Chemical Engineering Commons^™

Effect Of Glycol Based Coolant Pollution On Pem Fuel Cells Stack And Recovery Measures, Cong-Yi Zhu, Xiao-Hui Li, Quan-Quan Gan

Journal of Electrochemistry

As the heat conduction medium of fuel cell cooling system, coolant is very important for the thermal management of fuel cell stack. In practical application, coolant leakage into the stack often occurs. Due to the randomness of fault location of components, the location of coolant leakage is uncertain, which may occur on the cathode side or anode side of some or all single cells. The main effects of coolant pollution on fuel cell stack are as follows: the output of open circuit voltage decreases sharply, the consistency of single cells voltage decreases and so on, which seriously affects the normal …

Formation And Morphological Evolution Of Nanoporous Anodized Iron Oxide Films, Jin-Wei Cao, Nan Gao, Zhao-Qing Gao, Chen Wang, Sheng-Yan Shang, Yun-Peng Wang, Hai-Tao Ma

Journal of Electrochemistry

The preparation of iron oxide films with nanoporous structure by anodization has attracted much attention for its potential applications. However, the formation mechanism of porous structure during anodization is still unclear. In this paper, the composition of anodic current during the formation of nanoporous anodized iron oxide film was analyzed in combination with the current density-potential response (I-V curve) and the derivation of Faraday’s law. The results showed that the anodic current consisted of an ionic current (leading to the migration of ions to form oxide) and an electronic current (leading to the oxygen evolution), and the …

Copper Nanoparticles In-Situ Anchored On Nitrogen-Doped Carbon For High-Efficiency Oxygen Reduction Reaction Electrocatalyst, Hui-Fang Yuan, Yue Zhang, Xing-Wu Zhai, Li-Bing Hu, Gui-Xian Ge, Gang Wang, Feng Yu, Bin Dai

Journal of Electrochemistry

Compared with noble metal platinum (Pt)-based catalysts, inexpensive non-noble metal electrocatalysts have attracted extensive attention for oxygen reduction reaction (ORR). Herein, chitosan as a kind of biomass resource rich in nitrogen and carbon was used to prepare nitrogen-doped carbon (N-C) and N-C in-situ anchored by copper nanoparticles (Cu/N-C). The as-obtained N-C and Cu/N-C nanoparticles were successfully used as non-noble eletrocatalysts tested for ORR. Compared with the N-C, the Cu/N-C showed the high surface area of 607.3 m ²·g^-1 with the mean pore size of 2.5 nm and the pore volume of 0.40 cm³·g^{-1 …}

Structure Analysis Of Pemfc Cathode Catalyst Layer, Rui-Qing Wang, Sheng Sui

Journal of Electrochemistry

The sluggish oxygen reduction reaction (ORR) on the cathode of the proton exchange membrane fuel cell (PEMFC) has always been one of the key factors limiting its commercialization. The optimization of the cathode catalytic layer structure plays an important role in improving fuel cell performance and reducing production costs. In this paper, two different catalysts (platinum nanoparticles (Pt-NPs) and platinum nanowires (Pt-NWs)) were prepared by using catalyst coated substrate (CCS) method. By constructing a double-layer catalytic layer structure, we analyzed the effect of different catalytic layer structures by performing a single cell test. The results showed that the dense platinum …

Methods Of Improving Complex Cleaning Of Sand Plugs In Khodjaobad Underground Gas Wells, Abdulaziz Murodov, Muhriddin Muydinov, Saidaziz Khabibullaev, Aziz Abidov

Technical science and innovation

The purpose of the study is to develop recommendations for improving the methods of cleaning complex sand plugs in wells of underground gas storage. To organize the correct and efficient use of underground gas storage, the bottom of wells must be kept clean. The article develops recommendations on the use of optimal methods for cleaning wells from complex sand jams on the example of Khujabad UGS. In addition, recommendations were developed for the operation of production wells in the horizons of the XX-XXI-XXII underground gas storage of Khujabad

Development Of Asphalt-Resin-Paraffin Deposits Solvent, Gulmira Todjiyeva, F Badriddinova, M Tursunov, H Kadirov, E Cherkasova

Technical science and innovation

A solvent which is a mixture of aromatic hydrocarbons of the C₉ fraction and aliphatic alcohols in a 1:1 ratio, a nonionic surfactant in an amount of 1 - 3% by weight has been developed. It leads to an increase in the dissolving and washing capabilities of the solvent for more than 2 times in relation to paraffin-type AS. The ability of the chemical composition, which is a solvent composition, to have a depressant-dispersing effect in relation to paraffin-type AS has been determined.

