Efficiency Analysis and Comparison of Different Radon Progeny Measurement Methods

Radon exposure to the public contributes more than half of all the radiation doses caused by natural radiation; accurate measurement of radon progeny is quite essential for the dose evaluation of radon exposure in environment. For the purpose of establishing a radon progeny standard and controlling measurement quality of commercial devices, it is quite important to analyze the efficiency of different measurement methods and determine which would be the most appropriate for radon progeny measurements. Through theoretical analysis and experimental measurement, some commonly used measurement methods were compared in this study and the development trends of those methods were reviewed. Results show that for radon progeny measurement, the spectroscopic analysis method is better than the gross count method, while least-square calculation methods is better than traditional three-count or five-count method. Multiperiod counting of α plus β spectrum as well as using weighted least-square calculation method might be the best choice for accurate measurement on radon progeny in standard radon chamber when calibrating commercial radon progeny monitors

De-fine: Decomposing and Refining Visual Programs with Auto-Feedback

Visual programming, a modular and generalizable paradigm, integrates different modules and Python operators to solve various vision-language tasks. Unlike end-to-end models that need task-specific data, it advances in performing visual processing and reasoning in an unsupervised manner. Current visual programming methods generate programs in a single pass for each task where the ability to evaluate and optimize based on feedback, unfortunately, is lacking, which consequentially limits their effectiveness for complex, multi-step problems. Drawing inspiration from benders decomposition, we introduce De-fine, a general framework that automatically decomposes complex tasks into simpler subtasks and refines programs through auto-feedback. This model-agnostic approach can improve logical reasoning performance by integrating the strengths of multiple models. Our experiments across various visual tasks show that De-fine creates more accurate and robust programs, setting new benchmarks in the field

An adaptive energy efficient MAC protocol for RF energy harvesting WBANs

Continuous and remote health monitoring medical applications with heterogeneous requirements can be realized through wireless body area networks (WBANs). Energy harvesting is adopted to enable low-power health applications and long-term monitoring without battery replacement, which have drawn significant interest recently. Because energy harvesting WBANs are obviously different from battery-powered ones, network protocols should be designed accordingly to improve network performance. In this article, an efficient cross-layer media access control protocol is proposed for radio frequency powered energy harvesting WBANs. We redesigned the superframe structure, which can be rescheduled by the coordinator dynamically. A time switching (TS) strategy is used when sensors harvest energy from radio frequency signals broadcast by the coordinator, and a transmission power adjustment scheme is proposed for sensors based on the energy harvesting efficiency and the network environment. Energy efficiency can be effectively improved that more packets can be uploaded using limited energy. The length of the energy harvesting period is determined by the coordinator to balance the channel resources and energy requirements of sensors and further improve the network performance. Numerical simulation results show that our protocol can provide superior system performance for long-term periodic health monitoring applications

A nine-level switched-capacitor step-up inverter with low voltage stress

This paper proposes a nine-level switched-capacitor step-up inverter (9LSUI) which can achieve a quadruple voltage gain with single dc source. Differing from other switched-capacitor inverters, the voltage stress of switches is effectively reduced due to the elimination of H-bridge, and the peak inverse voltage of all switches is kept within 2Vdc. In addition, the proposed inverter is able to integrate inductive load, and the capacitor voltage self-balancing can be achieved without any auxiliary circuits. Moreover, the topology structure can be flexibly extended to raise the output levels, and the peak inverse voltage of switches can remain constant with the increase of sub-modules in the extended structure. Comprehensive comparisons are performed to verify the outstanding advantages of the proposed inverter. Finally, the steady-state and dynamic performance of the proposed inverter is validated through an experimental prototype, and the experimental results are provided to prove the theoretical analysis

A modular switched-capacitor multilevel inverter featuring voltage gain ability

This paper proposes a modular switched-capacitor multilevel inverter with single dc source, which can obtain triple voltage gain by using two capacitors. It is worth noting that the inherent inversion capacity eliminates the Hbridge, which can effectively reduce the voltage stress of switches, and the maximum voltage stress (MVS) of all switches is kept within 2Vdc. In addition, the proposed inverter is able to integrate inductive load, and the capacitor voltage self-balancing can be achieved without any auxiliary circuits. Moreover, the modular inverter also has expandable structure which can generate more output levels and raise the voltage gain by employing multiple switchedcapacitor cells, meanwhile the MVS for all of the switches is kept within 2Vdc in the extended structure. Furthermore, comprehensive analysis and comparison with other multilevel inverter have been implemented to evaluate the superiority of the proposed topology. Finally, the steadystate and dynamic performance of the proposed inverter is validated through a seven-level inverter prototype, the correctness and feasibility of the proposed topology are verified by simulations and experiments

A novel process for separation of magnetite and phosphorous phases from a CaO-SiO2-FeO-P2O5 slag

Iron and phosphorus were successfully separated from CaO-SiO2-FeO-P2O5 slag through atmospheric control, B2O3 addition and a combination of magnetic separation and flotation. For the slag with basicity (CaO/SiO2) of 2.5 and B2O3 addition of 6% (weight percentage), iron and phosphorus in the slag were enriched in the form of magnetite (Fe3O4) and calcium phosphate (Ca10P6O25) phases respectively under Ar atmosphere. Using a combination of magnetic separation and flotation, the concentrates were obtained with Fe3O4 and P2O5 content of 92.84 % and 37.66 % respectively, corresponding to the recovery ratios of 85.8 % for iron and 91.3 % for phosphorus

SHQ1 regulation of RNA splicing is required for T-lymphoblastic leukemia cell survival

T-acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy with complicated heterogeneity. Although expression profiling reveals common elevated genes in distinct T-ALL subtypes, little is known about their functional role(s) and regulatory mechanism(s). We here show that SHQ1, an H/ACA snoRNP assembly factor involved in snRNA pseudouridylation, is highly expressed in T-ALL. Mechanistically, oncogenic NOTCH1 directly binds to the SHQ1 promoter and activates its transcription. SHQ1 depletion induces T-ALL cell death in vitro and prolongs animal survival in murine T-ALL models. RNA-Seq reveals that SHQ1 depletion impairs widespread RNA splicing, and MYC is one of the most prominently downregulated genes due to inefficient splicing. MYC overexpression significantly rescues T-ALL cell death resulted from SHQ1 inactivation. We herein report a mechanism of NOTCH1-SHQ1-MYC axis in T-cell leukemogenesis. These findings not only shed light on the role of SHQ1 in RNA splicing and tumorigenesis, but also provide additional insight into MYC regulation