Drawdown due to Temporally Varying Pumping Discharge: Inversely Estimating Aquifer Parameters

A ramp kernel method is proposed for accurately calculating the drawdown due to any temporal variation in pumping discharge. The use of the ramp kernels assumes the linear variation between the two consecutive measured pumping discharges. The prior studies assume a rectangular variation between the two consecutive measured pumping discharges. In the rectangular variation, a uniform pumping rate is assumed during a time span. An analytical equation for calculating the ramp kernel is derived. An optimization method is used with the proposed ramp kernels for inversely estimating the aquifer parameters from drawdown due to an arbitrary unsteady pumping discharge. Unlike the prior methods, the proposed method accurately identifies the parameters even when the sampling interval for the drawdown and pumping discharge is longer than that needed for assuming a linear variation. The proposed method outperforms the prior method. Application of the proposed method is illustrated using examples.     

Housing Law Is Dead. Long Live European Housing Law?

The U.K. discipline of housing law is closely linked to the advice needs of individuals and local councils who have many housing responsibilities. This interdisciplinary study supports people in need of housing, particularly assisting access to social housing, often owned by councils. In France similar groups are supported by a strongly expressed right to housing, which is a principle of constitutional value. However, the French local government is too small and fragmented to support U.K.-type responsibility and stronger rights of other local people can block access to social housing. European influences mean that the U.K. has imported a series of ideas that could mean less access to social housing for people in need and the U.K. discipline of housing law is more complex, diffused, and difficult to promote as a study unit. French legal study suggests European trends: primarily public law, not empirical and oriented to construction, although this is improving. Several ideas for new European legal subject groupings are suggested, particularly rights. The right to housing might be currently ineffective in France but it is unavoidable because of pervasive European use. The discipline of the U.K. housing law is threatened, but such lawyers could create new disciplines adapting its traditional strengths to new European groupings.     

Cropland Measurement Using Thematic Mapper Data and Radiometric Model

To halt erosion and desertification, it is necessary to quantify resources that are affected. Necessary information includes inventory of croplands and desert areas as they change over time. Several studies indicate the value of remote sensor data as input to inventories. In this study, the radiometric modeling of spectral characteristics of soil and vegetation provides the theoretical basis for the remote sensing approach. Use of Landsat Thematic Mapper images allows measurement of croplands in Saudi Arabia, demonstrating the capability of the approach. The inventory techniques and remote sensing approach presented are potentially useful in developing countries.     

Management of Fluid Mud in Estuaries, Bays, and Lakes. II: Measurement, Modeling, and Management

Techniques for measurement, modeling, and management of fluid mud are available, but research is needed to improve them. Fluid mud can be difficult to detect, measure, or sample, which has led to new instruments and new ways of using existing instruments. Multifrequency acoustic fathometers sense neither density nor viscosity and are, therefore, unreliable in measuring fluid mud. Nuclear density probes, towed sleds, seismic, and drop probes equipped with density meters offer the potential for accurate measurements. Numerical modeling of fluid mud requires solving governing equations for flow velocity, density, pressure, salinity, water surface, plus sediment submodels. A number of such models exist in one-, two-, and three-dimensional form, but they rely on empirical relationships that require substantial site-specific validation to observations. Management of fluid mud techniques can be classified as those that accomplish: Source control, formation control, and removal. Nautical depth, a fourth category, defines the channel bottom as a specific fluid mud density or alternative parameter as safe for navigation. Source control includes watershed management measures to keep fine sediment out of waterways and in-water measures such as structures and traps. Formation control methods include streamlined channels and structures plus other measures to reduce flocculation and structures that train currents. Removal methods include the traditional dredging and transport of dredged material plus agitation that contributes to formation control and/or nautical depth. Conditioning of fluid mud by dredging and aerating offers the possibility of improved navigability. Two examples—the Atchafalaya Bar Channel and Savannah Harbor—illustrate the use of measurements and management of fluid mud.     

ICP-AES法测定钢中微量La、Ce、Pr、Nd和Sm

采用ICP-AES测定钢中微量La、Ce、Pr、Nd、Sm,试验了元素的干扰情况,优化了仪器工作条件,选择了元素最佳分析谱线。方法准确、快速、简便。     

Optimal Instantaneous Unit Hydrograph from Multistorm Data

An optimization method for estimating an optimal smooth instantaneous unit hydrograph (IUH) from multistorm data taken simultaneously is proposed. A gamma IUH is used for representing the analytical IUH. The parameters of the analytical IUH are optimized. The method avoids oscillations in the tail end of IUH. It automatically takes care of the volume and nonnegativity constraints. The application of the method is illustrated through examples. The new method reliably estimates the optimal IUH.     

