Scintillation detector for carbon-14

Detector consists of plastic, cylindrical double-wall scintillation cell, which is filled with gas to be analyzed. Thin, inner cell wall is isolated optically from outer (guard) scintillator wall by evaporated-aluminum coating. Bonding technique provides mechanical support to cell wall when device is exposed to high temperatures

Vehicle infrastructure cooperative localization using Factor Graphs

Highly assisted and Autonomous Driving is dependent on the accurate localization of both the vehicle and other targets within the environment. With increasing traffic on roads and wider proliferation of low cost sensors, a vehicle-infrastructure cooperative localization scenario can provide improved performance over traditional mono-platform localization. The paper highlights the various challenges in the process and proposes a solution based on Factor Graphs which utilizes the concept of topology of vehicles. A Factor Graph represents probabilistic graphical model as a bipartite graph. It is used to add the inter-vehicle distance as constraints while localizing the vehicle. The proposed solution is easily scalable for many vehicles without increasing the execution complexity. Finally simulation indicates that incorporating the topology information as a state estimate can improve performance over the traditional Kalman Filter approac

Renormalization of a gapless Hartree-Fock approximation to a theory with spontaneously broken O(N)-symmetry

The renormalization of a gapless Phi-derivable Hartree--Fock approximation to the O(N)-symmetric lambda*phi^4 theory is considered in the spontaneously broken phase. This kind of approach was proposed by three of us in a previous paper in order to preserve all the desirable features of Phi-derivable Dyson-Schwinger resummation schemes (i.e., validity of conservation laws and thermodynamic consistency) while simultaneously restoring the Nambu--Goldstone theorem in the broken phase. It is shown that unlike for the conventional Hartree--Fock approximation this approach allows for a scale-independent renormalization in the vacuum. However, the scale dependence still persists at finite temperatures. Various branches of the solution are studied. The occurrence of a limiting temperature inherent in the renormalized Hartree--Fock approximation at fixed renormalization scale mu is discussed.Comment: 11 pages, 14 figures / Version accepted by Phys. Rev. D: title and one reference change

Optimal operating conditions and characteristics of acetone/CaF_2 detector for inverse photoemission spectroscopy

Performance and characteristics of a band-pass photon detector using acetone gas and CaF_2 window (acetone/CaF_2) have been studied and compared with an ethanol/MgF_2 detector. The optimal operating conditions are found to be 4 mbar acetone pressure and 745+/-20 V anode voltage. The count rate obtained by us is about a factor of 3 higher than what has been reported earlier for the acetone detector. Unlike other gas filled detectors, this detector works in the proportional region with very small dead time (4 micro sec). A detector band-pass of 0.48+/-0.01 eV FWHM is obtained.Comment: Review of Scientific Instruments 76, 066102 (2005

Submicrometric Films of Surface-Attached Polymer Network with Temperature-Responsive Properties

Temperature-responsive properties of surface-attached poly(N-isopropylacrylamide) (PNIPAM) network films with well-controlled chemistry are investigated. The synthesis consists of cross-linking and grafting preformed ene-reactive polymer chains through thiol--ene click chemistry. The formation of surface-attached and cross-linked polymer films has the advantage of being wellcontrolled without any caution of no-oxygen atmosphere or addition of initiators. PNIPAM hydrogel films with same cross-link density are synthesized on a wide range of thickness, from nanometers to micrometers. The swelling-collapse transition with temperature is studied by using ellipsometry, neutron reflectivity, and atomic force microscopy as complementary surface-probing techniques. Sharp and high amplitude temperature-induced phase transition is observed for all submicrometric PNIPAM hydrogel films. For temperature above LCST, surface-attached PNIPAM hydrogels collapse similarly but without complete expulsion of water. For temperature below LCST, the swelling of PNIPAM hydrogels depends on the film thickness. It is shown that the swelling is strongly affected by the surface attachment for ultrathin films below $\sim$150 nm. For thicker films above 150 nm (to micrometers), surface-attached polymer networks with the same cross-link density swell equally. The density profile of the hydrogel films in the direction normal to the substrate is confronted with in-plane topography of the free surface. It results that the free interface width is much larger than the roughness of the hydrogel film, suggesting pendant chains at the free surface.Comment: in Langmuir, American Chemical Society, 2015, LANGMUIR, 31 (42), pp.11516-1152

