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71.
It is necessary to determine whether to implement a retrofit measure or not based on its energy saving and economic benefits, when conducting a retrofit project. The common way to do that is to set up a building simulation model and calculate its energy saving and economic benefits. Because of the great discrepancy between the actuality and the building simulation model, it is very important to use the factual energy use to calibrate the model, so as to accurately predict the benefits of retrofit measures. Although the energy efficiency retrofit of residential buildings in north China is implemented in a large scale, it seldom knows whether the commonly used retrofit packages are optimized. Therefore, a typical residential building is selected in Beijing, and the energy saving and economic benefits of different retrofit measures are analyzed using a simulation model calibrated with its actual space heating energy use, and the optimized retrofit packages are put forward. Results shows the retrofit of space heating system is a very attractive measure due to its relatively low investment but good energy saving benefit, and roof retrofit is also cost effective, while window retrofit and wall retrofit are not economic to conduct separately. Four optimized retrofit packages are figured out to realize the 50% and 65% reductions of space heating intensity required in the energy efficiency standards, which have less investment costs compared with currently widely used packages, and the retrofit packages for the 65% reduction is more cost-effective than the packages for the 50% reduction. 相似文献
72.
Experimental study on the solvent regeneration of a CO2‐loaded MEA solution using single and hybrid solid acid catalysts 下载免费PDF全文
Zhiwu Liang Raphael Idem Paitoon Tontiwachwuthikul Fanghui Yu Helei Liu Wichitpan Rongwong 《American Institute of Chemical Engineers》2016,62(3):753-765
The performance of a hybrid solid acid catalyst consisting of a physical mixture of γ‐Al2O3 and H‐ZSM‐5 in terms of the rate and heat duty for solvent regeneration (i.e., CO2 stripping) of a CO2‐rich MEA solution was compared with the individual performance of γ‐Al2O3, H‐ZSM‐5, and H‐Y solid acid catalysts using MEA (2–7 mol/L), with initial CO2 loading of 0.5 mol CO2/mol MEA at 378 K. It was observed that any catalyst significantly decreased the energy required for CO2 regeneration. The performance of the catalysts investigated ranked as follows: γ‐Al2O3/H‐ZSM‐5 = 2/1 > γ‐Al2O3 > H‐ZSM‐5 > H‐Y if the process is in the lean CO2 loading region whereas it was H‐ZSM‐5 > γ‐Al2O3/H‐ZSM‐5 = 2/1 > γ‐Al2O3 > H‐Y if the process is in the rich CO2 loading region. These results highlight the joint dependence on Brønsted/Lewis acidity and mesopore surface area of heat duty for solvent regeneration. © 2015 American Institute of Chemical Engineers AIChE J, 62: 753–765, 2016 相似文献
73.
This study presents information obtained by the synthesis of Fe(3) oxide/hydroxide nanoparticles sol (NanoFe) and NanoFe-impregnated granular activated carbon as adsorbents for boron removal from solutions. The research describes an adsorption method for cleaning a solution containing boron contaminants followed by recovery of the adsorbent and the adsorbed material for safe removal or further reuse. The technology provides an efficient method of boron removal from water. A marked effect of NanoFe and NanoFe-impregnated GAC adsorbents concentration and pH level on boron removal efficiency was demonstrated. At least 95–98% boron recovery efficiency is possible using NanoFe sol and Fe-impregnated GAC that in fact also recover the adsorbent for reuse. Boron adsorption onto the NanoFe-impregnated GAC adsorbent may be described by pseudo-second-order reaction kinetics and the Langmuir isotherm model. The boron adsorption capacity on iron (3) oxide nanoparticles and Fe-impregnated GAC at an equilibrium concentration of 0.3 mg/dm3 as B in the solution is much higher than these values for similar adsorbents reported in the literature. 相似文献
74.
