Miracle-dz/UniFAR-FTUs huggingface dataset:
A Preliminary Design Study for a Small Passive Lead-bismuth Cooled Fast Reactor

The lead-cooled fast reactor (LFR) is a competitive type of nuclear energy system among the six generation IV nuclear energy systems selected by The Generation IV International Forum (GIF). It has excellent neutron physical characteristics, thermohydraulic characteristics, and chemical characteristics. This thesis proposes the design study for a primary system and a passive residual heat removal system (PRHRS) of a small lead-bismuth eutectic (LBE) cooled fast reactor (SPARK). In this thesis, the primary system adopts a pool-type structure and natural circulation design. The steady-state operational parameters of the primary system are derived from SPARK's design parameters. According to these parameters, the operating process and the components of the system are designed, including the structure and dimension of the steam generator (heat transfer tube size, tubes’ layout, quantity of tubes, heat transfer area, etc.), the layout of the steam generators, the layout in the primary vessel. The design and study of the PRHRS are carried out following the accomplishment of primary system design. The operating process of the PRHRS and the main components including the condenser and the water tank are designed. MATLAB is selected as a tool to conduct the thermal-hydraulic calculation for primary system design and PRHRS design. Finally, RELAP5 code is employed to analyse both systems’ performance. The results for the thermal-hydraulic calculation show that the total heat transfer area of steam generators is 88.06 m, which satisfies the heat transfer requirement. The primary system adopts an integrated design. Twelve steam generators are evenly distributed around the core barrel. Every four steam generators are a train, and the water-steam cycle is used to take away the core heat. The height needed for the natural circulation of primary system is 7 m. The PRHRS is designed as a closed natural circulation system to remove the decay heat, which consists of steam generators, a condenser, a water tank as the ultimate heat sink, an upstream isolation valve, two downstream isolation valves, a steam release valve and connecting pipes. It has two trains, and capacity of each train is arranged corresponding to the rated power of 1.5%. The heat transfer area needed by the condenser and the water tank volume of the PRHRS are also determined, which can ensure the capability of residual heat removal and prevent solidification of LBE during accident. The results form RELAP5 show that the peak fuel centreline temperature, peak cladding temperature, and peak LBE velocity all meet the safety requirements of steady-state operation. The PRHRS can cope with the accidents like station blackout (SBO), mitigate the impact of the accident, and protect the reactor integrity and safety. The peak cladding temperature is 635 K during a hypothetical SBO accident, which is lower than the safety limit (923 K). Moreover, the results of sensitivity analysis show that the increase of heat transfer area can enhance the performance of PRHRS, while height of and venting pressure of PRHRS are insignificant.
Keyphrase Generation Based on Self-Attention Mechanism

: Keyphrase greatly provides summarized and valuable information. This information can help us not only understand text semantics, but also organize and retrieve text content effectively. The task of automatically generating it has received considerable attention in recent decades. From the previous studies, we can see many workable solutions for obtaining keyphrases. One method is to divide the content to be summarized into multiple blocks of text, then we rank and select the most important content. The disadvantage of this method is that it cannot identify keyphrase that does not include in the text, let alone get the real semantic meaning hidden in the text. Another approach uses recurrent neural networks to generate keyphrases from the semantic aspects of the text, but the inherently sequential nature precludes parallelization within training examples, and distances have limitations on context dependencies. Previous works have demonstrated the benefits of the self-attention mechanism, which can learn global text dependency features and can be parallelized. Inspired by the above observation, we propose a keyphrase generation model, which is based entirely on the self-attention mechanism. It is an encoder-decoder model that can make up the above disadvantage effectively. In addition, we also consider the semantic similarity between keyphrases, and add semantic similarity processing module into the model. This proposed model, which is demonstrated by empirical analysis on five datasets, can achieve competitive performance compared to baseline methods.
3D optical surface profiler for quantifying leaf surface roughness

