Search

At present decreasing of costs and increasing of efficiency are the most priority directions in any industry. Developing in this way, JSC “Ural steel” together with FGUP “CNIIchermet after I.P. Barding” had mastered production of sheet metal product with increased resistivity against atmosphere corrosion made of steel 14ХГНДЦ for construction of bridges. Because of specific chemical composition of the steel, in the process of metal structures running in the open air, a solid strong oxide film is formed on the metal of the structures which prevents further corrosion without painting. For bridge builders elimination of costly operation of painting of span structures will enable to decrease considerably the costs of bridges construction and running. Having many advantages, steel 14ХГНДЦ has some restrictions in applications for steel structures without painting, as follows: - in sea zone according to domestic norms no close than 500 m from coastline; - in case of disorderly conditions of protective film formation and/or application of salt solutions for surface cleaning (as a rule the restrictions refer to traffic area of bridge span). In view of that for JSC “Ural Steel”, as the leading producer of bridge steel in Russia, an actual task erose: to elaborate and create a weatherproof steel, which could not only operate the whole period of a bridge running without additional protection at bridges con­struction through sea areas or close to coastline, but also withstand severe climate conditions of our country, including areas of High North with temperature lower -50°С. To solve the task together with OJSC “Institute Giprostroymost” and JSC BNIIZhT, a research work was accomplished to elaborate a system of alloying new steel 06ГН3МД with nickel content ~3.0 %, as well as production modes ensuring required corrosion resistance for operation in sea zone. Results of laboratory studies of the new weatherproof steel 06ГН3МД for application in bridge structures for coastal conditions and sea areas presented. Results of mechanical, technological, corrosion as well as fatigue tests of rolling products of the elaborated steel presented. It was established by laboratory studies that the new steel is weatherproofed and ensures lower corrosion losses, higher impact toughness at negative temperatures and plasticity comparing with steels used at present. It was shown that the strength class, technology and modes of factory welding of steel 06ГН3МД meet the requirements to steel span structures of bridges. Base on the results of the studies, the chemical composition of the steel 06ГН3МД was specified, as well as modes of heat treatment, ensuring the required characteristics with significant acceding. It was established that samples of the new steel 06ГН3МД showed considerably higher corrosion resistance - in average by 20% comparing with steel 14ХГНДЦ. At that corrosion resistance tests of welded joints of the new steel showed even higher resistance of the seam comparing with the basic metal, which speaks about quality selection of welding modes and welding materials.

The behavior of adhesive joints of D16AT An. Ox. chrom. aluminum alloy, made with the use of epoxy and phenolic-rubber adhesives, while exposed to constant tensile load and climatic factors in humid subtropics, both in open air and under a canopy, which made it possible to develop recommendations for the protection of adhesive compounds from exposure climatic factors.

Background: The microwave technique of drying dental stone to achieve improved hardness and strength has been suggested in recent years. However, its effect on the wear properties of dental stone has not been thoroughly examined. Aim: The present study was conducted in vitro to determine the abrasion resistance of three commercially available Type IV dental stones using three different drying techniques. Materials and Methods: A total of 180 samples were prepared from 3 Type IV dental stones; namely Eliterock, Zhermack (Italy), Kalrock, Kalabhai industries (India), and Gyprock (Rajkot, India). Samples were subjected to drying in open air for 2 h, hot air oven at a temp of 230°C for 1 h and microwave oven for 5 min at 900Watts. Abrasion resistance was determined using a customized metallic abrasion resistance tester. Results: Microwave oven drying produced samples with increased abrasion resistance values when compared to samples dried in hot air oven and air-dried specimens. Eliterock showed significantly higher mean abrasion resistance values followed by Kalrock and Gyprock. Conclusion: Drying type IV dental stone in a microwave oven at 900W for 5 min increased the abrasion resistance within short time.

A new compound Cs2AlB5O10 was synthesized by a high temperature solution method in open air. It features a DUV cutoff edge below 190 nm and a moderate SHG response (0.8 × KDP at 1064 nm), indicating that it may have certain application prospects in the UV nonlinear optical region.

Lead iodide (PbI2) thin films were grown and converted to methyl ammonium lead triiodide (MAPbI3) perovskites through a two-step chemical vapour deposition process, addressing the issue of stable and scalable synthesis of perovskites layers. High quality, stable under open air, large perovskite grains close to micrometre size with full surface coverage were realised after 60 min conversion from the pre-deposited PbI2. The relationship between the PbI2 layer deposited in the first step and the converted perovskite is discussed. The performance of the planar perovskite device was investigated with different thicknesses of the hole transport layer under open air. The devices performed relatively poor with highest efficiency of 4.35% obtained when a thicker hole transport layer thickness used, which is attributed to protruding grains of perovskite film through the hole transport layer, thereby corroding the silver metal electrode.

