Design of a single-chip pH sensor using a conventional 0.6-μm CMOS process

A pH sensor fabricated on a single chip by an unmodified, commercial 0.6-/spl μm CMOS process is presented. The sensor comprises a circuit for making differential measurements between an ion-sensitive field-effect transistor (ISFET) and a reference FET (REFET). The ISFET has a floating-gate structure and uses the silicon nitride passivation layer as a pH-sensitive insulator. As fabricated, it has a large threshold voltage that is postulated to be caused by a trapped charge on the floating gate. Ultraviolet radiation and bulk-substrate biasing is used to permanently modify the threshold voltage so that the ISFET can be used in a battery-operated circuit. A novel post-processing method using a single layer of photoresist is used to define the sensing areas and to provide robust encapsulation for the chip. The complete circuit, operating from a single 3-V supply, provides an output voltage proportional to pH and can be powered down when not required

A system-on-chip digital pH meter for use in a wireless diagnostic capsule

This paper describes the design and implementation of a system-on-chip digital pH meter, for use in a wireless capsule application. The system is organized around an 8-bit microcontroller, designed to be functionally identical to the Motorola 6805. The analog subsystem contains a floating-electrode ISFET, which is fully compatible with a commercial CMOS process. On-chip programmable voltage references and multiplexors permit flexibility with the minimum of external connections. The chip is designed in a modular fashion to facilitate verification and component re-use. The single-chip pH meter can be directly connected to a personal computer, and gives a response of 37 bits/pH, within an operating range of 7 pH units

Tranching in the Syndicated Loan Market

We use data comprising over 100,000 loans from 115 countries during 1995-2009 to examine factors that affect the extent of loan tranching, and the range of tranche spreads. The data show five factors that drive them: asymmetric information, borrower risk, transaction costs, the presence of institutional investors, and the legal system. Tranching is more extensive and generates greater differences in spreads between tranches of a same loan when asymmetric information and risk are more pronounced. Economic and institutional factors driving tranching are more directly applicable to non-investment grade loans. For developing countries, the data highlight factors that affect the extent of tranching but such factors show little sensitivity to the pricing of the relative spreads.Loan;Debt finance;Tranche;Law and finance

Run-up of Acquirer's Stock in Public and Private Acquisitions

Manuscript Type: Empirical Research Question/Issue: This paper empirically examines whether there is pre-announcement movement of an acquirer's share price and trading volume prior to the announcement of acquisitions in ways consistent with insider trading. Prior papers focus on insider trading of a target's stock; our paper differs by examining for the first time run-up of acquirer's stock, and considers both public and private acquisitions, including private-equity backed acquisitions. Research Findings/Insights: Acquisition announcements generate predictable movements in the price of the acquirer's stock. Pre-announcement trading in acquirer's stock is more likely to be attributable to insider trading when the pre-announcement price changes match the expected post-announcement acquirer returns. Based on a sample of Canadian acquirers and public and private acquisition targets from Canada, the US and 31 other countries over the years 1991-2008, we find evidence consistent with insider trading of acquirer's stock. Theoretical/Academic Implications: The evidence consistent with insider trading in this paper is limited to specific situations and is far from generalizable to all types of acquisition announcements. Post-announcement returns are typically negative for high Tobin's q acquirers, stock transactions, and foreign targets, but positive for private equity-backed private targets. We find economically and statistically significant evidence that pre-announcement run-ups move in ways that match these expected post-announcement effects. Pre-announcement movement in acquirer's stock largely depends on the type of acquisition announcement. Practitioner/Policy Implications: Our findings have significant policy implications for the allocation of surveillance efforts for initiating insider trading investigations. © 2011 Blackwell Publishing Ltd.preprin

The European Union in Sudan: a missed opportunity?

International organisations active in Africa are often criticised for their ineffectiveness. So too is the European Union (EU), which is also accused of failing to assume a more prominent conflict management role in war-torn countries. This article examines the EU’s capacity and readiness to take on such a role in one such country, the former Republic of Sudan, home to Africa’s longest-running civil wars and the first ‘genocide’ of the 21st century. It begins by outlining the EU’s record in Darfur and the North–South Peace Process. Drawing upon 25 interviews and Hill’s ‘capabilities–expectations model’, it then questions whether the EU’s ‘capabilities’ (resources, instruments, unity) were ‘fit for purpose’ in Sudan’s hostile target setting. It concludes by identifying settings that have been more propitious for a conflict-related management function and by suggesting that the EU should better manage expectations about future security roles

Multi-spectral materials: hybridisation of optical plasmonic filters and a terahertz metamaterial absorber

Multi-spectral materials, using hybridised plasmonic and metamaterial structures, can simultaneously exhibit unique resonant phenomena over several decades of wavelengths. A multi-spectral material that combines a plasmonic colour filter array and a terahertz metamaterial absorber into a single material is a promising prospect for a coaxial multi-spectral imager operating in the visible, near IR, and terahertz wavebands

Prevalence, incidence and etiology of hyponatremia in elderly patients with fragility fractures

Peer reviewedPublisher PD

Exchange trading rules and stock market liquidity

We examine stock exchange trading rules for market manipulation, insider trading, and broker-agency conflict, across countries and over time, in 42 stock exchanges around the world. Some stock exchanges have extremely detailed rules that explicitly prohibit specific manipulative practices, but others use less precise and broadly framed rules. We create new indices for market manipulation, insider trading, and broker-agency conflict based on the specific provisions in the trading rules of each stock exchange. We show that differences in exchange trading rules, over time and across markets, significantly affect liquidity. © 2010 Elsevier B.V.preprin