Statistical analysis of concrete cover in new highway bridges

Abstract: Quality control is one of the important aspects of any major construction works, that is to be undertaken to ensure work execution according to design requirements. The work presented in this paper involved measurement of cover thickness in three newly constructed highway bridges. Testing was conducted to ensure that specified requirements were attained prior to commissioning of the structures; otherwise, the quality control survey would identify problem areas for consideration of corrective measures. A total of 328 data sets were obtained during cover measurements. In this paper, the results obtained are discussed and evaluated. Data are characterised on the basis of statistical quantitie

Window screening, ceilings and closed eaves as sustainable ways to control malaria in Dar es Salaam, Tanzania.

BACKGROUND\ud \ud Malaria transmission in Africa occurs predominantly inside houses where the primary vectors prefer to feed. Human preference and investment in blocking of specific entry points for mosquitoes into houses was evaluated and compared with known entry point preferences of the mosquitoes themselves.\ud \ud METHODS\ud \ud Cross-sectional household surveys were conducted in urban Dar es Salaam, Tanzania to estimate usage levels of available options for house proofing against mosquito entry, namely window screens, ceilings and blocking of eaves. These surveys also enabled evaluation of household expenditure on screens and ceilings and the motivation behind their installation.\ud \ud RESULTS\ud \ud Over three quarters (82.8%) of the 579 houses surveyed in Dar es Salaam had window screens, while almost half (48.9%) had ceilings. Prevention of mosquito entry was cited as a reason for installation of window screens and ceilings by 91.4% (394/431) and 55.7% (127/228) of respondents, respectively, but prevention of malaria was rarely cited (4.3%, 22/508). The median cost of window screens was between US $21-30 while that of ceilings was between US$301-400. The market value of insecticide-treated nets, window screening and ceilings currently in use in the city was estimated as 2, 5 and 42 million US$. More than three quarters of the respondents that lacked them said it was too expensive to install ceilings (82.2%) or window screens (75.5%).\ud \ud CONCLUSION\ud \ud High coverage and spending on screens and ceilings implies that these techniques are highly acceptable and excellent uptake can be achieved in urban settings like Dar es Salaam. Effective models for promotion and subsidization should be developed and evaluated, particularly for installation of ceilings that prevent entry via the eaves, which are the most important entry point for mosquitoes that cause malaria, a variety of neglected tropical diseases and the nuisance which motivates uptake

Relativistic mean field calculation of parity-violating observables in francium

A formalism developed previously to study the smaller nuclear spin-dependent parity-violating effects using the relativistic mean field theory has been generalized to the case of odd-odd nuclear systems such as Fr-210. Because of the recent success in trapping Fr atoms, parity-violation experiments for Fr seem feasible. The nuclear spin-dependent parameters eta and eta' are calculated using the anapole moment parameters kappa(p) and kappa(n). They are used to calculate the hyperfine transition amplitudes for the 6S-->7S transition in Cs-134 and 7S -->8S in Fr-210. The calculated hyperfine transition amplitudes in Fr are one order of magnitude larger than those in Cs

A mathematical model to measure instantaneous moisture content in transformer insulation cellulose

Solid transformer insulation is mainly composed of cellulosic materials, in the form of pressboard, Kraft paper and wood. Oil is used to impregnate voids in the cellulose. The water content of cellulose usually increases over the life of the transformer, caused by both moisture ingress and the gradual degradation of cellulose, which produces moisture as an aging by-product. Equilibrium curves are used to estimate the moisture content of cellulosic insulation using the vapor pressure of water dissolved in the oil. However, a very long duration is required for water to attain this equilibrium partition, much longer than the usual daily cyclic temperature profile of a transformer, and thus it is very unlikely for the insulation to reach this state. In this paper a novel method to estimate the moisture in cellulose during non-equilibrium conditions is presented. The water adsorbed by the cellulose migrates in and out the oil, and the diffusivity depends on the temperature and the concentration of moisture in the cellulosic insulation. This diffusion is mainly governed by Fick's law. For a transformer, the change in moisture content of oil in a small duration is mainly due to the moisture content in the cellulosic insulation. This paper presents a method to estimate the moisture content of cellulosic insulation of the transformer at that instant from the change in the moisture content of the oil

