Development of Mechanical Anchor for CFRP Tendons Using Integrated Sleeve

A durable and very efficient external strengthening system is achieved if steel tendons for posttensioning applications can be replaced with carbon fiber-reinforced polymer (CFRP) tendons, and if reliable anchorage systems are developed. This paper presents a newly developed and simple-to-use, two-piece wedge anchorage for CFRP tendons with an integrated sleeve and a differential angle between barrel and wedge sections. Three longitudinal slits are cut into the one-piece wedge, with one slit open and the other two stopping 1 mm from the inner wedge hole. The integrated sleeve holds the wedge’s sections together during presetting and loading, resulting in a circumferential confined gripping of the CFRP tendon and optimized surface friction area. Therefore, the one-piece wedge differs from conventional wedge systems, where the wedges act separately with adjacent spaces, wedging the separate tendon sleeve in the longitudinal direction. Evaluation of the failure modes during testing was one of the main keys in achieving an increasingly better performance of the anchorage until the final anchorage was developed. The obtained failure modes are therefore described to enlighten the importance of addressing them when testing. The test setup used and measured behavior are described further together with the loading procedure. The anchorage reached the full capacity of the CFRP tendon and was seen to ensure a stable load of fracture.     

Evaluation of assisting agents for electrodialytic removal of Cd,Pb, Zn,Cu and Cr from MSWI fly ash

Different assisting agents (0.25 M ammonium citrate/1.25% NH(3), 0.25 M Na-citrate, 2.5% NH(3), DI water) have been used for aiding the removal of heavy metals during electrodialytic treatment of municipal solid waste incineration (MSWI) fly ash. In this study, the effectiveness of the different agents was evaluated. The heavy metal speciation in solution was discussed and simulated at the different conditions using the geochemical equilibrium model Visual MINTEQ. The heavy metals examined were Cd, Pb, Zn, Cu and Cr.The 2.5% NH(3) solution was the best assisting agent for removal of Cd, probably due to formation of stable tetraammine complexes; whereas the best Pb removal was obtained with 0.25 M Na-citrate (Pb forms very stable chelates with citrate). The best compromise for removal of all five metals was obtained with the 0.25 M ammonium citrate/1.25% NH(3) solution.     

Surveyance of disease frequency in a population by linkage to diagnostic laboratory databases. A system for monitoring the incidences of hyper- and hypothyroidism as part of the Danish iodine supplementation program

In Denmark an increase in iodine intake through salt iodization has been introduced in 1998. In parallel a program for surveyance of thyroid diseases in the population was developed as recommended by UNICEF and WHO. OBJECTIVE: To develop and evaluate a computer based system to identify and register new cases of hyper- and hypothyroidism in a well defined cohort, by linkage to diagnostic laboratory databases. DESIGN AND RESULTS: (1) Two sub cohorts for monitoring were defined (n=535,859), and evaluated to minimize loss of new cases. Collaboration was established with laboratories covering thyroid hormone analyses in the cohort; (2) a diagnostic algorithm was defined and evaluated against clinical practice; (3) evaluation of the laboratory methods employed by the four participating laboratories, to ensure they would reach the same diagnosis in a patient; (4) a register database was developed which used data imported from the laboratory databases to automatically identify previously unknown cases of hyper- and hypothyroidism and record diagnostic activity in the area. All parts of the registration were carefully evaluated. CONCLUSION: We describe for the first time a computer based system for prospective measuring the incidence rate of hyper- and hypothyroidism. The system is particularly useful for monitoring of iodine supplementation programmes.     

