Mm In Inner Diameter Research Articles

The Immediate Effect of Straw Phonation in Children With Repaired Cleft Palate

ObjectiveThis study aims to investigate the immediate effect of straw phonation on the phonation of Persian-speaking children with repaired cleft palate. Study DesignQuasi-experimental intervention pre and post intervention. MethodsSeventeen children with repaired cleft palate and velopharyngeal dysfunction (VPD) were investigated. A control group was established comprising children without a cleft palate (control group), carefully matched in terms of age and gender. All participants underwent straw phonation and assessment. The assessments were made two times: at baseline and immediately after straw phonation. Each participant performs straw phonation (a short straw measuring 3mm in inner diameter and 20 cm in length) once for 3 minutes. The acoustic analysis including parameters such as jitter, shimmer, harmonics-to-noise ratio (HNR), cepstral peak prominence (CPP) parameters, as well as the electroglottography (CQ) analysis were performed at pretreatment and immediately after treatment. ResultsCompared with the pretreatment values, after treatment observation demonstrated a significant reduction in Jitt % and Shimm %, and a significant enhancement in HNR and CPP among children with repaired cleft palate. No significant difference intragroup data just in the CPP and CQ in pretreatment. ConclusionsThe proposed straw phonation technique results in an immediate positive change on the quality of voice in both groups. Moreover, assessments in clinical group showed a significantly decrease shimmer and jitter perturbation, alongside elevated levels of HNR and CPP subsequent to straw phonation, irrespective of the phonatory task.

Three-Dimensional Printing of Yttrium Oxide Transparent Ceramics via Direct Ink Writing.

The utilization of 3D printing technology for the fabrication of intricate transparent ceramics overcomes the limitations associated with conventional molding processes, thereby presenting a highly promising solution. In this study, we employed direct ink writing (DIW) to prepare yttrium oxide transparent ceramics using a ceramic slurry with excellent moldability, solid content of 45 vol%, and shear-thinning behavior. A successfully printed transparent yttrium oxide ring measuring 30 mm in diameter, 10 mm in inner diameter, and 0.9 mm in thickness was obtained from the aforementioned slurry. After de-binding and sintering procedures, the printed ceramic exhibited in-line transmittance of 71% at 850 nm. This work not only produced complex yttria transparent ceramics with intricate shapes, but also achieved in-line transmittance that was comparable to that of the CIP method (79%), which can meet certain optical applications.

Application of near-infrared spectroscopy to assess the effect of the cupping size on the spatial hemodynamic response from the area inside and outside the cup of the biceps.

Cupping therapy is a popular intervention for improving muscle recovery after exercise although clinical evidence is weak. Previous studies demonstrated that cupping therapy may improve microcirculation of the soft tissue to accelerate tissue healing. However, it is unclear whether the cupping size could affect the spatial hemodynamic response of the treated muscle. The objective of this study was to use 8-channel near-infrared spectroscopy to assess this clinical question by assessing the effect of 3 cupping sizes (35, 40, and 45 mm in inner diameter of the circular cup) under -300 mmHg for 5 min on the muscle hemodynamic response from the area inside and outside the cup, including oxyhemoglobin and deoxy-hemoglobin in 18 healthy adults. Two-way factorial design was used to assess the interaction between the cupping size (35, 40, and 45 mm) and the location (inside and outside the cup) and the main effects of the cupping size and the location. The two-way repeated measures ANOVA demonstrated an interaction between the cupping size and the location in deoxy-hemoglobin (P = 0.039) but no interaction in oxyhemoglobin (P = 0.100), and a main effect of the cup size (P = 0.001) and location (P = 0.023) factors in oxyhemoglobin. For the cupping size factor, the 45-mm cup resulted in a significant increase in oxyhemoglobin (5.738±0.760 μM) compared to the 40-mm (2.095±0.312 μM, P<0.001) and 35-mm (3.134±0.515 μM, P<0.01) cup. Our findings demonstrate that the cupping size and location factors affect the muscle hemodynamic response, and the use of multi-channel near-infrared spectroscopy may help understand benefits of cupping therapy on managing musculoskeletal impairment.

