Engineering Commons^™

Energy And Resource-Saving Method For Enriching The Waste Water Purified Without Sufficient Purification With Oxygen, Dilobar Khurramova, Mukhtor Khurramov, Sharifa Ganieva, Zulqaynar Nazirov

CHEMISTRY AND CHEMICAL ENGINEERING

In order to implement a reliable and environmentally safe, economically viable method of wastewater enrichment, the goal is to develop an energy- and resource-saving method of oxygen enrichment of wastewater that has not undergone sufficient treatment. Cleaning is carried out in a tank, which is built using rock, which is an algal limestone. Limestone contributes to the improvement of the oxygen regime due to the “conservation” of organic matter in anoxic bottom layers and the acceleration of the process of photosynthesis of unicellular algae. Calcium carbonate is a reagent that provides not only automatic stabilization of water pH at 2/dm …

Kinetics Of Carboxymethylation Reaction Of Cellulose Samples With Different Degree Of Crystallinity, Ilkhom Goyibnazarov, Sherzod Yuldoshov, Abdushukhur Sarimsokov

CHEMISTRY AND CHEMICAL ENGINEERING

No abstract provided.

Mathematical Modeling Of Synthesis 4´,4´´-Di-(1-Methyl-1-Hydroxy-2-Phenylethynyl)-Dibenzo-18-Crown-6, Lyubov Kozinskaya, Dilorom Mirkhamitova

CHEMISTRY AND CHEMICAL ENGINEERING

The main goal of this study is the mathematical modeling of the optimal conditions for the synthesis of 4´,4´´-di-(1-methyl-1-hydroxy-2-phenylethynyl)-dibenzo-18-crown-6 by the least squares method. In the STAT program, iconograms of mathematical modeling of the synthesis and the dependence of the rate of formation of 4´,4´´-di-(1-methyl-1-hydroxy-2-phenylethynyl)-dibenzo-18-crown-6 on temperature and reaction time were obtained, the corresponding analytical dependencies are determined. Mathematical processing of the results of the synthesis of 4´,4´´-di-(1-methyl-1-hydroxy-2-phenylethynyl)-dibenzo-18-crown-6 was carried out, a system of linear equations was compiled using the matrix method. The average reaction rate and the optimum of the mathematical model were determined, and the experimental and calculated …

Synthesis Of Aromatic Acetylene Alcohols Based On Benzaldehyde And Its Halogenated Products, Sanat Samatov, Abduvakhab Ikramov, Saida Abdurakhmanova, Odiljon Ziyadullayev, Guzal Otamukhamedova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this study is to synthesize the corresponding aromatic acetylenic alcohols by alkylation with phenylacetylene in a complex catalytic system based on Zn(OTf)₂ and TBAF·3H₂O for the first time with benzaldehyde and some of its halogen derivatives. The selectivity and stability of catalysts used for the yields of reactions for the synthesis of aromatic acetylene alcohols were analyzed. The effect of benzaldehyde and its halogenated derivatives on the product yield was analyzed. The nature, structure, isomerism, spatial structure and other properties influenced to this reactions were studied. Some features of reactions of synthesis of aromatic …

Study Of Sorption Of Some Metal Ions By The Obtained Phosphoric Acid Cation Exchanger Of Polycondensation Type, Malika Berdieva, Rano Nazirova, Alisher Yuldashev, Umida Sharipova, Dilmurod Azimov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this work is to investigate the sorption of Cu²⁺, Co²⁺, Ni²⁺, UO₂²⁺ ions, etc. depending on the ionic form of the cationite and the pH of the medium on phosphoric acid cationite obtained by forsforylation of a polymer based on cubic waste of the Shurtan gas-chemical complex and a secondary product of the hydrolysis industry – furfural. It was found that copper and UO₂²⁺ ions are best sorbed by cationite when the cationite is in Na form. The UO₂²⁺ ion is sorbed fairly well in …

Thermal Properties Of Polyelectrolyte Complexes Of Bombyx Mori Chitosan With Collagen, Shuhrat Khudoyberdiev, Noira Vokhidova, Mukhitdin Abdurazakov, Sayora Rashidova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the work was to study the thermal behavior of the polyelectrolyte complexes of Bombyx mori ChS with collagen. As a result of the studies, the thermal properties of polyelectrolyte complexes based on Bombyx mori chitosan with collagen in wt. rel. 1:0,1 and 1:0,2 respectively. It has been determined that the most significant weight changes for chitosan with a molecular weight of 15×10³ and the degree of deacetylation of 85% occur at a temperature is 270 °C, when the mass loss rate reaches its maximum value. For collagen, the same temperature is 277 °C. For complexes ChS/collagen …

Glass Micro-Beads For Road Markings On The Basis Of Local Raw Materials, Farrukh Erkinov, Mastura Aripova, Jae-Shin Lee

CHEMISTRY AND CHEMICAL ENGINEERING

One of the priorities for the development of chemical and technological processes in the field of road-building materials and their quality is the production of materials for road markup based on glass micro-beads.

