Optimal control of fluctuations of the “liquid substance - pipeline” system in terms of speed during transportation of a liquid substance

The process of transporting a liquid substance (oil, petroleum products, gas mixtures) the pipeline network and related engineering facilities, being a dynamically non-equilibrium physical system, are often carried out in extreme modes, which can form dangerous wave phenomena accompanied by various instabilities, generating undesirable consequences and even catastrophes. Similar phenomena can occur in technical devices and apparatuses containing in their design hydraulic networks for the transfer of continuous media (aircraft, energy objects). Eliminate (extinguish or reduce the intensity) such phenomena are possible in the shortest possible time by making additional structural changes to the pipeline network, which make it possible to use external devices for dynamic influence on the “liquid substance – pipeline” system and eliminate (or minimize) the possibility of negative wave effects. The paper is devoted to the problem of eliminating dangerous vibrations initiated by a liquid substance transported through a pipeline network, provided that time resources are spent minimally. A mathematical model of the wave process and the problem of optimal control over the speed of such a model are considered. The control effect on the “liquid substance-pipeline” system is carried out at the initial and final points of the pipeline network, while the necessary information about the state of the system is used in a finite number of points distributed along the entire length of the pipeline, which makes it possible to calculate external influences on the system. In order to simplify the presentation of the results, a linear carrier of a liquid substance is used (in applications, a pipeline without branches) and a one-dimensional wave equation – the length of the pipeline is much larger than its diameter.

A problem of measuring quantity of liquid inside moving tank and possible ways to resolve it

The article describes a problem of measuring quantity of liquid substance inside moving tank. The problem consists in low accuracy in this type of measurement that is significantly lower than accuracy of such measurements provided in unmovable fixed tanks. Mostly, this problem is spread in transport: aviation, sea vessels, space rockets and automobiles, and it refers for measuring fuel in tanks, coolant volume, amount of various liquid substance under transportation etc. Low accuracy of obtained measurement data affects vehicle technical performance, leads to financial losses and even provokes some safety issues. There are several factors that increase measurement error during measuring inside a tank that is being under dimensional and angular motion. All of them change shape and position of liquid surface and make measuring process more complicated. Influence of some of these factors could be eliminated if the tank has symmetrical form, level sensor is installed along tank axe, and measurements are provided at middle part of tank height. If there are no such conditions, we face the discussed problem. The abovementioned factors are: tank inclination, tank acceleration, free motion of liquid surface, drastic changes in the shape of the liquid surface in case if the liquid surface position is shifting while it is located at nearby tank top or bottom area.Author made a review with the aim to analyze how this problem is treated in various transportation systems. The review shows that the problem of measuring quantity of liquid substance inside moving tank is not resolved in general. Some partial solutions are presented, in particular, for measuring fuel quantity inside tanks of swinging sea-based launch vehicle. But it is still needed to find a general solution.The problem couldn't be solved only by instrumental methods. Some published papers indicate the possible ways to resolve the problem. They are related to computational methods of data processing. Thus, development of this methods and creation of the corresponding information and measuring technology should be recognized as a most perspective way to resolve the problem of measuring quantity of liquid inside moving tank.

Pentane-1-ol and its isomers. Determination in workplace air with GC with Flame Ionization Detector (GC-FID)

Amyl alcohol (pentan-1-ol) – C5H12O or C5H11OH – is an organic chemical compound from the group of saturated monohydric aliphatic alcohols. There are 8 known isomers of pentanol: pentan-1-ol (CAS:71-41-0), pentan-2-ol (CAS: 6032-29-7), pentan-3-ol (CAS: 584-02-1), 2-metylobutan-1-ol (CAS: 137-32-6), 3-metylobutan-1-ol (CAS: 123-51-3), 2-metylobutan-2-ol (CAS: 75-85-4), 3-metylobutan-2-ol (CAS: 598-75-4) i 2,2-dimetylopropan-1-ol (CAS: 75-84-3). All of them are commonly referred to as amyl alcohols. Pentanol isomers exhibit chemical properties characteristic of aliphatic alcohols, they are obtained by hydration of pentene isomers, hydrolysis of chloropentanes or by reaction of butene and carbon monoxide isomers. They are used as solvents for fats, resins and waxes. Pentan-1-ol is absorbed into the human body through the respiratory tract, skin, gastrointestinal tract. Symptoms of acute intoxication are usually tearing eyes, redness of the conjunctiva, irritation of the mucous membrane of the nose and throat. In higher concentrations it may cause headache, dizziness, nausea, vomiting, diarrhea, delirium, disturbances of consciousness, coma. Arrhythmia and respiratory disorders may cause redness and burning, as well as symptoms such as inhalation poisoning, eye contamination with liquid substance causes pain, burning of the eyes, redness of the conjunctiva, with the risk of long-lasting and permanent changes. Repeated skin contact with the liquid substance may cause its drying and inflammation. It is suggested that long-term exposure of the skin to the substance at high concentration may lead to changes in the nervous system. The aim of this study was to develop and validate a sensitive method of determining 8 pentan-1-ol isomers in the working environment in the range from 1/10 to 2 of the MAC values. The gas chromatography method with a flame ionization detector (GC-FID) was used to determine pentan-1-ol and its isomers. It was decided to develop a method that ensures the determination of at least 1/10 of the MAC values. Further considerations of the possibility of determining this substance in the air are based on previously developed analytical methods. The use of the HP-5 capillary column enables the selective determination of pentan-1-ol in the presence of carbon disulphide, methanol and other co-existing compounds. The detector's response to the analyzed pentan-1-ol concentrations is linear (r2 = 0.9998) in the concentration range 10–2000 μg/ml, which corresponds to the range of 1–200 mg/m3 (0.01–2 of the MAC values) for a 10-L air sample. The limit of quantification (LOQ) of this method is 0.026 μg/ml. The developed method is characterized by good precision and accuracy and meets the requirements of Standard No. PN-EN 482 for procedures regarding the determination of chemical agents. The developed method for determining pentan-1-ol has been recorded in the form of an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Акустический расходомер

The design and metrological characteristics of the acoustic flowmeter of a flow of a gaseous or liquid substance are considered. It is shown that the device has a simple design, is characterized by high accuracy (relative error of measuring the volume flow rate is less than 1%) and high speed (the time to determine the flow rate is not more than a few milliseconds).

Improving the Efficiency of Suspension for Automobiles Using Ferrofluid

In automobile application, suspensions are used for various purposes. To improve the stability and to withstand maximum load we are trying to add additional source which is called suspension. These suspensions are made attached along with the ordinary suspension. This is manufactured using magnetic fluid called ferrofluid. Here the complete preparation of ferrofluid was done and their characteristics were studied. In this, the experimental setup of suspension has been studied and working was analyzed. The fluid was prepared and compared the viscosity with ordinary fork oil. This liquid substance which acts as a source of suspension, which has maximum efficiency when compared to ordinary fluid. These can be varied to different shapes depending on the application and needs.

Structure and charge density studies on 1,1-difluoroallene and tetrafluoroallene

Single crystals of 1,1-difluoroallene and tetrafluoroallene (mp 136 K and 108 K) were grown in situ on a four-circle diffractometer from the liquid substance in a cold N