Experimental Setup Research Articles

Simulation and quantitative evaluation of three surgical techniques of endoscopic enucleation of prostate on a realistic phantom model.

To evaluate the impact of three different AEEP techniques on the training performance of novices using a realistic hydrogel prostate phantom model. The experimental setup utilized realistic prostate phantom model provided by the Max Planck Institute for Intelligent Systems, Germany. For the enucleation, we utilized a new solid-state pulsed thulium laser (Thulio®, Dornier MedTech, Weßling, Germany). We explored three different AEEP techniques-bilobar, trilobar, and en-bloc-repeated ten times each, totaling 30 procedures. Median enucleation time was 9.5 min (range: 6-16), median laser time was 4.29 min (3.21-6.34), median total energy used was 25.8 kJ (19.4-38.1), and median number of laser pulses was 12.8 thousand (9.7-17). There were no significant differences in operation time, laser time, pulses, or joules among the en-bloc, two-lobe, and three-lobe techniques (p = 0.113, 0.143, 0.148, 0.141 respectively). Ultrasound evaluations showed the one-lobe technique to be superior in accuracy, smoothness, and circularity (p = 0.0002, 0.012, 0.00005 respectively) (Figs. 9, 10, 11), despite having the highest perforation rate, which was not statistically significant compared to other techniques (p = 1.4). The one-lobe technique's higher accuracy may increase the risk of perforation. In contrast, the three-lobe technique had the lowest perforation rate and removal efficiency due to its lower accuracy. The en-bloc, bilobar, and trilobar enucleation techniques exhibited comparable operation times. The one-lobe method emerged as superior in terms of accuracy, smoothness, and circularity. However, it also presented the highest rate of perforation.

A comprehensive dataset on cytotoxicity of ionic liquids

Ionic liquids (ILs) are structurally tunable salts with applications ranging from chemical synthesis to batteries, novel materials and medicine. Despite their potential, the toxicity of ILs poses significant environmental and biological challenges. This study introduces a comprehensive dataset of cytotoxicity of 1227 ILs, compiled from 151 research papers and encompassing 3837 data entries. For each entry, the following information is provided: substance name, empirical formula, CAS, SMILES, molecular weight, cytotoxicity value, details on the experimental setup (incubation time, cell line, assay used, etc.), and reference to the original publication. This dataset can be used for deriving structure‒activity relationships and establishing the major structural elements that govern the cytotoxic effects of ILs on eukaryotic cells. The dataset is available freely to all researchers.

Dung Beetles, Dung Burial, and Plant Growth: Four Scarabaeoid Species and Sorghum

This study examined the impact of dung beetles on both sorghum growth and the physico-chemical properties of the soil over a two-month period. Four dung beetle species (Onthophagus vacca, Onthophagus marginalis subsp. andalusicus, Euonthophagus crocatus, and Gymnopleurus sturmi) were introduced into experimental setups, consisting of containers filled with sterilised clay-loam soil, with three treatment groups: [cow dung + beetles], [cow dung only], and a control group (no dung nor beetles), in order to evaluate their effects on various growth parameters, including the plant height, biomass, leaf area, and chlorophyll concentration. Additionally, changes in soil properties were assessed, focusing on the organic matter content, pH, conductivity, enzyme activities (e.g., urease, phosphatase), and microbial load. The results revealed significant increases in all the measured parameters across the treatments involving dung beetles, emphasising their role in enhancing soil fertility and plant productivity. The study also highlights the variation in effectiveness among the species, suggesting that beetle diversity plays a crucial role in nutrient cycling. Integrating dung beetles into sustainable farming practices could, therefore, serve as a key strategy to promote resilient agriculture.

