Pressure System Research Articles

DELIGNIFICATION OF OIL PALM EMPTY FRUIT BUNCHES USING DEEP EUTECTIC SOLVENT IN PRESSURIZED REACTOR

Although lignin from oil palm empty fruit bunches (OPEFB) is a sustainable bioresource with several value-added uses, it is still difficult to extract lignin from lignocellulosic biomass economically. Lignin fractions are required for high-value applications and subsequently increase the feasibility of lignocellulosic biorefineries. Besides, the remaining cellulose could be further valorized into various chemical products. In this study, the delignification efficiency of OPEFB under inert and pressurized conditions has been studied as an effective pretreatment method for OPEFB. The optimal conditions of the high-pressure reactor to remove lignin from OPEFB were determined to be 80 °C at 30 bars with the presence of deep eutectic solvents (DES). It was identified that pressure affects the removal of lignin with the least amount of structural breakdown and the digestibility of cellulose. The effective removal of lignin from the OPEFB was established under mild conditions employing an inert nitrogen gas pressurized system. This work selectively removes lignin from the OPEFB of palm oil biomass plants using DES under mild extraction conditions. Solid residues were characterized by using FTIR, SEM, TGA, and XRD to investigate fractions under various reaction conditions, such as removal temperature, time, and pressure. The thermal stability of lignin was determined by TGA. In this study, 36.68% of lignin was removed under optimum pressure conditions at the lowest process temperature of 80 °C to determine how these factors influence the efficiency of lignin extraction in a high-pressure reactor.

Influence of Anatomical Spatial Architecture of Pinus devoniana on Pressure Gradients Inferred from Coupling Three-Dimensional CT Imaging and Numerical Flow Simulations

Conifer forests in Michoacán are facing climate change. Pinus devoniana Lindley, with natural distribution in the state, has shown certain adaptability, and knowing the influence of anatomy in the flow system is essential to delimit how it contributes to safety margins and water efficiency. For this, the pressure gradients in the cell lumens and their ramifications were analyzed by numerical simulations of flow throughout the real microstructure. Xylem were evaluated in radial, tangential and longitudinal directions. With the skeletonization of lumens and their constrictions, a branching system of interconnection between tracheids, ray cells, intercellular chambers, extensions, and blind pits were identified. In the simulation, the branched system bypasses the longitudinal fluid passage through the pores in membranes of pairs of pits to redirect it through the direct path branching, contributing to safety margins and water efficiency. Thus, resilience at low pressures because of the lower pressure drop in the extensions. The interface between the branching system and the cell lumens are sites of higher pressure gradient, more conducive to water-vapor formation or air leakage in the face of the lowest pressure system. The flow lines move along easy paths, regardless of the simulated flow direction. Deposits in the cell extensions were shown to be attached to the S3 layer of the cell wall, leaving the center of the duct free to flow. It is concluded that the spatial architecture of the xylem anatomy of Pinus dvoniana is a factor in the resilience at low pressures due to high water stress of the species.

Advanced progress of the relationship between renin-angiotensin-aldosterone system inhibitors and cancers.

Hypertension and cancers are the most common causes of death in humans, as well as common co-diseases among elderly population. Studies have shown that hypertension is associated with carcinogenesis. The renin-angiotensin-aldosterone system (RAAS) is a crucial regulatory system of blood pressure, fluid, and electrolyte homeostasis, which plays an essential role in the pathogenesis of hypertension, whose mechanism is relatively clear. Studies have indicated that RAAS also widely exists in cancer tissues of different systems, which can affect the risk of cancers by stimulating cancer angiogenesis, participating in cancer-related oxidative stress, and regulating cancer-related immunity. Therefore, inhibiting RAAS activity seems beneficial to decreasing the risk of cancers. As one of the most commonly used antihypertensive drugs, RAAS inhibitors have been widely used in clinical practice. However, the conclusions of clinical studies on the relationship between RAAS inhibitors and cancers are not entirely consistent, which has been widely concerned by clinicians. The latest findings suggest that while RAAS inhibitors may reduce the risk of digestive cancers, respiratory cancers, urological cancers, gynecological cancers, and skin cancers, ACEIs may increase the risk of lung cancer, endometrial cancer, basal cell carcinoma, and squamous cell carcinoma. This article comprehensively reviews animal experiments, clinical studies, and meta-analyses on the relationship between RAAS inhibitors and cancers, to provide references for related studies in the future.

