Experimental Instrument Research Articles

A CaSSIS and HiRISE map of the Clay-bearing Unit at the ExoMars 2022 landing site in Oxia Planum

In preparation for the operations of the ExoMars Rosalind Franklin rover, characterising its landing site in Oxia Planum is essential. Of particular interest is the extensive Clay-bearing Unit present at the site, a key target in the search for biosignatures. In this paper we provide a map based on variations in colour and spectral information within this unit, covering the 1σ landing envelope of the rover along with a 1 ​km buffer to account for minor shifts of the landing envelope ahead of launch (referred to going forward as the 1σ+ landing envelope). We used imagery from the Colour and Stereo Surface Imaging System (CaSSIS) and High Resolution Imaging Science Experiment (HiRISE) instruments, along with CaSSIS Band Ratio Composites with enhanced colour sensitivity to the presence of ferric (Fe3+) and ferrous (Fe2+) iron bearing materials. Our map is of a far higher resolution (map-scale 1:2000) than those previously available and, in contrast to previously available maps of this unit, differentiates between an Orange Subunit and a Blue Subunit which make up the Clay-bearing Unit. This mapping covered the ∼91% of the 1σ+ landing envelope where there was CaSSIS coverage and split the Clay-bearing Unit into three categories: one for each of the clay subunits, and another for exposures of the Clay-bearing Unit where either both subunits were too intermixed to reliably separate, or where it was difficult to determine which of the two were present.The results from our mapping shows that at least ∼35% of the 1σ+ envelope is covered by exposures of the Clay-bearing Unit: ∼18% by the Orange Subunit, ∼9% the Blue Subunit, and ∼12% were classified as Indeterminate. The spread of these two subunits varied substantially over the 1σ+ landing envelope, with the south-east half of the landing envelope dominated by the Orange Subunit (∼70% exposures in this area belonging to the Orange Subunit, ∼10% to the Blue Subunit and ∼20% to the Indeterminate category), while the north-west has more sporadic exposures of the Clay-bearing Unit (∼22% Orange, ∼37% Blue and ∼41% Indeterminate). The colour distinction between the two subunits is thought to be due to constituent mineralogical differences rather than differences in dust coverage of the two subunits. The scale of the fracturing present in the two subunits has also been assessed in this study, via qualitative observations of the fracture length and quantitative mapping out of fracture networks. While there were differences in the scale of fracturing between the two subunits, these were not as great as had previously been identified.

Cloud cover and its impact on Brazil's deforestation satellite monitoring program: Evidence from the cerrado biome of the Brazilian Legal Amazon

The creation of a satellite rapid alert programme (DETER-A) in 2004 was a cornerstone of the Brazilian government's strategy to reduce deforestation. This programme allowed authorities to detect and respond rapidly to periods of deforestation. Due to the fact that the policy instrument was based on multispectral remote radar, weather-related obstacles posed a continuous impediment to the study of deforestation. This paper investigates to what extent cloud cover has reduced the effectiveness of the DETER-A program to detect deforestation. To test this hypothesis, survival model analysis is undertaken on satellite data derived measures of local deforestation. The emphasis is on the state of Maranhão, which is separated into two areas by an arbitrary line of demarcation (Legal Amazon delimitation) where the forest on one side is covered by the satellite monitoring program while the other is not. The results suggest that following the implementation of the satellite monitoring program, there was more deforestation in those years with more cloud persistence in the area covered by the program. Counterfactual simulations indicate that the absence of clouds would have prevented deforestation equivalent to almost 7% of the study region, which is equivalent to 73 million tonnes of CO2 with a value of US$ 366 million. If the current monitoring system was replaced with the experimental policy instrument DETER-C/DETER INTENSO, cloud cover would be less of an impediment to deforestation detection.

