Strip System Research Articles

A study on the uncertainty of setpoint for reactor trip system of NPPs considering rectangular distributions

The setpoint of the reactor trip system shall be set to consider the measurement uncertainty of the instrument channel and provide a reasonable and sufficient margin between the analytical limit and the trip setpoint.A comparative analysis was conducted to find out an appropriate uncertainty combination method through an example problem. The four methods were evaluated; 1) ISA-67.04.01 method, 2) the GUM95 method, 3) the modified GUM method developed by Fotowicz, and 4) the modified IEC61888 method proposed by authors for the pressure instrument channel presented in ISA-RP67.04.02 example. The appropriateness of each method was validated by comparing it with the result of Monte Carlo simulation.As a result of the evaluation, all methods are appropriate when all measurement uncertainty elements are normally distributed as expected. But ISA-67.04 method and GUM95 method overestimated the channel uncertainty if there is a dominant input element with rectangular distribution among the uncertainty input elements.Modified GUM95 methods developed by Fotowicz and modified IEC61888 method by authors are able to produce almost the same level of channel uncertainty as the Monte Carlo method, even when there is a dominant rectangular distribution among the uncertainty components, without computer-assisted simulations.

Refinement of methodology for analytical assessment of contact interaction of elements of rolls - strip systems in four-roll stands

Refinement of methodology for analytical assessment of contact interaction of elements of rolls - strip systems in four-roll stands

Shared travel demand forecasting and multi-phase vehicle relocation optimization for electric carsharing systems

ABSTRACT Electric shared mobility is flourishing in urban transportation. However, the problem of uneven vehicle distribution and untimely vehicle charging hampers user trip experience and system operation efficiency. To overcome these challenges, this study proposed a multi-phase vehicle relocation optimization approach for one-way station-based carsharing systems. In phase one, a micro-level shared travel demand forecasting model was developed to capture the number of orders in the short-term future. In phase two, stations were divided into different categories based on the results of user travel demand forecast. In phase three, the minimization of driving mileage and carbon emissions was taken as the optimization objective, and a solution method combining Gurobi solver and charging priority ranking was designed. Finally, the effectiveness and advantages of the proposed model and algorithm were comprehensively validated through a case study using real passenger orders and geographic data from the city of Shanghai, China.

Simultaneous stripping and regeneration of chelate structure of vanadium through vanadium reduction and conversion in vanadium-bearing shale extraction

Chelating extractants have shown excellent selectivity in vanadium extraction. Nevertheless, the resulting extraction complex is stable, making the stripping of chelating extractant a challenge. The H2C2O4-H2SO4 system was proposed to stripping vanadium from the loaded organic phase of chelating extractant Mextral 984 H. The effects of process parameters of H2C2O4-H2SO4 system on the vanadium stripping percentage was investigated. The results show that the single-stage vanadium stripping percentage reached 93.12%, and the vanadium concentration in the single-stage stripping solution reached 13.44 g/L under optimum conditions: the H2SO4 concentration of 1.87 mol/L, the H2C2O4 concentration of 0.16 mol/L, the temperature of 80 °C, the time of 30 min, and phase ratio(O/A) of 4:1. In addition, the high extraction efficiency (>85%) was maintained after 10 cycles, indicating that the developed system can be used in the Mextral 984 H stripping system. The mechanism of stripping was also analysed using FT-IR and 1H NMR combined with thermodynamic and quantum calculations. It was summarized that after H2C2O4 reduces V(V) to V(IV), H+ can replace V(IV), the free V(IV) in organic phase is more prone to coordinated with C2O42- and SO42- and then goes into aqueous phase. Thus the stripping and regeneration of the loaded organic phase of Mextral 984 H can be occurred simultaneously. Meanwhile, the introduction of H+ can speed up the stripping process. The innovative method of the reduction stripping of vanadium is proposed in the black shale extraction field.

