Innovative Experimental Platform Research Articles

Experimental investigation of solid propellants combustion response to pressure oscillations using advanced high-resolution diagnostics

The combustion response of solid propellants plays a crucial role in determining the combustion stability of solid rocket motors (SRMs). This study employs multiple advanced combustion diagnostic techniques, including high-speed photomicrography, two-color pyrometry, and laser shadowgraphy, to simultaneously capture mesoscale flame dynamics and burning surface regression characteristics of AP/HTPB composite propellants under pressure oscillations. This experimental configuration enables the simultaneous achievement of high temporal resolution (0.25 ms) and spatial resolution (4.9μm/pixel). Pressure oscillations are generated by loudspeakers, cover a range of frequencies (168.9 Hz to 506.7 Hz) and amplitudes up to approximately 0.44% of the equilibrium pressure. The investigated propellants exhibit varying oxidizer characteristics, including coarse (330μm) and fine (150μm) AP particle sizes, as well as different AP mass fractions (81% and 86%). Results reveal that finer oxidizer particles and higher oxidizer content both result in an increased mean steady burning rate, with the former exhibiting a more pronounced influence on the burning rate increment. Under pressure oscillations, the mean burning rate increases with increasing pressure oscillation amplitude, accompanied by a reduction in flame height, an expansion in mean flame swing angle, and an elevation in mean flame temperature. The observed frequency dependency indicates a stronger combustion response when the oscillation frequency aligns with the characteristic frequency of propellant, which is closely associated with the mean burning rate, irrespective of the amplitude of pressure oscillation. This frequency-dependent phenomenon results in the highest combustion response, characterized by a maximum mean burning rate increment exceeding 165%. The innovative experimental platform employed in this study demonstrates the capability to simultaneously capture various flame fluctuation characteristics, such as flame swinging, flame temperature, and burning rate fluctuation in a single test. This facilitates a more thorough and comprehensive analysis of combustion responses in solid propellants under pressure oscillations.

Molecular pharmacodynamics of meropenem for nosocomial pneumonia caused by Pseudomonas aeruginosa.

Hospital-acquired pneumonia (HAP) is a leading cause of morbidity and mortality, commonly caused by Pseudomonas aeruginosa. Meropenem is a commonly used therapeutic agent, although emergent resistance occurs during treatment. We used a rabbit HAP infection model to assess the bacterial kill and resistance pharmacodynamics of meropenem. Meropenem 5 mg/kg administered subcutaneously (s.c.) q8h (±amikacin 3.33-5 mg/kg q8h administered intravenously[i.v.]) or meropenem 30 mg/kg s.c. q8h regimens were assessed in a rabbit lung infection model infected with P. aeruginosa, with bacterial quantification and phenotypic/genotypic characterization of emergent resistant isolates. The pharmacokinetic/pharmacodynamic output was fitted to a mathematical model, and human-like regimens were simulated to predict outcomes in a clinical context. Increasing meropenem monotherapy demonstrated a dose-response effect to bacterial kill and an inverted U relationship with emergent resistance. The addition of amikacin to meropenem suppressed the emergence of resistance. A network of porin loss, efflux upregulation, and increased expression of AmpC was identified as the mechanism of this emergent resistance. A bridging simulation using human pharmacokinetics identified meropenem 2 g i.v. q8h as the licensed clinical regimen most likely to suppress resistance. We demonstrate an innovative experimental platform to phenotypically and genotypically characterize bacterial emergent resistance pharmacodynamics in HAP. For meropenem, we have demonstrated the risk of resistance emergence during therapy and identified two mitigating strategies: (i) regimen intensification and (ii) use of combination therapy. This platform will allow pre-clinical assessment of emergent resistance risk during treatment of HAP for other antimicrobials, to allow construction of clinical regimens that mitigate this risk.IMPORTANCEThe emergence of antimicrobial resistance (AMR) during antimicrobial treatment for hospital-acquired pneumonia (HAP) is a well-documented problem (particularly in pneumonia caused by Pseudomonas aeruginosa) that contributes to the wider global antimicrobial resistance crisis. During drug development, regimens are typically determined by their sufficiency to achieve bactericidal effect. Prevention of the emergence of resistance pharmacodynamics is usually not characterized or used to determine the regimen. The innovative experimental platform described here allows characterization of the emergence of AMR during the treatment of HAP and the development of strategies to mitigate this. We have demonstrated this specifically for meropenem-a broad-spectrum antibiotic commonly used to treat HAP. We have characterized the antimicrobial resistance pharmacodynamics of meropenem when used to treat HAP, caused by initially meropenem-susceptible P. aeruginosa, phenotypically and genotypically. We have also shown that intensifying the regimen and using combination therapy are both strategies that can both treat HAP and suppress the emergence of resistance.

