Closing Force Evaluation of a Sample Return Capsule for a Phobos Sample Return Mission

The mission objective of the Phobos Sample Return is to collect and return 100 g of Phobos’ surface material to Earth inside a tight enclosure composed of a Vault, a Sample Container and sealing elements. One important aspect of the project was the development of a closing mechanism capable of ensuring a pushing force high enough compared to the available force of the robotic arm (40 N). The need for a higher pushing force derived from the design tests which were carried out to experimentally determine the necessary force to overcome the resistance of the sealing element when the vault is closed. Two types of sealing elements, custom made for this project, along with two SC with different geometrical shapes in the sealing area were tested. For better accuracy, the tests considered the imposed operational temperature domain for the vault, ECSS standards and the test rig set-up being performed at environmental temperature (+20 °C), −20 °C, −60 °C and +70 °C. The results of the tests highlighted that the negative temperature has a significant influence over the closing force, as this force is increasing once the operational temperature is decreasing. Based on the work performed, the most suitable type of sealing element was identified, in particular the piston geometry which allows a smaller force to close the vault.

Prevent Failures and Extend Asset Life: A Reliable Onsite Corrosion Inhibitor Residuals Method Using SERS

Asset integrity for oil and gas operations requires reliable chemical information to troubleshoot factors affecting chemical deliverability and performance. Accurate and precise measurement of corrosion inhibitor (CI) concentration in oilfield brine is significant to asset management. However, historically CI residual measurements are extremely problematic due to the surface-active nature of the chemicals which interact with a host of factors that parasitically deplete the CI solution concentration. It is typical to see >100% error on traditional residual measurements especially where dye transfer techniques are concerned. Current methods and sample handling for measuring residuals involves sending samples to a local laboratory for analysis. This time delay can add to the measurement error due to loss of inhibitor species to the sample container or solids that may form in transport. This paper describes the use of a simple, portable, handheld, onsite, nanotechnology-based, residual method to measure CI concentrations in oilfield brines. With more frequent and highly accurate CI residual feedback operators can react to system conditions that threaten to impact asset integrity. Using the CI residual data provided by a rapid, accurate analytical method, operators could extend asset life and prevent failures long before they become critical.

PIONEERING APPLICATION OF EMERGING TECHNOLOGIES TO THE CHALLENGE OF SAMPLING NEAR-SATURATED FLUIDS IN TIGHT RESERVOIRS

Openhole oil sampling in the tight Middle Cretaceous reservoirs of Alaska can be challenging due to the proximity of the reservoir pressure to the fluid’s saturation pressure. Existing focused probe technologies commonly used in other conditions have limited application in these conditions because their small flow area means slow pumping rates, high drawdowns, and nonrepresentative fluid samples. Nonfocused inlets, such as 3D radial probes and straddle packers, are mostly used to sample in these reservoirs, but deep invasion and slow pumping rates mean using these alternatives leads to long station times. A new wireline formation testing platform has been field tested in three wells since 2018. The objectives included the evaluation of the platform’s abilities to pump at controlled speeds to keep flowing pressures always above the fluid’s expected saturation pressures. A new inlet was tested for focused sampling and higher flow rates with the intention of cutting operating time and improving sample quality. Also, increased sample container capacity enabled the collection of required sample volumes in fewer bottles, which resulted in a shorter and lighter sampling string configuration. A legacy pressure tool was added to the bottom of the new platform for pressure testing benchmarking. During the operation, the tool was positioned at target depth, and an automated routine inflated the inlet assembly to contact the formation. This automation cycle enables the tool to be ready for pumping in less than 15 minutes. In contrast, technologies used in previous operations required 30 to 45 minutes setup time before fluid cleanup could commence. Fluids were then flowed through the tool’s sample and guard lines with a sequence of commingling and focused pumping periods using two simultaneous pumps while assessing fluid quality with a downhole fluid analyzer. Strict control of the 1-cm3/s selected rate for both pumps provided fast cleanup in focused mode with less than 100-psi drawdown. This has never been achieved before in these reservoirs. First hydrocarbon breakthrough was observed less than an hour into the pumping period. Previous operations reported 4 hours or more for first hydrocarbon breakthrough. Three stations were performed, and 10 single-phase samples were collected in as many bottles. Thin-bedded interval testing was possible given the ability of the new platform to collect samples with either the sample or guard lines. Total operating time to complete the program was 30 hours. Comparison with data from similar operations in previous campaigns shows a decrease of 50% in operating time, faster rig- up and rig-down, and decreased cable tension. These latter two aspects add to operational efficiency and mitigation of risks. This case study summarizes several pioneering aspects of the new generation of wireline formation testing platforms. It was the first time a combination of the new and legacy technology was deployed and the first time that high-volume multiphase sample bottles were used during a field test. It was also one of the first applications of this new technology in North America.

