Strengthening of a bridge pier capbeam using bonded FRP composite plates

Application of fiber reinforced polymer (FRP) composite plates to strengthen the capbeam of Pier 3 of East Church Street Bridge in Chemung County, New York, is discussed in this paper. Addition of a concrete wearing surface and a median barrier to the bridge superstructure increased dead load, contributing to deficiencies in moment and shear capacities of the capbeam structure. As a result, the concrete capbeam suffered flexural and shear cracking, and was considered for strengthening using bonded FRP composite plates. Service load tests were performed before and after the plates were installed, to investigate effectiveness of the strengthening system. Installation of the plates and results from the performed load tests related to flexural behavior of the beam are discussed in the paper.     

一般铁路桥梁墩、台的尺寸拟定

在工程设计中,根据工程的实际情况选定一种合适的墩、台形式后,就要拟定墩、台的基本尺寸。本文具体介绍了一般铁路桥梁墩、台的尺寸拟定方法。     

Sheltering as a protective measure against airborne virus spread.

The dispersion of airborne viruses can play an important role in the spread of a disease. Especially for short or moderate emission periods - such as emissions from farms or accidental releases from laboratories or industrial plants - indoor concentrations can be significantly lower than outdoor concentrations. The relationships between these two concentrations are analysed for continuous, temporary and instantaneous releases. The efficiency of sheltering as a protective measure for persons or animals is discussed.     

Montmorillonite functionalized with pralidoxime as a material for chemical protection against organophosphorous compounds

Montmorillonite K-10 functionalized with α-nucleophilic 2-pralidoxime (PAM) and its zwitterionic oximate form (PAMNa) is introduced as a versatile material for chemical protection against organophosphorous (OP) compounds such as pesticides and chemical warfare agents (CWA). Upon inclusion into the montmorillonite interlayer structure, the pyridinium group of PAMNa is strongly physisorbed onto acidic sites of the clay, leading to shrinking of the interplanar distance. Degradation of diethyl parathion by PAMNa-functionalized montmorillonite in aqueous-acetonitrile solutions occurred primarily via hydrolytic conversion of parathion into diethylthio phosphoric acid, with the initial stages of hydrolysis observed to be pseudo-first-order reactions. Hydrolysis catalyzed by the clay intercalated by PAMNa was 10- and 17-fold more rapid than corresponding spontaneous processes measured at 25 and 70 °C, respectively. Hydrolytic degradation of diisopropyl fluorophosphate (DFP), a CWA simulant, was studied on montmorillonite clay functionalized by PAMNa and equilibrated with water vapor at 100% relative humidity by 31P high-resolution magic angle spinning NMR and was observed to be rather facile compared with the untreated montmorillonite, which did not show any DFP hydrolysis within 24 h. The incorporation of the functionalized clay particles into elastomeric film of polyisobutylene was shown to be a means to impart DFP-degrading capability to the film, with clay particle content exceeding 18 wt %.     

The effect of circular bridge piers with different inclination angles toward downstream on scour

A fundamental principle in the safe design of bridge piers is to estimate maximum scour depth. As such, many researchers devoted their efforts to study the phenomenon of scour around bridge piers and to present relationships to estimate maximum scour depth. In the current research, scour around circular bridge piers with two different diameters and different inclination angles toward downstream has been investigated experimentally under clear water and different discharges. The obtained results revealed that increase in the inclination angle leads to a significant decrease in the scour depth, dimensions of sediment ridge and scour hole. Moreover, by comparing the data obtained from vertical bridge pier and well-known relationships, a relationship having the most agreement with the results was selected and modified to estimate equilibrium scour depth around inclined piers.     

The use of high-strength vacuum-deposited coatings as a means of protection against wear

It was shown that the wear resistance of high-strength vacuum-deposited films is considerably higher than that of electrodeposited coatings or case-hardened steel. The wear resistance of vacuum-deposited coatings may vary within wide limits depending on the deposition conditions.     

Evaluation of water absorption of concrete as a measure for resistance against carbonation and chloride migration

The pore structure of concrete is known to be of high importance for the durability of the material. A characterisation of this pore structure by means of a simple test is often investigated, in order to find a very simple compliance criterion with respect to concrete durability. Within some daily-used Belgian technical guidelines, the water absorption by immersion is considered to be a relevant parameter in this respect. Based on an extended experimental research programme, with test on 22 different concrete mixes (traditional concrete and self-compacting concrete), the relation between water absorption by immersion and some concrete durability issues is investigated. Within these tests, accelerated carbonation and chloride migration tests are realised. Furthermore, some technological parameters are investigated, related with the volume to surface ratio of the specimens used for the water absorption test. It is concluded that the influence of the volume-to-surface ratio of the specimens is not significant when considering the natural scatter on the test results. Furthermore, the water absorption by immersion is not a reliable parameter for the estimation of the concrete durability. The water absorption by immersion gives an estimation of the total (reachable) pore volume of the concrete, but gives no indication on the concrete permeability, which is more important with regard to durability.     

Patent statistics as a measure of technological vitality

Statistical patent data is useful as a relative measure when applied to patent applicants following similar strategies. This is contrasted with the use of such data in efforts to assess technological trends and assess vitality in an absolute sense. The value of consultation with the patent profession as part of a program of statistical assessment is underlined, owing to its experience of the evolving technological environment and the changing patent systems to which the data apply.     

