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The purpose of presented study is to investigate the development of the barreling obtaining the variation of the surface area during upsetting of cylindrical specimens for various metals and alloys.

Variations of the surface areas were first obtained analytically using mathematical equations for uniform and non‐uniform upsetting. Barreling contours were accepted as circular segments in the development of the equations. In the experimental part of the study, barreling radii and other related dimensions of upset specimens were measured and inserted into the developed equations in order to obtain the variations of total specimen surface areas.

As it is expected, barreling effects the variation of total surface areas of the specimen. It can be concluded that the total surface area first decreases at low upset ratios for all the test materials and then begins to increase as the upset ratios increases. Consequently, total surface areas for non‐uniform upsetting are always smaller that those of uniform upsetting.

Five kinds of materials were used in the experimental part of the study. Specimens were also upset without lubrication. A relatively slow hydraulic press was used during the experiments with 5 mm/s ram speed.

Although the study has not direct implications for the practical purposes in forging area, results can be used as a very useful source of information for researchers in this field to plan their studies. Variation character of total surface area obtained in the study may give useful data in analyzing the deformation patterns in upsetting.

The effects of barreling on the material behavior in upsetting for non‐uniform conditions were analyzed with respect to variation of total specimen surface area. This point of view may be extended for different materials and friction conditions.

Wear greatly influences the machine lifetime, performance and reliability and its quantification is very important. This paper aims to propose a modified bearing area curve method by combining the theory of the bearing area curve, and the relocation technique to calculate wear accurately and efficiently.

H13 steel was chosen as the material of wear pair, and the wear experiments were carried out at 50 N, 60 r/min for 20 min. The surface was measured before and after wear experiments. The relocation was made by comparing the mean lines (planes) of the unworn and worn surface profiles. The calculated results using the proposed method were compared with that of the surface profile method for a two-dimensional surface to validate its accuracy. The method was then applied for a three-dimensional (3D) wear analysis.

The worn surface shows clearly displacement compared to the unworn surface and implies the importance of including relocation in the bearing area curve method. The results from the proposed method are 98 per cent close to that from the surface profile method, indicating that the method is accurate for wear evaluation.

As no feature point or relocation mark is needed to calculate the relocation value using the proposed method, the method can be applied to mild to severe wear. Also, as the deviation of different scans does not affect the relocation calculation, and no matching and stitching is required, this method can be easily applied to a wide wear area and 3D surface wear analysis.

The purpose of this paper is to address the concern of some stainless steel users. To understand the effect of surface white spots on corrosion performance of stainless steel.

White spots appeared on some component surfaces made of 316 L stainless steel in some industrial applications. To address the concern about the pitting performance in the spot areas, the pitting corrosion potential and corrosion resistance were measured in the spot and non-spot areas by means of potentiodynamic polarization and electrochemical impedance spectroscopy and the two different surface characteristics were analytically compared by using optical microscopy, laser confocal microscopy, scanning electron microscopy, x-ray diffraction, energy dispersive spectroscopy and auger energy spectroscopy. The results indicated that the pitting performance of the 316 L stainless steel was not negatively influenced by the spots and the white spots simply resulted from the slightly different surface morphology in the spot areas.

The white spots are actually the slightly rougher surface areas with some carbon-containing species. They do not reduce the pitting resistance. Interestingly, the white spot areas even have slightly improved general corrosion resistance.

Not all surface contamination or roughening can adversely affect the corrosion resistance of stainless steel.

Stainless steel components with such surface white spots are still qualified products in terms of corrosion performance.

The surface spot of stainless steel was systematically investigated for the first time for its effect on corrosion resistance and the conclusion was new to the common knowledge.

This study aims to strengthen implications about hotel cleaning outcomes by comparing guests’ perception of the amount of contact they have with cleanliness of hotel surfaces.

This study used two data-collection methods, a survey and an adenosine triphosphate (ATP) test. Data were collected from recent hotel guests using Amazon Mechanical Turk. Guests were asked to identify hotel surfaces that they touch most frequently. Actual hotel cleanliness was measured using empirical data collected with ATP meters. The two data sets were used to compare guests’ perceptions about the amount of contact they have with actual cleanliness measurements of those hotel surfaces.

This study found that amount of guest contact was related to cleanliness of surfaces in guestrooms. Significant differences were found in guest perception between high- and low-touch areas and between guestrooms and hotel public areas. More high-touch areas and higher ATP readings were found in guestrooms than in hotel public areas.

To the best of the authors’ knowledge this study is the first to compare guest contact with hotel surfaces to a scientific measure of hotel cleanliness. In addition, this study is unique because it assesses guest contact and cleanliness of public areas to provide a holistic view of hotel-cleaning needs. The study offers industry empirically based results from guest perception and scientifically based data that can be used to improve hotel housekeeping programs.