The use of glass micro-beads ensures the required retro-reflection of road marking and indicators of resistance to external influences, compliance with the requirements of regulatory documents. Therefore, the task of developing research approaches to develop a composition and control of road marking, which provide high performance and reduce accidents is an urgent problem.

For this purpose, on the basis of local raw materials, the theoretical foundations of …

Research Of The Process Of Obtaining Crystalline Monocalcium Phosphate Based On Extraction Phosphoric Acid From Phosphorites Of Central Kyzylkums, Kholtura Mirzakulov, Gavkhar Melikulova, Mohichehra Shaymardanova, Sherzod Khujamberdiev

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the research is to establish the optimal parameters of the technological process for the production of feed, crystalline monocalcium phosphate based on defluorinated and desulphated extraction phosphoric acid obtained from phosphorites of the Central Kyzylkum and limestone.

The influence of technological parameters, such as the norms and concentration of phosphoric acid, the process temperature on the filtration rate indicators, the rheological properties of the suspension and the mother liquor, as well as the dependence of the change in the commercial property of crystalline feed monocalcium phosphate, were studied.

It is shown that, regardless of the initial acid …

Investigations Of Roasting Process And Fractional Composition Of Zinc Concentrate Of Khandiza Deposit, Jasur Makhmayorov, Zafar Khakimov, Bakhrom Makhkamov, Murodjon Samadiy

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study is to study the effect of the process of calcining zinc concentrate from the Khandiza deposit on the degree of zinc extraction and fractional composition. For this, the chemical composition of the concentrate was established and it was shown that the main components are zinc, silicon, potassium, calcium, iron, copper, cadmium, and lead. Titanium, manganese, cobalt, and molybdenum are also contained in small amounts.

Extraction of zinc from a concentrate, calcined at 900 °C for 90 minutes with sulfuric acid with concentration of 18-25% in an autoclave at a temperature of 75 °C, a ratio …

Technology For Producing Alumosilicate Refractory Products Based On Non-Traditional Raw Materials Of Uzbekistan, Ripsime Mkrtchyan

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study is to develop a technology for producing aluminosilicate refractory products based on non-traditional raw materials - clay shale from the Jerdanak deposit and quartz-pyrophyllite rock from the Boynaksai deposit. The characteristics of prototypes of refractory materials were studied at different ratios of chamotte and binder. Quartz-pyrophyllite rock in its natural state and clay shale after firing at a relatively low temperature (1000 °C) were used as fireclay. The phase composition of the obtained materials was studied by X-ray diffraction and their fine structure by electron microscopy. Technological schemes for obtaining refractory products based on clay …

Understanding The Photodegradation Mechanism Of Gaseous Acetaldehyde Over Bi2wo6 – Modified Znwo4 Photocatalyst Under Uv Light Irradiation, Mirabbos Hojamberdiev, Ronald Vargas, Shahlo Daminova, Zuhra Kadirova

CHEMISTRY AND CHEMICAL ENGINEERING

Indoor air quality has a significant impact on human health as people spend more time indoors. As a common indoor air pollutant, acetaldehyde is considered toxic when exposed to it for a prolonged period. The aim of this study is the enhancement of the photocatalytic activity of ZnWO₄ with a monoclinic wolframite structure for degradation of gaseous acetaldehyde by modifying its surface with Bi₂WO₆ layered structure. The mechanisms behind the enhanced photocatalytic activity and the pathways for acetaldehyde photodegradation over the Bi₂WO₆-modified ZnWO₄ photocatalyst are discussed.

Modelling Of Reаctive Distillаtion Process For Etherificаtion Reаction, Adham Norkobilov, Olimjon Mаksudov, Abdulaziz Bаkhtiyorov, Orifjon Zаripov, Abbos Elmаnov

CHEMISTRY AND CHEMICAL ENGINEERING

А reаctive distillаtion system is exаmined to produce for the production of Ethyl tert butyl ether (ETBE) viа etherificаtion of isobutene with ethаnol. Optimizаtion methods using heаt integrаtion аre аlso conducted. The molаr reflux rаtio аnd reboiler duty аre cаlculаted using sensitivity аnаlysis. The bottom streаm with the sаtisfied purity of ETBE is integrаted for heаting the feed streаm to the column. Heаt integrаtion from reаctor heаt to the initiаl feed streаm аnd from bottom streаm of the column to the column inlet streаm with the purpose of аchieving tаrget feed temperаture leаds to high conversion in the reаctive distillаtion …

Study Of Various Quality Characteristics Of Polyester Fibers Obtained On The Basis Of Primary And Secondary Polyethylene Terephthalate, Samida Ernzarova, Asror Juraev, Muzaffar Alimukhamedov, Farhod Magrupov

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of study is comprehensive determination of various quality characteristics of polyester fibers obtained on the basis of primary and secondary polyethylene terephthalate. The analysis of the raw material base of pre-oriented yarns (POY) threads has been carried out. The technological, physicomechanical properties, as well as the structure of the primary and secondary polyethylene terephthalate used in the production of the threads have been studied. The structure and properties of polyethylene terephthalate changed: the properties were worse, the structure were amorphous, the molecular weight decreased. The structure of recycled polyethylene terephthalate changed as a result of technological conversions in …

