Novel Rotating Machinery Structural Faults Signal Adaptive Multiband Filtering and Automatic Diagnosis

To realize an automatic diagnosis of rotating machinery structure faults, this paper presents a novel fault diagnosis model based on adaptive multiband filter and stacked autoencoders (SAEs). First, to solve the problem where the actual rotating frequency and its harmonics cannot be accurately extracted in engineering applications, an improved adaptive multiband filtering method is designed. This method takes the theoretical rotating frequency as the search center, extracts the maximum within the positive and negative deviation as the actual rotating frequency, and sets a threshold according to the actual value to realize multiband filtering. This method can effectively remove background noise and accurately extract the actual rotating frequency and its harmonics. Second, an unsupervised SAE multiclassification model is established to realize an automatic diagnosis of fault types. This model can automatically extract the in-depth features of the filtered signal and improve the fault classification accuracy. Third, engineering and comparative experiments were carried out to verify the effectiveness and superiority of this model. Results show that the proposed automatic diagnosis model can extract the characteristic components abundantly and accurately recognize rotating machinery structural faults.

Effect of phosphorus on the density and molar volume of Al–Si alloy without solidification shrinkage

The Al–Si alloys exhibit many unique properties, but not enough work has been dedicated to their thermophysical properties. In this work, the effect of phosphorus modifier on the density, molar volume and solidification shrinkage rate of Al-25% Si alloys was investigated by using the indirect Archimedes method. The results show that both density–temperature and molar volume–temperature curves show three inflection points: the liquidus temperature point, the eutectic transformation starting point and the finishing point. The density of the solidus linearly decreases and that of the liquidus linearly increases with phosphorus modifier content. Compared with Vegard’s law, the molar volumes show a negative deviation. Finally, the solidification shrinkage rate is calculated from the densities of solidus and liquidus.

Experimentally Calculated Study of the Effectiveness on the Process of Non-Catalytic Synthesis of Biodiesel in Reactors of Various Type

It was experimentally established that the dependence of the partial pressure of methanol on the molar fraction of methanol in oil shows a pronounced negative deviation from Raoul’s law, which significantly changes the idea of the influence of a large excess of methanol during non-catalytic synthesis of biodiesel. The efficiency of use of a molar excess of methanol is reduced as it grows, and with a more than 10-fold molar excess of the amount of reacted methanol, is practically constant. The comparison of biodiesel production processes in the range 220–235 °C showed that a slight change in the process temperature more effectively affects the biodiesel yield than an increase in the molar excess of methanol. A mathematical model of the process of transesterification of rapeseed oil in reactors of various types (batch and tubular reactors) is developed. A satisfactory correlation between the experimental and calculated data was observed. The calculation showed that the rate constants of the reverse reactions at 230 °C were not significant.

Assessment of Deviations in Iraqi Banks’ Balance Sheet Budgets

Deviations are the difference between the planning budget and the actual for financial periods and specific financial accounts, and it is the tool that management uses it to control and to know the reality of achieving pre-set plans. The success of the budget and its positive deviation is evidence of achieving the institution’s financial goals, and the negative deviation of the budget is evidence of the failure to achieve the budget, and then the administration must identify the causes of the deviation and address it. The research aims to analyze the results of the balance sheet budget and comparing them with the actual results, and determine the deviations if they are negative or positive for a sample of Iraqi private banks that are Consisting of (Islamic banks and commercial banks). In addition, the study sample consisted of Baghdad Bank, the Middle East Bank, Iraqi Islamic Bank, and National Islamic Bank for the fiscal years 2016 and 2017, as these institutions were chosen because they published discretionary budgets in their financial statements. Furthermore, the SPSS statistical tool was used in the study to analyze the deviation data. Islamic banks are better than commercial banks in terms of the rate of implementation of planning budgets since the majority of their statistical results are positive, which was one of the researchers’ most important findings.