Biological efficiency of pesticide droplets is affected by leaf surface fine structures; however, few reliable methods exist to physically measure and quantify surface roughness. A 3D optical surface profiler was evaluated for its effectiveness as a novel and reliable method to measure and quantify leaf surface roughness in terms of areal roughness parameters. Evaluations included its accuracy for measuring 3D roughness parameters relating mean roughness length, Sa, skewness, Ssk, and kurtosis, Sku. Their values were compared with the wettability of seven leaf types ranging from easy-to-wet to very difficult-to-wet. Measurement accuracy was validated by a qualitative visual analysis comparing 3D surface renderings of measured leaf surfaces generated by the profiler and micrographs taken with a scanning electron microscope (SEM). The accuracy was also validated by measuring and comparing the micrometer and sub-micrometer scaled roughness on leaf types with hierarchical (multi-scale) structuring and smooth surfaces. Both the renderings and the SEM showed visual agreement in surface variations from waxes and trichomes. The measured roughness lengths for the multi-scale and smooth surfaces were on the same order of magnitude for micrometer scale roughness, approximately 1×100 μm, but different orders of magnitude for sub-micrometer scale roughness, approximately 1×10−1 μm and 1×10−3 μm, respectively. Comparisons for Ssk and Sku to wettability were inconclusive, however, comparisons between Sa and wettability showed a positive linear fit, suggesting that Sa could be a viable metric for relating leaf surface roughness to wettability. The results from the micrometer and sub-micrometer scale surface roughness quantification could be used to improve pesticide spray deposition quality, leading to reductions in pesticide use and negative environmental impact.
Adhesive bonding of 3D-printed plastic components

ABSTRACT Tensile strength of adhesive bonds with three different commercial epoxy resins and laser sintered polyamide 12 (PA 12) has been evaluated by means of Centrifugal Adhesion Testing Technology (CATT, LUMiFrac Adhesion Analyzer). Different post treatment states (as received and chemically smoothed) and pre-treatment states (as received and atmospheric plasma) of the PA 12 surface have been considered. It has been shown that the epoxy resins infiltrate the surface porosity of the laser sintered material, which leads to a special fracture pattern. Tensile strength of the adhesive bonds has been significantly improved after atmospheric plasma pretreatment. Chemical smoothing had a neglicable effect on the tensile strength of the tested specimens, but lead to a change in fracture pattern, especially without atmosphric plasma pretreatment.
The electrochemical decoration of multi-walled carbon nanotubes with nickel oxide coating

In this paper, nickel coatings have been deposited on the multi-walled carbon nanotubes (MWCNT). In the first stage, MWCNT powder was ultra-wave mixed in the acid bath (H2SO4 and HNO3). The acid treating activates inert carbon surface introducing functional –OH and –COOH groups on the MWCNT surface. The mixture was diluted with distilled water and filtered for several times. The filtered sediment was dried in a plasma cleaner. The powder of such cleaned functionalized MWCNTs (fMWCNTs) was ultrasonicated with deionized water to produce stable colloid. Nickel atoms were injected into the colloid from a positive nickel electrode (with a negative graphite one). The Ni containing tubular nanostructures decorated the fMWCNTs at the specified regulated conditions (temperature, colloid concentration, electric current density). The electrochemically treated colloid was filtered and dried to a powder state (Ni-containing-fMWCNT powder). Hollow NiO nanotubes were produced by the annealing of the powder at 600°C (tubular nanostructured NiO powder). Both powders were examined by the Raman spectroscopy (RS), high-temperature X-ray diffraction (HTXRD), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). The estimated high specific surface area of the nanostructured NiO powder is up to 97 m2/g at least and may be varied by time and the electric current of the electrochemical process.
Application of atmospheric pressure plasma technology for textile surface modification

