Residual Removal Research Articles

Comparison of Enamel Surface Roughness between Light-cured and Self-cured Composites used in Orthodontic Bonding by using Atomic Force Microscopy

Introduction: Debonding is a procedure of removing orthodontic attachments along with the entire residual adhesives from the surface of enamel following orthodontic treatment completion. The objective of the orthodontists should be to restore the surface of enamel as closely as possible to natural enamel without inducing iatrogenic injury and with minimal loss of enamel structure. Bonding of brackets on enamel involves surface etching, application of primer, and adhesive. All these steps involve the risk of damaging the enamel surface and changing its original morphology. Upon completion of orthodontic treatment, the debonding procedure followed by residual resin removal further damages the enamel, producing scratches, cracks, grooves, removal of fluoride-rich external enamel layer, and increasing the enamel roughness. The rough enamel surface inhibits proper cleaning and thus invites plaque deposition, bacterial retention, stain formation, and thus dampening the aesthetic appearance of the teeth. Restoring the enamel to its original morphology is a challenge. A variety of mechanical methods have been proposed to achieve satisfactory resin removal with least possible enamel damage following bracket debonding. The Enhance finishing and Pogo polishing system (Dentsply, Milford, USA) is also widely used and is made up of polymerized urethane dimethacrylate resin, aluminium oxide, silicon dioxide, and fine diamond powder. Methods: The sample of 50 tooth extracted for orthodontic purpose was procured as per the inclusion criteria. Buccal surfaces of teeth on the area where bracket is bonded and then debonding is done. After residual resin removal with Enhance system finishing and polishing bur. Measurements for each specimen were measured and mean was calculated and evaluated with the help of Atomic Force Microscopy (Baseline roughness data). Result: Self cure composite gives relatively lesser surface roughness when compared to light cure composites. Conclusion: The study shows that the self cure adhesive gives the smoother enamel surface when compared to the tooth treated with light cure adhesive after debonding and finishing and polishing.

Accuracy characterization of Shack–Hartmann sensor with residual error removal in spherical wavefront calibration

Accuracy characterization of Shack–Hartmann sensor with residual error removal in spherical wavefront calibration

Transient Thermal-hydraulic Characteristics Analysis of Air-Cooling Residual Heat Removal System based on CFD

Transient Thermal-hydraulic Characteristics Analysis of Air-Cooling Residual Heat Removal System based on CFD

A High-Resolution Imaging Method for ISAR Based on Sparse Reconstruction

For the problem of first-order and second-order range migration in ISAR imaging under the condition of wide angle and wide bandwidth, a method for sparse azimuth data is proposed to obtain high-resolution ISAR images. After stretch processing, envelope alignment and residual video phase removal, the sparse recovery algorithm that sparse base is constructed by the Keystone transform is used to achieve range migration correction and the missing range profile reconstruction, and then the second-order phase estimation method based on fractional Fourier transform is used to estimate and compensate the second-order rotational phase. Simulation results show the method can effectively improve the imaging quality.

Assessing the Effectiveness of Saponins from Alfalfa (Medicago sativa L.) to Mitigate Cypermethrin Residues in Apples

Pesticide residues on fruits and vegetables are of major health concern around the world. Some of these pesticide residues are extremely toxic and can become a major causative factor for various diseases such as cardiovascular disorders (CVDs), lung, endocrine, and nervous system damage, as well as the circulatory system, and reproductive system problems. This study was aimed at investigating the effectiveness of saponins isolated from alfalfa (Medicago sativa L.) seeds for mitigating cypermethrin residues on apples (Malus domestica Borkh.) in comparison to tap water, citric acid, and baking soda. Cypermethrin concentration applied to apples was 1 ml/L. After washing the apples with varying concentrations of different washing solutions, analysis for cypermethrin residues was performed using a UV/VIS spectrophotometer at a wavelength of 535 nm. The maximal removal of residues recorded for baking soda, tap water, and citric acid was 92.98, 72.50, and 74.59 % respectively. Saponins exhibited a maximum of 13.90 % of residual removal which was not as effective as other washing agents.