Temperatures of the Lacus Mortis Region of the Moon

AbstractOver 11 years of data acquired by the Diviner Lunar Radiometer Experiment instrument aboard Lunar Reconnaissance Orbiter have been compiled into a comprehensive data set of surface temperatures in the Lacus Mortis region which includes the landing ellipse of the Astrobotic Mission One lander mission. These data provide diurnal brightness temperatures at 128 pixels per degree (ppd) spatial resolution and 0.1 hr of local time resolution. From this data set, we highlight several features that display variations in radiative and thermophysical properties in the Lacus Mortis region and characterize the temperatures of the Astrobotic Mission One landing ellipse. We identify distinctly contrasting properties of materials in the walls of Bürg crater, hummocks of materials on the southeast margin of the mare basalts, and materials exposed or excavated by impacts. Additionally, we describe an exceptionally rocky fault scarp that predates the formation of Bürg crater suggesting the observed boulders are replenished on a timescale <1 Ga. Within the Astrobotic landing ellipse, temperatures are observed to range from ∼88 to ∼359 K with sunrise and sunset local times constrained to 5.8–6.3 hr and 17.8 and 18.1 hr respectively.

Hypermentalizing and Borderline Personality Disorder: A Meta-Analytic Review.

A hypermentalizing impairment, or tendency to overattribute mental states to others, has been identified among individuals with borderline personality disorder. However, associations between hypermentalizing and other disorders call into question the specificity of this impairment to borderline personality disorder. This study aimed to evaluate the relative strength of the association between hypermentalizing and borderline personality disorder compared with other disorders and to assess the impact of moderators on the relationship between hypermentalizing and psychopathology. The authors conducted a meta-analysis of 36 studies (N=4,188 people) to investigate the relative strength of the association between hypermentalizing and borderline personality disorder, compared with other disorders, and to assess the impact of moderators on this relationship. The Movie for the Assessment of Social Cognition, an ecologically valid experimental instrument, was used to measure hypermentalizing. Results indicated support for an association between psychopathology and hypermentalizing (r=0.24, 95% confidence interval [CI]=0.17 to 0.31), but the association was not significantly stronger for borderline personality disorder (r=0.26, 95% CI=0.12 to 0.39) than for other disorders (r=0.24, 95% CI=0.14 to 0.33). Neither age nor gender significantly moderated the association between psychopathology and hypermentalizing. Hypermentalizing may be related to psychopathology in general rather than borderline personality disorder in particular. The findings are discussed in view of the possibility that features of borderline personality disorder associated with other psychopathology may explain the overall association between psychopathology and hypermentalizing. Clinical implications for mentalization-based treatment and concerns that the measurement used for hypermentalization may be too narrow and not representative of variations in functioning across cultures and race-ethnicity also are discussed.

Improving Vocabulary Reading Skills with Word Card and Picture Card for Moderate Intellectual Disabilities

Teaching reading functional vocabulary to students with intellectual disability (ID’s) is a challenge for teachers in special schools. They face many obstacles in teaching vocabulary which are caused by various factors, especially student characteristics and learning structures that are less practical and tend to be academic. This study aims to measure the effectiveness of using word cards and picture cards to improve vocabulary reading skills in moderate ID’s students. The type of research applied is single subject research, with multiple baseline across subject designs. The research subjects were two moderately ID’s students in grade 5 and grade 2 SLB-C1 Bhakti Luhur Malang. An instructor and an observer played an important role in this study. The experimental instrument used is Lesson Plan which consists of three units, each teaching two vocabularies. Data analysis is carried out by performing graphical inspections that focus on trend, latency, and level changes. The effectiveness was confirmed by Percentage of All Non-overlapping Data (PAND) in the intervention condition against the baseline-1 condition. The results showed that with the intervention, the target behavior in the form of vocabulary understanding had a trend of grades rising gradually touching a high level of score, and settling at a high level in the baseline-2 condition. The average PAND for subject-1 reached 80.55 percent (effective), and subject-2 reached 96.67 percent (very effective).

Progressive collapse of post-tensioned subframes following the removal of an interior column

Experimental investigations about the post-tensioned concrete substructures are still imperative to be conducted to assess the structural performances against progressive collapse. Four half-scaled framed substructures were tested to evaluate the dynamic resistant behaviors under a scenario of sudden removal of an interior column. Then, to evaluate the performances against progressive collapse at the large deformation stage, the residual substructures were tested under the pseudo-static loading regime. Various responses at the prescribed locations were monitored with the experimental instruments. The variables in the research included diameters of the post-tensioned strands (PTS), bonded form of PTS, and unboned form of PTS. By comparison, the differences among the reinforced concrete counterpart (RC), bonded post-tensioned concrete substructures (BPC), and unbonded post-tensioned concrete substructure (UPC) were highlighted. Dynamic experimental results indicate that the PTS can have significant influences on damping ratio and enhance the vertical stiffness of RC specimens. Moreover, the ultimate bearing capacity of UPC can reach 2.09 times larger than that of the RC substructures, and the PTS with a larger diameter can enhance the ultimate bearing capacity more than that with a small diameter. Additionally, the proposed analytical model can well agree with the failure modes at the catenary action (CA) stage, and the theoretical formulas can be well utilized to evaluate the ultimate bearing capacity.

