Phase System Research Articles

Aqueous-organic and aqueous-vapor interfacial phenomena for three phase systems containing CO2, CH4, n-butanol, n-dodecane and H2O at saturation conditions

A fundamental understanding of the interfacial properties at elevated pressure is essential for processes in the context of the energy transition, such as the storage of CO2, H2 or CH4. Systems in such processes have traces of impurities. This work aims to systematically investigate these multi-component systems through simplified vapor-liquid-liquid systems comprising H2O, (n-butanol or n-dodecane), and (CO2 or CH4). The model systems are theoretically investigated using the density gradient theory and the PCP-SAFT. The interfacial tension and saturated phase density of the model systems are experimentally measured by the pendant drop and the oscillating tube method, respectively. Good agreement between the theoretical and experimental results is found. It was found that the pure and binary systems of these mixtures can be described well by the introduced model, delivering high quality predictions.

Improvement of mechanical properties of Mg2Si phase system by doping transition metals: a first-principles study

Improvement of mechanical properties of Mg2Si phase system by doping transition metals: a first-principles study

Simultaneous quantitative analysis of some main components in cinnamon leaves (Cinnamomum cassia) by HPLC-PDA

Cinnamon leaves, a part of the cinnamon tree, are used as raw materials to extract cinnamon essential oil and as a spice in food processing. Trans-cinnamaldehyde is the main ingredients that have biological effects and high concentration in cinnamon, cinnamic acid is often used as a marker in the quantification methods of cinnamon, coumarin is the ingredient that needs to be controlled due to risk of liver toxicity. So that, cinnamaldehyde (CAL), cinnamic acid (CA) and coumarin (CM) have been choosen to determin quality of cinnamon leaves. The analytes in the test sample were extracted with methanol:water ratio 9:1 by ultrasound twice 30 minutes and resting for 30 minutes between extractions. The ultrasonic extract was analyzed using an HPLC-PDA, C18 column (250×4.6 mm, 5 µm) at 25°C, mobile phase system consisting of acetonitrile and 0.05% phosphoric acid is eluted according to the program's gradient, detection wavelength 280 nm. The method was determined according to AOAC 2016 guidelines with appropriate specificity and linearity ranging from 51.90-691.31 µg/mL for coumarin, 1.00-20.10 µg/mL for cinnamic acid and 52.45-609.8 µg/mL for trans-cinnamaldehyde, good repeatability with RSD from 0.46% to 0.61%, accuracy of coumarin, cinnamic acid and cinnamaldehyd were 101.0%, 100.7% and 100.7% respectively, meets AOAC requirements at 3 concentration levels. The study applied quantitative research methods to quantify coumarin, cinnamic acid and transcinnamaldehyde on 17 C. cassia leaves samples collected in provinces in Vietnam. In result, analyte concentrations varied widely between samples, with coumarin ranging from 0.53- 2.47%, cinnamic acid from 0.01-0.08%, and cinnamaldehyde from 0.95-2.56%.

Surface Tension of Cu-Ti Alloys and Wettability in a Liquid Alloy-Refractory Material-Gaseous Phase System.

The study involved measurements of surface tension of liquid binary copper-titanium alloys with respect to their chemical composition and temperature as well as investigations of the liquid alloy-refractory material-gaseous phase system wettability using usual refractory materials, i.e., graphite, aluminum oxide and magnesium oxide. The experiments were performed with the use of the sessile drop method and a high-temperature microscope coupled with a camera and a computer. The aim of this study was to determine the influence of titanium content in the Cu-Ti alloy on the surface tension and contact angle at the interface between the liquid alloy and the refractory material. The influence of temperature on these parameters was also examined. The tests were carried out for copper-titanium alloys with a maximum content of 1.5% wt. Ti, in the temperature range of 1373 to 1573 K. The test results indicate that as the titanium content in the alloy increases, its surface tension increases slightly. However, an increase in temperature causes a decrease in the surface tension of the alloys. In the case of an alloy containing 1.5% wt. Ti, surface tension at a temperature of 1373 K reaches 1351 mN∙m-1, and at a temperature of 1573 K, it decreases to 1315 mN∙m-1. As the temperature and titanium content in the alloy increase, a decrease in the contact angle is observed. The highest values of contact angles were recorded in the case of contact of the liquid alloy with graphite. For an alloy containing 0.1% wt. Ti at a temperature of 1373 K, the contact angle reaches 132°, while at a temperature of 1573 K, it decreases to 128°. For an alloy containing 1.5% wt. Ti, the values of contact angles are 100° and 96°, respectively. However, the contact angles have the lowest values for magnesium oxide. In the case of a temperature of 1573 K and an alloy containing 1.5% wt. Ti, the contact angle reaches 49°. Such a significant impact of titanium content on the contact angles may be due to its high affinity for oxygen (contact with a substrate made of Al2O3 and MgO and its reactivity with carbon (contact with graphite).