Owing to sluggish ionic mobility at low temperatures, supercapacitors, as well as other energy-storage devices, always suffer from severe capacity decay and even failure under extreme low-temperature circumstances. Solar-thermal-enabled self-heating promises an attractive approach to overcome this issue. Here, we report a unique H-bonding charge-transfer complex with a high photothermal conversion efficiency of 79.5% at 405 nm based on chloranilic acid and albendazole. Integrated with a microsupercapacitor, the chloranilic acid-albendazole complex (CAC) film prompts an apparent temperature increase of 22.7 °C under 1 sun illumination at −32.6 °C, effectively elevating the working temperature of devices. As a result, the rate capability of the microsupercapacitor has been significantly improved with a 17-fold increase in capacitance at a current density of 60 μA cm−2, leading to outstanding low-temperature performances. Importantly, the integrated device is capable of working at a low temperature of −30 °C in the open air, which demonstrates the potential of CAC in practical applications for low-temperature ultracapacitive energy-storage devices.

Long-term stable perovskite solar cells (PSCs) fabricated in ambient conditions are highly desirable. However, the stable perovskite film has yet to be easily controlled in open air, especially emp...

The structural use of concrete depends largely on its strength, especially compressive strength.Various tests were carried out to ascertain the properties of concrete materials, whereas test performances ofthe concrete with different mix ratios at specific ages of curing were undertaken. The study determined thecompressive strength of concrete using different curing methods. Four different methods of curing (ponding,continuous wetting, open-air curing and sprinkling with water) were used. Seventy-two (72) cubes were castusing a mix ratio of 1:2:4 and 1:3:6 with 0.5 water cement ratio and with 0.6 waters cement ratio respectively.The compressive strengths were determined after 7 days, 14 days and at 28 days of curing. Findings showthat for 1:2:4 concrete, maximum of 28-day compressive was the highest for concrete cured by ponding andthe least was by sprinkling water. Further findings show that for 1:3:6 concrete, maximum of 28-daycompressive strength was obtained using ponding and the least was open air curing. Despite ponding methodproducing the highest compressive strength of concrete, it is practically impossible to cure cubes aboveground structural elements. Wet-covering method is recommended for structural elements, such as columns,beams and slabs in other to produce concreteof a required compressive strength.

We report, for the first time to our knowledge, on the polymer nanocomposite sunlight spectrum down-converters made by the concurrent multi-beam multi-target pulsed laser deposition (CMBMT-PLD) of phosphor and polymer in ambient air. Phosphor PLD targets were made of down-converting rare-earth (RE)-doped fluorides NaYF4:Yb3+,Er3+, and NaYF4:Yb3+,Tm3+ with a Stokes shift of 620 nm (from 360 to 980 nm), minimizing the effect of re-absorption. The phosphors were synthesized by the wet method. Polymer target was made of poly (methyl methacrylate) known as PMMA. Target ablation was conducted with 1,064 nm beams from an Nd:YAG Q-switched laser. Beam intensity was 2.8 × 1016 W/cm2 for both targets. The substrate was a microscope glass slide. Phosphor nanoparticles with a size ranging from 10 to 50 nm were evenly distributed in the polymer matrix during deposition. The nanoparticles retained the crystalline structure and the fluorescent properties of the phosphor target. There was no noticeable chemical decomposition of the deposited polymer. The products of laser-induced reaction of the polymer target with atmospheric gases did not reach the substrate during PLD. Post-heating of the substrate at ∼90°C led to fusion of separate polymer droplets into uniform coating. Quantum yield of the down-conversion polymer nanocomposite film was estimated to be not less than ∼5%. The proposed deposition method can find its application in making commercial-size down-converter coatings for photo-voltaic solar power applications.

Herein we show the versatility of coordination chemistry to design and expand a family of 2D materials by incorporating F groups at the surface of the layers. Through the use of a prefuntionalized organic linker with F groups, it is possible to achieve a layered magnetic material based on Fe(ii) centers that are chemically stable in open air, contrary to the known 2D inorganic magnetic materials. The high quality of the single crystals and their robustness allow to fabricate 2D molecular materials by micromechanical exfoliation, preserving the crystalline nature of these layers together with the desired functionalization., This work has been supported by the EU (ERC Advanced Grant MOL-2D 788222 and ERC Consolidator Grant S-CAGE 724681), grants PID2020-117177GB-I00, PID2020-117152RB-I00 and CEX2019-000919-M, funded by MCIN/AEI/10.13039/501100011033, and the Generalitat Valenciana (PROMETEO program, IDIFEDER/2018/061 and iDiFEDER/2020/063). J. L.-C. acknowledges the Universitat de València for an “Atracció de Talent” fellowship.

