In-house Calibration Research Articles

Artificial neural networks trained on simulated multispectral data for real-time imaging of skin microcirculatory blood oxygen saturation.

Imaging blood oxygen saturation ( ) in the skin can be of clinical value when studying ischemic tissue. Emerging multispectral snapshot cameras enable real-time imaging but are limited by slow analysis when using inverse Monte Carlo (MC), the gold standard for analyzing multispectral data. Using artificial neural networks (ANNs) facilitates a significantly faster analysis but requires a large amount of high-quality training data from a wide range of tissue types for a precise estimation of . We aim to develop a framework for training ANNs that estimates in real time from multispectral data with a precision comparable to inverse MC. ANNs are trained using synthetic data from a model that includes MC simulations of light propagation in tissue and hardware characteristics. The model includes physiologically relevant variations in optical properties, unique sensor characteristics, variations in illumination spectrum, and detector noise. This approach enables a rapid way of generating high-quality training data that covers different tissue types and skin pigmentation. The ANN implementation analyzes an image in 0.11s, which is at least 10,000 times faster than inverse MC. The hardware modeling is significantly improved by an in-house calibration of the sensor spectral response. An in-vivo example shows that inverse MC and ANN give almost identical values with a mean absolute deviation of 1.3%-units. ANN can replace inverse MC and enable real-time imaging of microcirculatory in the skin if detailed and precise modeling of both tissue and hardware is used when generating training data.

Calibration of Boundary-Type Earth Pressure Cells with Sand

Abstract Earth pressure cells (EPCs) are a major part of any instrumentation project, whether in the field or laboratory. The reliability of EPC output mainly depends on its calibration before its installation. The calibration chart provided by manufacturers cannot be used directly because their charts are developed by applying fluid pressure, but when sand is used as contact material, EPCs’ response changes significantly. The major factor that causes deviation of EPC response in fluid and sand is that in fluid calibration, the applied load is fully transferred to EPC, irrespective of the size of the chamber, but for sand, the applied load and load reaching EPC are different because of arching, intergranular friction, and sidewall friction in a calibration chamber. In the present study, an in-house calibration chamber is developed to calibrate boundary-type EPC with Grade II sand as contact material. A load cell is attached just below the EPC to measure the actual load, which is reaching at EPC location. The output of EPC is correlated with load cell output rather than applied loading to determine calibration values of EPC for reliable measurements. A methodology for correcting the calibration factor of EPC is proposed and the effect of sidewall friction and sand layer thickness as well as the effect of load cell placement is discussed. The calibration factor of EPC is found to be dependent on the sand layer thickness and sidewall friction. It is recommended to calibrate boundary-type EPC by the proposed method along with the use of friction reduction measures.

Calibration and characterization of optical and x-ray streak cameras using a Ti:Sapphire laser system.

Optical and x-ray streak cameras are used to study transient phenomena, particularly in the high-energy density physics regime. The Orion laser facility employs many different types of streak cameras, which are used to collect data on laser-plasma interactions as well as to verify the temporal profile and timing between the multiple Orion beamlines. Streak cameras are complex devices with very precise timing associated with them, which can often malfunction, resulting in the loss of shot data. Since Orion is a kJ-class Nd:glass laser system, it is not optimal to try and fault-find using Orion shots since this is both time consuming and prohibitively expensive. To enable the facile set-up, fault-finding, timing-in, and in-house calibration of Orion optical and x-ray diagnostics, a single laboratory system has been commissioned to provide an adjustable stimulus to streak cameras and other Orion short pulse diagnostics (such as pulse dilation photomultiplier tubes). The system comprises a Ti:Sapphire laser system capable of generating 400nm or 266nm laser pulses of duration less than 0.1ps; an optical system to deliver single pulses, pulse pairs, or a train of pulses; and timing electronics to synchronize the streak cameras with the laser and to record output data. The system can operate at Hertz repetition rates rather than the sub-mHz rate of the Orion laser. We present the commissioned system and results from initial testing of both optical and x-ray streak cameras used on Orion laser-plasma experiments.

