Dynamic relationship between precious metals

We use a relatively new approach to endogenously detect the volatility shifts in the returns of four major precious metals (gold, silver, platinum and palladium) from 1999 to 2013. We reveal that the turbulent year of 2008 has no significant effect on volatility levels of gold and silver however causes an upward shift in the volatility levels of palladium and platinum. Using the consistent dynamic conditional correlations, we show that precious metals get strongly correlated with each other in the last decade which reduces the diversification benefits across them and indicates a convergence to a single asset class. We endogenously detect the shifts in these dynamic correlation levels and reveal uni-directional volatility shift contagions among precious metals. The results show that gold has a uni-directional volatility shift contagion effect on all other precious metals and silver has a similar effect on platinum and palladium. However, the latter two do not matter in terms of volatility shift contagion. Thus, investors that hedge with precious metals should, in particular, monitor the volatility levels of gold and silver.     

Prenatal sonographic features of esophageal and ileal duplications at 18 weeks of gestation

We present a case of esophageal and ileal duplications at 18 weeks of gestation. Transabdominal ultrasonography of the fetus showed multiple cystic masses of 12 to 17 mm in diameter and continuity with each other in the abdomen and a unilocular cystic mass of 15 mm in diameter in the posterior mediastinum. The cystic mass filled the abdominal cavity with signs of intestinal obstruction. The thoracic cystic mass was tubular, sausage-shaped and behind the heart, which was displaced to the antero-lateral wall of the chest. Amniocentesis revealed a normal fetal karyotype 46,XY. Peristaltic movements in the abdominal cystic structure at 30 weeks of gestation suggested dilated intestinal loops. Follow-up ultrasound examinations showed polyhydramnios with amniotic fluid index of 30 cm and gradual enlargement of the cystic structures to 50 mm in the abdomen and 30 mm in the posterior mediastinum at 38 weeks of gestation. A male infant weighing 3900 g was delivered. Postnatal ultrasonographic examination and the findings of magnetic resonance imaging also suggested enteric duplication cysts. Prenatal diagnosis allowed prompt neonatal evaluation and surgical treatment of the esophageal and the ileal duplications, which was confirmed by pathological examination. Copyright © 2004 John Wiley & Sons, Ltd.     

Enhancing employees' duty orientation and moral potency: Dual mechanisms linking ethical psychological climate to ethically focused proactive behaviors

Based on social cognitive theory (SCT), we develop and test a model that links ethical psychological climate to ethically focused proactive behavior (i.e., ethical voice and ethical taking charge) via two distinct mechanisms (i.e., duty orientation and moral potency). Results from multi-wave field studies conducted in the United States, Turkey, France, Vietnam, and India demonstrate that an ethical psychological climate indirectly influences employees' ethical voice and ethical taking charge behaviors through the dual mechanisms of duty orientation and moral potency. Additionally, we find that individuals' moral attentiveness strengthened these mediating processes. Together, these findings suggest that ethical psychological climate is an important antecedent of ethically focused proactive behavior by stimulating individuals' sense of duty and enhancing their moral potency, particularly when employees are already highly attuned to moral issues.     

Assessing water quality in the Ceyhan River basin (Turkey) with the use of aquatic macrophytes

As a major biotic component of many lotic ecosystems, macrophytes consist a major component of running waters are often used as indicators within the European Water Framework Directive (WFD) to establish ecological quality. In this study, we investigated macrophyte community structure (e.g. composition, abundance and diversity) in Ceyhan River Basin located in the Southeastern Anatolian Region in Turkey. Data was collected during 2014–2015 from river sites located throughout the basin to evaluate the relationship between aquatic vegetation and river physico-chemical factors. The ecological status of the river basin was also calculated based on Macrophyte Biological Index for River (IBMR). In total, 33 macrophyta taxa were observed. According to their biological classification (life form), filamentous algae (FA), free floating (FF), floating leaved (FL) and submersed (S) macrophytes reached their maximum abundance value in summer, while emergent (E) macrophytes were at their maximum abundance in both summer and autumn. The ecological status of the Ceyhan River basin ranged from moderate to bad. The values found are reasonably comparable to IBMR scores recorded in rivers of other Mediterranean countries. IBMR index may be suitable to some extent to establish a basis for ecological quality assessment in Turkish River systems.     

Addressing the operational problems in a composting and recycling plant

The Istanbul composting and recycling plant, constructed in 2001, is one of the few composting plants in Turkey. During test operations of the plant, it was reported that the weight of the oversize materials (OM) above a 80-mm sieve was about 40% of the total incoming waste. They mainly consist of plastic bags that were full of garbage, which resulted in operational problems in the plant. In this paper, the composition of OM was determined and evaluated, particularly to find the economic losses in the plant. It was determined that approximately 58% of the OM transferred to the landfill area due to operational failures and interruptions could be used at the plant with improved operational conditions. Otherwise, the plant would realize an annual economic loss of about 640,800 US$. Compost quality in the plant has been satisfactory, but source separated collection, at least the separation of the wet from the dry fraction, is needed to increase the amount of compost and recovered materials.     

