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Adaptive bitrate (ABR) algorithms are critical techniques for high quality-of-experience (QoE) Internet video delivery. Early ABR algorithms conducting the overall QoE function of fixed parameters are limited by the fact that the QoE of end-users are diverse such that the video bitrate is often chosen in a misleading way. State-of-the-art ABR algorithms like MPC and Pensieve utilize offline modeling techniques and result in performance degradation for online QoE diversity adaptation. To address this issue, we propose Elephanta, an online ABR algorithm for edge users, which incorporates user QoE perception interface and adaptation algorithm with flexible parameters. In order to avoid overhead from updating parameters online, we model video streaming as a renewal system and formulate the specific QoE function into flexible formats by setting constraints on corresponding QoE metrics. To validate parameter settings, we emulate Elephanta under 1500 throughput traces, including FCC broadband, $3G$ HSDPA data set from the Internet, as well as the $4G$ /LTE data set we collect. Evaluation results show that Elephanta achieves QoE improvement of 7% over MPC and 3% over Pensieve under QoE diversity in part because of its superior adaptability to QoE diversity. We implemented Elephanta in dash.js at the client side for subjective experiments. We observed the diverse QoE preferences across users and 19/21 users (strongly) agree that Elephanta is responsive to parameter changes while watching videos.

Chronic cold exposure, which is the main inducer of lung diseases in high latitudes, affects production efficiency and restricts the development of aquaculture. Although the relationship between cold exposure and susceptibility to the lungs is widely accepted, but the influence between them has not been fully explored. The aim of this study is to understand the underlying mechanism. In the present study, the mice, which are used to establish cold stress (CS)-induced lung injury model, are exposed to cold temperature (4 °C) for 3 h each day for 4 weeks. The results indicate that the expression of heat shock protein 70 (HSP70) is augmented by cold exposure. In addition, chronic cold exposure aggravate the formation of malondialdehyde (MDA) and lead to a significant decrease in the contents of micrococcus catalase (CAT) and glutathione (GSH). Moreover, chronic cold exposure significantly exacerbates the expression of inflammation- and apoptosis-related proteins. The activation of Bax and caspase-3 are significantly augmented. However, that of Bcl-2 is decreased. These results are different from those in room team. The results show that chronic cold exposure plays an important roles in the activation of multiple signaling pathways, such as pyroptosis-related, inflammation-related and oxidative stress-regulated signaling pathways. In summary, these investigations support that chronic cold exposure increase the risk of lung injury by activating inflammation, oxidative stress and pyroptosis.

Today’s video service providers all desire to deeply understand the ever changing factors on user QoE to attract more users. In this paper, we study the user engagement with respect to video quality metrics and improve user engagement in adaptive video streaming systems. We conduct a comprehensive study of the real data from iQIYI, covering 700K users and 150K videos. We find bitrate switch becomes the new dominant factor on user engagement instead of rebuffering events. We also observe the impact of rate of rebuffering is more dominant than rebuffering time. We examine novel interdependencies between quality metrics in the system, e.g., the positive correlation between bitrate switch and average bitrate, which is due to the context system strategy, i.e., conservative bitrate enhancing strategy adopted by iQIYI. To improve user engagement, we propose a new engagement centric QoE function based on real data and design server side ABR algorithm which leverages our new QoE function. We evaluate our method for online test in iQIYI, with 490K real users viewing 666K streams. The results show our approach outperforms existing approaches by significantly improving the viewing time, i.e., 2.8 minutes longer viewing time per user.

Advancements in service-life prediction of concrete in freeze-thaw environments are reviewed to help inform concrete design, specification, and future areas of research. Critical degree of saturation and the formation of calcium oxychloride are specifically reviewed due to recent research progress and the ability to model the service-life of concrete in freeze-thaw prone environments is discussed. The current theory, numerical modeling, and experimental efforts used to investigate critical degree of saturation and calcium oxychloride formation are summarized and a discussion of how critical degree of saturation and calcium oxychloride develop due to environmental exposure and transport of water or calcium chloride, resulting in expansive stresses (i.e., freezing or calcium oxychloride formation) is presented. Areas of future work are identified related to advancements in experimental and numerical techniques, improved on-site evaluation tools of concretes, and the adoption of design specifications and construction practices that ensure service-life under the reviewed degradation mechanisms.