TPTF horizontal flow prediction by SYS-TH codes – Recent analyses made within the FONESYS network

The horizontal stratification occurrence in water cooled nuclear reactors (WCNR) plays an important role in many transients such as loss of coolant accidents and loss of residual heat removal by influencing the liquid mass repartition, the natural circulation and reflux condenser modes, and the break or leak flowrate. A benchmark activity on horizontal flow prediction conducted in the framework of FONESYS is here presented. FONESYS is a network among code developers who share the common objective to strengthen current technology. The aim of the network is to highlight the capabilities and the robustness as well as the limitations of current SYS-TH codes to predict the main phenomena during transient scenarios in nuclear reactors for safety issues.One-hundred-twenty-six runs performed with the Two-Phase Test Facility (TPTF) are considered. Tests were selected aiming to support and complement an ongoing activity on the scalability of codes’ closure laws, currently focusing on the horizontal stratification criteria, the onset of droplet entrainment and entrainment fraction criteria. Therefore, experimental tests performed with the 4-inch and 8-inch tests sections, at pressure ranging from 30 bar to 118 bar, in different flow regimes are considered. Focus is put on the capability of ATHLET, CATHARE 3, MARS-KS, RELAP5, RELAP5-3D, SPACE and TRACE in predicting void fractions, the transition to slug flow and the onset of droplet entrainment.Overall, the benchmark results show reasonably good capabilities of codes in predicting horizontal flow. However, some noticeable limitations emerged related to flow regime transition criteria, interfacial friction, and to the prediction of non-established flow. The scalability of closure laws and possible ways for improving them are discussed.

A new algorithm for estimating radioxenon concentrations

A new algorithm (Xcounts) is introduced for estimating the activity concentrations of the xenon isotopes 131mXe, 133mXe, 133Xe, and 135Xe using beta-gamma coincidence data. The algorithm simultaneously estimates the decay counts associated with the four xenon isotopes, background, and radon in contrast to the net-counts method that uses sequential residual removal to account for background and interferences. Calibration data for background counts are determined from gas-background measurements and simulation. In Xcounts, the false positive count rates for 131mXe and 133mXe are lower than those for 133Xe and 135Xe. This algorithm appears to reliably detect the metastable isotopes at lower activity levels than the net-counts method and have similar performance for the other isotopes.

Aluminum-based electrocoagulation for residual fluoride removal during per- and polyfluoroalkyl substances (PFASs) wastewater treatment

The residual fluorion (F–) generated during per- and polyfluoroalkyl substances (PFASs) treatment presents a new environmental burden, while minimum attention has been redirected to its removal. In this study, Al-based electrocoagulation (EC) technique was optimized to effectively remove the residual F– during PFASs wastewater treatment. At EC’s optimal operating conditions, it can achieve over 81.7 % removal efficiency within 30 min. Furthermore, EC exhibited a stable performance on removing F– across a wide range of pH (3–11), and could form stable flocs under neutral pH conditions. The in-depth characterization of flocs has revealed the dynamic change of Al-F species along the EC process, and removal mechanisms were proved to be a combination of complexation, ion exchange, hydrogen bonding and precipitation. In addition, the optimized EC showed stable removal efficiency of F– with the co-existence of multiple PFASs. Hence, we have effectively removed the residual F– during PFASs wastewater treatment, and provide new insights to better understand the defluorination mechanisms in the EC process.

Morphology extraction of fetal ECG using temporal CNN-based nonlinear adaptive noise cancelling.

Noninvasive fetal electrocardiography (FECG) offers many advantages over alternative fetal monitoring techniques in evaluating fetal health conditions. However, it is difficult to extract a clean FECG signal with morphological features from an abdominal ECG recorded at the maternal abdomen; the signal is usually contaminated by the maternal ECG and various noises. The aim of the work is to extract an FECG signal that preserves the morphological features from the mother's abdominal ECG recording, which allows for accurately estimating the fetal heart rate (FHR) and analyzing the waveforms of the fetal ECG. We propose a novel nonlinear adaptive noise cancelling framework (ANC) based on a temporal convolutional neural network (CNN) to effectively extract fetal ECG signals from mothers' abdominal ECG recordings. The proposed framework consists of a two-stage network, using the ANC architecture; one network is for the maternal ECG component elimination and the other is for the residual noise component removal of the extracted fetal ECG signal. Then, JADE (one of the blind source separation algorithms) is applied as a postprocessing step to produce a clean fetal ECG signal. Synthetic ECG data (FECGSYNDB) and clinical ECG data (NIFECGDB, PCDB) are used to evaluate the extraction performance of the proposed framework. The statistical and visual results demonstrate that our method outperforms the other state-of-the-art algorithms in the literature. Specifically, on the FECGSYNDB, the mean squared error (MSE), signal-to-noise ratio (SNR), correlation coefficient (R) and F1-score of our method are 0.16, 7.94, 0.95 and 98.89%, respectively. The F1-score on the NIFECGDB reaches 98.62%. The value of the F1-score on the PCDB is 98.62%. As opposed to the existing algorithms being restricted to fetal QRS complex detection, the proposed framework can preserve the morphological features of the extracted fetal ECG signal well, which could support medical diagnoses based on the morphology of the fetal ECG signal.

