Single-magnet rotary flowmeter for liquid metals

We present a theory of single-magnet flowmeter for liquid metals and compare it with experimental results. The flowmeter consists of a freely rotating permanent magnet, which is magnetized perpendicularly to the axle it is mounted on. When such a magnet is placed close to a tube carrying liquid metal flow, it rotates so that the driving torque due to the eddy currents induced by the flow is balanced by the braking torque induced by the rotation itself. The equilibrium rotation rate, which varies directly with the flow velocity and inversely with the distance between the magnet and the layer, is affected neither by the electrical conductivity of the metal nor by the magnet strength. We obtain simple analytical solutions for the force and torque on slowly moving and rotating magnets due to eddy currents in a layer of infinite horizontal extent. The predicted equilibrium rotation rates qualitatively agree with the magnet rotation rate measured on a liquid sodium flow in stainless steel duct.Comment: 15 pages, 6 figures, revised version, to appear in J. Appl. Phy

A comparison between the chemical behaviour of lead-gold and lead-bismuth eutectics towards 316L stainless steel

Lead-gold eutectic (LGE) has been recently proposed as an alternative target material for high power spallation sources. In order to compare the corrosive properties of LGE to the better-studied eutectic of lead-bismuth (LBE), an isothermal twin-loop made of SS 316L was built and operated at the Institute of Physics of the University of Latvia. We have measured the concentration of steel alloying elements dissolved in both alloys at the end of two test campaigns via ICP-OES. In case of LGE, a pronounced concentration increase of Fe, Ni, Mn and Cr is found in the liquid metal, which is significantly higher compared to LBE. Similar results were obtained during complementary investigations on material samples exposed to both alloys in this twin-loop at 400 ◦C and 450 ◦C. These findings indicate that in contact with LGE, SS 316L steel suffers from substantial chemical attack. Detailed investigations using structure materials other than SS 316L have to be undertaken before qualifying LGE as a serious alternative to LB

Theory of the Lorentz force flowmeter

A Lorentz force flowmeter is a device for the contactless measurement of flow rates in electrically conducting fluids. It is based on the measurement of a force on a magnet system that acts upon the flow. We formulate the theory of the Lorentz force flowmeter which connects the measured force to the unknown flow rate. We first apply the theory to three specific cases, namely (i) pipe flow exposed to a longitudinal magnetic field, (ii) pipe flow under the influence of a transverse magnetic field and (iii) interaction of a localized distribution of magnetic material with a uniformly moving sheet of metal. These examples provide the key scaling laws of the method and illustrate how the force depends on the shape of the velocity profile and the presence of turbulent fluctuations in the flow. Moreover, we formulate the general kinematic theory which holds for arbitrary distributions of magnetic material or electric currents and for any velocity distribution and which provides a rational framework for the prediction of the sensitivity of Lorentz force flowmeters in laboratory experiments and in industrial practice.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58171/2/njp7_8_299.pd

Application of compulsory measures of a correctional nature to minors for committing criminal offences

Tiesību zinātneTiesību zinātneLaw ScienceLaw ScienceBakalaura darba mērķis ir noskaidrot būtiskākās problēmas attiecībā uz audzinoša rakstura piespiedu līdzekļu piemērošanu nepilngadīgajiem par noziedzīga nodarījuma izdarīšanu. Audzinoša rakstura piespiedu līdzekļus tiesā piemēro arvien retāk, lai gan statistikas dati parādā, ka nepilngadīgiem ir nosliece uz jaunu, atkārtotu noziedzīgu nodarījumu izdarīšanu, kā arī tiesu prakse parāda, ka audzinoša rakstura piespiedu līdzekļu mērķis netiek lietderīgi un efektīvi izmantots, gala rezultātā nesasniedzot tam paredzēto mērķi. Pētījuma mērķis ir izzinot audzinoša rakstura piespiedu līdzekļu tiesiskā regulējuma piemērošanu nepilngadīgajiem par noziedzīga nodarījuma izdarīšanu, un analizējot nacionālo un starptautisko tiesisko regulējumu šajā jomā, identificēt problēmas un piedāvāt tiesiskā regulējuma pilnveidi. Rakstot bakalaura darbu autors identificēja virkni problēmu, kas saistītas ar audzinoša rakstura piespiedu līdzekļu piemērošanu, kā viena no galvenajām problēmām, kas paver aiz sevis vēl virkni neatrisinātu problēmu- ir tā- ka audzinoša rakstura piespiedu līdzekļi kā kriminālsoda alternatīva nepilngadīgajiem, kuri izdarījuši noziedzīgu nodarījumu, bieži nesasniedz savu mērķi. Bakalaura darbs sastāv no 58 lapaspusēm; bakalaura darba izstrādei tika izmantoti 72 literatūras avoti.The aim of bachelor's work is to clarify the main problems regarding the application of coercive measures of a correctional nature to minors for committing a criminal offence. Coercive measures of a correctional nature are being applied less and less in court, although statistical data show that minors are inclined to commit new, repeated criminal offences, as well as case-law shows that the purpose of coercive measures of a correctional nature is not effectively and efficiently used without ultimately achieving its intended purpose. The study aims at identifying problems and proposing improvements to the legal framework of coercive measures of an educational nature for juveniles for committing a criminal offence and analyzing the national and international legal framework in this field. In writing a Bachelor's thesis, the author identified a number of problems related to the application of coercive measures of a correctional nature as one of the main problems that open up a number of unresolved problems - is that coercive measures of a correctional nature as an alternative to criminal punishment for juveniles who have committed a criminal offence often fail to achieve their purpose. The Bachelor's thesis consists of 58 pages; 72 literature sources were used to develop the Bachelor's thesis

