Ramsey's Method of Separated Oscillating Fields and its Application to Gravitationally Induced Quantum Phaseshifts

We propose to apply Ramsey's method of separated oscillating fields to the spectroscopy of the quantum states in the gravity potential above a vertical mirror. This method allows a precise measurement of quantum mechanical phaseshifts of a Schr\"odinger wave packet bouncing off a hard surface in the gravitational field of the earth. Measurements with ultra-cold neutrons will offer a sensitivity to Newton's law or hypothetical short-ranged interactions, which is about 21 orders of magnitude below the energy scale of electromagnetism.Comment: 7 pages, 6 figure

A solenoidal electron spectrometer for a precision measurement of the neutron β\beta-asymmetry with ultracold neutrons

We describe an electron spectrometer designed for a precision measurement of the neutron $\beta$-asymmetry with spin-polarized ultracold neutrons. The spectrometer consists of a 1.0-Tesla solenoidal field with two identical multiwire proportional chamber and plastic scintillator electron detector packages situated within 0.6-Tesla field-expansion regions. Select results from performance studies of the spectrometer with calibration sources are reported.Comment: 30 pages, 19 figures, 1 table, submitted to NIM

Information exchange and future plans of Slovenian cattle farmers under EU policies

After accession to EU, farmers in the new-member states have to adjust to the EU agricultural policies and market. In Slovenia an analysis is made of the farm development plans and information exchange under quota and CAP. Three research questions were addressed: what information is received and how; how does the farmer prefer to receive information and what kind; how to make decisions to react to the new EU policies concerning farm management and future plans. These questions were linked to the base variables, being the farm and farmers’ characteristics. As tool a questionnaire was distributed to dairy farmers. 1114 questionnaires, 22% of the distributed ones have been returned anonymously, implying that 11% of the dairy farmers’ population is part of the analysis. It appeared that the research sample of farmers used represents the more future oriented farmers. As main factors describing the farm and farmers’ characteristics were found farm size, age and number of other activities than dairy. Results show that nearly all farmers did receive information about some specific aspects of the quota system. Communication channels dealing with this administrative info and also with farm management advice are divers, but frequency of direct contact with advisors may be less than predicted. Results also indicate a very significant demand for info about strategic planning, farm management aspects and EU premium programs, especially about CAP general policies and milk premiums, and a considerable activity in farm planning. About 40% of farmers choose for keeping the farm business the same and 50% intend to develop the farm further.CAP, Slovenian cattle farmers, information, decisions, future plans, Community/Rural/Urban Development, Q18,

Micro Laser Melting: Analyses of Current Potentials and Restrictions for the Additive Manufacturing of Micro Structures

Although there is a significant requirement for complex micro parts, current metal processing additive manufacturing techniques are limited in achievable part accuracy and geometric resolution. Due to the recently developed process of Micro Laser Melting (MLM) new potentials in micro manufacturing are realizable. This paper gives an overview of the present potentials of MLM using 316L steel powder. While using powder material with a grain size of ≤ 5 µm this technique enables layer thicknesses from 5 to 7 µm. Due to the use of different exposure strategies and laser modes (pulsed and continuous radiation) high aspect ratios up to 260 could be realized with thin wall structures. Furthermore, the influence of laser mode and exposure sequence on the part density, surface quality and accuracy of lattice structures with a minimum wall thickness lower than 40 µm is analyzed.Mechanical Engineerin

A SiGe HEMT Mixer IC with Low Conversion Loss

The authors present the first SiGe HEMT mixer integrated circuit. The active mixer stage, operating up to 10GHz RF, has been designed and realized using a 0.1µ µµ µm gate length transistor technology. The design is based on a new large-signal simulation model developed for the SiGe HEMT. Good agreement between simulation and measurement is reached. The mixer exhibits 4.0dB and 4.7dB conversion loss when down-converting 3.0GHz and 6.0GHz signals, respectively, to an intermediate frequency of 500MHz using high-side injection of 5dBm local oscillator power. Conversion loss is less than 8dB for RF frequencies up to 10GHz with a mixer linearity of –8.8dBm input related 1dB compression point

Measurement of the neutron lifetime using a gravitational trap and a low-temperature Fomblin coating

We present a new value for the neutron lifetime of 878.5 +- 0.7 stat. +- 0.3 syst. This result differs from the world average value (885.7 +- 0.8 s) by 6.5 standard deviations and by 5.6 standard deviations from the previous most precise result. However, this new value for the neutron lifetime together with a beta-asymmetry in neutron decay, Ao, of -0.1189(7) is in a good agreement with the Standard Model.Comment: 11 pages, 9 figures; extended content with some correction

Selective Laser Melting of Porous Structures

Within the Center of Smart Interfaces “Understanding and Designing Fluid Boundaries”, a German Excellence Initiative, the Institute of Production Management, Technology and Machine Tools examines the manufacturing of porous structures by using selective laser melting (SLM). In this paper two different strategies are presented in order to obtain porosity: One strategy is to manufacture geometrically defined lattice structures. SLM allows here complex geometries that cannot be manufactured by conventional technologies to be built. The second approach is to manufacture geometrically undefined porosity by a specific modification of exposure parameters. The SLM generated porous structures are investigated with respect to the heat and mass transfer. The research focus is to increase the efficiency of spraycooling effects and the manipulation of the Leidenfrost point.Mechanical Engineerin