Outer Chamber Research Articles

INTRATEST TRACE ELEMENT VARIABILITY IN POLAR AND SUBPOLAR PLANKTIC FORAMINIFERA: INSIGHTS INTO VITAL EFFECTS, ONTOGENY, AND BIOMINERALIZATION PROCESSES

ABSTRACT To use planktic foraminiferal tests as paleoproxy substrates, it is necessary to delineate environmental versus biological controls on trace element incorporation. Here we utilize laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to explore interspecies, chamber-to-chamber, and intratest trace element (i.e., Mg, Na, Sr, Ba, Mn, Zn) variability in thickly-calcified specimens of the polar and subpolar planktic foraminifera Neogloboquadrina incompta, N. pachyderma, and Turborotalita quinqueloba collected from plankton tows in the Northern California Current. Among the study taxa, test Mg/Ca, Na/Ca, and Sr/Ca are likely dominantly controlled by depth habitat. The neogloboquadrinids record higher Ba/Ca and Mn/Ca and also show positive covariance between these elements, possibly due to calcifying in an oxygen-depleted marine snow microhabitat. Trace elements are found to be more enriched in the lamellar calcite than the outer chamber wall dominated by gametogenic crust. The data presented herein provide insight into potential vital effects, paleoproxy considerations, ontogeny, and biomineralization processes.

PGRMC2 and HLA-G regulate immune homeostasis in a microphysiological model of human maternal-fetal membrane interface

Chorion trophoblasts (CTCs) and immune cell-enriched decidua (DECs) comprise the maternal-fetal membrane interface called the chorio-decidual interface (CDi) which constantly gets exposed to maternal stressors without leading to labor activation. This study explored how CTCs act as a barrier at CDi. The roles of human leukocyte antigen (HLA)-G and progesterone receptor membrane component 2 (PGRMC2) in mediating immune homeostasis were also investigated. The CDi was recreated in a two-chamber microfluidic device (CDi-on-chip) with an outer chamber of primary DECs and immune cell line-derived innate immune cells and an inner chamber of wild-type or PGRMC2 or HLA-G knockout immortalized CTCs. To mimic maternal insults, DECs were treated with lipopolysaccharide, poly(I:C), or oxidative stress inducer cigarette smoke extract. Expression levels of inflammation and immunity genes via targeted RNA sequencing, production of soluble mediators, and immune cell migration into CTCs were determined. In CDi-on-chip, decidua and immune cells became inflammatory in response to insults while CTCs were refractory, highlighting their barrier function. HLA-G and PGRMC2 are found to be vital to immune homeostasis at the CDi, with PGRMC2 serving as an upstream regulator of inflammation, HLA-G expression, and mesenchymal-epithelial transition, and HLA-G serving as a frontline immunomodulatory molecule, thus preventing fetal membrane compromise.

Implementation of Heat Exchanger Palm Fruit Cooker for Optimum Production of Palm Oil

Palm oil as a product of palm fruit, is currently in high demand in Nigeria. The demand for the product is far higher than the supply. With this increase in demand, the price of the product is significantly in the increase. There is need to develop ways of efficiently producing the product from the available palm fruit. The heat exchanger palm fruit cooker designed has two chambers; the inner and outer chamber, the outer is for water content and the inner for the palm fruit to undergo the cooking process. The component has heat energy requirement of 46kJ with use of 45kg of fuel (firewood) to cook the palm fruit. It is made up of mild steel consisting of 6mm for the outer chamber and 2mm for the inner chamber for easy conduction of heat from the boiled water in the outer chamber. The study concludes by showing the economic benefits of constructing the cooker which produces more oil than the normal cooking pots in use.