Monte Carlo analysis of a 400N electric pump-fed engine powered by green propellants: Key trends towards an optimal subsystem design

This paper presents a Monte Carlo analysis for electric pump-fed systems. By leveraging the tool, it is possible to determine the optimal values of the main parameters involved in the design, operation, and selection of the pressurization system, enabling an agile system design. The study is conducted for a 400 N electric pump-fed engine powered by green propellants. This process aims at identifying the optimal operational conditions towards wet mass minimization and, eventually, assess whether a system featuring green propellants and electric pump feeding can represent an environmentally friendly alternative to conventional pressure-fed systems powered by MMH and NTO, known for their high toxicity and operational costs. The results obtained confirm similar performance to the state of the art, both in wet mass and delta-v capabilities, these last ones analyzed for different mission profiles involving orbit raising and RAAN phasing. Finally, based on the results obtained, the paper highlights the key trends towards an optimum design of electric pump-fed systems.

Comparing adaptations from blood flow restriction exercise training using regulated or unregulated pressure systems: A systematic review and meta-analysis.

No study has examined outcomes derived from blood flow restriction exercise training interventions using regulated compared with unregulated blood flow restriction pressure systems. Therefore, we used a systematic review and meta-analyses to compare the chronic adaptations to blood flow restriction exercise training achieved with regulated and unregulated blood flow restriction pressure systems. The electronic database search included using the tool EBSCOhost and other online database search engines. The search included Medline, SPORTDiscus, CINAHL, Embase and SpringerLink. Included studies utilised chronic blood flow restriction exercise training interventions greater than two weeks duration, where blood flow restriction was applied using a regulated or unregulated blood flow restriction pressure system, and where outcome measures such as muscle strength, muscle size or physical function were measured both pre- and post-training. Studies included in the meta-analyses used an equivalent non-blood flow restriction exercise comparison group. Eighty-one studies were included in the systematic review. Data showed that regulated (n = 47) and unregulated (n = 34) blood flow restriction pressure systems yield similar training adaptations for all outcome measures post-intervention. For muscle strength and muscle size, this was reaffirmed in the included meta-analyses. This review indicates that practitioners may achieve comparable training adaptations with blood flow restriction exercise training using either regulated or unregulated blood flow restriction pressure systems. Therefore, additional factors such as device quality, participant comfort and safety, cost and convenience are important factors to consider when deciding on appropriate equipment to use when prescribing blood flow restriction exercise training.

Transient hydraulic analysis of the water delivery pipeline in mountainous areas for cascade pressurized pump stations

ABSTRACT Aiming at the problem that cascade pressurized pump stations in mountainous areas are more prone to pump shutdown accidents compared to single-stage pressurized pump stations. Various pump shutdown accidents that may occur in the pressurized water supply system of the terrace pumping station were analyzed in a targeted manner. Additionally, it was also explored that in addition to water hammer protection measures, remote-control measures for water pumps based on PLC (Programmable Logic Controller) may be used to reduce the severity of accidents. A single-factor experimental method was used to numerically analyze various accident conditions of a simplified model of a three-stage series pressurized water delivery system consisting of a water intake pump station, a midway pump station, and a final-stage pump station, without water hammer protection devices. The impact of different control variables on the transient hydraulic calculations of pumping stations at all levels was evaluated. The results showed that optimizing the precedence of shutdowns, and the sequential shutdown times of each stage pump station could be assisted to some extent in water hammer protection by the PLC. This provides technical support and detailed optimization for the scientific control of cascade booster pumping stations in mountainous areas.

