982 research outputs found
Characterization of membrane foulants in a pilot-scale tunnel construction wastewater treatment process
No full textA pilot-scale combination of a microfiltration (MF) and a reverse osmosis (RO) membrane system was applied on-site to treat tunnel construction wastewater. The MF membrane system initially removed contaminants (turbidity of less than 0.3 NTU) in the form of particulate materials in the feed water, thereby allowing the combined MF-RO system to efficiently remove more than 99% of known organic and inorganic contaminants and qualify the reclaimed water for reuse. The MF membrane autopsy analysis using X-ray fluorescence (XRF) and inductively coupled plasma-mass spectrometry (ICP-MS) revealed that the dominant foulants were inorganic deposits involving Si, Al and Fe, comprising the main components of cement materials, as well as deposits involving heavy metals such as Mn, Cu and Zn in the form of particles. Thus, thick cake contaminants shown by field emission scanning electron microscope (FE-SEM) images might be induced via suspended solids consisting of cement and clay materials and metalsclose
Optimization of operating variables in a pilot-scale reverse osmosis membrane process for reclamation of tunnel construction wastewater
No full textThe goal of this study was to investigate the individual and combined effects of temperature, salinity, and pressure on permeate flux and salt rejection of the reverse osmosis (RO) process used for reclamation of tunnel construction wastewater. Regardless of changes in temperature, higher operating pressures enhanced both permeate flux and salt rejection, while effects of temperatures on performance varied depending on the operating pressures. Increasing temperatures to less than 35 bar did not improve the permeate flux and salt rejection, while to more than 50 bar led to higher rejection as well as more permeate flux of reclaimed wastewater. Based on analysis of model equations developed, the extent of flux and salt rejection required for reuse of the reclaimed wastewater occurred under different optimal conditions depending on variations in seasons and salinity of wastewater. In particular, it was necessary to add additional pressure exceeding 50 bar or increase the temperature to over 20??C when wastewater of more than 20??? salinity flows into the treatment system. Adjustment of influential variables can provide an implementable approach to improve operation of the RO process as well as optimize a process for practical construction on-site applications. © 2015 Balaban Desalination Publications. All rights reservedclose0
Efficient harvesting of Synechocystis sp. PCC 6803 with filamentous fungal pellets
No full textCyanobacteria play a major role as direct producers of biofuels, such as ethanol and butanol, with the aid of genetic engineering. However, development of a new harvesting-technology is essential to achieve economic viability of biofuel production from cyanobacteria. In this study, we demonstrated the feasibility of harvesting the unicellular cyanobacterium Synechocystis sp. PCC 6803 using pre-made filamentous fungal pellets and investigated key factors affecting efficiency of harvest, including fungal strain, pellet quantity (number of pellets), initial pH, and organic carbon source. Synechocystis sp. PCC 6803 cells attached to Aspergillus oryzae pellets, indicating that this fungal pellet had a desirable harvesting effect, while Rhizopus oryzae pellets had no effect on harvesting. Increasing pellet quantity and adding organic carbon sources, such as glucose and xylose, improved the harvesting efficiency of Aspergillus oryzae pellet; efficiency was not affected by the initial pH.11Nsciescopu
sj-docx-2-apm-10.1177_01466216221084218 – Supplemental material for Evaluation of the Linear Composite Conjecture for Unidimensional IRT Scale for Multidimensional Responses
No full textSupplemental material, sj-docx-2-apm-10.1177_01466216221084218 for Evaluation of the Linear Composite Conjecture for Unidimensional IRT Scale for Multidimensional Responses by Tyler Strachan, Uk Hyun Cho, Terry Ackerman, Shyh-Huei Chen, Jimmy de la Torre and Edward H. Ip in Applied Psychological Measurement</p
sj-doc-1-apm-10.1177_01466216221084218 – Supplemental material for Evaluation of the Linear Composite Conjecture for Unidimensional IRT Scale for Multidimensional Responses
No full textSupplemental material, sj-doc-1-apm-10.1177_01466216221084218 for Evaluation of the Linear Composite Conjecture for Unidimensional IRT Scale for Multidimensional Responses by Tyler Strachan, Uk Hyun Cho, Terry Ackerman, Shyh-Huei Chen, Jimmy de la Torre and Edward H. Ip in Applied Psychological Measurement</p
Yield ratios of the isomeric pair 85 m,gSr formed in natSr(γ,xn) reactions
No full textThe yield ratios of 85m,gSr were measured in the natSr(γ,xn)85m,gSr reactions with the bremsstrahlung end-point
energies of 55-, 60-, and 65-MeV. The experiment was carried out by the activation method in combination with
high resolution HPGe γ-ray spectroscopy. In order to improve the accuracy of the experimental results, appropriate
experimental procedure was used to reduce the influence of the strong annihilation peak (511 keV) to the
514 keV γ-ray peak of 85gSr. The experimental results are compared to theoretical predictions using code TALYS-
1.6. The present results for 55-, and 60-MeV bremsstrahlung end-point energies have been measured for the first
time.11Nsciescopu
Measurement of isomeric yield ratios of Rh-99m,Rh-g;101m,Rh-g;102m,Rh-g in the (nat)pd(gamma, pxn) reactions with the bremsstrahlung end-point energies of 50-70 MeV
No full textThe isomeric yield ratios of Rh-99m,Rh-g, Rh-101m,Rh-gg, and Rh-102m,Rh-g isomeric pairs produced from the (nat)pd(gamma,pxn) reactions were measured with the bremsstrahlung end-point energies of 50-, 55-, 60-, 65-, and 70-MeV at the 100 MeV electron linac of the Pohang Accelerator Laboratory, Korea. The measurements were carried out with the activation method in combination with off-line gamma-ray spectrometry. In order to improve the accuracy of the activity measurements, the separation of the overlapping gamma-rays and the necessary corrections for the counting losses were made. The new experimental results are compared with the theoretical values of the TALYS-1.6 code.111sciescopu
Systems metabolic engineering of Streptomyces venezuelae for improved pikromycin production
No full textResonance parameters of Gd isotopes derived from capture measurements at GELINA
No full textNeutron capture yields for Gd-155, Gd-156, Gd-157, Gd-158, and Gd-160 were determined applying the total energy detection principle technique using four C6D6 liquid scintillators and a 10B-loaded ionization chamber. Time-of-flight experiments were carried out at a 30 m flight path station of the GELINA facility using enriched samples. Parameters for resonances in the energy region between 5 and 500 eV were obtained from a resonance shape analysis with REFIT. Resonance integrals for Gd-155 and Gd-157 derived from the parameters are 1511 (25) b and 801 (19) b, respectively. Average level spacings, average radiation widths and neutron strength functions were derived. The results were compared with data that are reported in the literature and recommended in evaluated data libraries.11Nsciescopu
State feedback control of real-time discrete event systems with infinite states
No full textIn this paper, we study a state feedback supervisory control of timed discrete event systems (TDESs) with infinite number of states modelled as timed automata. To this end, we represent a timed automaton with infinite number of untimed states (called locations) by a finite set of conditional assignment statements. Predicates and predicate transformers are employed to finitely represent the behaviour and specification of a TDES with infinite number of locations. In addition, the notion of clock regions in timed automata is used to identify the reachable states of a TDES with an infinite time space. For a real-time specification described as a predicate, we present the controllability condition for the existence of a state feedback supervisor that restricts the behaviour of the controlled TDES within the specification
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