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排序方式: 共有800条查询结果,搜索用时 15 毫秒
41.
B. Adhikari T. Howes B. R. Bhandari V. Truong 《International Journal of Food Properties》2013,16(3):323-351
Levitation and free‐flight techniques applied to investigate the drying kinetics and morphology of single drops containing dissolved solids and suspensions are reviewed. A review of works related to receding interface model proposed to quantify the drying kinetics of single drops along with techniques to measure the kinetic parameters such as moisture diffusivity, thermal conductivity and specific heat capacity is presented. Problems associated with spray drying of sugar‐rich compounds are briefly discussed and possible links of stickiness and flavor retention with glass transition temperature (Tg), temperature history, drying rate and morphological changes including skin formation, as monitored through single drop experiments, are explored. 相似文献
42.
Effect of ultrasound on removal of persistent organic pollutants (POPs) from different types of soils 总被引:2,自引:0,他引:2
Reena Amatya Shrestha Thuy Duong Pham Mika Sillanp 《Journal of hazardous materials》2009,170(2-3):871-875
A new and promising technology is utilization of sonochemistry on decontamination of polluted soil. The feasibility of this technology on treatment of contaminated soils (synthetic clay, natural farm clay, and kaolin) was studied by using two target persistent organic pollutants (POPs): hexachlorobenzene (HCB) and phenanthrene (PHE). The soils were highly contaminated in 500 mg/kg. The laboratory experiments were conducted with various conditions (moisture, power, and time duration). The effects of these parameters on ultrasonication (as well as the removal of contaminants) were examined. The reasonable moisture ratio of the slurry could be in range of 2:1–3:1. The process did not change pH values of soils. Experimental results showed that ultrasonication has a potential to reduce the high concentrations of these POPs. 相似文献
43.
We report stabilization of a thulium-holmium codoped fiber soliton laser with a saturable absorber based on carbon nanotubes. The laser generates transform-limited 750-fs pulses with 0.5-nJ energy. 相似文献
44.
Abowd G.D. Hayes G.R. Iachello G. Kientz J.A. Patel S.N. Stevens M.M. Truong K.N. 《Pervasive Computing, IEEE》2005,4(4):67-73
Conducting user-centered design is a primary challenge in ubiquitous computing. Two kinds of prototyping techniques can be particularly effective for developing mobile and ubiquitous computing applications: compound prototypes and situated experience prototypes. Compound prototypes combine the final product's user interface (UI) with a computational implementation that runs on a separate system without the resource constraints of the target device. This model lets researchers and designers evaluate a new application's physicality and aesthetics as well as its functionality. Situated experience prototypes, or paratypes, include experimental protocols that attempt to reproduce user interaction with the system in real situations, and can optionally use common prototyping instruments such as paper mock-ups or physical props. Using our Personal Audio Loop (PAL) project as a case study, we discuss how you can fruitfully employ compound prototypes and paratypes when designing and developing mobile and ubiquitous computing applications. 相似文献
45.
While existing work concentrates on developing QoS models of business workflows and Web services, few tools have been developed
to support the monitoring and performance analysis of scientific workflows in Grids. This paper describes novel Grid services
for dynamic instrumentation of Grid-based applications, performance monitoring and analysis of Grid scientific workflows.
We describe a Grid dynamic instrumentation service that provides a widely accessible interface for other services and users
to conduct the dynamic instrumentation of Grid applications during the runtime. We introduce a Grid performance analysis service
for Grid scientific workflows. The analysis service utilizes various types of data including workflow graphs, monitoring data
of resources, execution status of activities, and performance measurements obtained from the dynamic instrumentation of invoked
applications, and provides a rich set of functionalities and features to support the online monitoring and performance analysis
of scientific workflows. Workflows and their relevant information including performance metrics are stored and utilized for
comparing the performance of constructs of different workflows and for supporting multi-workflow analysis.
The work described in this paper is supported in part by the Austrian Science Fund as part of the Aurora Project under contract
SFBF1104 and by the European Union through the IST-2002-511385 project K-WfGrid. 相似文献
46.
The sterol substrate analog 25-thialanosterol and its corresponding sulfonium salt were evaluated for their ability to serve
as antifungal agents and to inhibit sterol methyltransferase (SMT) activity in Candida albicans. Both compounds inhibited cell proliferation, were fungistatic, interrupted the yeastlike-form to germ-tube-form transition,
and resulted in the accumulation of zymosterol and related Δ24-sterols concurrent with a decrease in ergosterol, as was expected for the specific inhibition of SMT activity. Feedback on
sterol synthesis was evidenced by elevated levels of cellular sterols in treated vs. control cultures. However, neither farnesol
nor squalene accumulated in significant amounts in treated cultures, suggesting that carbon flux is channeled from the isoprenoid
pathway to the sterol pathway with minor interruption or redirection until blockage at the C-methylation step. Activity assays using solubilized C. albicans SMT confirmed the inhibitors impair SMT action. Kinetic analysis indicated that 25-thialanosterol inhibited SMT with the
properties of a time-dependent mechanismbased inactivator K
i of 5 =gmM and apparent k
inact of 0.013 min−1, whereas the corresponding sulfonium salt was a reversible-type transition state analog exhibiting a K
i of 20 nM. The results are interpreted to imply changes in ergosterol homeostasis as influenced by SMT activity can control
growth and the morphological transition in C. albicans, possibly affecting disease development. 相似文献
47.