Thermal and Structural Modelling of Laboratory-Scale Pyrolysis Reactor

This paper presents the steady-state thermal and static structural modelling of a laboratory-scale pyrolysis reactor for the thermal degradation of biomass wastes. A laboratory-scale pyrolysis reactor of volume 9.203 x 10-3m3 was developed to pyrolyse Palm Kernel Shell (PKS) and Palm Fruit Bunch (PFB) at varying temperatures of 350oC, 400oC, 450oC, 500oC, and 550oC. The reactor chamber was simulated for static-steady thermal and static structural analysis to determine the temperature distribution and thermal stresses induced in it. The model was developed using SolidWorks software, and a Computational Fluid Dynamics (CFD) simulation was carried out using ANSYS Workbench 19. A total number of 2,459 elements was generated composed of 8630 nodes using Hexahedra dominant meshing method. It was observed from the simulation result that the temperature distribution inside and outside the reactor chamber were 454.29oC and 550oC respectively. The maximum heat flux of 8.3466e+005 W/m² occurred at the inner chamber of the reactor due to the high concentration of the biomass waste and devolatization reaction, and the maximum equivalent (von-Mises) stresses the material can withstand at higher temperature is 1.6674e+009 Pa without rupture. It was found out from the simulation result that at a maximum temperature of 550oC, the equivalent (von Mises) stresses induced at the outer and inner chamber is 1.8585e+008 Pa, which is far lower than the maximum stress the material can withstand without rupture. Thus, the reactor is safe to operate at a temperature higher than 550oC without failure.

A Volume-Adjustable Artificial Womb for Extremely Preterm Infants.

More than 13 million children are born preterm annually. Prematurity-related mortality accounts for 0.9 million deaths worldwide. The majority of those affected are Extremely Preterm Infants (gestational age less than 28weeks). Immaturity causes organ failure and specific morbidities like germinal matrix hemorrhage, bronchopulmonary dysplasia, and necrotizing enterocolitis. Artificial womb and placenta technologies address these issues. As a bridge-to-life technology, they provide a liquid environment to allow organ maturation under more physiological conditions. The proposed artificial womb can adapt to fetal growth. Volume adjustment is achieved by removing fluid from the interspace between an inner and outer chamber. Results of the in vitro tests showed a temperature constancy of 36.8°C ± 0.3°C without pressure loss over 7days. The volume of the inner sac was variable between 3.6 and 7.0L. We designed a filtration and disinfection system for this particular purpose. This system has proven strong disinfection capabilities, effective filtering of metabolic waste, and the ability to avoid phospholipid washout. The presented artificial womb has sufficient volume variability to adapt to the physiologic growth of an extremely preterm neonate over a 4-week period. We regard this as an important step in the development of this bridge-to-life technology.

A porcine model of thoracic aortic aneurysms created with a retrievable drug infusion stent graft mirrors human aneurysm pathophysiology

ObjectiveAneurysm pathophysiology remains poorly understood, in part from the disparity of murine models with human physiology and the requirement for invasive aortic exposure to apply agents used to create aneurysm models. A retrievable drug infusion stent graft (RDIS) was developed to isolate the aortic wall intraluminally for drug exposure. We hypothesized that an RDIS could deliver aneurysm-promoting enzymes to create a porcine model of thoracic aneurysms without major surgical exposure. MethodsRetrievable nitinol stent graft frames were designed with an isolated drug delivery chamber, covered with polytetrafluoroethylene, and connected to a delivery wire with a drug infusion catheter installed to the outer chamber. Institutional Animal Care and Use Committee-approved Yorkshire pigs (n = 5) underwent percutaneous access of the femoral artery, baseline aortogram and stent placement in the thoracic aorta followed by 30-minute exposure to a cocktail of elastase, collagenase, and trypsin. After aspiration of excess drug, stent retrieval, and femoral artery repair, animals were recovered, with angiograms at 1 and 4 weeks followed by explant. Histological analysis, in situ zymography, and multiplex cytokine assays were performed. ResultsThe RDIS isolated a segment of anterior aorta angiographically, while the center lumen preserved distal perfusion during drug treatment (baseline femoral mean arterial pressure, 70 ± 14 mm Hg; after RDIS, 75 ± 12; P = .55). Endovascular induction of thoracic aneurysms did not require prior mechanical injury and animals revealed no evidence of toxicity. Within 1 week, significant aneurysmal growth was observed in all five animals (1.4 ± 0.1 cm baseline to 2.9 ± 0.7 cm; P = .002) and only within the treated region of the aorta. Aneurysms persisted out to 4 weeks. Aneurysm histology demonstrated loss of elastin and collagen that was otherwise preserved in untreated aorta. Proinflammatory cytokines and increased matrix metalloproteinase activity were increased significantly within the aneurysm. ConclusionsAn RDIS achieves isolated drug delivery while preserving distal perfusion to achieve an endovascular porcine model of thoracic aneurysms without major surgery. This model may have value for surgical training, device testing, and to better understand aneurysm pathogenesis. Most important, although the RDIS was used to simulate aortic pathology, this tool offers intriguing horizons for focused therapeutic drug delivery directly to aneurysms and, more broadly, focused locoregional drug delivery to vessels and vascular beds.