In cementitious materials exposed to solutions containing chloride, chloride binding typically results from the chemical reactions between chloride ions and aluminate phases to form Friedel's salt, and the interaction between chloride ions and calcium silicate hydrates (C S H). Calcium oxychloride can also form when Ca(OH)2 in cementitious materials reacts with CaCl2 solutions. This paper examines the chloride binding of hydrated cement pastes containing fly ash exposed to CaCl2 solutions of varying concentrations at 5 and 23 °C. Thermogravimetric analysis was used to quantify the chloride binding associated with Friedel's salt and calcium oxychloride. The amount of bound chloride by Friedel's salt is relatively independent of the exposure temperature, and as the chloride concentration [Cl−] increases, it increases until a plateau is reached at [Cl−] greater than 2 M. The addition of fly ash results in an increase in the chloride binding due to Friedel's salt. A lower exposure temperature leads to a greater amount of bound chloride associated with calcium oxychloride. In this study, no chloride binding associated with calcium oxychloride was observed in the cement pastes with 40% and 60% fly ash. The temperature-dependent chloride binding associated with C S H is a significant portion of the total chloride binding (19.8 %–70.8%) when cement pastes are exposed to CaCl2 solutions. As the replacement level of fly ash increases, the chloride binding by C S H increases first and then decreases. The amount of bound chloride by C S H increases linearly as the pH of the exposure solution decreases.

Although calcium oxychloride (Ca-Oxy) is known to damage cementitious materials exposed to calcium chloride (CaCl2) deicers, there is little direct observation of Ca-Oxy in the field due to its instability. This paper uses optical microscopy (OM) and scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM-EDX) to detect the formed Ca-Oxy and quantify its associated damage in a field mortar subject to freeze-thaw cycles and deicer applications. The characterized damage in the field mortar is compared to that in lab-cast portland cement paste and mortar which are submerged in a CaCl2 solution of 25 wt. % under freeze-thaw cycles (-8 to 25 °C). The field and lab-cast mortars show similar cracking patterns that are parallel to the exposure surface with a variation of 30-45° in the preferred orientation due to the constraints of sand particles. During each lab-controlled freeze-thaw cycle, the high CaCl2 concentration of 25 wt. % stabilizes the formed Ca-Oxy, which continually damages the mortar and eventually results in 3-4 times higher crack density compared to that in the field mortar. SEM-EDX analysis confirms the presence of secondary deposits including Friedel’s salt, ettringite and Ca-Oxy. Image analysis on thin section photomicrographs shows a reduction of 86.4% in calcium hydroxide (Ca(OH)2) content in the damaged field mortar compared to the undamaged field mortar, suggesting significant leaching of Ca(OH)2 to form Ca-Oxy due to the deicer application.

As innate immune effector cells in the central nervous system (CNS), microglia not only are essential for the normal development of nervous system but also act on different neurological diseases, including Alzheimer’s disease (AD), Huntington's disease (HD), and other neuroinflammatory diseases. Mogroside V (Mog), a natural plant active ingredient and isolated form of Momordica grosvenori, has been shown to possess anti-inflammatory action, but few studies were carried out to investigate the effects of Mog on neuroinflammation. This study aimed to investigate the role of Mog in lipopolysaccharide- (LPS-) induced neuroinflammation and neuronal damage, revealing the underlying mechanisms. Our data indicated that Mog significantly inhibited the LPS-induced production of proinflammatory factors, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-18, IL-6, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and high mobility group box 1 (HMGB1) in BV-2 cells. We found that Mog also suppressed toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), the phosphorylation of mitogen-activated protein kinases (MAPKs), adenosine 5′-monophosphate- (AMP-) activated protein kinase (AMPK), nuclear factor kappa-B (NF-κB), and protein kinase B (AKT). Moreover, Mog also enhanced the expression of γ-glutamyl cysteine synthetase catalytic subunit (GCLC), modifier subunit (GCLM), heme oxygenase-1 (HO-1), and quinine oxidoreductase 1 (NQO1) proteins, mostly depending on the nuclear translation of nuclear factor erythroid-2 related factor 2 (Nrf2). In contrast, pretreatment with inhibitors of AKT can suppress the phosphorylation of AMPK, Nrf2, and its downstream proteins expression. In summary, Mog might play a protective role against LPS-induced neurotoxicity by inhibiting the TLR4-MyD88 and activation of AMPK/AKT-Nrf2 signaling pathway.

