21 research outputs found

    Nonuniform Woven Solar Shading Screens: Shading, Mechanical, and Daylighting Performance

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    This study investigated the potential of using a nonuniform woven panel with nonuniform strips—thick sticks and thin battens—as an external solar shading screen that addressed daylighting, shading, and mechanical performance factors. The sustainable material, namely, bamboo, was used as the demonstration material for the screen. An on-site experiment and ANSYS simulation were carried out to investigate the basic solar optical performance and structural strength of the proposed screen, respectively. Then, a series of daylighting simulations were conducted to optimize the configuration of the screen. The results showed that the nonuniform woven solar shading screen reduced up to 80.3% of the solar radiation gain in a room during summer months while ensuring a relatively even distribution of useful daylight during the year. Moreover, the screen effectively reduced the negative impact of glare to a level below “imperceptible” and enabled a relatively clear view through the window and shading. Regarding the structural strength, the screen with a size smaller than or equal to 1 × 1 m withstood a wind load of 12 m/s. Furthermore, this study proposed two optimal configurations: a screen woven of square sticks and battens with a distance of 10 mm between them, and a screen woven of round sticks and battens with a distance of 8 mm between them. This study illustrated the superiority of the nonuniform woven solar shading screens, which supports a wider application of solar shading screens made of other materials with similar structures and reflectance values

    The Perivascular Fat Attenuation Index Improves the Diagnostic Performance for Functional Coronary Stenosis

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    Background: Coronary computed tomography angiography (CCTA) is an established first-line test in the investigation of patients with suspected coronary artery disease (CAD), while the perivascular fat attenuation index (FAI) derived from CT seems to be a feasible and efficient tool for the identification of ischemia. The association between the FAI and lesion-specific ischemia as assessed by fractional flow reserve (FFR) remains unclear. Methods: In a total of 261 patients, 294 vessels were assessed for CCTA stenosis, vessel-specific FAI, lesion-specific FAI, and plaque characteristics. The diagnostic accuracies of each parameter and the combined approach were analyzed via the receiver operating characteristic curve (ROC) with FFR as the reference standard. The determinants of FAI were statistically analyzed. Results: The cutoff values of vessel-specific FAI and lesion-specific FAI scores calculated according to the Youden index were −70.97 and −73.95 HU, respectively. No significant differences were noted between them; however, they exhibited a strong correlation. No significant differences were noted between the area under the curve (AUC) scores of vessel-specific FAI (0.677), lesion-specific FAI (0.665), and CCTA (0.607) (p > 0.05 for all) results. The addition of two FAI measures to the CCTA showed improvements in the discrimination (AUC) and reclassification ability (relative integrated discrimination improvement (IDI) and category-free net reclassification index (NRI)), vessel-specific FAI (AUC, 0.696; NRI, 49.6%; IDI, 5.9%), and lesion-specific FAI scores (AUC, 0.676; NRI, 43.3%; IDI, 5.4%); (p Conclusion: The combined approach of adding vessel-specific FAI or lesion-specific FAI scores could improve the identification of ischemia compared with CCTA alone. The LAP volume was the independent risk factor for both tools

    Stimulated Parotid Saliva Is a Better Method for Depression Prediction

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    Background: Saliva cortisol is considered to be a biomarker of depression prediction. However, saliva collection methods can affect the saliva cortisol level. Objective: This study aims to determine the ideal saliva collection method and explore the application value of saliva cortisol in depression prediction. Methods: 30 depressed patients and 30 healthy controls were instructed to collect saliva samples in the morning with six collection methods. Simultaneous venous blood was collected. Enzyme-linked immunosorbent assay was used to determine the cortisol level. The 24-observerrated Hamilton depression rating scale (HAMD-24) was used to assess the severity of depression. Results: The significant differences in saliva cortisol levels depend on the saliva collection methods. The level of unstimulated whole saliva cortisol was most correlated with blood (r = 0.91). The stimulated parotid saliva cortisol can better predict depression. The area under the curve was 0.89. In addition, the saliva cortisol level of the depression patients was significantly higher than the healthy controls. The correlation between the cortisol level and the HAMD-24 score was highly significant. The higher the saliva cortisol level, the higher the HAMD-24 score. Conclusions: All the above findings point to an exciting opportunity for non-invasive monitoring of cortisol through saliva

    Preparation Process of Straw-based Activated Carbon for Uranium Wastewater Treatment

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    A process and equipment for preparing activated carbon from straw and its application in treating uranium wastewater are proposed. The ZnCl2-microwave carbonization method is adopted, which flexibly applies the wave absorbing ability of zinc element and greatly reduces the carbonization time. At the same time, the dehydrogenation of ZnCl2 limits the formation of coal tar and improves the carbon formation rate. Through citric acid modification, a functional group with specific adsorbability to uranyl ions is formed, which can produce high-efficiency complexation effect with uranyl ions and improve the adsorption capacity of uranyl ions. When the wastewater is mixed with other heavy metal elements, uranyl ions occupy the main adsorption sites, which can still maintain excellent targeted adsorption effect and can be targeted to treat uranyl ions in radioactive uranium wastewater. The key equipment in the process consists of cleaning and impurity removal components, raw material crushing components and carbonization components. The whole production process is completed in the same equipment. The optimum adsorption capacity (Ac) of 4.98 mg/g and uranium adsorption rate (Ar) of 99% were obtained by using soybean straw as raw material under the preparation conditions of 20% ZnCl2 solution and 15% citric acid solution

    Synthesis and characterization of novel anion exchange membranes based on imidazolium-type ionic liquid for alkaline fuel cells

