by a combination of mechanics, hydraulics, electrics/electronics and, more and more, software. In the past, the development of the various electric/electronic, mechanical or hydraulic components tended to happen at separate levels, nowadays the focus is more on a comprehensive approach to the overall system. In this context, the integrated development of 'mechatronic' components, including the respective software, leads to a targeted solution. (orig.) [German] Staendig steigende Anforderungen hinsichtlich Kraftstoffverbrauch, Emissionen sowie Sicherheit und Komfort bedingen immer komplexere Funktionalitaeten im Kraftfahrzeug. Sie werden in der Regel durch eine Kombination von Mechanik, Hydraulik, Elektrik/Elektronik und zunehmend auch Software realisiert. Nachdem in der Vergangenheit die Entwicklung meist noch auf getrennten Ebenen verlief, steht heute ein uebergreifender, das Gesamtsystem umfassender Ansatz im Vordergrund. Dieser Beitrag der Robert Bosch GmbH berichtet ueber aktuelle Mechatronik-Entwicklungen. Dabei sorgt die integrierte Entwicklung der 'mechatronischen' Komponenten unter Einbezug der zugehoerigen Software fuer eine zielgerichtete Loesung. (orig.)

Discovery of dominant and dormant genes from expression data using a novel generalization of SNR for multi-class problems

Directory of Open Access Journals (Sweden)

Chung I-Fang

2008-10-01

Full Text Available Abstract Background The Signal-to-Noise-Ratio (SNR is often used for identification of biomarkers for two-class problems and no formal and useful generalization of SNR is available for multiclass problems. We propose innovative generalizations of SNR for multiclass cancer discrimination through introduction of two indices, Gene Dominant Index and Gene Dormant Index (GDIs. These two indices lead to the concepts of dominant and dormant genes with biological significance. We use these indices to develop methodologies for discovery of dominant and dormant biomarkers with interesting biological significance. The dominancy and dormancy of the identified biomarkers and their excellent discriminating power are also demonstrated pictorially using the scatterplot of individual gene and 2-D Sammon's projection of the selected set of genes. Using information from the literature we have shown that the GDI based method can identify dominant and dormant genes that play significant roles in cancer biology. These biomarkers are also used to design diagnostic prediction systems. Results and discussion To evaluate the effectiveness of the GDIs, we have used four multiclass cancer data sets (Small Round Blue Cell Tumors, Leukemia, Central Nervous System Tumors, and Lung Cancer. For each data set we demonstrate that the new indices can find biologically meaningful genes that can act as biomarkers. We then use six machine learning tools, Nearest Neighbor Classifier (NNC, Nearest Mean Classifier (NMC, Support Vector Machine (SVM classifier with linear kernel, and SVM classifier with Gaussian kernel, where both SVMs are used in conjunction with one-vs-all (OVA and one-vs-one (OVO strategies. We found GDIs to be very effective in identifying biomarkers with strong class specific signatures. With all six tools and for all data sets we could achieve better or comparable prediction accuracies usually with fewer marker genes than results reported in the literature using the

Nitrogen and phosphorus treatment of marine wastewater by a laboratory-scale sequencing batch reactor with eco-friendly marine high-efficiency sediment.

Science.gov (United States)

Cho, Seonghyeon; Kim, Jinsoo; Kim, Sungchul; Lee, Sang-Seob

2017-06-22

We screened and identified a NH 3 -N-removing bacterial strain, Bacillus sp. KGN1, and a [Formula: see text] removing strain, Vibrio sp. KGP1, from 960 indigenous marine isolates from seawater and marine sediment from Tongyeong, South Korea. We developed eco-friendly high-efficiency marine sludge (eco-HEMS), and inoculated these marine bacterial strains into the marine sediment. A laboratory-scale sequencing batch reactor (SBR) system using the eco-HEMS for marine wastewater from land-based fish farms improved the treatment performance as indicated by 88.2% removal efficiency (RE) of total nitrogen (initial: 5.6 mg/L) and 90.6% RE of total phosphorus (initial: 1.2 mg/L) under the optimal operation conditions (food and microorganism (F/M) ratio, 0.35 g SCOD Cr /g mixed liquor volatile suspended solids (MLVSS)·d; dissolved oxygen (DO) 1.0 ± 0.2 mg/L; hydraulic retention time (HRT), 6.6 h; solids retention time (SRT), 12 d). The following kinetic parameters were obtained: cell yield (Y), 0.29 g MLVSS/g SCOD Cr ; specific growth rate (µ), 0.06 d -1 ; specific nitrification rate (SNR), 0.49 mg NH 3 -N/g MLVSS·h; specific denitrification rate (SDNR), 0.005 mg [Formula: see text]/g MLVSS·h; specific phosphorus uptake rate (SPUR), 0.12 mg [Formula: see text]/g MLVSS·h. The nitrogen- and phosphorus-removing bacterial strains comprised 18.4% of distribution rate in the microbial community of eco-HEMS under the optimal operation conditions. Therefore, eco-HEMS effectively removed nitrogen and phosphorus from highly saline marine wastewater from land-based fish farms with improving SNR, SDNR, and SPUR values in more diverse microbial communities. DO: dissolved oxygen; Eco-HEMS: eco-friendly high efficiency marine sludge; F/M: food and microorganism ratio; HRT: hydraulic retention time; ML(V)SS: mixed liquor (volatile) suspended solids; NCBI: National Center for Biotechnology Information; ND: not determined; qPCR: quantitative real-time polymerase

Use of zero power plutonium reactor measurements as a support of criticality prediction for the SNR-300

International Nuclear Information System (INIS)

Pilate, S.; de Wouters, R.; Wehmann, U.; Helm, F.; Scholtyssek, W.

1978-01-01

Evaluations of criticality measurements performed in various SNEAK and Zero Power Plutonium Reactor (ZPPR) cores are compared. The best available methods of calculations (including transport theory) are used. The ZPPR results support well the trend indicated by the SNEAK evaluations for clean cores and for cores with followers; for cores with absorbers partially inserted, the agreement is only rough. Evaluations of control rod worth measurements are therefore also compared, using the routine method of calculation for SNR-300 (diffusion theory). The control rod worths are largely underestimated in SNEAK (C/E = 0.89), but only slightly underestimated in the ZPPR (C/E = 0.97). The difference in the nature of core fuel (uranium in SNEAK, plutonium in the ZPPR) could be at the origin of this discrepancy

Efficient power allocation for fixed-gain amplify-and-forward relaying in rayleigh fading

KAUST Repository

Zafar, Ammar

2013-06-01

In this paper, we study power allocation strategies for a fixed-gain amplify-and-forward relay network employing multiple relays. We consider two optimization problems for the relay network: 1) optimal power allocation to maximize the end-to-end signal-to-noise ratio (SNR) and 2) minimizing the total consumed power while maintaining the end-to-end SNR over a threshold value. We assume that the relays have knowledge of only the channel statistics of all the links. We show that the SNR maximization problem is concave and the power minimization problem is convex. Hence, we solve the problems through convex programming. Numerical results show the benefit of allocating power optimally rather than uniformly. © 2013 IEEE.

Background- and simulated leak-noise measurements on ASB-loop, KNK II- and SNR 300-steam generators

International Nuclear Information System (INIS)

Voss, J.; Arnaoutis, N.; Foerster, K.; Moellerfeld, H.

1990-01-01

During several leak propagation experiments in the ASB sodium loop noise measurements were performed showing the acoustic behaviour of evoluting leaks in a tube bundle section under sodium. Effects like self evolution, secondary leaks and tube ruptures by overheating occurred during these tests and were reflected in the course of acoustic signals. In one of the KNK II steam generators simulated leak noise was detected against background noise throughout the operating power range. Experimental arrangements and results are described. In SNR 300 all of the SGUs are equipped with waveguides and some with accelerometers for background noise measurements. First measurement under isothermal conditions were performed in the past. A gas injection device for acoustic leak simulation is under construction. The design of the experimental acoustic system and first results are presented. (author). 1 ref., 21 figs, 2 tabs

Two-dimensional geometrical corner singularities in neutron diffusion. Part 2: Application to the SNR-300 benchmark

International Nuclear Information System (INIS)

Cacuci, D.G.; Univ. of Karlsruhe; Kiefhaber, E.; Stehle, B.

1998-01-01

The explicit solution developed by Cacuci for the multigroup neutron diffusion equation at interior corners in two-dimensional two-region domains has been applied to the SNR-300 fast reactor prototype design to obtain the exact behavior of the multigroup fluxes at and around typical corners arising between absorber/fuel and follower/fuel assemblies. The calculations have been performed in hexagonal geometry using four energy groups, and the results clearly show that the multigroup fluxes are finite but not analytical at interior corners. In particular, already the first-order spatial derivatives of the multigroup fluxes become unbounded at the corners between follower and fuel assemblies. These results highlight the need to treat properly the influence of corners, both for the direct calculation and for the reconstruction of pointwise neutron flux and power distributions in heterogeneous reactor cores

Effects of image processing on the detective quantum efficiency

Science.gov (United States)

Park, Hye-Suk; Kim, Hee-Joung; Cho, Hyo-Min; Lee, Chang-Lae; Lee, Seung-Wan; Choi, Yu-Na

2010-04-01

Digital radiography has gained popularity in many areas of clinical practice. This transition brings interest in advancing the methodologies for image quality characterization. However, as the methodologies for such characterizations have not been standardized, the results of these studies cannot be directly compared. The primary objective of this study was to standardize methodologies for image quality characterization. The secondary objective was to evaluate affected factors to Modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) according to image processing algorithm. Image performance parameters such as MTF, NPS, and DQE were evaluated using the international electro-technical commission (IEC 62220-1)-defined RQA5 radiographic techniques. Computed radiography (CR) images of hand posterior-anterior (PA) for measuring signal to noise ratio (SNR), slit image for measuring MTF, white image for measuring NPS were obtained and various Multi-Scale Image Contrast Amplification (MUSICA) parameters were applied to each of acquired images. In results, all of modified images were considerably influence on evaluating SNR, MTF, NPS, and DQE. Modified images by the post-processing had higher DQE than the MUSICA=0 image. This suggests that MUSICA values, as a post-processing, have an affect on the image when it is evaluating for image quality. In conclusion, the control parameters of image processing could be accounted for evaluating characterization of image quality in same way. The results of this study could be guided as a baseline to evaluate imaging systems and their imaging characteristics by measuring MTF, NPS, and DQE.

New evidence for efficient collisionless heating of electrons at the reverse shock of a young supernova remnant

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, Hiroya; Petre, Robert [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States); Eriksen, Kristoffer A. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Badenes, Carles [Department of Physics and Astronomy and Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC), University of Pittsburgh, 3941 O' Hara St, Pittsburgh, PA 15260 (United States); Hughes, John P. [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Brickhouse, Nancy S.; Foster, Adam R.; Patnaude, Daniel J.; Slane, Patrick O.; Smith, Randall K., E-mail: hiroya.yamaguchi@nasa.gov [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2014-01-10

Although collisionless shocks are ubiquitous in astrophysics, certain key aspects of them are not well understood. In particular, the process known as collisionless electron heating, whereby electrons are rapidly energized at the shock front, is one of the main open issues in shock physics. Here, we present the first clear evidence for efficient collisionless electron heating at the reverse shock of Tycho's supernova remnant (SNR), revealed by Fe K diagnostics using high-quality X-ray data obtained by the Suzaku satellite. We detect Kβ (3p → 1s) fluorescence emission from low-ionization Fe ejecta excited by energetic thermal electrons at the reverse shock front, which peaks at a smaller radius than Fe Kα (2p → 1s) emission dominated by a relatively highly ionized component. Comparisons with our hydrodynamical simulations imply instantaneous electron heating to a temperature 1000 times higher than expected from Coulomb collisions alone. The unique environment of the reverse shock, which is propagating with a high Mach number into rarefied ejecta with a low magnetic field strength, puts strong constraints on the physical mechanism responsible for this heating and favors a cross-shock potential created by charge deflection at the shock front. Our sensitive observation also reveals that the reverse shock radius of this SNR is about 10% smaller than the previous measurement using the Fe Kα morphology from the Chandra observations. Since strong Fe Kβ fluorescence is expected only from low-ionization plasma where Fe ions still have many 3p electrons, this feature is key to diagnosing the plasma state and distribution of the immediate postshock ejecta in a young SNR.

New Evidence for Efficient Collisionless Heating of Electrons at the Reverse Shock of a Young Supernova Remnant

Science.gov (United States)

Yamaguchi, Hiroya; Eriksen, Kristoffer A.; Badenes, Carles; Hughes, John P.; Brickhouse, Nancy S.; Foster, Adam R.; Patnaude, Daniel J.; Petre, Robert; Slane, Patrick O.; Smith, Randall K.

2013-01-01

Although collisionless shocks are ubiquitous in astrophysics, certain key aspects of them are not well understood. In particular, the process known as collisionless electron heating, whereby electrons are rapidly energized at the shock front, is one of the main open issues in shock physics. Here, we present the first clear evidence for efficient collisionless electron heating at the reverse shock of Tycho's supernova remnant (SNR), revealed by Fe K diagnostics using high-quality X-ray data obtained by the Suzaku satellite. We detect K beta (3p yields 1s) fluorescence emission from low-ionization Fe ejecta excited by energetic thermal electrons at the reverse shock front, which peaks at a smaller radius than Fe K alpha (2p yields 1s) emission dominated by a relatively highly ionized component. Comparisons with our hydrodynamical simulations imply instantaneous electron heating to a temperature 1000 times higher than expected from Coulomb collisions alone. The unique environment of the reverse shock, which is propagating with a high Mach number into rarefied ejecta with a low magnetic field strength, puts strong constraints on the physical mechanism responsible for this heating and favors a cross-shock potential created by charge deflection at the shock front. Our sensitive observation also reveals that the reverse shock radius of this SNR is about 10% smaller than the previous measurement using the Fe K alpha morphology from the Chandra observations. Since strong Fe K beta fluorescence is expected only from low-ionization plasma where Fe ions still have many 3p electrons, this feature is key to diagnosing the plasma state and distribution of the immediate postshock ejecta in a young SNR.

EVALUATION OF THE EFFECT OF SPUTUM STORAGE CONDITIONS ON THE VITAL PROPERTIES OF TUBERCULOUS MYCOBACTERIA

Directory of Open Access Journals (Sweden)

Yu. D. Rodionova

2017-01-01

Full Text Available Goal of the study: to enhance efficiency of laboratory diagnostics of tuberculous infection through investigating the effect of various storage conditions of samples on the growth properties of Tuberculosis complex mycobacteria.Materials and Methods. 2058 samples of sputum collected by coughing were examined. All sputum samples were aliquoted into 5 parts stored under various conditions: in the fridge under +7°С for 2 hours; frozen for 7 days; by room indoor temperature for 48-72 hours; with the use preservative 10% solution of triple-substituted natrium phosphate for 48 hours; in the fridge under +7°С for 2 hours with consequent treatment by 1% solution of N-acetyl-L-cysteine.Results. The most optimal sputum storage conditions are freezing by -20°С, providing maximum safety of mycobacteria and minimum contamination of the samples with foreign bacteria. Sputum storage by indoor room temperature for 2-3 days reduces the number of positive results of cultures on nutritive media. Using 10% solution of triple-substituted natrium phosphate provides high positive results of bacterioscopic and cultural testing techniques. Time prolongation for biomaterials storage in the preservative solution for more than 72 hours results in the death tuberculous mycobacteria. 

A GPS Sensing Strategy for Accurate and Energy-Efficient Outdoor-to-Indoor Handover in Seamless Localization Systems

Directory of Open Access Journals (Sweden)

Yungeun Kim

2012-01-01

Full Text Available Indoor localization systems typically locate users on their own local coordinates, while outdoor localization systems use global coordinates. To achieve seamless localization from outdoors to indoors, a handover technique that accurately provides a starting position to the indoor localization system is needed. However, existing schemes assume that a starting position is known a priori or uses a naïve approach to consider the last location obtained from GPS as the handover point. In this paper, we propose an accurate handover scheme that monitors the signal-to-noise ratio (SNR of the effective GPS satellites that are selected according to their altitude. We also propose an energy-efficient handover mechanism that reduces the GPS sampling interval gradually. Accuracy and energy efficiency are experimentally validated with the GPS logs obtained in real life.

Nuclear Power Station Kalkar, 300 MWe Prototype Nuclear Power Plant with Fast Sodium Cooled Reactor (SNR-300), Plant description

International Nuclear Information System (INIS)

1984-06-01

The nuclear power station Kalkar (SNR-300) is a prototype with a sodium cooled fast reactor and a thermal power of 762 MW. The present plant description has been made available in parallel to the licensing procedure for the reactor plant and its core Mark-Ia as supplementary information for the public. The report gives a detailed description of the whole plant including the prevention measures against the impact of external and plant internal events. The radioactive materials within the reactor cooling system and the irradiation protection and surveillance measures are outlined. Finally, the operation of the plant is described with the start-up procedures, power operation, shutdown phases with decay heat removal and handling procedures

Seismic risk analysis for the fast breeder prototype SNR-300 in Kalkar (FRG)

International Nuclear Information System (INIS)

Hosser, D.

1983-01-01

This paper summarizes the seismic part of the SNR-300 Risk Oriented Analysis. Two different approaches were used for the seismic hazard description. In the first one, similar to the German Risk Study for PWR, the seismic input was given by a site-independent mean acceleration response spectrum and duration of strong motion prescribed for the design of the plant; the spectrum was scaled with the peak ground acceleration the probability of exceedance of which at the site Kalkar had been calculated in a former seismic hazard tudy. For the second approach, site- and intensity- dependent mean acceleration response spectra and duration of strong motion were derived and the probability of exceedance of the site intensity was evaluated in a probabilistic seismic hazard analysis. The seismic responses of safety related and other important buildings were calculated by time-history analyses using artificial acceleration time-histories with the given frequency content and duration of strong motion. The influence of uncertainties in dynamic soil parameters and structural modelling was assessed in parametric studies. Some important structural elements within the buildings were investigated in more detail. Their seismic performance was evaluated using ultimate limit state definitions according to the respective design codes or rotation limits for nonlinear dynamic calculations. (orig./RW)

Long-distance transport of natrium in bean plants

International Nuclear Information System (INIS)

Marschner, H.; Ossenberg-Neuhaus, H.

1976-01-01

After Na + -application to a certain zone of the root or after application to the tip or to the base of a primary leaf or along the stem of bean plants, the long-distance transport of Na + was studied. The age of the plants was 8 d when root application took place, 10 d at the time of leaf application. After application to the root zone, the long-distance transport of Na + in the direction of the shoot was strongly prevented, and the transport in the direction of the root point could be neglected. Presence of K + in the ambient nutritive solution led to a strong increase of Na + efflux from the roots. Within 48 hrs., 30-40% of the Na + applied to a primary leaf were transported towards the roots. The Na + efflux to the ambient nutritive solution came from the basal regions; it was mostly more than 10% of the amount recepted through the leaf and was only slightly increased by the presence of K + in the external solution. In the case of Na + application through the hypokotyl, this Na + -efflux from the roots was even more than 25% within 12 hrs. Both with leaf and with stem application, only 1% of the Na + taken up was transported in the direction of the shoot point. The separation of the hypocotyl tissue in the bark and in the central cylinder showed the extremely high Na + storage capacity of the central cylinder. The transfer of Na + from the central cylinder into the bark seems to be fast in the hypocotyl, while the escape of Na + from the phloem of the bark into the central cylinder is rather limited. Long-distance transport of Na + in the phloem of the bark is highly basispetal and of high efficiency. Low Na + -contents in bean leaves are thus due to several regulation mechanisms: K + -stimulated Na + -efflux in the root, restricted long-distance transport in the xylemadue to high storage capacity of the xylemparenchyma, Na + influx pumps at the phloem in stem and leaf and strictly basipetal phloem-retransport of Na + in the root and efflux into the surrounding

Fluctuations of the SNR at the output of the MVDR with Regularized Tyler Estimators

KAUST Repository

Elkhalil, Khalil

2016-12-27

This paper analyzes the statistical properties of the signal-to-noise ratio (SNR) at the output of the Capon\\'s minimum variance distortionless response (MVDR) beamformers when operating over impulsive noises. Particularly, we consider the supervised case in which the receiver employs the regularized Tyler estimator in order to estimate the covariance matrix of the interference-plus-noise process using n observations of size N×1N×1. The choice for the regularized Tylor estimator (RTE) is motivated by its resilience to the presence of outliers and its regularization parameter that guarantees a good conditioning of the covariance estimate. Of particular interest in this paper is the derivation of the second order statistics of the SINR. To achieve this goal, we consider two different approaches. The first one is based on considering the classical regime, referred to as the n-large regime, in which N is assumed to be fixed while n grows to infinity. The second approach is built upon recent results developped within the framework of random matrix theory and assumes that N and n grow large together. Numerical results are provided in order to compare between the accuracies of each regime under different settings.

Mycotic aneurysm of the superior mesenteric artery after septic embolism; Entwicklung eines mykotischen Aneurysmas der A. mesenterica superior nach septischer Embolie

Energy Technology Data Exchange (ETDEWEB)

Schmidt, F.; Dinkel, H.P. [Institut fuer Diagnostische Radiologie, Inselspital, Universitaetsklinik Bern (Switzerland)

2002-07-01

Mycotic aneurysms of the aorta and the visceral arteries are life-threatening diseases, due to potential rupture and organ or limb ischemia. They occur in endocarditis, immunodeficiency, bacteremia and fungemia, and have a poor prognosis.We report on a case of a 54-year-old male patient suffering from abdominal angina after mitral valve replacement for septic mycotic endocarditis. In presence of a mycotic-embolic occlusion of the left popliteal artery and multiple septic organ infarctions a mycotic aneurysm of the superior mesenteric artery was found in abdominal spiral-CT.Based on sequential spiral-CT examinations, this case demonstrates the development of a septic aneurysm of the superior mesenteric artery. (orig.) [German] Mykotische Aneurysmen der Aorta und ihrer Aeste stellen wegen Rupturgefahr und moeglicher Minderperfusion von Organen und Extremitaeten eine lebensgefaehrliche Erkrankung mit unguenstiger Prognose dar. Beguenstigende Faktoren sind geschwaechte Immunabwehr, Endokarditis, Bakteriaemie und Fungaemie.Wir berichten ueber einen 54-jaehrigen Patienten, der nach einem Mitralklappenersatz bei mykotischer Endokarditis zunehmende abdominelle Beschwerden im Sinne einer Angina abdominalis entwickelte. Die abdominelle Spiralcomputertomographie zeigte ein mykotisches Aneurysma der A. mesenterica superior. Daneben bestanden ein mykotischer Verschluss der linken A. poplitea und multiple septische Organinfarkte.Der Fall demonstriert anhand sequentieller Computertomographien eindrucksvoll die Entwicklung eines septischen Viszeralarterienaneurysmas. (orig.)

Efficient FIR Filter Implementations for Multichannel BCIs Using Xilinx System Generator

Directory of Open Access Journals (Sweden)

Usman Ghani

2018-01-01

Full Text Available Background. Brain computer interface (BCI is a combination of software and hardware communication protocols that allow brain to control external devices. Main purpose of BCI controlled external devices is to provide communication medium for disabled persons. Now these devices are considered as a new way to rehabilitate patients with impunities. There are certain potentials present in electroencephalogram (EEG that correspond to specific event. Main issue is to detect such event related potentials online in such a low signal to noise ratio (SNR. In this paper we propose a method that will facilitate the concept of online processing by providing an efficient filtering implementation in a hardware friendly environment by switching to finite impulse response (FIR. Main focus of this research is to minimize latency and computational delay of preprocessing related to any BCI application. Four different finite impulse response (FIR implementations along with large Laplacian filter are implemented in Xilinx System Generator. Efficiency of 25% is achieved in terms of reduced number of coefficients and multiplications which in turn reduce computational delays accordingly.

Efficient FIR Filter Implementations for Multichannel BCIs Using Xilinx System Generator.

Science.gov (United States)

Ghani, Usman; Wasim, Muhammad; Khan, Umar Shahbaz; Mubasher Saleem, Muhammad; Hassan, Ali; Rashid, Nasir; Islam Tiwana, Mohsin; Hamza, Amir; Kashif, Amir

2018-01-01

Background . Brain computer interface (BCI) is a combination of software and hardware communication protocols that allow brain to control external devices. Main purpose of BCI controlled external devices is to provide communication medium for disabled persons. Now these devices are considered as a new way to rehabilitate patients with impunities. There are certain potentials present in electroencephalogram (EEG) that correspond to specific event. Main issue is to detect such event related potentials online in such a low signal to noise ratio (SNR). In this paper we propose a method that will facilitate the concept of online processing by providing an efficient filtering implementation in a hardware friendly environment by switching to finite impulse response (FIR). Main focus of this research is to minimize latency and computational delay of preprocessing related to any BCI application. Four different finite impulse response (FIR) implementations along with large Laplacian filter are implemented in Xilinx System Generator. Efficiency of 25% is achieved in terms of reduced number of coefficients and multiplications which in turn reduce computational delays accordingly.

Measurement of moisture motion under a temperature gradient in a concrete for SNR-300 using thermal neutrons

International Nuclear Information System (INIS)

Zelinger, A.

1975-01-01

For describing the behavior of the moisture in the concrete of the containment of SNR-300 in a hypothetical accident parameters were determined experimentally. The method is based on transmission of thermal neutrons through a plate of concrete. When a temperature of 170 deg C was applied at one end of the plate migration of moisture and evaporation took place. This could be observed by neutron radiography giving a gross picture of moisture migration. Furthermore the intensity of the transmitted neutron beam was measured with a neutron counter. From these values profiles of the change of moisture concentration could be obtained with a spatial resolution of few millimeters. The method used is entirely different from the conventional moisture meters which use fast neutrons. From the experimental data the mass transfer coefficient of vapour, the diffusion coefficient of vapour in concrete and the porosity of the concrete could be determined

Analysis on frequency response of trans-impedance amplifier (TIA) for signal-to-noise ratio (SNR) enhancement in optical signal detection system using lock-in amplifier (LIA)

Science.gov (United States)

Kim, Ji-Hoon; Jeon, Su-Jin; Ji, Myung-Gi; Park, Jun-Hee; Choi, Young-Wan

2017-02-01

Lock-in amplifier (LIA) has been widely used in optical signal detection systems because it can measure small signal under high noise level. Generally, The LIA used in optical signal detection system is composed of transimpedance amplifier (TIA), phase sensitive detector (PSD) and low pass filter (LPF). But commercial LIA using LPF is affected by flicker noise. To avoid flicker noise, there is 2ω detection LIA using BPF. To improve the dynamic reserve (DR) of the 2ω LIA, the signal to noise ratio (SNR) of the TIA should be improved. According to the analysis of frequency response of the TIA, the noise gain can be minimized by proper choices of input capacitor (Ci) and feed-back network in the TIA in a specific frequency range. In this work, we have studied how the SNR of the TIA can be improved by a proper choice of frequency range. We have analyzed the way to control this frequency range through the change of passive component in the TIA. The result shows that the variance of the passive component in the TIA can change the specific frequency range where the noise gain is minimized in the uniform gain region of the TIA.

An Energy-Efficient Target Tracking Framework in Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Zhijun Yu

2009-01-01

Full Text Available This study devises and evaluates an energy-efficient distributed collaborative signal and information processing framework for acoustic target tracking in wireless sensor networks. The distributed processing algorithm is based on mobile agent computing paradigm and sequential Bayesian estimation. At each time step, the short detection reports of cluster members will be collected by cluster head, and a sensor node with the highest signal-to-noise ratio (SNR is chosen there as reference node for time difference of arrive (TDOA calculation. During the mobile agent migration, the target state belief is transmitted among nodes and updated using the TDOA measurement of these fusion nodes one by one. The computing and processing burden is evenly distributed in the sensor network. To decrease the wireless communications, we propose to represent the belief by parameterized methods such as Gaussian approximation or Gaussian mixture model approximation. Furthermore, we present an attraction force function to handle the mobile agent migration planning problem, which is a combination of the node residual energy, useful information, and communication cost. Simulation examples demonstrate the estimation effectiveness and energy efficiency of the proposed distributed collaborative target tracking framework.

SNR and Standard Deviation of cGNSS-R and iGNSS-R Scatterometric Measurements.

Science.gov (United States)

Alonso-Arroyo, Alberto; Querol, Jorge; Lopez-Martinez, Carlos; Zavorotny, Valery U; Park, Hyuk; Pascual, Daniel; Onrubia, Raul; Camps, Adriano

2017-01-19

This work addresses the accuracy of the Global Navigation Satellite Systems (GNSS)-Reflectometry (GNSS-R) scatterometric measurements considering the presence of both coherent and incoherent scattered components, for both conventional GNSS-R (cGNSS-R) and interferometric GNSS-R (iGNSS-R) techniques. The coherent component is present for some type of surfaces, and it has been neglected until now because it vanishes for the sea surface scattering case. Taking into account the presence of both scattering components, the estimated Signal-to-Noise Ratio (SNR) for both techniques is computed based on the detectability criterion, as it is done in conventional GNSS applications. The non-coherent averaging operation is considered from a general point of view, taking into account that thermal noise contributions can be reduced by an extra factor of 0.88 dB when using partially overlapped or partially correlated samples. After the SNRs are derived, the received waveform's peak variability is computed, which determines the system's capability to measure geophysical parameters. This theoretical derivations are applied to the United Kingdom (UK) TechDemoSat-1 (UK TDS-1) and to the future GNSS REflectometry, Radio Occultation and Scatterometry on board the International Space Station (ISS) (GEROS-ISS) scenarios, in order to estimate the expected scatterometric performance of both missions.

Dose efficiency and low-contrast detectability of an amorphous silicon x-ray detector for digital radiography

International Nuclear Information System (INIS)

Aufrichtig, Richard

2000-01-01

The effect of dose reduction on low-contrast detectability is investigated theoretically and experimentally for a production grade amorphous silicon (a-Si) x-ray detector and compared with a standard thoracic screen-film combination. A non-prewhitening matched filter observer model modified to include a spatial response function and internal noise for the human visual system (HVS) is used to calculate a signal-to-noise ratio (SNR) related to object detectability. Other inputs to the SNR calculation are the detective quantum efficiency (DQE) and the modulation transfer function (MTF) of the imaging system. Besides threshold detectability, the model predicts the equivalent perception dose ratio (EPDR), which is the fraction of the screen-film exposure for which the digital detector provides equal detectability. Images of a contrast-detail phantom are obtained with the digital detector at dose levels corresponding to 27%, 41%, 63% and 100% of the dose used for screen-film. The images are used in a four-alternative forced choice (4-AFC) observer perception study in order to measure threshold detectability. A statistically significant improvement in contrast detectability is measured with the digital detector at 100% and 63% of the screen-film dose. There is no statistical difference between screen-film and digital at 41% of the dose. On average, the experimental EPDR is 44%, which agrees well with the model prediction of 40%. (author)

Fevers and Chills: Separating thermal and synchrotron components in SNR spectra

Science.gov (United States)

Fedor, Emily Elizabeth; Martina-Hood, Hyourin; Stage, Michael D.

2018-06-01

Spatially-resolved spectroscopy is an extremely powerful tool in X-ray analysis of extended sources, but can be computationally difficult if a source exhibits complex morphology. For example, high-resolution Chandra data of bright Galactic supernova remnants (Cas A, Tycho, etc.) allow extractions of high-quality spectra from tens to hundreds of thousands of regions, providing a rich laboratory for localizing emission from processes such as thermal line emission, bremsstrahlung, and synchrotron. This soft-band analysis informs our understanding of the typically nonthermal hard X-ray emission observed with other lower-resolution instruments. The analysis is complicated by both projection effects and the presence of multiple emission mechanisms in some regions. In particular, identifying regions with significant nonthermal emission is critical to understanding acceleration processes in remnants. Fitting tens of thousands of regions with complex, multi-component models can be time-consuming and involve so many free parameters that little constraint can be placed on the values. Previous work by Stage & Allen ('06, '07, '11) on Cas A used a technique to identify regions dominated by the highest-cutoff synchrotron emission by fitting with a simple thermal emission model and identifying regions with anomalously high apparent temperatures (caused by presence of the high-energy tail of the synchrotron emission component). Here, we present a similar technique. We verify the previous approach and, more importantly, expand it to include a method to identify regions containing strong lower-cutoff synchrotron radiation. Such regions might be associated with the reverse-shock of a supernova. Identification of a nonthermal electron population in the interior of an SNR would have significant implications for the energy balance and emission mechanisms producing the high-energy (> 10 keV) spectrum.