This report describes the results of a petrographic investigation aimed at quantifying the degree of damage associated with alkali-silica reaction (ASR).

The durability of in-place concrete is a high priority issue for concrete pavements and bridges. Several studies have been conducted by INDOT to use electrical resistivity as a measure of fluid transport properties. Resistivity is dependent on the chemistry of the cement and supplementary cementitious system used, as such it has been recommended that rather than specifying resistivity it may be more general to specify the formation factor. Samples were tested to establish the current levels of performance for concrete pavements in the state of Indiana. Temperature and moisture corrections are presented and acceptable accelerated aging procedure is presented. A standardized testing procedure was developed (AASHTO TP 119–Option A) resulting in part from this study that provides specific sample conditioning approaches to address pore solution composition, moisture conditioning, and testing procedures. An accelerated aging procedure is discussed to obtain later age properties (91 days) after only 28 days.

Sound and durable concrete mixtures are essential in environments where microbial induced corrosion (MIC) is a concern. In this study three concrete mixtures prepared with different binders (ordinary portland cement (OPC), calcium aluminate cement (CAC) and alkali-activated cement (AAC) were petrographically examined after exposure to laboratory-controlled MIC conditions. Analytical techniques included reflected light microscopy, polarized and fluorescent transmitted light microscopy (FLM) and scanning electron microscopy equipped with an energy-dispersive X-ray spectrometer (SEM/EDX). SEM/EDX analyses obtained from the same areas provided information on chemical and mineralogical alteration, while quantitative image analysis with FLM affords an opportunity to quantify the variation in capillary porosity of the paste within alteration zonation. The microscopic observations indicate that the change in normalized capillary porosity coincide broadly with different alteration zones, which are in turn dependent on the type of binder. The OPC concrete shows the greatest deterioration where the paste is largely replaced by gypsum and high capillary porosity is lined to leaching of a calcium. The formation of ettringite densifies the paste and lowers the capillary porosity inboard of the gypsum zone in the OPC concrete. The CAC and AAC mixtures show better resistance to leaching than the OPC mixture, which explains their superior resistance to MIC. These findings are consistent with independent macroscopic observations that indicate the OPC mixture deteriorated more rapidly and severely than the CAC and AAC mixtures.

Friedel’s salt forms in cementitious materials exposed to NaCl solutions. This paper quantifies the amount of Friedel’s salt that forms and relates the formation of Friedel’s salt to the damage. Thermogravimetric analysis (TGA) is used to quantify the amount of Friedel’s salt. The volume change associated with the formation of Friedel’s salt is measured. Flexural strength is measured for cement pastes exposed to NaCl solutions using the ball-on-three-ball test. While Friedel’s salt was observed, no calcium oxychloride was detected in cement pastes exposed to NaCl solutions. As the NaCl concentration increases, the amount of Friedel’s salt formed in the cement pastes increases before remaining constant at high concentrations. For the same NaCl concentration, similar amounts of Friedel’s salt are obtained in cement pastes with varying water-to-cementitious materials ratios (w/cm), while a greater amount of Friedel’s salt exists in cement pastes with a higher fly ash replacement level. As the NaCl solution concentration increases, the flexural strength of the cement paste decreases. There is a greater flexural strength reduction in the cement pastes with higher w/cm. For cement pastes with a higher fly ash replacement, the flexural strength shows a smaller decrease when exposed to NaCl. Since TGA confirmed little leaching of Ca(OH)2 in the cement paste, the strength reduction appears to be mainly due to the formation of Friedel’s salt. Little volume change is associated with the formation of Friedel’s salt, which indicates that the damage may primarily be attributed to the crystallization pressure associated with the formation of Friedel’s salt in pores.