Influence of vaccination against infectious diseases on the carbon footprint of fattening pigs: a systematic review

IntroductionIn all sectors of the economy, including livestock production, there is an increasing focus on sustainability criteria. The carbon footprint is therefore an important target value in pig production. The aim is to minimize this value. Infectious diseases may affect the performance negatively, potentially leading to a higher carbon footprint. Therefore, vaccinations may be a useful tool to ensure a high level of sustainability in pork production.Materials and methodsThe aim of this evaluation was to assess the impact of vaccinations against Porcine Circovirus Type 2 (PCV2), Mesomycoplasma hyopneumoniae (M. hyo), both PCV2 and M. hyo, and Lawsonia intracellularis (LI) in epidemic situations in Europe on performance parameters using results from former publications on these diseases. These parameters were then used to calculate the carbon footprint of the pigs using life cycle assessment (LCA). The data collection with PubMed was based on the PRISMA guidelines for systematic reviews and meta-analyses, from which, however, some deviations were made. In total, 14 trials on PCV2, 10 trials on M. hyo, 14 trials on M. hyo and PCV2, and 17 trials on LI fulfilled the criteria and were included in this evaluation. In general, review articles and studies published before 1990 were excluded as were studies with incomplete data concerning the performance parameters and studies from non-European countries if the published body weights, genetics used, or other details in the experimental setup suggested they were not comparable to European standards.ResultsThe mean carbon footprint was up to 12.1% (PCV2), 2.5% (M. hyo), 9.3% (PCV2 and M. hyo), or 3.5% (LI) lower following a vaccination.DiscussionThis evaluation clearly shows that healthy animals can achieve a reduced carbon footprint through better performance with lower resource consumption, which is extremely important for sustainable animal husbandry. The use of health preserving measures such as vaccination can be a useful and important tool for reaching this goal.

Light-guided dynamic phantom to mimic microvasculature for biomedical applications: an exploration for pulse oximeter.

Dynamic phantoms capable of changing optical properties by control are essential for standardizing and calibrating spectroscopy systems such as the pulse oximeter. However, current liquid dynamic phantoms containing human blood have a short shelf life and require complex experimental setups. Some solid dynamic phantoms are influenced by the angular-dependent performance of the liquid crystal display (LCD), some have a low spatial resolution, and some have slow control of optical properties. We aimed to develop a solid dynamic phantom, which can overcome these obstacles by changing the optical properties rapidly and generating dynamic biological signals. The absorption properties of the phantom can be controlled in real time by modulating an LCD. A light guide was employed to avoid the angular-dependent performance of the LCD by isolating the scattering top-layer tissue-mimicking silicone phantom from the LCD. The dynamic phantom was characterized at 940, 660, 530, and 455nm to create a lookup table. Photoplethysmography signals of different heart rates from 80 to 120 beats per minute were synthesized, and oxygen saturation levels at 86%, 90%, 95%, and 100% were generated at multiple wavelengths. The design, characterization, and potential applications of the dynamic phantom have been presented. This dynamic phantom can simulate various biological signals by applying corresponding modulation signals and has the potential to calibrate and validate pulse oximeter, imaging, and spectroscopy systems.

Analyzing the Impact of Responding to Joint Attention on the User Perception of the Robot in Human-Robot Interaction

The concept of joint attention holds significant importance in human interaction and is pivotal in establishing rapport, understanding, and effective communication. Within social robotics, enhancing user perception of the robot and promoting a sense of natural interaction with robots becomes a central element. In this sense, emulating human-centric qualities in social robots, such as joint attention, defined as the ability of two or more individuals to focus on a common event simultaneously, can increase their acceptability. This study analyses the impact on user perception of a responsive joint attention system integrated into a social robot within an interactive scenario. The experimental setup involves playing against the robot in the “Odds and Evens” game under two conditions: whether the joint attention system is active or inactive. Additionally, auditory and visual distractors are employed to simulate real-world distractions, aiming to test the system’s ability to capture and follow user attention effectively. To assess the influence of the joint attention system, participants completed the Robotic Social Attributes Scale (RoSAS) after each interaction. The results showed a significant improvement in user perception of the robot’s competence and warmth when the joint attention system was active.