Despite a large number of studies devoted to the development of technologies for the removal of …

Research Of New Fireproof Supplied Polymer Composites Based On Epoxy Resin For Metal Structures, Kuvondiq Murtazaev, F.N. Nurkulov, D.N. Mukhiddinov, M.T. Аbdirova

Technical science and innovation

In the article proposes new compositions based on fire retardant expanded polymer composites of epoxy resin ED-20 and phosphorus-containing oligomers, catalysts, aluminum hydroxide and nitrogen-containing compounds.

The obtained sample of fire retardant expanded polymer composites based on epoxy resin, as well as the initial substances, were investigated by IR spectroscopy (Nicolet 5700), thermogravimetric analysis (TG) (SDT Q600) of physical and chemical properties and determination of fire retardant efficiency according to GOST R 53295-2009.

Infrared spectroscopy has been used to determine the bends and epoxy groups that characterize composites, as well as to determine the frequencies of phosphorus, nitrogen, and metal-containing …

A Proper Framework For Studying Noise From Jets With Non-Compact Sources, Woutijn J. Baars, Nathan E. Murray, Charles E. Tinney

Faculty and Student Publications

A quantitative assessment of the acoustic source field produced by a laboratory-scale heated jet with a gas dynamic Mach number of 1.55 and an acoustic Mach number of 2.41 is performed using arrays of microphones that are traversed across the axial and radial plane of the jet's acoustic field. The nozzle contour comprises a method of characteristics shape so that shock-related noise is minimal and the dominant sound production mechanism is from Mach waves. The spatial topography of the overall sound pressure level is shown to be dominated by a distinct lobe residing on the principal acoustic emission path, which …

Design Lifecycle Management Of Technological Processes, Yusuf Shodiyevich Avazov

Chemical Technology, Control and Management

The issues of life cycle management of design processes of complex technological processes are considered. An analysis of works devoted to the automated design of technological processes and industries, product life cycle management, and the use of predominant modeling in design is presented. A structure for the implementation of the design of technological processes is proposed and it’s components are described. An algorithm is proposed to reduce the life cycle of the design of a technological process. The sequence of selection of the most optimal project options with the help of the proposed algorithm is described. It is shown that …

Uncertainty Of The Ultrasonic Method For Determining The Strength Of Concrete, Ortagoli Sharipovich Hakimov, Zamira Khudoyberdiyevna Ernazarova

Chemical Technology, Control and Management

The issues of measuring the strength of concrete by the method of surface sounding by ultrasound are considered. A measurement model and formulas for estimating the total standard measurement uncertainty, information about the standards used, measurement tools and methods, and environmental parameters are given. Information about the estimation of uncertainty in the form of "eight steps", such as: measurement task; mathematical model of measurement; analysis of input values; observation results; correlations; uncertainty budget; expanded uncertainty; measurement result. It has been established that the uncertainty of type B of the ultrasonic method for determining the strength of concrete is much less …

Quality Control Of Combustion Of Gaseous Fuel In Furnaces, Azamat Toirovich Rajabov

Chemical Technology, Control and Management

The issues of research and development of systems for monitoring the availability and quality of the process of fuel combustion in industrial furnaces are interpreted. The perspective of using new elements in control systems - communication sensors for the presence and quality in gas-burning installations and furnaces are shown. A method has been developed to control the optimal aeration coefficient based on the extreme of the total integral amplitude-frequency characteristic of the flame conductivity pulsations, which makes it possible to control the quality characteristics of gas-burner devices and control the ratio of the components of the combustible mixture with high …

Regular Algorithms For Adaptive Identification Of Linear Non-Stationary Systems, H.Z. Igamberdiyev, H.I. Sotvoldiev, U.F Mamirov

Chemical Technology, Control and Management

The article deals with the formation of regular algorithms for adaptive parametric spline identification of linear non-stationary systems. Analyzed the issues of constructing adaptive identification of continuous linear non-stationary systems with monotonic and sign-constant parameters. In this case, in a non-stationary system, the entire observation interval is in some way divided into sub-intervals. Identification is carried out at each of the parameter constancy intervals, while the parameter matrix is re-evaluated for the next interval. The input data of the system are determined with an error depending on the error of approximating the state of the system by splines and approximating …

Algorithm For Calculating The Parameters Of A Multi-Position Electromagnetic Linear Mechatronic Module, Nazarov Khayriddin Nuritdinovich, Matyokubov Nurbek Rustamovich, Temurbek Omonboyevich Rakhimov

Chemical Technology, Control and Management

Currently, in the world in the field of science, engineering and technology, including in mechatronics and robotics, the creation of multi-coordinate mechatronic systems that perform power and control functions is becoming of paramount importance, this is due to a number of important positive qualities of the systems, such as simplicity and compactness of the design, the possibility of obtaining significant efforts, high accuracy and stability of the establishment of fixed positions, ease of control and high reliability. This article presents the calculation of the parameters of multi-position mechatronic modules based on linear execution elements. In the construction of this model, …

Developing Advanced Process Control System For Manufacturing Processes Using Virtual Analyzer, Elyor Erkinovich Samadov

Chemical Technology, Control and Management

This research reflects outlines the main potential features of Advanced Process Control (APC) systems for improved control of technological processes and production. It is shown developing APC systems using a virtualized analyzer (VA) is a very effective technique to increase the efficiency of industrial production. This research reflects the main steps of generating VA as part of the APC system and also describes the key features of each step-in terms of analyzer synthesis.

