Increasing Service Life and System Efficiency of Parallel Pumps Using Combined Pump Regulation

The paper discusses the use of the combined control for a system of two parallel pumps to increase its service life. Using the combined control, the pumping system is controlled together by change the speed, throttling, and bypass. The power consumption of the pumping system is calculated for three methods of flow control: with minimum energy consumption, with maximum reliability, and control with a trade-off between efficiency and reliability. In the case of control with maximum reliability, the energy consumption of the pumping system is higher than in the case of control with minimum energy consumption by 29.2%. In the case of the proposed trade-off control, which provides acceptable reliability, the power consumption is higher than with the minimum energy consumption control by only 7.3%.

Improving Reliability and Energy Efficiency of Three Parallel Pumps by Selecting Trade-Off Operating Points

Reliability, along with energy efficiency, is an important characteristic of pump units in various applications. In practical pump applications, it is important to strike a balance between reliability and energy efficiency. These indicators strongly depend on the applied control method of the pump unit. This study analyzes a trade-off method for regulating a system with three parallel pumps equipped with only one frequency converter (multi-pump single-drive system). A typical operating cycle of a pumping system with variable flow rate requirements is considered. The proposed trade-off method is compared with the traditional regulation, when a change in the operating point of the pump is achieved only by changing the rotation speed, and with the method for maximum reliability. It is shown that the proposed trade-off method makes it possible to ensure sufficient reliability of the multi-pump system operation without a significant increase in energy consumption.

AC-DC Microgrid Optimal Power Flow

Electricity market deregulation has opened the door for novel electricity production schemes within the existing central production paradigm that dominates the electricity power industry. The Microgrid concept allows generation and load located in close vicinity to be organized so that the local load is served as far as possible with local generation. The Microgrid examined in this thesis consists of both AC and DC network components connected using power converters. The varied Microgrid power sources (microturbine generators, PV, battery, power imports from the grid etc.) are scheduled over 24 hours to satisfy load demand at minimum cost and maximum reliability. Towards this end, a dual objective problem is formulated using Fuzzy sets and the final problem takes the form of a Mixed-Integer Nonlinear optimization problem. The interplay between the disparate objectives of minimum cost and maximum reliability and the battery is then examined.

AC-DC Microgrid Optimal Power Flow

Electricity market deregulation has opened the door for novel electricity production schemes within the existing central production paradigm that dominates the electricity power industry. The Microgrid concept allows generation and load located in close vicinity to be organized so that the local load is served as far as possible with local generation. The Microgrid examined in this thesis consists of both AC and DC network components connected using power converters. The varied Microgrid power sources (microturbine generators, PV, battery, power imports from the grid etc.) are scheduled over 24 hours to satisfy load demand at minimum cost and maximum reliability. Towards this end, a dual objective problem is formulated using Fuzzy sets and the final problem takes the form of a Mixed-Integer Nonlinear optimization problem. The interplay between the disparate objectives of minimum cost and maximum reliability and the battery is then examined.

Analysis of staged treatment and some socio-hygienic and biological factors for the onset and course of gastric ulcer and duodenal ulcer

In a social-hygienic study, some factors influencing the occurrence and dynamics of the course of gastric ulcer and duodenal ulcer in 379 patients were studied. The results of the data show that the complete staged treatment (polyclinic, hospital, sanatorium) is not carried out for all patients (24.3%) for the entire study period. In the first year of the disease, it was carried out in only 6.8% of patients. To determine the strength of the influence of some socio-hygienic and biological factors on the dynamics of the course of peptic ulcer disease, we used the method of analysis of variance. The analysis of the dynamics of gastric ulcer and duodenal ulcer with the calculation of a static assessment, which reliability is quite convincing, made it possible to conclude with maximum reliability that the dynamics of the disease, in addition to surgical treatment 45.1% (with complications in the form), is most strongly influenced by the nutrition factor 8.5% ... The effect of other factors is approximately the same: material housing conditions 6.6%, the psychological factor 6.5% and working conditions 4.5%.

Optimization for Die Attach Film Delamination on Nickel-Palladium-Gold Die Pad

In the Semiconductor Industry, the delamination performance of integrated circuit packaging is being aggressively improved. However, this task is complicated and difficult, as the defective failure is highly dependent on the compatibility of the material characteristics that may affect the entire Integrated Circuit package system under certain stress levels, both mechanical and thermal. This research work aims to study Die Attach process optimization in DAF adhesive for Nickel-Palladium-Gold Die Pad leadframe to achieve maximum reliability performance under IPC / JEDEC Moisture Sensitivity Level 1 (MSL1) at 260°C reflow. Strategic optimization of the Die Attach process is needed to ensure robust reliability. And one of the solutions is to apply the Scrubbing method, which is a machine feature used at a constant temperature to aid in the wetting of adhesives and the removal of voids.

