Effect of Non-Equilibrium Condensation of Moist Air on Flow Field in Ludwieg Tube

The time-dependent behavior of non-equilibrium condensation of moist air through a Ludwieg tube with a diaphragm downstream is investigated by using a computational fluid dynamics work. The two-dimensional, compressible, Navier-Stokes equations, fully coupled with the condensate droplet growth equations, are numerically solved by a third-order MUSCL type TVD finite-difference scheme with a second-order fractional time step. Baldwin-Lomax turbulence model is employed to close the governing equations. The present computations represent the experimental flows well. The results obtained show that for an initial relative humidity over 40 %, the periodic excursions of the condensation shock occurs in the Ludwieg tube, and the frequency increases with the initial relative humidity. It is also found that total pressure loss due to non-equilibrium condensation in the Ludwieg tube should not be ignored even for a very low initial relative humidity. Furthermore, the variations of condensation properties are also di     

Stochastic wave energy calculation formulation

The wave energy potential is directly proportional to the wave period and second power of wave height averaged over a suitable time period. The wave height and period have temporal and spatial stochastic variations. It is the main purpose of this paper to derive the most general wave energy formulation by considering simultaneously the temporal variations both in the wave height and period. The correction factor is derived explicitly in terms of cross-correlation and the coefficients of variation. The application of the methodology is performed for wave measurement stations located in the Pacific Ocean off the west coast of the US.     

Signal Transduction of Barnacle Egg-Hatching Pheromone: Pharmacological Assays Indicate a Comparatively Simple Mechanism of Eicosanoid Action

Eicosanoids are generally regarded as autocoids that act via G-protein-linked receptors. There are exceptions to this model, however, both in terms of function and mechanism of action. The present paper concerns one such example, an hydroxy fatty acid that acts as a pheromone, not an autocoid, in inducing barnacle egg hatching. Preliminary findings of pharmacological assays on the mechanism of action of this eicosanoid pheromone do not support the involvement of G proteins, Ca²⁺, or protein kinase C in signal transduction. Instead it is concluded, tentatively, that barnacle egg hatching pheromone acts via a comparatively simple pathway involving the second messenger, cyclic AMP.     

KAIST image computing system (KICS): A parallel architecture for real-time multimedia data processing

An efficient parallel architecture is proposed for high-performance multimedia data processing using multiple multimedia video processors (MVP; TMS320C80), which are fully programmable general digital signal processors (DSP). This paper describes several requirements for a multimedia data processing system and the system architecture of an image computing system called the KAIST Image Computing System (KICS). The performance of the KICS is evaluated in terms of its I/O bandwidth and the execution time for some image processing functions. An application of the KICS to the real-time Moving Picture Expert Group 2 (MPEG-2) encoder is introduced. The programmability and the high-speed data-access capability of the KICS are its most important features as a high-performance system for real-time multimedia data processing.     

纤维素酶制备纳米纤维素晶体的研究

采用超声渡预处理棉纤维,用纤雏素酶制备纳米纤维素晶体(NCC).研究了反应方式、反应时间、反应温度、酶用量等对酶解反应的影响,确定了最佳酶解条件:酶液与底物比为8(mL:g),pH值为4.8,酶解温度为45℃,酶解时间为2 d.在此条件下制备的NCC单分散性比较好.     

Energy dissipation and power deposition of electromagnetic waves in the plasma sheath

Energy dissipation and power deposition of electromagnetic waves(EMW) in the reentry plasma sheath provide an opportunity to investigate ‘communication blackout' phenomena. Based on afinite element method(FEM) simulation, we analyze variation of EMW energy dissipation and power deposition profiles dependent on the wave polarization, wave incident angle, plasma density profile and electron collision frequency. Cutoff and resonance of EMW in the plasma sheath are crucial in explaining the regulation of energy dissipation and power deposition.     

Terminal Protection of Small Molecule-Linked DNA for Small Molecule–Protein Interaction Assays

Methods for the detection of specific interactions between diverse proteins and various small-molecule ligands are of significant importance in understanding the mechanisms of many critical physiological processes of organisms. The techniques also represent a major avenue to drug screening, molecular diagnostics, and public safety monitoring. Terminal protection assay of small molecule-linked DNA is a demonstrated novel methodology which has exhibited great potential for the development of simple, sensitive, specific and high-throughput methods for the detection of small molecule–protein interactions. Herein, we review the basic principle of terminal protection assay, the development of associated methods, and the signal amplification strategies adopted for performance improving in small molecule–protein interaction assay.     

The Role of Pericytes in Neurovascular Unit Remodeling in Brain Disorders

Neurons are extremely vulnerable cells that tightly rely on the brain’s highly dynamic and complex vascular network that assures an accurate and adequate distribution of nutrients and oxygen. The neurovascular unit (NVU) couples neuronal activity to vascular function, controls brain homeostasis, and maintains an optimal brain microenvironment adequate for neuronal survival by adjusting blood-brain barrier (BBB) parameters based on brain needs. The NVU is a heterogeneous structure constituted by different cell types that includes pericytes. Pericytes are localized at the abluminal side of brain microvessels and contribute to NVU function. Pericytes play essential roles in the development and maturation of the neurovascular system during embryogenesis and stability during adulthood. Initially, pericytes were described as contractile cells involved in controlling neurovascular tone. However, recent reports have shown that pericytes dynamically respond to stress induced by injury upon brain diseases, by chemically and physically communicating with neighboring cells, by their immune properties and by their potential pluripotent nature within the neurovascular niche. As such, in this paper, we would like to review the role of pericytes in NVU remodeling, and their potential as targets for NVU repair strategies and consequently neuroprotection in two pathophysiologically distinct brain disorders: ischemic stroke and Alzheimer’s disease (AD).     

FEATURE EXTRACTION OF VIBRATION SIGNALS BASED ON WAVELET PACKET TRANSFORM

A method is proposed for the analysis of vibration signals from components of rotating machines, based on the wavelet packet transformation (WPT) and the underlying physical concepts of modulation mechanism. The method provides a finer analysis and better time-frequency localization capabilities than any other analysis methods. Both details and approximations are split into finer components and result in better-localized frequency ranges corresponding to each node of a wavelet packet tree. For the purpose of feature extraction, a hard threshold is given and the energy of the coefficients above the threshold is used, as a criterion for the selection of the best vector. The feature extraction of a vibration signal is accomplished by computing the reconstruction signal and its spectrum. When applied to a rolling bear vibration signal feature extraction, the proposed method can lead to be very effective.