Department of Physical and Technical Sciences

Abstract This case study performed at the largest gold mining village in the Philippines compares four methods for gold recovery: amalgamation, cyanide leaching, a shaking sluice, and Cleangold® sluices. The results show that a combination of manual panning or Cleangold® sluices followed by cyanidation is the best solution under present conditions, followed by cyanidation alone. Based on the knowledge obtained, remarks on suitable policy actions, which may be applied also in other gold fields, are made.

We subjected 18 carbonate samples < 1-46 Ma in age from Holes 706A, 707A, 708A, 709C, 710A, and 711A on or near the Mascarene Plateau and Madingley Rise and from Holes 712A, 713A, and 716A on or near the Chagos Bank-Maldives Ridge to instrumental neutron activation analysis to measure 32 major, minor, and trace elements and to determine the Ce anomalies (Ce A *) in the carbonates relative to NASC (North American Shale Composite). Five carbonates, 32-46 Ma,^yielded an average Ce A * value of 0.14 0.05, corrected for small (0.1%-1.8%) detrital clay particulates. This Ce A * value is considered to represent the inferred Ce A value in the western Indian Ocean during the 32-46-Ma interval and compares to an average Ce A value of 0.05 0.02 in the Pacific Ocean during the past ~ 35 Ma and from 93 to 97 Ma. These inferred Ce

Corrosion is one of the main electrochemical processes that damage metal materials. The combination of cyclic stresses and a corrosive environment causes wear-fatigue damage, called corrosion-mechanical fatigue. The paper investigates the problem of predicting this type of wear-fatigue damage, which occurs in almost all branches of technology, especially in the chemical, oil, metallurgical industries, transport. The work consists of several parts. In the first part a technique for estimating the fatigue limit in a given corrosive environment (direct effect) is developed. The second part analyzes the reverse effect, i.e. the effect of acting stresses on the corrosion rate of metals and alloys, and proposes a method for predicting corrosion-erosion damage with the reverse effect based on the energy criterion. In the future, it is planned to discuss the mechanisms of corrosion-mechanical fatigue with direct and reverse effects at different stages of complex damage.

We subjected 18 carbonate samples < 1-46 Ma in age from Holes 706A, 707A, 708A, 709C, 710A, and 711A on or near the Mascarene Plateau and Madingley Rise and from Holes 712A, 713A, and 716A on or near the Chagos Bank-Maldives Ridge to instrumental neutron activation analysis to measure 32 major, minor, and trace elements and to determine the Ce anomalies (Ce A *) in the carbonates relative to NASC (North American Shale Composite). Five carbonates, 32-46 Ma,^yielded an average Ce A * value of 0.14 0.05, corrected for small (0.1%-1.8%) detrital clay particulates. This Ce A * value is considered to represent the inferred Ce A value in the western Indian Ocean during the 32-46-Ma interval and compares to an average Ce A value of 0.05 0.02 in the Pacific Ocean during the past ~ 35 Ma and from 93 to 97 Ma. These inferred Ce

Abstract The style and explosivity of volcanic eruptions are primarily governed by the interplay between conduit dynamics (e.g. magma ascent rate and volatile outgassing) and pre-eruptive magmatic conditions (e.g. P-T-X), both of which influence magma rheology and degassing processes. To better understand the controls on explosivity in peralkaline magmas (e.g. trachytes and phonolites), we investigated the pre-eruptive magmatic reservoir that fed the ~4 ka Rungwe Pumice (RP) Plinian eruption in the southern Tanzania. Evolved peralkaline magmas (yielding agpaitic index &amp;gt;1) are typically volatile-rich (up to 8 wt % H2O) and exhibit relatively low viscosities compared to their metaluminous counterparts. Despite their rheological properties, which might suggest moderate explosivity, such magmas have produced both highly explosive and effusive eruptions across the East African Rift. To reconstruct the final stages of the RP magmatic plumbing system, we analyzed haüyne-hosted melt inclusions (MIs), revealing the presence of an evolved magma body stored at shallow depths prior to eruption. Water concentrations in MIs, measured via transmitted Fourier-transform infrared spectroscopy, indicate up to ~4.8 wt % H2O and shallow water saturation depths (~3.5 km). Our findings suggest that volatile concentration alone does not fully explain the explosive behaviour; rather, the degree of water undersaturation and conduit dynamics must also be considered as key factors influencing eruption style.

Floor-by-floor survey of installed elements of an elevator shaft using coordinate method and tacheometer is also inhibited by the necessity to determine device installation points for floors of every mounting horizon that leads to additional measurements due to conditions of the completed building framework and presence of a great number of situational disturbances and then it entails significant time expenditure and diminution of accuracy in the obtained results. Technical capabilities of the modern electronic tacheometer substantially simplify an accomplishment of the mission because the device can be applied not only in function of vertical projection but it can be used for preand post-construction survey of the elevator shaft with the help of advanced radiation method. While using the given method the electronic tacheometer equipped with diagonal ocular is installed over a bearing sign in the elevator pit and control points of the elevator shaft are determined with the help of specially developed portable beam deflector in the form of disc with radius r, which is fixed to a handle rod and orientated perpendicularly to a laser beam. An innovation diagram for preand post-construction survey of elevator shaft has been developed while applying this type of deflector. The diagram is characterized by high efficiency due to the fact that one tacheometer installation makes it possible to execute highly accurate, complete plane and high-level surveying of the whole elevator shaft including doorways, door sills and jambs.The paper proposes a new method for pre and post construction survey of the elevator shaft using the electronic tacheometer while applying specially developed beam deflector that ensures a geometric fixing of one or simultaneously two surveying points to spatial coordinate system where the preand post-construction survey is carried out. The method is characterized by high geometric accuracy and technological efficiency.

Bambusuril macrocycles allow qualitative and quantitative sensing of anion mixtures in water using 1H NMR spectroscopy.