Small Protoplanetary Disks in the Orion Nebula Cluster and OMC1 with ALMA

The Orion Nebula Cluster (ONC) is the nearest dense star-forming region at ∼400 pc away, making it an ideal target to study the impact of high stellar density and proximity to massive stars (the Trapezium) on protoplanetary disk evolution. The OMC1 molecular cloud is a region of high extinction situated behind the Trapezium in which actively forming stars are shielded from the Trapezium’s strong radiation. In this work, we survey disks at high resolution with Atacama Large Millimeter/submillimeter Array at three wavelengths with resolutions of 0.″095 (3 mm; Band 3), 0.″048 (1.3 mm; Band 6), and 0.″030 (0.85 mm; Band 7) centered on radio Source I. We detect 127 sources, including 15 new sources that have not previously been detected at any wavelength. 72 sources are spatially resolved at 3 mm, with sizes from ∼8–100 au. We classify 76 infrared-detected sources as foreground ONC disks and the remainder as embedded OMC1 disks. The two samples have similar disk sizes, but the OMC1 sources have a dense and centrally concentrated spatial distribution, indicating they may constitute a spatially distinct subcluster. We find smaller disk sizes and a lack of large (>75 au) disks in both our samples compared to other nearby star-forming regions, indicating that environmental disk truncation processes are significant. While photoevaporation from nearby massive Trapezium stars may account for the smaller disks in the ONC, the embedded sources in OMC1 are hidden from this radiation and thus must truncated by some other mechanism, possibly dynamical truncation or accretion-driven contraction.

Those Who Have Continuing Radiation Anxiety Show High Psychological Distress in Cases of High Post-Traumatic Stress: The Fukushima Nuclear Disaster

Background: this cross-sectional study aimed to clarify the associations among media utilization, lifestyles, and the strong radiation anxiety that has persisted 9 years after the 2011 nuclear accident. Moreover, the relationships among psychological distress, post-traumatic stress, and strong radiation anxiety were examined. Methods: for the multivariate regression analysis, the independent variables were radiation anxiety at the time of the accident and the current status, categorized as “continuing/emerging strong radiation anxiety”. Media utilization (local, national, internet, and public broadcasts, and public relations information) and lifestyle variables (sleep quality, regular exercise, and drinking habits) were set as the dependent variables. Moreover, the psychological distress of residents with continuing/emerging strong radiation anxiety was examined by an analysis of covariance stratified by post-traumatic stress. Result: there was no significant association between lifestyle variables and media utilization, except for local media (OR: 0.435, 95% CI: 0.21–0.90). Conversely, significantly high psychological distress was confirmed among residents with continuing/emerging radiation anxiety. The K6 score, representing psychological distress, for those with higher post-traumatic stress was 12.63; for those with lower post-traumatic stress, it was 5.13 (p = 0.004). Conclusions: residents with continuing/emerging strong radiation anxiety showed high psychological distress, which has been strengthened by higher post-traumatic stress.

Racemate Resolution of Alanine and Leucine on Homochiral Quartz, and Its Alteration by Strong Radiation Damage

Homochiral proteins orchestrate biological functions throughout all domains of life, but the origin of the uniform l-stereochemistry of amino acids remains unknown. Here, we describe enantioselective adsorption experiments of racemic alanine and leucine onto homochiral d- and l-quartz as a possible mechanism for the abiotic emergence of biological homochirality. Substantial racemate resolution with enantiomeric excesses of up to 55% are demonstrated to potentially occur in interstitial pores, along grain boundaries or small fractures in local quartz-bearing environments. Our previous hypothesis on the enhanced enantioselectivity due to uranium-induced fission tracks could not be validated. Such capillary tubes in the near-surface structure of quartz have been proposed to increase the overall chromatographic separation of enantiomers, but no systematic positive correlation of accumulated radiation damage and enantioselective adsorption was observed in this study. In general, the natural l-quartz showed stronger enantioselective adsorption affinities than synthetic d-quartz without any significant trend in amino acid selectivity. Moreover, the l-enantiomer of both investigated amino acids alanine and leucine was preferably adsorbed regardless of the handedness of the enantiomorphic quartz sand. This lack of mirror symmetry breaking is probably due to the different crystal habitus of the synthetic z-bar of d-quartz and the natural mountain crystals of l-quartz used in our experiments.

