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The COVID-19 pandemic emerged in Wuhan, China, towards the end of 2019 and affected the whole world. People who were confined to their homes for a long time due to the global pandemic, which caused many deaths in the world, connected with the outside world through their balconies. The purpose of this research is to determine the impact of the COVID-19 pandemic on individuals' habits of using balconies at their homes. The survey prepared to determine the change in the balcony usage habits of people experiencing the pandemic period in Turkey in 2020-2021, when the COVID-19 pandemic was intense, was applied to 462 people and statistical analyzes were employed. According to the finding; approximately 81% of the participants stated that they spent time on the balcony during the pandemic period, 68% stated that the time spent on the balcony increased, 53% stated that they made changes to their balconies, and 54% stated that spending time on the balcony had a positive effect on the treatment process. 24% of the participants stated that the balconies of their residences were not large enough and comfortable and that they wanted to move to another residence with a balcony of sufficient size and comfort. In this study shows that having balconies of sufficient size and comfort in newly planned residences, the use of furniture on the balcony, and the production of ornamental plants will provide a great advantage in psychologically recovering from future epidemics and in establishing connections with the outdoors for people who have to stay in quarantine. [ABSTRACT FROM AUTHOR]

Alcohol groups and β‐O‐4 (C−C) linkages are widespread in biomass feedstock that are abundant renewable resource for value‐added chemicals. The development of sustainable protocols for direct oxidation or oxidative cleavage of feedstock materials in a controlled fashion, using open air as an oxidant is an intellectually stimulating task to produce industrially important value‐added carbonyls. Further, the oxidative depolymerization of lignin into fine chemicals has evoked interest in recent times. Herein, we report the first example of a catalyst system that could activate molecular oxygen from atmospheric air for controlled oxidation and oxidative cleavage/depolymerization of feedstock materials such as alcohols, β‐O‐4 (C−C) linkages and real lignin in water under open air conditions. The selectivity of carbonyl products is controlled by altering the pH between ~7.0 and ~12.0. The current strategy highlights the non‐involvement of any external co‐catalyst, oxidant, radical additives, and/or destructive organic solvents. The catalyst shows a wide substrate scope and eminent functional group tolerance. The upscaled multigram synthesis using an inexpensive catalyst and easily available oxidant evidences the practical utility of the developed protocol. A plausible mechanism has been proposed with the help of a few controlled experiments, and kinetic and computational studies. [ABSTRACT FROM AUTHOR]

We present a two-step physical method for the fabrication of composite nanoparticle-based nanostructures. The proposed method is based on the pulsed laser deposition (PLD) technique performed sequentially in vacuum and in air. As a first step, thin-alloyed films of iron with noble metal were deposited by PLD in vacuum. The films were prepared by ablation of a mosaic target formed by equal iron and gold sectors. As a second step, the as-prepared alloyed films were ablated in air at atmospheric pressure as the laser beam scanned their surface. Two sets of experiments were performed in the second step, namely, by applying nanosecond (ns) and picosecond (ps) laser pulses for ablation. The structure, microstructure, morphology, and optical properties of the samples obtained were studied with respect to the laser ablation regime applied. The implementation of the ablation process in open air resulted in the formation of nanoparticle and/or nanoparticle aggregates in the plasma plume regardless of the ablation regime applied. These nanoparticles and/or nanoaggregates deposited on the substrate formed a complex porous structure. It was found that ablating FeAu films in air by ns pulses resulted in the fabrication of alloyed nanoparticles, while ablation by ps laser pulses results in separation of the metals in the alloy and further oxidation of Fe. In the latter case, the as-deposited structures also contain core–shell type nanoparticles, with the shell consisting of Fe-oxide phase. The obtained structures, regardless of the ablation regime applied, demonstrate a red-shifted plasmon resonance with respect to the plasmon resonance of pure Au nanoparticles. [ABSTRACT FROM AUTHOR]

This work demonstrated the feasibility of an industrial-scale aerated static pile composting system for treating one of the common biowastes—soybean curd residue. The mixing ratios of the feedstock were optimized to achieve a carbon–nitrogen ratio and a moisture level in the ranges of 25–35 and 60–70%, respectively. This open-air composting system required 6–7 months to obtain a mature compost. Solvita and seed germination tests further confirmed the maturity of the compost, with 25% compost extract concentration yielding the best germination index in the absence of phytotoxicity. The bacterial and fungal compositions of the compost piles were further examined with metagenomic analysis. Thermoactinomyces spp., Oceanobacillus spp., and Kroppenstedtia spp. were among the unique bacteria found, and Diutina rugosa, Thermomyces dupontii, and Candida taylorii were among the unique fungi found in the compost piles, suggesting the presence of good microorganisms for degrading the organic biowastes. [ABSTRACT FROM AUTHOR]

