440 research outputs found

    A method using granulated coal ash for disposal of the sludge carried by tsunami

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    Large amounts of sludge and debris accumulated on agricultural and residential areas after the Great East\ud Japan Earthquake. Since the sludge carried by the Tsunami has high contents of unstable-form organic matter ???UFOM???\ud (burned at 300??C), this sludge is considered to be the origin of malodorous gas generation that affects human activities.\ud Therefore, disposal of the sludge plays an important role in the reconstruction effort. Previously, it is obvious that\ud granulated coal ash (GCA) comprised of silica (44%), calcium oxide (21%) and aluminum oxide (13%) improves the\ud organic condition of sewage sludge. For example, the generation of malodorous gases, e.g. hydrogen sulfide and\ud ammonia, was greatly reduced after mixing GCA with the sewage sludge. In this study, we aim to propose a method\ud using GCA to disposal the sludge carried by Tsunami. For this purpose, changes in organic conditions and malodorous\ud gas generation of the sludge after mixing GCA are investigated based on laboratory experiments. In the laboratory\ud experiments, the sludge was mixed with GCA, and then was burned at 200??C to 600??C (intervals of 100??C) in 4 hours at\ud each temperature step. Furthermore, other experiments were conducted to measure amounts of gas generated from the\ud sludge in the absence and the presence of GCA. It was found that ignition behaviors of the sludge with and without\ud GCA were different, namely, the ignition loss at 300??C of the sludge mixing with GCA was lower than that of the sludge\ud without mixing GCA. This ensures that organic conditions (e.g. decreases in amounts of UFOM) of the sludge changes\ud after mixing GCA. Moreover, it was also found that malodorous gases did not generate from the sludge mixing with\ud GCA, indicating that GCA affects the digestion process of organic matter. It is expected that our proposed method is\ud also useful for the capitalization of dredged soil and the development of lowland

    Hydrodynamic Fingering Instability Induced by a Precipitation Reaction

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    A method for investigation of sediment retention in sandy tidal flats

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    Recently, coastal environmental engineers have made attempts to understand the role of sediment (particulate organic matter adsorbed on fine soil particles, diameter range 1???100 ??m) in subsurface environment which is considered to be related to the biodiversity of estuaries. Since the retention amount of sediment is one of important factors in considering the biodiversity, understanding sediment retention is vital to good management of the estuarine environment. In this study, laboratory experiments were conducted to propose a model for investigating the sediment retention based on variations of water head in a sand bed. Field observations were also conducted to verify the validity of the proposed model. From laboratory experiments, variations of water head in the sand bed could be represented by our proposed model with a maximum relative error of 3%. As the proposed model takes the porosity and the hydraulic conductivity of the sand bed into account, sediment retention in the sand bed can be evaluated on the basis of variances in the porosity and the hydraulic conductivity when variations of water heads at the boundary and in the sand bed are known. A method was proposed to measure variations of river water head and water head in a tidal flat. Furthermore, sand material of the tidal flat was sampled in order to determine the porosity and the hydraulic conductivity of the tidal flat. Based on the observation results, the variation of water head in the tidal flat could be reproduced by the proposed model when the porosity and the hydraulic conductivity of the tidal flat were applied into the model. In other words, the porosity and the hydraulic conductivity of the tidal flat can be predicted by the proposed model when variations of river water head and water head in the tidal flat are measured, leading to the understanding of sediment retention in the tidal flat from temporal changes in the porosity and the hydraulic conductivity

    Effect of temperature on rheology behaviour of banana peel pectin extracted using hot compressed water

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    Banana peel pectin is extracted from banana peel waste using a hot compressed water extraction (140-160°C, 5 minutes, 1.18 mm particle size). Physicochemical contents of banana peel pectin were found to be in a similar range with commercial pectin, and is comprised of moisture (7.44-8.47%), ash (3.45-4.98%), protein (1.08-1.92%), fat (0.04-3.42), carbohydrate (83-86%), total sugar (1.77-3.41%), energy (353-369 kcal/100g) and specific heat (1.42-1.62 kJ/kg°C). These contents possibly related to their flow deformation of rheological behaviour. Regression analysis displayed good agreements in all models applied, apart from the Casson Model. Flow behaviour indices, n<1 and decreasing of apparent viscosity within increasing of shear rate indicates that banana peel pectin has excellent shear thinning behaviour with a presence of yield stress

    Patterns and flow in frictional fluid dynamics

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    Pattern-forming processes in simple fluids and suspensions have been studied extensively, and the basic displacement structures, similar to viscous fingers and fractals in capillary dominated flows, have been identified. However, the fundamental displacement morphologies in frictional fluids and granular mixtures have not been mapped out. Here we consider Coulomb friction and compressibility in the fluid dynamics, and discover surprising responses including highly intermittent flow and a transition to quasi-continuodynamics. Moreover, by varying the injection rate over several orders of magnitude, we characterize new dynamic modes ranging from stick-slip bubbles at low rate to destabilized viscous fingers at high rate. We classify the fluid dynamics into frictional and viscous regimes, and present a unified description of emerging morphologies in granular mixtures in the form of extended phase diagrams

    Sodium Phenylbutyrate Controls Neuroinflammatory and Antioxidant Activities and Protects Dopaminergic Neurons in Mouse Models of Parkinson’s Disease

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    Neuroinflammation and oxidative stress underlie the pathogenesis of various neurodegenerative disorders. Here we demonstrate that sodium phenylbutyrate (NaPB), an FDA-approved therapy for reducing plasma ammonia and glutamine in urea cycle disorders, can suppress both proinflammatory molecules and reactive oxygen species (ROS) in activated glial cells. Interestingly, NaPB also decreased the level of cholesterol but involved only intermediates, not the end product of cholesterol biosynthesis pathway for these functions. While inhibitors of both geranylgeranyl transferase (GGTI) and farnesyl transferase (FTI) inhibited the activation of NF-κB, inhibitor of GGTI, but not FTI, suppressed the production of ROS. Accordingly, a dominant-negative mutant of p21rac, but not p21ras, attenuated the production of ROS from activated microglia. Inhibition of both p21ras and p21rac activation by NaPB in microglial cells suggests that NaPB exerts anti-inflammatory and antioxidative effects via inhibition of these small G proteins. Consistently, we found activation of both p21ras and p21rac in vivo in the substantia nigra of acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson’s disease. Oral administration of NaPB reduced nigral activation of p21ras and p21rac, protected nigral reduced glutathione, attenuated nigral activation of NF-κB, inhibited nigral expression of proinflammatory molecules, and suppressed nigral activation of glial cells. These findings paralleled dopaminergic neuronal protection, normalized striatal neurotransmitters, and improved motor functions in MPTP-intoxicated mice. Consistently, FTI and GGTI also protected nigrostriata in MPTP-intoxicated mice. Furthermore, NaPB also halted the disease progression in a chronic MPTP mouse model. These results identify novel mode of action of NaPB and suggest that NaPB may be of therapeutic benefit for neurodegenerative disorders
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