Design and Manufacture of a Test Cryostat With MgB2 Superconducting Magnet Significantly Reducing Helium Consumption

A test cryostat equipped with a conduction-cooled MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> high-temperature superconducting bias magnet has been designed, manufactured, and demonstrated. This cryostat is more environmental-friendly and user-friendly than the conventional cryostat with an immersion-cooled NbTi superconducting magnet. Liquid helium consumption is reduced by almost half of that of a previous conventional cryostat because the MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> magnet does not need liquid helium for cooling itself. A ramp-up rate of the bias magnet has also been improved to 1 A/s, which is almost 10 times faster than that of the previous NbTi magnet, due to the high stability of the superconducting MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> magnet. A maximum bias magnetic field is 1 T at the center of the magnet. A helium vessel of the cryostat is 212 mm in inner diameter so that various superconducting samples such as bulks, short samples of wires, and small coils, could be immersion-cooled by cryogen and tested in it. A performance demonstration was also successfully conducted.

Ion microsource integrated with scanning electron microscope for sample preparation

The authors developed the Ar+ ion microsource, which can generate a filamentary ion beam of a few tens of µm at its half-power diameter with a target current up to 50 µA at − 4 kV extracting voltage. This comprises a ceramic discharge capillary of 1 mm in inner diameter and 10 mm long with a very small copper anode and a cathode outlet aperture of 0.5 mm in diameter at its ends. The arrangement has been examined in three alternative designs equipped with cathodes of different shapes and materials and two extraction voltage supply schemes, i.e., with the negatively biased sample and the earthed cathode or the earthed sample and the cathode at a floating positive potential (recommended solution). Numerous other factors were considered that can affect the standard SEM operation, such as excessive working gas leakage and jamming with discharge interferences, e.g., streamers. The microsource makes a compact structure that can be positioned above the sample inside a standard SEM without any changes to its original structure and collisions with standard modes of the SEM operation. Such a tool enables the removal of target microvolumes in chosen places, so it can be used for some technological purposes, such as making small apertures. However, its main goal is to uncover the bulk internal structure of the specimen, imaging it in a 3D form. Therefore, the microsource is placed on the movable arm and coupled with the semiconductor four-quadrant backscattered electron (BSE) detector, which enables 3D imaging of the uncovered structure with the multidetector method. This implies taking in one scan a set of images from four or five directions, using both material- and topography-sensitive channels of information (BSE and secondary electron SE), which facilitates their interpretation.

Evaluation of subcooled void fraction in downward flow under low mass flux condition by using neutron radiography

In downward flow, complex two-phase flow is caused by buoyancy of bubbles. It affects not only a void fraction profile but also a point of net vapor generation (PNVG). In order to understand the fundamental characteristics of the void fraction on subcooled boiling in downward flow, the void fraction was measured by using neutron radiography. The test sections were made of stainless steel tubes that had 400 mm in heated length with 10 and 15 mm in inner diameters. They were heated by direct Joule heating applying D.C. power. The void fraction characteristics were explained by dividing into three regions: i.e., a wall voidage region, a detached voidage region, and a bulk voidage region. PNVG was defined as the boundary between the detached voidage region and the bulk voidage region. In a downward flow, the thermal equilibrium quality at PNVG is smaller than in an upward flow. “Secondary PNVG” was also observed which was caused by the influence of a reverse flow of bubbles. A difference of thermal equilibrium quality between at primary PNVG and at secondary PNVG is lager in 15 mm in inner diameter than in 10 mm. The void fraction profile and PNVG characteristics in downward flow show dependence of inner diameter as well as mass flux. To demonstrate the void fraction profile involving with the influence of a reverse flow in a downward flow, an empirical void fraction correlation based on a drift-flux model with Lahey’s flow quality model was developed. This correlation well agreed with the experimental results.