Evaluation, Rehabilitation Planning, and Stay-Cable Replacement Design for the Hale Boggs Bridge in Luling, Louisiana

The Hale Boggs Bridge opened to traffic on October 5, 1983. At the time, it was the first U.S. cable-stayed crossing over the Mississippi River. The PE (polyethylene) protective sheathing was damaged in many of the cables before and during installation, and after the opening of the bridge to traffic. Repairs were attempted to correct the defects in cable sheathing. Many of the repairs performed poorly and failed to protect the main tension element. The condition of 39 out of 72 cables indicated a critical need for repair and timely action was recommended. To address these damages, and to assure the structural integrity of the bridge structure, several strategies involving a range of repair and replacement options were evaluated using life cycle cost analysis. It was concluded that the strategy to replace all cables presents the best value among evaluated alternatives. The design of the complete 72 cable array replacement is the first occasion on which this process is attempted in North America. The final design of the replacement cables is heavily influenced by the geometric restrictions of the existing anchorage locations. The replacement cables are being designed for a 75-year design life and incorporated with the latest advancements in corrosion protection and vibration control. Maintenance of traffic design is an essential part of the project. The bridge is a critical regional link and constitutes a hurricane evacuation route. Traffic maintenance during cable replacement was designed to be as unobtrusive to the public and commerce as practical. This paper describes efforts associated with cable condition assessment, rehabilitation strategy, and design considerations and concepts, undertaken by the writers since 2002 to improve the condition of this major river crossing.     

Behavior of Corrugated Web I-Girders under In-Plane Loads

A theoretical formulation of the linear elastic in-plane and torsional behavior of corrugated web I-girders under in-plane loads is presented. A typical corrugated web steel I-girder consists of two steel flanges welded to a corrugated steel web. Under a set of simplifying assumptions, the equilibrium of an infinitesimal length of a corrugated web I-girder is studied, and the cross-sectional stresses and stress resultants due to primary bending moment and shear are deduced. The analysis shows that a corrugated web I-girder will twist out-of-plane simultaneously as it deflects in-plane under the action of in-plane loads. In the paper, the in-plane bending behavior is analyzed using conventional beam theory, whereas the out-of-plane torsional behavior is analyzed as a flange transverse bending problem. The results for a simply supported span subjected to a uniformly distributed load are presented. Finally, finite element analysis results are presented and compared to the theoretical results for validation.     

The value of a comparative perspective: Theoretical comment on Pearce et al. (2005).

J. M. Pearce, D. N. George, M. Haselgrove, J. T. Erichson, and M. Good (2005) (see record 2005-13804-017) report that damage to the hippocampus does not impair either delay conditioning, a biconditional discrimination, or a series of complex visual and spatial discriminations that require feature binding, but does impair trace conditioning and the ability to perform a working and reference memory maze task. The J. M. Pearce et al. study highlights the value of a comparative perspective and the value of appreciating the multiple ways in which animals can solve tasks, which together will provide a deeper understanding of the function of the hippocampus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Case Study of Fluvial Modeling of River Responses to Dam Removal

A plan was made to remove Matilija Dam on the Ventura River. With dam removal, the delta in the reservoir and the downstream channel were expected to undergo major changes in morphology. The FLUVIAL-12 model was employed to simulate reservoir and river channel responses after dam removal. As a first step, the model was calibrated using the Ventura River data to establish its validity. In calibration, the model was used to simulate the fluvial processes starting from the time of dam completion. The simulated sediment deposition above the Matilija Dam matches closely with the deposits measured by the U.S. Bureau of Reclamation. A large amount of sediment was stored in the reservoir; some of the stored sediment would be transported downstream after dam removal. An important consequence of dam removal is the major increase of sediment release to the river channel downstream. The sediment supply to the downstream reach is not only from the stored sediment in the reservoir but also from natural sediment inflow from the upstream watershed. Therefore, sediment supply to the downstream reach will exceed the natural sediment flow before the dam presence. This situation tends to overload the downstream reach with sediment, resulting in excessive deposition. The amount of sediment release from the area above the removed dam is closely related to the changes in reservoir morphology. It is necessary to model changes in the channel bed profile and channel width during erosion in order to determine the amount of sediment removal. The amount of sediment release may not be simulated using an erodible-bed model but it may be determined using an erodible boundary model.     

Sham reasoning, Humpty Dumpty, and the burden of proof.