A low-cost 3D-printable differential scanning fluorometer for protein and RNA melting experiments

Differential scanning fluorimetry (DSF) is a widely used biophysical technique with applications to drug discovery and protein biochemistry. DSF experiments are commonly performed in commercial real-time polymerase chain reaction (qPCR) thermal cyclers or nanoDSF instruments. Here, we report the construction, validation, and example applications of an open-source DSF system for 176€, which, in addition to protein-DSF experiments, also proved to be a versatile biophysical instrument for less conventional RNA-DSF experiments. Using 3D-printed parts made of polyoxymethylene, we were able to fabricate a thermostable machine chassis for protein-melting experiments. The combination of blue high-power LEDs as the light source and stage light foil as filter components was proven to be a reliable and affordable alternative to conventional optics equipment for the detection of SYPRO Orange or Sybr Gold fluorescence. The ESP32 microcontroller is the core piece of this openDSF instrument, while the in-built I2S interface was found to be a powerful analog-to-digital converter for fast acquisition of fluorescence and temperature data. Airflow heating and inline temperature control by thermistors enabled high-accuracy temperature management in PCR tubes (±0.1 °C) allowing us to perform high-resolution thermal shift assays (TSA) from exemplary biological applications.

Low-Cost, User-Friendly, All-Integrated Smartphone-Based Microplate Reader for Optical-Based Biological and Chemical Analyses.

The quantitative detection of different molecular targets is of utmost importance for a variety of human activities, ranging from healthcare to environmental studies. Bioanalytical methods have been developed to solve this and to achieve the quantification of multiple targets from small volume samples. Generally, they can be divided into two different classes: point of care (PoC) and laboratory-based approaches. The former is rapid, low-cost, and user-friendly; however, the majority of the tests are semiquantitative, lacking in specificity and sensitivity. On the contrary, laboratory-based approaches provide high sensitivity and specificity, but the bulkiness of experimental instruments and complicated protocols hamper their use in resource-limited settings. In response, here we propose a smartphone-based device able to support laboratory-based optical techniques directly at the point of care. Specifically, we designed and fabricated a portable microplate reader that supports colorimetric, fluorescence, luminescence, and turbidity analyses. To demonstrate the potential of the device, we characterized its analytical performance by detecting a variety of relevant molecular targets (ranging from antibodies, toxins, drugs, and classic fluorophore dyes) and we showed how the estimated results are comparable to those obtained from a commercial microplate reader. Thanks to its low cost (<$300), portability (27 cm [length] × 18 cm [width] × 7 cm [height]), commercially available components, and open-source-based system, we believe it represents a valid approach to bring high-precision laboratory-based analysis at the point of care.

Using near–surface temperature data to vicariously calibrate high-resolution thermal infrared imagery and estimate physical surface properties

Thermal response of the surface to solar insolation is a function of the topography and the thermal physical characteristics of the landscape, which include bulk density, heat capacity, thermal conductivity and surface albedo and emissivity. Thermal imaging is routinely used to constrain thermal physical properties by characterizing or modeling changes in the diurnal temperature profiles. Images need to be acquired throughout the diurnal cycle – typically this is done twice during a diurnal cycle, but we suggest multiple times. Comparison of images acquired over 24 hours requires that either the data be calibrated to surface temperature, or the response of the thermal camera is linear and stable over the image acquisition period. Depending on the type and age of the thermal instrument, imagery may be self-calibrated in radiance, corrected for atmospheric effects, and pixels converted to surface temperature. We used an experimental instrumentation where the calibration should be stable, but calibration coefficients are unknown. Cases may occur where one wishes to validate the camera's calibration. We present a method to validate and calibrate the instrument and characterize the thermal physical properties for areas of interest. Finally, in situ high-temporal-resolution oblique thermal imaging can be invaluable in preparation for conducting overflight missions. We present the following:•The use of oblique thermal high temporal resolution thermal imaging over diurnal or multiday periods for the characterization of landscapes has not been widespread but poses great potential.•A method of collecting and analyzing thermal data that can be used to either determine or validate thermal camera calibration coefficients.•An approach to characterize thermophysical properties of the landscape using oblique temporally high-resolution thermal imaging, combined with in situ ground measurements.