ANGULAR MOMENTUM IN JUMPS WITH ROTATIONS ON THE LONGITUDINAL AXIS IN FIGURE SKATING -3D-ANALYSES AND COMPUTER SIMULATION

INTRODUCTION -In analyses of athletic technique in figure skating primarily jumps with tripie or four-time rotations on the longitudinal axis are considered The quality of these jumps is essentially influenced by vertical momentum and angular momentum. While vertical momentum can be obtained without problems from flight parameters the calculation of angular momentum does represent a much more complicated problem. The task is to optimise vertical and angular momentum and to answer the question for reasons causing that the longitudinal axis is tilted during flight. This is important since a slightly tilled position of this axis can cause a fall in figure skating. Analyses of errors therefore mostly concentrate on the identification of reasons for this tilted position during flight already in the take-off. Therefore 3D monitoring only is insufficient for recommendations on sports techniques but additional 3D calculations (e.g. calculation and three-dimensional presentation of angular momentum) have to be performed. METHODS -A procedure for a threedimensional presentation of angular momentum as vector is presented. Using this procedure reasons for errors can be determined and general orientations for sport technical models can be characterised. Another procedure offers the opportunity to quantify the partial contribution of individual parts of the body in producing angular momentum. To determine the efficient use of the produced angular momentum 3D computer simulation is applied RESULTS 1. The influence of the angle between longitudinal axis and direction of angular momentum on the efficient use of the produced angular momentum is determined as a result of computer simulation 2 The influence of movements of individual parts of the body on the production of the total angular momentum as a reason for tilting the longitudinal axis during flight is studied. 3. We study practical applications in sports practice to present conclusions for the training of sports technique We give recommendations for individual solutions concerning sports technique res. general models to optimise sports technique of the most complicated technical elements. Using the example of the triple Axel, the most complicated triple jump in figure skating, we present opportunities for an interpretation of our results in sports practice

The German Vision of Industry 4.0 Applied in Organic Farming

The first industrial revolution was the invention of the steam engine. With the advent of conveyor belts and electricity, the second industrial revolution arose. After the third revolution, the automation, the fourth industrial revolution takes place with the complete networking of all machines, workers, consumers, and products. In Germany, this is called Industry 4.0. Increasing digitization makes it possible to collect, store, analyze, and communicate large amounts of data. By digitizing farms, a network of different sensors can analyze the nutrient content and the soil texture in real time. This information can be evaluated and the plant distribution can be managed across all networked farms. This leads to the right field being used for the right plant at the right time. Real-time data processing makes it possible to monitor and control the nutrient intake over the entire growth period. This allows the field to specifically ask for water or the right fertilizer for its plants. This saves resources and protects the environment. All the prepared information can give the farmer an exact status about his products and fields via an interface. This horizontal networking within the farm and the vertical networking across different farms can lead to increased efficiency and cheaper products. The use of robots can create a fully automatic farm. For this undertaking, it is necessary to process the complex information of a farm with a self-learning system. At the Westcoast University of Applied Science, for example, a robot is being researched to automatically remove the weeds. The prototype of the robot that moves fully autonomously across the field classifies the plants and destroys the weeds

S Corp ESOP Legislation Benefits and Costs: Public Policy and Tax Analysis

Samuel Zell’s acquisition of the Tribune Company in December 2007 using an S corporation employee stock ownership plan (S ESOP) brought S ESOPs to national attention. An S ESOP is a trust that holds shares of an S corporation (a closely held corporation whose shareholders are taxed on a pass-through basis similarly to partners in a partnership) for the benefit of the corporation’s employees. S ESOPs, which have only existed since 1998 are not as well known as C ESOPs, an ESOP that holds shares of a C corporation (a separately taxed corporation). Enron, Polaroid and United Airlines, all of which had ESOPs when they went bankrupt, were C corporations. Perhaps because they have only existed for ten years, little academic attention has focused on S ESOPs. In this paper we draw on the extensive existing employee ownership literature to describe the benefits and costs to employees, to firms and to society at large from the legislation that authorizes S ESOPs, and, where possible, we quantify these costs and benefits. We estimate that annual contributions to S ESOPs on behalf of employees total $14 billion, which represent additional compensation that would not have been paid without an ESOP. Annual gains attributable to increased job stability also save employees approximately$3 billion annually. Accumulated stakes, which are essentially forced savings and usually do not displace other savings, lead to additional annual accruals of $34 billion. Employers pay for ESOP contributions out of firm-level productivity and sales gains of$33 billion annually attributable to employee ownership. We estimate that one quarter of the annual gain, $8 billion ultimately goes to the federal treasury, which thereby also benefits from the adoption of S ESOPs

Origin of resolution enhancement by co-doping of scintillators: Insight from electronic structure calculations

It was recently shown that the energy resolution of Ce-doped LaBr$_3$ scintillator radiation detectors can be crucially improved by co-doping with Sr, Ca, or Ba. Here we outline a mechanism for this enhancement on the basis of electronic structure calculations. We show that (i) Br vacancies are the primary electron traps during the initial stage of thermalization of hot carriers, prior to hole capture by Ce dopants; (ii) isolated Br vacancies are associated with deep levels; (iii) Sr doping increases the Br vacancy concentration by several orders of magnitude; (iv) $\text{Sr}_\text{La}$ binds to $V_\text{Br}$ resulting in a stable neutral complex; and (v) association with Sr causes the deep vacancy level to move toward the conduction band edge. The latter is essential for reducing the effective carrier density available for Auger quenching during thermalization of hot carriers. Subsequent de-trapping of electrons from $\text{Sr}_\text{La}-V_\text{La}$ complexes then can activate Ce dopants that have previously captured a hole leading to luminescence. This mechanism implies an overall reduction of Auger quenching of free carriers, which is expected to improve the linearity of the photon light yield with respect to the energy of incident electron or photon