Indoor relative humidity is an important parameter to determine indoor air quality, occupants’ thermal comfort and building energy consumption. As recommended by ASHRAE, the appropriate indoor ...relative humidity range for a healthy and comfortable indoor environment is between 40% and 65% RH. In order to meet the requirements, the most commonly used method is mechanical dehumidification/humidification system by using electricity. However, this approach is energy consuming. In this paper, a novel precise humidity control material (PHCM) based on Metal-Organic Frameworks (MOFs) is synthesized and its application in built environment is investigated. This material has an S-shape isotherm, high porosity and very high water vapor uptake of 1.62 g/g at 80% RH. It can rapidly adsorb moisture as the indoor relative humidity exceeds 60%, and release moisture as relative humidity drops below 45%. Unlike the conventional desiccants, e.g. zeolites, silica gel etc., MOF-PHCM can autonomously control indoor relative humidity within the desired comfort range at room temperature. Hygrothermal properties of the new material are measured. Numerical simulations have been carried out to study the effect of MOF-PHCM on indoor hygrothermal conditions and building energy consumption in five different climates worldwide (i.e. hot desert, semi-arid, Mediterranean, temperate, and humid subtropical). The results show that MOF-PHCM can effectively control indoor relative humidity fluctuations and reduce building energy consumption in most climates without any additional energy input. MOF-PHCM can be easily regenerated by either night ventilation (e.g. in hot desert, semi-arid, Mediterranean climates) or heating system powered by low-grade energy (e.g. in humid climates).
•The basic concept of Precise Humidity Control Material was proposed.•A new PHCM based on Metal-Organic Frames (MOFs) was synthesized.•MOF-PHCM has an operating RH range between 45% and 60%.•MOF-PHCM can effectively control indoor RH within the desired comfort range.•The regeneration temperature of MOF-PHCM is around 60 °C.
Aiming at the problems of modeling error and uncertain external disturbance in the multi-joint robot control model, an adaptive block compensation trajectory tracking controller based on LuGre ...friction model is proposed. Firstly, the algorithm divides the interference term of LuGre friction model into three parts with different physical quantities. Secondly, an adaptive neural network compensator is designed to assess the three parts of the LuGre friction model. Thirdly, a robust sliding mode controller is developed to reduce the influence of these estimation errors of neural network compensator and other uncertain disturbances and ensure that the system converges in a finite time at the same time. Finally, numerical simulations under different input and disturbance signals for the planar multi-joint robot and the inverted pendulum are conducted to validate the effectiveness of the proposed controller, and the performance of the proposed controller is compared with conventional sliding mode controller to illustrate the usefulness and efficiency of the proposed controller.
•DIC technology is used to study crack propagation at rock-concrete interface.•A shorter full FPZ length makes rock-concrete interface more brittle than concrete.•FPZ at peak load is much longer in a ...rock-concrete specimen under FPS than under TPB.•Increase in Mode II component makes crack divert into rock for small a0/D.•Fracture mode rapidly falls into Mode I for a composite beam with large a0/D.
The digital image correlation (DIC) technique is employed to investigate the fracture process at rock-concrete interfaces under three-point bending (TPB), and four-point shearing (FPS) of rock-concrete composite beams with various pre-crack positions. According to the displacement fields obtained from experiment, the crack width, and propagation length during the fracture process can be derived, providing information on the evolution of the fracture process zone (FPZ) at the interface. The results indicated that under TPB, the fracture of the rock-concrete interface is mode I dominated fracture although slight sliding displacement was also observed. Under FPS, the mode II component may increase in the case of a small notched crack length-to-depth ratio, resulting in the crack kinking into the rock. It was also observed that the FPZ length at the peak load is far longer for a specimen under FPS than under TPB.
•Initial fracture toughness is employed to determine crack propagation in concrete.•Three types of FPZ evolution depending on a0/D are discovered for concrete.•FPZ evolution curve of plates with ...lower a0/D envelops those with higher a0/D.•FPZ evolution affects the shape of KR-curve for concrete.•KR-curve for concrete is found to be size-dependent by considering FPZ evolution.
