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Sample records for amplifies stent-based drug

  1. Luminal flow amplifies stent-based drug deposition in arterial bifurcations.

    Directory of Open Access Journals (Sweden)

    Vijaya B Kolachalama

    2009-12-01

    Full Text Available Treatment of arterial bifurcation lesions using drug-eluting stents (DES is now common clinical practice and yet the mechanisms governing drug distribution in these complex morphologies are incompletely understood. It is still not evident how to efficiently determine the efficacy of local drug delivery and quantify zones of excessive drug that are harbingers of vascular toxicity and thrombosis, and areas of depletion that are associated with tissue overgrowth and luminal re-narrowing.We constructed two-phase computational models of stent-deployed arterial bifurcations simulating blood flow and drug transport to investigate the factors modulating drug distribution when the main-branch (MB was treated using a DES. Simulations predicted extensive flow-mediated drug delivery in bifurcated vascular beds where the drug distribution patterns are heterogeneous and sensitive to relative stent position and luminal flow. A single DES in the MB coupled with large retrograde luminal flow on the lateral wall of the side-branch (SB can provide drug deposition on the SB lumen-wall interface, except when the MB stent is downstream of the SB flow divider. In an even more dramatic fashion, the presence of the SB affects drug distribution in the stented MB. Here fluid mechanic effects play an even greater role than in the SB especially when the DES is across and downstream to the flow divider and in a manner dependent upon the Reynolds number.The flow effects on drug deposition and subsequent uptake from endovascular DES are amplified in bifurcation lesions. When only one branch is stented, a complex interplay occurs - drug deposition in the stented MB is altered by the flow divider imposed by the SB and in the SB by the presence of a DES in the MB. The use of DES in arterial bifurcations requires a complex calculus that balances vascular and stent geometry as well as luminal flow.

  2. Gastric Outlet Obstruction Palliation: A Novel Stent-Based Solution

    Directory of Open Access Journals (Sweden)

    Natasha M. Rueth

    2010-06-01

    Full Text Available Gastric outlet obstruction (GOO after esophagectomy is a morbid outcome and significantly hinders quality of life for end-stage esophageal cancer patients. In the pre-stent era, palliation consisted of chemotherapy, radiation, tumor ablation, or stricture dilation. In the current era, palliative stenting has emerged as an additional tool; however, migration and tumor ingrowth are ongoing challenges. To mitigate these challenges, we developed a novel, hybrid, stent-based approach for the palliative management of GOO. We present a patient with esophageal cancer diagnosed with recurrent, metastatic disease 1 year after esophagectomy. She developed dehydration and intractable emesis, which significantly interfered with her quality of life. For palliation, we dilated the stenosis and proceeded with our stent-based solution. Using a combined endoscopic and fluoroscopic approach, we placed a 12-mm silicone salivary bypass tube across the pylorus, where it kinked slightly because of local tumor biology. To bridge this defect and ensure luminal patency, we placed a nitinol tracheobronchial stent through the silicone stent. Clinically, the patient had immediate relief from her pre-operative symptoms and was discharged home on a liquid diet. In conclusion, GOO and malignant dysphagia after esophagectomy are significant challenges for patients with end-stage disease. Palliative stenting is a viable option, but migration and tumor ingrowth are common complications. The hybrid approach presented here provides a unique solution to these potential pitfalls. The flared silicone tube minimized the chance of migration and impaired tumor ingrowth. The nitinol stent aided with patency and overcame the challenges of the soft tube. This novel strategy achieved palliation, describing another endoscopic option in the treatment of malignant GOO.

  3. Fiber Amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten

    2017-01-01

    The chapter provides a discussion of optical fiber amplifiers and through three sections provides a detailed treatment of three types of optical fiber amplifiers, erbium doped fiber amplifiers (EDFA), Raman amplifiers, and parametric amplifiers. Each section comprises the fundamentals including...... the basic physics and relevant in-depth theoretical modeling, amplifiers characteristics and performance data as a function of specific operation parameters. Typical applications in fiber optic communication systems and the improvement achievable through the use of fiber amplifiers are illustrated....

  4. Field-amplified sample stacking capillary electrophoresis with electrochemiluminescence applied to the determination of illicit drugs on banknotes.

    Science.gov (United States)

    Xu, Yuanhong; Gao, Ying; Wei, Hui; Du, Yan; Wang, Erkang

    2006-05-19

    Capillary electrophoresis (CE) with Ru(bpy)3(2+) electrochemiluminescence (ECL) detection system was established to the determination of contamination of banknotes with controlled drugs and a high efficiency on-column field-amplified sample stacking (FASS) technique was also optimized to increase the ECL intensity. The method was illustrated using heroin and cocaine, which are two typical and popular illicit drugs. Highest sample stacking was obtained when 0.01 mM acetic acid was chosen for sample dissolution with electrokinetical injection for 6 s at 17 kV. Under the optimized conditions: ECL detection at 1.2 V, separation voltage 10.0 kV, 20 mM phosphate-acetate (pH 7.2) as running buffer, 5 mM Ru(bpy)3(2+) with 50 mM phosphate-acetate (pH 7.2) in the detection cell, the standard curves were linear in the range of 7.50x10(-8) to 1.00x10(-5) M for heroin and 2.50x10(-7) to 1.00x10(-4) M for cocaine and detection limits of 50 nM for heroin and 60 nM for cocaine were achieved (S/N = 3), respectively. Relative standard derivations of the ECL intensity and the migration time were 3.50 and 0.51% for heroin and 4.44 and 0.12% for cocaine, respectively. The developed method was successfully applied to the determination of heroin and cocaine on illicit drug contaminated banknotes without any damage of the paper currency. A baseline resolution for heroin and cocaine was achieved within 6 min.

  5. Operation amplifier

    NARCIS (Netherlands)

    Tetsuya, Saito; Nauta, Bram

    2008-01-01

    To provide an operation amplifier which improves power source voltage removal ratios while assuring phase compensation characteristics, and therefore can be realized with a small-scale circuit and low power consumption. SOLUTION: The operation amplifier comprises: a differential amplifier circuit 1;

  6. Operational amplifiers

    CERN Document Server

    Dostal, Jiri

    1993-01-01

    This book provides the reader with the practical knowledge necessary to select and use operational amplifier devices. It presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits.Provides the reader with practical knowledge necessary to select and use operational amplifier devices. Presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits

  7. Operation Amplifier

    NARCIS (Netherlands)

    Tetsuya, Saito; Nauta, Bram

    2011-01-01

    PROBLEM TO BE SOLVED: To provide an operation amplifier which improves power source voltage removal ratios while assuring phase compensation characteristics, and therefore can be realized with a small-scale circuit and low power consumption. SOLUTION: The operation amplifier comprises: a

  8. Operation Amplifier

    NARCIS (Netherlands)

    Tetsuya, S.; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an operation amplifier which improves power source voltage removal ratios while assuring phase compensation characteristics, and therefore can be realized with a small-scale circuit and low power consumption. ; SOLUTION: The operation amplifier comprises: a

  9. Amplifier Distortion

    Science.gov (United States)

    Keeports, David

    2006-12-01

    By definition, a high fidelity amplifier's instantaneous output voltage is directly proportional to its instantaneous input voltage. While high fidelity is generally valued in the amplification of recorded music, nonlinearity, also known as distortion, is desirable in the amplification of some musical instruments. In particular, guitar amplifiers exploit nonlinearity to increase both the harmonic content and sustain of a guitar's sound. I will discuss how both modifications in sound result from saturation of triode tubes and transistors. Additionally, I will describe the difference in the symmetry of saturation curves for transistors and tubes and the reason why tube guitar amplifiers are generally considered to be superior to solid-state amplifiers. Finally, I will discuss attempts to use solid-state electronics to replicate the sound of tube amplifiers.

  10. Evaluation of a Bioabsorbable Self-Expandable Vein Stent-Base Made of Poly(l-lactide) In Vitro and In Vivo

    Energy Technology Data Exchange (ETDEWEB)

    Løvdal, Alexandra Liv Vest, E-mail: alvlo@nanotech.dtu.dk [Technical University of Denmark, Department of Micro- and Nanotechnology (Denmark); Calve, Sarah [Purdue University, Weldon School of Biomedical Engineering (United States); Yang, Shuo; Alstine, William Van [Cook Research Incorporated (United States); Binkert, Christoph A. [Institut für Radiologie, Kantonsspital Winterthur (Switzerland); Klausen, Kasper [William Cook Europe (Denmark)

    2017-01-15

    PurposeThis study was designed to evaluate performance and tissue response to a self-expandable bioabsorbable vein stent-base cut from a tube with enhanced stiffness and strength in vitro and in vivo.MethodsA diamond-shaped stent-base was cut from a sequential biaxially strained poly(l-lactide) (PLLA) tube for optimized performance. The performance of the stent-base was evaluated in a finite element analysis model, and validation was attempted in vitro through a cyclic flat-plate compression and radial force measurement. The performance of the stent-base was tested in vivo using 3 sheep with 2 implants each for 2 and 3½ weeks, respectively.ResultsIn vitro the stent-base showed an elliptical deformation but no fractures. In vivo the stent-base showed adequate radial force and no migration. All implanted stent-bases showed multiple fractures not only at the predicted stress zones but at all connecting points. Fragments of the caudal stent-base stayed in the vein wall indicating sufficient tissue coverage to avoid embolization of the fractured stent pieces, whereas fragments from the cranial device remaining were few. Neointima formation was confirmed histologically at 2 and 3½ weeks.ConclusionA bioabsorbable self-expandable stent-base made from PLLA for large veins seems feasible, but over time, the PLLA used in this study appears too stiff and lacks the sufficient flexibility to move with the vena cava, causing multiple fractures.

  11. Evaluation of a Bioabsorbable Self-Expandable Vein Stent-Base Made of Poly(l-lactide) In Vitro and In Vivo

    International Nuclear Information System (INIS)

    Løvdal, Alexandra Liv Vest; Calve, Sarah; Yang, Shuo; Alstine, William Van; Binkert, Christoph A.; Klausen, Kasper

    2017-01-01

    PurposeThis study was designed to evaluate performance and tissue response to a self-expandable bioabsorbable vein stent-base cut from a tube with enhanced stiffness and strength in vitro and in vivo.MethodsA diamond-shaped stent-base was cut from a sequential biaxially strained poly(l-lactide) (PLLA) tube for optimized performance. The performance of the stent-base was evaluated in a finite element analysis model, and validation was attempted in vitro through a cyclic flat-plate compression and radial force measurement. The performance of the stent-base was tested in vivo using 3 sheep with 2 implants each for 2 and 3½ weeks, respectively.ResultsIn vitro the stent-base showed an elliptical deformation but no fractures. In vivo the stent-base showed adequate radial force and no migration. All implanted stent-bases showed multiple fractures not only at the predicted stress zones but at all connecting points. Fragments of the caudal stent-base stayed in the vein wall indicating sufficient tissue coverage to avoid embolization of the fractured stent pieces, whereas fragments from the cranial device remaining were few. Neointima formation was confirmed histologically at 2 and 3½ weeks.ConclusionA bioabsorbable self-expandable stent-base made from PLLA for large veins seems feasible, but over time, the PLLA used in this study appears too stiff and lacks the sufficient flexibility to move with the vena cava, causing multiple fractures.

  12. Evaluation of a Bioabsorbable Self-Expandable Vein Stent-Base Made of Poly(L-lactide) In Vitro and In Vivo

    DEFF Research Database (Denmark)

    Løvdal, Alexandra Liv Vest; Calve, Sarah; Yang, Shuo

    2017-01-01

    Purpose  This study was designed to evaluate performance and tissue response to a self-expandable bioabsorbable vein stent-base cut from a tube with enhanced stiffness and strength in vitro and in vivo. Methods  A diamond-shaped stent-base was cut from a sequential biaxially strained poly(L-lacti...

  13. Arrhythmogenic drugs can amplify spatial heterogeneities in the electrical restitution in perfused guinea-pig heart: An evidence from assessments of monophasic action potential durations and JT intervals.

    Science.gov (United States)

    Osadchii, Oleg E

    2018-01-01

    Non-uniform shortening of the action potential duration (APD90) in different myocardial regions upon heart rate acceleration can set abnormal repolarization gradients and promote arrhythmia. This study examined whether spatial heterogeneities in APD90 restitution can be amplified by drugs with clinically proved proarrhythmic potential (dofetilide, quinidine, procainamide, and flecainide) and, if so, whether these effects can translate to the appropriate changes of the ECG metrics of ventricular repolarization, such as JT intervals. In isolated, perfused guinea-pig heart preparations, monophasic action potentials and volume-conducted ECG were recorded at progressively increased pacing rates. The APD90 measured at distinct ventricular sites, as well as the JTpeak and JTend values were plotted as a function of preceding diastolic interval, and the maximum slopes of the restitution curves were determined at baseline and upon drug administration. Dofetilide, quinidine, and procainamide reverse rate-dependently prolonged APD90 and steepened the restitution curve, with effects being greater at the endocardium than epicardium, and in the right ventricular (RV) vs. the left ventricular (LV) chamber. The restitution slope was increased to a greater extent for the JTend vs. the JTpeak interval. In contrast, flecainide reduced the APD90 restitution slope at LV epicardium without producing effect at LV endocardium and RV epicardium, and reduced the JTpeak restitution slope without changing the JTend restitution. Nevertheless, with all agents, these effects translated to the amplified epicardial-to-endocardial and the LV-to-RV non-uniformities in APD90 restitution, paralleled by the increased JTend vs. JTpeak difference in the restitution slope. In summary, these findings suggest that arrhythmic drug profiles are partly attributable to the accentuated regional heterogeneities in APD90 restitution, which can be indirectly determined through ECG assessments of the JTend vs. JTpeak

  14. Arrhythmogenic drugs can amplify spatial heterogeneities in the electrical restitution in perfused guinea-pig heart: An evidence from assessments of monophasic action potential durations and JT intervals.

    Directory of Open Access Journals (Sweden)

    Oleg E Osadchii

    Full Text Available Non-uniform shortening of the action potential duration (APD90 in different myocardial regions upon heart rate acceleration can set abnormal repolarization gradients and promote arrhythmia. This study examined whether spatial heterogeneities in APD90 restitution can be amplified by drugs with clinically proved proarrhythmic potential (dofetilide, quinidine, procainamide, and flecainide and, if so, whether these effects can translate to the appropriate changes of the ECG metrics of ventricular repolarization, such as JT intervals. In isolated, perfused guinea-pig heart preparations, monophasic action potentials and volume-conducted ECG were recorded at progressively increased pacing rates. The APD90 measured at distinct ventricular sites, as well as the JTpeak and JTend values were plotted as a function of preceding diastolic interval, and the maximum slopes of the restitution curves were determined at baseline and upon drug administration. Dofetilide, quinidine, and procainamide reverse rate-dependently prolonged APD90 and steepened the restitution curve, with effects being greater at the endocardium than epicardium, and in the right ventricular (RV vs. the left ventricular (LV chamber. The restitution slope was increased to a greater extent for the JTend vs. the JTpeak interval. In contrast, flecainide reduced the APD90 restitution slope at LV epicardium without producing effect at LV endocardium and RV epicardium, and reduced the JTpeak restitution slope without changing the JTend restitution. Nevertheless, with all agents, these effects translated to the amplified epicardial-to-endocardial and the LV-to-RV non-uniformities in APD90 restitution, paralleled by the increased JTend vs. JTpeak difference in the restitution slope. In summary, these findings suggest that arrhythmic drug profiles are partly attributable to the accentuated regional heterogeneities in APD90 restitution, which can be indirectly determined through ECG assessments of the

  15. Development and application of stent-based image guided navigation system for oral and maxillofacial surgery

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Woo Jin; Kim, Dae Seung [Interdisciplinary Program in Radiation Applied Life Science, Dental Research Institute and BK21, College of Medicine, Seoul National University, Seoul (Korea, Republic of); Yi, Won Jin; Lee, Sam Sun; Choi, Soon Chul; Heo, Min Suk; Huh, Kyung Hoe; Kim, Myung Jin; Lee, Jee Ho [Department of Oral and Maxillofacial Surgery, Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2009-09-15

    The purpose of this study was to develop a stent-based image guided surgery system and to apply it to oral and maxillofacial surgeries for anatomically complex sites. We devised a patient-specific stent for patient-to-image registration and navigation. Three dimensional positions of the reference probe and the tool probe were tracked by an optical camera system and the relative position of the handpiece drill tip to the reference probe was monitored continuously on the monitor of a PC. Using 8 landmarks for measuring accuracy, the spatial discrepancy between CT image coordinate and physical coordinate was calculated for testing the normality. The accuracy over 8 anatomical landmarks showed an overall mean of 0.56 {+-} 0.16 mm. The developed system was applied to a surgery for a vertical alveolar bone augmentation in right mandibular posterior area and possible interior alveolar nerve injury case of an impacted third molar. The developed system provided continuous monitoring of invisible anatomical structures during operation and 3D information for operation sites. The clinical challenge showed sufficient accuracy and availability of anatomically complex operation sites. The developed system showed sufficient accuracy and availability in oral and maxillofacial surgeries for anatomically complex sites.

  16. Development and application of stent-based image guided navigation system for oral and maxillofacial surgery

    International Nuclear Information System (INIS)

    Lee, Woo Jin; Kim, Dae Seung; Yi, Won Jin; Lee, Sam Sun; Choi, Soon Chul; Heo, Min Suk; Huh, Kyung Hoe; Kim, Myung Jin; Lee, Jee Ho

    2009-01-01

    The purpose of this study was to develop a stent-based image guided surgery system and to apply it to oral and maxillofacial surgeries for anatomically complex sites. We devised a patient-specific stent for patient-to-image registration and navigation. Three dimensional positions of the reference probe and the tool probe were tracked by an optical camera system and the relative position of the handpiece drill tip to the reference probe was monitored continuously on the monitor of a PC. Using 8 landmarks for measuring accuracy, the spatial discrepancy between CT image coordinate and physical coordinate was calculated for testing the normality. The accuracy over 8 anatomical landmarks showed an overall mean of 0.56 ± 0.16 mm. The developed system was applied to a surgery for a vertical alveolar bone augmentation in right mandibular posterior area and possible interior alveolar nerve injury case of an impacted third molar. The developed system provided continuous monitoring of invisible anatomical structures during operation and 3D information for operation sites. The clinical challenge showed sufficient accuracy and availability of anatomically complex operation sites. The developed system showed sufficient accuracy and availability in oral and maxillofacial surgeries for anatomically complex sites.

  17. Development of SCAR (sequence-characterized amplified region) markers as a complementary tool for identification of ginger (Zingiber officinale Roscoe) from crude drugs and multicomponent formulations.

    Science.gov (United States)

    Chavan, Preeti; Warude, Dnyaneshwar; Joshi, Kalpana; Patwardhan, Bhushan

    2008-05-01

    Zingiber officinale Roscoe (common or culinary ginger) is an official drug in Ayurvedic, Indian herbal, Chinese, Japanese, African and British Pharmacopoeias. The objective of the present study was to develop DNA-based markers that can be applied for the identification and differentiation of the commercially important plant Z. officinale Roscoe from the closely related species Zingiber zerumbet (pinecone, bitter or 'shampoo' ginger) and Zingiber cassumunar [cassumunar or plai (Thai) ginger]. The rhizomes of the other two Zingiber species used in the present study are morphologically similar to that of Z. officinale Roscoe and can be used as its adulterants or contaminants. Various methods, including macroscopy, microscopy and chemoprofiling, have been reported for the quality control of crude ginger and its products. These methods are reported to have limitations in distinguishing Z. officinale from closely related species. Hence, newer complementary methods for correct identification of ginger are useful. In the present study, RAPD (random amplification of polymorphic DNA) analysis was used to identify putative species-specific amplicons for Z. officinale. These were further cloned and sequenced to develop SCAR (sequence-characterized amplified region) markers. The developed SCAR markers were tested in several non-Zingiber species commonly used in ginger-containing formulations. One of the markers, P3, was found to be specific for Z. officinale and was successfully applied for detection of Z. officinale from Trikatu, a multicomponent formulation.

  18. Amplifier for nuclear spectrometry

    International Nuclear Information System (INIS)

    Suarez Canner, E.

    1996-01-01

    The spectroscopy amplifier model AE-020 is designed to adjust suitable the pulses coming from nuclear radiation detectors. Due to is capacity and specifications, the amplifier can be used together with high and medium resolution spectroscopy system

  19. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ; SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and

  20. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2010-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ;SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and can

  1. RF power amplifiers

    CERN Document Server

    Albulet, Mihai

    2001-01-01

    This text presents a full account of RF amplifiers and provides a thorough understanding of power amplifier principles and their applications. This comprehensive book covers all important design techniques for power amplifiers and includes mathematical derivations and the assumptions used to develop design rules.

  2. Wireless Josephson amplifier

    International Nuclear Information System (INIS)

    Narla, A.; Sliwa, K. M.; Hatridge, M.; Shankar, S.; Frunzio, L.; Schoelkopf, R. J.; Devoret, M. H.

    2014-01-01

    Josephson junction parametric amplifiers are playing a crucial role in the readout chain in superconducting quantum information experiments. However, their integration with current 3D cavity implementations poses the problem of transitioning between waveguide, coax cables, and planar circuits. Moreover, Josephson amplifiers require auxiliary microwave components, like directional couplers and/or hybrids, that are sources of spurious losses and impedance mismatches that limit measurement efficiency and amplifier tunability. We have developed a wireless architecture for these parametric amplifiers that eliminates superfluous microwave components and interconnects. This greatly simplifies their assembly and integration into experiments. We present an experimental realization of such a device operating in the 9–11 GHz band with about 100 MHz of amplitude gain-bandwidth product, on par with devices mounted in conventional sample holders. The simpler impedance environment presented to the amplifier also results in increased amplifier tunability.

  3. Antares laser power amplifier

    International Nuclear Information System (INIS)

    Stine, R.D.; Ross, G.F.; Silvernail, C.

    1979-01-01

    The overall design of the Antares laser power amplifier is discussed. The power amplifier is the last stage of amplification in the 100-kJ Antares laser. In the power amplifier a single, cylindrical, grid-controlle, cold-cathode electron gun is surrounded by 12 large-aperture CO 2 electron-beam sustained laser discharge sectors. Each power amplifier will deliver 18 kJ and the six modules used in Antares will produce the required 100 kJ for delivery to the target. A large-scale interaction between optical, mechanical, and electrical disciplines is required to meet the design objectives. Significant component advances required by the power amplifier design are discussed

  4. Digital automatic gain amplifier

    Science.gov (United States)

    Holley, L. D.; Ward, J. O. (Inventor)

    1978-01-01

    A circuit is described for adjusting the amplitude of a reference signal to a predetermined level so as to permit subsequent data signals to be interpreted correctly. The circuit includes an operational amplifier having a feedback circuit connected between an output terminal and an input terminal; a bank of relays operably connected to a plurality of resistors; and a comparator comparing an output voltage of the amplifier with a reference voltage and generating a compared signal responsive thereto. Means is provided for selectively energizing the relays according to the compared signal from the comparator until the output signal from the amplifier equals to the reference signal. A second comparator is provided for comparing the output of the amplifier with a second voltage source so as to illuminate a lamp when the output signal from the amplifier exceeds the second voltage.

  5. Auto-Zero Differential Amplifier

    Science.gov (United States)

    Quilligan, Gerard T. (Inventor); Aslam, Shahid (Inventor)

    2017-01-01

    An autozero amplifier may include a window comparator network to monitor an output offset of a differential amplifier. The autozero amplifier may also include an integrator to receive a signal from a latched window comparator network, and send an adjustment signal back to the differential amplifier to reduce an offset of the differential amplifier.

  6. Noise in Optical Amplifiers

    DEFF Research Database (Denmark)

    Jeppesen, Palle

    1997-01-01

    Noise in optical amplifiers is discussed on the basis of photons and electromagntic fields. Formulas for quantum noise from spontaneous emission, signal-spontaneous beat noise and spontaneous-spontaneous beat noise are derived.......Noise in optical amplifiers is discussed on the basis of photons and electromagntic fields. Formulas for quantum noise from spontaneous emission, signal-spontaneous beat noise and spontaneous-spontaneous beat noise are derived....

  7. Electrospun amplified fiber optics.

    Science.gov (United States)

    Morello, Giovanni; Camposeo, Andrea; Moffa, Maria; Pisignano, Dario

    2015-03-11

    All-optical signal processing is the focus of much research aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for efficient signal transmission. However, the complex fabrication methods involving high-temperature processes performed in a highly pure environment slow the fabrication process and make amplified components expensive with respect to an ideal, high-throughput, room temperature production. Here, we report on near-infrared polymer fiber amplifiers working over a band of ∼20 nm. The fibers are cheap, spun with a process entirely carried out at room temperature, and shown to have amplified spontaneous emission with good gain coefficients and low levels of optical losses (a few cm(-1)). The amplification process is favored by high fiber quality and low self-absorption. The found performance metrics appear to be suitable for short-distance operations, and the large variety of commercially available doping dyes might allow for effective multiwavelength operations by electrospun amplified fiber optics.

  8. Fast pulse amplifier

    International Nuclear Information System (INIS)

    Lepetit, J.; Poussier, E.

    1984-01-01

    This amplifier comprises an inverter transformer, the primary circuit of which receives a pulse and the secondary circuit of which is connected to several amplifying elements in parallel. The inverter transformer is made of coaxial cable segments winded around a magnetic torus; the cable cores connected in series constitute the primary circuit and the braiding of cables, connected in parallel, are the secondary circuit. The transformer comprises, besides, delay lines in series with each braiding of the secondary circuit, these ones are such that pulses issued from each braiding arrive together to the secondary circuit connectors. This invention applies, noticeably in the case of a high voltage amplifier, to the control of deflection blocks of particles used in medicine or in particle accelerators [fr

  9. A micropower electrocardiogram amplifier.

    Science.gov (United States)

    Fay, L; Misra, V; Sarpeshkar, R

    2009-10-01

    We introduce an electrocardiogram (EKG) preamplifier with a power consumption of 2.8 muW, 8.1 muVrms input-referred noise, and a common-mode rejection ratio of 90 dB. Compared to previously reported work, this amplifier represents a significant reduction in power with little compromise in signal quality. The improvement in performance may be attributed to many optimizations throughout the design including the use of subthreshold transistor operation to improve noise efficiency, gain-setting capacitors versus resistors, half-rail operation wherever possible, optimal power allocations among amplifier blocks, and the sizing of devices to improve matching and reduce noise. We envision that the micropower amplifier can be used as part of a wireless EKG monitoring system powered by rectified radio-frequency energy or other forms of energy harvesting like body vibration and body heat.

  10. Electronic amplifiers for automatic compensators

    CERN Document Server

    Polonnikov, D Ye

    1965-01-01

    Electronic Amplifiers for Automatic Compensators presents the design and operation of electronic amplifiers for use in automatic control and measuring systems. This book is composed of eight chapters that consider the problems of constructing input and output circuits of amplifiers, suppression of interference and ensuring high sensitivity.This work begins with a survey of the operating principles of electronic amplifiers in automatic compensator systems. The succeeding chapters deal with circuit selection and the calculation and determination of the principal characteristics of amplifiers, as

  11. Simplified design of IC amplifiers

    CERN Document Server

    Lenk, John

    1996-01-01

    Simplified Design of IC Amplifiers has something for everyone involved in electronics. No matter what skill level, this book shows how to design and experiment with IC amplifiers. For experimenters, students, and serious hobbyists, this book provides sufficient information to design and build IC amplifier circuits from 'scratch'. For working engineers who design amplifier circuits or select IC amplifiers, the book provides a variety of circuit configurations to make designing easier.Provides basics for all phases of practical design.Covers the most popular forms for amplif

  12. Building valve amplifiers

    CERN Document Server

    Jones, Morgan

    2013-01-01

    Building Valve Amplifiers is a unique hands-on guide for anyone working with tube audio equipment--as an electronics hobbyist, audiophile or audio engineer. This 2nd Edition builds on the success of the first with technology and technique revisions throughout and, significantly, a major new self-build project, worked through step-by-step, which puts into practice the principles and techniques introduced throughout the book. Particular attention has been paid to answering questions commonly asked by newcomers to the world of the valve, whether audio enthusiasts tackling their first build or

  13. Low Noise Optical Amplifiers

    Science.gov (United States)

    2010-05-01

    Technical University of Denmark, Oersteds Plads 343, DK-2800 Kgs. Lyngby, Denmark lris@fotonik.dtu.dk, karo@fotonik.dtu.dk Abstract: Impact on the second...1990). 9. P. Kylemark, H. Sunnerud, M. Karlsson, and P. A. Andrekson, “Semi-analytic saturation theory of fiber optical parametric amplifiers,” J...a flat broadband gain over 87 nm. 2. Theory In general we consider an electric field consisting of four CW waves, at frequencies ω1 through ω4. In non

  14. Wideband amplifier design

    CERN Document Server

    Hollister, Allen L

    2007-01-01

    In this book, the theory needed to understand wideband amplifier design using the simplest models possible will be developed. This theory will be used to develop algebraic equations that describe particular circuits used in high frequency design so that the reader develops a ""gut level"" understanding of the process and circuit. SPICE and Genesys simulations will be performed to show the accuracy of the algebraic models. By looking at differences between the algebraic equations and the simulations, new algebraic models will be developed that include parameters originally left out of the model

  15. Superconducting digital logic amplifier

    International Nuclear Information System (INIS)

    Przybysz, J.X.

    1989-01-01

    This paper describes a superconducting digital logic amplifier for interfacing between a Josephson junction logic circuit having output current and a higher voltage semiconductor circuit input. The amplifier comprising: an input terminal for connection to a; an output terminal for connection to a semiconductor circuit input; an input, lower critical current, Josephson junction having first and second terminals; a first series string of at least three lower critical current Josephson junctions. The first series string being connected to the first terminal of the input Josephson junction such that the first series string is in series with the input Josephson junction to provide a series combination. The input terminal being connected to the first terminal of the input Josephson junction, and with the critical current of the lower critical current Josephson junctions of the input Josephson junction and the first series Josephson junctions being less than the output current of the low voltage Josephson junction circuit; a second series string of at least four higher critical current Josephson junctions. The second string being connected in parallel with the series combination to provide parallel strings having an upper common connection and a lower common connection. The lower common connection being connected to the second terminal of the input Josephson junction and the upper common connection being connected to the output terminal; and a pulsed DC current source connected the parallel strings at the upper common connection. The DC current source having a current at least equal to the critical current of the higher critical current Josephson junctions

  16. Metatronic transistor amplifier

    Science.gov (United States)

    Chettiar, Uday K.; Engheta, Nader

    2015-10-01

    Utilizing the notion of metamaterials, in recent years the concept of a circuit and lumped circuit elements have been extended to the optical domains, providing the paradigm of optical metatronics, i.e., metamaterial-inspired optical nanocircuitry, as a powerful tool for design and study of more complex systems at the nanoscale. In this paper we present a design for a new metatronic element, namely, a metatronic transistor that functions as an amplifier. As shown by our analytical and numerical paper here, this metatronic transistor provides gain as well as isolation between the input and output ports of such two-port device. The cascadability and fan-out aspects of this element are also explored.

  17. Modeling of semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Mørk, Jesper; Bischoff, Svend; Berg, Tommy Winther

    We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed.......We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed....

  18. CERN: Energy amplifier

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Even under the heavy burden of responsibility as CERN's Director General from 1989-3 the fertile mind of Carlo Rubbia the scientist was never still. A long-time Rubbia 'hobby' has been the search for new sources of nuclear energy, exploiting knowledge and skills from high energy physics. An initial objective was to adopt heavy ion techniques to induce controlled thermonuclear fusion, but in 1994 this quest changed direction. Putting the problems of thermonuclear fusion aside, Rubbia began to explore an alternative route to energy production through controlled nuclear fission. The idea is to use a particle accelerator producing neutrons by spallation (interaction of particles with a target) to feed a fuel/moderator assembly where the neutrons multiply by fission chain reactions. If the energy liberated becomes substantially greater than that needed to drive the accelerator, the process has a net gain and becomes selfsupporting. Hence the name ''Energy Amplifier'' (EA). Similar systems for energy production or for nuclear waste incineration have been proposed at Los Alamos and in Japan and Russia, but appear to require the prior development of innovative linear accelerators. For Rubbia's Amplifier, the requisite accelerator is a reasonable extrapolation of an existing cyclotron such that at the Swiss Paul Scherrer Institute. Moreover, the EA would require fuel rods very similar to those of conventional reactors, rather than demand-ing new technology using liquid fuel loops (molten salts) with on-line separation of radioactive products. Unlike a reactor, the EA's fission reaction is not self-sustaining: it is sub-critical and needs a continuous supply of neutrons from the accelerator. This makes Chernobyl-type meltdowns unlikely: if the accelerator stops, the reaction stops too. Another major advantage is that the old dream of using thorium as a fuel is now made possible. Thorium is not itself fissile, but under neutron

  19. Fully differential cryogenic transistor amplifier

    Science.gov (United States)

    Beev, Nikolai; Kiviranta, Mikko

    2013-10-01

    We have constructed a dc-coupled differential amplifier capable of operating in the 4.2 K-300 K temperature range. The amplifier can be operated at high-bias setting, where it dissipates 5 mW, has noise temperature TN ≈ 0.7 K at RS ≈ 5 kΩ and >40 MHz bandwidth at 4.2 K bath temperature. The bias setting can be adjusted: at our lowest tested setting the amplifier dissipates 2 MHz bandwidth. The 1/f noise corner frequency is a few times 10 kHz. We foresee the amplifier to have an application in the readout of Superconducting Quantum Interference Devices (SQUIDs), Superconducting Tunnel Junction Detectors (STJs) and Transition Edge Sensors (TESes). We have verified the practical use of the amplifier by reading out a 4.2 K 480-SQUID array with 40 MHz bandwidth and <8 × 10-8 Φ0/Hz1/2 flux noise.

  20. Millimeter-wave power amplifiers

    CERN Document Server

    du Preez, Jaco

    2017-01-01

    This book provides a detailed review of millimeter-wave power amplifiers, discussing design issues and performance limitations commonly encountered in light of the latest research. Power amplifiers, which are able to provide high levels of output power and linearity while being easily integrated with surrounding circuitry, are a crucial component in wireless microwave systems. The book is divided into three parts, the first of which introduces readers to mm-wave wireless systems and power amplifiers. In turn, the second focuses on design principles and EDA concepts, while the third discusses future trends in power amplifier research. The book provides essential information on mm-wave power amplifier theory, as well as the implementation options and technologies involved in their effective design, equipping researchers, circuit designers and practicing engineers to design, model, analyze, test and implement high-performance, spectrally clean and energy-efficient mm-wave systems.

  1. Small signal microwave amplifier design

    CERN Document Server

    Grosch, Theodore

    2000-01-01

    This book explains techniques and examples for designing stable amplifiers for high-frequency applications in which the signal is small and the amplifier circuit is linear. An in-depth discussion of linear network theory provides the foundation needed to develop actual designs. Examples throughout the book will show you how to apply the knowledge gained in each chapter leading to the complex design of low noise amplifiers. Many exercises at the end of each chapter will help students to practice their skills. The solutions to these design problems are available in an accompanying solutions book

  2. New Packaging for Amplifier Slabs

    Energy Technology Data Exchange (ETDEWEB)

    Riley, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thorsness, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Suratwala, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Steele, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rogowski, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-03-18

    The following memo provides a discussion and detailed procedure for a new finished amplifier slab shipping and storage container. The new package is designed to maintain an environment of <5% RH to minimize weathering.

  3. Operational amplifiers theory and design

    CERN Document Server

    Huijsing, Johan

    2017-01-01

    This proven textbook guides readers to a thorough understanding of the theory and design of operational amplifiers (OpAmps). The core of the book presents systematically the design of operational amplifiers, classifying them into a periodic system of nine main overall configurations, ranging from one gain stage up to four or more stages. This division enables circuit designers to recognize quickly, understand, and choose optimal configurations. Characterization of operational amplifiers is given by macro models and error matrices, together with measurement techniques for their parameters. Definitions are given for four types of operational amplifiers depending on the grounding of their input and output ports. Many famous designs are evaluated in depth, using a carefully structured approach enhanced by numerous figures. In order to reinforce the concepts introduced and facilitate self-evaluation of design skills, the author includes problems with detailed solutions, as well as simulation exercises. Provides te...

  4. TARC: Carlo Rubbia's Energy Amplifier

    CERN Multimedia

    Laurent Guiraud

    1997-01-01

    Transmutation by Adiabatic Resonance Crossing (TARC) is Carlo Rubbia's energy amplifier. This CERN experiment demonstrated that long-lived fission fragments, such as 99-TC, can be efficiently destroyed.

  5. Spectroscopic amplifier for pin diode

    International Nuclear Information System (INIS)

    Alonso M, M. S.; Hernandez D, V. M.; Vega C, H. R.

    2014-10-01

    The photodiode remains the basic choice for the photo-detection and is widely used in optical communications, medical diagnostics and field of corpuscular radiation. In detecting radiation it has been used for monitoring radon and its progeny and inexpensive spectrometric systems. The development of a spectroscopic amplifier for Pin diode is presented which has the following characteristics: canceler Pole-Zero (P/Z) with a time constant of 8 μs; constant gain of 57, suitable for the acquisition system; 4th integrator Gaussian order to waveform change of exponential input to semi-Gaussian output and finally a stage of baseline restorer which prevents Dc signal contribution to the next stage. The operational amplifier used is the TLE2074 of BiFET technology of Texas Instruments with 10 MHz bandwidth, 25 V/μs of slew rate and a noise floor of 17 nv/(Hz)1/2. The integrated circuit has 4 operational amplifiers and in is contained the total of spectroscopic amplifier that is the goal of electronic design. The results show like the exponential input signal is converted to semi-Gaussian, modifying only the amplitude according to the specifications in the design. The total system is formed by the detector, which is the Pin diode, a sensitive preamplifier to the load, the spectroscopic amplifier that is what is presented and finally a pulse height analyzer (Mca) which is where the spectrum is shown. (Author)

  6. Low-Noise Band-Pass Amplifier

    Science.gov (United States)

    Kleinberg, L.

    1982-01-01

    Circuit uses standard components to overcome common limitation of JFET amplifiers. Low-noise band-pass amplifier employs JFET and operational amplifier. High gain and band-pass characteristics are achieved with suitable choice of resistances and capacitances. Circuit should find use as low-noise amplifier, for example as first stage instrumentation systems.

  7. Capacitively-coupled chopper amplifiers

    CERN Document Server

    Fan, Qinwen; Huijsing, Johan H

    2017-01-01

    This book describes the concept and design of the capacitively-coupled chopper technique, which can be used in precision analog amplifiers. Readers will learn to design power-efficient amplifiers employing this technique, which can be powered by regular low supply voltage such as 2V and possibly having a +\\-100V input common-mode voltage input. The authors provide both basic design concepts and detailed design examples, which cover the area of both operational and instrumentation amplifiers for multiple applications, particularly in power management and biomedical circuit designs. Discusses basic working principles and details of implementation for proven designs; Includes a diverse set of applications, along with measurement results to demonstrate the effectiveness of the technique; Explains advantages and drawbacks of the technique, given particular circumstances.

  8. Drug repurposing screen identifies lestaurtinib amplifies the ability of the poly (ADP-ribose) polymerase 1 inhibitor AG14361 to kill breast cancer associated gene-1 mutant and wild type breast cancer cells

    OpenAIRE

    Vazquez-Ortiz, Guelaguetza; Chisholm, Cristine; Xu, Xiaoling; Lahusen, Tyler J; Li, Cuiling; Sakamuru, Srilatha; Huang, Ruili; Thomas, Craig J; Xia, Menghang; Deng, Chuxia

    2014-01-01

    Introduction Breast cancer is a devastating disease that results in approximately 40,000 deaths each year in the USA. Current drug screening and chemopreventatitive methods are suboptimal, due in part to the poor specificity of compounds for cancer cells. Poly (ADP-ribose) polymerase 1 (PARP1) inhibitor (PARPi)-mediated therapy is a promising approach for familial breast cancers caused by mutations of breast cancer-associated gene-1 and -2 (BRCA1/2), yet drug resistance frequently occurs duri...

  9. Low Cost RF Amplifier for Community TV

    Science.gov (United States)

    Ch, Syafaruddin; Sasongko, Sudi Mariyanto Al; Made Budi Suksmadana, I.; Mustiko Okta Muvianto, Cahyo; Ariessaputra, Suthami

    2016-01-01

    he capability of television to deliver audio video makes this media become the most effective method to spread information. This paper presents an experiment of RF amplifier design having low-cost design and providing sufficient RF power particularly for community television. The RF amplifier consists of two stages of amplifier. The first stage amplifier was used to leverage output of TV modulator from 11dBm to enable to drive next stage amplifier. CAD simulation and fabrication were run to reach optimum RF amplifier design circuit. The associated circuit was made by determining stability circle, stability gain, and matching impedance. Hence, the average power of first stage RF amplifier was 24.68dBm achieved. The second stage used RF modules which was ready match to 50 ohm for both input and output port. The experiment results show that the RF amplifier may operate at frequency ranging from 174 to 230MHz. The average output power of the 2nd stage amplifier was 33.38 Watt with the overall gain of 20.54dB. The proposed RF amplifier is a cheap way to have a stable RF amplifier for community TV. The total budget for the designed RF amplifier is only a 1/5 compared to local design of final TV amplifier.

  10. Linearisation of RF Power Amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Per Asbeck

    2001-01-01

    This thesis deals with linearisation techniques of RF power amplifiers (PA), PA design techniques and integration of the necessary building blocks in a CMOS technology. The opening chapters introduces the theory of transmitter architectures, RF-signal representation and the principles of digital...... modulation. Furthermore different types of power amplifiers, models and measures of non-linearities are presented. A chapter is also devoted to different types of linearisation systems. The work carried out and described in this thesis can be divided into a more theoretical and system oriented treatment...... the polar loop architecture and it’s suitability to modern digital transmitters is discussed. A proposal of an architecture that is suitable for digital transmitters, which means that it has an interface to the digital back-end, defined by low-pass signals in polar form, is presented. Simulation guidelines...

  11. Single conversion stage amplifier - SICAM

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.

