Development of a Pressure-Sensitive Conductive Rubber Sensor for Analyzing Meniscal Injury in Porcine Models

The assessment of the distribution of contact pressure on the meniscus is important in the elucidation of kinematics, etiology of joint diseases, and establishment of treatment methods. Compared with sensors widely used in recent years, pressure-sensitive conductive rubber sensors are easy to mold, flexible, durable, and resistant to shearing forces. This study is aimed at developing a rubber sensor for meniscal research and evaluating the pressure distribution after meniscal injury using porcine models. After confirming the reliability of the rubber sensor, contact pressure was obtained from the rubber sensor using the medial meniscus and femur of the porcine knee. Three test conditions of intact meniscus, radial tear, and meniscectomy were prepared, and a compressive load of 100 N was applied. After confirming the high reliability of the rubber sensor, the intact meniscus had the most uniform pressure distribution map, while the pressure in the meniscectomy model was concentrated in the resection region. The high-pressure region was significantly smaller in the intact group than in the radial tear models after 80 and 100 N ( P < 0.05 ). The rubber sensor captured the pressure concentration specific to each examination group and was useful for evaluating the relationship between the pattern of meniscal injury and changes in the biomechanical condition of the knee.

Parameters Affecting Efficiency of Centrifugal Pump - A Review

The pump is used as one of the most significant components in chemical industry so without its existence process may not be completed, because for any fluid to flow, initial driving force is required and it is fulfilled by the pump by consuming electrical energy and converting it to pressure energy. So, the selection of pump is very important in every field of section, depending on the property of process fluid. The Centrifugal pump is most demanding nowadays because it has simple design, less maintenance, can handle large quantities of fluids, and provides very high flow rates. The Centrifugal pump has mainly two components rotating components and stationary components. Shaft and impeller (open, semi-enclosed, and fully-enclosed) comes under the category of rotating components and casing (Volute, Vortex, and circular) comes under stationary components. Various parameters of process fluid like liquid viscosity, temperature, specific gravity, vapor pressure, concentration, shear sensitive and abrasive or non-abrasive, MOC, pump environment, pressure, flow rate, etc. are calculated to gain the desired efficiency and prevent a problem like cavitation if not properly handled. In this paper, a single-stage centrifugal pump is reviewed and studied how to increase performance and efficiency of centrifugal pump.

Effects of Pressure Level and Time Treatment of High Hydrostatic Pressure (HHP) on Inulin Gelation and Properties of Obtained Hydrogels

The aim of this study was the evaluation of the influence of different HHP levels (150 and 300 MPa) and time treatment (5, 10, 20 min) on the gelation and properties of hydrogels with different inulin concentration (15, 20, 25 g/100 g). High-pressure treatment, in tested ranges, induces inulin gels and allows obtaining gel structures even at a lowest tested inulin content (i.e., 15 g/100 g). Selecting the pressure parameters, it is possible to modify the characteristics of the created hydrogels. The use of higher pressure (i.e., 300 MPa) allows to increase the stability of the hydrogels and change their structure to more compressed, which results in higher yield stress, lower spreadability, harder and more adhesive structure. For example, increasing the inulin gelling induction pressure (concentration 20 g/100 g) from 150 to 300 MPa with a time treatment of 10 min resulted in an increase in yield stress from 38.1 to 711.7 Pa, spreadability force from 0.59 to 4.59 N, firmness from 0.11 to 1.46 N, and adhesiveness from −0.06 to −0.65 N. Extending the time treatment of HHP increases this effect, but mainly when higher pressure and a higher concentration of inulin are being used. For example, extension of time treatment at 300 MPa pressure from 5 to 20 min resulted in an increase in yield stress from 774.8 to 1273.8 Pa, spreadability force from 6.28 to 8.43 N, firmness from 1.87 to 2.98 N, and adhesiveness from −0.94 to −1.27 N. The obtained results indicate the possibility of using HHP to create inulin hydrogels tailored to the characteristics in a specific food product.

Numerical Simulation on the Dissociation, Formation, and Recovery of Gas Hydrates on Microscale Approach

Investigations into the structures of gas hydrates, the mechanisms of formation, and dissociation with modern instruments on the experimental aspects, including Raman, X-ray, XRD, X-CT, MRI, and pore networks, and numerical analyses, including CFD, LBM, and MD, were carried out. The gas hydrate characteristics for dissociation and formation are multi-phase and multi-component complexes. Therefore, it was important to carry out a comprehensive investigation to improve the concept of mechanisms involved in microscale porous media, emphasizing micro-modeling experiments, 3D imaging, and pore network modeling. This article reviewed the studies, carried out to date, regarding conditions surrounding hydrate dissociation, hydrate formation, and hydrate recovery, especially at the pore-scale phase in numerical simulations. The purpose of visualizing pores in microscale sediments is to obtain a robust analysis to apply the gas hydrate exploitation technique. The observed parameters, including temperature, pressure, concentration, porosity, saturation rate, and permeability, etc., present an interrelationship, to achieve an accurate production process method and recovery of gas hydrates.