Report from the HarmoSter study: different LC-MS/MS androstenedione, DHEAS and testosterone methods compare well; however, unifying calibration is a double-edged sword.

Current liquid chromatography-tandem mass spectrometry (LC-MS/MS) applications for circulating androgen measurements are technically diverse. Previously, variable results have been reported for testosterone. Data are scarce for androstenedione and absent for dehydroepiandrosterone sulfate (DHEAS). We assessed the agreement of androstenedione, DHEAS and testosterone LC-MS/MS measurements among nine European centers and explored benefits of calibration system unification. Androgens were measured twice by laboratory-specific procedures in 78 patient samples and in EQA materials. Results were obtained by in-house and external calibration. Intra- and inter-laboratory performances were valued. Intra-laboratory CVs ranged between 4.2-13.2 % for androstenedione, 1.6-10.8 % for DHEAS, and 4.3-8.7 % and 2.6-7.1 % for female and male testosterone, respectively. Bias and trueness in EQA materials were within ±20 %. Median inter-laboratory CV with in-house vs. external calibration were 12.0 vs. 9.6 % for androstenedione (p<0.001), 7.2 vs. 4.9 % for DHEAS (p<0.001), 6.4 vs. 7.6 % for female testosterone (p<0.001) and 6.8 and 7.4 % for male testosterone (p=0.111). Median bias vs. all laboratory median with in-house and external calibration were-13.3 to 20.5 % and-4.9 to 18.7 % for androstenedione,-10.9 to 4.8 % and-3.4 to 3.5 % for DHEAS,-2.7 to 6.5 % and-11.3 to 6.6 % for testosterone in females, and-7.0 to 8.5 % and-7.5 to 11.8 % for testosterone in males, respectively. Methods showed high intra-laboratory precision but variable bias and trueness. Inter-laboratory agreement was remarkably good. Calibration system unification improved agreement in androstenedione and DHEAS, but not in testosterone measurements. Multiple components, such as commutability of calibrators and EQA materials andinternal standard choices, likely contribute to inter-laboratory variability.

Report from the HarmoSter study: inter-laboratory comparison of LC-MS/MS measurements of corticosterone, 11-deoxycortisol and cortisone.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) panels that include glucocorticoid-related steroids are increasingly used to characterize anddiagnose adrenal cortical diseases. Limited information is currently available about reproducibility of these measurements among laboratories. The aim of the study was to compare LC-MS/MS measurements of corticosterone, 11-deoxycortisol and cortisone at eight European centers and assess the performance after unification of calibration. Seventy-eight patient samples and commercial calibrators were measured twice by laboratory-specific procedures. Results were obtained according to in-house and external calibration. We evaluated intra-laboratory and inter-laboratory imprecision, regression and agreement against performance specifications derived from 11-deoxycortisol biological variation. Intra-laboratory CVs ranged between 3.3 and 7.7%, 3.3 and 11.8% and 2.7 and 12.8% for corticosterone, 11-deoxycortisol and cortisone, with 1, 4 and 3 laboratories often exceeding the maximum allowable imprecision (MAI), respectively. Median inter-laboratory CVs were 10.0, 10.7 and 6.2%, with 38.5, 50.7 and 2.6% cases exceeding the MAI for corticosterone, 11-deoxycortisol and cortisone, respectively. Median laboratory bias vs. all laboratory-medians ranged from-5.6 to 12.3% for corticosterone,-14.6 to 12.4% for 11-deoxycortisol and-4.0 to 6.5%for cortisone, with few cases exceeding the total allowable error. Modest deviations were found in regression equations among most laboratories. External calibration did not improve 11-deoxycortisol and worsened corticosterone and cortisone inter-laboratory comparability. Method imprecision was variable. Inter-laboratory performance was reasonably good. However, cases with imprecision and total error above the acceptable limits were apparent for corticosterone and 11-deoxycortisol. Variability did not depend on calibration but apparently onimprecision, accuracy and specificity of individual methods. Tools for improving selectivity and accuracy are required to improve harmonization.

