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With the development of printed electronics technology, the demand for printed conductive inks had also put forward higher standards. The shortcomings of traditional printed circuit boards, such as complex technology, consumables, and pollution, had also been resolved with the development of 3D printing technology. In this paper, low-content silver nanoparticles were blended with graphene alcohol slurry and dissolved in a non-polluting solvent such as absolute ethanol. The synergistic effect of the composite of the hexagonal structure of the graphene sheet and the silver nanoparticles improved the ink’s performance of electrical conductivity, adding water-based polyurethane/acrylic resin system to improve the adhesion between ink and paper. The conductive ink can be used to 3D print circuit circuits on paper. After drying, the resistance was measured. After the battery, diode, and switch were connected, a circuit diagram was made. After pressing the diode emits was lighted. This work is expected to be applied to flexible circuit boards to provide basic research.

In this study, the easy-to-operate silver mirror reaction (SMR) was used for metallizing chromatography paper. The SMR-metallized paper was characterized by water contact angle measurements, a surface profiler, x-ray photoelectron spectroscopy, UV–Vis spectroscopy, x-ray diffraction, and electrical resistance measurement. The characterization results show that Ag was successfully synthesized on cellulose fibers and was electrically conductive after cyclic bending. Moreover, this SMR-metallized paper was used as electrodes for fabricating a supercapacitor. This SMR-metallized paper could be used for realizing cost-effective flexible electronics applied in on-site biochemical sensing in resource-limited settings.

Paper-based microfluidics has been widely used in chemical and medical analysis applications. In the conventional paper-based microfluidic approach, fluid is propagating inside the porous structure, and the flow direction of the fluid propagation is usually controlled with the pre-defined hydrophobic barrier (e.g. wax). However, the fluid propagation velocity inside the paper-based microfluidic devices largely depends on the material properties of paper and fluid, the relative control method is rarely reported. In this study, a fluid propagation velocity control method is proposed for paper-based microfluidics: hydrophobic pillar arrays with different configurations were deposited in the microchannels in paper-based microfluidics for flow speed control, the result indicates the deposited hydrophobic pillar arrays can effectively slow down the fluid propagation at different levels and can be used to passively control the fluid propagation inside microchannels for paper-based microfluidics. For the demonstration of the proposed fluid control methods, a paper-based microfluidic device for nitrite test in water was also fabricated. The proposed fluid control method for paper-based microfluidics may have significant importance for applications that involve sequenced reactions and more actuate fluid manipulation.

The main idea of this research is to design a rechargeable paper battery from local cheap and available materials. The practical part is represented by adding Polyvinyl alcohol (PVA) to conductive polymer (PSS PEDOT) with adding different mineral salts for then study the quantum of electrical conductivity and heat influence on electrical conductivity and acidity factors of the Electrolyte solution.The next step was to produce a rechargeable, flexible battery manufactured from regular cellulose paper, sulfone, and ionic solution.The measurements were made using modern laboratory devices to study the electrical properties, conductivity, resistance (Hall Effect), and voltage quantum of the ionic solution. Through the results we obtained, we noticed an increase in the conductivity of the ionic solution when adding mineral salts. The voltage quantum of one battery ranged between 0.3-0.3 volts, also several batteries were connected in series, and the result was 1.8 volts. Manufactured paper batteries can be recharged with a direct current source and recover their efficiency marked up 98-99%.

Iranian Light Source Facility (ILSF) is a 3 GeV synchrotron radiation laboratory in the detailed design stage. The main building site is being excavated in Qazvin, 150 km from Tehran. The Booster ring of this facility with a circumference of 504 m and a low emittance of 3.5 nm rad accelerates electrons from 150 MeV to 3 GeV. Using POISSON and OPERA codes, we designed the ILSF booster ring magnets including dipoles, quadrupoles, sextupoles, and separate correctors. Cooling and electrical calculations are done, and ramping effects are considered. The ILSF has also been attempting to practice mechanical designs and to build prototype magnets at this stage too.

Pulp and paper products in the modern world are used in a variety of types and areas, due to which the issue of improving paper production technologies is relevant. The article presents the results of grinding fibrous semi-finished products using the knife method. A disc mill with an original knife set was used as the unit under study. For the most effective modes of grinding were selected to obtain raw materials with high quality indicators.

The microstructure of green-emitting InGaN/GaN quantum well (QW) samples grown at different temperatures was studied using cross-section scanning transmission electron microscopy (STEM) and plan-view cathodoluminescence (CL). The sample with the lowest InGaN growth temperature exhibits microscale variations in the CL intensity across the sample surface. Using STEM analysis of such areas, the observed darker patches do not correspond to any observable extended defect. Instead, they are related to changes in the extent of gross-well width fluctuations in the QWs, with more brightly emitting regions exhibiting a high density of such fluctuations, whilst dimmer regions were seen to have InGaN QWs with a more uniform thickness.

Trapped-flux magnets comprising stacked superconducting tape constitute a promising development to increase the power density of electrical machines, whilst at the same time keeping the complexity required in their construction in manageable levels that allow their use in applications such as aircraft propulsion. However, the conditions in which superconducting stacks operate inside an electrical motor differ quite significantly from the materials characterization experiments commonly developed to model their behaviour. This work presents the results of studying the applicability of these devices as magnetic flux source in the rotor of synchronous machines considering the influence of whole magnetic circuit. Several aspects are assessed, such as flux harmonics, magnetization, losses and demagnetization. Analytical expressions, which provide limited accuracy but allow fast calculations, are used for this purpose. The results illustrate the different trade-offs that arise during the design of a synchronous electric motor using trapped-flux magnets.