The influence of the reactivity ramp on the course of the power transient in the MARK 1A core of the SNR 300

International Nuclear Information System (INIS)

Froehlich, R.; Schmuck, P.

1976-01-01

The course of a hypothetic transient overpower accident caused by the onset of a not further specified reactivity ramp accompanied by the simultaneous failure of both shutdown systems must be analyzed in the SNR 300 Mark 1A core licensing procedure. The present study is limited to the discussion of the starting and shutdown phases of such accidents for the fresh core. Depending on the operational state of the reactor, the core geometry is still intact during the starting phase. In the following shutdown phase (core disassembly phase), large-scale mass transfer leads to the nuclear shutdown of the reactor. (orig./AK) [de

Efficient multi-site two-photon functional imaging of neuronal circuits.

Science.gov (United States)

Castanares, Michael Lawrence; Gautam, Vini; Drury, Jack; Bachor, Hans; Daria, Vincent R

2016-12-01

Two-photon imaging using high-speed multi-channel detectors is a promising approach for optical recording of cellular membrane dynamics at multiple sites. A main bottleneck of this technique is the limited number of photons captured within a short exposure time (~1ms). Here, we implement temporal gating to improve the two-photon fluorescence yield from holographically projected multiple foci whilst maintaining a biologically safe incident average power. We observed up to 6x improvement in the signal-to-noise ratio (SNR) in Fluorescein and cultured hippocampal neurons showing evoked calcium transients. With improved SNR, we could pave the way to achieving multi-site optical recording of fluorogenic probes with response times in the order of ~1ms.

Low SNR capacity for MIMO Rician and Rayleigh-product fading channels with single co-channel interferer and noise

KAUST Repository

Zhong, Caijun

2010-09-01

This paper studies the ergodic capacity of multiple-input multiple-output (MIMO) systems with a single co-channel interferer in the low signal-to-noise-ratio (SNR) regime. Two MIMO models namely Rician and Rayleigh-product channels are investigated. Exact analytical expressions for the minimum energy per information bit, {Eb/N0min, and wideband slope, S0, are derived for both channels. Our results show that the minimum energy per information bit is the same for both channels while their wideband slopes differ significantly. Further, the impact of the numbers of transmit and receive antennas, the Rician K factor, the channel mean matrix and the interference-to-noise-ratio (INR) on the capacity, is addressed. Results indicate that interference degrades the capacity by increasing the required minimum energy per information bit and reducing the wideband slope. Simulation results validate our analytical results. © 2010 IEEE.

Development of a new thin film technology for PV systems: Open-system CCSVT process for production of ZnSe/CuGaSe{sub 2} hetero diodes. Final report; Entwicklung einer neuen Duennschichttechnologie fuer die Photovoltaik: CCSVT-Verfahren im offenen System zur Herstellung von ZnSe/CuGaSe{sub 2}-Heterodioden. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Lux-Steiner, M.C.; Jaeger-Waldau, A.

2000-07-01

A new technology for fast, large-surface deposition of high-quality semiconducting thin films for PV systems. The new technology, CSVT (close-space vapour transport), is based on a combination of VPE (vapour phase epitaxy) in open systems and CVT (chemical vapour phase transport) in closed systems. The two-source CVD experiments with two different transport gases, i.e. Cu{sub 2}Se with iodine and Ga{sub 2}Se{sub 3} with HCl, enabled controlled variation of the Cu:Ga ratio in the gaseous phase. The solar cells produced had efficiencies of more than 4%. The best solar cell produced had an efficiency of 4.8% and an open terminal voltage of 863 mV. [German] Ziel des Vorhabens war die Entwicklung einer neuen Technologie zur schnellen, grossflaechigen Abscheidung von qualitativ hochstehenden, halbleitenden Duennschichten fuer die Photovoltaik. Das Konzept des neuen Abscheideverfahrens, CSVT (close-space vapour transport) im offenen System, basiert auf einer Kombination der etablierten Methoden VPE (vapour phase epitaxy) im offenen und CVT (chemical vapour phase transport) im geschlossenen System. Die 2-Quellen-CVD-Experimente mit den zwei unterschiedlichen Transportgasen (Cu{sub 2}Se mit Iod; Ga{sub 2}Se{sub 3} mit HCl) ermoeglichten die kontrollierte Variation des Cu:Ga=Verhaeltnisses in der Gasphase. Bisher konnten so Solarzellen mit Wirkungsgraden ueber 4% hergestellt werden, wobei bei der bisher besten Solarzelle ein Wirkungsgrad von {eta}=4.8% und eine offene Klemmenspannung von V{sub oc}=863 mV erreicht wurde. (orig.)

Continuous method of natrium purification

International Nuclear Information System (INIS)

Batoux, B.; Laurent-Atthalin, A.; Salmon, M.

1975-01-01

An improvement of the known method for the production of highly pure sodium from technically pure sodium which still contains several hundred ppm metallic impurities is proposed. These impurities, first of all Ca and Ba, are separated by oxidation with sodium peroxide. The continuous method is new which can also be performed on a technically large scale and which results in a degree of purity of less than 10 ppm Ca. Under N 2 -atmosphere, highly dispersed sodium peroxide is added to a flow of sodium, and at 100 0 C to 150 0 C, thoroughly mixed, the suspension is heated under turbulence to 200 0 C to 300 0 C, and the forming oxides are separated. Exact data for an optimum reaction guide as well as a flow diagram are supplied. (UWI) [de

Continuous method of natrium purification

Energy Technology Data Exchange (ETDEWEB)

Batoux, B; Laurent-Atthalin, A; Salmon, M

1975-05-28

An improvement of the known method for the production of highly pure sodium from technically pure sodium which still contains several hundred ppm metallic impurities is proposed. These impurities, first of all Ca and Ba, are separated by oxidation with sodium peroxide. The new continuous method can be performed on a technically large scale and results in a degree of purity of less than 10 ppm Ca. Under N/sub 2/ -atmosphere, highly dispersed sodium peroxide is added to a flow of sodium, and at 100/sup 0/C to 150/sup 0/C, thoroughly mixed, the suspension is heated under turbulence to 200/sup 0/C to 300/sup 0/C, and the forming oxides are separated. Exact data for an optimum reaction guide as well as a flow diagram are supplied.

From the components to the stack. Developing and designing 5kW HT-PEFC stacks; Von der Komponente zum Stack. Entwicklung und Auslegung von HT-PEFC-Stacks der 5 kW-Klasse

Energy Technology Data Exchange (ETDEWEB)

Bendzulla, Anne

2010-12-22

The aim of the present project is to develop a stack design for a 5-kW HTPEFC system. First, the state of the art of potential materials and process designs will be discussed for each component. Then, using this as a basis, three potential stack designs with typical attributes will be developed and assessed in terms of practicality with the aid of a specially derived evaluation method. Two stack designs classified as promising will be discussed in detail, constructed and then characterized using short stack tests. Comparing the stack designs reveals that both designs are fundamentally suitable for application in a HT-PEFC system with on-board supply. However, some of the performance data differ significantly for the two stack designs. The preferred stack design for application in a HT-PEFC system is characterized by robust operating behaviour and reproducible high-level performance data. Moreover, in compact constructions (120 W/l at 60 W/kg), the stack design allows flexible cooling with thermal oil or air, which can be adapted to suit specific applications. Furthermore, a defined temperature gradient can be set during operation, allowing the CO tolerance to be increased by up to 10 mV. The short stack design developed within the scope of the present work therefore represents an ideal basis for developing a 5-kW HT-PEFC system. Topics for further research activities include improving the performance by reducing weight and/or volume, as well as optimizing the heat management. The results achieved within the framework of this work clearly show that HTPEFC stacks have the potential to play a decisive role in increasing efficiency in the future, particularly when combined with an on-board supply system. (orig.) [German] Ziel der vorliegenden Arbeit ist die Entwicklung eines Stackkonzeptes fuer ein 5 kW-HT-PEFC System. Dazu wird zunaechst fuer jede Komponente der Stand der Technik moeglicher Materialien und Prozesskonzepte diskutiert. Darauf aufbauend werden drei

SNR and Standard Deviation of cGNSS-R and iGNSS-R Scatterometric Measurements

Directory of Open Access Journals (Sweden)

Alberto Alonso-Arroyo

2017-01-01

Full Text Available This work addresses the accuracy of the Global Navigation Satellite Systems (GNSS-Reflectometry (GNSS-R scatterometric measurements considering the presence of both coherent and incoherent scattered components, for both conventional GNSS-R (cGNSS-R and interferometric GNSS-R (iGNSS-R techniques. The coherent component is present for some type of surfaces, and it has been neglected until now because it vanishes for the sea surface scattering case. Taking into account the presence of both scattering components, the estimated Signal-to-Noise Ratio (SNR for both techniques is computed based on the detectability criterion, as it is done in conventional GNSS applications. The non-coherent averaging operation is considered from a general point of view, taking into account that thermal noise contributions can be reduced by an extra factor of 0.88 dB when using partially overlapped or partially correlated samples. After the SNRs are derived, the received waveform’s peak variability is computed, which determines the system’s capability to measure geophysical parameters. This theoretical derivations are applied to the United Kingdom (UK TechDemoSat-1 (UK TDS-1 and to the future GNSS REflectometry, Radio Occultation and Scatterometry on board the International Space Station (ISS (GEROS-ISS scenarios, in order to estimate the expected scatterometric performance of both missions.

Energy conservation potentials in the countries of Central and Eastern Europe - an expose of theses; Die Energiespeicherpotentiale in den Laendern Mittel- und Osteuropas - eine Darstellung der Thesen

Energy Technology Data Exchange (ETDEWEB)

Riesner, W. [Hochschule fuer Technik, Wirtschaft und Sozialwesen Zittau/Goerlitz FH, Zittau (Germany)

1996-07-01

The report compares western and eastern Europe in terms of their supply with fossil energy, the development of their primary and end-use energy consumption, and the development of their gross power generation. The technical state of energy conversion plants and electrothermal power plants, Russia`s energy conservation potential, and the efficacy of measures for enhancing electric energy efficiency in the Ukraine are described. Finally, a comparison of energy input coefficients and energy costs between the old and new federal states of Germany is made. (DG) [Deutsch] Bezueglich der Versorgung mit fossiler Energie, der Entwicklung des Primaer- und Endenergieverbrauchs und der Entwicklung der Brutto-Stromerzeugung werden West- und Osteuropa miteinander verglichen. Der technische Stand der Energieumwandlungsanlagen und der Elektrowaermeanlagen sowie das Energieeinsparungspotential in Russland und die Effektivitaet von Massnahmen zur Elektroenergieeffizienzsteigerung in der Ukraine werden dargestellt. Schliesslich erfolgt ein Vergleich der Energieintensitaets- und Energiekosten zwischen den alten und neuen Bundeslaendern der BRD. (DG)

Fluorescence detection using optical waveguide collection device with high efficiency on assembly of nitrogen vacancy centers in diamond

Science.gov (United States)

Zhang, Shaowen; Ma, Zongmin; Qin, Li; Fu, Yueping; Shi, Yunbo; Liu, Jun; Li, Yan Jun

2018-01-01

In this letter, we propose a fluorescence waveguide excitation and collection (FWEC) method that allows for an excess of 45% collection efficiency of pump photons into optically detected magnetic resonance. The FWEC system used can collect fluorescence 96 times higher than the confocal system under spin manipulation with a microwave. Furthermore, the signal-to-noise ratio (SNR) of the FWEC system is improved 9 times compared with that of the confocal system. In addition, the increase in contrast observed using the FWEC system shows that the integration of the system is much improved with 3D printing technology. Thus, this research has a great potential application in subsequent magnetic detection and quantum optics.

ON THE RADIO POLARIZATION SIGNATURE OF EFFICIENT AND INEFFICIENT PARTICLE ACCELERATION IN SUPERNOVA REMNANT SN 1006

Energy Technology Data Exchange (ETDEWEB)

Reynoso, Estela M. [Instituto de Astronomia y Fisica del Espacio (IAFE), C. C. 67, Suc. 28, 1428 Buenos Aires (Argentina); Hughes, John P. [Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854-8019 (United States); Moffett, David A., E-mail: ereynoso@iafe.uba.ar, E-mail: jph@physics.rutgers.edu, E-mail: david.moffett@furman.edu [Department of Physics, Furman University, Greenville, SC 29613 (United States)

2013-04-15

Radio polarization observations provide essential information on the degree of order and orientation of magnetic fields, which themselves play a key role in the particle acceleration processes that take place in supernova remnants (SNRs). Here we present a radio polarization study of SN 1006, based on combined Very Large Array and Australia Telescope Compact Array observations at 20 cm that resulted in sensitive images with an angular resolution of 10 arcsec. The fractional polarization in the two bright radio and X-ray lobes of the SNR is measured to be 0.17, while in the southeastern sector, where the radio and non-thermal X-ray emission are much weaker, the polarization fraction reaches a value of 0.6 {+-} 0.2, close to the theoretical limit of 0.7. We interpret this result as evidence of a disordered, turbulent magnetic field in the lobes, where particle acceleration is believed to be efficient, and a highly ordered field in the southeast, where the acceleration efficiency has been shown to be very low. Utilizing the frequency coverage of our observations, an average rotation measure of {approx}12 rad m{sup -2} is determined from the combined data set, which is then used to obtain the intrinsic direction of the magnetic field vectors. While the orientation of magnetic field vectors across the SNR shell appear to be radial, a large fraction of the magnetic vectors lie parallel to the Galactic plane. Along the highly polarized southeastern rim, the field is aligned tangent to the shock, and therefore also nearly parallel to the Galactic plane. These results strongly suggest that the ambient field surrounding SN 1006 is aligned with this direction (i.e., from northeast to southwest) and that the bright lobes are due to a polar cap geometry. Our study establishes that the most efficient particle acceleration and generation of magnetic turbulence in SN 1006 is attained for shocks in which the magnetic field direction and shock normal are quasi-parallel, while

ON THE RADIO POLARIZATION SIGNATURE OF EFFICIENT AND INEFFICIENT PARTICLE ACCELERATION IN SUPERNOVA REMNANT SN 1006

International Nuclear Information System (INIS)

Reynoso, Estela M.; Hughes, John P.; Moffett, David A.

2013-01-01

Radio polarization observations provide essential information on the degree of order and orientation of magnetic fields, which themselves play a key role in the particle acceleration processes that take place in supernova remnants (SNRs). Here we present a radio polarization study of SN 1006, based on combined Very Large Array and Australia Telescope Compact Array observations at 20 cm that resulted in sensitive images with an angular resolution of 10 arcsec. The fractional polarization in the two bright radio and X-ray lobes of the SNR is measured to be 0.17, while in the southeastern sector, where the radio and non-thermal X-ray emission are much weaker, the polarization fraction reaches a value of 0.6 ± 0.2, close to the theoretical limit of 0.7. We interpret this result as evidence of a disordered, turbulent magnetic field in the lobes, where particle acceleration is believed to be efficient, and a highly ordered field in the southeast, where the acceleration efficiency has been shown to be very low. Utilizing the frequency coverage of our observations, an average rotation measure of ∼12 rad m –2 is determined from the combined data set, which is then used to obtain the intrinsic direction of the magnetic field vectors. While the orientation of magnetic field vectors across the SNR shell appear to be radial, a large fraction of the magnetic vectors lie parallel to the Galactic plane. Along the highly polarized southeastern rim, the field is aligned tangent to the shock, and therefore also nearly parallel to the Galactic plane. These results strongly suggest that the ambient field surrounding SN 1006 is aligned with this direction (i.e., from northeast to southwest) and that the bright lobes are due to a polar cap geometry. Our study establishes that the most efficient particle acceleration and generation of magnetic turbulence in SN 1006 is attained for shocks in which the magnetic field direction and shock normal are quasi-parallel, while inefficient

Magnetic resonance imaging of sacroiliitis: anatomy, histological pathology, MR-morphology, and grading; Magnetresonanztomographie der Sakroiliitis: Anatomie, Pathohistologie, MR-Morphologie und Graduierung

Energy Technology Data Exchange (ETDEWEB)

Hermann, K.G.A.; Fischer, T. [Institut fuer Radiologie, Charite Universitaetsmedizin Berlin (Germany); Braun, J. [Rheumazentrum Ruhrgebiet, St. Josefs-Krankenhaus, Herne (Germany); Reisshauer, H. [Gemeinschaftspraxis fuer Pathologie, Neubrandenburg (Germany); Bollow, M. [Institut fuer Radiologie, Augusta-Kranken-Anstalt, Bochum (Germany)

2004-03-01

Roentgenbild der Sakroiliakalgelenke (SIG) die Basis fuer die Diagnosestellung einer Spondyloarthritis. Bei klinisch-radiologischer Befunddiskrepanz hat sich fuer die fruehe Diagnostik einer Sakroiliitis die kontrastmittelgestuetzte Magnetresonanztomographie als sensitives Verfahren bewaehrt. Die Kenntnis der Morphologie der Sakroiliakalgelenke und der pathologischen Mikro- und Makroanatomie der Sakroiliitis und Enthesitis sind hilfreich fuer das Verstaendnis der magnetresonanztomographischen Befunde. Zu den Charakteristika einer SIG-Arthritis gehoeren subchondrale Sklerosierungen, Erosionen, transartikulaere Knochenbruecken, periartikulaere Fettakkumulationen, juxtaartikulaere Osteitiden, Synovitiden, Kapsulitiden und Enthesitiden. Histologisch dominiert bei aktiver Sakroiliitis ein proliferatives, pannusartiges Bindegewebe, welches Knorpel und Knochen destruiert. Dieses besteht neben Fibroblasten und Fibrozyten aus T-Zellen und Makrophagen. Dabei ist die CD4/CD8-Ratio zugunsten der CD4-T-Helferzellen verschoben. Die bewaehrte Graduierung der magnetresonanztomographischen Befunde durch einen Chronizitaetsgrad und einen Aktivitaetsindex, der quantitativ auf der Basis der dynamischen MRT ermittelt wird, soll durch einen alternativ anzuwendenden semiquantitativen Aktivitaetsgrad erweitert werden. Auf Basis der Short-tau-inversion-recovery-(STIR-)Sequenz oder der T1-gewichteten fettgesaettigten Spinechosequenz wurden folgende Abstufungen pro Quadrant (iliakal ventral, iliakal dorsal, sakral ventral, sakral dorsal) des SIG definiert:0: keine Signalvermehrungen,1: Signalvermehrungen lokalisiert im Gelenkspalt bzw. in Erosionen,2: geringe juxtaartikulaere Signalvermehrungen,3: maessige paraartikulaere Signalvermehrungen,4: flaechige Signalvermehrungen.Die Werte pro Quadrant werden zum Aktivitaetsgrad summiert (Spanne 0-16). Diese Modifikation des Graduierungsschemas soll zu einer weiteren Verminderung des Untersuchungs- und Befundungsaufwands beitragen. (orig.)

Measurement and analysis of vibrational behavior of an SNR-fuel element in sodium flow

International Nuclear Information System (INIS)

Hess, B.F.H.; Ruppert, E.; Schmidt, H.; Vinzens, K.

1975-01-01

Within the framework of SNR-300 fuel element development programme a complete full size fuel element dummy has been tested thoroughly for nearly 3000 hours at 650 deg C system temperature in the AKB sodium loop at Interatom, Bensberg. It is known that the coolant flow through a subassembly can induce flutter or vibrations of structural parts such as single pins, the wrapper and the total pin bundle all of which have been of interest during this test. To detect these vibrations of different structural parts simultaneously with a minimum of instrumentation only 3 weldable high temperature strain gauges were employed. These strain gauges were especially prepared and bent in such a way as to form a bridge between the inner wrapper and a fuel pin top and spot-welded to both the wrapper and the fuel pin. Although this arrangement seems to be a rather unusual one, the simultaneous-measurement of bundle, wrapper and pin vibrations was possible and periodic flow fluctuations were also detected. The presented results are only relative due to calibration difficulties with these deformed strain gauges which were first used during this test. It is, however, believed that this arrangement, in connection with the proposed anlytical approach, leads to a simple and technical representation of the vibrational behavior of core elements during sodium tests. Detailed information needed for check and calibration of computer codes are however displayed by the respective power spectral density functions

A note on the manipulation of sodium and potassium concentrations in the rumen of reindeer and the possible effect on digestibility

Directory of Open Access Journals (Sweden)

Hans Staaland

1987-06-01

Full Text Available Rumen Na+ and K+ concentrations in reindeer were manipulated by introducing 4 M KC1 or 4 M NaCl into the reindeer rumen. A positive correlation was found between salivary and ruminal concentrations of Na+ and K+. Decreased ruminal Na+ concentrations seemed to decrease dry matter digestibility in nylon bags incubated in the rumen.Om manipulering av natrium og kalium konsentrasjoner i vomma hos rein og om de mulige effekter på fordøyeligheten.Abstract in Norwegian / Sammendrag: Na+ og K+ konsentrasjoner i vomma hos rein ble regulert ved å gi reinen 4 M KC1 eller 4 M NaCl direkte i vomma. Det ble funnet en positiv korrelasjon mellom spytt og vomkonsentrasjoner av Na+ og K+. Redusert Na+ konsentrasjon i vomma synes å redusere tørrstoff-fordøyelighet i nylonposer plassert i vomma.Poron pötsin natrium- ja kaliumkonsentraation kokeellisesta mu-uttamisesta ja tämän mahdollisesta vaikutuksesta sulavuuteen.Abstract in Finnish / Yhteenveto: Poron potsin natrium- ja kaliumkonsentraatioita muutettiin antamalla 4 M KC1 tai 4 M NaCl suo-raan potsiin. Syljen ja potsin Na ja K -konsentraatioiden vålillå todettiin positiivinen korrelaatio. Alentunut Na -konsentraatio potsisså nåyttåå våhentåvån kuiva-aineen sulavuutta potsiin sijoitetuissa nailonpusseissa.

Spectral and Energy Efficiencies in mmWave Cellular Networks for Optimal Utilization

Directory of Open Access Journals (Sweden)

Abdulbaset M. Hamed

2018-01-01

Full Text Available Millimeter wave (mmWave spectrum has been proposed for use in commercial cellular networks to relieve the already severely congested microwave spectrum. Thus, the design of an efficient mmWave cellular network has gained considerable importance and has to take into account regulations imposed by government agencies with regard to global warming and sustainable development. In this paper, a dense mmWave hexagonal cellular network with each cell consisting of a number of smaller cells with their own Base Stations (BSs is presented as a solution to meet the increasing demand for a variety of high data rate services and growing number of users of cellular networks. Since spectrum and power are critical resources in the design of such a network, a framework is presented that addresses efficient utilization of these resources in mmWave cellular networks in the 28 and 73 GHz bands. These bands are already an integral part of well-known standards such as IEEE 802.15.3c, IEEE 802.11ad, and IEEE 802.16.1. In the analysis, a well-known accurate mmWave channel model for Line of Sight (LOS and Non-Line of Sight (NLOS links is used. The cellular network is analyzed in terms of spectral efficiency, bit/s, energy efficiency, bit/J, area spectral efficiency, bit/s/m2, area energy efficiency, bit/J/m2, and network latency, s/bit. These efficiency metrics are illustrated, using Monte Carlo simulation, as a function of Signal-to-Noise Ratio (SNR, channel model parameters, user distance from BS, and BS transmission power. The efficiency metrics for optimum deployment of cellular networks in 28 and 73 GHz bands are identified. Results show that 73 GHz band achieves better spectrum efficiency and the 28 GHz band is superior in terms of energy efficiency. It is observed that while the latter band is expedient for indoor networks, the former band is appropriate for outdoor networks.

Short version of the 1996 environmental expertise on the implementation of a sustainable, environmentally acceptable development. Conclusions and recommendations for action; Kurzfassung des Umweltgutachtens 1996 zur Umsetzung einer dauerhaft-umweltgerechten Entwicklung. Schlussfolgerungen und Handlungsempfehlungen

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-02-01

The aim of the present expertise is to set new orientation marks for the tedious, conflict-laden procedure of bringing the ideal of a sustainable, environmentally acceptable development to realisation. By submitting this expertise the Environmental Council has acted in accordance with its assignment to report periodically on certain well-defined issues; specifically, to analyse generic questions of environmental protection, describe the environmental situation in Germany with regard to selected sectors of environmental protection, and give a critical valuation of current environmental policy. (orig./SR) [Deutsch] Das vorliegende Gutachten hat das Ziel, weitere Markierungen fuer den langwierigen und konflikttraechtigen Weg zur Umsetzung des Leitbildes einer dauerhaft-umweltgerechten Entwicklung zu setzen. Der Umweltrat kommt auch in diesem Gutachten seinem Auftrag nach, im Rahmen der periodischen Begutachtung uebergreifende Fragen des Umweltschutzes zu analysieren und fuer ausgewaehlte Umweltschutzsektoren die Umweltsituation in Deutschland zu beschreiben und die Umweltpolitik kritisch zu bewerten. (orig./SR)

Explaining the morphology of supernova remnant (SNR) 1987A with the jittering jets explosion mechanism

Science.gov (United States)

Bear, Ealeal; Soker, Noam

2018-04-01

We find that the remnant of supernova (SN) 1987A shares some morphological features with four supernova remnants (SNRs) that have signatures of shaping by jets, and from that we strengthen the claim that jets played a crucial role in the explosion of SN 1987A. Some of the morphological features appear also in planetary nebulae (PNe) where jets are observed. The clumpy ejecta bring us to support the claim that the jittering jets explosion mechanism can account for the structure of the remnant of SN 1987A, i.e., SNR 1987A. We conduct a preliminary attempt to quantify the fluctuations in the angular momentum of the mass that is accreted on to the newly born neutron star via an accretion disk or belt. The accretion disk/belt launches the jets that explode core collapse supernovae (CCSNe). The relaxation time of the accretion disk/belt is comparable to the duration of a typical jet-launching episode in the jittering jets explosion mechanism, and hence the disk/belt has no time to relax. We suggest that this might explain two unequal opposite jets that later lead to unequal sides of the elongated structures in some SNRs of CCSNe. We reiterate our earlier call for a paradigm shift from neutrino-driven explosion to a jet-driven explosion of CCSNe.

Discrete rate and variable power adaptation for underlay cognitive networks

KAUST Repository

Abdallah, Mohamed M.

2010-01-01

We consider the problem of maximizing the average spectral efficiency of a secondary link in underlay cognitive networks. In particular, we consider the network setting whereby the secondary transmitter employs discrete rate and variable power adaptation under the constraints of maximum average transmit power and maximum average interference power allowed at the primary receiver due to the existence of an interference link between the secondary transmitter and the primary receiver. We first find the optimal discrete rates assuming a predetermined partitioning of the signal-to-noise ratio (SNR) of both the secondary and interference links. We then present an iterative algorithm for finding a suboptimal partitioning of the SNR of the interference link assuming a fixed partitioning of the SNR of secondary link selected for the case where no interference link exists. Our numerical results show that the average spectral efficiency attained by using the iterative algorithm is close to that achieved by the computationally extensive exhaustive search method for the case of Rayleigh fading channels. In addition, our simulations show that selecting the optimal partitioning of the SNR of the secondary link assuming no interference link exists still achieves the maximum average spectral efficiency for the case where the average interference constraint is considered. © 2010 IEEE.

Three-Dimensional Terahertz Coded-Aperture Imaging Based on Matched Filtering and Convolutional Neural Network.

Science.gov (United States)

Chen, Shuo; Luo, Chenggao; Wang, Hongqiang; Deng, Bin; Cheng, Yongqiang; Zhuang, Zhaowen

2018-04-26

As a promising radar imaging technique, terahertz coded-aperture imaging (TCAI) can achieve high-resolution, forward-looking, and staring imaging by producing spatiotemporal independent signals with coded apertures. However, there are still two problems in three-dimensional (3D) TCAI. Firstly, the large-scale reference-signal matrix based on meshing the 3D imaging area creates a heavy computational burden, thus leading to unsatisfactory efficiency. Secondly, it is difficult to resolve the target under low signal-to-noise ratio (SNR). In this paper, we propose a 3D imaging method based on matched filtering (MF) and convolutional neural network (CNN), which can reduce the computational burden and achieve high-resolution imaging for low SNR targets. In terms of the frequency-hopping (FH) signal, the original echo is processed with MF. By extracting the processed echo in different spike pulses separately, targets in different imaging planes are reconstructed simultaneously to decompose the global computational complexity, and then are synthesized together to reconstruct the 3D target. Based on the conventional TCAI model, we deduce and build a new TCAI model based on MF. Furthermore, the convolutional neural network (CNN) is designed to teach the MF-TCAI how to reconstruct the low SNR target better. The experimental results demonstrate that the MF-TCAI achieves impressive performance on imaging ability and efficiency under low SNR. Moreover, the MF-TCAI has learned to better resolve the low-SNR 3D target with the help of CNN. In summary, the proposed 3D TCAI can achieve: (1) low-SNR high-resolution imaging by using MF; (2) efficient 3D imaging by downsizing the large-scale reference-signal matrix; and (3) intelligent imaging with CNN. Therefore, the TCAI based on MF and CNN has great potential in applications such as security screening, nondestructive detection, medical diagnosis, etc.

Developments for the ultrasonic in-service inspection of the inner near surface zone of circular welds in the vessel of the fast breeder-reactor SNR 300

International Nuclear Information System (INIS)

Salzburger, H.J.; Huebschen, G.; Neuschwander, R.; Kleffner, G.; Wessels, J.

1990-01-01

For in-service, ultrasonic inspection of the inner near-surface zone of the welds 1 and 6 of the vessel of the SNR-300, an automated system has been developed for scanning, manipulation and evaluation tasks. The scanning system which currently is tested and qualified as a prototype system uses heat-resistant EMUS probes which do not require coupling agents, and which have been optimized for three different testing tasks. The required electronic equipment has also been developed to prototype stage, and both have been incorporated into the automated manipulation, data acquisition and evaluation system. (orig.) [de

Ethik und Sicherheitstechnik. Eine Handreichung

NARCIS (Netherlands)

Ammicht-Quinn, Regina; Nagenborg, Michael Herbert; Rampp, Benjamin; Wolkenstein, Andreas F.X.; Ammicht-Quinn, Regina

2013-01-01

Mit dem Programm „Forschung für die zivile Sicherheit“ fördert die Bundesregierung im Rahmen der „Hightech-Strategie für Deutschland“ erstmals unmittelbar die Entwicklung von Techniken, die der Schaffung und Bewahrung von ziviler Sicherheit dienen. Bei der Erforschung und Entwicklung von

A study of Tycho's SNR at TeV energies with the HEGRA CT-System

Science.gov (United States)

Aharonian, F. A.; Akhperjanian, A. G.; Barrio, J. A.; Bernlöhr, K.; Börst, H.; Bojahr, H.; Bolz, O.; Contreras, J. L.; Cortina, J.; Denninghoff, S.; Fonseca, V.; Gonzalez, J. C.; Götting, N.; Heinzelmann, G.; Hermann, G.; Heusler, A.; Hofmann, W.; Horns, D.; Ibarra, A.; Jung, I.; Kankanyan, R.; Kestel, M.; Kettler, J.; Kohnle, A.; Konopelko, A.; Kornmeyer, H.; Kranich, D.; Krawczynski, H.; Lampeitl, H.; Lorenz, E.; Lucarelli, F.; Magnussen, N.; Mang, O.; Meyer, H.; Mirzoyan, R.; Moralejo, A.; Padilla, L.; Panter, M.; Plaga, R.; Plyasheshnikov, A.; Prahl, J.; Pühlhofer, G.; Rauterberg, G.; Röhring, A.; Rhode, W.; Rowell, G. P.; Sahakian, V.; Samorski, M.; Schilling, M.; Schröder, F.; Stamm, W.; Tluczykont, M.; Völk, H. J.; Wiedner, C.; Wittek, W.