Direct, efficient and selective capture of low concentration of CO2 from natural gas flue gas using a high temperature tubular carbon capture membrane

Natural gas (NG) fired power plants emit low concentration (4–5%) of CO2, which presents additional technical and economic challenges to the current benchmark amine absorption technology. The newly emerged high-temperature multiphase membranes operated on molten carbonate (MC) chemistry for CO2 capture/separation/conversion have been demonstrated with great potential to meet this challenge. In this study, we report on the CO2 capture performance of such a membrane in tubular geometry from a mockup NG flue gas. The membrane is comprised of a mixture of Gd0.20Ce0.80O1.95 (GDC) and MC, in which GDC forms a porous skeleton to contain MC. We show that the membrane with a dimension of 6.1 mm in outer diameter, 5.1 mm in inner diameter and 5 cm in effective length (resulting in 4 cm2 effective surface area) can achieve a CO2 flux density of 0.46–0.55 mL/min·cm2 at 650 °C, capturing 97% pure CO2 at a rate of 37–42% from 5%CO2–N2 using moistened Ar as the sweep gas. The level of performance demonstrated by this study suites the membrane well for stationary CO2 capture from NG power plants.

Hybrid nanoassembly with two-tier host-guest architecture and regioselective enrichment capacity for repetitive SERS detection

Due to the challenge of controlling analyte-particle and particle-particle distances in the SERS detection matrix, the most promising nanosensor systems still suffer from difficulties in increasing the sensing stability and repeatability. Herein, a host-guest assembly strategy was developed to build two-tier nanoarchitecture based SERS device for a highly repetitive detection system. Specifically, gold nanoparticles were installed on the outer surface of mesoporous polydopamine nanoparticles and modified with a self-assembled monolayer of 11-Mercapto-1-undecanol to drive the regioselective enrichment of analytes in the mesopores. Subsequently, the host-guest nanosensor particles were assembled into a uniform coffee ring pattern (~4 mm in inner diameter and 500 µm in width) on the surface of a porous host (polyvinylidene fluoride film with a pore size of 0.45 µm) through fast particle packing (20 s) driven by water infiltration in membrane pores. Finally, the sensing system achieved highly repeatable (RSD 3.1%−3.4%) analysis of organic dyes (limit-of-detection, LOD 24.1–59.6 fM) and miRNA (LOD 308.5 fM). The nanoassembly platform with distance constraint and enrichment effects is expected to pave a new avenue for interfacial engineering strategies of SERS sensors.

A novel method of measuring microtube wall temperatures by thermocouples to investigate sCO2 flows

Experimental study on convective heat transfer through microtubes encounters many challenges such as measuring the wall temperature of the tube with a reasonable uncertainty, relatively high heat loss from the outer surface of the tube, and difficulty in measuring the fluid bulk temperature at the tube outlet. These issues become exacerbated with flow at low Reynolds numbers. The present study presents a new method to measure the tube wall temperature with a small solder cast where a thermocouple is embedded. The net heat flux to flows, determined with the heat loss on the outer surface and the axial heat conduction, is integrated to obtain the local mean enthalpy of fluid and then the fluid mean temperature along the tube. Thus, convection heat transfer coefficients are calculated without measuring the mean temperature at the outlet. The new method is successfully validated with laminar water flows through a horizontally configured microtube, 0.501 mm in inner diameter. All Nusselt numbers are found to lie between 4.36 and 4.36 + 10%. Finally, the method developed in this study is applied to supercritical CO2 flowing upward at 8.0 MPa through a microtube, 0.509 mm in inner diameter. For both high and low mass flow rates, a local maximum of the convection heat transfer coefficient is observed at a location where the film temperature is close to the pseudo-critical temperature. On the other hand, the second local maximum of the convection heat transfer coefficient appears only at low mass flow rates.

Continuous bed motion in a silicon photomultiplier-based scanner provides equivalent spatial resolution and image quality in whole body PET images at similar acquisition times using the step-and-shoot method.