Implementing Component Degradations into a Modelica Model of an iPWR System to Develop Health Monitoring Techniques

The economic operation of small modular reactors will partly rely on managing and reducing inspection and maintenance activities while supporting new operational paradigms like load-following. Turbine control valves throttle the steam from the steam generator into the steam turbine while maintaining the pressure within the steam generator at a constant set point. Degradation of these components could impact the ability to manage electrical power production. Utilizing the Idaho National Laboratory Hybrid repository and the Oak Ridge National Laboratory TRANSFORM library developed for multiphysics simulations in Dymola/Modelica, an integral pressurized water reactor system was modeled based on the available specifications of the NuScale power module. The effects of various component degradation modes have been implemented into the model in order to simulate faulted plant data during both steady-state and load-following operations. The fault modes resemble different physical fault modes that may occur at an operating nuclear power plant; a leaking turbine control valve and a valve actuator failure due to loss of hydraulic pressure have been implemented. A neural network autoencoder is employed in conjunction with statistical analysis, namely, simple signal thresholding (SST) or sequential probability ratio testing (SPRT), to identify the presence of a fault. Fuzzy logic is additionally employed in a novel and promising manner to classify the state of the system based on the cumulative sum of the neural network residuals. SST and SPRT are both successfully validated using healthy data and proved capable of identifying both fault types; fuzzy logic identified the false positives and classified the faulted data correctly.

ICESat-2 Shows Sea Ice Leads Have Little Overall Effects on the Arctic Cloudiness in Cold Months

Abstract The effect of leads in Arctic sea ice on clouds is a potentially important climate feedback. We use observations of clouds and leads from the Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) to study the effects of leads on clouds. Both leads and clouds are strongly forced by synoptic weather conditions, with more clouds over both leads and sea ice at lower sea level pressure. Contrary to previous studies, we find that the overall lead effect on low-level cloud cover is −0.02, a weak cloud dissipating effect in cold months, after the synoptic forcing influence is removed. This is due to compensating contributions from the cloud dissipating effect by newly frozen leads under high pressure systems and the cloud enhancing effect by newly open leads under low pressure system. The lack of proper representation of lead effect on clouds in current climate models and reanalyses may impact their performance in winter months, such as in sea ice growth and Arctic cyclone development.

Sedimentary build-ups of pre-salt isolated carbonate platforms and formation of deep-water giant oil fields in Santos Basin, Brazil

In response to the problems of unclear distribution of deep-water pre-salt carbonate reservoirs and formation conditions of large oil fields in the Santos passive continental margin basin, based on comprehensive utilization of geological, seismic, and core data, and reconstruction of Early Cretaceous prototype basin and lithofacies paleogeography, it is proposed for the first time that the construction of pre-salt carbonate build-ups was controlled by two types of isolated platforms: inter-depression fault-uplift and intra-depression fault-high. The inter-depression fault-uplift isolated platforms are distributed on the present-day pre-salt uplifted zones between depressions, and are built on half- and fault-horst blocks that were inherited and developed in the early intra-continental and inter-continental rift stages. The late intra-continental rift coquinas of the ITP Formation and the early inter-continental rift microbial limestones of the BVE Formation are continuously constructed; intra-depression fault-high isolated platforms are distributed in the current pre-salt depression zones, built on the uplifted zones formed by volcanic rock build-ups in the early prototype stage of intra-continental rifts, and only the BVE microbial limestones are developed. Both types of limestones formed into mound-shoal bodies, that have the characteristics of large reservoir thickness and good physical properties. Based on the dissection of large pre-salt oil fields discovered in the Santos Basin, it has been found that both types of platforms could form large-scale combined structural-stratigraphic traps, surrounded by high-quality lacustrine and lagoon source rocks at the periphery, and efficiently sealed by thick high-quality evaporite rocks above, forming the optimal combination of source, reservoir and cap in the form of “lower generation, middle storage, and upper cap”, with a high degree of oil and gas enrichment. It has been found that the large oil fields are all bottom water massive oil fields with a unified pressure system, and they are all filled to the spill-point. The future exploration is recommended to focus on the inter-depression fault-uplift isolated platforms in the western uplift zone and the southern section of eastern uplift zones, as well as intra-depression fault-high isolated platforms in the central depression zone. The result not only provides an important basis for the advanced selection of potential play fairways, bidding of new blocks, and deployment of awarded exploration blocks in the Santos Basin, but also provides a reference for the global selection of deep-water exploration blocks in passive continental margin basins.