Characterizing Scattering Parameters of Superconducting Quantum Integrated Circuits at Milli-Kelvin Temperatures

Designing large-scale superconducting quantum circuits involves complex microwave engineering to minimize loss, spurious reflections, and signal crosstalk. Essential for engineering more complex circuits is precise knowledge of devices’ microwave performance, which can be characterized by measuring its calibrated scattering parameters (S-parameters) at mK temperatures. In this work, we introduce a full 2-port calibrated S-parameter measurement setup which can characterize superconducting quantum integrated circuits and other RF integrated circuits operating at mK temperatures. The design and architecture of the measurement system consisting of in-house developed microwave calibration unit (MCU) housing the newly designed cryogenic calibration standards and the device under test (DUT) is discussed in detail. The measurement setup is then used to demonstrate the first calibrated S-parameter measurements of an in-house developed superconducting qubit integrated circuit at mK temperature.

S734 IBD Patients’ Treatment Preferences Are Heterogeneous, but Largely Affected by the Avoidance of Abdominal Pain and Side Effects (P-POWER IBD Study)

Introduction: Multiple treatments are approved for inflammatory bowel disease (IBD), each offering unique attribute profiles. Therapeutic targets historically included clinical and endoscopic outcomes, but updated guidelines1 also include absence of disability and restoration of quality of life (QoL). Optimising QoL requires understanding patient (pt) priorities and considering their preferences in treatment selection. This pt preference study (P-POWER IBD) quantified tradeoffs pts would make between treatment attributes. Methods: Adults with self-confirmed Crohn’s disease (CD) or ulcerative colitis (UC) receiving IBD treatment took part in an online cross-sectional survey. In a discrete choice experiment (DCE), pts were asked to choose between hypothetical treatments described by six attributes: administration, risk of mild or moderate side effects, risk of serious infections, and impact on abdominal pain, bowel urgency and fatigue. Attributes were selected based on foundational qualitative research and literature review.2 Qualitative and quantitative pilots were used to pre-test the DCE. Relative Attribute Importance (RAI) scores and maximum acceptable risk (MAR) of mild-to-moderate side effects were estimated from a mixed multinomial logit model. Results: A total of 400 pts (CD: 54%; UC: 46%; female: 38%; mean age: 41 years [range: 18–78]) were recruited. All attributes significantly affected treatment preferences with preference heterogeneity observed (Fig 1a). While all attributes were important, their relative importance differed (Fig 1b). Avoiding abdominal pain was most important (RAI 33%) followed by the risk of mild or moderate side effects (RAI 27%), risk of serious infections (RAI 16%), treatment administration (RAI 10%), fatigue (RAI 9%), and bowel urgency (RAI 6%). CD pts placed greater importance on abdominal pain (p< 0.05) than UC pts and UC pts greater importance on bowel urgency than CD pts (p< 0.05). MAR indicated the increased risks of side effects pts would accept to improve other attributes (Fig 1c). Notably, to reduce abdominal pain from severe to moderate, pts would accept an additional 19% risk of mild or moderate side effects and 31% if the pain was reduced to mild. Conclusion: Pts with IBD had strong preferences that varied greatly and were willing and able to make tradeoffs between various important treatment attributes, in particular abdominal pain. Individual preferences should be considered in clinical practice as they may impact long-term targets and QoL.Figure 1.: Deming’s Slope of Measured ADA by HMSA using In-house vs. WHO Calibration 31 specimens across the dynamic range were processed 6 consecutive times.

Determination of phase relations of the olivine\u2013ahrensite transition in the Mg2SiO4\u2013Fe2SiO4 system at 1740\xa0K using modern multi-anvil techniques

The phase relations of iron-rich olivine and its high-pressure polymorphs are important for planetary science and meteoritics because these minerals are the main constituents of terrestrial mantles and meteorites. The olivine–ahrensite binary loop was previously determined by thermochemical calculations in combination with high-pressure experiments; however, the transition pressures contained significant uncertainties. Here we determined the binary loop of the olivine–ahrensite transition in the (Mg,Fe)2SiO4 system at 1740 K in the pressure range of 7.5–11.2 GPa using a multi-anvil apparatus with the pressure determined using in situ X-ray diffraction, compositional analysis of quenched run products, and thermochemical calculation. Based on the determined binary loop, a user-friendly software was developed to calculate pressure from the coexisting olivine and ahrensite compositions. The software is used to estimate the shock conditions of several L6-type chondrites. The obtained olivine–ahrensite phase relations can also be applied for precise in-house multi-anvil pressure calibration at high temperatures.