The paper reports on the investigation of honey as the electrolyte gate dielectrics of graphene field effect transistors. Transfer and output characteristics of graphene transistors were collected at room temperature and 40 °C under open air. Typical behaviors such as Dirac neutrality point and linear relation of drain current with drain-source voltage at low field and various gate bias voltages were achieved. In addition, cleaning and reapplication of honey on transistors only show slight changes in those characteristics.

The quest to deliver construction projects within the shortest possible time handled many engineers to maneuver curing ages of concrete and this has been a major concern in construction industries due to associated failures of concrete members emanating from improper curing. This study therefore aimed at investigating the effect of different curing methods on density and compressive strength of concrete with a view to enhancing technological self-reliance of the nation. Concrete cube specimens (150 mm × 150 mm × 150 mm) were cast using mix ratio 1:2:4 with 0.5 water-cement ratio. The concrete specimens were cured for 28 days using open air, ponding, sprinkling and dry covering curing methods. The compressive strength and density were evaluated. The data were validated. The results showed that the compressive strength increases with increasing curing age. The respective compressive strength values obtained for ponding, sprinkling, dry covering and open air curing methods were 22.04, 20.48, 17.28 and 16.02 respectively. The curing methods have compressive strengths in the order Ponding < sprinkling < dry covering < open air. The results of the curing methods on density were also noticed to be directly proportional to strength. Appropriate curing methods of concrete had greater impact in influencing physical and mechanical properties of concrete.Keywords: Concrete, Curing methods, Strength, Sustainable growth

The rapid development of modern society has increased the demand for high-performance geo-materials. As an advanced cementitious composite, fiber-reinforced concrete has attracted much attention and has been widely applied to various buildings and civil infrastructure. A basalt fiber-reinforced concrete is proposed as an advanced geo-material and the mechanical and thermal properties were investigated in this study. The basalt fiber-reinforced concrete was compared with ordinary concrete to confirm its superiority by determination of the physical parameters, static compressive test, and dynamic compressive test. The static compressive test was performed using the YAW-2000C constant stress pressure experimental machine under different heating temperatures and cooling methods, while the dynamic compressive test was performed using the 75-mm split-Hopkinson pressure bar under different loading rates, heating temperatures, and cooling methods. For the basic physical parameters, it was found that the mass loss and wave velocity of concrete decrease with the increase of the temperature. In the static compressive test, the static compressive strength for both the ordinary concrete and the fiber-reinforced concrete decreased with the increase of the temperature, and greater strength was observed with the air-cooled compared to the water-cooled method. It was found that the strength of basalt fiber-reinforced concrete is greater than that of ordinary concrete. In the dynamic compressive test, the strength increased with an increasing loading rate and descended with an increasing temperature, while for the same heating temperature and loading rate, water cooling produced more irregular and smaller fragments than air cooling. The dynamic compressive strength of basalt fiber-reinforced concrete was bigger than that of ordinary concrete.

International audience

Serious environmental pollution will occur if corn stalk materials are discarded randomly or burned in open air. This study presents a possible method for using corn stalk materials to make...

This project work focuses on the comparison of the engineering properties ofPyrus communisunder solar and air-drying method. Green samples of the wood were dried simultaneously in both solar kiln and open air for 15 days. The daily moisture content reduction (%MC) under both drying conditions were observed and recorded. Mechanical tests (shear strength, compressive strength, hardness and tensile strength) were conducted. The results showed that open air-dried woods attained fibre saturation point (30-25%MC) within three days. Timbers dried in solar kiln attained lower %MC (12.9, 11.0, 14.3, 12.3) when compared to open-air dried samples (22.1, 18.5, 21.1, 17.1). For all the mechanical tests conducted, solar kiln dried timber had higher mechanical properties than the open air-dried woods.

We report an industrially relevant approach to both scalable and fast open-air perovskite photovoltaic (PV) module production. This work resolves some of the most formidable barriers to module-level scaling that the perovskite community has been facing. Key advances include scalable large-area spray deposition, new monolithic integration scribing techniques, advanced photoluminescence characterization, and reproducible high-throughput manufacturability. Our rapid spray processing techniques enabled the highest perovskite PV efficiency produced in open-air. Innovations in scribing techniques enabled the first single-source laser process to achieve perovskite module monolithic integration and technoeconomic analysis led to a comprehensive cost model for perovskite module manufacturing. We report significant progress in reducing perovskite manufacturing costs necessary to potentially compete with incumbent Si-based PV for utility-scale power generation.

