Aggressive Liquids Research Articles

Анализ изменения стойкости бетонных конструкций в промышленности при химическом воздействии с учетом потенциальных рисков для работников и окружающей среды

The requirements for industrial facilities’ resistance to external impacts and reliability are higher when compared with other facilities. The most common construction material, inter alia, in various industrial sectors is concrete due to its easy production and use, relatively low cost, and wide application. The environmental cleanliness is traditionally considered one of the advantages of concrete. All lifecycle stages of concrete, however, from the production process until the end of the service life of ready-to-use objects, imply serious environmental risks. Therefore, already at the design stage of (ferro)concrete structures, it is necessary to consider, in addition to the functions of the future object, the external impacts it will be exposed to. Concrete properties are not constant and change from the moment of mixing, during the transportation, and until its complete hardening. Apart from the composition and compliance with standards, many factors affect the properties. One of the main factors is an aggressive environment, whose impact can not only damage but completely disable building structures. The design service life of structures must exceed the operation lifecycle or comply with it. Concrete is considered durable if, during the design service life, it withstands loads and negative impacts of external factors and remains undamaged, taking into account industrial operation and timely maintenance. Already at the beginning of design jobs, the duration of the design service life must be estimated correctly. Both under- and overestimation of the design service life of ferroconcrete structures reduce safety and reliability and cause an unjustified rise in production and operating costs. The authors of the study analyze problems that may arise at the plants of the chemical industry in case of destruction of concrete under the impact of the aggressive liquid medium by conducting a practical study in conditions as realistic as possible. Within the framework of accelerated study, the authors examined the changes in concrete strength by control samples under pressure impacted by hydrochloric acid and sodium hydroxide. Test trials have clearly demonstrated the importance of the correct definition of concrete class in accordance with the medium of application. This must be considered during the practical work of employees of disaster protection agencies at industrial facilities with tanks to collect and store aggressive liquids, including firewater.

Assessment of the characteristics of professional protective equipment, monitoring compliance with professional safety rules by nursing staff

Health system are more than three million working now, thousands of treatmentand- prophylactic, pharmaceutical, sanitary and epidemiologic institutions, tens research institutes, centers, highest and average educational institutions at which various household and communication equipment is operated, various medical equipment, are used toxic agents and aggressive liquids. In harmful and adverse working conditions hundreds of thousands workers of health care, including average health workers are occupied. Questions of professional safety of nursing staff on a workplace define a level of quality of labor life of experts and are the most important indicator of quality of the provided medical care. In this regard there is actual a question of means of professional protection of average health workers and observance of rules of professional safety by them.

Ca-bentonite/polymer blends to compose GCLs for effective containment of mining leachates

This study investigates the swelling potential of blends of a Brazilian sodium-activated calcium bentonite with linear structure polymers and a cross-linked structure polymer in contact with aggressive mining solutions (sodium hydroxide, calcium chloride, simulated bauxite liquor, copper tailing and gold tailing leachates). Results showed that the polymer addition contributed to the swelling of the bentonite under aggressive solutions. The effectiveness of the polymers varied with the permeant liquid and concentration. Sodium Polyacrylate and Carboxymethyl Cellulose proved the most effectiveness in bentonite swelling capacity. Research presents valuable insights into the chemical compatibility of bentonitepolymer blends when exposed to aggressive liquids.

NOVEL THERMOPLASTIC ELASTOMERS BASED ON PVDF/SKF-32: EFFECT OF COMPOSITION ON TECHNOLOGICAL AND PERFORMANCE CHARACTERISTICS