In this paper, a numerical approach is developed to investigate the evolution of fracture process zone (FPZ) during the complete fracture process in concrete structures by using stress intensity factor-superposition method. In this approach, the initial fracture toughness KICini, as an inherent material property, is introduced to form a crack propagation criterion for concrete. The developed numerical approach is then employed to analyze the complete fracture process of three series of notched concrete beams under three-point bending. It is found that the numerical results agree well with experimental ones published in literature through which the developed numerical approach, with an initial fracture toughness based crack propagation criterion, for fracture analysis of concrete is validated. The verified numerical approach is then utilized to simulate the complete fracture process of a series of concrete square plates with different sizes and/or initial crack length-to-depth ratio (a0/D). The effects of a0/D on evolution of FPZ length (aFPZ), especially after the FPZ is fully developed, are examined based on numerical analysis results. It is found that there are three different types of aFPZ variation with respect to a0/D, viz. (i) aFPZ keeps increasing after FPZ is fully developed. (ii) aFPZ turns to decrease from the peak value after FPZ is fully developed. (iii) FPZ is not fully developed. Finally, features of KR-curve for concrete are investigated based on the developed numerical method, and it is found that KR-curve of concrete is size-dependent when the effects of FPZ variation are taken into account.
In this study, we present a straightforward and highly effective photo-triggered hydrogenation method for aryl halides, devoid of transition-metal catalysts. Through the synergistic utilization of ...light, PhNHNH2, and a base, we have successfully initiated the desired radical-mediated hydrogenation process. Remarkably, utilizing mild reaction conditions, a wide range of aryl halides, including fluorides, chlorides, bromides, and iodides, can be selectively transformed into their corresponding (hetero)arene counterparts, with exceptional yields. Additionally, this approach demonstrates a remarkable compatibility with diverse functional groups and heterocyclic compounds, highlighting its versatility and potential for use in various chemical transformations.
► The DIC method is used to investigate the FPZ properties in concrete. ► The FPZ length initially increases and then decreases with the crack propagation. ► The FPZ length at peak load increases ...with an increase in ligament length. ► The crack extension length at the peak load is about 0.25 times the ligament length.
This paper presents an experimental investigation on the properties of the fracture process zone (FPZ) in concrete using the digital image correlation (DIC) technique. Based on the experimental results, it is found that the FPZ length increases during crack propagation but decreases after the FPZ is fully developed. The FPZ length at the peak load and the maximum FPZ length increase with an increase in specimen height, but decrease by increasing the notch depth to specimen height ratio. It is also found that the crack extension length at the peak load is about 0.25 times the ligament length.
In-situ immobilization does not remove Cd from the contaminated soil. It is vital to investigate the effects of fertilizers on soil Cd mobility during remediation with amendments. In the current ...study, a pot experiment was conducted to investigate the effects of calcium magnesium phosphate (CMP) and calcium superphosphate (SSP) on the remediation of Cd-contaminated soil by sepiolite. We mainly focused on changes in soil Cd immobilization, plant toxicity, and soil microbial communities after applying two phosphates during Cd-contaminated soil remediation by sepiolite. The results demonstrated that sepiolite decreased Cd concentration in brown rice, straw, and roots by 32.66%, 38.89%, and 30.94%, respectively. During soil remediation by sepiolite, the Cd concentrations of brown rice and straw were not affected by CMP or SSP, except for the treatment with sepiolite plus high-dose CMP. Sepiolite significantly decreased HCl-extractable Cd and DTPA-extractable Cd by 32.21% and 10.50%, respectively. During soil remediation by sepiolite, the HCl-extractable and DTPA-extractable Cd further decreased with CMP or SSP. The decreasing amplitude with CMP was 40.57–72.60% and 7.05–14.53%, and that of SSP was 37.68–59.66% and 20.71–25.07%, respectively. The superoxide dismutase, peroxidase, catalase activities, and malondialdehyde concentration in rice roots decreased inordinately with the addition of sepiolite, CMP, and SSP, indicating that the application of sepiolite, CMP, or SSP alleviated Cd-induced rice root stress and protected rice roots from Cd toxicity. Alpha diversity estimators (including the Chao, ACE, and Shannon indices) indicated that sepiolite, CMP, or SSP applications had no adverse effects on soil bacterial richness and diversity. Hierarchical clustering analysis revealed that the two phosphate fertilizers and sepiolite were the main factors affecting changes in the bacterial communities structure. Redundancy analysis revealed that soil pH, Eh, and soil-extractable Cd were critical factors affecting the structure of the bacterial communities.
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•CMP or SSP have positively influenced soil Cd immobilization by sepiolite.•CMP or SSP does not affect brown rice Cd during the remediation by sepiolite.•Sepiolite, CMP, and SSP application alleviated the root Cd stress.•P fertilizers and sepiolite led to the difference in soil bacteria communities.
