加卸载响应比(Load/Unload Response Ratio)、能量加速释放(AE/MR)的临界区尺度及地震预测

加卸载响应比理论的主要思路是 :系统在稳定状态时加载响应与卸载响应的比值与非稳定状态时加载响应与卸载响应的比值是完全不同的。大震前加卸载响应比升高和能量加速释放这两种现象可以用来对地震进行中期预报。同时 ,加卸载响应比理论和能量加速释放可能有相同的物理机制。为了验证这种地震预报方法的可行性 ,我们研究了几例发生在澳大利亚与中国 ,M 5 0～ 7 9之间的地震 ,其中包括破坏严重的澳大利亚纽卡斯尔地震和中国的唐山地震。我们利用以震源中心一定范围内的数据计算了震前的加卸载响应比和能量加速释放的幂律拟合。能量幂律加速释放存在一组最佳的拟合 ,一定范围内加卸载响应比达最大值表明加卸载响应比也有一个临界区尺度。进一步讲 ,加卸载响应比与能量加速释放的临界区尺度是相似的。这些结果表明加卸载响应比与能量加速释放有相同的物理机制。进一步的研究可能会对这种物理机制提供更好的解释 ,同时也能对地震的中期预报提供理论基础

Joannis Clerici ars critica, in qua ad studia linguarum latinae, graecae, et hebraicae via munitur : veterumque emendandorum spuriorum scriptorum a genuinis dignoscendorum, & judicandi de eorum libris ratio traditur

Jean Le Clerc nasceu em Genebra em 1657 e morreu em Amsterdã em 1736. Erudito suíço distinguiu-se como historiador, crítico, teólogo e filósofo. Suas doutrinas filosóficas carecem de unidade e foram, basicamente, fundamentadas em obras de escritores ingleses. Como pastor protestante exerceu o sacerdócio em Londres, tendo aplicado em seus estudos de teologia e exegese bíblica um critério de extrema liberdade, o que o levou a ser acusado de sociniano. Alguns de seus trabalhos foram publicados sob o pseudônimo de Joannes Phereponus. ‘Ars critica’ teve sua primeira edição em 1697. Editado em dois volumes. Contém regras para o estudo dos autores gregos e latinos clássicos, constituindo um tratado de crítica geral e dicionário para o entendimento desses autores. A quarta edição de ‘Ars critica’ foi acrescida de um terceiro volume. Considera-se a edição de 1730 a melhor dentre as publicadas. E uma obra que exigiu uma imensa erudição e grande conhecimento filosófico para sua realização

Release of Sulfur and Chlorine during Cofiring RDF and Coal in an Internally Circulating Fluidized Bed

An internally circulating fluidized bed (ICFB) was applied to investigate the behavior of chlorine and sulfur during cofiring RDF and coal. The pollutant emissions in the flue gas were measured by Fourier transform infrared (FTIR) spectrometry (Gasmet DX-3000). In the tests, the concentrations of the species CO, CO2, HCl, and SO2 were measured online. Results indicated when cofiring RDF and char, due to the higher content of chlorine in RDF, the formation of HCl significantly increases. The concentration of SO2 is relatively low because alkaline metal in the fuel ash can absorb SO2. The concentration of CO emission during firing pure RDF is relatively higher and fluctuates sharply. With the CaO addition, the sulfur absorption by calcium quickly increases, and the desulfuration ratio is bigger than the dechlorination ratio. The chemical equilibrium method is applied to predict the behavior of chlorine. Results show that gaseous HCl emission increases with increasing RDF fraction, and gaseous KCl and NaCl formation might occur.

Physical Modeling of Current-Induced Seabed Scour around a Vibrating Submarine Pipeline

Most of the existing researches either focus on vortex-induced-vibrations (VIV) of a pipeline near a rigid boundary, or on seabed scour around a fixed pipeline. In the fields, pipeline vibration and seabed scour are actually always coupled. Based on the similarity analysis, a series of tests were conducted with a hydro-elastic facility to investigate the influence of pipe vibration on the local scour and the effects of scour process on the pipeline dynamic responses. Experimental results indicate that, there exist two phases in the process of sand scouring around the pipeline with small embedment, i.e. Phase I: scour beneath pipe without VIV, and Phase II: scour with VIV of pipe. It is also found that the gap-to-diameter ratio (e/D) has much effect upon the scour depth for the fixed pipes. For a given value of e/D, the vibrating pipes with close proximity to seabed may induce a deeper scour hole than the fixed ones. Within the examined gap-to-diameter ratio range (425 < e/D < 0.75), the influences of gap-to-diameter ratio on the maximum values of scour-depth for the case of vibrating pipes are not as much as those for the case of fixed pipes.