Polymer Adsorbents vs. Functionalized Oxides and Carbons: Particulate Morphology and Textural and SurfaceCharacteristics

Various methods for morphological, textural, and structural characterization of polymeric, carbon, and oxide adsorbents have been developed and well described. However, there are ways to improve the quantitative information extraction from experimental data for describing complex sorbents and polymer fillers. This could be based not only on probe adsorption and electron microscopies (TEM, SEM) but also on small-angle X-ray scattering (SAXS), cryoporometry, relaxometry, thermoporometry, quasi-elastic light scattering, Raman and infrared spectroscopies, and other methods. To effectively extract information on complex materials, it is important to use appropriate methods to treat the data with adequate physicomathematical models that accurately describe the dependences of these data on pressure, concentration, temperature, and other parameters, and effective computational programs. It is shown that maximum accurate characterization of complex materials is possible if several complemented methods are used in parallel, e.g., adsorption and SAXS with self-consistent regularization procedures (giving pore size (PSD), pore wall thickness (PWTD) or chord length (CLD), and particle size (PaSD) distribution functions, the specific surface area of open and closed pores, etc.), TEM/SEM images with quantitative treatments (giving the PaSD, PSD, and PWTD functions), as well as cryo- and thermoporometry, relaxometry, X-ray diffraction, infrared and Raman spectroscopies (giving information on the behavior of the materials under different conditions).

The Influence of Friction Blocks Connection Configuration on High-speed Railway Brake Systems Performance

The influence of friction blocks connection configuration on the interfacial tribology behavior and FIVN (friction-induced vibration and noise) of high-speed railway braking system is systematically investigated with a scaled brake test bench. The potential relationship among interface contact status, friction, wear, pressure distribution, heat distribution and vibration noise of the system is studied under dragging test condition. The results indicate that the connection configuration of the friction blocks has a significant impact on systematic interfacial tribology behavior, heat distribution and vibration noise. A floating connection mode can suppress the vibration noise of brake system. The interfacial heat distribution and systematic vibration noise are quite relevant with the contact status, interfacial wear and pressure distribution. The increase of interfacial wear will lead to an expansion of pressure concentration area and an aggravation of vibration noise. The result of this research is helpful for a further design optimization and noise reduction of railway brake system.

Reinventing Aerosol Containment Unit for Use in Medical Operating Theatre

The aerosol containment box or intubation box is medical tool invented to help protect healthcare workers from airborne aerosols while performing procedures such as intubation that are close to the mouth of the patient. The current design of the aerosol containment box is used heavily during the COVID-19 pandemic due to the virus being present in airborne aerosol particles from a patient’s breath. However, the current design has been reported to be flawed in its design aspects. Adding ergonomic considerations into the design is expected to provide improved mobility and better usage of medical instruments. The research conducted analyzed how effective the current design in containing the spread of aerosols from the patient. To execute the research, the current design is modelled in a 3D render using SOLIDWORKS 2020 using dimensions to scale. The 3D model is imported into ANSYS 18.2 to conduct an airflow analysis when a patient cough or breathes to analyses the spread of the aerosols from the patient. The patient coughing was simulated using a nozzle with the boundary space of the model based on the size of the intubation box. The key outcome of the project that the present design is not verry effective in containing aerosol spread as there is still airflow of the particles leaving the intubation box into the environment. The improved design of the intubation box prevents flow of the aerosols into the environment by using suction and seals to close of outlets. The data gained from the study of the aerosol spread proves that there is a higher pressure concentration of the aerosols particles on the walls of the outlets in the existing design in the market as compared to the improved design suggested. This data can help better justify the dimensions and criteria needed to further enhance the current design of the aerosol containment box.

Effectiveness of Pressure-Relieving Shoes/Insoles on Lowering the Plantar Pressure of Diabetic Foot: A Meta-Analysis

Since current reports demonstrated a higher prevalence of foot ulcers in diabetic patients who suffer from foot complication, the preventing occurrence of foot ulcers were the primary target in foot care. Clinical consensus introduced a variety of pressure-relieving products to diabetic patients and clinicians prescribed these products to their patients and recommended them used in daily life. However, available data were still controversial and whether these products could effectively reduce plantar pressure or not were uncertain. Thereby, this meta-analysis aimed first to summary all relevant findings in current database and secondly to explore whether pressure-relieving insoles/shoes can really relieve plantar pressure and what’s differences between customized products (shoes/insoles) and standard ones in reducing plantar pressure. We first searched published articles cited from Web of Science, Medline via OVID, CINAHL, SCOPUS, INFORMIT, Cochrane Central and EMBASE via OVID. Then we filtered observational studies reporting experimental effect of pressure-relieving insoles/shoes. Meanwhile, we set up primary outcome as overall mean peak plantar pressure (MPP) and secondary outcomes as MPP at various plantar regions and MPP at insoles/shoes with various structure designs. Our results show that pressure-relieving products (shoes/insoles) did lower the amplitude of pressure concentration; effect of custom-made and pre-fabricated products on pressure-relieving were similar. These findings suggested that no matter pressure-relieving products were custom-made or prefabricated standard one, if they were designed targeting to increase overall plantar contact areas, such as designed based on plantar model, or to provide extra arch supports or plug-in structures to transfer pressure concentration, they were all useful in diabetic foot care to prevent occurrence of ulceration. Overall, it is recommended that diabetic patients shall wear pressure-relieving insoles/shoes while walking.