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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2005.09.025 Byline: Pete Bettinger (a), Kevin Boston (b), Young-Hwan Kim (c), Jianping Zhu (a) Keywords: Heuristics; Combinatorial optimization; Large scale optimization; Environment; Forest landscape planning Abstract: Spatial and temporal scheduling of forest management activities is becoming increasingly important due to recent developments in environmental regulations, goals and policies. A forest planning model was developed to select activities for stands in a forested area (178,000ha), from a set of stand-centric optimal prescriptions, to best meet a higher-level landscape objective. The forest-level management problem addressed is complex, if not impossible to solve optimally, with current computing technologies, as integer decision variables are assumed. The higher-level landscape objective is to achieve the highest even-flow of timber harvest volume. Three types of tabu search processes were examined in the model: (1) a process with 1-opt moves only; (2) a process with 1-opt moves and a region-limited 2-opt move process; and (3) a process with 1-opt moves and 10 iterations through a smaller region-limited 2-opt move process. Aspiration criteria and short-term memory were employed within tabu search in an attempt to avoid becoming trapped in local optima. While the 1-opt move process alone created solutions (forest plans) that were adequate, and contained higher average harvest volumes than the other methods, the addition of the 2-opt move processes improved the solutions generated by intensifying the search around local optima. The solutions produced using the 2-opt move processes had less variation in periodic harvest volumes across the planning horizon. While the basic 1-opt tabu search process provides adequate feasible solutions to large, complex forest planning problems, we reinforce the notion suggested, but not proven with previous research, that 2-opt neighborhoods can help improve quality of large scale forest plans generated by tabu search. The contribution of this research is the description of a process which be developed for large forest planning problems (the problem examined is at least 1 order of magnitude greater than previous research, in terms of forested stands modeled), a process that could enable one to produce more efficient forest planning solutions than one could otherwise with standard 1-opt tabu search. In addition, we describe here the use of a set of optimal stand-level prescriptions to choose from when utilizing the 2-opt process, rather than a set of clearcut periods to consider. With this in mind, this research represents a fundamentally new application of operations research techniques to realistic forest planning problems. Author Affiliation: (a) Warnell School of Forest Resources, University of Georgia, Athens, GA 30602, United States (b) Department of Forest Engineering, Oregon State University, Corvallis, OR 97331, United States (c) Department of Forest Resources, Oregon State University, Corvallis, OR 97331, United States Article History: Received 25 March 2004; Accepted 23 September 2005

The present study focuses on the development of a Low Calcium CO 2 Sequestration Binder (LCCSB) composed primarily of α-CS, C 3 S 2 , and C 2 AS. The carbonation properties, carbonation products, and microstructure of various nano-SiO 2 (NS) were comprehensively characterized using XRD, TGA, pH, conductivity, LF NMR, and SEM techniques. The influence mechanism of incorporating NS on the carbonation reaction of LCCSB was elucidated. The findings demonstrated that the incorporation of NS enhances the carbonation performance of LCCSB, accelerates the reaction process between CO 2 and minerals, promotes the generation of aragonite, and reduces porosity. The carbonation performance exhibits optimal results with an NS content of 0.06%. The results present a promising application prospect for the cement industry in the development of low calcium carbon cement. [Display omitted] • The integration of nano-SiO 2 enhanced the rate of carbonation reaction in LCCSB. • The introduction of nano-SiO 2 optimizes the pore structure of carbonized LCCSB. • The introduction of nano-SiO 2 augmented the growth of aragonite. [ABSTRACT FROM AUTHOR]