Study and Extraction of Ammoniacal Nitrogen from Wastewater

Abstract: In order to avoid environmental pollution, ammoniacal nitrogen must be removed from wastewater. This study contrasts the vacuum stripping system and di- electrophoresis as two ways for removing ammoniacal nitrogen from artificial effluent. The wastewater evaporating and ammoniacal nitrogen is separated from water using the vacuum stripping process. The di- electrophoresis system uses an electric field to separate charged compounds from the wastewater, including ammoniacal nitrogen. According to experimental results, both procedures are effective at removing ammoniacal nitrogen from wastewater, still the vacuum stripping approach has a better effectiveness than the di- electrophoresis procedure. the di- electrophoresis has the benefit of being a nonstop process with a less processing time. The vacuum stripping is more economically feasible for smallscale operations, whereas the di- electrophoresis process is more applicable for large- scale artificial operations, according to an profitable feasibility analysis that considered capital and functional costs. In conclusion, the choice of fashion for removing ammoniacal nitrogen from wastewater will depend on variables such the necessary effectiveness, recycling duration, and fiscal viability. The information from this study can be used to choose the proper method for removing ammoniacal nitrogen from wastewater.

A Comparison of Multiple Macroalgae Cultivation Systems and End-Use Strategies of Saccharina latissima and Gracilaria tikvahiae Based on Techno-Economic Analysis and Life Cycle Assessment

Macroalgae can be processed into various products with the potential to substitute land-based crops; their cultivation can bioextract nutrients from coastal waters. This study investigated the economic cost and environmental impacts of multiple seaweed cultivation platforms, cultivation strategies, and processing/end-use strategies through techno-economic analysis (TEA) and life cycle assessment (LCA) with a focus on Saccharina latissima and Gracilaria tikvahiae. Cultivation platforms included single-layer longline, dual-layer longline, single-layer strip, and dual-layer strip systems. Processing/end-use products included seaweed to biofuel, dried sea vegetables, marketable commercial fertilizer, and animal feed. Economic and environmental costs decreased with dual-layer and strip cultivation systems. Cultivation costs were highest using the common single-layer longline system ($4.44 kg−1 dry weight (dw) S. latissima and $6.73 kg−1 dw G. tikvahiae when cultivated on rotation). The use of the dual-layer strip system reduced cultivation costs to $2.19 kg−1 dw for S. latissima and $3.43 kg−1 dw for G. tikvahiae. Seaweed drying was the major contributor to economic and environmental costs for macroalgae processing. Yet, all scenarios achieved environmental benefits for marine eutrophication. The best environmental performance was observed when biomass was processed to dry sea vegetables, assuming the offset of land-based vegetable production, or used as biofeedstock for anaerobic digestion for combined heat and power.

Species composition and features of weed control on irrigated lands in the system of forest strips

Under irrigation conditions, weeds reduce agricultural production. On irrigated lands in the conditions of the Volga region in the system of forest strips, weeds grow faster. The measures applied in the fight against weeds, depending on the species composition, are primarily an obstacle to their penetration into the fields and measures that are used in the fight against weeds in the irrigated field. In agricultural production, when irrigation is carried out in the system of forest strips, weed control must be carried out taking into account the species composition of weeds that determine the type of contamination and the economic threshold of harmfulness. Agrotechnical weed control measures have the maximum effect in the weed control system, primarily in combination with chemical protection of crops from weeds.

Rapid Screening Detection of Genetically Modified Papaya by Loop-Mediated Isothermal Amplification.

A loop-mediated isothermal amplification (LAMP)-mediated screening detection method for genetically modified (GM) papaya was developed targeting the 35S promoter (P35S) of the cauliflower mosaic virus. LAMP products were detected using a Genie II real-time fluorometer. The limit of detection (LOD) was evaluated and found to be ≤0.05% for papaya seeds. We also designed a primer set for the detection of the papaya endogenous reference sequence, chymopapain, and the species-specificity was confirmed. To improve cost-effectiveness, single-stranded tag hybridization (STH) on a chromatography printed-array strip (C-PAS) system, which is a lateral flow DNA chromatography technology, was applied. LAMP amplification was clearly detected by the system at the LOD level, and a duplex detection of P35S and chymopapain was successfully applied. This simple and quick method for the screening of GM papaya will be useful for the prevention of environmental contamination of unauthorized GM crops.