This study investigated the spatial resolution and image quality of the continuous bed motion (CBM) method in a sensitive silicon photomultiplier (SiPM)-based positron emission tomography (PET)/computed tomography (CT) system compared with the traditional step-and-shoot (SS) method. Methods: Siemens Biograph Vision was used in this study. Data acquisition using the SS method was performed for 3 min per bed. In the CBM method, the bed speed ranged from 0.5 to 3.3 mm/s. The acquisition time equivalent to the SS method was 1.1 mm/s for 2-bed ranges and 0.8 mm/s for seven-bed ranges. The spatial resolution was investigated using 18F point sources and evaluated using the full width at half maximum. Image quality was investigated using a National Electrical Manufacturers Association International Electrotechnical Commission body phantom with six spheres 10-, 13-, 17-, 22-, 28-, and 37-mm inner diameters. The radioactivity concentration ratio of the 18F solution in all spheres and the background was approximately 4:1. The detectability of each sphere was visually evaluated on a five-step score. Image quality was physically evaluated using the noise equivalent count rate (NECphantom), contrast percentage of the 10-mm hot sphere (QH,10mm), background variability percentage (N10mm), and contrast-noise ratio (QH,10mm/N10mm). Results: The spatial resolution was not affected by the difference of acquisition methods and bed speeds. The detectability of the 10-mm sphere with a bed speed of 2.2 mm/s or faster was significantly inferior to that of the SS 2-bed method. In evaluating image quality, no significant difference in the contrast percentage was observed among the acquisition methods and speeds in the CBM method. However, the increasing bed speed in the CBM method increased the N10mm and decreased the NECphantom. When comparing the SS 2-bed method with the CBM method at 0.8 mm/s, no significant differences in all parameters were observed. Conclusion: In a SiPM-based PET/CT scanner, the CBM method provides equivalent spatial resolution and image quality in whole body PET images with same acquisition time using the SS method.

1-D Modeling of Two Phase Flow Process in Concentric Annular Heat Pipe and Experimental Investigation

As the heat dissipation of smart devices increases, cutting-edge cooling solutions are becoming increasingly important. The heat pipe is an efficient device that boosts heat transfer and is recommended to reduce thermal management power. In this study, a concentric annular heat pipe (CAHP) with distilled water as a working fluid is proposed to enhance heat transfer, and experiments and one-dimensional analysis were carried out to predict thermal characteristics and evaluate performance. The CAHP was 90 mm in length, 62 mm in inner diameter, 70 mm in outer diameter, and 0.4 mm in thickness. At the outer surface of the internal CAHP, a two-layer screen mesh wick (500 mesh, Stainless Steel 304) that is 0.34 mm in layer thickness was installed. A ceramic heater (20 mm × 20 mm) was attached to the middle of the outer surface, and the hollow region with 48 fins was cooled by an electric fan. The experiment was carried out with variations in the heat load, the filling ratio of the working fluid, the pitch angle, the roll angle, and the airflow speed, and the one-dimensional analysis was modeled by AMESIM. The experimental results showed that the best thermal resistance of the CAHP was 3.74 °C/W with a supplied heat of 20 W, a pitch angle of −15°, and a Vair of 3 m/s. In addition, the CAHP’s 1-D simulation model using AMESIM was verified through the experimental results. However, although the modeling results according to the inclination angle could not be reflected due to the difficulty of implementing multiple orientation structures in the one-dimensional simulation model, the simulation results were found to be almost consistent with the experimental results. Case studies were conducted to understand the various characteristics of the CAHP using the model, and the optimal volume fraction, the porosity, and the number of layers of the wicks were determined to be 10, 0.345, and 2, respectively.