Efficient separation of carbon dioxide and methane in high-pressure and wet gas mixtures using Zr-MOF-808

The capture and separation of carbon dioxide (CO2) has been the focus of a plethora of research in order to mitigate its emissions and contribute to global development. Given that CO2 is commonly found in natural gas streams, there have been efforts to seek more efficient materials to separate gaseous mixtures such as CO2/CH4. However, there are only a few reports regarding adsorption processes within pressurized systems. In the offshore scenario, natural gas streams still exhibit high moisture content, necessitating a greater understanding of processes in moist systems. In this article, a metal-organic framework synthesis based on zirconium (MOF-808) was carried out through a conventional solvothermal method and autoclave for the adsorption of CO2 and CH4 under different temperatures (45–65 °C) and pressures up to 100 bar. Furthermore, the adsorption of humid CO2 was evaluated using thermal analyses. The MOF-808 synthesized in autoclave showed a high surface area (1502 m2/g), a high capacity for CO2 adsorption at 50 bar and 45 °C and had a low selectivity to capture CH4 molecules. It also exhibited a fine stability after five cycles of CO2 adsorption and desorption at 50 bar and 45 °C − as confirmed by structural post-adsorption analyses while maintaining its adsorption capacity and crystallinity. Furthermore, it can be observed that the adsorption capacity increased in a humid environment, and that the adsorbent remained stable after adsorption cycles in the presence of moisture. Finally, it was possible to confirm the occurrence of physisorption processes through nuclear magnetic resonance (NMR) analyses, thus validating the choice of mild temperatures for regeneration and contributing to the reduction of energy consumption in processing plants.

Use of a controlled negative pressure system for the treatment of periprosthetic breast complications

Background. One of the most common methods of breast reconstruction after mastectomy for malignant tumors is reconstruction using an endoprosthesis. However, this technique is associated with the risk of developing periprosthetic complications. The classic solution to this problem is to remove the endoprosthesis, achieve complete remission of the infectious process and repeat the cycle of reconstructive measures. In this work we present a new approach to the treatment of periprosthetic complications.Aim. To evaluate the effectiveness of the controlled negative pressure system (CNP) in the treatment of periprosthetic breast complications.Materials and methods. From 2019 to 2023, the study included 23 patients who underwent combined/complex treatment for breast cancer, including reconstructive plastic surgery with the installation of endoprostheses, and 1 patient who underwent aesthetic surgery was included. All patients experienced various complications after the reconstructive stage: protrusion of the endoprosthesis, ischemia of the flap and/or local inflammation. To relieve the complications that arose, treatment was carried out using a flushing system and a CNP.Results. The duration of therapy with the sequential installation of a flushing system followed by replacement with a СNP averaged 15 days. In 7 cases out of 24, it was not possible to preserve or reinstall endoprostheses due to thinning of the musculocutaneous flap, resistance of the microflora to the treatment, or relapse of the infectious process. In 17 cases, no complications were recorded after re-installation of endoprostheses for 2 years. As a result of the work, in most cases, within one hospitalization, it was possible to preserve the skin sheath, achieve complete regression of complications and perform repeated reconstructive interventionConclusion. In most cases, the use of a CNP allows you to save the bed for the full installation of a new endoprosthesis. To do this, a number of conditions must be met: absence of microflora growth; presence of granulation after treatment; full thickness and integrity of the musculocutaneous flap. Systemic treatment and a history of radiation therapy are not a contraindication to retaining endoprostheses.