Мulti-Layer Fibrous Material Based On Textile Waste, Sevara Alimkhanova, Nodir Mirzaev, Adham Rafikov

CHEMISTRY AND CHEMICAL ENGINEERING

At the textile and sewing and knitting enterprises of the Republic of Uzbekistan, the number of which increases every year, a sufficient amount of technological waste is accumulated, which formed in the processes of sizing yarn, starting and setting up equipment, designing and sewing products. Meanwhile, there is a shortage of warm, comfortable, light, soft lining materials for clothes and shoes based on natural raw materials. With the purpose of rational use of textile waste - shredded, disheveled scraps of fabric and knitwear, a multilayer nonwoven material for details of clothing and footwear has been obtained. The material formed by …

Spectral Features And Hydrogen Bond Structure Of Aqueous Solutions Of Ethanol, Dilbar Bozorova, Shukur Gofurov, Mavlonbek Ziyayev, Abdulmutallib Kokhkharov, Oksana Ismailova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is develop an approach that makes it possible to study the spectral properties and structure of intermolecular hydrogen bonds in aqueous solutions of ethanol formed in systems whose existence in a gaseous medium or an isolated state is practically impossible. This approach bases on the combined use of infrared spectroscopy and molecular dynamics (MD) methods. An analysis give the structural reorganization of water molecules depending on the concentration of ethanol alcohol. It has been shown that the method of molecular dynamics with classical force fields makes it possible to explicitly take into account the molecules …

Determination Of The Stability Of Complex Compounds Of Copper (Ii), Zinc (Ii), Cadmium (Ii) And Silver (I) With Covalently Immobilized Sulfur Contain Ligands, Sherzod Kasimov, Khayit Turaev, Abdulakhat Jalilov, Farkhod Narmuratov, Zulkhumor Jumayeva

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this study is to determine the stability of the obtained coordination compounds of some d-metals with covalent immobilized sulfur-containing ligands. To achieve this goal, coordination compounds of copper (II), zinc (II), cadmium (II) and silver (I) ions with covalent immobilized sulfur-containing ligands - О,О-di- (2-aminoethyl) -dithiophosphate potassium - polyester matrix (KD2AEDTP-PEM), O,O-di- (2-aminoethyl) -dithiophosphate potassium - carbamide-formaldehyde matrix (KD2AEDTP-KFM). Studies were carried out to determine the acid-base properties of covalent-immobilized sulfur-containing ligands - KD2AEDTP-PEM, KD2AEDTP-KFM and the concentration stability of the obtained coordination compounds with ions of copper (II), zinc (II), cadmium (II), and silver (I). Based …

Synthesis And Spectroscopic Study Of Complex Compounds Mn(Ii), Co(Ii), Cu(Ii) And Zn With 5-Amino-2-Mercaptobenzimidazole, Lobar Gapurova, Dilnoza Rakhmonova, Shakhnoza Kadirova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is to study the effect of the nature of electron-donor and electron-withdrawing substituents in the molecules of heterocyclic ligands, the nature of acidoligands and transition metal ions on the properties of the synthesized coordination compounds. A method for the synthesis of new complex compounds of Mn (II), Cо (II), Cu (II) and Zn with 5-amino-2-mercaptobenzimidazole has been developed and the composition and structure of the synthesized complex compounds have been studied using modern physicochemical methods, such as elemental, thermogravimetric, X-ray phase analysis and IR spectroscopy. Coordination competing donor centers, electronic and geometric structures of the …

Resistance Of Polystyrol Concrete To Dynamic Impact Loads, Natalya Dubovitskaya, Zamira Mukhamedbaeva, Abduvali Mukhamedbaev

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study is to increase the resistance of polystyrene concrete obtained from recycled polystyrene to dynamic shock loads. The issues of resistance of polystyrene concrete to compression forces with increasing load are considered. It was found that in terms of impact resistance, polystyrene concrete can be classified as a viscous material capable of absorbing high energy of shock loads. It has been determined that when Na₂SO₄ is introduced as a hardening accelerator, polystyrene concrete samples can absorb an impact energy of more than 178.5 J.

Features Of The Formation Of The Coating Structure On Titanium-Based Alloys, Uchkun Rakhimov, Nasiba Abduraimova, Yulbarskhon Mansurov

CHEMISTRY AND CHEMICAL ENGINEERING

Previously shown that coatings formed on titanium by plasma electrolytic oxidation (PEO) in an electrolyte with zirconium sulfate Zr(SO₄)₂ consisted of ZrO₂ and TiO₂ oxides, their surface layer is enriched with zirconium, they have good protective properties in chlorine-containing media. The resulting layers have a fairly regular distribution of relatively small pores, with a diameter of about 1 μm or less, on the surface. The composition and structure of PEO layers depend on both the composition of the electrolyte and the modes of formation. It is of scientific and practical interest to elucidate the effect …