Spot Position Research Articles

Implementing dispersion measurement as part of scanning proton therapy commissioning and quality assurance

Introduction. Dispersion in an accelerator quantifies the deviation of the proton trajectory when there is a momentum deviation. We present for the first time a safe method of measuring dispersion in the clinic, using a scintillator detector and the momentum deviations within a spill. This is an important accelerator quantity as we found that this is the reason behind the large dose fluctuation in our absolute dosimetry measurement. Methods. Dispersions are measured for nine energies in a Hitachi ProBeat system at three locations (isocenter and at two profile monitors) and at two gantry angles (0 and 90 degrees) by first measuring the spot position and momentum drift within a spill. The spot position drift is measured by the XRV-4000 at the isocenter, and by the two profile monitors located at 0.57 and 2.27 m from the isocenter. The momentum drift is calculated from the intra-spill range drift which is measured using the Ranger accessory. The dispersion at isocenter and its gradient are calculated using the weighted least square regression on the measured dispersions at the three locations. A constraint is formulated on the dispersion and its gradient to ensure minimal intra-spill spot position deviation around the isocenter. Results. The measured intra-spill range and spot positional drift at isocenter are less than and respectively. The momentum spread calculated from the range drift are less than 0.08%. The dispersion at the isocenter ranged from to and the zero-crossing happens upstream of isocenter for all energies. 2 of the 9 energies (168.0 and 187.5 MeV) violated the constraint and has an intra-spill spot positional deviation greater than within from the isocenter. Conclusion. This measurement is recommended as part of commissioning and annual quality assurance for accelerator monitoring and to ensure intra-spill spot deviations remain low.

Nature of the Eclipsing Polar 1RXS J184542.4+483134

We have carried out a comprehensive study of the poorly investigated eclipsing polar1RXS J184542.4+483134 with a short orbital period Porb ≈ 79 min. An analysis of its long-term lightcurves points to a change in the position and sizes of the accretion spot as the accretion rate changes.Narrow and broad components, which are probably formed on the ballistic segment of the accretion streamand on the magnetic trajectory, respectively, are identified in the emission line profiles. An inversion ofthe line profiles from emission to absorption due to the obscuration of the accretion spot by the accretionstream is observed. Based on the eclipse duration and the radial velocities of the narrow line component,we impose constraints on the white dwarf mass, 0.49 ≤ M1/M ≤ 0.89, and the orbital inclination,79.7◦ ≤ i ≤ 84.3◦. An analysis of the cyclotron spectra points to the presence of two accretion spotswith magnetic field strengths B1 = 28.4+0.1−0.2 MG and B2 = 30 − 36 MG. The main spot has a complexstructure that apparently has a dense core and a less dense periphery emitting a spectrum with cyclotronharmonics. Polarization observations reveal a circular polarization sign reversal during the orbital periodand an anticorrelation of the polarization with the brightness of the polar. Our modeling of polarizationobservations using the simple model of an accreting white dwarf shows that the polarization propertiescan be interpreted in terms of two-pole accretion with different optical depths of the accretion spots(τ1/τ2 ∼ 10). An analysis of the Swift/XRT observations points to a predominance of bremsstrahlungin the X-ray radiation from the system.

IoT based Smart Car Parking System using RFID in a Community

With the growth of technology in the current decade, we are confronting a parking challenge. Because large towns have a dense population, there are many vehicles on the road, which causes parking and traffic problems. The globe is confronted with a new challenge that is vehicle parking. It is estimated that one million automobiles use oil on a daily basis. This paper proposes an RFID based car parking system in a community. This system was created with the assistance of the internet of things (IOTs). IoT mainly involves the exchange of information or data between two physical devices. In the suggested system, an Arduino Uno microcontroller, ESP32, RFID sensors and IR sensors are used. The value of automation is growing every day. The primary function of Arduino in the proposed system is to serve as a platform for communicating digital devices and interactive objects capable of sensing and controlling physical components. The proposed system was built using an Arduino Uno board for vehicle parking and a ESP32 to connect the parking area to the web. In order to obtain information regarding the vacancy position of the parking slot, the suggested system included an infrared sensor in each slot. Therefore, to determine whether or not a person is in the database for the car parking system, RFID sensors are used. If the driver is listed in the database, the car will be allowed to enter the parking lot and the gate will open when the motors rotate in a clockwise direction. When the gate closes, the door will rotate in an anticlockwise direction and shows the user via led. From this proposed system, we get the information about the vacancy position of parking spot and notify the user through website. Keywords—IOT, RFID, IR Sensors, ESP32, Arduino

