Ultrastructure of Felis catus whole fetus (Fcwf-4) cell culture following infection with feline coronavirus

Feline coronavirus (FCoV) consists of two biotypes based on their growth in cell culture and their antigenicity. Infections with FCoV are highly prevalent in the cat population worldwide. In this study, Felis catus whole fetus (Fcwf-4)cell culture was infected with FCoV UPM11C/08. Virus multiplication in cell culture was monitored and examined under the transmission electron microscope. The virus particles revealed the characteristic morphology of feline FCoV represented by envelope viruses surrounded by peplomers. Virus attachment and entry into the cell occurred 15?h post-infection (pi), and the myriad of virus particles were observed both extracellularly and intracellularly after 48?h pi. Thereafter, intracellular virus particles were observed to be present in vacuoles or present freely in the cytoplasm.     

Periodic open-cell foams: Pressure drop measurements and modeling of an ideal tetrakaidecahedra packing

Periodic open-cell foams of ideal tetrakaidecahedron geometry were manufactured by selective electron beam melting (SEBM) and characterized with respect to the morphological parameters, namely strut diameter, window diameter and porosity. The pressure drop over these periodic foam samples of different pore size and porosity was determined experimentally. The basic form of the Ergun equation (which contains no empirical coefficients) was modified to develop a new correlation for the prediction of the pressure drop in periodic open-cell foams of ideal tetrakaidecahedron geometry. The correlation was successfully validated by the experimental results of the pressure drop measured for the periodic open-cell foam samples. With the new correlation it is possible to predict the pressure drop in periodic open-cell foams by using only two geometrical parameters, namely the open porosity and the window diameter.The applicability of the new correlation for a large range of porosities was examined by comparing the experimental and simulated friction factors for the porous media with both high (foam structure) and low porosities (packed beds) for a large range of the Reynolds number. It was demonstrated that the correlation can successfully predict the pressure drop of foam structures as well as packed beds.     

Evaluation of the source rock potential of the Unyazah Formation (late Carboniferous-Early Permian) in Dukhan Field,Qatar

Twenty samples were collected from the Unayzah Formation in three wells from Dukhan Field, Qatar. Many samples were of poor quality due to the low TOC content containing gas prone-kerogen type III and IV. The Rock-Eval maturity parameters indicate that many samples were immature, while the mature samples generated dry gas. The C15+ extracts GC suggests a marine input, while they have kerogen type III and IV which are usually derived from terrestrial input. This may be due to the abundance of G. Prisca which was probably recycled from older sediments. The organic matter may also have been subjected to oxidation, leaching, biodegradation or recycling due to the changing nature of the depositional environment that ranged from braided river system to marine settings.     

120 Gb/s all-optical NAND logic gate using reflective semiconductor optical amplifiers

In this paper, the unique features of the reflective semiconductor optical amplifiers (RSOAs) are exploited to numerically simulate the ultrafast performance of an all-optical NOT-AND (NAND) logic gate for the first time using a return-to-zero modulation format at a data rate of 120 Gb/s. A comparison is made between RSOAs and conventional SOAs through studying the dependence of the gate’s quality factor (QF) on the critical operational parameters, including the effects of both amplified spontaneous emission and operating temperature to get more realistic results. The results show that the all-optical NAND logic gate can be executed at 120 Gb/s using the RSOAs scheme with a higher QF than when using conventional SOAs.     

Galvanic Corrosion of Steel in Agitated Vessels Used in Fertilizer Industry

Theoretical Foundations of Chemical Engineering - Rates of mass transfer controlled Fe/Cu galvanic corrosion at the wall lining of a cylindrical agitated vessel in different fertilizer electrolytic...     

TraceAnalyzer: a system for processing performance traces

The performance of a program often varies significantly over the course of the program's run. Thus, to understand the performance of a program it is valuable to look not just at end‐to‐end metrics (e.g. total number of cache misses) but also the time‐varying performance of the program. Unfortunately, analyzing time‐varying performance is both cumbersome and difficult. This paper makes three contributions, all geared toward helping others in working with traces. First, it describes a system, the TraceAnalyzer, designed specifically for working with performance traces; a performance trace captures the time‐varying performance of a program run. Second, it describes lessons that we have learned from many years of working with these traces. Finally, it uses a case study to demonstrate how we have used the TraceAnalyzer to understand a performance anomaly. Copyright © 2010 John Wiley & Sons, Ltd.     

Effect of Zr on microstructure and mechanical properties of the Al–Cu–Er alloy

ABSTRACT

The microstructure and mechanical properties of the Al–4Cu–2.7Er–0.3Zr alloy were investigated. The precipitates of the L1₂ structured phase with sizes 37?±?12?nm were formed in lines and homogenously distributed inside the aluminium matrix after annealing at 605°C for 1?h. The as-rolled Al–4Cu–2.7Er–0.3Zr alloy developed an increased hardness after 1?h annealing at 100–550°C and 0.5–6?h annealing at 150–250°C due to precipitation of the Al₃(Er,Zr) phase. Addition of Zirconium improved the tensile properties relative to those of the Zr-free alloy by approximately 20?MPa: yield strength?=?273–296?MPa and ultimate tensile strength?=?296–328?MPa in the alloys annealed at 100–150°C.     

Degradation analysis of a heavy-duty gas turbine engine under full and part load conditions

This paper describes the degradation analysis and the performance diagnostics of the gas-turbine (GT) cycle of a combined cycle power plant (CCPP). Three different operating loads, which are 100%, 75%, and 50%, were tested at different ambient conditions, namely, temperature, pressure, and humidity. First, a degradation model to simulate the GT performance with these various operating loads and conditions has been developed. It is then demonstrated how this degradation affects the GT and its components. The degradation analysis has been performed on 2500 readings obtained during 2 years of operation. After applying the load determining criteria, 60 readings were obtained to represent the full load operation and 40 reading points for each part-load operation. The degradation analysis has been carried out on the basis of actual data obtained from a CCPP; this differentiates this study from the others in the same area. Based on the commissioning test performance of the GT cycle, the model has been validated. The results show that the rate of degradation increases dramatically as the load increases. Moreover, the degradation rate also increases with an increase in the ambient air temperature. However, the degradation rate for the various studied parameters, namely, polytropic efficiencies, GT exhaust mass flow rate, and the overall GT efficiency, has been found to decrease with time. The maximum degradation percentage has been estimated to be −1.71% at full load conditions in comparison with −1.33% and −1.16% at 75% and 50% load, respectively.