Microstructure Control and Performance Evolution of Aluminum Alloy 7075 by Nano-Treating.

Nano-treating is a novel concept wherein a low percentage of nanoparticles is used for microstructural control and property tuning in metals and alloys. The nano-treating of AA7075 was investigated to control its microstructure and improve its structural stability for high performance. After treatment with TiC nanoparticles, the grains were significantly refined from coarse dendrites of hundreds of micrometers to fine equiaxial ones smaller than 20 μm. After T6 heat treatment, the grains, with an average size of 18.5 μm, remained almost unchanged, demonstrating an excellent thermal stability. It was found that besides of growth restriction factor by pinning behavior on grain boundries, TiC nanoparticles served as both an effective nucleation agent for primary grains and an effective secondary phase modifier in AA7075. Furthermore, the mechanical properties of nano-treated AA7075 were improved over those of the pure alloy. Thus, nano-treating provides a new method to enhance the performance of aluminum alloys for numerous applications

Physical and Radiobiological Evaluation of Radiotherapy Treatment Plan

Radiation treatment planning plays an important role in modern radiation therapy; it could simulate to plan the geometric, radiobiological, and dosimetric aspects of the therapy using radiation transport simulations and optimization. In this chapter, we have reviewed several quantitative methods used for evaluating radiation treatment plans and discussed some important considering points. For the purpose of quantitative plan evaluation, we reviewed dosimetrical indexes like PITV, CI, TCI, HI, MHI, CN, COSI, and QF. Furthermore, radiobiological indexes like Niemierko’s EUD-based TCP and NTCP were included for the purpose of radiobiological outcome modeling. Additionally, we have reviewed dose tolerance for critical organs including RTOG clinical trial results, QUENTEC data, Emami data, and Milano clinical trial results. For the purpose of clinical evaluation of radiation-induced organ toxicity, we have reviewed RTOG and EORTC toxicity criteria. Several programs could help for the easy calculation and analysis of dosimetrical plan indexes and biological results. We have reviewed the recent trend in this field and proposed further clinical use of such programs. Along this line, we have proposed clinically optimized plan comparison protocols and indicated further directions of such studies

Demonstration of SDN-Based Heterogeneous Quantum Key Distribution Chain Orchestration over Optical Networks

Heterogeneous quantum key distribution chain orchestration over optical networks is demonstrated with software-defined networking (SDN), achieving the control-layer interoperability for BB84 (Bennett-Brassard-1984) and TF (Twin-Field) based quantum key distribution devices

Quantum Key Distribution (QKD) over Software-Defined Optical Networks

Optical network security is attracting increasing research interest. Currently, software-defined optical network (SDON) has been proposed to increase network intelligence (e.g., flexibility and programmability) which is gradually moving toward industrialization. However, a variety of new threats are emerging in SDONs. Data encryption is an effective way to secure communications in SDONs. However, classical key distribution methods based on the mathematical complexity will suffer from increasing computational power and attack algorithms in the near future. Noticeably, quantum key distribution (QKD) is now being considered as a secure mechanism to provision information-theoretically secure secret keys for data encryption, which is a potential technique to protect communications from security attacks in SDONs. This chapter introduces the basic principles and enabling technologies of QKD. Based on the QKD enabling technologies, an architecture of QKD over SDONs is presented. Resource allocation problem is elaborated in detail and is classified into wavelength allocation, time-slot allocation, and secret key allocation problems in QKD over SDONs. Some open issues and challenges such as survivability, cost optimization, and key on demand (KoD) for QKD over SDONs are discussed

Minimally modified LDL upregulates endothelin type B receptors in rat coronary artery via ERK1/2 MAPK and NF-kappa B pathways