Open Bite Treatment with Combined Aligners and Myofunctional Appliances: A Case Report

This case report describes an 18-year-old female patient with a skeletal class I pattern, mandibular asymmetry, a molar class III on the right side, a molar class II on the left side, and an anterior open bite (AOB). Treatment of AOB is often difficult for orthodontists and a multidisciplinary approach is sometimes required to rehabilitate the correct function and posture of the tongue. In this case the AOB was treated using the Nuvola® OP System: a treatment system that combines orthodontic aligners and a myofunctional elastodontic device called Freedom. An upper molar intrusion with miniscrews was performed during the first phase of the treatment programme, and then the aligner treatment began. The Nuvola® OP System ’s aligners are characterized by lingual pins that guide the tongue to the palatal spot position and take advantage of tongue function. The patient was instructed to wear the Freedom device for 30 min a day and to clench every 3 s with closed lips while wearing the aligners. These exercises improve the fitting of the aligners, improve the tongue’s posture, and take advantage of the masticatory forces to resolve the malocclusion. The patient was successfully treated, thus demonstrating that the Nuvola® OP System is a valid alternative for the treatment of AOB.

A dynamic star spots extraction method based on pixel association

Star trackers are devices that determine high-accuracy attitude by observing stars. As aerospace technology develops, the dynamic performance of the star tracker becomes increasingly important. In the star images taken under high dynamic conditions, the star spots will be tailed or fractured. It will cause a sharp decrease in Signal-to-Noise Ratio (SNR) and make it a challenge to extract and position star spots. In this paper, an Object-to-Pixel star spots extraction and positioning method based on pixel association was proposed, which is a breakthrough compared to the existing Pixel-to-Object extraction method. In the proposed method, rough extraction of star spots is carried out by the Radon transform and image entropy. Precise positioning of star spots is carried out by Gaussian mixture model (GMM) and maximum likelihood estimation (MLE). Experimental results indicate that the proposed method can achieve reliable extraction for star spots with SNR less than 3 or even close to 1. Meanwhile, the positioning accuracy can be improved by at least twice compared with the conventional threshold method.

The first investigation of spot-scanning proton arc (SPArc) delivery time and accuracy with different delivery tolerance window settings

Objective. To investigate the impact of various delivery tolerance window settings on the treatment delivery time and dosimetric accuracy of spot-scanning proton arc (SPArc) therapy. Approach. SPArc plans were generated for three representative disease sites (brain, lung, and liver cancer) with an angle sampling frequency of 2.5°. An in-house dynamic arc controller was used to simulate the arc treatment delivery with various tolerance windows (±0.25, ±0.5, ±1, and ±1.25°). The controller generates virtual logfiles during the arc delivery simulation, such as gantry speed, acceleration and deceleration, spot position, and delivery sequence, similar to machine logfiles. The virtual logfile was then imported to the treatment planning system to reconstruct the delivered dose distribution and compare it to the initial SPArc nominal plan. A three-dimensional gamma index was used to quantitatively assess delivery accuracy. Total treatment delivery time and relative lost time (dynamic arc delivery time—fix beam delivery time)/fix beam delivery time) were reported. Main Results. The 3D gamma passing rate (GPR) was greater than 99% for all cases when using 3%/3 mm and 2%/2 mm criteria and the GPR (1%/1 mm criteria) degraded as the tolerance window opens. The total delivery time for dynamic arc delivery increased with the decreasing delivery tolerance window length. The average delivery time and the relative lost time (%) were 630 ± 212 s (253% ± 68%), 322 ± 101 s (81% ± 31%), 225 ± 60 s (27% ± 16%), 196 ± 41 s (11% ± 6%), 187 ± 29 s (6% ± 1%) for tolerance windows ±0.25, ±0.5, ±1, and ±1.25° respectively. Significance. The study quantitatively analyzed the dynamic SPArc delivery time and accuracy with different delivery tolerance window settings, which offer a critical reference in the future SPArc plan optimization and delivery controller design.