Transducer module apodization to reduce bone heating during focused ultrasound uterine fibroid ablation with phased arrays: A numerical study.

During magnetic resonance-guided focused ultrasound (MRgFUS) surgery for uterine fibroids, ablation of fibrous tissues in proximity to the hips and spine is challenging due to heating within the bone that can cause patients to experience pain and potentially damage nerves. This far-field bone heating limits the volume of fibroid tissue that is treatable viaMRgFUS. To investigate transducer module apodization for improving the ratio of focal-to-bone heating ( ) when targeting fibroid tissue close to the hips and spine, to enable MRgFUS treatments closer to thebone. Acoustic and thermal simulations were performed using 3D magnetic resonance imaging (MRI)-derived anatomies of ten patients who underwent MRgFUS ablation for uterine fibroids using a low-frequency ( ) 6144-element flat fully-populated modular phased array system (Arrayus Technologies Inc., Burlington, Canada) at our institution as part of a larger clinical trial (NCT03323905). Transducer modules ( per module) whose beams intersected with no-pass zones delineated within the field were identified, their output power levels were reduced by varying blocking percentage levels, and the resulting temperature field distributions were evaluated across multiple sonications near the hip and spine bones in each patient. Acoustic and thermal simulations took approximately ( ) and ( ) to run for a single near-spine (near-hip) target,respectively. For all simulated sonications, transducer module blocking improved compared to the no blocking case. In just over half of sonications, full module blocking maximized (increase of 82% 38% in 50% of hip targets and 49% 30% in 62% of spine targets vs. no blocking; mean±SD), at the cost of more diffuse focusing (focal heating volumes increased by 13%±13% for hip targets and 39%±27% for spine targets) and thus requiring elevated total (hip: 6%±17%, spine: 37%±17%) and peak module-wise (hip: 65%±36%, spine: 101%±56%) acoustic power levels to achieve equivalent focal heating as the no blocking control case. In the remaining sonications, partial module blocking provided further improvements in both (increased by 29%±25% in the hip and 15%±12% in the spine) and focal heating volume (decrease of 20%±10% in the hip and 34%±17% in the spine) relative to the full blocking case. The optimal blocking percentage value was dependent on the specific patient geometry and target location of interest. Although not all individual target locations saw the benefit, element-wise phase aberration corrections improved the average compared to the no correction case (increase of 52%±47% in the hip, 35%±24% in the spine) and impacted the optimal blocking percentage value. Transducer module blocking enabled ablative treatments to be carried out closer to both hip and spine without overheating or damaging the bone (no blocking: / , full blocking: / , optimal partial blocking: / for hip/spine). The proposed transducer apodization scheme shows promise for improving MRgFUS treatments of uterine fibroids, and may ultimately increase the effective treatment envelope of MRgFUS surgery in the body by enabling tissue ablation closer to bonystructures.

CUSTR- A VHF phased array radar for observation of atmospheric dynamics and ionospheric plasma irregularities

A VHF phased array radar for atmospheric dynamics observation is installed at the University of Calcutta, Kolkata. The Calcutta University Stratosphere-Troposphere Radar (CUSTR) operates at 53 MHz with 475 three sub-element Yagi-Uda antenna array. The CUSTR system is a high-power fully active phased array system with a dedicated 2 kW solid-state Transmit-Receiver Module (TRM) attached to each antenna, providing a total peak power of 950 kW with 47.5 kW average power at 5% maximum duty ratio. The system provides electronic beam steering capability to steer the beam 360° in azimuth direction with a maximum off-zenith angle of 40°. The array is configured with 25 sub-arrays and operates either in a combined mode in Doppler Beam Swinging or in Spaced Antenna mode using a multi-channel digital receiver system. The TRM has been designed to provide a very short pulse of 0.5 µs and a long pulse of 128 µs. The system description along with the initial scientific observations such as atmospheric boundary layer, troposphere-lower stratosphere wind measurements along with preliminary wind validation, mesosphere echoes and ionosphere irregularities are presented.

