University of Windsor

About: University of Windsor is a education organization based out in Windsor, Ontario, Canada. It is known for research contribution in the topics: Population & Argumentation theory. The organization has 10654 authors who have published 22307 publications receiving 435906 citations. The organization is also known as: UWindsor & Assumption University of Windsor.

Synthesis of silver nanoparticles with controllable surface charge and their application to surface-enhanced Raman scattering.

Abstract: The objective of the present work was to explore new methods of synthesis of silver nanocolloids using amino acids as reducing agents. The goal of the study was to fabricate nanostructures with controllable surface charge (zeta potential) that may allow optimizing the adsorption of target molecules for ultrasensitive analysis using surface-enhanced Raman scattering (SERS). The average SERS properties of these colloids are tested with two organic analytes and compared with those obtained by using the most commonly used citrate Ag sols.

The Relationship Among Athlete Leadership Behaviors and Cohesion in Team Sports

Abstract: This study examined the influence of athlete leadership behaviors on perceptions of team cohesion. The participants were 312 athletes from 25 varsity and club level teams. Each participant completed the Group Environment Questionnaire (Carron, Widmeyer, & Brawley, 1985) that assessed cohesion and the Leadership Scale for Sports (Chelladurai & Saleh, 1980) that assessed athlete leadership behaviors. Overall, it was found that individual perceptions of Training and Instruction, and Social Support positively influenced all four dimensions of cohesion (ATG-T, ATG-S, GI–T, GI-S). Furthermore, Autocratic Behavior was negatively associated with the four dimensions of cohesion. Finally, Democratic Behavior was positively related to ATG-T. These findings provide researchers, sport psychology consultants, athletes, and coaches with some initial evidence that it is important to foster the development of athlete leader behaviors to influence the team environment. The construct of cohesion has historically been viewed by some researchers as one of the most important small group variables (e.g., Lott & Lott, 1965) and is defined as “a dynamic process that is reflected in the tendency for a group to stick together and remain united in the pursuit of its instrumental objectives and/ or for the satisfaction of member affective needs” (Carron, Brawley, & Widmeyer, 1998, p. 213). As Carron, Bray, and Eys (2002) noted, the definition of cohesion implicitly suggests that higher levels of cohesion are related to greater team performance. In fact, a meta-analysis examining the strength of the cohesion-performance relationship found a moderate to large effect size between these two constructs in sport (Carron, Colman, Wheeler, & Stevens, 2002). Given the significance of the cohesion-performance relationship, it is not surprising that Westre and Weiss (1991) emphasized the importance of identifying factors that influence the development of cohesion. To guide research, Carron (1982) advanced a conceptual model of the factors or antecedents that were hypothesized to influence perceptions of cohesion. The antecedents of the model were classified as environmental, personal, team,

Subaerial exposure and meteoric diagenesis of the Cenomanian-Turonian Upper Sarvak Formation, southwestern Iran

