Comparative Experimental Study Research Articles

Comparative experimental study on photothermal conversion and shape memory properties of MF-based flexible composite phase change materials loaded with carbon nanotubes and polydopamine

Efficient use of solar energy can effectively alleviate the problem of energy shortages. Currently, extensive researches have been carried out on photothermal conversion materials. However, factors such as photothermal conversion and thermal conductivity limit the practical implementation of photothermal materials. In this research, a novel flexible composite phase change material (CPCM) with melamine foam (MF) as the supporting skeleton, carbon nanotube (MWCNT)/polydopamine (PDA) as the light-absorbing coating and polyethylene glycol (PEG) as the energy storage material was successfully prepared. The results show that the MF-based CPCMs have good shape stability with a leakage of only 0.9 %, and high phase change enthalpies, the melting enthalpy was above 172.0 J/g. In addition, the thermal conductivity was improved due to the introduction of light-absorbing coatings into the CPCMs. Compared with MF/PEG, MWCNT/MF/PEG, and PDA/MF/PEG, MWCNT/PDA/MF/PEG were improved by 35.21 %, 8.6 % and 29.46 %, respectively. Finally, the average charging efficiency of MWCNT/PDA/MF/PEG is 96.26 %, which is 62.33 % and 20.1 % higher than that of MWCNT/MF/PEG and PDA/MF/PEG respectively, indicating that MWCNT and PDA nanofillers played a synergistic role in enhancing the performance of CPCMs. This study provides new and innovative ways for the design of photothermal materials.

A proposed model for enhancing e-bank transactions: an experimental comparative study

In this paper, we introduce a novel approach to address the dynamic prediction of customer activity in electronic payment transactions for individual clients. Our approach is founded on customer online payment transaction records from registered UK-based online retailers between 01/12/2009 and 09/12/2011. These retailers primarily specialize in unique gift items for various occasions, catering to a wide range of clients, including wholesalers. We used classification analysis based on the correlation coefficient to measure and describe a customer's electronic payment capability based on the quality of products they purchase. Furthermore, we trained multi-layered models (linear model, deep learning, random forest, and support vector machines (SVM)) to capture the dynamics of e-bank transaction reinforcement for retail customers using machine learning. Real transaction data from a UK online retailer was employed in our study. The experimental results consistently demonstrated the effectiveness of our proposed strategy.

Histopathological Evaluation of Bipolar and Microneedle Radiofrequency Energy on the Skin and Fat of the Abdominal Region of the Rat.

Radiofrequency (RF)-based devices are frequently used in plastic surgeries. In the current literature, no comparative experimental study has demonstrated the histological and immunological effects of these devices that are frequently used in the facial area. In this study, we investigated the histological and immunological effects of Bipolar RF (BodyTite) and Microneedle RF (Morpheus 8) devices in the rat abdominal region. 24 rats were used in this study. The rats were divided into four groups: group I: Control. In group II, BodyTite was applied to the abdominal region. Group III: Morpheus 8 was applied to the abdominal region. Group IV: Both Morpheus 8 and BodyTite were applied to the abdominal region. The histological and immunological features of the tissues in the groups were examined using light microscopy, and collagen formation and desmosome structures were examined using light microscopy. Collagens in Group II were thinner than those in the other groups. In addition, there were fewer vessels in Group III. The collagen scores were as follows: Group II:1.5; Group III:2; and Group IV:3. The VEGF scores were II:2.5, group III:2, and IV:3, respectively. The collagen score in group II and VEGF score in group III were significantly lower than those in the other groups. In addition, the bonds between desmosomes in group III were found to be looser using electron microscopy. Collagen morphology in groups III and IV was found to be similar to that in group I. The conclusion of comparison RF-based devices increased tissue regeneration and healing. The use of radiofrequency devices has increased in plastic surgery practice over the past two decades, particularly emerging as a unique alternative for non-surgical candidates. There is a lack of experimental studies concerning these commonly used devices in clinical practice.

