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Bolt-ball joints are widely adopted in grid structures due to their high installation accuracy and short construction period. Since the bolt is inside the joint, it is challenging to evaluate its health status from outside the structure. A finite-element plane-truss structure model, based on the actual grid structure, was constructed to investigate the influence of the rod's preload on the overall stiffness and bearing capacity of the grid structure. Moreover, a model of the grid structure, with a bolt-ball joint connection, was constructed to analyze the influence of the preload loss in bolted-ball joints on the overall mechanical performance of the local members and structures. The results show that the release of preload on the outer web rod is less effective in terms of the overall stiffness and bearing capacity of the structure than on the inner web rod. The preload of the larger span direction rod plays an important role, and the preload of the upper chord has a greater impact, while the preload of the web rod and the upper chord in the smaller span direction has no significant effect on the normal stress in the surrounding rods. [ABSTRACT FROM AUTHOR]

Bolted spherical joints are widely used in space grid structures. However, the preload loss, which may arise from fabrication error, insufficient twist of the screw and some other unknown reasons can undermine the structural integrity and even lead to the collapse of the whole structure. Therefore, a method for evaluating the preload status of bolted spherical joints is vital to the structural health monitoring of the space grid structures. To this end, a non-destructive evaluation of the preload loss of bolted spherical joints based on time reversal acoustics (TRA) is presented. In this method, an excited signal generated by a lead zirconate titanate (PZT) patch at the bolted sphere is reconstructed after the signal recorded by another PZT patch at the bar is time-reversed and re-emitted. The deviation of the reconstructed signal from the initial signal allows identification of preload loss of the bolted spherical joint. This method is demonstrated to be effective by a finite element simulation. Furthermore, the effect of preload loss of the bolted spherical joint on its ultimate flexural capacity is studied, which highlights the necessity for the non-destructive evaluation. [ABSTRACT FROM AUTHOR]

Purpose. To investigate the incidence, severity, and influencing factors of dry eye in systemic lupus erythematosus (SLE) patients without secondary Sjögren's syndrome (sSS). Methods. A total of 78 patients who were diagnosed with systemic lupus erythematosus and met inclusion criteria were selected as the study subjects in this cross-sectional study. Tear meniscus height (TMH) and noninvasive Keratograph tear breakup time (NIKBUT) including NIKBUT-first and NIKBUT-average of the subjects were measured using a noninvasive ocular analyzer, the Keratograph 5M (Oculus, Wetzlar, Germany). Symptoms related to dry eye were assessed using the Ocular Surface Disease Index (OSDI). The severity of SLE was evaluated by Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K). Results of the levels of 4 serum antibodies were collected from the patients' medical records. Correlations between SLEDAI and various ocular surface parameters were analyzed, and multiple-factor binary logistic regression analysis was conducted. Results. In the study subjects, mean TMH was 0.22 mm, mean NIKBUT-first was 9.12 s, and mean OSDI was 13.14. The subjects (19 eyes) whose NIKBUT-average was < 10 s and OSDI was ≥ 13 accounted for 24.36% of all the included patients. SLEDAI showed a statistically significant correlation with TMH (r = −0.233, p=0.040), NIKBUT-first (r = −0.254, p=0.025), NIKBUT-average (r = −0.343, p=0.002), and OSDI (r = 0.256, p=0.024). According to multiple-factor binary logistic regression analysis, SLEDAI could be considered as a risk factor of the incidence of dry eye in SLE patients without sSS. Conclusions. One-fourth of the SLE patients without sSS suffered from dry eye, and the severity of dry eye correlated with the activity of SLE. [ABSTRACT FROM AUTHOR]