Hydrogen production by steam gasification of Hungarian brown coal char

Presently, the hydrogen is mainly generated from fossil fuels (natural gas and coal). The thermochemical conversion processes of carbon-based materials to hydrogen-rich gas has been widely described in the literatures. In which, the steam gasification is highly recommended for this purpose. The experimental steam gasification of Hungarian brown coal char was conducted in a single stage fixed-bed reactor with 80 mm of inner diameter and 1,200 mm of effective length. The experiments were carried out at 700, 800 and 900 °C of gasification temperature within 5 g/min of steam flow rate and 5, 7.5 and 10 g/min of steam flow rate within 900 °C of gasification temperature. The aim of this study is to determine the performance of Hungarian brown coal char during the gasification with the variation of gasification temperature and steam flow rate, as well as the hydrogen production during the gasification process. The gasification temperature plays an important role in the conversion process in the gasifier, as well as the change in the synthesis gas composition. The introduction of higher steam flow rate can also improve the reduction process. The highest total hydrogen yield of 1.8 Nm3 was gained at 900 °C of gasification temperature and 10 g/min of steam flow rate for 3 kg of initial coal.

Experimental Study of the Heat-Transfer Performance of an Extra-Long Gravity-Assisted Heat Pipe Aiming at Geothermal Heat Exploitation

The installation and operation of enhanced geothermal systems (EGS) involves many challenges. These challenges include the high cost and high risk associated with the investment capital, potential large working-fluid leakage, corrosion of equipment, and subsiding land. A super-long heat pipe can be used for geothermal exploitation to avoid these problems. In this paper, a high aspect-ratio heat pipe (30 m long, 17 mm in inner diameter) is installed vertically. Experiments are then carried out to study its heat-transfer performance and characteristics using several filling ratios of deionized water, different heating powers, and various cooling-water flowrates. The results show that the optimal filling-ratio is about 40% of the volume of the vaporizing section of the heat pipe. Compared with a conventional short heat pipe, the extra-long heat pipe experiences significant thermal vibration. The oscillation frequency depends on the heating power and working-fluid filling ratio. With increasing cooling-water flow rate, the heat-transfer rate of the heat pipe increases before it reaches a plateau. In addition, we investigate the heat-transfer performance of the heat pipe for an extreme working-fluid filling ratio; the results indicate that the lower part of the heat pipe is filled with vapor, which reduces the heat-transfer to the top part. Based on the experimental data, guidelines for designing a heat pipe that can be really used for the exploitation of earth-deep geothermal energy are analyzed.

Natural gas versus methane: Ignition kinetics and detonation limit behavior in small tubes

Detonation properties of methane and natural gas were studied using ZND simulations and detonation limit experiments. The experiments were performed in two tube sizes, 32 mm and 6.4 mm in inner diameter over a range of initial pressures (between 3.4 kPa and 35 kPa) and with stoichiometric fuel-oxygen compositions. The fuels considered are high purity methane, high purity methane with dopant ozone, a real natural gas, and a family of natural gas surrogates. The natural gas surrogates were developed based on North American natural gas composition variations and designed to capture the expected mean and variance of fundamental combustion properties of natural gases. All natural gases tested in this work show a substantially smaller detonation induction length (about 40%) and lower detonation pressure limit (30% in terms of limiting pressure) than high purity methane. The ozonated methane at 3000 PPMv of ozone doping performed similarly to the natural gases. Overall, the results suggest that in methane-based mixtures, a smaller induction length correlates with a more predictable detonation behavior as evidenced by a lower detonation pressure limit. As such, natural gases are expected to have a wider operating range when used as a fuel for detonation-based engines. As importantly, induction length calculation results reveal that the variability in detonation and combustion behaviors resultant from composition variability is expected to be similar between natural gases and commercial methane. Finally, the results suggest that for safety-related studies, neat methane is a poor surrogate for studying natural gas explosions.

