Demonstration of combined zero-valent iron and electrical resistance heating for in situ trichloroethene remediation

The effectiveness of in situ treatment using zero-valent iron (ZVI) for nonaqueous phase or significant sediment-associated contaminant mass can be limited by relatively low rates of mass transfer to bring contaminants in contact with the reactive media. For a field test in a trichloroethene (TCE) source area, combining moderate-temperature subsurface electrical resistance heating with in situ ZVI treatment was shown to accelerate TCE treatment by a factor of about 4 based on organic daughter products and a factor about 8 based on chloride concentrations. A mass-discharge-based analysis was used to evaluate reaction, dissolution, and volatilization processes at ambient groundwater temperature (~10 °C) and as temperature was increased up to about 50 °C. Increased reaction and contaminant dissolution were observed with increased temperature, but vapor- or aqueous-phase migration of TCE out of the treatment zone was minimal during the test because reactions maintained low aqueous-phase TCE concentrations.     

DPAD2—A Field Programmable Analog Array

DPAD2 is a Field Programmable Analog Array (FPAA) based on CMOS switched capacitor technology. This paper describes the major design decisions that went into creating DPAD2 with respect to the ultimate goal of the work, being a mixed signal field programmable silicon solution. Two major compromises exist in the design of an FPAA, one between flexibility and performance, the other between functionality and die size; DPAD2 overcomes the first with a novel field programmable hierarchic routing scheme and the second by careful analysis of many disparate designs to arrive at a best compromise solution. Results from prototype silicon are presented where a single analog cell is reconfigured to perform a number of different analog signal processing functions. Bandwidth of the DPAD2 device is 500 kHz and the SNR is typically 60 dB, although both are application dependent. Introduction of the FPAA now enables a designer to have working silicon within one day, by a simple configuration of the silicon chip via a PC parallel interface. Software libraries of analog circuits are provided and allow very rapid creation of large and complex analog circuits.     

Performance measurement of cross-culture supply chain partnership: a case study in the Chinese automotive industry

This study explores a performance measurement system for a dynamic supply chain partnership in a cross-cultural context. An initial framework is constructed by reviewing the existing literature, followed by an in-depth case study in the Chinese automotive industry, where the framework is refined to address the multi-cultural setting. A performance measurement, system which includes the relationship strategy and operational measurement criteria for a supply chain partnership, has been developed. The relationship strategy contains elements of strategy orientation, management style, interdependence, mutual organisational characteristics and common goals. The operational measurement criteria consist of commitment, trust, communication behaviour, information sharing, participation decision, quality, production performance, delivery, cost, supplier strength, attitude, compromise and loyalty. The last three operational measurement criteria are found to be particularly relevant to the cross-cultural feature. While existing studies tend to focus on either specific measures or individual organisations, this paper for the first time proposes a comprehensive framework to measure the performance of supply chain partnerships. The cross-cultural perspective provides a further unique view on how a performance measurement system can be responsive to the dynamics in practice.     

WATER RE-USE - CAPTURING A WASTE RESOURCE

The east and south-east of England has the lowest rainfall in the UK, water resources are limited and under pressure through increased demand and population growth. In the late 1990's AW Innovation (the AW R&D group) developed a process that could produce high purity water from sewage effluent using membrane technology. In late 1999 Texas Utilities (TXU) signed a contract with Alpheus Environmental for the supply of high purity water for Peterborough Power Station. The novel treatment plant was built in 1999 - 2000 and opened in July 2000 by the Mayor of Peterborough. This paper is a review of the plant design, the technology used for the treatment process and a summary of the first four years of operation.
Changing from potable water to high purity water produced from sewage effluent has brought significant benefits for the power station resulting in higher purity steam generation while reducing chemical, power and effluent discharge costs. In addition Anglian Water is now saving 1,000 m³/day of potable water.     

Substance prioritisation for the development of EU Acute Exposure Toxicity Thresholds (AETLs)

The aim of the EU Acute Exposure project, ACUTEX, is to develop a methodology for establishing European Acute Exposure Threshold Levels, EU AETLs, for toxic substances in relation to harm to people by inhalation. The development of AETLs is initially in the context of the risks of major accidents from chemical sites and in particular their regulation through the EU 'Seveso II' Directive. It is intended that AETLs can be used within Member States, where appropriate, to inform decisions on land-use planning and emergency planning. AETLs will not have a regulatory status. This paper describes: the selection of 21 preliminary substances to use as case studies in the development and testing of the AETL's methodology; and the development of a prioritisation methodology to inform initial substance selection for a possible further AETLs program. The work was based on consultation with experts drawn from EU major stakeholder groups. It included a Validation Exercise working with three Member States, which account for between approximately 40% and 50% of all EU Seveso II sites. From this Validation Exercise we infer that, if these three Member States are representative in terms of numbers of priority substances, then the number of EU higher priority substances for further AETLs development is unlikely to be much in excess of 50.     

Lung cancer--management and outcome in Glasgow, 1991-92

Current practice and outcome for patients with lung cancer were determined by retrospective case note review of a random sample of all lung cancer cases registered for a calendar year and augmented by review of all surgical and radical radiotherapy cases. A total of 262 patients - 231 patients less than 75 years of age and 31 patients more than 75 years of age - represented 83% of the random sample. Eighty-three per cent of patients were seen within 2 weeks of referral. One-third reported symptoms occurring for less than 1 month and one-third had experienced symptoms for more than 3 months. The median time interval from first hospital contact until the making of a management decision was 18 days. The median interval from first contact to surgery was 63 days, and to starting radical radiotherapy 70 days. Histological confirmation was obtained in 69% of patients. Ten per cent of all lung cancer patients were calculated to have received chemotherapy. Five per cent of the whole cohort had definitive surgery and 64% of these were judged to be free of the disease at 3 years. Overall survival was 9% at 3 years, with no differences relating to cell type or area of residence. Many areas of good practice have been identified, but the lack of tumour staging or performance status data, the low proportion receiving chemotherapy or definitive surgery and the poor outcome after radical radiotherapy indicate the need for prospective audit and feedback of results. The long time interval from management decision to surgery and radiotherapy suggests organizational issues which need attention.     

New switched-current integrator

A switched-current integrator configuration with greatly improved insensitivity to transistor mismatch is described. A universal integrator configuration is developed which performs an algorithm identical to the well known switched-capacitor universal integrator. This permits signal flowgraph synthesis of switched-current filters with similar properties to those of their switched-capacitor counterparts.<>     

Diamond shaped cathode pads for the longitudinal coordinate from a drift chamber

Results are presented for a system of diamond shaped cathode pads which give the coordinate of an avalanche along the length of the wire of a large area drift chamber to an accuracy of 1 mm. To first order the method is insensitive to small lateral displacements of the signal wire and to the pulse height. Two sets of such pads, above and below the wire, and offset relative to one another longitudinally by a quarter of the repeat distance, provide a check sum which (1) validates the data, (2) helps to calibrate the non-linearities and (3) determines the resolution.