Calcium chloride (CaCl2) can react with calcium hydroxide (Ca(OH)2) to form calcium oxychloride which can reduce flexural strength and damage concrete. This paper aims to characterize the reduction in flexural strength of cement pastes exposed to CaCl2 solutions using the ball-on-three-balls test. The amounts of Ca(OH)2 and calcium oxychloride in the cement paste are measured using thermogravimetric analysis and low-temperature differential scanning calorimetry, respectively. The volume change that occurs as a result of the reactions between the cement paste and CaCl2 is also measured. The reduction in flexural strength increases as the concentration of the CaCl2 solution increases and the exposure temperature decreases. The flexural strength reduction can be mitigated by increasing the amount of supplementary cementitious materials (fly ash) in the cement pastes. Lowering the water-cementitious materials ratio also reduces the flexural strength reduction. The flexural strength reduction is correlated with the amount of calcium oxychloride and the volume change in the cement pastes exposed to the CaCl2 solution. While the flexural strength reduction is believed to be primarily due to the formation of calcium oxychloride, the formation of Friedel's salt and Kuzel's salt also contributes to the flexural strength reduction.

Chloride-based deicers, especially CaCl2 and MgCl2, can damage cementitious materials due to the formation of mineral phases such as calcium oxychloride and brucite. However, there are only limited direct observations of calcium oxychloride formed in cementitious materials in the field. This paper uses petrographic methods to evaluate damage of an in-service cementitious mortar substrate subject to freeze-thaw cycles and deicers for six years. The amount of calcium hydroxide in the mortar was quantified using thermogravimetric analysis. Changes in hydration products and microstructure were characterized by optical microscopy. Scanning electron microscopy coupled with energy dispersive X-ray spectroscopy was used to examine the morphology and elemental composition of secondary deposits related to the deicer damage. The mortar with less than 3% air exhibits horizontal cracks and microcracks cutting around aggregate particles. The cracks and microcracks are partially filled with calcium oxychloride due to the application of CaCl2. A densified crust of brucite and calcite, likely associated with the usage of MgCl2, covers the top surface of the damaged mortar. The deicer exposure results in leaching of calcium hydroxide mainly due to the formation of calcium oxychloride. Calcium leaching increases the apparent paste porosity in the damaged mortar, which likely weakens the physicomechanical properties of the mortar and accelerates the ingress of external deicer solutions. Moreover, the deicer application results in air-void-filling by calcium oxychloride and secondary ettringite, which may reduce the space available to release the internal stresses associated with ice formation and thus compromises the freeze-thaw durability.

Adaptive bitrate (ABR) algorithms have been critical techniques for high quality-of-experience (QoE) Internet video delivery. Prior work designs ABR algorithms by conducting the overall QoE function of fixed parameters. However, the QoE of end users are diverse and video bitrate may be chosen in a misleading way when leaving out the diversity. State-of-the-art ABR algorithms like MPC, Pensieve utilize off-line modeling techniques and result in performance degradation for online QoE diversity adaption. To address this issue, we propose Elephanta, an online flexible ABR algorithm for edge users which incorporates (1) user QoE perception interface and (2) adaption algorithm with flexible parameters. To avoid overheads for updating parameters online, we model video streaming as a renewal system and formulate specific QoE function into flexible formats by setting constraints on corresponding QoE metrics. To validate parameter setting, we emulate Elephanta under 5 thousand throughput traces including FCC broadband, 3G HSDPA data set from the Internet and 4G/LTE data set collected by ourselves. Accordingly, we implement Elephanta in dash.js at client side for user test. Evaluation results show that Elephanta achieves QoE improvement by 21.1% over MPC, in part for its superior adaptability to QoE diversity.

With the popularization of advanced cellular networks, mobile video occupies nearly three quarters of cellular network traffic. While previous adaptive bitrate (ABR) algorithms perform well under broadband network, their performance degrades in cellular networks due to throughput fluctuation. Through real world 4G/LTE network measurement, we find that throughput in cellular networks exhibits high fluctuation. It follows Markov behaviors with different states and different transition probability among states. We further find that the transition probability is stable along time but varies significantly under different environments. This inspires us to design ABR algorithms by improving throughput prediction in cellular networks. We propose NEIVA, a network environment identification based video bitrate adaption method in cellular networks. NEIVA trains a network environment identifier based on throughput data and trains a hidden Markov model (HMM) based throughput predictor for different environments. In online video bitrate selection, NEIVA utilizes the environment identifier to select the model for corresponding environment. Then NEIVA predicts future network performance by combining offline model and online throughput data. We implement NEIVA with MPC and evaluate it in real environment. The evaluation results show that with manually identifying environment, NEIVA improves 20% -- 25% bandwidth prediction accuracy and 11% -- 20% QoE improvement over the baseline predictors. With online environment identification, online NEIVA achieves 3.8% and 11.1% average QoE improvement over MPC and HMM, respectively.