2001-07-01

Tycho's supernova remnant (SNR) was observed during 1997 and 1998 with the HEGRA Čerenkov Telescope System in a search for gamma-ray emission at energies above ~ 1 TeV. An analysis of these data, ~ 65 hours in total, resulted in no evidence for TeV gamma-ray emission. The 3sigma upper limit to the gamma-ray flux (>1 TeV) from Tycho is estimated at 5.78x 10-13 photons cm-2 s-1, or 33 milli-Crab. We interpret our upper limit within the framework of the following scenarios: (1) that the observed hard X-ray tail is due to synchrotron emission. A lower limit on the magnetic field within Tycho may be estimated B>=22 mu G, assuming that the RXTE-detected X-rays were due to synchrotron emission. However, using results from a detailed model of the ASCA emission, a more conservative lower limit B>=6 mu G is derived. (2) The hadronic model of Drury and (3) the more recent time-dependent kinetic theory of Berezhko & Völk. Our upper limit lies within the range of predicted values of both hadronic models, according to uncertainties in physical parameters of Tycho, and shock acceleration details. In the latter case, the model was scaled to suit the parameters of Tycho and re-normalised to account for a simplification of the original model. We find that we cannot rule out Tycho as a potential contributor at an average level to the Galactic cosmic-ray flux.

Uplink SDMA with Limited Feedback: Throughput Scaling

Directory of Open Access Journals (Sweden)

Jeffrey G. Andrews

2008-01-01

Full Text Available Combined space division multiple access (SDMA and scheduling exploit both spatial multiplexing and multiuser diversity, increasing throughput significantly. Both SDMA and scheduling require feedback of multiuser channel sate information (CSI. This paper focuses on uplink SDMA with limited feedback, which refers to efficient techniques for CSI quantization and feedback. To quantify the throughput of uplink SDMA and derive design guidelines, the throughput scaling with system parameters is analyzed. The specific parameters considered include the numbers of users, antennas, and feedback bits. Furthermore, different SNR regimes and beamforming methods are considered. The derived throughput scaling laws are observed to change for different SNR regimes. For instance, the throughput scales logarithmically with the number of users in the high SNR regime but double logarithmically in the low SNR regime. The analysis of throughput scaling suggests guidelines for scheduling in uplink SDMA. For example, to maximize throughput scaling, scheduling should use the criterion of minimum quantization errors for the high SNR regime and maximum channel power for the low SNR regime.

Dual vehicle - Development, construction and testing of a dual vehicle for passenger transport on roads and railways. Final report; Zweiwegefahrzeug - Entwicklung, Bau und Erprobung eines Zweiwegefahrzeuges zur Personenbefoerderung Strasse/Schiene. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This feasibility study investigated a prototype dual vehicle for railways and roads. Technical problems, acceptance specifications, legal and economic aspects were gone into. [German] Zielstellung fuer das Vorhaben war die Untersuchung ausgewaehlter technischer Fragestellungen hinsichtlich der Machbarkeit der Entwicklung und Erprobung eines Prototypes fuer ein Zweiwegefahrzeug fuer den Personenverkehr, das fuer den Einsatz auf der Schiene und der Strasse vorgesehen und dafuer entsprechend technisch ausgestattet ist. Damit erbringt das Vorhaben technisch-konstruktive Loesungsansaetze fuer ein vollstaendig neues Fahrzeuggrundkonzept und traegt hinsichtlich eines solchen zukuenftigen Fahrzeugtyps - zur Klaerung technischer Fragen (statische Zusammenbauuntersuchungen, geometrische und massliche Bedingungen sowie Konzipierung, Leistungsanforderungen der Komponenten, Konzept fuer Ein- und Ausspuren sowie fuer Ein- und Ausstieg), - zur Pruefung der technischen Zulassungsfaehigkeit des Fahrzeuges, - zur Klaerung von Rechtsfragen fuer die Sicherung des Betriebes des Fahrzeuges - sowie zum Nachweis des wirtschaftlicheren Betriebes des Fahrzeuges bei. Das Vorhaben unterbreitet unter Beruecksichtigung sicherheitstechnischer, gesetzlicher und wirtschaftlicher Rahmenbedingungen Loesungsvorschlaege fuer die konstruktive Konzipierung des Fahrgestells und ein technisches Konzept fuer das Ein- und Ausspuren fuer einen neuen Fahrzeugtyp, der sowohl fuer die Strassenbenutzung als auch fuer den Schienenverkehr zugelassen ist. (orig.)

Solar-aided air conditioning through sorption. Final report. Phase 2; Solar unterstuetzte Klimatisierung ueber Sorption. Endbericht zur Phase 2

Energy Technology Data Exchange (ETDEWEB)

Laevemann, E; Kessling, W; Peltzer, M

1996-09-24

The present article reports on possibilities of using solar energy for cooling buildings. It contains the following chapters: Current state of research and development; room air conditioning; planning and results of the studies; theory; experimental studies on the sorption dehumidifier; development of exchange surfaces; development of solution distributors; cooling of exchange surfaces; construction of a sorption dehumidifier. (HW) [Deutsch] Die Arbeit berichtet ueber Moeglichkeiten der Anwendung von Solarenergie zur Kuehlung von Gebaeuden. Die Arbeit enthaelt folgende Kapitel: - Stand der Forschung und Entwicklung - Raumklimatisierung - Planung und Ergebnis der Untersuchungen - Theorie - Experimentelle Untersuchungen am Sorptionsentfeuchter - Entwicklung von Austauschflaechen - Entwicklung von Loesungsverteilern - Kuehlung von Austauschflaechen - Konstruktion eines Sorptionsentfeuchters. (HW)

PA de Villiers A. Smith Melkwinningis 'n arbllidsintensieweproses en ...

African Journals Online (AJOL)

Die invloed van melkintervalle op melk-, bottervet- en proteienproduksie en bottervet-, proteien- en natriumkonsentrasie. Verandering in: Melkproduksie. Bottervet-. Proteitm-. Bottervet-. Proteiim-. Natrium- produksie produksie konsentrasie konsentrasie konsentrasie. A.g.v. toenemende melk- intervalle van: 12 tot 16 uur.

The Prevalence of Power-Sharing: Exploring the Patterns of Post-Election Peace Die Verbreitung von Power-Sharing: Bedingungen für eine friedliche Entwicklung nach Wahlen

Directory of Open Access Journals (Sweden)

Anna K. Jarstad

2009-01-01

Statistiken aus der Post-Accord Elections (PAE Datensammlung, die in diesem Artikel präsentiert werden, haben gleichwohl ergeben, dass Frieden, Power-Sharing und Demokratie eng miteinander verflochten sind; Friedensabkommen sehen heute in den meisten Fällen sowohl Power-Sharing als auch Wahlen vor. Im Gegensatz zu früheren Forschungen, die von der Annahme ausgingen, das Power-Sharing ein Instrument zur Beendigung von Gewalt darstellt, belegen die Daten, dass der Konflikt häufig nach Unterzeichnung eines Abkommens fortlebt, auch wenn Regelungen zur Machtteilung vorgesehen sind. Dass Power-Sharing Wahlen begünstigt, lässt sich nicht belegen; im Gegenteil, es kommt häufiger vor, dass nach einem Friedensprozess ohne Power-Sharing-Abkommen Wahlen abgehalten werden. Eine Periode der Machtteilung vor Wahlen scheint eine anschließende friedliche Entwicklung nicht zu fördern; Wahlen sind in diesem Fall ähnlich konfliktreich wie Wahlen, die nach Friedensvereinbarungen ohne Machtteilungsklauseln abgehalten wurden. Als gute Nachricht kann gelten, dass Power-Sharing keinen negativen Effekt auf eine friedliche Entwicklung nach Wahlen zu haben scheint.

The TEX-I real-time expert system, applied to situation assessment for the SNR-300 reactor

International Nuclear Information System (INIS)

Schmal, N.; Leder, H.J.; Schade, H.J.

1988-01-01

Interatom, a subsidiary company of Siemens, is developing expert systems for the technical domain. These systems are operating in various industrial applications like flexible manufacturing or plant configuration, based on a domain-specific expert system shell, developed by Interatom. Additional projects are focusing on real-time diagnostics, e.g., for nuclear power plants. The authors report in this paper about a diagnosis expert system for the liquid-metal fast breeder reactor SNR-300, which uses new real-time tools, developed within the German TEX-I project (technical expert systems for data interpretation, diagnosis, and process control). The purpose of the system is to support the reactor operators in assessing plant status in real time, based on readings from many sensors. By on-line connection to the process control computer, it can monitor all incoming signal values, check the consistency of data, continuously diagnose the current plant status, detect unusual trends prior to accidents, localize faulty components, and recommended operator response in abnormal conditions. In the present knowledge acquisition and test phase, the expert system is connected to a real-time simulation of the reactor. The simulator is based on a thermohydraulic code for simulation of the transient behavior of temperatures and flow rates in the reactor core, plena, pipes, pumps, valves, intermediate heat exchangers, and cooling components. Additionally, the system's response to an asynchronous operator interaction can be simulated

Material correlations and models for the irradiation behavior of fissile and fertile material in SNR-300, Mark-II and KNK II, third core

International Nuclear Information System (INIS)

Fenneker; Steinmetz; Toebbe

1986-07-01

The report contains the material correlations and models used in the fuel pin design code IAMBUS for the irradiation behavior of PuO 2 -UO 2 fissile materials and UO 2 fertile materials of the SNR-300 Mark-II reload and the KNK II third core. They are applicable for pellet densities of more than 90 % of the theoretical density. The presented models of the fuel behavior and the applied material correlations have been derived either from single experiments or from the comparison of theoretically predicted integral fuel behavior with the results of fuel pin irradiation experiments. The material correlations have been examined and extended in the frame of the collaborations INTERATOM/KWU and INTERATOM/KfK. French and British results were included, when available from the European fast reactor knowledge exchange [de

MOULDING MIXTURES HARDENING PROCESS BASED ON LIGNIN-BASE SULPHONATE BINDER

Directory of Open Access Journals (Sweden)

V. N. Ektova

2004-01-01

Full Text Available Hardening of agglutinant sands on lignosulphonate binding agent is the result of two processes: oxidation-reduction in the system lignosulphonate acids — persulfuric natrium in the early stages of hardening and hydration of cement in the latter stages.

Development of a regional concept for energy management for the region of Karlsruhe. Final report; Entwicklung eines regionalen Energiemanagement-Konzeptes und Anwendung auf die TechnologieRegion Karlsruhe. Endbericht

Energy Technology Data Exchange (ETDEWEB)

Rentz, O.; Fichtner, W.; Frank, M. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Industriebetriebslehre und Industrielle Produktion; Wolf, M.A.; Rejman, M.; Eyerer, P. [Fraunhofer-Institut fuer Chemische Technologie (ICT) (Germany); Reimert, R.; Schulz, A.; Buren, V. v. [Karlsruhe Univ. (T.H.) (Germany). Engler-Bunte-Institut Bereich 1 - Gas, Erdoel und Kohle; Schaefers, B.; Bernart, Y. [Karlsruhe Univ. (T.H.) (DE). Institut fuer Soziologie (IfSoz) (Germany)

2002-09-01

Major objectives of this project are: to prepare a cross-disciplinary analysis of all characteristic aspects of the energy supply and demand patterns of a group of selected energy-intensive companies in the Karlsruhe and Rhine harbour area (5 industrial power consumers, 1 utility), to identify practical approaches for optimization and integration of energy and material flows, (networking), and to develop optimised investment and energy supply options within the framework of given conditions. The basis of the optimal solution and energy network presented and explained in detail is a new combined-cycle power plant running as a gas-fired CHP plant, substituting about 50% of the systems formerly used. (orig./CB) [German] Fragestellungen der Effizienzsteigerung und der Verwertung von Abfaellen und Abwaerme gewinnen an Relevanz vor dem Hintergrund der begrenzten Aufnahmekapazitaet der Umweltmedien fuer Schadstoffe. Im Rahmen des Projektes wurde am Beispiel der Region Karlsruhe (5 Industrieunternehmen und 1 EVU) die Entwicklung betriebsuebergreifender Energieversorgungssysteme (Netzwerke) interdisziplinaer analysiert und beschrieben. Zielsetzungen des Projekts waren unter anderem: Bestimmung von zukunftsfaehigen Optionen, intelligente Vernetzung von Energiestroemen, wirtschaftliche Optimierung betriebsuebergreifender Energiemanagement-Loesungen. Die optimale vorgestellte Loesung ist charakterisiert durch den Neubau einer zentralen, gasgefeuerten GuD-Anlage, die etwa die Haelfte der bisherigen Anlagen ersetzt und zusammen mit den weiterhin genutzten Anlagen die Energieversorgung der Unternehmen sicherstellt. (orig./CB)

Energy Efficiency Analysis of Antenna Selection Techniques in Massive MIMO-OFDM System with Hardware Impairments

Directory of Open Access Journals (Sweden)

Anuj Singal

2018-01-01

Full Text Available In massive multiple-input multiple-output (M-MIMO systems, a large number of antennas increase system complexity as well as the cost of hardware. In this paper, we propose an M-MIMO-OFDM model using per-subcarrier antenna selection and bulk antenna selection schemes to mitigate these problems. Also, we derive a new uplink and downlink energy efficiency (EE equation for the M-MIMO-OFDM system by taking into consideration the antenna selection schemes, power scaling factor (g=0.25,  0.5, and a range of hardware impairments {κBS, κUEϵ (0, 0.052, 0.12}. In addition, we investigate a trend of EE by varying various parameters like number of base station antennas (BSAs, SNR, level of hardware impairments, total circuit power consumption, power optimization, antenna selection schemes, and power scaling factor in the proposed M-MIMO-OFDM model. The simulation results thus obtained show that the EE increases with increase in the value of SNR. Also, it increases abruptly up to 100 number of BSA. However, the increase in the EE is not significant in the range of 125 to 400 number of BSA. Further, the bulk antenna selection technique has comparatively more EE than the per-subcarrier antenna selection. Moreover, EE gaps between antenna selection schemes decrease with increase in the value of hardware impairments and power scaling factor. However, as the hardware degradation effect increases, the EE of the bulk antenna selection scheme suffers more degradation as compared to the Per-subcarrier antenna selection scheme. It has also been observed that EE performance is inversely proportional to the total circuit power consumption (λ+γ and it increases with the power optimization.

Energy report for Bavaria, 1998/99. Data on the development of the Bavarian energy industry, with an energy balance; Energiebericht Bayern 1998/99. Daten zur Entwicklung der bayerischen Energiewirtschaft mit Energiebilanz

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

The energy report presents an annotated statistical review of energy supply in Bavaria and addresses the energy policy and resulting activities of the Bavarian Land government. The energy balance and tabulated data for the various branches of the energy industry predominantly cover the year 1997, but whenever available, data for the years 1998 and 1999 have been included. As in previous energy reports, an annex to the report contains statements of the Bavarian Land government in reply to written questions of members of the Land Parliament, and energy policy decisions of the Land Parliament taken within the reporting period. (orig./CB) [German] Der vorliegende Bericht zeigt die Entwicklung der Energieversorung in Bayern und gibt einen Ueberblick ueber die energiepolitischen Aktivitaeten der Staatsregierung. Die Energiebilanz und die Datentabellen zu den einzelnen Energiezweigen beziehen sich im allgemeinen auf das Jahr 1997. Soweit bei einigen Energietraegern bereits Zahlen fuer 1998 und 1999 vorliegen, wurden sie in den Bericht mit aufgenommen. Im Anhang des Energieberichts sind wieder Stellungnahmen der Bayerischen Staatsregierung zu Schriftlichen Anfragen von Abgeordneten sowie Beschluessen des Bayerischen Landtags zur Energiepolitik aus dem Berichtszeitraum wiedergegeben. (orig.)

United Nations conference of environment and development, held at Rio de Janeiro in June 1992. Documents. Agenda 21; Konferenz der Vereinten Nationen fuer Umwelt und Entwicklung im Juni 1992 in Rio de Janeiro. Dokumente. Agenda 21

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-31

With the translation of Agenda 21 all the documents released in connection with the United Nations Conference of Environment and Development (UNCED) at Rio de Janeiro (June 1992) have now been made generally available also in the German language. Agenda 21, which in 40 chapters discusses the basic political platforms of environment-oriented sustainable development, is an action programme for the 21st century adopted at Rio by more than 170 states. The action programme contains detailed instructions as to the practices to be abandoned to prevent any further deteriorations as well as strategies to be adopted to gradually relieve the situation and to ensure a reasonable and sustainable exploitation of our natural resources. One important approach to this goal is that environmental issues are considered within a global context, thus being a prominent factor in all political spheres. The rules set up in this action programme are applicable to industrial and developing countries alike. It offers - in broad outline - prescriptions for the combatting poverty, control of overpopulation, reconciliation of commercial and environmental interests, disposal of refuse and chemicals, for climate, energy and agricultural policies as well as the ways in which industrial and developing countries could cooperate both financially and in terms of shared technologies. The bilateral and multilateral development policies of the Federal Government are largely based on Agende 21. (orig./HP) [Deutsch] Mit der Uebersetzung der Agenda 21 sind nunmehr alle Dokumente der Konferenz fuer Umwelt und Entwicklung der Vereinten Nationen (UNCED) in Rio de Janeiro (June 1992) auch in deutscher Sprache der Oeffenlichkeit zugaenglich. Die Agenda 21, die mit ihren 40 Kapiteln alle wesentlichen Politikbereiche einer umweltvertraeglichen, nachhaltigen Entwicklung anspricht, ist das in Rio von mehr als 170 Staaten verabschiedete Aktionsprogramm fuer das 21. Jahrhundert. Mit diesem Aktionsprogramm werden

Development of a dynamic short-term test method for installed thermal solar systems; Entwicklung eines dynamischen Kurzzeittestverfahrens fuer installierte thermische Solaranlagen

Energy Technology Data Exchange (ETDEWEB)

Beikircher, T.; Gut, M.; Kronthaler, P.; Oberdorf, C.; Schoelkopf, W. [Bayerisches Zentrum fuer Angewandte Energieforschung, Muenchen (Germany). Abt. Solarthermie und Biomasse

1998-12-31

A short-term test method for in-situ measurement of the collector field, pipelines and heat exchanger of large-surface solar systems was developed at ZAE Bayern, together with the necessary technical systems (mobile acquisition of meteorological data via telemetering, non-invasive surface temperature sensors and ultrasonic volume flow measuring instruments). Dynamic measurements were made for 11 days in a large-surface solar system of the ``Solarthermie 2000`` programme using the new measuring system. In order to optimize the evaluation procedure, the plant was simulated, and the influence of different models and operating conditions during the measurements on the prediction quality was investigated in detail. On this basis, it was possible to predict the long-term collector yield of the ZfS Hilden, which was measured for a period of 7 months, with an error of less than 5%. The method will be validated in two further industrial-scale systems. [Deutsch] Am ZAE Bayern wurde ein Kurzzeittestverfahren zur insitu-Vermessung des Kollektorkreises (Kollektorfeld, Rohrleitungen, Waermetauscher) grosser Solaranlagen entwickelt. Hierzu wurde eine der Aufgabenstellung angepasste Messtechnik entwickelt (Mobile meteorologische Datenerfassung mit Funkbetrieb, nicht-invasive Oberflaechen-Temperaturfuehler und Ultraschall-Volumenstrommessgeraete). Der Kollektorkreis einer grossen Solaranlage aus dem Programm Solarthermie 2000 wurde dynamisch ueber 11 Tage (29.10.-8.11.1997) mit der neuen Messtechnik vermessen. Zur Entwicklung eines geeigneten Auswerteverfahrens wurde die Anlage simulatorisch abgebildet und der Einfluss verschiedener Modellansaetze und der Betriebsbedingungen waehrend des Mess- und Vorhersagezeitraums auf die Vorhersageguete im Detail untersucht. Mit dem entwickelten Verfahren konnte aus der dynamischen Kurzzeitvermessung der in einer Langzeitmessung der ZfS Hilden ueber 7 Monate ermittelte Kollektorertrag nach dem solaren Waermetauscher auf deutlich besser als 5

Development of an application-oriented multi-frequency eddy current procedure for the outer reactor vessel- and store vessel wall of the SNR-300

International Nuclear Information System (INIS)

Hoeft, E.

1991-08-01

The following companies participated in the development of the application oriented multi-frequency eddy current procedure for the outer reactor vessel- and store vesselwall of the SNR-300: Interatom GmbH (coordinator), MAN-Energie GmbH (ME, subcontractor), Fraunhofer Institut IzfP, own promotion project). The precisely defined work packages of the participating companies Interatom and IzfP were supported by the Federal Minister for Research and Technology in separate promotion project. The present report comprises the work performed at Interatom and ME for developing the manipulator and the subsystems. The development aim was reached largely. Manufactoring of the manipulator with all necessary peripherical equipments was finished and accepted in partial function tests at the manufacturer. Tests at the Interatom teststand however with the fully mounted systems at ambient- and reactor temperature could not be done within the appropriated timeschedule and finance frame. (orig.) [de

Comparison of entrance exposure and signal-to-noise ratio between an SBDX prototype and a wide-beam cardiac angiographic system

International Nuclear Information System (INIS)

Speidel, Michael A.; Wilfley, Brian P.; Star-Lack, Josh M.; Heanue, Joseph A.; Betts, Timothy D.; Van Lysel, Michael S.

2006-01-01

The scanning-beam digital x-ray (SBDX) system uses an inverse geometry, narrow x-ray beam, and a 2-mm thick CdTe detector to improve the dose efficiency of the coronary angiographic procedure. Entrance exposure and large-area iodine signal-to-noise ratio (SNR) were measured with the SBDX prototype and compared to that of a clinical cardiac interventional system with image intensifier (II) and charge coupled device (CCD) camera (Philips H5000, MRC-200 x-ray tube, 72 kWp max). Phantoms were 18.6-35.0 cm acrylic with an iohexol-equivalent disk placed at midthickness (35 mg/cm 2 iodine radiographic density). Imaging was performed at 15 frame/s, with the disk at mechanical isocenter and an 11-cm object-plane field width. The II/CCD system was operated in cine mode with automatic exposure control. With the SBDX prototype at maximum x-ray output (120 kVp, 24.3 kWp), the SBDX SNR was 107%-69% of the II/CCD SNR, depending on phantom thickness, and the SBDX entrance exposure rate was 10.7-9.3 R/min (9.4-8.2 cGy/min air kerma). For phantoms where an equal-kVp imaging comparison was possible (≥23.3 cm), the SBDX SNR ranged from 47% to 69% of the II/CCD SNR while delivering 6% to 9% of the II/CCD entrance exposure rate. From these measurements it was determined that the relative SBDX entrance exposure at equal SNR would be 31%-16%. Results were consistent with a model for relative entrance exposure at equal SNR, which predicted a 3-7 times reduction in entrance exposure due to SBDX's comparatively low scatter fraction (5.5%-8.1% measured, including off-focus radiation), high detector detective quantum efficiency (66%-73%, measured from 70 to 120 kVp), and large entrance field area (1.7x-2.3x, for the same object-plane field width). With improvements to the system geometry, detector, and x-ray source, SBDX technology is projected to achieve conventional cine-quality SNR over a full range of patient thicknesses, with 5-10 times lower skin dose

Filaggrin and skin reactivity to irritants - Epidemiological and Experimental studies

DEFF Research Database (Denmark)

Bandier, Josefine

2015-01-01

grupper i henhold til børneeksem og filaggrinmutationsstatus. Vi analyserede hudens reaktion over for en kendt hudirriterende detergent, natrium lauryl sulfat (SLS), ved tre forskellige doser (0,25, 0,50 og 1% SLS). Graden af barrierepåvirkning blev vurderet ved laser Doppler flowmetry, transepidermalt...

Study of the sulfuric acid leaching and bacterial leaching of low grade uranium ore by orbital shaker experiment

International Nuclear Information System (INIS)

Li Guangyue; Liu Yulong; Wang Yongdong; Ding Dexin

2009-01-01

The sulphuric acid leaching and bacteria leaching by orbital shaker experiments were conducted for the low grade uranium ore from a uranium mine in Guangdong Province. The results show that, when the concentration of sulphuric acid and that of slurry were 30 g/L and 25%, respectively, the conditions were most favourable for sulphuric acid leaching and the rate of leaching reached 92.92%, that, when pH value was 1.5, inoculation amount, 10%, concentration of slurry, 10%, the conditions were most favourable for bacteria leaching and the rate of leaching reached 95.93%, that, compared with sulphuric acid leaching, bacteria leaching decreased sulphuric acid consumption by 17.2% and increased the rate of leaching by 3%, and that, under the most favourable conditions for suphuric acid leaching, if 1% natrium chlorate was added, the rate of leaching increased to 96.46%, but 10 kg of natrium chlorate was consumed for 1 ton of uranium ore. (authors)

Preparasi Katalis Cu/Silika Gel dari Kristobalit Alam Sabang serta Uji Aktivitasnya pada Reaksi Dehidrogenasi Etanol

Directory of Open Access Journals (Sweden)

Surya Lubis

2009-06-01

Full Text Available Cu/Silica gel catalyst preparation by using silica content which is obtained from Sabang natural crystobalit has been done. Isolated silica from crystobalit is reacted with natrium hidroxide to produce silicate natrium that reacted further with sulphate acid to produce silica gel. Silica gel is characterized by infra red spektroscopy dan BET test. BET test result showed that silica gel obtained has specific surface area 260,04 m2/gram and ion Cu  impregnation into silica gel pores produce Cu/silica gel catalyst with spesific surace area 158,53 m/gram ith Cu2+ metal content = 193 ppm. Catalyst activation test Cu/silica gel at dehidrogenation reaction of etanol to produce asetaldehide was done at temperature 100oC – 300oC. Reseach showed that the highest asetaldehide consentration (20,24% is obtained at temperature 300oC.   Keywords: asetaldehide, crystobalit, Cu/silica gel, dehidrogenation, ethanol

Transformation

OpenAIRE

Laux, Gunther

2007-01-01

Die Arbeit befasst sich mit der These, dass jegliche technologische Entwicklung ihre Widerspiegelung in Gesellschaft, Wirtschaft und Stadt findet. In diesem Zusammenhang wird untersucht ob, wodurch, inwieweit oder warum eine Veränderung des europäischen Stadtbildes und des Raumbegriffs aufgrund der aktuellen Medientechnologie stattfindet. Vor dem Hintergrund situativer, phänomenologischer, historischer, soziologischer, regulativer und ökonomischer Betrachtungen bildet die Entwicklung einer al...

Fuel cells in railway systems. Project report; Brennstoffzellen im Schienenverkehr. Projektbericht

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-06-01

The project report describes the state of the art of fuel cell technology and the specific requirements of railway systems. Potential applications in the state of Schleswig-Holstein are gone into. [German] In diesem Projektbericht wird der Stand der Brennstoffzellentechnik und die Entwicklung von Anforderungen des Schienenverkehrs an diese Technik ermittelt. Darueber hinaus wird untersucht, inwieweit eine Modellregion Schleswig-Holstein zur weiteren Entwicklung der Technik beitragen kann.

The acceleration rate of cosmic rays at cosmic ray modified shocks

Science.gov (United States)

Saito, Tatsuhiko; Hoshino, Masahiro; Amano, Takanobu

It is a still controversial matter whether the production efficiency of cosmic rays (CRs) is relatively efficient or inefficient (e.g. Helder et al. 2009; Hughes et al. 2000; Fukui 2013). In upstream region of SNR shocks (the interstellar medium), the energy density of CRs is comparable to a substantial fraction of that of the thermal plasma (e.g. Ferriere 2001). In such a situation, CRs can possibly exert a back-reaction to the shocks and modify the global shock structure. These shocks are called cosmic ray modified shocks (CRMSs). In CRMSs, as a result of the nonlinear feedback, there are almost always up to three steady-state solutions for given upstream parameters, which are characterized by CR production efficiencies (efficient, intermediate and inefficient branch). We evaluate qualitatively the efficiency of the CR production in SNR shocks by considering the stability of CRMS, under the effects of i) magnetic fields and ii) injection, which play significant roles in efficiency of acceleration. By adopting two-fluid model (Drury & Voelk, 1981), we investigate the stability of CRMSs by means of time-dependent numerical simulations. As a result, we show explicitly the bi-stable feature of these multiple solutions, i.e., the efficient and inefficient branches are stable and the intermediate branch is unstable, and the intermediate branch transit to the inefficient one. This feature is independent of the effects of i) shock angles and ii) injection. Furthermore, we investigate the evolution from a hydrodynamic shock to CRMS in a self-consistent manner. From the results, we suggest qualitatively that the CR production efficiency at SNR shocks may be the least efficient.

An efficient multiple exposure image fusion in JPEG domain

Science.gov (United States)

Hebbalaguppe, Ramya; Kakarala, Ramakrishna

2012-01-01

In this paper, we describe a method to fuse multiple images taken with varying exposure times in the JPEG domain. The proposed algorithm finds its application in HDR image acquisition and image stabilization for hand-held devices like mobile phones, music players with cameras, digital cameras etc. Image acquisition at low light typically results in blurry and noisy images for hand-held camera's. Altering camera settings like ISO sensitivity, exposure times and aperture for low light image capture results in noise amplification, motion blur and reduction of depth-of-field respectively. The purpose of fusing multiple exposures is to combine the sharp details of the shorter exposure images with high signal-to-noise-ratio (SNR) of the longer exposure images. The algorithm requires only a single pass over all images, making it efficient. It comprises of - sigmoidal boosting of shorter exposed images, image fusion, artifact removal and saturation detection. Algorithm does not need more memory than a single JPEG macro block to be kept in memory making it feasible to be implemented as the part of a digital cameras hardware image processing engine. The Artifact removal step reuses the JPEGs built-in frequency analysis and hence benefits from the considerable optimization and design experience that is available for JPEG.

Development and testing of redundant optical fiber sensing systems with self-control, for underground nuclear waste disposal site monitoring. Vol. 1: Summary and evaluation. Final report; Entwicklung und Erprobung redundanter faseroptischer Messsysteme mit Selbstkontrolle zur Endlagerueberwachung. Bd. 1: Zusammenfassung und Auswertung. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Jobmann, M.; Fischer, S.; Voet, M.

2000-01-01

Fiber optic sensors have been developed or further developed, for specific tasks of the research project reported, as for instance detecting and signalling changes of geophysical or geochemical parameters in underground waste storage sites which are of relevance to operating safety. Such changes include e.g. materials dislocations, extensions, temperatures, humidity, pH value and presence of gaseous carbon dioxide and hydrogen. The measuring principle chosen is the fiber Bragg Grating method, as a particularly versatile method easy to integrate into fiber optic networks. After development and successful lab-scale testing of all sensors, except for the gas sensors, field test systems have been made for underground applications and have been tested in situ in the experimental Konrad mine of DBE. Most of the problems discovered with these tests could be resolved wihtin the given project period, so that finally field-test proven sensing systems are available for further activities. The report explains the system performance with a concrete example which shows inter alia beneficial aspects of the system with respect to on-site operation, and the potentials offered in establishing more direct connections between numerical safety analyses and measured results. (orig./CB) [German] Im Rahmen dieses Forschungsprojektes wurden faseroptische Sensoren entwickelt bzw. weiterentwickelt, die in der Lage sind, Veraenderungen relevanter geophysikalischer und geochemischer Groessen im Bereich der Grubenraeume zu signalisieren, die zu einer Gefaehrdung der Betriebssicherheit fuehren koennten. Im einzelnen sind dies Verschiebungen, Dehnungen, Temperatur, Feuchtigkeit, pH-Werte und Gasgehalte an Kohlendioxid und Wasserstoff. Als Messprinzip wurde aus den moeglichen optischen Verfahren das 'Bragg-Gitter' Prinzip zur Entwicklung gewaehlt, da es besonders vielseitig ist und sich gut in groessere optische Netzwerke integrieren laesst. Nach Entwicklung und erfolgreichem Test der

Biological and chemical development of mining lakes. Status report 1998/1999. Data acquisition, methods, trends; Biologische und chemische Entwicklung von Bergbaurestseen. Statusbericht 1998/1999. Bestandsaufnahme, Methoden und Entwicklungen

Energy Technology Data Exchange (ETDEWEB)

Friese, K; Tuempling, W von [eds.