We report high throughput open-air processing techniques for the scalable production of all device and barrier layers for perovskite photovoltaics (PV). This work discusses and resolves some of the most formidable barriers to module-level scaling that the perovskite community has been facing. Our advanced technoeconomic manufacturing analysis indicates that vacuum-based processes with high capital expenditures (CapEx) and low throughputs dominate the cost of production. Open-air fabrication methods offer low CapEx routes to manufacturing, but achieving reproducibility in ambient conditions with varying relative humidity has been a persistent challenge. The use of rapid processing methods with plasma curing to convert films from the solution-state enables reproducibility, moisture immunity, and the highest perovskite PV efficiency produced in open-air. These methods are readily translatable to in-line processing where layers are sequentially deposited without the need for lengthy post-annealing steps that reduce throughput and involve additional equipment. Significant progress is demonstrated in reduced manufacturing costs as perovskites contend as a commercially viable next-generation thin film PV technology.

This work represents an overview on types of wounds according to their definition, classification and dressing treatments. Natural and synthetic polymeric wound dressings types have been analyzed, providing a historical overview, from ancient to modern times. Currently, there is a wide choice of materials for the treatment of wounds, such as hydrocolloids, polyurethane and alginate patches, wafers, hydrogels and semi-permeable film dressings. These systems are often loaded with drugs such as antibiotics for the simultaneous delivery of drugs to prevent or cure infections caused by the exposition of blood vessel to open air. Among the presented techniques, a focus on foams has been provided, describing the most diffused branded products and their chemical, physical, biological and mechanical properties. Conventional and high-pressure methods for the production of foams for wound dressing are also analyzed in this work, with a proposed comparison in terms of process steps, efficiency and removal of solvent residue. Case studies, in vivo tests and models have been reported to identify the real applications of the produced foams.

Four new deep ultraviolet (DUV) borates Li7Na2KRb2B12O24, Li7.35Na2.36K1.50Cs0.78B12O24, Li6.97Na2.63K1.24Cs1.15B12O24, and Li7.27Na2.67Rb2.06B12O24 have been produced by high temperature solution method in open air. The structural analysis suggests that they all crystallize in the same trigonal space group R 3 ¯ (No. 148), and possess the identical isolated B12O24 groups. Structural comparison among alkali-metal borates with BnO2n in their chemical formulas have been discussed. In addition, infrared spectra were used to verify their structural validity. Furthermore, the UV–Vis–NIR diffuse reflectance spectra reveal that they exhibit short cutoff edges below 180 nm (6.88 eV). The first-principles theoretical studies carried out to increase the understanding of electronic structure and linear optical property.

Two borate-carbonates Ba4M(CO3)2(BO3)2 (M = Ba, Sr) have been successfully synthesized in the open air representing the first examples of borate-carbnate complex. Their structures were determined by single crystal X-ray diffraction and they both crystallize in same space group, Pnma . Their structures feature a Ba/Sr-based three dimensional framework composed of the BaO8 polyhedra (the SrO8 polyhedra), isolated BO3 and CO3 triangles. Detailed structure analysis shows that the intergrowth of [Ba3(BO3)2]/ [Ba2Sr(BO3)2] and [BaCO3] layers favors the formation of these two borate-carbonates. In addition, their syntheses, spectroscopic properties and thermal behaviors were investigated.

The article presents the studies of the climate resistance of polyethylene composites containing different stabilizers. To carry out complex climatic studies, we chose materials with the highest and most stable mechanical characteristics and density. It has been found that the use of sulfur-containing stabilizing additives leads to a color change of the samples after 1 month of exposure, probably due to the formation of quinone during decomposition of stabilizing additives. It is shown that one of the most sensitive indicators of polyethylene aging is elongation at rupture. The study of the dependence of elongation at rupture on the period of exposure in the open air showed that the use of stabilizers of grades СО3 and СО4 in an amount of 0.3-0.5 wt.% is sufficient to maintain stable work of products and constructions for 1 year. Whereas the original polyethylene and the composite containing Stafen stabilizer become embrittled after 9 months of exposure. The electron microscopic studies have shown that the submolecular structure of the composites significantly depends on the exposure conditions. The most prominent changes in the structural characteristics were found for the composites exposed in the open air. Significant temperature drops during the test period cause these changes. In the general case, it has been found that the use of stabilizers of grades СО3 and СО4 can extend the service life of products and constructions of unpainted polyethylene in the climatic conditions of the Sakha Republic (Yakutia) by 25% (from 9 to 12 months).

