971 resultados para applicant pool


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Upper Old Tampa Bay, a 17-square mile area of Old Tampa Bay, Florida, has been proposed for conversion to a fresh-water lake. The amount of runoff to the proposed lake and its chemical quality are both adequate to freshen and sustain a fresh-water lake in this part of the bay. During 1950-66 runoff to the proposed lake, including discharge from Lake Tarpon, would have averaged 134 mgd (million gallons per day) and would have displaced the volume of the proposed lake at normal pool stage (2.5 feet above mean sea level) about 1.7 times per year. Without discharge from Lake Tarpon, the volume of the proposed lake would have been displaced 1.2 times. If the lake level was initially at a normal pool stage during a critically dry year, such as 1956, the proposed lake would have declined 0.25 to 0.5 foot below the minimum design level, (1.5 feet above mean sea level). (44 page document)

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利用控制加热电压和加热面平均温度两种方法,实验研究了常压(0.1MPa)、室温(16℃)条件下除气后的R113在直径60μm细铂丝表面的池沸腾传热现象,观测了单相对流、核态沸腾、双模态过渡沸腾和膜态沸腾4种传热模式中的汽相分布及其传热特征,发现充分发展的核态沸腾传热曲线、膜态沸腾传热曲线及临界热流的数值分别与文献中常用关联式的预测一致,而核态沸腾和膜态沸腾共存的稳定双模态过渡沸腾曲线被一极小值点分为两个连续分支,邻近膜态沸腾的右支上热流与过热度成正比,而邻近核态沸腾的左支上热流则随过热度增长而下降,并且只出现在加热面平均温度受控的实验中.

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本文利用我国第22颗返回式卫星开展了微重力条件下过冷池沸腾传热实验研究。实验中采用桥式自反馈电路控制加热面温度,加热元件为长30mm、直径60pm的铂丝,实验工质为0.1MPa压力下过冷度为26℃的R113。实验发现,沸腾起始温度不受重力水平影响,而微重力核态沸腾传热略有增强,汽泡脱落行为也有着不同的特征。

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本文报道了空间微重力池沸腾过程中的汽泡脱落现象,观测到微重力条件下小汽泡行为与常重力时相似,但在中等尺寸范围内,汽泡往往粘附在加热丝上做横向振动,并不断合并所碰到的小汽泡,直到超过临界尺寸后脱落。本文在Lee模型(1992)的基础上引入热毛细作用力,成功地解释了实验观测到的独特的汽泡动力学行为特征。

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本文对准稳态加热条件下的微重力核态池沸腾中的汽泡行为特征进行了实验研究,分析了初始核化过程、汽泡数密度、汽泡尺寸及其运动速度等的变化趋势,探讨了过冷度及加热历史等因素对相关特性的影响。实验发现:微重力条件下汽泡生成后沿加热面不停地移动;原生汽泡会聚合形成大汽泡,大汽泡不断捕掠小汽泡而长大,直到大汽泡覆盖整个加热面;汽泡生长速度随过冷度增加而变慢。

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This paper sets out to assess the workability of the regulation currently in force in the European anchovy fishery of the VIII division. Particular attention is paid to the importance of the institutional regime in the allocation of natural resources. The study uses a bio-economic approach and takes into account the fact that, not only the European Union and the individual countries involved, but also some of the resource users or appropriators intervene in its management. In order to compare the effectiveness of the rules which, at the various levels, have been set up to restrict exploitation of the resource, the anchovy fishery is simulated in two extreme situations: open access and sole ownership. The results obtained by effective management will then be contrasted with those obtained from the maximum and zero profit objectives related with the two above-mentioned scenarios. Thus, if the real data come close to those derived from the sole ownership model it will have to be acknowledged that the rules at present in force are optimal. If, on the other hand, the situation more closely approach the results obtained from the open access model, we will endeavour in our conclusions to provide suggestions for economic policy measures that might improve the situation in the fishery.

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Investigation of kerosene combustion in a Mach 2.5 flow was carried out using a model supersonic combustor with cross-section area of 51 mm?70 mm, with special emphases on the characterization of effervescent atomization and the flameholdering mechanism using different integrated fuel injector/flameholder cavity modules. Direct photography, Schlieren imaging, and Planar Laser Induced Fluorescence (PLIF) imaging of OH were utilized to examine the cavity characteristics and spray structure, with and without gas barbotage. Schlieren images illustrate the effectiveness of gas barbotage in facilitating atomization and the importance of secondary atomization when kerosene sprays interacting with a supersonic crossflow. OH-PLIF images further substantiate our previous finding that there exists a local high temperature radical pool within the cavity flameholder and this radical pool plays a crucial role in promoting kerosene combustion in a supersonic combustor. The present results also demonstrate that the cavity characteristics can be different in non-reacting and reacting supersonic flows. As such, the conventional definition of cavity characteristics based on non-reacting flows needs to be revised.

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[EN] Neurodegeneration together with a reduction in neurogenesis are cardinal features of Alzheimer’s disease (AD) induced by a combination of toxic amyloid-β peptide (Aβ) and a loss of trophic factor support. Amelioration of these was assessed with diverse neurotrophins in experimental therapeutic approaches. The aim of this study was to investigate whether intranasal delivery of plasma rich in growth factors (PRGF-Endoret), an autologous pool of morphogens and proteins, could enhance hippocampal neurogenesis and reduce neurodegeneration in an amyloid precursor protein/presenilin-1 (APP/PS1) mouse model. Neurotrophic and neuroprotective actions were firstly evident in primary neuronal cultures, where cell proliferation and survival were augmented by Endoret treatment. Translation of these effects in vivo was assessed in wild type and APP/PS1 mice, where neurogenesis was evaluated using 5-bromodeoxyuridine (BdrU), doublecortin (DCX), and NeuN immunostaining 5 weeks after Endoret administration. The number of BrdU, DCX, and NeuN positive cell was increased after chronic treatment. The number of degenerating neurons, detected with fluoro Jade-B staining was reduced in Endoret-treated APP/PS1 mice at 5 week after intranasal administration. In conclusion, Endoret was able to activate neuronal progenitor cells, enhancing hippocampal neurogenesis, and to reduce Aβ-induced neurodegeneration in a mouse model of AD.

