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331.
The preparation of yeast starter culture (Pied de Cuve) for producing sparkling wine with the traditional method is a key factor for manufacturing a good Prise de mousse. In this paper, the evolution of total yeast population, its viability during Pied de Cuve preparation, and the pressure profile during the 2nd fermentation in 2 different base wines made from Bombino bianco and Chardonnay grapes were investigated using 4 different commercial active dried yeasts. The study proves that despite the initial differences observed throughout the acclimatization phase, all the tested strains showed similar results on either the total population (from 8.2 × 107 cells/mL to 1.3 × 108 cells/mL) or cellular viability (from 70% to 84%). Independently from the base wine tested, the kinetic of sugar consumption was faster during the gradual acclimatization to the alcoholic medium (phase II) and slower during the preparation of starter culture in active growth phase (phase III). During both of these phases Saccharomyces cerevisiae bayanus Vitilevure DV10® (Station ?notechnique de Champagne) proved to have a higher sugar consumption rate than the other strains. During the Prise de mousse, S. cerevisiae bayanus Lalvin EC‐1118® (Lallemand) reached the maximum pressure increase within time in both base wines.  相似文献   
332.
Flooding for Reliable Multicast in Multi-Hop Ad Hoc Networks   总被引:1,自引:0,他引:1  
Obraczka  Katia  Viswanath  Kumar  Tsudik  Gene 《Wireless Networks》2001,7(6):627-634
Ad hoc networks are gaining popularity as a result of advances in smaller, more versatile and powerful mobile computing devices. The distinguishing feature of these networks is the universal mobility of all hosts. This requires re-engineering of basic network services including reliable multicast communication. This paper considers the special case of highly mobile fast-moving ad hoc networks and argues that, for such networks, traditional multicast approaches are not appropriate. Flooding is suggested as a possible alternative for reliable multicast and simulation results are used to illustrate its effects. The experimental results also demonstrate a rather interesting outcome that even flooding is insufficient for reliable multicast in ad hoc networks when mobility is very high. Some alternative, more persistent variations of flooding are sketched out.  相似文献   
333.
Transformation of high bit-rate optical time-domain multiplexed (OTDM) signals into a multitude of lower bit-rate wavelength-division-multiplexed (WDM) channels is demonstrated by means of a single monolithically integrated indium phosphide Mach-Zehnder interferometer with semiconductor optical amplifiers in its arms. Full demultiplexing of 10-Gb/s OTDM signals into 4×10-Gb/s WDM channels is demonstrated. Bit-error-rate penalties are below 1.5 dB for polarization independent signal conversion throughout the 1.55-μm wavelength range  相似文献   
334.
User mobility is of critical importance when designing mobile networks. In particular, "waypoint" mobility has been widely used as a simple way to describe how humans move. This paper introduces the first modeling framework to model waypoint-based mobility. The proposed framework is simple, yet general enough to model any waypoint-based mobility regimes. It employs first order ordinary differential equations to model the spatial density of participating nodes as a function of (1) the probability of moving between two locations within the geographic region under consideration, and (2) the rate at which nodes leave their current location. We validate our model against real user mobility recorded in GPS traces collected in three different scenarios. Moreover, we show that our modeling framework can be used to analyze the steady-state behavior of spatial node density resulting from a number of synthetic waypoint-based mobility regimes, including the widely used Random Waypoint model. Another contribution of the proposed framework is to show that using the well-known preferential attachment principle to model human mobility exhibits behavior similar to random mobility, where the original spatial node density distribution is not preserved. Finally, as an example application of our framework, we discuss using it to generate steady-state node density distributions to prime mobile network simulations.  相似文献   
335.
Pneumatic Networks for Soft Robotics that Actuate Rapidly   总被引:1,自引:0,他引:1       下载免费PDF全文
Soft robots actuated by inflation of a pneumatic network (a “pneu‐net”) of small channels in elastomeric materials are appealing for producing sophisticated motions with simple controls. Although current designs of pneu‐nets achieve motion with large amplitudes, they do so relatively slowly (over seconds). This paper describes a new design for pneu‐nets that reduces the amount of gas needed for inflation of the pneu‐net, and thus increases its speed of actuation. A simple actuator can bend from a linear to a quasi‐circular shape in 50 ms when pressurized at ΔP = 345 kPa. At high rates of pressurization, the path along which the actuator bends depends on this rate. When inflated fully, the chambers of this new design experience only one‐tenth the change in volume of that required for the previous design. This small change in volume requires comparably low levels of strain in the material at maximum amplitudes of actuation, and commensurately low rates of fatigue and failure. This actuator can operate over a million cycles without significant degradation of performance. This design for soft robotic actuators combines high rates of actuation with high reliability of the actuator, and opens new areas of application for them.  相似文献   
336.