An equiatomic TiFeNiCrCo high entropy alloy (HEA) has been synthesized through mechanical alloying (MA) and the effect of annealing on phase evolution and their correlation with magnetic behavior is investigated. It has been found that FCC and BCC phases are formed at as synthesized state. DSC analysis confirms that the synthesized phases are stable up to 767°C. This is also confirmed by annealing of the synthesized HEA at different temperatures (500 and 700°C) under different conditions (open air and vacuum). Open air annealed HEAs exhibits an oxide phase along with the synthesized phases. The value of Ms and Hc for synthesized TiFeNiCrCo HEA is found to be11.96emu/g and 152.32Oe respectively. Moreover, after vacuum annealing at 500 and 700°C the value of Ms and Hc are found similar to the synthesized HEA. However, open air annealed sample exhibits high value of Ms and Hc as compared to the synthesized sample. For open air annealed at 700°C, the value of Ms is increased significantly up to 21.93emu/g from 11.96emu/g. The present study describes that the magnetic behavior of the synthesized TiFeNiCrCo HEA can be improved after annealing at different temperatures under different conditions.

The physicomechanical and X-ray investigations of high entropy oxide coating obtained by the cathode sputtering of multicomponent alloy CrFeCoNiMn in plasma of compressed vacuum-arc gaseous discharge have been conducted. The hardness of high entropy oxide coating is shown to reach the level of 27 GPa at the elasticity modulus of 270 GPa, which decreases to 17 GPa after annealing at temperature 1100°C during 300 min in the open air. The friction coefficient of coating at small sliding velocities amounts to 0.045–0.132 depending on the coating hardness.

The development of open-air, high-throughput, low-cost thin film fabrication techniques has immense potential and interest in optoelectronics. However, the oxygen-rich atmosphere associated with su...

Reducing biofouling while increasing lubricity of inserted medical catheters is highly desirable to improve their comfort, safety, and long-term use. We report here a simple method to create thin (∼30 μm) conformal lubricating hydrogel coatings on catheters. The key to this method is a three-step process including shape-forming, gradient cross-linking, and swell-peeling (we label this method as SGS). First, we took advantage of the fast gelation of agar to form a hydrogel layer conformal to catheters; then, we performed a surface-bound UV cross-linking of acrylamide mixed in agar in open air, purposely allowing gradual oxygen inhibition of free radicals to generate a gradient of cross-linking density across the hydrogel layer; and finally, we caused the hydrogel to swell to let the non-cross-linked/loosely attached hydrogel fall off, leaving behind a surface-bound, thin, and mostly uniform hydrogel coating. This method also allowed easy incorporation of different polymerizable monomers to obtain multifunctionality. For example, incorporating an antifouling, zwitterionic moiety sulfobetaine in the hydrogel reduced both in vitro protein adsorption and in vivo foreign-body response in mice. The addition of a biocidal N-halamine monomer to the hydrogel coating deactivated both Staphylococcus aureus ( S. aureus) and Escherichia coli ( E. coli) O157:H7 within 30 min of contact and reduced biofilm formation by 90% compared to those of uncoated commercial catheters when challenged with S. aureus for 3 days. The lubricating, antibiofouling hydrogel coating may bring clinical benefits in the use of urinary and venous catheters as well as other types of medical devices.

When two high-speed trains pass through a tunnel, the aerodynamic changes are more complex and drastic than in open air owing to the interference of the tunnel wall and the entry effect. The impact on the carbody fatigue strength is very significant in the fatigue reliability design of the carbody. In this paper, the sequential coupling method was used for the first time to study the effect of pressure waves on the fatigue strength in a large-scale and complex carbody structure. The computational fluid dynamics method was used to calculate and analyze the aerodynamic pressure wave of the intersection of the trains in a long and short tunnel. A full-scale finite element shell model of the carbody structure was established. Then, the time integration method was used to convert the transient pressure wave into the aerodynamic loads bearing by the side wall of the carbody. The inhomogeneous stress concentrations at the restraint points were eliminated by the inertial release method; moreover, a finite element analysis of the carbody was carried out under the combined aerodynamic and mechanical loads. The Goodman fatigue strength curve of the aluminum alloy carbody was drawn. The influence of the aerodynamic load on the fatigue strength of the vehicle body was analyzed and compared under the entry effect of the short tunnel. The results show that the aerodynamic load of the short tunnel has a significant impact on the fatigue strength of the carbody owing to the train's entry effect. The safety factor of the fatigue strength is 15% less than that of the long tunnel aerodynamic load. In this paper, computational fluid dynamics and finite element method were used to analyze and evaluate the impact of the pressure wave on the fatigue strength of the carbody, which is of great reference value in the structural design of the carbody subjected to complex aerodynamic loads.

