Effect of bitumen and migrated oil on hydrocarbon generation kinetic parameters derived from Rock-Eval pyrolysis

Thermally immature whole rock and related bitumen-extracted samples were pyrolyzed. Investigating the influence of high molecular weight hydrocarbons and degradation products of non-hydrocarbon constituents of bitumen and associated migrated oil (i.e. resins and asphaltenes) on petroleum generation kinetic parameters derived from Rock-Eval pyrolysis is the main aim of this study. Based on the optimized kinetic parameters, frequency factor values of the bitumen-free samples show an obvious increase compared to whole rocks, while the range of activation energies for them is narrower. On the other hand, the predicted geological temperatures of the onset (TR 10%) and the peak hydrocarbon generation (geological T_max) from the whole rocks are generally lower than the corresponding extracted samples. In other words, the whole rock samples underestimate the petroleum formation temperatures. Thus, the results of this study suggest the extraction of bitumen prior to Rock-Eval pyrolysis in order to obtain precise kinetic parameters for the source rocks bearing a large amounts of heavy bitumen or migrated oil.     

Ductile moment-resisting frames using cold-formed steel sections: An analytical investigation

This paper presents an investigation on the potential use of cold-formed steel sections (CFS sections) in moment-resisting frames (MRFs) for seismic applications. The main limitation of CFS sections is the low out-of-plane stiffness of their thin-walled elements which leads to low ductility. The main components of MRFs are beams, beam-column connections and columns. In earthquake resistant MRFs, the beams are designed to provide considerable ductility, whereas the other elements are mainly limited to their elastic range. The performance of a new shape of CFS beam with curved flange is examined analytically and compared with that of conventional shapes. The proposed beam-column connections include through plates which potentially limit the out-of-plane action of the forces transferred through the connections. The behaviour of both individual CFS beam sections and CFS beam-column connections is studied by means of finite element analysis (FEA). The results of the analyses show that the new beam cross sections and connections exhibit a good ductile behaviour, something which cannot be achieved by conventional cold-formed frame elements.     

Seismic evaluation of a 56‐storey residential reinforced concrete high‐rise building based on nonlinear dynamic time‐history analyses

In recent decades, shear walls and tube structures have been the most appropriate structural forms for the construction of high‐rise concrete buildings. Thus, recent Reinforced Concrete (RC) tall buildings have more complicated structural behaviour than before. Therefore, studying the structural systems and associated behaviour of these types of structures is very important. The main objective of this paper is to study the linear and nonlinear behaviour of one of the tallest RC buildings, a 56‐storey structure, located in a high seismic zone in Iran. In this tower, shear wall systems with irregular openings are utilized under both gravity and lateral loads and may result in some especial issues in the behaviour of structural elements such as shear walls and coupling beams. The analytical methodologies and the results obtained in the evaluation of life‐safety and collapse prevention of the building are also discussed. The weak zones of the structure based on the results are introduced, and a detailed discussion of some important structural aspects of the high‐rise shear wall system with consideration of the concrete time dependency and constructional sequence effects is also included. Copyright © 2010 John Wiley & Sons, Ltd.     

Design of an Optimized 2.5 GHz CMOS Differential LC Oscillator with Nonlinear Analysis for MOS Varactor

The oscillation amplitude and supply current relations for a differential CMOS oscillator are derived by using an analytic method. A simplified model to predict the phase noise performance of the oscillator is developed. The large signal analysis of a nonlinear inversion mode MOS varactor is presented. The derived expressions can help to design an optimized oscillator in terms of minimum phase noise and power consumption. The validity of the method has been verified by designing an LC CMOS oscillator in a 0.25 μm CMOS technology. The predictions are in good agreement with simulation results over a wide range of supply voltage.     

PILOT PLANT STUDIES AND MODELLING OF A SEMI-BATCH POLYESTERIFICATION PROCESS

A novel unsaturated polyester formulation was developed recently in our laboratories. The polyester resin, which was designed as a green-house glazing material, exhibited excellent optical properties and superior resistance to weathering conditions. This study describes the scale-up procedure followed in preparing the resin in a 200 L pilot plant reactor starting from its preparation in a 1 L reactor. The paper analyzes the major variables affecting the polyesterification process and presents a semi-empirical model capable of predicting the pilot plant kinetic data from laboratory reactor data. The model is based on a recently developed third order kinetic equation for the reaction of non-stoichiometric amounts of hydroxyl and carboxylic groups. The model quantifies the effects of reaction temperature and inert gas flow rate on reaction rate and provides a basis for the polyesterification process scale-up. The reaction temperature dependence is assumed Arrhenius, whereas the gas flow rate dependence is empirically determined as a function of the molar ratio of reactants to inert gas. Application of the model to commercial sized reactors will be highlighted.     