This work demonstrated the feasibility of an industrial-scale aerated static pile composting system for treating one of the common biowastes—soybean curd residue. The mixing ratios of the feedstock were optimized to achieve a carbon–nitrogen ratio and a moisture level in the ranges of 25–35 and 60–70%, respectively. This open-air composting system required 6–7 months to obtain a mature compost. Solvita and seed germination tests further confirmed the maturity of the compost, with 25% compost extract concentration yielding the best germination index in the absence of phytotoxicity. The bacterial and fungal compositions of the compost piles were further examined with metagenomic analysis. Thermoactinomyces spp., Oceanobacillus spp., and Kroppenstedtia spp. were among the unique bacteria found, and Diutina rugosa, Thermomyces dupontii, and Candida taylorii were among the unique fungi found in the compost piles, suggesting the presence of good microorganisms for degrading the organic biowastes.

This study proposes a near-infrared (NIR) imaging method for two-dimensional distributions of water vapour (WV) in the open air. A wavelength of 1872 nm, at which the dependence of the absorption coefficient on the WV concentration is the largest in the v 2 + v 3 band of water molecules, was employed for imaging. The measurement system was a star imaging system, comprising a laser light source and an NIR camera. A measurement space with 0.08 m diameter and 0.30 m length was ensured to obtain the 2D absorbance images of moist air emitted from a gas nozzle and the breath air exhaled from a human subject with and without a mask. The images clearly showed the distributions of WV that flowed around a pipe and impinged on a plate. The exhaled air was clearly visualised, and the difference in air permeability between the masks was demonstrated. These results indicate the potential of the NIR imaging method for various applications that require WV flow visualisation, WV source identification, and evaporation process observation. [ABSTRACT FROM AUTHOR]

To achieve the goal of green chemistry and sustainable development, catalyst-free reactions and use of naturally abundant resources are gaining importance. In last two decades, C–H functionalization has gained attention for the synthesis of organic molecules. Here, we report a catalyst-free cross-dehydrogenative coupling reaction promoted by visible light for the synthesis of 1,3-oxazines. When α-aminoalkylnaphthols/phenols, commonly known as Betti bases, are irradiated with white light-emitting diode (LED, 23 W) in dimethyl sulfoxide (DMSO) solvent in an open reaction vessel at room temperature, cyclization takes place via α-C–H activation of tertiary amine moiety and forms a new C–O bond. Biologically important 1,3-oxazines are obtained in 58–85% yields. The various advantages of this methodology are (i) the reaction is catalyst-free, (ii) only aerial oxygen is needed as the oxidant, (iii) the reaction is visible light-promoted and (iv) a broad range of 1,3-oxazines are synthesized by varying the tertiary amine moiety or naphthols/phenols or the aryl substituent of the substrate Betti bases. [ABSTRACT FROM AUTHOR]

The ketones and benzoic acids are very useful chemicals as the precursors and intermediates in both laboratory and synthetic industrial applications, which are usually obtained by selective catalytic oxidation of alcohols using a amount of certain expensive oxidants or metal catalysts. Here, an efficient and practical oxidation the aryl secondary and primary alcohols to corresponding carbonyl compounds using NaOtBu in open air at room temperature has been developed. And utilizing NaOtBu/air/ toluene, a series of ketones or benzoic acids were obtained from secondary and primary alcohols in high yields, respectively. More importantly, most of the substrates with electron‐withdrawing or electron‐donating groups could be converted to the corresponding products in high to excellent yields. Furthermore, the practicality of the reaction was demonstrated through 1.0 gram‐scale reaction with excellent yield. [ABSTRACT FROM AUTHOR]

Double unit trains running at high speeds may create additional aerodynamic challenges due to two streamlined structures with close proximity, exploring the aerodynamic performance of double unit trains is now critical. In this study, detached eddy simulation (DES) approach was employed to study the aerodynamic performance and the nearby flow patterns of a double unit train, whose results were compared and analyzed with that of a single-unit train with a same length. The results showed that the coupling method could change the aerodynamic drag on each car and tended to increase the overall drag of the double unit train. The lift force of the front car near the coupler was significantly increased. Similar slipstream distributions were found around the front half single and double-unit train except in a region close to the coupler. Due to the coupling structure, the slipstream of the rear half of double unit train was much stronger compared to single unit train. The vortex region behind the double-unit train was much wider than that of the single-unit train and was accompanied by greater vortex-shedding.