Structure of the accretion flow of IX Velorum as revealed by high-resolution spectroscopy

Context. Several high mass-transfer cataclysmic variables show evidence of outflow from the system, which could play an important role in their evolution. We investigate the system IX Vel, which was proposed to show similar characteristics. Aims. We study the structure of the IX Vel system, particularly the structure of its accretion flow and accretion disc. Methods. We used high-resolution time-resolved spectroscopy to construct radial velocity curves of the components in IX Vel. We computed Doppler maps of the system, which we used to estimate the temperature distribution maps. Results. We have improved the spectroscopic ephemeris of the system and its orbital period Porb = 0.19392793(3) d. We constructed Doppler maps of the system based on hydrogen and helium emission lines and the Bowen blend. The maps show features corresponding to the irradiated face of the secondary star, the outer rim of the accretion disc, and low-velocity components located outside the accretion disc and reaching towards L3. We constructed a temperature distribution map of the system using the Doppler maps of Balmer lines. Apart from the features found in the Doppler maps, the temperature distribution map shows a region of high temperature in the accretion disc connecting the expected position of a bright spot and the inner parts of the disc. Conclusions. We interpret the low-velocity emission found in the Doppler map as emission originating in the accretion disc wind and in an outflow region located in the vicinity of the third Lagrangian point L3. This makes IX Vel a member of the RW Sex class of cataclysmic variables.

Novel approach of combined planar and cross-sectional defect analysis of stressed normally-on HEMT devices with leaky Schottky gates

The clear correlation of defect localization by Electroluminescence to nanometer sized defects at Schottky gate contacts of GaN HEMTs are always challenging and limiting the root cause analysis of the stress related electrical degradation of the devices. In this paper a novel approach combining large area planar TEM defect screening followed by cross sectional preparation at identified defect sites is demonstrated to get access to relevant structural damages at the gate. The analysis flow is applied for normally-on GaN HEMT devices with an increased leakage at the Schottky gates observed after electrical stressing. To initiate electrical active degradation these devices were stressed up to significant changes in the electrical performance and then Electroluminescence spots were detected identifying possible defect positions. Metal intrusions into the AlGaN/ GaN stack underneath the Schottky gate contacts of only 20 nm size could be found by the newly combined planar/ cross-sectional analysis flow in good correlation to the EL spot positions. Analytical TEM investigations of the defects reveal Pt and Au inside the semiconductor reaching the 2DEG at a threading dislocation of the HEMT. These intrusions contribute to the gate leakage current and are causing the increased leakage current after electrical testing.

Deep Learning-Based Dose Prediction Model for Automated Spot-Scanning Proton Arc Planning

Spot-scanning proton arc (SPArc) is a novel technique that employs a planning optimization algorithm to select the energies and positions of spots along a dynamic rotational arc trajectory. The SPArc technique has the potential to achieve superior dose conformality and treatment delivery efficiency over intensity-modulated proton therapy. However, creating such a SPArc plan using existing approaches is time-consuming and computationally extensively. This study investigated the feasibility of using the deep learning (DL) technique to predict the 3D dose distribution of the SPArc treatment plan, leveraging the prior knowledge acquired from conventional intensity-modulated radiation therapy (IMRT) plans. A DL model, 3D-Unet with residual connections and attention gates, was trained using an open-source database of CT images, critical structures, and IMRT plans from 340 head and neck cancer patients (HNC) as the base model. Transfer learning technique was applied to fine-tune the model parameters using the SPArc treatment plans created on the HNC patients from an in-house dataset, where the SPArc treatment plans (including control point sampling, energy layer distribution, arc trajectory, etc.,) were optimized using a previously developed iterative approach. The performance of the DL model was evaluated by comparing predicted and planned doses over 17 SPArc treatment plans by using 4-fold cross-validation. The SPArc planning time per patient was 8∼12 hours, while the dose prediction time was reduced to 2∼3 minutes using the proposed DL model. The deviation of D95 in the target was (-1.8±1.6) %. The deviation of the mean dose in the parotids, cord, mandible, and brainstem were (2.5±6.5) %, (-0.5±4.3) %, (1.4±3.9) %, and (3.4±8) % of the prescription, respectively. The dice similarity coefficients of the 80%, 70%, and 60% isodose lines were (0.9±0.09), (0.93±0.01), and (0.94±0.01), respectively. Our results demonstrate that a DL-based dose prediction model can be created with a limited number of SPArc treatment plans through transfer learning. The DL model can directly predict the 3D dose distribution in minutes for automated planning. This study paves the roadmap to develop a quick clinical decision platform for the optimal selection among the multi-treatment modalities.