Distress has recently been observed in the joints of some concrete pavements, primarily in the wet-freeze states. This distress often begins in longitudinal joints, followed by transverse joints and results in the significant loss of material from the joint area. Although it may only affect approximately 10% of the concrete pavements system-wide, it greatly reduces the service life and increases maintenance costs of the pavements it effects. Primary issues that emerged from studies on this phenomenon include the importance of the timing of joint sawing, the width of the joint opening, degree of concrete or joint sealing, drainage and degree of saturation of the concrete at the joint, quality of the air void system, role of deicing chemicals, quality of curing, and the degree of restraint at the joint. Although this broad collection of issues implies that we still lack complete understanding of all causes of joint deterioration, it also makes it pretty clear that the observed damage is a result of combination of several factors. This study synthesizes completed research related to concrete pavements joint deterioration and provides information to advance the knowledge and understanding of the variables involved in in this deterioration process and suggests the best practices that can lead to its reduction or mitigation.

ASTM C1556-11a [ASTM (2016). Standard Test Method for Determining the Apparent Chloride Diffusion Coefficient of Cementitious Mixtures by Bulk Diffusion] provides a systematic procedure to ...

Autogenous shrinkage (AS) and thermal shrinkage often lead to cracking in high performance concrete (HPC) under restraint conditions. MgO-CaO blended expansive agent (MC) and temperature rising inhibitor (TRI) has been adopted to reduce the AS and thermal shrinkage of HPC. The macroscopic properties of HPC strongly depend on the pore structure. Therefore, this paper studied the effects of MC and TRI on the pore structure evolution of HPC under multiple curing temperatures using low-field nuclear magnetic resonance spectroscopy (LF-NMR). Experimental results showed that the most probable pore diameter (MPPD) and porosity of mortar increased as the MC content increased due to the crystallization pressure by the hydration of MC. But MPPD and porosity decreased as the TRI content increased owing to a better filling effect of hydration products. Meanwhile, the mortar with the combined use of MC and TRI exhibited notably smaller MPPD and porosity than the plain mortar. In addition, as the curing temperature increased, the porosity of mortar containing both TRI and MC first decreased and then increased, while MPPD increased continuously. MPPD and porosity of mortar with both MC and TRI addition cured at 20 °C and 40 °C continued to decrease with age. However, MPPD and porosity dramatically increased with age at 60 °C as a result of the over-accelerated hydration of MgO.

This paper studies the mechanical properties and hydration of green concrete which is made from ground granulated blast-furnace slag (GGBS), desulfurization gypsum (DG) and electric arc furnace reducing slag (EAFRS) as cementitious materials. The green concrete with a water to cementitious materials ratio of 0.32 yields a compressive strength over 50 MPa at 28 days. The hydration mechanisms of GGBS-DG-EAFRS systems are studied using isothermal calorimetry (IC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDX). Although gypsum alone is able to slowly activate GGBS, the addition of EAFRS significantly accelerates the activation of GGBS. Compared to the portland cement paste, the ternary GGBS-DG-EAFRS pastes exhibit similar hydration heat evolution patterns but significantly lower hydration heat. The results from TGA and XRD show negligible amounts of Ca(OH)2 and Mg(OH)2, which is beneficial in the soundness of the green concrete. The results of XRD and SEM-EDX confirm that the main hydration products in the ternary GGBS-DG-EAFRS systems are ettringite, hydrotalcite and amorphous C–S–H with a low Ca/Si ratio (1.15–1.73) and a high Al/Ca ratio (0.02–0.42), which is favorable in obtaining good mechanical properties in the green concrete. The green GGBS-DG-EAFRS concrete sheds light on recycling industrial solid wastes, lowering the material cost and improving the sustainability in concrete industries.