The SARS-CoV-2 pandemic has revived the debate about the routes of virus transmission and their likelihoods. It is of utmost importance to assess the risks of contamination of susceptible people by infectious individuals and to evaluate the level of SARS-CoV-2 and other respiratory viruses transmission in the community. Most countries have imposed non-pharmaceutical measures to contain SARS-CoV-2 transmission, including physical distancing and mask wearing. Here we evaluated the spreading of viruses in open air using harmless Escherichia coli bacteriophages as a surrogate. Phages were sprayed towards Petri dishes seeded with bacteria at different lengths and angles. Our results showed that the transmission rate decreased exponentially with distance. The highest recorded transmission rate was 9 × 10 - 6 PFU/plate when phages were sprayed from a 1 m distance, suggesting that the probability of transmission of a single virus at a 1 m distance is 1:100,000. [ABSTRACT FROM AUTHOR]

Siega Verde was the third open-air rock art site to be discovered in the Iberian Peninsula, even before Côa and the controversy that followed that discovery. Its practicable size and the study carried out without any publicity allowed the analysis of a new reality that would change the interpretation of Palaeolithic art. From the start of the research, stylistic criteria were used to date the art in the absence of archaeological excavations. Although this has often been criticized, it meant that Siega Verde and Côa could be dated from Leroi-Gourhan's Style II onwards. Excavations at Fariseu, a site belonging to Côa in Portugal, have proved that hypothesis archaeologically, as well as supporting the applicability of Leroi-Gourhan's styles. Siega Verde is a good representative of Palaeolithic art in the open, on rocks by a river-bank or on prominent hills, but it is not the only form that can be catalogued as open-air rock art, because there are intermediate forms. These are found in cave entrances and in rock-shelters all over the Iberian Peninsula, especially in areas where little evidence of Palaeolithic art used to be known, such as on the southern Mediterranean coast and in Andalusia. This site possesses an exterior Upper Palaeolithic art ensemble, similar to the art found inside caves and of the same age, but in a different location. Formal relationships are usual inside and outside the caves and in both cases they represent a communicative code that did not need the dark and mystery to be expressed. [ABSTRACT FROM AUTHOR]

Double unit trains running at high speeds may create additional aerodynamic challenges due to two streamlined structures with close proximity, exploring the aerodynamic performance of double unit trains is now critical. In this study, detached eddy simulation (DES) approach was employed to study the aerodynamic performance and the nearby flow patterns of a double unit train, whose results were compared and analyzed with that of a single-unit train with a same length. The results showed that the coupling method could change the aerodynamic drag on each car and tended to increase the overall drag of the double unit train. The lift force of the front car near the coupler was significantly increased. Similar slipstream distributions were found around the front half single and double-unit train except in a region close to the coupler. Due to the coupling structure, the slipstream of the rear half of double unit train was much stronger compared to single unit train. The vortex region behind the double-unit train was much wider than that of the single-unit train and was accompanied by greater vortex-shedding. [ABSTRACT FROM AUTHOR]