Temporospatial Feathering of Hot Spots for Computed Tomography-Guided Stereotactic Adaptive Radiotherapy (CT-STAR) for the Ultra-Central Thorax

SBRT to the ultra-central thorax is limited by potential toxicity. It has been demonstrated that exposing proximal bronchial tree or pulmonary arteries to high dose per fraction (fx) treatment may induce bronchopulmonary hemorrhage, amongst other serious complications. Online adaptive radiotherapy is a technique that adjusts a treatment plan to the anatomy-of-the-day and benefits have been demonstrated in ultra-central thoracic disease. In addition, feathering is a treatment planning technique that generates several plans to avoid consistent organ-at-risk (OAR) doses throughout treatment. With daily adaptation, it may be possible to adjust the position of a hot spot (>120% prescription (Rx)) within the tumor each fx (temporospatial feathering) while respecting hard OAR constraints. We investigated the feasibility and plan quality of using CBCT-guided stereotactic adaptive radiotherapy (CT-STAR) for ultra-central lung tumors with hotspot temporospatial feathering. Seven patients with ultra-central thoracic disease (6 patients with parenchymal tumors in contact with the trachea, proximal bronchial tree, great vessels, esophagus, or heart; 1 patient with a subcarinal lymph node) receiving standard of care radiotherapy were enrolled on an imaging study. An in-silico planning study first generated an SBRT plan (in silico Rx: 55 Gy in 5fx) that used a GTV_OPT (GTV minus OAR plus a safety margin) to optimize the location of the plan hotspot. Five spherical boost structures were manually created inside of the GTV_OPT structure. The same planning template was used except the boost structures were iteratively used in plan optimization instead of the GTV_OPT structure, to simulate the five CT-STAR fx hotspot temporospatially feathering. The five-plan composite was compared to the initial plan. All plans generated met strict OAR constraints. Table 1 shows the mean difference in PTV, GTV, and OARs percent coverage by various isodose levels. Feathering the hotspot had negligible impact on target coverage by 50 Gy and 55 Gy isodose lines as well as OAR doses compared to the base SBRT plan. The feathered plan sum resulted in 14.7% increase in V66 Gy of the GTV. One patient saw a decrease in V66 Gy coverage to all target structures, though V50 Gy and V55 Gy were not affected. We demonstrated the feasibility and utility of temporospatially adapting the hotspot for central lung SBRT, which safely increases the amount of tumor receiving more than 120% Rx.

Monte Carlo simulation-based patient-specific QA using machine log files for line-scanning proton radiation therapy.

Quality assurance (QA) is a prerequisite for safe and accurate pencil-beam proton therapy. Conventional measurement-based patient-specific QA (pQA) can only verify limited aspects of patient treatment and is labor-intensive. Thus, a better method is needed to ensure the integrity of the treatment plan. Line scanning, which involves continuous and rapid delivery of pencil beams, is a state-of-the-art proton therapy technique. Machine performance in delivering scanning protons is dependent on the complexity of the beam modulations. Moreover, it contributes to patient treatment accuracy. A Monte Carlo (MC) simulation-based QA method that reflects the uncertainty related to the machine during scanning beam delivery was developed and verified for clinical applications to pQA. Herein, a tool for particle simulation (TOPAS) for nozzle modeling was used, and the code was commissioned against the measurements. To acquire the beam delivery uncertainty for each plan, patient plans were delivered. Furthermore, log files recorded every 60 μs by the monitors downstream of the nozzle were exported from the treatment control system. The spot positions and monitor unit (MU) counts in the log files were converted to dipole magnet strengths and number of particles, respectively, and entered into the TOPAS. For the 68 clinical cases, MC simulations were performed in a solid water phantom, and two-dimensional (2D) absolute dose distributions at 20-mm depth were measured using an ionization chamber array (Octavius 1500, PTW, Freiburg, Germany). Consequently, the MC-simulated 2D dose distributions were compared with the measured data, and the dose distributions in the pre-treatment QA plan created with RayStation (RaySearch Laboratories, Stockholm, Sweden). Absolute dose comparisons were made using gamma analysis with 3%/3mm and 2%/2mm criteria for 47 clinical cases without considering daily machine output variation in the MC simulation and 21 cases with daily output variation, respectively. All cases were analyzed with 90% or 95% of passing rate thresholds. For 47 clinical cases not considering daily output variations, the absolute gamma passing rates compared with the pre-treatment QA plan were 99.71% and 96.97%, and the standard deviations (SD) were 0.70% and 3.78% with the 3%/3mm or 2%/2mm criteria, respectively. Compared with the measurements, the passing rate of 2%/2mm gamma criterion was 96.76% with 3.99% of SD. For the 21 clinical cases compared with pre-treatment QA plan data and measurements considering daily output variations, the 2%/2mm absolute gamma analysis result was 98.52% with 1.43% of SD and 97.67% with 2.72% of SD, respectively. With a 95% passing rate threshold of 2%/2mm criterion, the false-positive and false-negative were 21.8% and 8.3% for without and with considering output variation, respectively. With a 90% threshold, the false-positive and false-negative reduced to 11.4% and 0% for without and with considering output variation, respectively. A log-file-based MC simulation method for patient QA of line-scanning proton therapy was successfully developed. The proposed method exhibited clinically acceptable accuracy, thereby exhibiting a potential to replace the measurement-based dosimetry QA method with a 90% gamma passing rate threshold when applying the 2%/2mm criterion.