Removal Analysis of Residual Photoresist Particles Based on Surface Topography Affected by Exposure Times of Ultraviolet and Developer Solution

Particle removal from the surface of a substrate has been an issue in numerous fields for a long time. In semiconductor processes, for instance, the formation of clean surfaces by removing photoresist (PR) must be followed in order to create neat patterns. Although PR removal has been intensively investigated recently, little is known about how ultraviolet (UV) and developer solutions alter the PR resin (and in what manner) near the surface. While varying the exposure times of UV and developer solution, we investigated the topographic changes on the surfaces of PR resin films and particles. The measured surface properties were then correlated with the detachment force determined using films, and eventually with the residual PR particle removal percentages obtained in a microchannel. Using a positive PR and a base developer solution, we demonstrated that UV causes the surface of PR resin to become hydrophilic and wavy, whereas the developer solution produces a surface with a larger degree of roughness by swelling and partially dissolving the resin. Ultimately, the increased roughness decreased the effective contact area between PR resins, hence decreasing the detachment force and increasing the particle removal percentages. We anticipate that our findings will help understand residual particle issues, particularly on the removal mechanism of PR resins based on surface topography.

Long-term national climate strategies bet on forests and soils to reach net-zero

The deployment of carbon dioxide removal is essential to reach global and national net-zero emissions targets, but little attention has been paid to its practical deployment by countries. Here, we analyse how carbon dioxide removal methods are integrated into 41 of the 50 Long-term Low Emission Development Strategies submitted to the United Nations Framework Convention on Climate Change (UNFCCC), before 2022. We show that enhancing forest and soil carbon sinks are the most advocated strategies but are only explicitly quantified in 12. Residual emissions by 2050 are only quantified in 20 strategies and most of them use forests to achieve national net-zero targets. Strategies that quantify both residual emissions and carbon dioxide removal identify national constraints, such as wildfire risks to forests and limited geological CO2 storage capacity. These strategies also highlight the need for international cooperation. Taken together, we suggest that the UNFCCC should urgently strengthen its reporting requirements on long-term national climate strategies.

Indocyanine green as a near-infrared theranostic agent for ferroptosis and apoptosis-based, photothermal, and photodynamic cancer therapy.

Ferroptosis is a recently discovered programmed cell death pathway initiated by reactive oxygen species (ROS). Cancer cells can escape ferroptosis, and strategies to promote cancer treatment are crucial. Indocyanine green (ICG) is a near-infrared (NIR) fluorescent molecule used in the imaging of residual tumor removal during surgery. Growing attention has been paid to the anticancer potential of ICG-NIR irradiation by inducing ROS production and theranostic effects. Organic anion transmembrane polypeptide (OATP) 1B3 is responsible for ICG metabolism. Additionally, the overexpression of OATP1B3 has been reported in several cancers. However, whether ICG combined with NIR exposure can cause ferroptosis remains unknown and the concept of treating OATP1B3-expressing cells with ICG-NIR irradiation has not been validated. We then used ICG as a theranostic molecule and an OATP1B3-transfected fibrosarcoma cell line, HT-1080 (HT-1080-OATP1B3), as a cell model. The HT-1080-OATP1B3 cell could promote the uptake of ICG into the cytoplasm. We observed that the HT-1080-OATP1B3 cells treated with ICG and exposed to 808-nm laser irradiation underwent apoptosis, as indicated by a reduction in mitochondrial membrane potential, and upregulation of cleaved Caspase-3 and Bax but downregulation of Bcl-2 expression. Moreover, lipid ROS production and consequent ferroptosis and hyperthermic effect were noted after ICG and laser administration. Finally, in vivo study findings also revealed that ICG with 808-nm laser irradiation has a significant effect on cancer suppression. ICG is a theranostic molecule that exerts synchronous apoptosis, ferroptosis, and hyperthermia effects and thus can be used in cancer treatment. Our findings may facilitate the development of treatment modalities for chemo-resistant cancers.