Construction and Optimization of Deep Learning-based Innovative Experimental Platform for Mathematical Intelligence in Electricity Major

Construction and Optimization of Deep Learning-based Innovative Experimental Platform for Mathematical Intelligence in Electricity Major

Breaking through the bending limit of Al-alloy tubes by cryogenic effect controlled mechanical properties and friction behaviours

Aluminium alloy (Al-alloy) tubes, especially large-diameter thin-walled tubes with a tough bending radius, have been widely utilised in different industrial clusters owing to their high strength-to-weight ratio and good corrosion resistance. However, achieving such extreme specifications is challenging because severe and nonuniform bending deformation may cause tension and compression instabilities, such as overthinning, cracking, and wrinkling. Considering possible improvements in mechanical properties and friction behaviours of Al-alloy at cryogenic temperature (CT), the cryogenic bending potential of the 6061-O tubes with an extreme ratio of D/t of 89 (diameter/wall thickness) was explored at different deformation temperatures, including room temperature (RT) 20 °C, −60 °C, −120 °C, and −180 °C. First, the cryogenic mechanical properties and friction behaviour of the tubes were characterised. It was found that the overall mechanical properties of the Al-alloy tube were improved because of sub-grain formation and a more uniform distribution of dislocations at CT. The coefficient of friction between the tube and tooling exhibited a varying degree of reduction owing to the sensitivity of the tubes and the lubricant to CT. Subsequently, an innovative experimental platform for cryogenic bending was designed, and a finite element model of cryogenic bending was established. Third, cryogenic tube bendability and mechanism were explored. It was found that 6061-O tube formability can be effectively improved by cryogenic bending; however, there is no monotonic relationship between the bendability improvement and temperature decrease. The temperature to obtain the best bendability is −60 °C, at which the average wrinkle height is decreased by 81.4 %, and the average wall thickness reduction rate is reduced by 23.8 %. The bending limit represented by the bending radius is reduced from a 3.0D bending radius at RT to 1.0D at −60 °C, which is realised by the different or even opposite effects of the mechanical properties of tubes and the friction coefficient between the multiple contact interfaces on wall thinning and wrinkling.

Mechanical performance of oil-well cement slurries cured and tested under high-temperatures and high-pressures for deep-well applications

The American Petroleum Institute testing standard (API TR 10TR7) recommends determining the mechanical performance of oil-well cement slurries in an ambient-temperature testing environment. However, with exploration and exploitation resources moving toward deep formations, cement slurries for oil, gas, and geothermal wells are increasingly being utilized in high-temperature and high-pressure (HTHP) in-site formations. It is unknown if the current standard is suitable for assessing the mechanical performance of cement slurry under in-site HTHP conditions in deep wells. To fill this research gap, an innovative experimental platform was developed for this study to mimic the in-site HTHP environments in real production wells; then oil-well cement slurries were cast, cured, and tested at elevated temperatures (i.e., 90 °C, 115 °C, 140 °C) and the confining-pressure (i.e., 20 MPa). The mechanical performance of cement slurries was evaluated under triaxial compression and cyclic loads. The microstructures of cement slurries were also studied. This study revealed that the high-temperature testing environment accelerated the crack propagation and stress drop of stress-strain curves, decreased the failure stress (up to 14.0 %), Young's modulus (up to 16.4 %), and Poisson's ratio (up to 31.7 %), and resulted in more brittle characteristics of cement slurry samples. This study confirmed that using the current standard will significantly overestimate the mechanical properties of oil-well cement slurries in HTHP environments. The authors suggest updating the standard to take HTHP environments into consideration, which should ultimately meet the increasing demands of developing deep oil, gas, or geothermal wells.