Designing plates for minimum internal resonances

Internal resonance is a nonlinear phenomenon for a structure when the eigenfrequencies of the structure are commensurable or close to being commensurable. Using optimization we have the possibility to control the eigenfrequencies, i.e., move an eigenfrequency, maximize a given eigenfrequency, or maximize the gap between eigenfrequencies. It is therefore also possible to design a structure that is as free as possible of internal resonance up to mode of order n.We consider plates made of two materials. The designs depend on the boundary conditions and on the frequency range within which the plate should be as free of internal resonance as possible. The two materials can either be two physical materials, or one can be a physical material and the other a weakening of the first material. By doing this we are in principle solving three different problems: a reinforcement problem, a problem of where to put holes in the structure, and, finally the more involved case (from a manufacturing point of view), of two different materials. The optimizations are performed using the finite element method for analysis and the topology optimization approach for design. The optimization problem is formulated using a bound formulation where the objective is to maximize a minimum detuning parameter. Special attention is given to the formulation of the conditions for internal resonance. Using the method presented in this paper it is possible to remove an unwanted nonlinear phenomenon without the use of a nonlinear model and without knowledge of the nonlinearities present in the system.     

A Deformable Template Model, with Special Reference to Elliptical Templates

This paper suggests a high-level continuous image model for planar star-shaped objects. Under this model, a planar object is a stochastic deformation of a star-shaped template. The residual process, describing the difference between the radius-vector function of the template and the object, is allowed to be non-stationary. Stationarity is obtained by a time change. A parametric model for the residual process is suggested and straightforward parameter estimation techniques are developed. The deformable template model makes it possible to detect pathologies as demonstrated by an analysis of a data set of cell nuclei from a benign and a malignant tumour, using stochastic deformations of ellipses.     

Influence of bovine antiserum (Bo-Bac 2X) injection on colostral immunoglobulin G absorption in neonatal dairy calves

On the background of positive survival data from farms in Mississippi, treating calves with antiserum injection in addition to normal colostrum administration, the objective of the present study was to evaluate the influence of a single subcutaneously administered bovine antiserum injection (0.031 g of IgG/kg of body weight) and pooled colostrum administration on efficiency of Ig absorption and on 24-h plasma IgG concentration in neonatal bull calves. Twenty-nine male dairy calves (21 Holsteins and 8 Jerseys) were assigned randomly at parturition to receive one of four treatments: 1) colostrum (n = 9), 2) colostrum and bovine antiserum injection (n = 7), 3) milk replacer (n = 5), or 4) milk replacer and bovine antiserum injection (n = 8). At birth, calves either did or did not receive an injection of bovine antiserum and were fed pooled colostrum or milk replacer (Holsteins, 3.8 L; Jerseys, 1.9 L) via an esophageal feeder. Blood was collected immediately before administration of the colostrum or milk replacer, then again at 24 and 48 h postpartum. Immunoglobulin G concentrations of colostrum, milk replacer, antiserum, and plasma were monitored by single radial immunodiffusion. Colostrum administration and injection of bovine antiserum each increased plasma Ig concentration at 24 h posttreatment. In addition, antiserum injection increased the apparent efficiency of absorption of colostral Ig by 42% over that for calves fed colostrum alone. The increase in plasma IgG for antiserum-treated calves exceeded the total amount of IgG administered in the antiserum injection; hence, this increase appeared to be the result of an increase in total absorption of colostral IgG, or possibly antiserum injection somehow triggered active synthesis of IgG. Injection of antiserum might possibly serve as a beneficial adjunct to a colostrum management program by enhancing the acquisition of passive immunity from colostral sources.     

Gain and noise performance of fibre amplifiers operating in new pump configurations

New configurations of erbium-doped fibre amplifiers have been investigated for the 0.98 mu m and 1.48 mu m pump wavelengths. A doubling of the gain coefficient has been predicted for reflective type amplifiers at the cost of a noise figure increase of 1.5 dB.<>     

Myocardial rupture during exercise ECG

We report a case of heart rupture in connection with a stress test performed nine days after an otherwise uncomplicated myocardial infarction. The Danish Association of Cardiologists recommend stress testing 5-20 days after myocardial infarction. We question whether this timing is appropriate considering the vulnerability of the myocardium at that time.