Comparative experimental study of different fetch distances, interpolation algorithms, source substrate noise, sampling point counts, and resolution for NF of BDFA

Noise figure (NF) is a key metric for Fiber amplifier (FA), which affects the performance of signal transmission. The main factors affecting the NF are related to the amplified spontaneous emission (ASE) characteristics of the active fiber itself. However, during our study of NF, we found some easily overlooked factors that can have a significant impact on the results, such as the fetch distances and interpolation algorithm for calculating the ASE where the signal wavelength is located. Further, to date, we have also found little relevant research on whether the sampling characteristics of the instrument and the substrate noise contribute to the NF. On the other hand, bismuth-doped fiber amplifiers (BDFA) have developed rapidly in recent years. In this work, we use BDFA as an example, using different fetch distances, interpolation algorithms, substrate noise, and sampling variables (resolution and point counts), to comprehensively compare and analyze the impact caused by NF. The experimental results suggest that the distance between the sampling locations on either side of the signal and the center wavelength must exceed the signal’s bandwidth to obtain the actual NF; Linear interpolation and cubic interpolation are more suitable for calculating the NF; Even using a high power input signal of 0 dBm, the NF is only degraded by about 1.8% compared to the case where the substrate noise is ignored; In addition, the effect of different sampling point counts and resolutions have less influence on the NF. We believe this work provides a reliable reference value for calculating the accuracy of NF and will be useful for practical applications of active-fiber amplifiers.

A comparative experimental study on the collection and analysis of DNA samples from under fingernail material

A comparative experimental study on the collection and analysis of DNA samples from under fingernail material

Shortest-length and coarsest-granularity constructs vs. reducts: An experimental evaluation

In the domain of rough set theory, super-reducts represent subsets of attributes possessing the same discriminative power as the complete set of attributes when it comes to distinguishing objects across distinct classes in supervised classification problems. Within the realm of super-reducts, the concept of reducts holds significance, denoting subsets that are irreducible.Contrastingly, constructs, while serving the purpose of distinguishing objects across different classes, also exhibit the capability to preserve certain shared characteristics among objects within the same class. In essence, constructs represent a subtype of super-reducts that integrates information both inter-classes and intra-classes. Despite their potential, constructs have garnered comparatively less attention than reducts.Both reducts and constructs find application in the reduction of data dimensionality. This paper exposes key concepts related to constructs and reducts, providing insights into their roles. Additionally, it conducts an experimental comparative study between optimal reducts and constructs, considering specific criteria such as shortest length and coarsest granularity, and evaluates their performance using classical classifiers.The outcomes derived from employing seven classifiers on sixteen datasets lead us to propose that both coarsest granularity reducts and constructs prove to be effective choices for dimensionality reduction in supervised classification problems. Notably, when considering the optimality criterion of the shortest length, constructs exhibit clear superiority over reducts, which are found to be less favorable.Moreover, a comparative analysis was conducted between the results obtained using the coarsest granularity constructs and a technique from outside of rough set theory, specifically correlation-based feature selection. The former demonstrated statistically superior performance, providing further evidence of its efficacy in comparison.

A comparative experimental study on front and back laser cutting technology for mass separation of N-TOPCon crystal silicon solar cells

Generally, the Thermal Laser Separation (TLS) technology is used to pre-groove from the back of the cell, which is the first process of half-cell module preparation. However, this benchmark practice may result in forming new leakage points in the grooves at both ends of the cell. Hence, we investigate the mechanism behind the formation of leakage points after grooving and the impact on N-TOPCon's cell efficiency and module power. It is discovered that the diffusion of P element is the main reason for the increase in the proportion of leakage points. The front cutting is accordingly proposed to alleviate problem. A comprehensive experimental study on its feasibility has been conducted. It has been confirmed that the leakage current under the reverse bias voltage is smaller, the data convergence is better, and the breakdown performance is more stable for N-TOPCon. Furthermore, the module power is higher.