2000-07-01

Acidification of mining lakes in central Germany and the Lausitz was investigated for three aspects: 1.) biological dynamics and material effects on plancton abundance and variety; 2.) Chemical and microbiological interactions between sediments influenced by mining (authochthone, allochthone) and water phase 3. 3.) Limnological and hydrochemical development of water systems in abandoned mining areas with a view to environmental quality and/or utilisation. The following objects were investigated. a) Goitsche open-cast mine (Bitterfeld district); b) Lake 111 (Koyne/Pllessa district), - Lakes 107, 117 (Koyne/Plessa district), Lake b (Schlabendorf-Nord district). [German] Kernproblem in den Braunkohlengebieten der neuen Bundeslaender ist die Versauerung von Bergbauseen. Die Bearbeitung des Verbundprojektes konzentriert sich in den Bergbaufolgelandschaften der Regionen Mitteldeutschland und Lausitz auf bergbaulich gestoerte und in Veraenderung befindliche Oberflaechenwasser-Systeme. Arbeitziele sind 1.) die Vertiefung der Kenntnisse zur biologischen Dynamik und zum stofflichen Einfluss auf die Diversitaet und Abundanz von Plankton in sauren Bergbauseen 2) Untersuchungen zu spezifischen Wechselwirkungen (chemisch, mikrobiologisch) zwischen bergbaulich beeinflussten Sedimenten (autochthon, allochthon) und der Wasserphase 3. Betrachtungen der limnologischen und hydrochemischen Entwicklung der Wassersysteme in Bergbaufolgelandschaften hinsichtlich Umweltqualitaetszielen und/oder Nutzungszielen. Im Rahmen des Verbundprojektes werden von den Sektionen Gewaesserforschung, Hydrogeologie, Analytik, Bodenforschung und Umweltmikrobiologie in Mitteldeutschland und der Lausitz folgende Objekte bearbeitet: a) Tagebaukomplex Goitsche (Bitterfelder Revier) und b) Restloch 111 (Revier Koyne/Plessa), - Restloch 107, 117 (Revier Koyne/Plessa), - Restloch B (Revier Schlabendorf-Nord). (orig.)

Technology development for crystalline silicon thin-film solar cells (TEKSI). Final report; Technologieentwicklung fuer kristalline Silizium-Duennschicht-Solarzellen (TEKSI). Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Wettling, W.; Hurrle, A.; Bau, S.; Eyer, A.; Haas, F.; Huljic, D.; Kieliba, T.; Lautenschlager, H.; Luedemann, R.; Lutz, F.; Preu, R.; Reber, S.; Rentsch, J.; Schaefer, S.; Schetter, C.; Schillinger, N.; Warta, W.; Zimmermann, W.

2002-10-01

The results of a project aimed at the development of crystalline solar wafers are presented. All process stages were reviewed in detail with a view to industrial fabrication. This included also the further development of machinery, e.g. for selective zone melting recrystallisation, CVD silicon deposition, and characterisation of deposited films and solar cells. Not all the envisaged goals were achieved. For example, efficiencies up to 17.6 percent were possible on direct epitactic, highly doped CZ-Si substrates and with a high-efficiency process, but the normal efficiencies of solar cells on SSP or on ceramic substrates were in the range of 8-11 percent. This underlines the need for further research on the development of appropriate substrates with reproducible properties. [German] Im vorliegenden Bericht werden die Ergebnisse eines mehrjaehrigen Projekts zur Entwicklung der kristallinen Silizium-Duennschichtsolarzelle (KSD-Solarzelle) vorgestellt. Die Arbeiten waren eine konsequente Fortsetzung der bereits in einem Vorgaengerprojekt (FKZ 0328986B) bearbeiteten Themen. Alle zur Herstellung solcher Solarzellen noetigen Prozessschritte im Rahmen des am Fraunhofer ISE verfolgten Hochtemperaturpfads wurden detailliert untersucht, insbesondere im Hinblick auf eine industrielle Fertigung. Ein wesentlicher Teil der Arbeiten befasste sich deshalb auch mit der Weiterentwicklung von Geraeten, so z. B. fuer die Zonenschmelzrekristallisation, fuer die Silizumabscheidung mittels CVD-Verfahren und fuer die Charakterisierung abgeschiedener Schichten und Solarzellen. Nicht alle der ehrgeizigen Projektziele konnten erreicht werden. Auf direkt epitaxierten, hochdotierten CZ-Si-Substraten konnten zwar mit einem High-Efficiency-Prozess Wirkungsgrade bis zu 17.6%, mit fertigungsrelevanter Siebdrucktechnologie bis 13% erzielt werden. Die Wirkungsgrade von Solarzellen auf SSP oder auf Keramiksubstraten lagen aber alle im Bereich von 8-11%. Dies zeigt deutlich, dass die Entwicklung

An Efficient Neural-Network-Based Microseismic Monitoring Platform for Hydraulic Fracture on an Edge Computing Architecture

Directory of Open Access Journals (Sweden)

Xiaopu Zhang

2018-06-01

Full Text Available Microseismic monitoring is one of the most critical technologies for hydraulic fracturing in oil and gas production. To detect events in an accurate and efficient way, there are two major challenges. One challenge is how to achieve high accuracy due to a poor signal-to-noise ratio (SNR. The other one is concerned with real-time data transmission. Taking these challenges into consideration, an edge-computing-based platform, namely Edge-to-Center LearnReduce, is presented in this work. The platform consists of a data center with many edge components. At the data center, a neural network model combined with convolutional neural network (CNN and long short-term memory (LSTM is designed and this model is trained by using previously obtained data. Once the model is fully trained, it is sent to edge components for events detection and data reduction. At each edge component, a probabilistic inference is added to the neural network model to improve its accuracy. Finally, the reduced data is delivered to the data center. Based on experiment results, a high detection accuracy (over 96% with less transmitted data (about 90% was achieved by using the proposed approach on a microseismic monitoring system. These results show that the platform can simultaneously improve the accuracy and efficiency of microseismic monitoring.

An Efficient Neural-Network-Based Microseismic Monitoring Platform for Hydraulic Fracture on an Edge Computing Architecture.

Science.gov (United States)

Zhang, Xiaopu; Lin, Jun; Chen, Zubin; Sun, Feng; Zhu, Xi; Fang, Gengfa

2018-06-05

Microseismic monitoring is one of the most critical technologies for hydraulic fracturing in oil and gas production. To detect events in an accurate and efficient way, there are two major challenges. One challenge is how to achieve high accuracy due to a poor signal-to-noise ratio (SNR). The other one is concerned with real-time data transmission. Taking these challenges into consideration, an edge-computing-based platform, namely Edge-to-Center LearnReduce, is presented in this work. The platform consists of a data center with many edge components. At the data center, a neural network model combined with convolutional neural network (CNN) and long short-term memory (LSTM) is designed and this model is trained by using previously obtained data. Once the model is fully trained, it is sent to edge components for events detection and data reduction. At each edge component, a probabilistic inference is added to the neural network model to improve its accuracy. Finally, the reduced data is delivered to the data center. Based on experiment results, a high detection accuracy (over 96%) with less transmitted data (about 90%) was achieved by using the proposed approach on a microseismic monitoring system. These results show that the platform can simultaneously improve the accuracy and efficiency of microseismic monitoring.

Impact of SNR, masker type and noise reduction processing on sentence recognition performance and listening effort as indicated by the pupil dilation response

DEFF Research Database (Denmark)

Ohlenforst, Barbara; Wendt, Dorothea; Kramer, Sophia E

2018-01-01

Recent studies have shown that activating the noise reduction scheme in hearing aids results in a smaller peak pupil dilation (PPD), indicating reduced listening effort, at 50% and 95% correct sentence recognition with a 4-talker masker. The objective of this study was to measure the effect...... of the noise reduction scheme (on or off) on PPD and sentence recognition across a wide range of signal-to-noise ratios (SNRs) from +16 dB to -12 dB and two masker types (4-talker and stationary noise). Relatively low PPDs were observed at very low (-12 dB) and very high (+16 dB to +8 dB) SNRs presumably due...... to 'giving up' and 'easy listening', respectively. The maximum PPD was observed with SNRs at approximately 50% correct sentence recognition. Sentence recognition with both masker types was significantly improved by the noise reduction scheme, which corresponds to the shift in performance from SNR function...

Delphi report 1995 on developments in science and technology. Mini Delphi; Delphi-Bericht 1995 zur Entwicklung von Wissenschaft und Technik. Mini-Delphi

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

In August 1993 the first German `Delphi Report on Developments in Science and Technology` was published. It was elaborated by the Fraunhofer Institute for System Engineering and Innovation Research (FhG-ISI) in cooperation with the Japanese National Institute of Science and Technology Policy (NISTEP). The `MINI-DELPHI` now completed by FhG-ISI, again in cooperation with NISTEP, is a further development of the Delphi approach in that it is more differentiated in its questions and assessment criteria than its predecessors. `MINI-DELPHI` is not intended as a comprehensive forecast on technology in general but rather focusses on key topics. Its emphasis is on technology demand and the relevance of technologies to social issues. Although the Mini-Delphi study was primarily aimed at further refining the methodology employed, it nevertheless contains a wealth of information and details on circumscript questions. The requisite database is provided by tables on the results of two inquiry rounds among Japanese and German experts. (orig./RHM) [Deutsch] Im August 1993 wurde der erste deutsche `Delphi-Bericht zur Entwicklung von Wissenschaft und Technik` veroeffentlicht. Er war vom Fraunhofer-Institut fuer Systemtechnik und Innovationsforschung (FhG-ISI) in Zusammenarbeit mit dem japanischen National Institute of Science and Technology Policy (NISTEP) erarbeitet worden. Mit dem jetzt vorliegenden `MINI-DELPHI` hat das FhG-ISI - wieder in Zusammenarbeit mit dem NISTEP - den Delphi-Ansatz fortentwickelt und sowohl hinsichtlich der Fragen als auch der Beurteilungskriterien weiter ausdifferenziert. `MINI-DELPHI` bezweckt keine umfassende Technologievorausschau, sondern konzentriert sich auf Schluesselthemen. Im Vordergrund steht der Gedanke des Technikbedarfs und die Relevanz fuer gesellschaftliche Fragestellungen. Obwohl die Mini-Delphi-Studie vorrangig der Weiterentwicklung der Methodik dient, enthaelt sich eine Fuelle von Informationen und Details zu Einzelfragen. Die im Bericht

A cut-off in the TeV gamma-ray spectrum of the SNR Cassiopeia A

Science.gov (United States)

Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.; Arcaro, C.; Babić, A.; Banerjee, B.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Berti, A.; Bhattacharyya, W.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Carosi, R.; Carosi, A.; Chatterjee, A.; Colak, M.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Cumani, P.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Lotto, B.; de Oña Wilhelmi, E.; Di Pierro, F.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher Glawion, D.; Elsaesser, D.; Engelkemeier, M.; Fallah Ramazani, V.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M. V.; Font, L.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Gaug, M.; Giammaria, P.; Godinović, N.; Gora, D.; Guberman, D.; Hadasch, D.; Hahn, A.; Hassan, T.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Inada, T.; Ishio, K.; Konno, Y.; Kubo, H.; Kushida, J.; Kuveždić, D.; Lelas, D.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; Maggio, C.; Majumdar, P.; Makariev, M.; Maneva, G.; Manganaro, M.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Minev, M.; Mirzoyan, R.; Moralejo, A.; Moreno, V.; Moretti, E.; Neustroev, V.; Niedzwiecki, A.; Nievas Rosillo, M.; Nilsson, K.; Ninci, D.; Nishijima, K.; Noda, K.; Nogués, L.; Paiano, S.; Palacio, J.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Pedaletti, G.; Peresano, M.; Perri, L.; Persic, M.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Garcia, J. R.; Reichardt, I.; Rhode, W.; Ribó, M.; Rico, J.; Righi, C.; Saito, T.; Satalecka, K.; Schroeder, S.; Schweizer, T.; Shore, S. N.; Sitarek, J.; Šnidarić, I.; Sobczynska, D.; Stamerra, A.; Strzys, M.; Surić, T.; Takalo, L.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Torres-Albà, N.; Treves, A.; Vanzo, G.; Vazquez Acosta, M.; Vovk, I.; Ward, J. E.; Will, M.; Zarić, D.

2017-12-01

It is widely believed that the bulk of the Galactic cosmic rays is accelerated in supernova remnants (SNRs). However, no observational evidence of the presence of particles of PeV energies in SNRs has yet been found. The young historical SNR Cassiopeia A (Cas A) appears as one of the best candidates to study acceleration processes. Between 2014 December and 2016 October, we observed Cas A with the MAGIC telescopes, accumulating 158 h of good quality data. We derived the spectrum of the source from 100 GeV to 10 TeV. We also analysed ∼8 yr of Fermi-LAT to obtain the spectral shape between 60 MeV and 500 GeV. The spectra measured by the LAT and MAGIC telescopes are compatible within the errors and show a clear turn-off (4.6σ) at the highest energies, which can be described with an exponential cut-off at E_c = 3.5(^{+1.6}_{-1.0})_{stat} (^{+0.8}_{-0.9})_{sys} TeV. The gamma-ray emission from 60 MeV to 10 TeV can be attributed to a population of high-energy protons with a spectral index of ∼2.2 and an energy cut-off at ∼10 TeV. This result indicates that Cas A is not contributing to the high energy (∼PeV) cosmic ray sea in a significant manner at the present moment. A one-zone leptonic model fails to reproduce by itself the multiwavelength spectral energy distribution. Besides, if a non-negligible fraction of the flux seen by MAGIC is produced by leptons, the radiation should be emitted in a region with a low magnetic field (B⪅180 μG) like in the reverse shock.

Automatic Modulation Classification of LFM and Polyphase-coded Radar Signals

Directory of Open Access Journals (Sweden)

S. B. S. Hanbali

2017-12-01

Full Text Available There are several techniques for detecting and classifying low probability of intercept radar signals such as Wigner distribution, Choi-Williams distribution and time-frequency rate distribution, but these distributions require high SNR. To overcome this problem, we propose a new technique for detecting and classifying linear frequency modulation signal and polyphase coded signals using optimum fractional Fourier transform at low SNR. The theoretical analysis and simulation experiments demonstrate the validity and efficiency of the proposed method.

Polen, Deutschland, die EU und Russland

OpenAIRE

Wilkiewicz, Zbigniew

2009-01-01

Besonders seit dem EU-Beitritt Polens ist es um die deutsch-polnischen Beziehungen nicht besonders gut bestellt. In den vergangenen Jahren hat man sich in erster Linie an bilateralen Konflikten abgearbeitet und keine gemeinsame Europapolitik betrieben. Im Beitrag wird diese Entwicklung rekonstruiert und danach gefragt, ob es angesichts einer solchen Entwicklung Aussichten auf die Wiederherstellung der deutsch-polnischen Interessengemeinschaft gibt oder die Interessen beider Staaten so stark d...

Die Sprache des Marketings und ihre Übersetzung: Morphologische und semantische Aspekte der Terminologie

OpenAIRE

Konovalova, Anastasia; Ruiz Yepes, Guadalupe

2016-01-01

Mit der schnellen Entwicklung der Fachsprachen im Bereich Wirtschaft wird auch die Wichtigkeit der Fachkommunikation in internationalen Unternehmen immer deutlicher. Für die Fachübersetzer wirtschaftlicher Texte bedeutet diese Entwicklung oft eine große Herausforderung. Dieser Aufsatz widmet sich der kontrastiven Analyse der Terminologie des Marketings für das Sprachenpaar Deutsch-Spanisch. Das analysierte Korpus besteht aus wirtschaftswissenschaftlichen Beiträgen aus dem Bereich Marketing, d...

T-Zell-Zytokinexpression bei gestillten vs. nicht-gestillten Kindern

OpenAIRE

Aulenbach, Julia

2015-01-01

Das Bestreben, den Aufbau, die Funktion sowie die Entwicklung des Immunsystems zu verstehen, steht schon lange Zeit im Zentrum des Interesses vieler Forschungsarbeiten, insbesondere um auf Grundlage der gewonnenen Erkenntnisse neue Behandlungsansätze für immunologisch relevante Krankheitsbilder zu entwickeln. Stillen könnte ein wichtiger Faktor sein, der bei der Entwicklung und Differenzierung von T-Zell-Subpopulationen und Zytokinmustern im Säuglings- und Kindesalter eine bedeutende Roll...

Polish Qualitative Sociology. The General Features and Development

OpenAIRE

Konecki, Krzysztof T.; Kacperczyk, Anna M.; Marciniak, Lukasz T.

2005-01-01

In dem vorliegenden Beitrag wird die Entwicklung der qualitativen Soziologie in Polen rekonstruiert, indem deren wesentliche intellektuelle Wurzeln und einige Hauptthemen der polnischen Soziologie vorgestellt werden. Romantizismus und die induktive Methode sind essenzielle Elemente für die Entwicklung der Disziplin in Polen gewesen und Charakteristika ihrer Besonderheit. Die Bedeutung von Florian ZNANIECKI für die Entstehung der polnischen qualitativen Soziologie wird gewürdigt. The articl...

KETERTARIKAN LALAT BUAH BACTROCERA PADA EKSTRAK OLAHAN LIMBAH KAKAO BERPENGAWET

Directory of Open Access Journals (Sweden)

Dyah Rini Indriyanti

2012-09-01

Full Text Available Lalat buah Bactrocera spp. (Diptera: Tephritidae merupakan salah satu hama pen ting menyerang tanaman buah-buahan dan sayuran. B. carambolae di laboratorium tertarik pada olahan limbah kakao. Hasil uji coba di lapangan belum memuaskan karena olahan limbah kakao mudah rusak. Tujuan penelitian ini mengkaji respon lalat buah Bactrocera yang diberi umpan ekstrak olahan limbah kakao berpenga wet. Pengawet yang digunakan yakni: Natrium klorida (NaCl, Natrium benzoat (C7H5NaO2 dan Potasium sorbat (C6H7KO2. Konsentrasi yang dipakai masing-masing pengawet 0,1%; 0,2% dan 0,3%. Pengamatan dilakukan selama satu ming gu. Hasil pengamatan menunjukkan bahwa daya tahan limbah yang diberi penga wet dan yang tidak dilihat secara secara fisik (warna dan tekstur tidak berbeda nyata, namun ada perbedaan bau. Limbah yang tidak diberi pengawet ada kecen derungan baunya tidak sedap dibanding yang diberi pengawet. Hal ini yang mempengaruhi ketertarikan lalat terhadap olahan limbah kakao. Respon ketertarikan lalat Bactrocera terhadap olahan limbah kakao yang diberi pengawet berbeda antara satu dengan yang lain. Respon ketertarikan tertinggi Bactrocera cenderung pada olahan limbah kakao yang diberi pengawet Natrium klorida 0,3%, Potasium sorbat 0,2% dan Natrium benzoat 0,1%.The fruit fly Bactrocera spp. (Diptera: Tephritidae is one of the important pests attacking crops of fruits and vegetables. In the laboratory, B. carambolae was attracted by the processed cocoa waste. The results of field trials have not been satisfactory yet, because the processed cocoa waste was easily damaged. The purpose of the study wast to examine the response of Bactrocera to the bait made of processed cocoa extract waste containing preservatives. The preservatives used were: Sodium chloride (NaCl, sodium benzoate (C7H5NaO2 and potassium sorbate (C6H7KO2. The concentration of each preservative was 0.1%; 0.2% and 0.3%. A one-week observation was made. The result showed that there was no

Enhancing the efficiency of constrained dual-hop variable-gain AF relaying under nakagami-m fading

KAUST Repository

Zafar, Ammar; Radaydeh, Redha Mahmoud; Chen, Yunfei; Alouini, Mohamed-Slim

2014-01-01

-to-end signal-to-noise-ratio (SNR) and the overall power consumed is minimized while maintaining this constraint. This problem is considered under two different assumptions of the available channel state information (CSI) at the relays, namely full CSI

Corrosion of reinforcement induced by environment containing ...

Indian Academy of Sciences (India)

... the action of chloride solutions may intensify the process of corrosion of steel reinforcement in comparison to the converse sequence of the action of mentioned media. At the same time the natrium chloride solution has been shown as a more aggressive medium opposite to the calcium and magnesium chloride solutions.

Highly accelerated cardiovascular MR imaging using many channel technology: concepts and clinical applications

International Nuclear Information System (INIS)

Niendorf, Thoralf; Sodickson, Daniel K.

2008-01-01

Cardiovascular magnetic resonance imaging (CVMRI) is of proven clinical value in the non-invasive imaging of cardiovascular diseases. CVMRI requires rapid image acquisition, but acquisition speed is fundamentally limited in conventional MRI. Parallel imaging provides a means for increasing acquisition speed and efficiency. However, signal-to-noise (SNR) limitations and the limited number of receiver channels available on most MR systems have in the past imposed practical constraints, which dictated the use of moderate accelerations in CVMRI. High levels of acceleration, which were unattainable previously, have become possible with many-receiver MR systems and many-element, cardiac-optimized RF-coil arrays. The resulting imaging speed improvements can be exploited in a number of ways, ranging from enhancement of spatial and temporal resolution to efficient whole heart coverage to streamlining of CVMRI work flow. In this review, examples of these strategies are provided, following an outline of the fundamentals of the highly accelerated imaging approaches employed in CVMRI. Topics discussed include basic principles of parallel imaging; key requirements for MR systems and RF-coil design; practical considerations of SNR management, supported by multi-dimensional accelerations, 3D noise averaging and high field imaging; highly accelerated clinical state-of-the art cardiovascular imaging applications spanning the range from SNR-rich to SNR-limited; and current trends and future directions. (orig.)

Efficient DS-UWB MUD Algorithm Using Code Mapping and RVM

Directory of Open Access Journals (Sweden)

Pingyan Shi

2016-01-01

Full Text Available A hybrid multiuser detection (MUD using code mapping and a wrong code recognition based on relevance vector machine (RVM for direct sequence ultra wide band (DS-UWB system is developed to cope with the multiple access interference (MAI and the computational efficiency. A new MAI suppression mechanism is studied in the following steps: firstly, code mapping, an optimal decision function, is constructed and the output candidate code of the matched filter is mapped to a feature space by the function. In the feature space, simulation results show that the error codes caused by MAI and the single user mapped codes can be classified by a threshold which is related to SNR of the receiver. Then, on the base of code mapping, use RVM to distinguish the wrong codes from the right ones and finally correct them. Compared with the traditional MUD approaches, the proposed method can considerably improve the bit error ratio (BER performance due to its special MAI suppression mechanism. Simulation results also show that the proposed method can approximately achieve the BER performance of optimal multiuser detection (OMD and the computational complexity approximately equals the matched filter. Moreover, the proposed method is less sensitive to the number of users.

Signal to Noise Ratio (SNR Enhancement Comparison of Impulse-, Coding- and Novel Linear-Frequency-Chirp-Based Optical Time Domain Reflectometry (OTDR for Passive Optical Network (PON Monitoring Based on Unique Combinations of Wavelength Selective Mirrors

Directory of Open Access Journals (Sweden)

Christopher M. Bentz

2014-03-01

Full Text Available We compare optical time domain reflectometry (OTDR techniques based on conventional single impulse, coding and linear frequency chirps concerning their signal to noise ratio (SNR enhancements by measurements in a passive optical network (PON with a maximum one-way attenuation of 36.6 dB. A total of six subscribers, each represented by a unique mirror pair with narrow reflection bandwidths, are installed within a distance of 14 m. The spatial resolution of the OTDR set-up is 3.0 m.

Inter renewal travelling wave reactor with rotary fuel columns

International Nuclear Information System (INIS)

Terai, Yuzo

2016-01-01

To realize the COP21 decision, this paper proposes Inter Renewal Travelling Wave Reactor that bear high burn-up rate 50% and product TRU fuel efficiently. The reactor is based on 4S Fast Reactor and has Reactor Fuel Columns as fuel assemblies that equalize temperature in the fuel assembly so that fewer structure is need to restrain thermal transformation. To equalize burn-up rate of all fuel assemblies in the reactor, each rotary fuel column has each motor-lifter. The rotary fuel column has two types (Cylinder type and Heat Pipe type using natrium at 15 kPa which supply high temperature energy for Ultra Super Critical power plant). At 4 years cycle all rotary fuel columns of the reactor are renewed by the metallurgy method (vacuum re-smelting) and TRU fuel is gotten from the water fuel. (author)

Effects of image processing on the detective quantum efficiency

Energy Technology Data Exchange (ETDEWEB)

Park, Hye-Suk; Kim, Hee-Joung; Cho, Hyo-Min; Lee, Chang-Lae; Lee, Seung-Wan; Choi, Yu-Na [Yonsei University, Wonju (Korea, Republic of)

2010-02-15

The evaluation of image quality is an important part of digital radiography. The modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE) are widely accepted measurements of the digital radiographic system performance. However, as the methodologies for such characterization have not been standardized, it is difficult to compare directly reported the MTF, NPS, and DQE results. In this study, we evaluated the effect of an image processing algorithm for estimating the MTF, NPS, and DQE. The image performance parameters were evaluated using the international electro-technical commission (IEC 62220-1)-defined RQA5 radiographic techniques. Computed radiography (CR) posterior-anterior (PA) images of a hand for measuring the signal to noise ratio (SNR), the slit images for measuring the MTF, and the white images for measuring the NPS were obtained, and various multi-Scale image contrast amplification (MUSICA) factors were applied to each of the acquired images. All of the modifications of the images obtained by using image processing had a considerable influence on the evaluated image quality. In conclusion, the control parameters of image processing can be accounted for evaluating characterization of image quality in same way. The results of this study should serve as a baseline for based on evaluating imaging systems and their imaging characteristics by MTF, NPS, and DQE measurements.

Effects of image processing on the detective quantum efficiency

International Nuclear Information System (INIS)

Park, Hye-Suk; Kim, Hee-Joung; Cho, Hyo-Min; Lee, Chang-Lae; Lee, Seung-Wan; Choi, Yu-Na

2010-01-01

The evaluation of image quality is an important part of digital radiography. The modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE) are widely accepted measurements of the digital radiographic system performance. However, as the methodologies for such characterization have not been standardized, it is difficult to compare directly reported the MTF, NPS, and DQE results. In this study, we evaluated the effect of an image processing algorithm for estimating the MTF, NPS, and DQE. The image performance parameters were evaluated using the international electro-technical commission (IEC 62220-1)-defined RQA5 radiographic techniques. Computed radiography (CR) posterior-anterior (PA) images of a hand for measuring the signal to noise ratio (SNR), the slit images for measuring the MTF, and the white images for measuring the NPS were obtained, and various multi-Scale image contrast amplification (MUSICA) factors were applied to each of the acquired images. All of the modifications of the images obtained by using image processing had a considerable influence on the evaluated image quality. In conclusion, the control parameters of image processing can be accounted for evaluating characterization of image quality in same way. The results of this study should serve as a baseline for based on evaluating imaging systems and their imaging characteristics by MTF, NPS, and DQE measurements.

MR Imaging of the Spine at 3.0T with T2-Weighted IDEAL Fast Recovery Fast Spin-Echo Technique

International Nuclear Information System (INIS)

Ren, Ai Jun; Guo, Yong; Tian, Shu Ping; Shi, Li Jing; Huang, Min Hua

2012-01-01

To compare the iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) method with a fat-saturated T2-weighted (T2W) fast recovery fast spin-echo (FRFSE) imaging of the spine. Images acquired at 3.0 Tesla (T) in 35 patients with different spine lesions using fat-saturated T2W FRFSE imaging were compared with T2W IDEAL FRFSE images. Signal-to-noise ratio (SNR)-efficiencies measurements were made in the vertebral bodies and spinal cord in the mid-sagittal plane or nearest to the mid-sagittal plane. Images were scored with the consensus of two experienced radiologists on a four-point grading scale for fat suppression and overall image quality. Statistical analysis of SNR-efficiency, fat suppression and image quality scores was performed with a paired Student's t test and Wilcoxon's signed rank test. Signal-to-noise ratio-efficiency for both vertebral body and spinal cord was higher with T2W IDEAL FRFSE imaging (p < 0.05) than with T2W FRFSE imaging. T2W IDEAL FRFSE demonstrated superior fat suppression (p < 0.01) and image quality (p < 0.01) compared to fat-saturated T2W FRFSE. As compared with fat-saturated T2W FRFSE, IDEAL can provide a higher image quality, higher SNR-efficiency, and consistent, robust and uniform fat suppression. T2W IDEAL FRFSE is a promising technique for MR imaging of the spine at 3.0T.

Reprocessing of nonoptimally exposed holograms

International Nuclear Information System (INIS)

Phipps, G.S.; Robertson, C.E.; Tamashiro, F.M.

1980-01-01

Two reprocessing techniques have been investigated that are capable of correcting the effects of nonoptimum optical density of photographic amplitude holograms recorded on Agfa-Gevaert type 10E75 plates. In some cases a reprocessed hologram will exhibit a diffraction efficiency even higher than that obtainable from a hologram exposed and processed to the optimum density. The SNR of the reprocessed holograms is much higher than that of the same holograms belached with cupric bromide. In some cases the SNR approaches the optimum value for a properly exposed amplitude hologram. Subjective image quality and resolution of reprocessed hologram reconstructins appear to be no different than for normal single-development holograms. Repeated reprocessing is feasible and in some cases desirable as a means of increasing diffraction efficiency

Statistically Efficient Methods for Pitch and DOA Estimation

DEFF Research Database (Denmark)

Jensen, Jesper Rindom; Christensen, Mads Græsbøll; Jensen, Søren Holdt

2013-01-01

, it was recently considered to estimate the DOA and pitch jointly. In this paper, we propose two novel methods for DOA and pitch estimation. They both yield maximum-likelihood estimates in white Gaussian noise scenar- ios, where the SNR may be different across channels, as opposed to state-of-the-art methods......Traditionally, direction-of-arrival (DOA) and pitch estimation of multichannel, periodic sources have been considered as two separate problems. Separate estimation may render the task of resolving sources with similar DOA or pitch impossible, and it may decrease the estimation accuracy. Therefore...

Integrated systems and modules for engine cooling and vehicle air-conditioning; Integrierte Systeme und Module zur Motorkuehlung und Innenraumklimatisierung

Energy Technology Data Exchange (ETDEWEB)

Loehle, M.; Kern, J.; Kampf, H. [Behr GmbH (Germany)

1998-12-01

The high level of function and quality achieved today in modern vehicles cannot be simply increased by the isolated development of advanced single components alone. By contrast, the holistic optimization of systems opens up new potential. Modern cooling modules and integrated HVAC systems by Behr GmbH and Co. combine several components to form a single compact module whose integrated parts are perfectly matched to each other. Developing complete cockpits at such a high level of integration is another step towards advancing the system concept. Understanding a holistic system allows engineers to develop concepts for an efficient thermal management in the cooling system and to improve ecological compatibility of the vehicle air-conditioning system by using suitable simulation tools. (orig.) [Deutsch] Die gesamtheitliche Optimierung von Systemen eroeffnet neue Potentiale in der Automobilentwicklung. Moderne Kuehlmodule und integrierte Heiz-/Klimageraete der Behr GmbH and Co. fassen zahlreiche Komponenten zu einem kompakten Modul zusammen, dessen Einzelteile aufeinander abgestimmt sind. Die Entwicklung vollstaendiger Cockpits mit einem hohen Integrationsgrad fuehrt den Systemgedanken konsequent weiter. Das Verstaendnis des gesamten Systems erlaubt im Verbund mit geeigneten Simulationswerkzeugen die Entwicklung von Konzepten fuer ein effizientes Thermomanagement im Kuehlsystem und fuer die Verbesserung der Umweltvertraeglichkeit der Kaelteanlage. (orig.)