► The glucose solution is used as simulative drinks in Pb(II) adsorption on thiol-functionalized absorbent cotton. ► There was no loss of glucose during the adsorption process. ► The increase of ...initial glucose concentrations makes contribution to Pb(II) adsorption. ► The modified cellulosic biomass with more effective groups presents greater adsorption capacity. ► The modified cellulosic biomass may be a promising adsorbent for heavy metal ions removal in beverage industry.
Absorbent cotton, wood sawdust, buckwheat hull were thiol-functionalized to facilitate selective adsorption of Pb(II) from glucose solution. Fourier transform infrared (FTIR) spectroscopic analysis confirmed the formation of S–H modifications. While unmodified absorbent cotton had a Pb(II) adsorption capacity of 10.78mg/g, thiol-modified absorbent cotton was able to adsorb 28.67mg/g at optimum pH 6.0. The Pb(II) adsorption capacity increased as the concentration of Pb(II) or glucose increased without loss of glucose during the adsorption process. Wood sawdust and buckwheat hull exhibited greater Pb(II) uptake both before and after modification (wood sawdust: 17.03mg/g and 43.14mg/g, buckwheat hull: 34.06mg/g and 44.84mg/g), because these cellulosic biomass contained more helpful functional groups for metal binding. The results suggested that modified cellulosic biomass might be a promising adsorbent for heavy metal ion uptake in beverage industry.
Obtaining written informed consent from participants before enrolment in a study is essential. A previous study showed that only 50% of the participants in clinical trials understood the components ...of informed consent, and the methods of participants' understanding of informed consent were controversial. This updated meta-analysis aimed to estimate the proportion of participants in clinical trials who understand the different informed consent components. PubMed, EMBASE, the Cochrane Library, and Scopus were searched till April 2023. Therapeutic misconception, ability to name one risk, knowing that treatments were being compared, and understanding the nature of the study, the purpose of the study, the risks and side-effects, the direct benefits, placebo, randomization, voluntariness, freedom to withdraw, the availability of alternative treatment if withdrawn from the trial, confidentiality, compensation, or comprehension were evaluated. This meta-analysis included 117 studies (155 datasets; 22,118 participants). The understanding of the risks and side-effects was investigated in the largest number of studies (n = 100), whereas comparehension was investigated in the smallest number (n = 11). The highest proportions were 97.5%(95% confidence interval (CI): 97.1-97.9) for confidentiality, 95.9% (95% confidence interval (CI): 95.4-96.4) for compensation, 91.4% (95% CI: 90.7-92.1) for the nature of study, 68.1% (95% CI: 51.6-84.6) for knowing that treatments were being compared, and 67.3% (95% CI: 56.6-78) for voluntary nature of participants. The smallest proportions were the concept of placebo (4.8%, 95%CI: 4.4-5.2) and randomization(39.4%, 95%CI: 38.3-40.4). Our findings suggested that most participants understood the fundamental components of informed consent (study confidentiality, nature, compensation, voluntariness, and freedom to withdraw). The understanding of other components, such as placebo and randomization was less satisfactory.
Eventually, 108 consecutive patients received 174 surgeries were enrolled, experienced new or expanded infarction occured in 13 (7.47%) surgeries, which showed higher Suzuki stage on the ...non-operative side, more posterior cerebral artery (PCA) involvement, and more intraoperative hypotension compared to those without infarction(p < .05). The Suzuki stage on the non-operative side had the highest area under the curve (AUC) of 0.737, with a sensitivity of 0.692 and specificity of 0.783. Combination of the three factors showed better efficiency, with an AUC of 0.762, a sensitivity of 0.692, and a specificity of 0.907.RESULTSEventually, 108 consecutive patients received 174 surgeries were enrolled, experienced new or expanded infarction occured in 13 (7.47%) surgeries, which showed higher Suzuki stage on the non-operative side, more posterior cerebral artery (PCA) involvement, and more intraoperative hypotension compared to those without infarction(p < .05). The Suzuki stage on the non-operative side had the highest area under the curve (AUC) of 0.737, with a sensitivity of 0.692 and specificity of 0.783. Combination of the three factors showed better efficiency, with an AUC of 0.762, a sensitivity of 0.692, and a specificity of 0.907.Revascularization was a safe option for patients with MMD, higher Suzuki stage on the non-operative side, PCA involvement, and intraoperative hypotension might be the risk factors for new or expanded infarction after revascularization in patients with MMD.CONCLUSIONSRevascularization was a safe option for patients with MMD, higher Suzuki stage on the non-operative side, PCA involvement, and intraoperative hypotension might be the risk factors for new or expanded infarction after revascularization in patients with MMD.
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