This paper gives an overview of atmospheric pressure plasma types used in the textile industry and recent developments in plasma treatments of textiles. It investigates the topic of the influence of atmospheric pressure plasma treatment on the surface properties of materials made from natural and synthetic fibers. Through plasma induced physical and chemical reactions occurring in the textile surface layer, significant modifications in micromorphology and reactivity can be achieved. In addition to cleaning, etching, and activation, great efforts have been made in the development of plasma polymerization processes under atmospheric pressure. Utilization of atmospheric pressure plasma technology in the textile industry offers a new perspective on surface modification and functionalization. This paper gives a summary of textile properties achieved using plasma and the underlying processes based on relevant findings obtained from prominent research.
Strength Improvement and Stress Analysis of E-Glass Laminated Plates with Circular Notches Using Digital Image Correlation

In the current work, the stress concentration and tensile strength degradation of E-glass/epoxy laminates are addressed in the present investigation through a combination of both experimental and numerical studies. The numerical study is performed using finite element method (FEM). The main aim of this work is to improve the ultimate strength of perforated composite plates, by using defense hole system (DHS) technique. The samples are manufactured from commercially avail-able unidirectional (UD) E-glass and clear 1070 resin epoxy. Digital image correlation (DIC) technique is also used to get the full-field surface strain measurements in perforated samples with various open hole diameters and DHS configurations, in order to show their effects on failure strength. Based on the experimental results, the ultimate strength can be improved by introducing two circular auxiliary holes along with the principal stress directions.
Synthesis and Enhancement of Electroactive Biomass/Polypyrrole Hydrogels for High Performance Flexible All‐Solid‐State Supercapacitors

Recently, electroactive biomass‐based hydrogels have attracted great attention for flexible supercapacitor electrodes due to its porous, renewable, earth‐abundant, low‐cost, and environmentally friendly characters. However, it is challenging to facilely prepare biomass‐based hydrogels with simultaneously possesses high mechanical strength and excellent electrochemical performance. In this work, the lignosulfonate/polypyrrole (Lig/PPy) hydrogel (LP54) is obtained. In order to further improve the mechanical strength and electrochemical performance of LP54, functionalized porous carbon nanospheres/lignosulfonate/polypyrrole hydrogel (FPCSLP54) is prepared by introducing a trace of FPCS (≈4.5 wt%) fabricated by hydrothermal treatment the mixture of PCS and pyrrole into the prepared LP54 system. FPCS can be uniformly anchored into Lig/PPy framework. The LP54 and FPCSLP54 exhibit compressive strength of 6.0 and 9.3 kPa with the water content of 94.9% and 94.3%, respectively. Meanwhile, as‐prepared LP54 and FPCSLP54 are separately assembled into symmetric flexible supercapacitors with cellulose/H2SO4 hydrogel electrolytes, which exhibit superior areal capacitance (463 and 522 mF cm−2), good rate capability and outstanding energy density (41.2 and 72.5 µWh cm−2). Remarkably, flexible supercapacitors present outstanding electrochemical stability even suffering 1000 bending cycles. In this work, the strategy to construct electroactive biomass‐based hydrogels is contributed and a new method to enhance the properties of hydrogels is provided.
In-vitro biodegradation study of poly(ε-caprolactone) films using a 3D printed helical flow prototype to simulate the physiological conditions for cardiovascular implanted devices

Current in-vitro biodegradation test methods for characterizing bioabsorbable polymer implants including ASTM F1635-11, focus on testing mechanical and chemical properties of samples under static conditions. These tests oversimplify the implant service environment and yield limited data due to the lack of fluid flow, stresses, and pressures. The effects of the helical or spiral blood flow observed in arterial vessels are of particular interest for biodegradable polymer cardiovascular stents due to its promising biomedical uses and relatively recent discovery. In this study, a novel 3D printed prototype flow device was designed and developed to simulate in-vivo conditions including flow rates, flow characteristics, pressures, temperatures, and chemical environment. The in-vitro biodegradation behavior of poly(ε-caprolactone) (PCL), in phosphate buffer solution (PBS) was used to study the influence of flow conditions compared to a standard static ASTM method over 5 weeks. Characterization of the polymer degradation was performed by evaluating changes in weight loss, molecular weight and the degree of crystallinity as a function of time. The number average molecular weight of the polymer showed the largest decline, decreasing linearly with time by 22% and 5% for the samples tested using the flow device and ASTM method, respectively. Similarly, the degree of crystallinity was found to increase linearly by 16% and 6% for the flow device and ASTM method, respectively. Helical/spiral flow at the flow rates as low as 1 cm3 s−1 were found to enhance the bulk degradation of PCL by up to 80% when compared to the static ASTM method. A combination of bulk and surface erosion mechanisms were proposed for the degradation behavior of the PCL in the flow prototype. This indicates that by more accurately mimicking physiological conditions, including blood dynamics, this 3D printed prototype can serve as an improved method for testing bioabsorbable and biodegradable polymers for implanted devices.
Flexible low-voltage paper transistors harnessing ion gel/cellulose fiber composites