Slife and Reber ask of psychologists that they recognize their prejudice against theism and the incompatibility between theistic and naturalistic worldviews. Yet, the subtext of their article is that theism and naturalism are equally valid and that psychology’s secularism is a mistake. Given that theism is not beyond reason, the only sufficient ground for charging psychologists with prejudice is if (i) theism has survived serious attempts at conceptual and empirical test, and (ii) psychology ignores or disguises this fact. So, the grounds for believing in the reality of a supernatural existent are highly relevant to the authors’ allegation. However, their concept of God affords no such grounds. They disavow the logic involved in the ordinary meaning of the term “incompatible” and they ignore a crucial distinction between conditions of existence and qualities of things or processes. The consequence is that either God is this-worldly, and there is no ontological basis to Slife and Reber’s incompatibility thesis, or God’s mode of existence is quite different from the mode of existence of ordinary things and all the problems of dualism follow. Either way, their charge of prejudice is without foundation. The burden of proof rests with the defender of theism and, for now, psychology’s secularism can be considered a mark of the discipline’s (sometimes questionable) rationality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New Orleans Levee System Performance during Hurricane Katrina: London Avenue and Orleans Canal South

Hurricane Katrina was one of the worst natural disasters in U.S. history. The effects of the hurricane were particularly devastating in the city of New Orleans. Most of the damage was due to the failure of the levee system that surrounds the city to protect it from flooding. This paper presents the results of centrifuge models conducted at Rensselaer Polytechnic Institute and the U.S. Army Corps of Engineers simulating the behavior of the levees at London Avenue North and South that failed during Hurricane Katrina. Those levees failed without being overtopped by the storm surge. Also included are the results of a centrifuge model of one levee section at Orleans Canal South, which did not fail during the hurricane. The key factor of the failure mechanism of the London Avenue levees was the formation of a gap between the flooded side of the levee and the sheetpile. This gap triggered a reduction of the strength at the foundation of the protected side of the levee. The results are fully consistent with field observations.     

Action embellishment: An intention bias in the perception of success.

Na?ve theories of behavior hold that actions are caused by an agent's intentions, and the subsequent success of an action is measured by the satisfaction of those intentions. However, when an action is not as successful as intended, the expected causal link between intention and action may distort perception of the action itself. Four studies found evidence of an intention bias in perceptions of action. Actors perceived actions to be more successful when given a prior choice (e.g., choose between 2 words to type) and also when they felt greater motivation for the action (e.g., hitting pictures of disliked people). When the intent was to fail (e.g., singing poorly), choice led to worse estimates of performance. A final experiment suggested that intention bias works independent from self-enhancement motives. In observing another actor hit pictures of Hillary Clinton and Barack Obama, shots were distorted to match the actor's intentions, even when it opposed personal wishes. Together these studies indicate that judgments of action may be automatically distorted and that these inferences arise from the expected consistency between intention and action in agency. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Lessons Learned from Failures of the Building Envelope in Windstorms

Lessons learned from failures of the building envelope in windstorms are encapsulated in three principal findings. The building envelope is crucial to the performance of buildings in windstorms. Windborne debris is decisive in shaping the performance of the building envelope. Design attention should be given to postimpact behavior of building-envelope systems. Reviews of damage documentation, insurance records, and computer simulations of building failures establish the importance of the building envelope to satisfactory building performance. These reviews also establish the decisive role of windborne debris in causing damage. The imperative for considering the postimpact behavior of building envelope systems is discussed, and innovative glazing products that meet new design criteria are presented. It is concluded that the building envelope should be given status equal to the principal structural frame in terms of design attention.     

Comment on Natterson (2003).

The author views J. M. Natterson's (2003) article as a return to Freud's emphasis on the centrality of love in psychoanalysis freshly conceptualized within a contemporary intersubjective perspective. Natterson's definition of love is viewed by the author as consisting of 3 independent components (attachment, recognition, and mutuality) that may harmonize or conflict. The author notes the rarity of Natterson's intimate disclosure of the specifics of his own subjectivity to the reader, and their value in advancing the understanding of psychoanalytic process and theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Below-Average Bidding Method

The low-bid method, typically used for competitive bidding in the United States, may result in a contract with a firm that submits either accidentally or deliberately an unrealistically low-bid price. Such an occurrence hurts both the owner and the contractor by promoting disputes, increased costs, and schedule delays. To address this problem, other countries have adopted bidding methods based on the average of the bids submitted. One such approach is the below-average method where the winning bid is closest to but below the average of all bids. A competitive bidding model for the below-average-bid method is presented and its merits relative to the average-bid method and the low-bid method are explored. The below-average-bid process is investigated analytically and through Monte Carlo simulation. The results of bidding models for the below-average, the average, and the low-bid methods are presented in four easy-to-use nomograms which allow contractors to determine the optimal lump-sum bid price for each method without the need for complicated analysis. A comparison of the three methods provides information and insights to help owners with the difficult choice of a suitable bidding method for the project at hand.     

