scholarly journals Determination of the variable density of the rod from natural frequencies of longitudinal vibrations

2021 ◽  
Vol 2099 (1) ◽  
pp. 012049
Author(s):  
I M Utyashev

Abstract Rods of various configurations are elements of many structures and machines. Therefore, the acoustic and vibration diagnostics of such parts has been widely developed. The paper considers the problem of determining the variable density of the rod from the natural frequencies of longitudinal vibrations. It is assumed that the density changes along the axis and is described by a polynomial function. This approach allows one to determine the law of density variation from a finite set of eigenvalues. The results of the study can find applications for finding hidden defects in steel and composite rods, which arise during the production process or due to corrosion.

2019 ◽  
Vol 13 (2) ◽  
pp. 187-202
Author(s):  
Hamid Pongoliu
Keyword(s):  
The Will ◽  

Gorontalo has a customary principle derived from sharia law, and the sharia law is sourced from the Qur'an, hadith, ijmak and qiyas (adati-hula'a to syara'a, syara'a hula'a to Kitabi), which should reflect the existence of the implementation of the distribution of inheritance in Islam in the Gorontalo community. This customary principle can be a source of law if it is a rational act, not immorality, done always repeatedly, does not bring harm and does not conflict with the law of sharak. But in reality there is the implementation of inheritance that violates Islamic law, namely the distribution by way of deliberation, the determination of the amount of heirs equally, the delay in the distribution of inheritance, wills with houses given to girls, wills not to distribute inheritance, distribution of assets it depends on the will of the heir and the delay in the distribution of inheritance on the grounds that one of the parents is still alive. The distribution by deliberation and determination of the amount of the portion for each heir are equally acceptable as long as they follow the guidelines of the Compilation of Islamic Law article 183 and the concept of takharruj which was previously preceded by the Shari'a division. After the heirs know the size of the portion, then they may agree to share it in their own way or leave the inheritance according to Shari'a and agree to give to each other with other heirs.


2017 ◽  
Vol 30 (1) ◽  
pp. 273-289
Author(s):  
Anmari Meerkotter

The Constitutional Court (CC) judgment of Lee v Minister of Correction Services 2013 2SA 144 (CC) is a recent contribution to transformative constitutional jurisprudence in the field of the law of delict. This matter turned on the issue of factual causation in the context of wrongful and negligent systemic omissions by the state. In this case note, I explore the law relating to this element of delictual liability with specific regard to the traditional test for factual causation – the conditio sine qua non (‘but-for’) test. In particular, I note the problems occasioned by formalistic adherence to this test in the context of systemic state omissions as evidenced by the SCA judgment in the same matter. I also consider the manner in which English courts have addressed this problem. Thereafter, I analyse the CC’s broader approach to the determination of factual causation as one based on common sense and justice. I argue that this approach endorses a break from a formalistic application of the test and constitutes a step towards an approach which resonates with the foundational constitutional values of freedom, dignity and equality. Furthermore, it presents an appropriate solution to the problems associated with factual causation where systemic omissions are concerned. I then consider the transformative impact of the Lee judgment. In particular, I argue that the broader enquiry favoured by the CC facilitates the realisation of constitutionally guaranteed state accountability, and amounts to an extension of the existing norm of accountability jurisprudence. Hence, I contend that the judgment presents a further effort by the Constitutional Court to effect wholesale the constitutionalisation of the law of delict, as well as a vindicatory tool to be used by litigants who have been adversely affected by systemic state omissions.


2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.


2019 ◽  
Vol 14 (2) ◽  
pp. 138-141
Author(s):  
I.M. Utyashev

Variable cross-section rods are used in many parts and mechanisms. For example, conical rods are widely used in percussion mechanisms. The strength of such parts directly depends on the natural frequencies of longitudinal vibrations. The paper presents a method that allows numerically finding the natural frequencies of longitudinal vibrations of an elastic rod with a variable cross section. This method is based on representing the cross-sectional area as an exponential function of a polynomial of degree n. Based on this idea, it was possible to formulate the Sturm-Liouville problem with boundary conditions of the third kind. The linearly independent functions of the general solution have the form of a power series in the variables x and λ, as a result of which the order of the characteristic equation depends on the choice of the number of terms in the series. The presented approach differs from the works of other authors both in the formulation and in the solution method. In the work, a rod with a rigidly fixed left end is considered, fixing on the right end can be either free, or elastic or rigid. The first three natural frequencies for various cross-sectional profiles are given. From the analysis of the numerical results it follows that in a rigidly fixed rod with thinning in the middle part, the first natural frequency is noticeably higher than that of a conical rod. It is shown that with an increase in the rigidity of fixation at the right end, the natural frequencies increase for all cross section profiles. The results of the study can be used to solve inverse problems of restoring the cross-sectional profile from a finite set of natural frequencies.


