Habitat suitability for the Caucasian frog <Emphasis Type="Italic">Rana macrocnemis</Emphasis> Boulenger, 1885 (Amphibia:Anura: Ranidae)

Modeling the distribution patterns of species is a generally efficient tool to assess their ecological characteristics. In this study, we compared ecological niche factor analysis (ENFA) and maximum entropy (Maxent) techniques to predict the most suitable distribution range of Rana macrocnemis. The Maxent model predicted potential suitable habitats for R. macrocnemis with high success rates (AUC Training data = 0.877 ± 0.039). According to the map constructed, three important variables had high contribution to species presence: temperature (50.4%), land cover (24.6%) and elevation (14.4%) variables. The ENFA results were relatively similar to Maxent jackknife analysis. The results implied that R. macrocnemis prefers grassland and needle leaf deciduous forest with high elevations, and low temperature.     

Environmental protection stability of river bed and banks using convex, concave, and linear bed sills

River bed scourings are a major environmental problem for fish and aquatic habitat resources. In this study, to prevent river bed and banks from scouring, different types of bed sills including convex, concave and linear patterns were installed in a movable channel bed in a laboratory flume. The bed sills were tested with nine different arrangements and under different flow conditions. To find the most effective bed sill pattern, the scouring depth was measured downstream of the bed sill for a long experimental duration. The scour depth was measured at the middle and at the end of each experimental test for different ratios of the arch radius to the channel width $(r/\emph{w})$ . The experimental results indicated that the convex pattern with $r/\emph{w}=0.35$ produced minimum bed scouring depth at the center line whereas the concave pattern with $r/\emph{w}=0.23$ produced the minimum scour depth at the wall banks. Therefore, the convex pattern was the most effective configuration for prevention of scouring at the center line of the river while the concave pattern was very effective to prevent scouring at the river banks. These findings can be suggested to be used in practical applications.     

Petroleum pollution in mangrove forests sediments from Qeshm Island and Khamir Port—Persian Gulf, Iran

The concentrations of total polycyclic aromatic hydrocarbons (?PAHs) and 22 individual PAH compounds in 42 surface sediments collected from the mangrove forest of Qeshm Island and Khamir Port (Persian Gulf) were analyzed. ?PAHs concentrations ranged from 259 to 5,376 ng?g^?1 dry weight with mean and median values of 1,585 and 1,146 ng?g^?1, respectively. The mangrove sediments had higher percentages of lower molecular weight PAHs and the PAH profiles were dominated by naphthalene. Ratio values of specific PAH compounds were calculated to evaluate the possible source of PAH contamination. This ratios suggesting that the mangrove sediments have a petrogenic input of PAHs. Sediment quality guidelines were conducted to assess the toxicity of PAH compounds. The levels of total PAHs at all of stations except one station, namely Q₆, were below the effects range low. Also, concentrations of naphthalene in some stations exceeded the effects range median.     

Oil contamination in surface sediment of Anzali Wetland in Iran is primarily even carbon number <Emphasis Type="Italic">n</Emphasis>-alkanes

To determine the extent of oil contamination and biodegradation in Anzali Wetland of Iran, we examined aliphatic hydrocarbons in surface sediment of this area (n=20). Petroleum hydrocarbon levels (mean 1585 ± 1117; range 316 to 4358 μg g?¹ dry weight) were similar in value to reports from other highly contaminated areas, such as New York Bight, Saudi and Kuwaiti coasts of the Persian Gulf, and Dubai shorelines. Even carbon homologs dominated distribution of n-alkanes in surface sediment of Anzali, which is rarely reported elsewhere. Multiple factors used in our study point to petrogenic source for n-alkanes in Anzali Wetland. Anzali receives multiple industrial and agricultural runoffs from the surrounding area. Shipping industry and oil industry are responsible for a major portion of pollutants entering Anzali. Municipal wastewater discharges are another source of Anzali pollution. To determine why even carbon number n-alkanes predominate in Anzali, we examined the following indices: existence of unresolved complex mixtures (UCM), ratio of UCM to resolved alkanes (RA), ratio of low-molecular weight to high-molecular weight molecules, presence of degraded oil residue, high-relative biodegradation, and the degree of hydrocarbon weathering in the surface sediment of the area. Our findings corroborate with such predominance.     

Biodegradation of phenol by Ralstonia eutropha in a Kissiris-immobilized cell bioreactor

This study examined the biodegradation of phenol by Ralstonia eutropha in a Kissiris-immobilized cell bioreactor (ICB), operated in a repeated batch recycling mode. The steady biodegradation rate of 23.7 mg/g/h, over a wide range of the initial phenol concentrations up to 1400 mg/L in the ICB, indicated an increased tolerance limit of the Kissiris-immobilized cells towards phenol. Both Haldane and Luong substrate inhibition models were used to describe biodegradation kinetic of free cells system. The Haldane equation gave the following values for the biokinetic parameters: micro(max) = 0.36 h(-1), Ks = 40.48 mg/L, and Ki = 181.9 mg/L. However, according to the Luong model, these parameters were micromax) = 0.23 h(-1), Ks = 24.8 mg/L, Sm = 1018 mg/L, and n = 1.3. By following appropriate operational conditions and use of the ICB, it was found to be possible to extend the efficiency of the highly porous structure of the siliceous mineral Kissiris in cell immobilization. This holds significant promise for pollutant biodegradation issues.     

Developing a sustainable operational management system using hybrid Shapley value and Multimoora method: case study petrochemical supply chain

Environment, Development and Sustainability - In this research, a new method to determine the supply chain performance based on its sustainable strategies is proposed. This method consists of a...     

A new method for calculating saddle seat height with an emphasis on optimal posture based on trigonometric relations

Introduction. Based on the literature, the ergonomic saddle chair provides the most appropriate posture for users. Determination of the seat height is critical to establish the proper posture, carried out using various methods of anthropometry. This study aimed to develop a simple and applied method for determining the saddle seat height with an emphasis on appropriate posture. Methods. In this study, anthropometric dimensions including weight, body height, popliteal height and seat height at 135° knee angle in 150 male and female dentists were measured. In the laboratory, to determine the ‘acetabuloischial number’, 25 male and female natural hip bones were measured. The mean saddle-chair height with knee angle of 135° was then compared by two different methods, field measurement and the new calculation method. Results. The results showed a strong correlation between data gathered from the two different methods, the field measurement and the new calculation method (98%), and Cronbach’s α from the intraclass correlation was equal to 0.994 (p?<?0.05). This indicated that the two methods produced similar results. Conclusion. The new method can be applied to calculate the optimal height of the saddle seat based on body height and popliteal height.