Field trials involving typical pavement constructability and rehabilitation issues at the Federal Aviation Administration’s National Airport Pavement Test Facility, the Minnesota Road Research Project, and various in service pavements using MIRA were verified. The trials indicate that, while the device is a useful portable pavement diagnostic alternative capable of consistent thickness measurement, reinforcement location, and distress evaluation, significant efforts and user expertise are required for measurement and data interpretation of large scale applications. Thus, a couple productive, objective signal interpretation methods are presented for automated analysis of reinforcement location in continuously reinforced concrete pavement as well as an initial distress indicator using two-dimensional ultrasonic signature analysis. This type of automation for multiple applications shows promise for the use of ultrasonic tomography to improve large scale pavement quality assurance, quality control, and rehabilitation projects in the future. Innovative imaging methods such as synthetic aperture focusing technique panoramic reconstructions and synthetic aperture focusing technique three-dimensional visualizations were also introduced to improve the ability to obtain relational information when dealing with larger scanned areas. Ultrasonic tomography is shown to be an accurate, reliable, and convenient alternative/supplement to traditional techniques or can be used to replace or reduce the need for forensic methods such as coring.

MIT Scan-2 has been identified by the FHWA as a practical implementation-ready product that has the potential to improve quality of concrete pavements. Since MIT Scan-2 has been brought to the United States, evaluations of MIT Scan-2 have shown it to be a reliable tool for locating dowels with high accuracy for dowels inserted with cut dowel baskets or DBIs. This device was also found to be useful in qualitative measurement of uncut misaligned dowel baskets. The efficiency and ease of use of the device was also found to be robust fo application to investigations that require large amounts of measurements in a wide range of environments. Munerous field evaluations of typical concrete pavement sections have shown that with proper construction practices, the dowels can be placed at relatively low misalignment levels. This technology may help the contractor ensure that the dowel bars are installed properly. However, this paper does not provide guidelines for dowel misalignment, as those will be developed in the NCHRP 10-69 study to be completed in 2008.

Air void content is one of the most important characteristics of in-place asphalt concrete, substantially affecting early deterioration and long term performance. Destructive measures at limited locations, such as coring, are typically conducted as part of the air-void content evaluation after the pavement has been fully constructed. In this paper, use of an air coupled step-frequency array system for nondestructive assessment of air-void variability is explored. The dielectric properties of the asphalt were determined from the asphalt surface reflection amplitude of all 21 adjacent transmitting and receiving pairs of the array and related to air void content through plotting of dielectric changes with core measured air void content. This approach is an extension of the procedure developed for a single bistatic antenna pair determining properties within top millimeters of the asphalt surface. While cores provide information concerning bulk properties across the depth, the proposed method with an array system provides an opportunity for increased lateral coverage. The case study demonstrated good repeatability and correspondence with core measured air void content. The array-based method improves the coverage and productivity of the measurements, making it an attractive alternative to current state-of-the-practice procedures.

Although dowel bars are an essential design feature of jointed concrete pavements to prevent pumping and faulting, few studies dealing with the constructability of dowel alignment have been conducted. With the emergence of the Magnetic Imaging Tools (MIT) Scan-2 as a nondestructive, robust method of locating dowels, it is now possible to efficiently evaluate the construction quality of dowel bar placement without damaging the newly constructed pavement. A brief review is presented of the results of recent field studies aimed at examining the constructability of doweled joints in concrete pavements. The dowel bar alignment data collected in this study encompass a wide range of design and environmental conditions and show that alignment within reasonable levels—considering equipment, mix design, as well as workmanship and consistency—is achievable in the field. Distress and performance analyses show that within these levels of misalignment, the pavement performance is not significantly affected. However, misalignment at a greater level may not be detrimental to pavement performance, and therefore performance-based guidelines may be less strict than the constructability levels collected in this study. Nevertheless, the results shed light on the level of alignment that can be reasonably achieved in the field.

Background: Delayed diagnosis of head and neck cancer is often caused by patient-related factors. However, the primary health care provider may also be responsible.Objectives: To define patient, professional and total delay, and to identify factors that may increase delay.Methods: The study group consisted of 102 patients with oral or pharyngeal cancer referred to Princess Margaret Hospital, Toronto, Ontario. The study took place from September 2005 to September 2006.Results: Median patient, professional and total delays were 4.5 weeks, 11.8 weeks and 22.5 weeks, respectively. Significantly longer delays were found among women (p < 0.01), non-smokers (p < 0.01), patients who were not referred following initial consultation (p < 0.001) and patients who did not visit their dentist (p < 0.05).Conclusions: Clinicians should adopt a "universal index of suspicion" in screening for head and neck cancer, with attention to the risk indicators for delay. Patients must also be encouraged to visit their dentist regularly to increase the rate of early detection.

This paper presents the results of an evaluation of the effectiveness of an innovative process for installing dowel bars in construction joints without drilling. The procedure involves inserting plastic sleeves with the same outside dimensions as the drilled holes into plastic concrete to create the holes for installation of the dowel bar, rather than drilling. The plastic sleeves are later removed, and the dowel bars are inserted in the holes left behind. To avoid any deleterious effects, the technique must produce dowel bar alignments that are comparable with those of the bars installed under the conventional method and must not cause any other problems. A field test was conducted to evaluate the viability of the new technique. The evaluation is based on the key factors that determine the engineering feasibility of the new procedure, which include dowel bar alignment, consolidation of concrete around the plastic sleeves, and the impact of the insertion techniques on pavement surface profile. The test results showed that the plastic sleeves can produce dowel bar alignments that are comparable with or better than those produced by the conventional drilling method, without any deleterious effects.

Maintaining hemodialysis grafts remains a difficult problem. Before the early 1990s, graft declotting was usually performed in the surgical suite. Percutaneous declotting has been evolving since the mid-1980s. Initially, a low-dose thrombolytic infusion of streptokinase through a single catheter was used. Crossing catheters with a higher-dose infusion of urokinase was then introduced. This technique was modified with the adjunctive use of pharmacomechanical techniques with the use of compliant balloons and the adjunctive use of heparin. The advent of the "lyse-and-wait" technique provided a simpler and quicker way to declot thrombosed grafts by using urokinase, with similar outcomes. Since the removal of urokinase from the market, multiple mechanical devices have been used with similar success. Recent reports concerning the use of newer-generation thrombolytic agents report similar outcomes, with a reduction in total cost.