Jie Li Lyes Bennamoun Laurent Fraikin Thierry Salmon Dominique Toye Raphael Schreinemachers 《Drying Technology》2014,32(14):1706-1717
Convective drying of wastewater sludges and sawdust/sludge mixtures was studied. The first part of this work was an experimental study performed in a cross-flow convective dryer using 500 g of wet material extruded through a disk with circular dies of 12 mm. The results showed that the sawdust addition has a positive impact on the drying process from a mass ratio of 2/8, on a dry basis, with observed drying rates higher than the original sludge. The second part of this work consisted of developing a drying model in order to identify the internal diffusion coefficient and convective mass transfer coefficient from the experimental data. A comparison was made between fitted drying curves, well represented by the Newton's model, and the analytical solutions of the diffusion equation applied to a finite cylinder. Variations of dimensional characteristics, such as the volume and exchange surface of the sample bed, were obtained by X-ray tomography. This technique allowed us to confirm that shrinkage, which is an important phenomenon occurring during sludge and sawdust/sludge mixture drying, must be taken into account. The results showed that both the internal diffusion coefficient and convective mass transfer coefficient were affected by mixing and sawdust addition. The internal diffusion coefficient changed from 7.77 × 10?9 m2/s for the original sludge to 7.01 × 10?9 m2/s for the mixed sludge and then increased to 8.35 × 10?9 m2/s for the mixture of a mass ratio of 4/6. The convective mass transfer coefficient changed from 9.70 × 10?8 m/s for the original sludge to 8.67 × 10?8 m/s for the mixed sludge and then increased to 12.09 × 10?8 m/s for the mixture of a mass ratio of 4/6. These results confirmed that sawdust addition was beneficial to the sludge drying process as the mass transfer efficiency between the air and material increased. Reinforcing the texture of sludge by adding sawdust can increase the drying rate and decrease the drying time, and then the heat energy supply will be reduced significantly. The study also showed that neglecting shrinkage phenomenon resulted in an overestimation for the internal diffusion coefficient for the convective drying of sludges and sawdust/sludge mixtures. 相似文献
75.
Christiane L. Ojaimi Julieta A. Ferreira Adilson L. Chinelatto Raphael E. P. Salem Adriana S. A. Chinelatto Eliria M. J. A. Pallone 《International Journal of Applied Ceramic Technology》2020,17(4):1619-1628
Composites of Al2O3/ZrO2 (containing 25, 50, and 75 vol% ZrO2) were prepared by mixing Al2O3 and ZrO2 suspensions. The microstructural control via two-step sintering (TSS) was the main objective of this work. For this purpose, different sintering curves were constructed, aiming to achieve the best temperature combination for the sintering steps that provides higher density and finer microstructure. The results were compared with single-step sintering (SSS). Furthermore, microhardness and fracture toughness were measured for the best TSS specimens under each composition. The results showed that the high densities were obtained, and the reduction of grain size was greater than 40% for two-step sintered specimens, compared to SSS ones. Consequently, microhardness values increased. However, fracture toughness values remained unchanged. 相似文献
76.
Investigation mechanism of DEA as an activator on aqueous MEA solution for postcombustion CO2 capture 下载免费PDF全文
Helei Liu Moxia Li Xiao Luo Zhiwu Liang Raphael Idem Paitoon Tontiwachwuthikul 《American Institute of Chemical Engineers》2018,64(7):2515-2525
In this work, Diethanolamine (DEA) was considered as an activator to enhance the CO2 capture performance of Monoethanolamine (MEA). The addition of DEA into MEA system was expected to improve disadvantages of MEA on regeneration heat, degradation, and corrosivity. To understand the reaction mechanism of blended MEA‐DEA solvent and CO2, 13C nuclear magnetic resonance (NMR) technique was used to study the ions (MEACOO‐, DEACOO–, MEA, DEA, MEAH+, DEAH+, , ) speciation in the blended MEA‐DEA‐CO2‐H2O systems with CO2 loading range from 0 to 0.7 mol CO2/mol amine at the temperature of 301 K. The different ratios of MEA and DEA (MEA: DEA = 2.0:0, 1.5:0.5, 1.0:1.0, and 0:2.0) were studied to comprehensively investigate the role of DEA in the system of MEA‐DEA‐CO2‐H2O. The results revealed that DEA performs the coordinative role at the low CO2 loading and the competitive role at high CO2 loading. Additionally, the mechanism was also proposed to interpret the reaction process of the blended solvent with CO2. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2515–2525, 2018 相似文献
77.