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本文以丝状加热表面上的池沸腾传热现象为主要研究对象,利用地面常重力实验,研究了不同热丝直径、不同过冷度下((0~40℃)的丝状加热片面FC-72液体和丙酮液体的池沸腾传热特性。 本文利用自主研发的一套可控过冷度池沸腾实验设备,使用纯度为99.99%的铂丝同时作为加热元件和测温元件,加热丝直径分别为0.06mm、0.025mm、0.1mm,长度为30mm。实验采用控制加热电压按阶梯形式增长或下降(时间常数约20s)的稳态加热方式。 实验所得单相自然对流传热数据同Kuehn-Goldstein(1976)换热公式预测结果具有较高的一致性,说明实验设备可靠、实验数据可信。 实验过程中发现,在相同压力条件下,随着过冷度的增加,沸腾传热强化;CHF值在低过冷度时呈线性增加,然后增加趋势变缓。丙酮实验中,0.06mm热丝和0.1mm热丝在低过冷度(2.5~10℃)情况下都出现了从自然对流直接进入双膜态现象,不过,当降低加热电压时,膜态沸腾仍转化为核态沸腾,此时继续增高加热电压,沸腾曲线仍沿常规核态沸腾曲线上升至CHF后,再转换为膜态沸腾。对于同等直径热丝,无论核态沸腾或双膜态沸腾,在丙酮中所产生汽泡尺寸明显偏大。 过冷沸腾中,临界热流随过冷度的增加呈现出非线性依赖关系。在低过冷度线性区,FC-72中实验结果与几种低过冷度线性模型较一致;丙酮中实验结果 随 变化斜率明显高于几种低过冷度线性模型的预测,显示出对尺度的依赖关系。这说明在小Bond数时存在尺度效应对过冷度的影响,即对于小Bond数情况过冷度和尺度效应的耦合作用是非常重要的。 饱和沸腾中,FC-72和丙酮的CHF值随热丝直径的减小而不断增加,其中,FC-72的CHF数值尽管比LD模型预测结果略低,但定性地依然可用LD模型进行描述,尽管相比于LD模型原始的适用范围 已扩大了1~2个数量级;但丙酮的实验数据却远小于LD模型预测结果。综合分析表明,尽管热丝直径相同,但物性的差异使得FC-72和丙酮实验中的数据点分别处于不同的尺度特征区域,反映了小Bond数情形下分区准则的物性依赖性。

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A considerable amount of national EU funds for supporting fisheries has been transferred to the German fish processing in-dustry. The recently ratified European Fisheries Fund (EFF) again provides a significant sum. Yet the EU is lacking a data pool of sufficient precision, which is required as a basis to develop apt EU regulations in the future. Regulation No. 1639/2001 of the EU Commission commits the member states to collect these data. In this paper specifics of the data to be collected and the collection procedure are presented and linked to the CFP and to characteristics of the German fish processing industry.

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For efficiently cooling electronic components with high heat flux, experiments were conducted to study the flow boiling heat transfer performance of FC-72 over square silicon chips with the dimensions of 10 × 10 × 0.5 mm3. Four kinds of micro-pin-fins with the dimensions of 30 × 60, 30 × 120, 50 × 60, 50 × 120 μm2 (thickness, t × height, h) were fabricated on the chip surfaces by the dry etching technique for enhancing boiling heat transfer. A smooth surface was also tested for comparison. The experiments were made at three different fluid velocities (0.5, 1 and 2 m/s) and three different liquid subcoolings (15, 25 and 35 K). The results were compared with the previous published data of pool boiling. All micro-pin-fined surfaces show a considerable heat transfer enhancement compared with a smooth surface. Flow boiling can remarkably decrease wall superheat compared with pool boiling. At the velocities lower than 1 m/s, the micro-pin-finned surfaces show a sharp increase in heat flux with increasing wall superheat. For all surfaces, the maximum allowable heat flux, qmax, for the normal operation of LSI chips increases with fluid velocity and subcooling. For all micro-pin-finned surfaces, the wall temperature at the critical heat flux (CHF) is less than the upper limit for the reliable operation of LSI chips, 85◦C. The largest value of qmax can reach nearly 148 W/cm2 for micro-pin-finned chips with the fin height of 120 μm at the fluid velocity of 2 m/s and the liquid subcooling of 35 K. The perspectives for the boiling heat transfer experiment of the prospective micro-pin-finned sur- faces, which has been planned to be made in the Drop Tower Beijing/NMLC in the future, are also presented.

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本文实验研究了微重力条件下的准稳态核态池沸腾现象中的气泡动力学特征及其对传热特性的影响,发现在低过冷度沸腾中,聚合汽泡表面的强烈振荡促进了整个加热面上的核化过程与核态沸腾传热;而高过冷沸腾中,聚合气泡在表面张力作用下呈球状,难以覆盖整个加热表面,导致核态沸腾向膜态沸腾的过度过程表现为"核态沸腾+局部的干斑扩展"现象,相应的传热曲线没有明显转折.微重力条件下池沸腾临界热流随过冷度和压力的增加而升高,与地面结果定性相符.