Hydrodynamics and Mass Transfer in a Concentric Internal Jet-Loop Airlift Bioreactor Equipped with a Deflector

The gas–liquid hydrodynamics and mass transfer were studied in a concentric tube internal jet-loop airlift reactor with a conical bottom. Comparing with a standard design, the gas separator was equipped with an adjustable deflector placed above the riser. The effect of riser superficial gas velocity uSGR on the total gas holdup εGT, homogenization time tH, and overall volumetric liquid-phase mass transfer coefficient kLa was investigated in a laboratory bioreactor, of 300 mm in inner diameter, in a two-phase air–water system and three-phase air–water–PVC–particle system with the volumetric solid fraction of 1% for various deflector clearances. The airlift was operated in the range of riser superficial gas velocity from 0.011 to 0.045 m/s. For the gas–liquid system, when reducing the deflector clearance, the total gas holdup decreased, the homogenization time increased twice compared to the highest deflector clearance tested, and the overall volumetric mass transfer coefficient slightly increased by 10–17%. The presence of a solid phase shortened the homogenization time, especially for lower uSGR and deflector clearance, and reduced the mass transfer coefficient by 15–35%. Compared to the gas–liquid system, the noticeable effect of deflector clearance was found for the kLa coefficient, which was found approx. 20–29% higher for the lowest tested deflector clearance.

The Characteristics of LPG Detonation Wave Propagation Behind Porous Media Model

LPG-air mixture enriched with oxygen is usually used for generating heat in industry sector. However, it is possible that LPG-oxygen will mix and react independently and the mixture could generate detonation wave. This condition could harm people, environment, and piping system, thus detonation quenching to guarantee safety becomes very important. The present study aims to investigate the characteristics of the detonation wave after propagating through the porous media model. The experiments used a detonation test tube with 50 mm of inner diameter and 6 m of total length. The test tube consists of two sections, 1 m long driver section and 5 m long driven section. The driver section and driven section are separated by Mylar film to prevent mixing between driver gas and driven gas, which consists of different gas mixture with different pressure. The driver section contained a stoichiometric H2-O2 mixture at constant initial pressure, which function as a direct initiator for detonation in the driven section. Besides, the driven section contained a stoichiometric mixture of LPG-oxygen and LPG-air at the initial pressure varied from 20 kPa to 100 kPa with an interval of 10 kPa. The stainless-steel porous media with masses of 15 g and 20 g were inserted in a cylindrical case which had been perforated with small holes on its cross-sectional surface to enable detonation wave to propagate through it. The observation of detonation wave propagation was conducted at upstream and downstream of the model. Two mechanisms of detonation wave propagation were observed in the downstream of the porous media model for combustion of the LPG-oxygen mixture; they are detonation re-initiation and detonation transmission. However, the LPG-air mixture could not generate a detonation wave. Additionally, the 5 g increments of the stainless-steel porous media mass only significantly increase the re-initiation distance of detonation (Dri) for mixture with low initial pressure, 20 kPa up to 50 kPa and did not significantly influence re-initiation distance of detonation for mixture with a high initial pressure of 60 kPa to 100 kPa.

Effect of non-condensable gas on heat transfer within the hollow fin condenser of metallic and polymer vapor chambers

• Effect of non-condensable gas (NCG) in condensers with hollow fins is investigated. • Thermal behavior and performance of polymer and aluminum condensers are compared. • Predictions of the numerical diffusion model agree well with experimental data. • Performance of air-cooled polymer and aluminum condensers is comparable. • Aluminum condensers are more sensitive to NCG than polymer ones. A vapor chamber with hollow fins was manufactured and tested with condensers made of polymer and aluminum. The fins are 5.3 mm in inner diameter and cooled by forced air convection. The use of polymer instead of aluminum has little influence on the performance: it is of interest for weight reduction when the cooling medium is air. The impact of non-condensable gas (NCG) is studied experimentally using IR temperature measurements on the fins and performance monitoring over time. To complete the study, a numerical model of film condensation inside a vertical tube in the presence of NCG is developed. The model combines hydrodynamic and axial mass diffusion phenomena with 2D heat conduction in the wall. A good agreement is found between experimental results and model predictions. The effect of the NCG mass, heat load, external cooling coefficient and wall thermal conductivity is studied though a parametric analysis. When the wall thermal conductivity increases, so does the volume occupied by NCG inside the fins and the performance degradation. In other words, aluminum condensers are more sensitive to NCG than polymer ones, and the difference is all the more important as external cooling is efficient.