Thermoplastic elastomers (TPE) based on SKF-32 fluorine rubber and polyvinylidene fluoride, PVDF (polyvinylidene fluoride content ranges from 30 to 70% relative to rubber) were investigated. The mixes have been produced by using a Brabender-type rotary micromixer. Such thermoplastic elastomers can be an alternative to traditional oil & fuel resistant butadiene-nitrile-based rubbers and can be used in manufacture of sleeves, hoses and tubes for pumping aggressive liquids and gases, wires/cables insulation, fuel storage tanks, valves, etc. Traditional methods of plastics processing can be used to manufacture this materials. It was established that the crystallinity degree increases with the rise of PVDF content. That fact is confirmed by the IR-Fourier spectroscopy data and differential scanning calorimetry. It was shown that the hardness and strength of TPEs increases with the rise of PVDF content. The tensile stress for TPEs containing 50% or more of PVDF are higher than those for conventional oil & fuel resistant rubber IRP 1078. The obtained TPEs possess high resistance against AI-92 grade gasoline, 80% sulfuric acid, 50% sodium hydroxide, and I-40 oil. They also retain their physical and mechanical properties even after three cycles of reprocessing. The TPE with the 1:1 thermoplastic : elastomer ratio, has been vulcanized using a peroxide vulcanizing system at varying concentrations. The dynamic vulcanization is confirmed by a decrease in the swelling degree of the obtained materials in solvents with an increase in the content of the vulcanizing agent. Peroxide dynamic vulcanization has not lead to a significant increase in physical and mechanical parameters, however, it resulted in an increase in chemical resistance of against aggressive solvents.

Stereotactic Radiosurgery as an Effective and Safe Treatment Modality in Central Nervous System Lymphoma, a Single Institution Experience

CNS lymphoma (CNSL) is an aggressive liquid cancer with the potential for rapid progression. Standard treatment regimens for CNSL have included chemotherapy and whole brain radiotherapy (WBRT). WBRT carries a high risk of leukoencephalopathy (LE) manifesting as cognitive decline and is identifiable on brain MRI as fluid attenuation inversion recovery (FLAIR) changes. Stereotactic radiosurgery (SRS) can precisely deliver higher biologically effective doses of radiation, while minimizing damage to surrounding healthy brain tissue. SRS offers enhanced local control in CNSL with minimal risk of LE. Patients undergoing SRS at an NCI-designated comprehensive cancer center from 2000 to 2022 were prospectively enrolled into a database. Twenty-nine consecutive patients diagnosed with relapsed primary CNSL (59%) or secondary CNSL (41%) were included in this study. Median age at diagnosis was 70 (range 23-91) years and 14 were female. Follow up MRI imaging was obtained at 1-, 3-, 6- and 12-months post-procedure. Measurement of tumor volumes was performed at treatment and each subsequent follow-up by image co-registration and tumor segmentation. Pre and post SRS brain MRIs were independently reviewed by a neuro-radiologist to score the grade of LE for each patient. Progression-free survival (PFS) and overall survival (OS) were calculated using Kaplan-Meier analyses and Log-rank tests using statistical software. Twenty-nine patients treated for 50 tumors were studied. Twenty-four patients were treated for a single tumor, and 5 for multiple tumors. Six patients underwent repeat SRS treatment for 10 out-of-field recurrences and 1 patient for an in-field recurrence. Of the 35 SRS procedures performed, 32 (88%) were single session delivery and 3 were hypofractionated. Stereotactic immobilization was achieved with frame (57%) or thermoplastic mask (43%). Median prescribed dose was 14 Gy (range 10-21) to the 50% isodose line (range 40-100). Median coverage, selectivity and gradient index were 0.97, 0.69, and 2.9 respectively. Median follow-up time was 4.5 months (range 0.5-64). Twenty-six (52%) tumors completely responded to treatment with no residual enhancement, while the rest decreased in volume. No tumor failed to respond to treatment. Median time to best volumetric response was achieved in 2.9 months (range 1-6.1) and median volume of best response was zero cc (range 0-1.19). The median OS of the cohort was 7.0 months (95% CI 5.1-8.9), while the median PFS was 5.0 months (95% CI 1.2-8.8). Median score of LE was zero, and only one patient experienced grade 3 MRI FLAIR changes. With a median time to response of 2.9 months, a 100% initial response rate and a single in-field failure, our analysis demonstrates a rapid and effective response of CNSL to SRS. Distant failures were controlled with repeat SRS. The absence of LE in the treated patients provides further evidence for safety and tolerability of SRS in CNSL.

ПРОЕКТИРОВАНИЕ СТАНЦИЙ ПЕРЕКАЧКИ ЗАГРЯЗНЕННЫХ И АГРЕССИВНЫХ ЖИДКИХ СРЕД НА ОСНОВЕ ЦИФРОВЫХ ИНФОРМАЦИОННЫХ МОДЕЛЕЙ

An informational description of the pump station for polluted and aggressive liquids has been given. The stages of designing stations using a digital information model and a scheme for using the model in design have been presented. An algorithm of designing pump stations of polluted and aggressive liquids has been developed.