Air quality in the residential areas adjacent to the industrial regions is of great concern due to the association with particulate matter and toxic gaseous which has adverse effects on human health. Therefore, the present study aimed to investigate the air quality in term of PM10 concentrations and toxic gaseous (CO and NO) at University Hussein Onn Malaysia (UTHM) residential college which is adjacent to a wood processing, electronic and fibre board factories. Four Stations defined as Station 1 (KKM), Station 2 (KKP), Station 3 (KKTDI) and Station 4 (KKTU) were selected for this investigation. PM10 concentrations were measured using the E-Sampler Particulate Matter for 24 hours period within the dry season (February –May 2016) which was associated with the heavily haze phenomenon in Malaysia. The distribution of selected toxic gases in UTHM student hostels was determined using the TSI IAQ (CO) and Dragger X-am 7000 (NO). PM10 and toxic gaseous levels were compared to the Ambient Air Quality Standard (AAQS) and to compute the assumption of the sources of PM10 by using Open Air R Package Software. Data were analysed using the R Software and packages (Open-air, BRT, Akima). The highest concentration of PM10 was 114 µg/m3 recorded at KKTDI followed by 58 µg/m3 at KKP. The maximum CO concentrations noted at KKP (1.8 ppm). However, both PM10 and CO concentrations not exceeded the AAQS of 150 µg/m3 and 30 ppm respectively. Moreover, concentrations of NO at KKP (0.61 ppm) and KKM (2.18 ppm) exceeded the AAQS (0.17 ppm) indicating the possibility of presence health risk for students at UTHM due to poor air quality. The air quality is directly associated to level of energy consumption which causes climate changes and accumulation of greenhouse gases.

• The stability of Sn(C≡CPh) 4 complex allows the ROP of ε-caprolactone in open air • The presence of −OH on the surface of GG allows to graft covalently the PCL on GG • The molecular weight of PCL chains was controlled by the guar gum content This study reports the grafting of poly(ε-caprolactone) (PCL) on guar gum (GG) by in-situ ring-opening polymerization using tetra(phenylethynyl)tin (Sn(C≡CPh) 4) as catalyst. The hydroxyl groups of guar gum act as initiators for ε-caprolactone ring-opening polymerization and the resulting poly(ε-caprolactone) binds covalently to the polysaccharide. The highest stability of Sn(C≡CPh) 4 allows the reaction in open-air, thereby reducing the cost of the synthesis and provides polymers with high molar mass. Fourier transform infrared (FTIR) and the long-term stability of the suspension PCL-g-GG in dichloromethane confirmed the effectiveness of grafting of PCL into GG. The size exclusion chromatography (SEC) results show that the molar masse of grafted PCL could be modulated by varying the amount of guar gum. From thermogravimetric analysis and differential scanning calorimetry results the thermal stability of PCL-g-GG is greatly improved with different content of guar gum, also the melting temperature and crystallinity increased by increasing the GG content. The scanning electron microscopy (SEM) analyses showed the good adhesion between GG and PCL with 5% of GG contents. It was also revealed by contact angle measurements that the grafting of PCL to GG leads to a decrease of hydrophobicity of PCL. The micro-indentation hardness properties of the prepared PCL-g-GG were significantly improved, as compared to neat PCL. [ABSTRACT FROM AUTHOR]

Purpose of the article is to substantiate the artistic and pedagogical paradigm of mimesis in the training of future specialists in the visual arts in the open air. The methodology is based on the terminological principle, the application of general scientific methods (analysis, synthesis, synthesizing). The scientific novelty lies in the fact that for the first time: the content of the category «artisticpedagogical paradigm» is defined, the methodology is revealed and its universalism is proved in the training of future specialists in fine arts in the open air on the basis of ancient principles of mimesis, and advantages and disadvantages of this process are justified. Conclusions. The artistic and pedagogical paradigm of mimesis in the training of future specialists in the visual arts in the open air covers the appropriate objectives, selection and application of methods, techniques and means of depicting nature as an aesthetic semiotic successful implementation of color, tonal, plastic, rhythmic and compositional tasks of creating an objectively valuable artistic image of nature. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have been synthetized and deposited on cp Ti substrates in one-step process by the use of laser ablation in open air. The nanoparticles are produced by ablating Ag foil using two different lasers and an inert gas jet oriented into the interaction zone to prevent oxidation and to direct the ablated material to the substrate. The HRTEM images and FFT confirmed the crystalline nature of the obtained silver nanoparticles with the presence of oxidized ones, while FE-SEM revealed that the nanoparticles were uniformly distributed on Ti substrates. The Ag-containing Ti substrates showed good antibacterial activity against Lactobacillus salivarius . [ABSTRACT FROM AUTHOR]

