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The development of ultralightweight expanded perlite-based thermal insulation panel using alkali activator

Damla Nur ÇELİK; Gökhan DURMUŞ

《结构与土木工程前沿（英文）》 2022年第16卷第11期页码 1486-1499 doi: 10.1007/s11709-022-0881-6

摘要： The International Energy Agency (IEA) states that global energy consumption will increase by 53% by 2030. Turkey has 70% of the world’s perlite reserves, and in order to reduce energy consumption a thermal insulation panel was developed in Turkey using different particle sizes of expanded perlite (EP). In this study, 0–1.18 mm (powder) and 0–3 mm (granular) EP particle sizes were selected, since they have the lowest thermal conductivity coefficients among all the particle sizes. In addition, an alkali activator solution was used as a binder in the mixtures. The alkaline activator solution was obtained by mixing sodium hydroxide solution (6, 8, 10, and 12 mol·L⁻¹) and sodium silicate (Module 3) at the different ratios of Na₂SiO₃ to NaOH of 1, 1.5, 2, and 2.5. This study aimed to experimentally determine the optimum binder and distribution ratio of EP, with the lowest coefficient of thermal conductivity and the lowest density. The lowest thermal conductivity and the lowest density were determined as 0.04919 W·m⁻¹·K⁻¹ and 133.267 kg/m³, respectively, in the sample prepared with 83.33% powder-size EP, 6 mol·L⁻¹ sodium hydroxide solution, and ratio of Na₂SiO₃ to NaOH of 1.5. The density, thermal conductivity, and compressive strength of the sample showed the same trends of behavior when the Na₂SiO₃ to NaOH ratio was increased. In addition, the highest compressive strength was measured in 12 mol·L⁻¹ NaOH concentration regardless of particle size. In conclusion, the study predicts that the EP-based thermal insulation panel can be used as an insulation material in the construction industry according to the TS825 Thermal Insulation Standard.

关键词： expanded perlite alkali activator thermal insulation panel thermal conductivity

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Assessment and prediction of the mechanical properties of ternary geopolymer concrete

Jinliang LIU; Wei ZHAO; Xincheng SU; Xuefeng XIE

《结构与土木工程前沿（英文）》 2022年第16卷第11期页码 1436-1452 doi: 10.1007/s11709-022-0889-y

摘要： This paper utilized granulated blast furnace slag (GBFS), fly ash (FA), and zeolite powder (ZP) as the binders of ternary geopolymer concrete (TGC) activated with sodium silicate solution. The effects of alkali content (AC) and alkaline activator modulus (AAM) on the compressive strength, flexural tensile strength and elastic modulus of TGC were tested and the SEM micrographs were investigated. The experimental results were then compared with the predictions based on models of mechanical properties, and the amended models of TGC were proposed taking account of the effects of AC and AAM. The results indicated that increasing AC and reducing AAM which were in the specific ranges (5% to 7% and 1.1 to 1.5, respectively) had positive effects on the mechanical properties of TGC. In addition, the flexural tensile strength of TGC was 27.7% higher than that of OPC at the same compressive strength, while the elastic modulus of TGC was 25.8% lower than that of OPC. Appropriate prediction models with the R² of 0.945 and 0.987 for predicting flexural tensile strength and elastic modulus using compressive strength, respectively, were proposed. Fitting models, considering the effects of AC and AAM, were also proposed to predict the mechanical properties of TGC.

关键词： Ternary Geopolymer Concrete (TGC) alkaline activator modulus alkali content mechanical properties assessment

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Chemotactic effect of urokinase-type plasminogen activator on mouse spermatozoa