Tracheal Anastomosis Leaks Across Suture Techniques and Tensions: A Biomechanical Ex Vivo Study.

Anastomotic leak after tracheal resection may occur while coughing in the early postoperative period. We investigated the varying effects of suturing technique, stretch, and tension on anastomotic leaks during simulated coughs. End-to-end anastomoses were performed using continuous or interrupted sutures on excised porcine larynges. Tracheas were secured to a pressurized system simulating cough forces, submerged in a water bath, and stretched to 1, 2, and 3 cm above baseline. Peak pressure, incomplete cough generation, and observed leakages were recorded. Parameters were analyzed using Analysis of Variance (ANOVA), multiple linear regression, and logistic regression modeling. Peak tension (B = -0.660, p < 0.001) and stretch lengths (B = -0.329, p = 0.006) were associated with variance in peak pressure (R2 = 0.77, F(3,294) = 8.182, p < 0.001). Incomplete coughs increased with higher peak tension (odds ratio [OR] = 15.627, p < 0.001) and stretching to 3 cm above baseline (OR = 4.335, p < 0.007). Similarly, leak occurrences, primarily from the posterior tracheal wall, increased with higher peak tension (OR = 1.787, p < 0.001) and stretching to 3 cm (OR = 2.613, p = 0.017). No significance was identified with suturing technique. Interrupted and continuous suture techniques do not differ in anastomotic strength during simulated coughs. Increased peak tracheal tension is associated with a weaker anastomosis, and tracheal stretch to 3 cm was associated with a weaker anastomosis. Our study supports the commonly held clinical belief that, to create a stronger anastomosis, tension should be minimized, and particular attention should be placed at the posterior tracheal wall during closure. N/A, Benchtop study Laryngoscope, 2024.

Understanding Chinese Bureaucracy: A Systematic Literature Review

An in-depth study of Chinese bureaucracy and its characteristics is an inseparable research topic in the field of social science in contemporary China. The historical lineage of Chinese bureaucracy shows a development from monarchical bureaucracy to cadre system. The Chinese bureaucratic organization is regarded as a cadre system with Chinese characteristics, characterized by hierarchy, centralization, political loyalty, meritocracy, and personification; the pressure system, administrative contract system, and project system are its operation mechanisms. China's bureaucracy has been transformed from a revolutionary group to a modern bureaucracy, and has now entered a period of adjustment and improvement. Chinese officials pay attention to moral cultivation and character building, and their selection and appointment emphasizes the principles of both virtue and talent, and puts virtue first. The structure of Chinese officials represents a hierarchical pyramid structure, and relationship is the core concept in understanding the interpersonal network of Chinese officials. The emphasis on informatization, transparency, specialization, and innovation is the focus and trend of future research on Chinese bureaucracy.

Reversible Raman D-band changes: A new probe into the pressure-induced collapse of carbon nanotubes

The control of the geometry of carbon nanotubes has a high potential for electro-optical technology developments. We report here the use of a new spectroscopic signature for the detection and characterization of the pressure induced radial buckling of single walled carbon nanotubes using Raman spectroscopy combined with sapphire anvil cell pressure systems. We follow the appearance of a defect-free Raman D-band contribution in bundled samples which is assigned to the pressure-induced radial buckling, as already shown on radially collapsed nanotubes at ambient pressure. On pressure release, this contribution to the D-band disappears, confirming the reversibility of the process. We applied this approach to the study of isolated tubes and followed the collapse transition of a 1.7 nm diameter tube, most likely identified as a (16,8) chirality, starting at 1 GPa and ending at 2 GPa. Our study further illustrates the potential of utilizing the D-band as a new spectroscopic probe to explore geometrical changes in carbon nanotubes.

