The interplay between leadership and organizational culture in the Turkish construction sector

Organizational culture and leadership are purported to be deeply integrated and intertwined within an organization. Although there is a substantial amount of research demonstrating the importance of the interplay of culture and leadership, there exist few empirical examinations of the nature of this link. To examine this link, based on Cameron and Quinn's Organizational Culture Assessment Instrument and Hofstede's Values Survey Module, a questionnaire survey was conducted. The sample consists of 499 managerial personnel out of 107 contracting firms. With the aim of achieving a better understanding of how leadership style is influenced by organizational culture, Multinomial Logistic Regression was used. The findings demonstrate that managers in the contracting companies with different cultural characteristics tend to adopt different leadership styles to lead their employees to succeed in their business. Information contained in this paper will feed into country-specific understanding of leadership and organizational culture within the construction industry.     

Nitrogen Transformations during Soil–Aquifer Treatment of Wastewater Effluent—Oxygen Effects in Field Studies

Depth-dependent oxygen concentrations and aqueous-phase total ammonia and nitrate/nitrite ion concentrations were measured in the field during the infiltration of wastewater effluent. Measurements illustrated the dependence of nitrogen fate and transport on oxygen availability. Infiltration basins were operated by alternating wet (infiltration) and dry periods. During infiltration periods, ammonia was removed within the top few feet of sediments via adsorption. Biochemical activity rapidly eliminated residual molecular oxygen in the infiltrate, making the soil profile anoxic. During dry periods, oxygen reentered the basin profile and sorbed ammonia was converted to nitrate via nitrification. Oxygen penetrated to a depth of about 0.6?m?(2?ft) within the first few days of dry periods. At greater depths, oxygen levels increased more slowly due to a combination of slow transport kinetics and biochemical (nitrogenous) oxygen demand. During normal wet/dry basin cycles consisting of about 4 wet and 4 dry days, the local vadose zone remained anoxic at depths greater than about 1.5?m?(5?ft) below land surface. As a consequence, conditions for denitrification were satisfied in the deeper sediments. That is, the nitrate nitrogen produced in near surface sediments moved freely downward with infiltrating water where it encountered an extensive anoxic zone before reaching local monitoring or extraction wells. The relative importance of dissolved organics and sorbed ammonia as electron donors for denitrification reactions remains to be established.     

Photodecomposition of Bil3 films

The effect of illumination on the transmittance and the structure of Bil₃ films was investigated. Photoexcitation was found to induce structural variation and decomposition of the films into metallic bismuth and free iodine. Moreover, measurements of the electrical conductivity during heating show thermal decomposition of the films and it was found that the temperature of decomposition depends on the thickness of the film.     

Treatment of olive mill wastewater by different physicochemical methods and utilization of their liquid effluents for biological hydrogen production

In this study various two-stage processes were investigated for biological hydrogen production from olive mill wastewater (OMW) by Rhodobacter sphaeroides O.U.001. Two-stage processes consist of physicochemical pretreatment of OMW followed by photofermentation for hydrogen production. Explored pretreatment methods were chemical oxidation with ozone and Fenton's reagent, photodegradation by UV radiation, and adsorption with clay or zeolite. Among these different two-stage processes, strong chemical oxidants like ozone and Fenton's reagent have the highest color removal (90%). However, their effluents were observed to be unsuitable for both hydrogen production and bacterial growth. On the other hand, clay treatment method was selected as the optimum process that allows fast and low-cost treatment as well as its effluent found to have the highest hydrogen production potential (31.5 m³ m^?3). Spent-clay regeneration was also investigated on the grounds that solid waste minimization is important for the overall efficiency of this process.     

Anisotropic Dielectric and Electrical Properties of Hot-Forged SrBi4Ti4O15 Ceramics

The effect of grain orientation on the dielectric and electrical properties of SrBi₄Ti₄O₁₅ ceramics are studied by impedance and modulus spectroscopy. The degree of orientation calculated from the X-ray diffraction pattern is found to be 94.2% along the c-axis of the crystal structure. The ratio of permittivity along the perpendicular to parallel direction is found to be ∼2.5 at the Curie temperature. The nonsuperimposition of the normalized Z″ and M″ versus frequency plot revealed that the conduction is localized and deviate from ideal Debye-like behavior. The conduction mechanism has been explained on the basis of jump relaxation model.     

Convenient new chemical actinometer based on aqueous acetone, 2-propanol, and carbon tetrachloride

A convenient new chemical actinometer was developed to measure the spectral output of laboratory ultraviolet (UV) light sources over the wavelength range of 260-330 nm. It can also be used to measure solar UV irradiance (< or =325 nm). The actinometer is based on the photoreduction of aqueous carbon tetrachloride (CT) to chloroform (CF) in the presence of acetone (the chromophore) and 2-propanol (the reductant). In all cases, CT disappearance (and CF formation) followed zero-order kinetics over 95% of the reaction. The slope of the linear decay curve forms the basis of the new actinometer, which was calibrated using ferrioxalate actinometry. Quantum yields were measured at 10 nm intervals and were found to be uniform throughout the range of 260-300 nm. As expected, quantum yields gradually decreased to zero asthe wavelength was increased from 300 to 340 nm. The high quantum yields (approximately 150), low sensitivityto room light, and the straightforward determination of [CT] and [CF] by gas chromatography offer significant advantages over some other chemical actinometers, which might require the preparation and purification of light-sensitive compounds in a darkened environment and long exposure times.