Paper transistors are indispensable devices for paper-based electronic biosensing systems. Existing paper transistors mainly use paper as a mechanical support in a passive fashion. By taking advantage of the cellulose fibers in paper, here we report a transistor-in-paper where paper is employed as an essential part to allow for low-voltage operation, which addresses the long-standing challenge of high-voltage operation with existing paper transistors. Such a low-threshold voltage is because of the ion gel/cellulose fiber composite dielectric formed by modifying the paper with ion gels. We further developed paper-based inverters as examples of logic gates and an integrated tactile sensing mat based on a transistor array–enabled multiplexing device. The results collectively indicate that the ion gel–modified paper leads to a class of flexible, low-voltage transistors and integrated electronic devices, which hold promise in many applications.
Measurement of metal–roll interface during metal rolling using normal and oblique ultrasonic reflection

It is important to monitor the roll bite interface during metal rolling to maintain the product size and homogeneity so as to minimize the material wastage. However, the harsh nature of cold rolling makes installation of sensors in metal roll for industrial applications difficult. The present study used a novel ultrasonic measurement technique whereby an ultrasonic signal went through an external sensor layout arrangement to study the metal-roll interface. The reflection coefficient obtained from the roll-strip interface at 0° to the roll surface (normal ultrasonic measurement technique) and 19° (oblique ultrasonic measurement technique) were modelled and experimentally investigated on an instrumented pilot metal rolling mill. Variances of 6.4% and 8.8% were obtained in the reflection coefficient of the techniques from experimental and modelling approaches, respectively. This showed that both techniques could be used to study the effect of the angle of incidence wave on the reflection coefficient.
Interface Microstructure and Nanoindentation Characterization of Laser Offset Welded 5052 Aluminum to Press-Hardened Steel Using a Brass Interlayer

Laser offset welding of 5052 aluminum to press-hardened steel using a brass interlayer was carried out. The cross-sectioned macrostructure and tensile strength were governed by varying the thickness of the brass interlayer. The maximum tensile strength reached 56.4 MPa when the thickness of brass interlayer was 0.05 mm. Subsequently, the interface microstructure, the nanoindentation characterization, and the fracture behavior were evaluated experimentally by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDS), and micro-X-ray diffraction (micro-XRD), respectively. It was found that the intermetallic compound (IMC) layer at the interface consisted of an Fe2Al5 layer and an FeAl layer, and the estimated nanohardness of Fe2Al5, FeAl, and Fe3Al were 16.11 GPa, 9.48 GPa, and 4.13 GPa, respectively. The fracture of the joint with the 0.05 mm brass interlayer was a mixture of cleavage fracture and intergranular fracture, while that of the joint with the 0.1 mm brass interlayer exhibited the characterization of a major dendrite arm, leaving a metallurgical connected zone consisting of the Al2Cu and the α-Al phase.
Studies on the Preparation and Application of Tetramethylsilylcellulose from Rain Tree Sawdust