Many State Highway Agencies have been working to develop performance-based specifications for concrete pavements and concrete bridge decks in freeze-thaw environments. A time to reach critical saturation (TTRCS) model has been proposed to estimate the freeze-thaw performance of concrete. This study evaluates the TTRCS model for thirty different concrete mixtures with varying w/c, air volumes, and quality of air void (size and spacing). Simple quality control test procedures are used to determine the input parameters for the TTRCS model. The estimated time to reach critical saturation is compared with the measured durability factor using ASTM C 666–15. Results indicate that 86% of the mixtures with air volume above 4.5% and a Sequential Air Method (SAM) Number below 0.30 have a normalized time to reach critical saturation of greater than 20, and a durability factor that is greater than 75%. The mixtures with a high range water reducer require a higher volume fraction of entrained air to satisfy the recommended limit for the durability factor. This appears to be due to an interaction between the high range water reducer and air entraining admixture which results in greater air void spacing (i.e., larger air voids). However, the addition of high range water reducer was also found to increase the time to reach critical saturation in the mixtures with a low w/c due to a refined pore structure with a reduction in the connectivity of the matrix pores. Reducing the w/c improves the freeze-thaw performance due to a reduction in the pore volume, connectivity, and absorption rate of the concrete. A relationship is developed to estimate the time to reach critical saturation based on SAM Number and apparent formation factor. In addition, a relationship is proposed to estimate the critical degree of saturation based on air void content and quality.

Magnesium chloride (MgCl2) reacts with cement pastes resulting in calcium leaching and the formation of calcium oxychloride, which can cause damage. This paper examines the damage in different cement pastes exposed to MgCl2 solutions. Volume change measurement and low temperature differential scanning calorimetry are used to characterize the formation of calcium oxychloride. Thermogravimetric analysis and X-ray fluorescence are used to quantify calcium leaching from Ca(OH)2 and C-S-H. The ball-on-three-balls test is used to quantify the flexural strength reduction. Calcium oxychloride can form in cement pastes exposed to MgCl2 solutions with a (Ca(OH)2/MgCl2) molar ratio larger than 1. As the MgCl2 concentration increases, two-stages of flexural strength reduction are observed in the plain cement pastes, with the initial reduction primarily due to calcium leaching from Ca(OH)2 and the additional reduction due to the calcium leaching from C-S-H (at MgCl2 concentrations above 17.5 wt%). For the cement pastes containing fly ash, there is a smaller reduction in flexural strength as less Ca(OH)2 is leached, while no additional reduction is observed at high MgCl2 concentrations due to the greater stability of C-S-H with a lower Ca/Si ratio. The addition of fly ash can mitigate damage in the presence of MgCl2 solutions.

Wicking occurs in concrete in practice when fluid absorption takes place at one surface of the element and drying at another surface. This paper examines chloride diffusion and wicking in c...

Calcium chloride (CaCl2) from deicing salts can react chemically with calcium hydroxide [Ca(OH)2] from hydrated cement paste to form an expansive product, calcium oxychloride, that can dama...

Shrinkage-reducing admixtures (SRAs) influence moisture and ionic transport in concrete by altering the properties of the pore solution (the surface tension, viscosity, and contact angle). ...

Calcium chloride (CaCl2), which is commonly used as a deicing salt, can react with calcium hydroxide (Ca(OH)2) in cement-based materials to form calcium oxychloride. This reaction causes damage that typically manifests itself as flaking of concrete pavements at the joints and leads to expensive repairs and a reduction of the service life. In this paper, cement pastes with different fly ash replacement levels were prepared to provide pastes with differing amounts of Ca(OH)2. Thermogravimetric analysis was used to quantify the Ca(OH)2 content in these pastes. Low-temperature differential scanning calorimetry (LT-DSC) was used to quantify the amount of calcium oxychloride formed when these pastes were exposed to CaCl2 solutions. The reduction in the flexural strength of these pastes saturated with different CaCl2 solutions was also measured. As the concentration of CaCl2 increases, the reduction in flexural strength increases. There is a lower flexural strength reduction in pastes with fly ash, because these pastes have lower Ca(OH)2 and form lower amounts of calcium oxychloride. The strength reduction is directly correlated to the amount of formed calcium oxychloride.