Universal Jurisdiction as a Customary International Law Norm

Bakalaura darba „Universālā jurisdikcija kā starptautisko paražu tiesību norma” mērķis ir izpētīt universālo jurisdikciju no starptautisko paražu tiesību viedokļa, respektīvi, vai universālās jurisdikcijas princips ir izveidojies par paražu tiesību normu un attiecībā uz kādiem noziegumiem. Bakalaura darbs sastāv no trijām nodaļām. Pirmā nodaļa sniedz ieskatu teorijā par universālo jurisdikciju, otrā nodaļa koncentrējas uz starptautiskajām paražu tiesībām un nosaka, kādiem kritērijiem ir jāpiepildās, lai kādu praksi varētu atzīt par izveidojušos paražu tiesību. Trešajā nodaļā tiek pētīts, vai universālā jurisdikcija atbilst šiem kritērijiem. Bakalaura darbā tiek izmantoti gan vietējo, gan ārzemju autoru darbi, kā arī dažādas starptautiskas konvencijas un tiesu nolēmumi.The bachelor work „Universal Jurisdiction as a Customary International Law Norm” focuses on analyzing weather universal jurisdiction is subject to international customary law and which crimes can be associated with universal jurisdiction. The bachelor work consists of the preface, three chapters and the conclusion. The first chapter gives and introduction to universal jurisdiction, the second one focuses on defining international customary law and the criteria that must be met so that certain praxis can be subject to international customary law and the third chapter is devoted to analyzing weather universal jurisdiction meets those criteria of international customary law. Both local and foreign author works have been used, mostly foreign as well as different international conventions and judgments

The Preamble as a Component of Constitutions

Maģistra darba tēmas „Preambula kā konstitūciju sastāvdaļa” mērķis ir izpētīt Satversmes preambulas grozījumu kārtību un nozīmīgumu. Lai mērķi īstenotu, nepieciešams salīdzināt dažādu valstu konstitūcijas, kuras satur preambulu, lai konstatētu preambulu mērķi un nozīmi konstitūcijās. Maģistra darba mērķis ir kritiski izvērtēt Satversmes preambulas grozījumu pieņemšanu, ņemot vērā citu valstu praksi attiecībā uz konstitūcijas ievadu. Pētījuma rezultātā tiks gūts priekšstats par preambulu lomu, nozīmi un piemērošanas īpatnībām. Iegūtie rezultāti ļaus izvērtēt grozīto Latvijas Republikas Satversmes preambulu, salīdzināt ar citu valstu konstitūciju preambulām un sniegt viedokli par Satversmes preambulas iespējamo lomu nākotnē. Atslēgvārdi: konstitūcija, preambula, Satversme, salīdzinošās konstitucionālās tiesības.The purpose of the master’s thesis „Preamble as a Component of Constitutions” is to explore the order and importance of the amendments which have been made to the preamble of the constitution of Latvia – “Satversme”. To achieve this goal it is necessary to compare the constitutions of different countries, which contain a preamble. The purpose of the master’s thesis is to make a critical assessment of the made amendments to the preamble based on the practice of other countries concerning the preamble of the constitution. The results of the research will give a view on the role, importance and application specifics of preambles. The obtained results will help in assessing the amended preamble of “Satversme”, the constitution of Latvia, compare it with the preambles of other states and offer an opinion on the possible role of the preamble in the future. Keywords: constitution, preamble, Satversme, comparative constitutional law

Efficiency of EM Induction Permanent Magnets Pumps

The efficiency of EM induction pumps on permanent magnets are defined by their main constructive parameters the optimal values of which, in its turn, are depending on specified nominal productivity of pump (developed pressure head and provided flow rate) and its operating conditions, mainly temperature of liquid metal being pumped. The influence on the efficiency of pumps of such main parameters as magnetic field strength, geometry of magnetic active system and channel of pump are considered