This paper numerically computed the problem of pressure fluctuations in the open air and tunnel based on the virtual computer technology, and experimentally verified the correctness of the numerically computational model. In the open air, pressure fluctuation at the nose tip of train head was serious and presented two obvious valley and peak values. Pressure at the nose tip of train tail did not present obvious fluctuations. Pressure at the train head was obviously more than that at the train tail. For different observation points, the peak and valley values of far-field pressures only showed translation with the increased running time. In the tunnel, pressures at the nose tip of train head had obvious peak and valley values and were far more than those in the open air. For different observation points, the peak and valley values of far-field pressures did not simply present translation with the increased running time, which indicated that there was wall effect in the tunnel. In addition, the absolute values of the maximum positive and negative pressures of the high-speed train in the near and far fields obviously increased with the increased running time. The pressure fluctuation caused by the high-speed train in the tunnel was the superposition of the inlet pressure wave and air disturbance caused by the passing train. The size of local air pressure was related to tunnel length, train length and speed. The peak value of positive pressures in the tunnel appeared when the train entered the tunnel. The valley value of negative pressures in the tunnel would appear in the area where the expansion wave of train head was superimposed with the compression wave of train tail. According to tunnel length, train length and speed, the specific positions where the peak and valley values of positive and negative pressures appeared could be approximately obtained. If the tunnel was very long, it was possible to present the peak value of positive pressures caused by the superposition of more continuous compression waves or the valley value of negative pressures caused by the superposition of more continuous expansion waves. [ABSTRACT FROM AUTHOR]

The use of double-unit trains is becoming a common means of increasing passenger capacity for a rail network. However, their expanded usage may create additional aerodynamic challenges. The present work obtains the characteristics of the slipstream caused by single and double unit trains using the detached eddy simulation (DES) method for 1/20th scaled models. The numerical results are verified by full-scale experiments. The slipstream velocities and pressures obtained by the two train models at different distances from the center of track (COT) and the top of rail (TOR) are compared. The coupling structure of the double-unit train model is found to produce a velocity peak that is much greater than that of the single-unit train model in the same position. At the area away from the COT and close to the TOR, the velocity of the far wake region is larger for the double-unit train model. The coupling structure also leads to a positive pressure change in the coupling region, and its value is comparable to or even much greater than that caused by the nose. It is considerable that the subsequent pressure criteria could take the positive pressure on the coupling region into account for the double-unit train. [ABSTRACT FROM AUTHOR]

We report on the formation of three-dimensional nanostructures composed of nanoparticles by applying the technology of pulsed laser deposition in the air at atmospheric pressure. The depositions were performed by ablating targets synthesized of ZnO and TiO 2 in different ratios as initial materials. Our attention was focused on the structure and morphology, as well as on the optical and photoluminescent properties of the as-deposited structures. It was found that the structure of the samples represented a composite of ZnO and Zn 2 TiO 4 nanoparticles with different ratios between the phases depending on the initial materials. Although the samples consisted of nanoparticles of similar shape and size distribution, the ratio between the different crystal phases influences the morphology of the material deposited on the substrates. The samples' optical properties are strongly affected by their thickness since the accumulation of material led to the formation of strongly absorbing media. A small amount of Zn 2 TiO 4 nanoparticles introduced in the ZnO structure significantly changes the sample photoluminescence response, with the ratio between ultraviolet and visible emission significantly differing from that of the pure ZnO sample. A potential application of such composite structures as gas sensor elements was demonstrated. [Display omitted] • High porosity composite structures were fabricated by PLD in open air. • Composites consist of aggregated nanoparticles from ZnO and Zn 2 TiO 4. • ZnO/Zn 2 TiO 4 ratio determines the morphology and optical properties of the composite. • Zn 2 TiO 4 introduced in the ZnO structures had a significant effect on their PL. • Composite samples were used as a sensor element activated by UV light. [ABSTRACT FROM AUTHOR]