Based on fundamental research of above-threshold-power laser radiation by C. Townes (laser beam splitting) and G. A. Askaryan (self-focusing and sublimation evaporation), a new highperformance technology for growing nanowhiskers of metal and their oxides, semiprecious crystals, and composite materials based on polycarbonate in open air is developed. Some possibilities of its practical applications are shown.

The synthesis of semiconductor nanocrystals (NCs) with low cost and in large scale is important for a variety of applications. In this work, a facile, non-vacuum solvothermal method was used to synthesize plate-shaped Cu3ZnInSnSe6 (CZITSe) NCs with zincblende structure. Elemental mapping and XPS were utilized to establish the presence of all key elements. The bandgap of these CZITSe NCs is determined to be 1.22 eV. Thin films fabricated from the CZITSe NC suspension show clear photoresponse under illumination of a solar simulator, suggesting that these NCs can be photoabsorbers for thin-film solar cells. This study demonstrates a simple and economical method to synthesize CZITSe NCs with plate shape potentially useful for applications including solar energy conversion.

Laser-induced breakdown spectroscopy (LIBS) is a versatile spectrochemical technique that probes the elemental composition of materials, exploiting the light emitted by a transient plasma generated as a result of the interaction between a short laser pulse and the sample or object being examined. It has been increasingly employed in the analysis of archaeological and historical objects, monuments and works of art for assessing the qualitative, semiquantitative and quantitative elemental content of diverse materials such as pigments, pottery, glass, stone, metals, minerals, biomaterials and fossils. In this chapter, the basic physical background of LIBS is briefly outlined and technical details are presented concerning the instrumentation and how analysis is performed and data are interpreted and used. Case studies are presented to illustrate how LIBS has been employed in support of archaeological science, art history and conservation studies.

We report on the fabrication of highly porous metal-oxide nanostructures by pulsed laser deposition performed in air at atmospheric pressure. The depositions were performed by ablating synthesized ZnO and a mixed target of ZnO and TiO2 as initial materials. The attention was focused on the structure, morphology, optical and photocatalytic properties of the as-deposited nanostructures of the ZnO-TiO2 system. The technology applied leads to the formation of nanostructures composed of nanoparticles. The as-prepared samples possess a high transmittance in the visible and near IR region with an optical band gap in the range of 3.1 - 3.2 eV. It was demonstrated that the as-deposited ZnO and ZnO-TiO2 nanostructures degrade Rhodamine B up to 43 - 44% after 300-min UV irradiation.

In the present work, we report the design and fabrication of a copper-containing ionic liquid supported magnetic nanocatalyst via a convenient and straightforward synthetic approach for the formation of 2-phenylquinazolin-4(3H)-ones using o-aminobenzamide and benzaldehydes as the reaction partners. The successful formation and properties of the as-prepared catalyst have been thoroughly investigated using diverse physico-chemical techniques including FT-IR, XRD, FE-SEM, TEM, ICP, VSM, BET and TGA. Using this nanocatalytic system, a variety of 2-phenylquinazolin-4(3H)-ones are synthesized in excellent yields with operational ease and short reaction times in an environmentally preferable solvent under open air and without using any external oxidizing agent. Besides, the catalyst possessed facile magnetic recoverability and remarkable reusability for six consecutive runs without any appreciable decrease in the catalytic efficiency.

Emerging moisture sensitive devices require robust encapsulation strategies to inhibit water ingress and prevent premature failure. A scalable, open-air plasma process has been developed to deposit alternating layers of conformal organosilicate and dense SiO2 thin-film barriers to prevent moisture ingress. The in situ low-temperature process is suitable for direct deposition on thermally sensitive devices and is compatible with flexible polymeric substrates. Using optical calcium testing, low water vapor transmission rates on the order of 10-3 g/m2/day at an accelerated aging condition of 38 °C and 90% relative humidity (RH) are achieved. Using moisture-sensitive perovskite devices as a representative moisture-susceptible device, devices retain over 80% of their initial performance for over 660 h in a 50 °C 50% RH accelerated aging environment. The ability of the multilayer barrier to enable device resistance to humid environments is crucial toward realizing longer operating lifetimes.