A metasurface-based direct-reading linear polarization analyzer

Polarization state is one of the fundamental properties of electromagnetic (EM) wave, which has been widely investigated in fields of information encryption, remote sensing and multifunctional devices etc The existing methods for polarization detection are generally based on the measurement of Stokes parameters or the amplitude and phase difference between orthogonal components or polarization-dependent imaging. However, they generally requires post-possessing process to identify the polarization state or suffer from the shortcomings of limited detection states, which results in less intuitiveness and limited practical values of those methods. Here, we proposed a metasurface-based and direct-reading linear polarization analyzer, which could reveal the polarization angle of linearly incident plane wave in imaging way by utilizing geometric phase effect. Different linear polarization angles lead to the different positions of the brightest spot, and the polarization state of incident wave could be directly read out by comparing the position of the brightest spot and the index of reference spots above. Besides, this method could be generalized to simplify the process of detecting arbitrary polarization states, with which only the intensity ratio between orthogonal circularly polarized components needs to be measured. Moreover, a digital linear polarization analyzer is designed based on the similar method, which helps to reveal the linear polarization angle digitally and is much more straightforward for linear polarization detection. The proposed direct-reading linear polarization analyzer has the potential of being applied in fields of smart sensing and the development of human-computer interaction system etc.

Dynamic Measuring Method of Laser Beam Incident Angle for Laser Doppler Vibrometer

Accurately measuring the incident angle of the laser Doppler vibrometer (LDV) laser beam is crucial for calculating the accurate dynamic response of a target. Nonetheless, conventional measuring methods may encounter limitations due to spatial constraints. To address this issue, a novel high-precision dynamic measuring method is proposed based on the measuring principle of LDV. Furthermore, a compact dynamic measuring device is constructed to facilitate this method. The proposed method involves the simulation of various tangential velocities utilizing a high precision rotating disk system. Subsequently, the laser beam incident angle is computed based on the projection relationship established between the average value of LDV measurements and the simulated velocities. To validate the feasibility of the dynamic measuring method and the correctness of the obtained incident angle, the paper compares this angle with that obtained through a conventional laser beam measuring method and device. This paper analyzes four key factors that may affect the angle measuring results theoretically and experimentally: environmental noise, laser spot position error, roll angle, and pitch angle of the rotating disk. The results indicate that the laser spot position error and the pitch angle of the rotating disk are more influential than the other two factors. Corresponding optimization measures are also proposed to improve the measuring accuracy.

