FBR System Research Articles

Lack of Change Information and End User Grumbling: Mediating Role of Fear of Unknown and Moderating Role of Emotional Regulation

User resistance is a complex phenomenon and is considered a major constraint towards the successful implementation and usage of information technology. Hence, in order to investigate the factors that may lead to user resistance; the current study proposes and investigates the mediating role of fear of unknown between lack of change information and end-user grumbling, and the moderating role of emotional regulation between the relationship. Emotional self-regulation theory has been used as an overarching theory that explains the research model proposed and tested in the study. Using a Quantitative approach, the survey was conducted and data was collected from 334 users of FBR systems. With the help of SPSS and MACRO PROCESS, statistical tests were conducted and links were tested. Results revealed that all hypotheses were accepted. Along with these discussions, research implications and recommendations are also provided.

The Performance of a Fixed-Bed Anaerobic Bioreactor Using Sulfate-Reducing Bacterial Consortium from Sikidang Crater Sediments

This research explored the performance of a fixed-bed anaerobic bioreactor system (FBR) using sulfate-reducing bacteria (SRB) from the sediment of Sikidang Crater in Indonesia. Indonesian natural zeolite was used as an inert medium in this bioreactor system. This bioreactor performance was analyzed based on its sulfate reduction efficiency, Cu removal, pH profile, SRB growth, and the changes in mineral composition of the zeolite surface. Based on a batch experiment, the FBR system was operated at 30 °C with a hydraulic retention time (HRT) of 7 days using a zeolite dose of 100 g/L. After its operation, a large amount of SRB (up to 1.5 × 105 cells/mm2) was entrapped and present in the zeolite. This bacterial consortium could reduce sulfate and copper by around 68% and 99.96%, respectively. In addition, the pH value of the bioreactor changed to neutral, which indicated a good performance of the operation. The result of the Energy-Dispersive X-ray (EDX) confirmed that copper removal was caused by the formation of copper-sulfide precipitation. Mapping also revealed that both copper and sulfur were precipitated at the same location.

Effect of Zn doping on the antiferromagnetism in kagomeCu4−xZnx(OH)6FBr

Barlowite Cu$_4$(OH)$_6$FBr shows three-dimensional (3D) long-range antiferromagnetism, which is fully suppressed in Cu$_3$Zn(OH)$_6$FBr with a kagome quantum spin liquid ground state. Here we report systematic studies on the evolution of magnetism in the Cu$_{4-x}$Zn$_x$(OH)$_{6}$FBr system as a function of $x$ to bridge the two limits of Cu$_4$(OH)$_6$FBr ($x$=0) and Cu$_3$Zn(OH)$_6$FBr ($x$=1). Neutron-diffraction measurements reveal a hexagonal-to-orthorhombic structural change with decreasing temperature in the $x$ = 0 sample. While confirming the 3D antiferromagnetic nature of low-temperature magnetism, the magnetic moments on some Cu$^{2+}$ sites on the kagome planes are found to be vanishingly small, suggesting strong frustration already exists in barlowite. Substitution of interlayer Cu$^{2+}$ with Zn$^{2+}$ with gradually increasing $x$ completely suppresses the bulk magnetic order at around $x$ = 0.4, but leaves a local secondary magnetic order up to $x\sim 0.8$ with a slight decrease in its transition temperature. The high-temperature magnetic susceptibility and specific heat measurements further suggest that the intrinsic magnetic properties of kagome spin liquid planes may already appear from $x>0.3$ samples. Our results reveal that the Cu$_{4-x}$Zn$_x$(OH)$_6$FBr may be the long-thought experimental playground for the systematic investigations of the quantum phase transition from a long-range antiferromagnet to a topologically ordered quantum spin liquid.

EFFECT OF HARVESTING MICROALGAE (Chlorella sp.) CONTINUOUSLY TO ITS GROWTH IN THE FOTOBIOREAKTOR

Currently, the photobioreactor (FBR) has been developed and utilized to investigate (knowing in detail) the metabolic processes of cells of microorganisms, such as microalgae. FBR technology MTAP (Multi Tubular Photobioreactor Airlift) is a continuous system that is closed and controled for the growth. Then, this technology conducted continuous harvesting trial. Continuous harvesting system is cultivated by reducing of microalgae solution volume then is added by new solution of FBR MTAP system in operation. The number of reactors in the FBR MTAP are two reactors were used that Reactor 1 and Reactor 2. Microalgae was grown in 21 DAP (Days After Planting) and then harvested by reducing the volume 16.7% in each reactor in DAP 12. Based on the results of cells density, harvesting in the first phase, the optimum growth occurred at DAP 7 for Reactor 1 and Reactor 2, while harvesting their optimum growth phase II DAP 16 for Reactor 1 and DAP 19 for Reactor 2. Comparison of cell density on both reactors FBR MTAP conducted trial period of harvesting microalgae Chlorella sp. freshwater DAP 12 and DAP 21 are optimal to be done continuously without dewatering and sterilization performed the FBR system MTAP.Key words: photobioreactor, continuous harvesting, microalgae growth, cell density, Chlorella sp.