With the nickel foam made by the technique of electrodeposition on polymer foam, the purpose of this paper is to investigate the influence of several deferent processes on the surface morphology and the specific surface area of this porous product.

The surface morphologies of the nickel foam were examined by SEM. The specific surface area of the porous product was measured by gas (N₂) permeability method and also calculated by the reported formula.

The nickel foam from sintering in NH₃ decomposition atmosphere at 850°C will achieve the same specific surface area as that at 980°C, whether this porous structure after electrodeposition comes through direct sintering in NH₃ decomposition atmosphere, or through burning in air at 600°C for 4 min beforehand then the same reductive sintering.

There have been some studies on the preparation and application of nickel foam, but few works focus on the processing influence on the specific surface of this porous product. The present work provides the investigations on the difference of the product made under different producing conditions, and the influence of several deferent processes on the specific surface area of the product.

The purpose of this paper is to study the influence of large-area texture/slip surface, especially the area and position of large-area texture surface on journal bearing, and improve the tribological performances of journal bearing.

A modified texture/slip numerical boundary condition with double parameters is presented and is applied onto the region where surface textures locate to represent the impact of actual texture/slip surface. A phase change condition is used to analyze cavitation phenomena.

The global/cumulative texture effect can be represented by applying texture/slip condition onto the region where it locates. The area and position of texture/slip surface would significantly affect the cavitation and load-carrying capacity. Texture/slip surface would not affect the pressure and load-carrying capacity when it locates at cavitation zone. The effect of texture/slip surface on load-carrying capacity would be beneficial if it locates at the pressure rise region, but its effect would be adverse if it locates at the pressure drop region. Well-designed texture/slip surface can improve tribological performances.

The developed texture/slip boundary condition can be a suitable and useful tool to analyze the effect of large-area texture/slip surface and especially to optimize the area and position of large-area texture surface. This approach can be complementary to conventional approach which is used to analyze the influence of textures’ real configurations and parameters.

This paper aims to characterize the mineral composition of Martian surfaces based on Thermal Emission Spectrometer (TES; Mars Global Surveyor) as measured in the infrared thermal range. It presents modeling and interpreting of TES spectral data from selected Martian regions from which the atmospheric influences had been removed using radiative transfer algorithm and deconvolution algorithm. The spectra from the dark area of Cimmeria Terra and the bright Isidis Planitia were developed in Philip Christensen’s and Joshua Bandfield’s publications, where these spectra were subjected to spectral deconvolution to estimate the mineral composition of the Martian surface. The results of the analyses of these spectra were used for the modeling of dusty and non-dusty surface of Mars. As an additional source, the mineral compositions of Polish basalts and mafic rocks were used for these surfaces as well as for modeling Martian meteorites Shergottites, Nakhlites and Chassignites. Finally, the spectra for the modeling of the Hellas region were obtained from the Planetary Fourier Spectrometer (PFS) – (Mars Express) and the mineralogical compositions of basalts from the southern part of Poland were used for this purpose. The Hellas region was modeled also using simulated Martian soil samples Phyllosilicatic Mars Regolith Simulant and Sulfatic Mars Regolith Simulant, showing as a result that the composition of this selected area has a high content of sulfates. Linear spectral combination was chosen as the best modeling method. The modeling was performed using PFSLook software written in the Space Research Centre of the Polish Academy of Sciences. Additional measurements were made with an infrared spectrometer in thermal infrared spectroscopy, for comparison with the measurements of PFS and TES. The research uses a kind of modeling that successfully matches mineralogical composition to the measured spectrum from the surface of Mars, which is the main goal of the publication. This method is used for areas where sample collection is not yet possible. The areas have been chosen based on public availability of the data.

The infrared spectra of the Martian surface were modeled by applying the linear combination of the spectra of selected minerals, which then are normalized against the measured surface area with previously separated atmosphere. The minerals for modeling are selected based on the expected composition of the Martian rocks, such as basalt. The software used for this purpose was PFSLook, a program written in C++ at the Space Research Centre of the Polish Academy of Sciences, which is based on adding the spectra of minerals in the relevant percentage, resulting in a final spectrum containing 100 per cent of the minerals.

The results of this work confirmed that there is a relationship between the modeled, altered and unaltered, basaltic surface and the measured spectrum from Martian instruments. Spectral deconvolution makes it possible to interpret the measured spectra from areas that are potentially difficult to explore or to choose interesting areas to explore on site. The method is described for mid-infrared because of software availability, but it can be successfully applied to shortwave spectra in near-infrared (NIR) band for data from the currently functioning Martian spectroscopes.

