A new approach to monitor wear tracks propagation on-site with electromechanical impedance technique

Author(s):  
Mesut Tekkalmaz ◽  
Ümit Er ◽  
Fatih Hayati Çakir ◽  
Fatih Bozkurt

Generally, the determination of the wear in the mechanical systems is done by checking the critical components in periodic maintenance or by monitoring the secondary indicators such as vibration, noise, and temperature. These indicators can only be recognized after the wear reaches a certain level. In this study, an approach has been carried out on the use of the electromechanical impedance (EMI) method. In this study, EMI measurements were carried out depending on the different test samples, representing a different amount of wear level and wear location of the AISI 1040 steel block. The test samples were worn out in a controlled laboratory environment. The impedance measurements were taken before and after wear tests for each sample. Different measurements were made, and damage metrics were calculated and compared with the reference measurement made; the amount of the wear could be monitored primarily using the Root Mean Square Deviation (RMSD) method without dismantling the system. The location of wear could be determined by Correlation Coefficient Deviation (CCD) technique. In this study, it has been demonstrated that it could be possible to monitor the progress of wear in sensitive mechanical systems periodically without disturbing the integrity of the machine system.

2019 ◽  
Vol 30 (15) ◽  
pp. 2189-2197 ◽  
Author(s):  
Xiujuan Li ◽  
Wenzhong Qu ◽  
Li Xiao ◽  
Ye Lu

Electromechanical impedance technique has been widely used in the area of structural health monitoring. However, both damage and variation in environmental temperature can cause the changes in electromechanical impedance signature, which may cause false damage diagnosis. The temperature effect on the electromechanical impedance-based method has been one of its main drawbacks in practical application. This article proposes a new approach based on cointegration to eliminate temperature interference in the electromechanical impedance technique. The augmented Dickey–Fuller test is used to analyze the stationary characteristics of the time series and determine the degree of non-stationarity. The Johansen test is used to obtain the cointegrating residuals instead of the direct electromechanical impedance responses for damage detection. The proposed method is verified on the undamaged and damaged steel plates with the consideration of environmental temperature variations. The damage detection was based on the electromechanical impedance technique in which the peak frequency is chosen as a cointegrated variable. The experimental results show that the cointegration method can remove the temperature effect on the electromechanical impedance responses, and the cointegrating residuals are effective indices to indicate the occurrence of damage.


1964 ◽  
Vol 12 (01) ◽  
pp. 119-125 ◽  
Author(s):  
Y Shamash ◽  
A Rimon

SummaryA new method for the assay of plasmin inhibitors in human plasma is described. The method consists of determination of the caseinolytic activity of a standard plasmin solution before and after incubation with the inhibitor, with lysine added to the mixture as a stabilizer of plasmin. Using this method, it was found that plasma contains enough inhibitors to inactivate 30 caseinolytic units of plasmin, or 10 times the normal amount of plasminogen in human plasma.


1962 ◽  
Vol 41 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Pentti A. Järvinen ◽  
Sykkö Pesonen ◽  
Pirkko Väänänen

ABSTRACT The fractional determination of 17-ketosteroids in the daily urine was performed in nine cases of hyperemesis gravidarum and in four control cases, in the first trimester of pregnancy both before and after corticotrophin administration. The excretion of total 17-KS is similar in the two groups. Only in the hyperemesis group does the excretion of total 17-KS increase significantly after corticotrophin administration. The fractional determination reveals no difference between the two groups of patients with regard to the values of the fractions U (unidentified 17-KS), A (androsterone) and Rest (11-oxygenated 17-KS). The excretion of dehydroepiandrosterone is significantly higher in the hyperemesis group than in the control group. The excretion of androstanolone seems to be lower in the hyperemesis group than in the control group, but the difference is not statistically significant. The differences in the correlation between dehydroepiandrosterone and androstanolone in the two groups is significant. The high excretion of dehydroepiandrosterone and low excretion of androstanolone in cases of hyperemesis gravidarum is a sign of adrenal dysfunction.