This paper is focused on the production plastic parts. It is describing two technologies-injection moulding and additive technology. The production process of the metal mould for the new parts takes about ten weeks. It is necessary to make some reductions after the mould is produced. It is increasing the time which is necessary for the prototype of products. This time (from the initial design of mould to the prototype of product) can take about six months. Additive technologies can be used for decreasing this time and for cost reduction. Moulds produced by the additive technology are mostly special inserts which can be implemented in the universal design of mould. It is also possible to produce whole moulds from plastic material. These moulds can have integrated cooling channels. There are high demands on the material of the mould with respect to the thermal resistivity, toughness and surface quality. There are really often used SLA technologies, which are considering the High Temp Resin and Material Jetting Digital ABS. Other options used in the factories are Somos PerFORM and Digital ABS Plus. This paper deals with the possibility of usage of the HP Jet Fusion technology with the material PA12 GB for the production of mould inserts and it is evaluating this process and repeatability of process.

We investigated the use of dielectric layers produced by atomic layer deposition (ALD) as an approach to strain mitigation in composite silicon/superconductor devices operating at cryogenic temperatures. We show that the addition of an ALD layer acts to reduce the strain of spins closest to silicon/superconductor interface where strain is highest. We show that appropriately biasing our devices at the hyperfine clock transition of bismuth donors in silicon, we can remove strain broadening and that the addition of ALD layers left T 2 (or temporal inhomogeneities) unchanged in these natural silicon devices.

As a composite product, particleboard has disadvantages related to low dimensional stability. The research purpose was to analyze the effect of immersion in acetic acid and NaOH solution on the quality of the particleboard sandwich. Sandwich particleboard (SPb) was made in a size of 25 cm length and 25 cm width. The target thickness and density are 1 cm and 0.75 g/cm3, respectively. The adhesive used was isocyanate adhesive with a content of 7%. First, The particles, which were in the form of wood shavings and bamboo strands, were soaked in a solution of acetic acid and NaOH at various concentrations (0, 1, 2, and 3%). The moisture content of the particles to be made SPb was set at 7%. After evenly mixing the particles (wood shavings and bamboo strands) and the adhesive, the sheet was created. The board sheets were made into three layers, namely 40% face layer in the form of a bamboo strand, 20% core layer in the form of wood shavings, and 40% back layer in the form of the bamboo strand. The next stage was the hot pressing process at 160 °C for 5 min and 30 kg/cm2pressure. The following process was conditioning the board for seven days. Testing of quality refers to the standard JIS A5908 (2003). The results showed that the immersion of Raru wood particles in acetic acid and NaOH significantly affected the value of density, water absorption, thickness swelling, modulus of elasticity, modulus of rupture, and internal bond. Except for the moisture content on the AA3 and NA2 boards and the internal bond value on the untreated (control) board, all of the panel properties in this study met the standard.

Experiments were carried out by treating the waste samples with electrocoagulation technology. This is done to determine the effectiveness of the removal of the electrocoagulation device against textile waste. The sample used is a synthetic sample with a concentration of 1091 mg/L Pt-Co units. The research was conducted twice with the first experiment being conducted to determine the most effective electrical voltage to remove the existing COD and color pollutants while the second experiment was conducted to determine the type of anode and cathode that was most effective in removing COD, Color, and heavy metal pollutants. In the first experiment, it was found that the electric voltage that could produce the best removal was 4 amperes and in the second experiment, the anode-cathode type with the highest % removal was Fe-Fe with % COD removal of 64.09639% and % color removal of 60.00619%. It was concluded that electrocoagulation method could effectively remove color and COD in waste water.

The world Health Organization (WHO) declared a pandemic caused by SARS-CoV-2 or Covid-19 in 2020. Indonesia in one of the countries affected by the Corona Virus Disease (Covid-19) for a long time. Education is one aspect of life that is affected. Research on drying is one solution for students to carry out scientific activities at home by utilizing solar energy and natural materials such as radishes as samples. This study found that the thickness of the sample and environmental conditions such as temperature of the surrounding operating conditions affect the drying rate and drying time.

The study investigates the effect of sludge waste from mining and washing of limestone on the properties of geopolymer binders based on metakaolin and blast furnace slag. The effect of adding two types of limestone sludge on workability, setting time, compressive strengths, durability and pore distribution was investigated. Limestone sludge was dosed in an amount of 0–30 %. Sodium water glass was used as an alkaline activator in the ratio of 5:4. A linear correlation between the flowability and limestone sludge content was observed, and very satisfactory results of compressive strength after 90 days were obtained for samples with sodium water glass (about 55 MPa). The positive effect of CaCO3 on strength was confirmed. The increased content of clay components resulted in a reduction of compressive strength.