Possibilities and prospects for experimental and clinical instrumentation techniques for determining the primary stability of dental implants in comparative analysis

The high primary stability of dental implants provides a favorable prognosis for orthopedic treatment with implant-supported structures. The importance of assessing the stability and the bone tissue surrounding the implant as a whole is due to the fact that the process of osseointegration is a structural and functional connection between the bone and the loaded surface of the implant. Determination of the dynamics of the stability of dental implants allows timely monitoring of unpredictable changes at the stages of osseointegration and remodeling of bone tissue around the implant. Currently, in addition to clinical and radiation diagnostic methods, there are generally recognized by clinicians frequency resonance analysis and periotestometry. However, there are some scientific discrepancies indicating the lack of objectivity of these methods and the impossibility of their full-fledged application without the support of radiation and clinical diagnostic methods. In addition to these methods, there are many experimental and less common methods in clinical practice for assessing the primary stability of implants, but with reasonable objectivity. Thus, the reasons are given that for a full assessment of the relationship between the efforts exerted on implants and their movements in the space of bone tissue, devices are needed that reflect the stability and density of the contact of the implant with bone tissue in physical quantities. In particular, methods based on lasers, sound, quantitative ultrasound, and others have found experimental practical application. The ultrasound method of assessing the primary stability of the implant is estimated as the most promising, since it allows you to demonstrate the results of studies in certain physical quantities, as well as to compare these results with histomorphological indicators of osseointegration of dental implants.

Integrating Research-Based Learning into the Undergraduate Curriculum: Challenges and Solutions

Integrating undergraduate research into introductory level courses can improve student accessibility, inclusion, and retention. Herein, we discuss two one-on-one research projects that are being scaffolded into the undergraduate curriculum. We will describe the design and application of CUREs (course-based undergraduate research experiences) in forensic biology as well as physics and astronomy degree programmes. The forensic biology CURE includes trace evidence analysis and models the experimental methods, techniques, and instrumentation students will use in their future careers. In the Eclipsing Binaries CURE, students are introduced to coding and computational physics through modelling spectroscopic and photometric data. The lessons learned through scaling up these interdisciplinary models can apply to other fields of study.

Becoming ‘Smart’: An Examination of Infrastructure Canada's Smart City Challenge as a Public Policy Experiment and Research Instrument

Becoming ‘Smart’: An Examination of Infrastructure Canada's Smart City Challenge as a Public Policy Experiment and Research Instrument

Nonlinear Boussinesq and Rosseland approximations on 3D flow in an interruption of Ternary nanoparticles with various shapes of densities and conductivity properties

