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2020

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Articles 4441 - 4470 of 10642

Full-Text Articles in Engineering

Flow Simulation Considering Adsorption Boundary Layer Based On Digital Rock And Finite Element Method, Yong Fei Yang, Ke Wang, Qian Fei Lv, Roohollah Askari, Qing Yan Mei, Jun Yao, Jie Xin Hou, Kai Zhang, Ai Fen Li, Chen Chen Wang Jun 2020

Flow Simulation Considering Adsorption Boundary Layer Based On Digital Rock And Finite Element Method, Yong Fei Yang, Ke Wang, Qian Fei Lv, Roohollah Askari, Qing Yan Mei, Jun Yao, Jie Xin Hou, Kai Zhang, Ai Fen Li, Chen Chen Wang

Michigan Tech Publications, Part 1

Due to the low permeability of tight reservoirs, throats play a significant role in controlling fluid flow. Although many studies have been conducted to investigate fluid flow in throats in the microscale domain, comparatively fewer works have been devoted to study the effect of adsorption boundary layer (ABL) in throats based on the digital rock method. By considering an ABL, we investigate its effects on fluid flow. We build digital rock model based on computed tomography technology. Then, microscopic pore structures are extracted with watershed segmentation and pore geometries are meshed through Delaunay triangulation approach. Finally, using the meshed digital …

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Multipath Exploitation-Based Indoor Target Localization Model Using Single Marginal Antenna, Joseph Sisala Jun 2020

Multipath Exploitation-Based Indoor Target Localization Model Using Single Marginal Antenna, Joseph Sisala

Tanzania Journal of Engineering and Technology (TJET)

Recently, indoor target localization became an area of interest due to its diverse applications. In indoor target localization, surrounding environment creates multipath components, which can be exploited to aid in localization process. A number of studies have been proposed to employ multipath exploitation in localizing indoor targets. However, their localization errors can still be improved. This study proposed a new localization model based on multipath exploitation techniques by using triangulation method. Ultra-wide band signals were resolved and associated using marginal antenna-based scheme. The estimate of the target location was then obtained using measured round-trip time delays. The location was determined …

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Automatic Delamination Segmentation For Bridge Deck Based On Encoder-Decoder Deep Learning Through Uav-Based Thermography, Chongsheng Cheng, Zhexiong Shang, Zhigang Shen Jun 2020

Automatic Delamination Segmentation For Bridge Deck Based On Encoder-Decoder Deep Learning Through Uav-Based Thermography, Chongsheng Cheng, Zhexiong Shang, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

Concrete deck delamination often demonstrates strong variations in size, shape, and temperature distribution under the influences of outdoor weather conditions. The strong variations create challenges for pure analytical solutions in infrared image segmentation of delaminated areas. The recently developed supervised deep learning approach demonstrated the potentials in achieving automatic segmentation of RGB images. However, its effectiveness in segmenting thermal images remains under-explored. The main challenge lies in the development of specific models and the generation of a large range of labeled infrared images for training. To address this challenge, a customized deep learning model based on encoder-decoder architecture is proposed …

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Evaluating Cracking Performance Of Polymer Enhanced And Fiber Reinforced Microsurface Mixtures Using Asphalt Laboratory Testing, George Joseph Shackil Jun 2020

Evaluating Cracking Performance Of Polymer Enhanced And Fiber Reinforced Microsurface Mixtures Using Asphalt Laboratory Testing, George Joseph Shackil

Theses and Dissertations

This study presents a method to improve and evaluate the cracking resistance of microsurfacing mixtures using common asphalt laboratory testing. A preliminary optimal timing study and a study to evaluate improvements to cracking performance were conducted. The control mixture was based on NJDOT standard mix design specifications. Three mixtures were tested in this study: a fiber reinforced mixture using one-quarter inch glass fibers, an emulsion with increased SBR (polymer) contents, and a mixture using the one-quarter inch glass fibers combined with the increased polymer contents. Three laboratory tests were used to evaluate three different cracking resistance parameters: crack initiation (Semi-Circular …

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Distributed Firewall For Iot, Ryan Lund, Anthony Fenzl, Chelsea Villanueva Jun 2020

Distributed Firewall For Iot, Ryan Lund, Anthony Fenzl, Chelsea Villanueva

Computer Science and Engineering Senior Theses

Minimal local resources, lack of consistency in low level protocols and market pressures contribute to IoT devices being more vulnerable than traditional computing devices. These devices not only have a wide variety of processors and implementations, but they often serve different purposes and generate unique network traffic. Current IoT network security solutions fail to account for and handle both the scale at which IoT devices can be deployed and the heterogeneous nature of the traffic they produce. In order to accommodate these differences and improve on current solutions, we propose the implementation of a microsegmented firewall for IoT networks. Unlike …

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Climate Change Impacts The Subsurface Transport Of Atrazine And Estrone Originating From Agricultural Production Activities, Renys Enrique Barrios, Simin Akbariyeh, Chuyang Liu, Khalid Muzamil Gani, Margarita T. Kovalchuk, Xu Li, Yusong Li, Daniel D. Snow, Zhenghong Tang, John Gates, Shannon L. Bartelt-Hunt Jun 2020

Climate Change Impacts The Subsurface Transport Of Atrazine And Estrone Originating From Agricultural Production Activities, Renys Enrique Barrios, Simin Akbariyeh, Chuyang Liu, Khalid Muzamil Gani, Margarita T. Kovalchuk, Xu Li, Yusong Li, Daniel D. Snow, Zhenghong Tang, John Gates, Shannon L. Bartelt-Hunt