To obtain high-quality grain and seeds, it is necessary to clean the combine heap of weeds. Modern air-screen grain cleaners equipped with a screen cleaning systems, flat screens and a double-aspiration pneumatic system with pre-screen and post-screen cleaning channels are used. The fractional principle of post-harvest grain processing is promising. To create a universal grain cleaning machine to isolate the main fraction from the grain heap at the first stage of post-harvest processing, Voronezh State Agar University named after Emperor Peter I carried out theoretical and experimental studies, which made it possible to develop OZF-50, OZF-80 and SVS-30 separators. The machines have higher productivity, the original sieve design with an increased share of sorting sieves and an exclusive aspiration system. A number of new technical solutions have been used in the design of the separators, protected by patents of the Russian Federation. Theoretical prerequisites established the possibility of increasing the productivity 1.6-1.8 times according to GOST R 52325-2005. The total air consumption of the pneumatic system of grain cleaning machines can be reduced by 25-40%. Further improvement of separators requires a deeper study of the grain fractionation process, aerodynamic characteristics of aspiration systems, receiving and distribution devices, and establishment of close mutually beneficial relations between scientific institutions and agricultural engineering enterprises. This can contribute to the development of both domestic agricultural science and grain cleaning equipment production.

Concept of sustainable construction has gradually become one of the concern issues in our construction industry in recent years. Concrete which acts as an important construction material has contributed to excessive consumption of natural resources. Simultaneously, tonnes of waste materials were produced from agricultural activity in form of palm oil fuel ash (POFA) while mussel shell from marine hatchery. Utilization of agricultural waste as cement replacement is an option to reduce the environmental impact from the construction industry. In this study, these waste materials were used as partial cement replacement to produce foamed concrete in wet density of 1800 kg/m3. The main purpose of this research is to study the workability and mechanical properties of foamed concrete which contain uniform 20% of POFA combined with 5% to 10% of mussel shell powder (MSP) and mussel shell ash (MSA) respectively. The cube specimens were cast in dimension 100 mm x 100 mm x100 mm to test the compressive strength at 7th and 28th. The cylinder specimens were cast in 100 mm diameter x 200 mm diameter for split tensile test to determine the tensile strength and compression test to determine modulus of elasticity at 28th day. The result showed workability of foamed concrete decreased as more cement was replaced by POFA combined with MSP and MSA. Foamed concrete mixture with 20% POFA and 5% MSP was selected as optimum percentage of cement replacement due to reduction less than 5% compromised performance in compressive strength at 16.52MPa while tensile strength at 1.83MPa.

Dragon blood’s resin is obtained by extracting the dragon blood’s fruit with organic or non-organic solvents. Following extraction, drying process is usually carried out to dry the wet resin. The drying techniques used is assumed to affect not only the drying performance but also the quality of the dragon blood’s resin, in particular its active ingredient content (dracorhodin). The purpose of this study was to measure and compare the effect of solar and oven drying on the drying performance and quality of dragon blood’s resin. The oven temperature used was 60°C. Both drying techniques were executed until the resin dried which was indicated by color change and its easiness to rupture. The results showed that solar drying of dragon blood required shorter time (210 minutes) with higher drying rate (0.25%/minute) than the oven drying process which need 250 minutes to finish with a drying rate of 0.14%/minute. Except the ash content of solar dried resin, other post-drying quality parameters of dragon blood resin from both drying techniques have met the Indonesia standard for trading purpose (SNI 8663:2018). Further statistical analysis confirmed that the drying techniques applied significantly affected the drying rate and post-drying quality values of dragon blood’s resin.

Polylactic acid (PLA) has been used as an additive material in 3D printing due to its toxic-free and environmentally friendly property. Lignin with complex and branched chemical structures had been used as a filler to improve the mechanical strength of PLA. The availability of oil palm empty fruit bunches (OPEFB) in Malaysia had made this material a good source for lignin extraction. Thus, in this research, we aim to study the mechanical strength of PLA bio-composite material with reinforcement of lignin from OPEFB. The lignin was extracted by 1,4-dioxane with hydrochloric acid as a catalyst. The recovery of lignin from extraction solvent was done by precipitation. The lignin was successfully extracted from OPEFB with 9.04% of lignin extraction yield. The PLA/lignin bio-composite filament with 0.1% (w/w) lignin was performed by filament extruder and then used for 3D printing. The prepared sample in the form of filament and 3D printed material was characterized for mechanical strength and surface morphology. The Young’s modulus, ultimate strength and elongation at break of the PLA/lignin bio-composite sample had increased 11%, 7% and 10% respectively. After the filament was used for 3D printing, the reduction of mechanical strength had been observed. The morphology by scanning electron microscopy (SEM) confirmed the presence of lignin on the fracture surface of PLA bio-composite material. Apart from that, the interlayer adhesion had been observed in the 3D printed PLA/lignin bio-composite that caused the drop in mechanical strength of the material.

Tofu wastewater is dangerous for the aquatic environment because it contains high BOD, COD, and TSS, which will damage life in the river. Tofu home industries in Semanan have not used a proper wastewater treatment system, and this study was conducted to test the electrocoagulation system to reduce the levels of BOD, COD, and TSS. According to several studies, the electrocoagulation system can reduce BOD, COD, and TSS. It is hoped that this electrocoagulation system can solve environmental problems caused by tofu wastewater. From the research that has been done, namely with the stirring variable at a speed of 150 RPM and at a detention time of 10 minutes with a discharge of 0.6 liter/minute, the percentage of COD removal is 36%, the percentage of BOD removal is 27%, and the percentage of TSS removal is 51%. Then on the stirring variable at a speed of 100 RPM and at a detention time of 10 minutes with a discharge of 0.6 liter/minute, the percentage of COD removal is 32%, the percentage of BOD removal is 15%, and the percentage of TSS removal is 58%.