Application of laser-optical diagnostics for the support of direct-injection gasoline combustion process development; Einsatz laseroptischer Messverfahren zur Unterstuetzung der Entwicklung von Brennverfahren mit Benzin-Direkteinspritzung

Energy Technology Data Exchange (ETDEWEB)

Hentschel, W.; Meyer, H.; Stiebels, B. [Volkswagenwerk AG, Wolfsburg (Germany). Abt. Forschung und Entwicklung

2000-07-01

The development of direct-injection gasoline engines at Volkswagen was supported strictly from the beginning by the means of optical diagnostics and CFD-simulations. Basic phenomena, such as the formation of the in-cylinder flow field, the penetration of the spray formed by a hollow-cone swirl-type injector at high fuel pressure, the interaction of spray and flow and the formation of an ignitable mixture were analysed in details. The paper describes the laser-optical techniques-particle-image-velocimetry, laser-Doppler-anemometry, videostroboscopy, high-speed cinematography and laser-induced fluorescence - which were used during the development of the DI gasoline combustion process. Examples taken from engines with optical access to the combustion chamber demonstrate the capability of the techniques and pinpoint where the design of the combustion process benefits from experimental and simulation investigations. (orig.) [German] Die Entwicklung von Ottomotoren mit Benzin-Direkteinspritzung wurde bei Volkswagen von Beginn an konsequent durch den Einsatz optischer Messverfahren und CFD-Simulationen unterstuetzt. Damit konnten grundlegende Phaenomene, wie die Ausbildung des Stroemungsfeldes im Motorbrennraum, die Ausbreitung des durch einen Hohlkegel-Drallinjektor unter hohem Druck eingespritzten Kraftstoffs sowie die Wechselwirkung der Luftstroemung im Zylinder mit den Einspritzstrahlen und die Bildung einer zuendfaehigen Ladungswolke detailliert untersucht werden. Das Paper beschreibt die laseroptischen Messverfahren - Particle-Image-Velocimetry, Laser-Doppler-Anemometry, Video-Stroboskopie, Hochgeschwindikgkeits-Kinematographie und Laserinduzierte Fluoreszenz - die bei der Brennverfahrensentwicklung eingesetzt werden und zeigt anhand einer Reihe von konkreten Beispielen, wo Antworten auf Grundsatzfragen zur Auslegung des Brennverfahrens durch Messergebnisse an optisch zugaenglichen Motoren und durch CFD-Simulationen erarbeitet werden koennen. (orig.)

The value of magnetic resonance imaging (MRI) in the treatment planning of vertebral metastasis considering economic aspects. A cost benefit-analysis; Die Wertigkeit der Magnetresonanztomographie (MRT) unter oekonomischen Aspekten bei der Bestrahlungsplanung von Wirbelkoerpermetastasen. Eine Kosten-Nutzen-Analyse

Energy Technology Data Exchange (ETDEWEB)

Prott, F.J.; Schlehuber, E.; Scharding, B.J.; Rinast, E. [Strahlentherapie Wiesbaden, St.-Josefs-Hospital (Germany); Micke, O. [Klinik und Poliklinik fuer Strahlentherapie - Radioonkologie, Universitaetsklinikum Muenster (Germany)

2002-05-01

Is magnetic resonance imaging (MRI) based target volume definition for treatment planning of vertebral metastasis effective under economic considerations.From 1994 to 1999, a total of 137 patients with bone metastases affecting the vertebral column underwent MRI of the cercival, thoracic, or lumbar spine for the treatment planning of palliative radiation therapy. The following radiation treatment consisted in a irradiation of the affected vertebral region up to a total dose of 30-40 Gy.The cost calculation for radiotherapy and magnetic resonance tomography was done using the common tariff model (EBM) of the German Health Insurances.In 73% of patients (101 patients), magnetic resonance imaging resulted in marked corrections of the irradiation fields which would have resulted in the necessity of treatment for recurrence in the case of treatment planning without MRI.Consequently, the higher cost of MRI of 345.00 DEM (176,40 EUR) lead to a saving of 497.00 DEM (254,11 EUR) compared to a recurrence treatment of 10 fractions and of 1,428.00 DEM (730,12 EUR) compared to 20 fractions. The transport expenses for the second treatment could be saved as well.Even under economic considerations MRI is effective. (orig.) [German] Ist eine MRT-gestuetzte Zielvolumendefinition bei der Strahlentherapie von Knochenmetastasen ein sinnvolles Vorgehen unter oekonomischen Gesichtspunkten?1994-1999 wurde bei 137 Patienten mit einem ossaer metastasierenden Tumor und Befall der Wirbelsaeule eine Magnetresonanztomographie (MRT) zur Planung einer palliativen Radiatio durchgefuehrt. Die nachfolgende Strahlentherapie bestand aus einer Radiatio des betroffenen Wirbelkoerperabschnitts bis zu einer Gesamtherddosis von 30-40 Gy. Fuer die Berechnung der Kosten wurde der einheitliche Bewertungsmassstab der Deutschen Krankenkassen zugrunde gelegt.Aufgrund der MRT-Untersuchungen wurde bei 73% der Patienten eine Veraenderung des Bestrahlungsfeldes vorgenommen, die im Falle einer nicht MRT

Elektrische Energieversorgung

Science.gov (United States)

Schulz, Detlef

Nur mit einer zuverlässigen und wirtschaftlichen elektrischen Energieversorgung ist eine nachhaltige gesellschaftliche Entwicklung von Industrienationen möglich. Gleichzeitig muss diese selbst so nachhaltig, d. h. umweltverträglich gestaltet werden, dass auch zukünftige Generationen nicht in ihrer Entfaltung behindert werden. Eine versorgungssichere, wirtschaftliche und umweltverträgliche Energiebereitstellung ergibt sich nicht zwingend allein aus einer technisch evolutionären Entwicklung und ist auch bis heute nicht ausschließlich nur mit einer der bekannten Wandlungstechnologien nachweislich realisierbar.

Eine praktische Anwendung von CMC-Flächen in der Bionik

OpenAIRE

Apeltauer, Christian

2011-01-01

Die vorliegende Arbeit beschäftigt sich mit den theoretischen Grundlagen für die Entwicklung von Oberflächen, die unter Wasser möglichst lange eine Luftschicht an sich halten können. Ein natürliches Vorbild für solche Oberflächen ist die Pflanze Salvinia molesta; technisch interessieren solche Oberflächen zur Verringerung des Wasserwiderstandes von Schiffen und als Schutz vor Besiedlung durch Wasserorganismen. Wichtigste Gleichung bei der Entwicklung solcher Oberflächen ist...

Two-way cooperative AF relaying in spectrum-sharing systems: Enhancing cell-edge performance

KAUST Repository

Xia, Minghua; Aï ssa, Sonia

2012-01-01

signal-to-noise ratio (SNR). These important findings provide fresh perspectives for system designers to improve spectral efficiency of secondary users in next-generation broadband spectrum-sharing wireless systems. © 2012 IEEE.

Selective sodium removal from lithium chloride brine with novel ...

African Journals Online (AJOL)

Natrium superionic conductor (NASICON) ceramics present interesting sensitive and selective properties against alkaline cations due to their structure. The powder of Li1.4La0.4Zr1.6(PO4)3 has been synthesized by a solid phase reaction. The removal of sodium was studied in an extensive series of tests involving different ...

Throughput Estimation Method in Burst ACK Scheme for Optimizing Frame Size and Burst Frame Number Appropriate to SNR-Related Error Rate

Science.gov (United States)

Ohteru, Shoko; Kishine, Keiji

The Burst ACK scheme enhances effective throughput by reducing ACK overhead when a transmitter sends sequentially multiple data frames to a destination. IEEE 802.11e is one such example. The size of the data frame body and the number of burst data frames are important burst transmission parameters that affect throughput. The larger the burst transmission parameters are, the better the throughput under error-free conditions becomes. However, large data frame could reduce throughput under error-prone conditions caused by signal-to-noise ratio (SNR) deterioration. If the throughput can be calculated from the burst transmission parameters and error rate, the appropriate ranges of the burst transmission parameters could be narrowed down, and the necessary buffer size for storing transmit data or received data temporarily could be estimated. In this paper, we present a method that features a simple algorithm for estimating the effective throughput from the burst transmission parameters and error rate. The calculated throughput values agree well with the measured ones for actual wireless boards based on the IEEE 802.11-based original MAC protocol. We also calculate throughput values for larger values of the burst transmission parameters outside the assignable values of the wireless boards and find the appropriate values of the burst transmission parameters.

Studies for reconstruction efficiency and background measurements of {tau} lepton identification in Z {yields} {tau}{tau} decays in data of the ATLAS experiment; Studien zur Messung von Rekonstruktionseffizienz und Untergrund der {tau}-Lepton-Identifikation im Zerfall Z {yields} {tau}{tau} beim ATLAS-Experiment aus Daten

Energy Technology Data Exchange (ETDEWEB)

Johnert, Sebastian

2008-11-15

In this diploma thesis two methods are presented, by which {tau} leptons shall be studied in the future data of the ATLAS experiment. The first part is formed by the determination of misidentification rates of jets from QCD 2-jet events as {tau} particles. The second part is the development of a method for the determination of the {tau} reconstruction and identification efficiency relatively to the {mu} efficiency. In this connection invariant masses from Z{yields}ll events are determined, the masses from Z{yields}{tau}{tau} events compared with those from Z{yields}ee and Z{yields}{mu}{mu}, {tau} efficiencies averaged over all ranges and in different {eta} ranges calculated as well as a mehtod for the determination of {tau} efficiencies in different transverse-momentum ranges presented. Furthermore an improved estimation of the QCD background is performed and the behaviour of the {tau} efficiency under regardment of the trigger studied. [German] In dieser Diplomarbeit werden zwei Methoden vorgestellt, mit denen {tau}-Leptonen in den zukuenftigen Daten des ATLAS-Experiments untersucht werden sollen. Den ersten Teil bildet die Bestimmung von Missidentifikationsraten von Jets aus QCD-2-Jet-Ereignissen als {tau}-Leptonen. Der zweite Teil ist die Entwicklung einer Methode zur Bestimmung der {tau}-Rekonstruktions und -Identifikationseffizienz relativ zur {mu}-Effizienz. In diesem Zusammenhang werden invariante Massen aus Z {yields} ll-Ereignissen bestimmt, die Massen aus Z {yields} {tau}{tau}-Ereignissen mit denen aus Z {yields} ee und Z {yields} {mu}{mu} verglichen, {tau}-Effizienzen gemittelt ueber alle Bereiche und in verschiedenen {eta}-Bereichen berechnet sowie eine Moeglichkeit zur Bestimmung von {tau}-Effizienzen in unterschiedlichen Transversalimpulsbereichen vorgestellt. Des Weiteren wird eine verbesserte Abschaetzung des QCD-Untergrunds vorgenommen und das Verhalten der {tau}-Effizienz unter Beruecksichtigung des Triggers untersucht. (orig.)

Development and application of efficient strategies for parallel magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Breuer, F.

2006-07-01

artifacts. Unfortunately, parallel imaging is associated with a loss in signal-to-noise ratio (SNR) and therefore is limited to applications which do not already operate at the SNR limit. An additional limitation is the fact that the coil array must provide sufficient sensitivity variations throughout the object under investigation in order to offer enough spatial encoding capacity. This doctoral thesis exhibits an overview of my research on the topic of efficient parallel imaging strategies. Based on existing parallel acquisition and reconstruction strategies, such as SENSE and GRAPPA, new concepts have been developed and transferred to potential clinical applications. (orig.)

Development and application of efficient strategies for parallel magnetic resonance imaging

International Nuclear Information System (INIS)

Breuer, F.

2006-01-01

. Unfortunately, parallel imaging is associated with a loss in signal-to-noise ratio (SNR) and therefore is limited to applications which do not already operate at the SNR limit. An additional limitation is the fact that the coil array must provide sufficient sensitivity variations throughout the object under investigation in order to offer enough spatial encoding capacity. This doctoral thesis exhibits an overview of my research on the topic of efficient parallel imaging strategies. Based on existing parallel acquisition and reconstruction strategies, such as SENSE and GRAPPA, new concepts have been developed and transferred to potential clinical applications. (orig.)

Diffusion-weighted MRI of the prostate at 3.0 T: Comparison of endorectal coil (ERC) MRI and phased-array coil (PAC) MRI—The impact of SNR on ADC measurement

International Nuclear Information System (INIS)

Mazaheri, Yousef; Vargas, H. Alberto; Nyman, Gregory; Shukla-Dave, Amita; Akin, Oguz; Hricak, Hedvig

2013-01-01

Purpose: To compare ADC values measured from diffusion-weighted MR (DW-MR) images of the prostate obtained with both endorectal and phased-array coils (ERC + PAC) to those from DW-MRI images obtained with an eight-channel torso phased-array coil (PAC) at 3.0 T. Methods: The institutional review board issued a waiver of informed consent for this HIPAA-compliant study. Twenty-five patients with biopsy-proven prostate cancer underwent standard 3-T MRI using 2 different coil arrangements (ERC + PAC and PAC only) in the same session. DW-MRI at five b-values (0, 600, 1000, 1200, and 1500 s/mm 2 ) were acquired using both coil arrangements. On b = 0 images, signal-to-noise ratios (SNRs) were measured as the ratio of the mean signal from PZ and TZ ROIs to the standard deviation from the mean signal in an artifact-free ROI in the rectum. Matching regions-of-interest (ROIs) were identified in the peripheral zone and transition zone on ERC-MRI and PAC-MRI. For each ROI, mean ADC values for all zero and non-zero b-value combinations were computed. Results: Mean SNR with ERC-MRI at PZ (66.33 ± 27.07) and TZ (32.69 ± 12.52) was 9.27 and 5.52 times higher than with PAC-MRI ((7.32 ± 2.30) and (6.13 ± 1.56), respectively) (P < 0.0001 for both). ADCs from DW-MR images obtained with all b-values in the PZ and TZ were significantly lower with PAC-MRI than with ERC-MRI (P < 0.001 for all). Conclusion: Lower SNR of DW-MR images of the prostate obtained with a PAC can significantly decrease ADC values at higher b-values compared to similar measurements obtained using the ERC. To address these requirements, clinical MR systems should have image processing capabilities which incorporate the noise distribution

Regulatorische Anforderungen an die Produktion und Qualität pflanzlicher Arzneimittel

Directory of Open Access Journals (Sweden)

Hagels, Hansjörg

2014-09-01

Full Text Available Entwicklung, Zulassung, Produktion sowie die Vermarktung und der Vertrieb von Arzneimitteln unterliegen in Europa harmonisierten Regularien, die im Gemeinschaftskodex für Humanarzneimittel (Richtlinie 2001/83/EG zusammengefasst sind und auch pflanzliche Arzneimittel einschließen. Bevor Pflanzensammler/anbauer oder Extrakthersteller sich mit der Entwicklung oder auch Produktion von Arzneimittel-Ausgangs- und Rohstoffen beschäftigen ist es deshalb unumgänglich, diese Regularien zu beherrschen und in die Prozesse einzuarbeiten, um eine langfristige konstruktive Kooperation mit pharmazeutischen Unternehmen als Kunden sicher zu stellen.

Innovation for improvement of pedestrian protection as the challenge for the development of front-end structures of passenger cars; Innovationen zur Verbesserung des Fussgaengerschutzes als Herausforderung fuer die Entwicklung von PKW-Vorbaustrukturen

Energy Technology Data Exchange (ETDEWEB)

Kramer, F.; Weidemann, W.; Jansohn, W.; Schneider, M. [EDAG Engineering and Design AG, Fulda (Germany)

2001-07-01

Requirements for improvement of pedestrian protection are the result of real-world accidents and test conditions, which take an important role in development of front-end structures of passenger cars at present, based on legal regulations (EU directives expected in 2005) and on car assessment programmes (application as per EuroNCAP since 1997). Styling and packaging are major considerations in conceptual realisation on a large scale. Furthermore, demands for minimisation of weight and cost have to be considered as marginal conditions. Solutions for this conflict of aims, which results from the new safety requirements and performance criteria for front-end structures, are to be represented and discussed based on concrete examples. (orig.) [German] Anforderungen zur Verbesserung des Fussgaengerschutzes resultieren einerseits aus dem Unfallgeschehen und andererseits aus Versuchsbedingungen, die derzeit auf der Basis von gesetzlichen Regelungen (erwartete EU-Richtlinie etwa im Jahr 2005) und von Sicherheitsbewertungen (Anwendung im Rahmen von EuroNCAP seit 1997) in der Vorbau-Entwicklung von Personenkraftwagen eine bedeutende Rolle einnehmen. Die konzeptionelle Umsetzung tangiert sowohl Styling als auch Packaging in erheblichem Umfang, darueber hinaus sind als Randbedingungen die Forderungen nach der Minimierung von Gewicht und Kosten zu beruecksichtigen. Die Loesungen dieses Zielkonfliktes, deren Wirkungsfeld durch die neuen Sicherheitsanforderungen und die Auslegungskriterien fuer Vorbaustrukturen aufgespannt wird, sollen anhand von konkreten Beispielen dargestellt und diskutiert werden. (orig.)

Methodological principles for optimising functional MRI experiments; Methodische Grundlagen der Optimierung funktioneller MR-Experimente

Energy Technology Data Exchange (ETDEWEB)

Wuestenberg, T. [Georg-August-Universitaet Goettingen, Abteilung fuer Medizinische Psychologie (Germany); Georg-August-Universitaet, Abteilung fuer Medizinische Psychologie, Goettingen (Germany); Giesel, F.L. [Deutsches Kebsforschungszentrum (DKFZ) Heidelberg, Abteilung fuer Radiologische Diagnostik (Germany); Strasburger, H. [Georg-August-Universitaet Goettingen, Abteilung fuer Medizinische Psychologie (Germany)

2005-02-01

Functional magnetic resonance imaging (fMRI) is one of the most common methods for localising neuronal activity in the brain. Even though the sensitivity of fMRI is comparatively low, the optimisation of certain experimental parameters allows obtaining reliable results. In this article, approaches for optimising the experimental design, imaging parameters and analytic strategies will be discussed. Clinical neuroscientists and interested physicians will receive practical rules of thumb for improving the efficiency of brain imaging experiments. (orig.) [German] Die funktionelle Magnetresonanztomographie (fMRT) des Zentralnervensystems ist eine der meistgenutzten Methoden zur Lokalisierung neuronaler Aktivitaet im Gehirn. Obwohl die Sensitivitaet der fMRT vergleichsweise gering ist, kann durch die Auswahl geeigneter experimenteller Parameter die Empfindlichkeit dieses bildgebenden Verfahrens gesteigert und die Reliabilitaet der Ergebnisse gewaehrleistet werden. In diesem Artikel werden deshalb Ansaetze fuer die Optimierung des Paradigmendesigns, der MR-Bildgebung und der Datenauswertung diskutiert. Klinischen Forschern und interessierten Aerzten sollen dadurch Richtgroessen fuer die Durchfuehrung effektiver fMRT-Experimente vermittelt werden. (orig.)

Development and prototypical application of analysis methods for complex anion mixtures in waters and heavy metal organyls in sediments; Entwicklung und prototypische Anwendung von Analysenverfahren fuer komplexe Anionengemische in Waessern und Schwermetallorganylen in Sedimenten. Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Anders, B.; Knoechel, A.; Potgeter, H.; Staub, S.; Stocker, M.

2002-07-01

When it comes to assessing the hazards emanating from heavy pollutants in waters mere elemental analysis provides too little information. Due to the great differences in toxicity and mobility it is important to know more about the exact species in question. This is particularly true of heavy metals that form stable organyls, specifically As, Pb, Sn and Hg, but also of alkylated arsenic acids, which need to be measured in complex anion mixtures. The purpose of the present project was to develop robust, powerful analysis methods and thus overcome the existing deficit in reliable analysis methods for these substances. An important approach in this connection is the use of coupled chromatography and detection systems for separation and analysis. [German] Hinsichtlich der von einer Schwermetallbelastung in Gewaessern ausgehenden Gefahren liefert die reine Elementanalytik nur unzureichende Aussagen. Aufgrund der grossen Unterschiede in Toxiditaet und Mobilitaet ist die Kenntnis der jeweils vorliegenden Spezies bedeutungsvoll. Dies gilt in besonderem Masse fuer die stabile Organyle bildenden Schwermetalle As, Pb, Sn und Hg sowie die alkylierten Arsensaeuren, die es innerhalb komplexer Anionengemische zu bestimmen gilt. Hinsichtlich ihrer sicheren Bestimmung bestehen methodische Defizite, die das vorliegende Projekt durch die Entwicklung robuster, nachweisstarker Analysenverfahren zu beseitigen versucht. Grosse Bedeutung kommt dabei gekoppelten Systemen aus Chromatographie und Detektion als Trenn- und Bestimmungsmethode zu. (orig.)

Annual meeting on nuclear technology 1980. Technical meeting: Early detection methods

International Nuclear Information System (INIS)

1980-01-01

The practical methods refer to the neutron noise analysis of BWR-type reactors, the development and implementation of an early detection system for BWR-type reactors and the possibilities of the noise analysis in natrium-cooled fast breeder reactors. The mathematical methods are concerned with the stochastic analysis, high-frequency acoustic monitoring and early detection of damage in PWR-type reactors. (DG) [de

Barodiffusion phenomena at active transport of na+ and K+ ions through the cell membrane

International Nuclear Information System (INIS)

Khrapijchuk, G.V.; Chalyi, A.V.; Nurishchenko, N.Je.

2010-01-01

The influence of ultrasound as the significant motive force of barodiffusion phenomena at the processes of active transport of Na + and K + ions through the cell membrane is considered. The dependence of membrane potential is theoretically estimated at active transport of natrium and potassium ions on the ultrasound intensity and pressure overfall between external and internal medium of the cell.

The TEX-I real-time expert system applied to situation assessment for the SNR-300 reactor

International Nuclear Information System (INIS)

Schmal, N.; Doerbecker, K.; Leder, H.J.; Rueckert, M.; Schade, H.J.

1990-01-01

Within the German TEX-I Project, which was sponsored by the Federal Ministry for Research and Technology, several companies developed industrial applications of technical expert systems for data interpretation, diagnosis and process control. The purpose of the diagnosis expert system reported here is to support the operators of the LMFBR SNR-300 in assessing plant status in real-time, based on readings from a large number of sensors. By online connection to the process control computer, it can monitor all incoming signal values, check the consistency of data, continuously diagnose the current plant status, detect unusual trends prior to accidents, localize faulty components and recommend operators response in abnormal conditions. The systems architecture consists of two basic subsystems, an inference engine and an intelligent process interface, implemented in Lisp on a Symbolics-Workstation. The inference engine has been derived from BABYLON, a hybrid shell developed by the German computer research institute GMD. This shell includes rules, prologue, constraints and an object oriented frame processor. The extended version has a component description language and a top-down diagnosis scheme including a mechanism of attention focusing. Inference run as independent, quasi-parallel processes. These so-called inference tasks can interrupt or abort each other, if higher priority events must be processed. The complete system is modelled in an object oriented matter and is divided into several subsystems and each subsystem into its physical components. At present the expert system is connected to a real-time simulation of the reactor. The simulation is based on a thermohydraulic code for simulation of the transient behaviour of temperatures and flow rates in the reactor core, plena, pipes, pumps, valves, intermediate heat exchangers and cooling components. Additionally, the systems response to an asynchronous operator interaction can be simulated. Several types of anomalies

150 years of electrical engineering. A review and future prospects for power plant construction; 150 Jahre Elektrotechnik. Rueckblick und Vision im Kraftwerksbau

Energy Technology Data Exchange (ETDEWEB)

Boehm, H. [Siemens AG Unternehmensbereich KWU, Erlangen (Germany). Bereich Energieerzeugung

1997-12-01

The development of power plant construction both in the last 150 years and also relative to the deduced major trends for the future is illustrated by the important milestones. In this respect, the important role of modern power stations is very prominent in ensuring enduring economic development. (orig.) [Deutsch] Anhand von wichtigen Meilensteinen wird die Entwicklung im Kraftwerksbau sowohl in den letzten 150 Jahren als auch entsprechend den sich abzeichnenden grossen Trends fuer die Zukunft beleuchtet. Dabei steht die wichtige Rolle moderner Kraftwerke fuer eine nachhaltige Entwicklung im Vordergrund. (orig.)

Asymmetry between ON and OFF α ganglion cells of mouse retina: integration of signal and noise from synaptic inputs.

Science.gov (United States)

Freed, Michael A

2017-11-15

Bipolar and amacrine cells presynaptic to the ON sustained α cell of mouse retina provide currents with a higher signal-to-noise power ratio (SNR) than those presynaptic to the OFF sustained α cell. Yet the ON cell loses proportionately more SNR from synaptic inputs to spike output than the OFF cell does. The higher SNR of ON bipolar cells at the beginning of the ON pathway compensates for losses incurred by the ON ganglion cell, and improves the processing of positive contrasts. ON and OFF pathways in the retina include functional pairs of neurons that, at first glance, appear to have symmetrically similar responses to brightening and darkening, respectively. Upon careful examination, however, functional pairs exhibit asymmetries in receptive field size and response kinetics. Until now, descriptions of how light-adapted retinal circuitry maintains a preponderance of signal over the noise have not distinguished between ON and OFF pathways. Here I present evidence of marked asymmetries between members of a functional pair of sustained α ganglion cells in the mouse retina. The ON cell exhibited a proportionately greater loss of signal-to-noise power ratio (SNR) from its presynaptic arrays to its postsynaptic currents. Thus the ON cell combines signal and noise from its presynaptic arrays of bipolar and amacrine cells less efficiently than the OFF cell does. Yet the inefficiency of the ON cell is compensated by its presynaptic arrays providing a higher SNR than the arrays presynaptic to the OFF cell, apparently to improve visual processing of positive contrasts. Dynamic clamp experiments were performed that introduced synaptic conductances into ON and OFF cells. When the amacrine-modulated conductance was removed, the ON cell's spike train exhibited an increase in SNR. The OFF cell, however, showed the opposite effect of removing amacrine input, which was a decrease in SNR. Thus ON and OFF cells have different modes of synaptic integration with direct effects on

Controlling T2 blurring in 3D RARE arterial spin labeling acquisition through optimal combination of variable flip angles and k-space filtering.

Science.gov (United States)

Zhao, Li; Chang, Ching-Di; Alsop, David C

2018-02-09

To improve the SNR efficiency and reduce the T 2 blurring of 3D rapid acquisition with relaxation enhancement stack-of-spiral arterial spin labeling imaging by using variable refocusing flip angles and k-space filtering. An algorithm for determining the optimal combination of variable flip angles and filtering correction is proposed. The flip angles are designed using extended phase graph physical simulations in an analytical and global optimization framework, with an optional constraint on deposited power. Optimal designs for correcting to Hann and Fermi window functions were compared with conventional constant amplitude or variable flip angle only designs on 6 volunteers. With the Fermi window correction, the proposed optimal designs provided 39.8 and 27.3% higher SNR (P variable flip angle designs. Even when power deposition was limited to 50% of the constant amplitude design, the proposed method outperformed the SNR (P variable flip angles can be derived as the output of an optimization problem. The combined design of variable flip angle and k-space filtering provided superior SNR to designs primarily emphasizing either approach singly. © 2018 International Society for Magnetic Resonance in Medicine.

Simultaneous engineering; Simultaneous Engineering bei der Entwicklung der Motorenbaureihen

Energy Technology Data Exchange (ETDEWEB)

Reifenscheid, O. [Entwicklung Kommerzielle Motoren, MTU, Friedrichshafen (Germany)

1997-10-01

At a time when the German industry is faced with world-wide competition and the recent recession has not been fully overcome, the subject of simultaneous engineering is very popular. A series of punch words such as Lean Management, TQM, (Total Quality Management), Lean Production, KVP, Kaizen, Value Management, etc. are considered as synonyms for strategies by which product development is to be made more efficient and production more economical, faster and more flexible. In this respect the co-ordination between market, company the human element, procedure and structure play a major role. The present paper describes Simultaneous Enginering (SE) from the standpoint of the research engineer; provides information regarding the degree of implementation of SE at MTU and presents some of the author`s personal thoughts and experiences for discussion. (orig.)

Comparison of cavitation tests on the SNR 300 prototype sodium pump, carried out using water at room temperature and liquid sodium at 5800C

International Nuclear Information System (INIS)

Fakkel, R.H.; Hoornweg, C.J.; Kamerling, B.; Ten Wolde, Tj.; Heslenfeld, M.W.; Mendte, W.K.; Bunjies, J.H.

1976-01-01

This paper gives results of tests carried out on a centrifugal pump in both a water and a sodium test facility. The pump tested is a prototype of the primary circulation pumps intended for a LMFBR 300 MWe nuclear power station (the SNR reactor) under construction at Kalkar, West Germany. The pump characteristics under various NPSH-conditions were investigated, and a comparison is made in the paper between the results of cavitation tests using water and liquid sodium. An attempt is made to account for differences in pump characteristics in both types of tests by referring to the physical properties of the liquids used (water and sodium). An attempt is also made to correlate the results obtained with the full-scale prototype to those obtained previously with a half-scale model of the impeller. The various test circuits used should be made identical, in order to avoid that differences in geometry should obscure essential features resulting from using different liquids. Yet, it showed that in this respect, the tests did not obey to this key-rule, reasons why the test results did not fully reveal the essential physical properties of either fluid under cavitating conditions. (author)

Centimeter-Level Positioning Using an Efficient New Baseband Mixing and Despreading Method for Software GNSS Receivers

Directory of Open Access Journals (Sweden)

G. Lachapelle

2007-10-01

Full Text Available This paper presents an efficient new method for performing the baseband mixing and despreading operations in a software-based GNSS receiver, and demonstrates that the method is capable of providing measurements for centimeter-level positioning accuracy. The method uses a single frequency carrier replica for the baseband mixing process, enabling all satellites to perform mixing simultaneously and yielding considerable computational savings. To compensate for signal-to-noise ratio (SNR losses caused by using a single frequency carrier replica, the integration interval after despreading is divided into subintervals, and the output from each subinterval then compensated for the known frequency error. Using this approach, receiver processing times are shown to be reduced by approximately 21% relative to the next fastest method when tracking seven satellites. The paper shows the mathematical derivation of the new algorithm, discusses practical considerations, and demonstrates its performance using simulations and real data. Results show that the new method is able to generate pseudorange and carrier phase measurements with the same accuracy as traditional methods. Stand-alone positioning accuracy is at the meter level, while differential processing can produce fixed ambiguity carrier phase positions accurate to the centimeter level.

The Sr-90 waste treatment by using sodium carbonat as a carrier

International Nuclear Information System (INIS)

Suroto.

1978-01-01

The coprecipitation processes of the Sr-90 wastes, with the lime-soda treatment, that followed by the mechanism of isomorph substitution, have shown a good performance in pH 7-8. Excess of natrium carbonate in the lime-soda treatment caused the decrease of the decontamination factor. This research shows that the coprecipitation by calcite-phosphate was better than the lime-soda treatment. (author)

Contrast Invariant SNR

DEFF Research Database (Denmark)

Weiss, Pierre; Escande, Paul; Dong, Yiqiu

We design an image quality measure independent of local contrast changes, which constitute simple models of illumination changes. Given two images, the algorithm provides the image closest to the first one with the component tree of the second. This problem can be cast as a specific convex progra...... algorithms based on interior point methods. The algorithm has potential applications in change detection, color image processing or image fusion. A Matlab implementation is available at http://www.math.univ-toulouse.fr/_weiss/PageCodes.html....

Wertigkeit der Schnittbilddiagnostik in der Evaluation des pädiatrischen Schädel-Hirn-Traumas

OpenAIRE

Schäffeler, Christoph

2010-01-01

Die vorliegende Arbeit untersucht die diagnostische Wertigkeit von Computertomographie (CT) und Magnetresonanztomographie (MRT) in der Diagnostik des pädiatrischen Schädel-Hirn-Traumas. In einer retrospektiven Auswertung der Bildgebung von 64 Patienten im Alter von 0-15 Jahren wurden die Vor- und Nachteile der CT und MRT - Diagnostik bei der Darstellung intrakranieller Traumfolgen herausgearbeitet. Die Ergebnisse räumen der CT weiterhin einen hohen Stellenwert in der Akutdiagnostik ein, zeige...

Electric energy storage systems in a market-based economy. Comparison of emerging and traditional technologies

International Nuclear Information System (INIS)

Kazempour, S. Jalal; Moghaddam, M. Parsa; Haghifam, M.R.; Yousefi, G.R.