When high-speed trains were passing through a tunnel, pressure wave will change seriously and cause large aerodynamic loads, which may bring problems to the comfort of passengers and the aerodynamic fatigue failure of train bodies, components and fixed equipment in the tunnel. Therefore, this paper systematically studied aerodynamic characteristics of a high-speed train under three kinds of situation including open air, entering a tunnel and completely in a tunnel, experimentally verified the correctness of numerically computational model. In the open air, vortexes of the high-speed train were mainly distributed in the bogie and compartment connections. Sound pressure level curves had many peak and valley points and the maximum sound pressure level was 72 dB. Sound pressure levels gradually decreased with the increase of analyzed frequency. In addition, sound energy was mainly distributed below 2000 Hz. Aerodynamic noises presented an obvious directivity and attenuation distribution. In the entering the tunnel, peak and valley values of pressures at train head and tail appeared at different time. The maximum pressures at the observation points of train head and tail were 345 Pa and -450 Pa respectively, while the minimum negative pressures at the observation points of train head and tail were -2900 Pa and -3260 Pa respectively. Computational pressures of observation points were basically consistent with the experimental test, and the relative error was only within 2 %, which indicated that the adopted numerical simulation can better simulate aerodynamic characteristics of the high-speed train. The change of the length of the tunnel had no an obvious effect on the aerodynamic lift of the high-speed train. When the length of the tunnel was less than 800 m, the negative peak of the aerodynamic lift increased continuously with the extension of the tunnel, but the increased rate was gradually reduced. When the length of the tunnel was more than 800 m, the negative peak of the aerodynamic lift was gradually reduced. According to the acoustic panel contribution, these panels which had an obvious effect on the interior noise of the high-speed train were recognized. Composite sound absorption material was then applied to these panels and the interior noise at the observation points was improved obviously. [ABSTRACT FROM AUTHOR]

The paper deals with the numerical investigation of aerodynamic loads on railway track vicinity within the passage of the train set consisting of the electric locomotive ŠKODA 109E and three passenger carriages. In agreement with requirements specified in TSI (Technical specification for Interoperability) railway safety standards following two different train operating modes were simulated – train passage in open space and train passage along the platform. In both the cases the train operates on a straight track with 200 km/h speed of motion, which is the maximum operational speed of the locomotive. The main results of the problem solution represent time-variations of pressure and velocity recorded in defined locations in track vicinity and a report of the aerodynamic force affecting the reference cylinder in a horizontal plane within the train passage. The values obtained are compared to the relevant reference values, which are published in TSI safety standards for the particular train operating mode.

Purpose – The purpose of this paper is to offer a state of the art description of open air markets (OAM), a little-known phenomenon that is indispensable in Africa’s consumer packaged goods industry. Design/methodology/approach – A qualitative methodology comprising in-depth semi-structured interviews and direct observation was employed. Findings – Analysis of data from Nigeria, Africa’s largest economy and most populous country, reveals that channel members have roles that are different from that of their Western counterparts. For example, distributors often do not distribute and principals are expected to actively sell on behalf of their distributors to empty the latter’s warehouse. Also, while many end-users in developing countries expect credit sales and opportunity to bargain, extant literature does not include these demands in the formal list of service output demands. Another major finding is the surprising order underlying OAM. It is the bedrock of commercial activities: for most consumer packaged goods manufacturers, sales through OAM account for over 90 percent of revenue. Research limitations/implications – The focus on one industry and country limits the generalizability of the above findings. Practical implications – Africa is the next growth frontier. Tapping into this growth requires a deep understanding and appreciation of the important role played by its unique marketing channels. Originality/value – Given the dearth of documented knowledge about marketing channels in emerging markets, this study addresses an important gap. Its findings could inform theory development and encourage more research on marketing channels in developing countries. [ABSTRACT FROM AUTHOR]

Method of sliding mesh and segregated compressible large eddy simulation was used to simulate the flow field of a 1/25 scale eight-coach China Railway train running from open air into long tunnel, validated by the same scale Intercity Express 2 (ICE2) train. Side force fluctuation increases greatly when train enters tunnel. Short-time Fourier transform on side force coefficients of Coach 5 and 8 presents the peak frequency at about 95Hz. The hunting motion of laterally swinging airflow in lower space near the train is analyzed. Correlation analyses of pressure time histories reflect its traveling mode. Propagating velocity is 57–62% in open air, and 75–80% in tunnel of the operating speed. Wavelength is both in the range of 0.3–0.6m. Spectral Proper Orthogonal Decomposition (SPOD) and POD extract the transverse pattern of hunting motion. Total POD energy increases when hunting motion appears. Consistent to side force spectrums, SPOD energy spectrums present peak frequencies at 95Hz, where energy is larger in tunnel than open air. Mode 1 of POD and SPOD under peak frequencies presents similar spatial distribution: anti-symmetrical streamwise velocity fluctuation, vortex pairs outside bogie cavities and large-scale circulation. The relation between coherent structures and side forces is well established by SPOD. • Aerodynamic forces and flow patterns of train from open air into tunnel are numerically investigated. • Transverse pattern of hunting motion is extracted by Spectral Proper Orthogonal Decomposition (SPOD) and POD. • The relation between side forces and hunting motion is established by SPOD. • Aerodynamic forces in transition section are analyzed by sliding average and short-time Fourier transform. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have attracted much attention as a subject of investigation due to their well-known properties, such as good conductivity, antibacterial and catalytic effects, etc. They are used in many different areas, such as medicine, industrial applications, scientific investigation, etc. There are different techniques for producing Ag nanoparticles, chemical, electrochemical, sonochemical, etc. These methods often lead to impurities together with nanoparticles or colloidal solutions. In this work, laser ablation of solids in open air conditions (LASOA) is used to produce silver nanoparticles and collect them on glass substrates. Production and deposition of silver nanoparticles are integrated in the same step to reduce the process. The obtained particles are analysed and the nanoparticles formation mechanism is discussed. The obtained nanoparticles were characterized by means of transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and UV/VIS absorption spectroscopy. The obtained nanoparticles consisted of Ag nanoparticles showing rounded shape with diameters ranging from few to 50 nm [ABSTRACT FROM AUTHOR]