Background: The rate of patients with unilateral hearing impairments (UHI) increase with age and are characterized by asymmetric auditory afferents in which auditory information is asymmetrically transmitted to the brain. Long-term bilateral hearing imbalance can cause abnormal functional changes in the cerebral cortex. However, the relationship between functional alterations in the brain and the severity of the hearing impairment remains unclear.Methods: This study included 33 patients with UHI (left-sided impairment in 17 and right-sided impairment in 16) and 32 healthy patients. All participants underwent resting-state, blood oxygen level dependent functional magnetic resonance imaging. Fractional amplitude of low frequency fluctuation (fALFF) values were calculated after data preprocessing and compared among the left-sided and right-sided impairment groups and the control group. Pure tone audiometry was used to evaluate patients' hearing impairment level. The correlation between fALFF values of abnormal brain regions and the duration and severity of hearing impairment was analyzed.Results: Results provide evidence for altered resting-state functional activities in the brain of patients with left or right long-term UHI, with significantly increased fALFF values in the Heschl's gyrus, superior temporal gyrus, and insula were observed. Moreover, complicated networks reorganization involved in the visual, cognitive, sensorimotor and information transmission functions except for the auditory function and some brain regions exhibited functional changes only in the one-sided impairment group. In addition, the severity of hearing impairment is related with the functional activities in the bilateral Heschl's gyrus, bilateral insula, right superior temporal gyrus, and left middle frontal gyrus.Conclusion: In conclusion, alterations in functional activity are observed in the brains of patients with long-term hearing impairments and multiple brain regions within different functional networks are involved in the brain functional remodeling. The brain reintegration mechanism appears to be asymmetrical and the lateralization pattern in the contralateral brain hemisphere for auditory information processing related with the severity of hearing impairment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The coupling effects of Cl− and Mg2+ in marine tidal zone were assessed. • High concentrations (≥0.2 mol/L) Mg2+ is detrimental to the chemically bound chloride ions. • Cementitious materials mixed with GGBS can chemically bound more chloride than those mixed with FA. • Cementitious materials mixed with GGBS can reduce the total pore volume than those mixed with FA. To reveal the deterioration mechanism of cementitious materials serving in the marine tidal environment, this study investigates the microstructures of cementitious materials under the coupling effects of Cl− and Mg2+. This study mainly analyzes the phase composition, pore structure distribution, and micromorphology of the hardened cementitious materials with 30 % fly ash (FA), 30 % ground granulated blast furnace slag (GGBS), or a combination of 15 % FA and 15 % GGBS under different Mg2+ concentrations. The effects of Mg2+ concentration and mineral admixture type on chemically bound chloride ions and their microstructures are investigated. The results show that a large amount of Friedel's salt is formed under the coupling effects of 0.6 mol/l Cl− and 0.1 mol/l Mg2+. A corrosive solution with a high concentration of Mg2+ is not conducive to the forming of Friedel's salt. In a Cl− or Cl−-Mg2+ environment, GGBS can chemically bind more chloride ions than FA. With the increase of Mg2+ concentration, more pores and cracks appear on the sample surface. In a Cl−-Mg2+ corrosive solution, cementitious materials with mineral admixtures are more porous than pure cementitious materials. Cementitious materials hardened with GGBS are more porous than those materials hardened with FA. Thus, GGBS is more conducive to improving the materials' resistance to chloride ions than FA. [ABSTRACT FROM AUTHOR]

• Financial pressure could improve volatility forecasting performance of health care stock. • The prediction contribution of financial pressure is much stronger in China than in the USA. • Different lag periods of financial pressure have an asymmetric predictive contribution. • The prediction contribution about five dimension of financial pressure is discrete. This study analyzes the role of financial pressure in forecasting the volatility of health care stock. The main finding shows that financial pressure helps to improve the volatility forecasting performance of the health care stock in both China and the USA. Empirical analysis further suggests that XGBoost performance outperforms other benchmark models, especially advanced machine learning models. This study also interprets predictions to help financial institutions and investors make correct decisions using Shapley additive explanations. The results illustrate that the prediction contribution of financial pressure is much stronger in China than in the USA. The prediction contribution distribution of the five-dimensional indicator of financial pressure in China is more discrete than in the USA. Different lag periods of financial pressure have an asymmetric predictive contribution to the volatility of the health care stock. The volatility of Chinese health care stock is mainly influenced by the five-dimensional indicator of financial pressure at the medium and late period lag but at the front and medium period lag for the USA. These findings are crucial for policymakers and investors in promoting the sustained health care stock market through financial pressure regulation. [ABSTRACT FROM AUTHOR]