Analysis of mechanical impurities contained in pumped liquids at the fields of Western Siberia

Purpose of the study: analyze the mechanical impurities contained in the pumped liquids. To achieve this goal, the paper set the task of conducting a physicochemical analysis of the composition of solid deposits on parts that come into contact with an aggressive liquid. Scientific hypothesis Improving the reliability of field pipeline and pumping hydraulic systems is one of the most important tasks in oil production. In addition to oil, a significant amount of corrosive fluid is increasingly released from the reservoir during production, damaging the parts through which it passes. This naturally leads to the appearance of the most important complication during operation - deposits of paraffins and hydrates. The article is devoted to the study of the mineralogical and granulometric composition of mechanical impurities that destroy the pipeline network and pumping hydraulic system in the fields of Western Siberia. In this paper, mechanical impurities contained in pumped liquids at the Samotlor and Khokhryakovskoye fields are analyzed. Premature failure of the productive operation of the equipment is due to the aggressiveness of groundwater injected into the reservoir. A physicochemical analysis of the compositions of solid deposits on damaged parts of oilfield equipment was carried out - a laboratory analysis of the granulometric and mineralogical composition of mechanical impurities was carried out. Appropriate conclusions are drawn . Proposed measures to prevent the processes of salt deposition.

Research of hydroabrasive wear resistance of organomineral coatings depending on operating environment conditions

The critical importance of corrosion protection puts it forward as a leading economic and applied problem for all countries. Costs associated with corrosion, even in developed countries, range from 1 to 3.5 per cent of gross domestic product (GDP). This article discusses issues related to the development of the composition of anti-corrosion materials from organo-mineral heterocomposites for use in structures for the storage and transportation of various aggressive liquids. Experiments were carried out in real operating conditions of equipment for storage and transportation of oil and oil products. Based on the study of the composition of associated water, taking into account the influence of mechanical impurities, the phenomena occurring on the surface of the metal were studied and the optimal composition was selected, the use of which will increase the service life.

State of the art: Correlation self-healing agent and corrosion on concrete

Corrosion is a common problem in reinforced concrete construction. Corrosion in reinforced concrete can be initiated by cracks forming on the surface of the concrete. Widening the cracks will facilitate the ingress of aggressive liquids or gases from the surrounding environment, which will cause problems with the reinforcement and form corrosion. Self-healing methods on concrete can make efforts to prevent crack widening. The self-healing concrete method is an effort to repair damage to concrete that doesn't rely too much on the role of humans. The self-healing concrete is expected to reduce the level of cracking in concrete and reduce the diffusion rate of chloride ions in concrete to extend the concrete's life and maintain the concrete's ability to deal with environmental conditions that are too acidic. Some literature also mentions that adding self-healing agents to the concrete mixture can increase the concrete's compressive and flexural strength value. This paper describes several prospective self-healing agents for use in self-healing concrete, also the relationship between the effect of adding self-healing agents on corrosion in reinforced concrete.

Permeability and solute sorption of unamended and polymer-enhanced geosynthetic clay liners

Polymer treatment is an increasingly adopted approach to mitigate the impact of aggressive liquids on the hydraulic performance of geosynthetic clay liners (GCLs). Dense prehydrated (DPH) GCLs are particular products that combine polymer treatment, prehydration and densification to improve the overall containment performance. This study investigated the saturated hydraulic conductivity, k, and heavy-metal retention in a conventional GCL and a DPH GCL. Both materials were permeated first with water and then with a synthetic solution containing zinc (Zn), copper (Cu) and lead (Pb), also with the purpose of extending a previous study where a solution of the same solutes at higher concentrations had been used. The k of the conventional GCL increased by one order of magnitude with respect to that of water upon permeation with the synthetic solution. The solutes were partly retained, and the increase in k was associated with the breakthrough of solutes. Upon permeation with the same solution, the k of the DPH GCL decreased by a factor of 1.6 with respect to that of water. No significant breakthrough of metals was observed, despite the considerably longer test duration. Under the adopted testing conditions, owing to polymer amendment and densification, the hydraulic performance and solute retention properties of the DPH GCLs were superior to those of the conventional GCL.