    2005-12-15

    This Ph.D. thesis presents a thorough analysis of the so called SICAM - SIngle Converter stage AMplifier approach to building direct energy conversion audio power amplifiers. The mainstream approach for building isolated audio power amplifiers today consists of isolated DC power supply and Class D amplifier, which essentially represents a two stage solution, where each of the components can be viewed as separate and independent part. The proposed SICAM solution strives for direct energy conversion from the mains to the audio output, by dedicating the operation of the components one to another and integrating their functions, so that the final audio power amplifier represents a single-stage topology with higher efficiency, lower volume, less board space, lower component count and subsequently lower cost. The SICAM approach is both applicable to non-isolated and isolated audio power amplifiers, but the problems encountered in these two cases are different. Non-isolated SICAM solutions are intended for both AC mains-connected and battery-powered devices. In non-isolated mains-connected SICAMs the main idea is to simplify the power supply or even provide integrated power factor correction (PFC) functions, while still maintaining low component stress and good audio performance by generally decreasing the input voltage level to the Class D audio power amplifier. On the other hand, non-isolated battery-powered SICAMs have to cope with the ever changing battery voltage and provide output voltage levels which are both lower and higher than the battery voltage, while still being simple and single-stage energy conversion solutions. In isolated SICAMs the isolation transformer adjusts the voltage level on the secondary side to the desired level, so the main challenges here are decreasing the size of the magnetic core and reducing the number and size of bulky reactive components as much as possible. The main focus of this thesis is directed towards the isolated SICAMs and

  12. Superconducting switch and amplifier device

    International Nuclear Information System (INIS)

    Faris, S.M.

    1982-01-01

    An amplifying or switching superconductive device is described whose current-voltage characteristic is drastically altered by heavy injection of excess energetic quasi-particles. In this device, the superconducting bandgap of a superconducting layer is greatly altered by overinjection of energetic quasi-particles so that the bandgap changes greatly with respect to its thermal equilibrium value, and in most cases is made to vanish. In a preferred embodiment, a three electrode device is fabricated where at least one of the electrodes is a superconductor. Tunnel barriers are located between the electrodes. A first tunnel junction is used to heavily inject energetic quasi-particles into the superconducting electrode to change its superconducting bandgap drastically. In turn, this greatly modifies the currentvoltage characteristics of the second tunnel junction. This device can be used to provide logic circuits, or as an amplifier, and has an output sufficiently large that it can drive other similar devices

  13. Identification of amplified fragment length polymorphism (AFLP ...

    African Journals Online (AJOL)

    Identification of amplified fragment length polymorphism (AFLP) fragments linked to soybean mosaic virus resistance gene in Glycine soja and conversion to a sequence characterized amplified regions (SCAR) marker for rapid selection.

  14. Higher order mode optical fiber Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Friis, Søren Michael Mørk; Usuga Castaneda, Mario A.

    2016-01-01

    We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations.......We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations....

  15. High power regenerative laser amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Miller, John L. (Livermore, CA); Hackel, Lloyd A. (Livermore, CA); Dane, Clifford B. (Dublin, CA); Zapata, Luis E. (Livermore, CA)

    1994-01-01

    A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse.

  16. SPS RF System Amplifier plant

    CERN Multimedia

    1977-01-01

    The picture shows a 2 MW, 200 MHz amplifier plant with feeder lines. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also increased: to the first 2 MW plant a second 2 MW plant was added and by end 1979 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X.

  17. Improved charge amplifier using hybrid hysteresis compensation

    Science.gov (United States)

    Amin-Shahidi, Darya; Trumper, David L.

    2013-08-01

    We present a novel charge amplifier, with a robust feedback circuit and a method for compensating piezoelectric actuator's hysteresis at low frequencies. The amplifier uses a modified feedback circuit which improves robustness to the addition of series load impedance such as in cabling. We also describe a hybrid hysteresis compensation method for enabling the charge amplifier to reduce hysteresis at low frequencies. Experimental results demonstrate the utility of the new amplifier design.

  18. Switching power amplifier for TAR3

    OpenAIRE

    Moore, Eric Wesley

    1995-01-01

    This thesis describes the theory, design, construction, and testing of a switching power amplifier. The major emphasis of the research and development effort reported herein is to design and construct an efficient power amplifier for varying load conditions which provides 40 Watts of power, at 85% efficiency, and with no more than 10% harmonic distortion. The power amplifier will need one voltage supply and one input audio signal. The amplifier will be used to power demonstration thermoacoust...

  19. Balanced Amplifier dengan Menggunakan Driver Op Amp

    OpenAIRE

    Khoswanto, Handry; T.D.S, Yohanes; Wahyudi, Iwan

    2004-01-01

    In Bahasa Indonesia : Pada umumnya amplifier konvensional melibatkan jalur power supply (ground) yang berhubungan dengan jalur audio. Hal ini mengakibatkan pengolahan sinyal audio akan muncul IHM (Interval Hum Modulation) noise. Oleh karena itu, untuk dapat menekan timbulnya noise seminimal mungkin, maka dibuat sebuah amplifier yang tidak bereferensi pada ground power supply. Amplifier tersebut harus benar-benar balance dari input sampai ke output. Untuk merealisasikan balance amplifier ...

  20. Challenges in higher order mode Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Nielsen, Kristian; Friis, Søren Michael Mørk

    2015-01-01

    A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed......A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed...

  1. European Research on THz Vacuum Amplifiers

    DEFF Research Database (Denmark)

    Brunetti, F.; Cojocarua, C.-S.; de Rossi, A.

    2010-01-01

    The OPTHER (OPtically Driven TeraHertz AmplifiERs) project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within this project is a consolidation of efforts at the international level from the main players of the Eu...

  2. Spontaneous emission from saturated parametric amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Ott, Johan Raunkjær; Steffensen, Henrik

    2009-01-01

    Noise performance of parametric amplifiers is typically calculated assuming un-depleted operation. However, in many applications especially when applied as regenerative amplifiers in systems based on phase shift keyed modulation schemes, this assumption is not valid. Here we show the impact...... on accumulated spontaneous emission for a parametric amplifier operated in saturation....

  3. low pump power photonic crystal fibre amplifiers

    DEFF Research Database (Denmark)

    Hougaard, Kristian G.; Broeng, Jes; Bjarklev, Anders Overgaard

    2003-01-01

    Designs of low pump power optical amplifiers, based on photonic crystal fibres are presented. The potential of these fibre amplifiers is investigated, and it is demonstrated that such amplifiers may deliver gains of more than 15 dB at 1550 nm with less than 1 mW of optical pump power....

  4. Radio frequency amplifier with effective decoupling

    NARCIS (Netherlands)

    Besling, W.F.A.; Bakker, T.W.; Lamy, Y.; Kochupurackal, J.; Roozeboom, F.

    2011-01-01

    A variety of circuits, methods and devices are implemented for radiofrequency amplifiers. According to one such implementation, a radiofrequency amplifier circuit is implemented in a SMD package. The circuit amplifies a radiofrequency signal having a base-band portion and a plurality of carrier

  5. Series transistors isolate amplifier from flyback voltage

    Science.gov (United States)

    Banks, W.

    1967-01-01

    Circuit enables high sawtooth currents to be passed through a deflection coil and isolate the coil driving amplifier from the flyback voltage. It incorporates a switch consisting of transistors in series with the driving amplifier and deflection coil. The switch disconnects the deflection coil from the amplifier during the retrace time.

  6. Remote Acquisition Amplifier For 50-Ohm Cable

    Science.gov (United States)

    Amador, Jose J.

    1995-01-01

    Buffer-amplifier unit designed to drive 50-Ohm cables up to 100 ft. (30 m) long, compensating for attenuation in cables and enabling remote operation of oscilloscopes. Variable resistor provides for adjustment of gain of amplifier, such that overall gain from input terminals of amplifier to output end of cable set to unity.

  7. Semiconductor quantum-dot lasers and amplifiers

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Borri, Paola; Ledentsov, N. N.

    2002-01-01

    -power surface emitting VCSELs. We investigated the ultrafast dynamics of quantum-dot semiconductor optical amplifiers. The dephasing time at room temperature of the ground-state transition in semiconductor quantum dots is around 250 fs in an unbiased amplifier, decreasing to below 50 fs when the amplifier...... is biased to positive net gain. We have further measured gain recovery times in quantum dot amplifiers that are significantly lower than in bulk and quantum-well semiconductor optical amplifiers. This is promising for future demonstration of quantum dot devices with high modulation bandwidth...

  8. High temperature charge amplifier for geothermal applications

    Energy Technology Data Exchange (ETDEWEB)

    Lindblom, Scott C.; Maldonado, Frank J.; Henfling, Joseph A.

    2015-12-08

    An amplifier circuit in a multi-chip module includes a charge to voltage converter circuit, a voltage amplifier a low pass filter and a voltage to current converter. The charge to voltage converter receives a signal representing an electrical charge and generates a voltage signal proportional to the input signal. The voltage amplifier receives the voltage signal from the charge to voltage converter, then amplifies the voltage signal by the gain factor to output an amplified voltage signal. The lowpass filter passes low frequency components of the amplified voltage signal and attenuates frequency components greater than a cutoff frequency. The voltage to current converter receives the output signal of the lowpass filter and converts the output signal to a current output signal; wherein an amplifier circuit output is selectable between the output signal of the lowpass filter and the current output signal.

  9. Specific circuit design: electrocardiogram amplifier

    International Nuclear Information System (INIS)

    Laribiere, Laurent

    1991-01-01

    The electrocardiogram amplifier is a specific integrated circuit. It is based on a linear array of Raytheon. This circuit is fitted with the following functions and characteristics: - electrocardiogram signals amplification, - pacemaker detection, - electrode un-sticking detection, - defibrillator overload protection, - battery-powered, - internal regulation 5 V, - low supply current 2.5 mA, - according to French norms on electrocardiogram surveillance devices - 28 pin package, available in CMS version It can be used for any surveillance device, requiring an analog processing of cardiac signals. (author) [fr

  10. Audio power amplifier design handbook

    CERN Document Server

    Self, Douglas

    2013-01-01

    This book is essential for audio power amplifier designers and engineers for one simple reason...it enables you as a professional to develop reliable, high-performance circuits. The Author Douglas Self covers the major issues of distortion and linearity, power supplies, overload, DC-protection and reactive loading. He also tackles unusual forms of compensation and distortion produced by capacitors and fuses. This completely updated fifth edition includes four NEW chapters including one on The XD Principle, invented by the author, and used by Cambridge Audio. Cro

  11. Cathode-follower power amplifier

    International Nuclear Information System (INIS)

    Giordano, S.; Puglisi, M.

    1983-01-01

    In circular accelerators and particularly in storage rings it is essential that the total impedance, as seen by the beam, be kept below some critical value. A model of the accelerating system was built using a single-ended cathode-follower amplifier driving a ferrite-loaded cavity. The system operated at 234.5 kHz with a peak output voltage of +-10 kV on the gap. The dynamic output impedance, as measured on the gap, was < 15 ohms

  12. A system for biasing a differential amplifier

    International Nuclear Information System (INIS)

    Barbier, Daniel; Ittel, J.M.; Poujois, Robert

    1975-01-01

    This invention concerns a system for biasing a differential amplifier. It particularly applies to the integrated differential amplifiers designed with MOS field effect transistors. Variations in the technological parameters may well cause the amplifying transistors to work outside their usual operational area, in other words outside the linear part of the transfer characteristic. To ensure that these transistors function correctly, it is necessary that the value of the voltage difference at the output be equally null. To do this and to centre on the so called 'rest' point of the amplifier transfer charateristic, the condition will be set that the output potentials of each amplifier transistor should have a zero value or a constant value as sum. With this in view, the bias on the source (generally a transistor powered by its grid bias voltage) supplying current to the two amplifying transistors fitted in parallel, is permanently adjusted in a suitable manner [fr

  13. An Implantable CMOS Amplifier for Nerve Signals

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Lehmann, Torsten

    2001-01-01

    on the amplifier input nodes. The method for signal recovery from noisy nerve signals is presented. A prototype amplifier is realized in a standard digital 0.5 μm CMOS single poly, n-well process. The prototype amplifier features a gain of 80 dB over a 3.6 kHz bandwidth, a CMRR of more than 87 dB and a PSRR......In this paper, a low noise high gain CMOS amplifier for minute nerve signals is presented. By using a mixture of weak- and strong inversion transistors, optimal noise suppression in the amplifier is achieved. A continuous-time offset-compensation technique is utilized in order to minimize impact...... greater than 84 dB. The equivalent input referred noise in the bandwidth of interest is 5 nV/√Hz. The amplifier power consumption is 275 μW....

  14. Transverse pumped laser amplifier architecture

    Science.gov (United States)

    Bayramian, Andrew James; Manes, Kenneth; Deri, Robert; Erlandson, Al; Caird, John; Spaeth, Mary

    2013-07-09

    An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

  15. Silicon Germanium Cryogenic Low Noise Amplifiers

    Science.gov (United States)

    Bardin, J. C.; Montazeri, S.; Chang, Su-Wei

    2017-05-01

    Silicon germanium heterojunction bipolar transistors have emerged in the last decade as an excellent option for use in cryogenic low noise amplifiers. This paper begins with a review of the critical developments that have led to today’s cryogenic low noise amplifiers. Next, recent work focused on minimizing the power consumption of SiGe cryogenic amplifiers is presented. Finally, open issues related to the cryogenic noise properties of SiGe HBTs are discussed.

  16. Short Rayleigh Range Free Electron Laser Amplifiers

    CERN Document Server

    Yu, L H; Murphy, J B; Rose, J; Shaftan, T V; Wang, X J; Watanabe, T

    2005-01-01

    An important requirement for a high average power laser system is a manageable power density on the first optical element. One possibility to achieve this is a single pass amplifier which generates a short Rayleigh range (SRL) light beam. We present design parameters and calculated performances for several SRL configurations. These include a simulation of the optically guided (pinched) MW class FEL [1], the scalloped beam FEL amplifier [2] and high gain TOK amplifiers we propose to explore at our SDL facility.

  17. Dynamics of soliton cascades in fiber amplifiers.

    Science.gov (United States)

    Arteaga-Sierra, F R; Antikainen, A; Agrawal, Govind P

    2016-11-15

    We study numerically the formation of cascading solitons when femtosecond optical pulses are launched into a fiber amplifier with less energy than required to form a soliton of equal duration. As the pulse is amplified, cascaded fundamental solitons are created at different distances, without soliton fission, as each fundamental soliton moves outside the gain bandwidth through the Raman-induced spectral shifts. As a result, each input pulse creates multiple, temporally separated, ultrashort pulses of different wavelengths at the amplifier output. The number of pulses depends not only on the total gain of the amplifier but also on the width of the input pulse.

  18. Reflection amplifiers in self-regulated learning

    NARCIS (Netherlands)

    Verpoorten, Dominique

    2012-01-01

    Verpoorten, D. (2012). Reflection amplifiers in self-regulated learning. Doctoral thesis. November, 9, 2012, Heerlen, The Netherlands: Open Universiteit (CELSTEC). Datawyse / Universitaire Pers Maastricht.

  19. HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS.

    Energy Technology Data Exchange (ETDEWEB)

    BEN-ZVI, ILAN, DAYRAN, D.; LITVINENKO, V.

    2005-08-21

    Historically, the first demonstration of the optical FEL was in an amplifier configuration at Stanford University [l]. There were other notable instances of amplifying a seed laser, such as the LLNL PALADIN amplifier [2] and the BNL ATF High-Gain Harmonic Generation FEL [3]. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance FEL's with average power of 100 kW or more. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting Energy Recovery Linacs (ERL) combine well with the high-gain FEL amplifier to produce unprecedented average power FELs. This combination has a number of advantages. In particular, we show that for a given FEL power, an FEL amplifier can introduce lower energy spread in the beam as compared to a traditional oscillator. This properly gives the ERL based FEL amplifier a great wall-plug to optical power efficiency advantage. The optics for an amplifier is simple and compact. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Linac which is under construction at Brookhaven National Laboratory's Collider-Accelerator Department.

  20. Distributed feedback laser amplifiers combining the functions of amplifiers and channel filters

    DEFF Research Database (Denmark)

    Wang, Z.; Durhuus, T.; Mikkelsen, Benny

    1994-01-01

    A dynamic model for distributed feedback amplifiers, including the mode coupled equations and the carrier rate equation, is established. The presented mode coupled equations have taken into account the interaction between fast changing optical signal and the waveguide with corrugations. By showin...... the possibility of amplifying 100 ps pulses without pulse broadening, we anticipate that a distributed feedback amplifier can be used as a combined amplifier and channel filter in high bit rate transmission systems....

  1. Design and development of a spectroscopy amplifier

    International Nuclear Information System (INIS)

    Ahmad, N.; Khalaf, M.A.

    1998-01-01

    Spectroscopy amplifier is an integral part of my detection system used for the measurement and spectroscopy of nuclear radiations. Its performance determination the contribution of the electronics to the energy resolution of the system. A spectroscopy amplifier has been designed and developed using locally available components. The design and description of this unit is discussed in this article. (author)

  2. Bevalac injector final stage RF amplifier upgrades

    International Nuclear Information System (INIS)

    Howard, D.; Calvert, J.; Dwinell, R.; Lax, J.; Lindner, A.; Richter, R.; Ridgeway, W.

    1991-01-01

    With the assistance of the DOE In-house Energy Management Program, the Bevalac injector final stage RF amplifier systems have been successfully upgraded to reduce energy consumption and operating costs. This recently completed project removed the energy-inefficient plate voltage modulator circuits that were used in conjunction with the final stage RF amplifiers. Construction, design, and operating parameters are described in detail

  3. BROADBAND TRAVELLING WAVE SEMICONDUCTOR OPTICAL AMPLIFIER

    DEFF Research Database (Denmark)

    2010-01-01

    Broadband travelling wave semiconductor optical amplifier (100, 200, 300, 400, 800) for amplification of light, wherein the amplifier (100, 200, 300, 400, 800) comprises a waveguide region (101, 201, 301, 401, 801) for providing confinement of the light in transverse directions and adapted...

  4. A CMOS current-mode operational amplifier

    DEFF Research Database (Denmark)

    Kaulberg, Thomas

    1993-01-01

    A fully differential-input, differential-output, current-mode operational amplifier (COA) is described. The amplifier utilizes three second-generation current conveyors (CCIIs) as the basic building blocks. It can be configured to provide either a constant gain-bandwidth product in a fully balanc...

  5. Enhanced Gain in Photonic Crystal Amplifiers

    DEFF Research Database (Denmark)

    Ek, Sara; Semenova, Elizaveta; Hansen, Per Lunnemann

    2012-01-01

    We experimentally demonstrate enhanced gain in the slow-light regime of quantum well photonic crystal amplifiers. A strong gain enhancement is observed with the increase of the group refractive index, due to light slow-down. The slow light enhancement is shown in a amplified spontaneous emission...

  6. High Average Power Optical FEL Amplifiers

    CERN Document Server

    Ben-Zvi, I; Litvinenko, V

    2005-01-01

    Historically, the first demonstration of the FEL was in an amplifier configuration at Stanford University. There were other notable instances of amplifying a seed laser, such as the LLNL amplifier and the BNL ATF High-Gain Harmonic Generation FEL. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance a 100 kW average power FEL. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting energy recovery linacs combine well with the high-gain FEL amplifier to produce unprecedented average power FELs with some advantages. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Li...

  7. An Implantable CMOS Amplifier for Nerve Signals

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Lehmann, Torsten

    2003-01-01

    . A continuous-time current-steering offset-compensation technique is utilized in order to minimize the noise contribution and to minimize dynamic impact on the amplifier input nodes. The method for signal recovery from noisy nerve signals is presented. A prototype amplifier is realized in a standard digital 0...

  8. Self-pulsation in Raman fiber amplifiers

    DEFF Research Database (Denmark)

    Pedersen, Martin Erland Vestergaard; Ott, Johan Raunkjær; Rottwitt, Karsten

    2009-01-01

    Dynamic behavior caused by Brillouin scattering in Raman fiber amplifiers is studied. Modes of self-pulsation steady state oscillations are found. Their dependence on amplification scheme is demonstrated.......Dynamic behavior caused by Brillouin scattering in Raman fiber amplifiers is studied. Modes of self-pulsation steady state oscillations are found. Their dependence on amplification scheme is demonstrated....

  9. Detection of Non-Amplified Genomic DNA

    CERN Document Server

    Corradini, Roberto

    2012-01-01

    This book offers a state-of-the-art overview on non amplified DNA detection methods and provides chemists, biochemists, biotechnologists and material scientists with an introduction to these methods. In fact all these fields have dedicated resources to the problem of nucleic acid detection, each contributing with their own specific methods and concepts. This book will explain the basic principles of the different non amplified DNA detection methods available, highlighting their respective advantages and limitations. The importance of non-amplified DNA sequencing technologies will be also discussed. Non-amplified DNA detection can be achieved by adopting different techniques. Such techniques have allowed the commercialization of innovative platforms for DNA detection that are expected to break into the DNA diagnostics market. The enhanced sensitivity required for the detection of non amplified genomic DNA has prompted new strategies that can achieve ultrasensitivity by combining specific materials with specifi...

  10. Design of an 1800 nm Raman Amplifier

    DEFF Research Database (Denmark)

    Svane, Ask Sebastian; Rottwitt, Karsten

    , also extended band amplifiers are required. As a solution to the latter challenge, Raman amplifiers are suggested as promising candidates. The main hurdle when designing a long wavelength Raman amplifier is the increased intrinsic fiber attenuation which as a consequence leads to an increase...... in the pump power requirement and deteriorated noise properties. Here we demonstrate a Raman amplifier designed for signal wavelengths around 1800 nm. The amplification fiber is an OFS PM Raman fiber, and is pumped by a Raman fiber laser emitting at 1680 nm [4]. The amplifier was pumped co......-polarized and backward, with respect to the singal. In Fig. 2 a measured Raman on/off gain exceeding 9 dB for 285 mW of injected pump power is obtained in a 4.35 km long fiber. A broadband supercontinuum source was used as a signal from 1700 nm to 1900 nm....

  11. Dual-range linearized transimpedance amplifier system

    Science.gov (United States)

    Wessendorf, Kurt O.

    2010-11-02

    A transimpedance amplifier system is disclosed which simultaneously generates a low-gain output signal and a high-gain output signal from an input current signal using a single transimpedance amplifier having two different feedback loops with different amplification factors to generate two different output voltage signals. One of the feedback loops includes a resistor, and the other feedback loop includes another resistor in series with one or more diodes. The transimpedance amplifier system includes a signal linearizer to linearize one or both of the low- and high-gain output signals by scaling and adding the two output voltage signals from the transimpedance amplifier. The signal linearizer can be formed either as an analog device using one or two summing amplifiers, or alternately can be formed as a digital device using two analog-to-digital converters and a digital signal processor (e.g. a microprocessor or a computer).

  12. Design of an 1800nm Raman amplifier

    DEFF Research Database (Denmark)

    Svane, Ask Sebastian; Rottwitt, Karsten

    2013-01-01

    We present the experimental results for a Raman amplifier that operates at 1810 nm and is pumped by a Raman fiber laser at 1680 nm. Both the pump laser and the Raman amplifier is polarization maintaining. A challenge when scaling Raman amplifiers to longer wavelengths is the increase...... in transmission loss, but also the reduction in the Raman gain coefficient as the amplifier wavelength is increased. Both polarization components of the Raman gain is characterized, initially for linearly co-polarized signal and pump, subsequently linearly polarized orthogonal signal and pump. The noise...... performance of the amplifier is also investigated for both configurations. Our results show an on/off gain exceeding 20 dB at 1810 nm for which the obtained effective noise figure is below 3 dB....

  13. Ultrafast disk lasers and amplifiers

    Science.gov (United States)

    Sutter, Dirk H.; Kleinbauer, Jochen; Bauer, Dominik; Wolf, Martin; Tan, Chuong; Gebs, Raphael; Budnicki, Aleksander; Wagenblast, Philipp; Weiler, Sascha

    2012-03-01

    Disk lasers with multi-kW continuous wave (CW) output power are widely used in manufacturing, primarily for cutting and welding applications, notably in the automotive industry. The ytterbium disk technology combines high power (average and/or peak power), excellent beam quality, high efficiency, and high reliability with low investment and operating costs. Fundamental mode picosecond disk lasers are well established in micro machining at high throughput and perfect precision. Following the world's first market introduction of industrial grade 50 W picosecond lasers (TruMicro 5050) at the Photonics West 2008, the second generation of the TruMicro series 5000 now provides twice the average power (100 W at 1030 nm, or 60 W frequency doubled, green output) at a significantly reduced footprint. Mode-locked disk oscillators achieve by far the highest average power of any unamplified lasers, significantly exceeding the 100 W level in laboratory set-ups. With robust long resonators their multi-microjoule pulse energies begin to compete with typical ultrafast amplifiers. In addition, significant interest in disk technology has recently come from the extreme light laser community, aiming for ultra-high peak powers of petawatts and beyond.

  14. Fundamentals of RF and microwave transistor amplifiers

    CERN Document Server

    Bahl, Inder J

    2009-01-01

    A Comprehensive and Up-to-Date Treatment of RF and Microwave Transistor Amplifiers This book provides state-of-the-art coverage of RF and microwave transistor amplifiers, including low-noise, narrowband, broadband, linear, high-power, high-efficiency, and high-voltage. Topics covered include modeling, analysis, design, packaging, and thermal and fabrication considerations. Through a unique integration of theory and practice, readers will learn to solve amplifier-related design problems ranging from matching networks to biasing and stability. More than 240 problems are included to help read

  15. Quantum electronics maser amplifiers and oscillators

    CERN Document Server

    Fain, V M; Sanders, J H

    2013-01-01

    Quantum Electronics, Volume 2: Maser Amplifiers and Oscillators deals with the experimental and theoretical aspects of maser amplifiers and oscillators which are based on the principles of quantum electronics. It shows how the concepts and equations used in quantum electronics follow from the basic principles of theoretical physics.Comprised of three chapters, this volume begins with a discussion on the elements of the theory of quantum oscillators and amplifiers working in the microwave region, along with the practical achievements in this field. Attention is paid to two-level paramagnetic ma

  16. A parallel input composite transimpedance amplifier

    Science.gov (United States)

    Kim, D. J.; Kim, C.

    2018-01-01

    A new approach to high performance current to voltage preamplifier design is presented. The design using multiple operational amplifiers (op-amps) has a parasitic capacitance compensation network and a composite amplifier topology for fast, precision, and low noise performance. The input stage consisting of a parallel linked JFET op-amps and a high-speed bipolar junction transistor (BJT) gain stage driving the output in the composite amplifier topology, cooperating with the capacitance compensation feedback network, ensures wide bandwidth stability in the presence of input capacitance above 40 nF. The design is ideal for any two-probe measurement, including high impedance transport and scanning tunneling microscopy measurements.

  17. Self-Amplified Optical Pattern Recognizer

    Science.gov (United States)

    Liu, Hua-Kuang

    1993-01-01

    Self-amplified optical pattern recognizers developed for use in recognition of patterns, in optical computing, and in optoelectronic neural networks. In recognizer, photorefractive crystal serves as medium in which one holographically records diffraction-grating filter representing pattern with which recognition sought. Apparatus "self-amplified" because signal amplified within filter to many orders of magnitude greater than in prior optical pattern recognizers. Basic principle of operation applicable to many types of correlation filters, including (but not limited to) Vander Lugt matched filters, joint-transform filters, and phase-only filters.

  18. Noiseless attenuation using an optical parametric amplifier

    Science.gov (United States)

    Brewster, R. A.; Nodurft, I. C.; Pittman, T. B.; Franson, J. D.

    2017-10-01

    The process of heralded noiseless amplification, and the inverse process of heralded noiseless attenuation, have potential applications in the context of quantum communications. Although several different physical implementations of heralded noiseless amplifiers have now been demonstrated, the research on heralded noiseless attenuators has been largely confined to a beam-splitter based approach. Here we show that an optical parametric amplifier (OPA), combined with appropriate heralding, can also serve as a heralded noiseless attenuator. The counterintuitive use of an optical amplifier as an attenuator is only possible due to the probabilistic nature of the device.

  19. Methylphenidate alters selective attention by amplifying salience.

    Science.gov (United States)

    ter Huurne, Niels; Fallon, Sean James; van Schouwenburg, Martine; van der Schaaf, Marieke; Buitelaar, Jan; Jensen, Ole; Cools, Roshan

    2015-12-01

    Methylphenidate, the most common treatment of attention deficit hyperactivity disorder (ADHD), is increasingly used by healthy individuals as a "smart drug" to enhance cognitive abilities like attention. A key feature of (selective) attention is the ability to ignore irrelevant but salient information in the environment (distractors). Although crucial for cognitive performance, until now, it is not known how the use of methylphenidate affects resistance to attentional capture by distractors. The present study aims to clarify how methylphenidate affects distractor suppression in healthy individuals. The effect of methylphenidate (20 mg) on distractor suppression was assessed in healthy subjects (N = 20), in a within-subject double-blind placebo-controlled crossover design. We used a visuospatial attention task with target faces flanked by strong (faces) or weak distractors (scrambled faces). Methylphenidate increased accuracy on trials that required gender identification of target face stimuli (methylphenidate 88.9 ± 1.4 [mean ± SEM], placebo 86.0 ± 1.2 %; p = .003), suggesting increased processing of the faces. At the same time, however, methylphenidate increased reaction time when the target face was flanked by a face distractor relative to a scrambled face distractor (methylphenidate 34.9 ± 3.73, placebo 26.7 ± 2.84 ms; p = .027), suggesting enhanced attentional capture by distractors with task-relevant features. We conclude that methylphenidate amplifies salience of task-relevant information at the level of the stimulus category. This leads to enhanced processing of the target (faces) but also increased attentional capture by distractors drawn from the same category as the target.

  20. Microwave parametric amplifiers using externally pumped Josephson junctions

    DEFF Research Database (Denmark)

    Sørensen, O. H.; Mygind, Jesper; Pedersen, Niels Falsig

    1978-01-01

    Externally pumped parametric amplifiers are discussed. Theory and experiments on the singly degenerate parametric amplifier based on a Josephson junction are presented. Advantages and limitations of the singly degenerate and doubly degenerate parametric amplifiers are discussed. Some plans and pr...

  1. Genetic differentiation and inheritance of random amplified ...

    African Journals Online (AJOL)

    ufuoma

    2013-09-11

    populations; the pectoral spine phenotypic groups ... Key words: Random amplified polymorphic DNA (RAPD) marker, morphologic and genetic variability, Clarias gariepinus. ..... However, genetic variability of the stock will have to be.

  2. Noise in phase-preserving linear amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Shashank; Jiang, Zhang; Combes, Joshua [Center for Quantum Information and Control, University of New Mexico, Albuquerque, NM 87131-0001 (United States); Caves, Carlton M. [Center for Quantum Information and Control, University of New Mexico, Albuquerque, NM 87131-0001, USA and Centre for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072 (Australia)

    2014-12-04

    The purpose of a phase-preserving linear amplifier is to make a small signal larger, so that it can be perceived by instruments incapable of resolving the original signal, while sacrificing as little as possible in signal-to-noise. Quantum mechanics limits how well this can be done: the noise added by the amplifier, referred to the input, must be at least half a quantum at the operating frequency. This well-known quantum limit only constrains the second moments of the added noise. Here we provide the quantum constraints on the entire distribution of added noise: any phasepreserving linear amplifier is equivalent to a parametric amplifier with a physical state σ for the ancillary mode; σ determines the properties of the added noise.

  3. Complementary DNA-amplified fragment length polymorphism ...

    African Journals Online (AJOL)

    Complementary DNA-amplified fragment length polymorphism (AFLP-cDNA) analysis of differential gene expression from the xerophyte Ammopiptanthus mongolicus in response to cold, drought and cold together with drought.

  4. (ISSR) and randomly amplified polymorphic DNA

    African Journals Online (AJOL)

    ajl yemi

    2011-12-19

    Dec 19, 2011 ... The phylogenic relationship within four species of Polygonum (including Polygonum hyrcanicum Rech. f. (three samples), Polygonum persicaria Boiss & Bushe Boiss, Polygonum avicular L., and Polygonum hydropiper L. subsp. Hydropiper) was investigated by randomly amplified polymorphic DNA ...

  5. Relationship between morphological and amplified fragment length ...

    African Journals Online (AJOL)

    Relationship between morphological and amplified fragment length polymorphism (AFLP) marker based genetic distance with heterosis in hot pepper (Capsicum annuum L.) SL Krishnamurthy, A Mohan Rao, K Madhavi Reddy, S Ramesh, Shailaja Hittalmani, Rao M. Gopinath ...

  6. Quantum-Limited Directional Amplifiers with Optomechanics

    Science.gov (United States)

    Malz, Daniel; Tóth, László D.; Bernier, Nathan R.; Feofanov, Alexey K.; Kippenberg, Tobias J.; Nunnenkamp, Andreas

    2018-01-01

    Directional amplifiers are an important resource in quantum-information processing, as they protect sensitive quantum systems from excess noise. Here, we propose an implementation of phase-preserving and phase-sensitive directional amplifiers for microwave signals in an electromechanical setup comprising two microwave cavities and two mechanical resonators. We show that both can reach their respective quantum limits on added noise. In the reverse direction, they emit thermal noise stemming from the mechanical resonators; we discuss how this noise can be suppressed, a crucial aspect for technological applications. The isolation bandwidth in both is of the order of the mechanical linewidth divided by the amplitude gain. We derive the bandwidth and gain-bandwidth product for both and find that the phase-sensitive amplifier has an unlimited gain-bandwidth product. Our study represents an important step toward flexible, on-chip integrated nonreciprocal amplifiers of microwave signals.

  7. EQUIPMENT WITH HYDROSTATIC AMPLIFIER MODELED 3D

    Directory of Open Access Journals (Sweden)

    EFTIMIE Dorin

    2013-11-01

    Full Text Available The equipment with hydrostatic amplifier is a new constructive solution modeled 3D using NX 7.5 software. Hydraulic equipment allows the amplification of a constant torque of a DC electric motor of low power at a variable speed. The hydrostatic speed amplifier of constant torque with electric control device is a hydraulic device which provides by design a bridge between the conventional hydraulic and the servo-hydraulic.

  8. EQUIPMENT WITH HYDROSTATIC AMPLIFIER MODELED 3D

    OpenAIRE

    EFTIMIE Dorin; FRONE Alexandru

    2013-01-01

    The equipment with hydrostatic amplifier is a new constructive solution modeled 3D using NX 7.5 software. Hydraulic equipment allows the amplification of a constant torque of a DC electric motor of low power at a variable speed. The hydrostatic speed amplifier of constant torque with electric control device is a hydraulic device which provides by design a bridge between the conventional hydraulic and the servo-hydraulic.

  9. Multiple excitation regenerative amplifier inertial confinement system

    International Nuclear Information System (INIS)

    George, V.E.; Haas, R.A.; Krupke, W.F.; Schlitt, L.G.

    1980-01-01

    The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation

  10. Proposal of Switching Power Amplifier Using Small Capacity Linear Amplifier and LC Filter

    Science.gov (United States)

    Kamada, Jo; Funato, Hirohito; Ogasawara, Satoshi

    The higher efficiency and the low noise in output voltage and current has been required in some applications, i.e. audio-video equipment, medical equipment and so on. This paper proposes a power amplifier in which a PWM inverter is used as a main circuit. In the proposed power amplifier, a hybrid filter composed of a simple and general LC filter and a small capacity linear amplifier is connected to the output of the inverter. The linear amplifier is inserted in series to the filter capacitor to improve the filtering effect of the LC filter. Switching ripples and LC resonances are considerably suppressed by controlling the amplifier using the proposed method and a low distortion switching power amplifier is realized. The effects of the proposal circuit are verified by simulations and experiments. As a result, the proposed circuit achieves low noise about THD=0.68% in simulation and THD=1.7% in experiment.

  11. Advances in high-power rf amplifiers

    International Nuclear Information System (INIS)

    Tallerico, P.J.

    1979-01-01

    Several powerful accelerators and storage rings are being considered that will require tens or even hundreds of megawatts of continuous rf power. The economics of such large machines can be dictated by the cost and efficiency of the rf amplifiers. The overall design and performance of such narrow-band amplifiers, operating in the 50- to 1500-MHz region, are being theoretically studied as a function of frequency to determine the optimum rf amplifier output power, gain, efficiency, and dc power requirements. The state of the art for three types of amplifiers (gridded tubes, klystrons, and gyrocons) is considered and the development work necessary to improve each is discussed. The gyrocon is a new device, hence its various embodiments are discussed in detail. The Soviet designs are reviewed and the gyrocon's strengths and weaknesses are compared to other types of microwave amplifiers. The primary advantages of the gyrocon are the very large amount of power available from a single device and the excellent efficiency and stable operation. The klystron however, has much greater gain and is simpler mechanically. At very low frequencies, the small size of the gridded tube makes it the optimum choice for all but the most powerful systems

  12. Transpermeance Amplifier Applied to Magnetic Bearings

    Directory of Open Access Journals (Sweden)

    Jossana Ferreira

    2017-02-01

    Full Text Available The most conventional approach of controlling magnetic forces in active magnetic bearings (AMBs is through current feedback amplifiers: transconductance. This enables the operation of the AMB to be understood in terms of a relatively simple current-based model as has been widely reported on in the literature. The alternative notion of using transpermeance amplifiers, which approximate the feedback of gap flux rather than current, has been in commercial use in some form for at least thirty years, however is only recently seeing more widespread acceptance as a commercial standard. This study explores how such alternative amplifiers should be modeled and then examines the differences in behavior between AMBs equipped with transconductance and transpermeance amplifiers. The focus of this study is on two aspects. The first is the influence of rotor displacement on AMB force, commonly modeled as a constant negative equivalent mechanical stiffness, and it is shown that either scheme actually leads to a finite bandwidth effect, but that this bandwidth is much lower when transpermeance is employed. The second aspect is the influence of eddy currents. Using a very simple model of eddy currents (a secondary short-circuited coil, it is demonstrated that transpermeance amplifiers can recover significant actuator bandwidth compared with transconductance, but at the cost of needing increased peak current headroom.

  13. ZigBee Radio with External Power Amplifier and Low-Noise Amplifier

    Directory of Open Access Journals (Sweden)

    Allan HUYNH

    2010-07-01

    Full Text Available This paper presents the performance study of a ZigBee module with both an external power amplifier and a low-noise amplifier, measured in outdoor and indoor environments, respectively. Our previous study has already shown that the indoor campus environment such as walls and floors would reduce the radio link range drastically and the packet error rate increased. In this study, both an external power amplifier and a low-noise amplifier have been added to a ZigBee module to increase both the transmitter power and receiver sensitivity. It is shown that with an external power amplifier and a low-noise amplifier the outdoor radio range can reach up to 1600 m with a negligible packet error rate compared to 144 m without any external amplifier for point-to-point radio connection. Thus, by increasing both the transmitter power and receiver sensitivity the radio range can be increased significantly. The power consumption issue with the added amplifiers is studied as well, indicating that the module can still be battery driven with a battery lifetime of about 9 years at a normal sampling rate to the sensor.

  14. The OPTHER Project: Progress toward the THz Amplifier

    DEFF Research Database (Denmark)

    Paoloni, C; Brunetti, F; Di Carlo, A

    2011-01-01

    This paper describes the status of the OPTHER (OPtically driven TeraHertz AmplifiERs) project and progress toward the THz amplifier realization. This project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within th...

  15. Wideband Low Noise Amplifiers Exploiting Thermal Noise Cancellation

    NARCIS (Netherlands)

    Bruccoleri, F.; Klumperink, Eric A.M.; Nauta, Bram

    2005-01-01

    Low Noise Amplifiers (LNAs) are commonly used to amplify signals that are too weak for direct processing for example in radio or cable receivers. Traditionally, low noise amplifiers are implemented via tuned amplifiers, exploiting inductors and capacitors in resonating LC-circuits. This can render

  16. Design Of A Doherty Power Amplifier For GSM Systems

    OpenAIRE

    Saad Wasmi Osman

    2013-01-01

    This paper presents the design and analysis of Doherty power amplifier. The Doherty amplifier is used in  a base station for mobile system because of its high efficiency. The class AB power amplifier used in the configuration of the main and auxiliary amplifier. The result obtained shows that the Doherty power amplifier can be used on a wide band spectrum, the amplifier works at 900MHz and has very good power added efficiency (PAE) and gain. The amplifier can also work at 1800MHz at input pow...

  17. Wideband pulse amplifiers for the NECTAr chip

    Energy Technology Data Exchange (ETDEWEB)

    Sanuy, A., E-mail: asanuy@ecm.ub.es [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Delagnes, E. [IRFU/DSM/CEA, CE-Saclay, Bat. 141 SEN Saclay, F-91191, Gif-sur-Yvette (France); Gascon, D. [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Sieiro, X. [Departament d' Electronica, Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Bolmont, J.; Corona, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Barre 12-22, 1er etage, 4 place Jussieu, 75252 Paris (France); Feinstein, F. [LUPM, Universite Montpellier II and IN2P3/CNRS, CC072, bat. 13, place Eugene Bataillon, 34095 Montpellier (France); Glicenstein, J-F. [IRFU/DSM/CEA, CE-Saclay, Bat. 141 SEN Saclay, F-91191, Gif-sur-Yvette (France); Naumann, C.L.; Nayman, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Barre 12-22, 1er etage, 4 place Jussieu, 75252 Paris (France); Ribo, M. [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); and others

    2012-12-11

    The NECTAr collaboration's FE option for the camera of the CTA is a 16 bits and 1-3 GS/s sampling chip based on analog memories including most of the readout functions. This works describes the input amplifiers of the NECTAr ASIC. A fully differential wideband amplifier, with voltage gain up to 20 V/V and a BW of 400 MHz. As it is impossible to design a fully differential OpAmp with an 8 GHz GBW product in a 0.35 CMOS technology, an alternative implementation based on HF linearized transconductors is explored. The output buffer is a class AB miller operational amplifier, with special non-linear current boost.

  18. Transistorized pulse amplifiers (A.I.T.)

    International Nuclear Information System (INIS)

    Feyt, J.; Couly, J.P.

    1962-01-01

    The two amplifiers whose design and operation are described in this report have been studied for neutron detection units used in piles. They are designed to allow an important reduction of the volume and of the weight of the detector and its amplifier, and to simplify the operation of the detection assembly. To these characteristics can be added the mechanical and electrical robustness and the very reduced micro-phony. The first transistorized amplifier (AIT.1) is simple, very robust, and can be used for radioprotection installations. The second (AIT.4) has a better performance and makes it possible to replace the APT.2 in most of its applications (it has even been used satisfactorily in an apparatus where the micro-phony and the sensitivity to interference of the APT.2 made this latter unusable). (author) [fr

  19. Predistortion of a Bidirectional Cuk Audio Amplifier

    DEFF Research Database (Denmark)

    Birch, Thomas Hagen; Nielsen, Dennis; Knott, Arnold

    2014-01-01

    Some non-linear amplifier topologies are capable of providing a larger voltage gain than one from a DC source, which could make them suitable for various applications. However, the non-linearities introduce a significant amount of harmonic distortion (THD). Some of this distortion could be reduced...... using predistortion. This paper suggests linearizing a nonlinear bidirectional Cuk audio amplifier using an analog predistortion approach. A prototype power stage was built and results show that a voltage gain of up to 9 dB and reduction in THD from 6% down to 3% was obtainable using this approach....