SPACE CALIBRATION OF THE ROBOT SYSTEM IN PUNCTURE SURGERY

Traditional manual puncture surgery has low positioning accuracy and poor stability. Moreover, the computed tomography method can cause strong radiation damage. Therefore, this study intends to establish a robotic system in puncture surgery, which is based on optical registration to improve safety, accuracy, and efficiency. As the accuracy of surgical space calibration influences the accuracy of the surgical system, this study proposes an improved automatic calibration algorithm for linear rotation. The algorithm can reduce error caused by manual calibration and system noise. Recalibration is not required provided that the pose of the digital reference frame is unchanged, thereby improving accuracy and efficiency. The proposed algorithm is experimentally verified to prove its effectiveness. Results show that the average errors of position and posture are 0.25[Formula: see text]mm and 0.2∘, respectively. The accuracy of calibration fully meets the needs of surgery.

Formation of the BeH+ and BeD+ Molecules in Be+ + H/D Collisions Through Radiative Association

Cross sections and rate coefficients for the formation of BeH+ and BeD+ molecules in Be+ + H/D collisions through radiative association are calculated using quantum mechanical perturbation theory and Breit-Wigner theory. The local thermodynamic equilibrium limit of the molecule formation is also studied, since the process is also relevant in environments with high-density and/or strong radiation fields. The obtained rate coefficients may facilitate the kinetic modelling of BeH+/BeD+ production in astrochemical environments as well as the corrosion chemistry of thermonuclear fusion reactors.

Hybrid (Oscillator-Amplifier) Free Electron Laser and New Proposals

The present work analyses a hybrid free electron laser (FEL) scheme where the oscillator is based on a radiation source operating with a slow-wave guiding structure as, for instance, a Cerenkov FEL or a Smith–Purcell FEL. Such devices, often running in transverse magnetic (TM) modes, present a longitudinal electric field which can easily affect the longitudinal electrons’ velocities, inducing an energy modulation on the beam. Such a modulation, properly controlled, can induce a strong radiation emission in a magnetic undulator properly designed to operate as a radiator. General considerations will be exposed together with a practical numerical example in the far infrared region of the spectrum.

Exploring the Flexible Talent Introduction Mechanism for the Development of Airport industry in G City from the Perspective of Talent Governance

Promoting flexible talent introduction is an important part of innovative talent governance, and an effective mechanism to promote the flow of talents and release the vitality of talents. As an airport industry relying on resources such as convenient transportation, advanced logistics and strong radiation effects from large-scale hub airports, its core resources are still human resources. It is a strategic choice for the rapid development of the airport industry to quickly tap and introduce talents and give full play to the advantages of talents. At present, the theoretical and practical circles still lack in-depth discussions on the flexible talent introduction mechanism of the airport industry. This research focuses on the problems and causes analysis of the flexible introduction of talents in the airport industry in G City, and tries to start from the three governance concepts of collaborative governance, dynamic governance and risk governance, and proposes innovations in the talent policy system that promotes flexible introduction of talents, and innovations in talent introduction methods. Flexible introduction of countermeasures and suggestions for risk aversion. Hope to promote the in-depth study of the flexible talent introduction model.

The low-frequency improvement with loading soft magnetic ferrite films for multiband antenna applications

This work presents an easy way to improve the low-frequency properties in a small-size LTE/WWAN smartphone antenna by just loading a soft magnetic ferrite film on the strong radiation area. The base non-magnetic antenna, which only takes up an 11 mm × 30 mm no-ground space, can achieve hexa-band operation covering 822–914/1710–3244 MHz bands by co-designing a meandering strip and a T-shaped feeding strip. With loading a small-size ferrite film (2 mm × 15 mm) at the strong radiation strip, the frequencies can be shifted to cover the range of 692–1191/1698–3020 MHz, which shows a fully covering of octa-band operation, especially including the best long-term-evolution band, LTE700, without enlarging the size of base antenna. In addition, the radiation characteristics of the magnetic antenna with ferrite film loading show a limited change at upper bands (1710–2690 MHz) but an acceptable level at lower bands (698–960 MHz). Both experimental and simulated results have been taken out and shown the consistent tendency. This optimization method of low-frequency properties by introducing a commercial ferrite film on the antenna has provided a simple and convenient way to solve the frequency deviation in the practical smartphone applications.