&lt;abstract&gt; &lt;p&gt;In current days, hybrid models have become more essential in a wide range of systems, including medical treatment, aerosol particle handling, laboratory instrument design, industry and naval academia, and more. The influence of linear, nonlinear, and quadratic Rosseland approximations on 3D flow behavior was explored in the presence of Fourier fluxes and Boussinesq quadratic thermal oscillations. Ternary hybrid nanoparticles of different shapes and densities were also included. Using the necessary transformation, the resulting partial differential system is transformed into a governing ordinary differential system, and the solution is then furnished with two mixed compositions (Case-Ⅰ and Case-Ⅱ). Combination one looked at aluminum oxide (Platelet), graphene (Cylindrical), and carbon nanotubes (Spherical), whereas mixture two looked at copper (Cylindrical), copper oxide (Spherical), and silver oxide (Platelet). Many changes in two mixture compositions, as well as linear, quadratic, and nonlinear thermal radiation situations of the flow, are discovered. Case-1 ternary combinations have a wider temperature distribution than Case-2 ternary mixtures. Carbon nanotubes (Spherical), graphene (Cylindrical), and aluminum oxide (Platelet) exhibit stronger conductivity than copper oxide (Spherical), copper (Cylindrical), and silver oxide (Platelet) in Case 1. (Platelet). In copper oxide (Spherical), copper (Cylindrical), and silver (Platelet) compositions, the friction factor coefficient is much higher. The combination of liquids is of great importance in various systems such as medical treatment, manufacturing, experimental instrument design, aerosol particle handling and naval academies, etc. Roseland's quadratic and linear approximation of three-dimensional flow characteristics with the existence of Boussinesq quadratic buoyancy and thermal variation. In addition, we combine tertiary solid nanoparticles with different shapes and densities. In many practical applications such as the plastics manufacturing and polymer industry, the temperature difference is remarkably large, causing the density of the working fluid to vary non-linearly with temperature. Therefore, the nonlinear Boussinesq (NBA) approximation cannot be ignored, since it greatly affects the flow and heat transport characteristics of the working fluid. Here, the flow of non-Newtonian elastomers is controlled by the tension of an elastic sheet subjected to NBA and the quadratic form of the Rosseland thermal radiation is studied.&lt;/p&gt; &lt;/abstract&gt;

Developmental Trajectories of Anhedonia in Preclinical Models.

This chapter discusses how the complex concept of anhedonia can be operationalized and studied in preclinical models. It provides information about the development of anhedonia in the context of early-life adversity, and the power of preclinical models to tease out the diverse molecular, epigenetic, and network mechanisms that are responsible for anhedonia-like behaviors.Specifically, we first discuss the term anhedonia, reviewing the conceptual components underlying reward-related behaviors and distinguish anhedonia pertaining to deficits in motivational versus consummatory behaviors. We then describe the repertoire of experimental approaches employed to study anhedonia-like behaviors in preclinical models, and the progressive refinement over the past decade of both experimental instruments (e.g., chemogenetics, optogenetics) and conceptual constructs (salience, valence, conflict). We follow with an overview of the state of current knowledge of brain circuits, nodes, and projections that execute distinct aspects of hedonic-like behaviors, as well as neurotransmitters, modulators, and receptors involved in the generation of anhedonia-like behaviors. Finally, we discuss the special case of anhedonia that arises following early-life adversity as an eloquent example enabling the study of causality, mechanisms, and sex dependence of anhedonia.Together, this chapter highlights the power, potential, and limitations of using preclinical models to advance our understanding of the origin and mechanisms of anhedonia and to discover potential targets for its prevention and mitigation.

Improving Vocabulary Reading Skills with Word Card and Picture Card for Moderate Intellectual Disabilities

Teaching reading functional vocabulary to students with intellectual disability (ID’s) is a challenge for teachers in special schools. They face many obstacles in teaching vocabulary which are caused by various factors, especially student characteristics and learning structures that are less practical and tend to be academic. This study aims to measure the effectiveness of using word cards and picture cards to improve vocabulary reading skills in moderate ID’s students. The type of research applied is single subject research, with multiple baseline across subject designs. The research subjects were two moderately ID’s students in grade 5 and grade 2 SLB-C1 Bhakti Luhur Malang. An instructor and an observer played an important role in this study. The experimental instrument used is Lesson Plan which consists of three units, each teaching two vocabularies. Data analysis is carried out by performing graphical inspections that focus on trend, latency, and level changes. The effectiveness was confirmed by Percentage of All Non-overlapping Data (PAND) in the intervention condition against the baseline-1 condition. The results showed that with the intervention, the target behavior in the form of vocabulary understanding had a trend of grades rising gradually touching a high level of score, and settling at a high level in the baseline-2 condition. The average PAND for subject-1 reached 80.55% (effective), and subject-2 reached 96.67% (very effective)

Resonance. (Re)forming an Artistic Identity through Intercultural Dialogue and Collaboration