1968 ◽  
Vol 57 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Hironori Nakajima ◽  
Mitsunori Murala ◽  
Masumitsu Nakata ◽  
Takeshi Naruse ◽  
Seiji Kubo

ABSTRACT The in vitro resin uptake of 3H-prednisolone was used for the determination of blood cortisol after addition of radioactive prednisolone followed by Amberlite CG 400 Type 1 to the test serum, and incubation of the mixture. The radioactivity of the supernatant was compared before and after the addition of the resin. The principle of this method is similar to that of the 131I-triiodothyronine resin uptake for the thyroid function test. The tests for the specificity, reproducibility and sensitivity gave satisfactory results. The mean basal value ± SD of the 3H-prednisolone resin uptake was 35.3 ± 9.2% in normal subjects, and 27.1 ± 4.8% in pregnant women. This method was valid in various adrenal function tests, i. e. the adrenal circadian rhythm, corticotrophin (ACTH) test, dexamethasone suppression test and the adrenal response to lysine-8-vasopressin. It proved to be a sensitive indicator of the adrenal function. These results suggest that this method should be useful for a routine adrenal function test.


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.


Author(s):  
Е.Б. Ганина ◽  
Ю.В. Червинец ◽  
Н.В. Грудинин ◽  
В.Г. Шестакова ◽  
В.М. Червинец ◽  
...  

Цель исследования - охарактеризовать микробиологическую картину стоматита до и после его лечения высокоактивными культурами лактобацилл, дать оценку эффективности их применения при экспериментальном стоматите. Методика. Опыты проводились на 32 самках беспородных белых крыс массой 230 г. Моделирование стоматита включало 2 этапа: моделирование травматического стоматита и воспроизведение бактериального стоматита на базе травматического. У крыс контрольной и опытных серий на всех этапах эксперимента брали мазки с поверхности десен для характеристики микробиоценоза ротовой полости. Результаты. После обработки слизистой оболочки полости рта (СОПР) культурой патогенного штамма Staphylococcus aureus существенно снизились частота встречаемости и количество условно-патогенных микроорганизмов. Лечение стоматита у крыс культурами лактобацилл ( Lactobacillus 11 зв., Lactobacillus 2 п.рта, Lactobacillus 24 д.ст.) и их комбинацией приводило к снижению распространенности S. aureus вплоть до его исчезновения, а также к нормализации количества условно-патогенной микробиоты. Заключение. Исследования показали эффективность использования отдельных высокоактивных штаммов лактобацилл или их комбинации при лечении заболеваний СОПР, в частности бактериального стоматита. Aim. To characterize the microbiological picture of stomatitis in intact rats before and after the treatment with highly active cultured lactobacilli and to evaluate the effectiveness of this treatment in experiments on white rats. Methods. Experiments were carried out on 32 mongrel female white rats weighing 230 g. Smears were taken from the gum surface of control and experimental rats at all stages of the experiment to characterize the oral cavity microbiocenosis. Results. After treatment of the oral cavity with cultured Staphylococcus aureus , the occurrence and quantity of opportunistic microorganisms significantly decreased. The treatment of stomatitis in rats with cultured lactobacillus ( Lactobacillus 11 zv., Lactobacillus 2 p.r., Lactobacillus 24 d.st. and their combination) led to a decrease in S. aureus prevalence up to its extinction and to normalization of the quantitative composition of opportunistic microbiota. Conclusions. The study showed the effieacy of highly active lactobacillus strains individually or their combinations in the treatment of oral diseases, in particular, bacterial stomatitis.


Author(s):  
Romain Desplats ◽  
Timothee Dargnies ◽  
Jean-Christophe Courrege ◽  
Philippe Perdu ◽  
Jean-Louis Noullet

Abstract Focused Ion Beam (FIB) tools are widely used for Integrated Circuit (IC) debug and repair. With the increasing density of recent semiconductor devices, FIB operations are increasingly challenged, requiring access through 4 or more metal layers to reach a metal line of interest. In some cases, accessibility from the front side, through these metal layers, is so limited that backside FIB operations appear to be the most appropriate approach. The questions to be resolved before starting frontside or backside FIB operations on a device are: 1. Is it do-able, are the metal lines accessible? 2. What is the optimal positioning (e.g. accessing a metal 2 line is much faster and easier than digging down to a metal 6 line)? (for the backside) 3. What risk, time and cost are involved in FIB operations? In this paper, we will present a new approach, which allows the FIB user or designer to calculate the optimal FIB operation for debug and IC repair. It automatically selects the fastest and easiest milling and deposition FIB operations.


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