The role of potassium in depth profiling of the tumor border in bone-invasive oral cancer using laser-induced breakdown spectroscopy (LIBS): a pilot study

PurposeMicroscopic tumor spread beyond the macroscopically visible tumor mass in bone represents a major risk in surgical oncology, where the spatial complexity of bony resection margins cannot be countered with rapid bone analysis techniques. Laser-induced breakdown spectroscopy (LIBS) has recently been introduced as a promising option for rapid bone analysis. The present study aimed to use LIBS-based depth profiling based on electrolyte disturbance tracking to evaluate the detection of microscopic tumor spread in bone.MethodsAfter en bloc resection, the tumor-infiltrated mandible section of a patient’s segmental mandibulectomy specimen was natively investigated using LIBS. Spectral and electrolytic depth profiles were analyzed across 30 laser shots per laser spot position in healthy bone and at the tumor border. For the histological validation of the lasered positions, the mandibular section was marked with a thin separating disc.ResultsSolid calcium (Ca) from hydroxyapatite and soluble Ca from dissolved Ca can be reliably differentiated using LIBS and reflect the natural heterogeneity of healthy bone. Increased potassium (K) emission values in otherwise typically healthy bone spectra are the first spectral signs of tumorous bone invasion. LIBS-based depth profiles at the tumor border region can be used to track tumor-associated changes within the bone with shot accuracy based on the distribution of K.ConclusionDepth profiling using LIBS might enable the detection of microscopic tumor spread in bone. In the future, direct electrolyte tracking using LIBS should be applied to other intraoperative challenges in surgical oncology to advance rapid bone analysis by spectroscopic–optical techniques.

Super-resolution imaging method assisted by a left-handed medium slab based on a neural network.

In this study, a super-resolution imaging method is proposed that combines the physical properties of a left-handed medium (LHM) slab and the mathematical methods of a neural network. Firstly, for the problem of super-resolution information loss in the received scattering field in general scenes, the LHM slab is used to construct a perfect lens to recover the evanescent wave component that carries super-resolution information. Secondly, the compressed sensing (CS) method is applied to image the sparse targets under the LHM environment. However, the perfect focus only occurs in spot or line positions. Therefore, the imaging width of conventional methods is limited and a more powerful mathematical method is needed. Finally, the neural network method is introduced to relax the limitations of target imaging width due to its strong non-linear fitting capability. The simulation results demonstrate that the imaging resolution can reach λ/10 with the assistance of LHM, while the CS method can realize super-resolution imaging of λ/20 based on prior information of spatially sparse targets. In addition, the neural network method proposed in this paper relaxes the limitation of targets, realizing super-resolution imaging of λ/20 for general targets.

Periodic nanostructures on single-crystal copper for SERS substrate fabricated by using AFM dynamic lithography

The fabrication of periodic nanostructures on noble metals as surface enhanced Raman scattering (SERS) substrate is still challenging through facile and cost-effective process. Dynamic lithography under AFM tapping mode has been applied to the fabrication of nanogrooves on single-crystal copper to reduce the feature size. However, there was a lack of fundamental understanding of the effect of the fabrication of periodic nanostructures due to dynamic lithography and then SERS enhancement. To this end, this study aims to investigate the variation of the energy dissipation and the corresponding fabricated nanogrooves at different laser spot positions. It was found that improper laser position was contributed to the increased energy dissipation and irregular nanogrooves were thus obtained with much larger machined depth. On the contrary, at the optimal laser position, the minimal sensitivity was associated with the maximum voltage value on the photodiode. In this case, regular nanogrooves with controlled feature size can be produced for the fabrication of periodic nanostructures. And checkerboard nanodots with a period of 200 nm were fabricated by the combination of arrays of nanogrooves, which indicated advantages of high stability for AFM dynamic lithography. In addition, rhodamine 6G (R6G) was selected as the detecting target to measure SERS spectra of fabricated substrates. Results indicated the Raman enhancement factors can be promoted due to uniform shape of nanogroove and high resolution in horizon dimension.

Lateral photovoltaic effect in silicon-based hybrid structures under external magnetic field

Charge transport in semiconductor devices is highly sensitive to light, which opens up wide application prospects. The lateral photovoltaic effect (LPE) is widely used in position sensitive detectors due to its high sensitivity to the light spot position. We report on the features of the LPE in silicon-based metal/insulator/semiconductor structures at helium temperatures. To investigate the LPE, Fe/SiO2/p-Si and Mn/SiO2/n-Si structures have been fabricated by molecular beam epitaxy. It has been found by studying the lateral photovoltage that the SiO2/Si interface plays a significant role in transport of photogenerated carriers, mainly via the interface states, which induce electron capture/emission processes at certain temperatures. The value of the photovoltage is likely affected not only by the metallic film thickness, but also by the substrate conductivity type and Schottky barrier. The effect of the magnetic field on the LPE is driven by two mechanisms. The first one is the well-known action of the Lorentz force on photogenerated carriers and the second one is shifting of the interface state energy levels. Basically, the magnetic field suppresses the contribution of the interface states to the LPE, which suggests that the interface-induced transport can be controlled magnetically.