Green growth and OECD countries: measurement of country performances through distance-based analysis (DBA)

When we measure countries’ socioeconomic development, the standalone National Income approach does not to reflect well-being of the citizens. An analysis of a country's welfare should consider the combination of different aspects such as economic indicators, environmental and resource productivity, and economic opportunities. In the light of these discussions, the concept of green growth arose as a contemporary approach to reframe the mainstream growth model and to re-evaluate many of the investment decisions in meeting agricultural, energy and water needs and the resource demands of economic development. This paper evaluates the green growth performance of OECD countries by applying the I-distance method by integrating the economic, social, and environmental aspects of countries’ performances simultaneously. Using multivariate I-distance approach, selected green growth indicators and numerous different variables have been synthesized into one value. According to our analysis, Sweden, Luxemburg, Norway and Denmark occupy the top places by their outstanding green performance. On the other hand, Mexico, Poland and Greece are placed at the bottom as a consequence of their relatively weak environmental performance.

     

A Fuzzy Logic Approach to Assess Groundwater Pollution Levels Below Agricultural Fields

A fuzzy logic approach has been developed to assess the groundwater pollution levels below agricultural fields. The data collected for Kumluca Plain of Turkey have been utilized to develop the approach. The plain is known with its intensive agricultural activities, which imply excessive application of fertilizers. The characteristics of the soils and underlying groundwater for this plain were monitored during the years 1999 and 2000. Additionally, an extensive field survey related to the types and yields of crops, fertilizer application and irrigation water was carried out. Both the soil and groundwater have exhibited high levels of nitrogen, phosphorus and salinity with considerable spatial and temporal variations. The pollution level of groundwater at several established stations within the plain were assessed using Fuzzy Logic. Water Pollution Index (WPI) values are calculated by Fuzzy Logic utilizing the most significant groundwater pollutants in the area namely nitrite, nitrate and orthophosphate together with the groundwater vulnerability to pollution. The results of the calculated WPI and the monitoring study have yielded good agreement. WPI indicated high to moderate water pollution levels at Kumluca plain depending on factors such as agricultural age, depth to groundwater, soil characteristics and vulnerability of groundwater to pollution. Fuzzy Logic approach has shown to be a practical, simple and useful tool to assess groundwater pollution levels.     

Effect of addition diatomite powder on mechanical strength,elevated temperature resistance and microstructural properties of industrial waste fly ash-based geopolymer

This study examines the use of fly ash, a thermal power plant waste, and the effect of diatomite, a fossil algae type, on waste-based geopolymers in the production of sustainable geopolymer binders. The effects of 1%, 2%, 3%, 4% and, 5% diatomite substitution on waste-based mortars were investigated. Mortars containing 10% and 12% Na⁺ by weight based on the binder material were cured at 75 °C for 48 h. The flexural and compressive strength, abrasion resistance, determination of ultrasonic pulse velocity, and resistance to high temperatures of geopolymer mortar samples were investigated. In addition, FESEM images, EDX and XRD analyses of geopolymer mortar samples were made, and their microstructures were examined. 2% diatomite substitution increased flexural and compressive strength. In parallel with this situation, it was concluded that the abrasion resistance and ultrasonic pulse velocity of the geopolymer mortar with 2% diatomite substituted increased. In addition, it has been shown in FESEM images that the microstructure has a denser morphology. All geopolymer mortars lost strength after the high temperatures of 300 °C, 600 °C and 900 °C. As a result, it was concluded that diatomite containing highly reactive silica can be used in geopolymer systems.

     

Material conversion from used oil sorbents by pyrolysis

Journal of Material Cycles and Waste Management - A lab-prepared cellulosic oil sorbent—used for oil spill cleanup—was pyrolyzed in a quartz, pipe-type horizontal furnace at different...     

Heavy metals in water, sediment and tissues of Leuciscus cephalus from a stream in southwestern Turkey

Concentrations of heavy metals (Cd, Cr, Cu, Pb and Zn) were measured in water, bottom sediment and tissues (muscle and gills) of Leuciscus cephalus from the Dipsiz stream in the Yatagan basin (southwestern Turkey), the site of a thermal power plant. Results for levels in water were compared with national and international water quality guidelines, as well as literature values were reported for streams and rivers. Comparisons were made of metal concentrations in water and sediment with those in the muscle and gills of L. cephalus caught from the Dipsiz stream. We found that there was metal accumulation in the gills compared to the muscle. Concentrations of Cd, Pb, Zn and Cr in the gills were higher than that in the muscle; however, Cu levels were higher in muscle than that in gills. Concentrations of heavy metals in L. cephalus muscle were below the legal limits for human consumption, although Cr, Pb and Zn levels in the gills were above the limits in the fish taken from the Dipsiz stream. On the other hand, no correlation was found between metal concentrations in water and sediment or between metal concentrations in water and muscle and gills of L. cephalus. A positive correlation was found between concentrations of Cu and Zn in the sediment and in fish tissue, whereas there was no relationship between other metal concentrations in the sediment and water, and muscle and gills of L. cephalus. As with water, Pb and Cd concentrations in particular were higher in sediment than that in background levels. The results show that the pollutants from the thermal power plant may be a source of these elements.