Development and validation of a model for whole course aging of nickel added to a wide range of soils using a complementary error function

Geoderma ◽  
2019 ◽  
Vol 348 ◽  
pp. 54-59
Author(s):  
Shi-Wei Li ◽  
Helian Li ◽  
Xuemei Han ◽  
Yibing Ma
Keyword(s):  
Error Function ◽  
Complementary Error Function ◽  
Wide Range ◽  
Development And Validation

scholarly journals Current Trends and Challenges for Rapid SMART Diagnostics at Point-of-Site Testing for Marine Toxins

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2499
Author(s):  
Michael Dillon ◽  
Maja A. Zaczek-Moczydlowska ◽  
Christine Edwards ◽  
Andrew D. Turner ◽  
Peter I. Miller ◽  
...  
Keyword(s):  
Method Development ◽  
Regulatory Control ◽  
Detection Methods ◽  
Control Individual ◽  
Mouse Bioassay ◽  
Future Market ◽  
Site Testing ◽  
Wide Range ◽  
Development And Validation ◽  
Analytical Standards

In the past twenty years marine biotoxin analysis in routine regulatory monitoring has advanced significantly in Europe (EU) and other regions from the use of the mouse bioassay (MBA) towards the high-end analytical techniques such as high-performance liquid chromatography (HPLC) with tandem mass spectrometry (MS). Previously, acceptance of these advanced methods, in progressing away from the MBA, was hindered by a lack of commercial certified analytical standards for method development and validation. This has now been addressed whereby the availability of a wide range of analytical standards from several companies in the EU, North America and Asia has enhanced the development and validation of methods to the required regulatory standards. However, the cost of the high-end analytical equipment, lengthy procedures and the need for qualified personnel to perform analysis can still be a challenge for routine monitoring laboratories. In developing regions, aquaculture production is increasing and alternative inexpensive Sensitive, Measurable, Accurate and Real-Time (SMART) rapid point-of-site testing (POST) methods suitable for novice end users that can be validated and internationally accepted remain an objective for both regulators and the industry. The range of commercial testing kits on the market for marine toxin analysis remains limited and even more so those meeting the requirements for use in regulatory control. Individual assays include enzyme-linked immunosorbent assays (ELISA) and lateral flow membrane-based immunoassays (LFIA) for EU-regulated toxins, such as okadaic acid (OA) and dinophysistoxins (DTXs), saxitoxin (STX) and its analogues and domoic acid (DA) in the form of three separate tests offering varying costs and benefits for the industry. It can be observed from the literature that not only are developments and improvements ongoing for these assays, but there are also novel assays being developed using upcoming state-of-the-art biosensor technology. This review focuses on both currently available methods and recent advances in innovative methods for marine biotoxin testing and the end-user practicalities that need to be observed. Furthermore, it highlights trends that are influencing assay developments such as multiplexing capabilities and rapid POST, indicating potential detection methods that will shape the future market.

GT36 Turbine Aero-Thermal Development and Validation

2017 ◽  
Author(s):  
S. Naik ◽  
J. Krueckels ◽  
M. Henze ◽  
W. Hofmann ◽  
M. Schnieder
Keyword(s):  
Gas Turbine ◽  
High Speed ◽  
Pressure Sensors ◽  
Thermal Design ◽  
Local Pressure ◽  
Cooling Systems ◽  
Wide Range ◽  
Turbine Vanes ◽  
Thermal Development ◽  
Development And Validation

This paper describes the aero-thermal development and validation of the GT36 heavy duty gas turbine. The turbine which has evolved from the existing and proven GT26 design, consists of an optimised annulus flow path, higher lift aerofoil profiles, optimised aerodynamic matching between the turbine stages and new and improved cooling systems of the turbine vanes and blades. A major design feature of the turbine has been to control and reduce the aerodynamic losses, associated with the aerofoil profiles, trailing edges, blade tips, endwalls and coolant ejection. The advantages of these design changes to the overall gas turbine efficiency have been verified via extensive experimental testing in high-speed cascade test rigs and via the utilisation of high fidelity multi-row computational fluid dynamics design systems. The thermal design and cooling systems of the turbine vanes, blades have also been improved and optimised. For the first stage vane and blade aerofoils and platforms, multi-row film cooling with new and optimised diffuser cooling holes have been implemented and validated in high speed linear cascades. Additionally, the internal cooling design features of all the blades and vanes were also improved and optimised, which allowed for more homogenous metal temperatures distributions on the aerofoils. The verification and validation of the internal thermal designs of all the turbine components has been confirmed via extensive testing in dedicated Perspex models, where measurements were conducted for local pressure losses, overall flow distributions and local heat transfer coefficients. The turbine is currently being tested and undergoing validation in the GT36 Test Power Plant in Birr, Switzerland. The gas turbine is heavily instrumented with a wide range of validation instrumentation including thermocouples, pressure sensors, strain gauges and five-hole probes. In addition to performance mapping and operational validation, a dedicated thermal paint validation test will also be performed.