The influences of colloidal nanoBoehmite (CNB) and colloidal nanoSiO 2 (CNS) on fly ash cement mortar hydration and microstructure development of fly ash cement pastes were investigated. The results revealed that fly ash cement hydration was accelerated by CNB and CNS at early age thus enhancing the early age strength of the materials. Although higher content of nanoparticles significantly hindered cement hydration, adding appropriate amount of CNB and CNS benefited the development of compressive strength both at early and later age. [ABSTRACT FROM AUTHOR]

Abstract: Fineness is one of the key factors in determining the hydration activity factor of slag. The present research investigates the effect of particle size distribution (PSD) of slag on water requirement, setting time, and compressive strength. For this purpose, a reference and 17 cement samples containing different blast furnace slag are made and the properties are tested. When slags with proper PSD are prepared the cement properties can be better than the reference. [Copyright &y& Elsevier]

Abstract: The successful release of the IEEE 802.15.4 standard offers a great convenience to applications of low-power and low-rate wireless sensor networks (WSNs) which almost touch upon all aspects of our life. Analyses of the IEEE 802.15.4 Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) scheme have received considerable attention on saturated or homogeneous traffic recently. More realistic stochastic analysis approach to evaluate the performance of CSMA/CA scheme with heterogeneous unsaturated traffic is proposed in our applications. We adopt two modified semi-Markov chains and one macro-Markov chain to characterize such an asymmetric system, in which traffic arrivals and packets accessing the channel are bestowed with non-preemptive priority over each other instead of prioritization, and the behaviors of heterogeneous nodes interact with each other rather than simple independent behavior superposition. Throughput, packet delay and energy consumption of unsaturated, unacknowledged IEEE 802.15.4 beacon enabled networks are predicted based on these models. Comprehensive simulations demonstrate that the analysis results of these simplified models match well with the simulation results, and not undermine the accuracy at the same time. [Copyright &y& Elsevier]

When solving time-dependent partial differential equations on parallel computers using the nonoverlapping domain decomposition method, one often needs numerical boundary conditions on the boundaries between subdomains. These numerical boundary conditions can significantly affect the stability and accuracy of the final algorithm.In this paper, a stability and accuracy analysis of the existing methods for generating numerical boundary conditions will be presented, and a new approach based on explicit predictors and implicit correctors will be used to solve convection-diffusion equations on parallel computers, with application to aerospace engineering for the solution of Euler equations in computational fluid dynamics simulations. Both theoretical analyses and numerical results demonstrate significant improvement in stability and accuracy by using the new approach. [Copyright &y& Elsevier]

Glutamatergic and GABAergic synaptic transmission controls excitation and inhibition of postsynaptic neurons, whereas activity of ion channels modulates neuronal intrinsic excitability. However, it is unclear how excessive neuronal excitation affects intrinsic inhibition to regain homeostatic stability under physiological or pathophysiological conditions. Here, we report that a seizure-like sustained depolarization can induce short-term inhibition of hippocampal CA3 neurons via a mechanism of membrane shunting. This depolarization-induced shunting inhibition (DShI) mediates a non-synaptic, but neuronal intrinsic, short-term plasticity that is able to suppress action potential generation and postsynaptic responses by activated ionotropic receptors. We demonstrate that the TRESK channel significantly contributes to DShI. Disruption of DShI by genetic knockout of TRESK exacerbates the sensitivity and severity of epileptic seizures of mice, whereas overexpression of TRESK attenuates seizures. In summary, these results uncover a type of homeostatic intrinsic plasticity and its underlying mechanism. TRESK might represent a therapeutic target for antiepileptic drugs. [Display omitted] • A sustained seizure-like depolarization induces a transient shunting inhibition • This non-synaptic form of short-term plasticity contributes to seizure termination • TRESK, a subtype of K+ channels, contributes to this shunting inhibition • Activating TRESK shortens seizure duration and prolongs postictal depression Huang et al. find sustained depolarization-induced shunting inhibition (DShI) which is induced by seizure-like and seizure-mimicking sustained depolarizations. The inhibitory action and time course of DShI is sufficient to explain the termination of ictal epileptiform activity and postictal depression. TRESK contributes to DShI and modulates seizures. [ABSTRACT FROM AUTHOR]