Unsteady conjugate heat transfer simulation of wall heat loads for rotating detonation combustor

Rotating detonation engines (RDEs) are the most promising pressure-gain combustion devices, but their long-duration operations are hindered by the harsh thermal environment inside the chamber. This study analyzes the instantaneous and average heat loads on chamber walls of RDEs based on the newly developed unsteady conjugate heat transfer (CHT) OpenFOAM solver named multiRegionBYRFoam. To enhance accuracy in predicting heat transfer characteristics compared to decoupled simulations focusing solely on fluid or solid behavior, three-dimensional CHT simulations are conducted for a premixed H2/air annular RDE coupling the detonation simulation with heat conduction in both inner and outer chamber walls. The transient time evolutions of wall heat flux in RDEs are numerically captured for the first time and agree well with experiments. The calculated peak wall heat flux is 1.98 MW/m2 at the inner wall and 2.63 MW/m2 at the outer wall when a single detonation wave propagates with a mass flow rate of 0.227 kg/s. By investigating the influence of inlet flow conditions and detonation modes, valuable guidelines on designing efficient thermal management systems for RDEs are obtained: larger mass flow rates and multi-wave modes result in higher average wall heat flux; the heat flux at the outer wall exceeds that at the inner wall while both walls require effective cooling for gas turbine engines with a rotating detonation combustor. Furthermore, a novel heat transfer model for RDEs is proposed based on a thermal operation map depicting total heat transfer rates to describe the nonlinear impact of mass flow rate and number of detonation waves, which can be employed to predict total wall heat loads under specific operation conditions of RDE.

백제지역 무덤 용어에 대한 논의

This study started with the problem consciousness that the concept of each terminology should be clearly established prior to research on Baekje tombs. Therefore, the concept of tomb (墳墓) and mounded tomb (古墳) were examined along with the problem of Bungumyo (墳丘墓), and a new classification and name were presented based on the research of Baekje tombs.
 First, the tomb was used as a collective term for all tombs, regardless of temporality and hierarchy, and the mounded tomb was named only for some tombs what hierarchy is clearly revealed after the middle of 3rd century. In addition, the tomb that appear from the middle of the 3rd century but are relatively low hierarchy was defined as Myo (墓), and tomb with high hierarchy was defined as Bun (墳). On the other hand, it was defined as Chong (塚) only in some tomb with large external facility that was stoned, reflecting their political stature. On the other hand, it was judged that the Bungumyo is difficult to use in Korean archaeology because there is a big difference in concepts used among researchers and regions, and also a difference from the concept used in Japanese archaeology.
 Next, Baekje tombs are classified based on the material, shape, and structure of the burial facility. First, it was classified into wooden, stone, brick, jar according to constructive material. Next, among coffin, outer coffin, and chamber, which are the shape of the burial facility, the outer coffin and chamber were clearly distinguished according to the existence of access facility, In addition, vertical style, corridor style, and open-enterance style were classified according to the structure of the burial facility.
 Lastly, the tombs with high hierarchy that appeared after the middle of the 3rd century, which is defined the mounded tombs (古墳) and high mounded tombs (古塚) were classified into wooden coffin mounded tombs (木棺墳), wooden outer coffin mounded tombs (木槨 墳), the stone lined mounded tombs with vertical style (竪穴式 石槨墳), the stone chamber mounded tomb with corrider style (橫口式 石室墳), the stone chamber mounded tomb with open-entrance style (橫穴式 石室墳), brick chamber mounded tomb (塼築墳). stone mounded tomb (積石塚), The tombs with low hierarchy were classified wooden coffin tomb (木棺墓), stone lined tomb (石槨墓), jar coffin tomb (甕棺墓), stone tomb (積石墓). However, tombs that have already been accepted universly, such as pit tomb (土壙墓), open-entrance tomb(橫穴墓), crematory tomb (火葬墓), pit tomb with the ditch (周構土壙墓) were named as they are used. In addition, as considering regional characteristics in the the Yeongsan river basin, the wooden coffins mounded tombs (木棺古墳) and the jar coffins mounded tombs (甕棺古墳) were named, and the tombs similar to the keyhole-shaped tombs of Japan should be named as the keyhole-shaped style mouned tombs (前方後圓形古墳).