Rapid determination of 54 dye components in hair dyes by liquid chromatography coupled to quadrupole orbitrap high-resolution mass spectrometry.

Chemical hair dye components can have allergenic, reproductive, and carcinogenic risks. Detecting restricted and prohibited ingredients in these products is challenging due to product diversity, isomer separation, instability, and wide polarity range. A method was developed using HPLC-high-resolution mass spectrometry for the qualitative and quantitative analysis of 54 hair dye components in various products. Samples were extracted with a 70% methanol solution, ultrasonicated in an ice bath, centrifuged, filtered, diluted with 25% methanol solution and 25% methanol solution containing 0.05% D-isoascorbic acid. Separation was achieved using an ACE Excel 3 C18 column (2.1 mm × 150 mm, 3 μm) with analysis conducted via quadrupole Orbitrap mass spectrometry. It showed good linear correlations, with detection limits of 0.1-23.5 ng mL-1, and quantitation limits of 0.2-78.1 ng mL-1. Average recovery ranged from 60.0% to 118.4%, with repeatability from 4.0% to 14.9%. Stability was confirmed within 48 hours. When applied to 20 batches of commercially available hair dyes, 24 hair dye components were found within permissible levels. The method is crucial for quality control of hair dyes, covering 10 common prohibited and 44 permissible hair dye components outlined in the Safety and Technical Standards for Cosmetics (2015 Edition). Compared to the standard methods, it can separate isomers in a single mobile phase system within 15 minutes in positive ion mode while maintaining sensitivity for phenol, hydroquinone, and other components in negative ion mode. Moreover, the pre-treatment strategy significantly improved stability and accuracy, enabling precise analysis of the 54 hair dye components.

Maintenance satellite modular docking mechanism design for on orbit servicing to nanosatellites

PurposeAs a result of space debris problem, it is necessary to deorbit uncontrollable satellites or repair them to extend mission duration to avoid sending a new satellite. The purpose of this paper is to develop a docking mechanism that can be easily customized for different missions, providing on-orbit servicing for nanosatellites.Design/methodology/approachThis research outlines a system and mechanism design for the docking phase of on-orbit servicing to nanosatellites. The umbrella-inspired mechanism is designed with utmost simplicity to minimize the likelihood of failure. CAD, structural analyse and mechanism analyse tools are used for designing and analysing the system. To ensure that the design attains the desired durability, numerous iterations are conducted. A three-dimensional (3D)-printed prototype is generated for mechanism verification in laboratory conditions.FindingsThe aimed mechanism is generated successfully. A 3D-printed prototype is assembled to verify the mechanism. Also, an equation for customis the presented design is generated for different mission requirements in the future.Practical implicationsThe usage of the proposed design can help increase the lifespan of satellites.Originality/valueThe primary innovation in this study is the development of a docking mechanism featuring a movable platform to provide servicing for nanosatellites in orbit. The mechanism presented can be displaced without initiating the unfolding process. This provides a customizable coupling distance for different mission requirements. Therefore, the presented mechanism can serve both different types of satellites and more than one satellite on-orbit with a cost-effective design. Also, the presented design can be easily customized to enable adaptation for the different mission requirements in the future.

A Novel Topology of a 3 × 3 Series Phased Array Antenna with Aperture-Coupled Feeding.

This paper presents a novel 3 × 3 phased array antenna optimized for 4 GHz operation, achieving a realized gain of 13.2 dBi and enabling 30-degree beam steering with a minimal capacitance variation of 1.5 pF. The design features a series aperture-coupled feeding mechanism that not only reduces the antenna's size but also simplifies the fabrication process, making the device both cost-effective and compact. Integrating cost-efficient quadrature-hybrid phase shifters and novel power splitters with cascaded quadrature hybrids ensures uniform power distribution and precise beam steering. The innovative use of these components addresses common challenges in phased array systems, such as space constraints, high costs, and complex power distribution.