Effects of Loading and Boundary Conditions on the Performance of Ultrasound Compressional Viscoelastography: A Computational Simulation Study to Guide Experimental Design

Most biomaterials and tissues are viscoelastic; thus, evaluating viscoelastic properties is important for numerous biomedical applications. Compressional viscoelastography is an ultrasound imaging technique used for measuring the viscoelastic properties of biomaterials and tissues. It analyzes the creep behavior of a material under an external mechanical compression. The aim of this study is to use finite element analysis to investigate how loading conditions (the distribution of the applied compressional pressure on the surface of the sample) and boundary conditions (the fixation method used to stabilize the sample) can affect the measurement accuracy of compressional viscoelastography. The results show that loading and boundary conditions in computational simulations of compressional viscoelastography can severely affect the measurement accuracy of the viscoelastic properties of materials. The measurement can only be accurate if the compressional pressure is exerted on the entire top surface of the sample, as well as if the bottom of the sample is fixed only along the vertical direction. These findings imply that, in an experimental validation study, the phantom design should take into account that the surface area of the pressure plate must be equal to or larger than that of the top surface of the sample, and the sample should be placed directly on the testing platform without any fixation (such as a sample container). The findings indicate that when applying compressional viscoelastography to real tissues in vivo, consideration should be given to the representative loading and boundary conditions. The findings of the present simulation study will provide a reference for experimental phantom designs regarding loading and boundary conditions, as well as guidance towards validating the experimental results of compressional viscoelastography.

An international multi-center investigation on the accuracy of radionuclide calibrators in nuclear medicine theragnostics

Background Personalized molecular radiotherapy based on theragnostics requires accurate quantification of the amount of radiopharmaceutical activity administered to patients both in diagnostic and therapeutic applications. This international multi-center study aims to investigate the clinical measurement accuracy of radionuclide calibrators for 7 radionuclides used in theragnostics: 99mTc, 111In, 123I, 124I, 131I, 177Lu, and 90Y. Methods In total, 32 radionuclide calibrators from 8 hospitals located in the Netherlands, Belgium, and Germany were tested. For each radionuclide, a set of four samples comprising two clinical containers (10-mL glass vial and 3-mL syringe) with two filling volumes were measured. The reference value of each sample was determined by two certified radioactivity calibration centers (SCK CEN and JRC) using two secondary standard ionization chambers. The deviation in measured activity with respect to the reference value was determined for each radionuclide and each measurement geometry. In addition, the combined systematic deviation of activity measurements in a theragnostic setting was evaluated for 5 clinically relevant theragnostic pairs: 131I/123I, 131I/124I, 177Lu/111In, 90Y/99mTc, and 90Y/111In. Results For 99mTc, 131I, and 177Lu, a small minority of measurements were not within ± 5% range from the reference activity (percentage of measurements not within range: 99mTc, 6%; 131I, 14%; 177Lu, 24%) and almost none were outside ± 10% range. However, for 111In, 123I, 124I, and 90Y, more than half of all measurements were not accurate within ± 5% range (111In, 51%; 123I, 83%; 124I, 63%; 90Y, 61%) and not all were within ± 10% margin (111In, 22%; 123I, 35%; 124I, 15%; 90Y, 25%). A large variability in measurement accuracy was observed between radionuclide calibrator systems, type of sample container (vial vs syringe), and source-geometry calibration/correction settings used. Consequently, we observed large combined deviations (percentage deviation > ± 10%) for the investigated theragnostic pairs, in particular for 90Y/111In, 131I/123I, and 90Y/99mTc. Conclusions Our study shows that substantial over- or underestimation of therapeutic patient doses is likely to occur in a theragnostic setting due to errors in the assessment of radioactivity with radionuclide calibrators. These findings underline the importance of thorough validation of radionuclide calibrator systems for each clinically relevant radionuclide and sample geometry.