A comparative experimental study on the rough machining methods of centrifugal three-dimensional impellers

A comparative experimental study on the rough machining methods of centrifugal three-dimensional impellers

After-meal blood glucose level prediction for type-2 diabetic patients

Type 2 Diabetes, a metabolic disorder disease, is becoming a fast growing health crisis worldwide. It reduces the quality of life, and increases mortality and health care costs unless managed well. After-meal blood glucose level measure is considered as one of the most fundamental and well-recognized steps in managing Type 2 diabetes as it guides a user to make better plans of their diet and thus control the diabetes well. In this paper, we propose a data-driven approach to predict the 2 h after meal blood glucose level from the previous discrete blood glucose readings, meal, exercise, medication, & profile information of Type 2 diabetes patients. To the best of our knowledge, this is the first attempt to use discrete blood glucose readings for 2 h after meal blood glucose level prediction using data-driven models. In this study, we have collected data from five prediabetic and diabetic patients in free living conditions for six months. We have presented comparative experimental study using different popular machine learning models including support vector regression, random forest, and extreme gradient boosting, and two deep layer techniques: multilayer perceptron, and convolutional neural network. We present also the impact of different features in blood glucose level prediction, where we observe that meal has some modest and medication has a good influence on blood glucose level.

Quantification of the Improvement in Sustainability after a Comparative Experimental Study of Single-Family Homes with Façade Rehabilitation Using the External Thermal Insulation Composite System

This study emerged from the necessity to analyze the most effective energy-saving strategies within the current real estate market and substantiate their application with empirical data. Undoubtedly, the adoption of External Thermal Insulation Composite Systems (ETICSs) stands out as one of the prevalent approaches. This article presents temperature-monitoring data collected on-site from the facades of two single-family homes initially constructed with identical compositions, materials, construction dates, locations, and orientations. The thermal envelope of one home underwent rehabilitation using the ETICS, while the other remained in its original state. Continuous temperature recordings on the southern and northwestern facades of both homes were conducted using thermocouples over a 15-day period. The data analysis yielded insights into facade performance before and after this rehabilitation approach. The findings suggest that the implementation of ETICS results in more stable interior temperatures, significantly reducing indoor temperatures in comparison to outdoor conditions, leading to a notable decrease in heat energy loss. Consequently, this research underscores the tangible benefits of employing ETICS in building rehabilitation, emphasizing its role as a passive energy-saving strategy. By demonstrating the positive impact on thermal performance and energy efficiency, this study reinforces the vital connection between research endeavors and sustainability objectives.

A comparative experimental and theoretical calculation study of CaAl-LDH modified with various aromatic inhibitors for corrosion protection study in epoxy coatings

The in-depth influence mechanism of the functional groups and conjugated structure of aromatic inhibitor on the corrosion protection ability of CaAl layered double hydroxide (CaAl-LDH) in epoxy coatings was investigated by performing the inhibitor modification using three typical aromatic inhibitors. The electrochemistry impedance spectroscopy (EIS) measurement demonstrated that CaAl-LDH-MBT showed superior protection for carbon steel in epoxy coatings. Density functional theory (DFT) calculation and molecular dynamic (MD) simulation indicated that the aromatic conjugated structure with larger π electron clouds and heteroatoms with lone pair electrons would contribute to the enhanced corrosion protection.

A modeling and experimental comparative study of a closed-loop forward osmosis-nanofiltration and standalone nanofiltration systems for fouling-prone wastewater treatment

The forward osmosis-nanofiltration (FO-NF) process presents a potential alternative for the treatment of wastewater effluents, compared to pressure-driven systems like reverse osmosis (RO)/nanofiltration (NF). This work bridges the gap in exploring the impact of continuous draw solute regeneration in FO-NF hybrid, and its influence on the performance over standalone NF at module-scale. The Speigler-Kedem model, along with the concentration polarization model, is used to describe the local mass transport in the membrane. Following this, the combined mathematical models for FO and NF are integrated into the hybrid FO-NF system at module-scale. Subsequent process optimization reveals that NF hydraulic pressure and inlet draw concentration control the NF retentate concentration and then simulate the desired operating conditions for the hybrid system when the NF retentate stream is directly used as a draw solution for the FO process. Further results show that in non-fouling feed solution, the FO-NF system is inferior to standalone NF in terms of SEC. In contrast, for fouling-prone feed solution, the standalone-NF performance degrades with time, which gradually mitigates water recovery from 40 to 15.6 % while increasing the SEC from 0.89 to 2.38 kWh/m3. At the same time, the FO-NF hybrid system performs better with Na2SO4 and MgSO4 as draw solutes with nearly constant water recovery of 32.6 % and 28.6 %, and negligible SEC fluctuations of 3.26 kWh/m3 and 4.70 kWh/m3 for the two draw solutes respectively. Despite this, compared with other state-of-the-art desalination technologies, the FO-NF hybrid exhibits comparably lower water cost (average 0.31 USD/m3) and effectively handles fouling-prone wastewater.