The upcycling process of agricultural waste for cellulose production has been attempted. In this study, cellulose was extracted from sawdust of the rain tree using 4% (w/v) NaOH solution. 1.5 g of extracted cellulose was soaked in water and N,N-dimethylacetamide (DMA) respectively. The soaked cellulose was dissolved in dimethylacetamide/LiCl and reacted with hexamethyldisilazane (HMDS) yielding tetramethylsilylcellulose (TMSC). The IR spectrum shows the presence of-Si (CH3)3 groups: νSi-O at 1047 cm-1, νC-Si at 1252, 843 and 750 cm-1. The 1H-NMR result confirms the presence of-Si (CH3)3 groups at  0 ppm and pyranose ring protons in the range of 2.8-4.5 ppm. SEM image of TMSC shows the fibrous characteristics of cellulose while the EDX shows the presence of Si. The degree of substitution (DS) values calculated from FT-IR and EDX data are 2.33 and 2.08 respectively. 1.0% w/v TMSC solution in THF was prepared. A Small piece (2.0 cm x 4.0 cm) of filter paper was dipped into the TMSC solution for 30 min. The coated paper has an average contact angle of 116o. However the characteristic bands of the TMSC were not observed from FT-IR analysis. While the EDX shows the presence of Si on the paper surface.
Methods for in-situ reinforcing of concrete building structures with external reinforcement based on carbon fiber to restore their service able technical state

In this article, a method is proposed for calculating the reinforcement of concrete ceiling slabs with carbon composite materials based on the finite element model in the computer program SCAD Office PC. This method allows the most complete and accurate representation to be obtained of the structure stress-strain state before and after reinforcement with composite materials. Therefore, it allows high-quality designing and reduces the cost conducting calculations and tests on a large scale. The design values are taken from the initial data, and include conclusions based on the results of analysis of the technical state of the structures and drawings from the calculation section of the CS (reinforced concrete structures).
Development of graphitic carbon nitride based assemblies for sunlight driven photocatalysis

This present work focused on the development of binary graphitic carbon nitride (g-C3N4) composite for sunlight driven photocatalysis. In the 1st project, the binary composite was achieved by doping noble metals such as gold (Au), silver (Ag) and palladium (Pd) with g-C3N4 through sunlight photodeposition. The deposition of Ag nanoparticles (NPs) (7.5 nm) resulted in the degradation of Bisphenol A (BPA) which was 2.15 fold higher than that of g-C3N4. For 2nd project, carbon dots (CDs) were successfully derived from water hyacinth leaves and the binary composite was achieved by incorporating CDs with g-C3N4 through hydrothermal treatment. The average particle size of CDs was found to be 3.1 nm and a blue-green fluorescence was emitted under the UV light irradiation. Both of 20CDs/g-C3N4 and 40CDs/g-C3N4 achieved the highest degradation efficiency of 2,4-dichlorophenol (2,4-DCP) with 1.7 times higher than that of pure g-C3N4. Both projects successfully improved the properties of g-C3N4 by elongating the lifetime of photogenerated electrons and widening the visible light response. The M/g-C3N4 (M=Au, Ag and Pd) in 1st project fully degraded BPA within 70 min while CDs/g-C3N4 (2nd project) degraded 94% of 2,4-DCP within 120 min. Despite of higher photocatalytic efficiency in the 1st project, CDs/g-C3N4 was recommended for further exploration from the aspect of low production cost and high sustainability.
Numerical Analysis of Thermal Friction Stir Weld-ing (FSW) Application in Aerospace Industry

: In this work, Friction Stir Welding (FSW) of 2017A-T451 aluminum alloy for a constant tool rotational speed 1250 rpm is investigated and analyzed. 3D numerical simulation has been carried out with the aid of ANSY code. In this context, two steps are performed; a mesh system is adapted to the geometry (plaque and tool) in order to use the finite ele-ments. Secondly; the predicted result of plate temperature has been compared to experimental result. The surface temperature of the plate increases with the passage of the rotating tool; this is due to the increasing of friction between the tool and plate. This increase is slow until 300 s then it decreases rapidly. A good agreement is noted between the experimental and predicted results. According to this result, ANSYS provides a satisfactory prediction for the FSW.