Effect of DC Deep-Well Ground Electrode Materials on gas Evolution

The uniqueness of DC deep-well ground electrodes (DWGEs) lies in their low area requirements. However, the gas produced by DWGEs during electrolysis may cause more severe exhaust problems than those caused by conventional electrodes. To investigate the influence of different electrode materials on the gas evolution of DWGEs, an innovative U-shaped experimental platform is proposed for the separate collection of cathode and anode gases. The metal–electrolyte contact interface in a DWGE project was simulated, and gas evolution experiments were performed on three typical ground electrode materials. The gas evolution rates of the electrode materials when operate as cathodes and anodes were obtained. Polarization curves were used to compare the corrosion rates of the three materials and evaluate the effects of these rates on the gas evolution rates of the materials. The results revealed that when operated as anodes, mixed metal oxide (MMO) and high-silicon cast iron produced oxygen, whereas carbon steel did not. Furthermore, the evolution of O₂ in MMO was faster than that in high-silicon cast iron. When operated as cathodes, the three materials generated hydrogen, and carbon steel exhibited the slowest H₂ evolution rate. The current distribution in the different gas evolution processes was summarized. The supplied current was used as the reaction current of metal corrosion and for gas generation. Under the same current, quicker corrosion corresponded to a lower amount of gas evolution for a material.

Multicolor Patterning of 2D Semiconductor Nanoplatelets.

Nanocrystal micro/nanoarrays with multiplexed functionalities are of broad interest in the field of nanophotonics, cellular dynamics, and biosensing due to their tunable electrical and optical properties. This work focuses on the multicolor patterning of two-dimensional nanoplatelets (NPLs) via two sequential self-assembly and direct electron-beam lithography steps. By using scanning electron microscopy, atomic force microscopy, and fluorescence microscopy, we demonstrate the successful fabrication of fluorescent nanoarrays with a thickness of only two or three monolayers (7-11 nm) and a feature line width of ∼40 nm, which is three to four NPLs wide. To this end, first, large-area thin films of red-emitting CdSe/ZnyCd1-yS and green-emitting CdSe1-xSx/ZnyCd1-yS core/shell NPLs are fabricated based on Langmuir-type self-assembly at the liquid/air interface. By varying the concentration of ligands in the subphase, we investigate the effect of interaction potential on the film's final characteristics to prepare thin superlattices suitable for the patterning step. Equipped with the ability to fabricate a uniform superlattice with a controlled thickness, we next perform nanopatterning on a thin film of NPLs utilizing a direct electron-beam lithography (EBL) technique. The effect of acceleration voltage, aperture size, and e-beam dosage on the nanopattern's resolution and fidelity is investigated for both of the presented NPLs. After successfully optimizing EBL parameters to fabricate single-color nanopatterns, we finally focus on fabricating multicolor patterns. The obtained micro/nanoarrays provide us with an innovative experimental platform to investigate biological interactions as well as Förster resonance energy transfer.

Field tests on the blast-resisting performance of mild steel circular tubes after exposure to fire

Fires and blasts usually take place simultaneously and threaten the safety of engineering structures. In the present work, field tests were carried out to understand the blast-resisting performance of Q390B mild steel circular tubes after exposure to natural fire. An innovative experimental platform was designed to enable the loading of a blast load within seconds after a fire. By defining and quantifying the deformation characteristics of the circular tubes, four typical failure modes were summarized. In addition, it was found that the occurrence of a fracture influenced the variation of relevant deformation parameters. Results of the metallographic examination of the sag area after the explosion impact revealed that the pearlite distribution in Q390B steel was relatively dispersed and disordered compared with that at high temperature, which might have resulted in relatively greater resistance to the dislocation movement. The scanning electron microscopy (SEM) of the fracture showed that many dimples were distributed on the surface of the fracture, and the dimples were larger and deeper at high temperature. Finally, the engineering calculation formulas for the influences of the temperature and the blast scaled distance on the global deflection of the circular tubes were established.

Construction and Implementation of Open Computer Innovation Experiment Teaching Mode

The organic combination of open and innovative practice teaching mode and computer application helps to improve the backward practice education mode and enhance the design, comprehensiveness and innovation of innovative experimental teaching, so it has high research value. Based on this, this paper first analyses the current situation and problems of open innovation experimental teaching, then studies the construction of open computer innovation experimental teaching platform, and finally gives the implementation strategy of open computer experimental teaching mode.