Analysis of Influence of Tube Failure on Performance of Passive Residual Heat Removal Heat Exchanger

A passive residual heat removal system plays an important role in cooling the reactor core under accident conditions. The computational fluid dynamics (CFD) software package ANSYS Fluent is used to analyze the influence of malfunction of any 2 of 12 tubes of a passive residual heat removal heat exchanger (PRHR HX) on its performance. Then the computation was validated using the published experimental data. Five different scenarios and a normal condition are computed to analyze the influence of locations of the malfunctioning tubes on the heat transfer performance of the PRHR HX. The results show that the tube defect reduces the amount of heat transferred by the PRHR HX. However, it is correlated with the size of the surface area of the deficient tubes instead of their locations. In other words, analysis suggests that defect tubes with the same surface area should result in similar damage regardless of the location.

Characteristic analysis of natural circulation residual heat removal in small reactor

In order to study the characteristics of small helium-xenon cooled nuclear reactor that only relies on natural circulation to remove residual heat after shutdown, this paper carries out geometric and physical modeling of helium-xenon cooled nuclear reactor, and uses CFD to simulate the process of natural circulation residual heat removal. Variation laws of the hot spot temperature on the surface of fuel cladding and the mass flow of helium-xenon mixed gas under different working conditions are calculated, and the transient characteristics of temperature, flow and other related parameters in the system loop are analyzed. The calculation results show that during the natural circulation residual heat removal process, the overall change trend of the hot spot temperature on the surface of the fuel cladding, the average temperature of the primary coolant and reactor outlet temperature first rises to the highest value and then decreases, and the mass flow of helium-xenon mixed gas shows an exponential decay trend; Increasing the initial mass flow of helium-xenon mixed gas and reducing the residual heat of the reactor core can reduce the maximum hot spot temperature on the surface of the fuel cladding. The relevant research results provide a useful reference for the optimal design of natural circulation residual heat removal of helium-xenon cooled nuclear reactor.

Evaluation of the bisphenol released in the saliva after residual adhesive removal in orthodontic patients by using ultrasonic scaling and rotary system: A single-center randomized clinical trial

Bisphenol A (BPA) is a substance commonly used in dental materials with noxious properties. Monomers of this substance may be dissolved in the saliva and cause adverse effects. This study aimed to evaluate the amount of BPA released in the saliva after residual adhesive removal in orthodontic patients using an ultrasonic scaler (US) and tungsten carbide bur (TCB). This single-center randomized clinical trial was conducted on 40 subjects whose stainless-steel brackets were bonded directly with light-cured bonding and composite. The subjects were randomly divided into 2 equal groups (n= 20) of TCB or US according to the adhesive removal method. The salivary BPA level was determined using high-performance liquid chromatography-mass spectrometry. And adhesive cleaning time was measured by a stopwatch. Data were analyzed by SPSS using an independent t test and paired-samples t test (P<0.05). The mean salivary BPA level was significantly lower in the TCB method than in the US method. (1.008 ± 0.061 μg/mL and 2.83 ± 0.24 μg/mL, respectively) (P<0.001). The mean adhesive cleanup time was significantly shorter in the TCB method than in the US method (8.86 ± 0.83 minutes and 13.20±1.02 minutes, respectively) (P<0.001). According to the results, residual adhesive removal with TCB released less BPA in saliva and shortened the adhesive cleaning time than the US method. The trial was registered at the Iranian Registry of Clinical Trials (IRCT20200702047988N1). The protocol was not published before trial commencement.

Urine volume as an estimator of residual renal clearance and urinary removal of solutes in patients undergoing peritoneal dialysis

In non-anuric patients undergoing peritoneal dialysis (PD), residual kidney function (RKF) is a main contributor to fluid and solute removal and an independent predictor of survival. We investigated if urine volume could be used to estimate renal clearances and removal of urea, creatinine, and phosphorus in PD patients. The observational, cross-sectional study included 93 non-anuric prevalent PD patients undergoing continuous ambulatory PD (CAPD; n = 34) or automated PD (APD; n = 59). Concentrations of urea, creatinine and phosphorus in serum and in 24-h collections of urine volume were measured to calculate weekly residual renal clearance (L/week) and removed solute mass (g/week). Median [interquartile range], 24-h urine output was 560 [330–950] mL and measured GFR (the mean of creatinine and urea clearances) was 3.24 [1.47–5.67] mL/min. For urea, creatinine and phosphorus, residual renal clearance was 20.60 [11.49–35.79], 43.02 [19.13–75.48] and 17.50 [8.34–33.58] L/week, respectively, with no significant differences between CAPD and APD. Urine volume correlated positively with removed solute masses (rho = 0.82, 0.67 and 0.74) and with weekly residual renal clearances (rho = 0.77, 0.62 and 0.72 for urea, creatinine, and phosphorus, respectively, all p < 0.001). Residual renal clearances and urinary mass removal rates for urea, creatinine, and phosphorus correlate strongly with 24-h urine volume suggesting that urine volume could serve as an estimator of typical values of residual solute removal indices in PD patients.