On-chip high-dimensional entangled photon sources

Abstract High-dimensional quantum entanglement is an important resource for emerging quantum technologies such as quantum communication and quantum computation. The scalability of metres-long experimental setups limits high-dimensional entanglement in bulk optics. Advancements in quantum technology hinge on reproducible, and reconfigurable quantum devices — including photon sources, which are challenging to achieve in a scalable manner using bulk optics. Advances in nanotechnology and CMOS-compatible integration techniques have enabled the generation of entangled photons on millimeter-scale chips, significantly enhancing scalability, stability, replicability, and miniaturization for real-world quantum applications. In recent years we have seen several chip-scale demonstrations with different degrees of freedom including path, frequency-bin, time-bin, and transverse modes, on many material platforms. A complete quantum photonic integrated circuit requires the generation, manipulation, and detection of qudits, involving various active and passive quantum photonic components which further increase the degree of complexity. Here, we review and introduce the nonlinear optical processes that facilitate on-chip high-dimensional entangled photon sources and the currently used material platforms. We discuss a range of current implementations of on-chip high-dimensional entangled photon sources and demonstrated applications. We comment on the current challenges due to the limitations of individual material platforms and present future opportunities in hybrid and heterogeneous integration strategies for the next generation of integrated quantum photonic chips.

An Experiment of AI-Based Assessment: Perspectives of Learning Preferences, Benefits, Intention, Technology Affinity, and Trust

The rising integration of AI-driven assessment in education holds promise, yet it is crucial to evaluate the correlation between trust in general AI tools, AI-based scoring systems, and future behavioral intention toward using these technologies. This study explores students’ perspectives on AI-assisted assessment in higher education. We constructed a comprehensive questionnaire supported by relevant studies. Several hypotheses grounded in the literature review were formulated. In an experimental setup, the students were tasked to read a designated chapter of a paper, answer an essay question about this chapter, and then have their answers evaluated by an AI-based essay grading tool. A comprehensive data analysis using Bayesian regression was carried out to test several hypotheses. The study finds that remote learners are more inclined to use AI-based educational tools. The students who believe that AI-based essay grading is less effective than teacher feedback have less trust in AI-based essay grading, whereas those who find it more effective perceive more benefit from it. In addition, students’ affinity for technology does not significantly impact trust or perceived benefits in AI-based essay grading.

Multiple Electromechanical-Failure Detection in Induction Motor Using Thermographic Intensity Profile and Artificial Neural Network

The use of artificial intelligence-based techniques to solve engineering problems is increasing. One of the most challenging tasks facing industry is the timely diagnosis of failures in electromechanical systems, as they are an essential part of production systems. In this sense, the earlier the detection, the higher the economic loss reduction. For this reason, this work proposes the development of a new methodology based on infrared thermography and an artificial intelligence-based classifier for the detection of multiple faults in an electromechanical system. The proposal combines the intensity profile of the grey-scale image, the use of Fast Fourier Transform and an artificial neural network to perform the detection of twelve states for the state of an electromechanical system: healthy, bearing defect, broken rotor bar, misalignment and gear wear on the gearbox. From the experimental setup, 50 thermographic images were obtained for each state. The method was implemented and tested under different conditions to verify its reliability. The results show that the precision, accuracy, recall and F1-score are higher than 99%. Thus, it can be concluded that it is possible to detect multiple conditions in an electromechanical system using the intensity profile and an artificial neural network, achieving good accuracy and reliability.

Using a Piecewise Linear Spring to Approximate an Essentially Nonlinear Spring: Design and Validation

This study develops a procedure for designing a piecewise linear spring (PLS) to approximate an essentially nonlinear spring (ENS). The PLS is constructed with a cantilever beam constrained by a pair of single- or double-stop blocks. The design begins by determining the restoring force of the desired ENS using the equivalent stiffness which quantifies the characteristics of a cubic polynomial. Then, based on the force-deflection model of a cantilever beam with an overhang, the configuration parameters for single- and double-stop blocks are determined through a least squares optimization. The numerical simulation demonstrates that the PLS with double-stop blocks approximates the desired ENS behaviors better in terms of the restoring force, potential energy, and instantaneous frequency transition. An experiment apparatus with four tunable stop blocks is developed to validate the numerical simulation results. The static experimental tests verify the accuracy of the analytical model. The dynamic experimental tests show that within the achievable range of displacement, the PLSs behave similarly to the ENS. However, the maximum displacement is smaller than the designed one due to an insufficient exciting force. To address this issue, the desired displacement range is reduced by half. With the redesigned PLSs, the improved experimental results are obtained.