The Regularization Technique in Modeling of the Plane E-Polarized EM Wave Scattering by Coplanar System of Electrically Conducting Flat Strips

The integral equations technique has been successfully modified for studying the plane E-polarized electromagnetic wave scattering by multilevel coplanar systems of zero-thickness impedance strips. Reformulation of the scattering problem in the form of the second-kind regular integral equations has been realized on the base of the Carleman regularization technique. Two novel and original classes of specific Cantor functions have been presented and analyzed. Using new Cantor functions, it is easy to create a lot of non-classical orderings for specific multilevel coplanar strips systems. That sort of system can be useful for modeling irregular natural processes and zones in the future. Considerable attention was focused on the plane E-polarized electromagnetic wave scattering by sparsely filled coplanar systems of electrically narrow impedance strips. An explicit solution of the scattering problem has been obtained for such case of strips system.

Investigation of control performance on an absorption/stripping system to remove CO2 achieving clean energy systems

Control study is crucial to ensure smooth operation of any unit operation for clean energy system. There has been growing attention on the utilization of advanced model-based controllers in control studies for CO2 capture. However, such advanced controllers are expensive hence proper performance justifications are needed prior to investment. In the current study, both Proportional-Integral (PI) and Model Predictive Control (MPC) control strategies are investigated and implemented on a pilot scale natural gas CO2 absorption/ stripping system running at higher pressure as well as higher CO2 content, utilizing MATLAB/SIMULINK-Aspen Plus Dynamics interface. The novelty of the work is mainly on the investigation study between the efficiency of the standard PI and MPC controllers for a high pressure and high CO2 content pilot-scale CO2 absorption system. For such high pressure and high CO2 content system, it is imperative to evaluate whether special focus on the control strategy is needed or not. This work simulates and investigates the dynamic behavior and performances of PI and MPC controllers of a high-pressure absorption/stripping system. In addition, a second order model of the system has been developed, which is useful for future studies. Controller performance of the Proportional-Integral (PI) and Model Predictive Controller (MPC) are compared using the features of the responses as well as the residual error index i.e., Integral Absolute Error (IAE). The performance of the PID and MPC controllers based on set point tracking of both the controlled variables for 5% and 15% step changes have been evaluated. Compared to the PI controller, the MPC controller has no peak overshoots, i.e., it shows 10% and 2.86% lower error in the IAE index, and it is capable of handling interactions between the variables of the absorption/stripping system.

History and Evolution of Capillary Glucose Monitoring

Abstract Monitoring of blood glucose levels is an inevitable part of diabetes management. The last decade was marked by path-breaking and transformational changes in diabetes technologies that ushered in the introduction of a wide spectrum of glucose monitoring devices that are more reliable and user-friendly. This review describes the evolution of capillary glucose monitoring from simple urine sugar screening tests to reagent strip systems and to sophisticated glucose monitors over the past four decades since the introduction of the first glucose meter in 1970.

Evidence for Hidden Nearby Companions to Hot Jupiters

The first discovered extrasolar worlds—giant, “hot Jupiter” planets on short-period orbits—came as a surprise to solar system–centric models of planet formation, prompting the development of new theories for planetary system evolution. The near absence of observed nearby planetary companions to hot Jupiters has been widely quoted as evidence in support of high-eccentricity tidal migration, a framework in which hot Jupiters form further out in their natal protoplanetary disks before being thrown inward with extremely high eccentricities, stripping systems of any close-in planetary companions. In this work, we present new results from a search for transit timing variations across the full 4 yr Kepler data set, demonstrating that at least 12% ± 6% of hot Jupiters have a nearby planetary companion. This subset of hot Jupiters is expected to have a quiescent dynamical history such that the systems could retain their nearby companions. We also demonstrate a ubiquity of nearby planetary companions to warm Jupiters (≥70% ± 16%), indicating that warm Jupiters typically form quiescently. We conclude by combining our results with existing observational constraints to propose an “eccentric migration” framework for the formation of short-period giant planets through postdisk dynamical sculpting in compact multiplanet systems. Our framework suggests that hot Jupiters constitute the natural end stage for giant planets spanning a wide range of eccentricities, with orbits that reach small enough periapses—either from their final orbital configurations in the disk phase or from eccentricity excitation in the postdisk phase—to trigger efficient tidal circularization.

