A Reagent Dispense Verification System for a Fully-Automated, Amplified Nucleic Acid Diagnostic Instrument

2003 ◽  
Author(s):  
Mark R. Kennedy ◽  
Raul Pacheco ◽  
John Van Doorn ◽  
Rommel Hipolito
Keyword(s):  
Nucleic Acid ◽  
Pressure Drop ◽  
Diagnostic Instrument ◽  
Probe Design ◽  
Hydraulic Pressure ◽  
Verification System ◽  
Flow Through ◽  
And Performance ◽  
And Control ◽  
Measurement And Control

Amplified nucleic acid diagnostics have brought extraordinarily powerful biochemical tools to bear on screening for and diagnosing infectious diseases. For example, current assays routinely permit the detection of 100 particles of human immunodeficiency virus or hepatitis C virus in one mL of blood. Such assays are used for screening the blood supply. To permit reliable automation of these complex and sensitive assays fluidic measurement and control systems are required. Such controls are needed to ensure that correct reagents are reliably dispensed into the reaction tubes. In this paper we will review the design and performance of a prototype Reagent Dispense Verification system for use on a fully-automated, amplified, nucleic acid diagnostic instrument. The system design utilizes hydraulic pressure drop and conductivity as the primary dispense parameters. In addition to the dispense verification function, the system provides a capacitive liquid level sensing function. The pipetting probe design and manufacturing process provide two conductive surfaces separated by an electrically insulating gap over which conductivity is measured. Hydraulic pressure drop is measured with an in-line, flow-through pressure transducer. The time-varying pressure and conductivity signals are used to classify each dispense operation as acceptable or not. Overall system performance data are presented demonstrating the viability of the design.

Thermal, Electrical, and Thermoelectric Measurements by Scanning Probe Microscopy

2002 ◽  
Author(s):  
Andrew C. Miner ◽  
Michael Chapp ◽  
Deyu Li ◽  
Arun Majumdar
Keyword(s):  
Mechanical Design ◽  
Flux Measurement ◽  
Scanning Probe ◽  
Measurement Tool ◽  
Probe Design ◽  
Scanning Thermal Microscopy ◽  
Electrical Measurements ◽  
Thermoelectric Measurements ◽  
And Control ◽  
Measurement And Control

This work brings together aspects of scanning thermal microscopy (SThM) and scanning spreading resistance microscopy (SRM) into a single tool for thermoelectric measurement. The measurement tool presented here allows simultaneous electrical and thermal measurement of samples using a probe tip of radius on the order of 50 nm. Thermal and mechanical design allow topographic resolution on the order of 4Å while minimizing detrimental heat flow from the probe to sample. This tool integrates sensors allowing for heat flux measurement and control, enabling a variety of thermal, electrical and thermoelectric measurements. Preliminary thermal and electrical measurements of bismuth telluride nanowire arrays demonstrate the capabilities of this scanning probe design.

An Overview of Initial Operational Experience With the Closed-Loop sCO2 Test Facility at Cranfield University

2019 ◽  
Author(s):  
Eduardo Anselmi ◽  
Ian Bunce ◽  
Vassilios Pachidis
Keyword(s):  
Closed Loop ◽  
Lessons Learned ◽  
Test Facility ◽  
Working Fluid ◽  
Operational Experience ◽  
And Performance ◽  
The Uk ◽  
And Control ◽  
Measurement And Control ◽  
Initial Objective

Abstract An experimental facility is currently operating at Cranfield University in the UK and it is being used to explore supercritical carbon dioxide as a working fluid for future bottoming power cycle applications. The initial objective of this experimental programme is to de-risk and demonstrate the robustness of a closed-loop system, whilst proving the function and performance of individual components and various measurement and control modules. This paper describes the first operational experience gained whilst operating the test facility. More specifically, it summarizes the lessons learned from the commissioning phase and first test campaigns carried out in 2018.

scholarly journals Cyber-Physical Observer for Fluidized Bed-Chemical Looping Control Applications

2017 ◽  
Author(s):  
Lawrence Shadle ◽  
David Tucker ◽  
Ronald Breault ◽  
Samuel Bayham ◽  
Justin Weber ◽  
...  
Keyword(s):  
Multiphase Flow ◽  
Fluidized Bed ◽  
Gas Flow ◽  
Flow Behavior ◽  
Chemical Looping ◽  
Flow Paths ◽  
Response Data ◽  
Flow Through ◽  
And Performance ◽  
And Control