Post-cyclic Strength Degradation of Undisturbed and Remolded Marine Silty Clay

A series of static and cyclic-static tri-axial compression tests under consolidated-undrained conditions are carried out to study the characteristics of post-cyclic strength of the undisturbed and the remolded samples of marine silty clay. It is found that the post-cyclic monotonic strength decreases if the cyclic strain or pore pressure is over a certain value. The maximum degradation is 10% for undisturbed samples while 70% for remolded ones. The relationship between normalized undrained shear strength and apparent overconsolidation ratio, which is determined by the excess pore pressure induced by cyclic loading, is also established. Static consolidated-undrained tests on overconsolidated remolded samples are also performed. It is proposed that the static consolidated-undrained tests may be substituted for the cyclic-static consolidated-undrained tests if the post-cyclic strength degradation of remolded silty clay is needed to be evaluated simply.

The Annual Economic Survey of Federal Gulf Shrimp Permit Holders: Report on the Design, Implementation, and Descriptive Results for 2006

This technical memorandum documents the design, implementation, data preparation, and descriptive results for the 2006 Annual Economic Survey of Federal Gulf Shrimp Permit Holders. The data collection was designed by the NOAA Fisheries Southeast Fisheries Science Center Social Science Research Group to track the financial and economic status and performance by vessels holding a federal moratorium permit for harvesting shrimp in the Gulf of Mexico. A two page, self-administered mail survey collected total annual costs broken out into seven categories and auxiliary economic data. In May 2007, 580 vessels were randomly selected, stratified by state, from a preliminary population of 1,709 vessels with federal permits to shrimp in offshore waters of the Gulf of Mexico. The survey was implemented during the rest of 2007. After many reminder and verification phone calls, 509 surveys were deemed complete, for an ineligibility-adjusted response rate of 90.7%. The linking of each individual vessel’s cost data to its revenue data from a different data collection was imperfect, and hence the final number of observations used in the analyses is 484. Based on various measures and tests of validity throughout the technical memorandum, the quality of the data is high. The results are presented in a standardized table format, linking vessel characteristics and operations to simple balance sheet, cash flow, and income statements. In the text, results are discussed for the total fleet, the Gulf shrimp fleet, the active Gulf shrimp fleet, and the inactive Gulf shrimp fleet. Additional results for shrimp vessels grouped by state, by vessel characteristics, by landings volume, and by ownership structure are available in the appendices. The general conclusion of this report is that the financial and economic situation is bleak for the average vessels in most of the categories that were evaluated. With few exceptions, cash flow for the average vessel is positive while the net revenue from operations and the “profit” are negative. With negative net revenue from operations, the economic return for average shrimp vessels is less than zero. Only with the help of government payments does the average owner just about break even. In the short-term, this will discourage any new investments in the industry. The financial situation in 2006, especially if it endures over multiple years, also is economically unsustainable for the average established business. Vessels in the active and inactive Gulf shrimp fleet are, on average, 69 feet long, weigh 105 gross tons, are powered by 505 hp motor(s), and are 23 years old. Three-quarters of the vessels have steel hulls and 59% use a freezer for refrigeration. The average market value of these vessels was $175,149 in 2006, about a hundred-thousand dollars less than the average original purchase price. The outstanding loans averaged $91,955, leading to an average owner equity of $83,194. Based on the sample, 85% of the federally permitted Gulf shrimp fleet was actively shrimping in 2006. Of these 386 active Gulf shrimp vessels, just under half (46%) were owner-operated. On average, these vessels burned 52,931 gallons of fuel, landed 101,268 pounds of shrimp, and received $2.47 per pound of shrimp. Non-shrimp landings added less than 1% to cash flow, indicating that the federal Gulf shrimp fishery is very specialized. The average total cash outflow was $243,415 of which $108,775 was due to fuel expenses alone. The expenses for hired crew and captains were on average $54,866 which indicates the importance of the industry as a source of wage income. The resulting average net cash flow is $16,225 but has a large standard deviation. For the population of active Gulf shrimp vessels we can state with 95% certainty that the average net cash flow was between $9,500 and $23,000 in 2006. The median net cash flow was $11,843. Based on the income statement for active Gulf shrimp vessels, the average fixed costs accounted for just under a quarter of operating expenses (23.1%), labor costs for just over a quarter (25.3%), and the non-labor variable costs for just over half (51.6%). The fuel costs alone accounted for 42.9% of total operating expenses in 2006. It should be noted that the labor cost category in the income statement includes both the actual cash payments to hired labor and an estimate of the opportunity cost of owner-operators’ time spent as captain. The average labor contribution (as captain) of an owner-operator is estimated at about $19,800. The average net revenue from operations is negative $7,429, and is statistically different and less than zero in spite of a large standard deviation. The economic return to Gulf shrimping is negative 4%. Including non-operating activities, foremost an average government payment of $13,662, leads to an average loss before taxes of $907 for the vessel owners. The confidence interval of this value straddles zero, so we cannot reject, with 95% certainty, that the population average is zero. The average inactive Gulf shrimp vessel is generally of a smaller scale than the average active vessel. Inactive vessels are physically smaller, are valued much lower, and are less dependent on loans. Fixed costs account for nearly three quarters of the total operating expenses of $11,926, and only 6% of these vessels have hull insurance. With an average net cash flow of negative $7,537, the inactive Gulf shrimp fleet has a major liquidity problem. On average, net revenue from operations is negative $11,396, which amounts to a negative 15% economic return, and owners lose $9,381 on their vessels before taxes. To sustain such losses and especially to survive the negative cash flow, many of the owners must be subsidizing their shrimp vessels with the help of other income or wealth sources or are drawing down their equity. Active Gulf shrimp vessels in all states but Texas exhibited negative returns. The Alabama and Mississippi fleets have the highest assets (vessel values), on average, yet they generate zero cash flow and negative $32,224 net revenue from operations. Due to their high (loan) leverage ratio the negative 11% economic return is amplified into a negative 21% return on equity. In contrast, for Texas vessels, which actually have the highest leverage ratio among the states, a 1% economic return is amplified into a 13% return on equity. From a financial perspective, the average Florida and Louisiana vessels conform roughly to the overall average of the active Gulf shrimp fleet. It should be noted that these results are averages and hence hide the variation that clearly exists within all fleets and all categories. Although the financial situation for the average vessel is bleak, some vessels are profitable. (PDF contains 101 pages)

