Effects of indoor color on mood and cognitive performance

In this study, the impact of indoor color use, gender and age on mood and cognitive performance was examined. It was hypothesized that indoor color for decoration in stores is an effective source that may convey emotional meanings differentiated by gender, age, or both. In order to study this, a two-stage work was carried out in a café/restaurant, in which interior yellow walls were changed to violet. In both stages, furniture and decorations remained the same. Each appearance (yellow and violet) was tested by using visual attributes through the use of bipolar scales. Results from approximately 250 participants for each stage showed that violet interiors were more positively perceived when compared to yellow. Compared to females, male users evaluated the space more positively. In addition, young customers had a more positive tendency than older customers towards the perception of atmospheric attributes, including color of store interiors.     

Perceived crowding in a café/restaurant with different seating densities

In this study, the impact on the perception of the density of seating elements used in a café/restaurant has been examined. Spatial factors, like the density of seating, were assumed to influence the perceived crowding and perception of a space. A two-stage study was carried out in a café/restaurant where a dense amount of seating elements was later changed to less dense. Each situation was tested by using atmospheric attributes through the use of bipolar scales. Results from 465 participants showed that when the seating elements were less dense, respondents answered more positively. The effect of gender on performance appraisal task was also examined. Compared to female users, male users were more favorable to both moderate and high-density conditions.     

Physical Properties and Diffusion-Coefficient Calculation of Iron Diffused Bi-2223 System

This study includes two parts: (I)?investigation of the effect of different annealing time (10?h, 30?h, and 60?h) on physical, superconducting, and microstructural properties of Fe-diffused Bi-2223 superconductor ceramics prepared by the conventional solid-state reaction method with the aid of the X-ray diffraction (XRD), scanning electron microscopy (SEM), dc resistivity (???CT) and transport critical current density (J _c ) measurements, and (II) determination of the diffusion coefficient and the activation energy of iron in the Bi-2223 system. In the former part, the zero-resistivity transition temperature (T _c ), phase purity, volume fraction, hole-carrier concentration, lattice parameters, surface morphology, texturing, crystallinity, grain connectivity, grain size, and room temperature resistivity values of the bulk samples are found and compared with each other. The results obtained show that both the zero resistivity transition temperature (T _c ) and transport critical current density (J _c ) regularly enhance with the increment in the diffusion-annealing time. The maximum T _c of 107±0.2 K and J _c of 50.0?A?cm^?2 are observed for the sample annealed at 830?°C for 60?h. As for the XRD investigations, according to the refinement of cell parameters done by considering the structural modulation, the enhancement in the diffusion-annealing is confirmed by both a decrease of the cell parameter a and an increase of the lattice parameter c of the samples, meaning that the greatest Bi-2223 phase fraction belongs to the sample annealed at 830?°C for 60?h. Moreover, SEM images display that the sample has the best crystallinity, grain connectivity, and largest grain size. Based on the results, the superconducting and microstructural properties improve with the increase in the diffusion-annealing time. In the latter part, Fe diffusion in the Bi-2223 system is examined in a range of 500?C830?°C by the variation of the lattice parameters evaluated from the XRD patterns. The temperature dependence of the Fe diffusion coefficient is described by the Arrhenius relation D=4.27×10^?5exp(?1.27±0.10) eV/k_BT, and the related activation energy of the iron in the Bi-2223 system is found to be about 1.27?eV. The relatively low value of activation energy obtained illustrates that the migration of the Fe ions primarily proceeds through defects such as pore surfaces and grain boundaries in the polycrystalline structure, leading to the improvement of the microstructural and superconducting properties of the samples, supported by the results of part?I. All in all, the aim of the present study is not only to analyze the role of diffusion-annealing time on superconducting and microstructural properties of Fe-diffused Bi-2223 superconductors, but also to find the diffusion coefficient and activation energy of Fe in the Bi-2223 system.     

The technical and economical feasibility study of offshore wind farms in Turkey

Clean Technologies and Environmental Policy - A large part of the electricity generation is from imported fossil fuels, which makes Turkey heavily dependent on fossil fuels. For this reason, Turkey...     

Mitigating insider threat by profiling users based on mouse usage pattern: ensemble learning and frequency domain analysis

International Journal of Information Security - Exploring novel security layers in academia and industry is always a concern due to the types of malware developing currently. Adding a widely...     