The doping mechanism of Ba in sulfoaluminate cement (SAC) clinker was systematically studied. Results from density functional theoretical simulations, backscattered electron diffraction and X-ray diffraction show that Ba ions prefer to incorporate into the mineral C 4 A 3 S ¯ by substituting Ca atoms while little enter into the other two minerals, C 2 S and C 4 AF. Such doping preference was also certified by the results of individual mineral of C 4 A 3 S ¯ and C 4 AF, respectively. Further analyses from partial density of states, electron density difference and local distortions indicate that the Ba-doping preference in C 4 A 3 S ¯ is attributed to the efficiency of newly formed bonds, which is enhanced by electronic structure matching and small local distortions. The understandings are essential in guiding the production of Ba-bearing SAC clinker by utilizing industrial barium slags, thus should be very important in sustainable production of SAC clinkers, environmental governance and industrial collaborative disposal of waste. [Display omitted] • Ba ions prefer to incorporate into the mineral C 4 A 3 S̅ by substituting Ca atoms. • Almost no Ba ions enter into the other two minerals of C 2 S and C 4 AF. • The small local distortion between Ca–O/Ba–O determines the preference in C 4 A 3 S̅. • It provides a possibility of producing sulfoaluminate cement with Ba-bearing waste. [ABSTRACT FROM AUTHOR]

JLX001, a new dihydrochloride of Cyclovirobuxine D (CVB-D), has bioactivities against ischemia injury. The blood-brain barrier (BBB) disruption is involved in the pathogeneses of ischemic stroke. This study was designed to explore the effect and potential mechanism of JLX001 on the BBB after ischemic stroke. Rats were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) to mimic cerebral ischemia in vivo. In vitro, rat primary brain microvascular endothelial cells (PBMECs) were cultured and exposed to oxygen-glucose deprivation/reoxygenation (OGD/R). Posttreatment of JLX001 for 15 days after MCAO/R improved the behavior, learning and memory ability. Pretreatment of JLX001 for 3 days significantly attenuated infarct volume, lessened brain edema, mitigated BBB disruption and decreased the neurological deficit score in MCAO/R rats. Moreover, JLX001 increased cell viability and reduced sodium fluorescein leakage after OGD/R injury. In addition, JLX001 increased the expressions of Claudin-5 and Occludin, decreased the expression of MMP-9 both in vivo and in vitro. Moreover, immunofluorescence staining and western immunoblotting results showed that JLX001 increased the expressions of tight junction proteins via activating Wnt/β-catenin signal pathway in vivo and in vitro, which may be associated with the activation of PI3K/Akt signaling. Besides, XAV939 (an inhibitor of the Wnt/β-catenin pathway) proved the connection of JLX001 and Wnt/β-catenin pathway. These results suggest that JLX001 alleviates BBB disruption after MCAO/R and OGD/R possibly by alleviating MMP-9 and activating the Wnt/β-catenin signaling pathway. [ABSTRACT FROM AUTHOR]

