SOME ASPECTS OF PRACTICAL BALANCING RIGID ROTORS IN OWN SUPPORTS

2021 ◽  
pp. 48-57
Author(s):  
V. A. Sidorov ◽  
N. V Gichun

The balancing of rotors of fans, pumps, smoke exhausters, blowers (with a capacity of 50...500 kW, with a rotational speed of 950...3000 rpm) in their own supports is carried out most often at industrial enterprises. The effectiveness of this operation is ensured by the implementation of a number of rules, confirmed by practical experience. Some stages of balancing of rotors are considered in the work. A preliminary examination of the mechanism provides an accurate diagnosis and an informed decision for balancing. Correct determination of the angle of installation of the test cargo at various places of installation of the vibration and photo sensor allows reducing the level of vibration and additional loads on the elements of the mechanism during the test run. Controlling the values of the dynamic coefficient of influence during the balancing process allows you to control the change in the stiffness of the base, loosening of threaded connections, which are often the cause of unsuccessful balancing. The above provisions are confirmed by the results of research and practical application.

2021 ◽  
Vol 116 ◽  
pp. 00012
Author(s):  
Mikhail Gorodilov ◽  
Marina Naam ◽  
Yulia Murashova ◽  
Tatiana Ketova

This paper analyzes important accounting and financial problems associated with identification, determination of the moment of recognition, proper assessment of intellectual properties that are part of intangible assets, determination of their useful life, as well as the search for relevant methods of their depreciation. According to the generalization of theoretical and their own practical experience, the authors propose the approaches to solve these problems, designed to increase the level of reporting reliability for stakeholders, as well as to ensure proper accounting and control of these objects in order to provide their safety and rational use at industrial enterprises.


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.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2412
Author(s):  
Inés Ferrer ◽  
Ariadna Manresa ◽  
José Alberto Méndez ◽  
Marc Delgado-Aguilar ◽  
Maria Luisa Garcia-Romeu

Ultrasonic molding (USM) is a good candidate for studying the plasticization of polymer mixtures or other composite materials due to either the little amount of material needed for processing, low waste or the needed low pressure and residence time of the mold. Thus, the novelty of this research is the capability of USM technology to process PLA/PCL blends and their corresponding neat materials, encompassing all the production stages, from raw material to the final specimen. The major findings of the work revealed that the thermal properties of the blends were not affected by the USM process, although the crystallinity degree experienced variations, decreasing for PLA and increasing for PCL, which was attributed to the crystallization rate of each polymer, the high process speed, the short cooling time and the small particle size. The employed ultrasonic energy increased the molecular weight with low variations through the specimen. However, the degradation results aligned with the expected trend of these material blends. Moreover, this study also showed the effect pellet shape and dimensions have over the process parameters, as well as the effect of the blend composition. It can be concluded that USM is a technology suitable to successfully process PLA/PCL blends with the correct determination of process parameter windows.


Author(s):  
Robert Skov ◽  
David R Lonsway ◽  
Jesper Larsen ◽  
Anders Rhod Larsen ◽  
Jurgita Samulioniené ◽  
...  

Abstract Objectives Correct determination of penicillin susceptibility is pivotal for using penicillin in the treatment of Staphylococcus aureus infections. This study examines the performance of MIC determination, disc diffusion and a range of confirmatory tests for detection of penicillin susceptibility in S. aureus. Methods A total of 286 consecutive penicillin-susceptible S. aureus blood culture isolates as well as a challenge set of 62 MSSA isolates were investigated for the presence of the blaZ gene by PCR and subjected to penicillin-susceptibility testing using broth microdilution MIC determination, disc diffusion including reading of the zone edge, two nitrocefin tests and the cloverleaf test. Results Using PCR-based detection of blaZ as the gold standard, both broth microdilution MIC testing and disc diffusion testing resulted in a relatively low accuracy (82%–93%) with a sensitivity ranging from 49%–93%. Among the confirmatory tests, the cloverleaf test performed with 100% accuracy, while zone edge interpretation and nitrocefin-based tests increased the sensitivity of β-lactamase detection to 96%–98% and 82%–96% when using MIC determination or disc diffusion as primary test, respectively. Conclusions This investigation showed that reliable and accurate detection of β-lactamase production in S. aureus can be obtained by MIC determination or penicillin disc diffusion followed by interpretation of the zone edge as a confirmatory test for apparently penicillin-susceptible isolates. The more cumbersome cloverleaf test can also be used. Nitrocefin-based tests should not be used as the only test for confirmation of a presumptive β-lactamase-negative isolate.