The effects of multiple firefighting activities on information processing and work performance in a smoke‐diving room: An intervention study

Firefighters perform various tasks during firefighting operations under unknown and unpredictable conditions. The present study investigated the impact of firefighting activities and cooling tactics on information processing and work performance. Firefighters performed typical firefighting tasks in the four experimental conditions, namely i) no cooling device (NC), ii) cooling gel (CG), iii) cool vest (CV), and iv) cooling gel and cool vest (CG + CV). The measurement of information processing, Paced Auditory Serial Addition Test (PASAT) scores decreased significantly after the firefighting activities in the four conditions, relative to baseline. The results revealed no significant difference in PASAT scores among the four conditions. However, the performance time (PT) was significantly shorter for the CV and CG + CV compared to the NC and CG conditions. The findings confirmed that the firefighting activities have a detrimental effect on information processing. The CG + CV and CV were more effective than CG and NC in improving PT during firefighting. However, the cooling strategies have a negligible effect on improving information processing performance.     

Physiological strain and decision making affected by different cooling tactics following live‐fire training

Multiple factors, including different environmental, physical, and psychophysiological agents, influence firefighters’ health and safety in real fire and rescue operations. This experimental study investigated the effect of live‐fire training and cooling strategies on both physiological response and decision making. Twenty‐three healthy male firefighters performed live‐fire tasks in four separate conditions: namely rest or without cooling method (WCM), cool vest (CV), forearm immersion (FI), and cool vest and forearm immersion (CV + FI). Cooling effects of the employed interventions were evaluated based on heart rate (HR), tympanic temperature (TT), and Iowa gambling task (IGT) scores. At the end of the four experimental conditions, HR and TT increased, whereas IGT scores as a measure of decision making decreased relative to baseline. HR (beats per minute) and TT (°C) were significantly lower at the end of the experiment in the CV, FI, and CV + FI compared with the WCM conditions. There was no significant difference in Iowa scores between experimental conditions. These consequences demonstrate that live‐fire tasks are effective in raising the physiological and decision‐making responses following firefighting activities. It is concluded that CV, FI, and CV + FI were more effective than the WCM in attenuating physiological responses and decision making during live‐fire training.     

Fuzzy Logic-Based Multicast Routing in Multiradio Multichannel Wireless Mesh Networks

The availability of bandwidth in wireless mesh networks (WMNs) introduces it as a prominent choice for implementing bandwidth sensitive services. Multicast services such as teleconferencing, push-based systems, multiplayer games, etc., can be implemented in an efficient way in such networks. Moreover, the severe performance degradations that can result from the interference generated by concurrent data transmissions and environmental noises call for the development of interference-aware routing mechanisms. This paper investigates the impact of wireless interference on network performance for multicast transmission in WMNs. We show that by taking wireless interference into consideration in the design of routing mechanisms, better resource usage can be achieved. Hence, a fuzzy logic–based approach is proposed to choose optimal routes from source to the multicast group in multichannel case. Three fuzzy variables are considered in route selection phase, which are interference, available bandwidth, and hop count. Extensive simulations are conducted aiming at verifying the high performance of the proposed algorithm. Simulation results demonstrated that our proposed algorithm outperforms Link-Controlled Multi-Rate Multi-Channel (LC-MRMC) and Channel Assignment with Multiple Factor (CAMF) algorithms in terms of throughput, packet delivery ratio, and end-to-end delay.     

Short to Long-Term Forecasting of River Flows by Heuristic Optimization Algorithms Hybridized with ANFIS

Water Resources Management - Accurate forecast of short-term to long-term streamflow prediction is of great importance for water resources management. However, with the advent of novel hybrid...     

Dietary PUFA Increase Apoptosis in Stomach of Patients with Dyspeptic Symptoms and Infected with <Emphasis Type="Italic">H. pylori</Emphasis>

Drug-resistant strains of Helicobacter pylori and poor treatment response are the main reasons for the failure in eradicating it in patients. Polyunsaturated fatty acids (PUFA) have an inhibitory effect on bacterial growth. The aim of this study was to investigate the effect of PUFA in combination with standard triple therapy on apoptosis in H. pylori infected subjects with dyspeptic symptoms. This study was a double-blind clinical trial in which 34 H. pylori infected subjects with dyspeptic symptoms were randomly divided into two groups of 17 patients. The control group received standard triple therapy (amoxicillin, clarithromycin and omeprazole) and the experimental group received the standard therapy and PUFA for two weeks. Gene expression levels of caspase-3, BCL-2 and Bad proteins were studied with real-time PCR, while protein levels were quantified in frozen sections and using immunohistochemistry. Compared with the control group, a significant increase (p < 0.01) was observed in the expression of caspase-3 and Bad genes and a significant reduction (p < 0.05) in the expression of Bcl-2 gene. The protein level of active caspase-3 and Bad protein was significantly increased and the level of Bcl-2 protein was significantly decreased (p < 0.05). The results of this study show that oral administration of PUFA in combination with the standard triple therapy increased apoptosis in H. pylori-infected patients with dyspeptic symptoms. This increase in apoptosis may partly reduce drug resistance in these patients. Our results suggest inclusion of a dietary PUFA containing fatty acid supplement may improve treatment of patients that are refractory to the standard triple therapy.