A boundary-integral method for the interaction of large-amplitude ocean waves with a compliant floating raft such as a sea-ice floe

The interaction of large-amplitude water waves with a compliant floating raft such as a sea-ice floe or a pontoon-type VLFS (very large floating structure) is considered. The solution is expressed as a series using a perturbation expansion, the first two components of which are solved inductively using a boundary-integral method. The primary interest of this paper is to the ways in which the second-order potential can be modified in order to apply the boundary-integral method and to the comparison of results with those derived using eigenfunction matching methods.     

Contact resistance as a measure of the superconducting order parameter

We have shown experimentally that the electrical contact resistance between a thin copper wire and a bulk superconductor contains a small contribution that varies with temperature below T _c . The observed temperature dependence is always close to that of the energy gap in the superconductor.     

Minimum detectable dose as a measure of bioassay programme capability

This paper suggests that minimum detectable dose (MDD) be used to describe the capability of bioassay programmes for which intakes are expected to be rare. This allows expression of the capability in units that correspond directly to primary dose limits. The concept uses the well established analytical statistic minimum detectable amount (MDA) as the starting point, and assumes MDA detection at a prescribed time post-intake. The resulting dose can then be used as an indication of the adequacy or capability of the programme for demonstrating compliance with the performance criteria. MDDs can be readily tabulated or plotted to demonstrate the effectiveness of different types of monitoring programmes. The inclusion of cost factors for bioassay measurements can allow optimisation.     

Defining triadic patent families as a measure of technological strength

Objective  This paper aimed to examine the reliability of co-citation clustering analysis in representing the research history of subject by comparing the results from co-citation clustering analysis with a review written by authorities. Methods  Firstly, the treatment of traumatic spinal cord injury was chosen as an investigated subject to be retrieved the resource articles and their references were downloaded from Science Citation Index CD-ROM between 1992 and 2002. Then, the highly cited papers were arranged chronologically and clustered with the method of co-citation clustering. After mapping the time line visualization, the history and structure of treatment of spinal cord injury were presented clearly. At last, the results and the review were compared according the time period, and then the recall and the precision were calculated. Results  The recall was 37.5%, and the precision was 54.5%. The research history of traumatic spinal cord injury treatment analyzed by co-citation clustering was nearly consistent with authoritative review, although some clusters had shorter period than which was summarized by professionals. Conclusion  This paper concluded that co-citation clustering analysis was a useful method in representing the research history of subject, especially for the information researchers, who do not have enough professional knowledge. Its demerit of low recall could be offset by combination this method with other analytic techniques.     

Analysis of a negative impedance converter as a temperature compensator for bridge sensors

In this paper, we present an in-depth analysis of a negative impedance converter (NIC) as a temperature compensation device for bridge sensors. Even though its use has been proposed in some application notes and a patent, no theoretical justification has been reported so far, at least to the best of our knowledge. This paper attempts to fill this gap, giving closed-form expressions for a correct use of the NIC in any application. The influence of second-order effects in the temperature compensation is also considered. Experimental results are provided in order to verify the principles presented.     

The volume of information as a measure of the chaos synchronization

A characteristic is suggested for the evaluation of the degree of synchronization of the chaotic oscillations in a system of two coupled oscillators. The proposed value is tested by application to the case of two unidirectionally coupled logistic maps. It is shown that this characteristic is stable with respect to a low noise and a nonlinear distortion of the signal.     

Modelling and forecasting contact time as a measure of item informativeness

The value or informativeness of an item in a library collection or database has been measured by its frequency of circulation or access. This paper presents a more discriminating measure, user contact time, and develops a model for its distribution over users and over time. The model is applied to the problem of predicting future informativeness of an item.     

Driver licenses as a measure of older drivers' exposure: a methodological note

The limitations of the number of driver licenses as an estimate of driving exposure were demonstrated by comparing Finnish and Swedish driver licensing practices, licensing rates and accident rates of older drivers. In Sweden, there is no screening for older license holders, and most of them keep their licenses for life. In Finland, there is a heavy and costly medico-legal control system for older license holders, leading to both screening and self-screening. Consequently, in the two countries, the numbers of driver licenses do not reflect the numbers of active older drivers in the same manner. This difference affects the comparative accident statistics: with respect to population, Finland and Sweden have similar age trends in accidents risk, but with respect to the number of driver licenses, the Finnish older drivers seem to have a higher risk of accident than the Swedish ones. It is concluded that if group comparisons of accident risk are presented using the number of driver licenses as an estimate of exposure, the licensing legislation and practice should affect all the groups in an identical manner for the comparison to be valid.     

Citer analysis as a measure of research impact: library and information science as a case study

The investigators studied author research impact using the number of citers per publication an author’s research has been able to attract, as opposed to the more traditional measure of citations. A focus on citers provides a complementary measure of an author’s reach or influence in a field, whereas citations, although possibly numerous, may not reflect this reach, particularly if many citations are received from a small number of citers. In this exploratory study, Web of Science was used to tally citer and citation-based counts for 25 highly cited researchers in information studies in the United States and 26 highly cited researchers from the United Kingdom. Outcomes of the tallies based on several measures, including an introduced ch-index, were used to determine whether differences arise in author rankings when using citer-based versus citation-based counts. The findings indicate a strong correlation between some citation and citer-based measures, but not with others. The findings of the study have implications for the way authors’ research impact may be assessed.