Effects of IPR by mechanical oscillating strips system on biological structures: a quantitative and qualitative evaluation

BackgroundTo evaluate by means of profilometric analysis and scanning electronic microscope (SEM) the effects on enamel surfaces of oscillating mechanical systems for interproximal enamel reduction (IPR). Fifteen complete (Group 1) oscillating IPR sequence and 15 single metallic strips (Group 2) for active IPR phase of 0.2 mm were selected and tested on 30 freshly extracted teeth by means of tribological tests with alternative dry-sliding motion (Linear Reciprocating Tribometer, C.S.M. Instruments, Peseaux, Switzerland). Enamel surface roughness and waviness measurements were assessed by contact probe surface profiler (TalySurf CLI 2000; Taylor Hobson, Leicester, UK) and a TayMap software for the 3D analysis. Statistical analysis was performed with independent samples t-test. Significance was established at the P < .05 level. SEM analysis of enamel surfaces was conducted with a FEI Quanta 200 (Hillsboro, USA) in high vacuum at 30.00 kV. Images were acquired at 30X, 100X, and 300X of magnification.ResultsTeeth undergone Group 1 showed lower values of surface roughness (Ra − 0.34 µm, Rt − 1.55 µm) and significant increase of waviness parameters (Wa 0.25 µm, Wt 4.02 µm) when compared with those treated with Group 2. SEM evaluation showed smoothers and more regular surfaces when IPR was performed by complete IPR sequence. Single metallic strip determined more irregular surfaces characterized by extended grooves, alternated with enamel ridges and irregular fragments.ConclusionThe adoption of a standardized oscillating IPR sequence determines more regular and harmonious enamel surfaces at the end of the procedure. An adequate polishing after IPR plays a crucial role to guarantee a good long-term prognosis and a good respect of biological structures.

Optimum maintenance strategy for CRTS II slab track based on time-dependent system reliability

CRTS (China Railway Track System) II slab track is a vertical multi-layer and longitudinal anisotropic strip system, which has been widely constructed in China’s high-speed railway. In this study, an innovative optimum maintenance strategy is proposed for CRTS II slab track, based on the concept of time-dependent system reliability and life-cycle cost analysis. System limit state function of the track structure is constructed with consideration of important serviceability failure modes. The time-dependent system reliability of the track structure is investigated and utilized as the indicator of track performance, which is estimated by an innovative outcrossing method based on the system limit state function considering time-dependent correlation among failure modes. At each maintenance time, all critical failure modes and components are identified and repaired to decrease the system failure probability under the acceptable level. Application of the proposed maintenance strategy is demonstrated by a worked example of a track structural system on bridge. It is found that: (1) appropriate maintenance strategy is important to ensure service reliability of the track system and extend the service life; and (2) the proposed maintenance strategy can be utilized to predict when, where, and what failure mode for maintenance and it can help to minimize the expected life-cycle cost without compromising the service reliability of the track structure.

Moving towards the Application of Biocatalysis in Food Waste Biorefinery

Waste valorization is an important strategy to reduce environmental pollution and dependency on petroleum-based fuels. In this regard, utilization of food waste as a versatile and low-cost resource is important. Several advanced catalytic methods for the valorization of food waste have been widely investigated for the production of liquid biofuels. Along this line, chemical catalysts have been explored for the synthesis of liquid biofuels. Chemo-catalysis is mainly metal based, which requires harsh process conditions. Alternatively, biocatalysts are currently being investigated as a result of several advantages such as mild reaction conditions, recyclability, selectivity and biodegradability. In this work, recent biocatalytic technologies for the preparation of liquid biofuels through food waste valorization are discussed thoroughly. Lipases are employed for the synthesis of biodiesel and the upgradation of bio-oil, whereas methane mono-oxygenases could be explored for the production of methanol via the oxidation of methane generated from food wastes. Industrial production of ethanol from food waste using bioconversion technologies is a success story. To date, there has been no specific report on the use of food waste for propanol preparation using enzymes. The ABE process (Acetone–Butanol–Ethanol) (using suitable microorganisms) is used for butanol preparation, where the vacuum stripping system is integrated to remove butanol from the broth and circumvent inhibition. The synthesis of hydrocarbon fuels from fatty acids and triglycerides can be carried out using enzymes, such as carboxylic acid reductase and fatty acid photodecarboxylase (an algal photoenzyme). Both carboxylic acid reductase and fatty acid photodecarboxylase have not yet been applied in the direct valorization of food wastes. Furthermore, limitations of the reported methods, societal and economic aspects and a fresh perspective on the subject, along with important examples, are described.