Probability analysis method for well kick under uncertain formation pressure conditions

Drilling safety and efficiency are greatly impacted by kick, a major problem that is hard to diagnose, assess, and predict due to the complexity and high uncertainty of the deep water drilling formation pressure system. This article forms a pre-drilling well kick probability prediction method by establishing a calculation model for wellbore ECD and using the numerical solution method of Monte Carlo simulation algorithm. The bottomhole pressure uncertainty range gradually increases with well depth, according to simulation calculations, and the probability of a well kick decreases with drilling fluid volume. Theoretically, safe well control in deepwater drilling can be guided by the well-established kick diagnosis and formation pressure assessment techniques.

An algorithm to analyse long‐term tendencies of pressure systems over Europe

AbstractClimate change is associated with the modification of the polar jet stream, cyclone tracks and corresponding circulation patterns over midlatitudes. To apply these synoptic changes on regional climate, the changing sensitivity of a specific location to different pressure centre regions must be studied. An automated, objective circulation pattern detection method was developed to investigate the evolution of cyclonic and anticyclonic influence at any specific point within the European domain. The algorithm was used to assign each location to influencing low‐ or high‐pressure centres within the domain. Pressure centre displacements and the frequency redistribution among different centres were studied for each location. The 180‐year (January 1836–December 2015) mean sea level pressure dataset on the European domain with a 0.703° × 0.702° spatial and daily temporal resolution was obtained from NOAA 20th Century Reanalysis project. The presented method can apply the continental‐scale changes to specific locations. A significant increase of anticyclonic influence was found in southern and central Europe, in line with the northward displacement of Atlantic cyclones. Hundred and eighty year (180‐year) change of the number of days with anticyclonic versus cyclonic influence was found to be between +10% and 15% in the Mediterranean and +2% and 10% in most of Europe. The increasing anticyclonic influence in central Europe was strongest in the spring and the winter and was most attributable to the eastern European anticyclone. Results highlight the importance of research on the dynamical climate response of anticyclonic pressure systems.

Review of Literature on Determinants of Loan Repayment Performance in Microfinance Institutions

This article presents a comprehensive literature review on the determinants of loan repayment performance in microfinance institutions (MFIs). The review aims to enhance the understanding of borrower behaviour regarding loan repayment, focusing on socio-economic, institutional, and motivational factors. It synthesises findings from various studies, including the Indian Institute for Mother and Child (IIMC), a nonprofit Indian MFI, to identify critical determinants influencing borrowers' ability to repay loans. Factors such as income stability, education level, financial literacy, and family size are highlighted as significant socio-economic determinants. Loan-specific factors, including loan size, repayment period, and supervision, are also critical. Institutional practices like credit assessment techniques, loan structuring, and technological adoption are examined alongside social factors such as peer pressure, social cohesiveness, and community support systems. Additionally, the review explores borrowers' motivation for taking out additional loans, finding that the drive to reach the maximum loan level positively impacts repayment performance. Empirical evidence suggests that repayment rates increase as borrowers approach their loan limits. The article concludes with recommendations for MFIs to improve their operational strategies by addressing these determinants, thereby enhancing loan repayment rates and contributing to the sustainability and effectiveness of microfinance programs.