Real-time sensor fault diagnosis method for closed-loop system based on dynamic trend

To solve the common problems of sensor fault detection, fault setting and fault location in the first-order closed-loop control system, a static fault diagnosis model based on the real-time trend of dynamic data flow is constructed. Aiming at the common fixed-value system and servo system in the first-order closed-loop control system, a data processing model based on sliding window is designed by collecting and analysing a large amount of real-time data, and the fault is isolated in the window based on the calibration parameters. Then, the adaptive threshold binarisation method is used to calculate the fault vector, and then the analytical model of fault location is obtained by the linear regression method. Finally, the feasibility and validity of closed-loop sensor fault diagnosis method based on dynamic data flow trend are verified by online simulation of “complex process system innovation experimental platform” based on OPC communication technology.

Mapping neuronal network dynamics in developing cerebral organoids

Mapping neuronal network dynamics in developing cerebral organoids

Innovative Experiment Platform Design and Teaching Application of the Internet of Things

By analyzing the current situation of experimental platforms which is based on the Internet of Things (IOT) and the cultivation of talents, we established the talents' cultivating orientation and experiment platform for innovation. In accordance with the requirements of a students' practical and creative ability curriculum, the method of modularization was adopted to design this platform. With this, the platform can basically satisfy the needs of the varying teaching experiments, which can increase opportunities for the students on their comprehensive application. The platform was widely used in experimental and practice teaching in the past three years, such as synthetic experiment, graduate programs, and practice project in Zhongkai University of Agriculture and Engineering, Guilin University of Technology etc. Result shows that the innovation experimental platform has broad application prospects, and effectiveness to meet the requirements of students' in-depth learning and research of IOT technologies. Meanwhile, the platform expanded the students' basic understanding of IOT and improved their innovation.

Nucleation Studies of Active Pharmaceutical Ingredients in an Air-Segmented Microfluidic Drop-Based Crystallizer

In this work, an innovative experimental platform to study the nucleation behavior of an active pharmaceutical ingredient (API) using a gas-segmented flow produced by a microfluidic T-junction device with fine perfluoroalkoxy alkane (PFA) tubing is presented. In the experiments, a continuous airflow was used to segment the supersaturated liquid phase into nearly monodispersed droplets (with a coefficient of variance about 15% of the drop size distribution) at the T-junction. As the API molecules have relatively low gas/solvent partition coefficients, mass transfer between phases is effectively inhibited. Nucleation then occurred within the drops in the temperature-controlled capillary crystallizer. By treating the probability of crystal nucleation in each drop as a nonstationary Poisson process, the effect of process conditions on lactose and aspirin nucleation was studied. In lactose nucleation studies, the Poisson rate process effectively captures the nucleation behavior, and the estimated nucleation parameters show good agreement to literature values. However, the lactose nucleation rate increased more sharply with a supersaturation ratio than predicted by classical nucleation theory. The validation of aspirin nucleation studies from ethanol demonstrates the application of this newly design system for crystallization of relatively nonpolar organic molecules from nonaqueous solvents to give crystals with controlled attributes.

An innovative audiovisual immersion space and its prospects for cultural heritage advancement

ARTE270 is an innovative experimental platform that combines panoramic optical projection video and photography with surround sound. The idea is to immerse the spectator/listener into audiovisual content both in realistic and artistic terms. It initially emerged in order to perform artistic experimentation on data derived from the flourishing natural environment of the Ionian Islands. Nevertheless, in the course of time, it comes up that a very important potential application lies with sustainable development. Our platform has been tried as part of a holistic approach for capturing, preserving and promoting further forms of cultural heritage as well as cultural networking through the new rendering capabilities of digital media.

Research and Construction of Automation Comprehensive Experimental Platform

According to the automation and related professional laboratory present situation, combining with the main courses of teaching content, an automation integrated innovation experimental teaching platform is designed based on the current situation of the laboratory for automation specialty and related majors. This platform integrates advanced theory and technology of sensor, measurement computer control,information engineering and communication engineering, which can complete the basic experiment of main courses, but also develop some comprehensive, professional design and innovative experiments. So the platform can maximize the effect of teaching, experiment and research.

Efficient Resource Scheduling Scheme in Innovation Network Practical Platform

Innovative network practice and experimental platform is a very important issue in information technology research area. In this paper, with fully considering the characteristics of the advanced innovative network practical platform, an efficient resource scheduling scheme (RSS) is proposed to improve the utility and practice ability, which merges curriculum knowledge, assessment methods and the organic integration of four systems to improve the students practice and innovation ability. RSS formulates the resource scheduling as a control action, and provides an optimized resource allocation for new requests, which first gives certain characterizations of the optimal solution. With detailed numerical and experimental results, it shows that the proposed RSS can achieve better performance in user fairness index, packet loss rate and throughput.