Author(s):  
Kubo Mačák

This chapter analyses the practical application of the law of belligerent occupation in internationalized armed conflicts in its temporal, geographical, and personal dimensions. Firstly, from a temporal perspective, the law is shown to apply once one of the conflict parties consolidates its control over the enemy territory and substitutes its own authority for that of the displaced enemy. Secondly, the chapter assesses the geographical scope of the applicable law and draws specific guidelines for the determination of the territory subject to the law of occupation in various types of internationalized armed conflicts. Thirdly, the chapter endorses the allegiance-based approach to the designation of protected persons under the law of occupation and applies it to the reality of internationalized armed conflict. Overall, the chapter presents a workable toolkit for the application of the law of occupation to internationalized armed conflicts.


2020 ◽  
pp. 1-28
Author(s):  
Jakub Mácha

Abstract Understanding Hegel's account of particularity has proven to be anything but straightforward. Two main accounts of particularity have been advanced: the particular as an example or instance and the particular as a subjective perspective on a universal concept. The problem with these accounts is that they reduce particularity either to singularity or to universality. As Derrida's analyses make apparent, the ‘structure of exemplarity’ in Hegel is quite intricate. Hegel uses ‘example’ in three senses: it means (1) ‘instance’, ‘illustration’, or (2) ‘model’, ‘exemplary individual’, ‘paradigm’, or (3) a by-play (a meaning derived from Hegel's neologism beiherspielen, in which Beispiel is understood quasi-etymologically as a ‘by-play’ of accidental moments). A Beispiel in the first sense can be replaced by another instance in a free play (by-play). This play of accidental moments, however, is not entirely free; it generates a series (of replacements) that ultimately leads to an example in the second sense, to an exemplary individual. I argue that particularity can be taken as exemplarity of this kind, oscillating between a singular example and a universal paradigm. Within this by-play, the universal concept, its law, is supposed to be mediated and determined. However, out of the differences between the examples the by-play induces another law, the law of non-mediation, which may, in Derrida's view, actually negate the dialectical movement towards universality. I argue, utilizing Malabou's concept of plasticity, that this disruption may be recovered. This implies that each individual example within a series is a particular determination of the universal. Hence, we can take literally Hegel's claim that the movement of the concept is play.


2018 ◽  
Vol 41 (2) ◽  
Author(s):  
Stephanie Jowett ◽  
Belinda Carpenter ◽  
Gordon Tait

This article examines the role of coroners in making legal determinations of suicide in Australia. Research indicates that the requirement to make findings of intent and capacity in unexpected, violent deaths can be difficult for coroners and recent government inquiries have suggested that the law contributes to the problem. A review of laws and commentary that guide coroners in Australian states and territories reveals not only that coroners are the only persons tasked with making routine legal determinations of suicide, but that such legal guidance lacks clarity. This article concludes that law reform would aid coroners by clarifying definitional issues, removing inconsistency between state jurisdictions and increasing the transparency of case law. Along with requirements for a determination of intent, which is a practical matter previously raised by the Victorian Coronial Council, such changes would go some way to ensuring that Australian suicide statistics are more reliably created.


Author(s):  
Mahesh M. Bhat ◽  
V. Ramamurti ◽  
C. Sujatha

Abstract Steam turbine blade is a very complex structure. It has geometric complexities like variation of twist, taper, width and thickness along its length. Most of the time these variations are not uniform. Apart from these geometric complexities, the blades are coupled by means of lacing wire, lacing rod or shroud. Blades are attached to a flexible disc which contributes to the dynamic behavior of the blade. Root fixity also plays an important role in this behavior. There is a considerable variation in the frequencies of blades of newly assembled turbine and frequencies after some hours of running. Again because of manufacturing tolerances there can be some variation in the blade to blade frequencies. Determination of natural frequencies of the blade is therefore a very critical job. Problems associated with typical industrial turbine bladed discs of a 235 MW steam turbine are highlighted in this paper.


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