Minimally modified low density lipoprotein (mmLDL) is a well-known risk factor for coronary artery disease. Upregulation of vascular endothelin type B (ETB) receptors on the vascular smooth muscle cells is predicted to be the molecular mechanism that leads to cardiovascular pathogenesis. The objective of the present study was to examine the hypothesis that mmLDL upregulates ETB receptors in rat coronary artery. The contractile responses to sarafotoxin 6c (ETB receptor agonist) were studied using a sensitive myograph. ETB receptor mRNA and protein expression was determined using real-time PCR and Western blot analysis. The results showed that organ culture increased the contractile responses induced by sarafotoxin 6c and the levels of ETB receptor mRNA and protein. This increase was further enhanced by the addition of mmLDL (10 mu g/mL). Specific ERK1/2 inhibitors (SB386023 and U0126) and an NF-kappa B inhibitor (wedelolactone) attenuated the mmLDL-increased ETB receptor-mediated contraction and ETB receptor mRNA and protein levels. Wedelolactone significantly attenuated the mmLDL-decreased I kappa B-alpha protein expression. Consistent with this result, I kappa B-alpha protein expression was significantly decreased by culture with mmLDL compared to the level of expression in the organ culture group. However, the JNK inhibitor, SP600125 or p38 pathway inhibitor, SB203580 did not inhibit mmLDL-enhanced effects. The PKC inhibitor, staurosporine attenuated only culture-alone-increased effects. In conclusion, mmLDL upregulates the ETB receptors in rat coronary arterial smooth muscle cells, mainly via activation of the ERK1/2 MAPK and the downstream transcriptional factor NF-kappa B. (C) 2011 Elsevier B.V. All rights reserved

Multi-Tenant Provisioning for Quantum Key Distribution Networks with Heuristics and Reinforcement Learning: A Comparative Study

Quantum key distribution (QKD) networks are potential to be widely deployed in the immediate future to provide long-term security for data communications. Given the high price and complexity, multi-tenancy has become a cost-effective pattern for QKD network operations. In this work, we concentrate on addressing the online multi-tenant provisioning (On-MTP) problem for QKD networks, where multiple tenant requests (TRs) arrive dynamically. On-MTP involves scheduling multiple TRs and assigning non-reusable secret keys derived from a QKD network to multiple TRs, where each TR can be regarded as a high-security-demand organization with the dedicated secret-key demand. The quantum key pools (QKPs) are constructed over QKD network infrastructure to improve management efficiency for secret keys. We model the secret-key resources for QKPs and the secret-key demands of TRs using distinct images. To realize efficient On-MTP, we perform a comparative study of heuristics and reinforcement learning (RL) based On-MTP solutions, where three heuristics (i.e., random, fit, and best-fit based On-MTP algorithms) are presented and a RL framework is introduced to realize automatic training of an On-MTP algorithm. The comparative results indicate that with sufficient training iterations the RL-based On-MTP algorithm significantly outperforms the presented heuristics in terms of tenant-request blocking probability and secret-key resource utilization

Study on coalface stray current safety early warning based on ANFIS

AbstractBy analyzing the DC traction supply system in coal mine, we confirmed the following four parameters to be the characteristic parameters of workface stray current safe early warning, that is, the leakage current of contacting line, resistance of insulating splint, the distance between workface and subtraction substation and the stray voltage of contacting line. After that, we developed a safety early warning model of coal mining workface stray current danger grade with ANFIS as its core, choosing data sets measured online to do the training and early warning of safe early warning model. Results indicate that the model can be able to complete safety early warning of workface stray current. Besides, a monitoring and early warning system of stray current was introduced

Analysis of contrast sensitivity on examination for pilots

AIM: To study the influential factors of the contrast sensitivity function(CSF), we tested and investigated the CSF of navy pilots. METHODS: Totally 58 pilots(116 eyes)were examined by CSF under the nighttime, nighttime & periglare, daytime, daytime & periglare conditions for 5 spacial frequencies with OPTEC6 500 Vision Tester. RESULTS: From mean diagram of curves, the peak of CSF under the nighttime, nighttime & periglare conditions was at 3-6c/d, daytime, daytime & periglare conditions was at 6c/d. CONCLUSION: The distant CSF is better than the near CSF in navy pilots,the binoculus CSF is better than that of the single eye. The spatial characteristics of CSF in navy pilots were reflected by present study