Calibration of gas flow meters using choked flow and an evacuated vessel

The measurement of gas flow rates is of great importance in a wide range of modern technologies. This paper introduces a simple, yet accurate technique for in-house calibration of gas FMs (mass and volumetric) even under harsh environmental conditions such as encountered during field measurement campaigns. The method requires only readily available, low cost components: a vessel of known volume, an air pump, a pressure sensor and a metal plate orifice or a needle valve to act as a CO. The unique property of choked flow in the CO is used here for flow calibration. In the method presented here a vessel is evacuated to below the critical pressure (<0.53 of upstream pressure) and then allowed to refill with ambient air (or some other process gas) under so-called choked flow conditions through the CO. The method presented here leverages that the flow rate upstream of the CO is not only constant but readily determined from (a) the known V VESS, (b) the measured time rate of change of the absolute pressure in the vessel and (c) the ideal gas law. This calculated flow rate can be used for calibration of FMs. The accuracy of the method depends only on the accuracy of the pressure measurement, the timer and the value of the V VESS. The flow rate computed in this way is found to be in excellent agreement (typically 1% difference) with the flow rate measured by a soap film FM (Gilibrator). As expected from theory this method is found to work for all kinds of CFRs (here: various types of metal plate orifices and needle valves were tested), gas types (here: air, Argon, and CO2) and upstream pressures (here: between 650 hPa and 1400 hPa). The accuracy of this technique (∼1%) is as good as that of standard volume displacement methods (e.g. soap film FMs) (typically 1% difference), the standard of laboratory-based flow calibrators, but less expensive and more suitable for harsh environments.

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S0874 Performance Characteristics of Homogenous Mobility Shift Assay Method Against World Health Organization International Standard for Infliximab Bioactivity and Impact of Dosing Regimens on Exposure

INTRODUCTION: Therapeutic drug monitoring (TDM) of Infliximab remains an important clinical decision tool to improve outcomes in Inflammatory bowel diseases (IBD). However, one limitation of TDM in clinical gastroenterology practice is the lack of standardization across available technology platforms. Recently, the 1st international standard for infliximab (IFX) bioactivity was characterized and produced by World Health Organization (WHO). Our objective was to evaluate the performance characteristics of the Homogenous Mobility Shift assay (HMSA) against WHO calibration. METHODS: All IFX testing was conducted in a clinical laboratory accredited by the American College of Pathologists (Prometheus Biosciences, San Diego) using liquid chromatography size exclusion HMSA calibrated in house using IFX standards purchased independently from WHO. WHO Standard (NIBSC code: 16/170) was purchased as lyophilized powder, re-suspended to a final concentration of 50 µg/ml in normal healthy serum and stored at -80°C. IFX concentrations measured using in-house and WHO calibration methods were compared using de-identified specimens submitted for IFX testing. Data were analyzed using Deming’s regression and linear mixed effect models for repeated measures. IFX levels in relation to dosing intervals from patient specimens presenting with ICD-10 specific IBD codes were also evaluated. RESULTS: Between run (n = 6) precision was 9.5% (median CV; range 3.9–19.4%) and 8.6% (range: 5.2–17.8%) for 28 IFX specimens measured using in-house and WHO calibration, respectively. As presented in Figure 1, IFX levels measured using in-house calibration method (mean 13.8 ± 0.9 µg/ml) were comparable to those recovered from WHO calibration method (mean 13.9 ± 0.9 µg/ml) (Deming’s slope 1.00 CI 95%: 0.97–1.03). Linear mixed effect models also indicated comparable IFX levels between calibrations (slope = 0.986 ± 0.012; intercept = 0.11 ± 0.22; R2 = 0.97). Table 1 highlights IFX exposure levels in a total of 19,013 specimens submitted with dosing information between 2015 and 2020. A 5mg/Kg every 8 weeks dosing interval associated with 57% specimens above 5 µg/ml. Shorter intervals resulted in higher exposure. CONCLUSION: Our data indicate that IFX levels measured by HMSA in the reference laboratory yield comparable estimates to those from WHO. Calibration with WHO standards may facilitate harmonization of TDM in clinical gastroenterology practice.Figure 1Table 1