  20. Analysis of bipolar and CMOS amplifiers

    CERN Document Server

    Sodagar, Amir M

    2007-01-01

    The classical approach to analog circuit analysis is a daunting prospect to many students, requiring tedious enumeration of contributing factors and lengthy calculations. Most textbooks apply this cumbersome approach to small-signal amplifiers, which becomes even more difficult as the number of components increases. Analysis of Bipolar and CMOS Amplifiers offers students an alternative that enables quick and intuitive analysis and design: the analysis-by-inspection method.This practical and student-friendly text demonstrates how to achieve approximate results that fall within an acceptable ran

  1. Optimization of a high efficiency FEL amplifier

    International Nuclear Information System (INIS)

    Schneidmiller, E.A.; Yurkov, M.V.

    2014-10-01

    The problem of an efficiency increase of an FEL amplifier is now of great practical importance. Technique of undulator tapering in the post-saturation regime is used at the existing X-ray FELs LCLS and SACLA, and is planned for use at the European XFEL, Swiss FEL, and PAL XFEL. There are also discussions on the future of high peak and average power FELs for scientific and industrial applications. In this paper we perform detailed analysis of the tapering strategies for high power seeded FEL amplifiers. Application of similarity techniques allows us to derive universal law of the undulator tapering.

  2. Cavity enhanced rephased amplified spontaneous emission

    International Nuclear Information System (INIS)

    A Williamson, Lewis; J Longdell, Jevon

    2014-01-01

    Amplified spontaneous emission is usually treated as an incoherent noise process. Recent theoretical and experimental work using rephasing optical pulses has shown that rephased amplified spontaneous emission (RASE) is a potential source of wide bandwidth time-delayed entanglement. Due to poor echo efficiency the plain RASE protocol does not in theory achieve perfect entanglement. Experiments done to date show a very small amount of entanglement at best. Here we show that RASE can, in principle, produce perfect multimode time-delayed two mode squeezing when the active medium is placed inside a Q-switched cavity. (paper)

  3. Implementation of Digital Lock-in Amplifier

    Science.gov (United States)

    Bhattacharyya, Sabyasachi; Nasir Ahmed, Ragib; Bijoy Purkayastha, Basab; Bhattacharyya, Kaustubh

    2016-10-01

    The recovery of signal under the presence of noise is utmost essential for proper communication. The signals corrupted due to noise can be recovered using various techniques. However the weak signals are more prone to noise and hence they can be easily degraded due to noise. In such cases, a digital lock-in amplifier becomes an essential device for recovery of such weak signals. Keeping the cost, speed and other considerations, we will present the implementation of digital lock-in amplifier and how it recovers the weak signal under extreme noisy conditions.

  4. Predistortion of a Bidirectional Cuk Audio Amplifier

    DEFF Research Database (Denmark)

    Birch, Thomas Hagen; Nielsen, Dennis; Knott, Arnold

    2014-01-01

    using predistortion. This paper suggests linearizing a nonlinear bidirectional Cuk audio amplifier using an analog predistortion approach. A prototype power stage was built and results show that a voltage gain of up to 9 dB and reduction in THD from 6% down to 3% was obtainable using this approach....

  5. Amplifier Design for Proportional Ionization Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Baker, W. H.

    1950-08-24

    This paper presents the requirements of a nuclear amplifier of short resolving time, designed to accept pulses of widely varying amplitudes. Data are given which show that a proportional ionization chamber loaded with a 1,000-ohm resistor develops pulses of 0.5 microsecond duration and several volts amplitude. Results indicate that seven basic requirements are imposed on the amplifier when counting soft beta and gamma radiation in the presence of alpha particles, without absorbers. It should, (1) have a fast recovery time, (2) have a relatively good low frequency response, (3) accept pulses of widely varying heights without developing spurious pulsed, (4) have a limiting output stage, (5) preserve the inherently short rise time of the chamber, (6) minimize pulse integration, and (7) have sufficient gain to detect the weak pulses well below the chamber voltage at which continuous discharge takes place. The results obtained with an amplifier which meets these requirements is described. A formula is derived which indicates that redesign of the proportional ionization chamber might eliminate the need for an amplifier. This may be possible if the radioactive particles are collimated parallel to the collecting electrode.

  6. Optimization of Pr3+:ZBLAN fiber amplifiers

    DEFF Research Database (Denmark)

    Pedersen, B.; Miniscalco, J. W.; Quimby, R. S.

    1992-01-01

    Experimental parameters have been measured and used in a quantitative model of Pr3+-doped fluorozirconate fiber amplifiers. The optimum cutoff wavelength was determined to be 800 nm and the gain for 400 mW of pump was found to increase from 12 to 34 dB if the NA was increased from 0.15 to 0...

  7. Frequency Compensation of an Audio Power Amplifier

    NARCIS (Netherlands)

    van der Zee, Ronan A.R.; van Heeswijk, R.

    2006-01-01

    A car audio power amplifier is presented that uses a frequency compensation scheme which avoids large compensation capacitors around the MOS power transistors, while retaining the bandwidth and stable load range of nested miller compensation. THD is 0.005%@(1kHz, 10W), SNR is 108dB, and the

  8. Reducing Switching Artifacts in Chopper Amplifiers

    NARCIS (Netherlands)

    Kusuda, Y.

    2018-01-01

    This thesis describes the theory, design, and implementation of chopper operational amplifiers (op-amps) in CMOS integrated circuits (ICs). The chopping technique periodically corrects DC errors of such op-amps, so that low 1/f noise and stable, microvolt-level offset can be achieved. However,

  9. Compensation techniques for operational amplifier bias current

    International Nuclear Information System (INIS)

    Silva, M.S.

    1981-01-01

    Two techniques are proposed for the compensation of the input current on operational amplifiers that can be used on inverting and non-inverting configurations. A qualitative analysis of temperature drift problems is made, and as a practical application, the construction of a voltage follower for high impedance measurements is presented. (Author) [pt

  10. Feedback analysis of transimpedance operational amplifier circuits

    DEFF Research Database (Denmark)

    Bruun, Erik

    1993-01-01

    The transimpedance or current feedback operational amplifier (CFB op-amp) is reviewed and compared to a conventional voltage mode op-amp using an analysis emphasizing the basic feedback characteristics of the circuit. With this approach the paradox of the constant bandwidth obtained from CFB op...

  11. Application of randomly amplified polymorphic DNA (RAPD ...

    African Journals Online (AJOL)

    Jane

    2011-10-10

    Oct 10, 2011 ... Polymerase chain reaction (PCR) based molecular markers have become increasingly popular for fingerprinting and cultivars identification since the development of PCR technology. (Saiki et al., 1988). RAPD-PCR (randomly amplified polymorphic DNA) was first conducted by Williams et al. (1990).

  12. Molecular markers. Amplified fragment length polymorphism

    Directory of Open Access Journals (Sweden)

    Pržulj Novo

    2005-01-01

    Full Text Available Amplified Fragment Length Polymorphism molecular markers (AFLPs has been developed combining procedures of RFLPs and RAPDs molekular markers, i.e. the first step is restriction digestion of the genomic DNA that is followed by selective amplification of the restricted fragments. The advantage of the AFLP technique is that it allows rapid generation of a large number of reproducible markers. The reproducibility of AFLPs markers is assured by the use of restriction site-specific adapters and adapter-specific primers for PCR reaction. Only fragments containing the restriction site sequence plus the additional nucleotides will be amplified and the more selected nucleotides added on the primer sequence the fewer the number of fragments amplified by PCR. The amplified products are normally separated on a sequencing gel and visualized after exposure to X-ray film or by using fluorescent labeled primers. AFLP shave proven to be extremely proficient in revealing diversity at below the species level. A disadvantage of AFLP technique is that AFLPs are essentially a dominant marker system and not able to identify heterozygotes.

  13. Complementary DNA-amplified fragment length polymorphism ...

    African Journals Online (AJOL)

    owner

    2011-05-09

    May 9, 2011 ... Complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) technology was used to analyze ... that 9 of the studied expressed sequence tags (ESTs) are related to protein modification, 12 ESTs are involved in the .... primers were used during the first strand synthesis of our cDNA synthesis ...

  14. Design of a lock-amplifier circuit

    Science.gov (United States)

    Liu, H.; Huang, W. J.; Song, X.; Zhang, W. Y.; Sa, L. B.

    2017-01-01

    The lock-in amplifier is recovered by phase sensitive detection technique for the weak signal submerged in the noise background. This design is based on the TI ultra low power LM358, INA129, OPA227, OP07 and other chips as the core design and production of the lock-in amplifier. Signal generator by 10m ohms /1K ohm resistance points pressure network 10 mu V 1mV adjustable sine wave signal s (T). The concomitant interference signal together through the AC amplifier and band-pass filter signal x (T), on the other hand reference signal R (T) driven by square wave phase shift etc. steps to get the signal R (T), two signals and by phase sensitive detector are a DC full wave, again through its low pass filter and a DC amplifier to be measured signal more accurate detection, the final circuit through the AD conversion and the use of single-chip will display the output.

  15. Random amplified polymorphic DNA based genetic characterization ...

    African Journals Online (AJOL)

    Random amplified polymorphic DNA based genetic characterization of four important species of Bamboo, found in Raigad district, Maharashtra State, India. ... Bambusoideae are differentiated from other members of the family by the presence of petiolate blades with parallel venation and stamens are three, four, six or more, ...

  16. Amplified spontaneous emission spectrum and gain characteristic of a two-electrode semiconductor optical amplifier

    International Nuclear Information System (INIS)

    Wang Hanchao; Huang Lirong; Shi Zhongwei

    2011-01-01

    A two-electrode multi-quantum-well semiconductor optical amplifier is designed and fabricated. The amplified spontaneous emission (ASE) spectrum and gain were measured and analyzed. It is shown that the ASE spectrum and gain characteristic are greatly influencedby the distribution of the injection current density. By changing the injection current density of two electrodes, the full width at half maximum, peak wavelength, peak power of the ASE spectrum and the gain characteristic can be easily controlled. (semiconductor devices)

  17. Cryogenic cooling for high power laser amplifiers

    Directory of Open Access Journals (Sweden)

    Perin J.P.

    2013-11-01

    Full Text Available Using DPSSL (Diode Pumped Solid State Lasers as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YAG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz. The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100 K–170 K with a heat flux of 1 MW*m−2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser.

  18. High gain, multiatmosphere CO2 laser amplifier

    Science.gov (United States)

    Stuart, G. C.; Houtman, H.; Meyer, J.

    1987-02-01

    A novel TE discharge, 15-mm aperture, multiatmosphere, CO2 laser amplifier is described, with measured electrical characteristics and gain measurements on the 9.294-micron, 9R (16) line. The electrical circuit used in this amplifier is a realistic alternative to the Marx bank or conventional LC inversion circuit and, similarly, it would be useful for excitation of other gas lasers as well. This automatically preionized, double-sided, fourfold LC inversion circuit uses only one spark gap, and it is shown to provide small-signal gains of 5.7 percent/cm, at 120 J/l atm and 10 atm. The generalization to an n-stage device, which would be suitable for higher pressures, and larger apertures, is discussed.

  19. Amplified music exposure carries risks to hearing.

    Science.gov (United States)

    da Silva, Valéria Gomes; de Oliveira, Carlos Augusto Costa Pires; Tauil, Pedro Luíz; de Castro Silva, Isabella Monteiro; Sampaio, André Luiz Lopes

    2017-02-01

    To investigate the association between changes in the outer hair cells and exposure to amplified music in a group of high-school students. In this retrospective, case-control study, 86 subjects underwent audiometry, immittance audiometry, and distortion-product otoacoustic emission tests. The subjects were questioned about their listening habits and divided into 2 groups: exposed and unexposed. Most of the subjects had reduced function in their outer hair cells, mainly beginning at 8 kHz. Among 60 subjects-30 cases and 30 controls-75% were considered exposed and 25% unexposed. The exposed subjects were 9.33 times more likely to have altered outer hair cells than the unexposed subjects were. Exposure to amplified music is associated with reduced function in the hair cells. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  20. FGFR antagonist induces protective autophagy in FGFR1-amplified breast cancer cell

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yi [The School of Biomedical Sciences, Chengdu Medical College, Chengdu 610083 (China); Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu (China); Xie, Xiaoyan; Li, Xinyi; Wang, Peiqi [State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University (China); Jing, Qian; Yue, Jiaqi; Liu, Yang [The School of Biomedical Sciences, Chengdu Medical College, Chengdu 610083 (China); Cheng, Zhong [Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu (China); Li, Jingyi, E-mail: li--jingyi@hotmail.com [The School of Biomedical Sciences, Chengdu Medical College, Chengdu 610083 (China); Song, Haixing [The School of Biomedical Sciences, Chengdu Medical College, Chengdu 610083 (China); Li, Guoyu, E-mail: liguoyulisa@163.com [School of Pharmacy, Shihezi University, Shihezi 832003 (China); Liu, Rui, E-mail: liurui_scu@hotmail.com [State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University (China); Wang, Jinhui [School of Pharmacy, Shihezi University, Shihezi 832003 (China)

    2016-05-20

    Breast cancer, representing approximately 30% of all gynecological cancer cases diagnosed yearly, is a leading cause of cancer-related mortality for women. Amplification of FGFR1 is frequently observed in breast cancers and is associated with poor prognosis. Though FGFRs have long been considered as anti-cancer drug targets, and a cluster of FGFR antagonists are currently under clinical trials, the precise cellular responses under the treatment of FGFR antagonists remains unclear. Here, we show that PD166866, an FGFR1-selective inhibitor, inhibits proliferation and triggers anoikis in FGFR1-amplified breast cancer cell lines. Notably, we demonstrate that PD166866 induces autophagy in FGFR1-amplified breast cancer cell lines, while blockage of autophagy by Atg5 knockdown further enhances the anti-proliferative activities of PD166866. Moreover, mechanistic study reveals that PD166866 induces autophagy through repressing Akt/mTOR signaling pathway. Together, the present study provides new insights into the molecular mechanisms underlying the anti-tumor activities of FGFR antagonists, and may further assist the FGFRs-based drug discovery. -- Highlights: •FGFR1 antagonist inhibits cell viability in FGFR1-amplified breast cancer cells. •FGFR1 antagonist induces autophagy in FGFR1-amplified breast cancer cells. •FGFR1 antagonist-induced autophagy is protective. •FGFR1 antagonist induces autophagy by inhibiting Akt/mTOR pathway.

  1. FGFR antagonist induces protective autophagy in FGFR1-amplified breast cancer cell

    International Nuclear Information System (INIS)

    Chen, Yi; Xie, Xiaoyan; Li, Xinyi; Wang, Peiqi; Jing, Qian; Yue, Jiaqi; Liu, Yang; Cheng, Zhong; Li, Jingyi; Song, Haixing; Li, Guoyu; Liu, Rui; Wang, Jinhui

    2016-01-01

    Breast cancer, representing approximately 30% of all gynecological cancer cases diagnosed yearly, is a leading cause of cancer-related mortality for women. Amplification of FGFR1 is frequently observed in breast cancers and is associated with poor prognosis. Though FGFRs have long been considered as anti-cancer drug targets, and a cluster of FGFR antagonists are currently under clinical trials, the precise cellular responses under the treatment of FGFR antagonists remains unclear. Here, we show that PD166866, an FGFR1-selective inhibitor, inhibits proliferation and triggers anoikis in FGFR1-amplified breast cancer cell lines. Notably, we demonstrate that PD166866 induces autophagy in FGFR1-amplified breast cancer cell lines, while blockage of autophagy by Atg5 knockdown further enhances the anti-proliferative activities of PD166866. Moreover, mechanistic study reveals that PD166866 induces autophagy through repressing Akt/mTOR signaling pathway. Together, the present study provides new insights into the molecular mechanisms underlying the anti-tumor activities of FGFR antagonists, and may further assist the FGFRs-based drug discovery. -- Highlights: •FGFR1 antagonist inhibits cell viability in FGFR1-amplified breast cancer cells. •FGFR1 antagonist induces autophagy in FGFR1-amplified breast cancer cells. •FGFR1 antagonist-induced autophagy is protective. •FGFR1 antagonist induces autophagy by inhibiting Akt/mTOR pathway.

  2. Self-amplifying mRNA vaccines.

    Science.gov (United States)

    Brito, Luis A; Kommareddy, Sushma; Maione, Domenico; Uematsu, Yasushi; Giovani, Cinzia; Berlanda Scorza, Francesco; Otten, Gillis R; Yu, Dong; Mandl, Christian W; Mason, Peter W; Dormitzer, Philip R; Ulmer, Jeffrey B; Geall, Andrew J

    2015-01-01

    This chapter provides a brief introduction to nucleic acid-based vaccines and recent research in developing self-amplifying mRNA vaccines. These vaccines promise the flexibility of plasmid DNA vaccines with enhanced immunogenicity and safety. The key to realizing the full potential of these vaccines is efficient delivery of nucleic acid to the cytoplasm of a cell, where it can amplify and express the encoded antigenic protein. The hydrophilicity and strong net negative charge of RNA impedes cellular uptake. To overcome this limitation, electrostatic complexation with cationic lipids or polymers and physical delivery using electroporation or ballistic particles to improve cellular uptake has been evaluated. This chapter highlights the rapid progress made in using nonviral delivery systems for RNA-based vaccines. Initial preclinical testing of self-amplifying mRNA vaccines has shown nonviral delivery to be capable of producing potent and robust innate and adaptive immune responses in small animals and nonhuman primates. Historically, the prospect of developing mRNA vaccines was uncertain due to concerns of mRNA instability and the feasibility of large-scale manufacturing. Today, these issues are no longer perceived as barriers in the widespread implementation of the technology. Currently, nonamplifying mRNA vaccines are under investigation in human clinical trials and can be produced at a sufficient quantity and quality to meet regulatory requirements. If the encouraging preclinical data with self-amplifying mRNA vaccines are matched by equivalently positive immunogenicity, potency, and tolerability in human trials, this platform could establish nucleic acid vaccines as a versatile new tool for human immunization. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Fast Electrocardiogram Amplifier Recovery after Defibrillation Shock

    Directory of Open Access Journals (Sweden)

    Ivan Dotsinsky

    2005-04-01

    Full Text Available A procedure for fast ECG amplifier recovery after defibrillation shocks was developed and simulated in the MATLAB environment. Exponentially decaying post-shock voltages have been recorded. Signals from the AHA database are taken and mixed with the recorded exponential disturbances. The algorithm applies moving averaging (comb filter on the compound input signal, thereby obtaining the samples of the disturbance. They are currently subtracted from the input signal. The results obtained show that its recovery is practically instantaneous.

  4. Design and simulation of a gyroklystron amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, M. S., E-mail: mschauhan.rs.ece@iitbhu.ac.in; Swati, M. V.; Jain, P. K. [Centre of Research in Microwave Tubes, Department of Electronics Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005 (India)

    2015-03-15

    In the present paper, a design methodology of the gyroklystron amplifier has been described and subsequently used for the design of a typically selected 200 kW, Ka-band, four-cavity gyroklystron amplifier. This conceptual device design has been validated through the 3D particle-in-cell (PIC) simulation and nonlinear analysis. Commercially available PIC simulation code “MAGIC” has been used for the electromagnetic study at the different location of the device RF interaction structure for the beam-absent case, i.e., eigenmode study as well as for the electron beam and RF wave interaction behaviour study in the beam present case of the gyroklystron. In addition, a practical problem of misalignment of the RF cavities with drift tubes within the tube has been also investigated and its effect on device performance studied. The analytical and simulation results confirmed the validity of the gyroklystron device design. The PIC simulation results of the present gyroklystron produced a stable RF output power of ∼218 kW for 0% velocity spread at 35 GHz, with ∼45 dB gain, 37% efficiency, and a bandwidth of 0.3% for a 70 kV, 8.2 A gyrating electron beam. The simulated values of RF output power have been found in agreement with the nonlinear analysis results within ∼5%. Further, the PIC simulation has been extended to study a practical problem of misalignment of the cavities axis and drift tube axis of the gyroklystron amplifier and found that the RF output power is more sensitive to misalignments in comparison to the device bandwidth. The present paper, gyroklystron device design, nonlinear analysis, and 3D PIC simulation using commercially available code had been systematically described would be of use to the high-power gyro-amplifier tube designers and research scientists.

  5. Spaceflight 2 um Tm Fiber MOPA Amplifier, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Fibertek proposes to design, develop, and test a spaceflight prototype 2051 nm thulium (Tm)-doped fiber amplifier (TDFA) optical master oscillator power amplifier...

  6. Conversion of the random amplified polymorphic DNA (RAPD ...

    African Journals Online (AJOL)

    Conversion of the random amplified polymorphic DNA (RAPD) marker UBC#116 linked to Fusarium crown and root rot resistance gene (Frl) into a co-dominant sequence characterized amplified region (SCAR) marker for marker-assisted selection of tomato.

  7. Generalized Impedance Converter (GIC) Filter Utilizing Composite Amplifier

    National Research Council Canada - National Science Library

    Cheong, Heng W

    2005-01-01

    .... A composite operational amplifier utilizing the BiCMOS standard operational amplifier that was designed and introduced in a previous thesis is presented and its improved performance is investigated...

  8. Parametric Amplifiers for Readout of Low-Temperature Detectors

    Data.gov (United States)

    National Aeronautics and Space Administration — This project aims to make microwave parametric amplifiers with high gain, large bandwidth, ultra-low noise, and low power dissipation. Our amplifiers are designed to...

  9. Charge sensitive amplifies. The state of arts

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Kunishiro [Clear Pulse Co., Tokyo (Japan)

    1996-07-01

    In the radiation detectors, signals are essentially brought with charges produced by radiation, then it is naturally the best way to use a charge sensitive amplifier (CSA) system to extract those signals. The CSA is thought to be the best amplifier suitable to almost all the radiation detectors, if neglecting economical points of view. The CSA has been only applied to special fields like radiation detection because the concept of `charges` is not so universal against the concepts of `voltage` and `current`. The CSA, however, is low in noise and a high speed amplifier and may be applicable not only to radiation measurement but also piezoelectric devices and also bolometers. In this article, noise in the CSA, basic circuit on the CSA, concepts of `equivalent noise charge` (ENC), a method for the ENC, and importance of the `open-loop gain` in the CSA to achieve better performance of it and how to realize in a practical CSA were described. And, characteristics on a counting rate of the CSA, various circuit used in the CSA, and CSAs which are commercially available at present and special purpose CSAs were also introduced. (G.K.)

  10. Invited review article: The Josephson bifurcation amplifier.

    Science.gov (United States)

    Vijay, R; Devoret, M H; Siddiqi, I

    2009-11-01

    We review the theory, fabrication, and implementation of the Josephson bifurcation amplifier (JBA). At the core of the JBA is a nonlinear oscillator based on a reactively shunted Josephson junction. A weak input signal to the amplifier couples to the junction critical current I(0) and results in a dispersive shift in the resonator plasma frequency omega(p). This shift is enhanced by biasing the junction with a sufficiently strong microwave current I(rf) to access the nonlinear regime where omega(p) varies with I(rf). For a drive frequency omega(d) such that Omega=2Q(1-omega(d)/omega(p))>3, the oscillator enters the bistable regime where two nondissipative dynamical states O(L) and O(H), which differ in amplitude and phase, can exist. The sharp I(0) dependent transition from O(L) to O(H) forms the basis for a sensitive digital threshold amplifier. In the vicinity of the bistable regime (Omegaamplifier performance and discuss two specific applications--the readout of superconducting qubits (digital mode) and dispersive microwave magnetometry (analog mode).

  11. Pump to signal noise transfer in parametric fiber amplifiers

    DEFF Research Database (Denmark)

    Lund-Hansen, Toke; Rottwitt, Karsten; Peucheret, Christophe

    2010-01-01

    Fiber optic parametric amplifiers have been suggested due to their potential low spontaneous emission. However, by nature the parametric amplifier only work in a forward pumped configuration, which result in transfer of relative intensity noise in the pump to the signal.......Fiber optic parametric amplifiers have been suggested due to their potential low spontaneous emission. However, by nature the parametric amplifier only work in a forward pumped configuration, which result in transfer of relative intensity noise in the pump to the signal....

  12. High Efficiency Power Amplifier for High Frequency Radio Transmitters

    OpenAIRE

    Vasic, Miroslav; García Suárez, Oscar; Oliver Ramírez, Jesús Angel; Alou Cervera, Pedro; Díaz López, Daniel; Cobos Márquez, José Antonio; Gimeno Martín, Alejandro; Pardo Martin, José Manuel; Benavente Peces, César; Ortega González, Francisco Javier

    2010-01-01

    Modern transmitters usually have to amplify and transmit complex communication signals with simultaneous envelope and phase modulation. Due to this property of the transmitted signal, linear power amplifiers (class A, B or AB) are usually employed as a solution for the power amplifier stage. These amplifiers have high linearity, but suffer from low efficiency when the transmitted signal has high peak-to-average power ratio. The Kahn envelope elimination and restoration (EER) technique is used...

  13. Transient processes in high-power gas laser amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Bakanina, L.P.; Belonuchkin, V.E.; Kozel, S.M.; Kuznetsov, E.P.; Lokshin, T.R.

    1980-01-01

    A system of equations is derived which describes the laser onset process in a high-gain gas laser amplifier. The intrinsic, amplified spontaneous emission plays the determinate role in the transient processes. The transient processes for a HeFe (3.39 micrometers) laser amplifier are calculated on a computer for three amplifier lengths (40, 80 and 200 centimeters) with the instantaneous onset of inversion.

  14. RAMAN amplifier gain dynamics with ASE : Numerical analysis and ...

    African Journals Online (AJOL)

    ... understanding the basic properties of the gain medium. So in this work, we demonstrate an analytical formalism and a numerical horizon of the amplified spontaneous emission (ASE) noise power for distributed Raman amplifier (DRA). Keywords: Amplified spontaneous emission (ASE), optical noise, Raman amplification ...

  15. Digital system provides superregulation of nanosecond amplifier-discriminator circuit

    Science.gov (United States)

    Forges, K. G.

    1966-01-01

    Feedback system employing a digital logic comparator to detect and correct amplifier drift provides stable gain characteristics for nanosecond amplifiers used in counting applications. Additional anticoincidence logic enables application of the regulation circuit to the amplifier and discriminator while they are mounted in an operable circuit.

  16. Development of Randomly Amplified Polymorphic DNA Based SCAR Marker for Identification of Ipomoea mauritiana Jacq (Convolvulaceae

    Directory of Open Access Journals (Sweden)

    Kambiranda Devaiah

    2011-01-01

    Full Text Available Vidari is an Ayurvedic herbal drug used as aphrodisiac, galactagogue and is also used in the preparation of Chyavanaprash. Tubers of Ipomoea mauritiana Jacq. (Convolvulaceae, Pueraria tuberosa (Roxb. ex Willd. DC (Fabaceae, Adenia hondala (Gaertn. de Wilde (Passifloraceae and pith of Cycas circinalis L. (Cycadaceae are all traded in the name of Vidari, creating issues of botanical authenticity of the Ayurvedic raw drug. DNA-based markers have been developed to distinguish I. mauritiana from the other Vidari candidates. A putative 600-bp polymorphic sequence, specific to I. mauritiana was identified using randomly amplified polymorphic DNA (RAPD technique. Furthermore, sequence characterized amplified region (SCAR primers (IM1F and IM1R were designed from the unique RAPD amplicon. The SCAR primers produced a specific 323-bp amplicon in authentic I. mauritiana and not in the allied species.

  17. Development of Randomly Amplified Polymorphic DNA Based SCAR Marker for Identification of Ipomoea mauritiana Jacq (Convolvulaceae)

    Science.gov (United States)

    Devaiah, Kambiranda; Balasubramani, Subramani Paranthaman; Venkatasubramanian, Padma

    2011-01-01

    Vidari is an Ayurvedic herbal drug used as aphrodisiac, galactagogue and is also used in the preparation of Chyavanaprash. Tubers of Ipomoea mauritiana Jacq. (Convolvulaceae), Pueraria tuberosa (Roxb. ex Willd.) DC (Fabaceae), Adenia hondala (Gaertn.) de Wilde (Passifloraceae) and pith of Cycas circinalis L. (Cycadaceae) are all traded in the name of Vidari, creating issues of botanical authenticity of the Ayurvedic raw drug. DNA-based markers have been developed to distinguish I. mauritiana from the other Vidari candidates. A putative 600-bp polymorphic sequence, specific to I. mauritiana was identified using randomly amplified polymorphic DNA (RAPD) technique. Furthermore, sequence characterized amplified region (SCAR) primers (IM1F and IM1R) were designed from the unique RAPD amplicon. The SCAR primers produced a specific 323-bp amplicon in authentic I. mauritiana and not in the allied species. PMID:21738554

  18. A low-voltage sense amplifier with two-stage operational amplifier clamping for flash memory

    Science.gov (United States)

    Guo, Jiarong

    2017-04-01

    A low-voltage sense amplifier with reference current generator utilizing two-stage operational amplifier clamp structure for flash memory is presented in this paper, capable of operating with minimum supply voltage at 1 V. A new reference current generation circuit composed of a reference cell and a two-stage operational amplifier clamping the drain pole of the reference cell is used to generate the reference current, which avoids the threshold limitation caused by current mirror transistor in the traditional sense amplifier. A novel reference voltage generation circuit using dummy bit-line structure without pull-down current is also adopted, which not only improves the sense window enhancing read precision but also saves power consumption. The sense amplifier was implemented in a flash realized in 90 nm flash technology. Experimental results show the access time is 14.7 ns with power supply of 1.2 V and slow corner at 125 °C. Project supported by the National Natural Science Fundation of China (No. 61376028).

  19. Characterization of a Common-Source Amplifier Using Ferroelectric Transistors

    Science.gov (United States)

    Hunt, Mitchell; Sayyah, Rana; MacLeond, Todd C.; Ho, Pat D.

    2010-01-01

    This paper presents empirical data that was collected through experiments using a FeFET in the established common-source amplifier circuit. The unique behavior of the FeFET lends itself to interesting and useful operation in this widely used common-source amplifier. The paper examines the effect of using a ferroelectric transistor for the amplifier. It also examines the effects of varying load resistance, biasing, and input voltages on the output signal and gives several examples of the output of the amplifier for a given input. The difference between a commonsource amplifier using a ferroelectric transistor and that using a MOSFET is addressed.

  20. High sensitivity amplifier/discriminator for PWC's

    International Nuclear Information System (INIS)

    Hansen, S.

    1983-01-01

    The facility support group at Fermilab is designing and building a general purpose beam chamber for use in several locations at the laboratory. This pwc has 128 wires per plane spaced 1 mm apart. An initial production of 25 signal planes is anticipated. In proportional chambers, the size of the signal depends exponentially on the charge stored per unit of length along the anode wire. As the wire spacing decreases, the capacitance per unit length decreases, thereby requiring increased applied voltage to restore the necessary charge per unit length. In practical terms, this phenomenon is responsible for difficulties in constructing chambers with less than 2 mm wire spacing. 1 mm chambers, therefore, are frequently operated very near to their breakdown point and/or a high gain gas containing organic compounds such as magic gas is used. This argon/iso-butane mixture has three drawbacks: it is explosive when exposed to the air, it leaves a residue on the wires after extended use and is costly. An amplifier with higher sensitivity would reduce the problems associated with operating chambers with small wire spacings and allow them to be run a safe margin below their breakdown voltage even with an inorganic gas mixture such as argon/CO2, this eliminating the need to use magic gas. Described here is a low cost amplifier with a usable threshold of less than 0.5 μA. Data on the performance of this amplifier/discriminator in operation on a prototype beam chamber are given. This data shows the advantages of the high sensitivity of this design

  1. A new semicustom integrated bipolar amplifier for silicon strip detectors

    International Nuclear Information System (INIS)

    Zimmerman, T.

    1989-01-01

    The QPA02 is a four channel DC coupled two stage transimpedance amplifier designed at Fermilab on a semicustom linear array (Quickchip 2S) manufactured by Tektronix. The chip was developed as a silicon strip amplifier but may have other applications as well. Each channel consists of a preamplifier and a second stage amplifier/sharper with differential output which can directly drive a transmission line (90 to 140 ohms). External bypass capacitors are the only discrete components required. QPA02 has been tested and demonstrated to be an effective silicon strip amplifier. Other applications may exist which can use this amplifier or a modified version of this amplifier. For example, another design is now in progress for a wire chamber amplifier, QPA03, to be reported later. Only a relatively small effort was required to modify the design and layout for this application. 11 figs

  2. Low power RF amplifier circuit for ion trap applications

    Science.gov (United States)

    Noriega, J. R.; García-Delgado, L. A.; Gómez-Fuentes, R.; García-Juárez, A.

    2016-09-01

    A low power RF amplifier circuit for ion trap applications is presented and described. The amplifier is based on a class-D half-bridge amplifier with a voltage mirror driver. The RF amplifier is composed of an RF class-D amplifier, an envelope modulator to ramp up the RF voltage during the ion analysis stage, a detector or amplitude demodulation circuit for sensing the output signal amplitude, and a feedback amplifier that linearizes the steady state output of the amplifier. The RF frequency is set by a crystal oscillator and the series resonant circuit is tuned to the oscillator frequency. The resonant circuit components have been chosen, in this case, to operate at 1 MHz. In testings, the class-D stage operated at a maximum of 78 mW at 1.1356 MHz producing 225 V peak.

  3. On Distortion in Digital Microwave Power Amplifiers

    Science.gov (United States)

    Al-Mozani, Dhamia; Wentzel, Andreas; Heinrich, Wolfgang

    2017-01-01

    In this paper, a first study of distortion in digital power amplifiers (PA) is presented. The work is based on a voltage mode class-S PA with a GaN MMIC for the 900 MHz frequency band. The investigation focuses on the quasi-static amplitude-to-amplitude (AM-AM) and amplitude-to-phase (AM-PM) distortions. Different digital modulation schemes are applied and studied versus output power back-off. This includes two pulse-width modulation (PWM) versions as well as band-pass delta-sigma (BPDS) modulation. The results are verified by measurement data.

  4. Amplifier development for multiplexed cryogenic detectors

    Science.gov (United States)

    Kiviranta, Mikko

    2012-12-01

    We make some considerations on the question of driving the cable from the cryogenic stage of refrigerators to the room temperature, in the case of multiplexed detector array systems where a high total Shannon information capacity is required. We have constructed large SQUID arrays for the purpose, some of which exhibit lower than 5 × 10-8 Φ0 Hz-1/2 flux noise at 4.2 K and do not require magnetic shielding in a typical laboratory environment. The option of using class-D amplifiers to reduce the cryogenic heat load is briefly reviewed.

  5. EMG amplifier with wireless data transmission

    Science.gov (United States)

    Kowalski, Grzegorz; Wildner, Krzysztof

    2017-08-01

    Wireless medical diagnostics is a trend in modern technology used in medicine. This paper presents a concept of realization, architecture of hardware and software implementation of an elecromyography signal (EMG) amplifier with wireless data transmission. This amplifier consists of three components: analogue processing of bioelectric signal module, micro-controller circuit and an application enabling data acquisition via a personal computer. The analogue bioelectric signal processing circuit receives electromyography signals from the skin surface, followed by initial analogue processing and preparation of the signals for further digital processing. The second module is a micro-controller circuit designed to wirelessly transmit the electromyography signals from the analogue signal converter to a personal computer. Its purpose is to eliminate the need for wired connections between the patient and the data logging device. The third block is a computer application designed to display the transmitted electromyography signals, as well as data capture and analysis. Its purpose is to provide a graphical representation of the collected data. The entire device has been thoroughly tested to ensure proper functioning. In use, the device displayed the captured electromyography signal from the arm of the patient. Amplitude- frequency characteristics were set in order to investigate the bandwidth and the overall gain of the device.

  6. Discretization analysis of bifurcation based nonlinear amplifiers

    Science.gov (United States)

    Feldkord, Sven; Reit, Marco; Mathis, Wolfgang

    2017-09-01

    Recently, for modeling biological amplification processes, nonlinear amplifiers based on the supercritical Andronov-Hopf bifurcation have been widely analyzed analytically. For technical realizations, digital systems have become the most relevant systems in signal processing applications. The underlying continuous-time systems are transferred to the discrete-time domain using numerical integration methods. Within this contribution, effects on the qualitative behavior of the Andronov-Hopf bifurcation based systems concerning numerical integration methods are analyzed. It is shown exemplarily that explicit Runge-Kutta methods transform the truncated normalform equation of the Andronov-Hopf bifurcation into the normalform equation of the Neimark-Sacker bifurcation. Dependent on the order of the integration method, higher order terms are added during this transformation.A rescaled normalform equation of the Neimark-Sacker bifurcation is introduced that allows a parametric design of a discrete-time system which corresponds to the rescaled Andronov-Hopf system. This system approximates the characteristics of the rescaled Hopf-type amplifier for a large range of parameters. The natural frequency and the peak amplitude are preserved for every set of parameters. The Neimark-Sacker bifurcation based systems avoid large computational effort that would be caused by applying higher order integration methods to the continuous-time normalform equations.

  7. Discretization analysis of bifurcation based nonlinear amplifiers

    Directory of Open Access Journals (Sweden)

    S. Feldkord

    2017-09-01

    Full Text Available Recently, for modeling biological amplification processes, nonlinear amplifiers based on the supercritical Andronov–Hopf bifurcation have been widely analyzed analytically. For technical realizations, digital systems have become the most relevant systems in signal processing applications. The underlying continuous-time systems are transferred to the discrete-time domain using numerical integration methods. Within this contribution, effects on the qualitative behavior of the Andronov–Hopf bifurcation based systems concerning numerical integration methods are analyzed. It is shown exemplarily that explicit Runge–Kutta methods transform the truncated normalform equation of the Andronov–Hopf bifurcation into the normalform equation of the Neimark–Sacker bifurcation. Dependent on the order of the integration method, higher order terms are added during this transformation.A rescaled normalform equation of the Neimark–Sacker bifurcation is introduced that allows a parametric design of a discrete-time system which corresponds to the rescaled Andronov–Hopf system. This system approximates the characteristics of the rescaled Hopf-type amplifier for a large range of parameters. The natural frequency and the peak amplitude are preserved for every set of parameters. The Neimark–Sacker bifurcation based systems avoid large computational effort that would be caused by applying higher order integration methods to the continuous-time normalform equations.

  8. A Low-Noise Transimpedance Amplifier for BLM-Based Ion Channel Recording

    Directory of Open Access Journals (Sweden)

    Marco Crescentini

    2016-05-01

    Full Text Available High-throughput screening (HTS using ion channel recording is a powerful drug discovery technique in pharmacology. Ion channel recording with planar bilayer lipid membranes (BLM is scalable and has very high sensitivity. A HTS system based on BLM ion channel recording faces three main challenges: (i design of scalable microfluidic devices; (ii design of compact ultra-low-noise transimpedance amplifiers able to detect currents in the pA range with bandwidth >10 kHz; (iii design of compact, robust and scalable systems that integrate these two elements. This paper presents a low-noise transimpedance amplifier with integrated A/D conversion realized in CMOS 0.35 μm technology. The CMOS amplifier acquires currents in the range ±200 pA and ±20 nA, with 100 kHz bandwidth while dissipating 41 mW. An integrated digital offset compensation loop balances any voltage offsets from Ag/AgCl electrodes. The measured open-input input-referred noise current is as low as 4 fA/√Hz at ±200 pA range. The current amplifier is embedded in an integrated platform, together with a microfluidic device, for current recording from ion channels. Gramicidin-A, α-haemolysin and KcsA potassium channels have been used to prove both the platform and the current-to-digital converter.

  9. Direct coupled amplifiers using field effect transistors

    International Nuclear Information System (INIS)

    Fowler, E.P.

    1964-03-01

    The concept of the uni-polar field effect transistor (P.E.T.) was known before the invention of the bi-polar transistor but it is only recently that they have been made commercially. Being produced as yet only in small quantities, their price imposes a restriction on use to circuits where their peculiar properties can be exploited to the full. One such application is described here where the combination of low voltage drift and relatively low input leakage current are necessarily used together. One of the instruments used to control nuclear reactors has a logarithmic response to the mean output current from a polarised ionisation chamber. The logarithmic signal is then differentiated electrically, the result being displayed on a meter calibrated to show the reactor divergence or doubling time. If displayed in doubling time the scale is calibrated reciprocally. Because of the wide range obtained in the logarithmic section and the limited supply voltage, an output of 1 volt per decade change in ionisation current is used. Differentiating this gives a current of 1.5 x 10 -8 A for p.s.D. (20 sec. doubling time) in the differentiating amplifier. To overcome some of the problems of noise due to statistical variations in input current, the circuit design necessitates a resistive path to ground at the amplifier input of 20 M.ohms. A schematic diagram is shown. 1. It is evident that a zero drift of 1% can be caused by a leakage current of 1.5 x 10 -10 A or an offset voltage of 3 mV at the amplifier input. Although the presently used electrometer valve is satisfactory from the point of view of grid current, there have been sudden changes in grid to grid voltage (the valve is a double triode) of up to 10 m.V. It has been found that a pair of F.E.T's. can be used to replace the electrometer valve so long as care is taken in correct balance of the two devices. An investigation has been made into the characteristics of some fourteen devices to see whether those with very

  10. Class D audio amplifiers for high voltage capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis

    Audio reproduction systems contains two key components, the amplifier and the loudspeaker. In the last 20 – 30 years the technology of audio amplifiers have performed a fundamental shift of paradigm. Class D audio amplifiers have replaced the linear amplifiers, suffering from the well-known issues...... of high volume, weight, and cost. High efficient class D amplifiers are now widely available offering power densities, that their linear counterparts can not match. Unlike the technology of audio amplifiers, the loudspeaker is still based on the traditional electrodynamic transducer invented by C.W. Rice...... and E.W. Kellog in 1925 [1]. The poor efficiency of the electrodynamic transducer remains a key issue, and a significant limit of the efficiency of the complete audio reproduction systems. Also the geometric limits of the electrodynamic transducer imposes significant limits on the design of loudspeakers...