Li-SF 6 battery has been proposed as a novel energy conversion device for both reducing greenhouse-effect SF 6 and potentially providing large specific energy. However, the real discharge process of SF 6 remains ambiguous with fast cathode passivation and large polarization. Here we report that the Li-SF 6 chemistry is able to deliver an unprecedented capacity of >20,000 mA h g c −1 with reduced polarization and excellent rate capability by using a low-cost, high-surface-area porous carbon as cathode host. More importantly, by adjusting the SF 6 atmosphere, an approximately eight-electron transfer process with predominant products of LiF and Li 2 S is realized via two voltage steps, whereas previously only a little Li 2 S could be found with one plateau appearing. The eight-electron process leads to a high energy density about 2,300 W h kg−1 based on the mass of carbon and discharge products, which sheds light on SF 6 as a promising high-energy-density cathode. The high-surface-area porous carbon provides sufficient active sites for SF 6 absorption and reduction. The limited SF 6 avoids the cathode passivation by LiF, thereby maximizing the reduction to Li 2 S. Combination of both leads to the full reduction of SF 6 in lithium batteries with significantly improved discharge capacity and voltage. Image 1 • The gas electrode is optimized for the first time in Li-SF6 batteries. • Li-SF6 cells based on high-surface-area Ketjen Black gas electrode deliver great enhanced discharge capacities and voltages. • Firstly disclosing that the eight-electron reduction of SF6 to Li2S involves two voltage plateaus in Li-SF6 batteries. [ABSTRACT FROM AUTHOR]

Li 10 SnP 2 S 12 (LSPS) with high ionic conductivity and moderate price is a promising solid electrolyte for all-solid-state batteries. However, the instability of LSPS and LSPS/electrodes interfaces would cause poor cycle performance issues in the LSPS-based all-solid-state batteries, which have not been well understood. Herein, we address and unravel the decomposition products of LSPS and their Li+ transfer characteristics, especially on the surface of LSPS/electrodes by using solid-state nuclear magnetic resonance (ss NMR) spectroscopy coupled with X-ray photoelectron spectroscopy (XPS). The results reveal that the high mechanical energy during ball-milling process leads to the decomposition of LSPS into Li 4 SnS 4 and Li 3 PS 4. During charge/discharge cycling, specific capacity fading of batteries originates from the formation of new interfacial layer at LSPS/Acetylene black cathode and LSPS/Li metal anode interfaces. Furthermore, our results demonstrate that the rough and porous morphology of the interface formed after cycling, rather than the decomposition products, is the critical factor which results in the increases of the interfacial resistance at LSPS/Li interface and serious formation of Li dendrite. Our results highlight the significant roles of (electro)chemical and interfacial stability of sulfide solid electrolyte in the development of all-solid-state batteries. Image 1 • Study the effect of mechanical energy on the phase stability of LSPS during different processes. • Firstly analyze the interfacial kinetic information at LSPS/Li metal via ss NMR. • Systematic research on the (electro)chemical stability of LSPS in all solid-state batteries. [ABSTRACT FROM AUTHOR]

Sintering red mud (SRM) is an industrial alkaline waste residue generated from the sintering process in alumina production, which is often directly discarded and causes environmental issues. In this study, an innovative magnesium-modified wet carbonation method was proposed to convert sintering red mud to valuable calcium carbonate whiskers using CO 2 -containing flue gas. The effects of carbonation conditions including temperature, MgCl 2 concentration, and duration on the composition, microstructure, and morphology of carbonated products were systematically investigated. It was found that a high whisker content of 60% with an aspect ratio of ∼6 could be obtained under the optimal conditions of 80 °C, 0.4 M MgCl 2 , and 2 h reaction time. Besides the formation of whiskers, amorphous aluminosilicate gel was also generated during SRM carbonation. The effects of the as-prepared whisker-rich materials as partial cement replacement on the mechanical properties of cement paste were evaluated with 5 wt% replacement, the 28 d compressive strength was significantly improved by 20.5% compared to the control specimen. The effective reinforcement was ascribed to the fibrous whiskers and enhanced interfacial bonding. This method enables high-value utilization of SRM waste and CO 2 fixation, providing a green and low-cost approach to producing high-performance cementitious materials. [ABSTRACT FROM AUTHOR]