A Novel Device for Simultaneous Measurement of Nostril Air Flow Pressure and Temperature using Fiber Bragg Grating Sensor

This paper presents the design, development, calibration and demonstration of non-invasive, Nostril Pressure and Temperature Measurement Device (NPTD) employing Fiber Bragg Grating (FBG) sensors for the simultaneous, accurate and real-time measurement of nostril air flow pressure and temperature which can aid in clinical diagnosis of nasal dysfunction and associated nose disorders. The unique design of NPTD enables the comfortable measurement of randomly varying air flow pressure and temperature of both the nostrils simultaneously. To calibrate the pressure and temperature readouts of NPTD, suitable and in-house calibration techniques have been devised and adopted. The NPTD developed can provide certain critical features such as breathing pattern, rate of respiratory, individual nostril temperature/pressure, nostrils dominance pattern, body core temperature etc., which can aid clinicians in early diagnosis of breathing problems associated with heart, brain and lung malfunctioning. The developed NPTD is simple in design, practically implementable robust, EMI proof and non-electric, which are obligatory features for any clinical diagnostic tool used in a hospital environment.

Implementation of AASHTOWare Pavement ME Design Software for Asphalt Pavements in Kansas

Many highway agencies are transitioning from the 1993 AASHTO pavement design guide to the AASHTOWare Pavement ME Design (PMED). Pavement performance models embedded in the PMED software need to be calibrated for new and reconstructed hot-mix asphalt (HMA) pavements. Twenty-seven newly constructed HMA pavements were used to calibrate the prediction models—twenty-one for calibration and six for validation. Local calibration for permanent deformation, top-down fatigue cracking, and the International Roughness Index (IRI) models was done using the traditional split-sample method. Comparison with the results from the 1993 AASHTO design guide for ten new HMA pavement sections with varying traffic levels was done. The results show that the thicknesses obtained from locally calibrated PMED are within 1 inch of the AASHTO 1993 design guide prediction for low to medium-low traffic. For sections with high traffic level, the 1993 AASHTO design guide yielded higher thickness than PMED. The PMED implementation strategies adopted in Kansas and relevant concerns are discussed. Finally, an automated calibration technique has been proposed to help highway agencies to perform periodic in-house calibration of the performance models.

Calibration of Stainless Steel-edged V-Notch Weir Stop Logs for Water Level Control Structures

Abstract. Dependable flow rate measurements are necessary to calculate flow volumes and resulting nutrient loads from subsurface drainage systems and associated conservation practices. The objectives of this study were (1) to develop appropriate weir equations for a new stainless steel-edged 45° V-notch weir developed for AgriDrain inline water level control structures and (2) to determine if the equation was independent of flow depth in the structure. Weirs for 15 cm (6 in.) and 25 cm (10 in.) inline water level control structures were placed at three heights in each structure: at the base, 48 cm from the base, or 97 cm from the base, and the height of the nappe above the weir crest was recorded over a range of flow rates. The resulting data were fitted to equations of the form Q = aHb where Q is the flow rate, H is the height of the nappe above the weir crest, and a and b are fitted parameters. There were no significant differences in the fitted parameters across the two structure sizes or across the three weir placements. The fitted equation for these new stainless steel-edged V-notch weirs was Q = 0.011H2.28 with Q in liters per second and H in centimeters, and Q = 1.44H2.28, with Q in gallons per minute and H in inches. These equations can be used for measuring flow through AgriDrain in-line structures, although in-house weir calibration is highly recommended for specific applications, when possible. Keywords: Drainage, Flow monitoring, Subsurface drainage, V-notch weir, Weir calibration.