Abstract This study aims to utilize wood sawdust waste in the paint industry waste treatment. The first thing to do is a qualitative analysis of heavy metals before and after the processing. Furthermore, the parameters measured are temperature, pH, TDS, and dissolved oxygen (Dislove Oxgen). The use of wood sawdust as a heavy metal adsorbent in paint industry wastes is able to provide efficient results with no sediment formation when conducting qualitative analysis of Cu2+ and Cd2+ metal ions and raising the waste parameters to be environmentally friendly. This shows that the adsorption process works optimally.

Digital image correlation (DIC) is a widely used technique in experimental mechanics for full field measurement of displacements and strains. The subset matching based DIC requires surfaces containing a random pattern. Even though there are several techniques to create random speckle patterns, their applicability is still limited. For instance, traditional methods such as airbrush painting are not suitable in the following challenging scenarios: (i) when time available to produce the speckle pattern is limited and (ii) when dynamic loading conditions trigger peeling of the pattern. The development and application of some novel techniques to address these situations is presented in this paper. The developed techniques make use of commercially available materials such as temporary tattoo paper, adhesives and stamp kits. The presented techniques are shown to be quick, repeatable, consistent and stable even under impact loads and large deformations. Additionally, they offer the possibility to optimise and customise the speckle pattern. The speckling techniques presented in the paper are also versatile and can be quickly applied in a variety of materials.

Today, lightweight concretes with lightweight expanded aggregates (expanded clay, agloporite) are most commonly used. This paper deals with the production of lightweight concretes lightweighted with foamed glass-based aggregates. Foamed glass is a lightweight material characterised by a very good ratio of thermal insulation and mechanical properties. Foamed glass is made of approximately 90% recycled glass waste (mostly mixed), which cannot be used in any other way, as well as water glass and glycerine. When concrete is lightened with foamed glass, these concretes achieve unique properties while conserving primary aggregate resources, avoiding landfilling of glass waste and efficiently using the waste material to produce lightweight concrete with higher added value. The paper discusses the possibilities of developing lightweight structural concretes using glass foam based aggregates to achieve higher strength classes while reducing the weight and thermal conductivity of the concrete. As part of the research work, new types of lightweight concrete with a bulk density in the range of 1750 - 1930 kg/m3 and a thermal conductivity from 0.699 to 0.950 W / (m.K) were developed. TDnes se nejčastěji používají lehké betony s lehkým expandovaným kamenivem (keramzit, agloporit). Tento příspěvek se zabývá výrobou lehkých betonů lehčených kamenivem na bázi pěnového skla. Pěnové sklo je lehký materiál vyznačující se velmi dobrým poměrem tepelně izolačních a mechanických vlastností. Pěnové sklo je vyrobeno z cca 90 % recyklovaného skleněného odpadu (většinou smíšeného), který nelze jinak využít, stejně jako vodní sklo a glycerin. Když je beton vylehčován pěnovým sklem, dosahují tyto betony jedinečných vlastností a zároveň šetří primární zdroje kameniva, zabraňují skládkování skleněného odpadu a efektivně využívají odpadní materiál k výrobě lehkého betonu s vyšší přidanou hodnotou. Článek pojednává o možnostech vývoje lehkých konstrukčních betonů s použitím kameniva na bázi pěnového skla pro dosažení vyšších pevnostních tříd při snížení hmotnosti a tepelné vodivosti betonu. V rámci výzkumných prací byly vyvinuty nové typy lehkých betonů s objemovou hmotností v rozmezí 1750 – 1930 kg/m3 a tepelnou vodivostí od 0,699 do 0,950 W/(m·K).

The aim of this paper is to evaluate and compare the tribological properties of lubricating oil blends with added nano graphene and nano cerium oxide (CeO2) on the key friction pairs of diesel engines. Dispersion stability is the premise of the study of tribological properties. In this paper, nano CeO2 particles were self-made and high-quality nano graphene was purchased. The dispersion stability of the two nanomaterials in lubricating oil was studied after the same modification. According to the working conditions of the cylinder liner and piston ring, friction and wear tests of the lubricating oil blends containing the modified nanomaterials were carried out at different temperatures. The results showed that both nanomaterials were successfully modified with oleic acid and stearic acid. The dispersion stability of the modified nanomaterials in lubricating oil was improved. The dispersion stability of the lubricating oil blends with graphene before and after modification was slightly higher than that of lubricating oil blends with CeO2 before and after modification. At high temperature, the anti-friction properties of the two nano lubricating oil blends were similar. At ambient temperature, lubricating oil blends containing modified CeO2 did not play a role in reducing friction, while lubricating oil blends with modified graphene had the effect of reducing friction. Whether at ambient temperature or high temperature, the anti-wear property when lubricated with lubricating oil blends with modified CeO2 within the right concentration range was better than that when lubricated with lubricating oil blends containing modified graphene.

Carbon nanotubes (CNTs) were synthesized on quartz-based fibrous materials via chemical vapor deposition using camphor. Quartz wool with two different fiber diameters, and quartz filter paper were used as the substrate materials for the synthesis. Quartz wool produced a high yield of CNTs, and the arrays on the fibers had characteristic plate-shaped aligned structures. In addition, CNTs were grown on the quartz filter paper fibers; however, most of these CNTs were not aligned. The effects of the fiber diameter and interfiber distance of the substrate materials on the yield and morphology of the resulting CNTs are discussed.