Identification of proteins that contribute to flour strength among elite breeding lines in a breeding program

Gluten, which is a protein aggregate specific to wheat, is crucial in determining the physical properties of wheat flour dough. The gluten is primarily composed of glutenin and gliadin, which are multigenic and comprise diverse proteoforms. Consequently, it is difficult to analyze the quality of gluten by genetic analysis alone. Here, comprehensive protein analysis of wheat cultivars/strains was performed using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) that allows proteoforms to be resolved by spot position. AlveoConsistograph deformation energy (Fb value) was used as a metric for the strength of the dough. Major proteins resolved by 2D-DIGE were identified by LC/MS/MS. We verified that the Glu-B1al allele significantly influences the physical properties of the dough. Next, excluding the influence of the Glu-B1al allele, we identified proteins that contribute to the physical properties of the dough.Two γ-gliadins and five low molecular weight glutenins were identified. A positive correlation was observed between the spot volume ratio of γ-gliadin and its corresponding Fb value. Thus, γ-gliadin exists as multiple proteoforms, one of which may contribute to the physical properties of dough. Combining the proteins identified in this study will help breeders develop high quality flour.

Juno's Multi‐Instruments Observations During the Flybys of Auroral Bright Spots in Jupiter's Polar Aurorae

AbstractJuno's arrival at Jupiter in 2016 revealed unprecedented details about Jupiter's ultraviolet aurorae thanks to its unique suite of remote sensing and in situ instruments. Here we present results from in situ observations during Juno flybys above specific bright auroral spots in Jupiter's polar aurora. We compare data observed by Juno‐UVS, JEDI, JADE, Waves, and MAG instruments when Juno was magnetically connected to bright polar auroral spots (or their immediate vicinity) during perijove 3 (PJ3), PJ15, and PJ33. The highly energetic particles observed by JEDI show enhancements dominated by upward electrons, which suggests that the particle acceleration region takes place below the spacecraft. Moreover, brightness and upward particle flux were higher for the northern bright spot in PJ3 than the southern spots found in PJ15 and PJ33. In addition, we notice the intensification of whistler‐mode waves at the time of the particle enhancements, suggesting that wave‐particle interactions contribute to the acceleration of particles that cause the UV aurorae. The MAG data reveal magnetic perturbations during the PJ3 spot detection by Juno, which suggests the presence of significant field‐aligned electric currents. While the stable positions of the bright spots in System III suggest that the phenomenon is fixed to the planet's rotation, the presence of field‐aligned currents leaves the possibility of an origin rooted much farther in the magnetosphere.

Construction, Spectral Modeling, Parameter Inversion-Based Calibration, and Application of an Echelle Spectrometer.

We have developed a compact, asymmetric three-channel echelle spectrometer with remarkable high-spectral resolution capabilities. In order to achieve the desired spectral resolution, we initially establish a theoretical spectral model based on the two-dimensional coordinates of spot positions corresponding to each wavelength. Next, we present an innovative and refined method for precisely calibrating echelle spectrometers through parameter inversion. Our analysis delves into the complexities of the nonlinear two-dimensional echelle spectrogram. We employ a variety of optimization techniques, such as grid exploration, simulated annealing, genetic algorithms, and genetic simulated annealing (GSA) algorithms, to accurately invert spectrogram parameters. Our proposed GSA algorithm synergistically integrates the strengths of global and local searches, thereby enhancing calibration accuracy. Compared to the conventional grid exploration method, GSA reduces the error function by 22.8%, convergence time by 2.16 times, and calibration accuracy by 7.05 times. Experimental validation involves calibrating a low-pressure mercury lamp, resulting in an average spectral accuracy error of 0.0257 nm after performing crucial parameter inversion. Furthermore, the echelle spectrometer undergoes a laser-induced breakdown spectroscopy experiment, demonstrating exceptional spectral resolution and sub-10 ns time-resolved capability. Overall, our research offers a comprehensive and efficient solution for constructing, modeling, calibrating, and applying echelle spectrometers, significantly enhancing calibration accuracy and efficiency. This work contributes to the advancement of spectrometry and opens up new possibilities for high-resolution spectral analysis across various research and industry domains.