Design of novel fractional order FPGA based reactor protection and safety controllers for ACP1000 nuclear power plant in LabVIEW

In this research work, an advanced most modern ACP1000 Nuclear Power Plant is addressed. An enhanced fractional order model of ACP1000 nuclear power plant is adopted with an addition of protection and safety systems. The whole plant model is developed by using innovative hybrid technology of Visual Basic, LabVIEW, Fractional Order and Field Programmable Gate Array (FPGA). A reactor trip system is designed and modeled using FPGA technology in LabVIEW. Plant parameters are systematically modeled and panels are designed in LabVIEW for reactor protection controllers. Twenty one reactor trip controllers are designed and modeled based on complex digital logics using FPGA programming in LabVIEW. Two fractional order trip controllers are designed for over temperature protection and over power protection in LabVIEW. FPGA based safety controllers are designed for Engineered Safety Features (ESF) in LabVIEW. For enhanced model of ACP1000 nuclear power plant, 374 systems are modeled in modular form in Visual Basic Environment. Nine process controllers are configured in ANFIS framework in LabVIEW. In this research work, process controllers are used in conjunction with protection and safety controllers using FPGA. The parametric display of simulations is carried out in Visual Basic. The closed loop performance of proposed protection controllers is evaluated under reactor trip and turbine trip while that of safety controllers are evaluated under inadvertent opening of safety valves of pressurizer. Various parameters are simulated for severe transient conditions and the results are evaluated and validated against reference design data and Final Safety Analysis Report (FSAR) of ACP1000 nuclear power plant. All the results are well within the trip and safety systems design bounds under abnormal and severe operating conditions.

КОМП’ЮТЕРНЕ МОДЕЛЮВАННЯ РОЗСІЮВАННЯ Е-ПОЛЯРИЗОВАНИХ ХВИЛЬ НА ЕКРАНОВАНІЙ ПРЕДКАНТОРОВІЙ СИСТЕМІ РЕФЛЕКТОРІВ

Computer simulation of electromagnetic wave scattering on a shielded periodic reflector system, with a special period structure is considered. The electrodynamic reflective structure consists of a screen and a periodic system of strips. The cross-section of the strips is a system of segments formed by the principle of constructing a generalized Cantor set at each of the periods. Іt was used a mathematical model based on the reduction of the initial boundary value problems for the Helmholtz equation to systems of singular integral equations. The choice of this approach did not require analytical calculations when changing the number of lattice elements. Using this approach, it was not necessary to make changes to the computer implementation of the algorithm. The computer experiment has proved the possibility of applying the discrete singularities method computational scheme for the considered structure. It is proved that the structure constructed according to the proposed principle has the properties of broadband and multimode for the studied values of the structure parameters. In particular, for the studied structures, the resonance occurred when the wavenumber was changed from 0 to 50, with a significant increase in amplitude occurring at harmonics with numbers up to 40. This phenomenon led to a complex structure of the lines of the absolute values of the amplitude of the scattered electric field above the grating. The presence of small areas with an increase in the amplitude of the scattered field by a factor of 5-6 compared to the amplitude the incident electromagnetic wave was observed. These properties show practical interest in the use of this type of antennas to improve electronic camouflage and tactical radio communications. In the future, it is planned to conduct computer simulations for imperfectly conducting structures and compare the results with the numerical results for the ideal case discussed in this paper.