An international multi-center investigation on the accuracy of radionuclide calibrators in nuclear medicine theranostics

Background: Personalized molecular radiotherapy based on theragnostics requires accurate quantification of the amount of radiopharmaceutical activity administered to patients both in diagnostic and therapeutic applications. This international multi-center study aims to investigate the clinical measurement accuracy of radionuclide calibrators for 7 radionuclides used in theragnostics: 99mTc, 111In, 123I, 124I, 131I, 177Lu and 90Y.Methods: In total, 32 radionuclide calibrators from 8 hospitals located in the Netherlands, Belgium and Germany were tested. For each radionuclide, a set of four samples comprising two clinical containers (10-mL glass vial and 3-mL syringe) with two filling volumes were measured. The reference value of each sample was determined by two certified radioactivity calibration centers (SCK CEN and JRC) using two secondary standard ionization chambers. The deviation in measured activity with respect to the reference value was determined for each radionuclide and each measurement geometry. In addition, the combined systematic deviation of activity measurements in a theragnostic setting was evaluated for 5 clinically-relevant theragnostic pairs: 131I/123I, 131I/124I, 177Lu/111In, 90Y/99mTc and 90Y/111In.Results: For 99mTc, 131I, and 177Lu, a small minority of measurements were not within ±5% range from the reference activity (percentage of measurements not within range: 99mTc: 6%, 131I: 14%, 177Lu: 24%) and almost none were outside ±10% range. However, for 111In, 123I, 124I and 90Y more than half of all measurements were not accurate within ±5% range (111In: 51%, 123I: 83%, 124I: 63%, 90Y: 61%) and not all were within ±10% margin (111In: 22%, 123I: 35%, 124I: 15%, 90Y: 25%). A large variability in measurement accuracy was observed between radionuclide calibrator systems, type of sample container (vial vs syringe), and source-geometry calibration/correction settings used. Consequently, we observed large combined deviations (percentage deviation > ±10%) for the investigated theragnostic pairs, in particular for 90Y/111In, 131I/123I and 90Y/99mTc.Conclusions: Our study shows that substantial over- or under-estimation of therapeutic patient doses are likely to occur in a theragnostic setting due to errors in the assessment of radioactivity with radionuclide calibrators. These findings underline the importance of thorough validation of radionuclide calibrator systems for each clinically-relevant radionuclide and sample geometry.

Free space traveling–standing wave attenuation method for microwave sensing of grain moisture content

Moisture content is an important index to assess the grain quality and food processing conditions. A measurement system based on the traveling–standing microwave attenuation method is designed for a fast and nondestructive grain moisture content determination. The proposed system consists of a microwave cavity oscillator, microwave transmitting and receiving horn antennas, microwave detector, slide rail, sample container, weight sensor, temperature sensor, and controller. The traveling–standing wave caused by free space microwave multiple reflection is discussed. The moisture content calibration functions eliminated the interference of bulk density and temperature are proposed based on the attenuation of the maximum field strength of the transmission traveling–standing wave. The moisture content of rice, which ranges from 10.75% to 27.62%, is obtained with a standard error of prediction (SEP) of 0.586% and a coefficient of determination ( R2) of 0.988, whereas the moisture content of corn, which ranges from 7.72% to 24.46%, is obtained with a SEP of 0.340% and R2 of 0.991. The main results might provide technical support for the development of accurate and intelligent grain quality detection equipment.

The Effect of Addition of Used Styrofoam on the Characteristics of Asphalt Physical Properties

Styrofoam had many purposes, especially for the safety of electronic objects, because it is light, durable and strong. The volume of styrofoam is enormous, reaching 30% of total waste in the world. Therefore, it causes problems if disposed of and it will become a very inconvenient waste and it can undermine the environment. This study aims to determine the effect of adding former styrofoam waste to asphalt on the characteristics of the 60/70 pen asphalt. The sample was made by melting the Styrofoam with Xylene then putting it in heated asphalt and then stirring it evenly. Next, Styrofoam enters the material into the sample container and then is refrigerated outside for 1 hour. After that, the sample is immersed in water for 3 hours. The sample meets the asphalt requirements test for each sample including penetration test, softening point, flash point, burning point, density, and ductility. This shows that the higher the concentration, the addition of styrofoam mixed with asphalt resulted in conversion and increased performance of the mixture. While at density, it appears that the addition of Styrofoam results in a lower density value.