Measuring Precipitation via Microwave Bands with a High-Accuracy Setup

The urgent need for timely and accurate precipitation estimations in the face of ongoing climate change and the increasing frequency and/or intensity of extreme weather events underscores the necessity for innovative approaches. Recently, several studies have focused on estimating the precipitation rate through induced attenuation of radio frequency (RF) signals, which are abundant in modern communication systems. Most research has concentrated on frequencies exceeding 10 GHz, as attenuation at lower frequencies is minimal, posing measurement challenges. This study aims to confront this limitation by introducing a high-precision experimental setup capable of detecting this subtle attenuation at frequencies under 10 GHz. The setup includes a transmitter and receiver optimized for operation at 2.07, 4.63, and 6.22 GHz, where minimal worldwide research exists. A power resolution below 10−5 dB in preliminary measurements demonstrated its effectiveness in quantifying signal attenuation due to precipitation across the specified frequencies. Moreover, a strong power law relationship was observed between signal attenuation and precipitation rate for all three frequencies, while, as expected, the higher the frequency, the more pronounced the signal attenuation was.

Evaluation of the Antipyretic Effects of Methanolic Leaf Extract of Chromolaena odorata in Albino Rats

This study evaluates the antipyretic activity of methanolic leaf extract of Chromolaena odorata in albino rats. Pyrexia, commonly known as fever, is the medical term for an elevated body temperature. It occurs when the body's temperature rises above the normal range, typically over 38°C (100.4°F), as a response to infection, inflammation, or other stimuli. The experimental setup included five groups of albino rats, with two control groups receiving either normal saline (negative control) or acetaminophen (positive control), and the test groups receiving 200 mg/kg and 400 mg/kg of the leaf extract. Fever (pyrexia) was induced using 0.01 mL/kg of Escherichia coli suspension injected into the rats, after which varying doses of the methanolic leaf extract were administered. The results demonstrated a significant reduction in rectal temperature in the rats treated with the extract, showing a dose-dependent response. The highest antipyretic activity was observed in the group administered 400 mg/kg, where the rectal temperature decreased by 2.5°C within two hours of treatment. This effect was comparable to, and in some cases, exceeded that of acetaminophen, suggesting that the methanolic extract of Chromolaena odorata possesses significant antipyretic properties. The observed antipyretic effect may be attributed to the bioactive constituents of the plant, including flavonoids, terpenoids, and anthraquinones. Further research is recommended to isolate and characterize the active compounds responsible for the observed pharmacological activity.

Applied fault diagnosis with distributed monitoring systems: Bridging theory with practice

We address the feasibility of the pragmatic implementation of monitoring systems for real-time distributed fault diagnosis in complex processes. We delve into the integration of theoretical distributed estimation methods and practical distributed embedded systems. This study emphasizes the merger of distributed computing and signal processing to augment fault diagnosis in dynamic systems. We introduce a generic mathematical model for distributed fault diagnosis algorithms, laying the groundwork for a reference network computing architecture that details the essential components, organization, and operational characteristics necessary for distributed monitoring systems. Subsequently, we evaluate existing software and hardware solutions that facilitate the realization of these systems. The theoretical framework and system design are empirically validated through an experimental setup involving a liquid-level control system, demonstrating the efficacy and applicability of our approach.

The global effect of aortic coarctation on carotid and renal pulsatile hemodynamics.

Coarctation of the aorta (CoA) is a congenital disease characterized by the narrowing of the aorta, typically the descending portion after the left subclavian artery. If left untreated, by the time individuals reach 50 years of age, the mortality rate can reach 90%. Previous studies have highlighted the adverse effects of CoA on local hemodynamics. However, no study has investigated the global hemodynamic effects of CoA in end-organ (brain and kidney) damage. Clinical studies have shown that coarctation acts as a reflection site, potentially damaging the hemodynamics of the brain and kidneys. Our goal in this study is to investigate the underlying mechanisms of these altered wave dynamics and their impacts on the pulsatile hemodynamics of end-organs. In this study, we use a physiologically accurate in-vitro experimental setup that simulates the hemodynamics of systemic circulation. Experiments are conducted across various cardiac outputs, heart rates, and coarctation degrees using aortas across a wide range of aortic stiffnesses. Our principal finding is that CoA increases cerebral blood flow and harmful pulsatile energy transmission to the brain. Conversely, both renal blood flow and pulsatile energy transmission to the kidneys are reduced in CoA at every level of aortic stiffness.