Recently, when we sorting through published articles, we find a mistake: the transmission electron microscope (TEM) of PbSe QDs figure 1（d）from Nanotechnology 27 (2016) 405201 is incorrectly used as a TEM image of PbS QDs in the inset of figure 1(a) in my paper (Nanotechnology 28 (2017) 145201). We provide a corrected TEM image and replace the original TEM image of figure 1(a) in our paper (Nanotechnology 28 (2017) 145201). The corrigendum of our paper here is provided. The corrigendum does not affect the conclusions of that paper. The ACKNOWLEDGMENTS section should be added. The authors apologize for any inconvenience that this may have caused.

Proton-conducting ceramics (e.g. doped barium zirconates or cerates) are typically mixed ionic-electronic conductors (MIECs). The electronic conduction, typically in the form of positively charged small polarons or electron holes, leads to ‘electronic leakage.’ In an ideal steam-electrolysis cell, one gas-phase H2 molecule is produced from every two electrons delivered from an external power source. In other words, such ideal behavior achieves 100% faradaic efficiency. However, the electronic flux associated with MIEC membranes contributes to reduced faradaic efficiency. The present paper develops a model that predicts the behavior of faradaic efficiency as a function of electrolysis-cell operating conditions. Although the model framework is more general, the paper focuses on the behavior of a cell based upon a BaCe0.7Zr0.1Y0.1Yb0.1O 3 − δ (BCZYYb) membrane. The study predicts the effects of operating conditions, including temperature, pressure, and gas compositions.

FFT methods have become a fundamental tool in computational micromechanics since they were first proposed in 1994 by Moulinec and Suquet for the homogenization of composites. Since then many different approaches have been proposed for a more accurate and efficient resolution of the non-linear homogenization problem. Furthermore, the method has been pushed beyond its original purpose and has been adapted to a variety of problems including conventional and strain gradient plasticity, continuum and discrete dislocation dynamics, multi-scale modeling or homogenization of coupled problems such as fracture or multi-physics problems. In this paper, a comprehensive review of FFT approaches for micromechanical simulations will be made, covering the basic mathematical aspects and a complete description of a selection of approaches which includes the original basic scheme, polarization based methods, Krylov approaches, Fourier–Galerkin and displacement-based methods. Then, one or more examples of the applications of the FFT method in homogenization of composites, polycrystals or porous materials including the simulation of damage and fracture will be presented. The applications will also provide an insight into the versatility of the method through the presentation of existing synergies with experiments or its extension toward dislocation dynamics, multi-physics and multi-scale problems. Finally, the paper will analyze the current limitations of the method and try to analyze the future of the application of FFT approaches in micromechanics.

This paper presents a detailed investigation on an asymmetric magnetic-coupled bending-torsion piezoelectric energy harvester based on harmonic excitation. There is an eccentricity between the shape center of moving magnets and the axis of the piezoelectric beam, which results in the bending and torsion simultaneously in working condition. The distributed mathematical model is derived from the energy method to describe the dynamic characteristics of the harvester, and the correctness of the model is verified by experiments. To further demonstrate the improvement performance of the proposed energy harvester, the bending-torsion energy harvester (i.e. magnetic-coupled was not configured) is experimented and compared. The theoretical and experimental results indicate that the average power increases about 300% but the resonance frequency decreases approximately 2 Hz comparing to the harvester without magnetic-coupled. According to the characteristic of distributed parameter model, the magnetic force and the size of the piezoelectric beam are investigated respectively. And the lumped-parameter model is introduced to analyze the steady-state characteristic. Accordingly, this paper provides a feasible method to improve performance for piezoelectric energy harvester.

In fusion devices, various techniques are employed for coating the plasma facing components (PFCs) including the vessel wall with low-Z material like lithium, boron, and silicon in order to enhance the plasma parameters and control. In ADITYA-Upgrade tokamak, different techniques of lithium wall conditioning are developed and implemented to obtain uniform and sustainable coating of Li on PFCs and the vessel wall. In this paper, two techniques used to generate Li from the source are reported. In one of the technique, a heated (fixed temperature of ∼120 °C) Li-rod is placed inside the hydrogen glow discharge cleaning (H-GDC) plasma and the sputtered Li by hydrogen (H) ions and atoms coats the wall and periphery. In the second technique, the Li is vapourized using a high-temperature Li-evaporator and released into the H-GDC plasma for uniform coating of Li on the PFCs and vessel. Significantly enhanced plasma parameters are obtained after Li coating by both techniques, with the evaporated Li performed better than the Li rod case. With the Li coating obtained with evaporated Li at 600 °C (550 mg Li) with H-GDC, the Li wall conditioning has been observed to be sustaining for in a larger number of plasma discharges in comparison to non-H-GDC assisted Li deposition. As the melting temperature of lithium hydride (LiH) is much higher (688.7 °C) than that of lithium (180.5 °C), this enhance the longer Li-coating lifetime relatively due to the formation of Li–H molecules on the vessel wall and PFCs. In ADITYA-U the carbon impurity and hydrogen recycling, due to relatively high surface area of graphite PFCs as well as their proximity to the plasma, limits the plasma performance and effective controls. Hence, H-GDC, H-GDC with Li-rod sputtering or Li evaporation, helium-GDC, argon–hydrogen mixtures-GDC in particular sequence are carried out to obtain better plasma discharges. The Li coating techniques and their effect on tokamak plasma discharges of ADITYA-U are discussed in this paper.