Development of a QAMS Analysis Method for Industrial Lanolin Alcohol Based on the Concept of Analytical Quality by Design

The Analytical Quality by Design (AQbD) concept was adopted to establish a quantitative analysis of multi-components with a single marker (QAMS) method for industrial lanolin alcohol, targeting cholesterol, lanosterol, and 24,25-dihydrolanosterol. The potential critical method parameters (CMPs) were identified as column temperature, flow rate, and gradient. Definitive screening design and statistical modeling were employed to optimize the gradient conditions of the mobile phase, column temperature, and flow rate. The Method Operable Design Region (MODR) was determined using a risk-based quantification approach. The robustness was assessed using a Plackett–Burman experimental design, followed by methodological validation. Optimal analytical conditions were as follows: acetonitrile (B)—water (A) mobile phase system; flow rate of 1.58 mL/min; detection wavelength of 205 nm; injection volume of 10 µL; and column temperature of 37 °C. A gradient elution program was implemented as follows: 0–19.0 min, 90.5% B; 19.0–25.0 min, 90.5–100% B; and 25.0–55.0 min, 100% B. Cholesterol served as an internal standard for quantifying lanosterol and 24,25-dihydrolanosterol, with relative correction factors of 0.4227 and 0.8228, respectively. This analytical method utilized only the cholesterol reference substance as an internal standard to quantify the content of cholesterol, lanosterol, and 24,25-dihydrolanosterol in industrial lanolin alcohol. It reduced the testing costs and enhanced efficiency, making it potentially suitable for widespread adoption in lanolin alcohol processing industries.

Liquid-liquid equilibrium of FAEs – glycerol phase – ethanol in the ethanol regeneration and FAE separation stage

Extraction and purification of biofuel components are as important as their synthesis. Synthesis of fatty acid esters in a molar excess of ethanol above 1:30 results in the formation of a homogeneous phase including the ester and glycerol phases dissolved in ethanol. It was observed that when excess ethanol was removed, the separation of the system into ester and glycerol phases did not always occur. To improve the biodiesel purification process the experimental binodal curve for the FAE-ethanol-glycerol phase system was obtained in the synthesis of biodiesel from rapeseed oil. The data was obtained from homogeneous alkaline synthesis of FAE with molar excess of ethanol 1:50. The pseudocomponent glycerol phase contains glycerol and unreacted oil (triglycerides (TGA)). The calculated liquid-liquid equilibrium (LLE) data for FAE – ethanol – glycerol and FAE – ethanol – TGA ternary mixtures were obtained by the UNIFAC (UNIQUAC Functional-group Activity Coefficients) model and compared with experimental diagram. It was found that glycerol and unreacted triglycerides affect the behavior of the system by preventing or promoting the mixing of immiscible components. The obtained results show that, depending on the conversion, the phase behavior of the FAE-ethanol-glycerol phase system will correspond to the ternary system FAE-ethanol-glycerol or FAE-ethanol-TGA. The obtained data help to predict the separation of glycerol and ester phases at the ethanol recovery stage knowing the degree of rapeseed oil conversion at the synthesis stage. Successful separation of the glycerol and FAE phases is possible at oil conversion above 53 %.

Design of green DES-based aqueous two phase systems for lipolytic enzymes extraction

This study pioneers a novel green and cost-effective separation process using reline deep eutectic solvent (DES) for extracting Thermomyces lanuginosus lipase (TlL) from aqueous solutions. For the first time, it has been shown that various potassium organic salts combined with reline DES can induce phase separation in aqueous solutions of the biodegradable non-ionic surfactant Tergitol 15-S9, presenting a groundbreaking alternative to the banned surfactant Triton X-100. This work uniquely applies three different equations to describe the experimental solubility curves. The selection of reline DES is particularly innovative as it avoids significant deactivation effects with three commercial lipases: Candida antarctica lipases A and B, and TlL, with the latter undergoing a detailed study. This includes an unprecedented analysis of its thermodeactivation kinetics in reline DES aqueous solutions. Additionally, a novel investigation of immiscibility regions at different temperatures, involving comprehensive Tie-Line characterizations (slope and length), preceded the evaluation of lipase extraction. Remarkably, the study demonstrates that optimizing the feed composition to contain higher water concentrations can achieve exceptionally high extraction efficiencies (approximately 90%), suggesting a transformative potential for future applications in real aqueous cultures.