A rapid and high-throughput system for the detection of transgenic products based on LAMP-CRISPR-Cas12a

With the increasing acreage of genetically modified crops worldwide, rapid and efficient detection technologies have become very important for the regulation and screening of GM organisms. We constructed a method based on loop-mediated isothermal amplification (LAMP), CRISPR-Cas12a and lateral flow assay (LAMP-CRISPR-Cas12a-LFA). It is an intuitive, sensitive and specific fluorescence detection and test strip system to detect CP4-EPSPS and Cry1Ab/Ac genes in field screening. The LAMP-CRISPR-Cas12a-LFA method has a limit of detection (LOD) of 100 copies based on lateral flow test strips after optimization of the conditions with screened specific primers, and the entire detection process can be completed within 1 h at 61 °C. The system was used to evaluate field test samples and showed high reproducibility after testing products containing CP4-EPSPS and Cry1Ab/Ac genes, and both were detectable. The LAMP-CRISPR-Cas12a-LFA method established in this paper functions as a rapid field detection method. It requires only one portable thermostatic instrument, which renders it compatible with the rapid detection of field samples and useable at experimental workstations, in law enforcement field work, and in local inspection and quarantine departments.

Strip cropping in organically managed vegetable systems: agronomic and environmental effects

Abstract This study evaluated the agro-environmental and economic effectiveness of strips introduced in a diversified organic vegetable system. Two experiments of three experimental years (2018, 2019, 2020) were carried out within the 4-year rotation of MOnsampolo VEgetable organic Long-Term Experiment (MOVE LTE) in Central Italy to test strip cropping vs pure stand. The crop combinations in the two experiments were faba bean (Vicia faba L.)–tomato (Solanum Lycopersicum L.) and common wheat (Triticum aestivum)–zucchini (Cucurbita pepo L.). We determined the productive and economic performances, disease and weed control, nutritional differences and effectiveness in returning carbon to the soil. The two strip cropping systems allowed a better use of resources, enhancing plant biomass and crop residues, particularly for tomato (+24%) and zucchini (+63%). However, the greater plant biomass did not always result in an increase in crop yields. For example, while the wheat–zucchini strip system showed a land equivalent ratio &gt;1 in all three experimental years with a high yield performance in zucchini (+54% of yield), the faba bean–tomato system was more productive in strips only in 2018. On the contrary, this latter system contributed a carbon return &gt;1 in all three experimental years. No significant differences between strip and pure stand systems were observed for fusarium (Fusarium oxysporum f. sp. lycopersici) and oidium (Oidium spp.) diseases on tomato and zucchini crops, respectively, and for weed control. Lastly, greater labor costs associated in both experiments did not affect their profitability (+21% and +319% in faba bean–tomato and wheat–zucchini experiments, respectively). Overall, our findings pointed out that farmers could increase sustainability of their cropping systems with the introduction of a well-designed strip cropping system, which can lead to the reduction of economic risks, greater potential soil carbon and more efficient use of resources on the same land.

Dissolved Methane Recovery and Trace Contaminant Fate Following Mainstream Anaerobic Treatment of Municipal Wastewater.

Anaerobic treatment of municipal wastewater with the staged anaerobic fluidized bed membrane bioreactor (SAF-MBR) shows promise to transform secondary wastewater treatment into an energy-positive process. However, the dissolved methane in SAF-MBR effluent needs to be recovered to reach net energy positive. To recover this methane for energy generation, an air stripping system was constructed downstream of a pilot-scale SAF-MBR facility and operated for over 80 days. The process removed 98% of effluent dissolved methane, and with the addition of intermittent disinfection recovered an average of 90% of the dissolved methane. The exit gas from air-stripping comprised 1.5-2.5% methane and could be utilized by blending with biogas produced from primary solids digestion and the SAF-MBR in an on-site combustion process. The direct energy costs for air stripping methane are <1% of the energy recoverable from the dissolved methane, not accounting for siloxane or sulfide scrubbing. Only siloxanes were observed at levels impacting combustion in this study, with 1.6 mg Si/m3 present in the blended biogas and air stripping mixture. The fate of a subset of trace organic contaminants was examined across the air stripping unit to check for aerobic degradation by methanotrophs or other opportunistic aerobes. Only 1,4-dioxane and benzotriazole showed statistically significant removal among 17 compounds screened, with 0.53 ± 0.13 and 0.34 ± 0.15 fraction removal, respectively. Our results indicate that air stripping is an energy efficient and robust technology for dissolved methane removal and onsite utilization for heat and electricity generation from anaerobic treatment of municipal wastewater.