In this paper, the hydrogen diffusion behavior and hydrogen induced delayed fracture (HIDF) of Q-P980 (Q-P: Quenching and Partitioning) and MS980 (MS: Martensitic steel) steels were investigated using hydrogen penetration, slow strain rate tensile (SSRT) tests, thermal desorption spectroscopy (TDS) tests, fracture analysis, and microstructural examination in this paper. The austenite in Q-P980 is massive retained-austenite (RA) with low stability. The TRIP (Transformation Induced Plasticity) effect will occur in the process of strain and change into high carbon martensite. HIDF is caused by a substantial amount of surplus hydrogen being enriched at the border and flaws. The fracture has a broad cleavage surface and is a typical quasi-cleavage fracture. MS980 has been sufficiently tempered, resulting in a substantial quantity of distributed spherical cementite (150nm) precipitating around the lath martensite. This size and form of cementite may successfully trap hydrogen while maintaining the material’s mechanical characteristics. And tempering can effectively reduce the local stress level of steel, so MS980 has a very low HE susceptibility. HIDF is related to local stress and hydrogen accumulation. We suppose that Z is a constant and Z C is a critical value which associated to σ and C H (the local stress and local hydrogen concentration), rising as σ and C H rises. The atomic bonds at the crack tip, lattice position and the phase interface will fracture when Z C reaches a particular value Z. Tempering to minimize local stress and carbide precipitation to capture hydrogen are two strategies for reducing hydrogen embrittlement (HE) susceptibility, particularly for dislocation strengthened steel. Microalloying elements can generate precipitates that function as hydrogen traps and obstruct the HELP (Hydrogen Enhanced Localized Plasticity) process, lowering local stress and hydrogen accumulation.

In addition to electrical insulation properties, the thermal properties of nanodielectrics, such as glass transition temperature, thermal expansion coefficients, thermal conductivity, and mechanical properties, including Young’s modulus, bulk modulus, and shear modulus, are also very important. This paper describes the molecular dynamics simulations of epoxy resin doped with SiO2 nanoparticles and with SiO2 nanoparticles that have been surface grafted with hexamethyldisilazane (HMDS) at 10% and 20% grafting rates. The results show that surface grafting can improve certain thermal and mechanical properties of the system. Our analysis indicates that the improved thermal performance occurs because the formation of thermal chains becomes easier after the surface grafting treatment. The improved mechanical properties originate from two causes. First, doping with SiO2 nanoparticles inhibits the degree of movement of molecular chains in the system. Second, the surface grafting treatment weakens the molecular repulsion between SiO2 and epoxy resin, and the van der Waals excluded region becomes thinner. Thus, the compatibility between SiO2 nanoparticles and polymers is improved by the grafting treatment. The analysis method and conclusions in this paper provide guidance and reference for the future studies of the thermal and mechanical properties of nanodielectrics.

As an efficient approach to improve visibility, defogging technology is essential for the operation of ports and airports. This paper proposes a new and hybrid defogging technology, i.e. an electric–acoustic defogging method. Specifically, the droplets are charged by corona discharge, which is beneficial to overcome the hydrodynamic interaction force to improve the droplet collision efficiency. Meanwhile, sound waves (especially acoustic turbulence) promote the relative movement of droplets to increase the collision probability. In this study, the effects of acoustic frequency (f), sound pressure level (SPL), and voltage (V) on the droplet growth ratio were studied by orthogonal design analysis. The results of difference analysis and multi-factor variance analysis show that frequency and SPL are the dominant factors that affect the collision of droplets, and the effect of voltage is relatively weak. And f= 400 Hz, SPL = 132 dB, and V = −7.2 kV are the optimal parameters in our experiment. In addition, we further studied the impact of single factor on droplet growth ratio. The results show that there exists an experimental optimal frequency of 400 Hz. The droplet growth ratio increases with SPL and voltage level. The new technology proposed in this paper can provide a new approach for defogging in open space.

In this paper, an optically transparent structure that combines broadband absorption and low infrared (IR) emissivity for dual-band stealth is proposed. The whole structure includes two functional layers. The periodic resistive film of the upper functional layer acts on IR stealth. Its emissivity in the IR band of 8–14 μm is lower than 0.25. Another functional layer achieves greater than 90% wide absorption from 6 to 18.5 GHz. The whole optically transparent composite structure has a low profile of 0.141λ 0, where λ 0 is the wavelength of free space at the center frequency. It has absorptivity that is greater than 90% in the region of 5.7–16.5 GHz and has wide angular stability. The measured result is consistent with the simulation, which verifies the performance of the proposal. The IR-radar compatible stealth structure proposed in this paper has potential applications in the field of multi-spectrum compatible stealth.