A deep learning-powered intelligent microdroplet analysis workflow for in-situ monitoring and evaluation of a dynamic emulsion

Accurately determining microdroplet size and uniformity in dispersed phase systems is key for assessing emulsion stability, and essential for quality monitoring and control of emulsion products. Microscopic imaging probes have provided intuitive and advanced insights for characterizing particle microscopic morphology and dispersion in multiphase flows. However, wide size distributions, edge-cutting, overlapping, and high-density target droplets can compromise the image processing accuracy, thereby affecting the precise assessment of emulsion status. In this study, we present a deep learning-based intelligent workflow for microdroplet characterization using an in-situ high-speed particle imaging probe combined with advanced image processing techniques. With the assistance of progressive automatic annotation, a droplet image database was constructed for training the Mask R-CNN model. By incorporating image patching and supervised data augmentation strategies, our well-trained model with accuracy of 95.5% can precisely detect, localize, and segment microscale droplets with various patterns. Additionally, the shape reconstruction module visualizes true shapes of overlapping and edge-cutting droplets, facilitating precise quantification of droplet size information. To validate the feasibility and generalizability of the proposed workflow, we obtained sufficient droplet images through offline sampling during emulsion processes while employing back and front illumination for in-situ monitoring. The automated method achieves precise droplet detection and size measurement, demonstrating its immense potential in online monitoring, evaluation, and control of emulsion quality.

A Design Proposal Using Coherently Radiating Periodic Structures (CORPSs) for 2-D Phased Arrays of Limited Scanning

New configurations of 2-D phased arrays are proposed in this paper for reducing the number of phase shifters. This design methodology is based on the use of a novel coherently radiating periodic structures (CORPSs) block for 2-D phased arrays. Two new antenna systems for 2-D phased arrays are studied and analyzed utilizing the CORPSs blocks of four inputs and nine outputs. These CORPSs feeding blocks are applied in a smart way to feed the planar antenna arrays by generating the required phase plane and reducing the number of control ports. Interesting results are provided based on the experimental measurements and full-wave simulations. These results illustrate a great reduction of the active devices (phase shifters), providing a good design compromise in terms of the scanning range and side lobe level performance. Furthermore, the provided results illustrate a maximum reduction capability in the number of phase shifters of 81%, considering a scanning range of ±30° in azimuth and ±30° in elevation. A raised cosine distribution is applied to reach side lobe levels of −19 dB for ±18° and −17 dB for ±30° in elevation. These benefits could be of interest to designers of phased antenna systems.

Machine learning the electric field response of condensed phase systems using perturbed neural network potentials

The interaction of condensed phase systems with external electric fields is of major importance in a myriad of processes in nature and technology, ranging from the field-directed motion of cells (galvanotaxis), to geochemistry and the formation of ice phases on planets, to field-directed chemical catalysis and energy storage and conversion systems including supercapacitors, batteries and solar cells. Molecular simulation in the presence of electric fields would give important atomistic insight into these processes but applications of the most accurate methods such as ab-initio molecular dynamics (AIMD) are limited in scope by their computational expense. Here we introduce Perturbed Neural Network Potential Molecular Dynamics (PNNP MD) to push back the accessible time and length scales of such simulations. We demonstrate that important dielectric properties of liquid water including the field-induced relaxation dynamics, the dielectric constant and the field-dependent IR spectrum can be machine learned up to surprisingly high field strengths of about 0.2 V Å−1 without loss in accuracy when compared to ab-initio molecular dynamics. This is remarkable because, in contrast to most previous approaches, the two neural networks on which PNNP MD is based are exclusively trained on molecular configurations sampled from zero-field MD simulations, demonstrating that the networks not only interpolate but also reliably extrapolate the field response. PNNP MD is based on rigorous theory yet it is simple, general, modular, and systematically improvable allowing us to obtain atomistic insight into the interaction of a wide range of condensed phase systems with external electric fields.

Computing linear optical spectra in the presence of nonadiabatic effects on graphics processing units using molecular dynamics and tensor-network approaches.

We compare two recently developed strategies, implemented in open source software packages, for computing linear optical spectra in condensed phase environments in the presence of nonadiabatic effects. Both approaches rely on computing excitation energy and transition dipole fluctuations along molecular dynamics (MD) trajectories, treating molecular and environmental degrees of freedom on the same footing. Spectra are then generated in two ways: in the recently developed Gaussian non-Condon theory, the linear response functions are computed in terms of independent adiabatic excited states, with non-Condon effects described through spectral densities of transition dipole fluctuations. For strongly coupled excited states, we instead parameterize a linear vibronic coupling Hamiltonian directly from spectral densities of energy fluctuations and diabatic couplings computed along the MD trajectory. The optical spectrum is then calculated using powerful, numerically exact tensor-network approaches. Both the electronic structure calculations to sample system fluctuations and the quantum dynamics simulations using tensor-network methods are carried out on graphics processing units, enabling rapid calculations on complex condensed phase systems. We assess the performance of the approaches using model systems in the presence of a conical intersection and the pyrazine molecule in different solvent environments.

