Dating of impure carbonates – Utilizing laser ablation MC-ICPMS to reconstruct initial 230Th/232Th ratios

<p><span>Uranium series dating is a valuable and well-established tool for age determination of carbonates in paleoclimatology. However, detrital contamination can alter results. A correctional term is commonly used to account for additional Th introduced into the sample material as detritus. </span><span>This correction requires to make assumptions about the initial </span><sup><span>230</span></sup><span>Th/</span><sup><span>232</span></sup><span>Th ratio of the detrital material, since it is not possible to extract it from an individual measurement. Laser ablation multi collector ICPMS equipped with multiple ion counting detectors offers the possibility to use an isochrone technique to extract the initial </span><sup><span>230</span></sup><span>Th/</span><sup><span>232</span></sup><span>Th value from heterogeneous samples with a high detrital content. This decreases systematic errors and uncertainties introduced by the detrital correction term and therefore improves the possibility of dating impure carbonates.</span></p>

Quantum Optomechanics and Nanomechanics

The Les Houches Summer School 2015 covered the emerging fields of cavity optomechanics and quantum nanomechanics. Optomechanics is flourishing and its concepts and techniques are now applied to a wide range of topics. Modern quantum optomechanics was born in the late 70s in the framework of gravitational wave interferometry, initially focusing on the quantum limits of displacement measurements. Carlton Caves, Vladimir Braginsky, and others realized that the sensitivity of the anticipated large-scale gravitational-wave interferometers (GWI) was fundamentally limited by the quantum fluctuations of the measurement laser beam. After tremendous experimental progress, the sensitivity of the upcoming next generation of GWI will effectively be limited by quantum noise. In this way, quantum-optomechanical effects will directly affect the operation of what is arguably the world’s most impressive precision experiment. However, optomechanics has also gained a life of its own with a focus on the quantum aspects of moving mirrors. Laser light can be used to cool mechanical resonators well below the temperature of their environment. After proof-of-principle demonstrations of this cooling in 2006, a number of systems were used as the field gradually merged with its condensed matter cousin (nanomechanical systems) to try to reach the mechanical quantum ground state, eventually demonstrated in 2010 by pure cryogenic techniques and a year later by a combination of cryogenic and radiation-pressure cooling. The book covers all aspects—historical, theoretical, experimental—of the field, with its applications to quantum measurement, foundations of quantum mechanics and quantum information. Essential reading for any researcher in the field.

USING INNOVATION TECHNOLOGIES TO MEASURE STOREHOUSES OF DRY HYDROSCOPIC MATERIALS WITH DISSIMILAR DENSITY AND HUMIDITY

The article grounds the necessity to develop innovation methods of finding mass of dry raw materials. Today serious problems can be faced in production in case it is needed to find the mass of materials stored in storehouses in bulk. The use of tabular values of material density and humidity can decrease the accuracy of results. Available methods of measuring volume and mass of dry materials, such as visual, theoretical calculation, mine-surveyor measurement, laser 2D-scanning, laser 3D-scanning, radiolocation and acoustic scanning were analyzed. Their advantages and disadvantages were shown. The scientific novelty of the work is connected with innovation, highly accurate, automated method of finding mass of dry hydroscopic materials having different density and humidity, which is based on using the equipment for laser 3D-scanning. The authors propose to measure density and humidity of material at different levels of clamp, which can improve the accuracy of results. The article provides calculations proving the efficiency of the method during stock-taking of material resources at the enterprise. The article pays special attention to problems of stock-taking and registration of shortages in accounting and taxation.

Characterisation of Cellulose Nanofibres Derived from Chemical and Mechanical Treatments

Optimised routes have been established to obtain high aspect ratio cellulose microfibrils derived from plant feedstocks, involving a combination of a chemical and mechanical treatment using a high pressure microfluidizer. By this means, nano-cellulose was produced using different pretreatment protocols. The nanofibres produced were characterised for its particle size distribution measurement (laser diffraction and zeta potential analysis) and fourier transform infrared for its structural analysis. Results obtained and subsequent trends observed in chemical, mechanical and chemo-mechanical treated nanofibres were compared and contrasted. The chemomechanical treatment (TEMPO-oxidation and high pressure microfluidisation) yielded higher aspect ratio nanofibrils than nanofibrils made by solely chemical or mechanical treatment.

An Experimental Analysis of the Structural Response of Flexible Lightweight Hydrofoils in Cavitating Flow

This paper presents an original experimental study concerning the structural response of a flexible lightweight hydrofoil undergoing various flow conditions including partial cavitating flow. It is based on the analysis of the static deformation, the vibrations, the strains, and the stresses of a polyacetal NACA0015 cantilevered hydrofoil in a hydrodynamic tunnel, at Reynolds numbers ranging from 3 × 105 to 6 × 105. A specific distance measurement laser device was developed to measure the static deformation of the hydrofoil. The vibration response was measured by means of two laser vibrometers in order to identify the structural modal response. The strains and stresses were obtained from integrated strain gauges embedded in the foil close to the root section. A high-speed camera was used in order to analyze unsteady features of the cavitating flow. This paper presents the experimental setup and several results in both noncavitating and cavitating flow that should be very useful for numerical developments of fluid structure interaction (FSI) in heavy fluid. Several observations are reported in the paper showing the strong coupling between the fluid and the structure. Particularly, a frequency lock-in of the cavity frequency to the first bending mode is clearly observed for a narrow band of cavitation numbers.

Further Developments in Strip Thickness Measurement Laser-Based Strip Thickness Measurement

VTLG is a new type of laser-based strip thickness gauges for cold rolling mills and offersthe solution for strip thickness measurement that the industry has long been searching for:Irrespective of the alloy, contact-free, highly precise and reliable. This article describes thedevelopments which had to be done so that now with the VTLG a solution is possible that has notbeen possible to date.