The electro-mechanical impedance (EMI) technique has emerged as a cost-effective and non-destructive technique to detect the possible damages in the structure using a piezoelectric transducer, especially, lead zirconate titanate (PZT). The adhesive bond layer plays an important role in the PZT patch-host structure interaction for monitoring structural damage. Two bonding conditions are investigated in this research paper. Primarily, the debonding phenomenon of the adhesive bond layer may misinterpret the EMI response on the damage caused in structure. Subsequently, the investigation included the protective layer at the top of the PZT transducer to avoid sensor degradation. However, the analytical models developed so far have not considered a protective layer at the top of the PZT transducer. This paper presents the novel two-dimensional (2D) analytical model for incorporating debonding concepts and the new refined 2D analytical model to include a protective layer in the study of surface-bonded PZT transducers. The proposed analytical models are verified with the experimental studies. The experimental and analytical results show good agreement, which confirms the effectiveness of the new models. This paper also incorporated the effect of each bonding condition for monitoring structural damage by implementing the EMI technique. For the simulation, the numerical investigations on the PZT transducer bonded on the metallic (aluminum and steel) and concrete blocks are performed using coupled field analysis through finite element (FE) modeling. It is found that each bonding condition has influenced the resulting signatures. The signatures obtained from developed theoretical models and numerical simulations using three-dimensional FE models for each bonding condition are compared to highlight the influence on structural damage detection. The trend of signatures is found to be matching satisfactory. Several parametric studies have been conducted to show the efficacy of the new refined model with a protective layer. It considers the different input properties of an adhesive layer, host structure, and temperature conditions. The influence of debonding of the protective layer is also studied, and the obtained results support the need for a protective layer in the models.

In the course of flight, morphing skins play an important role in morphing aircrafts. Shape memory polymer (SMP) with variable stiffness performance is a good candidate material for skin. In this paper, a series of SMP morphing skins were prepared from hydro-epoxy resin, carboxyl-terminated butadiene acrylonitrile (CTBN) and maleic anhydride. By adjusting molecular weight and content of CTBN, in-plane properties and out-of-plane properties of morphing skins can be adjusted. Due to the in-plane tensile stress acting on the skin during flight, tensile test was carried out to study its in-plane performance. After testing, skin can resist maximum in-plane tensile strength of 63.7 MPa. As for the out-of-plane performance of the skin, shape memory test was studied in this paper. All morphing skins have 100% shape fixity rate (Rf) and fast shape recovery rate (Rr). When toughened by CTBN of 10% of 4000 molecular weight with a mass fraction, the skin can recover its out-of-plane deformed shape in 33 s. The SMP skins were proved to be a promising candidate for morphing skins.

The paper is devoted to experimental study of heat exchange and pressure drop of channel with various geometry twisted bands. The studies were carried out in the range of operating modes parameters of the nuclear power units’ heat exchange equipment. The three different designs of intensifiers are presented in the paper. The values of heat transfer coefficient and pressure drop are obtained. The dependences of the Nusselt number (Nu) on the Reynolds number (Re) were calculated. The comparative analysis of intensifiers is made. The efficiency factor was also calculated on experimental data. The most optimal geometry form of intensifier was selected.

Fused Filament Fabrication (FFF) technology is used to create metal parts in this paper. A binder formula is developed for 316L stainless steel powder, composed of polypropylene (PP), styrene ethylene butylene styrene (SEBS) and paraffin wax (PW). The binder is mixed with the 316L stainless steel powder to produce mixture which is then extruded into filament. The optimum binder formula, PP:SEBS:PW = 5:2:2, is obtained by orthogonal experiment. After optimization, mixture viscosity is reduced, filament tensile strength is guaranteed, rigidity is improved. The filament can be printed by a desktop FFF printer to obtain green parts. Binder within the green parts can be sufficiently removed by solvent and thermal debinding, and the shape of printed parts can be maintained well. After sintering, shrunken 316L stainless steel parts can be created, some pores distributed inside. With finer metal powder, the relative density of sintered part can be increased to 96%. The research ideas of this paper can provide effective methods for the development and optimization of binder.

In today’s industrial requirement, good wear resistant materials with the same or better mechanical properties are the need of the hour. In the present paper, an actuator that is used to lift the load is under study. It uses a linear actuation mechanism involving a screw-like motion to lift the loads. It employs a stainless steel of high quality. Since there are various types of wearing involved in the system, choice of the materials becomes the prime factor for determining the maintenance cost and the cycle life of the actuator. There are many research advances made in this field which provides us with the best type of material for its particular type of job. The present paper discusses the materials that could be substituted in place of the existing material choice i.e., in place of AMS5659 and aluminium-bronze. The two materials stated above are known for its superior wear handling and excellent mechanical properties.

In this study concentrated on the development of GPC by using industrial waste products such as fly ash, alccofine (1203) and GGBS. GPC is an advanced eco-friendly concrete manufactured by activating source minerals rich in alumina and silica by alkaline liquids to form aluminosilicates based on inorganic polymers. Where cement was complete replaced with mix proportion of 50% fly ash, 25% alccofine (1203) and 25% GGBS for different molarities (8M, 10M and 12M) of alkaline activators which is solving the problem of unsustainable usage of limestone and pollutant related to the manufacturing process of cement. The present paper reports the cube compressive strength, cylindrical split tensile strength and flexural strength of GPC and which is compared with M25 grade of control specimens. It was observed that the strength of GPC is increased than normal concrete as molarities increases of 8 M, 10M and 12M. The paper explains about the effectiveness of fly ash, alccofine (1203) and GGBS materials.

This paper investigates the potential sources of renewable energy, in particular biofuels. Biofuels tend to contain multiple harmful impurities that need to be separated if the biofuel is to have good energy performance, and the systems that run on it to produce electricity or heat are to operate more reliably. The paper discusses use of hydrocyclones as the most productive and reliable biofuel purification method. It dwells upon the factors that negatively affect separation of mixtures in a hydrocyclone, which are attributable to the complex hydrodynamics of the flow in such a unit. In order to eliminate these factors, the authors hereof have developed two hydrocyclone designs. An experimental test bench was designed and made to test these designs. Parts of the units were 3D printed from an environmentally friendly material. For testing, we used a biodiesel made from waste cooking oil with an impurity content of 23%. Experiments showed a maximum separation rate of 94.2%. The proposed solutions did improve the effectiveness of biodiesel mixture separation. These designs can be effectively used to separate non-homogeneous mixtures.