Design and Analysis of Bellows for High Temperature Application as Per RCC-MR

Bellows are specially engineered components. Bellows find wide range of applications in FBR systems such as in bellow-sealed valves and in piping systems for flexibility. Typical operating temperatures in FBR systems are around 550 °C, where failure modes such as creep and creep-fatigue interaction are significant. Conventional design codes for design of bellows such as standards of EJMA do not extensively address the high temperature failure modes. In this present work, methodology adapted for design of bellows for high temperature application, operating at 550 °C has been presented. The preliminary design of the bellows for temperatures below the creep range was completed by standards of EJMA, so that the failure modes such as fatigue, in-plane and column instability of bellows can be addressed. Subsequently, the preliminary design was analyzed using FEA as per the guidelines given by RCC-MR to address the failure modes such as creep and creep-fatigue interaction. Elevated temperature testing of the bellows showed close agreement between the design of the bellows by the above mentioned method and the experimental results.

ICONE19-43187 Development of real time sensor for under sodium viewer

For the commercialization of the sodium cooled FBR system, it is desirable to develop a plant concept that has economic competitiveness compatible with the LWR system and excels in safety. Since it is difficult to perform inspection and maintenance of the core internals at FBR, such as the reactor vessel inner wall and the core support structure, measures have been taken to ensure safety and reliability by allowing a sufficiently large margin in the design reducing the burden of inspection and maintenance. To date due to problems such as the effect of radiation penetrating from the reactor core, the opacity and high chemical activity of sodium, and the fact that the inspection of reactor vessel of the FBR is performed at a high temperature, approximately 200 degree C, to avoid freezing of sodium, no method of inspecting structures inside the reactor vessel has been developed. In this study, aims to experimentally produce a real-time sensor which is used for the underwater and under-sodium test to demonstrate their applicability to the FBR system. The real-time sensor would be a piezoelectric element type sensor with a resolution of approximately 2.0mm, a resolution of sufficient quality to allow for the identification of deformation, the failure or dropping of components, and an image processing time per one image of approximately 0.5 second. Concerning the backing material, aluminum titanate (alumatite), wollastonite and hexagonal boron nitride were selected for the first screening. Based on the test result, alumatite that has an excellent damping property was finally selected for the trial production of the sensor element. We have designed and made 256 channel matrix-arrayed sensor and high speed processing system. It was shown that the real-time sensor was achieved about 2.0mm resolution and about 0.5 seconds/frame signal processing time, and succeeded taking the first under-sodium movie of the world.

Pyrochemical reprocessing developments in Japan: overview and some topics

The latest developments in pyrochemical reprocessing technology in Japan is introduced in view of: the feasibility study FBR system; RD new projects and funding; basic studies in universities; new experimental facilities. Japanese pyrochemical reprocessing developments are being accelerated as new funding recently has been authorised by the government. While electrorefining of metallic fuels has made significant technological progress, attention has been focused on MOX fuels. Universities have participated in these developments by contributing to the basic studies for molten salt systems. Some critical technical subjects have been clarified, and they are being investigated aggressively by various organisations.

