The concentration of micron-size particles in used oil is generally obtained by atomic emission spectrometry. These accurate results can be considered as the most important index for real-time ...reliability evaluation including failure prediction and residual life assessment of power-shift steering transmission in tracked vehicles. Stochastic process and especially Wiener process can be applied in processing the oil spectral data. In this article, 50 used oil samples in total were collected and analyzed in sequence which covered 250 motor hours. The eigenvalue and mean value of elemental concentration in those samples were also revealed by linear regression analysis. Then, the increasing trends and the first hitting times for indicating elements were solved by simulating stochastic differential equations, which were based on the positive drift Wiener process. Comparing to the existing conditional maintenance time, the first hitting time increased about 27 motor hours more (13.7%). The results show that the maintenance frequency can be decreased by a longer time and finally can increase the cost-effectiveness ratio of maintenance.
Background/Purpose
APS ACTION Registry was created to study the outcomes of patients with persistently positive antiphospholipid antibodies (aPL) with or without other systemic autoimmune disease ...(SAIDx). Given that immunosuppression (IS) is used for certain aPL manifestations, for example, thrombocytopenia (TP), our primary objective was to describe the indications for IS in aPL-positive patients without other SAIDx. Secondly, we report the type of IS used in patients with selected microvascular or non-thrombotic aPL manifestations.
Methods
An online database is used to collect clinical data. The inclusion criteria are positive aPL based on the laboratory section of the APS Classification Criteria, tested at least twice within one year prior to enrollment. Patients are followed every 12 ± 3 months. For this descriptive retrospective and prospective analysis, we included aPL-positive patients without other SAIDx and excluded those with new SAIDx classification during follow-up. For each patient, we retrieved clinical data at baseline and follow-up including selected aPL manifestations (diffuse alveolar hemorrhage DAH, antiphospholipid-nephropathy aPL-N, livedoid vasculopathy LV-related skin ulcers, TP, autoimmune hemolytic anemia AIHA, cardiac valve disease VD), and IS medications.
Results
Of 899 patients enrolled, 537 were included in this analysis (mean age 45 ± 13 years, female 377 70%, APS Classification in 438 82%, and at least one selected microvascular or non-thrombotic aPL manifestation in 141 (26%)). Of 537 patients, 76 (14%) were reported to use IS (ever), and 41/76 (54%) received IS primarily for selected aPL manifestation. In six of 8 (75%) DAH patients, 6/19 (32%) aPL-N, 4/28 (14%) LV, 25/88 (28%) TP, 6/11 (55%) AIHA, and 1/43 (2%) VD, the IS (excluding corticosteroids/hydroxychloroquine) indication was specific for selected aPL manifestation.
Conclusion
In our international cohort, 14% of aPL-positive patients without other SAIDx were reported to receive IS; the indication was at least one of the selected microvascular and/or non-thrombotic aPL-related manifestations in half. Thrombocytopenia was the most frequent among those selected aPL-related manifestations; however, approximately one-third received IS specifically for that indication. Diffuse alveolar hemorrhage was frequently treated with IS followed by AIHA and aPL-N. Systematic controlled studies are urgently needed to better define the role of IS in APS.
We report a design work of a continuous-wave (cw) radio frequency quadrupole (RFQ) for the injector linac of the High Intensity heavy-ion Accelerator Facility project. The rf design and multiphysics ...analysis were conducted to enhance the long-term stability and reliability of the cavity. To minimize the peak modified Poynting vector and peak surface electric field associated with the rf breakdown rate, the cross section and the vanes segmentation of the RFQ cavity were optimized. Pi-mode stabilizing loops (PISLs) were adopted for the cavity to increase the mode separation between the quadrupole and the neighboring dipole modes, intending to reduce the emittance growth and beam loss caused by the field asymmetry of the quadrupole mode. Due to the lack of a universal criterion of acceptable mode separation, the field asymmetry of the quadrupole mode was directly used as the design criterion for the PISL. Tuners were designed to tune the cavity frequency and longitudinal field flatness. Thermal distributions on tuners with and without rf sealing were investigated, and we found that rf sealing was indispensable in decreasing the tuner’s temperature. A multiphysics analysis was carried out to maintain the cavity frequency while running with different rf power, in an attempt to avoid frequently adjusting the cooling water temperature when accelerating different ions. The analysis also verified that a large wall thickness could make the cavity possess a low stress and a minor deformation.
Off-line high-power tests of the fundamental power couplers prior to their on-line operations are of importance for ensuring their operating reliability and stability. To test the couplers using a ...limited power supply effectively, a movable standing wave (SW) resonant test system with an extraordinary power gain has been developed at Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS). The system consists of a movable resonator having two movable shorts for the enhancement and movement of the SW field, and a tunable secondary coupler for feeding power into the resonator without reflection. The proof-of-principle structure of the system has been built and tested both at the low-power and at the high-power levels. The low-power test demonstrates that the moving range of the SW resonant field is over half a wavelength which ensures that the fundamental couplers can be tested by SW field at all reflected phases, and the system can provide a power gain ranging from 50 to 94, corresponding to 200–376 (4×50–4×94) of power gain in the case of traveling wave resonant ring system. Two types of multipacting inside the couplers were observed during the high-power tests and the mechanism of their influences on the power gain was analyzed. This movable and high-power-gain solution can be beneficial for the promotion of SW resonant test systems for fundamental couplers.
