1,462 research outputs found

    Development of durable “green” concrete exposed to deicing chemicals via synergistic use of locally available recycled materials and multi-scale modifiers

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    From the economic and social perspectives, the use of waste materials would not be attractive until their costs and quality can satisfy the construction requirements. In this study, a pure fly ash paste (PFAP) was developed in place of ordinary Portland cement paste (OPCP). This PFAP was prepared at room temperature and without direct alkali activation. The samples were prepared using only the as-received class C coal fly ash, water, and a very small amount of borax (Na2B4O7). On average, the PFAP featured 28-d compressive strength of about 36 MPa, and micro-nano hardness and elastic modulus 29% and 5%, higher than the OPCP, respectively. These mechanical and other properties of the PFAP make it a viable “green” construction binder suitable for a host of structural and non-structural applications. Advanced characterization of the raw material and PFAP pastes was employed to elucidate the hydration mechanisms of this “green” binder. The obtained knowledge sheds light on the role of class C CFA in the hydration process and may benefit the expanded use of various CFAs in cementitious materials

    A Framework for Life Cycle Sustainability Assessment of Road Salt Used in Winter Maintenance Operations

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    It is important to assess from a holistic perspective the sustainability of road salt widely used in winter road maintenance (WRM) operations. The importance becomes increasingly apparent in light of competing priorities faced by roadway agencies, the need for collaborative decision-making, and growing concerns over the risks that road salt poses for motor vehicles, transportation infrastructure, and the natural environment. This project introduces the concept of Life Cycle Sustainability Assessment (LCSA), which combines Life Cycle Costing, Environmental Life Cycle Assessment, and Social Life Cycle Assessment. The combination captures the features of three pillars in sustainability: economic development, environmental preservation, and social progress. With this framework, it is possible to enable more informed and balanced decisions by considering the entire life cycle of road salt and accounting for the indirect impacts of applying road salt for snow and ice control. This project proposes a LCSA framework of road salt, which examines the three branches of LCSA, their relationships in the integrated framework, and the complexities and caveats in the LCSA. While this framework is a first step in the right direction, we envision that it will be improved and enriched by continued research and may serve as a template for the LCSA of other WRM products, technologies, and practices

    Therapeutic benefit of aripiprazole-olanzapine combination in the treatment of senile Alzheimer’s disease complicated by mental disorders

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    Purpose: To determine the clinical efficacy of aripiprazole-olanzapine combination treatment in elderly Alzheimer’s disease complicated with mental disorders. Methods: Ninety-two elderly patients with Alzheimer’s disease and mental disorders who were admitted to Binzhou People's Hospital, were enrolled in the study. They were randomized into control and study groups. Control group was treated with olanzapine, while the study group was treated with aripiprazole as an adjuvant therapy in addition to olanzapine. The clinical efficacy, scores on different scales (MMSE, ADAS-cog, CDR, ADL, NPI and CMAI), and incidence of adverse reactions were determined. Results: The overall degree of response was significantly higher in the study group than in the control group (p < 0.05). There were no significant differences in MMSE, ADAS-cog, CDR, ADL, NPI and CMAI scores between the two groups before treatment (p > 0.05). The MMSE score of the study group was significantly higher than that of the control group, and the scores in the other scales in the study group were significantly lower after treatment (p < 0.05). The study group had significantly lower incidence of adverse reactions than control group (p < 0.05). Conclusion: Aripiprazole-olanzapine combination has significant therapeutic benefit in the treatment of elderly Alzheimer’s disease patients complicated with mental disorders. It promotes recovery of neurological function, as well as produces a lower incidence of adverse reactions. Keywords: Aripiprazole, Olanzapine, Alzheimer’s disease, Mental disorder

    Stimulation of anterior thalamic nucleus protects hippocampus neural injury in kainic acid-induced epileptic rats

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    Anterior nucleus of thalamus (ANT) stimulation has been proved to be effective in the treatment of refractory epilepsy, but the underlying mechanisms remain to be elucidated. We examined the role of ANT stimulation on hippocampal neuron death after seizures induced by kainic acid (KA). Our data showed that ANT stimulation could significantly rescue neurons from death induced by seizures, by reducing the release of cytochrome c (cyto c) and also via apoptosis-inducing factor (AIF) induced by seizures through inhibiting the activated caspase-9 and caspase-3. Our data suggest that ANT stimulation may protect against neuronal loss and reduce neuronal injury in the ipsilateral CA3 region of the hippocampus in the KA-induced epileptic rats, and the underlying mechanism may be mediated by inhibiting mitochondrial caspase-dependent (cyto c release and the subsequent cleavage of caspase-) and caspase-independent (nuclear translocation of AIF) apoptosis pathways

    Attosecond streaking of Cohen-Fano interferences in the photoionization of H2+_2^+

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    We present the first numerical simulation of the time delay in the photoionization of the simplest diatomic molecule H2+_2^+ as observed by attosecond streaking. We show that the strong variation of the Eisenbud-Wigner-Smith time delay as a function of energy and emission angle becomes observable in the streaking time shift provided laser field-induced components are accounted for. The strongly enhanced photoemission time shifts are traced to destructive Cohen-Fano (or two-center) interferences. Signatures of these interferences in the streaking trace are shown to be enhanced when the ionic fragments are detected in coincidence

    Oxidation-induced Cu coating on steel surface

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    Abstract. Copper is accumulated in recycled steels and is difficult to be removed during steelmaking processes when steel scrap is used as steel sources. Meanwhile, copper characteristics are of importance both to human beings and to animals and plants. In this paper, integrated copper coating was observed on the surface of copper-containing steels when the steels were heated at around 1150℃. However, the copper was separately scattered in and under the surface rust after heating at 1000℃. The forming mechanisms of copper coating are discussed in detail. By choosing a proper descaling reagent, self-generated oxidation-induced copper coating appeared on the steel surface. The method proposed in this work is environmentally friendly for nontoxic chemicals being used. In addition, this provides a new concept for producing protective composite by oxidizing from the substrate directly and there is no bonding problem

    Distrontium lithium beryllium triborate, Sr2LiBeB3O8

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    Single crystals of distrontium lithium beryllium triborate, Sr2LiBeB3O8, were obtained by spontaneous nucleation from a high-temperature melt. In the Sr2Li[BeB3O8] structure, [BeB2O7]6− rings, made up from one BeO4 tetra­hedron and two BO3 triangles, are connected to each other by [BO3] triangles to form the smallest repeat unit {[BeB3O8]8−} and then form chains along the b axis. The Sr2+ cations are seven- or eight-­coordinated and Li+ cations are tetra-­coordinated and lie between the chains
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