Cost-effective synthesis of single walled carbon nanotube (SWCNT) and single walled carbon nanohorn (SWCNH) hybrids, in a single step, by electric arc discharge technique in open air, at lower current densities is reported. The rate of production of the hybrids is 3–5 g/h. The presence of SWCNTs and SWCNHs is confirmed by a transmission electron microscope (TEM). In addition to conventional larger Dahlia-like aggregates of nanohorns, unique nearly-spherical shaped and relatively smaller sized aggregates (mean size ~ 25 nm) of nanohorns are formed along with thin bundles (mean diameter ~ 5.7 nm) of SWCNTs. [ABSTRACT FROM AUTHOR]

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The theory and practice of train-induced aerodynamic pressure loads on surfaces near to the tracks is compromised by an incomplete understanding of trains operating in short tunnels, partially enclosed spaces, and next to simple structures such as vertical walls. Unique pressure-loading patterns occur in each case. This work has been carried out to obtain a fundamental understanding of how these loading patterns transition from one to the other as the infrastructure becomes more confined. It also considers the impact of the results on two separate European codes of practice applying to tunnels and other structures. A parametric moving-model study was undertaken, transitioning from the open air to single and double vertical walls, partially enclosed spaces, short single-track tunnels and a longer tunnel. The train model was based on a German ICE2, and was fired at 32 m/s past the structures. Multiple surface pressure tappings and in-flow probes were used, providing the opportunity to assess the three-dimensional nature of the pressure and velocity fields. The experiments successfully mapped the transition between the three loading patterns and isolated the geometric changes. Further loading patterns were discovered relating to the length of the train, the length of the tunnel and the distance from the tunnel entrance. The three-dimensional nature of the pressure was related to the length of the tunnel and the distance from the tunnel entrance. Issues surrounding the lack of provision in codes of practice for short tunnels were discussed. [ABSTRACT FROM PUBLISHER]

Atmospheric pressure low-temperature plasmas produced by dielectric barrier discharge (DBD) provide a promising approach for civilian application of pulsed power technology. In this paper, repetitive nanosecond pulses were generated using a magnetic compression solid-state pulsed power generator, and the rise time and pulse duration of the nanosecond pulse are \sim30 and 70 ns, respectively. The DBD in open air is created using two kinds of electrodes, i.e., water and metal electrodes. The electrical, luminous, and optical characteristics of the DBDs under these two electrodes are studied and compared. The experimental results show that no filaments are observed and the discharge is homogeneous when water electrodes are used. The DBD still behaves in a filamentary mode when the discharge gap is extended to 4 cm in the case of metal electrodes. The results are validated by fast images taken by an intensified charge-coupled device camera. In addition, some discussion about the experimental results is presented. Improvement of discharge uniformity is due to the effect of resistive stabilization using water electrodes. [ABSTRACT FROM PUBLISHER]