Nadi Thrangini : a pulse based diagnostic system

Ayurveda is a traditional medicine and natural healing system in India. Nadi-Nidan (pulse-based diagnosis) is a prominent method in Ayurveda, and is known to dictate all the salient features of a human body. In this paper, we provide details of our procedure for obtaining the complete spectrum of the nadi pulses as a time series. The system Nadi Thrangini(1) contains a diaphragm element equipped with strain gauge, a transmitter cum amplifier, and a digitizer for quantifying analog signal. The system acquires the data with 16-bit accuracy with practically no external electronic or interfering noise. Prior systems for obtaining the nadi pulses have been few and far between, when compared to systems such as ECG. The waveforms obtained with our system have been compared with these other similar equipment developed earlier, and is shown to contain more details. The pulse waveform is also shown to have the desirable variations with respect to age of patients, and the pressure applied at the sensing element. The system is being evaluated by Ayurvedic practitioners as a computer-aided diagnostic tool

Augmenting groundwater resources by artificial recharge (AGRAR): progress of activities May-November 2003

Progress of the DFID-funded KAR project entitled “Augmenting Groundwater Resources by Artificial Recharge” – AGRAR (R8169), was reviewed in early November 2003 at the three research sites and during a meeting of all partners in Ahmedabad, Gujarat. Draft inception reports for the three research sites and review reports for the two ancillary studies were presented and discussed by all partners. It was agreed that final draft versions of these reports would be prepared by mid-December 2003 for publication on the project web page in January 2004. The delay in initiating the instrumentation and surveys at the three research sites has resulted in significant loss of data during the 2003 monsoon season. However, the conceptual understanding of the sites has improved and aspects that need to be monitored have been more closely identified. For example, the understanding gained from monitoring water levels in wells around recharge structures has helped in the siting of observation boreholes that are currently being drilled in preparation for monitoring through the forthcoming monsoon season. The work undertaken, at some of the research sites, by the related ComMan1 project has provided a valuable basis on which to build in order to achieve the distinct objectives of AGRAR. This has been especially the case with the rural livelihoods surveys which, in ComMan, have addressed the issue of demand management in the context of community approaches to managing groundwater resources, and have set out to examine whether hydrogeological, institutional and socio-economic conditions exist to enable such user-based schemes to be set-up and sustained. The AGRAR project will complement these activities by focusing on the potential and effectiveness of augmenting groundwater resources, while ComMan will concentrate on the challenges associated with controlling the demand for groundwater. Surveys and methodologies have therefore been designed to build on the findings of ComMan in order to specifically address the impacts of artificial recharge structures on the livelihoods of the communities. The AGRAR project was commissioned by DFID to address the specific issue of the effectiveness of artificial recharge structures, from both the technical and socio-economic perspectives. This is being done in the context of other projects being undertaken by a range of organisations; government, NGOs and researchers. Contact with these organisations has been maintained in order to learn from their experience and hence avoid duplication. A brief review of the relationship of the activities of AGRAR in relation to other projects is given

A Novel and Fast Virtual Surgical System Using Fuzzy Logic

Virtual Reality (VR) and associated technologies are experiencing growing importance in medicine and surgery. VR demands fast and real time simulations. Finite element analysis can be used for cutting simulation; however, finite element analysis is computationally intensive and is unsuitable for real time applications involving cutting of a large amount of tissue. We have developed a fuzzy logic based system which involves significantly reduced computational times and provides real time simulations of cutting. The user-exerted forces on a simulated cutting tool held by the user are dynamically measured and fed to the fuzzy logic system. The user-exerted forces and the stiffness of the element are first fuzzified and fed to a fuzzy rule base to provide the output membership values. These output membership values are then defuzzified using the centroid defuzzification technique to provide a crisp output of the cutting depth. The technique has been implemented in real time. Experiments with human users have shown consistent results