I. Kruse Ursula Wolfensberger Raphael Badoud K. Eichner 《European Food Research and Technology》1997,205(1):31-38
The formation of CO2 in tomato powder, chosen as an example of a dry culinary product, was investigated at room temperature and at low values
of water activity (a
w). CO2 formation correlated well with parameters that represent the beginning and progression of the Maillard reaction. In the absence
of O2, CO2 formation decreased. Pectin and depolymerized pectin did not influence CO2 formation while galacturonic acid (GalA) had a large effect. Determination of 13CO2 in low-moisture model systems revealed that CO2 was not formed by decarboxylation of GalA alone. Only a small proportion of [1-13C]glycine and GalA was degraded by the Strecker pathway; however, glucose reacted with the labelled amino acid forming 13CO2 which amounted to over 90% of the total CO2 formed. Therefore, CO2 could be used as an early indicator for the beginning of the Maillard reaction in dry culinary products.
Received: 28 October 1996 相似文献
78.
79.
Swift Joshua K.; Callahan Jennifer L.; Heath Christopher J.; Herbert Gregory L.; Levine Jason C. 《Canadian Metallurgical Quarterly》2010,47(2):235
While previous research on deterioration has focused on identifying individuals at risk for negative outcomes, little is known about the nature or pattern by which deterioration occurs. The problem of deterioration is especially salient in training clinics; a setting in which higher deterioration rates have been reported. Two studies were designed to test the applicability of the phase model to deterioration in a training clinic and to replicate the model with a training clinic referral-base sample. In Study 1, the course of therapy was monitored for 135 clients. For the 38 clients who deteriorated during therapy, a model where increased symptoms (demediation) reliably preceded both decreased functioning (dehabilitation) and decreased well-being (demoralization) was found. In Study 2, the same three phases were prospectively monitored for 914 undergraduate students on a weekly basis throughout a single semester. For the 158 individuals who deteriorated during this time, a model where demediation reliably preceded dehabilitation, which preceded demoralization was found. These results have clinical implications for the use of tailored intervention strategies focusing on the deterioration phases. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
80.
Xianfeng Chen Holly J. Corbett Sally R. Yukiko Anthony P. Raphael Emily J. Fairmaid Tarl W. Prow Lorena E. Brown Germain J. P. Fernando Mark A. F. Kendall 《Advanced functional materials》2011,21(3):464-473
Densely packed dry‐coated microprojections are shown to deliver vaccines to targeted locations within the skin that are rich in immune cells, thus inducing protective immune responses against a lethal virus challenge. Selectively limiting the antigen coating to the tips of the projections, which penetrate the skin, would significantly reduce the amount of vaccine required in immunization. In this paper a simple technique, dip‐coating the microprojections, is introduced to meet this goal. By increasing the coating solution viscosity, an otherwise strong capillary action is mitigated and the desired controlled coating length on projections is achieved. Following application to the skin, most of the coated vaccine material is rapidly released from the projections (82.6% in mass within 2 min) to the target locations within the skin strata and a potent immune response is induced when a conventional influenza vaccine (Fluvax) is tested in a mouse model. The utility of this coating approach to a variety of molecules representative of vaccines (e.g., chicken egg ovalbumin (OVA) protein, DNA, and fluorescent dyes) is demonstrated. These collective attributes, together with the simplicity of the approach, position the dip‐coating method for practical utility in large vaccination campaigns. 相似文献