Evaluation of Nanopore Sequencing on Polar Bodies for Routine Pre-Implantation Genetic Testing for Aneuploidy.

Preimplantation genetic testing for aneuploidy (PGT-A) using polar body (PB) biopsy offers a clinical benefit by reducing the number of embryo transfers and miscarriage rates but is currently not cost-efficient. Nanopore sequencing technology opens possibilities by providing cost-efficient and fast sequencing results with uncomplicated sample preparation work flows. In this comparative experimental study, 102 pooled PB samples (99 passing QC) from 20 patients were analyzed for aneuploidy using nanopore sequencing technology and compared with array comparative genomic hybridization (aCGH) results generated as part of the clinical routine. Samples were sequenced on a Nanopore MinION machine. Whole-chromosome copy-numbers were called by custom bioinformatic analysis software. Automatically called results were compared to aCGH results. Overall, 96/99 samples were consistently detected as euploid or aneuploid in both methods (concordance = 97.0%, sensitivity = 0.957, specificity = 1.0, positive predictive value = 1.0, negative predictive value = 0.906). On the chromosomal level, concordance reached 98.7%. Chromosomal aneuploidies analyzed in this trial covered all 23 chromosomes with 98 trisomies, and 97 monosomies in 70 aCGH samples.The whole nanopore work flow is feasible in under 5 h (for one sample) with a maximum time of 16 h (for 12 samples), enabling fresh PB-euploid embryo transfer. A material cost of US$ 165 (EUR 150)/sample possibly enables cost-efficient aneuploidy screening. This is the first study systematically comparing nanopore sequencing with standard methods for the detection of PB aneuploidy. High concordance rates confirmed the feasibility of nanopore technology for this application. Additionally, the fast and cost-efficient work flow reveals the clinical utility of this technology, making it clinically attractive for PB PGT-A.

Experimental and numerical study of droplet generation in the normal and modified cross-junction

In this work, a visualization experimental combined with numerical approach was used to analyze the process intensification achieved by incorporating a rectangular obstacle into the downstream section of a cross-junction channel for droplet generation. A comparative experimental study was conducted to evaluate the performance of the droplet generation in the modified and normal cross-junction channel. Five typical flow regimes were observed, including squeezing, dripping, jetting, tubing and a first described tip-multi-breaking which differs from those previously reported in capillary devices. among these regimes, squeezing and dripping were found to be the preferred flow regime to generate monodisperse droplets with a variation coefficient of the droplet size less than 3 %. The presence of the rectangular obstacle in the modified channel increases the fluid resistance within the main channel, leading to a higher pressure drop before and on the obstacle, which induces the earlier appearance of necking stage and more prompt pinching-off of the thread in the modified channel. As a result, smaller monodisperse droplets with higher generation frequency were observed within a much wider distribution of squeezing and dripping regimes in the modified channel.

DFT modeling of new composite based on PANI/PVK functionalized With single-walled carbon nanotubes for optoelectronic applications

We present a comparative experimental and theoretical study of the vibrational, optical, and electronic properties of polyaniline at both emeraladine leuco-emeraldine forms and PVK. Our objective is first to select the appropriate form of PANI to be linked with PVK to form a hybrid polymer matrix. Then, on the basis of quantum chemical calculations, we present a theoretical study of a hybrid composite PANI/PVK functionalized with lower radius (5, 5) chiral single-walled carbon nanotubes (SWCNTs). The relationship structure-properties of the resulting nano-composite are proved based on the conformational and optical study made from Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) using B3LYP method with 6-31-G(d) basis set. First, it has been demonstrated that the resulting interaction between PANI and PVK leads to more advantageous properties, such as good optical absorption compatibility with the solar emission spectrum. It has also been found that after the incorporation of SWCNTs into the matrix of PANI/PVK hybrid polymer, a good organization of SWCNTs via π-staking interaction is imposed by polyaniline sequences. However, PVK moieties are grafted on the sidewalls of SWCNTs. Finally, the electronic structure of the resulting hybrid nano-composite PANI/PVK/SWCNTs was carried out with the use of different electrodes on both sides.