DING Xiaofang, LI Honggang, XIONG Chengliang

《医学前沿（英文）》 2008年第2卷第2期页码 195-199 doi: 10.1007/s11684-008-0037-7

摘要： The aim of this study is to investigate the chemotactic effect of urokinase-type plasminogen activator (uPA) on mouse spermatozoa. Capillary assays were applied to study the chemotactic activity of ascending and descending gradients of uPA. Firstly, the chemotactic effect of an ascending gradient of uPA on mouse spermatozoa was observed by counting the number of spermatozoa that migrated into the capillary after incubation with uPA for 5, 10, 20, and 30 min, respectively, compared with that after incubation with F10. Twenty minutes was a suitable incubation time to obtain a plateau of sperm accumulation. Meanwhile, to confirm the specific effect of uPA on mouse sperm chemotaxis, uPA inhibitor (PAI-1) and anti-uPAR rabbit IgG were added to the test solution containing 20 U/mL uPA, respectively. To exclude the possibility that PAI-1 and anti-uPAR rabbit IgG may affect sperm accumulation nonspecifically, PAI-1 and anti-uPAR rabbit IgG were added to F10, respectively. It was found that the chemotactic effect of uPA was neutralized completely by PAI-1 and anti-uPAR rabbit IgG. PAI-1 and anti-uPAR rabbit IgG had no neutralizing effect on the sperm chemotactic effect. Lastly, the sperm chemotaxis response to a descending gradient of uPA was also observed. Taken together, the results suggest that uPA can induce sperm chemotaxis by binding to its receptor on the sperm membrane and may act as a chemoattractant in precontacting sperm-egg communication thereby increasing the chance encounter of spermatozoa and eggs.

关键词： chemotactic activity receptor uPA inhibitor F10 chemoattractant

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Layered alkali titanates (ATiO): possible uses for energy/environment issues

《能源前沿（英文）》 2021年第15卷第3期页码 631-655 doi: 10.1007/s11708-021-0776-6

摘要： Uses of layered alkali titanates (A₂Ti_nO₂_n₊₁; Na₂Ti₃O₇, K₂Ti₄O₉, and Cs₂Ti₅O₁₁) for energy and environmental issues are summarized. Layered alkali titanates of various structural types and compositions are regarded as a class of nanostructured materials based on titanium oxide frameworks. If compared with commonly known titanium dioxides (anatase and rutile), materials design based on layered alkali titanates is quite versatile due to the unique structure (nanosheet) and morphological characters (anisotropic particle shape). Recent development of various synthetic methods (solid-state reaction, flux method, and hydrothermal reaction) for controlling the particle shape and size of layered alkali titanates are discussed. The ion exchange ability of layered alkali titanate is used for the collection of metal ions from water as well as a way of their functionalization. These possible materials design made layered alkali titanates promising for energy (including catalysis, photocatalysts, and battery) and environmental (metal ion concentration from aqueous environments) applications.

关键词： layered alkali titanates photocatalysis hydrogen evdution metal ions collection

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碱硅酸反应与碱碳酸盐反应

唐明述

《中国工程科学》 2000年第2卷第1期页码 34-40

摘要：

碱集料反应（AAR）可分为两类，即碱硅酸反应（ASR）与碱碳酸盐反应（ACR）。二者的共同点是与碱发生的化学反应可导致混凝土中集料的体积增大，从而可能使混凝土甚至整个建筑物或构筑物发生膨胀开裂。文章着重从膨胀过程和机理以及岩石的结构特征探讨二者的特性与差异。ASR类型岩石具有碱活性的前提条件是较低的二氧化硅结晶完整度。只有隐晶质、微晶质、玻璃质或发生过应变的二氧化硅才会具有较高的化学活性，导致混凝土破坏。通过系统研究证实，对碱碳酸盐反应，虽然结晶的完整程度以及白云石（CaCO₃·MgCO₃）分子式中Ca/Mg比也将影响其与碱反应的速率，但起决定作用的是白云石晶体的尺寸及其在岩石中的分布状态和被基质包围的紧密程度。从微观结构得出的这些特征将有助于加深对碱集料反应膨胀机理的认识。文中还介绍了形成活性白云石的地质环境和碱硅酸反应与碱碳酸盐反应的区分方法。

关键词：碱集料硅酸碳酸盐混凝土开裂机理

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Utilization of alkali-activated copper slag as binder in concrete

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 773-780 doi: 10.1007/s11709-021-0722-z

摘要： This study was focused on developing concrete using alkali-activated copper slag (AACS) as a binder. The properties of alkali-activated copper slag concrete (AACSC) were compared with portland cement concrete (PCC). Different AACSC mixes were prepared with varying Na₂O dosage (6% and 8% of the binder by weight) and curing methods. Hydration products in AACSC were retrieved using Fourier-transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) techniques. The test results indicate that the workability of AACSC was lesser than that of PCC. The AACSC mix with 6% Na₂O dosage has exhibited similar mechanical properties as that of PCC. The mechanical properties of AACSC were higher than PCC when 8% of Na₂O dosage was used. Heat curing was effective to upgrade the strength properties of AACSC at an early age of curing, but at a later age mechanical properties of ambient cured and heat-cured AACSC were comparable. The hydration products of AACSC were not identified in XRD patterns, whereas, in FTIR spectra of AACSC some alkali-activated reaction products were reflected. The AACSC mixes were found to be more sustainable than PCC. It has been concluded that AACSC can be produced similarly to that of PCC and ambient curing is sufficient.