  11. A highly linear power amplifier for WLAN

    International Nuclear Information System (INIS)

    Jin Jie; Shi Jia; Ai Baoli; Zhang Xuguang

    2016-01-01

    A three-stage power amplifier (PA) for WLAN application in 2.4-2.5 GHz is presented. The proposed PA employs an adaptive bias circuit to adjust the operating point of the PA to improve the linearity of the PA. Two methods to short the 2nd harmonic circuit are compared in the area of efficiency and gain of the PA. The PA is taped out in the process of 2 μm InGaP/GaAs HBT and is tested by the evaluation board. The measured results show that 31.5 dB power gain and 29.3 dBm P 1dB with an associated 40.4% power added efficiency (PAE) under the single tone stimulus. Up to 26.5 dBm output power can be achieved with an error vector magnitude (EVM) of lower than 3% under the 64QAM/OFDM WLAN stimulus. (paper)

  12. Rippled beam free electron laser amplifier

    Science.gov (United States)

    Carlsten, Bruce E.

    1999-01-01

    A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a TM.sub.0n mode. A waveguide defines an axial centerline and, a solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.

  13. Self-amplified optical pattern recognition system

    Science.gov (United States)

    Liu, Hua-Kuang (Inventor)

    1994-01-01

    A self amplifying optical pattern recognizer includes a geometric system configuration similar to that of a Vander Lugt holographic matched filter configuration with a photorefractive crystal specifically oriented with respect to the input beams. An extraordinarily polarized, spherically converging object image beam is formed by laser illumination of an input object image and applied through a photorefractive crystal, such as a barium titanite (BaTiO.sub.3) crystal. A volume or thin-film dif ORIGIN OF THE INVENTION The invention described herein was made in the performance of work under a NASA contract, and is subject to the provisions of Public Law 96-517 (35 USC 202) in which the Contractor has elected to retain title.

  14. Noise-driven neuromorphic tuned amplifier

    Science.gov (United States)

    Fanelli, Duccio; Ginelli, Francesco; Livi, Roberto; Zagli, Niccoló; Zankoc, Clement

    2017-12-01

    We study a simple stochastic model of neuronal excitatory and inhibitory interactions. The model is defined on a directed lattice and internodes couplings are modulated by a nonlinear function that mimics the process of synaptic activation. We prove that such a system behaves as a fully tunable amplifier: the endogenous component of noise, stemming from finite size effects, seeds a coherent (exponential) amplification across the chain generating giant oscillations with tunable frequencies, a process that the brain could exploit to enhance, and eventually encode, different signals. On a wider perspective, the characterized amplification process could provide a reliable pacemaking mechanism for biological systems. The device extracts energy from the finite size bath and operates as an out of equilibrium thermal machine, under stationary conditions.

  15. Gain characteristics of erbium doped fiber amplifier

    Science.gov (United States)

    Zhang, Lihua; Du, Yungang; Xi, Ying; Li, Jijun; Zhao, Chunwang

    2008-12-01

    In the design of Erbium Doped Fiber Amplifier (EDFA), improving flat-gain has great important significance. The working principle and gain characteristics of EDFA are introduced briefly, the influence of the factors such as Erbium doped fiber (EDF) length and pump power on the gain of EDFA is analyzed in detail, and the simulation experiments were carried out with Optisystem software. The result shows that, when pump power is constant, with EDF length departing the optimal value, the gain of each channel decreases at different degrees; when EDF length is constant, with pump power departing the optimal value, the gain of each channel changes at different degrees. Moreover, Er3+ concentration has significant effect on the gain, and there is an optimal Er3+ concentration to get the largest gain.

  16. Coherent combination of ultrafast fiber amplifiers

    International Nuclear Information System (INIS)

    Hanna, Marc; Guichard, Florent; Druon, Frédéric; Georges, Patrick; Zaouter, Yoann; Papadopoulos, Dimitris N

    2016-01-01

    We review recent progress in coherent combining of femtosecond pulses amplified in optical fibers as a way to scale the peak and average power of ultrafast sources. Different methods of achieving coherent pulse addition in space (beam combining) and time (divided pulse amplification) domains are described. These architectures can be widely classified into active methods, where the relative phases between pulses are subject to a servomechanism, and passive methods, where phase matching is inherent to the geometry. Other experiments that combine pulses with different spectral contents, pulses that have been nonlinearly broadened or successive pulses from a mode-locked laser oscillator, are then presented. All these techniques allow access to unprecedented parameter range for fiber ultrafast sources. (topical review)

  17. Compressed magnetic flux amplifier with capacitive load

    International Nuclear Information System (INIS)

    Stuetzer, O.M.

    1980-03-01

    A first-order analysis is presented for a compressed magnetic flux (CMF) current amplifier working into a load with a capacitive component. Since the purpose of the investigation was to gain a general understanding of the arrangement, a number of approximations and limitations were accepted. The inductance of the transducer varies with time; the inductance/resistance/capacitance (LRC) circuit therefore is parametric and solutions are different for the stable regime (high C), the oscillation regime (low C), and the transition case. Solutions and performance depend strongly on circuit boundary conditions, i.e., energization of the circuit by either an injected current or by an applied capacitor charge. The behavior of current and energy amplification for the various cases are discussed in detail. A number of experiments with small CMF devices showed that the first-order theory presented predicts transducer performance well in the linear regime

  18. InP Heterojunction Bipolar Transistor Amplifiers to 255 GHz

    Science.gov (United States)

    Radisic, Vesna; Sawdai, Donald; Scott, Dennis; Deal, William; Dang, Linh; Li, Danny; Cavus, Abdullah; To, Richard; Lai, Richard

    2009-01-01

    Two single-stage InP heterojunction bipolar transistor (HBT) amplifiers operate at 184 and 255 GHz, using Northrop Grumman Corporation s InP HBT MMIC (monolithic microwave integrated circuit) technology. At the time of this reporting, these are reported to be the highest HBT amplifiers ever created. The purpose of the amplifier design is to evaluate the technology capability for high-frequency designs and verify the model for future development work.

  19. Modeling and design techniques for RF power amplifiers

    CERN Document Server

    Raghavan, Arvind; Laskar, Joy

    2008-01-01

    The book covers RF power amplifier design, from device and modeling considerations to advanced circuit design architectures and techniques. It focuses on recent developments and advanced topics in this area, including numerous practical designs to back the theoretical considerations. It presents the challenges in designing power amplifiers in silicon and helps the reader improve the efficiency of linear power amplifiers, and design more accurate compact device models, with faster extraction routines, to create cost effective and reliable circuits.

  20. GaN-based Power amplifiers for microwave applications

    Directory of Open Access Journals (Sweden)

    Jorge Julián Moreno-Rubio

    2016-01-01

    Full Text Available This paper presents a discussion about the design strategies of different kind of power amplifiers for RF/Microwave appli- cations, such as the tuned load power amplifier, class F, class F-1 and Doherty. Furthermore, it is shown the continuous wave characterization of the amplifiers above mentioned. A comparison between the obtained results, in terms of gain, efficiency and output power is presented.

  1. Therapeutic Strategies Against Cyclin E1 Amplified Ovarian Cancers

    Science.gov (United States)

    2017-10-01

    hypothesize that HSP90-inhibitors may be effective against CCNE1-amplified ovarian tumors because they suppress HR, downregulate BRCA1, and...of FOXM1 and RB interaction is an effective approach for targeting CCNE1-amplified ovarian tumors . Specifically, suppression of FOXM1/RB...cells. In the third aim, we hypothesize that miR-1255b, miR-148b*, and miR-193b* may be effective against CCNE1- amplified ovarian tumors in

  2. Modeling a Common-Source Amplifier Using a Ferroelectric Transistor

    Science.gov (United States)

    Sayyah, Rana; Hunt, Mitchell; MacLeond, Todd C.; Ho, Fat D.

    2010-01-01

    This paper presents a mathematical model characterizing the behavior of a common-source amplifier using a FeFET. The model is based on empirical data and incorporates several variables that affect the output, including frequency, load resistance, and gate-to-source voltage. Since the common-source amplifier is the most widely used amplifier in MOS technology, understanding and modeling the behavior of the FeFET-based common-source amplifier will help in the integration of FeFETs into many circuits.

  3. Dual Band High Efficiency Power Amplifier Based on CRLH Lines

    Directory of Open Access Journals (Sweden)

    D. Segovia-Vargas

    2009-12-01

    Full Text Available In this paper we propose the use of Composite Right/Left Hand (CRLH and Extended Composite Right/Left Hand (ECRLH transmission lines for the design of dual band high efficiency power amplifiers working in CE class. The harmonic termination can be synthesized using the meta-lines is particularly suitable for CE class amplifiers, which have a termination not as sensitive to the third harmonic as F class amplifier. This paper presents the design procedure and the design equations. The nonlinear phase response of a CRLH and ECRLH transmission line has been utilized to design arbitrary dual-band amplifiers.

  4. Pulse shaping amplifier (PSA) for nuclear spectroscopy system

    International Nuclear Information System (INIS)

    Lombigit, L.; Maslina Mohd Ibrahim; Nolida Yusup; Nur Aira Abdul Rahman; Yong, C.F.

    2014-01-01

    Pulse Shaping Amplifier (PSA) is an essential components in nuclear spectroscopy system. This networks have two functions; to shape the output pulse and performs noise filtering. In this paper, we describes procedure for design and development of a pulse shaping amplifier which can be used for nuclear spectroscopy system. This prototype was developed using high performance electronics devices and assembled on a FR4 type printed circuit board. Performance of this prototype was tested by comparing it with an equivalent commercial spectroscopy amplifier (Model SILENA 7611). The test results show that the performance of this prototype is comparable to the commercial spectroscopic amplifier. (author)

  5. Nylon Sleeve for Cavity Amplifier Holds Tuning Despite Heat

    Science.gov (United States)

    Derr, Lloyd

    1964-01-01

    The problem: Detuning of cavity amplifiers with change in temperature. This results in deterioration of the performance of the amplifier at its design frequency. In cavity amplifiers and filters it is desirable that constant performance be maintained regardless of thermal changes. These changes often cause an "off resonance shift" in a cavity filter and a deterioration of performance in a cavity amplifier. The solution: Mount the tuning probe in a nylon sleeve. Thermal expansion and contraction of the nylon nullifies unwanted capacitive and inductive changes in the resonant elements.

  6. Switching-mode Audio Power Amplifiers with Direct Energy Conversion

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    has been replaced with a high frequency AC link. When compared to the conventional Class D amplifiers with a separate DC power supply, the proposed single conversion stage amplifier provides simple and compact solution with better efficiency and higher level of integration, leading to reduced......This paper presents a new class of switching-mode audio power amplifiers, which are capable of direct energy conversion from the AC mains to the audio output. They represent an ultimate integration of a switching-mode power supply and a Class D audio power amplifier, where the intermediate DC bus...

  7. Ring cavity for a Raman capillary waveguide amplifier

    Science.gov (United States)

    Kurnit, N.A.

    1981-01-27

    A regenerative ring amplifier and regenerative ring oscillator are described which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplified Stokes signal is synchronous with the mode-locked spikes of the incoming CO/sub 2/ laser pump signal.

  8. Controlling the dynamic range of a Josephson parametric amplifier

    International Nuclear Information System (INIS)

    Eichler, Christopher; Wallraff, Andreas

    2014-01-01

    One of the central challenges in the development of parametric amplifiers is the control of the dynamic range relative to its gain and bandwidth, which typically limits quantum limited amplification to signals which contain only a few photons per inverse bandwidth. Here, we discuss the control of the dynamic range of Josephson parametric amplifiers by using Josephson junction arrays. We discuss gain, bandwidth, noise, and dynamic range properties of both a transmission line and a lumped element based parametric amplifier. Based on these investigations we derive useful design criteria, which may find broad application in the development of practical parametric amplifiers. (orig.)

  9. Matching of scattered radiation with a laser amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Kozel, S.M.; Lokshin, G.R.

    1975-08-01

    The question of choosing the aperture of an optical system to be used for matching a weak scattered field with a laser amplifier is examined. It is shown that in the case of a regenerative amplifier the maximum energy of the received signal is equal to the energy of the radiation in the coherence area. In the case of a traveling-wave amplifier the effectively usable energy of the scattered field is determined by the amplifier geometry and can be significantly larger (by several orders of magnitude) than the average energy in one diffraction spot.

  10. Drug Facts

    Medline Plus

    Full Text Available ... Why Is It So Hard to Quit Drugs? Effects of Drugs Drug Use and Other People Drug ... Unborn Children Drug Use and Your Health Other Effects on the Body Drug Use Hurts Brains Drug ...

  11. Towards a THz Backward Wave Amplifier in European FP7 OPTHER Project

    DEFF Research Database (Denmark)

    Dispenza, Massimiliano; Cojocaru, C.-S.; De Rossi, Alfredo

    2010-01-01

    Within the EC funded international project OPTHER (OPtically Driven TeraHertz AmplifiERs) a considerable technological effort is being undertaken, in terms of technological development, THz device design and integration. The ultimate goal is to develop a miniaturised THz amplifier based on vacuum...... with a proper device configuration and careful optimization of the different parts of the amplifier. Two parallel schemes will be employed for amplifier realisation: THz Drive Signal Amplifier and Optically Modulated Beam THz Amplifier....

  12. A 205GHz Amplifier in 90nm CMOS Technology

    Science.gov (United States)

    2017-03-01

    disadvantages at the higher frequency range with the worst case scenario happening when the device operates near its fmax. This is chiefly due to...measured S-parameters of the fabricated 205GHz amplifier. C1     in out 14.17-17.50 GHz Signal Generator   Amplifier/ Multiplier   0.9 V

  13. A Power Efficient Audio Amplifier Combining Switching and Linear Techniques

    NARCIS (Netherlands)

    van der Zee, Ronan A.R.; van Tuijl, Adrianus Johannes Maria

    1998-01-01

    Integrated Class D audio amplifiers are very power efficient, but require an external filter which prevents further integration. Also due to this filter, large feedback factors are hard to realise, so that the load influences the distortion- and transfer characteristics. The amplifier presented in

  14. 47 CFR 2.815 - External radio frequency power amplifiers.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false External radio frequency power amplifiers. 2... AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.815 External radio frequency power amplifiers. (a) As used in this part, an external radio frequency power...

  15. External Peltier Cooler For Low-Noise Amplifier

    Science.gov (United States)

    Soper, Terry A.

    1990-01-01

    Inexpensive Peltier-effect cooling module made of few commercially available parts used to reduce thermal noise in microwave amplifier. Retrofitted to almost any microwave low-noise amplifier or receiver preamplifier used in communication, telemetry, or radar. Includes copper or aluminum cold plate held tightly against unit to be cooled by strap-type worm-gear clamps.

  16. Energy Efficient and Compact RF High-Power Amplifiers

    NARCIS (Netherlands)

    Calvillo Cortés, D.A.

    2014-01-01

    The main objectives of this thesis are to improve the energy efficiency and physical form-factor of high-power amplifiers in base station applications. As such, the focus of this dissertation is placed on the outphasing amplifier concept, which can offer high-efficiency, good linearity and excellent

  17. PHEMT Distributed Power Amplifier Adopting Broadband Impedance Transformer

    DEFF Research Database (Denmark)

    Narendra, K.; Limiti, E.; Paoloni, C.

    2013-01-01

    A non-uniform drain line distributed power amplifier (DPA) employing a broadband impedance transformer is presented. The DPA is based on GaAs PHEMT technology. The impedance transformer employs asymmetric coupled lines and transforms a low output impedance of the amplifier to a standard 50 Ω tran...

  18. Optically amplifying planar glass waveguides: Laser on a chip

    DEFF Research Database (Denmark)

    Guldberg-Kjær, Søren Andreas

    The objective of this work was to devlop optically amplifying planar wavguides, using erbium-doped germano-silicate glass films deposited by PECVD (Plasma Enhanced Chemical Vapour Deposition). The waveguides should exhibit enough gain to be useful as optical amplifiers in integrated planar lightw...

  19. Modeling Distortion Effects in Class-D Amplifier Filter Inductors

    DEFF Research Database (Denmark)

    Knott, Arnold; Stegenborg-Andersen, Tore; Thomsen, Ole Cornelius

    2010-01-01

    Distortion is generally accepted as a quantifier to judge the quality of audio power amplifiers. In switchmode power amplifiers various mechanisms influence this performance measure. After giving an overview of those, this paper focuses on the particular effect of the nonlinearity of the output...

  20. Methylation sensitive-sequence related amplified polymorphism (MS ...

    African Journals Online (AJOL)

    Methylation sensitive-sequence related amplified polymorphism (MS-SRAP) marker system and its application to de novo methylation detection in Brassica napus. ... Combined methylation sensitive restriction enzyme digested genomic DNA with SRAP and methylation sensitive-sequence related amplified polymorphism ...

  1. Ultrafast Dynamics of Quantum-Dot Semiconductor Optical Amplifiers

    DEFF Research Database (Denmark)

    Poel, Mike van der; Hvam, Jørn Märcher

    2007-01-01

    We report on a series of experiments on the dynamical properties of quantum-dot semiconductor optical amplifiers. We show how the amplifier responds to one or several ultrafast (170 fs) pulses in rapid succession and our results demonstrate applicability and ultimate limitations to application...

  2. A Review of High Voltage Drive Amplifiers for Capacitive Actuators

    DEFF Research Database (Denmark)

    Huang, Lina; Zhang, Zhe; Andersen, Michael A. E.

    2012-01-01

    This paper gives an overview of the high voltage amplifiers, which are used to drive capacitive actuators. The amplifiers for both piezoelectric and DEAP (dielectric electroactive polymer) actuator are discussed. The suitable topologies for driving capacitive actuators are illustrated in detail...

  3. CARM and harmonic gyro-amplifier experiments at 17 GHz

    International Nuclear Information System (INIS)

    Menninger, W.L.; Danly, B.G.; Alberti, S.; Chen, C.; Rullier, J.L.; Temkin, R.J.

    1993-01-01

    Cyclotron resonance maser amplifiers are possible sources for applications such as electron cyclotron resonance heating of fusion plasmas and driving high-gradient rf linear accelerators. For accelerator drivers, amplifiers or phase locked-oscillators are required. A 17 GHz cyclotron autoresonance maser (CARM) amplifier experiment and a 17 GHz third harmonic gyro-amplifier experiment are presently underway at the MIT Plasma Fusion Center. Using the SRL/MIT SNOMAD II introduction accelerator to provide a 380 kV, 180 A, 30 ns flat top electron beam, the gyro-amplifier experiment has produced 5 MW of rf power with over 50 dB of gain at 17 GHz. The gyro-amplifier operates in the TE 31 mode using a third harmonic interaction. Because of its high power output, the gyro-amplifier will be used as the rf source for a photocathode rf electron gun experiment also taking place at MIT. Preliminary gyro-amplifier results are presented, including measurement of rf power, gain versus interaction length, and the far-field pattern. A CARM experiment designed to operate in the TE 11 mode is also discussed

  4. A novel method to design variable gain amplifier | Mahdavi | Journal ...

    African Journals Online (AJOL)

    A novel method to design variable gain amplifier. S Mahdavi, A Soltani, M Jafarzadeh, T Moradi Khanshan. Abstract. A novel method to design of Variable gain Amplifiers (VGAs) is proposed. A low power VGA with wide range of gain variation and appropriate bandwidth using new technique is presented in this paper.

  5. Fast processes in semiconductor optical amplifiers: theory and experiment

    DEFF Research Database (Denmark)

    Mørk, Jesper

    2002-01-01

    We review the physical processes responsible for ultrafast gain and index dynamics in semiconductor optical amplifiers and discuss their impact on optical switching applications......We review the physical processes responsible for ultrafast gain and index dynamics in semiconductor optical amplifiers and discuss their impact on optical switching applications...

  6. Slow Light at High Frequencies in an Amplifying Semiconductor Waveguide

    DEFF Research Database (Denmark)

    Öhman, Filip; Yvind, Kresten; Mørk, Jesper

    2006-01-01

    We demonstrate slow-down of a modulated light signal in a semiconductor waveguide. Concatenated amplifying and absorbing sections simultaneously achieve both amplification and a controllable time delay at 15 GHz.......We demonstrate slow-down of a modulated light signal in a semiconductor waveguide. Concatenated amplifying and absorbing sections simultaneously achieve both amplification and a controllable time delay at 15 GHz....

  7. Efficiency of random amplified polymorphic DNA (RAPD) and inter ...

    African Journals Online (AJOL)

    Efficiency of random amplified polymorphic DNA (RAPD) and inter-simple sequence repeats (ISSR) markers for genotype fingerprinting and genetic diversity studies in canola ( ) ... The number of amplified fragments with RAPD primers ranged from 8 to 21, with the size of amplicons ranging from 162 to 3154 bp.

  8. Thermal-recovery of modal instability in rod fiber amplifiers

    DEFF Research Database (Denmark)

    Jørgensen, Mette Marie; Laurila, Marko; Noordegraaf, Danny

    2013-01-01

    We investigate the temporal dynamics of Modal instabilities (MI) in ROD fiber amplifiers using a 100 μm core rod fiber in a single-pass amplifier configuration, and we achieve ~200W of extracted output power before the onset of MI. Above the MI threshold, we investigate the temporal dynamics...

  9. Subjective test of class D amplifiers without output filter

    DEFF Research Database (Denmark)

    Agerkvist, Finn T.; Fenger, Lars M.

    2004-01-01

    This paper presents the results of subjective listening tests designed to determine whether the output filter on class D amplifiers used in active loudspeakers can be omitted without audible errors occurring. The frequency range of the amplifiers was limited to 0-3 kHz corresponding to a woofer...

  10. Gain characteristics of a saturated fiber optic parametric amplifier

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Lorenzen, Michael Rodas; Noordegraaf, Danny

    2008-01-01

    In this work we discuss saturation performance of a fiber optic parametric amplifier. A simple numerical model is described and applied to specific cases. A system experiment using a saturated amplifier illustrates a 4 dB improvement in required signal to noise ratio for a fixed bit error ratio....

  11. Amplifying Islam : Pluralism, Secularism, and Religious Sounds in The Netherlands

    NARCIS (Netherlands)

    Tamimi Arab, P.

    2015-01-01

    This dissertation is an ethnographic study of the amplified azan, the Islamic call to prayer, in the Netherlands, adding a sonic dimension to analyses of the politics of Islamic aesthetics in the western world. Often rejected by opponents as noise pollution, facilitating the amplified azan is an

  12. Fiber optic signal amplifier using thermoelectric power generation

    Science.gov (United States)

    Hart, Mark M.

    1995-01-01

    A remote fiber optic signal amplifier for use as a repeater/amplifier, such as in transoceanic communications, powered by a Pu.sub.238 or Sr.sub.90 thermoelectric generator. The amplifier comprises a unit with connections on the receiving and sending sides of the communications system, and an erbium-doped fiber amplifier connecting each sending fiber to each receiving fiber. The thermoelectric generator, preferably a Pu.sub.238 or Sr.sub.90 thermoelectric generator delivers power to the amplifiers through a regulator. The heat exchange surfaces of the thermoelectric generator are made of materials resistant to corrosion and biological growth and are directly exposed to the outside, such as the ocean water in transoceanic communications.

  13. Cryogenic ultra-low-noise SiGe transistor amplifier.

    Science.gov (United States)

    Ivanov, B I; Trgala, M; Grajcar, M; Il'ichev, E; Meyer, H-G

    2011-10-01

    An ultra-low-noise one-stage SiGe heterojunction bipolar transistor amplifier was designed for cryogenic temperatures and a frequency range of 10 kHz-100 MHz. A noise temperature T(N) ≈ 1.4 K was measured at an ambient temperature of 4.2 K at frequencies between 100 kHz and 100 MHz for a source resistance of ~50 Ω. The voltage gain of the amplifier was 25 dB at a power consumption of 720 μW. The input voltage noise spectral density of the amplifier is about 35 pV/√Hz. The low noise resistance and power consumption makes the amplifier suitable for readout of resistively shunted DC SQUID magnetometers and amplifiers.

  14. Airborne Methane Measurements using Optical Parametric Amplifiers

    Science.gov (United States)

    Riris, H.; Numata, K.; Li, S.; Wu, S.; Ramanathan, A.; Dawsey, M.; Abshire, J. B.; Kawa, S. R.; Mao, J.

    2012-12-01

    We report on airborne methane measurements with an active sensing instrument using widely tunable, seeded optical parametric generation (OPG). Methane is a strong greenhouse gas on Earth and it is also a potential biogenic marker on Mars and other planetary bodies. Methane in the Earth's atmosphere survives for a shorter time than CO2 but its impact on climate change can be larger than CO2. Carbon and methane emissions from land are expected to increase as permafrost melts exposing millennial-age carbon stocks to respiration (aerobic-CO2 and anaerobic-CH4) and fires. Methane emissions from clathrates in the Arctic Ocean and on land are also likely to respond to climate warming. However, there is considerable uncertainty in present Arctic flux levels, as well as how fluxes will change with the changing environment and more measurements are needed. In this paper we report on an airborne demonstration of atmospheric methane column optical depth measurements at 1.65 μm using widely tunable, seeded optical parametric amplifier (OPA) and a photon counting detector. Our results show good agreement between the experimentally derived optical depth measurements and theoretical calculations and follow the expected changes for aircraft altitudes from 3 to 11 km. The technique has also been used to measure carbon dioxide and monoxide, water vapor, and other trace gases in the near and mid-infrared spectral regions on the ground.

  15. Efficient and Compact Optical Amplifier Using EYDF

    Directory of Open Access Journals (Sweden)

    Sulaiman Wadi Harun

    2010-09-01

    Full Text Available An efficient Erbium/Ytterbium doped fiber amplifier (EYDFA is demonstrated using a 1058nm pumping wavelength, where the amplification is assisted by energy transfer between Yb and Er ions. The energy transfer increases the limit of erbium doping concentration that is imposed by concentration quenching in Erbium-doped fiber (EDF. Therefore, the gain and noise figure are severely degraded with 1480 nm pumping, where the energy transfer cannot be achieved. The use of optical isolator improves the small signal gain and noise figure by about 4.8 dB and 1.6 dB, respectively. By employing a double-pass configuration, a higher gain can be obtained with an expense of a noise figure penalty. The gain improvement of 17.0 dB is obtained at 20 mW and -50 dBm of pump and input signal powers. This shows that the double-pass configuration is an important aspect to consider when designing an efficient EYDFA.

  16. Gold Nanoparticle Labels Amplify Ellipsometric Signals

    Science.gov (United States)

    Venkatasubbarao, Srivatsa

    2008-01-01

    The ellipsometric method reported in the immediately preceding article was developed in conjunction with a method of using gold nanoparticles as labels on biomolecules that one seeks to detect. The purpose of the labeling is to exploit the optical properties of the gold nanoparticles in order to amplify the measurable ellipsometric effects and thereby to enable ultrasensitive detection of the labeled biomolecules without need to develop more-complex ellipsometric instrumentation. The colorimetric, polarization, light-scattering, and other optical properties of nanoparticles depend on their sizes and shapes. In the present method, these size-and-shape-dependent properties are used to magnify the polarization of scattered light and the diattenuation and retardance of signals derived from ellipsometry. The size-and-shape-dependent optical properties of the nanoparticles make it possible to interrogate the nanoparticles by use of light of various wavelengths, as appropriate, to optimally detect particles of a specific type at high sensitivity. Hence, by incorporating gold nanoparticles bound to biomolecules as primary or secondary labels, the performance of ellipsometry as a means of detecting the biomolecules can be improved. The use of gold nanoparticles as labels in ellipsometry has been found to afford sensitivity that equals or exceeds the sensitivity achieved by use of fluorescence-based methods. Potential applications for ellipsometric detection of gold nanoparticle-labeled biomolecules include monitoring molecules of interest in biological samples, in-vitro diagnostics, process monitoring, general environmental monitoring, and detection of biohazards.

  17. Status Report on the Energy Amplifier

    CERN Document Server

    Rubbia, Carlo

    1994-01-01

    0ne year after its first presentation,the Energy Amplifier (EA) Project holds its promises for a environmentally acceptable form of energy extraction from nuclei, namely to eliminate or at least greatly reduce(i) the environmental impact of the long-lived highly radioactive waste;(ii) the possibility of diversions toward military applications;(iii) the risks of an accidental divergence related to the critical operation of the chain reaction and (iv) make a more efficient use of a fuel which is less radio-toxic to extract and more abundant on Earth than Uranium. In these respects the EA (or equivalent scenarios from Los Alamos and elsewhere) is comparable in performance to Thermonuclear Fusion. Bot h approches offer pratically unl;imited fuel resources: the energetic content of Lithium on the Earth's crust needed by Fusion is estimated to be seven times the one of Thorium and they are both adequate for millions of years of very intensived utilisation.However the EA can be built economically,in a variety of siz...

  18. Globalization to amplify economic climate losses

    Science.gov (United States)

    Otto, C.; Wenz, L.; Levermann, A.

    2015-12-01

    Economic welfare under enhanced anthropogenic carbon emissions and associated future warming poses a major challenge for a society with an evolving globally connected economy. Unabated climate change will impact economic output for example through heat-stress-related reductions in productivity. Since meteorologically-induced production reductions can propagate along supply chains, structural changes in the economic network may influence climate-related losses. The role of the economic network evolution for climate impacts has been neither quantified nor qualitatively understood. Here we show that since the beginning of the 21st century the structural change of the global supply network has been such that an increase of spillover losses due to unanticipated climatic events has to be expected. We quantify primary, secondary and higher-order losses from reduced labor productivity under past and present economic and climatic conditions and find that indirect losses are significant and increase with rising temperatures. The connectivity of the economic network has increased in such a way as to foster the propagation of production loss. This supply chain connectivity robustly exhibits the characteristic distribution of self-organized criticality which has been shifted towards higher values since 2001. Losses due to this structural evolution dominated over the effect of comparably weak climatic changes during this decade. Our finding suggests that the current form of globalization may amplify losses due to climatic extremes and thus necessitate structural adaptation that requires more foresight than presently prevalent.

  19. Drug Facts

    Medline Plus

    Full Text Available ... Facts Search form Search Menu Home Drugs That People Abuse Alcohol Facts Bath Salts Facts Cocaine (Coke, ... Drugs? Effects of Drugs Drug Use and Other People Drug Use and Families Drug Use and Kids ...

  20. Drug Facts

    Medline Plus

    Full Text Available ... Get Addicted to Drugs? Does Addiction Run in Families? Why Is It So Hard to Quit Drugs? ... Drug Use and Other People Drug Use and Families Drug Use and Kids Drug Use and Unborn ...

  1. Drug Facts

    Medline Plus

    Full Text Available ... People Drug Use and Families Drug Use and Kids Drug Use and Unborn Children Drug Use and ... Children and Teens Stay Drug-Free Talking to Kids About Drugs: What to Say if You Used ...

  2. Fibrin-targeting peptide CREKA-conjugated multi-walled carbon nanotubes for self-amplified photothermal therapy of tumor.

    Science.gov (United States)

    Zhang, Bo; Wang, Huafang; Shen, Shun; She, Xiaojian; Shi, Wei; Chen, Jun; Zhang, Qizhi; Hu, Yu; Pang, Zhiqing; Jiang, Xinguo

    2016-02-01

    Inability of nanomedicine to efficiently home to tumor site still poses great challenge in tumor drug delivery. Inspired by the amplified formation of fibrin in clotting cascade, a self-amplified drug delivery system was developed for tumor photothermal therapy (CMWNTs-PEG) using multi-walled carbon nanotubes (MWNTs) with favorable photothermal effect as the vector, polyethylene glycol as the shelter, CREKA peptide with special affinity for fibrin as the targeting moiety and NIR illumination as the external power. The self-amplified targeting property was carefully characterized. The in vivo temperature monitoring experiment demonstrated that CMWNTs-PEG could significantly elevate the temperature in the tumor region than its counterpart 24 h post an initial NIR illumination. The in vivo imaging and biodistribution experiment showed IR783-labeled CMWNTs-PEG with illumination could accumulate in tumors tissues about 6.4-fold higher than control group, much stronger than other treatment groups. In vivo distribution experiments revealed Cy3-labeled CMWNTs-PEG could deposit on the wall of tumor vessels, intravascular and extravascular spaces, far more extensive than its counterpart in tumor slices. The pharmacodynamics experiment revealed that after four times of illumination, the CMWNTs-PEG almost totally eradiated the tumor xenografts. Altogether, the self-amplified targeting system CMWNTs-PEG showed strong tumor targeting capacity and powerful photothermal therapeutic efficacy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. A modular positive feedback-based gene amplifier

    Directory of Open Access Journals (Sweden)

    Bhalerao Kaustubh D

    2010-02-01

    Full Text Available Abstract Background Positive feedback is a common mechanism used in the regulation of many gene circuits as it can amplify the response to inducers and also generate binary outputs and hysteresis. In the context of electrical circuit design, positive feedback is often considered in the design of amplifiers. Similar approaches, therefore, may be used for the design of amplifiers in synthetic gene circuits with applications, for example, in cell-based sensors. Results We developed a modular positive feedback circuit that can function as a genetic signal amplifier, heightening the sensitivity to inducer signals as well as increasing maximum expression levels without the need for an external cofactor. The design utilizes a constitutively active, autoinducer-independent variant of the quorum-sensing regulator LuxR. We experimentally tested the ability of the positive feedback module to separately amplify the output of a one-component tetracycline sensor and a two-component aspartate sensor. In each case, the positive feedback module amplified the response to the respective inducers, both with regards to the dynamic range and sensitivity. Conclusions The advantage of our design is that the actual feedback mechanism depends only on a single gene and does not require any other modulation. Furthermore, this circuit can amplify any transcriptional signal, not just one encoded within the circuit or tuned by an external inducer. As our design is modular, it can potentially be used as a component in the design of more complex synthetic gene circuits.

  4. Class-E Amplifier Design Improvements for GSM Frequencies

    Directory of Open Access Journals (Sweden)

    Z. Nadir

    2011-06-01

    Full Text Available Efficient power amplifiers are essential in portable battery-operated systems such as mobile phones. Also, the power amplifier (PA is the most power-consuming building block in the transmitter of a portable system. This paper investigates how the efficiency of the power amplifier (which is beneficial for multiple applications in communcation sector can be improved by increasing the efficiency of switching mode class E power amplifiers for frequencies of 900 MHz and 1800 MHz. The paper tackles modeling, design improvements and verification through simulation for higher efficiencies. This is the continuation of previous work by the authors. These nonlinear power amplifiers can only amplify constant-envelope RF signals without introducing significant distortion. Mobile systems such as Advanced Mobile Phone System (AMPS and Global System for Mobile communications (GSM use modulation schemes which generate constant amplitude RF outputs in order to use efficient but nonlinear power amplifiers. Improvements in designs are suggested and higher efficiencies are achieved, to the tune of 67.1% (for 900 MHz and 67.0% (1800 MHz.

  5. MMIC DHBT Common-Base Amplifier for 172 GHz

    Science.gov (United States)

    Paidi, Vamsi; Griffith, Zack; Wei, Yun; Dahlstrom, Mttias; Urteaga, Miguel; Rodwell, Mark; Samoska, Lorene; Fung, King Man; Schlecht, Erich

    2006-01-01

    Figure 1 shows a single-stage monolithic microwave integrated circuit (MMIC) power amplifier in which the gain element is a double-heterojunction bipolar transistor (DHBT) connected in common-base configuration. This amplifier, which has been demonstrated to function well at a frequency of 172 GHz, is part of a continuing effort to develop compact, efficient amplifiers for scientific instrumentation, wide-band communication systems, and radar systems that will operate at frequencies up to and beyond 180 GHz. The transistor is fabricated from a layered structure formed by molecular beam epitaxy in the InP/InGaAs material system. A highly doped InGaAs base layer and a collector layer are fabricated from the layered structure in a triple mesa process. The transistor includes two separate emitter fingers, each having dimensions of 0.8 by 12 m. The common-base configuration was chosen for its high maximum stable gain in the frequency band of interest. The input-matching network is designed for high bandwidth. The output of the transistor is matched to a load line for maximum saturated output power under large-signal conditions, rather than being matched for maximum gain under small-signal conditions. In a test at a frequency of 172 GHz, the amplifier was found to generate an output power of 7.5 mW, with approximately 5 dB of large-signal gain (see Figure 2). Moreover, the amplifier exhibited a peak small-signal gain of 7 dB at a frequency of 176 GHz. This performance of this MMIC single-stage amplifier containing only a single transistor represents a significant advance in the state of the art, in that it rivals the 170-GHz performance of a prior MMIC three-stage, four-transistor amplifier. [The prior amplifier was reported in "MMIC HEMT Power Amplifier for 140 to 170 GHz" (NPO-30127), NASA Tech Briefs, Vol. 27, No. 11 (November 2003), page 49.] This amplifier is the first heterojunction- bipolar-transistor (HBT) amplifier built for medium power operation in this

  6. Fiber optical parametric amplifiers in optical communication systems

    DEFF Research Database (Denmark)

    Marhic, Michel E.; Andrekson, Peter A.; Petropoulos, Periklis

    2015-01-01

    The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time...... in excess of 14,000 Tb/s x km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed....

  7. Efficient performance simulation of class D amplifier output stages

    DEFF Research Database (Denmark)

    Nyboe, Flemming; Risbo, Lars; Andreani, Pietro

    2005-01-01

    Straightforward simulation of amplifier distortion involves transient simulation of operation on a sine wave input signal, and a subsequent FFT of the output voltage. This approach is very slow on class D amplifiers, since the switching behavior forces simulation time steps that are many orders...... of magnitude smaller than the duration of one period of an audio sine wave. This work presents a method of simulating the amplifier transfer characteristic using a minimum amount of simulation time, and then deriving THD from the results....

  8. Model of pulse extraction from a copper laser amplifier

    International Nuclear Information System (INIS)

    Boley, C.D.; Warner, B.E.

    1997-03-01

    A computational model of pulse propagation through a copper laser amplifier has been developed. The model contains a system of 1-D (in the axial direction), time-dependent equations for the laser intensity and amplified spontaneous emission (ASE), coupled to rate equations for the atomic levels. Detailed calculations are presented for a high-power amplifier at Lawrence Livermore National Laboratory. The extracted power agrees with experiment near saturation. At lower input power the calculation overestimates experiment, probably because of increased ASE effects. 6 refs., 6 figs

  9. Fast amplifier associated with the Saturne II detection systems

    International Nuclear Information System (INIS)

    Furtlehner, Jean Pierre

    1976-01-01

    This research thesis concerns the nuclear spectroscopy station which is beside the Saturne synchrotron in Saclay, and more particularly the design of the large bandwidth amplifier which aims at bringing the anode signal to a sufficient value to trigger an amplitude discriminator or a coincidence circuit. This amplifier must have a very short rise time in order not to introduce a hold, and its output base line must be as little sensitive as possible to the counting frequency, which implies a continuous link. The author describes in detail the rationale for the use of such an amplifier, and reports the calculated and measured assessment of its different characteristics [fr

  10. Power amplifier automatic test system based on LXI bus technology

    Science.gov (United States)

    Li, Yushuang; Chen, Libing; Men, Tao; Yang, Qingfeng; Li, Ning; Nie, Tao

    2017-10-01

    The power amplifier is an important part of the high power digital transceiver module, because of its great demand and diverse measurement indicators, an automatic test system is designed to meet the production requirements of the power amplifiers as the manual test cannot meet the demand of consistency. This paper puts forward the plan of the automatic test system based on LXI bus technology, introduces the hardware and software architecture of the system. The test system has been used for debugging and testing the power amplifiers stably and efficiently, which greatly saves work force and effectively improves productivity.

  11. Design of High Power Density Amplifiers: Application to Ka Band

    Science.gov (United States)

    Passi, Davide; Leggieri, Alberto; Di Paolo, Franco; Bartocci, Marco; Tafuto, Antonio

    2017-10-01

    Recent developments in the design of high-power-high-frequency amplifiers are assessed in this paper by the analysis and measurements of a high power density amplifier operating in the Ka Band. Design procedure is presented and a technical investigation is reported. The proposed device has shown over 23% of useful frequency bandwidth. It is an ensemble of 16 monolithic solid state power amplifiers that employees mixed technologies as spatial and planar combiners. Test performed have given maximum delivered power of 47.2 dBm.

  12. FDML swept source at 1060 nm using a tapered amplifier

    DEFF Research Database (Denmark)

    Marschall, Sebastian; Klein, Thomas; Wieser, Wolfgang

    2010-01-01

    We present a novel frequency-swept light source working at 1060nm that utilizes a tapered amplifier as gain medium. These devices feature significantly higher saturation power than conventional semiconductor optical amplifiers and can thus improve the limited output power of swept sources...... in this wavelength range. We demonstrate that a tapered amplifier can be integrated into a fiber-based swept source and allows for high-speed FDML operation. The developed light source operates at a sweep rate of 116kHz with an effective average output power in excess of 30mW. With a total sweep range of 70 nm...

  13. An 1 GHz Class E LDMOS Power Amplifier

    OpenAIRE

    Adahl, Andreas; Zirath, Herbert

    2003-01-01

    A class E power amplifier working at 1 GHz and with an LDMOS transistor as switching element has been developed.The circuit is implemented with lumped and distributed elements.An output power of 6.2 W at 69 %drain efficiency with a gain of 11 dB was obtained at 1 GHz.Both simulations and measurements of the amplifier are presented within this paper.This is to our knowledge the highest efficiency and output power reported for a class E amplifier at 1 GHz.

  14. Externally pumped millimeter-wave Josephson-junction parametric amplifier

    DEFF Research Database (Denmark)

    Levinsen, M.T; Pedersen, Niels Falsig; Sørensen, Ole

    1980-01-01

    A unified theory of the singly and doubly degenerate Josephson-junction parametric amplifier is presented. Experiments with single junctions on both amplifier modes at frequencies 10, 35, and 70 GHz are discussed. Low-noise temperature (∼100 K, single sideband (SSB)) and reasonable gain (∼8 d......B) were obtained at 35 GHz in the singly degenerate mode. On the basis of the theory and experiments, a general procedure for optimizing junction parameters is discussed and illustrated by the specific design of a 100-GHz amplifier....

  15. Modeling FWM and impairments aware amplifiers placement technique for an optical MAN/WAN: Inline amplifiers case

    Science.gov (United States)

    Singh, Gurpreet; Singh, Maninder Lal

    2015-08-01

    A new four wave mixing (FWM) model for an optical network with amplifiers and a comparative analysis among three proposed amplifiers placement techniques have been presented in this paper. The FWM model is validated with the experimental measured data. The novelty of this model is its uniqueness that on direct substitutions of network parameters like length, it works even for unequal inter amplifier separations. The novelty of the analysis done among three schemes is that it presents fair choice of amplifiers placement methods for varied total system length. The appropriateness of these three schemes has been analyzed on the basis of critical system length, critical number of amplifiers and critical bit error rate (10-9) in presence of four wave mixing (FWM) and amplified spontaneous emission noise (ASE). The implementation of analysis done has been given with the help of an example of a regenerative metropolitan area network (MAN). The results suggest that the decreasing fiber section scheme should be avoided for placements of amplifiers and schemes IUFS and EFS shows their importance interchangeably for different set of parameters.