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    Novel anion exchange membranes based on the copolymers of 1-allyl-3-methylimidazolium chloride (AmimCl) ionic liquid either with methyl methacrylate (MMA) or butyl methacrylate (BMA) have been prepared via free radical polymerization The structures and characteristic properties of the membranes are studied It is found that the hydroxyl ionic conductivity of the synthesized membrane can reach 3 33 x 10(-2) S cm(-1) in deionized water at 30 degrees C. The methanol permeability is less than 10(-9) mol cm(2) s(-1) even at 60 degrees C. These membranes with imidazolium salt functional groups exhibit superior stability both chemically and thermally as well compared to the alkyl quaternary ammonium functionalized polymers Therefore, the membranes have good perspectives and great potential for alkaline fuel cell applications. (C) 2010 Elsevier B V All rights reservedHigh-Tech Research and Development Program of China [2008AA05Z107]; National Nature Science Foundation of China [20876129

    Laparoscopic resection of a giant choledochal cyst: A rare case report

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    Giant choledochal cysts are rare, and so little data exist on the best surgical treatment method. We present here, a case of a giant choledochal cyst that was successfully excised by laparoscopic resection. A 37-year-old female presented with right upper abdominal pain and mild jaundice. On examination she had a right upper abdominal mass which on imaging was observed to be a giant choledochal cyst of type IVa, measuring approximately 129 mm × 190 mm. Her blood test results showed abnormal liver function. We successfully performed laparoscopic resection of the cyst, the patient recovered well and was discharged from hospital eight days post-operation without any complications. We wish to share the experience of this rare case and provide some clinical basis for future diagnosis and use of laparoscopic resection in the treatment of giant choledochal cysts

    Unstimulated Parotid Saliva Is a Better Method for Blood Glucose Prediction

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    Objective: Saliva glucose has been widely used in diagnosing and monitoring diabetes, but the saliva collection method will affect saliva glucose concentration. So, this study aims to identify the ideal saliva collection method. Method: A total amount of six saliva collection methods were employed in 80 healthy participants in the morning. Besides, three unstimulated saliva methods were employed in another 30 healthy participants in the morning; in the meantime the blood glucose of these 30 participants was detected with a Roche blood glucose meter. The glucose oxidase method with 2, 4, 6-tribromo-3-hydroxybenzoic acid (TBHBA) as the chromogen has been improved to be suitable for healthy people, through the selection of the optimal pH value and ionic strength of the reaction system. This method was used for the detection of saliva glucose. Results: The improved method obtained absorbance at the wavelength of 520 nm, and the optimized parameter combination was pH 6.5 and 5 mg/dL NaCl. The lower limit of glucose detection was 0.1 mg/dL. Unstimulated saliva glucose concentration was higher than stimulated saliva glucose concentration. Unstimulated parotid saliva glucose concentration was the highest. Besides, unstimulated saliva glucose has a better normal distribution effect. Meantime, it was found that unstimulated parotid saliva was the most highly correlated with blood glucose (R2 = 0.707). Conclusions: the saliva collection method was an important factor that affected saliva glucose concentration. Unstimulated parotid saliva was the most highly correlated with blood glucose, which provided a reference for prediction of diabetes mellitus

    Preparation and characterization of quaternized poly (2,2,2-trifluoroethyl methacrylate-co-N-vinylimidazole) membrane for vanadium redox flow battery

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    Aiming to develop a suitable ion exchange membrane for vanadium redox flow battery (VRB), a new kind of imidazolium salt type anion exchange membrane based on the copolymer of N-vinylimidazole and 2,2,2-trifluoroethyl methacrylate has been prepared. The membrane is characterized by means of water uptake, ion-exchange capacity, ionic conductivity, and thermal stability. Furthermore, a VRB with this membrane is assembled, and the performance of such VRB is evaluated. The permeability experiments show that this membrane has reasonable low permeability of vanadium ions. The coulombic efficiency (CE) and energy efficiency (EE) of VRB with the synthesized membrane are 99.5% and 75.0%, whereas the CE and EE of the VRB with Nafion (R) 117 membrane are 82.6% and 72.6%, respectively. The synthesized membrane shows good chemical stability in VRB via more than 4000 cycles test. Therefore, this membrane shows good applicable potential in VRB. Copyright (c) 2012 John Wiley & Sons, Ltd

    Novel anion exchange membrane based on copolymer of methyl methacrylate, vinylbenzyl chloride and ethyl acrylate for alkaline fuel cells

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    A series of novel anion exchange membranes based on the copolymer of methyl methacrylate, vinylbenzyl chloride and ethyl acrylate has been prepared for the potential applications for direct methanol alkaline fuel cell. The structure and thermal stability of the copolymer membranes have been characterized by FT-IR and thermo-gravimetric analysis (TGA). The ion exchange capacity (IEC), water uptake, chemical stability, methanol permeability and conductivity of these membranes have been investigated. It is found that the ionic conductivity of the membrane is as high as 1.479 x 10(-2) S cm(-1) in deionizer water at 30 degrees C and the ionic conductivity increases with the increase of temperature from 30 to 90 degrees C. The methanol permeability coefficient of the membrane is less than 10(-9) mol cm(-2) min(-1) at 1 mol L-1 in methanol solution within temperature between 30 and 60 degrees C. The membrane is stable in 1.0 M KOH solution at the temperature as high as 60 degrees C. (C) 2010 Elsevier B.V. All rights reserved.High-Tech Research and Development Program of China [2008AA05Z107]; National Nature Science Foundation of China [20876129
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