A Variable Stiffness Soft Gripper Based on Rotational Layer Jamming.

This article presents the design and fabrication of a variable stiffness soft gripper based on layer jamming. Traditional layer jamming units have some limitations, such as complicated multistep fabrication, difficulties in system integration, and diminishing in stiffen effect. In this article, a variable stiffness soft gripper is proposed based on the rotational jamming layers to reduce the slippery phenomenon between layers. To fabricate the proposed complex design, a two-step fabrication method is presented. First, multimaterial 3D printing is applied to directly print out the soft finger body with jamming layers. Second, mold casting is used to fabricate the outer vacuum chamber. The proposed gripper contains a main framework and three identical variable stiffness soft fingers. To demonstrate the effectiveness of the design, the soft gripper is mounted on a robotic arm to test its ability of grasping heavy objects while following complex grasping trajectory. The gripper can successfully grasp an object up to 360 g. Grasping robustness of the proposed gripper can be guaranteed when the robotic arm is moving at acceleration up to 7 m/s2. The results prove that the proposed design of the soft gripper can improve the grippers grasping robustness during high-speed movement.

Bacterial exclusion and wound healing potential of horizontal platelet-rich fibrin (H-PRF) membranes when compared to 2 commercially available collagen membranes.

The aim of the present study was to compare the barrier function during bacterial invasion and wound healing properties of 3 commonly used membranes including horizontal platelet-rich fibrin (H-PRF) against two commercially available resorbable collagen membranes. H-PRF membranes were prepared by collecting venous blood from 3 healthy volunteers using a 700g for 8-min centrifugation protocol followed by compression into membranes. To evaluate their barrier function, 3 groups (H-PRF membrane, collagen membrane A (Bio-Gide, Geistlich), collagen membrane B (Megreen, Shanxi Ruisheng Biotechnology Co) were placed between an inner chamber and outer chamber and inoculated with S. aureus. At 2h, 24h, and 48h post-inoculation, cultures from the inner and outer chambers were assessed for bacterial CFUs. Then, scanning electron microscope (SEM) was utilized to visualized the morphological destruction by bacteria of the inner and outer surfaces of the membranes. To assess the wound healing properties of each membrane, leachates from each group were applied to human gingival fibroblasts (HGF) and a scratch assay was performed at 24h and 48h. S. aureus showed a minimal bacterial attachment or invasion rate through either collagen membranes at 2h post-inoculation, yet over time demonstrated rapid degradation, especially on the rougher surface. While PRF demonstrated higher number of CFUs after 2h, no significant penetration/degradation of the H-PRF membranes was observed at 24h and 48h in the H-PRF group. Both collagen membranes demonstrated significant morphological changes 48h post-bacterial innoculation, while minimal obvious morphological changes were observed in the H-PRF group. The wound healing assay also demonstrated significantly better wound closure rates in the H-PRF group. H-PRF membranes exhibited better barrier function towards S. aureus over 2days of innoculation and better wound healing ability when compared to two commercially available collagen membranes. This study provides further evidence for the application of H-PRF membranes during guided bone regeneration by minimizing bacterial invasion. Furthermore, H-PRF membranes have significantly better ability to promote wound healing.

CARD8: A Gas-Exchange-Area-Adjustable Oxygenator for Extremely Preterm Infants

Purpose: Worldwide, 600,000 infants are born extremely premature (EP) each year. Supporting the immature lungs of these smallest patients today using mechanical ventilation can cause severe lung damage. Extracorporeal gas exchange (ECMO) used as an “artificial placenta” is expected to provide an alternative treatment to allow full maturation of the lungs. The long-term application for patients doubling their weight every six weeks, requires a new type of “growing” oxygenator. Materials & Methods: We developed a gas-exchange-area-adjustable oxygenator that allows to operate at two different size stages without changing the device nor increasing the flow resistance. Our prototype houses two concentric oxygenator-chambers of equal gas exchange area. When the outer chamber is in operation, the oxygenator provides the required gas exchange area for a 24-week infant. Single-chamber operation allows adaequate gas exchange of volume flows from 50 - 125 ml/min while double-chamber operation then covers flow-demands from 125 - 200 ml/min. Both operational modes in combination can cover the needs of infants from 24 to 28 weeks postmenstrual age. We performed gas-transfer measurements of the prototype in accordance with ISO 7199 and FDA guideline. Results: Gas transport performance for the outer cylinder operating at Vblood = 50 mL/min (24 week premature infant) is VO2 = 1.8 mL/min (= 36 mLO2/Lblood flow). At a flow of Vblood = 125 mL/min the second chamber was switched on and the gas transfer performance increased by 50.1 %. Both chambers have a gas transport performance of VO2 = 4.19 ml/min at Vblood = 150 ml/min (= 28 mLO2/Lblood flow) Conclusion: It could be demonstrated that the gas-transfer of the newly proposed volume-adjustable oxygenator design is sufficient to increase the gas transfer performance while increasing the blood volume flow. We consider this a first milestone for oxygenation of growing EP infants without the need to replace the extracorporeal circuit, avoiding the associated risks.