Effect of sustained service loads on the self-healing and corrosion of bacterial concretes

The application of bacterial urease driven carbonate precipitation has led to the development of a new biomaterial thatcanfillthecracks and pores of concrete automatically. In the structures, concrete cracks are formed due to different factors such as sustained service loads. Accordingly, increasing crack width facilitates permeation of aggressive liquids and/or gases in the concrete elements which results in considerable damages in reinforced concrete members. In this study, the effect of sustained service loads on the steel corrosion and self-healing process of reinforced concrete beams containing Sporosarcina pasteurii bacteria have been investigated. Therefore, bio-treated concretes containing culture medium and calcium nitrate-urea or calcium chloride-urea as bacteria nutrients were used in the mix designs. The physical, mechanical and hydraulic properties of bio-treated concretes (e.g., compressive strength, flexural bearing capacity, water flow through the cracks, and microstructural tests) were characterized to evaluate the performance of biological self-healing. Results showed that the compressive and tensile strength of bio-treated samples were increased relative to the control treatment by 44% and 36%, respectively. In addition, water flow tests showed that the bio-treated concretes are able to completely fill the cracks. However ultrasonic measurements as well as recovered tensile strength tests revealed that the healing is not complete, where up to 84% of healing degree was seen in the bio-treated concretes. Although applying the service loads significantly delays the self-healing process, the bio-treated concrete beams were completely healed up to 28 days of re-curing in the water flow test, where a slight healing was observed for the control beams. Moreover, results revealed that the corrosion probability of the reinforcements decreased when calcium nitrate used as bacteria nutrient, but it is significantly increased in case of calcium chloride usage. Finally, the morphology of precipitated CaCO3 crystals showed that CaCO3 was mainly precipitated in the form of calcite and vaterite crystals.

Boride Coatings on Steel Protecting it Against Corrosion by a Liquid Lead-Free Solder Alloy

The goal of this research is to study the applicability of the diffusion boriding process as a high-temperature thermochemical heat treatment to enhance the lifetime of steel selective soldering tools. The main purpose of the work is to discuss the behavior of double-phase (FeB/Fe2B) iron-boride coating on the surface of different steels (DC04, C45, CK60, and C105U) against the stationary SAC309 lead-free solder liquid alloy. The boride coating was formed on the surface of the steel samples through the powder pack boriding technique. The microstructure of the formed layer was examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The borided samples were first cut in half and then immersed into a stationary SAC309 lead-free solder liquid alloy (Sn–3Ag–0.9Cu) for 40 days. Microstructure examinations were performed by SEM with energy-dispersive spectroscopy and an elemental distribution map after the dissolution test. Excessive dissolution/corrosion of the original steel surface was observed at the steel/SAC interfaces, leading also to the formation of Fe–Sn intermetallic phases. This was found to be the major reason for the failure of selective soldering tools made of steel. On the contrary, no dissolution and no intermetallic compounds were observed at the FeB/SAC and at the Fe2B/SAC interfaces; as a result, the thicknesses of the FeB and Fe2B phases remained the same during the 40-day dissolution tests. Thus, it was concluded that both FeB and Fe2B phases show excellent resistance against the aggressive liquid solder alloy. The results of the dissolution tests show a good agreement with the thermodynamic calculations.

Design, development and test of a novel broach for long polypropylene tubes

Polymers are frequently used for a variety of applications in industry. One relevant field is plastic tubing. As plastic tubes are manufactured from thermoplastic material through hot-extrusion their dimensional accuracy is only moderate. Wherever high accuracy on tube diameters and roundness are required, the conventional production techniques reach their limits and more complex technologies are needed. Known approaches from metal machining are deep hole drilling and internal broaching. However, machining processes with chip removal on polymeric materials are not so common. Therefore, the authors studied cutting operations of polypropylene experimentally. Based on their findings they designed and built an internal broach for the machining of polypropylene tubes. Finally, the authors tested their developed broaching tool in a relevant industrial environment. The tool not only fulfills the dimensional machining requirements but also solves the present chip evacuation problem in a unique way. It enables free cutting through the whole operation and creates continuous straight chips with no need for chip breakers. Consequently, the timely cleaning step, required in traditional broaching, can be eliminated, which reduces the lead time significantly. Furthermore, the set of materials allows dry broaching. Coolant is not necessary. This leads to less waste, a cleaner production line, and avoids damage through aggressive liquids. Lastly, their design ensures that no loss of dimension occurs when resharpening the tool.