Study on the Lower Explosion Limit of Ventilation Air Methane at 700–1200℃

ABSTRACT Regenerative thermal oxidation (RTO) of Ventilation Air Methane (VAM) is an environmentally friendly technology for harnessing heat energy. Higher concentrations of methane can improve utilization efficiency, but it suffers from a high risk of explosion. The lower explosive limit (LEL) of methane at temperatures of 700–1200°C is determined using a self-designed experimental apparatus, and the mechanism at the LEL is analyzed using the GRTO (Gas regenerative thermal oxidation) model constructed by our research group. Results reveal that a linear correlation between the LEL and temperature within 700–1200°C. As the temperature rises, the LEL exhibits a consistent decline. Furthermore, the maximum concentration of VAM in RTO process is elucidated, with an average of 95.3% of LEL. The concentration of ·OH determines the explosive severity at the LEL, and methane explosions are dominated by H+O2⇔O+OH and H2+ OH⇔OH+H2O. 2CH3(+M)⇔C2H6(+M) plays a vital role in inhibiting methane explosion, and its inhibitory effect decreases by 59.5% at 1200°C compared to 700°C.

Potential of the CLARA test facility for VHEE radiotherapy research

The Compact Linear Accelerator for Research and Applications (CLARA) is a test facility at the STFC Daresbury Laboratory, which is capable of delivering ultra-bright electron bunches of up to 250 MeV beam energy. A new beam line has been designed to maximise the exploitation of the CLARA facility in a variety of scientific fields, including novel acceleration and new modalities of radiotherapy. In this paper, we present the specification and design of this beam line to explore the possibilities of pursuing R&D in very high-energy electron (VHEE) radiotherapy and VHEE with FLASH radiotherapy. We describe the beam line design, including the flexibility of the beam optics to focus the beam in a range of locations and present results from preliminary start-to-end simulations using Monte Carlo tracking codes. We highlight advantages of this beam line, including rapid access to the shielded experimental hutch and the possibilities for the installation of different experimental setups in two dedicated chambers. The beam line includes focussing magnets, extensive diagnostics, and allows in-air installation within the experimental beam line. The facility will allow an experimental programme towards addressing many outstanding issues related to this new radiotherapy modality. We also describe the available flexibility in beam parameters for both conventional dose rates and those entering into the FLASH regime. The possibility of both living cells and treatment planning studies is anticipated to be conducted at this world-class facility.

Quantitative assessment of refrigerant impact on vehicle air-conditioning systems via Z-Freq 2D statistical analysis

In this study, the impact of refrigerant types on the performance and efficiency of vehicle air-conditioning (AC) systems was quantitatively assessed using a novel two-dimensional Z-Freq 2D statistical analysis method. Wireless vibration accelerometers, capturing both horizontal and vertical vibrations, were utilized to measure the dynamic response of the air-conditioning compressor. Before data collection, meticulous calibration of sensors was conducted to ensure the accuracy and reliability of measurements. The introduction of the Z-Freq 2D statistical analysis technique, developed specifically for this research, allowed for a comprehensive examination of the vibrational data, facilitating a deeper understanding of the effects of different refrigerants on AC system performance. To validate the effectiveness and reliability of the Z-Freq 2D analysis, machine learning techniques were employed. These techniques provided a robust framework for the analysis of the statistical data, with performance evaluation indicators demonstrating the efficacy of the newly developed method. The experimental setup was based on an actual vehicle air-conditioning test rig, designed to simulate real-world operating conditions accurately. The findings of this research offer significant insights into the selection of refrigerants for vehicle AC systems, highlighting the potential for enhanced system performance and efficiency through the application of advanced statistical analysis and machine learning validation techniques. This study not only contributes to the field of automotive thermal management but also paves the way for future research in the optimization of vehicle AC systems.

