8,857 research outputs found

    Analyzing and Revisioning the Service Reduction Plan of Pierce Transit in Respect of Transit Equity

    Get PDF
    https://digitalcommons.tacoma.uw.edu/gis_projects/1048/thumbnail.jp

    Enhancement Of Volatile Fatty Acid Production From Anaerobic Treatment Of Palm Oil Mill Effluent

    Get PDF
    Biological treatment unit is widely used to treat high organic content wastewater such as palm oil mill effluent (POME). A treatment that can salvage the useful nutrient from the wastewater is needed to enhance the sustainability of the wastewater treatment process. Volatile fatty acid (VFA) has high potential to be applied on many application such as production of biogas or biodegradable plastic. The recovery of nutrient in the form of methane gas (end-product of anaerobic digestion) was well researched but the study on the enhancement of volatile fatty acid (VFA) (intermediate-product of anaerobic digestion) was still limited. VFA production is preferred over biogas production because VFA can be used to produce more valuable product such as polyhydroxyalkanoate (PHA) (a type of biodegradable plastic). The enhancement of VFA production was achieved through the elimination of methanogenesis process. In this study, a sequencing batch reactor was used to enrich the biomass in partial anaerobic treatment of POME to enhance the VFA production. The SBR has a working volume of 8 L and hydraulic retention time of 5 days. The influent concentration of POME contains about 33400 mgCOD/L. The anaerobic reactor managed to increase the VFA accumulation to about 10500 mg/L total VFA (about 43.8 % of VFA accumulation in the feed). The microbial population analysis had revealed that the growth of methanogen was suppressed and no methane gas was release during the treatment process. Further, it was discovered that the increase of ammoniacal nitrogen has increased the total VFA production. About 105.7 % VFA accumulation was achieved at COD:N ratio of about 40:5. However, inhibition on the VFA production occurred at ammoniacal nitrogen content of more than 4000 mg/L shock loading. Furthermore, the effluent from the VFA enhancement reactor was used as the feed to produce PHA. The aerobic reactor accumulating PHA using VFA enriched POME (AE1) has achieved output PHA concentration of about 3773 mgPHA/L (specific production of about 0.32 mgPHA/mgVSS). The results shows that the recovery of the VFA has high potential to produce biodegradable plastic (PHA). Additionally, the microbial growth kinetics was evaluated for the microorganism in VFA enhancement reactor and PHA production reactor. The result of the growth kinetics studies was used to simulate the VFA accumulation and the PHA production by using MATLAB software

    A theoretic model for sonogenetic antiarrhythmia

    Full text link
    Sonogenetics can be used as a new alternative for treating arrhythmia due to its advantages of noninvasive, high safety and strong penetration. In the treatment of arrhythmias by sonogenetics, cardiac myocytes are deformed by ultrasonic radiation force. We quantitatively calculated the shape variation of cardiomyocytes under ultrasonic radiation force, and the deformation of cardiomyocytes caused the change of membrane tension. Membrane tension consists of two parts, plasma membrane tension and cortical tension between the cell membrane and cytoskeleton. Since plasma membrane tension was mainly considered in existing experiments, we proposed a quantitative model of the relationship between ultrasonic radiation force and plasma membrane tension. The Boltzmann relationship between plasma membrane tension and ion channel opening probability is presented based on the experimental results of ion channel activation by stretching. Finally, a quantitative model was obtained for ultrasonic radiation force to regulate the opening probability of ion channel activated by stretching. Based on this quantitative model, we proposed the regulation mechanism of ultrasonic radiation force under hypercompression and hyperstretching, and verified that this mechanism can eliminate arrhythmias by sonogenetics.Comment: 13pages,5 figure

    Bis(μ-5-carb­oxy­benzene-1,3-dicarboxyl­ato)-κ3 O 1,O 1′:O 3;κ3 O 3:O 1,O 1′-bis­[(2-phenyl-1,3,7,8-tetra­aza­cyclo­penta­[l]phenanthrene-κ2 N 7,N 8)lead(II)]

    Get PDF
    In the title compound, [Pb2(C9H4O6)2(C19H12N4)2], the PbII atom is five-coordinated by two N atoms from a chelating 2-phenyl-1H-1,3,7,8-tetra­aza­cyclo­penta­[l]phenanthrene (L) ligand and three O atoms from two Hbtc ligands (H3btc is benzene-1,3,5-tricarb­oxy­lic acid), resulting in a distorted PbN2O3 coordination. Two PbII atoms are bridged by the Hbtc ligands, forming a discrete centrosymmetric dinuclear complex. Inter­molecular N—H⋯O and O—H⋯O hydrogen bonds and π–π inter­actions between the pyridine and imidazole rings, and between the pyridyl rings of the L ligands [centroid–centroid distances = 3.600 (6) and 3.732 (6) Å] lead to a three-dimensional supra­molecular structure
    corecore