2009-01-01

Unlike markets for storable commodities, electricity markets depend on the real-time balance of supply and demand. Although much of the present-day grid operate effectively without storage technologies, cost-effective ways of storing electrical energy can make the grid more efficient and reliable. This work addresses an economic comparison between emerging and traditional Electric Energy Storage (EES) technologies in a competitive electricity market. In order to achieve this goal, an appropriate Self-Scheduling (SS) approach must first be developed for each of them to determine their maximum potential of expected profit among multi-markets such as energy and ancillary service markets. Then, these technologies are economically analyzed using Internal Rate of Return (IRR) index. Finally, the amounts of needed financial supports are determined for choosing the emerging technologies when an investor would like to invest on EES technologies. Among available EES technologies, we consider NaS battery (Natrium Sulfur battery) and pumped-storage plants as emerging and traditional technologies, respectively. (author)

Development for LMR coolant technology - Development of a submersible-in-pool electromagnetic pump

Energy Technology Data Exchange (ETDEWEB)

Hong, Sang Hee; Kim, Hee Reyoung; Lee, Sang Don; Seo, Chun Ho [Seoul National University, Seoul (Korea, Republic of); Cho, Su Won [Kyungki University, Suwon (Korea, Republic of)

1995-08-01

The conceptual and detailed designs of an annular linear induction electromagnetic pump of small scale submersible-in-pool type are performed for the purpose of domestic development of the pumps used for the high-temperature natrium coolant transportation in liquid metal reactors. The pump drawings for and input power of 1,100 VA, an input frequency of 17 Hz, a maximum flowrate of 60 l/min and a maximum operation temperature of 600 deg C are obtained from the optimum design analyses by solving MHD and equivalent circuit equations. The characteristics of pump materials in the high temperature and neutron irradiation environment are reflected in designing the pump, and theoretical analyses for improving the pump performance and efficiency are tried through calculations of magnetic flux and temperature distributions inside the pump. The present project contributes to the further design of engineering proto-type electromagnetic pump with higher capacity and the development of liquid metal reactor with innovative simplicity. 44 refs., 4 tabs., 33 figs. (author)

Renewable energy and air pollution abatement in the Rhine-Neckar region. Assessment, potential, and perspectives of renewable energy sources in the Rhine-Neckar region; Klimaschutz durch Erneuerbare Energien in der Region Rhein-Neckar. Bestandsaufnahme, Potenziale und Entwicklungsperspektiven Erneuerbarer Energien im Wirtschaftsraum Rhein-Neckar

Energy Technology Data Exchange (ETDEWEB)

Hirschl, B.

2001-12-01

The study analyzed the situation, potential and obstacles of renewable energy sources and developed strategic recommendations on this basis for enhancing the use of renewables in the Rhein-Neckar region. [German] Gegenstand der nachfolgenden Untersuchung ist eine umfassende Bestandsaufnahme, Potenzial- und Hemmnisanalyse sowie die Entwicklung darauf basierender Strategieempfehlungen, die zu einer Initiative zur Foerderung Erneuerbarer Energien fuehren koennen. Dabei bilden die erstgenannten Bestandteile der Untersuchung die Basis fuer die Entwicklung von Vorschlaegen zur Strategieentwicklung, d.h. zur Identifizierung von inhaltlichen und konzeptionellen Vorschlaegen zur Ausgestaltung einer Initiative fuer Erneuerbare Energien in der Region Rhein-Neckar. (orig.)

Review: André du Pisani, Reinhart Kössler, and William A. Lindeke (eds., The Long Aftermath of War: Reconciliation and Transition in Namibia (2010 Buchbesprechung: André du Pisani, Reinhart Kössler und William A. Lindeke (Hrsg., The Long Aftermath of War: Reconciliation and Transition in Namibia (2010

Directory of Open Access Journals (Sweden)

Dag Henrichsen

2011-01-01

Full Text Available Review of the edited volume: André du Pisani, Reinhart Kössler, and William A. Lindeke (eds., The Long Aftermath of War: Reconciliation and Transition in Namibia (Freiburger Beiträge zu Entwicklung und Politik, 37, Freiburg: Arnold-Bergstraesser-Institut, 2010, ISBN 978-3-928597-55-5, 437 pp.Besprechung des Sammelbandes: André du Pisani, Reinhart Kössler und William A. Lindeke (Hrsg., The Long Aftermath of War: Reconciliation and Transition in Namibia (Freiburger Beiträge zu Entwicklung und Politik, 37, Freiburg: Arnold-Bergstraesser-Institut, 2010, ISBN 978-3-928597-55-5, 437 Seiten

My own Agenda 21 - My personal energy conservation scheme; Meine Agenda 21 - Energiesparbuch

Energy Technology Data Exchange (ETDEWEB)

Kregel, V. [ed.

1999-04-01

The title of this booklet imitates the name of the action programme Agenda 21, which has been adopted in 1992 at the UN conference on environment and development, also called the Rio de Janeiro Earth Summit, where the international community of states agreed to forthwith follow the paradigm of ''sustainable development''. (orig./CB) [German] Der Titel unseres Energiesparbuchs lehnt sich an das Aktionsprogramm Agenda 21 an, das auf der Konferenz fuer Umwelt und Entwicklung 1992 in Rio de Janeiro verabschiedet wurde. Damit verstaendigte sich die internationale Staatengemeinschaft auf das 'Leitbild der nachhaltigen Entwicklung'. (orig./RHM)

Enhancement of molecular sensitivity in positron emission tomography with quantum correlation of γ-ray photons

Science.gov (United States)

Sato, K.; Kobayashi, Y.

2015-05-01

Enhancement of molecular sensitivity in positron emission tomography (PET) has long been discussed with respect to imaging instrumentation and algorithms for data treatment. Here, the molecular sensitivity in PET is discussed on the basis of 2-dimensional coincident measurements of 511 keV γ ray photons resultant from two-photon annihilation. Introduction of an additional selection window based on the energy sum and difference of the coincidently measured γ ray photons, without any significant instrumental and algorithmic changes, showed an improvement in the signal-to-noise ratio (SNR) by an order of magnitude. Improvement of performance characteristics in the PET imaging system was demonstrated by an increase in the noise equivalent count rate (NECR) which takes both the SNR and the detection efficiency into consideration. A further improvement of both the SNR and the NECR is expected for the present system in real clinical and in-vivo environments, where much stronger positron sources are employed.

Enhancement of molecular sensitivity in positron emission tomography with quantum correlation of γ-ray photons

International Nuclear Information System (INIS)

Sato, K.; Kobayashi, Y.

2015-01-01

Enhancement of molecular sensitivity in positron emission tomography (PET) has long been discussed with respect to imaging instrumentation and algorithms for data treatment. Here, the molecular sensitivity in PET is discussed on the basis of 2-dimensional coincident measurements of 511 keV γ ray photons resultant from two-photon annihilation. Introduction of an additional selection window based on the energy sum and difference of the coincidently measured γ ray photons, without any significant instrumental and algorithmic changes, showed an improvement in the signal-to-noise ratio (SNR) by an order of magnitude. Improvement of performance characteristics in the PET imaging system was demonstrated by an increase in the noise equivalent count rate (NECR) which takes both the SNR and the detection efficiency into consideration. A further improvement of both the SNR and the NECR is expected for the present system in real clinical and in-vivo environments, where much stronger positron sources are employed

Reactive relay selection in underlay cognitive networks with fixed gain relays

KAUST Repository

Hussain, Syed Imtiaz

2012-06-01

Best relay selection is a bandwidth efficient technique for multiple relay environments without compromising the system performance. The problem of relay selection is more challenging in underlay cognitive networks due to strict interference constraints to the primary users. Generally, relay selection is done on the basis of maximum end-to-end signal to noise ratio (SNR). However, it requires large amounts of channel state information (CSI) at different network nodes. In this paper, we present and analyze a reactive relay selection scheme in underlay cognitive networks where the relays are operating with fixed gains near a primary user. The system model minimizes the amount of CSI required at different nodes and the destination selects the best relay on the basis of maximum relay to destination SNR. We derive close form expressions for the received SNR statistics, outage probability, bit error probability and average channel capacity of the system. Simulation results are also presented to confirm the validity of the derived expressions. © 2012 IEEE.

An efficient central DOA tracking algorithm for multiple incoherently distributed sources

Science.gov (United States)

Hassen, Sonia Ben; Samet, Abdelaziz

2015-12-01

In this paper, we develop a new tracking method for the direction of arrival (DOA) parameters assuming multiple incoherently distributed (ID) sources. The new approach is based on a simple covariance fitting optimization technique exploiting the central and noncentral moments of the source angular power densities to estimate the central DOAs. The current estimates are treated as measurements provided to the Kalman filter that model the dynamic property of directional changes for the moving sources. Then, the covariance-fitting-based algorithm and the Kalman filtering theory are combined to formulate an adaptive tracking algorithm. Our algorithm is compared to the fast approximated power iteration-total least square-estimation of signal parameters via rotational invariance technique (FAPI-TLS-ESPRIT) algorithm using the TLS-ESPRIT method and the subspace updating via FAPI-algorithm. It will be shown that the proposed algorithm offers an excellent DOA tracking performance and outperforms the FAPI-TLS-ESPRIT method especially at low signal-to-noise ratio (SNR) values. Moreover, the performances of the two methods increase as the SNR values increase. This increase is more prominent with the FAPI-TLS-ESPRIT method. However, their performances degrade when the number of sources increases. It will be also proved that our method depends on the form of the angular distribution function when tracking the central DOAs. Finally, it will be shown that the more the sources are spaced, the more the proposed method can exactly track the DOAs.

Performance of adaptive MS-GSC in the presence of cochannel interference

KAUST Repository

Daghfous, Mohamed A.

2011-07-01

Minimum-selection generalized selection combining (MS-GSC) has been proposed as a power-saving variant of conventional generalized selection combining (GSC). Existing performance results of this scheme are limited to interference-free environments under multipath fading. This paper addresses the scenario when the received desired signal on each diversity branch is corrupted by multiple interfering signals and background noise, wherein desired and undesired signals undergo mutually independent Rayleigh fading. In the absence of perfect tracking of the instantaneous interference power on diversity branches, the adaptation thresholds that are set on the combined signal-to-noise ratio (SNR) to enhance either the spectral efficiency or power efficiency in noise-limited environments may not guarantee the target performance. This paper aims to study the effect of cochannel interference on the performance of bandwidth- and power-efficient SNR-based MS-GSC. Through the analysis, new analytical results for some important performance measures of adaptive MS-GSC schemes are presented. Numerical comparisons to clarify the impact of cochannel interference on the achieved performance of the adaptation schemes under consideration are provided. © 2011 IEEE.

Phase diagrams of NaOCl-Na3PO4-H2O ternary system. Jiaensosan natrium-rinsan natrium-mizu sanseibun soheiko jotaizu

Energy Technology Data Exchange (ETDEWEB)

Hamano, A. (Sasebo College of Tehcnology, Nagasaki (Japan)); Kito, K. (Nippon Steel Chemical Co. Ltd., Tokyo (Japan))

1993-10-30

Sodium chlorate (NaOCl) aqueous solution is used widely as a bleach. Attempts have been made to extract crystals from this aqueous solution, but only with difficulty because of instability of the generated crystals. Generating Na3PO4 and solid solution has been attempted as a method to stabilize the crystals. The present study has prepared a phase equilibrium diagram for three components of NaOCl-Na3PO4-H2O at 5[degree]C and 10[degree]C for theoretical elucidation thereof. In the prepared diagram, the conjugate lines linking the saturated solution with the solution containing solid phase have not crossed at one point, but scattered on the solid phase line. This has made clear that no double salt has been generated, but solid solution has been produced. The mol ratio of NaOCl in the generated solid solution was 0.071 to 0.447 at 15[degree]C and 0.026 to 0.6 at 5[degree]C indicating that solid solution with composition of wider range than in literatures reported conventionally has been produced. 8 refs., 2 figs., 2 tabs.

Comparison and Optimization of 3.0 T Breast Images Quality of Diffusion-Weighted Imaging with Multiple B-Values.

Science.gov (United States)

Han, Xiaowei; Li, Junfeng; Wang, Xiaoyi

2017-04-01

Breast 3.0 T magnetic resonance diffusion-weighted imaging (MR-DWI) of benign and malignant lesions were obtained to measure and calculate the signal-to-noise ratio (SNR), signal intensity ratio (SIR), and contrast-to-noise ratio (CNR) of lesions at different b-values. The variation patterns of SNR and SIR were analyzed with different b-values and the images of DWI were compared at four different b-values with higher image quality. The effect of SIR on the differential diagnostic efficiency of benign and malignant lesions was compared using receiver operating characteristic curves to provide a reference for selecting the optimal b-value. A total of 96 qualified patients with 112 lesions and 14 patients with their contralateral 14 normal breasts were included in this study. The single-shot echo planar imaging sequence was used to perform the DWI and a total of 13 b-values were used: 0, 50, 100, 200, 400, 600, 800, 1000, 1200, 1500, 1800, 2000, and 2500 s/mm 2 . On DWI, the suitable regions of interest were selected. The SNRs of normal breasts (SNR normal ), SNR lesions , SIR, and CNR of benign and malignant lesions were measured on DWI with different b-values and calculated. The variation patterns of SNR, SIR, and CNR values on DWI for normal breasts, benign lesions, and malignant lesions with different b-values were analyzed by using Pearson correlation analysis. The SNR and SIR of benign and malignant lesions with the same b-values were compared using t-tests. The diagnostic efficiencies of SIR with different b-values for benign and malignant lesions were evaluated using receiver operating characteristic curves. Breast DWI had higher CNR for b-values ranging from 600 to 1200 s/mm 2 . It had the best CNR at b = 1000 s/mm 2 for the benign lesions and at b = 1200 s/mm 2 for the malignant lesions. The signal intensity and SNR values of normal breasts decreased with increasing b-values, with a negative correlation (r = -0.945, P < 0.01). The

Modelling and development of an analysis and decision component for a user dependent impact of efficiency; Modellierung und Entwicklung einer Analyse- und Entscheidungskomponente fuer nutzerabhaengige Effizienzbeeinflussung

Energy Technology Data Exchange (ETDEWEB)

Jahn, Franziska [Westsaechsische Hochschule Zwickau (Germany)

2010-07-01

The contribution under consideration reports on a solution of the software-based expansion of an existing Smart Home System (Gira FacilityServer) for the user-dependent influence on efficiency. The first section of this contribution describes the reasons for such a system and explains at which position the Gira FacilityServer is to be expanded. Then the necessary individual operations and applied methods are illustrated which preferably are prerequisite for modeling and developing of such a system. The third section presents the current results from the concept to the software technological realization with regard to the project progress. Afterwards, the specific project results are summarized, The sustainability of these projectresults are considered.

THE NATURE OF GAMMA-RAY EMISSION OF TYCHO'S SUPERNOVA REMNANT

International Nuclear Information System (INIS)

Berezhko, E. G.; Ksenofontov, L. T.; Völk, H. J.

2013-01-01

The nature of the recently detected high-energy and very high-energy γ-ray emission of Tycho's supernova remnant (SNR) is studied. A nonlinear kinetic theory of cosmic-ray (CR) acceleration in SNRs is employed to investigate the properties of Tycho's SNR and their correspondence with the existing experimental data, taking into account that the ambient interstellar medium (ISM) is expected to be clumpy. It is demonstrated that the overall steep γ-ray spectrum observed can be interpreted as the superposition of two spectra produced by the CR proton component in two different ISM phases: the first γ-ray component, extending up to about 10 14 eV, originates in the diluted warm ISM, whereas the second component, extending up to 100 GeV, comes from numerous dense, small-scale clouds embedded in this warm ISM. Given the consistency between acceleration theory and the observed properties of the nonthermal emission of Tycho's SNR, very efficient production of nuclear CRs in Tycho's SNR is established. The excess of the GeV γ-ray emission due to the clouds' contribution above the level expected in the case of a purely homogeneous ISM is inevitably expected in the case of Type Ia SNe.

Efficient use of energy - electric power. Model projects and relevant publications; Energie effizient nutzen - Schwerpunkt Strom. Modellvorhaben und Fachartikel

Energy Technology Data Exchange (ETDEWEB)

Radgen, P.; Jochem, E. [eds.

1999-10-26

The forum intended to provide written information for experts and to develop model projects for selected fields of industry in Baden-Wuerttemberg. However, these two instruments can only be part of an innovation initiative headed by the Land government in cooperation with the Baden-Wuerttemberg industry and science. [German] Der Schwerpunkt des Forums 'Strom effizient nutzen' konzentrierte sich auf die Erarbeitung von schriftlichen Informationen fuer den Fachmann sowie auf die Entwicklung einiger Modellvorhaben fuer einige ausgewaehlte Branchen Baden-Wuerttembergs. Diese beiden Instrumente koennen aber nur Teil einer Innovationsinitiative sein, die Regierung, Wirtschaft und Wissenschaft entwickeln muessten, wollte man einen sichtbaren Erfolg bei der Loesung des o.g. Zielkonfliktes verbuchen. Eine solche Initiative zu konzipieren und zu entfesseln, die der baden-wuerttembergischen Wirtschaft manch positive Impulse braechte, waere machbar; wie die Modellvorhaben dieses Projektes in ueberzeugender Weise belegen, gibt es hinreichend rentable Moeglichkeiten. (orig.)

Anwendung der isothermalen Mikrokalorimetrie zur physikochemischen Charakterisierung molekularer Interaktionen in pharmazeutischen Formulierungen

OpenAIRE

Schicke, Burkhard Christoph

2010-01-01

Die isothermalen Mikrokalorimetrie (IMC) ermöglicht die Erfassung von Wärmeflüssen im Mikrowattbereich. Der Nutzen und die Aussagekraft dieser Methode wurden bei folgenden physikochemischen Prozessen untersucht: Hydratation von Diclofenac-Natrium (DfNa) zum Tetrahydrat bei verschiedenen Temperaturen und relativen Feuchten, Kompatibilitäts¬untersuchungen von DfNa und amphiphiler Stärke bei 100% rH und Temperaturen bis zu 313 K, Kristallisationsverhalten von unterschiedlichen Triglycerid-Phosph...

Magnetic resonance imaging in epilepsy. Magnetresonanztomographie bei Epilepsien

Energy Technology Data Exchange (ETDEWEB)

Layer, G.; Elger, C.E.; Reiser, M. (Bonn Univ. (Germany). Klinik fuer Epileptologie)

1993-04-01

The most important causes of focal epilespy are hippocampal sclerosis, circumscribed tumors, vascular malformations, trauma and perinatal damage. At the moment MRI is the best radiological imaging modality for localizing and characterizing a focus. In many cases, however, even MRI is negative. Especially in hippocampal sclerosis the diagnostic role of MRI is still not well established. Diagnostic criteria are side differences with hippocampal atrophy and circumscribed signal increase on T2-weighted images of the affected temporal lobe. Circumscribed lesions caused by tumors or vascular malformations are demonstrated very reliably by paracoronal T2-weighted sequences. Routine administration of the paramagnetic contrast material Gd-DTPA is not necessary. (orig.).

Noise and pitch interact during the cortical segregation of concurrent speech.

Science.gov (United States)

Bidelman, Gavin M; Yellamsetty, Anusha

2017-08-01

Behavioral studies reveal listeners exploit intrinsic differences in voice fundamental frequency (F0) to segregate concurrent speech sounds-the so-called "F0-benefit." More favorable signal-to-noise ratio (SNR) in the environment, an extrinsic acoustic factor, similarly benefits the parsing of simultaneous speech. Here, we examined the neurobiological substrates of these two cues in the perceptual segregation of concurrent speech mixtures. We recorded event-related brain potentials (ERPs) while listeners performed a speeded double-vowel identification task. Listeners heard two concurrent vowels whose F0 differed by zero or four semitones presented in either clean (no noise) or noise-degraded (+5 dB SNR) conditions. Behaviorally, listeners were more accurate in correctly identifying both vowels for larger F0 separations but F0-benefit was more pronounced at more favorable SNRs (i.e., pitch × SNR interaction). Analysis of the ERPs revealed that only the P2 wave (∼200 ms) showed a similar F0 x SNR interaction as behavior and was correlated with listeners' perceptual F0-benefit. Neural classifiers applied to the ERPs further suggested that speech sounds are segregated neurally within 200 ms based on SNR whereas segregation based on pitch occurs later in time (400-700 ms). The earlier timing of extrinsic SNR compared to intrinsic F0-based segregation implies that the cortical extraction of speech from noise is more efficient than differentiating speech based on pitch cues alone, which may recruit additional cortical processes. Findings indicate that noise and pitch differences interact relatively early in cerebral cortex and that the brain arrives at the identities of concurrent speech mixtures as early as ∼200 ms. Copyright © 2017 Elsevier B.V. All rights reserved.

T2-weighted prostate MRI at 7 Tesla using a simplified external transmit-receive coil array: correlation with radical prostatectomy findings in two prostate cancer patients.

Science.gov (United States)

Rosenkrantz, Andrew B; Zhang, Bei; Ben-Eliezer, Noam; Le Nobin, Julien; Melamed, Jonathan; Deng, Fang-Ming; Taneja, Samir S; Wiggins, Graham C

2015-01-01

To report design of a simplified external transmit-receive coil array for 7 Tesla (T) prostate MRI, including demonstration of the array for tumor localization using T2-weighted imaging (T2WI) at 7T before prostatectomy. Following simulations of transmitter designs not requiring parallel transmission or radiofrequency-shimming, a coil array was constructed using loop elements, with anterior and posterior rows comprising one transmit-receive element and three receive-only elements. This coil structure was optimized using a whole-body phantom. In vivo sequence optimization was performed to optimize achieved flip angle (FA) and signal to noise ratio (SNR) in prostate. The system was evaluated in a healthy volunteer at 3T and 7T. The 7T T2WI was performed in two prostate cancer patients before prostatectomy, and localization of dominant tumors was subjectively compared with histopathological findings. Image quality was compared between 3T and 7T in these patients. Simulations of the B1(+) field in prostate using two-loop design showed good magnitude (B1(+) of 0.245 A/m/w(1/2)) and uniformity (nonuniformity [SD/mean] of 10.4%). In the volunteer, 90° FA was achieved in prostate using 225 v 1 ms hard-pulse (indicating good efficiency), FA maps confirmed good uniformity (14.1% nonuniformity), and SNR maps showed SNR gain of 2.1 at 7T versus 3T. In patients, 7T T2WI showed excellent visual correspondence with prostatectomy findings. 7T images demonstrated higher estimated SNR (eSNR) in benign peripheral zone (PZ) and tumor compared with 3T, but lower eSNR in fat and slight decreases in tumor-to-PZ contrast and PZ-homogeneity. We have demonstrated feasibility of a simplified external coil array for high-resolution T2-weighted prostate MRI at 7T. © 2013 Wiley Periodicals, Inc.

Planung einer Mobile Learning Application für medizinische Lerninhalte [Planning of a mobile learning application for medical contents

Directory of Open Access Journals (Sweden)

Walther, Patrick

2013-11-01

Full Text Available [english] Due to the high popularity of mobile devices barriers for mobile learning are becoming less. Place-and time-independent access to information is part of everyday life. The number of mobile applications is steadily growing. Currently there are more than 500,000 mobile applications, so-called apps, available for the Apple iPhone/iPad which can be downloaded in the Apple iTunes Store. More than ten percent of these apps are mobile learning applications.Before starting development of a mobile app we need to analyze all requirements accurately. This is due to the fact that there is a multiplicity of different operating systems with different functionalities. This paper shows general properties of so-called native, hybrid, and web applications and advantages and disadvantages in development and use of the finished application. In addition, current software, which supports the development of a mobile application is explained.Finally the differences of the various development options are shown based on concrete mobile applications.[german] Aufgrund der hohen Verbreitung mobiler Endgeräte werden die Barrieren für das mobile Lernen immer geringer und orts- und zeitunabhängiger Zugriff auf Informationen ist längst im Alltag angekommen. Die Zahl mobiler Applikation wächst stetig an. So stehen beispielsweise aktuell mehr als 500.000 mobile Applikationen, sogenannte Apps, für das Apple iPhone/iPad, dem Nutzer über den Apple iTunes Store bereit. Hiervon sind mehr als zehn Prozent mobile Lernapplikationen.Vor der eigentlichen Entwicklung einer App muss, u.a. aufgrund der Vielzahl mobiler Betriebssysteme und Funktionen der verschiedenen mobilen Endgeräte, zuvor eine genaue Bedarfsanalyse durchgeführt werden um die passende Entwicklungsvariante zu wählen.In diesem Beitrag werden die verschiedenen Möglichkeiten (nativ, hybrid, web zur Entwicklung einer mobilen Applikation, als auch deren Vor- und Nachteile bei der Entwicklung und Nutzung der

Structure, design and statistical programme library of the meteorological database of Potsdam-Institut fuer Klimaforschung; Struktur, Aufbau und statistische Programmbibliothek der meteorologischen Datenbank am Potsdam-Institut fuer Klimaforschung

Energy Technology Data Exchange (ETDEWEB)

Oesterle, H.; Glauer, J. [Potsdam-Institut fuer Klimafolgenforschung (PIK), Potsdam (Germany); Denhard, M. [Frankfurt Univ. (Germany). Inst. fuer Meteorologie und Geophysik

1999-01-01

The relational database management system (ORACLE) using different client interfaces (browser, SQL, precompiler) is the most important basis for data organization and storage. The creation of a data bank system at PIK includes: Acquisition of meteorological data series for the projects executed at PIK; development of a database structure on the basis of daily values; control, analysis and classification of data into given storage formats; development and application of statistical software. There are currently 20 different types of data sets with daily, monthly and annual data which are functionally interconnected and updated. All data sets are continuously updated. (orig.) [Deutsch] Wesentliche Grundlage der Datenorganisation und -speicherung bildet das relationale Datenbanksystem ORACLE mit den dazugehoerigen Werkzeugen (Browser, SQL- und Precompiler). Die Entwicklung des Datenbanksystems am PIK umfasst folgende Etappen: - Erwerb von meteorologischen Datensaetzen fuer die am Institut laufenden Forschungsvorhaben; - Entwicklung einer Speicherstruktur auf der Basis von Tageswerten; - Kontrolle, Analyse und Einordnung der Daten in die vorgegebenen Speicherformate; - Entwicklung der zur Datennutzung notwendigen statistischen Programmbibliothek. Zur Zeit gibt es 20 verschiedene Typen von Datensaetzen. Sie enthalten taegliche, monatliche und jaehrliche Daten und sind funktional miteinander verbunden. Alle Datensaetze werden kontinuierlich erweitert. (orig.)

Virtual power plants in energy industry law. Possible manifestations and from them resulting legal questions; Virtuelle Kraftwerke im Energiewirtschaftsrecht. Moegliche Erscheinungsformen und daraus resultierende Rechtsfragen

Energy Technology Data Exchange (ETDEWEB)

Kahlbrandt, Lea Katharina [Bucerius Law School, Hamburg (Germany)

2017-08-15

Although cogeneration plants are operated with fossil fuels are not quite as environmentally friendly as EEG systems they have a much more favorable effect due to their high efficiency climate as conventional power plants. In the future this could can even improve with the aid of fuel cell technology. Therefore, they play for the transition to a safe and secure more efficient power supply conditions for a merger of cogeneration plants overall favorable, in particular because that no influence on the or the emission trading obligation of the plant operators has. However, the complete elimination of avoided network charges could be counterproductive. Just virtual power plants of cogeneration plants have an effect on a feed-in that the grid not charged, so fees for a decentralized feed in these cases can be justified. Also the development of cogeneration development within the framework of the newly introduced calls will have a major impact on the development of virtual power stations. [German] Zwar sind KWK-Anlagen, die mit fossilen Brennstoffen betrieben werden, nicht ganz so umweltfreundlich wie EEG-Anlagen, doch haben sie aufgrund ihres hohen Wirkungsgrades eine viel guenstigere Klimabilanz als konventionelle Kraftwerke. In Zukunft koennte diese sich mithilfe der Brennstoffzellen-Technologie sogar noch verbessern. Daher spielen sie fuer den Uebergang zu einer sicheren und klimafreundlicheren Stromversorgung eine wichtige Rolle. Die Bedingungen fuer einen Zusammenschluss von KWK-Anlagen sind insgesamt guenstig, insbesondere weil jener keinen Einfluss auf die Foerdersaetze oder die Emissionshandelspflicht der Anlagenbetreiber hat. Allerdings koennte die vollstaendige Abschaffung vermiedener Netzentgelte kontraproduktiv sein. Gerade virtuelle Kraftwerke aus KWK-Anlagen wirken auf eine Einspeisung hin, die das Netz nicht ueberfordert, sodass Entgelte fuer eine dezentrale Einspeisung in diesen Faellen durchaus eine Rechtfertigung haben. Auch die Entwicklung des KWK

Three-layered radio frequency coil arrangement for sodium MRI of the human brain at 9.4 Tesla.

Science.gov (United States)

Shajan, G; Mirkes, Christian; Buckenmaier, Kai; Hoffmann, Jens; Pohmann, Rolf; Scheffler, Klaus

2016-02-01

A multinuclei imaging setup with the capability to acquire both sodium ((23) Na) and proton ((1) H) signals at 9.4 Tesla is presented. The main objective was to optimize coil performance at the (23) Na frequency while still having the ability to acquire satisfactory (1) H images. The setup consisted of a combination of three radio frequency (RF) coils arranged in three layers: the innermost layer was a 27-channel (23) Na receive helmet which was surrounded by a four-channel (23) Na transceiver array. The outer layer consisted of a four-channel (1) H dipole array for B0 shimming and anatomical localization. Transmit and receive performance of the (23) Na arrays was compared to a single-tuned (23) Na birdcage resonator. While the transmit efficiency of the (23) Na transceiver array was comparable to the birdcage, the (23) Na receive array provided substantial signal-to-noise ratio (SNR) gain near the surface and comparable SNR in the center. The utility of this customized setup was demonstrated by (23) Na images of excellent quality. High SNR, efficient transmit excitation and B0 shimming capability can be achieved for (23) Na MRI at 9.4T using novel coil combination. This RF configuration is easily adaptable to other multinuclei applications at ultra high field (≥ 7T). © 2015 Wiley Periodicals, Inc.

High-SNR spectrum measurement based on Hadamard encoding and sparse reconstruction

Science.gov (United States)

Wang, Zhaoxin; Yue, Jiang; Han, Jing; Li, Long; Jin, Yong; Gao, Yuan; Li, Baoming

2017-12-01

The denoising capabilities of the H-matrix and cyclic S-matrix based on the sparse reconstruction, employed in the Pixel of Focal Plane Coded Visible Spectrometer for spectrum measurement are investigated, where the spectrum is sparse in a known basis. In the measurement process, the digital micromirror device plays an important role, which implements the Hadamard coding. In contrast with Hadamard transform spectrometry, based on the shift invariability, this spectrometer may have the advantage of a high efficiency. Simulations and experiments show that the nonlinear solution with a sparse reconstruction has a better signal-to-noise ratio than the linear solution and the H-matrix outperforms the cyclic S-matrix whether the reconstruction method is nonlinear or linear.

Extending OFDM Symbols to Reduce Power Consumption

NARCIS (Netherlands)

Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria

2012-01-01

Existing communication standards have limited capabilities to adapt to low SNR environments or to exploit low data rate requirements in a power efficient way. Existing techniques like e.g. control coding do not reduce the computational load when reducing data rates. In this paper, we introduce

Evaluation of injuries of the upper cervical spine in a postmortem study with digital radiography, CT and MRI; Evaluation experimentell erzeugter Verletzungen der oberen Halswirbelsaeule mit digitaler Roentgentechnik, Computertomographie und Magnetresonanztomographie

Energy Technology Data Exchange (ETDEWEB)

Obenauer, S.; Herold, T.; Fischer, U.; Grabbe, E. [Goettingen Univ. (Germany). Abt. fuer Roentgendiagnostik; Fadjasch, G.; Saternus, K.S. [Goettingen Univ. (Germany). Abt. fuer Rechtsmedizin; Koebke, J. [Koeln Univ. (Germany). Anatomisches Inst.