Development of a Robotic Catheter Manipulation System Based on BP Neural Network PID Controller

In the process of artificial interventional therapy, the operation of artificial catheter is not accurate, which will bring strong radiation damage to surgeons. The purpose of this study is to develop a catheter operating system of surgical robot to assist doctors in remote operation and avoid the influence of radiation. BP neural network plays an important role in the flexibility and rapidity of control. According to the actual output of the system, the control parameters of the controller are constantly adjusted to achieve better output effect. This paper introduces the practical application of BP neural network PID controller in the remote operation of the system and compares with the traditional PID controller. The results show that the new control algorithm is feasible and effective. The results show that the synchronization performance of BP neural network PID controller is better than that of traditional PID controller.

Optimalisasi Ketebalan Timbal Untuk Mendapatkan Kualitas Citra Guna Mendukung Verifikasi Pada Pesawat Teleterapi 60Co

<p class="AbstractEnglish"><strong>Abstract: </strong>The quality of radiotherapy images supports the steps of verifying the accuracy of the dose and verifying the geometry, for example the area of field and the accuracy of the patient's position. Radiotherapy image capture requires a radiation filter that is thick enough, due to the strong radiation dose from the ⁶⁰Co source. Lead thickness optimization is needed so that the irradiation recording on the Imaging Plate produces an adequate image to be scanned via Computed Radiography. Analysis using Dose.Lab 4.1 software with the Region of Interest technique so that the Mean Gray Value (MGV) is obtained and the contrast is obtained by the Contrast to-Noise Ratio (CNR) analysis. Standard exposure of 2 seconds and 3 seconds at the collimation area (10 x 10) cm², using a 1,8 cm Pb filter shows the most optimal image. The thicker the Pb, the greater the MGV value, which indicates high radiation absorption. MGV will decrease with the addition of filters. The optimal thickness of Pb in decreasing the dose rate for irradiation of 1, 2 and 3 seconds, respectively, was starting from 2,7 cm and 4,5 cm, meanwhile for 3 seconds there is no optimal lead thickness.</p><p class="AbstrakIndonesia"><strong>Abstrak:</strong> Kualitas citra radioterapi mendukung tahapan verifikasi ketepatan dosis dan verifikasi geometri misalnya luas lapangan dan ketepatan posisi pasien. Pengambilan citra radioterapi memerlukan filter radiasi yang cukup tebal, disebabkan oleh kuatnya dosis radiasi dari sumber ⁶⁰Co. Diperlukan optimasi tebal timbal agar rekaman penyinaran pada <em>Imaging Plate </em>menghasilkan citra yang memadai untuk dipindai melalui <em>Computed Radiography</em>. Analisa menggunakan <em>Software Dose.Lab 4.1</em> dengan teknik <em>Region Of Interest</em> sehingga diperoleh <em>Mean Gray Value</em>(MGV) dan kontras diperoleh dengan analisa <em>Contrast to-Noise Ratio</em> (CNR). Eksposure standar 2 detik dan 3 detik pada luas kolimasi (10 x 10) cm², pemakaian 1,8 cm filter Pb menunjukkan citra yang paling optimal. Semakin tebal Pb maka nilai MGV semakin besar yang menunjukkan serapan radiasi tinggi. MGV akan menurun dengan penambahan filter. Tebal Pb yang optimal dalam menurunkan laju dosis untuk penyinaran 1 dan 2 detik masing-masing adalah mulai dari 2,7 cm dan 4,5 cm, sedangkan untuk 3 detik tidak ada tebal Pb yang optimal.</p>