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111.
Sarmiento Jon Marx P. Mendez Queenie Lynly T. Estaña Leo Manuel B. Giray Evette S. Nañola Cleto L. Alviola Pedro A. 《Environment, Development and Sustainability》2021,23(11):16786-16802
Environment, Development and Sustainability - The Philippine fisheries sector continues to play a critical role in the livelihood of coastal households; however, the country’s fisheries... 相似文献
112.
Matthew P. Davis Nancy I. Holcroft Edward O. Wiley John S. Sparks W. Leo Smith 《Marine Biology》2014,161(5):1139-1148
The vast darkness of the deep sea is an environment with few obvious genetic isolating barriers, and little is known regarding the macroevolutionary processes that have shaped present-day biodiversity in this habitat. Bioluminescence, the production and emission of light from a living organism through a chemical reaction, is thought to occur in approximately 80 % of the eukaryotic life that inhabits the deep sea (water depth greater than 200 m). In this study, we show, for the first time, that deep-sea fishes that possess species-specific bioluminescent structures (e.g., lanternfishes, dragonfishes) are diversifying into new species at a more rapid rate than deep-sea fishes that utilize bioluminescence in ways that would not promote isolation of populations (e.g., camouflage, predation). This work adds to our understanding of how life thrives and evolution shaped present-day biodiversity in the deep sea, the largest and arguably least explored habitat on earth. 相似文献
113.
114.
Richard M. Wheeler Leo M. Eisel Gerald D. Seinwill 《Journal of the American Water Resources Association》1980,16(2):326-335
ABSTRACT: The Federal Government's interest and involvement in water resource development in discussed in the context of project financing and cost sharing. After drawing a clear distinction between the two issues - who puts up the money, and who repays over time - the authors survey a number of Federal acts from which have evolved nearly 200 separate cost-sharing rules. Selected cost sharing and financing issues discussed include consistency in policies, rehabilitation of urban water supply systems, multipurpose water quality projects, and ground water management. Two proposals for cost/finance sharing reform introduced in the 96th Congress are discussed in detail and their impacts compared with current policy. The joint venture approach (Administration proposal) results in an effective composite cost share which changes significantly but not drastically (from 19 to 35 percent non-Federal share for a hypothetical project). The block grant approach (Domenici-Moynihan proposal) would alter the regional distribution of Federal water developement funding from the South and West to the Northwest and North Central States. 相似文献
115.
政府和工业界现在普遍偏爱以清洁生产为代表的预防性思路.然而,新概念和新术语往往造成混淆.本文意在帮助解这个"纠缠在一起的术语之网". 相似文献
116.
ABSTRACT. The purpose of this paper is to present and discuss a procedure for finding an optimal staging plan for implementing a multi-basin water resource system-a system that must meet, with tolerable shortages, pre-specified but highly variable demands for water that increase over time-a system such as the proposed Texas Water System. The paper stresses that, in the past, planners have paid little attention to quantifying explicitly the impact that uncertainty has on the decision process, and in that context, presents a means for explicitly evaluating the impact that uncertainty has on finding and evaluating the performance of the optimal and several alternate staging plans. The procedure presented evaluates the impact that uncertainty, in both the hydrologic and the economic variables, has on the decisions that need to be made. The decisions requiring resolution are (1) which of an over-specified set of facilities should be constructed, (2) how large each of the facilities should be at various points in time, and (3) how should the system be operated so as to minimize the capital plus operational costs over the planning period. 相似文献
117.
Leo M. Eisel Kimberly D. Mills Charles F. Leaf 《Journal of the American Water Resources Association》1988,24(4):815-820
ABSTRACT: Consumptive loss of water attributable to man-made snowmaking was estimated using an energy balance model and a mass balance procedure. Data from nine field experiments at Colorado ski areas were collected and used in these models. The mean consumptive loss using the energy balance model for the nine experiments was 6.0 percent and 5.8 percent for the mass balance model A thermodynamic relationship and a regression equation were developed to provide a procedure to estimate consumptive loss as a linear function of atmospheric temperature. 相似文献
118.