Butt CM Diamond ML Truong J Ikonomou MG Helm PA Stern GA 《Environmental science & technology》2004,38(13):3514-3524
The September 11th World Trade Center (WTC) terrorist attacks resulted in the large-scale release of contaminants that were deposited on the environment of New York City (NYC). Six weeks after the attacks, samples of an organic film on window surfaces were collected and analyzed for polybrominated diphenyl ethers (PBDE), polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), polycyclic aromatic hydrocarbons (PAH), and organochlorine pesticides (OCPs). Concentrations dropped by an order of magnitude within 1 km of the WTC and reached background concentrations by 3.5 km. Concentrations within 1 km of the WTC averaged 3280 ng/m2 for sigmaPBDE, 900 ng/m2 for sigmaPCB, 33 ng/m2 for sigmaPCN, and 77100 ng/m2 for sigmaPAH. Congener profiles of the sites nearest the WTC suggested a combination of combustion and evaporative sources of all compounds, whereas the background sites exhibited profiles consistent with evaporative sources. PBDE profiles showed enrichment in lower molecular weight congeners near the WTC, suggesting that these congeners were formed as a result of the combustion conditions. Homologue fractions of PCN combustion markers were approximately 2-9 times greater at near WTC sites compared to background NYC. Gas-phase air concentrations were back-calculated from measured film concentrations using the film-air partition coefficient (KFA), and calculated air concentrations followed spatial trends observed in films. 相似文献
48.
To increase battery life in IEEE 802.16e systems, it is essential to efficiently manage energy in mobile stations. The sleep-mode operation in power management helps to increase the life of a station by saving energy consumption. In power management, there are two important performance metrics energy consumption and the response delay of awakening medium access control (MAC) service data unit (SDU). While in a base station (BS) initiation of awakening, the two performance metrics should be simultaneously considered, in a mobile subscriber station (MSS) initiation of awakening, the response delay is not considered because it is self-operational. There performance metrics are affected by the minimum sleep interval (Tmin), the maximum sleep interval (Tmax), and the average interarrival time of awakening MAC SDUs (TI) during sleep-mode operation. Therefore, it is imperative to evaluate the two initiations of awakening depending on TI. To reach a fuller understanding of the performance, this paper shows an analytical mode and simulations results for the standard sleep-mode operation in the IEEE 802.16e MAC. 相似文献
49.
Dinh Thuy Phan Huy Jonathan Rodriguez Atílio Gameiro Rahim Tafazolli 《Wireless Personal Communications》2007,43(4):1727-1740
The Multicarrier CDMA Transmission Techniques for Integrated Broadband Cellular Systems (MATRICE) project addresses a candidate
solution for a Beyond 3G (B3G) air-interface based on Multi-Carrier Code Division Multiple Access (MC-CDMA). It investigates
dynamic resource allocation strategies at the Medium Access Control (MAC) layer to support the transport of Internet Protocol
(IP) packets over the air-interface in a cost effective manner and maximise the cell capacity with a target QoS. A candidate
Dynamic Resource Allocation (DRA) protocol architecture is proposed that is based on cross-layer signalling to provide reactive
resource allocation according to the fast channel and traffic variations. In-line with B3G expectations, the proposed DRA
handles a very large number of users with inherent flexibility and granularity necessary to support heterogeneous traffic,
and still with limited complexity. Thanks to the modular architecture of the DRA, various scheduling policies are investigated
and compared in terms of capacity and reactivity to the system environment. Simulation results have shown that the MATRICE
system has the potential to deliver broadband heterogenous services in a cost-effective manner, and emerge as a propespective
candidate air-interface for B3G cellular networks. 相似文献
50.
Hiroyuki Hirakata Yoshimasa Takahashi Do Van Truong Takayuki Kitamura 《International Journal of Fracture》2007,145(4):261-271
In order to elucidate the role of plasticity on interface crack initiation from a free edge and crack propagation in a nano-component,
delamination experiments were conducted by a proposed nano-cantilever bend method using a specimen consisting of ductile Cu
and brittle Si and by a modified four-point bend method. The stress fields along the Cu/Si interface at the critical loads
of crack initiation and crack propagation were analyzed by the finite element method. The results reveal that intensified
elastic stresses in the vicinity of the interface edge and the crack tip are very different, although the Cu/Si interface
is identical in both experiments. The plasticity of Cu was then estimated on the basis of the nano-cantilever deflection measured
by in situ transmission electron microscopy. The plasticity affects the stress fields; the normal stress near the interface
edge is intensified while that near the crack tip is much reduced. Both the elasto-plastic stresses are close to each other
in the region of about 10 nm. This suggests that the local interface fracture, namely, the crack initiation at the interface
edge and the crack propagation along the interface, is governed by elasto-plastic normal stress on the order of 10 nm. 相似文献