Measurement of small rotation angle of flange joints by a novel flexure magnifying mechanism

Bolted flange joints are indispensable components in process industries due to the good sealing, assemble and disassemble capacities. Generally, the flange rigidity characterized by the rotation angle is a key index to evaluate the sealing tightness of flange joints. However, the rotation angle of flange is usually too small (less than 1º) to monitor during the assemble and operation stages. Accordingly, a novel flexure magnifying mechanism is designed to measure the small rotation angle of flange joints under internal pressure and external bending moment. The magnification factor and calculation approach of the flexure amplification mechanism are deduced and verified by experimental data and finite element simulation. Results indicate that the proposed measuring apparatus has good performance to monitor the maximum rotation angle. It is of great interest that the measured location of the maximum rotation angle is in good agreement with that in the experiment, and the average error is 7.3%, which is acceptable for practical application. Additionally, the leakage rate at the top of flange joints slowly and almost linearly increases with the increment of external bending moment ascribing to the decrease the gasket stress near the top of flange joints

Analysis and Construction of Efficient RFID Authentication Protocol with Backward Privacy

Privacy of RFID systems is receiving increasing attentions in the RFID community and an important issue required as to the security of RFID system. Backward privacy means the adversary can not trace the tag later even if he reveals the internal states of the tag sometimes before. In this paper, we analyze two recently proposed RFID authentication schemes: Randomized GPS and Randomized Hashed GPS scheme. We show both of them can not provide backward privacy in Juels and Weis privacy model, which allows the adversary to know whether the reader authenticates the tag successfully or not. In addition, we present a new protocol, called Challenge-Hiding GPS, based on the Schnorr identification scheme. The challenge is hidden from the eavesdropping through the technique of Diffie-Hellman key agreement protocol. The new protocol can satisfy backward privacy, and it has less communication overheads and almost the same computation, compared with the two schemes analyzed

Adaptive Kalman Estimation in Target Tracking Mixed with Random One-Step Delays, Stochastic-Bias Measurements, and Missing Measurements

The objective of this paper is concerned with the estimation problem for linear discrete-time stochastic systems with mixed uncertainties involving random one-step sensor delay, stochastic-bias measurements, and missing measurements. Three Bernoulli distributed random variables are employed to describe the uncertainties. All the three uncertainties in the measurement have certain probability of occurrence in the target tracking system. And then, an adaptive Kalman estimation is proposed to deal with this problem. The adaptive filter gains can be obtained in terms of solutions to a set of recursive discrete-time Riccati equations. Examples in three scenarios of target tracking are exploited to show the effectiveness of the proposed design approach

Evolutionary and regulatory pattern analysis of soybean Ca2+ ATPases for abiotic stress tolerance

P2-type Ca2+ ATPases are responsible for cellular Ca2+ transport, which plays an important role in plant development and tolerance to biotic and abiotic stresses. However, the role of P2-type Ca2+ ATPases in stress response and stomatal regulation is still elusive in soybean. In this study, a total of 12 P2-type Ca2+ ATPases genes (GmACAs and GmECAs) were identified from the genome of Glycine max. We analyzed the evolutionary relationship, conserved motif, functional domain, gene structure and location, and promoter elements of the family. Chlorophyll fluorescence imaging analysis showed that vegetable soybean leaves are damaged to different extents under salt, drought, cold, and shade stresses. Real-time quantitative PCR (RT-qPCR) analysis demonstrated that most of the GmACAs and GmECAs are up-regulated after drought, cold, and NaCl treatment, but are down-regulated after shading stress. Microscopic observation showed that different stresses caused significant stomatal closure. Spatial location and temporal expression analysis suggested that GmACA8, GmACA9, GmACA10, GmACA12, GmACA13, and GmACA11 might promote stomatal closure under drought, cold, and salt stress. GmECA1 might regulate stomatal closure in shading stress. GmACA1 and GmECA3 might have a negative function on cold stress. The results laid an important foundation for further study on the function of P2-type Ca2+ ATPase genes GmACAs and GmECAs for breeding abiotic stress-tolerant vegetable soybean

Security Analysis of RAPP An RFID Authentication Protocol based on Permutation

One of the key problems in Radio Frequency Identification(RFID) is security and privacy. Many RFID authentication protocols have been proposed to preserve security and privacy of the system. Nevertheless, most of these protocols are analyzed and it is shown that they can not provide security against some RFID attacks. RAPP is a new ultralightweight authentication protocol with permutation. In RAPP, only three operations are involved: bitwise XOR, left rotation and permutation. In this paper, we give an active attack on RAPP. We first collect some authentication messages through impersonating valid tag and readers; Then we forge valid reader to communicate with the tag about times. Using the property of the left rotation and permutation operation, we can deduce the relationship of bits of random number or secret keys at different positions, thus obtain all the secret shared by the reader and the tag