  16. Packaged, cascadable wideband monolithic feedback amplifiers for radar systems applications

    OpenAIRE

    Alleva, V.; Calori, M.; Cetronio, A.; Lanzieri, C.; Proietti, C.; Rapisarda, S.

    1990-01-01

    Design criteria and fabrication of a packaged, monolithic, cascadable, feedback amplifier are presented. The good performances in term of bandwidth, gain, flatness, reproducibility and reliability makes this component highly suitable for many radar applications.

  17. Amplifying mirrors with saturated gain without and with a resonator

    DEFF Research Database (Denmark)

    Skettrup, Torben

    2007-01-01

    An investigation of amplifying mirrors with a view to their use in resonator structures has been performed. Both non-saturated and saturated amplifying mirrors are demonstrated. It was found that relatively high values of gain (typical 5-10 times) can be obtained even when saturation is taken...... into account. Several resonator structures containing from two up to four mirrors, some including beamsplitters, are investigated. It was found that the gain to a first approximation depends only on the ratio between the pumping power and the input power on the amplifying mirror. It was also found...... that the configuration with four mirrors is well suited as an amplifier device working as an optical transistor since high values of gain up to 40 times could be obtained....

  18. On the unlimited gain of a nonlinear parametric amplifier

    DEFF Research Database (Denmark)

    Sorokin, Vladislav

    2014-01-01

    The present paper is concerned with analysis of the response of a nonlinear parametric amplifier in abroad range of system parameters, particularly beyond resonance. Such analysis is of particular interestfor micro- and nanosystems, since many small-scale parametric amplifiers exhibit a distinctly...... nonlinearbehavior when amplitude of their response is sufficiently large. The modified method of direct separa-tion of motions is employed to study the considered system. As the result it is obtained that steady-stateamplitude of the nonlinear parametric amplifier response can reach large values in the case...... of arbitrarilysmall amplitude of external excitation, so that the amplifier gain tends to infinity. Very large amplifiergain can be achieved in a broad range of system parameters, in particular when the amplitude of para-metric excitation is comparatively small. The obtained results clearly demonstrate that very...

  19. High power X-band coaxial amplifier experiments

    International Nuclear Information System (INIS)

    Davis, T.J.; Nation, J.A.

    1991-01-01

    Studies are continuing on the development of X-band coaxial microwave amplifiers as a source for next generation linear colliders. Coaxial amplifiers employ an annular electron beam propagating between inner and outer drift tube conductors, a configuration which allows large increases in beam current over standard pencil beam amplifiers. Large average diameter systems may still be used without mode competition since TM mode cutoff frequencies are controlled by the separation between conductors. A number of amplifier configurations are being studied, all primed by a driven initial cavity which resonates around 9 GHz. Simple theory of coaxial systems and particle-in-cell simulations are presented, as well as initial experimental results using a 420 keV, 7-8 kA, 9 cm diameter annular beam

  20. Ka-Band Klystron Amplifier for CUBESATs, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We offer an ultra-compact klystron amplifier for remote sensing on CubeSats. It will operate at 35.7 GHz, have 400 MHz bandwidth, and output greater than 32 watts...

  1. Hearing Aids and Personal Sound Amplifiers: Know the Difference

    Science.gov (United States)

    ... For Consumers Home For Consumers Consumer Updates Hearing Aids and Personal Sound Amplifiers: Know the Difference Share ... or use them as substitutes—for approved hearing aids. "Hearing aids and personal sound amplification products (PSAPS) ...

  2. Application of random amplified polymorphic DNA (RAPD) markers ...

    African Journals Online (AJOL)

    SAM

    2014-06-11

    1998). DNA fingerprinting of strawberry (Fragaria X ananassa) cultivars using randomly amplified polymorphic DNA (RAPD) markers. Euphytica. 102:247-253. Doyle JJ, Doyle LJ (1990). Isolation of plant DNA from fresh tissue.

  3. High Energy Single Frequency Resonant Amplifier, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase I project proposes a single frequency high energy resonant amplifier for remote sensing. Current state-of-art technologies can not provide all...

  4. Parametric Amplifiers for Microwave Kinectic Inductance Detector (MKID) Readout

    Data.gov (United States)

    National Aeronautics and Space Administration — Build a microwave amplifier with near quantum-limited sensitivity, octave or greater bandwidth, gain > 20 dB for input signals in the frequency range 1 – 10 GHz,...

  5. Mapping of randomly amplified polymorphic DNA primer (RAPD) on ...

    African Journals Online (AJOL)

    Mapping of randomly amplified polymorphic DNA primer (RAPD) on chromosome 2A of common wheat. Khamsa Parveen, Inamullah Inamullah, Habib Ahmad, Muhammad Sajjad Iqbal, Fida Muhammad Abbassi, Aziz ud-Din, Abdullah Khan, Imtiaz Ahmad Khan ...

  6. Linear and nonlinear analysis of high-power rf amplifiers

    International Nuclear Information System (INIS)

    Puglisi, M.

    1983-01-01

    After a survey of the state variable analysis method the final amplifier for the CBA is analyzed taking into account the real beam waveshape. An empirical method for checking the stability of a non-linear system is also considered

  7. Fiber amplifiers under thermal loads leading to transverse mode instability

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Hansen, Kristian Rymann; Alkeskjold, Thomas Tanggaard

    2014-01-01

    Transverse mode instability (TMI) in rare-earth doped fiber amplifiers operating above an average power threshold is caused by intermodal stimulated thermal Rayleigh scattering due to quantum defect heating. We investigate thermally induced longitudinal waveguide perturbations causing power trans...

  8. Systematic Design of EMI-Resilient Negative-Feedback Amplifiers

    NARCIS (Netherlands)

    Van der Horst, M.J.

    2012-01-01

    The information transfer capacity of negative-feedback amplifiers, and electronic circuits in general, is limited by three fundamental limitations being noise, bandwidth, and signal power. Electromagnetic Interference (EMI) is not a fundamental limitation, but it also hampers the information

  9. High Efficiency S-Band 20 Watt Amplifier

    Data.gov (United States)

    National Aeronautics and Space Administration — This project includes the design and build of a prototype 20 W, high efficiency, S-Band amplifier.   The design will incorporate the latest semiconductor technology,...

  10. Common source cascode amplifiers for integrating IR-FPA applications

    Science.gov (United States)

    Woolaway, James T.; Young, Erick T.

    1989-01-01

    Space based astronomical infrared measurements present stringent performance requirements on the infrared detector arrays and their associated readout circuitry. To evaluate the usefulness of commercial CMOS technology for astronomical readout applications a theoretical and experimental evaluation was performed on source follower and common-source cascode integrating amplifiers. Theoretical analysis indicates that for conditions where the input amplifier integration capacitance is limited by the detectors capacitance the input referred rms noise electrons of each amplifier should be equivalent. For conditions of input gate limited capacitance the source follower should provide lower noise. Measurements of test circuits containing both source follower and common source cascode circuits showed substantially lower input referred noise for the common-source cascode input circuits. Noise measurements yielded 4.8 input referred rms noise electrons for an 8.5 minute integration. The signal and noise gain of the common-source cascode amplifier appears to offer substantial advantages in acheiving predicted noise levels.

  11. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  12. Effects of entanglement in an ideal optical amplifier

    Science.gov (United States)

    Franson, J. D.; Brewster, R. A.

    2018-04-01

    In an ideal linear amplifier, the output signal is linearly related to the input signal with an additive noise that is independent of the input. The decoherence of a quantum-mechanical state as a result of optical amplification is usually assumed to be due to the addition of quantum noise. Here we show that entanglement between the input signal and the amplifying medium can produce an exponentially-large amount of decoherence in an ideal optical amplifier even when the gain is arbitrarily close to unity and the added noise is negligible. These effects occur for macroscopic superposition states, where even a small amount of gain can leave a significant amount of which-path information in the environment. Our results show that the usual input/output relation of a linear amplifier does not provide a complete description of the output state when post-selection is used.

  13. A Doherty Amplifier with Envelope Tracking Technique and DSP for High Efficiency

    OpenAIRE

    Ambar Saxena; Rakesh Kumar; Sahab Ram

    2012-01-01

    A Doherty amplifier employing input signal envelope tracking technique. In the amplifier, gate bias of peaking amplifier is controlled according to the magnitude of the envelope. The performance of the microwave Doherty amplifier has been compared with class AB amplifier. DSP is used to dynamically adjust the gate bias of the auxiliary (peaking) amplifier at the rate of the signal envelope to obtain gain flatness. DSP is used as a digital predistortor to improve the overall linearity and eff...

  14. Design And Construction Of 300W Audio Power Amplifier For Classroom

    OpenAIRE

    Shune Lei Aung; Kyaw Soe Lwin and Hla Myo Tun

    2015-01-01

    Abstract This paper describes the design and construction of 300W audio power amplifier for classroom. In the construction of this amplifier microphone preamplifier tone preamplifier equalizer line amplifier output power amplifier and sound level indicator are included. The output power amplifier is designed as O.C.L system and constructed by using Class B among many types of amplifier classes. There are two types in O.C.L system quasi system and complementary system. Between them the comple...

  15. Use of a photonic crystal for optical amplifier gain control

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Shawn-Yu [Albuquerque, NM; Fleming, James G [Albuquerque, NM; El-Kady, Ihab [Albuquerque, NM

    2006-07-18

    An optical amplifier having a uniform gain profile uses a photonic crystal to tune the density-of-states of a gain medium so as to modify the light emission rate between atomic states. The density-of-states of the gain medium is tuned by selecting the size, shape, dielectric constant, and spacing of a plurality of microcavity defects in the photonic crystal. The optical amplifier is particularly useful for the regeneration of DWDM signals in long optical fibers.

  16. Femtosecond Amplifiers and Microlasers in the Deep Ultraviolet

    Science.gov (United States)

    2013-11-19

    the ultraviolet (UV) and visible regions of the spectrum, as well as their applications in photochemistry and medical therapeutics. We believe that...FEMTOSECOND AMPLIFIERS AND MICROLASERS IN DEEP ULTRAVIOLET J GARY EDEN UNIVERSITY OF ILLINOIS 11/19/2013 Final Report DISTRIBUTION A: Distribution...Performance Report 15/08/2010 - 14/08/2013 Femtosecond Amplifiers and Microlasers in the Deep Ultraviolet FA9550-10-1-0456 Eden, James Gary Professor

  17. An amplifier for VUV photomultiplier operating in cryogenic environment

    Energy Technology Data Exchange (ETDEWEB)

    Arneodo, F.; Benabderrahmane, M.L.; Dahal, S. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Di Giovanni, A., E-mail: adriano.digiovanni@nyu.edu [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); D' Inzeo, M.; Franchi, G. [Age Scientific srl – Capezzano Pianore (Italy); Pazos Clemens, L. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates)

    2016-07-11

    We present the characterisation of an amplifier potentially interesting for noble liquid detectors. The design has been conceived considering the requirements of low power consumption (less than 30 mW), low noise, amplification factor of 10 at 100 MHz and use of commercial components. The amplifier has been integrated onto an electronic board with a voltage divider to operate an Hamamatsu R11410 photomultiplier tube (used in XENON1T, Aprile et al. (2014) [1] dark matter experiment).

  18. Design of low noise transimpedance amplifier for intravascular ultrasound

    KAUST Repository

    Reda, Dina

    2009-11-01

    In this paper, we study transimpedance amplifiers for capacitive sensing applications with a focus on Intravascular Ultra Sound (IVUS). We employ RF noise cancellation technique on capacitive feedback based transimpedance amplifiers. This technique eliminates the input-referred noise of TIAs completely and enhances the dynamic range of front-end electronics. Simulation results verify the proposed technique used in two different TIA topologies employing shunt-shunt feedback. ©2009 IEEE.

  19. Amplified Luminescence Quenching of Phosphorescent Metal–Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Kent, Caleb A. [Department of Chemistry,; Liu, Demin [Department of Chemistry,; Meyer, Thomas J. [Department of Chemistry,; Lin, Wenbin [Department of Chemistry,

    2012-02-22

    Amplified luminescence quenching has been demonstrated in metal–organic frameworks (MOFs) composed of Ru(II)-bpy building blocks with long-lived, largely triplet metal-to-ligand charge-transfer excited states. Strong non-covalent interactions between the MOF surface and cationic quencher molecules coupled with rapid energy transfer through the MOF microcrystal facilitates amplified quenching with a 7000-fold enhancement of the Stern–Völmer quenching constant for methylene blue compared to a model complex.

  20. Ripple compensation for a class-D amplifier

    OpenAIRE

    Cox, Stephen M.; du Toit Mouton, Hendrik

    2015-01-01

    This paper presents the first detailed mathematical analysis of the ripple compensation technique for reducing audio distortion in a class-D amplifier with negative feedback. The amplifier converts a relatively low-frequency audio signal to a high-frequency train of rectangular pulses whose widths are slowly modulated according to the audio signal (pulse-width modulation, PWM). Distortion manifests itself through unwanted audio-frequency harmonics that arise in the output due to nonlinearitie...

  1. Photonic-band-gap gyrotron amplifier with picosecond pulses.

    Science.gov (United States)

    Nanni, Emilio A; Jawla, Sudheer; Lewis, Samantha M; Shapiro, Michael A; Temkin, Richard J

    2017-12-04

    We report the amplification of 250 GHz pulses as short as 260 ps without observation of pulse broadening using a photonic-band-gap circuit gyrotron traveling-wave-amplifier. The gyrotron amplifier operates with a device gain of 38 dB and an instantaneous bandwidth of 8 GHz. The operational bandwidth of the amplifier can be tuned over 16 GHz by adjusting the operating voltage of the electron beam and the magnetic field. The amplifier uses a 30 cm long photonic-band-gap interaction circuit to confine the desired TE 03 -like operating mode while suppressing lower order modes which can result in undesired oscillations. The circuit gain is >55 dB for a beam voltage of 23 kV and a current of 700 mA. These results demonstrate the wide bandwidths and a high gain achievable with gyrotron amplifiers. The amplification of picosecond pulses of variable lengths, 260-800 ps, shows good agreement with the theory using the coupled dispersion relation and the gain-spectrum of the amplifier as measured with quasi-CW input pulses.

  2. Power Amplifier Design for E-band Wireless System Communications

    DEFF Research Database (Denmark)

    Hadziabdic, Dzenan; Krozer, Viktor; Johansen, Tom Keinicke

    2008-01-01

    E-band wireless communications will become important as the microwave backhaul for high-speed data transmission. One of the most critical components is the front-end power amplifier in this system. The paper analyzes different technologies with potential in the E-band frequency range and present...... power and efficiency reported for an InP HBT power amplifier in this frequency range. The predicted power-added efficiency is higher than that of power amplifiers based on SiGe HBT and GaAs pHEMT technologies. The design shows the capabilities of InP DHBT for power amplifier applications...... a power amplifier design satisfying the E-band system specifications. The designed power amplifier achieves a maximum output power of ges 20 dBm with a state-of-the-art power-added efficiency of 15%. The power is realized using InP DHBT technology. To the best of our knowledge it is the highest output...

  3. Photonic-band-gap gyrotron amplifier with picosecond pulses

    Science.gov (United States)

    Nanni, Emilio A.; Jawla, Sudheer; Lewis, Samantha M.; Shapiro, Michael A.; Temkin, Richard J.

    2017-12-01

    We report the amplification of 250 GHz pulses as short as 260 ps without observation of pulse broadening using a photonic-band-gap circuit gyrotron traveling-wave-amplifier. The gyrotron amplifier operates with a device gain of 38 dB and an instantaneous bandwidth of 8 GHz. The operational bandwidth of the amplifier can be tuned over 16 GHz by adjusting the operating voltage of the electron beam and the magnetic field. The amplifier uses a 30 cm long photonic-band-gap interaction circuit to confine the desired TE03-like operating mode while suppressing lower order modes which can result in undesired oscillations. The circuit gain is >55 dB for a beam voltage of 23 kV and a current of 700 mA. These results demonstrate the wide bandwidths and a high gain achievable with gyrotron amplifiers. The amplification of picosecond pulses of variable lengths, 260-800 ps, shows good agreement with the theory using the coupled dispersion relation and the gain-spectrum of the amplifier as measured with quasi-CW input pulses.

  4. Design And Construction Of 300W Audio Power Amplifier For Classroom

    Directory of Open Access Journals (Sweden)

    Shune Lei Aung

    2015-07-01

    Full Text Available Abstract This paper describes the design and construction of 300W audio power amplifier for classroom. In the construction of this amplifier microphone preamplifier tone preamplifier equalizer line amplifier output power amplifier and sound level indicator are included. The output power amplifier is designed as O.C.L system and constructed by using Class B among many types of amplifier classes. There are two types in O.C.L system quasi system and complementary system. Between them the complementary system is used in the construction of 300W audio power amplifier. The Multisim software is utilized for the construction of audio power amplifier.

  5. Drug Addiction

    Science.gov (United States)

    ... attempt to stop taking the drug Recognizing unhealthy drug use in family members Sometimes it's difficult to ... sold to support drug use Recognizing signs of drug use or intoxication Signs and symptoms of drug ...

  6. Drug Allergy

    Science.gov (United States)

    ... Seizure Loss of consciousness Other conditions resulting from drug allergy Less common drug allergy reactions occur days ... reaction the first time you take the drug. Drugs commonly linked to allergies Although any drug can ...

  7. Genetic variation in hemp and marijuana (Cannabis sativa L.) according to amplified fragment length polymorphisms.

    Science.gov (United States)

    Datwyler, Shannon L; Weiblen, George D

    2006-03-01

    Cannabis sativa L. (Cannabaceae) is one of the earliest known cultivated plants and is important in the global economy today as a licit and an illicit crop. Molecular markers distinguishing licit and illicit cultivars have forensic utility, but no direct comparison of hemp and marijuana amplified fragment length polymorphism (AFLP) has been made to date. Genetic variation was surveyed in three populations of fiber hemp and a potent cultivar of marijuana using AFLP markers. Ten primer pairs yielded 1206 bands, of which 88% were polymorphic. Eighteen bands represented fixed differences between all fiber populations and the drug cultivar. These markers have practical utility for (1) establishing conspiracy in the cultivation and distribution of marijuana, (2) identifying geographic sources of seized drugs, and (3) discriminating illegal, potent marijuana cultivars from hemp where the cultivation of industrial hemp is permitted.

  8. Development and detection efficiency of sequence characterized amplified region markers for authentication of medicinal plant Ruta graveolens and its adulterant Euphorbia dracunculoides

    Directory of Open Access Journals (Sweden)

    Irum Gul

    2016-01-01

    Full Text Available Background: With the increase in demand of herbal medicines, adulteration in these drugs is also gaining momentum and remains an indispensable problem in domestic and export markets. Correct identification is the first step toward assuring quality, safety, and efficacy of indigenous herbal medicines. Materials and Methods: In this study, sequence characterized amplified region (SCAR markers were developed to discriminate Ruta graveolens from its adulterant Euphorbia dracunculoides. Random amplified polymorphic DNA (RAPD was performed and subsequently converted into SCAR markers. Results: After performing RAPD, SCAR primers were designed from the selected unique RAPD amplicons of the genuine drug as well as its adulterant. These primers produced 670 bp and 750 bp SCAR markers with genomic DNA sample of R. graveolens and E. dracunculoides, respectively. Conclusion: Development of these markers will help in the quality control of herbal drugs and monitoring widespread adulteration of these drugs by pharmaceutical industries and government agencies.

  9. Time resolved amplified FRET identifies protein kinase B activation state as a marker for poor prognosis in clear cell renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    James Miles

    2017-12-01

    General significance: The quantitative imaging technology based on Amplified-FRET can rapidly analyse protein activation states and molecular interactions. It could be used for prognosis and assess drug function during the early cycles of chemotherapy. It enables evaluation of clinical efficiency of personalised cancer treatment.

  10. Analysis of pirlimycin residues in beef muscle, milk and honey by a biotin-streptavidin-amplified enzyme-linked immunosorbent assay

    Science.gov (United States)

    Food contamination caused by veterinary drug residues is a world-wide public health concern and requires continuous monitoring. In this paper, we describe a biotin–streptavidin-amplified ELISA (BA-ELISA) for detecting pirlimycin residues in beef, milk, and honey. The IC50 value of the BA-ELISA was...

  11. Drug Facts

    Medline Plus

    Full Text Available ... some signs and symptoms of someone with a drug use problem? How Does Drug Use Become an Addiction? What Makes Someone More Likely ... So Hard to Quit Drugs? Effects of Drugs Drug Use and Other People Drug Use and Families Drug ...

  12. Drug allergies

    Science.gov (United States)

    Allergic reaction - drug (medication); Drug hypersensitivity; Medication hypersensitivity ... A drug allergy involves an immune response in the body that produces an allergic reaction to a medicine. The ...

  13. GAME EDUKASI PERAKITAN AMPLIFIER BERBASIS ANDROID UNTUK USER UMUM

    Directory of Open Access Journals (Sweden)

    Fundhi Fanju Hafili

    2015-04-01

    Full Text Available ABSTRAK Seiring dengan perkembangan dan kebutuhan teknologi saat ini pembelajaran elektro dapat dibuat menjadi lebih praktis dan menarik di ponsel berbasis android Mempelajari elektronika juga memerlukan usaha-usaha nyata yang ber-kesinambungan dan mengarah kepada tumbuhnya kesadaran untuk menjadikan elektronika sebagai perkembangan teknologi. Dengan adanya metode game, merupakan salah satu metode belajar merakit amplifier yang disusun secara praktis dan sistematis sehingga memudahkan setiap orang untuk belajar maupun mengajarkan merancang amplifier. Sementara itu metode pembelajaran yang ada saat ini yaitu melalui buku maupun dengan cara bertatap muka langsung dengan tentor dirasa masih kurang efektif. Untuk mengatasi masalah tersebut maka penulis membuat game edukasi elektro merancang amplifier, karena mudah dipahami dan memudahkan para calon teknisi elektro dalam belajar merancang amplifier. Perancangan ini dilakukan dengan pendekatan metode Research and Development adalah metode penelitian yang digunakan untuk menghasilkan produk tertentu dan menguji keefektifan produk tersebut. Dengan aplikasi ini diharapkan dapat membantu para pengguna yang ingin belajar merakit amplifier berbasis android. . Kata kunci: elektro, game, research and development.

  14. Demonstration of a reversible phase-insensitive optical amplifier

    Science.gov (United States)

    Yoshikawa, Jun-Ichi; Miwa, Yoshichika; Filip, Radim; Furusawa, Akira

    2011-05-01

    We experimentally demonstrate phase-insensitive linear amplification of a continuous variable system in the optical regime, preserving the ancilla system at the output. Since our amplification operation is unitary up to small excess noise, it is reversible beyond the classical limit. Here, entanglement between the amplified output system and the ancilla system is the resource for the reversibility, and the amplification gain is G=2.0. In addition, combining this amplifier with a beamsplitter, we also demonstrate approximate cloning of coherent states where an anticlone is present. We investigate the reversibility by reconstructing the initial state from the output correlations, and the results are slightly beyond the cloning limit. Furthermore, full characterization of the amplifier and cloner is given by using coherent states with several different mean values as inputs. Our amplifier is based on linear optics, offline-prepared additional ancillas in nonclassical states, and homodyne measurements followed by feedforward. Squeezed states are used as the additional ancillas, and nonlinear optical effects are exploited only for their generation. They introduce nonclassicality into the amplifying operation, making entanglement at the output.

  15. TUTORIAL: Integrated circuit amplifiers for multi-electrode intracortical recording

    Science.gov (United States)

    Jochum, Thomas; Denison, Timothy; Wolf, Patrick

    2009-02-01

    Significant progress has been made in systems that interpret the electrical signals of the brain in order to control an actuator. One version of these systems senses neuronal extracellular action potentials with an array of up to 100 miniature probes inserted into the cortex. The impedance of each probe is high, so environmental electrical noise is readily coupled to the neuronal signal. To minimize this noise, an amplifier is placed close to each probe. Thus, the need has arisen for many amplifiers to be placed near the cortex. Commercially available integrated circuits do not satisfy the area, power and noise requirements of this application, so researchers have designed custom integrated-circuit amplifiers. This paper presents a comprehensive survey of the neural amplifiers described in publications prior to 2008. Methods to achieve high input impedance, low noise and a large time-constant high-pass filter are reviewed. A tutorial on the biological, electrochemical, mechanical and electromagnetic phenomena that influence amplifier design is provided. Areas for additional research, including sub-nanoampere electrolysis and chronic cortical heating, are discussed. Unresolved design concerns, including teraohm circuitry, electrical overstress and component failure, are identified.

  16. Spectroscopic amplifier for pin diode; Amplificador espectroscopico para diodo Pin

    Energy Technology Data Exchange (ETDEWEB)

    Alonso M, M. S.; Hernandez D, V. M.; Vega C, H. R., E-mail: bebe.luna_s@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-10-15

    The photodiode remains the basic choice for the photo-detection and is widely used in optical communications, medical diagnostics and field of corpuscular radiation. In detecting radiation it has been used for monitoring radon and its progeny and inexpensive spectrometric systems. The development of a spectroscopic amplifier for Pin diode is presented which has the following characteristics: canceler Pole-Zero (P/Z) with a time constant of 8 μs; constant gain of 57, suitable for the acquisition system; 4th integrator Gaussian order to waveform change of exponential input to semi-Gaussian output and finally a stage of baseline restorer which prevents Dc signal contribution to the next stage. The operational amplifier used is the TLE2074 of BiFET technology of Texas Instruments with 10 MHz bandwidth, 25 V/μs of slew rate and a noise floor of 17 nv/(Hz)1/2. The integrated circuit has 4 operational amplifiers and in is contained the total of spectroscopic amplifier that is the goal of electronic design. The results show like the exponential input signal is converted to semi-Gaussian, modifying only the amplitude according to the specifications in the design. The total system is formed by the detector, which is the Pin diode, a sensitive preamplifier to the load, the spectroscopic amplifier that is what is presented and finally a pulse height analyzer (Mca) which is where the spectrum is shown. (Author)

  17. Low-Noise Amplifier for 100 to 180 GHz

    Science.gov (United States)

    Kangaslahti, Pekka; Pukala, David; Fung, King Man; Gaier, Todd; Mei, Xiaobing; Lai, Richard; Deal, William

    2009-01-01

    A three-stage monolithic millimeter-wave integrated-circuit (MMIC) amplifier designed to exhibit low noise in operation at frequencies from about 100 to somewhat above 180 GHz has been built and tested. This is a prototype of broadband amplifiers that have potential utility in diverse applications, including measurement of atmospheric temperature and humidity and millimeter-wave imaging for inspecting contents of opaque containers. Figure 1 depicts the amplifier as it appears before packaging. Figure 2 presents data from measurements of the performance of the amplifier as packaged in a WR-05 waveguide and tested in the frequency range from about 150 to about 190 GHz. The amplifier exhibited substantial gain throughout this frequency range. Especially notable is the fact that at 165 GHz, the noise figure was found to be 3.7 dB, and the noise temperature was found to be 370 K: This is less than half the noise temperature of the prior state of the art.

  18. Ways to suppress click and pop for class D amplifiers

    Science.gov (United States)

    Haishi, Wang; Bo, Zhang; Jiang, Sun

    2012-08-01

    Undesirable audio click and pop may be generated in a speaker or headphone. Compared to linear (class A/B/AB) amplifiers, class D amplifiers that comprise of an input stage and a modulation stage are more prone to producing click and pop. This article analyzes sources that generate click and pop in class D amplifiers, and corresponding ways to suppress them. For a class D amplifier with a single-ended input, click and pop is likely to be due to two factors. One is from a voltage difference (VDIF) between the voltage of an input capacitance (VCIN) and a reference voltage (VREF) of the input stage, and the other one is from the non-linear switching during the setting up of the bias and feedback voltages/currents (BFVC) of the modulation stage. In this article, a fast charging loop is introduced into the input stage to charge VCIN to roughly near VREF. Then a correction loop further charges or discharges VCIN, substantially equalizing it with VREF. Dummy switches are introduced into the modulation stage to provide switching signals for setting up BFVC, and the power switches are disabled until the BFVC are set up successfully. A two channel single-ended class D amplifier with the above features is fabricated with 0.5 μm Bi-CMOS process. Road test and fast Fourier transform analysis indicate that there is no noticeable click and pop.

  19. Integrated circuit amplifiers for multi-electrode intracortical recording.

    Science.gov (United States)

    Jochum, Thomas; Denison, Timothy; Wolf, Patrick

    2009-02-01

    Significant progress has been made in systems that interpret the electrical signals of the brain in order to control an actuator. One version of these systems senses neuronal extracellular action potentials with an array of up to 100 miniature probes inserted into the cortex. The impedance of each probe is high, so environmental electrical noise is readily coupled to the neuronal signal. To minimize this noise, an amplifier is placed close to each probe. Thus, the need has arisen for many amplifiers to be placed near the cortex. Commercially available integrated circuits do not satisfy the area, power and noise requirements of this application, so researchers have designed custom integrated-circuit amplifiers. This paper presents a comprehensive survey of the neural amplifiers described in publications prior to 2008. Methods to achieve high input impedance, low noise and a large time-constant high-pass filter are reviewed. A tutorial on the biological, electrochemical, mechanical and electromagnetic phenomena that influence amplifier design is provided. Areas for additional research, including sub-nanoampere electrolysis and chronic cortical heating, are discussed. Unresolved design concerns, including teraohm circuitry, electrical overstress and component failure, are identified.

  20. A numerical design approach for single amplifier, Active-RC Butterworth filter of order 5

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    2007-01-01

    filter applying just one operational amplifier coupled as a unity gain amplifier. It is shown that the influence from the real operational amplifier may be reduced by trimming just one resistor in the circuit. The unity gain amplifiers have the advantage of providing low power consumption, yielding...

  1. 47 CFR 97.315 - Certification of external RF power amplifiers.

    Science.gov (United States)

    2010-10-01

    .... (2) The amplifier was manufactured before April 28, 1978, and has been issued a marketing waiver by... that operator's station. (3) The amplifier is sold to an amateur radio operator or to a dealer, the amplifier is purchased in used condition by a dealer, or the amplifier is sold to an amateur radio operator...

  2. IMPATT power building blocks for 20 GHz spaceborne transmit amplifier

    Science.gov (United States)

    Asmus, J.; Cho, Y.; Degruyl, J.; Ng, E.; Giannakopoulos, A.; Okean, H. C.

    1982-01-01

    Single-stage circulator coupled IMPATT building block constituents of a 20-GHz solid state power amplifier (SSPA) currently under development for spaceborne downlink transmitter usage have been demonstrated as providing 1.5 to 2.0W RF power output at 4 to 5 dB operating gain over a 1 GHz bandwidth. Using either commercially available or recently developed in-house GaAs Schottky Read-profile IMPATT diodes, DC/RF power added efficiencies of 14 to 15% were achieved in these amplifier stages. A two stage IMPATT driver amplifier with similar RF output power capability exhibited 13 + or - 0.5 dB operating gain over a 1 GHz bandwidth.

  3. Modeling Distortion Effects in Class-D Amplifier Filter Inductors

    DEFF Research Database (Denmark)

    Knott, Arnold; Stegenborg-Andersen, Tore; Thomsen, Ole Cornelius

    2010-01-01

    Distortion is generally accepted as a quantifier to judge the quality of audio power amplifiers. In switchmode power amplifiers various mechanisms influence this performance measure. After giving an overview of those, this paper focuses on the particular effect of the nonlinearity of the output...... filter components on the audio performance. While the physical reasons for both, the capacitor and the inductor induced distortion are given, the practical in depth demonstration is done for the inductor only. This includes measuring the inductors performance, modeling through fitting and resulting...... into simulation models. The fitted models achieve distortion values between 0.03 % and 0.2 % as a basis to enable the design of a 200 W amplifier....

  4. Embedded control system for high power RF amplifiers

    International Nuclear Information System (INIS)

    Sharma, Deepak Kumar; Gupta, Alok Kumar; Jain, Akhilesh; Hannurkar, P.R.

    2011-01-01

    RF power devices are usually very sensitive to overheat and reflected RF power; hence a protective interlock system is required to be embedded with high power solid state RF amplifiers. The solid state RF amplifiers have salient features of graceful degradation and very low mean time to repair (MTTR). In order to exploit these features in favour of lowest system downtime, a real-time control system is embedded with high power RF amplifiers. The control system is developed with the features of monitoring, measurement and network publishing of various parameters, historical data logging, alarm generation, displaying data to the operator and tripping the system in case of any interlock failure. This paper discusses the design philosophy, features, functions and implementation details of the embedded control system. (author)

  5. Multi-path interferometric Josephson directional amplifier for qubit readout

    Science.gov (United States)

    Abdo, Baleegh; Bronn, Nicholas T.; Jinka, Oblesh; Olivadese, Salvatore; Brink, Markus; Chow, Jerry M.

    2018-04-01

    We realize and characterize a quantum-limited, directional Josephson amplifier suitable for qubit readout. The device consists of two nondegenerate, three-wave-mixing amplifiers that are coupled together in an interferometric scheme, embedded in a printed circuit board. Nonreciprocity is generated by applying a phase gradient between the same-frequency pumps feeding the device, which plays the role of the magnetic field in a Faraday medium. Directional amplification and reflection-gain elimination are induced via wave interference between multiple paths in the system. We measure and discuss the main figures of merit of the device and show that the experimental results are in good agreement with theory. An improved version of this directional amplifier is expected to eliminate the need for bulky, off-chip isolation stages that generally separate quantum systems and preamplifiers in high-fidelity, quantum-nondemolition measurement setups.

  6. Using MEMS Capacitive Switches in Tunable RF Amplifiers

    Directory of Open Access Journals (Sweden)

    Danson John

    2006-01-01

    Full Text Available A MEMS capacitive switch suitable for use in tunable RF amplifiers is described. A MEMS switch is designed, fabricated, and characterized with physical and RF measurements for inclusion in simulations. Using the MEMS switch models, a dual-band low-noise amplifier (LNA operating at GHz and GHz, and a tunable power amplifier (PA at GHz are simulated in m CMOS. MEMS switches allow the LNA to operate with 11 dB of isolation between the two bands while maintaining dB of gain and sub- dB noise figure. MEMS switches are used to implement a variable matching network that allows the PA to realize up to 37% PAE improvement at low input powers.

  7. Efficiency Optimization in Class-D Audio Amplifiers

    DEFF Research Database (Denmark)

    Yamauchi, Akira; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2015-01-01

    This paper presents a new power efficiency optimization routine for designing Class-D audio amplifiers. The proposed optimization procedure finds design parameters for the power stage and the output filter, and the optimum switching frequency such that the weighted power losses are minimized under...... the given constraints. The optimization routine is applied to minimize the power losses in a 130 W class-D audio amplifier based on consumer behavior investigations, where the amplifier operates at idle and low power levels most of the time. Experimental results demonstrate that the optimization method can...... lead to around 30 % of efficiency improvement at 1.3 W output power without significant effects on both audio performance and the efficiency at high power levels....

  8. Modal instabilities in very large mode area rod fiber amplifiers

    DEFF Research Database (Denmark)

    Jørgensen, Mette Marie; Hansen, Kristian Rymann; Laurila, Marko

    with the finite element method to allow complex micro structured fibers to be considered. Thereby the modal instability threshold is estimated for very large mode area fiber amplifiers of various photonic crystal fiber designs. Experimentally the modal instability threshold for very large mode area fiber......Optical fiber amplifiers have gained increased scientific and commercial interest due to high output powers with easy operation and maintenance. The main advantages of fiber amplifiers are good thermal properties, due to a large surface/volume ratio, excellent beam quality and stability [1]. Very...... large core fiber areas are highly desirable to mitigate various nonlinear processes, such as Kerr, four-wave mixing, Raman, and Brillouin effects. It is difficult to scale up the core area without going into a multi-moded regime. Microstructured fiber technology has allowed core diameters of 60...

  9. Experimental implementation of a quantum optical state comparison amplifier.

    Science.gov (United States)

    Donaldson, Ross J; Collins, Robert J; Eleftheriadou, Electra; Barnett, Stephen M; Jeffers, John; Buller, Gerald S

    2015-03-27

    We present an experimental demonstration of a practical nondeterministic quantum optical amplification scheme that employs two mature technologies, state comparison and photon subtraction, to achieve amplification of known sets of coherent states with high fidelity. The amplifier uses coherent states as a resource rather than single photons, which allows for a relatively simple light source, such as a diode laser, providing an increased rate of amplification. The amplifier is not restricted to low amplitude states. With respect to the two key parameters, fidelity and the amplified state production rate, we demonstrate significant improvements over previous experimental implementations, without the requirement of complex photonic components. Such a system may form the basis of trusted quantum repeaters in nonentanglement-based quantum communications systems with known phase alphabets, such as quantum key distribution or quantum digital signatures.

  10. Rare MYC-amplified Neuroblastoma With Large Cell Histology.

    Science.gov (United States)

    Matsuno, Ryosuke; Gifford, Andrew J; Fang, Junming; Warren, Mikako; Lukeis, Robyn E; Trahair, Toby; Sugimoto, Tohru; Marachelian, Araz; Asgharzadeh, Shahab; Maris, John M; Ikegaki, Naohiko; Shimada, Hiroyuki

    2018-01-01

    Background Although MYCN (aka N-myc) amplification is reported in ∼20% of neuroblastomas, MYC (aka C-myc) amplification appears to be a rare event in this disease. As of today, only 2 MYC-amplified neuroblastomas have been briefly mentioned in the literature. Methods We studied here the clinicopathological features of 3 MYC-amplified neuroblastomas. Results All 3 patients (2 females and 1 male) had stage 4 disease. One female is currently alive and well 52 months after the diagnosis, while the other female and male patients died of disease 24 and 20 months after the diagnosis, respectively. Further analysis on 2 tumors revealed unfavorable histology with MYC protein overexpression but with neither MYCN amplification nor MYCN protein overexpression. Both of these tumors exhibited "large cell neuroblastoma" histology with enlarged, uniquely open nuclei and nucleolar hypertrophy, along with "aberrant" desmin expression. Conclusions MYC-amplified neuroblastomas are extremely rare and seem to present with distinct clinicopathological features.

  11. Power Amplifier Linearization Techniques for 3rd Generation Handsets

    DEFF Research Database (Denmark)

    Nielsen, Troels Studsgaard

    Bm drive level and within a load VSWR of 5:1, measured and simulated adjacent channel power ratios deviates less than 2dB. Based on the model and a system simulator implementation of the linearizer, three system level studies are performed. A study of the polynomial workfunction composition reveals......Linearization is a systematic method for reducing an amplifier’s distortion. By distortion reduction, the linearizer allows the amplifier to produce more output power and thereby to operate at a higher level of efficiency for a given level of distortion. There exist a number of different Power...... Amplifier (PA) linearization techniques. These range from adding just a few extra components to the conventional amplifier design to complete and very complex transmitter designs. This dissertation deals with PA linearization techniques suitable for 3rd generation cellular handsets. In particular, focus...

  12. Drug Facts

    Medline Plus

    Full Text Available ... Drug Use and Kids Drug Use and Unborn Children Drug Use and Your Health Other Effects on ... Someone Find Treatment and Recovery Resources? Prevention Help Children and Teens Stay Drug-Free Talking to Kids ...

  13. Drug Facts

    Medline Plus

    Full Text Available ... Drug Use and Your Health Other Effects on the Body Drug Use Hurts Brains Drug Use and Mental Health Problems Often Happen Together The Link Between Drug Use and HIV/AIDS Treatment & ...

  14. Drug Facts

    Medline Plus

    Full Text Available ... Use and Unborn Children Drug Use and Your Health Other Effects on the Body Drug Use Hurts Brains Drug Use and Mental Health Problems Often Happen Together The Link Between Drug ...

  15. Drug Safety

    Science.gov (United States)

    ... over-the-counter drug. The FDA evaluates the safety of a drug by looking at Side effects ... clinical trials The FDA also monitors a drug's safety after approval. For you, drug safety means buying ...

  16. Drug Facts

    Medline Plus

    Full Text Available ... and symptoms of someone with a drug use problem? How Does Drug Use Become an Addiction? What ... Use Hurts Brains Drug Use and Mental Health Problems Often Happen Together The Link Between Drug Use ...

  17. A digitally assisted, signal folding neural recording amplifier.

    Science.gov (United States)

    Chen, Yi; Basu, Arindam; Liu, Lei; Zou, Xiaodan; Rajkumar, Ramamoorthy; Dawe, Gavin Stewart; Je, Minkyu

    2014-08-01

    A novel signal folding and reconstruction scheme for neural recording applications that exploits the 1/f(n) characteristics of neural signals is described in this paper. The amplified output is 'folded' into a predefined range of voltages by using comparison and reset circuits along with the core amplifier. After this output signal is digitized and transmitted, a reconstruction algorithm can be applied in the digital domain to recover the amplified signal from the folded waveform. This scheme enables the use of an analog-to-digital convertor with less number of bits for the same effective dynamic range. It also reduces the transmission data rate of the recording chip. Both of these features allow power and area savings at the system level. Other advantages of the proposed topology are increased reliability due to the removal of pseudo-resistors, lower harmonic distortion and low-voltage operation. An analysis of the reconstruction error introduced by this scheme is presented along with a behavioral model to provide a quick estimate of the post reconstruction dynamic range. Measurement results from two different core amplifier designs in 65 nm and 180 nm CMOS processes are presented to prove the generality of the proposed scheme in the neural recording applications. Operating from a 1 V power supply, the amplifier in 180 nm CMOS has a gain of 54.2 dB, bandwidth of 5.7 kHz, input referred noise of 3.8 μVrms and power dissipation of 2.52 μW leading to a NEF of 3.1 in spike band. It exhibits a dynamic range of 66 dB and maximum SNDR of 43 dB in LFP band. It also reduces system level power (by reducing the number of bits in the ADC by 2) as well as data rate to 80% of a conventional design. In vivo measurements validate the ability of this amplifier to simultaneously record spike and LFP signals.

  18. A model for phase noise generation in amplifiers.

    Science.gov (United States)

    Tomlin, T D; Fynn, K; Cantoni, A

    2001-11-01

    In this paper, a model is presented for predicting the phase modulation (PM) and amplitude modulation (AM) noise in bipolar junction transistor (BJT) amplifiers. The model correctly predicts the dependence of phase noise on the signal frequency (at a particular carrier offset frequency), explains the noise shaping of the phase noise about the signal frequency, and shows the functional dependence on the transistor parameters and the circuit parameters. Experimental studies on common emitter (CE) amplifiers have been used to validate the PM noise model at carrier frequencies between 10 and 100 MHz.