Monitoring compliance with the rules of professional safety medical personnel

Health system are more than three million working now, thousands of treatment-and-prophylactic, pharmaceutical, sanitary and epidemiologic institutions, tens research institutes, centers, highest and average educational institutions at which various household and communication equipment is operated, various medical equipment, are used toxic agents and aggressive liquids. In harmful and adverse working conditions hundreds of thousands workers of health care, including average health workers are occupied. Questions of professional safety of nursing staff on a workplace define a level of quality of labor life of experts and are the most important indicator of quality of the provided medical care. In this regard there is actual a question of means of professional protection of average health workers and observance of rules of professional safety by them.l

Experimental Study of the Resistance to Influence of Aggressive Liquids on Lightweight Concrete.

In light of the scientific research, the corrosion of concrete structures is one of the main problems that may reduce their durability due to the negative impact of the natural environment. The paper analyzes the influence of the type of component on the selected properties of lightweight concrete subjected to the influence of aggressive liquids. Four concrete mixes were prepared with a granular aggregate made of foamed glass (GEGA) and aggregate made of sintered fly ash (GAA) with the use of a mineral additive: silica fly ash. The prepared lightweight concrete after one year was exposed for 60 days to the following environments: strong acid—HCl, 1% and 2% concentration, weak acid—CH3COOH, 1% and 2% concentration, and an aqueous salt solution of Na2SO4, 1% and 2% concentration. Then, the compressive strength was tested, and the microstructure analysis of the ready-made lightweight concrete (LWC) was performed. The degree of penetration of aggressive solutions into the cracks of the samples was assessed by means of applying 1% phenolphthalein solution. Changes in the weight of lightweight concrete samples after the test period were estimated. The obtained test results indicate that the decrease in the durability of lightweight concrete can be classified as a long-term process. Concrete with GEGA and GAA showed high resistance to aggressive environments. Moreover, the environment containing chlorides turned out to be the most aggressive, while the environment containing sulfates proved to be the least aggressive. The higher the concentration of the destructive factor was, the faster the corrosion process went. This has been proven by measuring the pH using phenolphthalein and carrying out microscopic examination. Concretes containing aggregates made of foamed glass and sintered fly ash are suitable for use both in traditional construction and in facilities exposed to an aggressive environment (e.g., in the chemical industry and at gas stations).

Influence of the rotor speed of the water-ring pump on the vacuum transport unit operation

Vacuum transport units based on water-ring pumps are used for pumping aggressive liquids. The previously developed mathematical model of the liquid pumping process was used to assess the effect of changes in the rotor speed. The load characteristics of the ELRS-45 water-ring vacuum pump from ERSTVAK were used in the calculation. The numerical method was used to solve the system of differential equations. Increasing of the rotor speed leads to a decrease in the absolute pressure in the tank at the end of the first step. As a result, the volume of liquid pumped in one cycle increases significantly. The average performance of the unit is significantly increased. While energy efficiency decreases. The calculated parameters allow you to select the characteristics of automatic control of the system.

Fiber optic Lossy Mode Resonance based sensor for aggressive liquids

A fiber-optic sensor for chemically aggressive environments, such as concentrated solutions of acids and alkalis, has been manufactured. The sensor is based on a single-mode optical fiber with a chemically etched cladding, coated with a thin film of tin dioxide (SnO2) by metalorganic chemical vapor deposition (MOCVD). In the transmission spectra of a SnO2 coated taper lossy mode resonances (LMRs) were observed, the maximum of which shifted to the long-wavelength part of the spectrum, with an increase in the thickness of the deposited film. At a deposition temperature of 345 °C, it was possible to detect the separation of the transverse electric (TE) and transverse magnetic (TM) LMRs for resonances up to the third order. From the change in the position of the 1-st TE LMR, the refractive index and the molar concentration of acids and alkalis in such aggressive liquids as aqueous solutions of HCl, HNO3, H2SO4, NaOH were determined, which, according to our information, is demonstrated for the first time. The high chemical durability of the coating was confirmed by its insusceptibility to aqua regia (AR). The sensitivity of the sensor to changes in the surrounding medium refractive index (SMRI) and the molar concentration of acids was more than 5260 nm/RIU and 32 nm/M, respectively.