Engineering of axially vascularized bone tissue using natural coral scaffold and osteogenic bone marrow mesenchymal stem cell sheets

IntroductionBlood supply remains one of the obstacles to large bone tissue engineering. This study aimed to generate vascularized bone tissue by inducing axial vascularization into a construct combining natural coral scaffold and a bone marrow mesenchymal stem cells (BMSCs) sheet. Material and methodsIsolated BMSCs were cultured to form an osteogenic cell sheet using a continuous culture method. Natural coral scaffolds were prepared into customized shape with a cylinder of 20 mm length, 8 mm in outer diameter and 5 mm in inner diameter. Then, the freed superficial inferior epigastric vessel of rabbits was first wrapped with a cell sheet, and then inserted into the central passage of the scaffold, after being wrapped with another cell sheet, the complexes were implanted subcutaneously into a rabbit groin area. In contrast, the sheet-scaffold construct that implanted into groin subcutaneous area of the other side of the same rabbit with the distal end of the blood vessel was ligated, which was considered as control. New bone and vascularization formation were evaluated at 12 weeks postoperatively. ResultsThe volume of new bone formation and amount of capillary infiltration in the vascular circulation group were significantly greater than that in the vascular ligation group, which suggested that insertion of axial vessels could significantly promote angiogenesis and osteogenesis of the tissue-engineered bone. ConclusionsThese findings indicate that inserting an arteriovenous bundle into the constructs of mesenchymal stem cell sheet and coral has great potential for clinical applications to repair large bone defects.

A conceptual study of a high gradient trapped field magnet (HG-TFM) toward providing a quasi-zero gravity space on Earth

In this work, we propose a new concept of a high gradient trapped field magnet (HG-TFM). The HG-TFM is made from (RE)BaCuO bulk superconductors, in which slit ring bulks (slit-TFMs) are tightly stacked with TFM cylinders (full-TFMs), and state-of-the-art numerical simulations were used to investigate the magnetic and mechanical properties in detail during and after magnetization. A maximum value of the magnetic field gradient product of = 6040 T2 m−1 was obtained after conventional field cooled magnetization (FCM) with an applied field, B app, of 10 T of the HG-TFM with 60 mm in outer diameter and 10 mm in inner diameter. This value may be the highest value ever reported compared to any other magnetic sources. The value increased with decreasing inner diameter of the HG-TFM and with increasing B app during FCM. The electromagnetic stress in the HG-TFM during the FCM process mainly results from the hoop stress along the circumferential direction. The simulations suggested that there is no fracture risk of the bulk components during FCM from 10 T in a proposed realistic configuration of the HG-TFM where both TFM parts are mounted in Al-alloy rings and the whole HG-TFM is encapsulated in a steel capsule. A quasi-zero gravity space can be realized in the HG-TFM with a high value in an open space outside the vacuum chamber. The HG-TFM device can act as a compact and cryogen-free desktop-type magnetic source to provide a large magnetic force and could be useful in a number of life/medical science applications, such as protein crystallization and cell culture.

Влияния условий горения разряда на распределения параметров плазмы, генерируемой в несамостоятельном тлеющем разряде внутри полого катода

The parameters of the plasma of a non-self-sustaining glow discharge generated inside a metal hollow cathode 300 mm long and 25 mm in inner diameter are investigated. A feature of this system is the additional injection of electrons from the auxiliary discharge plasma, formed by a plasma source with a combined heated and hollow cathode «PINK». The dependences and combustion modes of a non-self-sustaining glow discharge are presented and described at a pressure in the range (0.06 ÷ 1.4) Pa and a combustion voltage (70 ÷ 300) V. Studies of plasma parameters using double Langmuir probes have shown that this discharge system provides generation nitrogen plasma inside the hollow cathode with inhomogeneity from ± 12 to ± 63%.