Effect of Alternating Stray Current Density on Corrosion Behavior of X80 Steel under Disbonded Coating

In this paper, the effect of alternating stray current (AC) density on the corrosion behavior of X80 steel under disbonded coating was studied by electrochemical methods, wire beam electrode (WBE) technology, and surface observation technology. The results showed that under the interference of different AC densities, the corrosion potential of X80 steel under disbonded coating underwent negative deviation, and the degree of negative deviation increased with the increase of AC density. The corrosion current density of X80 steel under disbonded coating with the action of 0~100 A/m2 AC density had few differences. While the corrosion current density of X80 steel with the action of 200~300 A/m2 AC density increased and the corrosion current density was higher than that under low AC density. The cathode area of the wire beam electrode under disbonded coating is mainly distributed outside and the edge of the gap between disbonded coating and X80 steel, while the anode area is mainly distributed inside the gap.

Thermodynamic Mixing Properties of Li–Mg Binary Alloy

Theoretical calculations of thermodynamic mixing properties viz., Gibbs’ free energy of mixing GM , heat of mixing HM , entropy of mixing SM , as well as the activity and its coeffi cients, are performed using the Bhatia–Hargrove complex formation model. The mixture is assumed to be pseudobinary. The components exhibit a negative deviation from Raoult’s behavior, and the system is weakly interacting in nature.

Effect of oxygen and bismuth impurities on the structural and physicochemical properties of nickel melts

There are practically no data in the literature on the combined effect of oxygen and bismuth impurities on the structural and physicochemical properties of nickel melts or heat-resistant alloys based on it. In the presented work, the state of pure nickel and nickel melts containing (0.005-0.01) bismuth and oxygen is considered in the process of refining from oxygen and bismuth impurities. The influence of these impurities on the structural and physicochemical properties was studied, which was evaluated by the parameters of the density and surface tension of the melts. In nickel melts with bismuth and oxygen, a compression effect and a negative deviation from Raoult’s law were observed. The effect of an increase in the surface tension of a nickel melt containing oxygen with an increase in the concentration of bismuth is found, which corresponds to the isotherm of desorption of excess substance from the surface into the bulk.

Organizational restructuring as a way to resolve the crisis caused by COVID 19, in agricultural sector

The crisis, as a negative deviation that is serious and can jeopardize the company's business usually doesn't occur suddenly, but gradually in individual areas, accumulating its effects. The crisis caused by the pandemic came suddenly and immediately caused a disruption of economic activities, without the possibility to predict and prevent it. It hit the agricultural sector with great intensity. The analysis of the business entities in agricultural sector in Serbia has shown that these entities suffered great damage and that it is necessary to take restructuring measures as soon as possible, primarily organizational ones. The results of the research showed that the crisis caused by COVID 19, mainly affected the entire long chain of participants in agriculture. Government measures, which included providing financial support and subsidies, are certainly welcome but not sufficient. The authors concluded that it is therefore necessary for companies to implement restructuring measures in order to ensure a speedy recovery.

Effects of adherence to pharmacological secondary prevention after acute myocardial infarction on health care costs – an analysis of real-world data

Background Acute myocardial infarction (AMI), a major source of morbidity and mortality, is also associated with excess costs. Findings from previous studies were divergent regarding the effect on health care expenditure of adherence to guideline-recommended medication. However, gender-specific medication effectiveness, correlating the effectiveness of concomitant medication and variation in adherence over time, has not yet been considered. Methods We aim to measure the effect of adherence on health care expenditures stratified by gender from a third-party payer’s perspective in a sample of statutory insured Disease Management Program participants over a follow-up period of 3-years. In 3627 AMI patients, the proportion of days covered (PDC) for four guideline-recommended medications was calculated. A generalized additive mixed model was used, taking into account inter-individual effects (mean PDC rate) and intra-individual effects (deviation from the mean PDC rate). Results Regarding inter-individual effects, for both sexes only anti-platelet agents had a significant negative influence indicating that higher mean PDC rates lead to higher costs. With respect to intra-individual effects, for females higher deviations from the mean PDC rate for angiotensin-converting enzyme (ACE) inhibitors, anti-platelet agents, and statins were associated with higher costs. Furthermore, for males, an increasing positive deviation from the PDC mean increases costs for β-blockers and a negative deviation decreases costs. For anti-platelet agents, an increasing deviation from the PDC-mean slightly increases costs. Conclusion Positive and negative deviation from the mean PDC rate, independent of how high the mean was, usually negatively affect health care expenditures. Therefore, continuity in intake of guideline-recommended medication is important to save costs.