Common Coupled Fixed Point Theorem for Geraghty-Type Contraction in Partially Ordered Metric Spaces

We study the existence and uniqueness of common coupled fixed point of four self-mappings for Geraghty-type contraction using weakly compatible mappings in partially ordered metric spaces with common limit range property (denoted by (CLRST)), the property of E.A, and so on. It is noted that the continuity of mappings and completeness of spaces can be removed. Our results improve, extend, complement, and generalize several existing results in the literature. Also, some examples are provided to illustrate the usability of our results

Accident Frequency Prediction Model for Flat Rural Roads in Serbia

Traffic accidents, by their nature, are random events; therefore, it is difficult to estimate the exact places and times of their occurrences and the true nature of their impacts. Although they are hard to precisely predict, preventative actions can be taken and their numbers (in a certain period) can be approximately predicted. In this study, we investigated the relationship between accident frequency and factors that affect accident frequency; we used accident data for events that occurred on a flat rural state road in Serbia. The analysis was conducted using five statistical models, i.e., Poisson, negative binomial, random effect negative binomial, zero-inflated Poisson, and zero-inflated negative binomial models. The results indicated that the random effect negative binomial model outperformed the other models in terms of goodness-of-fit measures; it was chosen as the accident prediction model for flat rural roads. Four explanatory variables—annual average daily traffic, segment length, number of horizontal curves, and access road density—were found to significantly affect accident frequency. The results of this research can help road authorities make decisions about interventions and investments in road networks, designing new roads, and reconstructing existing roads

The tungsten heteropolyacid supported on activated bentonites as catalyst for selective oxidation of 2-propanol

This paper provides the correlation between the catalytic activity and selectivity of catalysts with various loadings of heteropolyacids over bentonite in the vapour phase 2-propanol oxidation. The catalysts are characterised by energy dispersive spectroscopy, differential scanning calorimeter, ammonia temperature programmed desorption, infrared spectroscopy and a nitrogen adsorption/desorption method. Energy dispersive spectroscopy results have shown satisfactory agreement regarding chemical composition that corresponds to the desired content of heteropolyacids on bentonite. Thermal analysis confirmed the thermal stability of catalysts under the investigated region of oxidation reaction. NH3-TPD spectra demonstrated that all catalysts include two types of acidic sites: weak adsorption centres up to 390 K and a broad distribution of stronger acidic sites at higher temperatures. The catalysts were active in the vapour-phase conversion of 2-propanol to acetone in the temperature region of 343-553 K. An increase of HPW loading improves selectivity towards acetone formation

Catalytic activity of Pt catalysts promoted by MnOx for n-hexane oxidation

The deep oxidation of n-hexane was studied over Pt catalysts with small and large Pt crystallites, promoted by MnOx. The Mn was deposited on the Pt/Al2O3 by deposition-precipitation method using two alkalis, ammonia and dimethylamine. The strength of the base influenced morphology and performances of Mn-Pt catalysts. Ammonia formed mostly spherical structure of manganese oxide, while dimethylamine created fibrous needle-like shape of MnOx, typical for cryptomelane phase of manganese oxide. This was confirmed by XPS results that show an oxidation state of Mn close to that for cryptomelane. The Pt-Mn catalysts were more active than catalysts containing Pt only. Promoting effect of MnOx is more pronounced for larger Pt crystallites. Among Pt-Mn samples, catalysts synthesized with dimethylamine exhibited the highest activities. Mobility and reactivity of oxygen from Pt-O-Mn sites associated with cryptomelane phase may be responsible for increased activity