Abstract: A highly efficient, selective and green catalytic protocol for open air oxidation of primary benzylic alcohols into aldehydes by in situ made N-isopropyl-3,5-di-tert-butylsalicylaldimine (HL3)–Cu(II) complexes and TEMPO (2,2,6,6-tetramethyl-piperidinyloxyl radical) is introduced herein. Distilled water as a solvent the reaction proceeds at 80°C temperature without any auxiliarities such as base and/or co-solvent. For example, benzyl alcohol is quantitatively and selectively oxidized to benzaldehyde within a few hours under optimized reaction conditions [80°C, open air, 0.3mol% CuBr2, 2mol% HL3, 3mol% TEMPO and 5mL of distilled water]. Under anaerobic conditions, the catalyst decomposes to a free ligand and Cu2O nanoparticles (diameter >50nm) via anticipated Cu(I)-hydroxo complex. On the basis of these observations and deuteration studies, a plausible reaction mechanism is proposed for the catalytic system. [Copyright &y& Elsevier]

In the present study, carbon nanotubes (CNTs) were fabricated by a single pulse discharge using a micro-electrodischarge machining (MEDM) system in open air without a catalyst. The MEDM system could manipulate the discharge location, peak current, and pulse duration. By controlling the discharge points, patterning was made feasible. Controlling the peak current (3, 4, and 5 A) and pulse duration (fixed at 1,200 ms) made it possible to optimize the energy input to synthesize CNTs. Observations made using a field-emission scanning electron microscope and transmission electron microscope showed that multiwalled CNTs were formed within the discharge points. The CNTs grown at a peak current of 4 A exhibited a sharp end and a slight 10°bend. [ABSTRACT FROM AUTHOR]

Abstract: The discovery of Paleolithic rock art in the open air, which, from years 1990 became very important in the Iberian Peninsula, opened more prospective on the interpretation of graphics of the groups of hunters in southern Europe. The development of research, both in the field of stylistic analysis, and in the site Siega Verde, as in the analysis of archaeological contexts, as in the site of Foz Côa, defined the facets the most innovative of the Upper Paleolithic, creating a very different geography as the traditionally allowed for the Iberian Peninsula. Current research continues to provide new data which satisfy the Paleolithic–postpaleolithic sequences, in which the painted and engraved symbols marked and defined the territory of the oldest groups, constituting the ideological basis for the claim of these territories by the heirs more direct. [Copyright &y& Elsevier]

Abstract: Mediterranean Languedoc is a vast region in Southern France where Mousterian occupations, mainly concentrated in the eastern sector, are numerous. The three lithic series of the open-air sites presented in this article are yet unpublished. The techno-economical approach used to analyse these three stone assemblages has brought to light variability in Neandertal behaviour concerning raw material collection and economy in sectors more or less rich in siliceous resources, and also concerning the different production systems used and their goals. Comparisons made with other Mousterian stone assemblages in Languedoc seem to indicate ties with certain sites from the Rhône Valley. [Copyright &y& Elsevier]

El Retiro madrileño, el parque de María Luisa de Sevilla y el Colegio Mayor de la Moncloa (Madrid), fueron los lugares elegidos en los años 50 para la celebración de tres exposiciones de escultura al aire libre. En ellas, se dieron cita obras de los escultores españoles más importantes del panorama artístico de esa época, afanados en la renovación de la práctica escultórica más tradicional que triunfaba en las Exposiciones Nacionales de Bellas Artes.Park «El Retiro» in Madrid, park «María Luisa» in Seville and the school «Colegio Mayor de la Moncloa» (Madrid), were the places chosen in the 50´s for the celebration of three open air sculpture exhibitions. In those exhibitions, will join together the works of the most important Spanish sculptors in the artistic scene of that time; they strove for the renewal of the most traditional sculpture practice that succeed in the «Exposiciones Nacionales de Bellas Artes».

In the AC torch-arc method, multi-walled carbon nanotubes (MWCNTs) are obtained in arc spot crater, where the substrate surface is transformed from graphite to MWCNTs. The radius of the arc spot crater was observed as a function of process parameters and the thickness of the processed layer at the arc spot crater was microscopically observed. The large processed radius was obtained at a higher arc current and lower flow rate. The thicker layer was obtained at a shorter gap. Numerous MWCNTs were observed in the processed layer at a higher arc current. [Copyright &y& Elsevier]

Single-wall carbon nanotubes and nanohorns were fabricated by means of a torch arc method in open air. A graphite target containing Ni/Y catalyst was used as a counterelectrode of the welding arc torch. The target was blasted away by the DC arc, and soot was deposited on the substrate placed downstream of the arc plasma jet. The deposited soot was observed with a transmittance electron microscope, revealing that the soot contained single-wall carbon nanotubes and nanohorns. [Copyright &y& Elsevier]