关键词： binder concrete mechanical properties mineralogy workability

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碱激发矿渣混凝土的水化特性及微观结构研究进展 Review

傅强,卜梦鑫, 张兆瑞, 许文瑞, 元强, 牛荻涛

《工程（英文）》 2023年第20卷第1期页码 162-179 doi: 10.1016/j.eng.2021.07.026

摘要：

碱激发矿渣混凝土（alkali-activated slag concrete, AASC）是一种新型的绿色建材，与普通硅酸盐混凝土相比，

关键词：碱激发矿渣混凝土水化特性孔结构界面过渡区微观结构

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The Decarbonization of Construction—How Can Alkali-Activated Materials Contribute?

John L. Provis,Susan A. Bernal,Zuhua Zhang,

《工程（英文）》 doi: 10.1016/j.eng.2023.09.014

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井下裂缝连通技术在安棚碱矿的应用

齐铁新,刘建中,秦桂林,董峰

《中国工程科学》 2006年第8卷第7期页码 63-67

摘要：

介绍了在桐柏安棚碱矿，用微地震监测结合水准测量监测与注水井连通的原生裂隙带的理论、技术、方法和监测结果，并据此部署开采井位，把采液井打在与注水井连通的裂隙带上，实现了2条注、采井1 000m米井下裂隙带连通,使安棚碱矿可以连续注水、采出碱液，从而获得较高的生产水平和经济效益。

关键词：安棚碱矿湿法采碱井底裂缝连通水准测量微地震监测

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Modeling of alkali-silica reaction in concrete: a review

J.W. PAN, Y.T. FENG, J.T. WANG, Q.C. SUN, C.H. ZHANG, D.R.J. OWEN

《结构与土木工程前沿（英文）》 2012年第6卷第1期页码 1-18 doi: 10.1007/s11709-012-0141-2

摘要： This paper presents a comprehensive review of modeling of alkali-silica reaction (ASR) in concrete. Such modeling is essential for investigating the chemical expansion mechanism and the subsequent influence on the mechanical aspects of the material. The concept of ASR and the mechanism of expansion are first outlined, and the state-of-the-art of modeling for ASR, the focus of the paper, is then presented in detail. The modeling includes theoretical approaches, meso- and macroscopic models for ASR analysis. The theoretical approaches dealt with the chemical reaction mechanism and were used for predicting pessimum size of aggregate. Mesoscopic models have attempted to explain the mechanism of mechanical deterioration of ASR-affected concrete at material scale. The macroscopic models, chemo-mechanical coupling models, have been generally developed by combining the chemical reaction kinetics with linear or nonlinear mechanical constitutive, and were applied to reproduce and predict the long-term behavior of structures suffering from ASR. Finally, a conclusion and discussion of the modeling are given.

关键词： alkali-silica reaction (ASR) modeling concrete mesoscopic macroscopic

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Operando modeling and measurements: Powerful tools for revealing the mechanism of alkali carbonate-based

《能源前沿（英文）》 2023年第17卷第3期页码 380-389 doi: 10.1007/s11708-023-0872-x

摘要： Alkali carbonate-based sorbents (ACSs), including Na₂CO₃- and K₂CO₃-based sorbents, are promising for CO₂ capture. However, the complex sorbent components and operation conditions lead to the versatile kinetics of CO₂ sorption on these sorbents. This paper proposed that operando modeling and measurements are powerful tools to understand the mechanism of sorbents in real operating conditions, facilitating the sorbent development, reactor design, and operation parameter optimization. It reviewed the theoretical simulation achievements during the development of ACSs. It elucidated the findings obtained by utilizing density functional theory (DFT) calculations, ab initio molecular dynamics (AIMD) simulations, and classical molecular dynamics (CMD) simulations as well. The hygroscopicity of sorbent and the humidity of gas flow are crucial to shifting the carbonation reaction from the gas−solid mode to the gas−liquid mode, boosting the kinetics. Moreover, it briefly introduced a machine learning (ML) approach as a promising method to aid sorbent design. Furthermore, it demonstrated a conceptual compact operando measurement system in order to understand the behavior of ACSs in the real operation process. The proposed measurement system includes a micro fluidized-bed (MFB) reactor for kinetic analysis, a multi-camera sub-system for 3D particle movement tracking, and a combined Raman and IR sub-system for solid/gas components and temperature monitoring. It is believed that this system is useful to evaluate the real-time sorbent performance, validating the theoretical prediction and promoting the industrial scale-up of ACSs for CO₂ capture.