The MERLINTMCommunications System is a family of architecturally consistent small-business communications systems. The architecture is a star configuration with a central 8 bit microprocessor in the switch or Control Module for control of all telephone functions. The telephones and the processor exchange information over a proprietary four-pair protocol in a 24 bit message. In the Control Module, all I/O functions are memory mapped and under software control. The switch is an analog space-division solid-state crosspoint matrix, and the system capacities range from two CO lines and six telephones to eight CO lines and twenty telephones. Unlike many of its contemporaries, this system is designed to be installed, administered, and maintained by customers, although many users can be expected to opt for full-service support. Features and options can be added by a family of plug-in cartridges allowing the whole system to be sold directly from a catalog to a customer with limited training. Another design intent, simplified by stored-program control, is to incorporate many of the more popular and useful call-handling features of larger PBX's. A list of these is given in the Appendix. The stored program containing those features resides in a plug-in cartridge. This article will highlight the electrical and physical design of three of the MERLIN communications systems (CS): models 206, 410, and 820.  相似文献   
337.
Knowledge of fungal diversity in the environment is poor compared with bacterial biodiversity. In this study, we applied the denaturing high-performance liquid chromatography (D-HPLC) technique, combined with the amplification of the ITS1 region from fungal rDNA, for the rapid identification of major fungal species in 9 raw milk samples from cow, ewe and goat, collected at different periods of the year. A total of 27 fungal species were identified. Yeast species belonged to Candida, Cryptococcus, Debaryomyces, Geotrichum, Kluyveromyces, Malassezia, Pichia, Rhodotorula and Trichosporon genera; and mold species belonged to Aspergillus, Chrysosporium, Cladosporium, Engyodontium, Fusarium, Penicillium and Torrubiella genera. Cow milk samples harbored the highest fungal diversity with a maximum of 15 species in a single sample, whereas a maximum of 4 and 6 different species were recovered in goat and ewe milk respectively. Commonly encountered genera in cow and goat milk were Geotrichum candidum, Kluyveromyces marxianus and Candida spp. (C. catenulata and C. inconspicua); whereas Candida parapsilosis was frequently found in ewe milk samples. Most of detected species were previously described in literature data. A few species were uncultured fungi and others (Torrubiella and Malassezia) were described for the first time in milk.  相似文献   
338.
339.
An investigation was performed on the profile and the content of isoflavones in the concentrate of aqueous Defatted Soy Flour (DSF) extract obtained by nanofiltration. The effect of thermal treatments on these isoflavones was also evaluated according to a Central Composite Design (CCD 2k) with varying temperatures (70 to 90 °C) and times (15 to 45 min). Through nanofiltration it was possible to concentrate β-glucosides and malonyl glucosides (p < 0.05) in aqueous DSF extract but it was not possible to concentrate aglycones (p > 0.05). The thermal treatments applied on the concentrate showed that the malonyl glucosides were influenced by temperature (p < 0.05), while the β-glucosides were influenced not only by temperature but also by the time of interaction of the factors investigated (p < 0.05). Moreover, there was no alteration in the contents (p > 0.05) of aglycone or total isoflavones.  相似文献   
340.
In this paper, a model for computer simulation of the exposure and the development of the CAMP6 chemically amplified resist (CAR) during electron beam lithography is proposed. The distribution of the absorbed electron energy in the exposed resist is determined using our Monte Carlo algorithm and computer programs. A wider resist de-protection region due to the diffusion of the exposure catalyst product (acid) during the post-exposure bake (PEB) is estimated. It lays a special emphasis upon the development process simulation. Experimentally obtained time dependent macroscopic characteristics of the development (contrast curves, the development rate vs. the exposure dose) are taken into account, aiming to avoid the need for further calibration. The proposed model demonstrates qualitative agreement with the development kinetics of the resist developed profiles for the studied CAR.  相似文献   
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