Notch stress analyses of high‐frequency mechanical impact‐improved welds by using ρf = 1 mm and ρf = ρ + 1 mm approaches

This paper presents further assessments of the previously reported round‐robin fatigue data obtained from high‐frequency mechanical impact (HFMI)‐improved longitudinal welds. A detailed statistical analyses of geometry measurements of HFMI‐treated weld toe profiles are presented. The fatigue analyses based on notch stress as defined by the International Institute of Welding are performed using the finite element method. Notch stresses are assessed based on both the fictitious weld toe radius and the addition of measured actual notch radius to the fictitious radius. While no large differences are observed between the results of methods, the former one is found to be more practical and faster to implement from the end‐user point of view.     

Deposition of a nanocomposite (Ti,Al, Si)N coating with high thickness by high-speed physical vapor deposition

Nanocomposite coatings such as (Ti, Al, Si)N have been demonstrated as promising candidates for the use as protection against solid particle erosion for compressor blades. Typically, nanocomposite (Ti, Al, Si)N coatings are deposited by different physical vapor deposition (PVD) techniques. However, the relatively low coating thickness up to a few micrometers due to low deposition rates leads to a limited lifetime of the coatings under erosive particle bombardment. In this study, the deposition of a nanocomposite (Ti, Al, Si)N coating was performed by a hollow cathode gas flow sputtering method, the high-speed physical vapor deposition, which enables the high-rate deposition of thick coatings. Morphology and microstructure of the coating were investigated via scanning electron microscopy and transmission electron microscopy, respectively. Tribological characterization by impact tests and erosion tests demonstrates that the nanocomposite (Ti, Al, Si)N coated sample reveals a promising resistance against impact loads and the solid particle erosion. Summarily, nanocomposite (Ti, Al, Si)N coatings deposited by the high-speed physical vapor deposition provide a high potential for the erosion protection of compressor blades.     

Optimization of the Pore Structures of MOFs for Record High Hydrogen Volumetric Working Capacity

Metal–organic frameworks (MOFs) are promising materials for onboard hydrogen storage thanks to the tunable pore size, pore volume, and pore geometry. In consideration of pore structures, the correlation between the pore volume and hydrogen storage capacity is examined and two empirical equations are rationalized to predict the hydrogen storage capacity of MOFs with different pore geometries. The total hydrogen adsorption under 100 bar and 77 K is predicted as n_tot= 0.085× V_p − 0.013× V_p² for cage-type MOFs and n_tot= 0.076× V_p − 0.011× V_p² for channel-type MOFs, where V_p is the pore volume of corresponding MOFs. The predictions by these empirical equations are validated by several MOFs with an average deviation of 5.4%. Compared with a previous equation for activated carbon materials, the empirical equations demonstrate superior accuracy especially for MOFs with high surface area (i.e., S_BET over ≈3000 m² g⁻¹). Guided by these empirical equations, a highly porous Zr-MOF NPF-200 (NPF: Nebraska Porous Framework) is examined to possess outstanding hydrogen total adsorption capacity (65.7 mmol g⁻¹) at 77 K and record high volumetric working capacity of 37.2 g L⁻¹ between 100 and 5 bar at 77 K.     

Production and characterization of synthetic aragonite prepared from dolomite by eco-friendly leaching–carbonation process

Dolomite is an alternative material for producing precipitated calcium carbonate (PCC) particles, which have widespread industrial applications depending on their morphology and particle sizes. These properties are readily controlled by the production conditions such as reaction time, temperature, stirring speed, and CO₂ flow rate. In this paper, we investigate the influences of these experimental conditions on the production of synthetic aragonite crystals from dolomite using a leaching carbonation process. The proposed process is believed so be more eco-friendly than other methods suggested in the literature because the CO₂ released from the dolomite during the leaching stage is stored for use in the carbonation stage. The experimental results indicate that the morphology of the produced PCC is influenced not only by the reaction time and temperature, but also the stirring speed and CO₂ flow rate. The required reaction time decreases with an increase in the CO₂ flow rates. However, calcite forms along with the aragonite crystals at higher CO₂ flow rates. We successfully synthesized pure aragonite crystals in the reaction temperature range of 40–70 °C at a fixed CO₂ flow rate of 3.00 l/min, and at a stirring speed of 750 rpm. The d₉₀ values of the aragonite crystals at various temperatures ranged from 18.47 to 25.99 μm. We fit the experimental results by a single-term exponential model.Additionally, we obtained a Mg-rich solution and CO₂ gas as by-products, which are in high demand.