关键词： CO₂ capture carbonation theoretical modeling operando techniques reaction visualization

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Development of a dual temperature control system for isoprene biosynthesis in

《化学科学与工程前沿（英文）》 2022年第16卷第7期页码 1079-1089 doi: 10.1007/s11705-021-2088-0

摘要： Conflict between cell growth and product accumulation is frequently encountered in the biosynthesis of secondary metabolites. To address the growth-production conflict in yeast strains harboring the isoprene synthetic pathway in the mitochondria, the dynamic control of isoprene biosynthesis was explored. A dual temperature regulation system was developed through engineering and expression regulation of the transcriptional activator Gal4p. A cold-sensitive mutant, Gal4ep19, was created by directed evolution of Gal4p based on an internally developed growth-based high-throughput screening method and expressed under the heat-shock promoter P_SSA4 to control the expression of P_GAL-driven pathway genes in the mitochondria. Compared to the control strain with constitutively expressed wild-type Gal4p, the dual temperature regulation strategy led to 34.5% and 72% improvements in cell growth and isoprene production, respectively. This study reports the creation of the first cold-sensitive variants of Gal4p by directed evolution and provides a dual temperature control system for yeast engineering that may also be conducive to the biosynthesis of other high-value natural products.

关键词： transcriptional activator directed evolution dynamic control heat-shock isoprene

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Alkali-thermal gasification and hydrogen generation potential of biomass

Alexander B. Koven, Shitang S. Tong, Ramin R. Farnood, Charles Q. Jia

《化学科学与工程前沿（英文）》 2017年第11卷第3期页码 369-378 doi: 10.1007/s11705-017-1662-y

摘要： Generating hydrogen gas from biomass is one approach to lowering dependencies on fossil fuels for energy and chemical feedstock, as well as reducing greenhouse gas emissions. Using both equilibrium simulations and batch experiments with NaOH as a model alkaline, this study established the technical feasibility of converting various biomasses (e.g., glucose, cellulose, xylan and lignin) into H -rich gas via catalyst-free, alkali-thermal gasification at moderate temperatures (as low as 300 °C). This process could produce more H with less carbon-containing gases in the product than other comparable methods. It was shown that alkali-thermal gasification follows , with carbonate being the solid product which is different from the one suggested in the literature. Moreover, the concept of hydrogen generation potential (H -GP)—the maximum amount of H that a biomass can yield, was introduced. For a given biomass C H O , the H -GP would be moles of H . It was demonstrated experimentally that the H -GP was achievable by adjusting the amounts of H O and NaOH, temperature and pressure.

关键词： hydrogen generation potential biomass lignocellulose alkali-thermal gasification sodium hydroxide

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Fate of proteins of waste activated sludge during thermal alkali pretreatment in terms of sludge protein

Xiaoli Song, Zhenghua Shi, Xiufen Li, Xinhua Wang, Yueping Ren

《环境科学与工程前沿（英文）》 2019年第13卷第2期 doi: 10.1007/s11783-019-1114-7

摘要：

Maillard reaction between reducing sugars and amides happened during pretreatment.

Over 90 min of TAH at the optimal condition, 67.59% sludge proteins was solubilized.

15.84% soluble proteins broke down to materials with small molecular weight.

关键词： Sludge flocs Microbial cells Hydrolysate Protein breakdown Melanoidin

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碱处理对桉木纤维挤压结合机理的影响

彭万喜,林芝,李年存

《中国工程科学》 2014年第16卷第4期页码 64-68

摘要：

采用桉木纤维为原料，探讨碱处理对板材挤压结合机理的影响。结果表明：碱处理对木质素、半纤维素都有不同程度的降解作用；在热压制板过程中，经过降解作用的木材成分经适当的热压工艺能够发生聚合反应从而粘合成板；强碱（NaOH）对桉木纤维的影响大于弱碱溶液（Na2CO3），且处理时间为10 h 较适宜；碱处理过程产生的活性羟基，热压后可以缔合形成氢键，增加了纤维之间的结合力，有利于桉木纤维自身粘合成板。

关键词：桉木纤维碱处理傅立叶红外光谱扫描电子显微镜（SEM）