Minimizing power consumption is vitally important in embedded system design; power consumption determines battery lifespan. Ultra-low-power designs may even permit embedded systems to operate without batteries by scavenging energy from the environment. Moreover, managing power dissipation is now a key factor in integrated circuit packaging and cooling. As a result, embedded system price, size, weight, and reliability are all strongly dependent on power dissipation. Recent developments in nanoscale devices open new alternatives for low-power embedded system design. Among these, single-electron tunneling transistors (SETs) hold the promise of achieving the lowest power consumption. Unfortunately, most analysis of SETs has focused on single devices instead of architectures, making it difficult to determine whether they are appropriate for low-power embedded systems. Evaluating the use of SETs in large-scale digital systems requires novel architectural and circuit design. SET-based design imposes numerous challenges resulting from low driving strength, relatively large static power consumption, and the presence of reliability problems resulting from random background charge effects. We propose a fault-tolerant, hybrid SET/CMOS, reconfigurable architecture, named IceFlex, that can be tailored to specific requirements and allows tradeoffs among power consumption, performance requirements, operation temperature, fabrication cost, and reliability. Using IceFlex as a testbed, we characterize the benefits and limitations of SETs in embedded system designs. In particular, we focus on the use of SETs in room-temperature ultra-low-power embedded systems such as wireless sensor network nodes. We also consider high-performance applications such as multimedia consumer electronics. We see this work as a first step in determining the potential of ultra-low-power embedded system design using SETs. [ABSTRACT FROM AUTHOR]

Abstract: The layered double hydroxides (LDHs) containing nitrate as the interlayer anion has a high anion-exchange capacity in the presence of appropriate anions. In the light of this, ZnAl-NO3 LDHs have been employed to remove chloride ion from aqueous solution in a batch mode. The influences of conditions for chloride ion uptake, including dosage of LDHs, pH of aqueous solution, and temperature on anion-exchange have been investigated, respectively. The thermodynamic parameters including Gibbs free energy (ΔG 0), standard enthalpy change (ΔH 0), and standard entropy change (ΔS 0) for the process were calculated using the Langmuir constants. It was found from kinetics test that the pseudo-second order kinetics model could be used to well describe the uptake process. An E a value of 10.27kJ/mol provides evidence the anion-exchange process. The explanation of anion-exchange phenomenon has also been supported by X-ray diffraction and FT-IR spectra. [Copyright &y& Elsevier]

Objective: To investigate the differences in ocular surface characteristics, tear film quality, and the incidence of dry eye disease (DED) between Systemic Lupus Erythematosus (SLE) patients and healthy populations., Methods: This age and gender-matched cross-sectional study included 96 SLE patients without secondary Sjögren's syndrome (SS) and 72 healthy subjects. The Ocular Surface Disease Index (OSDI), tear meniscus height (TMH), non-invasive tear film breakup time (NIKBUT), meibography, and tear film lipid layer grade were assessed. A receiver operative characteristic (ROC) curve was constructed to evaluate the predictive value of risk factors., Results: Compared with the control subjects, a significantly greater proportion of SLE patients met the TFOS DEWS II DED diagnostic criteria (34.3 vs. 18.1%, P = 0.019). SLE patients without SS had higher OSDI scores [10.0 (4.5,18.0) vs. 5.0 (2.5,11.9), P < 0.001], and shorter NIKBUT [9.6 (6.6,15.0) vs. 12.3 (8.4, 15.8), P = 0.035]. Furthermore, TMH, Tear film lipid layer grade, and Meibomian gland (MG) dropout in SLE patients were worse than those in control subjects (all P < 0.05). For ROC analysis, the area under curve (AUC), sensitivity and specificity of prediction were 0.915, 75.8 and 92.1% for the combination of SLE disease activity index (SLEDAI), age and NIKBUT., Conclusions: SLE patients without SS exhibited a higher risk for DED than healthy subjects, and the poorer Meibomian gland function in SLE patients may potentially contribute to the development of DED. The combined parameters of SLEDAI, age and NIKBUT showed a high efficiency for the diagnosis of DED in SLE patients, with practical clinical applications., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gu, Lu, Zhang, Shuai and Liao.)