New standards of Bituminous mixtures and cement concrete

In the thesis paper “New standards of Bituminous mixtures and cement concrete” I describe the ways of acquiring a certificate of production control and introducing the building product to the market in order to serve its purposes. To master the certificate acquirement, a wide range of expert knowledge is necessary, and further education is obligatory with its development. In this field of expertise more and more knowledge is expected not only from the experts, but also from other participants in the building process. In many cases some individuals outside the building industry also wish to acquire the basic information. The thesis paper features all of the phases of acquirement and sustenance of the certificate, beginning with knowledge on the basic materials, forming rules of procedure and the type- examination. It also features the introduction of a production control system, the initial inspection and the inspection according to the acquirement of a certificate of production control, providing a conformity declaration and CE information, as well as conformity control and the permanent external control, the knowledge on the technological procedures and all the parallel activities, for example testing of the products. A comparison between the new and the abolished standards has also been included

Atomic ejection in the beam sputtering of nickel, by argon ions, in the threshold to 600 ev energy range

Using a low-energy, three stage, differentially pumped ion accelerator, similar to that used by Hagstrom for Auger electron ejection studies, permits, with the application of radiotracer methods, a new approach to the study of low energy sputtering. The experimental approach consisted of pumping down the experimental tube to 10⁻⁹ torr, outgassing the target by electron bombardment, introducing argon into the system, and bombarding a Ni⁶³ target for a time which is short compared to the time required for a monolayer of adsorbed gases to form at the existing residual partial pressure of adsorbable gases. The target consisted of Ni⁶³ plated on a cold-rolled nickel substrate. Heating the target above its recrystallization temperature produced an 80 percent oriented polycrystalline surface which approximated the (100) plane of a nickel single crystal. Mounting the target so that its surface normal made an angle of 30⁰ with respect to the incident beam direction and bombarding with argon ions produced the characteristic pattern for atoms sputtered from the close-packed directions or "chains" which terminate on the surface of a (100) plane. The target was mounted inside a cylindrical collector, slightly behind center. The ion beam impinged on the target through a narrow slit in the collector. Sputtered atoms were collected on a removable molybdenum foil which lined the outer collector cylinder support. After each bombardment, the molybdenum foil was removed, cut into narrow strips, and then the strips were analyzed by placing them under a G-M counter. The tracer technique permitted measuring the relative sputtering yields from individual crystallographic directions with respect to the angle of incidence of the ion beam. The method thus permitted a direct check on the Harrison-Magnuson theory of single-crystal sputtering thresholds. Contrary to their predictions, there was very little dependence of the threshold on angle of ion incidence with respect to a given chain direction. The observed sputtering yield curves flattened out or "saturated" at a much lower energy than those appearing in the literature. The saturation yield proved highly dependent on the angle of ion incidence. It appears, on the basis of the single direction yield curves, that the measurements appearing in the literature represent a superposition of independent yield curves--from and from directions, respectively. Reflection maxima of sputtered nickel atoms, which appeared behind the target on the collector surface, appear to be due to specular reflection from the primary maxima. A plot of the reflection ratios as a function of incident ion energy suggests that the specular reflection arises from resonance scattering from the interaction potential that the nickel atoms encounter at the molybdenum surface

Near-surface heater experiments

Full-scale near-surface heater experiments are presently being conducted by Sandia Laboratories in the Conasauga Formation at Oak Ridge, Tennessee, and in the Eleana Formation on the Nevada Test Site, Nevada. The purposes of these experiments are: (1) to determine if argillaceous media can withstand thermal loads characteristic of high level waste; (2) to provide data for improvement of themomechanical modeling of argillaceous rocks; (3) to identify instrumentation development needed for further in situ testing; and (4) to identify unexpected general types of behavior, if any. The basic instrumentation of these tests consists of a heater in a central hole, surrounded by arrays of holes containing various instrumentation. Temperatures, thermal profiles, vertical displacements, volatile pressurization, and changes in in situ stresses are measured in each experiment as a function of time, and compared with pretest modeling results. Results to date, though in general agreement with modeling results assuming conductive heat transfer within the rock, indicate that the presence of even small amounts of water can drastically affect heat transfer within the heater hole itself, and that small amounts of upward convection of water may be occurring in the higher temperature areas of the Conasauga experiments

Effectiveness and safety of anticoagulant versus antiplatelet therapy in patients after endovascular revascularisation of the lower limb

Background: After revascularisation, patients with peripheral arterial disease (PAD) are routinely prescribed antiplatelet treatment (APT). Patients who receive anticoagulant treatment (ACT) due to comorbidity are an exception. We set out to determine possible differences in the effectiveness and safety between ACT and APT in patients after endovascular revascularisation of the lower limb arteries. Methods: In a single-centre retrospective cohort study, we analysed the data of 1,587 PAD patients who underwent successful endovascular revascularisation of the lower limb arteries due to disabling intermittent claudication or chronic critical limb ischemia over a 5-year period. Patients were divided into the ACT and APT groups based on their prescribed treatment. After balancing both groups’ baseline characteristics with propensity score matching, we compared the effectiveness and safety of both treatment regimens in the first year after revascularisation. Results: Compared to patients with APT, patients with ACT were older, and more often reported arterial hypertension, diabetes, chronic kidney disease, congestive heart failure, ischaemic heart disease, and prior stroke or transient ischaemic attack. After matching, the odds ratio (OR) for an effective outcome with ACT versus APT was 0.78 (95% CI 0.39–1.59; p=0.502), while the OR for a safe outcome with ACT versus APT was 4.12 (95% CI 0.82–20.73; p=0.085). Conclusions: Patients who required ACT were elderly, had more cardiovascular risk factors and had more advanced PAD than patients with APT. After matching, we found no statistically significant difference in the effectiveness and safety of both treatment regimens; however the wide OR confidence intervals warrant further research