EARLY-STAGE EVOLUTION OF PARTICLE SIZE DISTRIBUTION DUE TO GRAVITATIONAL COAGULATION

ABSTRACT

Evolution of the particle size distribution of an aerosol undergoing gravitational coagulation in early time stages was numerically investigated. The moment method was also applied in initiating a simple approach to the changes of particle size distribution parameters. Finally, an analytical solution was developed approximating the collision kernel into a form suitable for the analysis. The results underwent analysis by comparison. The derived analytical solution was found to be in good agreement with the numerical moment method. However, the results of the moment method do not exactly coincide with the results of the direct numerical integration because the particle size distribution does not attain the log-normal size distribution form.     

RSA-based Proxy Signature for Media Independent Handover

This paper proposes an Authentication Interworking Protocol (AIP) based cn IEEE 802.21 Medi Independent Handover (MIH)in the heterogeneous networks.The proposed AIP with the RSA-based proxy signature reduces handover delay time and communication message overhead when the mobile rode moves between the heterogeneous networks.It defines new AIP Type Length Value (AIP TLV) in MIH frame format and uses the MIH Information Server (MIHIS) for issuing signature.The MIHIS can generate a signature on behalf of the AAA server and then the signature can be used by mobile node for a pre-authentication.For low handover delay,the proposed AIP performs pre-authentication processes with MIP protocol before layer 2handover.Also,this paper analyses the performance of the handover and compares with the non-secure MIH.     

Program-controlled soft switching PRDCL inverter with new space vector PWM algorithm

A soft switched space vector PWM inverter is developed using new parallel resonant DC-link (PRDCL). This PRDCL can operate on variable DC-link pulse position and width resulting in enhanced PWM capability, which is superior to other resonant DC-links. A new space vector algorithm is presented suitable for this PRDCL inverter. The suggested algorithm is able to eliminate narrow PWM pulses that impede DC-link operation. This PWM control, however, requires complex and precise timing sequences in relation to PRDCL operation, which is nicely solved by adopting a new programmed controller with a buffer and a programmable timer.     

Design and Implementation of User Centered Interface on Mobile Phone

Mobile device research has been increasing rapidly in Human Computer Interaction (HCI) recently.Following this trend,this paper proposes a user-centered interface,which has been designed,completely installed and independently run on a mobile phone.Video signal is streamed through its camera as the image input to the interface by employing techniques of image processing,computer vision and graphics to identify automaticclly absolute positions of human face,neck and two hands.A paradigm is also put up theoretically.And it embeds this interface to perceive the human postures and convert them into relaxed comic character according to its context.     

Applications of scaffolds: Tools for enhancing the immunomodulation of mesenchymal stromal cells

Exogenously delivered mesenchymal stromal cells (MSCs) are therapeutically beneficial owing to their paracrine effect; they secrete various cytokines, nucleic acids, and proteins. Multiple bioengineering techniques can help MSC cultures to release secretomes by providing stem cell niche-like conditions (both structurally and functionally). Various scaffolds mimic the natural extracellular matrix (ECM) using both natural and synthetic polymers, providing favorable environments for MSC proliferation and differentiation. Depending on material properties, either topographically or elastically structured scaffolds can be fabricated. Three-dimensional scaffolds have tunable substrate rigidities and structures, aiding MSC cultivation. Decellularized ECM-derived hydrogels are similar to the natural ECM, thus improving the paracrine effects of MSCs. Here, we discuss recent research on the application of scaffolds to maximize the immunomodulatory function of MSCs.     

含垂直裂纹的厚热障涂层的热稳定性及力学性能(英文)

采用循环热暴露及热震试验研究含或不含垂直裂纹的厚热障涂层的热稳定性和失效机制。先采用空气等离子喷涂技术在基体表面制备150μm厚的连接涂层,再在该涂层上采用空气等离子喷涂技术制备2000μm厚的热障涂层。含或不含垂直裂纹的热障涂层的粘附强度分别为24.7和11.0 MPa,表明含垂直裂纹的热障涂层的界面稳定性更高。循环热暴露及热震试验表明其热稳定性更高。含或不含垂直裂纹的热障涂层的硬度分别为6.6和5.3GPa,经循环热暴露试验后分别升高至9.5和5.5 GPa。实验表明上层涂层中垂直裂纹的存在有利于延长热障涂层高温环境的寿命。     

Fabrication of SiC_p/AA5083 composite via friction stir welding

Microstructure and mechanical properties of SiCp /AA5083 composite fabricated by friction stir welding (FSW) were investigated.The influence of the number of FSW passes on the distribution of SiC particles and mechanical properties in the joint was studied.After one pass,the SiC particles were entangled in the upper side of the stir zone (SZ).However,the particle distribution became more uniform after two passes due to the repeated stirring of the joint.As the SiC particles facilitate the grain refinement in the SZ by the pinning effect,the particle including region has much smaller grain size than the SZ without SiC particles.The SiCp /AA5083 composite region exhibits a Vickers hardness of HV90,which is much higher than the value of HV80 in the SZ produced by FSW without SiC particles.     

Low-power functionality of silicon-nanowire-assembled inverters on bendable plastics

In this paper, we demonstrate the low-power functionality of silicon nanowire (SiNW)-assembled inverters on bendable plastics. Our bendable inverters are capable of operating at supply voltages as low as 0.8 V with a switching (or standby) power consumption of ～0.2 nW (or ～6.6 pW). The low-power inverting operation with a voltage gain of ～18 is attributable to the near-ideal characteristics of the component transistors that have selectively thinned SiNW channels and exhibit low, symmetrical threshold voltages of 0.40 and ?0.39 V and low sub-threshold swing values of 81 and 65 mV/dec. Moreover, mechanical bendability reveals that the inverting operation has good, stable fatigue properties.

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Lipopeptide‐Based Nanosome‐Mediated Delivery of Hyperaccurate CRISPR/Cas9 Ribonucleoprotein for Gene Editing

A transient cytosolic delivery system for accurate Cas9 ribonucleoprotein is a key factor for target specificity of the CRIPSR/Cas9 toolkit. Owing to the large size of the Cas9 protein and a long negative strand RNA, the development of the delivery system is still a major challenge. Here, a size‐controlled lipopeptide‐based nanosome system is reported, derived from the blood‐brain barrier‐permeable dNP2 peptide which is capable of delivering a hyperaccurate Cas9 ribonucleoprotein complex (HypaRNP) into human cells for gene editing. Each nanosome is capable of encapsulating and delivering ≈2 HypaRNP molecules into the cytoplasm, followed by nuclear localization at 4 h post‐treatment without significant cytotoxicity. The HypaRNP thus efficiently enacts endogenous eGFP silencing and editing in human embryonic kidney cells (up to 27.6%) and glioblastoma (up to 19.7% frequency of modification). The lipopeptide‐based nanosome system shows superior delivery efficiency, high controllability, and simplicity, thus providing biocompatibility and versatile platform approach for CRISPR‐mediated transient gene editing applications.