A cyber-physical fluidized bed-chemical looping reactor (FB-CLR) is proposed to observe and control the multiphase flow behavior and improve process operations, stability, and performance. The cyber-physical observer (CPO) provides an opportunity to probe a duplicate, or mirrored, non-reacting, multiphase flow system in real-time and provide response data not available from the hot reacting system in order to control the hot unit. A control strategy was developed to share and integrate this information between to the two systems. During test operations the data from the shifting inventory of granular particles in the cold flow unit will be used to control some of the valves controlling the gas flow paths in the hot unit. Taken in conjunction with the inlet flows, temperatures, and pressures in the hot unit a control system is proposed to balance the exhaust flow through the various gas outlets of the different vessels. System identification studies are needed to characterize the process delays, time constants, and interactions between control parameters.

The Development of a Low-Shear Valve Suitable for Polymer Flooding

SPE Journal ◽  
2020 ◽  
Vol 25 (05) ◽  
pp. 2632-2647 ◽  
Author(s):  
Trygve Husveg ◽  
Mari Stokka ◽  
Rune Husveg ◽  
Stephane Jouenne
Keyword(s):  
Pressure Drop ◽  
Large Scale ◽  
Polymer Degradation ◽  
Mobility Control ◽  
Sweep Efficiency ◽  
Flow Channels ◽  
Shear Degradation ◽  
Geometrical Shapes ◽  
Flow Through ◽  
And Control

Summary Hydrolyzed polyacrylamides (HPAMs) are used as mobility-control agents to improve the macroscopic sweep efficiency of oil reservoirs. To maximize their viscosifying power, very-high-molecular-weight (MW) polymers are preferred, which in turn make them very sensitive to shear degradation. Shear degradation originates from chain stretching and breaking when the solution is subjected to a sudden acceleration. Fundamental development work is presented, where polymer degradation is studied in flow through reducers and expanders of various geometrical shapes, as well as through straight pipes and pipe coils of various diameters and lengths. The work also demonstrates that the creation of pressure drop through viscous pipe friction is very ineffective with regular tubes, most likely because of the drag-reducing effect of polymer. In addition, the arrangement of very long, straight, or coiled pipes in parallel is impractical and bulky. This paper further presents the development of a novel valve technology that solves these challenges. First, through the unique use of spiraling flow channels with optimally designed reducer and expansion zones, machined on the surface of disks, shear forces and thereby polymer degradation is controlled. Second, by arranging numerous such disks to form a disk stack, any target capacity can be met efficiently. Third, the disk-stack concept enables an easy and reliable plug-based solution for flow regulation and control. The performance of the new valve technology is demonstrated through small- and large-scale prototype tests. At very-shear-sensitive test conditions, it is demonstrated that polymer degradation of the new valve is less than 10% at 40- to 45-bar pressure drop, compared with 60 to 80% for a standard valve.

Measurement Problems in Rolling Mills

1971 ◽  
Vol 4 (2) ◽  
pp. T23-T24
Author(s):  
T. W. Johnson
Keyword(s):  
Ad Hoc ◽  
Cost Benefit ◽  
Measuring Instruments ◽  
Control Problems ◽  
Personal View ◽  
Unique Problem ◽  
Rolling Mills ◽  
And Performance ◽  
And Control ◽  
Measurement And Control

During the conference, a number of measuring instruments, control methods and strategies were described. This, the opening paper, set the broad background against which the later papers were discussed. The emphasis on the broad background is because measurement and control problems in rolling mills are not only technical, those of environment, which is usually the predominantly discussed feature, and performance, but include development, procurement, maintenance and operator acceptance and usage. These factors are combined in an overall concept of cost/benefit and it is the author's belief that, when embarking on a particular instrument or control development, as far as possible all these facets must be considered at the outset and not met individually on an ad hoc basis as the project develops. We should examine critically how much costs are inflated and problems multiplied by treating each installation and development as a separate and unique problem, particularly for the case of special instruments. This has been attempted in what follows which, it is emphasised, is a personal view.

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