Knowledge of the degree of saturation in concrete is useful for predicting service-life in a freeze-thaw environment. The degree of saturation increases as a result of fluid absorption. Conventional testing methods to determine fluid absorption (e.g., gravimetric mass measurements) measure cumulative fluid uptake; however, they cannot provide information on the spatial distribution of the absorbed fluid in the sample. Further, conventional test methods cannot determine the degree of saturation at each point in the sample. This paper uses neutron radiography to overcome these limitations and to quantify the volume of water and degree of saturation at each location in the sample. The Powers-Brownyard model is used to calculate pore volume (i.e., matrix pores) that are filled during 1-D capillary water absorption in air-entrained concrete. This information is used to quantify the volume of water in the matrix pores (capillary, chemical shrinkage and gel pores) and the volume of water in the air voids, and subsequently the rate of filling of each pore. This study examined the fluid absorption in concrete mixtures with three different water-to-cement (w/c) ratios (0.40, 0.45 and 0.50) and a range of air contents (2.5%–9.0%). Results show that the air voids filling process is slower than the filling of the matrix pores. The air content has negligible impact on the rate of water ingress in air voids at a given w/c. However, reducing the w/c of a mixture lowers the volume of filled air voids for a comparable period of water ingress due to the lower matrix permeability. As the air content increases, the time-dependent percentage of the air void that is filled (i.e., degree of saturation of air voids) decreases regardless of the w/c.

A Zn-containing aluminophosphate with ERI-zeotype structure was hydrothermally synthsized with 1,2-diaminocyclohexane(DACH) as the template. The result of the structural analysis indicates that the Zn-containing aluminosphate crystallized in the hexagonal space group of P63/m was constituted up by the alternating Al(Zn)O4 and PO4 tetrahedra. The organic amine DACH located in the ERI cages was used to balance the negative charge of the framework.

Self-assembly reaction of Ln(NO3)3.6H2O, 2-aldehyde-8-hydroxyquinoline and histamine dihydrochloride affords two mononuclear complex [Ln(hma)(NO3)2(CH3OH)]∙0.5C4H10 (Ln = Tb (1), Dy (2); Hhma = N-(2-(8-hydroxylquinolinyl)methane(2-(4-imidazolyl)ethylamine)). The structural analysis indicates that they are isomorphous where the Ln3 + is ligated to one ligand, two nitrates and one methanol molecule. Variable temperature magnetic susceptibility studies reveal the presence of antiferromagnetic interactions in 2 and the dynamic measurement reveals that 2 displays single molecular magnet behavior below 10 K under an applied field of 2000 Oe.

Concrete in service environments is often exposed to chloride ions which can accelerate the degradation process by causing corrosion of the reinforcing steel. Resistivity measurements have been gaining interest as a method to assess concrete quality. This chapter will discuss why the formation factor, a quantifiable material property that describes the pore network and its connectivity, is the preferred method to assess concrete quality. The chapter discusses how the formation factor can be easily calculated by using an electrical measurements and knowledge of the pore solution properties and how the measured formation factor can be used as an estimation of service life.

The interactions of mitomycin C (MMC), fluorouracil (FU), mercaptopurine (MP) and doxorubicin hydrochloride (DXR) with bovine serum albumin (BSA) were studied by spectroscopic method. Quenching of fluorescence of serum albumin by these drugs was found to be a static quenching process. The binding constants ( K A ) were 9.66×10 3 , 2.08×10 3 , 8.20×10 2 and 7.50×10 3 L mol −1 for MMC–, FU–, MP– and DXR–BSA, respectively, at pH 7.4 Britton–Robinson buffer at 28 °C. The thermodynamic functions such as enthalpy change (Δ H ), entropy change (Δ S ) and Gibbs free-energy change (Δ G ) for the reactions were also calculated according to the thermodynamic equations. The main forces in the interactions of these drugs with BSA were evaluated. It was found that the interactions of MMC and FU with BSA were exothermic processes and those of MP and DXR with BSA were endothermic. In addition, the binding sites on BSA for the four drugs were probed by the changes of binding properties of these drugs with BSA in the presence of two important site markers such as ibuprofen and indomethacin. Based on the Foster theory of non-radiation energy transfer, the binding distances between the drugs and tryptophane were calculated and they were 3.00, 1.14, 2.85, and 2.79 nm for MMC, FU, MP and DXR, respectively.