A pilot study for development of a pulmonary function test induction jacket to automate effort in performing the forced vital capacity manoeuvre

The pulmonary function test (PFT) induction jacket was invented to make the process of performing the forced vital capacity (FVC) manoeuvre with a computerized spirometer effortless and productive for both the patient and the medical practitioner. The jacket is composed of three layers of PVC material sealed together to form a single jacket with two chambers. The inner chamber is formed between the inner layer and the middle layer, in which cold water at a temperature of 10 °C is circulated using a connected water unit when triggered. Similarly, the outer chamber is formed between the middle layer and the outer layer, in which air is pressurized using a connected air unit. Thirty volunteers performed the FVC manoeuvre with and without wearing the jacket. There was no difference between the results in spirometry parameters in the participants without a jacket and those with a jacket. However, use of the jacket significantly reduced the number of trials the participants had to undergo to perform spirometry. The jacket automated the FVC manoeuvre by triggering a physiological inspiratory gasp using cold water and circumscribing pressurized air for expiration. Additionally, subsequent advancements in the jacket have been suggested.

Automated, high temporal resolution mechanics measurements during incubation of contractile tissues

Muscle tissue mechanics and contractility measurements have a great advantage over cultured cell level experiments as their mechanical and contractile properties are much closer to in vivo tissue properties. However, tissue level experiments cannot be combined with incubation with the same time resolution and consistency as cell culture studies. Here we present a system in which contractile tissues can be incubated for days while intermittently being tested for their mechanical and contractile properties. A two-chamber system was developed with control of temperature in the outer chamber and CO2 and humidity control in the inner, sterile chamber. Incubation medium, to which biologically active components may be added, is reused after each mechanics test to preserve both added and released components. Mechanics and contractility are measured in a different medium to which, through a high accuracy syringe pump, up to 6 different agonists in a 100-fold dose range can be added. The whole system can be operated through fully automated protocols from a personal computer. Testing data shows accurate maintenance of temperature, CO2 and relative humidity at pre-set levels. Equine trachealis smooth muscle tissues tested in the system showed no signs of infection after 72 h with incubation medium replacement every 24 h. Methacholine dosing and electrical field stimulation every 4 h showed consistent responses. In conclusion, the developed system is a great improvement on the manual incubation techniques being used thus far, improving on time resolution, repeatability and robustness, while reducing contamination risk and tissue damage from repeated handling.

Fluidic Hardware Strategies for Powering Combined Negative‐ and Positive‐Pressure Artificial Muscles

The performance of pneumatic artificial muscles (PAMs) depends in large part on the fluidic hardware used to add and remove air from their volume. A complete fluidic system usually contains tubing, pneumatic regulators, pneumatic valves, and pneumatic pumps. However, for most PAMs, the performance of the actuator depends on how fast air can be taken into and out of the chamber as the presence of a single chamber entails relatively simple fluidic strategies. In the previous work, a type of PAM called hyperbaric vacuum artificial muscles (Hyper‐VAM) which utilizes a negative‐pressure inner chamber placed inside a positive‐pressure outer chamber has been introduced. Herein, advanced fluidic strategies for this actuator by making use of the pressure equilibrium between these two chambers as the building block for advanced fluidic strategies are investigated. It is shown that it is possible to operate the Hyper‐VAM in sub‐ and hyper‐atmospheric conditions during closed‐loop actuation and to use the atmosphere as a natural pump starting from a sub‐ or hyper‐atmospheric equilibrium. Herein, these strategies are demonstrated and compared to basic fluidic strategies and fluidic systems capable of implementing cyclic actuation are demonstrated using these strategies.