Sander P. M. Ganzevles Fons S. W. van Nuland Leo R. M. Maas Huub M. Toussaint 《Die Naturwissenschaften》2009,96(4):449-456
In nautical literature, ‘dead-water’ refers to the obstructive effect encountered by ships moving in stratified water due
to the ship generating waves on an interface that separates different water masses. To investigate the hypothesis that open
water swimming may also be obstructed by an encounter of dead-water, possibly causing drowning, we performed two experiments
that assess the impact of stratified water on swimming. In the first experiment, subjects made a single front-crawl stroke
while lying on a carriage that was rolling just above the water surface. The gain in kinetic energy, as a result of the stroke,
was far less in stratified than in homogeneous water. In the second experiment, four subjects swam a short distance (5 m)
in homogeneous and in two different settings of stratified water. At the same stroke frequency, swimming in stratified conditions
was slower by 15%, implying a loss in propulsive power by 40%. Although in nature stratification will be less strong, extrapolation
of the results suggests that dead-water might indeed obstruct swimming in open water as well. This effect will be most pronounced
during fair weather, when stratification of a shallow surface layer is most easily established. Our findings indicate that
swimmers’ anecdotal evidence on ‘water behaving strangely’ may have to be taken more seriously than previously thought. 相似文献
119.
To understand the consequences of the invasion of the nonnative rainbow trout Oncorhynchus mykiss on the native marble trout Salmo marmoratus, we compared two distinct headwater sectors where marble trout occur in allopatry (MTa) or sympatry (MTs) with rainbow trout
(RTs) in the Idrijca River (Slovenia). Using data from field surveys from 2002 to 2009, with biannual (June and September)
sampling and tagging from June 2004 onwards, we analyzed body growth and survival probabilities of marble trout in each stream
sector. Density of age-0 in September over the study period was greater for MTs than MTa and very similar between MTs and
RTs, while density of trout ≥age-1 was similar for MTa and MTs and greater than density of RTs. Monthly apparent survival
probabilities were slightly higher in MTa than in MTs, while RTs showed a lower survival than MTs. Mean weight of marble and
rainbow trout aged 0+ in September was negatively related to cohort density for both marble and rainbow trout, but the relationship
was not significantly different between MTs and MTa. No clear depression of body growth of sympatric marble trout between
sampling intervals was observed. Despite a later emergence, mean weight of RTs cohorts at age 0+ in September was significantly
higher than weight of both MTs and MTa. The establishment of a self-sustaining population of rainbow trout does not have a
significant impact on body growth and survival probabilities of sympatric marble trout. The numerical dominance of rainbow
trout in streams at lower altitudes seem to suggest that while the low summer flow pattern of Slovenian streams is favorable
for rainbow trout invasion, the adaptation of marble trout to headwater environments may limit the invasion success of rainbow
trout in headwaters. 相似文献
120.
Objective: A new method is suggested for coordination of vehicle motion actuators; where driver feedback and capabilities become natural elements in the prioritization.Methods: The method is using a weighted least squares control allocation formulation, where driver characteristics can be added as virtual force constraints. The approach is in particular suitable for heavy commercial vehicles that in general are over actuated. The method is applied, in a specific use case, by running a simulation of a truck applying automatic braking on a split friction surface. Here the required driver steering angle, to maintain the intended direction, is limited by a constant threshold. This constant is automatically accounted for when balancing actuator usage in the method.Results: Simulation results show that the actual required driver steering angle can be expected to match the set constant well. Furthermore, the stopping distance is very much affected by this set capability of the driver to handle the lateral disturbance, as expected.Conclusion: In general the capability of the driver to handle disturbances should be estimated in real-time, considering driver mental state. By using the method it will then be possible to estimate e.g. stopping distance implied from this. The setup has the potential of even shortening the stopping distance, when the driver is estimated as active, this compared to currently available systems. The approach is feasible for real-time applications and requires only measurable vehicle quantities for parameterization. Examples of other suitable applications in scope of the method would be electronic stability control, lateral stability control at launch and optimal cornering arbitration. 相似文献