The research, development and application of high energy density lithium ion batteries are strictly restricted by several challenges, particularly the severe capacity degradation of the batteries at high voltage and elevated temperature. In this work, beneficial surface films are simultaneously formed on both electrodes of a 4.5 V graphite│LiNi 0.5 Mn 0.3 Co 0.2 O 2 pouch cell via reduction and oxidation polymerizations of a novel multifunctional additive Tripropargyl Phosphate (TPP). The results demonstrate that the addition of 1.0 wt% TPP into the pouch cell not only improves its initial coulombic efficiency by 4.4%, but also remarkably enhances its cycling stability at both 25 °C and 55 °C. The enhanced cycling stability at high temperature can be attributed to the capture of acidic corrosive species in the electrolyte and the construction of robust protective films on the surface of the electrodes. These two effects significantly mitigate the decomposition of Ethyl Methyl Carbonate (EMC), reduce the dissolution of transition metal from cathode, and eliminate the formation of cracks inside the LiNi 0.5 Mn 0.3 Co 0.2 O 2 and graphite particles. Image 1 • A novel phosphate compound with unsaturated triple bond is designed as an effective electrolyte additive. • Tripropargyl Phosphate suppresses the degradation of the electrolyte via reacting with the free radicals in the electrolyte. • In-situ formation of cathode electrolyte interface via oxidative polymerization. • In-situ formation of solid electrolyte interface via reductive polymerization. [ABSTRACT FROM AUTHOR]

Numerous studies have investigated the carbonation process of tricalcium silicate (C 3 S). However, research on the carbonation of its different crystal forms remains relatively limited. This study explored the effects of accelerated carbonation on the performance and microstructure of T-C 3 S and M-C 3 S. The findings indicated that both T-C 3 S and M-C 3 S exhibited a rapid carbonation reaction rate during the initial 12 h, which subsequently declined gradually. The carbonation products of T-C 3 S and M-C 3 S primarily consisted of calcite, with T-C 3 S also containing a proportion of aragonite calcium carbonate. The decomposition peak temperature of calcium carbonate weight loss increased with prolonged carbonation time for both C 3 S crystal forms. Prismatic or cubic morphology calcite formed in T-C 3 S and M-C 3 S during the initial carbonation stages, leading to a denser microstructure. As the carbonation duration increased, the particle size of calcite also grew, displaying a more irregular morphology. Furthermore, needle-like or rod-like aragonite calcium carbonate was observed in T-C 3 S. T-C 3 S exhibited superior compressive strength compared to M-C 3 S at all stages of carbonation. Additionally, a relationship was established between compressive strength, calcium carbonate content, and CO 2 uptake. This study provided evidence that the crystal structure of C 3 S not only influenced the rate of the carbonation reaction but also impacted the type and morphology of calcium carbonate products and the development of compressive strength. • Effects of accelerated carbonation on the performance and microstructure of T-C 3 S and M-C 3 S were investigated. • T-C 3 S showed a higher carbonation reactivity compared to M-C 3 S. • T-C 3 S had a higher compressive strength compared to M-C 3 S. [ABSTRACT FROM AUTHOR]

The reduction of CO 2 emissions from the cement industry remains a major challenge worldwide. This study investigates the feasibility of using high-magnesium limestone to prepare high-magnesium and low-calcium cementitious materials (HM-LCCs) with improved carbonation reactivity and CO 2 sequestration capacity. The carbonation reactivity, hardening properties, phase assemblage, microstructure, and pore distribution of HM-LCCs synthesized with varying proportions of high-magnesium limestone were characterized by XRD, TGA, FT-IR, SEM, and LF NMR. It is found that with increasing substitution of high-magnesium limestone, the main mineral phases in clinker transformed from C 2 MS 2 to C 3 MS 2 and eventually to β-C 2 S and MgO, along with markedly enhanced grindability. The carbonation reactivity and degree increased progressively with increasing substitution of high-magnesium limestone. Properly tailored HM-LCCs exhibited excellent strength development up to 94.56 MPa after carbonation, dense microstructure, and significantly higher CO 2 uptake. This study provides new insights into developing low-carbon cement by utilizing high-magnesian raw materials. The carbonation hardening and CO 2 sequestration capacity of cement can be optimized by tailoring the Mg/Ca ratio and calcium silicate phase assemblage. • HM-LCCs from high-magnesium limestone show excellent carbonation hardening and CO 2 sequestration. • Increasing high-magnesium limestone ratio transforms HM-LCCs to β-C 2 S/MgO, enhancing carbonation reactivity. • Optimizing HM-LCC mineral composition achieves high carbonation strength and CO 2 uptake. [ABSTRACT FROM AUTHOR]