Efficiency calibration of a coaxial HPGe detector-Marinelli beaker geometry using an 152Eu source prepared in epoxy matrix and its validation by efficiency transfer method

Abstract In this study, an in-house 152Eu calibration source was produced from a custom epoxy matrix with a density of ρ = 1.14 g cm−3, which is chemically stable and durable form after its solidification. The homogeneity of 152Eu in matrix was obtained better than 98%. For a Marinelli beaker geometry, an efficiency calibration procedure was applied to a n-type, coaxial, 78.5% relative efficient HPGe detector in the energy range of 121.7–1408.0 keV by using in-house 152Eu calibration source. Then the measured efficiencies for Marinelli geometry were compared with the results calculated by MEFFTRAN and ANGLE softwares for the validation. Although MEFFTRAN and ANGLE have two different efficiency transfer algorithms to calculate the efficiencies, they usually need to use a reliable and accurate reference efficiency values as input data. Hence, reference efficiency values were obtained experimentally from a multinuclide standard source for the same detector- Marinelli geometry. In the present source characterization, the corrections required for self-absorption and true coincidence summing effects for 152Eu gamma-rays were also obtained for a such close counting geometry condition. The experimental results confirmed the validity of efficiency calculations obtained by MEFFTRAN and ANGLE softwares that are calculation tools.

On the Accurate Determination of Shock Wave Time-Pressure Profile in the Experimental Models of Blast-Induced Neurotrauma.

Measurement issues leading to the acquisition of artifact-free shock wave pressure-time profiles are discussed. We address the importance of in-house sensor calibration and data acquisition sampling rate. Sensor calibration takes into account possible differences between calibration methodology in a manufacturing facility, and those used in the specific laboratory. We found in-house calibration factors of brand new sensors differ by less than 10% from their manufacturer supplied data. Larger differences were noticeable for sensors that have been used for hundreds of experiments and were as high as 30% for sensors close to the end of their useful lifetime. These observations were despite the fact that typical overpressures in our experiments do not exceed 50 psi for sensors that are rated at 1,000 psi maximum pressure. We demonstrate that sampling rate of 1,000 kHz is necessary to capture the correct rise time values, but there were no statistically significant differences between peak overpressure and impulse values for low-intensity shock waves (Mach number <2) at lower rates. We discuss two sources of experimental errors originating from mechanical vibration and electromagnetic interference on the quality of a waveform recorded using state-of-the-art high-frequency pressure sensors. The implementation of preventive measures, pressure acquisition artifacts, and data interpretation with examples, are provided in this paper that will help the community at large to avoid these mistakes. In order to facilitate inter-laboratory data comparison, common reporting standards should be developed by the blast TBI research community. We noticed the majority of published literature on the subject limits reporting to peak overpressure; with much less attention directed toward other important parameters, i.e., duration, impulse, and dynamic pressure. These parameters should be included as a mandatory requirement in publications so the results can be properly compared with others.

Cryogenic brines as diagenetic fluids: Reconstructing the diagenetic history of the Victoria Land Basin using clumped isotopes

The isotopic analyses (δ13C, δ18O, and Δ47) of carbonate phases recovered from a core in McMurdo Sound by ANtarctic geologic DRILLing (ANDRILL-2A) indicate that the majority of secondary carbonate mineral formation occurred at cooler temperatures than the modern burial temperature, and in the presence of fluids with δ18Owater values ranging between −11 and −6‰ VSMOW. These fluids are interpreted as being derived from a cryogenic brine formed during the freezing of seawater. The Δ47 values were converted to temperature using an in-house calibration presented in this paper. Measurements of the Δ47 values in the cements indicate increasingly warmer crystallization temperatures with depth and, while roughly parallel to the observed geothermal gradient, consistently translate to temperatures that are cooler than the current burial temperature. The difference in temperature suggests that cements formed when they were ∼260 ± 100 m shallower than at the present day. This depth range corresponds to a period of minimal sediment accumulation from 3 to 11 Myr; it is therefore interpreted that the majority of cements formed during this time. This behavior is also predicted by time-integrated modeling of cementation at this site. If this cementation had occurred in the presence of these fluids, then the cryogenic brines have been a longstanding feature in the Victoria Land Basin. Brines such as those found at this site have been described in numerous modern high-latitude settings, and analogous fluids could have played a role in the diagenetic history of other ice-proximal sediments and basins during glacial intervals throughout geologic history. The agreement between the calculated δ18Owater value and the measured values in the pore fluids shows how the Δ47 proxy can be used to identify the origin of negative δ18O values in carbonate rocks and that extremely negative values do not necessarily need to be a result of the influence of meteoric fluids or reaction at high temperature.