Abstract: The Sarvak Formation (Cenomanian–Turonian) forms one of the main reservoir rocks in many oilfields in southern Iran. Extensive lateral and vertical facies variations as well as effects caused mainly by the subaerial exposure associated with the regional Turonian unconformity have resulted in variable porosity and permeability. Dissolution affected the entire upper part of the Sarvak Formation and is the most important process related to subaerial exposure. Brecciation, development of palaeosol and formation of bauxite deposits are also limited to the upper few metres of the top of the Sarvak Formation and indicate warm and humid climatic conditions. Subaerial exposure had varying effects on the diagenesis depending on its duration, palaeotopography and the availability of meteoric water. The dO and dC values obtained from calcitic matrix, various generations of calcite cements and calcitic rudist shells in the Upper Sarvak overlap to a large extent, indicating their equilibration with fluids of similar isotopic composition. Negative dO values (i.e. 26.6‰ to 21.7‰) suggest a significant meteoric component. More O-depleted values (e.g.212.3‰) obtained from late calcite cements indicate their precipitatation from warm fluids. Positive dC values (i.e. 0.00‰ to 3.4‰) in the various carbonate phases reflect values of seawater coeval with an Oceanic Anoxic Event and later modified by meteoric waters. The Middle Cretaceous Sarvak Formation in southern Iran contains more than 20% oil-in-place of Iranian oil reservoirs, forming the second most important reservoir rocks after the Asmari Formation of the Oligo-Miocene. In addition to its petroleum significance, the Sarvak Formation forms productive groundwater aquifers feeding karstic springs in the Zagros region (Raeisi & Karami 1997; Ahmadipour 2002). Sarvak carbonates were deposited in a ramp environmental setting with extensive lateral and vertical facies variations (Setudehnia 1978). These carbonates were affected by a major unconformity (Turonian) that involved extensive erosion and karstification. Therefore, the variability and extent of diagenesis and the distribution of diagenetic phases could be due to the presence of the unconformity and associated karstification. This unconformity has been reported in several localities in southern Iran as well as elsewhere in the Persian Gulf region (James & Wynd 1965; Harris et al. 1984; Setudehnia 1978). Karstification of carbonate rocks by meteoric water during subaerial exposure is an important diagenetic process that contributes to the development of petroleum reservoirs by enhancing their porosity and permeability (e.g. Wright 1991; Lousk 1999; Wang & Al-Aasm 2002; Fu et al. 2006). Karstified systems are commonly affected by later diagenesis including cementation. Karstic features have great implications for sequence stratigraphy, palaeoenvironmental interpretation and, more importantly, the development of hydrocarbon reservoirs. However, identification of these features may be problematical in some instances in drilled cores. The high porosity and permeability of the karstified carbonates and the importance of palaeokarst processes in developing porosity have been widely documented in the literature (Mylroie & Carew 1995; Lousk 1999; among many others). Karstification could result in modification andredistributionofporosityandpermeability (Choquette & James 1988; Hopkins 1999), often significantly complicating exploration for oil and gas, as well as delineation of reservoir characteristics. The aim of this investigation is to identify diagenetic processes in the Upper Sarvak Formation, including extensive karstification, that were mainly controlled by subaerial exposure. These processes also greatly influenced reservoir quality. To obtain From: LETURMY, P. & ROBIN, C. (eds) Tectonic and Stratigraphic Evolution of Zagros and Makran during the Mesozoic–Cenozoic. Geological Society, London, Special Publications, 330, 253–272. DOI: 10.1144/SP330.12 0305-8719/10/$15.00 # The Geological Society of London 2010. a better understanding of the diagenetic processes, petrographic and stable carbon and oxygen isotope results of the Upper Sarvak carbonates from surface sections and subsurface cores from southwestern Iran have been integrated (see Fig. 1 for location of the study area). Data obtained from these investigations have been used to characterize the diagenetic fluid(s) involved. In addition, these data have been utilized to substantiate the greenhouse conditions and amplification of karst formation and the evolution of porosity in the Upper Sarvak Formation. Previous study of the Sarvak Formation The stratigraphy and sedimentology of the main lithostratigraphic units of the Zagros region in SW Iran are now well established (Alavi 2004). However, understanding the various petroleum systems in the region requires palaeogeographical reconstructions of these units, focusing on their regional and local lithofacies variations. The Middle Cretaceous Sarvak Formation of the Bangestan Group (i.e. Albian–Santonian) in the Zagros Mountains was deposited in a ramp setting during Cenomanian to Early Turonian time (Setudehnia 1978; Taghavi et al. 2006). Stratigraphically, this formation is equivalent to the Mauddud, Ahmadi and Mishrif formations in the Persian Gulf (Ghazban 2007), the Wara, Ahmadi and Mishrif formations in Iraq and Saudi Arabia (Fig. 2) and the Natih Formation in Oman (van Buchem et al. 2002). James & Wynd (1965) conducted the first systematic stratigraphic investigation of the Zagros Mountains including the Cenomanian–Turonian Sarvak Formation. Their work was followed by that of Setudehnia (1978), who reviewed the geology of the formation and examined depositional facies and their cyclicity in southwestern Iran. Boltz (1978) recognized the deposition of the Sarvak carbonates within a restricted intrashelf basin in Dezful Embayment and suggested a significant tectonic influence on general sedimentation patterns. Hajikazemi et al. (2002) demonstrated that much of the variability in diagenetic features and their spatial distribution in the Upper Sarvak Formation in the Sirri oilfields in the northeastern Persian Gulf could be related to the presence of a major Turonian unconformity and associated karstification. Taghavi et al. (2006) investigated the Upper Sarvak Formation in the Dehluran Field (c. 120 km NW of Ahwaz) and identified three major transgressive–regressive sequences. According to those workers the diagenetic processes, especially the regressive parts of each major sequence, were controlled by sea-level fluctuations. Beiranvand et al. (2007) recognized five facies association in the Sarvak Formation and identified Study area IR AN Bangestan Shah Neshin Shiraz