A novel radio frequency quadrupole (RFQ) resonant structure with bent vanes is proposed at the Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS). Compared with the traditional ...four-vane type RFQs, the bent-vane type structure is more compact at low frequency with significant reduction in the cross section size, and is capable of using a simple cooling system due to its rotationally symmetric structure. An 81.25 MHz proof-of-principle cavity is now under development at IMP. The beam dynamics design, electromagnetic optimizations with multipacting simulations, multiphysics analyses, and mechanical design of this novel bent-vane type RFQ (BV-RFQ) will be presented in this paper.
Development of the heavy ion RFQ for CAFE2 Gong, Lingyun; Wang, Zhijun; Dou, Weiping ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2024, Letnik:
1058
Journal Article
RF structure design of the China Material Irradiation Facility RFQ Li, Chenxing; He, Yuan; Xu, Xianbo ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2017, Letnik:
869
Journal Article
Recenzirano
The radio frequency structure design of the radio frequency quadrupole (RFQ) for the front end of China Material Irradiation Facility (CMIF), which is an accelerator based neutron irradiation ...facility for fusion reactor material qualification, has been completed. The RFQ is specified to accelerate 10 mA continuous deuteron beams from the energies of 20 keV/u to 1.5 MeV/u within the vane length of 5250 mm. The working frequency of the RFQ is selected to 162.5 MHz and the inter-vane voltage is set to 65 kV. Four-vane cavity type is selected and the cavity structure is designed drawing on the experience of China Initiative Accelerator Driven System (CIADS) Injector II RFQ. In order to reduce the azimuthal asymmetry of the field caused from errors in fabrication and assembly, a frequency separation between the working mode and its nearest dipole mode is reached to 17.66 MHz by utilizing 20 pairs of π-mode stabilizing loops (PISLs) distributed along the longitudinal direction with equal intervals. For the purpose of tuning, 100 slug tuners were introduced to compensate the errors caused by machining and assembly. In order to obtain a homogeneous electrical field distribution along cavity, vane cutbacks are introduced and output endplate is modified. Multi-physics study of the cavity with radio frequency power and water cooling is performed to obtain the water temperature tuning coefficients. Through comparing to the worldwide CW RFQs, it is indicated that the power density of the designed structure is moderate for operation under continuous wave (CW) mode.
A novel type dual-beam drift tube linac (DB-DTL) was proposed at the Institute of Modern Physics for ultra-high intensity heavy-ion acceleration. With two identical beam apertures located in the ...vertical direction with the same off-set from the cavity axis, two beams could be accelerated simultaneously by the DB-DTL and then be merged to one, thus double the current beam intensity limit, which is of great significance for ultra-high intensity heavy-ion acceleration. An 81.25 MHz proof-of-principle cavity was developed to demonstrate this new concept. Designed and optimized with the alternative phase focusing (APF) scheme, this prototype cavity was supposed to accelerate 10 mA protons beam from 0.56 MeV to 2.5 MeV in one meter with transmission efficiency more than 90%. Inter-digital H-mode (IH) structure was adopted by this DB-DTL, thus high shunt impedance could be achieved which significantly reduce the power loss. With efficient cooling, this cavity was capable to work at the pulsed mode with a maximum duty cycle of 10%. Beam dynamics simulations, electromagnetic design and optimization of the prototype cavity, and multi-physics analyses of this DB-DTL will be presented in this paper.
•The DB-DTL is firstly proposed to prove the feasibility of the multi-beam type DTL.•Based on the design results, the DB-DTL can be applied to accelerate two beams.
To assess whether patients with antiphospholipid syndrome (APS) and history of recurrent thrombosis have higher levels of adjusted Global AntiphosPholipid Syndrome Score (aGAPSS) when compared to ...patients without recurrent thrombosis.
In this cross-sectional study of antiphospholipid antibody (aPL)-positive patients, we identified APS patients with a history of documented thrombosis from the AntiPhospholipid Syndrome Alliance For Clinical Trials and InternatiOnal Networking (APS ACTION) Clinical Database and Repository (“Registry”). Data on aPL-related medical history and cardiovascular risk factors were retrospectively collected. The aGAPSS was calculated at Registry entry by adding the points corresponding to the risk factors: three for hyperlipidemia, one for arterial hypertension, five for positive anticardiolipin antibodies, four for positive anti-β2 glycoprotein-I antibodies and four for positive lupus anticoagulant test.
The analysis included 379 APS patients who presented with arterial and/or venous thrombosis. Overall, significantly higher aGAPSS were seen in patients with recurrent thrombosis (arterial or venous) compared to those without recurrence (7.8 ± 3.3 vs. 6 ± 3.9, p<0.05). When analyzed based on the site of the recurrence, patients with recurrent arterial, but not venous, thrombosis had higher aGAPSS (8.1 ± SD 2.9 vs. 6 ± 3.9; p<0.05).
Based on analysis of our international large-scale Registry of aPL-positive patients, the aGAPSS might help risk stratifying patients based on the likelihood of developing recurrent thrombosis in APS.
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