Experimental design for testing Local Lorentz Invariance violation in gravity

Abstract Local Lorentz invariance is an important foundation of General Relativity, and
its high-precision testing can help to explore the unified theories. In this work, we focus on the local Lorentz violating effect in pure gravity with mass dimension $d$=6, and study the experimental design for testing local Lorentz violation with precision torsion pendulum experiments. By designing the striped test and source masses, and setting the appropriate azimuth angles of the experimental setup, we found the constraint accuracy of the local Lorentz violation coefficients is expected to be improved by one to two orders of magnitude compared with the international optimal level. Moreover, considering the difficulty level of changing the azimuth angle of the experimental setup in practical experiments, we proposed two experimental strategies and separately studied the azimuth-angle configurations corresponding to the optimal constraint of the local Lorentz violating coefficients, which can guide the development of the later experiments.

Experimental Investigation of the Impact of Mixed Wettability on Pore-Scale Fluid Displacement: A Microfluidic Study.

Understanding rock wettability is crucial across various fields including hydrology, subsurface fluid storage and extraction, and environmental sciences. In natural subsurface formations like carbonate and shale, mixed wettability is frequently observed, characterized by heterogeneous regions at the pore scale that exhibit both hydrophilic (water-wet) and hydrophobic (oil-wet) characteristics. Despite its common occurrence, the impact of mixed wettability on immiscible fluid displacement at the pore scale remains poorly understood, creating a gap in effective modeling and prediction of fluid behavior in porous media. The primary objective of this study was to investigate how mixed wettability affects pore-scale fluid displacement dynamics, utilizing microfluidic devices designed to replicate rock-like structures with varied wettability properties. Current techniques for achieving mixed wettability within microfluidic devices often struggle with spatial control and resolution, limiting their accuracy. To address this limitation, a novel approach was employed that combined photolithography and molecular vapor deposition of perfluorodecyltrichlorosilane to precisely and selectively modify wettability within specific pore regions, achieving a mixed wettability distribution correlated with pore size for the first time. The experimental setup included five identical micromodels representing distinct wetting conditions, which were initially saturated with air and subsequently flooded by water. By systematically varying the ratio of hydrophilic to hydrophobic areas, we covered a range from fully hydrophilic to fully hydrophobic and intermediate mixed wettability configurations. Comparative displacement experiments revealed that pore-level mixed wettability has a pronounced effect on fluid displacement behavior, influencing the injection time, spatial invasion patterns, and dynamic pressure profiles. Results indicated that both the injection time and dynamic pressure decreased with an increase in the hydrophilic area fraction. Each wettability configuration displayed unique sequences of pore-filling events, emphasizing the critical role of the wettability distribution in influencing displacement dynamics. While mixed wettability exhibited a clear monotonic effect on invasion time and dynamic pressure, saturation behavior was notably nonmonotonic. Interestingly, mixed wettability scenarios with relatively medium to high hydrophilic fractions demonstrated enhanced overall sweep efficiency compared to the hydrophobic case and reduced the bypassed gas phase relative to the hydrophilic case. However, inefficiently distributed mixed wet zones were found to reduce the sweep efficiency. These findings highlight the critical influence of mixed wettability in fluid displacement processes, with significant implications for applications in oil recovery, CO2 sequestration, and other subsurface energy technologies.

Numerical investigation of the bridging and current flow of a positive DC streamer using a 1.5D model

Abstract Single streamers, at nanosecond-timescales, can be simulated using detailed computational models with a high-dimensional representation. These models are computationally impractical for parametric explorations and simulation of longer times, that can follow many-streamer pulsations and the influence of one streamer burst on the next. This work develops a 1.5D model of a positive DC streamer for simulations beyond the electrode-gap bridging phase, and uses it to parametrically explore the impact of different terms and operational parameters. The geometry of interest is that of a tip-to-plane electrode configuration under DC voltage, and the simulation is followed for the duration of one current pulse (order 500 ns). The numerical model uses an axisymmetric boundary element method to solve for the electric field, as well as a ‘stack’ of 3 different transient solvers to improve efficiency and allow solving over longer timescales. The model is able to resolve the development of the cathode sheath during the streamer bridging phase using a kinetic flux boundary condition. It also gives qualitative agreement to current waveforms using an equivalent experimental setup. The different phases of the current pulse (streamer propagation, bridging, and current-flow phase) are discussed in detail.