A method for determining the elastic modulus of polymeric materials from deformation diagrams of thin-walled circular cylindrical shells in compression and tension in the region of geometrical ...nonlinearity has been elaborated. A numerical solution is found by the finite-element method (ANSYS.) The existence of a unified deformation diagram in generalized coordinates is established, from which the elastic modulus is determined. To validate the method, the eigenfrequencies of cylindrical specimens were found experimentally. The results obtained are compared with FEM calculations.
Two optimization problems are formulated to improve the effectiveness and productivity of pultrusion processes, to preserve the quality of pultruded profiles, and to take into account the ambient ...industrial shop temperature and requirements of process technologists. To solve these problems, an optimization methodology using designed computer experiments and the response surface technique was developed. The effects of room temperature and curing allowed behind the die exit on the energy consumption and pull speed were investigated. A more accurate and realistic process optimization was achieved by the temperature control strategy with heater switch-on and -off operations. This indirect optimization methodology allowed us to develop interactive technological maps on the basis of an accessible-to-all Excel code for technologists working in industrial shops. As an example, demonstrating the effectiveness of the methodology developed and utilization of the interactive technological map, the optimization of a real pultrusion process, producing two rod profiles with ears simultaneously, is carried out.
Low-temperature antihydrogen atoms are an effective tool to probe the validity of the fundamental laws of Physics, for example the Weak Equivalence Principle (WEP) for antimatter, and -generally ...speaking- it is obvious that colder atoms will increase the level of precision.
After the first production of cold antihydrogen in 2002 1, experimental efforts have substantially progressed, with really competitive results already reached by adapting to cold antiatoms some well-known techniques pre- viously developed for ordinary atoms. Unfortunately, the number of antihydrogen atoms that can be produced in dedicated experiments is many orders of magnitude smaller than of hydrogen atoms, so the development of novel techniques to enhance the production of antihydrogen with well defined (and possibly controlled) conditions is essential to improve the sensitivity.
We present here some experimental results achieved by the AEgIS Collaboration, based at the CERN AD (Antiproton Decelerator) on the production of antihydrogen in a pulsed mode where the production time of 90% of atoms is known with an uncertainty of ~ 250 ns 2. The pulsed antihydrogen source is generated by the charge-exchange reaction between Rydberg positronium (
Ps*
) and an antiproton (
p¯
):
p¯
+
P
s
*
→
H¯
* +
e
−
, where
Ps*
is produced via the implantation of a pulsed positron beam into a mesoporous silica target, and excited by two consecutive laser pulses, and antiprotons are trapped, cooled and manipulated in Penning-Malmberg traps. The pulsed production (which is a major milestone for AEgIS) makes it possible to select the antihydrogen axial temperature and opens the door for the tuning of the antihydrogen Rydberg states, their de-excitation by pulsed lasers and the manipulation through electric field gradients.
In this paper, we present the results achieved by AEgIS in 2018, just before the Long Shutdown 2 (LS2), as well as some of the ongoing improvements to the system, aimed at exploiting the lower energy antiproton beam from ELENA 3.
The paper is concerned with the findings of a study into institutional issues, i.e. legislative acts and organisational structure related to real property formation in Latvia. It examines various ...terms and concepts accordingly to the topic and their usage. The problem domains serve as background for estimation and modelling of different binding processes like land privatisation, real property transactions or real property formation. Both existing legislation that regulates and organisational structure that administrates the real property formation process are far and wide reflected and analysed by this contribution. In consequence of the analysis of Latvia's situation, the problem domain of real property formation that can be used for deeper exploration and modelling real property formation process and closely related others is offered. Finally, significance of the institutional arrangements is substantiated.
Economic profitability of milk production in sheds with a small numbers of cows Priekulis, J.(Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Engineering. Inst. of Agricultural Machinery)E-mail:jurisp@cs.llu.lv; Latvietis, J.(Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture. Dept. of Animal Science)E-mail:egleg@cs.llu.lv; Auzins, V.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:valdisauzins@hotmail.com
2004
Publication
At present in Latvia 77.6% of cows are housed in small sheds where size of the herd does not exceed 19 cows. Wish such number of animals it is not useful to apply up-dated machinery and technology ...and therefore much manual is used. The aim of our research was to state the economic profitability of production of milk in small sheds in the present economic situation in Latvia as well as after integration in the European Union (EU). The results of the research show that production of milk can be profitable at any size of the herd. But it is not efficient to use wage labour force, especially after the introduction of the EU cost levels. In the present economic situation in Latvia the use of wage labour force increases the production cost of milk by 1.3-1.7 times, but with the EU cost level - 2.0-4.5 times.
Role of macrophages in the immune response Askonas, B A; Auzins, I; Unanue, E R
Bulletin de la Societe de chimie biologique,
1968-Sep-28, Volume:
50, Issue:
5
Journal Article
PDF