Experimental comparative study of a novel drug-eluting arteriovenous graft in a sheep model.

Arteriovenous (AV) grafts often develop severe complications of stenosis due to neointimal proliferation that occurs either at the venous anastomosis site or at the outflow receiving vein. This study compares primary patency during 12 months of follow up for a new experimental Biomodics© interpenetrating polymer network (IPN) drug-eluting graft prototype with state-of-the-art GORE® ACUSEAL (ACUSEAL) in an AV graft model in sheep. An end-to-end bypass from the common carotid artery to the jugularis vein was performed bilaterally in 12 sheep. The usage of ACUSEAL or the IPN, both 6.0 mm in diameter, was determined via randomization. The sheep were followed up every 4 weeks with ultrasonic duplex scanning to determine patency; the experienced observer was blinded to the randomization. One sheep died after 11 days, and the final sample accordingly consisted of 11 animals. When comparing neointimal hyperplasia after 12 months in the two grafts, Fisher's exact test showed a significant difference with none out of 11 in the IPN grafts and 9 out of 11 in the ACUSEAL graft (p < 0.001). However, the Biomodics© IPN exhibited severe deterioration over time. Almost all of the grafts occluded during the 12 months of follow up. Although the zwitterion-bounded interpenetrating drug eluting polymer network showed signs to impair neointimal hyperplasia and thrombosis, age-related degeneration hindered demonstrating a potential improvement in patency.

Characterizing microstructural evolutions in low-mature lacustrine shale: A comparative experimental study of conventional heat, microwave, and water-saturated microwave stimulations

Most of the shale oil reservoirs in China are of medium to low maturity. The effective exploitation of hydrocarbon resources in such formations is technically challenging. This study explores the impact of various thermal stimulation methods on low-maturity shale oil reservoirs, focusing on conventional heating, microwave heating, and water-saturated microwave heating methods. A suite of techniques, including small angle neutron scattering (SANS), mercury injection capillary pressure (MICP), and field emission-scanning electron microscopy (FE-SEM) after wood's metal injection were used to investigate the evolution of microstructures under different thermal stimulation. This integrated approach allows for a comprehensive characterization of reservoir connectivity and permeability across multiple scales, from visually observable centimetre and millimetre scales down to the nanoscale. The response of shale to thermal stimulation is significantly influenced by its mineral composition, with shales rich in absorbent minerals like pyrite undergoing selective heating when exposed to microwaves, leading to new pores and fracture formations. The use of CM-SANS has revealed substantial untapped hydrocarbon potential within the reservoir, emphasizing the importance of thermal stimulation in enhancing production. Furthermore, integrating microwave irradiation with hydraulic fracturing effectively increases the number of pores, micro-fractures, and natural fracture openings, mitigates the hydration effects of hydraulic fracturing, and increases permeability by three orders of magnitude. The results indicated that microwave combined with hydraulic fracturing positively impacts the production from low-maturity reservoirs and provides the theoretical basis for in-situ thermal recovery of shale oil.

Comparative experimental study of biomechanical features of suture materials in tendon repair

Introduction Many different suture configurations and pathomorphology of tendon repair have been described for tendon repair over the past 20 years. However, the biomechanical properties of suture material at primary flexor tendon repair have not been sufficiently explored. A cyclic loading test is performed to evaluate the performance of the different sutures under repeated loading conditions simulating dynamic conditions in postoperative rehabilitation procedures.The objective was to compare the strength of suture materials under cyclic loading on a biological model of a tendon.Material and methods Eighty porcine digital flexor tendons were examined in a pilot study. The sutured tendons were tested with a universal testing machine. Tendon repair was produced using polypropylene in group I, braided polyamide suture in group II, complex polytetrafluoroethylene thread in group III and a thread of superelastic titanium nickelide in group IV. The standard Chang protocol was used for cyclic loading.Results The percentage of intact sutures was 25 % in group I and in group II, 80 % in group III and 85 % in group IV after completing the entire load cycle. A pairwise comparison showed suture disruption being more common for group I and group II as compared to group III and group IV. Irreversible gap was more common for group 1 as compared to group IV. Neither knot ruptures nor tissue cutting were seen in the groups.Discussion The topic of biomechanical properties of suture material remains poorly understood. Although static load testing is commonly used in current experimental studies and cyclic testing is suitable for simulating postoperative conditions. The search continues for the “ideal” suture material for flexor tendon repair to prevent tears and retain tensile properties until the repair reaches strength.Conclusion The threads of polytetrafluoroethylene and nickelide-titanium showed the best biomechanical properties for tendon repair in the form of linear strength, good elasticity and low plasticity of the suture material. There were no significant differences between polypropylene and braided polyamide threads.