Biochar-amended composting of lincomycin fermentation dregs promoted microbial metabolism and reduced antibiotic resistance genes

Improper disposal of antibiotic fermentation dregs poses a risk of releasing antibiotics and antibiotic resistant bacteria to the environment. Therefore, this study evaluated the effects of biochar addition to lincomycin fermentation dregs (LFDs) composting. Biochar increased compost temperature and enhanced organic matter decomposition and residual antibiotics removal. Moreover, a 1.5- to 17.0-fold reduction in antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) was observed. Adding biochar also reduced the abundances of persistent ARGs hosts (e.g., Streptomyces, Pseudomonas) and ARG-related metabolic pathways and genes (e.g., ATP-binding cassette type-2 transport, signal transduction and multidrug efflux pump genes). By contrast, compost decomposition improved due to enhanced metabolism of carbohydrates and amino acids. Overall, adding biochar into LFDs compost reduced the proliferation of ARGs and enhanced microbial community metabolism. These results demonstrate that adding biochar to LFDs compost is a simple and efficient way to decrease risks associated with LFDs composting.

Experimental Study on Singlephase Natural Circulation Flow and Heat Transfer of Passive Residual Heat Removal System of Swimming Pool-type Low-temperature Heating Reactor

Experimental Study on Singlephase Natural Circulation Flow and Heat Transfer of Passive Residual Heat Removal System of Swimming Pool-type Low-temperature Heating Reactor

Formation of in-situ microemulsion and its efficiency for residual PCE removal in low temperature aquifers

Microemulsion is used extensively for enhanced oil recovery due to its efficient solubilization. Recently, in-situ microemulsion has been considered to have great potential for remediation of dense non-aqueous phase liquid contaminated aquifers. However, the temperature of aquifers is substantially below that of oilfields (30–120 °C), and the influence of temperature variation on in-situ microemulsion formation and solubilization is unclear. In this work, the efficient in-situ microemulsion for low temperature aquifers were established via the ε-β fishlike phase diagram; the solubilization capacity and size distribution of microemulsion at low temperature of about 10 °C were investigated; and the remediation efficiency of microemulsion flushing for residual tetrachloroethylene (PCE) removal was evaluated. Microemulsion precursor composition of 6.0 wt% compound surfactants (Tween80: SDS=3:2), 8.0 wt% isopropyl alcohol (IPA) and 3.0 wt% NaCl was prepared to form microemulsion with PCE in situ. The PCE apparent solubility was determined to be 80.28 g L−1 at 10 °C, which was three orders of magnitude higher than that in water at the same temperature, about 0.06 g L−1. The solubilization capacity was inversely proportional to temperature and IPA concentration, whereas proportional to Na+ concentration. The microemulsion droplets size were enlarged with the increase of IPA concentration, Na+ concentration and PCE solubilization by DLS experiments. Besides, sand column flushing using various eluents (water, micelle solution, in-situ microemulsion) was conducted to determine the removal efficiency for residual PCE. It was determined that in-situ microemulsion formulations can achieve removal efficiency of 97.1% for residual PCE, which was higher than that flushed via water and micelle solution, about 54.6% and 1.1%. In summary, the results confirm great feasibility of in-situ microemulsion for DNAPLs polluted aquifer remediation.

Numerical study on the thermal-hydraulic behavior in the ultimate heat sink of passive residual heat removal system in the SMART

Computational Fluid Dynamics (CFD) analysis was performed to evaluate the thermal–hydraulic characteristics of emergency cooldown tank (ECT) in a Passive Residual Heat Removal System (PRHRS) of SMART. ECT is the ultimate heat sink of the PRHRS. Experimental results about the small-break loss-of-coolant accident (SBLOCA) scenario for a 0.4 in. line break in the safety-injection system (SIS) were used to compare and validate the CFD results. The geometrical model for CFD considered only the ECT and internal heat exchanger. The boundary and initial conditions of CFD analysis were based on the experimental data. The transient analysis was performed for 6000 s. The temperature distribution of the CFD results is in good agreement with the experiment results. The water level in ECT increases due to the volume expansion according to the temperature, which was well simulated in CFD analysis.