Consideration on safety research strategy toward commercialization of FBRs

The situation of FBR enters upon development stage expecting to commercialize upto 2030's and has not yet established the concept of commercialized FBR plant. The primary subject is remarkable improvement of economy which can be accomplished through higher performance of plant systems, reduction of the amount of materials of the plant due to simplification of the plant systems and maximization of plant availability. This subject can be solved by development of foresighted plant design through full utilization of the inherent safety characteristics of FBR's. The secondary subject is acquirement of public confidence of FBR safety. If recriticality accident can be eliminated from the safety analysis for licensing of future FBRs with firm experimental evidences, then safety logic for the FBRs will more simple and thus friendly to the public. Then the public will be quite confident of safety securement of the FBR system and will be free from any anxiety. Discrepancy of the confidence level of FBR safety between the experts and the public will be significantly improved by showing experimental evidence of elimination of recriticality accidents. In addition, an optimized plant design for further reduction of the plant construction cost can be accomplished by elimination of recriticality accidents in an FBR plant design. In order to realize the above experiments and clarify these phenomena with a subassembly scale, development of new in-pile experimental facility using real materials in an FBR core is essential. Considering requirements of prototypicality or objectives for demonstration, it is concluded that the new in-pile experimental facility should be built early in the next century. The tertiary subject is reinforcement of FBR safety and reliability technologies in a more broad sense developed by the industry's voluntary safe-ensuring activities. These requirements have been realized through lessons learned from the sodium leak incident in the secondary heat transport system of Monju occurred on December 8th, 1995. For acquirement of social confidence on FBR safety by the public, significant amount of sodium leakage should be precluded, even if spilled sodium is non-radioactive and thus gives no radiological consequence to the public. Countermeasures for prevention and mitigation against such sodium leakage should be reinforced not as regulation-based activities but as the voluntary safe-ensuring activities by the utilities/development organizations. It thus appears that development of rules, standards and guidelines made by the industries in addition to reinforcement of wide range of sodium-related fundamental technology are essential for the future commercialization of FBRs. In order to solve the above-mentioned subjects, it is essential to optimize and clarify the roles between the government and industries, to execute safety researches based on the well-organized long-term plan and to make the most use of international cooperation.

Accumulation of Metabolic Intermediates during Shock Loads in Biological Fluidized Bed Reactors

Groundwater containing benzene, toluene, and p-xylene (BTX) was treated in fluidized bed reactors using nonactivated carbon (FBR) and activated carbon (BAC-FBR) as the biofilm carriers. BTX removal and accumulation of metabolic intermediates were studied at steady state and during single-substrate step-loading increases. At steady state (organic loading rate of 2.2 kg-COD/m3-d), no intermediates were detected in the effluents. However, intermediates were found in the effluents of both systems during a sevenfold p-xylene step increase under different supply levels of dissolved oxygen (DO) and nutrients. Intermediate concentrations increased with increasing dissolved oxygen in the influent but were not affected by the level of nutrients. The accumulation of intermediates was also evaluated quantitatively by subjecting both reactor systems to 20-, 12-, and 7-fold step increases in the organic loading rates of benzene, toluene, and p-xylene, respectively. In all of the step increase experiments, the effluent intermediate concentrations were less for the BAC-FBR than for the FBR system. We conclude that the combination of biological and adsorptive removal mechanisms in the BAC-FBR resulted in enhanced removal of both BTX and metabolic intermediates under shock-load conditions.

Role of adsorption in granular activated carbon‐fluidized bed reactors

A granular activated carbon‐fluidized bed reactor (GAC‐FBR) was used to treat groundwater contaminated with toluene. The performance of the reactor and the amount of adsorbed toluene on the GAC were investigated during start‐up, under pseudo‐steady‐state conditions, during a step‐increase in the applied organic loading rate (OLR) and after the OLR was returned to the initial level. Under constant, organic loading rate conditions (5.4 kg chemical oxygen demand/m3 day), 99.4% removal of an inlet toluene concentration of 2.7 mg/L was observed. The amount of adsorbed toluene was measured at various points in time by performing a solvent extraction on samples of GAC carrier removed from the FBR system. There were significant changes in the amount of toluene adsorbed onto the GAC during non‐steady state (start‐up and step OLR periods). This confirms the interpretation from previous biological activated carbon (BAC) studies that adsorption serves to dampen concentration changes in the system, thereby providing improved stability effluent quality and overall system efficiency compared with systems employing only biodegradation. The results also conclusively demonstrate that bioregeneration occurs in BAC systems such as the GAC‐FBR process configuration.

Presentation of the properties of the ferritic alloy 2.25 Cr-1 MoNiNb for steam generator application in FBR systems

2.25 Cr-1 MoNiNb steel, used for the construction of the steam generator of a fast breeder reactor, is subjected to operation at elevated temperature in the creep range. Although this operation condition is a limiting factor for allowable loads during normal operation, it is necessary to have sufficient knowledge of the strength-properties of this kind of steel after thermal aging. Experiences with this steel are described. It is shown that this stabilized ferritic steel reveals the common behaviour of all ferritic steels at elevated temperature. The change of mechanical properties can easily be quantified. Special attention was given to the analysis of strain-controlled tensile testing and the uniform elongation of s.g.-tubing.