Comparative experimental study of the biomechanical properties of retrograde tibial nailing and distal tibia plate in distal tibia fracture.

Objective: A biomechanical comparative analysis was conducted to evaluate the retrograde tibial nailing (RTN) and distal tibia plate techniques for the treatment of distal tibia fractures. Methods: Fourteen fresh adult tibia specimens were selected, consisting of seven males and seven females aged 34-55years. The specimens were randomly divided into two groups (Group A and Group B) using a numerical table method, with seven specimens in each group. Group A underwent internal fixation of distal tibial fractures using RTN, while Group B received internal fixation using a plate. The axial compression properties of the specimens were tested in the neutral positions under pressures of 100, 200, 300, 400, and 500N. Additionally, the torsional resistance of the two groups was assessed by subjecting the specimens to torques of 1.0, 2.0, 3.0, 4.0, and 5.0Nm. Results: At pressures of 400 and 500N, the axial compression displacement in Group A (1.11 ± 0.06, 1.24 ± 0.05) mm was significantly smaller than that in Group B (1.21 ± 0.08, 1.37 ± 0.11) mm (p = 0.023, 0.019). Moreover, at a pressure of 500N, the axial compression stiffness in Group A (389.24 ± 17.79) N/mm was significantly higher than that of the control group (362.37 ± 14.44) N/mm (p = 0.010). When subjected to torques of 4 and 5Nm, the torsion angle in Group A (2.97° ± 0.23°, 3.41° ± 0.17°) was significantly smaller compared to Group B (3.31° ± 0.28°, 3.76° ± 0.20°) (p = 0.035, 0.004). Furthermore, at a torque of 5Nm, the torsional stiffness in Group A (1.48 ± 0.07) Nm/° was significantly higher than that in Group B (1.36 ± 0.06) N·m/° (p = 0.003). Conclusion: The results obtained from the study demonstrate that the biomechanical performance of RTN outperforms that of the distal tibial plate, providing valuable biomechanical data to support the clinical implementation of RTN.

An experimental comparative study of the effects on the engine performance of using three different motion mechanisms in a beta-configuration Stirling engine

This study deals with three different Stirling engines with rhombic, slider-crank, and bell-crank motion mechanisms which have been designed and manufactured. Engine performance tests of Stirling engines with these three different motion mechanisms at different operating parameters have been carried out in a laboratory environment. During the experimental studies under consideration, the cooler and heater temperatures have been kept at 300 K (±5) and 1000 K (±10), respectively. Engine performance tests have been performed at different charging pressures using helium, nitrogen, and air as working fluids. Despite the fact that the Stirling engines with these three different motion mechanisms have the same sweeping volumes and technical specifications, engine performance values have been obtained differently from each other. The main reason for this difference can be explained as friction and other mechanical losses in motion mechanisms. The performance values obtained depending on the type of motion mechanism are rhombic, slider-crank, and bell-crank, from highest to lowest, respectively. The highest engine power measured among all experimental studies has been 215.48 W at 550 rpm and 4 bar charging pressure in tests using helium gas and rhombic motion mechanism. The lowest engine power among the maximum power values has been obtained as 82.5 W at 167 rpm and 4 bar charging pressure in experiments using air as the working fluid and the bell-crank motion mechanism. As a matter of fact, the highest engine power within the maximum engine power values is 161.2% higher than the lowest engine power.