Multi-platform experiment to cross a boundary between laboratory and real situational studies: experimental discussion of cross-situational consistency of driving behaviors

We constructed an innovative experimental platform to study cross-situational consistency in driving behavior, conducted behavioral experiments, and reported the data obtained in the experiment. To discuss cross-situational consistency, we separated situations in which people use some systems to conduct tasks into three independent conceptual factors: environment, context, and system. We report the experimental results with the following systems: a laboratory system with a gaming controller and steering/pedal controllers and a real system, COMS an instrumented vehicle. The results are summarized as follows. 1) The individual behaviors in each system were stable, and consistency was retained. 2) The consistency of the behaviors was also confirmed when the participants drove using different interfaces in identical systems. 3) However, only slight correlation was observed across different systems in a specific situation where a strong high-order cognitive constraint (i.e., rapid driving) and a weak low-order cognitive constraint (driving with easy handling toward a straight-line course) were given.

Testing Communication Strategies to Convey Genomic Concepts Using Virtual Reality Technology

Health professionals need to be able to communicate information about genomic susceptibility in understandable and usable ways, but substantial challenges are involved. We developed four learning modules that varied along two factors: (1) learning mode (active learning vs. didactic learning) and (2) metaphor (risk elevator vs. bridge) and tested them using a 2 × 2 between-subjects, repeated measures design. The study used an innovative virtual reality technology experimental platform; four virtual worlds were designed to convey the concept that genetic and behavioral factors interact to affect common disease risk. The primary outcome was comprehension (recall, transfer). Study participants were 42 undergraduates aged 19–23. The results indicated that the elevator metaphor better supported learning of the concept than the bridge metaphor. Mean transfer score was significantly higher for the elevator metaphor (p < 0.05). Mean change in recall was significantly higher for didactic learning than active learning (p < 0.05). Mean ratings for variables posited to be associated with better learning (e.g., motivation), however, were generally higher for the active learning worlds. The results suggested that active learning might not always be more effective than didactic learning in increasing comprehension of health information. The findings also indicated that less complex metaphors might convey abstract concepts more effectively.

MATTERS ARISING: Cavanagh replies:

Cortical reorganization occurring in multiple sclerosis (MS) patients is thought to play a key role in limiting the effect of structural tissue damage. Conversely, its exhaustion may contribute to the irreversible disability that accumulates with disease progression. Several aspects of MS-related cortical reorganization, including the overall functional effect and likely modulation by therapies, still remain to be elucidated. The aim of this work was to assess the extent of functional cortical reorganization and its brain structural/pathological correlates in Dark Agouti rats with experimental autoimmune encephalomyelitis (EAE), a widely accepted preclinical model of chronic MS. Morphological and functional MRI (fMRI) were performed before disease induction and during the relapsing and chronic phases of EAE. During somatosensory stimulation of the right forepaw, fMRI demonstrated that cortical reorganization occurs in both relapsing and chronic phases of EAE with increased activated volume and decreased laterality index versus baseline values. Voxel-based morphometry demonstrated gray matter (GM) atrophy in the cerebral cortex, and both GM and white matter atrophy were assessed by <i>ex vivo</i> pathology of the sensorimotor cortex and corpus callosum. Neuroinflammation persisted in the relapsing and chronic phases, with dendritic spine density in the layer IV sensory neurons inversely correlating with the number of cluster of differentiation 45-positive inflammatory lesions. Our work provides an innovative experimental platform that may be pivotal for the comprehension of key mechanisms responsible for the accumulation of irreversible brain damage and for the development of innovative therapies to reduce disability in EAE/MS. <b>SIGNIFICANCE STATEMENT</b> Since the early 2000s, functional MRI (fMRI) has demonstrated profound modifications in the recruitment of cortical areas during motor, cognitive, and sensory tasks in multiple sclerosis (MS) patients. Experimental autoimmune encephalomyelitis (EAE) represents a reliable model of the chronic-progressive variant of MS. fMRI studies in EAE have not been performed extensively up to now. This paper reports fMRI studies in a rat model of MS with somatosensory stimulation of the forepaw. We demonstrated modifications in the recruitment of cortical areas consistent with data from MS patients. To the best of our knowledge, this is the first report of cortical remodeling in a preclinical <i>in vivo</i> model of MS.