This artistic doctoral research examines how the third space emerging from intercultural dialogue and transcultural collaboration can be a catalyst for new musical discoveries, intercultural humility, and the (re)forming of artistic identities. The body of this project is centred around three doctoral concerts, a CD/LP recording, and a documentary film which took place between 2016 and 2021. In addition, I draw on the embodied experience of a five-year period that I spent living and collaborating with musicians and dancers in Tanzania and Zambia prior to the doctoral project.As a double bass player, multi-instrumentalist, and composer, I place myself in a series of different musical and multi-arts contexts, engaging in dialogue with musicians, dancers, and visual artists from Brazil, Colombia, Estonia, Finland, France, Madagascar, Mexico, Poland, Sápmi, Tanzania, the UK and Zambia. Various solo, duo, and ensemble settings act as case studies to examine how this process takes place, the new knowledge gained from the collaborations and their resulting artistic outcomes, and the effects of intercultural dialogue, collaboration, and co-creation on my own artistic identity. The instruments and forms of artistic expression used by my collaborators include the Brazilian berimbau, Chinese guzheng, dance, live electronics, experimental instrument making, Finnish Saarijärvi kantele, Sámi joik, vocals, percussion, live visuals, image manipulation, animation, photography and film.The key concepts that I investigate in this research are: artistic identity, global citizenship, hybridity, interculturalism, intercultural humility, liminality, third space theory, and resonance, the latter being viewed both as a physical phenomenon and as an approach to thinking about the ways in which we connect with the world around us. This research contributes to new knowledge and understandings in the areas of artistic identity formation, intercultural collaboration and interculturalism in music education through the interweaving of artistic processes, audio, video, photographs, artistic outcomes and text.Findings emerge in terms of new musical discoveries that surface from the dynamic third space created through transcultural collaboration; the expanding and deepening of musicianship through intercultural dialogue and collaboration; the interconnected nature of interculturalism in music and its reliance on openness, empathy, dialogue and constantnegotiation with sonic material, people and place; and the crucial role of fluidity and resonance in forming a personal artistic identity.Further research outcomes include new techniques and the expansion of the sonic palette of the double bass, enabled by developing custom-made attachments, preparations and electronic manipulation. The complete scope of this doctoral project includes four artistic components (three concerts and a recording), a documentary film and an artistic doctoral thesis comprising two peer-reviewed articles and an integrative chapter, all housed within the main multi-media exposition, Resonance: (Re)forming an Artistic Identity through Intercultural Dialogue and Collaboration.

Weakening wave impact on submarine-launched vehicles by imitating humpback whale belly grooves

Inspired by humpback whale belly grooves which may impart stability, we hypothesized that adding grooves to the head of submarine-launched vehicle (SLV) would weaken the effect of wave force. An experimental instrument was built to test a prototype submarine-launched vehicle (SLVP; no grooves) and 9 bionic submarine-launched vehicles (SLVBs) with different grooves on the head. The deflection angles of the SLVP and SLVBs were measured as they crossed the water-air interface in wavy conditions. The experimental results showed that the SLVBs had smaller deflection angles than the SLVP, which supported the initial hypothesis. The angular deflection of the SLVP and SLVBs in wavy conditions was then analyzed using a simulation. The simulated and experimental results agreed, confirming the validity of the simulated models. By measuring the torque experienced at the center of gravity of the SLVs and the flow field distributions near the heads of the SLVs in the simulation, the mechanism behind the differences in angular deflection of the SLVs with and without grooves was revealed.

A 500 MS/s waveform digitizer for PandaX dark matter experiments

Waveform digitizers are key readout instruments in particle physics experiments. In this paper, we present a waveform digitizer for the PandaX dark matter experiments. It supports both external-trigger readout and triggerless readout, accommodating the needs of low rate full-waveform readout and channel-independent low threshold acquisition, respectively. This digitizer is a 8-channel VME board with a sampling rate of 500 MS/s and 14-bit resolution for each channel. A digitizer system consisting of 72 channels has been tested in situ of the PandaX-4T experiment. We report the system performance with real data.