Second-to-Fourth Digit Ratio Has a Non-Monotonic Impact on Altruism

Gene-culture co-evolution emphasizes the joint role of culture and genes for the emergence of altruistic and cooperative behaviors and behavioral genetics provides estimates of their relative importance. However, these approaches cannot assess which biological traits determine altruism or how. We analyze the association between altruism in adults and the exposure to prenatal sex hormones, using the second-to-fourth digit ratio. We find an inverted U-shaped relation for left and right hands, which is very consistent for men and less systematic for women. Subjects with both high and low digit ratios give less than individuals with intermediate digit ratios. We repeat the exercise with the same subjects seven months later and find a similar association, even though subjects' behavior differs the second time they play the game. We then construct proxies of the median digit ratio in the population (using more than 1000 different subjects), show that subjects' altruism decreases with the distance of their ratio to these proxies. These results provide direct evidence that prenatal events contribute to the variation of altruistic behavior and that the exposure to fetal hormones is one of the relevant biological factors. In addition, the findings suggest that there might be an optimal level of exposure to these hormones from social perspective.

Stability and Limit Oscillations of a Control Event-Based Sampling Criterion

This paper investigates the presence of limit oscillations in an adaptive sampling system. The basic sampling criterion operates in the sense that each next sampling occurs when the absolute difference of the signal amplitude with respect to its currently sampled signal equalizes a prescribed threshold amplitude. The sampling criterion is extended involving a prescribed set of amplitudes. The limit oscillations might be interpreted through the equivalence of the adaptive sampling and hold device with a nonlinear one consisting of a relay with multiple hysteresis whose parameterization is, in general, dependent on the initial conditions of the dynamic system. The performed study is performed on the time domain.