Analysis of the hydrogen safety of the NPP with a VVER-1200/V-491 reactor in a severe beyond design based accident

The results of a computational analysis of possible modes of combustion of a hydrogen-air mixture in containment during the evolution of a severe beyond design basis accident (BDBA) with the COCOSYS code are presented. The containment of the NPP with a VVER-1200/V-491 reactor was selected as the object of study. BDBA with loss of coolant occurs due to a break of the injection pipeline of the pressurizer system (LOCA DN179) and the simultaneous failure of all active channels of the emergency core cooling system (ECCS). The calculated parameters of the thermodynamic state (pressure and temperature) of the gas mixture are given, and the values of the concentration distribution of hydrogen inside the containment are presented. After calculating the hydrogen distribution and mixing in all compartments of the containment, an evaluation was made of the flammability of the mixture and the potential for self-ignition in the containment by using a three-component Shapiro-Moffette diagram. It was concluded that in BDBA (LOCA DN179 with failure of active ECCS) detonation of the hydrogen-containing mixture is excluded, and deflagration is possible only in the emergency compartment of steam generators with a pipeline break. Thus, the hydrogen risk mitigation has been achieved in accordance with the standards established by the Belarusian regulator, provided that the localization safety systems are operational in the event of hydrogen deflagration. And the efficiency of the hydrogen removal system from the containment using catalytic recombination is considered sufficient for the considered BDBA.

Associations between static foot posture, dynamic in-shoe plantar foot forces and knee pain in people with medial knee osteoarthritis: A cross-sectional exploratory study

ObjectiveTo investigate relationships between static foot posture, dynamic plantar foot forces and knee pain in people with medial knee osteoarthritis (OA). DesignData from 164 participants with symptomatic, moderate to severe radiographic medial knee OA were analysed. Knee pain was self-reported using a numerical rating scale (NRS; scores 0-10; higher scores worse) and the Knee Injury and Osteoarthritis Outcome Score pain subscale (KOOS; scores 0-100; lower scores worse). Static foot posture was assessed using clinical tests (foot posture index, foot mobility magnitude, navicular drop). Dynamic plantar foot forces (lateral, medial, whole foot, medial-lateral ratio, arch index) were measured using an in-shoe plantar pressure system while walking. Relationships between foot posture and plantar forces (independent variables) and pain (dependent variables) were evaluated using linear regression models, unadjusted and adjusted for sex, walking speed, KL grade, shoe category, and body mass (for dynamic plantar foot forces). ResultsNo measure of static foot posture was associated with any knee pain measure. Higher medial-lateral foot force ratio at midstance, and a higher arch index during overall stance, were weakly associated with higher knee pain on the NRS (regression coefficient=0.69, 95% confidence interval (CI) 0.09 to 1.28) and KOOS (coefficient=3.03, 95% CI 0.71 to 5.35) pain scales, respectively. ConclusionDynamic plantar foot forces, but not static foot posture, were associated with knee pain in people with medial knee OA. However, the amount of pain explained by increases in plantar foot force was small, thus these associations are unlikely to be clinically meaningful.

Estimation of mean electron energy in helium surface ionization waves on dielectric substrates

The determination of basic plasma parameters in atmospheric pressure discharges is critical to advancing their use in applications. Atmospheric pressure plasma jets have found use in the fields of medicine, agriculture, material modification and others. Atmospheric pressure plasma jets often generate plasma surface ionization waves (SIW) which interact with and propagate over surfaces. Electrical diagnostics are challenging in SIW due to high collision frequencies and small scale of the plasma discharge. This work employs a passive optical emission line ratio technique to estimate the mean electron energy in SIW over planar dielectric substrates. The method uses an intensity ratio of two helium triplet lines: He( 33S ) at 706.5 nm and He( 33D ) at 587.56 nm. A collisional-radiative model is used to correlate line ratio to mean electron energy and determine dependencies on electron density and He/air gas mixture. Mean electron energies ranging from 3–8 eV are determined in He/air mixtures and are found to remain constant as the surface wave propagates radially. This work provides a 2D, time-resolved, mean electron energy diagnostic for surface ionization wave propagation and validation of numerical modeling in atmospheric pressure systems with spatially varying He/air gas mixtures. The model in question is designed for use with any He line ratio in the n = 3 excitation level.