159,992 research outputs found
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A ±25A Versatile Shunt-Based Current Sensor with 10kHz Bandwidth and ±0.25% Gain Error from -40°C to 85°C Using 2-Current Calibration
No full textAccurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is limited to a few tens of Hz, making them unsuitable for battery impedance or motor-current sensing. This paper presents a current sensor with a wide (10kHz) bandwidth and a tunable temperature compensation scheme (TCS), which allows it to be flexibly used with different types of shunts while maintaining high accuracy. A low-cost room-temperature calibration scheme is proposed to optimize gain flatness over temperature by exploiting the shunt's self-heating at large currents. Over the industrial temperature range and a ±25A current range, it achieves state-of-the-art gain error (±0.25%) with both low-cost PCB and stable metal-alloy shunts.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
Get PDFThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
Seung Soo You
No full text학위논문(석사)--아주대학교 일반대학원 :분자과학기술학과,2011. 2Surface modification of the biomaterials was widely investigated to improve bio compatibility. In particular, the PEG based hydrogel coating systems were developed due to various advantages of the hydrogels such as high hydrophilicity and lubricity. Heparin has been studied as a bio-active material for surface modification to produce not only bio compatible surface but also anti-coagulant surface. Heparin is the most commonly used anticoagulant reagent in clinical use and heparinization of surfaces which has been shown to be a successful strategy to prevent thrombus formation and to improve blood compatibility of blood-contacting medical devices. However, physical adsorption of hydrogels limits the durability in the long-term exposure in vivo.
In this study, in situ forming heparin and PEG based hydrogels as a coating material was developed to improve blood compatibility of the metal devices and the durability of the hydrogel coating layer on the surface. 316L stainless steel (SS) substrates were simply and rapidly coated with hydrogels via horseradish peroxidase (HRP) enzymatic reaction in presence of hydrogen peroxide (H2O2). After hydrogel coating, durability of the hydrogel coating layer was evaluated. Heparin and PEG based hydrogel coating layer was stable for 7 days. Hydrogel coated surface effectively inhibited the protein adsorption and platelet adhesion. Surface bound heparin has suppressed the coagulation on the hydrogel coated surface by inactivating antithrombin. Our results demonstrated that the in situ forming heparin and PEG based hydrogel has great potential for use as a surface coating materials to improved blood compatibility of the metal surface.I. INTRODUCTION 1
A.Biomaterial-body interaction at biointerface 1
B.Surface modifications for improved biocompatibility 4
1. Hydrogel 5
1) In situ forming hydrogel 6
2) Application of hydrogel 7
2. Heparin 9
1) Structure of heparin 9
2) Medical importance of heparin 12
3) Interaction of heparin with proteins 17
C. Hydrogel coating 21
D. Objectives 22
II. EXPERIMENTS 23
A. Materials 23
B. Synthesis of Tetronic-Tyramine/Dopamine (TTD) conjugates 24
C. Synthesis of NH2-PEG-Tyramine (NH2-PEG-TA) conjugates 26
D. Synthesis of HT and HPT conjugates 29
E. Preparation of heparin and PEG based hydrogel coated Surface 30
1. Mechanical property 30
2. Hydrogel coating 30
3. Coating stability test 31
F. Bloodcompatibility test 34
1. Factor Xa assay 34
2. Protein adsorption 35
3. Platelet adhesion 36
4. Hemolysis test 37
III. RESULTS AND DISCUSSION 38
A. Synthesis and characterizations 38
B. Mechanical strength 42
C. Hydrogel coating stability 44
D. Factor Xa Assay 46
E. In vitro blood compatibility test 48
IV. CONCLUSIONS 55
V. REFERENCES 56
Abstract (in Korean) 64Maste
A 210nW BJT-based Temperature Sensor with an Inaccuracy of ±0.15°C (3s) from -15°C to 85°C
No full textThis paper presents a 210nW BJT-based temperature sensor that achieves an inaccuracy of ±0.15°C (3s) from -15°C to 85°C. A dual-mode front-end (FE), which combines a bias circuit and a BJT core, halves the power needed to generate well-defined CTAT (VBE) and PTAT (?VBE) voltages. The use of a tracking ?S ADC reduces FE signal swing and further reduces system power consumption. In a 180-nm BCD process, the prototype achieves a 15mK resolution in 50ms conversion time, translating into a state-of-the-art FoM of 2.3pJK2. Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A 16 MHz CMOS RC Frequency Reference With ±90 ppm Inaccuracy From -45 °C to 85 °C
No full textThis article presents a 16-MHz RC frequency reference implemented in a standard 180-nm CMOS process. It consists of a frequency-locked loop (FLL) in which the output frequency of a digitally controlled oscillator (DCO) is locked to the frequency-phase characteristic of a Wien bridge RC filter. Since it is made from on-chip resistors and capacitors, the filter's characteristic is temperature dependent. To compensate for this, the control signal of the DCO is derived by digitizing the filter's output phase and combining it with the digital output of a Wheatstone bridge temperature sensor. After a two-point trim, this digital temperature compensation scheme achieves an inaccuracy of ±90 ppm from -45 °C to 85 °C. The frequency reference draws 220 from a 1.8-V supply, with a supply sensitivity of 0.12%/V and a 320-ppb Allan Deviation floor for a 10-s stride.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A 0.25mm<sup>2</sup> Resistor-Based Temperature Sensor with an Inaccuracy of 0.12°C (3σ) from -55°C to 125°C and a Resolution FOM of 32fJK<sup>2</sup>
No full textTemperature sensors based on Wheatstone bridges, e.g. [1,2], have recently achieved higher resolution and greater energy efficiency than conventional BJT-based sensors [3]. However, this comes at the expense of area, making them less attractive in industrial applications. This paper presents a Wheatstone-bridge sensor that uses a zoom-ADC architecture to reduce area (by 3x over [2]) and achieve state-of-the-art energy-efficiency for an integrated temperature sensor. After a 1st-order fit and a systematic non-linearity correction [2,4], it also achieves state-of-the-art inaccuracy: 0.12°C (3σ) over the full military temperature range (-55°C to 125°C).Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A CMOS Dual- RC Frequency Reference With ±200-ppm Inaccuracy From -45 °C to 85 °C
No full textThis paper presents a 7-MHz CMOS RC frequency reference. It consists of a frequency-locked loop in which the output frequency of a digitally controlled oscillator (DCO) is locked to the combined phase shifts of two independent RC (Wien bridge) filters, each employing resistors with complementary temperature coefficients. The filters are driven by the DCO's output frequency and the resulting phase shifts are digitized by high-resolution phase-to-digital converters. Their outputs are then combined in the digital domain to realize a temperature-independent frequency error signal. This digitally assisted temperature compensation scheme achieves an inaccuracy of ±200 ppm from -45 °C to 85 °C after a two-point trim. The frequency reference draws 430 μA from a 1.8-V supply, while achieving a supply sensitivity of 0.18%/V and a 330-ppb Allan deviation floor in 3 s of measurement time.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronics(OLD)Applied Quantum Architecture
Why you don't need to write much to be the world's bestselling author
Get PDFAn account of my use of stylometry to analyse the works of James Patterson, written for a public audience
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