Deformation behavior of PST-TiAl bicrystals at 800 °C

PST (polysynthetic twinned) TiAl crystal exhibits excellent mechanical properties, and thus, it has been regarded as a critical candidate for turbine blades in the aero-engine industry. For the first time, the deformation behavior of PST-TiAl bicrystals with two different α2/γ lamellar orientations was studied in this work. Ti-46Al-6Nb bicrystals were cut from directionally solidified ingots, and three bicrystals of B1 (10°–14°), B2 (10°–19°), B3 (6°–75°) together with a single crystal of S1 (3°) were stretched at 800 °C. Then, the deformation behaviors, including fracture morphology, crack propagation, and deformation mechanism, were analyzed. Interestingly, these bicrystals show good high-temperature tensile performance, and their deformation behaviors seem to be very anisotropic. The findings indicate that the misorientation disparity in bicrystals primarily determines their deformation coordination capacity and corresponding mechanical performance. Subsequently, the difference in deformation orientation between the two lamellae significantly controls fracture behavior and deformation compatibility. High slip potential and abundant variant choices in γ phases are supposed to be beneficial for deformation capacity improvement. Meanwhile, the deformation potential of ordinary dislocation and superlattice dislocation slip systems in the α2 phase was also examined. Results show that the disparity in dislocation motion ability between γ variants gradually amplifies the advantages of the easy-mode phase in deformation through strain coordination, while mitigating the disadvantages associated with the difficult-mode phase. During further deformation, the relatively low bicrystal misorientation and small deformation capacity differences between the two lamellae determine high deformation coordination and improved performance. Overall, our work reveals that bicrystal deformation initiates at the relatively softer lamellae and proceeds to the harder lamellae, and its final comprehensive performance is determined by the deformation coordination capacity between the two lamellae.

Diffraction and microstructure study of miscible interfaces in metallic multilayers

The structural characterization of two-metal phase systems at nanometer scale which present partial or total mixing, is extremely challenging. In the present work, a model to reproduce the x-ray diffraction patterns of multilayers composed by two miscible metals, Mo and W, is presented. Two different deposition conditions were used to obtain different stress states (compressive and tensile). From the proposed model, the contribution of each metal phase was discerned, the intra layer disorder and the level of mixing at the interface were quantified. The comparison between structures deposited sequentially, with others obtained by co-evaporation is also carried out to better understand the details of the interdiffusion and to separate them from the effects of roughness and elastic adaptation stresses. Microstructure characterization by scanning and transmission electron microscopy was compared and discussed with the diffraction analysis.

A novel approach for integrating BIM and green building rating systems in the construction projects design phase

A novel approach for integrating BIM and green building rating systems in the construction projects design phase

Factors influencing patients' decisions regarding participation in clinical trials: Review of current literature.

Obtaining timely data in clinical trials (CTs) is critical for drug registration. This depends directly on the speed at which patients are recruited. This paper provides an overview of selected scientific works and literature from different countries about patients' motivators and barriers to participating in CTs From 55 articles retrieved from PubMed, 5 were selected for the analysis. Additionally, 6 publications, including 2 by Polish authors, were reviewed. As a result, we identified 10 factors for further investigation: altruism, hope for personal benefit, access to better care, the role of a doctor, the opinions of close friends or relatives, financial compensation, side effects, the patient's role as a guinea pig, effort and time, and the use of placebo. Regardless of the therapeutic area, health status, study phase, country, geographic area, economic situation, or healthcare system, patients indicated very similar reasons when deciding to participate in a CT. Even if patients as a group had similar motives and concerns, there are individual elements or unusual factors that need to be better understood and evaluated to accelerate the recruitment process in order to avoid certain drugs or therapies being overlooked or underestimated. In this way, investigators can help patients make the best decisions and more effectively support the process of registering a new drug. Future research on factors influencing patients' decisions is still necessary: We do not know how the COVID-19 pandemic may have influenced patient motivation, how new regulations on CTs are changing patients' perceptions of CTs, and what may be important depending on the study, country, therapeutic area and other factors.