1999-12-01

Purpose: To compare digital X-ray, CT, and MRI in the evaluation of ligamentous and osseous lesions in upper cervical spine specimens after artificial craniocervical injury with the findings of macroscopic preparation. Materials and Methods: A rotation trauma of defined severity was applied to 19 human corpses. After dissection of the neck specimens, digital X-ray (DIMA Soft P41, Feinfocus), conventional and helical CT (CTi, High Speed, GE, collimation 1 mm; pitch 1.0), and MRI were performed from the skull base to C3. The findings were correlated with the macroscopic results of preparation. MR (Magnetom Vision, Siemens) imaging was obtained with a 1.5 T system using 2D- and 3D-sequences. Results: Preparation revealed 6 fractures of the vertebral bodies, 5 fractures of the dens axis, 1 fracture of the arcus anterior of the atlas, 4 osseous flakes at the occipital condylus, and 6 lesions of the alar ligaments. Digital radiography showed all fractures and 4 osseous flakes at the occipital condylus. With conventional and helical CT, all fractures and all ruptured alar ligaments could be detected. 2D MRI depicted 9 of the fractures and 3D MRI showed fractures. With 2D MRI, 2 of the 4 osseous flakes at the condylus could be detected and with 3D MRI one occipital condylus fracture could be depicted. Ligamentous injuries were visualized by 2D MRI in 2 of 6 cases and by 3 D MRI inone case. Conclusions: In post-mortem studies, CT was superior to MRI in the visualization of osseous and ligamentous injuries after trauma of the upper cervical spine. However, these results are not transferable to patients with rotation injury in general. (orig.) [German] Ziel: Vergleich verschiedener Techniken (digitale Roentgentechnik, Computertomographie, Magnetresonanztomographie) in der Detektion von ligamentaeren und ossaeren Laesionen der oberen Halswirbelsaeule nach definiertem Trauma sowie Korrelation mit den experimentellen Praeparateergebnissen. Material und Methoden: 19 menschliche

A Pattern Construction Scheme for Neural Network-Based Cognitive Communication

Directory of Open Access Journals (Sweden)

Ozgur Orcay

2011-01-01

Full Text Available Inefficient utilization of the frequency spectrum due to conventional regulatory limitations and physical performance limiting factors, mainly the Signal to Noise Ratio (SNR, are prominent restrictions in digital wireless communication. Pattern Based Communication System (PBCS is an adaptive and perceptual communication method based on a Cognitive Radio (CR approach. It intends an SNR oriented cognition mechanism in the physical layer for improvement of Link Spectral Efficiency (LSE. The key to this system is construction of optimal communication signals, which consist of encoded data in different pattern forms (waveforms depending on spectral availabilities. The signals distorted in the communication medium are recovered according to the pre-trained pattern glossary by the perceptual receiver. In this study, we have shown that it is possible to improve the bandwidth efficiency when largely uncorrelated signal patterns are chosen in order to form a glossary that represents symbols for different length data groups and the information can be recovered by the Artificial Neural Network (ANN in the receiver site.

Fetal source extraction from magnetocardiographic recordings by dependent component analysis

Energy Technology Data Exchange (ETDEWEB)

Araujo, Draulio B de [Department of Physics and Mathematics, FFCLRP, University of Sao Paulo, Ribeirao Preto, SP (Brazil); Barros, Allan Kardec [Department of Electrical Engineering, Federal University of Maranhao, Sao Luis, Maranhao (Brazil); Estombelo-Montesco, Carlos [Department of Physics and Mathematics, FFCLRP, University of Sao Paulo, Ribeirao Preto, SP (Brazil); Zhao, Hui [Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Filho, A C Roque da Silva [Department of Physics and Mathematics, FFCLRP, University of Sao Paulo, Ribeirao Preto, SP (Brazil); Baffa, Oswaldo [Department of Physics and Mathematics, FFCLRP, University of Sao Paulo, Ribeirao Preto, SP (Brazil); Wakai, Ronald [Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Ohnishi, Noboru [Department of Information Engineering, Nagoya University (Japan)

2005-10-07

Fetal magnetocardiography (fMCG) has been extensively reported in the literature as a non-invasive, prenatal technique that can be used to monitor various functions of the fetal heart. However, fMCG signals often have low signal-to-noise ratio (SNR) and are contaminated by strong interference from the mother's magnetocardiogram signal. A promising, efficient tool for extracting signals, even under low SNR conditions, is blind source separation (BSS), or independent component analysis (ICA). Herein we propose an algorithm based on a variation of ICA, where the signal of interest is extracted using a time delay obtained from an autocorrelation analysis. We model the system using autoregression, and identify the signal component of interest from the poles of the autocorrelation function. We show that the method is effective in removing the maternal signal, and is computationally efficient. We also compare our results to more established ICA methods, such as FastICA.

German energy market 2017; Deutscher Energiemarkt 2017

Energy Technology Data Exchange (ETDEWEB)

Schiffer, Hans-Wilhelm [Weltenergierat - Deutschland, Berlin (Germany). Arbeitsgruppe Energie fuer Deutschland; World Energy Council, London (United Kingdom). World Energy Resources

2018-03-15

The basic orientation of the German energy supply as specified in the energy concept of the Federal Government towards the increased use of renewable energies with simultaneous increase of energy efficiency still determines the market development. In the present case, a current overview of the German energy market 2017 is given, which provides a concentrated compilation of the key figures of the energy industry. As in previous years, the article not only summarizes general facts about the energy mix, but also deals in detail with the development of the individual energy sources oil, natural gas, brown and hard coal, nuclear energy and renewable energies. Furthermore, the price trends are explained on the international markets and inland. An overview of the development of greenhouse gas emissions from 1990 to 2017 concludes the contribution. [German] Die im Energiekonzept der Bundesregierung vorgegebene Grundausrichtung der deutschen Energieversorgung hin zur verstaerkten Nutzung erneuerbarer Energien bei gleichzeitiger Steigerung der Energieeffizienz bestimmt nach wie vor die Marktentwicklung. Vorliegend wird ein aktueller Ueberblick ueber den deutschen Energiemarkt 2017 gegeben, der eine konzentrierte Zusammenstellung der zentralen Eckdaten der Energiewirtschaft leistet. Wie in den Jahren zuvor fasst der Artikel nicht nur allgemeine Fakten zum Energiemix zusammen, sondern geht auch ausfuehrlich auf die Entwicklung der einzelnen Energietraeger Erdoel, Erdgas, Braun und Steinkohle, Kernenergie sowie regenerative Energien ein. Ferner werden die Preistendenzen auf den internationalen Maerkten und im Inland erlaeutert. Eine Uebersicht ueber die Entwicklung der Treibhausgas-Emissionen von 1990 bis 2017 schliesst den Beitrag ab.

German energy market 2016; Deutscher Energiemarkt 2016

Energy Technology Data Exchange (ETDEWEB)

Schiffer, Hans-Wilhelm [World Energy Council, London (United Kingdom). World Energy Resources; Weltenergierat, Berlin (Germany). Arbeitsgruppe Energie fuer Deutschland

2017-03-15

The basic orientation of the German energy supply to the increased use of renewable energies, while increasing energy efficiency, is prediscribed by the German government's energy concept and determines the market development. A current overview of the German energy market is given, which provides also this year a concentrated Compilation of the key data of the energy industry. As in the years before, the article not only summarizes general facts about the energy mix, but also goes into detail on the development of the individual energy sources, petroleum, natural gas, brown coal and hard coal, electricity as well as renewable energies. Furthermore, the price trends of international markets and in the domestic market are explained. A current overview of the development of greenhouse gas emissions concludes the contribution. [German] Die im Energiekonzept der Bundesregierung vorgegebene Grundausrichtung der deutschen Energieversorgung hin zur verstaerkten Nutzung erneuerbarer Energien bei gleichzeitiger Steigerung der Energieeffizienz bestimmt die Marktentwicklung. Vorliegend wird ein aktueller Ueberblick ueber den deutschen Energiemarkt gegeben, der auch in diesem Jahr eine konzentrierte Zusammenstellung der zentralen Eckdaten der Energiewirtschaft leistet. Wie in den Jahren zuvor fasst der Artikel nicht nur allgemeine Fakten zum Energiemix zusammen, sondern geht auch ausfuehrlich auf die Entwicklung der einzelnen Energietraeger Erdoel, Erdgas, Braun- und Steinkohle, Elektrizitaet sowie regenerative Energien ein. Ferner werden die Preistendenzen auf den internationalen Maerkten und im Inland erlaeutert. Eine aktuelle Uebersicht ueber die Entwicklung der Treibhausgas-Emissionen schliesst den Beitrag ab.

Experimental studies on the development of Falibaryt HD, a new high density barium meal for double contrast examination of the stomach

International Nuclear Information System (INIS)

Dietze, R.

1985-01-01

During the development of a new double contrast barium meal barium sulfate preparations with different densities, additives and particle size distributions were tested. Phantoms made of leather, rubber and dissected stomachs of cows and pigs. High density bariumsulfat suspension (200 - 250 % weight/volume) of low viscosity and suitable particle size spectrum containing additives improving the adherence (e.g. natrium citrate) displayed the best quality parameters for optimal imaging of the fine mucosal relief. (author)

Performance analysis of selective cooperation with fixed gain relays in Nakagami-m channels

KAUST Repository

Hussain, Syed Imtiaz; Hasna, Mazen Omar; Alouini, Mohamed-Slim

2012-01-01

Selecting the best relay using the maximum signal to noise ratio (SNR) among all the relays ready to cooperate saves system resources and utilizes the available bandwidth more efficiently compared to the regular all-relay cooperation. In this paper, we analyze the performance of the best relay selection scheme with fixed gain relays operating in Nakagami-. m channels. We first derive the probability density function (PDF) of upper bounded end-to-end SNR of the relay link. Using this PDF, we derive some key performance parameters for the system including average bit error probability and average channel capacity. The analytical results are verified through Monte Carlo simulations. © 2012 Elsevier B.V.

Performance analysis of selective cooperation with fixed gain relays in Nakagami-m channels

KAUST Repository

Hussain, Syed Imtiaz

2012-09-01

Selecting the best relay using the maximum signal to noise ratio (SNR) among all the relays ready to cooperate saves system resources and utilizes the available bandwidth more efficiently compared to the regular all-relay cooperation. In this paper, we analyze the performance of the best relay selection scheme with fixed gain relays operating in Nakagami-. m channels. We first derive the probability density function (PDF) of upper bounded end-to-end SNR of the relay link. Using this PDF, we derive some key performance parameters for the system including average bit error probability and average channel capacity. The analytical results are verified through Monte Carlo simulations. © 2012 Elsevier B.V.

Estimation of Radar Cross Section of a Target under Track

Directory of Open Access Journals (Sweden)

Hong Sun-Mog

2010-01-01

Full Text Available In allocating radar beam for tracking a target, it is attempted to maintain the signal-to-noise ratio (SNR of signal returning from the illuminated target close to an optimum value for efficient track updates. An estimate of the average radar cross section (RCS of the target is required in order to adjust transmitted power based on the estimate such that a desired SNR can be realized. In this paper, a maximum-likelihood (ML approach is presented for estimating the average RCS, and a numerical solution to the approach is proposed based on a generalized expectation maximization (GEM algorithm. Estimation accuracy of the approach is compared to that of a previously reported procedure.

Hybrid Accuracy-Time Trade-off Solution for Spectrum Sensing in Cognitive Radio Networks

DEFF Research Database (Denmark)

Ivanov, Antoni Stefkov; Mihovska, Albena Dimitrova; Poulkov, Vladimir

2018-01-01

parameters, therefore, a suitable trade-off is necessary for an optimal efficiency. We propose a dual-approach solution. The decision about the spectrum occupancy is made using the measured signal-to-noise ratio (SNR) and the received signal levels as inputs in a fuzzy logic algorithm. The result...

Toward imaging the body at 10.5 tesla.

Science.gov (United States)

Ertürk, M Arcan; Wu, Xiaoping; Eryaman, Yiğitcan; Van de Moortele, Pierre-François; Auerbach, Edward J; Lagore, Russell L; DelaBarre, Lance; Vaughan, J Thomas; Uğurbil, Kâmil; Adriany, Gregor; Metzger, Gregory J

2017-01-01

To explore the potential of performing body imaging at 10.5 Tesla (T) compared with 7.0T through evaluating the transmit/receive performance of similarly configured dipole antenna arrays. Fractionated dipole antenna elements for 10.5T body imaging were designed and evaluated using numerical simulations. Transmit performance of antenna arrays inside the prostate, kidneys and heart were investigated and compared with those at 7.0T using both phase-only radiofrequency (RF) shimming and multi-spoke pulses. Signal-to-noise ratio (SNR) comparisons were also performed. A 10-channel antenna array was constructed to image the abdomen of a swine at 10.5T. Numerical methods were validated with phantom studies at both field strengths. Similar power efficiencies were observed inside target organs with phase-only shimming, but RF nonuniformity was significantly higher at 10.5T. Spokes RF pulses allowed similar transmit performance with accompanying local specific absorption rate increases of 25-90% compared with 7.0T. Relative SNR gains inside the target anatomies were calculated to be >two-fold higher at 10.5T, and 2.2-fold SNR gain was measured in a phantom. Gradient echo and fast spin echo imaging demonstrated the feasibility of body imaging at 10.5T with the designed array. While comparable power efficiencies can be achieved using dipole antenna arrays with static shimming at 10.5T; increasing RF nonuniformities underscore the need for efficient, robust, and safe parallel transmission methods. Magn Reson Med 77:434-443, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

X-RAY STRIPES IN TYCHO'S SUPERNOVA REMNANT: SYNCHROTRON FOOTPRINTS OF A NONLINEAR COSMIC-RAY-DRIVEN INSTABILITY

International Nuclear Information System (INIS)

Bykov, Andrei M.; Osipov, Sergei M.; Uvarov, Yury A.; Ellison, Donald C.; Pavlov, George G.

2011-01-01

High-resolution Chandra observations of Tycho's supernova remnant (SNR) have revealed several sets of quasi-steady, high-emissivity, nearly parallel X-ray stripes in some localized regions of the SNR. These stripes are most likely the result of cosmic-ray (CR) generated magnetic turbulence at the SNR blast wave. However, for the amazingly regular pattern of these stripes to appear, simultaneous action of a number of shock-plasma phenomena is required, which is not predicted by most models of magnetic field amplification. A consistent explanation of these stripes yields information on the complex nonlinear plasma processes connecting efficient CR acceleration and magnetic field fluctuations in strong collisionless shocks. The nonlinear diffusive shock acceleration (NL-DSA) model described here, which includes magnetic field amplification from a CR-current-driven instability, does predict stripes consistent with the synchrotron observations of Tycho's SNR. We argue that the local ambient mean magnetic field geometry determines the orientation of the stripes and therefore it can be reconstructed with the high-resolution X-ray imaging. The estimated maximum energy of the CR protons responsible for the stripes is ∼10 15 eV. Furthermore, the model predicts that a specific X-ray polarization pattern, with a polarized fraction ∼50%, accompanies the stripes, which can be tested with future X-ray polarimeter missions.

MR imaging of the knee: Improvement of signal and contrast efficiency of T1-weighted turbo spin echo sequences by applying a driven equilibrium (DRIVE) pulse

Energy Technology Data Exchange (ETDEWEB)

Radlbauer, Rudolf, E-mail: rudolf.radlbauer@stpoelten.lknoe.a [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, 3100 St. Poelten (Austria); Lomoschitz, Friedrich, E-mail: friedrich.lomoschitz@stpoelten.lknoe.a [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, 3100 St. Poelten (Austria); Salomonowitz, Erich, E-mail: erich.salomonowitz@stpoelten.lknoe.a [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, 3100 St. Poelten (Austria); Eberhardt, Knut E., E-mail: info@mrt-kompetenzzentrum.d [MRT Competence Center Schloss Werneck, Balthasar-Neumann-Platz 2, 97440 Werneck (Germany); Stadlbauer, Andreas, E-mail: andi@nmr.a [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, 3100 St. Poelten (Austria); Department of Neurosurgery, University of Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen (Germany)

2010-08-15

The purpose of this study was to assess the effect of a driven equilibrium (DRIVE) pulse incorporated in a standard T1-weighted turbo spin echo (TSE) sequence as used in our routine MRI protocol for examination of pathologies of the knee. Sixteen consecutive patients with knee disorders were examined using the routine MRI protocol, including T1-weighted TSE-sequences with and without a DRIVE pulse. Signal-to-noise ratios (SNRs) and contrast-to-noise ratio (CNR) of anatomical structures and pathologies were calculated and compared for both sequences. The differences in diagnostic value of the T1-weighted images with and without DRIVE pulse were assessed. SNR was significantly higher on images acquired with DRIVE pulse for fluid, effusion, cartilage and bone. Differences in the SNR of meniscus and muscle between the two sequences were not statistically significant. CNR was significantly increased between muscle and effusion, fluid and cartilage, fluid and meniscus, cartilage and meniscus, bone and cartilage on images acquired using the DRIVE pulse. Diagnostic value of the T1-weighted images was found to be improved for delineation of anatomic structures and for diagnosing a variety of pathologies when a DRIVE pulse is incorporated in the sequence. Incorporation of a DRIVE pulse into a standard T1-weighted TSE-sequence leads to significant increase of SNR and CNR of both, anatomical structures and pathologies, and consequently to an increase in diagnostic value within the same acquisition time.

MR imaging of the knee: Improvement of signal and contrast efficiency of T1-weighted turbo spin echo sequences by applying a driven equilibrium (DRIVE) pulse

International Nuclear Information System (INIS)

Radlbauer, Rudolf; Lomoschitz, Friedrich; Salomonowitz, Erich; Eberhardt, Knut E.; Stadlbauer, Andreas

2010-01-01

The purpose of this study was to assess the effect of a driven equilibrium (DRIVE) pulse incorporated in a standard T1-weighted turbo spin echo (TSE) sequence as used in our routine MRI protocol for examination of pathologies of the knee. Sixteen consecutive patients with knee disorders were examined using the routine MRI protocol, including T1-weighted TSE-sequences with and without a DRIVE pulse. Signal-to-noise ratios (SNRs) and contrast-to-noise ratio (CNR) of anatomical structures and pathologies were calculated and compared for both sequences. The differences in diagnostic value of the T1-weighted images with and without DRIVE pulse were assessed. SNR was significantly higher on images acquired with DRIVE pulse for fluid, effusion, cartilage and bone. Differences in the SNR of meniscus and muscle between the two sequences were not statistically significant. CNR was significantly increased between muscle and effusion, fluid and cartilage, fluid and meniscus, cartilage and meniscus, bone and cartilage on images acquired using the DRIVE pulse. Diagnostic value of the T1-weighted images was found to be improved for delineation of anatomic structures and for diagnosing a variety of pathologies when a DRIVE pulse is incorporated in the sequence. Incorporation of a DRIVE pulse into a standard T1-weighted TSE-sequence leads to significant increase of SNR and CNR of both, anatomical structures and pathologies, and consequently to an increase in diagnostic value within the same acquisition time.

A current-excited triple-time-voltage oversampling method for bio-impedance model for cost-efficient circuit system.

Science.gov (United States)

Yan Hong; Yong Wang; Wang Ling Goh; Yuan Gao; Lei Yao

2015-08-01

This paper presents a mathematic method and a cost-efficient circuit to measure the value of each component of the bio-impedance model at electrode-electrolyte interface. The proposed current excited triple-time-voltage oversampling (TTVO) method deduces the component values by solving triple simultaneous electric equation (TSEE) at different time nodes during a current excitation, which are the voltage functions of time. The proposed triple simultaneous electric equations (TSEEs) allows random selections of the time nodes, hence numerous solutions can be obtained during a single current excitation. Following that, the oversampling approach is engaged by averaging all solutions of multiple TSEEs acquired after a single current excitation, which increases the practical measurement accuracy through the improvement of the signal-to-noise ratio (SNR). In addition, a print circuit board (PCB) that consists a switched current exciter and an analog-to-digital converter (ADC) is designed for signal acquisition. This presents a great cost reduction when compared against other instrument-based measurement data reported [1]. Through testing, the measured values of this work is proven to be in superb agreements on the true component values of the electrode-electrolyte interface model. This work is most suited and also useful for biological and biomedical applications, to perform tasks such as stimulations, recordings, impedance characterizations, etc.

Self-Seeded RSOA-Fiber Cavity Lasers vs. ASE Spectrum-Sliced or Externally Seeded Transmitters—A Comparative Study

Directory of Open Access Journals (Sweden)

Simon A. Gebrewold

2015-12-01

Full Text Available Reflective semiconductor optical amplifier fiber cavity lasers (RSOA-FCLs are appealing, colorless, self-seeded, self-tuning and cost-efficient upstream transmitters. They are of interest for wavelength division multiplexed passive optical networks (WDM-PONs based links. In this paper, we compare RSOA-FCLs with alternative colorless sources, namely the amplified spontaneous emission (ASE spectrum-sliced and the externally seeded RSOAs. We compare the differences in output power, signal-to-noise ratio (SNR, relative intensity noise (RIN, frequency response and transmission characteristics of these three sources. It is shown that an RSOA-FCL offers a higher output power over an ASE spectrum-sliced source with SNR, RIN and frequency response characteristics halfway between an ASE spectrum-sliced and a more expensive externally seeded RSOA. The results show that the RSOA-FCL is a cost-efficient WDM-PON upstream source, borrowing simplicity and cost-efficiency from ASE spectrum slicing with characteristics that are, in many instances, good enough to perform short-haul transmission. To substantiate our statement and to quantitatively compare the potential of the three schemes, we perform data transmission experiments at 5 and 10 Gbit/s.

Embedded DCT and wavelet methods for fine granular scalable video: analysis and comparison

Science.gov (United States)

van der Schaar-Mitrea, Mihaela; Chen, Yingwei; Radha, Hayder

2000-04-01

Video transmission over bandwidth-varying networks is becoming increasingly important due to emerging applications such as streaming of video over the Internet. The fundamental obstacle in designing such systems resides in the varying characteristics of the Internet (i.e. bandwidth variations and packet-loss patterns). In MPEG-4, a new SNR scalability scheme, called Fine-Granular-Scalability (FGS), is currently under standardization, which is able to adapt in real-time (i.e. at transmission time) to Internet bandwidth variations. The FGS framework consists of a non-scalable motion-predicted base-layer and an intra-coded fine-granular scalable enhancement layer. For example, the base layer can be coded using a DCT-based MPEG-4 compliant, highly efficient video compression scheme. Subsequently, the difference between the original and decoded base-layer is computed, and the resulting FGS-residual signal is intra-frame coded with an embedded scalable coder. In order to achieve high coding efficiency when compressing the FGS enhancement layer, it is crucial to analyze the nature and characteristics of residual signals common to the SNR scalability framework (including FGS). In this paper, we present a thorough analysis of SNR residual signals by evaluating its statistical properties, compaction efficiency and frequency characteristics. The signal analysis revealed that the energy compaction of the DCT and wavelet transforms is limited and the frequency characteristic of SNR residual signals decay rather slowly. Moreover, the blockiness artifacts of the low bit-rate coded base-layer result in artificial high frequencies in the residual signal. Subsequently, a variety of wavelet and embedded DCT coding techniques applicable to the FGS framework are evaluated and their results are interpreted based on the identified signal properties. As expected from the theoretical signal analysis, the rate-distortion performances of the embedded wavelet and DCT-based coders are very

Role of magnetic resonance imaging (MRI) establishing the indication for, planning, and following up uterine artery embolization (UAE) for treating symptomatic leiomyomas of the uterus; Stellenwert der Magnetresonanztomographie fuer Indikationsstellung, Interventionsplanung und Nachsorge bei transarterieller Embolisationsbehandlung des Uterus myomatosus

Energy Technology Data Exchange (ETDEWEB)

Kroencke, T.J. [Institut fuer Radiologie, Universitaetsklinikum Charite, Campus Mitte, Humboldt-Universitaet zu Berlin (Germany); Institut fuer Radiologie, Universitaetsklinikum Charite, Campus Mitte, Humboldt-Universitaet zu Berlin, Schumannstrasse 20/21, 10117, Berlin (Germany); Hamm, B. [Institut fuer Radiologie, Universitaetsklinikum Charite, Campus Mitte, Humboldt-Universitaet zu Berlin (Germany)

2003-08-01

To describe the role of magnetic resonance imaging (MRI) in establishing the indication for, planning, and following up uterine artery embolization (UAE) for treating symptomatic leiomyomas of the uterus on the basis of the current literature and our results. Retrospective analysis of the MRI findings obtained in 130 patients before and after UAE. Presentation of characteristic MRI features and their relevance in establishing the indication for, performing, and following up of UAE. Discussion of the results in conjunction with published data. The intermediate results of UAE reported in the literature show a successful improvement of leiomyoma-related symptoms in 82-94% of cases and an average reduction of leiomyoma size by 36-64%. The typical MRI appearance of degenerating leiomyomas is presented together with that of relevant differential diagnoses. MRI findings allow for establishing the indication for UAE by providing reliable information on the location, size, and number of uterine leiomyomas. Analysis of 60 patients of our study population showed solitary leiomyoma in 16% of cases, 2-10 leiomyomas in 47%, and over 10 in 37%. Subserosal, pedunculated leiomyomas cannot be treated by UAE; these were present in 5% of the patients. MR angiography is useful in assessing pelvic vascular anatomy before the intervention and identifies collateral vascular supply to the uterus. Contrast-enhanced imaging is suitable for monitoring successful devascularization following embolization and evaluating complications. (orig.) [German] Darstellung des Stellenwerts der Magnetresonanztomographie fuer die Indikationsstellung, Interventionsplanung und Nachsorge bei der transarteriellen Embolisationsbehandlung des symptomatischen Uterus myomatosus unter Beruecksichtigung der aktuellen Literatur sowie eigener Ergebnisse. Retrospektive Auswertung der MRT-Untersuchungen vor und nach Myomembolisation eines Kollektivs von 130 Patientinnen. Darlegung charakteristischer

Environmental information systems. Fundamental concepts and applications. 2. new rev. and enl. ed.; Umweltinformationssysteme. Grundlegende Konzepte und Anwendungen

Energy Technology Data Exchange (ETDEWEB)

Fischer-Stabel, Peter (ed.) [Hochschule Trier (Germany). Professur Geomatik und Visualisierung; Hochschule Trier (Germany). Inst. fuer Softwaresysteme in Wirtschaft, Umwelt und Verwaltung

2013-07-01

Environmental Information Systems (EIS) of different dimensions today represent important tools to ensure a fast and qualified action in the face of the ever-growing needs of the environment. This publication is an interdisciplinary textbook which contents convey the conception and development of environmental information systems. Accessing the innovations of the last five years in the development of EIS in their 2nd Edition: in addition to the various disciplines which traditionally have to contribute in the development of environmental information systems, new topics had been modified in the present edition, to take into account of the extended interests of students in the framework of environmental information technology education. [German] Umweltinformationssysteme (UIS) der verschiedensten Dimensionen stellen heute wichtige Hilfsmittel dar, um angesichts der staendig wachsenden Anforderungen im Umweltbereich ein schnelles und qualifiziertes Handeln sicherzustellen. Diese Publikation ist ein interdisziplinaer angelegtes Lehrbuch, dessen Inhalte die Konzeption und Entwicklung von Umweltinformationssystemen vermitteln. Sie greift in ihrer 2. Auflage die Innovationen der letzten fuenf Jahre in der Entwicklung von UIS auf: Neben den verschiedenen Disziplinen, welche traditionell bei der Entwicklung von Umweltinformationssystemen Beitraege leisten muessen, wurden in der vorliegenden Auflage auch neue Themenfelder bearbeitet, um den erweiterten Interessen der Studierenden im Rahmen einer umweltbezogenen informationstechnischen Ausbildung Rechnung zu tragen.

Novel iterative reconstruction method with optimal dose usage for partially redundant CT-acquisition

International Nuclear Information System (INIS)

Bruder, H; Raupach, R; Sunnegardh, J; Allmendinger, T; Klotz, E; Stierstorfer, K; Flohr, T

2015-01-01

resolution of the source image data.For different CT applications: dual energy imaging, liver imaging, spiral imaging, cardiac imaging, we show that SNR can efficiently be transferred from the composite image to the source image data at constant patient dose, while maintaining resolution properties of the source data. (paper)

Novel iterative reconstruction method with optimal dose usage for partially redundant CT-acquisition

Science.gov (United States)

Bruder, H.; Raupach, R.; Sunnegardh, J.; Allmendinger, T.; Klotz, E.; Stierstorfer, K.; Flohr, T.

2015-11-01

spatial resolution of the source image data. For different CT applications: dual energy imaging, liver imaging, spiral imaging, cardiac imaging, we show that SNR can efficiently be transferred from the composite image to the source image data at constant patient dose, while maintaining resolution properties of the source data.

Detective quantum efficiency: a standard test to ensure optimal detector performance and low patient exposures

Science.gov (United States)

Escartin, Terenz R.; Nano, Tomi F.; Cunningham, Ian A.

2016-03-01

The detective quantum efficiency (DQE), expressed as a function of spatial frequency, describes the ability of an x-ray detector to produce high signal-to-noise ratio (SNR) images. While regulatory and scientific communities have used the DQE as a primary metric for optimizing detector design, the DQE is rarely used by end users to ensure high system performance is maintained. Of concern is that image quality varies across different systems for the same exposures with no current measures available to describe system performance. Therefore, here we conducted an initial DQE measurement survey of clinical x-ray systems using a DQE-testing instrument to identify their range of performance. Following laboratory validation, experiments revealed that the DQE of five different systems under the same exposure level (8.0 μGy) ranged from 0.36 to 0.75 at low spatial frequencies, and 0.02 to 0.4 at high spatial frequencies (3.5 cycles/mm). Furthermore, the DQE dropped substantially with decreasing detector exposure by a factor of up to 1.5x in the lowest spatial frequency, and a factor of 10x at 3.5 cycles/mm due to the effect of detector readout noise. It is concluded that DQE specifications in purchasing decisions, combined with periodic DQE testing, are important factors to ensure patients receive the health benefits of high-quality images for low x-ray exposures.

Manual of Hemorrhagic Fever with Renal Syndrome

Science.gov (United States)

1989-04-01

added to form 2,000 ml solution. (3) Fresh guinea pig serum (GPS), which may be stored at -80’ C. (4) Dithiothreitol solution (DTT), 3 mg/ml, which...named Seoul virus, has been serol gically identified in Africa, North and South America, India, te Ihighlands of New Guinea , 3 Y/ j5 HFRS several...kalium and protein free and essentially natrium-free, is recommended. If parenteral alimentation is necessary, the usual treatment is to infuse

Development of a new high density (HD) barium meal (Falibaryt HD) for double contrast investigation of the stomach

International Nuclear Information System (INIS)

Dietze, R.

1986-01-01

During the development of a new double contrast barium meal barium sulfate preparations with various densities, additives and particle size distributions were tested. Phantoms made of leather, rubber and the opened stomachs of cows and pigs were used. A HD bariumsulfate suspension (200 - 250% W/V) of low viscosity and suitable grain size spectrum containing additives improving the adherence (e.g. natrium citrate) showed the best quality parameters for an optimal imaging of the fine mucosal relief. (author)

Studium vlastností tablet ze dvou typů mikrokrystalické celulosy

OpenAIRE

Lišková, Simona

2010-01-01

The thesis studies mechanical strenght and disintegration time of tablets from two types of Microcel - Microcel® MC - 12 a Microcel® MC - 500. These characteristics were studied depending on compression force (3, 4 and 5 kN) and addition of two types of lubricants (magnesium stearate, natrium stearyl fumarate) in two concentrations - 0, 5 % and 1 % and addition of two model active substances in concentration 50 % (acetylsalicylic acid and ascorbic acid). For compression with active substance ...