Comparative Profiling of Four Lignans (Phyllanthin, Hypophyllanthin, Nirtetralin, and Niranthin) in Nine Phyllanthus Species from India Using a Validated Reversed Phase HPLC-PDA Detection Method

2020 ◽  
Author(s):  
Jinal Patel ◽  
Padamnabhi Shanker Nagar ◽  
Kalpana Pal ◽  
Raghuraj Singh ◽  
Tushar Dhanani ◽  
...  
Keyword(s):  
Reversed Phase ◽  
Reversed Phase Hplc ◽  
Extraction Solvent ◽  
Plant Parts ◽  
Commercial Cultivation ◽  
Wide Range ◽  
Development And Validation ◽  
Herbal Formulations

Abstract Background Phyllanthus species exhibit a wide range of in vitro and in vivo pharmacological activities; however, little is known about the compounds present in the extracts that are responsible for such actions. Objective Development and validation of a simple reversed phase HPLC-PDA method for profiling of phyllanthin, hypophyllanthin, nirtetralin, and niranthin in extracts of Phyllanthus species was carried out. Methods Separation was achieved using an XBridge column® (150 × 4.6 mm, 5.0 µm id) in an isocratic elution mode with mobile phase comprising of a mixture of acetonitrile and water with TFA (0.05%, v/v, pH = 2.15) at ambient temperature with a flow rate of 1 mL/min. Results Phyllanthin, hypophyllanthin, nirtetralin, and niranthin were eluted at mean retention times of 10.47, 11.10, 13.67, and 14.53 min, respectively. LOD and LOQ for all four analytes were 0.75 and 3.00 μg/mL, respectively. RSDr values for intraday and interday precision for phyllanthin, hypophyllanthin, nirtetralin, and niranthin were 0.38–1.32 and 0.45–1.77%; 0.22–3.69 and 0.24–3.04%, 0.73–2.37 and 0.09–0.31%, and 1.56–2.77 and 0.12–0.68%, respectively. Conclusions The developed and validated HPLC-PDA method was applied for identification and quantification of phyllanthin, hypophyllanthin, nirtetralin, and niranthin in extracts of different plant parts of selected Phyllanthus species. The outcome of the present investigation could be useful for selection of best species to promote its commercial cultivation and suitable extraction solvent for preparation of lignan-enriched fractions. This HPLC-PDA method could be useful for quality control of herbal formulations containing plants from Phyllanthus species.

scholarly journals Saddle points of the complementary error function

1973 ◽  
Vol 27 (122) ◽  
pp. 409-409 ◽  
Author(s):  
Henry E. Fettis ◽  
James C. Caslin ◽  
Kenneth R. Cramer
Keyword(s):  
Error Function ◽  
Saddle Points ◽  
Complementary Error Function

Hyperasymptotics for integrals with finite endpoints

1992 ◽  
Vol 439 (1906) ◽  
pp. 373-396 ◽  
Keyword(s):  
Asymptotic Expansion ◽  
Complex Plane ◽  
Airy Function ◽  
Error Function ◽  
Steepest Descent ◽  
Similar Form ◽  
Complete Asymptotic Expansion ◽  
Complementary Error Function ◽  
Plane Passing ◽  
Method Of Steepest Descent

Berry & Howls (1991) (hereinafter called BH) refined the method of steepest descent to study exponentially accurate asymptotics of a general class of integrals involving exp {– kf ( z )} along doubly infinite contours in the complex plane passing over saddlepoints of f ( z ). Here we derive analogous results for integrals with integrands of a similar form, but whose local expansions in powers of 1/ k are made about the finite endpoints of semi-infinite contours of integration. We treat endpoints where f ( z ) behaves locally linearly or quadratically. Generically, local endpoint expansions made by the method of steepest descent diverge because of the presence of saddles of f ( z ). We derive ‘resurgence relations’ which express the original integral exactly as a truncated endpoint expansion plus a remainder, involving the global saddle structure of f ( z ) via integrals through certain ‘adjacent’ saddles. The saddles adjacent to the endpoint are determined by a topological rule. If the least term of the endpoint expansion is the N 0 ( k ) th, summing to here calculates the endpoint integral up to an error of approximately exp ( – N 0 ( k )). We develop a scheme, involving iteration of the new resurgence relations with a similar one derived in BH, which can reduce this error down to exp( – 2.386 N 0 ( k )). This ‘hyperasymptotic’ formalism parallels that of BH and incorporates automatically any change in the complete asymptotic expansion as the endpoint moves in the complex plane, provided that it does not coincide with other saddles. We illustrate the analytical and numerical use of endpoint hyperasymptotics by application to the complementary error function erfc( x ) and a constructed ‘incomplete’ Airy function.

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