A Microphysiological Device to Model the Choriodecidual Interface Immune Status during Pregnancy.

During human pregnancy the chorion (fetal) lines decidua (maternal) creating the feto-maternal interface. Despite their proximity, resident decidual immune cells remain quiescent during gestation and do not invade the chorion. Infection and infiltration of activated immune cells toward the chorion are often associated with preterm birth. However, the mechanisms that maintain choriodecidual immune homeostasis or compromise immune barrier functions remain unclear. To understand these processes, a two-chamber microphysiological system (MPS) was created to model the human choriodecidual immune interface under normal and infectious conditions invitro. This MPS has outer (fetal chorion trophoblast cells) and inner chambers (maternal decidual + CD45+ cells [70:30 ratio]) connected by microchannels. Decidual cells were treated with LPS to mimic maternal infection, followed by immunostaining for HLA-DR and HLA-G, immune panel screening by imaging cytometry by time of flight, and immune regulatory factors IL-8 and IL-10, soluble HLA-G, and progesterone (ELISA). LPS induced a proinflammatory phenotype in the decidua characterized by a decrease in HLA-DR and an increase in IL-8 compared with controls. LPS treatment increased the influx of immune cells into the chorion, indicative of chorionitis. Cytometry by time offlight characterized immune cells in both chambers as active NK cells and neutrophils, with a decrease in the abundance of nonproinflammatory cytokine-producing NK cells and T cells. Conversely, chorion cells increased progesterone and soluble HLA-G production while maintaining HLA-G expression. These results highlight the utility of MPS to model choriodecidual immune cell infiltration and determine the complex maternal-fetal crosstalk to regulate immune balance during infection.

Experimental study of storage system of a solar water heater equipped with an innovative absorber spherical double-walled tank immersed in a phase change material

In commercial active solar water heaters, during the thermal charge process, water is continuously circulated between the collector and the tank. The water is heated in the collector and then stored in a tank whose surface is insulated. The shape of the collector and tank is an important factor in the development of solar thermal storage systems. In this study, the collector and tank are made spherical, fixed, symmetrical and capable of tracking the sun regardless of the placement angle. Also, in an innovative idea, the solar thermal storage tank is designed as a double-walled spherical tank. The water heated by the collector is stored in the inner chamber of the double-walled tank, and this chamber is surrounded by a Phase Change Material (PCM) by embedding the PCM in the outer chamber of the tank. Therefore, the PCM has the two roles of thermal insulation and thermal storage. As well as removing the thermal insulation, it is also possible to absorb solar energy on the external surface of the tank. To reduce heat losses, the tank is surrounded by a transparent glass cover in a greenhouse space. The maximum storage temperature and the maximum thermal efficiency in the thermal charge process are 80.3 °C and 74 %, respectively, which occur at a flow rate of 1.75 l/min. In this situation, the warm water needed by 8.43 people is produced. The greatest thermal stratification occurs at a flow rate of 1.25 l/min, and it weakens by raising the flow rate.

The effect of impurity seeding into the closed divertor on plasma detachment in the HL-2A tokamak

Recent progress towards an increased understanding of detached divertor physics has been made with the highly closed divertor geometry in HL-2A. Non-intrinsic impurities were injected into the outer divertor chamber, and increased divertor neutral pressure and enhanced volumetric energy loss in the divertor were observed. Meanwhile the neutral pressure in the main chamber decreased slightly, and neutral compression between the divertor and main chamber increased greatly. This led to divertor detachment with a low upstream plasma line-averaged electron density (). In the H-mode, slight degradation of the core confinement, characterized by a decrease in plasma stored energy and pedestal pressure and an increase in edge-localized mode frequency, was observed, but the H-mode was still sustained well with H98 > 1. Pedestal density fluctuation was increased during detachment, implying that the enhanced pedestal transport might be responsible for the degradation. During the divertor detachment phase, the impurities were well controlled in the divertor without strong radiation near the X-point region, and the main plasma density did not increase but decreased slightly; this could be a benefit of the highly closed divertor geometry. The experimental results suggest that a closed divertor geometry has the advantages of volumetric energy loss, gas pumping and impurity control in the divertor without significant effects on the plasma confinement, thus giving a wider operating window for divertor detachment.