Study Investigates Highly Deviated Shroud-Type Downhole Separators

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 201127, “An Experimental Investigation of Highly Deviated Shroud-Type Downhole Separators,” by Jorge Lopez, Eduardo Pereyra, SPE, and Cem Sarica, SPE, The University of Tulsa, prepared for the 2020 SPE Virtual Artificial Lift Conference and Exhibition—Americas, 10–12 November. The paper has not been peer reviewed. An experimental study of a shroud-type downhole separator for a pumped horizontal or deviated well is presented in this study. The separator is located at high deviation angles (i.e., 45° to 80° from vertical). The effects of the upstream gas and liquid flow rates are evaluated in the performance of the downhole separator. The findings complement previous studies on shroud-type downhole separators and demonstrate the operational capability of downhole separators under a range of conditions. Introduction Even though free gas and gas interference at the pump intake is a well-known problem, a limited understanding exists of the mechanisms that result in free gas in the pump. The lack of knowledge may lead to installation of ineffective downhole separator pump assemblies that, in some cases, may be detrimental to pumping-system performance. Among downhole-separator types, gravity-driven separators take advantage of the density difference between the gas and liquid to achieve separation. The shroud-type separator is an uncomplicated yet robust design and the most well-known and applied in the field. Current horizontal wells present challenging operational problems to down-hole separators and artificial-lift systems. The correct design of the downhole separator must consider proper handling of new challenges. A limited number of studies exist on the current challenges of downhole separators. A few of these studies considered the flow upstream of the separator as a variable, a limited amount studied deviated cases, and none focused on high deviation angles. Experimental Setup The complete paper details the experimental facility and instrumentation. The Tulsa University Horizontal Wells Artificial Lift Projects’ low-pressure outdoor downhole separator facility was used in this study. Four gas and eight liquid flow rates were used in the experimental matrix. The deviations tested were from 45° to 80°. Some of the tests at higher liquid flow rates were not completed because, as the deviation increases, the higher liquid flow rate causes the casing to overflow, making completion of these experiments impossible. The considered gas and liquid flow rates allow the analysis of gas/liquid ratios varying from 5 to 1,800 scf/bbl. Experimental Results The authors found that separation efficiency depends strongly on the liquid flow rate and deviation angle. At 45° and 60°, the separator seemed to perform efficiently for all tested conditions. At higher liquid flow rates, the separation efficiency showed a slight decrease, but, because of facility limitations, not enough evidence existed to confirm the tendency. Therefore, an additional two tests at 45° were performed to validate this trend. The tested conditions were 1,360 B/D with 7 Mscf/D and 11.28 Mscf/D. The two additional tests at 45° confirmed that efficiency decreases as liquid production increases. The authors observed two regions of operations of the separator for vertical cases and different deviation angles (the highest deviation tested was 45°). For their conditions, the separator performed in a high-efficiency region (efficiency between 80 and 100%) for low liquid flow rates. As the liquid production increased, the separator efficiency decreased. The authors denote this area of operation as a disrupted-efficiency region. The authors did not observe the separator to fail at 45° despite testing the separator at higher liquid flow rates.

Modeling Inner Proton Belt Variability at Energies 1 to 10 MeV Using BAS‐PRO

AbstractGeomagnetically trapped protons forming Earth's proton radiation belt pose a hazard to orbiting spacecraft. In particular, solar cell degradation is caused by non‐ionising collisions with protons at energies of several megaelectron volts (MeV), which can shorten mission lifespan. Dynamic enhancements in trapped proton flux following solar energetic particle events have been observed to last several months, and there is a strong need for physics‐based modeling to predict the impact on spacecraft. However, modeling proton belt variability at this energy is challenging because radial diffusion coefficients are not well constrained. We address this by using the British Antarctic Survey proton belt model BAS‐PRO to perform 3D simulations of the proton belt in the region 1.15 ≤ L ≤ 2 from 2014 to 2018. The model is driven by measurements from the Radiation Belt Storm Probes Ion Composition Experiment and Magnetic Electron Ion Spectrometer instruments carried by the Van Allen Probe satellites. To investigate sensitivity, simulations are repeated for three different sets of proton radial diffusion coefficients DLL taken from previous literature. Comparing the time evolution of each result, we find that solar cycle variability can drive up to a ∼75% increase in 7.5 MeV flux at L = 1.3 over four years due to the increased importance of collisional loss at low energies. We also show how the anisotropy of proton pitch angle distributions varies with L and energy, depending on DLL. However we find that phase space density can vary by three orders of magnitude at L = 1.4 and μ = 20 MeV/G due to uncertainty in DLL, highlighting the need to better constrain proton DLL at low energy.