Numerical simulation of natural gas/diesel dual-fuel engine for investigation of performance and emission

Journal of Thermal Analysis and Calorimetry - Due to global concerns about the emissions, limited hydrocarbon fuel resources and high fuel prices, a lot of researches have been done to improve the...     

Evaluation of aerodynamic performance enhancement of Risø_B1 airfoil with an optimized cavity by PIV measurement

Journal of Visualization - Airfoils are mostly inefficient in their off-design conditions. In order to improve the aerodynamic performance of airfoils in these conditions, using an optimized cavity...     

Numerical simulation of dimethyl ether/natural gas blend fuel HCCI combustion to investigate the effects of operational parameters on combustion and emissions

Journal of Thermal Analysis and Calorimetry - Homogeneous charge compression ignition (HCCI) combustion phasing control is one of the most difficult challenges of operating this new concept of...     

A simple,rapid and sensitive method based on modified multiwalled carbon nanotube for preconcentration and determination of lead ions in aqueous media in natural pHs

In this study, multiwalled carbon nanotube (MWCNT) was modified by the pyridine group using a silane agent and characterized by infrared spectroscopy (IR), thermal analysis (TG/DTA), and elemental analysis (CHN) and scanning electron microscopy (SEM). The application of this sorbent was investigated in determination of lead ions in aqueous samples, using flame atomic absorption spectrometry (FAAS). Through this study, different parameters such as pH and sample flow rate on adsorption process and eluent concentration, volume and flow rate were optimized. The limit of detection (LOD), the relative standard deviation and the recovery of the method were 2 ng mL^?1, 1.3% and 99.7%, respectively. Two standard reference materials (NIST 1571 and NIST 1572) were used to verify accuracy of this method. Finally, the sorbent was successfully applied for extraction and determination of low levels of Pb(II) ions in aqueous samples.     

Effective enhancement of selectivities and capacities for CO2 over CH4 and N2 of polymers of intrinsic microporosity via postsynthesis metalation

A series of metalized C-PIM-M (M = Na⁺, Mg²⁺, Al³⁺, PIMs = polymers of intrinsic microporosity) materials were prepared from a carboxyl-functionalized PIM (C-PIMs). The C-PIM-Na exhibited a high CO₂ adsorption capacity of 2.44 mmol/g and extreme low CH₄ uptake of 0.28 mmol/g at 273 K and 101 kPa among three metallated PIMs. It showed remarkably high CO₂/CH₄ and CO₂/N₂ selectivities at both 273 and 293 K due to an advantageous pore-blocking effect of Na⁺ cation.     

Existence,uniqueness and stability of solutions for a class of nonlinear integral equations under generalized Lipschitz condition

In this paper, we prove the existence, uniqueness and the stability of solutions for some nonlinear functional-integral equations by using generalized Lipschitz condition. We prove a fixed point theorem to obtain the mentioned aims in Banach space X:= C([a, b],R). As application we study some Volterra integral equations with linear, nonlinear and singular kernel.     

Role of recording geometry in the performance of spectral diversity filters with spherical beam volume holograms

We present experimental demonstrations of spectral diversity filters with spherical beam volume holograms for multimodal multiplex spectroscopy. Major properties of filters under diffuse-light illumination are discussed. The comparisons of spectral diversity between the transmission geometry holograms and the reflection geometry holograms are also studied. The results show that there is a trade-off between the degree of the spatial coherence of the source and the spectral diversity of the filter. We also conclude that the reflection geometry holograms have better spectral diversity and less sensitivity to the spatial coherence of the source.     

Cell docking inside microwells within reversibly sealed microfluidic channels for fabricating multiphenotype cell arrays

We present a soft lithographic method to fabricate multiphenotype cell arrays by capturing cells within an array of reversibly sealed microfluidic channels. The technique uses reversible sealing of elastomeric polydimethylsiloxane (PDMS) molds on surfaces to sequentially deliver various fluids or cells onto specific locations on a substrate. Microwells on the substrate were used to capture and immobilize cells within low shear stress regions inside channels. By using an array of channels it was possible to deposit multiple cell types, such as hepatocytes, fibroblasts, and embryonic stem cells, on the substrates. Upon formation of the cell arrays on the substrate, the PDMS mold could be removed, generating a multiphenotype array of cells. In addition, the orthogonal alignment and subsequent attachment of a secondary array of channels on the patterned substrates could be used to deliver fluids to the patterned cells. The ability to position many cell types on particular regions within a two dimensional substrate could potentially lead to improved high-throughput methods applicable to drug screening and tissue engineering.     

A review on wound dressings with an emphasis on electrospun nanofibrous polymeric bandages

Wound dressings have experienced continuous and significant changes since the ancient times. The development starts with the use of natural materials to simply cover the wounds to the materials of the present time that could be specially made to exhibit various extraordinary functions. The modern bandage materials made of electrospun biopolymers contain various active compounds that are beneficial to the healing of wounds. These materials are fibrous in nature, with the size of fibers segments ranging from tens of nanometers to micrometers. With the right choices of biopolymers used for these fibrous materials, they could enhance the healing of wounds significantly compared with the conventional fibrous dressing materials, such as gauze. These bandages could be made such that they contain bioactive ingredients, such as antimicrobial, antibacterial, and anti‐inflammatory agents, which could be released to the wounds enhancing their healing. In an active wound dressing (AWD), the main purpose is to control the biochemical states of a wound in order to aid its healing process. This review provides an overview of different types of wounds, effective parameters in wound healing and different types of wound dressing materials with a special emphasis paid to those prepared by electrospinning. Copyright © 2009 John Wiley & Sons, Ltd.