Experimental tests of submersible vane pumps

The technical task of creating new designs of submersible vane pumps is to maintain stable operating parameters and increase the productivity of the pumping station with periodic regeneration and sediment removal. The pumping well station contains an outer chamber and an inner chamber, in which a pumping unit is installed, and pipelines are connected to the lower and upper pools. In the structure under study, the upper parts of the outer and inner chambers are equipped with a sealed head, and the lower part of the outer chamber is equipped with a stopper. The side surface of the inner chamber is made of elastically deformable material. An elastic pipeline with an ejector at its end with curvilinear helical grooves on the inner surface of the nozzle part of the ejector is connected to the pipeline connected to the tailpipe, and water level meters are installed in the outer chamber. The technique of balance testing of new designs of submersible vane pumps was applied because the existing technology is insufficient for correct balance tests. Research methods involve the design of the impeller, which is rigidly mounted on the shaft. The methodology has been adjusted to apply to multistage pumps with different types of impellers. In the energy balance of this pump, the power losses due to friction in the individual axial support of the impeller are additionally determined. Experimental work was carried out, resulting in measurements of the hydrodynamic moment acting on the guide vane grate. Experimental work was carried out on a vertical stand with new pump impellers ETsV-10-120-40 and with a service life of 1 year. Parametric tests made it possible to determine the change in the external parameters of the pump depending on changes in its operating conditions and network characteristics.

Flexibility Analysis and Experimental Design of Dual-Chamber Bellows Isolator for Low-Frequency Damping Performance

To achieve an effective and versatile solution for reducing vibrations and reducing maintenance costs, the dual-chamber flexible bellows isolator (D-CFBI) of rubber material is designed. The outer chamber of D-CFBI is used as an actuator to change its own variable stiffness and control the feedback force by filling negative pressure gas. The inner chamber is used as a rubber air spring to work as the main vibration isolation element. Under different loads and sinusoidal excitation forces, the damping characteristics and damping effects of the D-CFBI with different stiffness are investigated. By exciting the isolator, the frequency sweep experiment is carried out, the dynamic flexibility in the initial state is studied, and a preload of the D-CFBI is given to change the stiffness of the D-CFBI, and the changing trend between restoring force and amplitude and frequency is found out. Conclusions can be summarized that increasing the preload of the D-CFBI leads to increased stiffness and better damping effect. For compression amounts of 20% and frequencies higher than 7Hz or amplitudes lower than 2mm, the damping effect is also better. Consequently, this D-CFBI offers satisfactory damping and increased safety at low amplitudes and frequencies. To achieve optimal damping, it is recommended to adjust the stiffness of the driver.

Adapting an organ-on-chip device to study the effect of fetal sex and maternal race/ethnicity on preterm birth related intraamniotic inflammation leading to fetal neuroinflammation.

Fetal neuroinflammation has been linked to preterm birth-related intraamniotic infection and inflammation; However, the contribution of fetal sex and maternal race/ethnicity is unknown. To determine if fetal sex and maternal race/ethnicity influence neuroinflammation, an organ-on-chip (OOC) model were established under normal or pathologic conditions utilizing amniotic fluid. OOC is composed of two-cell culture chambers connected by Type IV collagen-coated microchannels. Human fetal astroglia (SVGp12) and microglia (HMC3) were co-cultured at an 80:20 ratio in the inner chamber. The outer chamber contained amniotic fluid (AF) from male and female fetuses of White Hispanic (WH) and African-American (AA) pregnant women with or without lipopolysaccharide (LPS-100ng/ml) and incubated for 48h. Glial migration (brightfield microscopy), activation (Immunocytochemistry), and cytokine production (Luminex assays) were quantified and compared (N=4 for each category of sex and race/ethnicity). In a pooled analysis, AF+LPS did not induce glial activation or inflammatory changes compared to AF alone. When stratified by sex, male AF+LPS promoted significant glial activation (high CD11b:p<0.05; low Iba1:p<0.01) compared to male AF without LPS; however, this was not associated with changes in pro-inflammatory cytokines. When stratified by race/ethnicity, AF+LPS induced glial activation in both groups, but a differential increase in pro-inflammatory cytokines was seen between WH and AA AF (WH-interleukin-1β: p<0.05; AA-interleukin-8: p<0.01). This OOC model of fetal neuroinflammation has determined that race/ethnicity differences do exist for perinatal brain injury. The fetal sex of neonates was not a determining factor of susceptibility to intraamniotic inflammation leading to neuroinflammation.