The in-situ polymerization of acrylamide (AM) was utilized to tailor the mechanical properties and microstructure of carbonated magnesium slag (MS) composites. The results revealed that appropriate AM incorporation substantially enhanced the flexural and compressive strengths. This enhancement was attributed to the flexible polyacrylamide gels in-situ polymerized from AM, which formed interpenetrating networks with the rigid MS carbonation products, thereby increasing compactness and toughness. AM incorporation did not alter the carbonation products but increased calcite formation. The polyacrylamide gels were uniformly dispersed in the carbonated matrix, reducing porosity and improving density. Moreover, AM formed stable chemical bonds with cations released from MS. The temperature rise and CO 2 pressure during carbonation served as the dominating factors that initiated the in-situ polymerization of AM. The established rigid-flexible networks synergistically amplified the flexural and fracture toughness. However, excessive AM reduced the strengths due to phase segregation. The above results provide an efficient approach to establishing polymer-inorganic interpenetrating networks in MS carbonation systems, remarkably improving the mechanical performance. • In-situ polymerized AM forms interpenetrating networks with carbonated MS. • PAM remarkably improves flexural and compressive strengths simultaneously. • Carbonation temperature/CO 2 pressure triggers acrylamide in-situ polymerization. [ABSTRACT FROM AUTHOR]

The influence of limestone powder (primarily composed of calcite) on hydration and properties of concrete has been extensively researched. However, there is limited understanding of how different calcium carbonate (CC) polymorphs affect cement hydration due to the difficulty in formation of vaterite. Therefore, preparing calcite and vaterite from solid waste carbide residue (CS) by wet carbonation and examining influence of these two CC polymorphs (0–20 %) on cement hydration and properties are comprehensive investigated in the paper. The results reveal that pure cubic calcite can be obtained through CS carbonation, while high-purity spherical vaterite can be synthesized using glycine as a regulator. The specific surface area (SSA) of spherical vaterite (15.47 m2/g) is approximately three times that of calcite (4.8 m2/g) with a comparable particle size distribution (PSD). The addition of calcite reduces the flowability of cement, whereas vaterite enhances it. The cement mortar with calcite demonstrates a lower compressive strength, while the incorporation of vaterite results in a higher or comparable compressive strength in contrast to control sample. Compared with control cement hydration, new hydration products, like monocarbonate aluminate and hemicarbonate aluminate, are formed with the addition of both calcite and vaterite. The metastable vaterite exhibits increased reactivity. The research presents a novel approach for the valorisation of solid wastes through CO 2 sequestration, offering insights into the preparation of highly added-value products. [ABSTRACT FROM AUTHOR]

China ranks currently as one of the top countries for organ transplantation according to types, capacity, related research, quality, and quantity of procedures. However, the management systems struggle to support these practices. This study aims to review the current situation with organ donation and transplantation in China recently. Data about organ donation and transplantation was collected by using web crawler technology from several news sections of representative portal websites in China. A total of 3475 documents about organ donation and transplantation were analyzed after data preprocessing. The documents were analyzed using machine learning to find out the relationship among the hot topics and their social popularity as well as to explore the dominant subtopics of the hot topics. The results of weighted correlation network analysis and documents clustering analysis identified 9 topics about organ donation and transplantation in China with a wide discussion: transplantation ethics, donor compensation, use of the remains, transportation guarantee of living organs, organ allocation, relevant national standards of organ donation and transplantation, legislation on organ donation, penalties for violation, and the Red Cross Society of China. This study found out the main problems and proposed them for future discussion with organ donation and transplantation system in China: the lack of publicity and education and the difficulty of standardizing legislation about ethical issues arousing ethical problems; the need to understand the relationship and the standardization among costs, expenses, and compensation; and the lack of more support from the government and public to ensure regular organ donation and transplantation. [ABSTRACT FROM AUTHOR]