1996 ◽  
Vol 15 (6) ◽  
pp. 497-503 ◽  
Author(s):  
T. Soriano ◽  
M. Menéndez ◽  
P. Sanz ◽  
M. Repetto

1 The described analytical procedure permits the simultaneous determination of the main n-hexane meta bolites in urine. 2-Hexanone, 2-hexanol, 2, 5-hexanediol and 2, 5-hexanedione, were chosen to dose the rats used in this study. All urine samples were collected and analysed on a daily basis, before and after acidic hydrolysis (pH 0.1) by GC/MS. 2-Hexanone, 2, 5-dimethylfurane, γ-valerolac tone and 2, 5-hexanedione were determined before hydro lysis ; 2-hexanol and 2, 5-hexanediol, after hydrolysis; and 5-hydroxy-2-hexanone and 4, 5-dihydroxy-2-hexanone were calculated by the difference between γ-valerolactone and 2, 5-hexanedione with and without hydrolysis, respectively. 2 A metabolic scheme was proposed reflecting the biotransformations undergone by the four compounds assayed. We consider 2, 5-dimethylfurane as a 'true metabolite' because the quantities detected were always greater before hydrolysis. 3 It has been reported that human and rat n-hexane metabolism follow a similar pattern. Therefore, as a practical application and without increasing either sample or time requirements, the simultaneous quantifi cation of the different metabolites and their excretion profile could provide better information about the metabolic situation of exposed workers than the determi nation of 2, 5-hexanedione alone. According to our experimental results, 4, 5-dihydroxy-2-hexanone itself would be a good toxicity indicator.


2016 ◽  
Vol 20 (1) ◽  
pp. 105-113
Author(s):  
Zongcheng Miao ◽  
Yang Zhao ◽  
Xiaoping Huo

Abstract Currently research of lactic acid bacteria focus primarily on the functional probiotics, which are major beneficial biota in the gastrointestinal tract, have been industrial manufactured. Probiotics confer health benefits on the host need adequate amounts. However, the absence of data makes it difficult to ensure the maintenance biological activities and population of probiotic. In this research, a fractional factorial design and steepest ascent experiment were used to analyze the influence of lyoprotectant as carbohydrates, prebiotics and amino acids on the survival of the probiotic Lactobacillus rhamnosus. The results indicated a maximum survival rate and population of viable bacteria of L. rhamnosus to be 55.84 % and 1.60 ×1011 CFU/g after freeze-dried by using a combination of 10 g/100mL Sucrose, 2.5 g/100mL Isomaltooligosaccharide, 12 g/100mL Hydroxyproline. To a large extent, the survival and viability were dependent on the cryoprotectant used and make probiotics more attractive from a practical application in industrial viewpoint.


Author(s):  
Sven H. Reese ◽  
Johannes Seichter ◽  
Dietmar Klucke

The influence of LWR coolant environment to the lifetime of materials has been discussed recent years. Nowadays the consideration of environmentally assisted fatigue is under consideration in Codes and Standards like ASME and the German KTA Rules (e.g. Standard No. 3201.2 and Standard No. 3201.4) by means of so called attention thresholds. Basic calculation procedures in terms of quantifying the influence of LWR coolant environment by the Fen correction factor were proposed by Higuchi and others and are given in NUREG/CR-6909. This paper deals with the application of the proposed assessment procedures of ANL and the application to plant conditions. Therefore conservative assessment procedures are introduced without assuming the knowledge of detailed stress and strain calculations or temperature transients. Additionally, detailed assessment procedures based on Finite-Element calculations, respecting in-service temperature measurements including thermal reference transients and complex operational loading conditions are carried out. Fatigue evaluation of a PWR primary circuit component is used in order to evaluate the influence of plant like conditions numerically. Conclusions regarding the practical application are drawn by means of comparing the ANL approach considering laboratory conditions, conservative assessment procedures for the determination of cumulative fatigue usage factors of plant components and detailed assessment procedures. Plant like loading conditions, complex component geometries, loading scenarios and reference temperature transients shall be taken into account. Practical issues like the determination of the mean temperature or the strain rate have to be considered adequately.


1979 ◽  
Vol 57 (2) ◽  
pp. 117-124 ◽  
Author(s):  
J. J. Myher ◽  
A. Kuksis

A method of simultaneous determination of stereospecific distribution and molecular association of acyl groups in triacylglycerols has been developed. The analysis is based on a random generation of rac-1, 2-diacylglycerols by Grignard degradation, synthesis of rac-phosphatidylcholines, and a stereospecific stepwise release of 1, 2-sn- and 2, 3-sn-diacylglycerols by phospholipase C. The exact structure of the original triacylglycerols is reconstituted on the basis of complete analysis of the molecular species of the 1, 2-sn- and 2, 3-sn-diacylglycerols as the tertiary-butyldimethylsilyl ethers by gas chromatography with mass spectrometry. The validity of the method is demonstrated by analyses of synthetic triacylglycerols of known structure. A practical application is illustrated by determination of the fatty acid distribution in lard.


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