Longitudinal Association between Selenium Levels and Hypertension in a Rural Elderly Chinese Cohort

Objectives Results from previous studies have been inconsistent on the association between selenium and hypertension, and very few studies on this subject have focused on the elderly population. The purpose of this study is to examine the relationship between selenium level and hypertension in a rural elderly Chinese cohort. Design A longitudinal study was implemented and data were analyzed using logistic regression models and Cox proportional hazards regression model adjusting for potential confounders. The associations between selenium level and prevalent hypertension at baseline and between selenium and incident hypertension were examined. Setting Community-based setting in four rural areas in China. Subjects A total of 2000 elderly aged 65 years and over (mean 71.9±5.6 years) participated in this study. Measurements Nail selenium levels were measured in all subjects at baseline. Blood pressure measures and self-reported hypertension history were collected at baseline, 2.5 years and 7 years later. Hypertension was defined as systolic blood pressure 140 mmHg or higher, diastolic blood pressure 90 mmHg or higher, or reported use of anti-hypertensive medication. Results The rate of baseline hypertension was 63.50% in this cohort and the mean nail selenium level is 0.413±0.183µg/g. Multi-covariate adjusted cross-sectional analyses indicated that higher selenium level was associated with higher blood pressure measures at baseline and higher rates of hypertension. For the 635 participants with normal blood pressure at baseline, 360 had developed hypertension during follow-up. The incidence rate for hypertension was 45.83%, 52.27%, 62.50%, 70.48%, and 62.79% from the first selenium quintile to the fifth quintile respectively. Comparing to the lowest quintile group, the hazard ratios were 1.41 (95%CI: 1.03 to1.94), 1.93 (95%CI: 1.40 to 2.67), 2.35 (95%CI: 1.69 to 3.26) and 1.94 (95%CI: 1.36 to 22.77) for the second selenium quintile to the fifth quintile respectively. Conclusions Our findings suggest that high selenium may play a harmful role in the development of hypertension. Future studies are needed to confirm our findings and to elucidate a plausible biological mechanism

Prognostic value and immune-infiltration pattern of FOXD3-AS1 in patients with glioma

Gliomas are difficult-to-treat brain tumors due to their aggressive nature, rapid proliferation, and high invasiveness (Zhang et al., J Cell Biochem, 2019, 120 (9), 15106–15118; Ge et al., Int J Biochem Cell Biol, 2021, 139, 106054). FOXD3-AS1 has been identified as an emerging potential target for tumor prediction and treatment in many studies (Qin et al., Front Oncol, 2021, 11, 688027). However, the utility of FOXD3-AS1 has not been reported in glioma patients (Li et al., Cancer Manag Res, 2021, 13, 9037–9048). The differential profiles of FOXD3-AS1 in TCGA–GBMLGG database were analyzed across clinical subgroups. The analysis of overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI) revealed that a high level of FOXD3-AS1 was associated with a poor prognosis and survival outcome. Based on the Cox regression analysis, FOXD3-AS1 was found to be a high-risk factor for glioma that affects prognosis outcomes independently. More importantly, because oxidative stress is closely linked to glioma prognosis, we focused on the potential mechanisms of six oxidative stress co-expressed genes with FOXD3-AS1. In addition, the predictive value of FOXD3-AS1 was determined for each clinical subgroup status. The ROC curve results showed that FOXD3-AS1 had a good predictive performance. A stratified clinicopathological subgroup analysis revealed that high expression of FOXD3-AS1 is associated with a poor prognosis. This also indicates a link between FOXD3-AS1 and tumorigenesis and prognosis, which has potential application value. Furthermore, the immune cell infiltration of FOXD3-AS1 and the signal marker correlation suggested that immune cell infiltration differed significantly between immune cell subsets. To the best of our knowledge, this is the first report to investigate FOXD3-AS1 in glioma and how it may modulate GBM and LGG immune microenvironments. Furthermore, FOXD3-AS1 was detected in tumor and paraneoplastic tissues using RT–qPCR. Transwell analysis verified the migration and invasion of the FOXD3-AS1 knockout group in vitro to a certain extent. In conclusion, FOXD3-AS1 can be used as a prognostic indicator for GBM and LGG, and it is closely related to immune infiltration and response to oxidative stress, which may contribute to the advancement of glioma immunotherapy research