The article presents original results of research of the dampers with passive and semi-active damping using polymer springs (also artificial muscles or nylon springs) with negative thermal expansion. Passive damping can be ensured by the strong damping effects of polymer springs. Semi-active damping can be provided by heating the springs from an additional heat source. According to design such dampers, mathematical models for analytical elastostatic and thermoelastostatic analyzes of dampers for selected load cases are processed in the paper. The permissible values of mechanical and thermal load of the dampers are determined. The obtained results are verified by numerical analysis using the finite element method. The elastostatics of the passive damper and its damping functionality have been verified on a real model of the damper. The compiled mathematical models can be used in the design of polymer dampers as well as in their automatic control. Designed and analysed dampers can be used in smaller mobile or stationary systems such as scooters, small car kits and the like. The elastodynamic functionality of the dampers with passive and semiactive damping will be presented and discussed in our further paper.

Structural health monitoring (SHM) systems have a potential to reduce lifecycle costs of structures. They may be used for maintenance planning which reduces the maintenance cost as well as for lifetime extension. As a result, there is a lot of active research in the area for SHM of civil and mechanical structures. The SHM system should be low cost, suitable for continuous monitoring, able to detect small levels of damage. Guided waves (GW) based SHM techniques allow monitoring of large plate-like structures with few sensors and have been identified as the most promising of techniques for SHM. Several different actuators and sensors have been developed and used for the GW based SHM. FBG sensors due to their low weight, and ability to be multiplexed have been long thought to be an ideal sensors for SHM. The recent development of the edge filtering approach has increased their sensitivity to GW sensing and made them ideal sensors. Unfortunately the FBG sensors are passive sensors and show directional sensitivity. These operational constraints make extension of the earlier developed GW based SHM techniques for FBG sensors difficult. Recently the authors developed a technique for damage detection specifically designed for a network with FBG sensors. This paper develops a methodology for a design of an actuator-sensor (AS) network for improving the damage assessment capability using the developed method. The paper develops a two-step methodology for the optimization of actuator placement for an AS network with FBG sensors. In the first step the number of actuators needed for the optimization are determined based on actuator densities. Once the number of actuators is known, a genetic algorithm (GA) is developed for the optimization of the their positions. The cost function is developed based on two new metrics (namely coverage2—coverage with at least 2 AS pairs and coverageR—radial coverage based on edge reflections) which are defined by the application demand. The optimized placement is then used to successfully detect and localize the damage. The study also shows the merit in the use of the specific metrics and the sufficiency of the metrics developed for improving the damage detection capability of the specific method.

Cladding tube is one of the key components in nuclear power reactor. In this paper, the forming process of a new cladding tube is investigated, namely ribbed tube. The influence of semi die angle on the forming process of ribbed tube is studied. Firstly, the strain-stress curves of 316L stainless steel (SS) at different strain rates are obtained. Based on the strain-stress curves, a modified Johnson-Cook constitutive model which ignore the influence of temperature are used, and the parameters of the modified model are determined. Then, the modified Johnson-Cook is used to establish the finite element (FE) model of ribbed tube drawing process, and two pass drawing process is adopted in this paper. Finally, the influence of semi die angle on the forming process (forming quality and drawing force) of ribbed tube is elucidated, and the credibility of the simulation is confirmed by comparing the simulation and experimental results. The results show that when the semi die angle less than 8 °, all the formed ribbed tubes meet the requirement, but there are inner grooves appear at the inner wall, and the inner grooves cannot be avoided in the drawing process. Moreover, when the semi die angle is 8 °, the inner grooves have smallest depth.

The manual inspection for the damage state of the electric energy metering box consumes a lot of time, the workload is large, and the data storage is difficult. In order to solve these problems, this paper proposes an automatic detection method for the damage state of the electric energy metering box based on the YOLOv5 algorithm. The actual metering box pictures taken by the operation and maintenance inspectors are used as the training set, LabelImage is used to annotate the data set, and YOLOv5s model is used to train the data set. The experimental results show that the method proposed in this paper can accurately mark the position of the metering box lid and accurately predict its damage state. The average accuracy reaches 98%, which can meet the requirements for the detection accuracy of the power metering box damage state in the operation and maintenance inspection work.

Metallic spiral-wound gasket sealing are generally applicable for the service conditions, which are subject to the periodic temperature and pressure changes, shocks or vibrations. The nominal size of the largest spiral wound gasket of flanges is according to the provisions of HG/T 20631; those more than this specification are in the scope of non-standard parts, which require customization and manufacturing. This paper aims for introducing the successful experience of the first application of customized for non-standard spiral-wound gasket sealing of the large opening flange used for pressure vessel which bears high temperature and high pressure. The paper demonstrated the basic principle and critical points for the design and application of customized non-standard spiral-wound gasket sealing for the large opening flange and provided the valuable reference of actual application experience for the design and manufacturing of similar components. This paper presents the experiences summary in the study field and provides valuable reference of actual application experience for the design and manufacturing of similar components.