This work is the only one attempting modeling the spectra of the surface of Mars with a separated atmosphere and to determine the mineralogical composition.

Although dependence of contact surface temperatures between rough sliding bodies on surface topography is more explicitly described in terms of three‐dimensional (3D) topographic parameters, no work has yet been reported on this aspect. The paper seeks to carry out experiments to systematically correlate the 3D surface parameters to the contact temperature rise.

The surface temperatures at the contact between a relatively smooth zinc sulphide pin held against a rotating mild steel disc of varying surface topography were measured using an infrared thermal imaging system under different load and sliding velocity conditions. The main objective was to study the effect of 3D surface roughness parameters on the contact temperature rise.

The results indicate a rise in maximum contact temperature with the increase in a number of 3D parameters, such as, average surface roughness Sa, ten‐point height parameter Sz, skewness of the surface height distribution Ssk, mean summit curvature Ssc, and developed interfacial area ratio parameter Sdr while temperature was found to decrease with increasing values of another set of parameters, such as, kurtosis of the 3D surface texture Sku, summit density of the surface Sds, surface bearing index Sbi, core fluid retention index Sci, valley fluid retention index Svi, and root mean square slope of the surface Sdq.

In any sliding system, with mixed or boundary lubricated conditions, it can be attempted to find the optimum value of the roughness parameters so that on suitable processing of the surfaces a lower contact temperature rise can be achieved.

No work has yet been reported on the effect of 3D roughness parameters on contact temperature.

This study aims to empirically assess restaurant surfaces’ cleanliness and compare them to customers’ perceptions about the cleanliness of surfaces when dining in a restaurant.

This study used two methods to collect data. The first was a survey method to gauge customers’ perceptions and an empirical test to measure cleanliness using an adenosine triphosphate (ATP) meter. Two data sets were collected to compare customers’ perceptions and actual cleanliness measurements. One data set surveyed respondents as to their perceptions of high- and low-touch restaurant surfaces among 19 areas of the dining room and 15 surfaces from the restroom, and their perceived cleanliness or dirtiness of those same surfaces. The second one conducted empirical measurements of the cleanliness of these surfaces using an ATP meter, which were then compared to customers’ perceptions.

Although all surfaces had higher ATP readings than a 30 relative light units’ threshold, there were significant differences in ATP readings among surfaces. Results showed a fair amount of consistency between the consumers’ perceptions of cleanliness and the actual results of ATP readings for the cleanest areas, but very little consistency in customers’ perceptions and experimental measurements for the dirtiest areas.

This study empirically demonstrated the need for improved cleaning techniques and the importance of proper training for foodservice employees. Especially during the COVID-19 pandemic, results of this study suggest an additional responsibility on managers and staff to ensure clean environments and the imperative to address the concerns of their customers.

Based on an extensive literature review, to the best of the authors’ knowledge, no prior studies have compared consumers’ cleanliness perceptions with empirical measurements of cleanliness in restaurant settings using an ATP meter. The results of this study provide restaurant managers a better understanding of customers’ perceptions of cleanliness. It also provides restaurant managers and staff information to develop more effective cleaning procedures. In the context of the COVID-19 pandemic, perceptions of cleanliness and measures of actual cleanliness are more important than they have been in the past.

In an internal combustion engine, piston ring-cylinder liner tribo pair is one among the most critical rubbing pairs. Most of the energy produced by an internal combustion engine is dissipated as frictional losses of which major portion is contributed by the piston ring-cylinder liner tribo pair. Hence, proper design of tribological parameters of piston ring-cylinder liner pair is essential and can effectively reduce the friction and wear, thereby improving the tribological performance of the engine. This paper aims to use surface texturing, an effective and feasible method, to improve the tribological performance of piston ring-cylinder liner tribo pair.

In this paper, influence of positive texturing (protruding) on friction reduction and wear resistance of piston ring surfaces was studied. The square-shaped positive textures were fabricated on piston ring surface by chemical etching method, and the experiments were conducted with textured piston ring surfaces against un-textured cylinder liner surface on pin-on-disc apparatus by continuous supply of lubricant at the inlet of contact zone. The parameters varied in this study are area density and normal load at a constant sliding speed. A comparison was made between the tribological properties of textured and un-textured piston ring surfaces.

From the experimental results, the tribological performance of the textured piston ring-cylinder liner tribo pair was significantly improved over a un-textured tribo pair. A maximum friction reduction of 67.6 per cent and wear resistance of 81.6 per cent were observed with textured ring surfaces as compared to un-textured ring surfaces.

This experimental study is helpful for better understanding of the potency of positive texturing on friction reduction and wear resistance of piston ring-cylinder liner tribo pair under lubricated sliding conditions.