Tropospheric and ionospheric media calibrations based on global navigation satellite system observation data

Context: Calibration of radiometric tracking data for effects in the Earth atmosphere is a crucial element in the field of deep-space orbit determination (OD). The troposphere can induce propagation delays in the order of several meters, the ionosphere up to the meter level for X-band signals and up to tens of meters, in extreme cases, for L-band ones. The use of media calibrations based on Global Navigation Satellite Systems (GNSS) measurement data can improve the accuracy of the radiometric observations modelling and, as a consequence, the quality of orbit determination solutions. Aims: ESOC Flight Dynamics employs ranging, Doppler and delta-DOR (Delta-Differential One-Way Ranging) data for the orbit determination of interplanetary spacecraft. Currently, the media calibrations for troposphere and ionosphere are either computed based on empirical models or, under mission specific agreements, provided by external parties such as the Jet Propulsion Laboratory (JPL) in Pasadena, California. In order to become independent from external models and sources, decision fell to establish a new in-house internal service to create these media calibrations based on GNSS measurements recorded at the ESA tracking sites and processed in-house by the ESOC Navigation Support Office with comparable accuracy and quality. Methods: For its concept, the new service was designed to be as much as possible depending on own data and resources and as less as possible depending on external models and data. Dedicated robust and simple algorithms, well suited for operational use, were worked out for that task. This paper describes the approach built up to realize this new in-house internal media calibration service. Results: Test results collected during three months of running the new media calibrations in quasi-operational mode indicate that GNSS-based tropospheric corrections can remove systematic signatures from the Doppler observations and biases from the range ones. For the ionosphere, a direct way of verification was not possible due to non-availability of independent third party data for comparison. Nevertheless, the tests for ionospheric corrections showed also slight improvements in the tracking data modelling, but not to an extent as seen for the tropospheric corrections. Conclusions: The validation results confirmed that the new approach meets the requirements upon accuracy and operational use for the tropospheric part, while some improvement is still ongoing for the ionospheric one. Based on these test results, green light was given to put the new in-house service for media calibrations into full operational mode in April 2017.

Development of PSP Technique for Vane Film Cooling Investigations

The present paper reports on the development of dual-luminophor Pressure Sensitive Paints (PSP) technique at University of Bergamo and on its application to the measurement of adiabatic film cooling effectiveness. An in-house calibration was carried out in order to assess the influence of temperature on PSP signal. Binary PSP have been then applied on a film cooled flat plate model for validation purposes and then used to measure the adiabatic film cooling effectiveness distribution over the leading and the trailing edge region of a high loaded high pressure nozzle guide vane. In both cases, PSP results have been compared with Liquid Crystal (TLC) data. Unlike the heat-transfer based techniques (i.e. TLC), binary PSP results are not affected by conduction phenomena, allowing to comply with adiabatic condition over test duration. PSP allowed to obtain highly resolved and high quality distributions even in the near hole exit region and where compressibility effects are relevant.

Thin-Film Gauges Using Carbon Nanotubes as Composite Layers

Measurement of transient temperature and heat flux has attained enormous importance with the recent advancement in technology. Certain situations demand transient measurements to be performed for extremely short durations (approximately few seconds) which in turn call for sensors capable of responding within microseconds or even less. Thin-film gauges (TFGs), a particular class of resistance temperature detectors (RTDs), are such kind of sensors which are suitable for above requirements due to their quick and precise measurements in transient environments. The present work aims at designing an in-house fabrication and calibration of fast response TFG prepared by depositing nanocarbon layer on silver films as a laminated composite topping to enhance thermal and electrical properties. A significant improvement in the thermal and electrical conductivity of the composite sensor is observed when compared to gauges made from pure metals.