SU-C-201-04: Noise and Temporal Resolution in a Near Real-Time 3D Dosimeter

Energy Technology Data Exchange (ETDEWEB)

Rilling, M [Department of physics, engineering physics and optics, Universite Laval, Quebec City, QC (Canada); Centre de recherche sur le cancer, Universite Laval, Quebec City, QC (Canada); Radiation oncology department, CHU de Quebec, Quebec City, QC (Canada); Center for optics, photonics and lasers, Universite Laval, Quebec City, Quebec (Canada); Goulet, M [Radiation oncology department, CHU de Quebec, Quebec City, QC (Canada); Beaulieu, L; Archambault, L [Department of physics, engineering physics and optics, Universite Laval, Quebec City, QC (Canada); Centre de recherche sur le cancer, Universite Laval, Quebec City, QC (Canada); Radiation oncology department, CHU de Quebec, Quebec City, QC (Canada); Thibault, S [Center for optics, photonics and lasers, Universite Laval, Quebec City, Quebec (Canada)

2016-06-15

Purpose: To characterize the performance of a real-time three-dimensional scintillation dosimeter in terms of signal-to-noise ratio (SNR) and temporal resolution of 3D dose measurements. This study quantifies its efficiency in measuring low dose levels characteristic of EBRT dynamic treatments, and in reproducing field profiles for varying multileaf collimator (MLC) speeds. Methods: The dosimeter prototype uses a plenoptic camera to acquire continuous images of the light field emitted by a 10×10×10 cm{sup 3} plastic scintillator. Using EPID acquisitions, ray tracing-based iterative tomographic algorithms allow millimeter-sized reconstruction of relative 3D dose distributions. Measurements were taken at 6MV, 400 MU/min with the scintillator centered at the isocenter, first receiving doses from 1.4 to 30.6 cGy. Dynamic measurements were then performed by closing half of the MLCs at speeds of 0.67 to 2.5 cm/s, at 0° and 90° collimator angles. A reference static half-field was obtained for measured profile comparison. Results: The SNR steadily increases as a function of dose and reaches a clinically adequate plateau of 80 at 10 cGy. Below this, the decrease in light collected and increase in pixel noise diminishes the SNR; nonetheless, the EPID acquisitions and the voxel correlation employed in the reconstruction algorithms result in suitable SNR values (>75) even at low doses. For dynamic measurements at varying MLC speeds, central relative dose profiles are characterized by gradients at %D{sub 50} of 8.48 to 22.7 %/mm. These values converge towards the 32.8 %/mm-gradient measured for the static reference field profile, but are limited by the dosimeter’s current acquisition rate of 1Hz. Conclusion: This study emphasizes the efficiency of the 3D dose distribution reconstructions, while identifying limits of the current prototype’s temporal resolution in terms of dynamic EBRT parameters. This work paves the way for providing an optimized, second

SU-C-201-04: Noise and Temporal Resolution in a Near Real-Time 3D Dosimeter

International Nuclear Information System (INIS)

Rilling, M; Goulet, M; Beaulieu, L; Archambault, L; Thibault, S

2016-01-01

Purpose: To characterize the performance of a real-time three-dimensional scintillation dosimeter in terms of signal-to-noise ratio (SNR) and temporal resolution of 3D dose measurements. This study quantifies its efficiency in measuring low dose levels characteristic of EBRT dynamic treatments, and in reproducing field profiles for varying multileaf collimator (MLC) speeds. Methods: The dosimeter prototype uses a plenoptic camera to acquire continuous images of the light field emitted by a 10×10×10 cm"3 plastic scintillator. Using EPID acquisitions, ray tracing-based iterative tomographic algorithms allow millimeter-sized reconstruction of relative 3D dose distributions. Measurements were taken at 6MV, 400 MU/min with the scintillator centered at the isocenter, first receiving doses from 1.4 to 30.6 cGy. Dynamic measurements were then performed by closing half of the MLCs at speeds of 0.67 to 2.5 cm/s, at 0° and 90° collimator angles. A reference static half-field was obtained for measured profile comparison. Results: The SNR steadily increases as a function of dose and reaches a clinically adequate plateau of 80 at 10 cGy. Below this, the decrease in light collected and increase in pixel noise diminishes the SNR; nonetheless, the EPID acquisitions and the voxel correlation employed in the reconstruction algorithms result in suitable SNR values (>75) even at low doses. For dynamic measurements at varying MLC speeds, central relative dose profiles are characterized by gradients at %D_5_0 of 8.48 to 22.7 %/mm. These values converge towards the 32.8 %/mm-gradient measured for the static reference field profile, but are limited by the dosimeter’s current acquisition rate of 1Hz. Conclusion: This study emphasizes the efficiency of the 3D dose distribution reconstructions, while identifying limits of the current prototype’s temporal resolution in terms of dynamic EBRT parameters. This work paves the way for providing an optimized, second-generational real-time 3D

Speziation von Gadolinium-MRT-Kontrastmitteln in Umweltmatrizes

OpenAIRE

Lindner, Uwe

2017-01-01

Gd-Kontrastmittel werden in der Medizin für die Magnetresonanztomographie (MRT) benötigt, um einen besseren Bildkontrast zu erzielen. Nach der Anwendung gelangen diese Arzneimittel über das Abwasser in die Klärwerke und von dort in die jeweiligen anliegenden Oberflächengewässer. Somit wird es notwendig, den Verbleib der Gd-MRT-Kontrastmittel in der Umwelt zu verfolgen und aufzuklären. In dieser Arbeit werden für die Analyse von Umweltproben Methoden zur Speziesanalytik von Gd-Kontrastmitteln ...

Cleaning of road accessories with powdered sodium bicarbonate; Jutansan natrium ryu wo mochiita doro fuzokubutsu no senjo

Energy Technology Data Exchange (ETDEWEB)

Yamashita, H.; Amagori, Y.; Mori, E. [Japan Highway Public Corporation, Tokyo (Japan)

1998-06-25

A method for cleaning highway accessories with powdered sodium bicarbonate is developed, to replace mechanical cleaning by a multi-purpose vehicle or manual cleaning, and thereby to reduce road maintenance cost. It pneumatically blows sodium bicarbonate particles by a blaster connected to a water tank and compressor onto a variety of stains to remove them. The cleaning system is applicable to a variety of purposes, allowing dry and wet cleaning modes to be easily switched from each other. Sodium bicarbonate, being naturally occurring, is harmless, and its type can be freely chosen. This method was applied in FY1996 mainly to cleaning interior plates in highways, to collect the basic data. Its cleaning effectiveness has been confirmed by applying it to the internal plates, which are difficult to clean by a multi-purpose vehicle, and illuminators in tunnels, whose cleaning areas are narrow. It recovers reflectivity of plates to 85% of the initial level at the highest, and shows 3 times higher efficiency for heavily stained plates. The test was continued in FY1997. It shows an approximately 5 times higher cleaning capacity than the conventional method, greatly reducing cleaning time, especially for illuminators in tunnels. 7 figs., 5 tabs.

Modeling of detective quantum efficiency considering scatter-reduction devices

Energy Technology Data Exchange (ETDEWEB)

Park, Ji Woong; Kim, Dong Woon; Kim, Ho Kyung [Pusan National University, Busan (Korea, Republic of)

2016-05-15

The reduction of signal-to-noise ratio (SNR) cannot be restored and thus has become a severe issue in digital mammography.1 Therefore, antiscatter grids are typically used in mammography. Scatter-cleanup performance of various scatter-reduction devices, such as air gaps,2 linear (1D) or cellular (2D) grids,3, 4 and slot-scanning devices,5 has been extensively investigated by many research groups. In the present time, a digital mammography system with the slotscanning geometry is also commercially available.6 In this study, we theoretically investigate the effect of scattered photons on the detective quantum efficiency (DQE) performance of digital mammography detectors by using the cascaded-systems analysis (CSA) approach. We show a simple DQE formalism describing digital mammography detector systems equipped with scatter reduction devices by regarding the scattered photons as additive noise sources. The LFD increased with increasing PMMA thickness, and the amounts of LFD indicated the corresponding SF. The estimated SFs were 0.13, 0.21, and 0.29 for PMMA thicknesses of 10, 20, and 30 mm, respectively. While the solid line describing the measured MTF for PMMA with 0 mm was the result of least-squares of regression fit using Eq. (14), the other lines were simply resulted from the multiplication of the fit result (for PMMA with 0 mm) with the (1-SF) estimated from the LFDs in the measured MTFs. Spectral noise-power densities over the entire frequency range were not much changed with increasing scatter. On the other hand, the calculation results showed that the spectral noise-power densities increased with increasing scatter. This discrepancy may be explained by that the model developed in this study does not account for the changes in x-ray interaction parameters for varying spectral shapes due to beam hardening with increasing PMMA thicknesses.

Decentralized hydrogen production for fuel cells; Dezentrale Wasserstoffproduktion fuer Brennstoffzellen. Entwicklung eines Kompaktreformers fuer erdgasbetriebene Brennstoffzellenheizgeraete

Energy Technology Data Exchange (ETDEWEB)

Trimis, Dimosthenis; Anger, Stephan [Technische Univ. Bergakademie Freiberg (Germany). Lehrstuhl fuer Gas- und Waermetechnische Anlagen; Otto, Bert; Nitzsche, Joerg [DBI - Gastechnologisches Institut gGmbH Freiberg (Germany); Grosser, Katrin [Riesaer Brennstoffzellentechnik GmbH, Glaubitz (Germany); Krause, Hartmut [DBI - Gastechnologisches Institut gGmbH Freiberg (Germany); DBI Gas- und Umwelttechnik GmbH, Leipzig (Germany)

2012-07-01

The reconstruction of energy-supply towards more sustainability has reached the boiler rooms. More and more innovative heating systems come into the market like heat pumps, solar-thermal applications and last but not least decentralized cogeneration plants like Sterling- or internal combustion engines. With fuel cells another high-performance technology is introduced, which comes along with especially high electrical efficiencies at low acoustic and noxious emissions. Efficient fuel processing systems are needed as an essential component of such devices. (orig.)

Energy price report for Baden-Wuerttemberg 2016. Final report; Energiepreisbericht fuer Baden-Wuerttemberg 2016. Endbericht

Energy Technology Data Exchange (ETDEWEB)

Guel, Sarah; Cherkasky, Jenny

2017-05-19

This report describes the historical development of energy prices in recent years up to and including 2016 in Germany and Baden-Wuerttemberg and estimates the future development until 2023. The report addresses the markets for oil, gas, electricity and heat, which are summarized below. In addition, an estimate of the energy costs for households and industry and the associated burden is made. [German] Der vorliegende Bericht beschreibt die historische Entwicklung der Energiepreise der letzten Jahre bis einschliesslich 2016 in Deutschland und in Baden-Wuerttemberg und schaetzt die zukuenftige Entwicklung bis 2023 ab. Dabei geht der Bericht auf die Maerkte fuer Oel, Gas, Strom und Waerme ein, welche im Folgenden zusammengefasst werden. Zudem wird eine Abschaetzung der Energiekosten fuer Haushalte und Industrie und der damit verbundenen Belastung vorgenommen.

Environmental policy in the Federal Republic of Germany

Energy Technology Data Exchange (ETDEWEB)

Simonis, U.E.

1991-12-31

After a short description of the basic aims of environmental policy the general development of environmental policy in the FRG is gone into. Here above all the sectors air pollution, water pollution, noise pollution and waste materials are dealt with. Finally the most important elements of the decision-making processes are explained and a short history of environmental policy in the FRG is given. (UA). [Deutsch] Nach einer kurzen Erlaeuterung der Grundziele der Umweltpolitik wird in kurzer Form auf die allgemeine Entwicklung der Umweltpolitik in der BRD eingegangen. Dabei werden insbesondere die Bereiche Luftverschmutzung, Wasserverschmutzung, Laermbelaestigung und Abfallmaterialien behandelt. Abschliessend werden die wichtigsten Grundzuege des Entscheidungs-Findungs-Prozesses erlaeutert, und es wird die historische Entwicklung der Umweltpolitik in der BRD skizziert. (UA).

Zur Rekonstruktion einer Typologie jugendlichen Medienhandelns gemäß dem Leitbild der Triangulation

Directory of Open Access Journals (Sweden)

Klaus Peter Treumann

2017-09-01

Full Text Available Die im Folgenden dargestellten Ergebnisse sind im Rahmen des von der DFG geförderten Forschungsprojekts „Eine Untersuchung zum Mediennutzungsverhalten 12- bis 20-Jähriger und zur Entwicklung von Medienkompetenz im Jugendalter“ entstanden, das gemeinsam von Klaus Peter Treumann, Uwe Sander und Dorothee Meister geleitet wird. Das Forschungsprojekt untersucht das Medienhandeln Jugendlicher sowohl hinsichtlich Neuer als auch alter Medien. Zum einen fragen wir dabei nach den Ausprägungen von Medienkompetenz in verschiedenen Dimensionen und zum anderen konzentrieren wir uns auf die Entwicklung einer empirisch fundierten Typologie jugendlichen Medienhandelns. Methodologisch ist die Untersuchung an dem Leitbild der Triangulation orientiert und kombiniert qualitative und quantitative Zugänge zum Forschungsfeld in Form von Gruppendiskussionen, leitfadengestützten Einzelinterviews und einer Repräsentativerhebung.

Verein Deutscher Kohlenimporteure. Annual report 2000; Verein Deutscher Kohlenimporteure. Jahresbericht 2000

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-04-25

Energy economy developments of the world, the EU and West Germany are gone into. The main aspects discussed are the coal market and trade which depends on political decisions and concepts, but also on the availability of other primary energy sources such as oil and nuclear power. The situation of the various countries in the field of coal is illustrated by so-called country reports. (HS) [German] Es wird auf die energiewirtschaftliche Entwicklung sowohl der Welt als auch der europaeischen Union und speziell der Bundesrepublik Deutschland eingegangen. Im Vordergrund steht dabei der Kohlenmarkt und -handel, der von politischen Erscheinungen und Konzepten abhaengig ist, aber auch von der Entwicklung anderer Primaerenergien wie Oel und Kernkraft. In den sogenannten Laenderberichten wird die kohlewirtschaftliche Diskussion einzelner Laender behandelt. (HS)

Verein Deutscher Kohlenimporteure. Annual report 2001; Verein Deutscher Kohlenimporteure. Jahresbericht 2001

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

Energy economy developments of the world, the EU and West Germany are gone into. The main aspects discussed are the coal market and trade which depends on political decisions and concepts, but also on the availability of other primary energy sources such as oil and nuclear power. The situation of the various countries in the field of coal is illustrated by so-called country reports. [German] Es wird auf die energiewirtschaftliche Entwicklung sowohl der Welt als auch der europaeischen Union und speziell der Bundesrepublik Deutschland eingegangen. Im Vordergrund steht dabei der Kohlenmarkt und -handel, der von politischen Erscheinungen und Konzepten abhaengig ist, aber auch von der Entwicklung anderer Primaerenergien wie Oel und Kernkraft. In den sogenannten Laenderberichten wird die kohlewirtschaftliche Diskussion einzelner Laender behandelt.

A Specialized Multi-Transmit Head Coil for High Resolution fMRI of the Human Visual Cortex at 7T.

Science.gov (United States)

Sengupta, Shubharthi; Roebroeck, Alard; Kemper, Valentin G; Poser, Benedikt A; Zimmermann, Jan; Goebel, Rainer; Adriany, Gregor

2016-01-01

To design, construct and validate radiofrequency (RF) transmit and receive phased array coils for high-resolution visual cortex imaging at 7 Tesla. A 4 channel transmit and 16 channel receive array was constructed on a conformal polycarbonate former. Transmit field efficiency and homogeneity were simulated and validated, along with the Specific Absorption Rate, using [Formula: see text] mapping techniques and electromagnetic simulations. Receiver signal-to-noise ratio (SNR), temporal SNR (tSNR) across EPI time series, g-factors for accelerated imaging and noise correlations were evaluated and compared with a commercial 32 channel whole head coil. The performance of the coil was further evaluated with human subjects through functional MRI (fMRI) studies at standard and submillimeter resolutions of upto 0.8mm isotropic. The transmit and receive sections were characterized using bench tests and showed good interelement decoupling, preamplifier decoupling and sample loading. SNR for the 16 channel coil was ∼ 1.5 times that of the commercial coil in the human occipital lobe, and showed better g-factor values for accelerated imaging. fMRI tests conducted showed better response to Blood Oxygen Level Dependent (BOLD) activation, at resolutions of 1.2mm and 0.8mm isotropic. The 4 channel phased array transmit coil provides homogeneous excitation across the visual cortex, which, in combination with the dual row 16 channel receive array, makes for a valuable research tool for high resolution anatomical and functional imaging of the visual cortex at 7T.

On the diversity enhancement and power balancing of per-subcarrier antenna selection in OFDM systems

KAUST Repository

Park, Kihong; Ko, Youngchai; Alouini, Mohamed-Slim

2010-01-01

In this paper, we consider multi-carrier systems with multiple transmit antennas under a power balancing constraint. Applying transmit antenna selection and discrete rate adaptive modulation using M-ary quadrature amplitude modulation (QAM) according to the channel variation per subcarrier, we develop an optimal antenna selection scheme in terms of maximum spectral efficiency where all the possible grouping to send the same information bearing signals in a group of subcarriers are searched and the groups of subcarriers to provide the frequency diversity gain are formed. In addition, we propose a suboptimal method to reduce the computational complexity of the optimal method. The suboptimal scheme consider only the subcarriers under outage and those are combined sequentially until it meets a required SNR. Numerical results show that the proposed suboptimal method with diversity combining outperforms the optimal antenna selection without diversity combining introduced in [1], especially for low SNR region and offers the spectral efficiency close to that of the optimal method with diversity combining, while maintaining lower complexity. ©2010 IEEE.

On the diversity enhancement and power balancing of per-subcarrier transmit antenna selection in OFDM systems

KAUST Repository

Park, Kihong

2011-01-01

In this paper, we consider multicarrier systems with multiple transmit antennas under a power-balancing constraint. Applying transmit antenna selection and discrete rate-adaptive modulation using M-ary quadrature-amplitude modulation (QAM) according to the channel variation per subcarrier, we develop an optimal transmit antenna selection scheme in terms of the maximum spectral efficiency, where all the possible groupings for sending the same information-bearing signals in a group of subcarriers are searched, and the groups of subcarriers for providing the frequency diversity gain are formed. In addition, we propose a suboptimal method for reducing the computational complexity of the optimal method. The suboptimal scheme considers only the subcarriers under outage, and these subcarriers are sequentially combined until the required signal-to-noise ratio (SNR) is met. Numerical results show that the proposed suboptimal method with diversity combining outperforms the optimal antenna selection without diversity combining, as introduced in the work of Sandell and Coon, particularly for low-SNR regions, and offers the spectral efficiency close to the optimal method with diversity combining while maintaining lower complexity. © 2011 IEEE.

On the diversity enhancement and power balancing of per-subcarrier antenna selection in OFDM systems

KAUST Repository

Park, Kihong

2010-09-01

In this paper, we consider multi-carrier systems with multiple transmit antennas under a power balancing constraint. Applying transmit antenna selection and discrete rate adaptive modulation using M-ary quadrature amplitude modulation (QAM) according to the channel variation per subcarrier, we develop an optimal antenna selection scheme in terms of maximum spectral efficiency where all the possible grouping to send the same information bearing signals in a group of subcarriers are searched and the groups of subcarriers to provide the frequency diversity gain are formed. In addition, we propose a suboptimal method to reduce the computational complexity of the optimal method. The suboptimal scheme consider only the subcarriers under outage and those are combined sequentially until it meets a required SNR. Numerical results show that the proposed suboptimal method with diversity combining outperforms the optimal antenna selection without diversity combining introduced in [1], especially for low SNR region and offers the spectral efficiency close to that of the optimal method with diversity combining, while maintaining lower complexity. ©2010 IEEE.

Development of a test system for the determination of biodegradability in surface waters; Entwicklung eines Testsystems fuer die Pruefung des biologischen Abbaus in Oberflaechengewaessern

Energy Technology Data Exchange (ETDEWEB)

Kalsch, W; Knacker, T; Robertz, M; Schallnass, H J

1997-04-01

The study presented here describes the development of a laboratory test system for the determination of aerobic biodegradability of substances at low concentrations in surface water. It was aimed to prepare a draft guideline for a biodegradation simulation test according to OECD format. The experimental approach was based on a literature study conducted within the frame of this project. Further useful information on the possible test design was derived from the German BBA guideline 5-1. Natural water and sediments were collected. Radiolabelled Lindane or 4-Nitrophenol was added. The test vessels (reactors) were aerated and incubated under controlled conditions for up to 92 days. The results showed biological stability of the sediment/water systems even without addition of nutrients and adherence to non-reducing conditions. Mineralisation of 4-Nitrophenol was influenced by the sediment type, the method of aeration and temperature. Factors affecting the mineralisation of Lindane were the method of application and again, the sediment type and temperature. Considerable amounts of the radioactivity were bound to the sediment and were to a large extent unextractable. The potential of a reactor to mineralise a test substance could not be correlated with the biological parameters measured. (orig.) [Deutsch] Die vorliegende Studie beschreibt die Entwicklung eines Labortestverfahrens zur Pruefung des aeroben Abbaus niedrig konzentrierter Stoffe in Oberflaechengewaessern. Dabei war es ein Ziel, das Verfahren so weit abzusichern, dass ein Entwurf fuer eine Pruefrichtlinie als Simulationstest im Format der OECD-Richtlinien abgefasst werden konnte. Grundlage fuer die Konzeption war eine zuvoerderst durchgefuehrte Literaturstudie. Hinweise auf ein moegliches Testdesign ergaben sich auch aus der BBA-Richtlinie 5-1. Wasser und Sediment wurden der Natur entnommen und nach Zugabe der radioaktiven Pruefsubstanz Lindan oder 4-Nitrophenol in einem beluefteten Gefaess unter

An Efficient Beam Steerable Antenna Array Concept for Airborne Applications

Directory of Open Access Journals (Sweden)

H. Aliakbarian

2014-04-01

Full Text Available Deployment of a satellite borne, steerable antenna array with higher directivity and gain in Low Earth Orbit makes sense to reduce ground station complexity and cost, while still maintaining a reasonable link budget. The implementation comprises a digitally beam steerable phased array antenna integrated with a complete system, comprising the antenna, hosting platform, ground station, and aircraft based satellite emulator to facilitate convenient aircraft based testing of the antenna array and ground-space communication link. This paper describes the design, development and initial successful interim testing of the various subsystems. A two element prototype used in this increases the signal-to-noise ratio (SNR by 3 dB which is corresponding to more than 10 times better bit error rate (BER.

Improvement of LOD in Fluorescence Detection with Spectrally Nonuniform Background by Optimization of Emission Filtering.

Science.gov (United States)

Galievsky, Victor A; Stasheuski, Alexander S; Krylov, Sergey N

2017-10-17

The limit-of-detection (LOD) in analytical instruments with fluorescence detection can be improved by reducing noise of optical background. Efficiently reducing optical background noise in systems with spectrally nonuniform background requires complex optimization of an emission filter-the main element of spectral filtration. Here, we introduce a filter-optimization method, which utilizes an expression for the signal-to-noise ratio (SNR) as a function of (i) all noise components (dark, shot, and flicker), (ii) emission spectrum of the analyte, (iii) emission spectrum of the optical background, and (iv) transmittance spectrum of the emission filter. In essence, the noise components and the emission spectra are determined experimentally and substituted into the expression. This leaves a single variable-the transmittance spectrum of the filter-which is optimized numerically by maximizing SNR. Maximizing SNR provides an accurate way of filter optimization, while a previously used approach based on maximizing a signal-to-background ratio (SBR) is the approximation that can lead to much poorer LOD specifically in detection of fluorescently labeled biomolecules. The proposed filter-optimization method will be an indispensable tool for developing new and improving existing fluorescence-detection systems aiming at ultimately low LOD.

Partial relay selection in underlay cognitive networks with fixed gain relays

KAUST Repository

Hussain, Syed Imtiaz; Alouini, Mohamed-Slim; Hasna, Mazen Omar; Qaraqe, Khalid A.

2012-01-01

In a communication system with multiple cooperative relays, selecting the best relay utilizes the available spectrum more efficiently. However, selective relaying poses a different problem in underlay cognitive networks compared to the traditional cooperative networks due to interference thresholds to the primary users. In most cases, a best relay is the one which provides the maximum end-to-end signal to noise ratio (SNR). This approach needs plenty of instantaneous channel state information (CSI). The CSI burden could be reduced by partial relay selection. In this paper, a partial relay selection scheme is presented and analyzed for an underlay cognitive network with fixed gain relays operating in the vicinity of a primary user. The system model is adopted in a way that each node needs minimal CSI to perform its task. The best relay is chosen on the basis of maximum source to relay link SNR which then forwards the message to the destination. We derive closed form expressions for the received SNR distributions, system outage, probability of bit error and average channel capacity of the system. The derived results are confirmed through simulations. © 2012 IEEE.

Partial relay selection in underlay cognitive networks with fixed gain relays

KAUST Repository

Hussain, Syed Imtiaz

2012-05-01

In a communication system with multiple cooperative relays, selecting the best relay utilizes the available spectrum more efficiently. However, selective relaying poses a different problem in underlay cognitive networks compared to the traditional cooperative networks due to interference thresholds to the primary users. In most cases, a best relay is the one which provides the maximum end-to-end signal to noise ratio (SNR). This approach needs plenty of instantaneous channel state information (CSI). The CSI burden could be reduced by partial relay selection. In this paper, a partial relay selection scheme is presented and analyzed for an underlay cognitive network with fixed gain relays operating in the vicinity of a primary user. The system model is adopted in a way that each node needs minimal CSI to perform its task. The best relay is chosen on the basis of maximum source to relay link SNR which then forwards the message to the destination. We derive closed form expressions for the received SNR distributions, system outage, probability of bit error and average channel capacity of the system. The derived results are confirmed through simulations. © 2012 IEEE.

Echo-planar MR imaging of dissolved hyperpolarized 129Xe. Potential for M angiography

International Nuclear Information System (INIS)

Maansson, S.

2002-01-01

Purpose: The feasibility of hyperpolarized 129 Xe for fast MR angiography (MRA) was evaluated using the echo-planar imaging (EPI) technique. Material and Methods: Hyperpolarized Xe gas was dissolved in ethanol; a carrier agent with high solubility for Xe (Ostwald solubility coefficient 2.5) and long relaxation times. The dissolved Xe was injected as a bolus into a flow phantom where the mean flow velocity was 15 cm/s. Ultrafast EPI images with 44 ms scan time were acquired of the flowing bolus and the signal-to-noise ratios (SNR) were measured. Results: The relaxation times of hyperpolarized Xe in ethanol were measured to T1=160±11 s and T2 ≅ 20 s. The resulting images of the flowing liquid were of reasonable quality and had an SNR of about 70. Conclusion: Based on the SNR of the obtained Xe EPI images; it was estimated that rapid in vivo MRA with 129 Xe may be feasible; provided that an efficient; biologically acceptable carrier for Xe can be found and polarization levels of more than 25% can be achieved in isotopically enriched 129 Xe

Bidirectional Fano Algorithm for Lattice Coded MIMO Channels

KAUST Repository

Al-Quwaiee, Hessa

2013-05-08

Recently, lattices - a mathematical representation of infinite discrete points in the Euclidean space, have become an effective way to describe and analyze communication systems especially system those that can be modeled as linear Gaussian vector channel model. Channel codes based on lattices are preferred due to three facts: lattice codes have simple structure, the code can achieve the limits of the channel, and they can be decoded efficiently using lattice decoders which can be considered as the Closest Lattice Point Search (CLPS). Since the time lattice codes were introduced to Multiple Input Multiple Output (MIMO) channel, Sphere Decoder (SD) has been an efficient way to implement lattice decoders. Sphere decoder offers the optimal performance at the expense of high decoding complexity especially for low signal-to-noise ratios (SNR) and for high- dimensional systems. On the other hand, linear and non-linear receivers, Minimum Mean Square Error (MMSE), and MMSE Decision-Feedback Equalization (DFE), provide the lowest decoding complexity but unfortunately with poor performance. Several studies works have been conducted in the last years to address the problem of designing low complexity decoders for the MIMO channel that can achieve near optimal performance. It was found that sequential decoders using backward tree 
search can bridge the gap between SD and MMSE. The sequential decoder provides an interesting performance-complexity trade-off using a bias term. Yet, the sequential decoder still suffers from high complexity for mid-to-high SNR values. In this work, we propose a new algorithm for Bidirectional Fano sequential Decoder (BFD) in order to reduce the mid-to-high SNR complexity. Our algorithm consists of first constructing a unidirectional Sequential Decoder based on forward search using the QL decomposition. After that, BFD incorporates two searches, forward and backward, to work simultaneously till they merge and find the closest lattice point to the

Regional Cooperation Efforts in the Mekong River Basin: Mitigating river-related security threats and promoting regional development

Directory of Open Access Journals (Sweden)

Susanne Schmeier

2009-01-01

Full Text Available The development of international rivers is often perceived as leading to conflicts or even water wars. However, as the development of the Mekong River shows, cooperation has not only prevailed in the last decades, but River Basin Organizations (RBOs, established to mitigate river-related conflicts and/or develop the river basin, have also contributed to the emergence of more general cooperation structures, mainly by creating spill-over effects in other issue-areas, bringing cooperation to policy fields beyond the river itself. This article assesses the contribution of the Mekong River Commission (MRC and the Greater Mekong Sub-Region (GMS to the sustainable development of the Mekong Region as well as to the promotion of regional cooperation in mainland South-East Asia in general. --- Die Entwicklung grenzüberschreitender Flüsse wird oft mit Konflikten oder gar Kriegen um Wasser assoziiert. Wie jedoch die Entwicklung im Mekong-Becken zeigt, waren die vergangenen Jahrzehnte nicht nur von Kooperation gezeichnet, sondern Flussbeckenorganisationen konnten außerdem dazu beitragen, weitreichendere Kooperationsstrukturen zu entwickeln, die sich auf andere Politikfelder ausdehnen. Dieser Artikel beschäftigt sich mit dem Beitrag der Mekong River Commission (MRC und der Greater Mekong Sub-Region (GMS zur nachhaltigen Entwicklung in der Mekong Region sowie zur Förderung allgemeiner regionaler Kooperation im Festländischen Südostasien.

Quantum Illumination-Based Target Detection and Discrimination

Science.gov (United States)

2014-06-30

photodiode with an estimated quantum efficiency of 85% and an ultralow-noise transimpedance amplifier . Compared with to our initial QI measurements...demonstrated high signal-to-noise ratio (SNR) quantum-illumination target detection in a lossy, noisy environment using an optical parametric amplifier ...Research Triangle Park, NC 27709-2211 quantum communication, target detection, entanglement, parametric downconversion, optical parametric amplifiers

Interaction of kaolin containing ores with natrium and calcium chlorides

International Nuclear Information System (INIS)

Sokhibov, I.Sh.; Dadabaeva, G.; Mirzoev, B.; Safiev, H.; Boboev, Kh.E.

1997-01-01

The impact of different factors on ore agglomeration at presence of carbon activators CaCl 2 and NaCl 2 was studied. The impact of different factors on water and hydrochloric acid processing of obtained cake was studied as well. The temperature influence was studied at temperature range 600-1000 deg C during 90 min sintering. The obtained cakes were leached by water in acid medium and were used as coagulants for water purification from suspended matters.

The low fault HTSL-SQUID cooling system. Final report; Stoerarmes HTSL-SQUID-Kuehlsystem. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Binneberg, A.; Spoerl, G.; Buschmann, H.

1997-03-01

In the context of the research project, work was done for HTSL-SQUID on (1) the development of a thermo-siphon cooler (low fault and continuously working) and (2) the development of a latent storage cooler (low fault and discontinuously working). Two development versions of the latent storage cooler were followed up, the development of a spherical latent storage cooler and the development of an annular vessel latent storage cooler. A further precondition for the construction of the cooler was the use of split Stirling refrigerators as units producing the cold. The experimental sample was built up with refrigerators which could produce a nominal cooling output of 1.2 W at 80 K. Two samples of the thermo-siphon cooler were built, tested and improved. The second sample was developed further as a demonstration model, introduced at meetings and prepared for testing the cooling of HTSL-SQUIDs. The thermo-siphon cooler can be designed for cooling output up to about 2 W at 80 K and can be used controlled for a temperature range of 90 K to 66 K. (orig./MM) [Deutsch] Im Rahmen des Forschungsvorhabens wurde fuer HTSL-SQUID`s an der (1) Entwicklung eines Thermosiphon-Kuehlers (stoerarm und kontinuierlich arbeitend) und (2) Entwicklung eines Latentspeicher-Kuehlers (stoerfrei und diskontinuierlich arbeitend) gearbeitet. Bei dem Latentspeicher-Kuehler wurden zwei Entwicklungsversionen verfolgt, und zwar Entwicklung eines Kugel-Latentspeicher-Kuehlers und Entwicklung eines Ringgefaess-Latentspeicher-Kuehlers. Eine weitere Praemisse zum Aufbau der Kuehler war der Einsatz von Split-Stirling-Kaeltemaschinen als kaelteerzeugende Baugruppe. Die Versuchsmuster wurden mit Kaeltemaschinen aufgebaut, die eine Nennkuehlleistung von 1,2 W bei 80 K erzeugen konnten. Der Thermosiphon-Kuehler wurde in zwei Musterexemplaren aufgebaut, erprobt und verbessert. Das Zweitmuster wurde als Demonstrator weiterentwickelt, zu Fachtagungen vorgestellt und zur Testung der Kuehlung von HTSL