Mathematical Modeling Of Processes Of Diagnostics Of Technical And Technological Objects, Azizbek Nodirbekovich Yusupbekov, Khurshid Salim Ugli Turayev

Chemical Technology, Control and Management

The work is an introduction to the technical diagnostics of technical (or technological) objects. It discloses the basic concepts and definitions of the reliability of dynamic systems as objects of diagnostic reference knowledge and their diagnosis. Structural schemes of diagnosing objects with individual and combined channels of influence are analyzed. Questions of rational construction of base of reference knowledge are stated.

A Novel Dental Re-Mineralizing Blend Of Hydroxyethyl-Cellulose And Cellulose Nanofibers Oral Film Loaded With Nepheline Apatite Glass: Preparation, Characterization And In Vitro Evaluation Of Re-Mineralizing Effect, Dalia Y. Zaki, Engie M. Safwat, Shaymaa M. Nagi, Haidy N. Salem, Tamer M. Hamdy, Lamiaa M. Moharam, Mohammad L. Hassan, E. M.A. Hamzawy

Chemical and Biochemical Engineering Faculty Research & Creative Works

The present investigation aimed to prepare and evaluate an innovated re-mineralizing oral films made from a blend of hydroxyethyl-cellulose (HEC) and cellulose nanofibers (CNF), loaded with nepheline fluorapatite glass powder. Evaluation of film thickness, folding endurance, disintegration time, surface pH, ions release, together with SEM were carried out. In vitro re-mineralizing effect of the prepared film on demineralized teeth was examined. Results revealed the uniformity in thickness of films, folding endurance more than 300, and the disintegration times more than 24 hrs. The pH values were nearly neutral and high concentrations of calcium and fluoride ions were released. SEM showed …

Predictive Analysis And Synthesis, Modeling And Control Of Complex Technological Processes And Systems, Zhahongir Sherboyevich Bekqulov

Chemical Technology, Control and Management

Consider the theoretical underpinnings of practically predictive analysis and synthesis, modeling and automatic control of complex chemical technological processes and systems, and the evolution of advanced (or advanced) APC (Advanced Process Control) control of technological processes and industries. The current state of industrial automation systems and the characteristics of their deployment are highlighted. The features of each stage of the analysis and synthesis of APC - advanced process control for complex dynamic objects are disclosed. The real situation and features of the implementation of industrial automation systems of industrial enterprises are reflected.

New Transformer Changer Static Characteristics Measuring Angle Silences Difference, Sultan Faizullayevich Аmirov, Nurulla Raxmatullayevich Yuldashev

Chemical Technology, Control and Management

Presented the specific features of the new transformer converter, which measures the difference in angular displacement, and examines the nonlinearity levels of static characteristics, sensitivity and static characteristics. Studies have shown that in a new measuring device, where one of the two moving parts consists of a magnetic conductor made in the form of an Archimedean spiral made of ferromagnetic material, the balance of the magnetic bridge changes not only depending on the angle of rotation of it’s shoulder resistances. the current is disturbed by the change in the magnitude of the combined air gap depending on the angle of …

Virtual Analyzers For Increasing The Intelligence Of Industrial Process Control Systems, Umidjon Abdimajotovich Ruziev Phd, Marufjon Kobuljanovich Shodiev

Chemical Technology, Control and Management

It is shown that the development and implementation of virtual analyzers of the quality of the final industrial products is an effective tool for increasing the efficiency of industrial production. The methodology and stages of development of virtual analyzers for predicting the quality of products, monitoring non-measurable or difficult-to-measure parameters of continuous and periodic technological processes are considered, and issues of supporting and adapting a virtual analyzer during its operation without restructuring are also considered.

Review—Concentration Measurements In Molten Chloride Salts Using Electrochemical Methods, Tyler Williams, Rankin Shum, Devin Rappleye

Faculty Publications

The electrochemical measurement of concentration in molten chloride salts is a valuable tool for the control of existing and potential industrial processes, recycling of precious materials and energy production. The electrochemical techniques commonly used to measure concentration and each techniques’ associated theory are discussed. Practices which improve measurement accuracy and precision are set forth. Exceptionally accurate and precise measurements published in the literature are evaluated based on their performance in specified concentration ranges. The strengths and weaknesses of the most accurate measurements are briefly explored. Chronopotentiometry (CP) and square wave voltammetry (SWV) are accurate and precise with low concentration measurements. …