Is There Empirical Evidence on How the Implementation of a Universal Basic Income (UBI) Affects Labour Supply? A Systematic Review

The objective of this article is to determine, as conclusively as possible, if the implementation of a Universal Basic Income (UBI) would lead to a significant reduction in the working age population labour supply. If this were true, implementation of a UBI may not be sustainable. To do this, we will compile empirical evidence from studies over the last few decades on the effects of implementation of a UBI on employment. We apply the PRISMA methodology to better judge their validity, which ensures maximum reliability of the results by avoiding biases and making the work reproducible. Given that the methodologies used in these studies are diverse, they are reviewed to contextualize the results taking into account the possible limitations detected in these methodologies. While many authors have been writing about this issue citing experiences or experiments, the added value of this article is that it performs a systematic review following a widely tested scientific methodology. Over 1200 documents that discuss the UBI/employment relationship have been reviewed. We found a total of 50 empirical cases, of which 18 were selected, and 38 studies with contrasted empirical evidence on this relationship. The results speak for themselves: Despite a detailed search, we have not found any evidence of a significant reduction in labour supply. Instead, we found evidence that labour supply increases globally among adults, men and women, young and old, and the existence of some insignificant and functional reductions to the system such as a decrease in workers from the following categories: Children, the elderly, the sick, those with disabilities, women with young children to look after, or young people who continued studying. These reductions do not reduce the overall supply since it is largely offset by increased supply from other members of the community.

Production of high-load diesel engines

Analysis of the development of modern engine building has shown that internal combustion engines have a leading position. It is fair to say that there are attempts to change this trend - for example, the serial electric car Tesla. But the oil industry is now a key sector of the global economy, and the dominance of internal combustion engines may remain the main one for many decades. The article analyses steel and aluminum pistons manufactured with application of technologies adapted to customer requirements. These technologies allow creation of heavy duty engines with maximum reliability and optimal combination of characteristics, reduction of emissions of harmful substances and reduction of fuel consumption.

ADAPTIVE CYBER-PHYSICAL SYSTEM OF THE MILK PRODUCTION PROCESS

The basic principles of adaptation of machine milking technical system to the physiology of milk ejection of cows are considered. Main adaptation parameters and conditions of the technical system are grounded, under these parameters and conditions the self-tuning of technical system is possible. The structure of modules of adaptive cyber-physical control system of machine milking is developed, its functionalities are revealed, the method of coordination between discreteness of measurement of information and the quantization period is developed to ensure maximum reliability of the information. The memory size of the operational information about the process parameters is justified, as well as their structure and functional content. Functional content and structure of information about the technological process of the database is formulated. The general view of the main elements of the adaptive cyber-physical system of cows milking is given, as well as the results of work of the experimental adaptive cyber-physical system of the milk production.

Development of Mathematical Anxiety Instruments with a Rasch Model Analysis

Background: This study was motivated by a large number of students who feel anxious when dealing with mathematics, which is an unpleasant feeling characterized by the presence of worry, anxiety, confusion, and stress. Objective: This study aims to test the instruments of mathematical anxiety using Rasch Model analysis. Materials and Methods: The study used descriptive analysis with a cross-sectional design. Subjects of the study were elementary school students in grade VI SDN Margarahayu, 13 male and 5 female students in grade VI A, 9 male and 3 female students in grade VI B. Results: The results of the analysis show that the instrument has a poor or not maximum reliability value (α = 0.56). Likewise, the respondent's reliability value (α = 0.49) is in the weak category and the item reliability (α = 0.93) is in the excellent category. Conclusion: The analysis of the instrument shows that 2 items do not meet the standard criteria for the measurement, including number 16 as bias genders are more profitable for female students, and number 9 misfits because it is too difficult for most students to agree on. 3 items are categorized as very difficult, including item number P13, P11, and P12. There are 5 items in difficult category, which include numbers P9, P15, P14, P16, and P10. There are 4 items in the easy category, including P6, P5, P4, and P3. While the very easy category has 4 items, including numbers P1, P7, P2, and P8.