The interactions of fish sperm deoxyribonucleic acid (DNA) with anthraquinones, such as chrysophanol, physcion and 1,8-dihydroxy anthraquinone, were investigated by using ethidium bromide (EB) as fluorescence probe. The binding constants of anthraquinones and DNA were obtained by the fluorescence quenching technique. Further, the binding mechanisms on the reaction of the three anthraquinones with DNA and effect of ionic strength on the fluorescence property of the system have also been investigated. The results of the assay indicate that the binding modes of chrysophanol, physcion and 1,8-dihydroxy anthraquinone with DNA were evaluated to be groove binding. And the binding constants of chrysophanol, physcion and 1,8-dihydroxy anthraquinone with DNA-EB complex were 1.64x10(4), 3.04x10(4) and 2.88x10(5) l mol(-1), respectively.

Binding of baicalein, wogonin and baicalin to fish sperm DNA was studied by using ethidium bromide dye as a fluorescence probe. To study the binding mechanism, the absorption, fluorescence, melting temperature and viscosity measurement were carried out. The experimental results indicated that the planar of flavonoids intercalated to the DNA helix. When bound to DNA, flavonoids showed hyperchromic and blue shift in the absorption spectra and fluorescence quenching (>50%) in the fluorescence spectra. Furthermore, the intercalative binding was consistent with the red shift in the position of λmax in the fluorescence spectra. It was also found that ionic strength had little or no effect on the binding of flavonoids and DNA. Stern–Volmer plots at 25 and 37 °C showed that the quenching of fluorescence by flavonoids was a combined quenching process. The binding site number n, apparent binding constant KA at 25 and 37 °C, and the corresponding thermodynamic parameters ΔG, ΔH, ΔS at 25 °C were obtained. The interaction of flavonoid–metal complexes with DNA was also studied by spectral methods, and the results suggested that the complexes intercalated into DNA.

Emodin interacting with deoxyribonucleic acid (DNA) has been studied by different spectroscopic techniques, such as fluorescence, ultraviolet and visible (UV–vis), and fourier transform infared (FT-IR) spectroscopies, using ethidium bromide (EB) as a fluorescence probe of DNA. The decrease in the fluorescence of DNA–EB system on addition of emodin shows that the fluorescence quenching of DNA–EB complex by emodin occurs. The binding constants of emodin with DNA in the presence of EB are 6.02 × 104, 9.20 × 104 and 1.17 × 105 L mol−1 at 20, 35 and 50 °C, respectively. FT-IR spectrum further suggests that both the phosphate groups and the bases of DNA react with emodin. The reaction of DNA with emodin in the presence of EB is affected by ionic strength and temperature. The values of melting temperature (Tm) of DNA–EB complex and emodin–DNA–EB complexes were determined, respectively. From the experiment evidences, the major binding mode of emodin with DNA should be the groove binding.

The interactions of flavonoids, such as quercetin, kaempferide and luteolin, with fish sperm deoxyribonucleic acid (DNA) were explored by using acridine orange (AO) as a fluorescence probe. The variations in the spectroscopic characteristics of DNA–AO in an aqueous medium upon addition of the three drugs were observed. Measurements of ultraviolet absorption and fluorescence spectra, determination of binding constants for flavonoids–double stranded DNA (dsDNA) or flavonoids–single stranded DNA (ssDNA), studies on competitive bindings among these drugs interacting with DNA–AO systems, melting temperature (Tm) curves and viscosity measurements were carried out to investigate binding mechanism of these flavonoids with DNA. The binding mode of quercetin, kaempferide and luteolin with DNA was evaluated to be groove binding. The binding constants of quercetin, kaempferide and luteolin with dsDNA (or ssDNA)–AO complex were 3.19 × 104 (or 1.19 × 104), 5.63 × 104 (or 4.58 × 104) and 2.33 × 104 (or 1.03 × 104) L mol−1, respectively.