A REVIEW OF ANALYTICAL METHODS FOR DETERMINATION OF TYPE- II ANTIDIABETIC DRUGS IN PHARMACEUTICALS AND BIOLOGICAL MATRICES

Its a meglitinide analog is an oral symptom designed to common hour aldohexose excursions. Through not an antidiabetic, it acts in AN analogous manner by binding to antidiabetic receptor likewise on alternative one distinct receptor-» closure of adenosine triphosphate dependent K+ channel-» of depolarization-» internal secretion unharnesses. Repaglinide induces fast onset short-lasting internal secretion discharged. It is administered antero every main meal to stabilize postprandial hyperglycemia; the dose ought to be emitted if a food material is incomprehensible. Because of less permanent action, it perhaps had a lower risk of the seriousness of hypoglycemia. Repaglinide is indicated solely in type-II DM as another to sulfonylureas, or to supplement metformin/long internal secretion. It ought to be avoided in disease. This review delivers a detail description totally different of various analytical ways were printed for the estimation of repaglinide and its combination medicine in prescription drugs and biological matrices. This assessment encompasses different analytical ways such as chemical analysis ways, aggressive liquid activity (HPLC), superior thin-layer activity (HPTLC), liquid chromatography-mass spectroscopic analysis (LC-MS), and ultra-performance liquid activity (UPLC), GC-MS, [LC-ESI-MS-MS], capillary activity (CE), titrimetric and chemical science technique, and designation study for the estimation of repaglinide and together with a mixture.

ОЦЕНКА ВОЗМОЖНОСТИ ПРИМЕНЕНИЯ ВИБРОПОГЛОЩАЮЩЕГО МАТЕРИАЛА НА ОСНОВЕ ПОЛИУРЕТАНА В КАЧЕСТВЕ УПЛОТНИТЕЛЕЙ

The article presents the results of a study of the operational properties of the VTP-1V grade material, including cold flow. It was found that the material of the VTP-1V grade hasn’t cold flow and, according to the complex of properties studied in the work, can be recommended as an alternative to layered polymeric composite materials used in the bolted joints of the aircraft wing rib. The possibility of operating VTP-1V in an environment of aggressive liquids was assessed and it was shown that the material is resistant to the effects of TC-1 fuel, including retaining low deformability under prolonged loading.

ОТХОДЫ ДРЕВЕСИНЫ И СТЕКЛОВОЛОКНО В КОМПОЗИЦИОННЫХ МАТЕРИАЛАХ ДЛЯ ИЗДЕЛИЙ ТРАНСПОРТНОГО СТРОИТЕЛЬСТВА

The results of experimental-theoretical work on the creation of new polymeric materials based on wood waste are considered. This material can be used in the outer layers of a wood-based polymer fiberglass composite in order to increase its strength properties. Instantaneous elastic moduli, conditional tensile strengths, and Poisson's ratio were determined, and the potential chemical activity of the components of the wood-based polymer fiberglass composite was revealed. The fiberglass polymer composite on the furfural-acetone monomer showed good performance when used as a structural composite of containers for storing aggressive liquids, chemically resistant tiles for shop floors, etc., which are exposed to electric current, aggressive liquids, and temperature. This material can be used in wood chemical production, capacities of energy chemical plants, furfural production, as well as in the outer layers of wood-based polymer fiberglass composite in order to increase its strength properties, specifically crack resistance. The basic compositions of the polymer fiberglass composite and its basic regulatory mechanical characteristics are given. This development is a kind of continuation of the theme of the use of forest industry waste for the production of competitive composite materials. This material will allow to utilize a huge amount of forest industry waste. In addition, the use of wood waste as a building material will make it possible to replace wood in some areas, which in turn will reduce logging and increase woodworking efficiency. All this will undoubtedly lead to an improvement in the ecological situation.