Influence of Rocking Motion on Vibratory Roller-Based Measurement of Soil Stiffness

Experimental data have shown that vibratory roller compactors often exhibit rotational kinematics in addition to translation during operation. This rotation is not considered in roller-integrated measurement systems that estimate soil stiffness based on drum vibration. To model and explore the effect of rotation, a lumped parameter roller/soil model was developed. The machine parameters for this model were tuned from suspended drum testing that isolated the drum from the ground. The model was then verified using field data collected over a range of excitation frequencies on spatially homogenous soil, and over transversely heterogeneous soil using one excitation frequency. Rotational motion was found to significantly influence roller-integrated measurement of soil stiffness based on single position drum vibration data. Rotational motion causes single position measurement system results to be nonunique and to vary depending on the direction of roller travel. Using the model, various alternative measurement schemes were investigated. The directional dependence was eliminated by deriving a measurement at the drum’s center of gravity, and dual-sided measurement is proposed to gain a measure of heterogeneity. A more theoretical approach was also created wherein the contact force between the drum and soil are measured rather then being calculated.     

Bridge Scour and Substructure Deterioration: Case Study

In 1988, the State of Mississippi set up its first statewide underwater bridge inspection program. During this inspection, serious damage was found on the substructure of two parallel bridges on I-10 near Biloxi. Significant scour had occurred, exposing the steel piling. These piles had severe corrosion with cross sections reduced by 50%. Because of the reduced cross section, the web and flanges of the piles had buckled locally. This damage was exacerbated by collisions associated with barge traffic on the waterway. This accumulation of problems resulted in a bridge on the verge of collapse. Two alternatives were used to repair the substructure. The more seriously damaged piles were encased in concrete, and the less seriously damaged ones were dewatered and a concrete seal was placed around the piles. After 10?years, the piers with pile encasements showed no additional scour effects. However, the piers with the large concrete seals had scoured by as much as 3?m (10?ft). Described in this paper is the analysis of damage, design of the repair, and a review of the performance of the two types of repair over a 10-year period.     

Pavement Structures Damage Caused by Hurricane Katrina Flooding

In September of 2005, Hurricane Katrina devastated New Orleans and caused sustained flooding. Limited pre- and postflooding tests indicated that the pavement structures tested were adversely impacted by the flood water. Consequently, the Louisiana Dept. of Transportation and Development hired an independent contractor to structurally test approximately 383 km (238?mi) of the region’s federally aided urban highway system both inside and outside of the flooding area. Falling weight deflectometer (FWD) tests were performed every 161 m (0.1?mi) over each selected roadway, along with other field tests. The FWD data were imported into a geographical information system and plotted against a USGS geo-referenced map. Comparative analyses were made possible through the use of extensive flood maps made available through NOAA and FEMA. This arrangement made it possible to classify spatially and graphically all test points on the basis of flooding versus nonflooding, short flooding duration versus longer flooding duration, shallow flooding versus deep flooding, and thin pavements versus thick pavements. Three pavement types, asphaltic concrete, Portland cement concrete, and composite, were considered in this analysis. The statistical inference about the difference in the means of compared data groups was conducted with 95% confidence.     

Oxygen Permeability of Fiber-Reinforced Polymers

Several independent studies have confirmed that fiber-reinforced polymers (FRP) used for repairing corrosion-damaged concrete structures slow down the corrosion rate. This suggests that in this application, FRP serves as a barrier to the ingress of moisture and oxygen that are critically important for sustaining electrochemical corrosion of steel in concrete. Because oxygen molecules are smaller than both water and chloride molecules, they diffuse faster. Therefore, their permeation through FRP is more critical. This paper presents results from an experimental study that determined the oxygen permeability of FRP laminates. Four different commercially available carbon-fiber-reinforced polymer (CFRP) and glass-fiber-reinforced polymer (GFRP) systems were investigated, and four different fiber orientations were evaluated for one-layer and two-layer configurations. The results showed that the oxygen permeability of FRP was somewhat poorer than the epoxy used for its fabrication. Single-layer FRP laminates were less permeable than two-layer laminates, a finding that had previously been reported but considered anomalous. Scanning electron micrographs indicated that this could be attributed to voids between the layers. The nonzero oxygen permeability of FRP explains why it can slow down but cannot completely stop chloride-induced corrosion of concrete.