  19. Accurate simulation of Raman amplified lightwave synthesized frequency sweeper

    DEFF Research Database (Denmark)

    Pedersen, Anders Tegtmeier; Olesen, Anders Sig; Rottwitt, Karsten

    2011-01-01

    with constant peak power and no significant growth of noise. The numerical simulation is based on careful measurements of the physical properties of the individual components and a well established Raman amplifier model. Very good agreement between the measured and the simulated data is found. (C) 2011 Optical......A lightwave synthesized frequency sweeper using a Raman amplifier for loss compensation is presented together with a numerical model capable of predicting the shape of individual pulses as well as the overall envelope of more than 100 pulses. The generated pulse envelope consists of 116 pulses...

  20. The Modulation Response of a Semiconductor Laser Amplifier

    DEFF Research Database (Denmark)

    Mørk, Jesper; Mecozzi, Antonio; Eisenstein, Gadi

    1999-01-01

    We present a theoretical analysis of the modulation response of a semiconductor laser amplifier. We find a resonance behavior similar to the well-known relaxation oscillation resonance found in semiconductor lasers, but of a different physical origin. The role of the waveguide (scattering) loss...... are analyzed. The nonlinear transparent waveguide, i.e. an amplifier saturated to the point where the stimulated emission balances the internal losses, is shown to be analytically solvable and is a convenient vehicle for gaining qualitative understanding of the dynamics of modulated semiconductor optical...

  1. PULSE MODULATION POWER AMPLIFIER WITH ENHANCED CASCADE CONTROL METHOD

    DEFF Research Database (Denmark)

    1998-01-01

    A digital switching power amplifier with Multivariable Enhanced Cascade Controlled (MECC) includes a modulator, a switching power stage and a low pass filter. In the first preferred embodiment an enhanced cascade control structure local to the switching power stage is added, characterised by havi...... and feedback path A to determine stable self-oscillating conditions. An implemented 250W example MECC digital power amplifier has proven superior performance in terms of audio performance (0.005 % distortion, 115 dB dynamic range) and efficiency (92 %)....

  2. A Method To ModifyCorrect The Performance Of Amplifiers

    Directory of Open Access Journals (Sweden)

    Rohith Krishnan R

    2015-01-01

    Full Text Available Abstract The actual response of the amplifier may vary with the replacement of some aged or damaged components and this method is to compensate that problem. Here we use op-amp Fixator as the design tool. The tool helps us to isolate the selected circuit component from rest of the circuit adjust its operating point to correct the performance deviations and to modify the circuit without changing other parts of the circuit. A method to modifycorrect the performance of amplifiers by properly redesign the circuit is presented in this paper.

  3. Quantum Dot Semiconductor Optical Amplifiers - Physics and Applications

    DEFF Research Database (Denmark)

    Berg, Tommy Winther

    2004-01-01

    respects is comparable to those of fiber amplifiers. The possibility of inverting the optically active states to a large degree is essential in order to achieve this performance. Optical signal processing through cross gain modulation and four wave mixing is modeled and described. For both approaches...... quantum dot amplifiers are found to be able to operate with high efficiency and at high bitrates. Strong spectral hole-burning arising from a relatively slow carrier capture time, is shown to play a dominant role is this context. The results obtained numerically are compared to the properties of bulk...

  4. Current-Driven Switch-Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Buhl, Niels Christian; Andersen, Michael A. E.

    2012-01-01

    The conversion of electrical energy into sound waves by electromechanical transducers is proportional to the current through the coil of the transducer. However virtually all audio power amplifiers provide a controlled voltage through the interface to the transducer. This paper is presenting...... a switch-mode audio power amplifier not only providing controlled current but also being supplied by current. This results in an output filter size reduction by a factor of 6. The implemented prototype shows decent audio performance with THD + N below 0.1 %....

  5. Dispersion-Engineered Traveling Wave Kinetic Inductance Parametric Amplifier

    Science.gov (United States)

    Zmuidzinas, Jonas (Inventor); Day, Peter K. (Inventor)

    2014-01-01

    A traveling wave kinetic inductance parametric amplifier comprises a superconducting transmission line and a dispersion control element. The transmission line can include periodic variations of its dimension along its length. The superconducting material can include a high normal state resistivity material. In some instances the high normal state resistivity material includes nitrogen and a metal selected from the group consisting of titanium, niobium and vanadium. The traveling wave kinetic inductance parametric amplifier is expected to exhibit a noise temperature below 100 mK/GHz.

  6. Optimal Operation of a Josephson Parametric Amplifier for Vacuum Squeezing

    Science.gov (United States)

    Malnou, M.; Palken, D. A.; Vale, Leila R.; Hilton, Gene C.; Lehnert, K. W.

    2018-04-01

    A Josephson parametric amplifier (JPA) can create squeezed states of microwave light, lowering the noise associated with certain quantum measurements. We experimentally study how the JPA's pump influences the phase-sensitive amplification and deamplification of a coherent tone's amplitude when that amplitude is commensurate with vacuum fluctuations. We predict and demonstrate that, by operating the JPA with a single current pump whose power is greater than the value that maximizes gain, the amplifier distortion is reduced and, consequently, squeezing is improved. Optimizing the singly pumped JPA's operation in this fashion, we directly observe 3.87 ±0.03 dB of vacuum squeezing over a bandwidth of 30 MHz.

  7. Amplifier input impedance in dry electrode ECG recording.

    Science.gov (United States)

    Assambo, Cedric; Burke, Martin J

    2009-01-01

    This paper presents a novel approach for designing the front-end of instrumentation amplifiers for use in dry electrode recording of the human electrocardiogram (ECG). The method relies on information provided by the characterization of the skin-electrode interface and the analysis of low frequency ECG criteria defined by international standards. Marginal measurements of capacitive elements of the skin-electrode interface as small as 0.01 microF, suggest values of input impedance in the order of 1.3 GOmega. However, results in 99% of the data analyzed indicate that a recording amplifier providing an input impedance of 500 MOmega should ensure clear signal sensing without distortion.

  8. Computer-aided design of broad band reflection type amplifiers

    DEFF Research Database (Denmark)

    Hammershaimb, Edgar; Jeppesen, Palle; Schjær-Jacobsen, Hans

    1974-01-01

    Microwave negative resistance reflection type amplifiers using stable transferred electron devices (TED's) are optimized by numerical optimization techniques programmed for an interactive graphic datascreen. The small signal impedance of packaged TED's is measured on an automatic network analyzer...... on a datascreen, which allows for interactive programming. Comparisons of predicted amplifier performance for packaged and unpackaged devices form a basis for evaluating the possible degrading effect of package parasitics. The predictions of the computer-aided design are in good agreement with experimental...... results. The design procedure imposes no restraint on the frequency variation of the active device impedance and is therefore useful for any stable broad-banded negative resistance device....

  9. Multi Carrier Modulation Audio Power Amplifier with Programmable Logic

    DEFF Research Database (Denmark)

    Christiansen, Theis; Andersen, Toke Meyer; Knott, Arnold

    2009-01-01

    While switch-mode audio power amplifiers allow compact implementations and high output power levels due to their high power efficiency, they are very well known for creating electromagnetic interference (EMI) with other electronic equipment. To lower the EMI of switch-mode (class D) audio power...... for performance and out of band spectral amplitudes. The basic principle in MCM is to use programmable logic to combine two or more Pulse Width Modulated (PWM) audio signals at different switching frequencies. In this way the out of band spectrum will be lowered compared with conventional class D amplifiers...

  10. Tapered amplifier laser with frequency-shifted feedback

    Directory of Open Access Journals (Sweden)

    A. Bayerle, S. Tzanova, P. Vlaar, B. Pasquiou, F. Schreck

    2016-10-01

    Full Text Available We present a frequency-shifted feedback (FSF laser based on a tapered amplifier. The laser operates as a coherent broadband source with up to 370GHz spectral width and 2.3us coherence time. If the FSF laser is seeded by a continuous-wave laser a frequency comb spanning the output spectrum appears in addition to the broadband emission. The laser has an output power of 280mW and a center wavelength of 780nm. The ease and flexibility of use of tapered amplifiers makes our FSF laser attractive for a wide range of applications, especially in metrology.

  11. Nonclassical photon streams using rephased amplified spontaneous emission

    International Nuclear Information System (INIS)

    Ledingham, Patrick M.; Naylor, William R.; Longdell, Jevon J.; Beavan, Sarah E.; Sellars, Matthew J.

    2010-01-01

    We present a fully quantum mechanical treatment of optically rephased photon echoes. These echoes exhibit noise due to amplified spontaneous emission; however, this noise can be seen as a consequence of the entanglement between the atoms and the output light. With a rephasing pulse one can get an 'echo' of the amplified spontaneous emission, leading to light with nonclassical correlations at points separated in time, which is of interest in the context of building wide bandwith quantum repeaters. We also suggest a wideband version of DLCZ protocol based on the same ideas.

  12. Gain dynamics and saturation in semiconductor quantum dot amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper; Hvam, Jørn Märcher

    2004-01-01

    Quantum dot (QD)-based semiconductor optical amplifiers offer unique properties compared with conventional devices based on bulk or quantum well material. Due to the bandfilling properties of QDs and the existence of a nearby reservoir of carriers in the form of a wetting layer, QD semiconductor...... optical amplifiers may be operated in regimes of high linearity, i.e. with a high saturation power, but can also show strong and fast nonlinearities by breaking the equilibrium between discrete dot states and the continuum of wetting layer states. In this paper, we analyse the interplay of these two...

  13. Spatial and spectral imaging of LMA photonic crystal fiber amplifiers

    DEFF Research Database (Denmark)

    Laurila, Marko; Lægsgaard, Jesper; Alkeskjold, Thomas Tanggaard

    2011-01-01

    We demonstrate modal characterization using spatial and spectral resolved (S2) imaging, on an Ytterbium-doped large-mode-area photonic crystal fiber (PCF) amplifier and compare results with conventional cut-off methods. We apply numerical simulations and step-index fiber experiments to calibrate...... our mathematical and experimental routines of our S2 imaging system. We systematically analyze higher order mode (HOM) content of a polarizing 40μm core double-clad PCF amplifier with various launching and coiling configurations. We demonstrate a HOM suppression of more than -24dB with variance of 2...

  14. On Instantaneous Power Dissipation in Class B Amplifier

    Directory of Open Access Journals (Sweden)

    Hristo Zhivomirov

    2014-08-01

    Full Text Available The present paper describes the analysis of the instantaneous power dissipation by the two active components in a class B power amplifier. Attention is paid to restrictions of the instantaneous power dissipation relations in reference literature, and the consequences of their misuse. A new generalized equation that takes into account the power dissipated by the two active devices is proposed. The theoretical statement is substantiated by Matlab® numeric computation and visualization, Cadence OrCAD® simulations and measurements of a real-world audio power amplifier performed by NI USB-6211 measurement complex.

  15. High power resonant tracking amplifier using admittance locking.

    Science.gov (United States)

    Mortimer, B; du Bruyn, T; Davies, J; Tapson, J

    2001-06-01

    A high power resonance tracking ultrasonic amplifier is described. The amplifier is a class D type inverter, configured as a half-bridge in which the output MOSFETs are driven into saturation when on. The resonance tracking system makes use of a new method of frequency locking; admittance locking is used to track the optimum power conversion frequency for the transducer. This new arrangement offers some advantages over phase locking and motional feedback methods. The system is capable of delivering up to 3 kW at up to 25 kHz in resonance tracking operation.

  16. Multi Carrier Modulator for Switch-Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael Andreas E.

    2008-01-01

    While switch-mode audio power amplifiers allow compact implementations and high output power levels due to their high power efficiency, they are very well known for creating electromagnetic interference (EMI) with other electronic equipment, in particular radio receivers. Lowering the EMI of switch......-mode audio power amplifiers while keeping the performance measures to excellent levels is therefore of high general interest. A modulator utilizing multiple carrier signals to generate a two level pulse train will be shown in this paper. The performance of the modulator will be compared in simulation...

  17. Efficient trigger signal generation from wasted backward amplified stimulated emission at optical amplifiers for optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Kim Seung Taek

    2015-01-01

    Full Text Available This paper propose an optical structure to generate trigger signals for optical coherence tomography (OCT using backward light which is usually disposed. The backward light is called backward amplified stimulated emission generated from semiconductor optical amplifier (SOA when using swept wavelength tunable laser (SWTL. A circulator is applied to block undesirable lights in the SWTL instead of an isolator in common SWTL. The circulator also diverts backward amplified spontaneous lights, which finally bring out trigger signals for a high speed digitizer. The spectra of the forward lights at SOA and the waveform of the backward lights were measured to check the procedure of the trigger formation in the experiment. The results showed that the trigger signals from the proposed SWTL with the circulator was quite usable in OCT.

  18. Design of a high-gain laser diode-array pumped Nd:YAG alternating precessive slab amplifier (APS amplifier)

    Science.gov (United States)

    Coyle, D. B.

    1991-01-01

    In the design of space-qualifiable laser systems for ranging and altimetry, such as NASA's Geodynamic Laser Ranging System (GLRS), the transmitter must be kept small, powerful yet efficient, and must consist of as few components as possible. A novel preamplifier design is examined which requires no external beam steering optics, yielding a compact component with simple alignment procedures. The gains achieved are comparable to multipass zigzag amplifiers using two or more sets of external optics for extra passes through the amplifying medium.

  19. Erbium-doped integrated waveguide amplifiers and lasers

    NARCIS (Netherlands)

    Bradley, J.; Pollnau, Markus

    Erbium-doped fiber devices have been extraordinarily successful due to their broad optical gain around 1.5–1.6 μm. Er-doped fiber amplifiers enable efficient, stable amplification of high-speed, wavelength-division-multiplexed signals, thus continue to dominate as part of the backbone of longhaul

  20. Giant Geometrically Amplified Piezoresistance in Metal-Semiconductor Hybrid Resistors

    DEFF Research Database (Denmark)

    Hansen, Ole; Reck, Kasper; Thomsen, Erik Vilain

    2008-01-01

    We show that very high geometrically amplified piezoresistance can indeed be obtained in microstructured metal-semiconductor hybrid devices, even significantly higher amplification factors than the factor of approximately 8 demonstrated recently by Rowe and co-workers may be achieved. However, we...

  1. A European Project on Vacuum Tube Amplifiers for THz Amplification

    DEFF Research Database (Denmark)

    Paoloni, Claudio; Di Carlo, Aldo; Brunetti, Francesca

    2012-01-01

    The OPTHER (Optically Driven THz amplifier) project supported by the European Commission within the Seventh Framework Program (FP7) represents the first joint European attempt to realize vacuum electron devices in THz range. The target of the project was to design and realize the first 1 THz vacuum...

  2. Multilevel inverter based class D audio amplifier for capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    The reduced semiconductor voltage stress makes the multilevel inverters especially interesting, when driving capacitive transducers for audio applications. A ± 300 V flying capacitor class D audio amplifier driving a 100 nF load in the midrange region of 0.1-3.5 kHz with Total Harmonic Distortion...

  3. Short pulse mid-infrared amplifier for high average power

    CSIR Research Space (South Africa)

    Botha, LR

    2006-09-01

    Full Text Available High pressure CO2 lasers are good candidates for amplifying picosecond mid infrared pulses. High pressure CO2 lasers are notorious for being unreliable and difficult to operate. In this paper a high pressure CO2 laser is presented based on well...

  4. A fully integrated 16 channel digitally trimmed pulse shaping amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Hearn, W.E.; Wright, M.E.

    1993-11-01

    A fully integrated CMOS pulse shaping amplifier has been developed at LBL. All frequency dependent networks are included on the chip. Provision is made for tuning to compensate for process variations. The overall architecture and details of the circuitry are discussed. Test results are presented.

  5. Semiconductor quantum dot amplifiers for optical signal processing

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Uskov, A. V.; Bischoff, Svend

    2001-01-01

    The dynamics of quantum dot semiconductor amplifiers are investigated theoretically with respect to the potential for ultrafast signal processing. The high-speed signal processing capacity of these devices is found to be limited by the wetting layer dynamics in case of electrical pumping, while...... optical pumping partly removes this limitation. Also, the possibility of using spectral hole burning for signal processing is discussed....

  6. ( Quercus spp. ) using random amplified polymorphic DNA (RAPD)

    African Journals Online (AJOL)

    Quercus is one of the most important woody genera of the Northern hemisphere and considered as one of the main forest tree species in Iran. In this study, genetic relationships in the genus Quercus, using random amplified polymorphic DNA (RAPD) was examined. Five species, including: Quercus robur, Quercus ...

  7. Application of random amplified polymorphic DNA (RAPD) markers ...

    African Journals Online (AJOL)

    The random amplified polymorphic DNA (RAPD) technique has been widely applied to identify different varieties of plants for molecular breeding. However, application of RAPD markers to identify parthenogenesis in plants has not been reported. In this investigation, we used pedigree and RAPD markers to differentiate ...

  8. Random amplified polymorphic DNA (RAPD) markers reveal genetic ...

    African Journals Online (AJOL)

    The present study evaluated genetic variability of superior bael genotypes collected from different parts of Andaman Islands, India using fruit characters and random amplified polymorphic DNA (RAPD) markers. Genomic DNA extracted from leaf material using cetyl trimethyl ammonium bromide (CTAB) method was ...

  9. Random amplified polymorphic DNA (RAPD) based assessment of ...

    African Journals Online (AJOL)

    Knowledge of genetic distances between genotypes is important for efficient organization and conservation of plant genetic resources for crop improvement programs. In this study genetic distances between genotype pairs (complements of Jaccard's similarity coefficient) were estimated from Random Amplified Polymorphic ...

  10. A fully integrated 16 channel digitally trimmed pulse shaping amplifier

    International Nuclear Information System (INIS)

    Hearn, W.E.; Wright, M.E.

    1993-11-01

    A fully integrated CMOS pulse shaping amplifier has been developed at LBL. All frequency dependent networks are included on the chip. Provision is made for tuning to compensate for process variations. The overall architecture and details of the circuitry are discussed. Test results are presented

  11. Self-pulsation threshold of Raman amplified Brillouin fiber cavities

    DEFF Research Database (Denmark)

    Ott, Johan Raunkjær; Pedersen, Martin Erland Vestergaard; Rottwitt, Karsten

    2009-01-01

    An implicit equation for the oscillation threshold of stimulated Brillouin scattering from Raman amplified signals in fibers with external feedback is derived under the assumption of no depletion. This is compared to numerical investigations of Raman amplification schemes showing good agreement...

  12. Application of amplified fragment length polymorphism (AFLPs) for ...

    African Journals Online (AJOL)

    Uapaca kirkiana Muell. Årg is a dioecious fruit tree species for priority domestication in Southern Africa. It reaches reproductive maturity in eight to ten years with male plants making up 50% of breeding populations. Early identification of sex of seedlings is a prerequisite for selection and tree improvement. The amplified ...

  13. Low-Noise MMIC Amplifiers for 120 to 180 GHz

    Science.gov (United States)

    Pukala, David; Samoska, Lorene; Peralta, Alejandro; Bayuk, Brian; Grundbacher, Ron; Oliver, Patricia; Cavus, Abdullah; Liu, Po-Hsin

    2009-01-01

    Three-stage monolithic millimeter-wave integrated-circuit (MMIC) amplifiers capable of providing useful amounts of gain over the frequency range from 120 to 180 GHz have been developed as prototype low-noise amplifiers (LNAs) to be incorporated into instruments for sensing cosmic microwave background radiation. There are also potential uses for such LNAs in electronic test equipment, passive millimeter- wave imaging systems, radar receivers, communication receivers, and systems for detecting hidden weapons. The main advantage afforded by these MMIC LNAs, relative to prior MMIC LNAs, is that their coverage of the 120-to-180-GHz frequency band makes them suitable for reuse in a wider variety of applications without need to redesign them. Each of these MMIC amplifiers includes InP transistors and coplanar waveguide circuitry on a 50- mthick chip (see Figure 1). Coplanar waveguide transmission lines are used for both applying DC bias and matching of input and output impedances of each transistor stage. Via holes are incorporated between top and bottom ground planes to suppress propagation of electromagnetic modes in the substrate. On the basis of computational simulations, each of these amplifiers was expected to operate with a small-signal gain of 14 dB and a noise figure of 4.3 dB. At the time of writing this article, measurements of noise figures had not been reported, but on-chip measurements had shown gains approaching their simulated values (see Figure 2).

  14. Population structure of Salmonella investigated by amplified fragment length polymorphism

    DEFF Research Database (Denmark)

    Torpdahl, M.; Ahrens, Peter

    2004-01-01

    Aims: This study was undertaken to investigate the usefulness of amplified fragment length polymorphism (AFLP) in determining the population structure of Salmonella. Methods and Results: A total of 89 strains were subjected to AFLP analysis using the enzymes BglII and BspDI, a combination...

  15. Ultrafast gain and index dynamics in quantum dot amplifiers

    DEFF Research Database (Denmark)

    Borri, Paola; Langbein, Wolfgang; Mørk, Jesper

    1999-01-01

    The ultrafast dynamics of gain and refractive index in an InAs/GaAs quantum dot amplifier are investigated at room temperature. The gain is observed to recover with a 90 fs time constant, ruling out problems of slow carrier capture into the dots, and making this component promising for high...

  16. Characterisation of random DFB Raman laser amplifier for WDM transmission.

    Science.gov (United States)

    Rosa, Paweł; Rizzelli, Giuseppe; Tan, Mingming; Harper, Paul; Ania-Castañόn, Juan Diego

    2015-11-02

    We perform a full numerical characterisation of half-open cavity random DFB Raman fibre laser amplifier schemes for WDM transmission in terms of signal power variation, noise and nonlinear impairments, showcasing the excellent potential of this scheme to provide amplification for DWDM transmission with very low gain variation.

  17. Picosecond mid-infrared amplifier for high average power.

    CSIR Research Space (South Africa)

    Botha, LR

    2007-04-01

    Full Text Available High pressure CO2 lasers are good candidates for amplifying picosecond mid infrared pulses. High pressure CO2 lasers are notorious for being unreliable and difficult to operate. In this paper a high pressure CO2 laser is presented based on well...

  18. Randomly amplified polymorphic DNA-polymerase chain reaction ...

    Indian Academy of Sciences (India)

    Genetic similarity and diversity of cultured catfish Silurus asotus populations collected from two areas in western Korea were examined using randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). Out of 20 random primers tested, 5 produced 1344 RAPD bands ranging from 8.2 to 13.6 polymorphic ...

  19. Development of a sequence characterized amplified region (SCAR ...

    African Journals Online (AJOL)

    The varieties of rice are difficult to be distinguished because of their similar morphological characters, therefore rice variety identification or differentiation is very important. The authentication by using molecular marker or DNA fingerprinting is the most accurate method. In this study, random amplified polymorphic DNA ...

  20. Ka-Band Klystron Amplifier for CUBESATs, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a Ka-Band klystron amplifier for use in CubeSats. It will operate at 35.7 GHz, have 400 MHz of bandwidth, and output at least 32 watts of saturated power....

  1. State-dependent linear-optical qubit amplifier

    Czech Academy of Sciences Publication Activity Database

    Bartkiewicz, K.; Černoch, Antonín; Lemr, K.

    2013-01-01

    Roč. 88, č. 6 (2013), "062304-1"-"062304-7" ISSN 1050-2947 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : linear-optical qubit amplifier * quantum cloning * quantum cryptography Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.991, year: 2013

  2. Strongly coupled, low noise DC-SQUID amplifiers

    NARCIS (Netherlands)

    Pleikies, J.

    2009-01-01

    The dc Superconducting Quantum Interference Device (dc-SQUID) is one of the most sensitive magnetic field sensors available. In this thesis we concentrate on its application as an amplifier. In this configuration, an input circuit of interest can be connected by means of a coupling coil. The

  3. On the dual symmetry between absorbing and amplifying random ...

    Indian Academy of Sciences (India)

    We re-examine the dual symmetry between absorbing and amplifying random media. By analysing the physically allowed choice of the sign of the square root to determine the complex wave vector in a medium, we draw a broad set of conclusions that enables us to resolve the apparent paradox of the dual symmetry and ...

  4. Increased Speed: 3D Silicon Sensors; Fast Current Amplifiers

    CERN Document Server

    Parker, S; Hasi, J; Da Via, C; Despeisse, M; Anelli, G; Kenney, C; Jarron, P

    2011-01-01

    The authors describe techniques to make fast, sub-nanosecond time resolution solid-state detector systems using sensors with 3D electrodes, current amplifiers, constant-fraction comparators or fast wave-form recorders, and some of the next steps to reach still faster results.

  5. Development and energization of IOT based RF amplifier

    International Nuclear Information System (INIS)

    Mandal, A.; Som, S.; Raj, P.R.; Manna, S.K.; Ghosh, S.; Seth, S.; Thakurta, S.; Thakur, S.K.; Saha, S.; Panda, U.S.

    2013-01-01

    A 704 MHz IOT based CW RF amplifier has been developed in VECC. It can also be used with proper tuning to power cavity modules operating at 650 MHz in high energy high intensity proton linear accelerator proposed to be built for ADSS/SNS programme in India and Project-X at Fermilab, USA. This IOT based amplifier provides up to 60 kW continuous wave RF power at 700 MHz. It required various power supplies, LCW cooling and forced air cooling for its operation. The auxiliary power supplies like Grid, Filament and Ion-pump, are floated and mounted on an isolated frame, i.e., HV deck. The mains inputs are electrically isolated by means of isolation transformer. Also, a Programmable Logic Controller (PLC) based interlocks along with high voltage collector power supply has been designed and developed for the safe operation of the RF amplifier. This paper discusses about various developments and energization of the IOT based RF amplifier with high power dummy load. (author)

  6. Nonlinear carrier dynamics in a quantum dash optical amplifier

    DEFF Research Database (Denmark)

    Hansen, Per Lunnemann; Ek, Sara; Yvind, Kresten

    2012-01-01

    Results of experimental pump-probe spectroscopy of a quantum dash optical amplifier biased at transparency are presented. Using strong pump pulses we observe a competition between free carrier absorption and two-photon induced stimulated emission that can have drastic effects on the transmission...

  7. Design considerations for an isfet multiplexer and amplifier

    NARCIS (Netherlands)

    Bergveld, Piet

    1984-01-01

    Design considerations for the multiplexing of pH-sensitive ISFETs are studied and discussed. Experimental results with an ordinary multiplex circuit show transients of the order of several seconds if the output voltage of the applied amplifier is required within an accuracy of 0.5 mV (corresponding

  8. Using a sequence characterized amplified region (SCAR) marker for ...

    African Journals Online (AJOL)

    This work used sequence characterized amplified region (SCAR) marker to detect the Bacillus cereus strain in strawberry fields. The purpose was to develop an effective molecular method for detecting the functional target microorganisms applied in agricultural fields. A 3×109 CFU/ml vegetative cell suspension based on ...

  9. Free electron laser amplifier driven by an induction linac

    International Nuclear Information System (INIS)

    Neil, V.K.

    1986-01-01

    This paper discusses the use of a free-electron laser amplifier as a means of converting the kinetic energy of an electron beam into coherent radiation. In particular, the use of an induction linear accelerator is discussed. The motion of the elections in the tapered and untapered wiggler magnets is discussed as well as the beam emittance, and the radiation fields involved

  10. The neutronics of an Accelerator-Driven Energy Amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, E.; Gudowski, W. [Royal Institute of Technology, Stockholm (Sweden)

    1995-10-01

    This study has been focused on an Accelerator-Driven Energy Amplifier, based on the concept proposed by the CERN-group. To analyze the performance of this system the extensive optimization of the core lattice was done, the temperature coefficients of reactivity were investigated, reactivity budget and power distribution were estimated.

  11. Minimizing Crosstalk in Self Oscillating Switch Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Ploug, Rasmus Overgaard

    2012-01-01

    The varying switching frequencies of self oscillating switch mode audio amplifiers have been known to cause interchannel intermodulation disturbances in multi channel configurations. This crosstalk phenomenon has a negative impact on the audio performance. The goal of this paper is to present...... by the implementation presented. Future work could include further refinement of the implementation of the concepts, electromagnetic interference investigations or PCB design....

  12. On the dual symmetry between absorbing and amplifying random ...

    Indian Academy of Sciences (India)

    Abstract. We re-examine the dual symmetry between absorbing and amplifying ran- dom media. By analysing the physically allowed choice of the sign of the square root to determine the complex wave vector in a medium, we draw a broad set of conclusions that enables us to resolve the apparent paradox of the dual ...

  13. The spectacular human nose: an amplifier of individual quality?

    Directory of Open Access Journals (Sweden)

    Åse Kristine Rognmo Mikalsen

    2014-04-01

    Full Text Available Amplifiers are signals that improve the perception of underlying differences in quality. They are cost free and advantageous to high quality individuals, but disadvantageous to low quality individuals, as poor quality is easier perceived because of the amplifier. For an amplifier to evolve, the average fitness benefit to the high quality individuals should be higher than the average cost for the low quality individuals. The human nose is, compared to the nose of most other primates, extraordinary large, fragile and easily broken—especially in male–male interactions. May it have evolved as an amplifier among high quality individuals, allowing easy assessment of individual quality and influencing the perception of attractiveness? We tested the latter by manipulating the position of the nose tip or, as a control, the mouth in facial pictures and had the pictures rated for attractiveness. Our results show that facial attractiveness failed to be influenced by mouth manipulations. Yet, facial attractiveness increased when the nose tip was artificially centered according to other facial features. Conversely, attractiveness decreased when the nose tip was displaced away from its central position. Our results suggest that our evaluation of attractiveness is clearly sensitive to the centering of the nose tip, possibly because it affects our perception of the face’s symmetry and/or averageness. However, whether such centering is related to individual quality remains unclear.

  14. Entanglement-based linear-optical qubit amplifier

    Czech Academy of Sciences Publication Activity Database

    Meyer-Scott, E.; Bula, M.; Bartkiewicz, K.; Černoch, Antonín; Soubusta, Jan; Jennewein, T.; Lemr, Karel

    2013-01-01

    Roč. 87, č. 1 (2013), "012327-1"-"012327-7" ISSN 1050-2947 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : quantum physics * photonics qubits * qubit amplifier Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.991, year: 2013

  15. RAMAN amplifier gain dynamics with ASE : Numerical analysis and ...

    African Journals Online (AJOL)

    DR OKE

    Raman fiber amplifier (RFA) has merit of arbitrary gain bandwidth, which were recently being recognized as an enabling ... has several advantages including lower noise figure (NF), flexibility on the selection of gain medium, and wide gain bandwidth ..... The Signal Gain (Gs) characteristic for varying Pump Power (Pp).

  16. Genetic dissimilarities between wild olives by random amplified ...

    African Journals Online (AJOL)

    ... method with arithmetic averages) UPGMA and neighbor joining method by using the data obtained with RAPD. Keywords: Random amplified polymorphic DNA (RAPD), Olea europaea, arbitrary primers, Jaccard, Sorensen Dice, Simple Matching, unweighted pair group method with arithmetic averages, neighbor joining ...

  17. 94 GHz High-Average-Power Broadband Amplifier

    National Research Council Canada - National Science Library

    Luhmann, Neville

    2003-01-01

    A state-of-the-art gyro-TWT amplifier operating in the low loss TE01 mode has been developed with the objective of producing an average power of 140 kW in the W-Band with a predicted efficiency of 28%, 50dB gain, and 5% bandwidth...

  18. Mapping of randomly amplified polymorphic DNA primer (RAPD) on ...

    African Journals Online (AJOL)

    Genet & Botany only

    2012-08-14

    Aug 14, 2012 ... 500. Figure 1. PCR amplification profile of the two genetic stocks of common wheat,. NT2A2B and NT1D1B using RAPD primer GLC-07. M = Molecular size marker (100 bp DNA ladder, Gene Link, USA). important crops species including wheat (T. aestivum L.). Among the DNA markers, randomly amplified.

  19. Detection of somaclonal variation by random amplified polymorphic ...

    African Journals Online (AJOL)

    Detection of somaclonal variation by random amplified polymorphic DNA analysis during micropropagation of Phalaenopsis bellina (Rchb.f.) Christenson. ... Among the primers used, P 16 produced the highest number of bands (29), while primer OPU 10 produced the lowest number (15). The range of similarity coefficient ...

  20. Inter simple sequence repeats (ISSR) and random amplified ...

    African Journals Online (AJOL)

    21 of 30 random amplified polymorphic DNA (RAPD) primers produced 220 reproducible bands with average of 10.47 bands per primer and 80.12% of polymorphism. OPR02 primer showed the highest number of effective allele (Ne), Shannon index (I) and genetic diversity (H). Some of the cultivars had specific bands, ...

  1. Frequency resolved transverse mode instability in rod fiber amplifiers

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Laurila, Marko; Maack, Martin D.

    2013-01-01

    Frequency dynamics of transverse mode instabilities (TMIs) are investigated by testing three 285/100 rod fibers in a single-pass amplifier setup reaching up to ~200W of extracted output power without beam instabilities. The pump power is increased well above the TMI threshold to uncover output dy...

  2. Amplified spontaneous emission pulses for high-power supercontinuum generation

    Directory of Open Access Journals (Sweden)

    Huan Huan Liu

    2016-03-01

    Full Text Available The authors demonstrate an incoherent light source based on a reflective semiconductor optical amplifier as pump for high-power supercontinuum generation for the first time. The obtained power level is about 160 mW and 20 dB spectral bandwidth is around 170 nm.

  3. Analysis of Power Amplifier Modeling Schemes for Crosscorrelation Predistorters

    NARCIS (Netherlands)

    Kokkeler, Andre B.J.

    2004-01-01

    Amplification of signals with fluctuating envelopes leads to distortion because of non-linear behavior of the Power Amplifier (PA). Digital Predistortion can counteract these non-linear effects. A crosscorrelation predistorter is a digital predistorter, based on the calculation of crosscorrelation

  4. Noise Shaping Filter Compensating PWM Distortion for Fully Digital Amplifier

    Science.gov (United States)

    Yoneya, Akihiko

    The full-digital audio amplifiers have several merits such as a high power enabling a small size of the amplifier and digital implementation of the signal processing which allows desired precision of the processing except for the final stage switching amplifiers. Unfortunately, the pulse width modulation (PWM) causes signal distortions because of the non-linearity of the modulation from the viewpoint of the transient response. This paper proposes a compensation method of the PWM distortion with feedback approach. In the noise-shaping filter of the delta-sigma modulator to calculate the pulse codes for the PWM, the distortion caused by the PWM is evaluated and fed it back to compensate the distortion. Eventually the filter is implemented as a state-variable filter with non-linear feedback from the quantizer. The calculation of the filter elements is also described. By using proposed filters, PWM signals with small distortions and small floor noise can be obtained to realize high-fidelity audio amplifiers.

  5. 2R Regeneration in Concatenated Semiconductor Optical Amplifiers and Electroabsorbers

    DEFF Research Database (Denmark)

    Christiansen, Lotte Jin; Xu, Lin; Yvind, Kresten

    2004-01-01

    We present a novel 2R regenerator with a large level separation and steep step a sharp, adjustable threshold based on concatenated semiconductor optical amplifiers and electroabsorbers. We demonstrate demonstrate improvements in both extinction-ratio and BER sensitivity atfor a 10 Gb/s NRZ signal....

  6. Random amplified polymorphic DNA (RAPD) and simple sequence ...

    African Journals Online (AJOL)

    Knowledge as to genetic diversity and relationships among maize hybrids is important for breeding strategies. The main aims of this study were to (1) estimate molecular genetic diversity among 30 maize hybrids by random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers; and (2) compare ...

  7. Multisine Decomposition Algorithm for RF Power Amplifier Characterization

    DEFF Research Database (Denmark)

    Palmisano, Davide; Galasso, Andrea; Tafuri, Felice Francesco

    2015-01-01

    outperforms state-of-the-art multisine design procedures by proposing a solution capable of achieving an arbitrarily low PAPR error with respect to the digital signal being decomposed. This innovative step enables a fast multisine-based power amplifier characterization with results that closely match...

  8. Optimum design of Nd-doped fiber optical amplifiers

    DEFF Research Database (Denmark)

    Rasmussen, Thomas; Bjarklev, Anders Overgaard; Lumholt, Ole

    1992-01-01

    The waveguide parameters for a Nd-doped fluoride (Nd:ZBLANP) fiber amplifier have been optimized for small-signal and booster operation using an accurate numerical model. The optimum cutoff wavelength is shown to be 800 nm and the numerical aperture should be made as large as possible. Around 80...

  9. Processing of optical combs with fiber optic parametric amplifiers

    Czech Academy of Sciences Publication Activity Database

    Slavík, Radan; Kakande, J.; Richardson, D.J.; Petropoulos, P.

    2012-01-01

    Roč. 20, č. 9 (2012), s. 10059-10070 ISSN 1094-4087 Institutional support: RVO:67985882 Keywords : Fiber - optic parametric amplifier * Phase sensitive * Spectral coverage Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.546, year: 2012

  10. Asymmetric gain-saturated spectrum in fiber optical parametric amplifiers

    DEFF Research Database (Denmark)

    Lali-Dastjerdi, Zohreh; Rottwitt, Karsten; Galili, Michael

    2012-01-01

    We demonstrate experimentally and numerically an unexpected spectral asymmetry in the saturated-gain spectrum of single-pump fiber optical parametric amplifiers. The interaction between higher-order four-wave mixing products and dispersive waves radiated as an effect of third-order dispersion...

  11. ytterbium- & erbium-doped silica for planar waveguide lasers & amplifiers

    DEFF Research Database (Denmark)

    Dyndgaard, Morten Glarborg

    2001-01-01

    The purpose of this work was to demonstrate ytterbium doped planar components and investigate the possibilities of making erbium/ytterbium codoped planar waveguides in germano-silica glass. Furthermore, tools for modelling lasers and erbium/ytterbium doped amplifiers. The planar waveguides were...

  12. Multilevel inverter based class D audio amplifier for capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    The reduced semiconductor voltage stress makes the multilevel inverters especially interesting, when driving capacitive transducers for audio applications. A ± 300 V flying capacitor class D audio amplifier driving a 100 nF load in the midrange region of 0.1-3.5 kHz with Total Harmonic Distortion...... plus Noise (THD+N) belo w1%is presented....

  13. Randomly Amplified Polymorphic DNA tests (RAPDs) cannot be ...

    African Journals Online (AJOL)

    The three South African crane species — the Blue Crane (Anthropoides paradisea), the Wattled Crane (Bugeranus carunculatus) and the Grey Crowned Crane (Balearica regulorum regulorum) — are listed as threatened by the IUCN. This study investigated the suitability of Randomly Amplified Polymorphic DNA markers in ...

  14. Optimizing learning of a locomotor task: amplifying errors as needed.

    Science.gov (United States)

    Marchal-Crespo, Laura; López-Olóriz, Jorge; Jaeger, Lukas; Riener, Robert

    2014-01-01

    Research on motor learning has emphasized that errors drive motor adaptation. Thereby, several researchers have proposed robotic training strategies that amplify movement errors rather than decrease them. In this study, the effect of different robotic training strategies that amplify errors on learning a complex locomotor task was investigated. The experiment was conducted with a one degree-of freedom robotic stepper (MARCOS). Subjects were requested to actively coordinate their legs in a desired gait-like pattern in order to track a Lissajous figure presented on a visual display. Learning with three different training strategies was evaluated: (i) No perturbation: the robot follows the subjects' movement without applying any perturbation, (ii) Error amplification: existing errors were amplified with repulsive forces proportional to errors, (iii) Noise disturbance: errors were evoked with a randomly-varying force disturbance. Results showed that training without perturbations was especially suitable for a subset of initially less-skilled subjects, while error amplification seemed to benefit more skilled subjects. Training with error amplification, however, limited transfer of learning. Random disturbing forces benefited learning and promoted transfer in all subjects, probably because it increased attention. These results suggest that learning a locomotor task can be optimized when errors are randomly evoked or amplified based on subjects' initial skill level.

  15. Amplified fragment length polymorphism (AFLP) studies on Indian ...

    African Journals Online (AJOL)

    Jane

    2011-07-11

    Jul 11, 2011 ... Amplified fragment length polymorphism (AFLP) technology was used to reveal the genetic variation in six species of Cycas collected from eleven natural populations. Two sets of primer with 4-selective nucleotides were used in this study and 78% polymorphism was found. The results correlated with.

  16. Genetic diversity of Santalum album using random amplified ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-06

    Jul 6, 2009 ... Sandalwood is found distributed all over the country with over 90% of the area in Karnataka and Tamil Nadu. It is of great economic importance because of its fragrant heartwood and oil. In the present study Random Amplified Polymorphic DNA (RAPD) technique was used to accesses the genetic diversity ...

  17. Theory of the singly quasidegenerate Josephson junction parametric amplifier

    DEFF Research Database (Denmark)

    Sørensen, O.H.; Dueholm, B.; Mygind, Jesper

    1980-01-01

    A comprehensive account of the theory of the singly quasidegenerate Josephson junction parametric amplifier is given. In this mode the signal and idler frequencies are both approximately equal to half the pump frequency, and hence the signal and idler channels have a common termination. It is shown...

  18. Nuclear magnetic resonance experiments with dc SQUID amplifiers

    International Nuclear Information System (INIS)

    Heaney, M.B.