The first example of the usefulness of titanium (IV) butoxide, as initiators for open air in-situ intercalative polymerization of ε-caprolactone (ε-CL) in the presence of organoclay is herein reported. The bionanocomposites based on poly(ε-caprolactone) (PCL) were prepared by in-situ Ring Opening Polymerization (ROP) of ε-caprolactone in the presence of different organomodified montmorillonite clay (ODA-MMT) loading (1, 3 and wt%). Structural, thermal and mechanical characterizations of the resulting bionanocomposites were investigated. The presence of the nanoclay increased PCL crystallinity, melting temperature and thermal stability, whereas some decrease in T was observed. TEM analyses confirmed the good dispersion of ODA-MMT with 1 and 3 wt% content into the PCL polymer as already asserted by XRD diffraction. Finally, the Young's modulus of the PCL nanocomposites was higher compared to the neat PCL, while a decrease of stress and strain at break for materials with different filler content was observed., Financial support for cooperative research came from the Hassan II Academy of Science and Technology of Morocco/CSIC-Spain (Project AH11STC-nano 2011 – 2012 and 2010MA003), the MESRSFC and CNRST of Morocco (PPR program), and the bilateral scientific committee programs of collaboration between Morocco and Tunisia (n 17/TM/20), and the Spanish Ministry of Science and Innovation (MICINN) through the project MAT2016-81138-R.

This paper carries out an experimental study to enhance the quality of the characteristic transmittance curve in the infrared range of 2.5–7 µm of the optical magnesium fluoride (MgF2) ceramic. This work evaluates the effectiveness of using vacuum environment in the MgF2 ceramic hot-pressing technique by comparing the density and the quality of the transmittance characteristic curve of two types of specimens manufactured by the hot-pressing technique corresponding to open air and vacuum environment under the same technological parameters including temperature 650°C, time 30 min, and pressure 200 MPa. The results present that, in comparison with using the hot-pressing technique in the open air, when using the hot-pressing technique in a vacuum environment, the transmittance increases about 4–10%, the characteristic transmittance curve is smoother and has fewer peak points, and the wide of peak points are smaller. When hot-pressing in a vacuum environment, the temperature can be up to 750°C in order to obtain the magnesium fluoride (MgF2) ceramic with the highest quality of characteristic line in the infrared range of 2.5–7 µm. Seventeen specimens are manufactured to conduct the experimental study in order to figure out the optimal set of technological parameters (temperature T = 640.9°C, time t = 33.0 min, and pressure P=231.4 MPa) when hot-pressing in a vacuum environment by the experimental planning approach.

This study investigates the effect of the contact size and the gross-slip sliding amplitude on the fretting wear rate of a steel flat-on-flat interface. Results confirm an asymptotic decrease of the wear rate with the contact size. This evolution is induced by an easier oxygen access to the interface favoring abrasive wear according to the Contact Oxygenation Concept (COC) and by a faster ejection of the protective debris particles from the interface according to the Third Body Theory (TBT). To decouple these COC and TBT contributions, the effect of the sliding amplitude and the contact orientation with respect to the sliding direction is assessed using an original macro-texturation test strategy. Wear rate evolutions as well as SEM-EDX fretting scar analyses suggested that COC is mainly driven by the minimum distance between the contact center and the open air contact edges ( L COC ), whereas TBT wear process is chiefly controlled by the ratio of the collinear contact length to the sliding amplitude ( L TBT / δ g ). Assuming a weighted influence of the contact oxygenation process on the TBT wear process, a simple power-law formulation is introduced to quantify the contact size effect on the energy wear rate fluctuation. A very good correlation with the experiments confirms the stability of the proposal.

The Humidification Dehumidification (HDH) desalination system is a promising method for production of potable water in isolated locations. Among different component constituting the HDH desalination system, humidifier and its packing are paramount factors in determining system productivity. Several experimental investigations were conducted to study the influence of packing on humidifier performance. However, numerical analysis dealing with performance of humidifier packing is still not available. Such an investigation will be useful to select the optimized packing for a humidifier. In the present work, performance analyses of 15 different types of random packing have been carried out using Scilab software. From this study, it is concluded that metal packing with highest surface area to volume ratio, lowest packing factor and smallest packing diameter functions as the best humidifier packing. Experimental study was also conducted in a pilot plant of open air open water HDH cycle using pall ring 25 mm diameter metal packing, which has shown the highest performance index in the numerical study. Experimental results obtained were found to be in agreement with the numerical results. Present work is a useful tool in designing new packing material of desired properties since the packing performance is a strong function of its geometrical properties.