    1990-11-01

    The development and fabrication of dc SQUIDs (Superconducting QUantum Interference Devices) with Nb/Al 2 O 3 /Nb Josephson junctions is described. A theory of the dc SQUID as a radio-frequency amplifier is presented, with an optimization strategy that accounts for the loading and noise contributions of the postamplifier and maximizes the signal-to-noise ratio of the total system. The high sensitivity of the dc SQUID is extended to high field NMR. A dc SQUID is used as a tuned radio-frequency amplifier to detect pulsed nuclear magnetic resonance at 32 MHz from a metal film in a 3.5 Tesla static field. A total system noise temperature of 11 K has been achieved, at a bath temperature of 4.2 K. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse is about 2 x 10 17 in a bandwidth of 25 kHz. In a separate experiment, a dc SQUID is used as a rf amplifier in a NQR experiment to observe a new resonance response mechanism. The net electric polarization of a NaClO 3 crystal due to the precessing electric quadrupole moments of the Cl nuclei is detected at 30 MHz. The sensitivity of NMR and NQR spectrometers using dc SQUID amplifiers is compared to the sensitivity of spectrometers using conventional rf amplifiers. A SQUID-based spectrometer has a voltage sensitivity which is comparable to the best achieved by a FET-based spectrometer, at these temperatures and operating frequencies

  19. BET bromodomain inhibition of MYC-amplified medulloblastoma.

    Science.gov (United States)

    Bandopadhayay, Pratiti; Bergthold, Guillaume; Nguyen, Brian; Schubert, Simone; Gholamin, Sharareh; Tang, Yujie; Bolin, Sara; Schumacher, Steven E; Zeid, Rhamy; Masoud, Sabran; Yu, Furong; Vue, Nujsaubnusi; Gibson, William J; Paolella, Brenton R; Mitra, Siddhartha S; Cheshier, Samuel H; Qi, Jun; Liu, Kun-Wei; Wechsler-Reya, Robert; Weiss, William A; Swartling, Fredrik J; Kieran, Mark W; Bradner, James E; Beroukhim, Rameen; Cho, Yoon-Jae

    2014-02-15

    MYC-amplified medulloblastomas are highly lethal tumors. Bromodomain and extraterminal (BET) bromodomain inhibition has recently been shown to suppress MYC-associated transcriptional activity in other cancers. The compound JQ1 inhibits BET bromodomain-containing proteins, including BRD4. Here, we investigate BET bromodomain targeting for the treatment of MYC-amplified medulloblastoma. We evaluated the effects of genetic and pharmacologic inhibition of BET bromodomains on proliferation, cell cycle, and apoptosis in established and newly generated patient- and genetically engineered mouse model (GEMM)-derived medulloblastoma cell lines and xenografts that harbored amplifications of MYC or MYCN. We also assessed the effect of JQ1 on MYC expression and global MYC-associated transcriptional activity. We assessed the in vivo efficacy of JQ1 in orthotopic xenografts established in immunocompromised mice. Treatment of MYC-amplified medulloblastoma cells with JQ1 decreased cell viability associated with arrest at G1 and apoptosis. We observed downregulation of MYC expression and confirmed the inhibition of MYC-associated transcriptional targets. The exogenous expression of MYC from a retroviral promoter reduced the effect of JQ1 on cell viability, suggesting that attenuated levels of MYC contribute to the functional effects of JQ1. JQ1 significantly prolonged the survival of orthotopic xenograft models of MYC-amplified medulloblastoma (P < 0.001). Xenografts harvested from mice after five doses of JQ1 had reduced the expression of MYC mRNA and a reduced proliferative index. JQ1 suppresses MYC expression and MYC-associated transcriptional activity in medulloblastomas, resulting in an overall decrease in medulloblastoma cell viability. These preclinical findings highlight the promise of BET bromodomain inhibitors as novel agents for MYC-amplified medulloblastoma. ©2013 AACR

  20. Evaluation of Genetic Predisposition for MYCN-Amplified Neuroblastoma.

    Science.gov (United States)

    Hungate, Eric A; Applebaum, Mark A; Skol, Andrew D; Vaksman, Zalman; Diamond, Maura; McDaniel, Lee; Volchenboum, Samuel L; Stranger, Barbara E; Maris, John M; Diskin, Sharon J; Onel, Kenan; Cohn, Susan L

    2017-10-01

    To investigate genetic predispositions for MYCN-amplified neuroblastoma, we performed a meta-analysis of three genome-wide association studies totaling 615 MYCN-amplified high-risk neuroblastoma cases and 1869 MYCN-nonamplified non-high-risk neuroblastoma cases as controls using a fixed-effects model with inverse variance weighting. All statistical tests were two-sided. We identified a novel locus at 3p21.31 indexed by the single nucleotide polymorphism (SNP) rs80059929 (odds ratio [OR] = 2.95, 95% confidence interval [CI] = 2.17 to 4.02, Pmeta = 6.47 × 10-12) associated with MYCN-amplified neuroblastoma, which was replicated in 127 MYCN-amplified cases and 254 non-high-risk controls (OR = 2.30, 95% CI = 1.12 to 4.69, Preplication = .02). To confirm this signal is exclusive to MYCN-amplified tumors, we performed a second meta-analysis comparing 728 MYCN-nonamplified high-risk patients to identical controls. rs80059929 was not statistically significant in MYCN-nonamplified high-risk patients (OR = 1.24, 95% CI = 0.90 to 1.71, Pmeta = .19). SNP rs80059929 is within intron 16 in the KIF15 gene. Additionally, the previously reported LMO1 neuroblastoma risk locus was statistically significant only in patients with MYCN-nonamplified high-risk tumors (OR = 0.63, 95% CI = 0.53 to 0.75, Pmeta = 1.51 × 10-8; Pmeta = .95). Our results indicate that common genetic variation predisposes to different neuroblastoma genotypes, including the likelihood of somatic MYCN-amplification. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. Drug Facts

    Medline Plus

    Full Text Available ... Drug Use Hurts Brains Drug Use and Mental Health Problems Often Happen Together The Link Between Drug Use and HIV/AIDS Treatment & Recovery Why Does a Person Need Treatment? Does Drug Treatment Work? What ... Institute on Drug Abuse (NIDA) is part of the National Institutes of Health (NIH) , the principal biomedical and behavioral research agency ...

  2. HIV subtype and drug resistance patterns among drug naïve ...

    African Journals Online (AJOL)

    SERVER

    2007-08-20

    Aug 20, 2007 ... To determine HIV-1 subtypes and antiretroviral drug resistance mutations for 16 infected, pregnant women in Jos, Nigeria, part of pol (1040 bp) was amplified from patient PBMC DNA, sequenced and analyzed. Eight of the samples were subtype G, three were CRF02_AG and 2 were unique recombinant.

  3. Amplified CWDM-based Next Generation Broadband Access Networks

    Science.gov (United States)

    Peiris, Sasanthi Chamarika

    The explosive growth of both fixed and mobile data-centric traffic along with the inevitable trend towards all-IP/Ethernet transport protocols and packet switched networks will ultimately lead to an all-packet-based converged fixed-mobile optical transport network from the core all the way out to the access network. To address the increasing capacity and speed requirements in the access networks, Wavelength-Division Multiplexed (WDM) and/or Coarse WDM (CWDM)-based Passive Optical Networks (PONs) are expected to emerge as the next-generation optical access infrastructures. However, due to several techno-economic hurdles, CWDM-PONs are still considered an expensive solution and have not yet made any significant inroads into the current access area. One of the key technology hurdles is the scalability of the CWDM-based PONs. Passive component optical insertion losses limit the reach of the network or the number of served optical network units (ONUs). In the recent years, optical amplified CWDM approaches have emerged and new designs of optical amplifiers have been proposed and demonstrated. The critical design parameter for these amplifiers is the very wide optical amplification bandwidth (e.g., 340 nm combined for both directions). The objective of this PhD dissertation work is first to engineer ring and tree-ring based PON architectures that can achieve longer unamplified PON reach and/or provide service to a greater number of ONUs and customers. Secondly is to develop new novel optical amplifier schemes to further address the scalability limitation of the CWDM-based PONs. Specifically, this work proposes and develops novel ultra wide-band hybrid Raman-Optical parametric amplifier (HROPA) schemes that operate over nearly the entire specified CWDM band to provide 340 nm bidirectional optical gain bandwidth over the amplified PON's downstream and upstream CWDM wavelength bands (about 170 nm in each direction). The performance of the proposed HROPA schemes is assessed

  4. Amplifier Module for 260-GHz Band Using Quartz Waveguide Transitions

    Science.gov (United States)

    Padmanabhan, Sharmila; Fung, King Man; Kangaslahti, Pekka P.; Peralta, Alejandro; Soria, Mary M.; Pukala, David M.; Sin, Seth; Samoska, Lorene A.; Sarkozy, Stephen; Lai, Richard

    2012-01-01

    Packaging of MMIC LNA (monolithic microwave integrated circuit low-noise amplifier) chips at frequencies over 200 GHz has always been problematic due to the high loss in the transition between the MMIC chip and the waveguide medium in which the chip will typically be used. In addition, above 200 GHz, wire-bond inductance between the LNA and the waveguide can severely limit the RF matching and bandwidth of the final waveguide amplifier module. This work resulted in the development of a low-loss quartz waveguide transition that includes a capacitive transmission line between the MMIC and the waveguide probe element. This capacitive transmission line tunes out the wirebond inductance (where the wire-bond is required to bond between the MMIC and the probe element). This inductance can severely limit the RF matching and bandwidth of the final waveguide amplifier module. The amplifier module consists of a quartz E-plane waveguide probe transition, a short capacitive tuning element, a short wire-bond to the MMIC, and the MMIC LNA. The output structure is similar, with a short wire-bond at the output of the MMIC, a quartz E-plane waveguide probe transition, and the output waveguide. The quartz probe element is made of 3-mil quartz, which is the thinnest commercially available material. The waveguide band used is WR4, from 170 to 260 GHz. This new transition and block design is an improvement over prior art because it provides for better RF matching, and will likely yield lower loss and better noise figure. The development of high-performance, low-noise amplifiers in the 180-to- 700-GHz range has applications for future earth science and planetary instruments with low power and volume, and astrophysics array instruments for molecular spectroscopy. This frequency band, while suitable for homeland security and commercial applications (such as millimeter-wave imaging, hidden weapons detection, crowd scanning, airport security, and communications), also has applications to

  5. Drug Facts

    Medline Plus

    Full Text Available ... Where Can Someone Find Treatment and Recovery Resources? Prevention Help Children and Teens Stay Drug-Free Talking ... You Used Drugs in the Past Drug Use Prevention Phone Numbers and Websites Search Share Listen English ...

  6. Hazardous Drugs

    Science.gov (United States)

    ... and hazardous drugs in the workplace. Pharmacy . OSHA Hospital eTool. Reviews safety and health topics related to hazardous drugs including drug handling, administration, storage, and disposal. OSHA has identified worker exposure ...

  7. Drug Facts

    Medline Plus

    Full Text Available ... Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth Pain Medicines Spice (K2) Tobacco/Nicotine Other Drugs You can call 1-800-662-HELP (4357) at any time to find drug treatment ...

  8. Drug Reactions

    Science.gov (United States)

    ... problem is interactions, which may occur between Two drugs, such as aspirin and blood thinners Drugs and food, such as statins and grapefruit Drugs and supplements, such as ginkgo and blood thinners ...

  9. Drug Facts

    Medline Plus

    Full Text Available ... symptoms of someone with a drug use problem? How Does Drug Use Become an Addiction? What Makes Someone More Likely to Get Addicted to Drugs? Does Addiction Run in Families? Why Is It So Hard to ...

  10. Club Drugs

    Science.gov (United States)

    ... Adolescent Brain Comorbidity College-Age & Young Adults Criminal Justice Drugged Driving Drug Testing Drugs and the Brain ... regarding prevention and treatment of MDMA. ( September 2017 ) View all related publications Related NIDA Notes Articles Narrative ...

  11. Drug Facts

    Medline Plus

    Full Text Available ... Other Effects on the Body Drug Use Hurts Brains Drug Use and Mental Health Problems Often Happen ... to prescription drugs. The addiction slowly took over his life. I need different people around me. To ...

  12. Drug Facts

    Medline Plus

    Full Text Available ... Facts Tobacco and Nicotine Facts Other Drugs of Abuse What is Addiction? What are some signs and symptoms of someone with a drug use problem? How Does Drug Use Become an Addiction? What ...

  13. Drug Facts

    Medline Plus

    Full Text Available ... Does a Person Need Treatment? Does Drug Treatment Work? What Are the Treatment Options? What Is Recovery? ... I want my daughter to avoid drugs. "Debbie" has been drug-free for years. She wants her ...

  14. Nanoparticles that Communicate In Vivo to Amplify Tumour Targeting

    Science.gov (United States)

    von Maltzahn, Geoffrey; Park, Ji-Ho; Lin, Kevin Y.; Singh, Neetu; Schwöppe, Christian; Mesters, Rolf; Berdel, Wolfgang E.; Ruoslahti, Erkki; Sailor, Michael J.; Bhatia, Sangeeta N.

    2012-01-01

    Nanomedicines have enormous potential to improve the precision of cancer therapy, yet our ability to efficiently home these materials to regions of disease in vivo remains very limited. Inspired by the ability for communication to improve targeting in biological systems, such inflammatory cell recruitment to sites of disease, we construct systems where synthetic biological and nanotechnological components communicate to amplify disease targeting in vivo. These systems are composed of ‘Signalling’ modules (nanoparticles or engineered proteins) that target tumours and then locally active the coagulation cascade to broadcast tumour location to clot-targeted ‘Receiving’ nanoparticles in circulation that carry a diagnostic or therapeutic cargo, thereby amplifying their delivery. We show that communicating nanoparticle systems can be composed from multiple types of Signalling and Receiving modules, can transmit information via multiple molecular pathways in coagulation, can operate autonomously, and can target over 40-fold higher doses of chemotherapeutics to tumours than non-communicating controls. PMID:21685903

  15. Self-amplified optical pattern-recognition technique

    Science.gov (United States)

    Liu, Hua-Kuang

    1992-01-01

    A self-amplified optical pattern-recognition technique that utilizes a photorefractive crystal as a real-time volume holographic filter with recording accomplished by means of laser beams of proper polarization and geometric configuration is described. After the holographic filter is recorded, it can be addressed with extremely weak object beams and an even weaker reference beam to obtain a pattern-recognition signal. Because of beam-coupling energy transfer from the input object beam to the diffracted beam, the recognition signal is greatly amplified. Experimental results of this technique using BaTiO3 crystal show that 5 orders of magnitude of amplification of a recognition signal can be obtained.

  16. Low-voltage CMOS operational amplifiers theory, design and implementation

    CERN Document Server

    Sakurai, Satoshi

    1995-01-01

    Low-Voltage CMOS Operational Amplifiers: Theory, Design and Implementation discusses both single and two-stage architectures. Opamps with constant-gm input stage are designed and their excellent performance over the rail-to-rail input common mode range is demonstrated. The first set of CMOS constant-gm input stages was introduced by a group from Technische Universiteit, Delft and Universiteit Twente, the Netherlands. These earlier versions of circuits are discussed, along with new circuits developed at the Ohio State University. The design, fabrication (MOSIS Tiny Chips), and characterization of the new circuits are now complete. Basic analog integrated circuit design concepts should be understood in order to fully appreciate the work presented. However, the topics are presented in a logical order and the circuits are explained in great detail, so that Low-Voltage CMOS Operational Amplifiers can be read and enjoyed by those without much experience in analog circuit design. It is an invaluable reference boo...

  17. Medium response limitations in short pulse amplifiers and absorbers

    International Nuclear Information System (INIS)

    Schappert, G.T.

    1976-07-01

    This report reviews some of the basic considerations which determine temporal pulse characteristics in amplifiers and absorbers. To concentrate on analytical results, the amplification or absorption of a step pulse is worked out in detail. It is shown that in the small signal regime the medium response time of T 2 is modified because of propagation effects to T 2 gL/2 for an amplifier of gain g and length L and T 2 /αl for an absorber of loss coefficient 1 and length L. Once saturation sets in, general analytical results are no longer possible except in the T 2 → 0, or rate equation limit. However, combining the finite T 2 small signals results with the rate equation results one can estimate risetime effects. Coherent effects, such as π pulses and self induced transparency have not yet found applications in high power, high pressure gas lasers. (orig.) [de

  18. A novel power amplifier structure for RFID tag applications

    International Nuclear Information System (INIS)

    Deng Jianbao; Zhang Shilin; Li De; Zhang Yanzheng; Mao Luhong; Xie Sheng

    2011-01-01

    A novel matching method between the power amplifier (PA) and antenna of an active or semi-active RFID tag is presented. A PCB dipole antenna is used as the resonance inductor of a differential power amplifier. The total PA chip area is reduced greatly to only 240 × 70 μm 2 in a 0.18 μm CMOS process due to saving two on-chip integrated inductors. Operating in class AB with a 1.8 V supply voltage and 2.45 GHz input signal, the PA shows a measured output power of 8 dBm at the 1 dB compression point. (semiconductor integrated circuits)

  19. Accurate Modeling and Analysis of Isolation Performance in Multiport Amplifiers

    Directory of Open Access Journals (Sweden)

    Marinella Aloisio

    2012-01-01

    Full Text Available A Multiport Amplifier (MPA is an implementation of the satellite power amplification section that allows sharing the payload RF power among several beams/ports and guarantees a highly efficient exploitation of the available DC satellite power. This feature is of paramount importance in multiple beam satellite systems where the use of MPAs allows reconfiguring the RF output power among the different service beams in order to handle unexpected traffic unbalances and traffic variations over time. This paper presents Monte Carlo simulations carried out by means of an ESA in-house simulator developed in Matlab environment. The objective of the simulations is to analyse how the MPA performance, in particular in terms of isolation at the MPA output ports, is affected by the amplitude and phase tracking errors of the high power amplifiers within the MPA.

  20. Physics of vertically integrated waveguide photodetectors and amplifiers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wright, E.M. [Univ. of Arizona, Tucson, AZ (United States). Optical Sciences Center

    1993-11-01

    This report describes the efforts supported by LLNL under the Subcontract No. B239593 at the University of Arizona during the Fiscal Year 1992. A solid physical foundation has been developed for understanding the operation of vertically integrated photodetectors and amplifiers. This has been achieved through a combination of numerical simulation and development of simple coupled-mode theories. Coupled-mode theory has been used to elucidate the physics underlying the operation of vertically integrated photodetectors. In particular, the relation between the spatial transients observed in experiments and numerical simulations, and the non-power orthogonality of the underlying modes has been clarified. The coupled-mode theory has been extended to the case of coupled waveguide-amplifiers.

  1. High power pulsed sources based on fiber amplifiers

    Science.gov (United States)

    Canat, Guillaume; Jaouën, Yves; Mollier, Jean-Claude; Bouzinac, Jean-Pierre; Cariou, Jean-Pierre

    2017-11-01

    Cladding-pumped rare-earth-doped fiber laser technologies are currently among the best sources for high power applications. Theses extremely compact and robust sources appoint them as good candidate for aeronautical and space applications. The double-clad (DC) fiber converts the poor beamquality of high-power large-area pump diodes from the 1st cladding to laser light at another wavelength guided in an active single-mode core. High-power coherent MOPA (Master Oscillator Power Amplifier) sources (several 10W CW or several 100W in pulsed regime) will soon be achieved. Unfortunately it also brings nonlinear effects which quickly impairs output signal distortions. Stimulated Brillouin scattering (SBS) and optical parametric amplification (OPA) have been shown to be strong limitations. Based on amplifier modeling and experiments we discuss the performances of these sources.

  2. GaN Monolithic Power Amplifiers for Microwave Backhaul Applications

    Directory of Open Access Journals (Sweden)

    Roberto Quaglia

    2016-06-01

    Full Text Available Gallium nitride integrated technology is very promising not only for wireless applications at mobile frequencies (below 6 GHz but also for network backhaul radiolink deployment, now under deep revision for the incoming 5G generation of mobile communications. This contribution presents three linear power amplifiers realized on 0.25 μ m Gallium Nitride on Silicon Carbide monolithic integrated circuits for microwave backhaul applications: two combined power amplifiers working in the backhaul band around 7 GHz, and a more challenging third one working in the higher 15 GHz band. Architectures and main design steps are described, highlighting the pros and cons of Gallium Nitride with respect to the reference technology which, for these applications, is represented by gallium arsenide.

  3. Laboratory reliability test on in-core flux detector amplifier

    International Nuclear Information System (INIS)

    Oprea, M.; Oprea, I.

    1995-01-01

    The paper presents an analysis of the reliability of the In-core Flux Detector Amplifier which will be used in the Reactor Regulating System (RRS) and Shut-Down Systems (SDS) of the Unit 1 Nuclear Power Plant Cernavoda. The preliminary established reliability is predicted on the bases of the calculated mean time between failures (MTBF), obtained by computing the failures of individual components making up the channel, based on the reliability figures given in the MIL-HDBK 217 C. The assessed reliability is based on the results obtained during the operating time of 7 years in the environmental conditions of the TRIGA reactor from the Nuclear Research Institute Pitesti for a NIM Bin equipped with 12 amplifiers, which was maintained under observation. (Author)

  4. Optical steganography based on amplified spontaneous emission noise.

    Science.gov (United States)

    Wu, Ben; Wang, Zhenxing; Tian, Yue; Fok, Mable P; Shastri, Bhavin J; Kanoff, Daniel R; Prucnal, Paul R

    2013-01-28

    We propose and experimentally demonstrate an optical steganography method in which a data signal is transmitted using amplified spontaneous emission (ASE) noise as a carrier. The ASE serving as a carrier for the private signal has an identical frequency spectrum to the existing noise generated by the Erbium doped fiber amplifiers (EDFAs) in the transmission system. The system also carries a conventional data channel that is not private. The so-called "stealth" or private channel is well-hidden within the noise of the system. Phase modulation is used for both the stealth channel and the public channel. Using homodyne detection, the short coherence length of the ASE ensures that the stealth signal can only be recovered if the receiver closely matches the delay-length difference, which is deliberately changed in a dynamic fashion that is only known to the transmitter and its intended receiver.

  5. Beam - and drive - controlled amplifier for the ISABELLE accelerating system

    International Nuclear Information System (INIS)

    Luccio, A.; Puglisi, M.

    1981-01-01

    The need of very low output impedance rf systems for heavy particle accelerators has led to the development of very sophisticated amplifier configurations. Among them, the use of a common-anode final amplifier seems most promising. If the output impedance is defined in the Thevenin Theorem sense, then class-A operation seems unavoidable. However, for particle dynamics only the voltage induced by the beam is of real concern and voltage requirements do not necessarily demand a time invariant output impedance. These considerations led to investigation of the conditions that must be met to obtain control over the beam-induced voltage. It was possible to demonstrate that in the common anode case the induced voltage can be largely independent of the bias applied to the final tube, if the beam loading is very strong

  6. Measurement of locus copy number by hybridisation with amplifiable probes

    Science.gov (United States)

    Armour, John A. L.; Sismani, Carolina; Patsalis, Philippos C.; Cross, Gareth

    2000-01-01

    Despite its fundamental importance in genome analysis, it is only recently that systematic approaches have been developed to assess copy number at specific genetic loci, or to examine genomic DNA for submicroscopic deletions of unknown location. In this report we show that short probes can be recovered and amplified quantitatively following hybridisation to genomic DNA. This simple observation forms the basis of a new approach to determining locus copy number in complex genomes. The power and specificity of multiplex amplifiable probe hybridisation is demonstrated by the simultaneous assessment of copy number at a set of 40 human loci, including detection of deletions causing Duchenne muscular dystrophy and Prader–Willi/Angelman syndromes. Assembly of other probe sets will allow novel, technically simple approaches to a wide variety of genetic analyses, including the potential for extension to high resolution genome-wide screens for deletions and amplifications. PMID:10606661

  7. Noise spectra in balanced optical detectors based on transimpedance amplifiers

    Science.gov (United States)

    Masalov, A. V.; Kuzhamuratov, A.; Lvovsky, A. I.

    2017-11-01

    We present a thorough theoretical analysis and experimental study of the shot and electronic noise spectra of a balanced optical detector based on an operational amplifier connected in a transimpedance scheme. We identify and quantify the primary parameters responsible for the limitations of the circuit, in particular, the bandwidth and shot-to-electronic noise clearance. We find that the shot noise spectrum can be made consistent with the second-order Butterworth filter, while the electronic noise grows linearly with the second power of the frequency. Good agreement between the theory and experiment is observed; however, the capacitances of the operational amplifier input and the photodiodes appear significantly higher than those specified in manufacturers' datasheets. This observation is confirmed by independent tests.

  8. A CMOS low-noise instrumentation amplifier using chopper modulation

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Bruun, Erik

    2005-01-01

    This paper describes a low-power, low-noise chopper stabilized CMOS instrumentation amplifier for biomedical applications. Low thermal noise is achieved by employing MOSTs biased in the weak/moderate inversion region, whereas chopper stabilization is utilized to shift 1/f-noise out of the signal...... band hereby ensuring overall low noise performance. The resulting equivalent input referred noise is approximately 7 nV/rootHz for a chopping frequency of 20 kHz. The amplifier operates from a modest supply voltage of 1.8 V, drawing 136 muA of current thus consuming 245 muW of power. The gain is 72.5 d...

  9. Maynard Smith: amplifying the reasons for signal reliability.

    Science.gov (United States)

    Harper, D G C

    2006-03-21

    One of the many questions to which John Maynard Smith contributed was that of why most animal signals are reliable. He initially rejected the "handicap" argument but gradually accepted it, a process I briefly describe. This episode illustrated his preference for mathematical models over verbal ones, and the generosity with which he could change his mind. Even after accepting that some signals are reliable because of their strategic costs, he argued for a pluralistic approach to signal reliability. Signal complexity was a developing interest when he died. Signals usually involve several components, some of which appear to amplify other signal components. The terms "amplifier" and "index" require more thought to reduce the scope for semantic confusion. I conclude by describing Maynard Smith's fascination with peacocks Pavo cristatus.

  10. An RF Power Amplifier in a Digital CMOS Process

    DEFF Research Database (Denmark)

    Nielsen, Per Asbeck; Fallesen, Carsten

    2002-01-01

    A two stage class B power amplifier for 1.9 GHz is presented. The amplifier is fabricated in a standard digital EPI-CMOS process with low resistivity substrate. The measured output power is 29 dBm in a 50 Omega load. A design method to find the large signal parameters of the output transistor...... is presented. It separates the determination of the optimal load resistance and the determination of the large signal drain-source capacitance. Based on this method, proper values for on-chip interstage matching and off-chip output matching can be derived. A envelope linearisation circuit for the PA...... is proposed. Simulations and measurements of a fabricated linearisation circuit are presented and used to calculate the achievable linearity in terms of the spectral leakage and the error vector magnitude of a EDGE (3 pi /8-8PSK) modulated signal....

  11. Compact cladding-pumped planar waveguide amplifier and fabrication method

    Science.gov (United States)

    Bayramian, Andy J.; Beach, Raymond J.; Honea, Eric; Murray, James E.; Payne, Stephen A.

    2003-10-28

    A low-cost, high performance cladding-pumped planar waveguide amplifier and fabrication method, for deployment in metro and access networks. The waveguide amplifier has a compact monolithic slab architecture preferably formed by first sandwich bonding an erbium-doped core glass slab between two cladding glass slabs to form a multi-layer planar construction, and then slicing the construction into multiple unit constructions. Using lithographic techniques, a silver stripe is deposited and formed at a top or bottom surface of each unit construction and over a cross section of the bonds. By heating the unit construction in an oven and applying an electric field, the silver stripe is then ion diffused to increase the refractive indices of the core and cladding regions, with the diffusion region of the core forming a single mode waveguide, and the silver diffusion cladding region forming a second larger waveguide amenable to cladding pumping with broad area diodes.

  12. Ground and airborne methane measurements with an optical parametric amplifier

    Science.gov (United States)

    Numata, Kenji; Riris, Haris; Li, Steve; Wu, Stewart; Kawa, Stephan R.; Dawsey, Martha; Ramanathan, Anand; Mao, Jianping; Krainak, Michael; Abshire, James

    2012-06-01

    We report on ground and airborne atmospheric methane measurements with a differential absorption lidar using an optical parametric amplifier (OPA). Methane is a strong greenhouse gas on Earth and its accurate global mapping is urgently needed to understand climate change. We are developing a nanosecond-pulsed OPA for remote measurements of methane from an Earth-orbiting satellite. We have successfully demonstrated the detection of methane on the ground and from an airplane at ~11-km altitude.

  13. LNA A 1.9 GHZ low noise amplifier

    Directory of Open Access Journals (Sweden)

    Jorge Julián Moreno-Rubio

    2006-12-01

    Full Text Available This paper shows the design, the simulation, and the layout from a low noise amplifier (LNA, designed with and approximate band from 25 to 80 MHz. The design results of the matching neworks are shown, its noise figure, its available and transduced gain according to its non lineal model (TOM, the DC network, crash inductors and matching capacitors with the large impedance transmission lines.

  14. High efficiency switching power amplifiers for multi-band radar

    Science.gov (United States)

    Lawler, Jarred; Wells, Justin; Mendez, Sal; Wurth, Tim

    2012-06-01

    The reduction of size, weight, power, and cost (SWaP-C) of radio frequency (RF) components is becoming increasingly important to meet industry requirements. In meeting the SWaP-C objectives, RF components will be required to be smaller and more power efficient than the current state- of- the- art while sustaining high performance functionality. In compliance with SWaP-C and high performance functionality is a High Efficiency Switching Power Amplifier. This study focuses on the more efficient breed of switching power amplifiers (PAs), particularly the Class F PA with new techniques to operate broadband on multiple radar bands. Efficiencies in the range of 60% to 80% for Class F PAs have been reported in literature; however, this efficiency is only attainable over narrow bandwidths on the order of 10%. Several innovative techniques have been identified to increase the efficiency and operational bandwidth of RF power amplifiers (PAs) for radar applications. The amplifier design also incorporates fast turn on and turn off circuits to achieve switching times of less than one microsecond (μs). This enables the PA to be switched off during the receive period to prevent self-generated noise from corrupting the received signal. Also, high-power transmit and receive (T/R) switches at the antenna feed can be eliminated. A wideband PA enables the design of a multi-band radar, reducing the number of components needed for operation in the L and X bands. A high efficiency PA is also key to reducing battery size and cooling requirements in radar applications.

  15. Ground and Airborne Methane Measurements with an Optical Parametric Amplifier

    Science.gov (United States)

    Numata, Kenji

    2012-01-01

    We report on ground and airborne atmospheric methane measurements with a differential absorption lidar using an optical parametric amplifier (OPA). Methane is a strong greenhouse gas on Earth and its accurate global mapping is urgently needed to understand climate change. We are developing a nanosecond-pulsed OPA for remote measurements of methane from an Earth-orbiting satellite. We have successfully demonstrated the detection of methane on the ground and from an airplane at approximately 11-km altitude.

  16. Digital predistortion for power amplifiers using separable functions

    OpenAIRE

    Jiang, Hong; Wilford, Paul

    2013-01-01

    This paper is concerned with digital predistortion for linearization of RF high power amplifiers (HPAs). It has two objectives. First, we establish a theoretical framework for a generic predistorter system, and show that if a postdistorter exists, then it is also a predistorter, and therefore, the predistorter and postdistorter are equivalent. This justifies the indirect learning methods for a large class of HPAs. Secondly, we establish a systematic and general structure for a predistorter th...

  17. Estimating modal instability threshold for photonic crystal rod fiber amplifiers

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Hansen, Kristian Rymann; Laurila, Marko

    2013-01-01

    We present a semi-analytic numerical model to estimate the transverse modal instability (TMI) threshold for photonic crystal rod amplifiers. The model includes thermally induced waveguide perturbations in the fiber cross section modeled with finite element simulations, and the relative intensity...... noise (RIN) of the seed laser, which seeds mode coupling between the fundamental and higher order mode. The TMI threshold is predicted to ~370 W – 440 W depending on RIN for the distributed modal filtering rod fiber....

  18. Ultrashort-pulse laser machining system employing a parametric amplifier

    Science.gov (United States)

    Perry, Michael D.

    2004-04-27

    A method and apparatus are provided for increasing the energy of chirped laser pulses to an output in the range 0.001 to over 10 millijoules at a repetition rate 0.010 to 100 kHz by using a two stage optical parametric amplifier utilizing a bulk nonlinear crystal wherein the pump and signal beam size can be independently adjusted in each stage.

  19. A New CMOS Current-Mode Folding Amplifier

    Directory of Open Access Journals (Sweden)

    M.A Al-Absi

    2013-09-01

    Full Text Available In this paper, a new CMOS current-mode folding amplifier is proposed. The circuit is designed using MOSFETs operating in strong inversion. The design produces a nearly ideal saw-tooth input-output characteristic which is a mandatory requirement in folding analog-to-digital converters. The functionality of the proposed circuit was confirmed using Tanner simulation tools in 0.35 µm CMOS technology. Simulation results are in excellent agreement with the theory.

  20. The radiation-wavefront instability in pulsed CO2 amplifiers

    Science.gov (United States)

    Fedorov, S. V.; Iur'ev, M. S.

    1987-07-01

    The space-time evolution of a small-scale perturbation against a background of a smooth input beam which is incident on a pulsed CO2 amplifier is studied theoretically. Ranges of transverse frequency, longitudinal coordinate, and time values are found in which the perturbation growth is exponential in nature. It is shown that the wavefront instability is stabilized by the amplification of the main beam and sound damping.

  1. Extraction of PCR-amplifiable genomic DNA from Bacillus anthracisspores

    Energy Technology Data Exchange (ETDEWEB)

    Torok, Tamas

    2003-05-19

    Bacterial endospore disruption and nucleic acid extractionresulting in DNA of PCR-amplifiable quality and quantity are not trivial.Responding to the needs of the Hazardous Materials Response Unit (HMRU),Laboratory Division, Federal Bureau of Investigation, protocols weredeveloped to close these gaps. Effectiveness and reproducibility of thetechniques were validated with laboratory grown pure spores of Bacillusanthracis and its close phylogenetic neighbors, and with spiked soils anddamaged samples.

  2. High Power Narrow Linewidth 1.26 Micron Ho-Doped Fiber Amplifier, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is for the development of an innovative, high power, and extremely reliable 1.26-micron Ho-doped fluoride fiber amplifier. The proposed fiber amplifier...

  3. High Power Narrow Linewidth 1.26 Micron Ho-Doped Fiber Amplifier, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is for the development of an innovative, high power, and extremely reliable 1.26-micron Ho-doped fluoride fiber amplifier. The proposed fiber amplifier...

  4. The Role of Amplified Wild-Type Neu in the Etiology of Breast Cancer

    National Research Council Canada - National Science Library

    Gould, Michael

    2002-01-01

    Many human breast cancers have amplified wild-type Neu (Her2) protooncogenes. It is still not known from either human or rodent models if amplified wild-type Neu is involved in the etiology of breast cancer...

  5. The Role of Amplified Wild-Type Neu in the Etiology of Breast Cancer

    National Research Council Canada - National Science Library

    Gould, Michael

    2003-01-01

    Many human breast cancers have amplified wild-type Neu (Her2) protooncogenes. It is still not known from either human or rodent models if amplified wild-type Neu is involved in the etiology of breast cancer...

  6. A Kinetics Model for KrF Laser Amplifiers

    Science.gov (United States)

    Giuliani, J. L.; Kepple, P.; Lehmberg, R.; Obenschain, S. P.; Petrov, G.

    1999-11-01

    A computer kinetics code has been developed to model the temporal and spatial behavior of an e-beam pumped KrF laser amplifier. The deposition of the primary beam electrons is assumed to be spatially uniform and the energy distribution function of the nascent electron population is calculated to be near Maxwellian below 10 eV. For an initial Kr/Ar/F2 composition, the code calculates the densities of 24 species subject to over 100 reactions with 1-D spatial resolution (typically 16 zones) along the longitudinal lasing axis. Enthalpy accounting for each process is performed to partition the energy into internal, thermal, and radiative components. The electron as well as the heavy particle temperatures are followed for energy conservation and excitation rates. Transport of the lasing photons is performed along the axis on a dense subgrid using the method of characteristics. Amplified spontaneous emission is calculated using a discrete ordinates approach and includes contributions to the local intensity from the whole amplifier volume. Specular reflection off side walls and the rear mirror are included. Results of the model will be compared with data from the NRL NIKE laser and other published results.

  7. Fiber optical parametric amplifiers in optical communication systems

    Science.gov (United States)

    Marhic (†), Michel E; Andrekson, Peter A; Petropoulos, Periklis; Radic, Stojan; Peucheret, Christophe; Jazayerifar, Mahmoud

    2015-01-01

    The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time-division multiplexed formats. High-quality mid-span spectral inversion has been demonstrated at 0.64 Tb/s, avoiding electronic dispersion compensation. All-optical amplitude regeneration of amplitude-modulated signals has been performed, while PSAs have been used to demonstrate phase regeneration of phase-modulated signals. A PSA with 1.1-dB noise figure has been demonstrated, and preliminary wavelength-division multiplexing experiments have been performed with PSAs. 512 Gb/s have been transmitted over 6,000 km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products in excess of 14,000 Tb/s × km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed. PMID:25866588

  8. Raman-Enhanced Phase-Sensitive Fibre Optical Parametric Amplifier

    Science.gov (United States)

    Fu, Xuelei; Guo, Xiaojie; Shu, Chester

    2016-01-01

    Phase-sensitive amplification is of great research interest owing to its potential in noiseless amplification. One key feature in a phase-sensitive amplifier is the gain extinction ratio defined as the ratio of the maximum to the minimum gains. It quantifies the capability of the amplifier in performing low-noise amplification for high phase-sensitive gain. Considering a phase-sensitive fibre optical parametric amplifier for linear amplification, the gain extinction ratio increases with the phase-insensitive parametric gain achieved from the same pump. In this work, we use backward Raman amplification to increase the phase-insensitive parametric gain, which in turn improves the phase-sensitive operation. Using a 955 mW Raman pump, the gain extinction ratio is increased by 9.2 dB. The improvement in the maximum phase-sensitive gain is 18.7 dB. This scheme can significantly boost the performance of phase-sensitive amplification in a spectral range where the parametric pump is not sufficiently strong but broadband Raman amplification is available. PMID:26830136

  9. New interferometric fiber-optic gyroscope with amplified optical feedback.

    Science.gov (United States)

    Shi, C X; Yuhara, T; Iizuka, H; Kajioka, H

    1996-01-20

    A novel interferometric fiber-optic gyroscope with amplified optical feedback by an Er-doped fiber amplifier (EDFA) is proposed and theoretically investigated (the proposed gyroscope is named the feedback EDFA-FOG, FE-FOG in what follows). The FE-FOG functions like a resonant fiber-optic gyro (R-FOG) because of its multiple utilization of the Sagnac loop; however, it is completely different because a low-coherence light source is used. In addition, the gyro output signal is pulsed because the modulation frequency of the phase modulator placed in the Sagnac loop is selected to match the total round-trip time delay of the light, which includes the Sagnac-loop delay plus that of the feedback loop of the fiber amplifier. The sharpness of the output pulse can be adjusted by both the gain of an EDFA and the modulation depth of the phase modulator. When rotation occurs the peak position of the output pulse is shifted as a result of the Sagnac effect. The resolution of the rotation measurement depends on the sharpness of the output pulse. The techniques of both the open-loop and closed-loop methods are described in detail, which shows the great advantage of the proposed gyroscope over the to the conventional interferometric fiber-optical gyroscope (I-FOG).

  10. Characteristics research on self-amplified distributed feedback fiber laser

    Science.gov (United States)

    Song, Zhiqiang; Qi, Haifeng; Guo, Jian; Wang, Chang; Peng, Gangding

    2014-09-01

    A distributed feedback (DFB) fiber laser with a ratio of the backward to forward output power of 1:100 was composed by a 45-mm-length asymmetrical phase-shifted fiber grating fabricated on the 50-mm erbium-doped photosensitive fiber. Forward output laser was amplified using a certain length of Nufern EDFL-980-Hp erbium-doped fiber to absorb the surplus pump power after the active phase-shifted fiber grating and get population inversion. By using OptiSystem software, the best fiber length of the EDFL to get the highest gain was simulated. In order to keep the amplified laser with the narrow line-width and low noise, a narrow-band light filter consisting of a fiber Bragg grating (FBG) with the same Bragg wavelength as the laser and an optical circulator was used to filter the amplified spontaneous emission (ASE) noise of the out-cavity erbium-doped fiber. The designed laser structure sufficiently utilized the pump power, and a DFB fiber laser with the 32.5-mW output power, 11.5-kHz line width, and -87-dB/Hz relative intensity noise (RIN) at 300 mW of 980 nm pump power was brought out.

  11. Demonstration of input-to-output gain and temporal noise mitigation in a Talbot amplifier

    OpenAIRE

    Maram, Reza; Seghilani, Mohamed; Jeon, Jinwoo; Li, Xiao-Zhou; Cortes, Luis Romero; van Howe, James; Azana, Jose

    2017-01-01

    We experimentally demonstrate intensity amplification of repetitive picosecond optical pulses with an input-to-output gain up to 5.5 dB using a passive Talbot amplifier. Through the dispersion-induced temporal Talbot effect, the amplifier uses electro-optic phase modulation and a low-loss dispersive medium to exploit and coherently redistribute the energy of the original pulse train into fewer, replica, amplified pulses. In addition, we show how our passive amplifier mitigates the pulse train...

  12. A low noise charge sensitive amplifier for use in vacuum photo diode readout

    International Nuclear Information System (INIS)

    Stephenson, R.

    1982-08-01

    The amplifier described consists of a charge sensitive pre-amplifier optimised for low noise with low values of input shunt capacitance, and a shaping amplifier providing both differentiation and integration. Amplifier gain is adjustable up to a maximum of approximately 100 μV/electron with a rise time of 2 μS to the peak of the output voltage, and with an open circuit input noise level of 150 electrons RMS. (author)

  13. Theoretical analysis of quantum dot amplifiers with high saturation power and low noise figure

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2002-01-01

    Semiconductor quantum dot amplifiers are predicted to exhibit superior characteristics such as high gain, and output power and low noise. The analysis provides criteria and design guidelines for the realization of high quality amplifiers.......Semiconductor quantum dot amplifiers are predicted to exhibit superior characteristics such as high gain, and output power and low noise. The analysis provides criteria and design guidelines for the realization of high quality amplifiers....

  14. Integrating switch mode audio amplifiers and electro dynamic loudspeakers for a higher power efficiency

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier.......The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier....

  15. Integrating switch mode audio power amplifiers and electro dynamic loudspeakers for a higher power efficiency

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier.......The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier....

  16. Ultra-low noise miniaturized neural amplifier with hardware averaging.

    Science.gov (United States)

    Dweiri, Yazan M; Eggers, Thomas; McCallum, Grant; Durand, Dominique M

    2015-08-01

    Peripheral nerves carry neural signals that could be used to control hybrid bionic systems. Cuff electrodes provide a robust and stable interface but the recorded signal amplitude is small (noise of less than 1 μVrms for a useful signal-to-noise ratio (SNR). Flat interface nerve electrode (FINE) contacts alone generate thermal noise of at least 0.5 μVrms therefore the amplifier should add as little noise as possible. Since mainstream neural amplifiers have a baseline noise of 2 μVrms or higher, novel designs are required. Here we apply the concept of hardware averaging to nerve recordings obtained with cuff electrodes. An optimization procedure is developed to minimize noise and power simultaneously. The novel design was based on existing neural amplifiers (Intan Technologies, LLC) and is validated with signals obtained from the FINE in chronic dog experiments. We showed that hardware averaging leads to a reduction in the total recording noise by a factor of 1/√N or less depending on the source resistance. Chronic recording of physiological activity with FINE using the presented design showed significant improvement on the recorded baseline noise with at least two parallel operation transconductance amplifiers leading to a 46.1% reduction at N = 8. The functionality of these recordings was quantified by the SNR improvement and shown to be significant for N = 3 or more. The present design was shown to be capable of generating noise when connected to a FINE placed on the sciatic nerve of an awake animal. An algorithm was introduced to find the value of N that can minimize both the power consumption and the noise in order to design a miniaturized ultralow-noise neural amplifier. These results demonstrate the efficacy of hardware averaging on noise improvement for neural recording with cuff electrodes, and can accommodate the presence of high source impedances that are associated with the miniaturized contacts and the high channel count in electrode arrays. This

  17. Ultra-low noise miniaturized neural amplifier with hardware averaging

    Science.gov (United States)

    Dweiri, Yazan M.; Eggers, Thomas; McCallum, Grant; Durand, Dominique M.

    2015-08-01

    Objective. Peripheral nerves carry neural signals that could be used to control hybrid bionic systems. Cuff electrodes provide a robust and stable interface but the recorded signal amplitude is small (noise of less than 1 μVrms for a useful signal-to-noise ratio (SNR). Flat interface nerve electrode (FINE) contacts alone generate thermal noise of at least 0.5 μVrms therefore the amplifier should add as little noise as possible. Since mainstream neural amplifiers have a baseline noise of 2 μVrms or higher, novel designs are required. Approach. Here we apply the concept of hardware averaging to nerve recordings obtained with cuff electrodes. An optimization procedure is developed to minimize noise and power simultaneously. The novel design was based on existing neural amplifiers (Intan Technologies, LLC) and is validated with signals obtained from the FINE in chronic dog experiments. Main results. We showed that hardware averaging leads to a reduction in the total recording noise by a factor of 1/√N or less depending on the source resistance. Chronic recording of physiological activity with FINE using the presented design showed significant improvement on the recorded baseline noise with at least two parallel operation transconductance amplifiers leading to a 46.1% reduction at N = 8. The functionality of these recordings was quantified by the SNR improvement and shown to be significant for N = 3 or more. The present design was shown to be capable of generating noise when connected to a FINE placed on the sciatic nerve of an awake animal. An algorithm was introduced to find the value of N that can minimize both the power consumption and the noise in order to design a miniaturized ultralow-noise neural amplifier. Significance. These results demonstrate the efficacy of hardware averaging on noise improvement for neural recording with cuff electrodes, and can accommodate the presence of high source impedances that are associated with the miniaturized contacts and

  18. Drug Facts

    Medline Plus

    Full Text Available ... Oxy, Vike) Facts Spice (K2) Facts Tobacco and Nicotine Facts Other Drugs of Abuse What is Addiction? What are some signs and symptoms of someone ... to you. This website talks about drug abuse, addiction, and treatment. Watch Videos Information About Drugs Alcohol Bath ... Spice (K2) Tobacco/Nicotine Other Drugs You can call 1-800-662- ...

  19. Drug Facts

    Medline Plus

    Full Text Available ... 4357) at any time to find drug treatment centers near you. I want my daughter to avoid drugs. "Debbie" has been drug-free for years. She wants her daughter to stay away from drugs. But she's afraid ...

  20. Drug Facts

    Medline Plus

    Full Text Available ... Resources? Prevention Help Children and Teens Stay Drug-Free Talking to Kids About Drugs: What to Say if You Used Drugs in the Past Drug Use ... Information about this page Click on the button that says "Listen" on any page and the computer will read the text to you. This website talks ...

  1. Identifying Drugs

    Science.gov (United States)

    ... and Affect Teens The Negative Health Effects of Marijuana Use State and Federal Drug Laws Treatment and Recovery Federal Student Aid and Consequences of a Drug Conviction School Failure VIDEO: Taking Prescription Drugs to Get High—A Bad Idea Drugged Driving—What You Should Know How ...

  2. Spectral shaping of a 10 W diode laser-Yb-fiber amplifier system

    NARCIS (Netherlands)

    Adhimoolam, B.; Lindsay, I.D.; Lee, Christopher James; Gross, P.; Boller, Klaus J.; Klein, M.E.

    2006-01-01

    We describe a continuous-wave master-oscillator power-amplifier system based on a distributed Bragg reflection diode laser and an Yb doped fiber amplifier. The observed optical spectrum of the amplified seed source can be tailored to arbitrary shapes and widths between 30 MHz and greater than 1 GHz

  3. Practical considerations for integrating switch mode audio amplifiers and loudspeakers for a higher power efficiency

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    An integration of electrodynamic loudspeakers and switch mode amplifiers has earlier been proposed in [1]. The work presented in this paper is related to the practical aspects of integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker’s voice coil as output...... filter, and the magnetic structure as heat sink for the amplifier....

  4. The Impact of Blood Rheology on Drug Transport in Stented Arteries: Steady Simulations

    Science.gov (United States)

    Vijayaratnam, Pujith R. S.; O’Brien, Caroline C.; Reizes, John A.; Barber, Tracie J.; Edelman, Elazer R.

    2015-01-01

    Background and Methods It is important to ensure that blood flow is modelled accurately in numerical studies of arteries featuring drug-eluting stents due to the significant proportion of drug transport from the stent into the arterial wall which is flow-mediated. Modelling blood is complicated, however, by variations in blood rheological behaviour between individuals, blood’s complex near-wall behaviour, and the large number of rheological models which have been proposed. In this study, a series of steady-state computational fluid dynamics analyses were performed in which the traditional Newtonian model was compared against a range of non-Newtonian models. The impact of these rheological models was elucidated through comparisons of haemodynamic flow details and drug transport behaviour at various blood flow rates. Results Recirculation lengths were found to reduce by as much as 24% with the inclusion of a non-Newtonian rheological model. Another model possessing the viscosity and density of blood plasma was also implemented to account for near-wall red blood cell losses and yielded recirculation length increases of up to 59%. However, the deviation from the average drug concentration in the tissue obtained with the Newtonian model was observed to be less than 5% in all cases except one. Despite the small sensitivity to the effects of viscosity variations, the spatial distribution of drug matter in the tissue was found to be significantly affected by rheological model selection. Conclusions/Significance These results may be used to guide blood rheological model selection in future numerical studies. The clinical significance of these results is that they convey that the magnitude of drug uptake in stent-based drug delivery is relatively insensitive to individual variations in blood rheology. Furthermore, the finding that flow separation regions formed downstream of the stent struts diminish drug uptake may be of interest to device designers. PMID:26066041

  5. Narrow-band laser amplifier system for tunable UV light generation

    International Nuclear Information System (INIS)

    Matsuoka, Leo; Hashimoto, Masashi; Yokoyama, Keiichi

    2013-01-01

    We developed a Ti:Sapphire narrow-band laser amplifier system for efficient third harmonic generation. The amplifier system was composed of a wavelength tunable narrow-band regenerative amplifier and a broadband multi-pass amplifier. With a pumping of ∼17 mJ by the second harmonics of a Nd:YLF laser, mode-locked seed pulses were amplified to ∼1.0 mJ at 1-kHz repetition. We obtained the third harmonic wave of ∼208-μJ pulse energy after the wavelength conversion by two β-BBO crystals. (author)

  6. Guidelines for designing BJT amplifiers with low 1/f AM and PM noise.

    Science.gov (United States)

    Ferre-Pikal, E S; Walls, F L; Nelson, C W

    1997-01-01

    In this paper we discuss guidelines for designing linear bipolar junction transistor amplifiers with low 1/f amplitude modulation (AM) and phase modulation (PM) noise. These guidelines are derived from a new theory that relates AM and PM noise to transconductance fluctuations, junction capacitance fluctuations, and circuit architecture. We analyze the noise equations of each process for a common emitter (CE) amplifier and use the results to suggest amplifier designs that minimize the 1/f noise while providing other required attributes such as high gain. Although we use a CE amplifier as an example, the procedure applies to other configurations as well. Experimental noise results for several amplifier configurations are presented.

  7. Modeling of Yb3+-sensitized Er3+-doped silica waveguide amplifiers

    DEFF Research Database (Denmark)

    Lester, Christian; Bjarklev, Anders Overgaard; Rasmussen, Thomas

    1995-01-01

    A model for Yb3+-sensitized Er3+-doped silica waveguide amplifiers is described and numerically investigated in the small-signal regime. The amplified spontaneous emission in the ytterbium-band and the quenching process between excited erbium ions are included in the model. For pump wavelengths...... between 860 and 995 nm, the amplified spontaneous emission in the ytterbium-band is found to reduce both the gain and the optimum length of the amplifier significantly. The achievable gain of the Yb3+-sensitized amplifier is found to be higher than in an Er3+-doped silica waveguide without Yb 3+ (18 d...

  8. Substance use - prescription drugs

    Science.gov (United States)

    Substance use disorder - prescription drugs; Substance abuse - prescription drugs; Drug abuse - prescription drugs; Drug use - prescription drugs; Narcotics - substance use; Opioid - substance use; Sedative - substance ...

  9. An orexin hotspot in ventral pallidum amplifies hedonic 'liking' for sweetness.

    Science.gov (United States)

    Ho, Chao-Yi; Berridge, Kent C

    2013-08-01

    Orexin (hypocretin) is implicated in stimulating appetite as well as arousal, and in both food reward and drug reward. The ventral pallidum (VP) receives orexin projections from lateral hypothalamus neurons (LH), and orexin terminals are especially dense in the posterior half of VP, which is also the location of an opioid hedonic hotspot. The VP hotspot is a roughly cubic-millimeter site where mu opioid stimulation can amplify the hedonic impact of sweetness, expressed as an increase in 'liking' reactions to sucrose taste. The anatomical overlap in posterior VP between opioid hotspot and orexin inputs raises the possibility that the hedonic hotspot might allow orexin to amplify 'liking' too. We examined whether microinjections of orexin-A into the VP hotspot enhance the hedonic impact of sucrose, as assessed via affective taste reactivity measures of 'liking' reactions, and additionally compared effects at nearby sites in adjacent LH and extended amygdala. Taste reactivity results indicated that orexin stimulation specifically in the VP hotspot nearly doubled the magnitude of positive 'liking' reactions elicited by the taste of sucrose. Mapping results for localization of function, aided by Fos plume measures of the local spread of orexin impact, suggested that hedonic enhancement was generated by essentially the same cubic-millimeter of posterior VP previously identified as the opioid hotspot. By contrast, microinjection sites in the anterior half of VP, or in LH or extended amygdala, generally failed to produce any hedonic enhancement. We conclude that an orexin hedonic hotspot exists in posterior VP, with similar boundaries to the opioid hotspot. An orexin hedonic hotspot may permit regulatory hypothalamic circuitry to make foods more 'liked' during hunger by acting through VP. Dysfunction in a VP orexin hotspot in addiction or mood disorders might also contribute to some types of affective psychopathology.

  10. Automatic alignment of double optical paths in excimer laser amplifier

    Science.gov (United States)

    Wang, Dahui; Zhao, Xueqing; Hua, Hengqi; Zhang, Yongsheng; Hu, Yun; Yi, Aiping; Zhao, Jun

    2013-05-01

    A kind of beam automatic alignment method used for double paths amplification in the electron pumped excimer laser system is demonstrated. In this way, the beams from the amplifiers can be transferred along the designated direction and accordingly irradiate on the target with high stabilization and accuracy. However, owing to nonexistence of natural alignment references in excimer laser amplifiers, two cross-hairs structure is used to align the beams. Here, one crosshair put into the input beam is regarded as the near-field reference while the other put into output beam is regarded as the far-field reference. The two cross-hairs are transmitted onto Charge Coupled Devices (CCD) by image-relaying structures separately. The errors between intersection points of two cross-talk images and centroid coordinates of actual beam are recorded automatically and sent to closed loop feedback control mechanism. Negative feedback keeps running until preset accuracy is reached. On the basis of above-mentioned design, the alignment optical path is built and the software is compiled, whereafter the experiment of double paths automatic alignment in electron pumped excimer laser amplifier is carried through. Meanwhile, the related influencing factors and the alignment precision are analyzed. Experimental results indicate that the alignment system can achieve the aiming direction of automatic aligning beams in short time. The analysis shows that the accuracy of alignment system is 0.63μrad and the beam maximum restoration error is 13.75μm. Furthermore, the bigger distance between the two cross-hairs, the higher precision of the system is. Therefore, the automatic alignment system has been used in angular multiplexing excimer Main Oscillation Power Amplification (MOPA) system and can satisfy the requirement of beam alignment precision on the whole.

  11. A CHI wiggler ubitron amplifier experiment: Wiggler characterization

    Energy Technology Data Exchange (ETDEWEB)

    Taccetti, J.M.; Jackson, R.H.; Freund, H.P. [Naval Research Lab., Washington, DC (United States)] [and others

    1995-12-31

    A 35 GHz CHI (Coaxial Hybrid Iron) wiggler ubitron amplifier experiment is under construction at the Naval Research Laboratory. The CHI wiggler configuration has the potential of generating high wiggler magnetic fields at short periods with excellent beam focusing and transport properties. This makes it a desirable configuration for the generation of high power coherent radiation in relatively compact systems. The CHI wiggler consists of alternating rings of magnetic and non-magnetic materials concentric with a central rod of similar alternating design but shifted along the axis by half a period. Once inserted in a solenoidal magnetic field, the CHI structure deforms the axial field to create a radial field oscillating with the same periodicity as the rings. An annular electron beam is propagated through the coaxial gap where the oscillating radial field imparts an azimuthal wiggle motion. The principal goals of the experiment are to investigate the performance tradeoffs involved in the CHI configuration for high frequency amplifiers operating at low voltages with small wiggler periods. The nominal design parameters are a center frequency of 35 GHz, wiggler period of 0.75 cm, and beam voltage of approximately 150 kV. Calculations have shown an intrinsic (untapered) efficiency of {approximately} 7% when operating at 6.3 kG axial field (wiggler field, B{sub w}{approximately}1270 G). The calculated gain was 36 dB, saturating at a distance of 46 cm. These parameters yield an instantaneous amplifier bandwidth of {approximately} 25%. There appears to be room for further improvement in efficiency, a matter which will be scrutinized more closely in the final design. A prototype CHI wiggler is presently being fabricated for use in conjunction with an existing 30 kG superconducting solenoid. The performance properties of the prototype will be characterized and compared with linear and non-linear calculations.

  12. The design of a 4’th order Bandpass Butterworth filter with one operational amplifier

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    2008-01-01

    A numerical design method is presented for the design of all pole band pass active-RC filters applying just one operational amplifier. The operational amplifier model used is the integrator model: ωt/s where ωt is the unity gain fre-quency. The design method is used for the design of a fourth order...... band pass filter with Butterworth poles applying just one operational amplifier coupled as a unity gain amplifier. The unity gain amplifiers have the advantage of providing low power consumption, yielding a large dynamic range, sometimes simplifying the amplifier design and being usable over a larger...... frequency range than conventional constant gain amplifiers. The Schoeffler sensitivity index is used as a basis for a practical realization of the circuit....

  13. Low-noise audio amplifiers and preamplifier for use with intrinsic thermocouples

    International Nuclear Information System (INIS)

    Langner, G.C.; Sachs, R.D.; Stewart, F.L.

    1979-03-01

    Two simple, low-noise audio amplifiers and one low-noise preamplifier for use with intrinsic thermocouples were designed, built, and tested. The amplifiers and the preamplifier have different front end designs. One amplifier uses ultralow-noise operational amplifiers; the other amplifier uses a hybrid component. The preamplifier uses ultralow-noise discrete components. The amplifiers' equivalent noise inputs, at maximum gain, are 4.09 nV and 50 nV; the preamplifier's input is 4.05 μV. Their bandwidths are 15 600 Hz, 550 Hz, and 174 kHz, respectively. the amplifiers' equivalent noise inputs were measured from approx. 0 to 100 Hz, whereas the preamplifier's equivalent noise input was measured from approx. 0 to 174 kHz

  14. All optical logic gates using semiconductor optical amplifiers

    Science.gov (United States)

    McAulay, Alastair D.

    2002-11-01

    All-optical logic can avoid expensive demultiplexing back to electronics in telecommunications. The term all-optical is used to described processing in which all signal paths are optical whether used for control or information. Semiconductor optical amplifiers (SOAs) can perform all optical logic because they have nonlinearity, low latency, and require low power. We use highly accurate computer models to simulate and evaluate NOR and NXOR logic gates using SOAs. These elements can act as building blocks for advanced logic systems. For example, in previous publications we described an approach to constructing arithmetic units from optical logic elements.

  15. Optimal linear detectors for nonorthogonal amplify-and-forward protocol

    KAUST Repository

    Ahmed, Qasim Zeeshan

    2013-06-01

    In this paper, we propose optimal linear detectors for non-orthogonal amplify-and-forward cooperative protocol when considering a single-relay scenario. Two types of detectors are proposed based on the principles of minimum mean square error (MMSE) and minimum bit error rate (MBER). The MMSE detector minimizes the mean square error, while the MBER minimizes the system bit error rate (BER). Both detectors exhibit excellent BER performance with relatively low complexity as compared to the maximal likelihood (ML) detector. The BER performance of both detectors is superior to the channel inversion, the maximal ratio combining, and the biased ML detectors. © 2013 IEEE.

  16. Recent advances in semiconductor optical amplifiers and their applications

    DEFF Research Database (Denmark)

    Stubkjær, Kristian; Mikkelsen, Benny; Djurhuus, Torsten

    1992-01-01

    The authors review recent advances in SOAs (semiconductor optical amplifiers) and some of their applications. SOAs are under rapid development to achieve polarization independent gain, low facet reflectivities, good coupling to optical fibers, and high saturation power. The package SOA can be made...... compact and possibly inexpensive, but its main advantage is the potential for optoelectronic integration. SOAs may be used as boosters and preamplifiers, but in the case of multichannel systems attention must be given to the inherent nonlinear behavior that is due to the short lifetime of the injected...

  17. New amplifying laser concept for inertial fusion driver

    International Nuclear Information System (INIS)

    Mourou, G A; Hulin, D; Labaune, C; Galvanauskas, A

    2008-01-01

    This paper presents a new amplifying laser concept designed to produce high energy in either short or long pulses using coherent or incoherent addition of few millions fibers. These are called respectively CAN for Coherent Amplification Network and FAN for Fiber Amplification Network. The fibers would be large core or Large Mode Area (LMA) which have demonstrated up to 10, mJ output energy per fiber 1 . Such a system could meet the driver criteria of Inertial Fusion Energy (IFE) power plants based on Inertial Confinement Fusion (ICF), in particular high efficiency and high repetition rate

  18. Amplified-fragment length polymorphism fingerprinting of Mycoplasma species

    DEFF Research Database (Denmark)

    Kokotovic, Branko; Friis, N.F.; Jensen, J.S.

    1999-01-01

    Amplified-fragment length polymorphism (AFLP) is a whole-genome fingerprinting method based on selective amplification of restriction fragments. The potential of the method for the characterization of mycoplasmas was investigated in a total of 50 strains of human and animal origin, including......I restriction endonucleases and subsequent ligation of corresponding site-specific adapters. The amplification of AFLP templates with a single set of nonselective primers resulted in reproducible fingerprints of approximately 60 to 80 fragments in the size range of 50 to 500 bp, The method was able...

  19. Amplify-and-forward relaying in wireless communications

    CERN Document Server

    Rodriguez, Leonardo Jimenez; Le-Ngoc, Tho

    2015-01-01

    This SpringerBrief explores the advantage of relaying techniques in addressing the increasing demand for high data rates and reliable services over the air. It demonstrates how to design cost-effective relay systems that provide high spectral efficiency and fully exploit the diversity of the relay channel. The brief covers advances in achievable rates, power allocation schemes, and error performance for half-duplex (HD) and full-duplex (FD) amplify-and-forward (AF) single-relay systems. The authors discuss the capacity and respective optimal power allocation for a wide range of HD protocols ov

  20. X-ray laser '' oscillator-amplifier'' experiments

    International Nuclear Information System (INIS)

    Shimkaveg, G.M.; Carter, M.R.; Young, B.K.F.; Walling, R.S.; Osterheld, A.L.; Trebes, J.E.; London, R.A.; Ratowsky, R.P.; Stewart, R.E.; Craxton, R.S.

    1993-01-01

    We present results from experiments directed toward increasing the degree of transverse coherence in x-ray laser beams. We have concentrated on the neon-like yttrium (Z=39) collisionally-pumped x-ray laser as the test system for these studies because of its unique combination of brightness, monochromaticity, and high-reflectivity optics availability. Attempts at improving laser performance using proximate feedback optics failed. Modest success has been found to date in ''double foil'' experiments, involving two x-ray lasers spatially separated by 29 cm and shot sequentially in an ''oscillator-amplifier'' configuration

  1. Megawatt-klystron amplifiers in L-band

    International Nuclear Information System (INIS)

    Schaffer, G.

    1989-01-01

    The purpose of this note is to serve as a short guide for the SSC-Linac Injector Workshop. It contains a general overview of historical development and of modern design of L-band klystron amplifiers in the range of about 1 to 30 Megawatt output (CW or pulse). Absolute power limits, efficiency, modulation characteristics, protection devices and typical application examples are briefly considered. It should be mentioned that this overview is not restricted to specific needs of the SSC-Injector Linac. 14 refs., 12 figs., 2 tabs

  2. Cryogenic Capacitive Transimpedance Amplifier for Astronomical Infrared Detectors

    OpenAIRE

    Nagata, Hirohisa; Shibai, Hiroshi; Hirao, Takanori; Watabe, Toyoki; Noda, Manabu; Hibi, Yasunori; Kawada, Mitsunobu; Nakagawa, Takao

    2004-01-01

    We have developed a new capacitive transimpedance amplifier (CTIA) that can be operated at 2 K, and have good performance as readout circuits of astronomical far-infrared array detectors. The circuit design of the present CTIA consists of silicon p-MOSFETs and other passive elements. The process is a standard Bi-CMOS process with 0.5$mu$m design rule. The open-loop gain of the CTIA is more than 300, resulting in good integration performance. The output voltage swing of the CTIA was 270 mV. Th...

  3. A Highly Responsive Silicon Nanowire/Amplifier MOSFET Hybrid Biosensor

    Science.gov (United States)

    2015-07-21

    Hybrid Biosensor Jieun Lee1,2, Jaeman Jang1, Bongsik Choi1, Jinsu Yoon1, Jee-Yeon Kim3, Yang-Kyu Choi3, Dong Myong Kim1, Dae Hwan Kim1 & Sung-Jin Choi1...This study demonstrates a hybrid biosensor comprised of a silicon nanowire (SiNW) integrated with an amplifier MOSFET to improve the current response...of field-effect-transistor (FET)-based biosensors . The hybrid biosensor is fabricated using conventional CMOS technology, which has the potential

  4. Amplifying human ability through autonomics and machine learning in IMPACT

    Science.gov (United States)

    Dzieciuch, Iryna; Reeder, John; Gutzwiller, Robert; Gustafson, Eric; Coronado, Braulio; Martinez, Luis; Croft, Bryan; Lange, Douglas S.

    2017-05-01

    Amplifying human ability for controlling complex environments featuring autonomous units can be aided by learned models of human and system performance. In developing a command and control system that allows a small number of people to control a large number of autonomous teams, we employ an autonomics framework to manage the networks that represent mission plans and the networks that are composed of human controllers and their autonomous assistants. Machine learning allows us to build models of human and system performance useful for monitoring plans and managing human attention and task loads. Machine learning also aids in the development of tactics that human supervisors can successfully monitor through the command and control system.

  5. High rate amplifier-digitizer system for liquid argon calorimeters

    International Nuclear Information System (INIS)

    Droege, T.F.; Lobkowicz, F.; Fukushima, Y.

    1978-01-01

    A low-cost charge amplifier for a liquid argon photon detector and a new method for pulse height analysis are described. This scheme is suitable for high-energy photon detection with high counting rate. Samples of preamplifer output are taken just before and just after the arrival of the charge from the detector. The difference of these samples provides a stable pedestal and rejects low frequency noise. Short two-pulse resolving time (approximately equal to 200ns) is achieved. 6 refs

  6. Nonlinearly driven oscillations in the gyrotron traveling-wave amplifier

    International Nuclear Information System (INIS)

    Chiu, C. C.; Pao, K. F.; Yan, Y. C.; Chu, K. R.; Barnett, L. R.; Luhmann, N. C. Jr.

    2008-01-01

    By delivering unprecedented power and gain, the gyrotron traveling-wave amplifier (gyro-TWT) offers great promise for advanced millimeter wave radars. However, the underlying physics of this complex nonlinear system is yet to be fully elucidated. Here, we report a new phenomenon in the form of nonlinearly driven oscillations. A zero-drive stable gyro-TWT is shown to be susceptible to a considerably reduced dynamic range at the band edge, followed by a sudden transition into driven oscillations and then a hysteresis effect. An analysis of this unexpected behavior and its physical interpretation are presented.

  7. Gain recovery dynamics and limitations in quantum dot amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Bischoff, Svend; Magnúsdóttir, Ingibjörg

    2001-01-01

    Summary form only given. While ultra-low threshold current densities have been achieved in quantum dot (QD) lasers, the predicted potential for high-speed modulation has not yet been realized despite the high differential gain. Furthermore, recent single pulse experiments demonstrated very fast...... gain recovery in a quantum dot amplifier, and it is thus not yet clear what the limiting processes for the device response are. We present the results of a comprehensive theoretical model, which agrees well with the experimental results, and indicates the importance of slow recovery of higher energy...

  8. Random amplified polymorphic DNA analysis of genetically modified organisms.

    Science.gov (United States)

    Yoke-Kqueen, Cheah; Radu, Son

    2006-12-15

    Randomly amplified polymorphic DNA (RAPD) was used to analyzed 78 samples comprises of certified reference materials (soya and maize powder), raw seeds (soybean and maize), processed food and animal feed. Combination assay of two arbitrary primers in the RAPD analysis enable to distinguish genetically modified organism (GMO) reference materials from the samples tested. Dendrogram analysis revealed 13 clusters at 45% similarity from the RAPD. RAPD analysis showed that the maize and soybean samples were clustered differently besides the GMO and non-GMO products.

  9. Propagation delay of femtosecond pulses in an optical amplifier

    DEFF Research Database (Denmark)

    Poel, Mike van der; Mørk, Jesper; Hvam, Jørn Märcher

    of 2.6 THz, through a quantum-dot (QD) semiconductor amplifier (SOA) at room temperature. This extremely large bandwidth, on the other hand, is at the cost of a rather small group index change of ?ng=4*10-3. We have performed two types of femtosecond pulse slow-down and advancement experiments....... In the first experiment, we prepare a narrow peak or dip in the SOA gain spectrum by injection of a strong pump pulse4. The resulting dispersion feature is then probed by a weak pulse. In the second experiment, we measure self-slowdown or advancement as pulse energy isincreased5. In both cases, we perform...

  10. Experimental Generation of Multimode Squeezing in an Optical Parametric Amplifier

    International Nuclear Information System (INIS)

    Liu Kui; Cui Shu-Zhen; Yang Rong-Guo; Zhang Jun-Xiang; Gao Jiang-Rui

    2012-01-01

    We experimentally demonstrate that HG 01 (Hermit—Gauss) and HG 10 squeezed states can be generated simultaneously in an optical parametric amplifier. The HG 01 mode is a bright squeezed state and the HG 10 mode is a vacuum squeezed state. The squeezing of the HG 01 mode is −2.8 dB, and the squeezing of the HG 10 mode is −1.6 dB. We also demonstrate that the output field is also continuous-variable entanglement with orbital angular momentum. (general)

  11. Optimal signal-to-noise in digital phase lock amplifiers

    Science.gov (United States)

    Doering, Charles R.; Harvey, Paul M.

    1987-01-01

    An expression for the optimal signal-to-noise ratio for linear phase lock amplifiers is derived. In its digital form the optimal method can be implemented by real-time signal processing techniques. The case of detector-noise-limited systems is analyzed in detail; it is found that the optimal technique can be used to eliminate effectively the detector's time constant from the set of parameters determining the overall efficiency. This has important implications for optical detection system design. Also reported is an experimental verification of the optimal method, thus establishing its practicality.

  12. Linear CMOS RF power amplifiers a complete design workflow

    CERN Document Server

    Ruiz, Hector Solar

    2013-01-01

    The work establishes the design flow for the optimization of linear CMOS power amplifiers from the first steps of the design to the final IC implementation and tests. The authors also focuses on design guidelines of the inductor's geometrical characteristics for power applications and covers their measurement and characterization. Additionally, a model is proposed which would facilitate designs in terms of transistor sizing, required inductor quality factors or minimum supply voltage. The model considers limitations that CMOS processes can impose on implementation. The book also provides diffe

  13. Amplified restriction fragment length polymorphism in parasite genetics.

    Science.gov (United States)

    Masiga, D K; Tait, A; Turner, C M

    2000-08-01

    The amplified restriction fragment length polymorphism (AFLP) technique is a relatively new method for the analysis of polymorphism that has not yet been widely used in parasitology. In this article, Dan Masiga, Andy Tait and Mike Turner provide a brief introduction to AFLP and illustrate how it can be used in the investigation of marker inheritance in genetic crosses and in the analysis of polymorphism of field populations. They also briefly highlight the strengths and weaknesses of AFLP in comparison with other methods for detecting polymorphism and conclude that AFLP is a very useful addition to the range of techniques available.

  14. Displacement of microwave squeezed states with Josephson parametric amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Ling; Baust, Alexander; Xie, Edwar; Schwarz, Manuel; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Fedorov, Kirill; Menzel, Edwin; Marx, Achim [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Betzenbichler, Martin; Pogorzalek, Stefan; Haeberlein, Max; Eder, Peter; Goetz, Jan; Wulschner, Karl Friedrich; Huebl, Hans; Deppe, Frank [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany)

    2015-07-01

    Propagating quantum microwaves are promising building blocks for quantum communication. Interestingly, such itinerant quantum microwaves can be generated in the form of squeezed photon states by Josephson parametric amplifiers (JPA). We employ a specific ''dual-path'' setup for both state reconstruction and JPA characterization. Displacement operations are performed by using a directional coupler after the squeezing. We compare our results with theory predictions. In particular, we discuss our experiments in the context of remote state preparation and quantum teleportation with propagating microwaves.

  15. Random amplified polymorphic DNA and restriction enzyme analysis of PCR amplified rDNA in taxonomy: Two identification techniques for food-borne yeasts

    NARCIS (Netherlands)

    Baleiras Couto, M.M.; Vogels, J.T.W.E.; Hofstra, H.; Veld, J.H.J. Huis in't; Vossen, J.M.B.M. van der

    1995-01-01

    The random amplified polymorphic DNA (RAPD) assay and the restriction enzyme analysis of PCR amplified rDNA are compared for the identification of the common spoilage yeasts Zygosaccharomyces bailii, Z. rouxii, Saccharomyces cerevisiae, Candida valida and C. lipolytica. Both techniques proved to be

  16. Drug Facts

    Medline Plus

    Full Text Available ... Tobacco and Nicotine Facts Other Drugs of Abuse What is Addiction? What are some signs and symptoms of someone with ... problem? How Does Drug Use Become an Addiction? What Makes Someone More Likely to Get Addicted to ...

  17. Drug Facts

    Medline Plus

    Full Text Available ... call 1-800-662-HELP (4357) at any time to find drug treatment centers near you. I ... prescription drugs. The addiction slowly took over his life. I need different people around me. To stop ...

  18. Drug Abuse

    Science.gov (United States)

    ... and child abuse. Drug abuse can lead to homelessness, crime, and missed work or problems with keeping a job. It harms unborn babies and destroys families. There are different types of treatment for drug ...

  19. Drug Facts

    Medline Plus

    Full Text Available ... Numbers and Websites Search Share Listen English Español Information about this page Click on the button that ... about drug abuse, addiction, and treatment. Watch Videos Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana ...

  20. Drug Facts

    Medline Plus

    Full Text Available ... Home Drugs That People Abuse Alcohol Facts Bath Salts Facts Cocaine (Coke, Crack) Facts Heroin (Smack, Junk) ... treatment. Watch Videos Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth Pain Medicines Spice ( ...

  1. Drug Facts

    Medline Plus

    Full Text Available ... symptoms of someone with a drug use problem? How Does Drug Use Become an Addiction? What Makes ... Options? What Is Recovery? What Is a Relapse? How Can Friends and Family Help? Where Can Someone ...

  2. Drug Metabolism

    Indian Academy of Sciences (India)

    IAS Admin

    Drug metabolism may be defined as the biochemical modifica- tion of one chemical form to another, occurring usually through ..... Endogenous. Enzyme. Drugs. Cofactor. Glucuronidation. UDP glucoronic. UDP-. Chloramphenicol, acid glucuronosyltransferase morphine, paracetamol, salicylic acid, fenoprofen, desipramine,.

  3. Drug Facts

    Medline Plus

    Full Text Available ... Search form Search Menu Home Drugs That People Abuse Alcohol Facts Bath Salts Facts Cocaine (Coke, Crack) ... Facts Tobacco and Nicotine Facts Other Drugs of Abuse What is Addiction? What are some signs and ...

  4. Drug Facts

    Medline Plus

    Full Text Available ... Nicotine Facts Other Drugs of Abuse What is Addiction? What are some signs and symptoms of someone ... use problem? How Does Drug Use Become an Addiction? What Makes Someone More Likely to Get Addicted ...

  5. Study Drugs

    Science.gov (United States)

    ... What Are Study Drugs? Doctors prescribe medicines like Adderall and Ritalin to treat conditions like attention deficit ... stimulants are used as study drugs: amphetamines like Adderall, Dexedrine, or Vyvanse methylphenidates like Ritalin or Concerta ...

  6. Drug Facts

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    Full Text Available ... abuse, addiction, and treatment. Watch Videos Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth Pain Medicines Spice (K2) Tobacco/Nicotine Other Drugs You can ...

  7. Drug Facts

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    Full Text Available ... form Search Menu Home Drugs That People Abuse Alcohol Facts Bath Salts Facts Cocaine (Coke, Crack) Facts ... addiction, and treatment. Watch Videos Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth Pain ...

  8. Drug Facts

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    Full Text Available ... abuse, addiction, and treatment. Watch Videos Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth ... 662-HELP (4357) at any time to find drug treatment centers near you. I want my daughter ...

  9. Orphan drugs

    OpenAIRE

    Goločorbin-Kon, Svetlana; Vojinović, Aleksandra; Lalić-Popović, Mladena; Pavlović, Nebojša; Mikov, Momir

    2013-01-01

    Introduction. Drugs used for treatment of rare diseases are known worldwide under the term of orphan drugs because pharmaceutical companies have not been interested in ”adopting” them, that is in investing in research, developing and producing these drugs. This kind of policy has been justified by the fact that these drugs are targeted for small markets, that only a small number of patients is available for clinical trials, and that large investments are required for the development of ...

  10. Drug Facts

    Medline Plus

    Full Text Available ... Makes Someone More Likely to Get Addicted to Drugs? Does Addiction Run in Families? Why Is It So Hard ... the text to you. This website talks about drug abuse, addiction, and treatment. Watch Videos Information About Drugs Alcohol ...

  11. Drug Facts

    Medline Plus

    Full Text Available ... Search form Search Menu Home Drugs That People Abuse Alcohol Facts Bath Salts Facts Cocaine (Coke, Crack) Facts ... text to you. This website talks about drug abuse, addiction, and treatment. Watch Videos Information About Drugs Alcohol Bath Salts Cocaine Heroin Marijuana MDMA Meth Pain ...

  12. Drug Facts

    Medline Plus

    Full Text Available ... the text to you. This website talks about drug abuse, addiction, and treatment. Watch Videos Information About Drugs ... adicción. English Español About the National Institute on Drug Abuse (NIDA) | About This Website Tools and Resources | Contact ...

  13. Drug Facts

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    Full Text Available ... to main content Easy-to-Read Drug Facts Search form Search Menu Home Drugs That People Abuse Alcohol Facts ... Past Drug Use Prevention Phone Numbers and Websites Search Share Listen English Español Information about this page ...

  14. Drug Facts

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    Full Text Available ... the computer will read the text to you. This website talks about drug abuse, addiction, and treatment. Watch Videos ... I want my daughter to avoid drugs. "Debbie" has been drug-free for years. She wants her daughter to stay away from ...

  15. Drug Resistance

    Science.gov (United States)

    ... infected with a drug-resistant strain of HIV. Drug-resistance testing results are used to decide which HIV medicines to include in a person’s first HIV regimen. After treatment is started, drug-resistance testing is repeated if ...

  16. Towards a generic operational amplifier with dynamic reconfiguration capability

    Directory of Open Access Journals (Sweden)

    S. K. Lakshmanan

    2006-01-01

    Full Text Available Analog and analog-digital mixed signal electronics needed for sensor systems are indispensable components which tend to drifts from the normal phase of operation due to the impact of manufacturing conditions and environmental influences like etching, aging etc. Precise design methodology, trimming / calibration are essential to restore functionality of the system. Recent block level granular approaches using Field Programmable Analog Array and the more recent approaches from evolutionary electronics providing transistor level granularity using Field Programmable Transistor Arrays offers considerable extensions. In our work, we started on a new medium granular level approach called Field Programmable medium-granular Mixed-signal Array (FPMA providing basic building blocks of heterogeneous array of active and passive devices to configure established circuit structures which are adaptive, biologically inspired and dynamically re-configurable. Our design objective is to create components of clear compatibility to that of the industrial standards having predictable behavior along with the incorporation of existing design knowledge. The cells can be used in as a single instance or multiple instances. Further, we will focus on a generic dynamic reconfigurable amplifier cell with flexible topology and dimension called Generic Operational Amplifier (GOPA. The incentive of our work comes from recent development in the field of measurement and instrumentation. The digital programming of analog devices is carried out using range of algorithms from simple to evolutionary. Physical realization of the basic cells is carried out in 0.35 μm CMOS technology.

  17. Regime for a Self-ionizing Raman Laser Amplifier

    International Nuclear Information System (INIS)

    Clark, D.S.; Fisch, N.J.

    2001-01-01

    Backward Raman amplification and compression at high power might occur if a long pumping laser pulse is passed through a plasma to interact resonantly with a counter-propagating short seed pulse [V.M. Malkin, et al., Phys. Rev. Lett. 82 (1999) 4448-4451]. One critical issue, however, is that the pump may be unacceptably depleted due to spontaneous Raman backscatter from intrinsic fluctuations in the amplifying plasma medium prior to its useful interaction with the seed. Premature backscatter may be avoided, however, by employing a gaseous medium with pump intensities too low to ionize the medium, and using the intense seed to produce the plasma by rapid photoionization as it is being amplified [V.M. Malkin, et al., Phys. Plasmas (2001)]. In addition to allowing that only rather low power pumps be used, photoionization introduces a damping of the short pulse which must be overcome by the Raman growth rate for net amplification to occur. The parameter space of gas densities, laser wavelengths, and laser intensities is surveyed to identify favorable regimes for this effect. Output laser intensities of 10(superscript ''17'') W/cm(superscript ''2'') for 0.5 mm radiation are found to be feasible for such a scheme using a pump of 10(superscript ''13'') W/cm(superscript ''2'') and an initial seed of 5 x 10(superscript ''14'') W/cm(superscript ''2'') over an amplification length of 5.6 cm in hydrogen gas

  18. Two-stage, high power X-band amplifier experiment

    International Nuclear Information System (INIS)

    Kuang, E.; Davis, T.J.; Ivers, J.D.; Kerslick, G.S.; Nation, J.A.; Schaechter, L.

    1993-01-01

    At output powers in excess of 100 MW the authors have noted the development of sidebands in many TWT structures. To address this problem an experiment using a narrow bandwidth, two-stage TWT is in progress. The TWT amplifier consists of a dielectric (e = 5) slow-wave structure, a 30 dB sever section and a 8.8-9.0 GHz passband periodic, metallic structure. The electron beam used in this experiment is a 950 kV, 1 kA, 50 ns pencil beam propagating along an applied axial field of 9 kG. The dielectric first stage has a maximum gain of 30 dB measured at 8.87 GHz, with output powers of up to 50 MW in the TM 01 mode. In these experiments the dielectric amplifier output power is about 3-5 MW and the output power of the complete two-stage device is ∼160 MW at the input frequency. The sidebands detected in earlier experiments have been eliminated. The authors also report measurements of the energy spread of the electron beam resulting from the amplification process. These experimental results are compared with MAGIC code simulations and analytic work they have carried out on such devices

  19. Initial tests of an 11.4 GHz magnicon amplifier

    International Nuclear Information System (INIS)

    Gold, S.H.; Sullivan, C.A.; Manheimer, W.M.; Hafizi, B.

    1994-01-01

    The magnicon, a scanning beam microwave amplifier related to the gyrocon, is a possible replacement for klystron amplifiers in future high-gradient linear accelerators. The magnicon circuit consists of a multicavity deflection system followed by an output cavity. The purpose of the deflection system is to spin up the electron beam phase-coherently to high transverse momentum. In order to do this, the deflection cavities employ rotating TM 11 modes, producing a gyrating electron beam whose centroid rotates about the cavity axis in synchronism with the advance in phase of the rf modes. The output cavity employs a cyclotron resonant mechanism to extract principally the transverse beam momentum. It employs an rf mode that rotates synchronously with the deflection cavity modes, and with the entry point of the electron beam into the output cavity, making possible a highly efficient interaction. The NRL magnicon uses a 100--200 A, 500 keV beam produced by a cold-cathode diode on the NRL Long-Pulse Accelerator Facility. The first cavity is externally driven at 5.7 GHz, while the output cavity is designed to produce megawatts of power at 11.4 GHz in the TM 210 mode. In this paper, the authors present a progress report on the NRL magnicon experiment. They will discuss the procedure used to cold test and calibrate the magnicon circuit, and present initial results from experimental operations

  20. Characteristics research of self-amplified distributed feedback fiber laser

    Science.gov (United States)

    Song, Zhiqiang; Qi, Haifeng; Guo, Jian; Wang, Chang; Peng, Gangding

    2013-09-01

    A distributed feedback (DFB) fiber laser with a ratio of backward to forward output power of 1:100 was composed by a 45mm length asymmetrical phase-shifted fiber grating fabricated on 50mm erbium-doped photosensitive fiber. Forward output laser was amplified using a certain length of Nufern EDFL980-Hp erbium-doped fiber to absorb surplus pump power after the active phase-shifted fiber grating and get population inversion. Using OptiSystem software, the best fiber length of the EDFL to get the highest gain was simulated. In order to keep the amplified laser with narrow line-width and low noise, a narrow-band light filter consisted of a FBG with the same Bragg wavelength as the laser and an optical circulator was used to filter the ASE noise of the out-cavity erbium-doped fiber. The designed laser structure sufficiently utilized the pump power, a DFB fiber laser of 32.5mW output power, 11.5 kHz line width, and -87dB/Hz relative intensity noise (RIN) at 300mW of 980 nm pump power was brought out.