Fabrication of most-promising CH3NH3PbI3 based perovskite solar cell in ambient condition is excessively essential to industrialize this revolutionary development. In this research work, an efficient, facile and economical technique has been developed to fabricate CH3NH3PbI3 perovskite solar cell in ambient condition which is termed as dual-step thermal engineering technique. In this dual-step thermal engineering technique, the perovskite precursor solution has been spin coated over a mildly hot substrate which was heated at 60 ⁰C for 10 min and followed by annealing at 80 °C for 30 min immediately after spin coating and compared with the perovskite film fabricated by conventional annealing in which the film was heated once at 120 °C for 60 min after spin coating. The comparative study shows that the newly developed dual-step thermal engineering technique is highly efficient and forms smooth, dense, well-crystallize, almost pinhole free perovskite solar cell at open air condition and exhibit remarkable enhanced efficiency over conventional annealing. This is because the precursor solution spontaneously started to develop a perovskite layer over the substrate during spin coating similarly as epitaxial-growth by utilizing the kinetic energy of the hot substrate and it serves as foundation layer for the high quality device.

A simulative industrial processing, slag refining under open air atmosphere conditions, has been established to observe the removal efficiency of impurities from molten Si at 1823 K. The behavior of Ca and its compounds in Si are investigated. The results show that, CaSi2 is a key compound on removing Fe, Al, Ca and P from Si. Ca in molten Si is produced from the reaction between CaO and Si at the melting stage of slag and Si, as well as at the beginning refining period of around 10 min, which is largely depends on the net content of single CaO phase. With the temperature going down to 1303 K gradually, most of Si is solidified and Ca percentage is increased, then species CaSi2 phase is generated from the melt composed of 61.4 wt% Si, while Fe is precipitated at the boundary between phases CaSi2 and Si. Furthermore, it is determined that, part of P in Si is oxidized to PO43− not by SiO2 but by CaO to form CaO·P2O5 slag phase, the other is more likely to be reduced to CaxSiyPz than to Ca3P2. Therefore, a slag rich in CaO will be much easier to produce Ca in Si and more efficient to remove impurities by acid leaching.

The consequences of asphalt pavement in a long tunnel under fire are much more serious than in open air conditions. Micropowder additives directly affect the characteristics of the asphalt ...

A NaCl-containing water droplet covered by simulated diluted bitumen was used to mimic the internal corrosion scenario that pipelines transporting diluted bitumen may encounter. The NaCl-containing droplet on the X100 pipeline steel shrank to a smaller droplet under the action of the simulated diluted bitumen. Hematite and lepidocrocite were identified in the corrosion products formed in the shrunken droplet. The dissolution of X100 pipeline steel primarily occurred at the edge of the central ring of the shrunken droplet. The corrosion attack morphology seen under these conditions is quite different from that of previous investigations for salty droplets in open air. The results point to a new mechanism of internal corrosion possibly appearing in diluted bitumen pipelines.

Although the use of perovskite materials in solar cells has drawn a tremendous amount of attention because of rewarding power-conversion efficiency of 22.1%, concerns persist that poor stability will hinder the commercial viability of perovskite-based photovoltaic devices. Chemical vapor deposition (CVD) is the most suitable technology for commercialization and could potentially provide a future perspective for stable and efficient perovskite-based electronic devices. Until now, systematic investigation has addressed neither the preparation nor the intrinsic stability of these materials under both dark and illuminated conditions given the high humidity of perovskite films deposited by CVD. In the present study, we investigated the stability of perovskite films under dark and illuminated conditions coupled with temperature under an open-air atmosphere via the tuning of various deposition parameters. CVD-deposited MAPbI3 films with no additives showed structural and optical properties at a predominant level...

The focus of my research is based on the gas electron multiplier (GEM) foil test, repairing and effective gain calculation of GEM detector. During my research work define procedure of GEM foil testing short-circuit, detection short-circuits in the foil. Study different ways to remove the short circuits in the foils. Set and define the GEM foil testing procedures in the open air, and with nitrogen gas. Measure the leakage current of the foil and applying different voltages with specified step size. Define the Quality Control (QC) tests and different components of GEM detectors before assembly. Calculate the effective gain of GEM detectors using 109 Cd and 55 Fe radioactive source.

Low-temperature solution processing of p-type transparent conducting oxides (TCOs) will open up new opportunities for applications on flexible substrates that utilize low-cost, large-area manufacturing. Here, we report a facile solution synthesis method that produces two p-type TCO thin films: copper chromium oxide and copper-doped chromium oxide. Using combustion chemistry, both films are solution processed at 180 °C, which is lower than most recent efforts. While adopting the same precursor preparation and annealing temperature, we find that annealing environment (solvent vapor vs open air) dictates the resulting film phase, hence the optoelectronic properties. The effect of annealing environment on the reaction mechanism is discussed. We further characterize the electronic, optical, and transport properties of the two materials, and compare the differences. Their applications in optoelectronic devices are successfully demonstrated in transparent p–n junction diodes and as hole transport layers in organ...