Nebraska Water Center: Faculty Publications

Climate change will impact soil properties such as soil moisture, organic carbon and temperature and changes in these properties will influence the sorption, biodegradation and leaching of trace organic contaminants to groundwater. In this study, we conducted a modeling case study to evaluate atrazine and estrone transport in the subsurface under current and future climate conditions at a field site in central Nebraska. According to the modeling results, in the future, enhanced evapotranspiration and increased average air temperature may cause drier soil conditions, which consequently reduces the biodegradation of atrazine and estrone in the water phase. On the other hand, …

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Increasing The Manufacturing Readiness Of Refill Friction Stir Spot Welding, Brigham Ammon Larsen Jun 2020

Increasing The Manufacturing Readiness Of Refill Friction Stir Spot Welding, Brigham Ammon Larsen

Theses and Dissertations

Refill friction stir spot welding (RFSSW) is an emerging technology, capable of joining thin sheets of aluminum alloys. The present thesis comprises two studies which were conducted to address two challenges faced by RFSSW: the long cycle time traditionally associated with welding and the poor life of existing RFFSW tools. In the first study, welds were made in AA5052-H36, at various cycle times and with various process parameters. It was shown that RPM, cycle time, and material thickness, all have an effect on the machine response. Decreasing RPM or weld duration leads to increased force and torque response during welding. …

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Action Recognition Using The Motion Taxonomy, Maxat Alibayev Jun 2020

Action Recognition Using The Motion Taxonomy, Maxat Alibayev

USF Tampa Graduate Theses and Dissertations

In the last years, modern action recognition frameworks with deep architectures have achieved impressive results on the large-scale activity datasets. All state-of-the-art models share one common attribute: two-stream architectures. One deep model takes RGB frames, while the other model is fed with pre-computed optical flow vectors. The outputs of both models are combined to be used as a final probability distribution for the action classes. When comparing the results of individual models with the fused model, it is common to see that that latter method is more superior. Researchers explain that phenomena with the fact that optical flow vectors serve …

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Lcm Permeability Characterization Over Mold Curvature, Benjamin Grant Betteridge Jun 2020

Lcm Permeability Characterization Over Mold Curvature, Benjamin Grant Betteridge

Theses and Dissertations

Composite flow simulation tools for LCM processing can be expensive and time-consuming but necessary to design a mold system with proper placement of resin inlets and vacuum outlets. Composites manufacturing engineers would benefit from data regarding the impact of mold curvature radius on resin flow. This could help determine whether or not a particular part and mold would require expensive simulation software designed to handle complex flow paths through curved fabric architectures exhibiting variable permeability over the curvature, or if simple flow modeling would provide accurate enough simulations for sound tooling setup decision making. Four molds, with double curvature having …

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Observing The Impact Of An Engineering-Based Unit Of Instruction On 6th Grade Students' Attitudes Towards Engineering As Theyengage In Building Electric Bikes, Gregg Allred Olsen Jun 2020

Observing The Impact Of An Engineering-Based Unit Of Instruction On 6th Grade Students' Attitudes Towards Engineering As Theyengage In Building Electric Bikes, Gregg Allred Olsen

Theses and Dissertations

In the past few decades, science, technology, engineering, and math (STEM) education has become a driving force for innovators throughout the world (Atkinson & Mayo, 2010; Bybee, 2010). STEM education has also become an economic factor in developing countries (Kennedy & Odell, 2014). Currently, many countries are struggling with how to effectively promote STEM education. The United States (U.S.) provides an interesting case study. Despite being one of the global economic leaders, it is behind in STEM education compared to other nations (Atkinson & Mayo, 2010; Dugger, 2010). STEM education helps to build world leaders including marketable and knowledgeable employees …

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Mobile Manipulating Drones, Paul Oh Jun 2020

Mobile Manipulating Drones, Paul Oh

INSPIRE Archived Webinars

In the past few years, robotic limbs have been attached to rotorcraft drones to perform aerial manipulation. Unlike simple object pick-and-place, such mobile-manipulating drones are dexterous to perform tasks like valve-turning, hatch-opening, and tool-handling. This is a paradigm shift where such drones actively interact with their environment rather than just passively surveil. Aerial manipulation is challenging because such interaction yields reaction forces and torques that destabilize the drone. This talk will provide an overview of aerial manipulation and showcase examples that could serve in infrastructure inspection, maintenance, and repair.

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The Gridded Retarding Ion Drift Sensor For The Petitsat Cubesat Mission, Ryan L. Davidson, B. Oborn, E. F. Robertson, S. Noel, G. D. Earle, J. Green, J. Kramer Jun 2020

The Gridded Retarding Ion Drift Sensor For The Petitsat Cubesat Mission, Ryan L. Davidson, B. Oborn, E. F. Robertson, S. Noel, G. D. Earle, J. Green, J. Kramer

Electrical and Computer Engineering Faculty Publications

The Gridded Retarding Ion Drift Sensor (GRIDS) is a small sensor that will fly on the 6 U petitSat CubeSat. It is designed to measure the three-dimensional plasma drift velocity vector in the Earth’s ionosphere. The GRIDS also supplies information about the ion temperature, ion density, and the ratio of light to heavy ions present in the ionospheric plasma. It utilizes well-proven techniques that have been successfully validated by similar instruments on larger satellite missions while meeting CubeSat-compatible requirements for low mass, size, and power consumption. GRIDS performs the functions of a Retarding Potential Analyzer (RPA) and an Ion Drift …

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Developing An Equivalent Solid Material Model For Bcc Lattice Cell Structures Involving Vertical And Horizontal Struts, Tahseen A. Alwattar, Ahsan Mian Jun 2020

Developing An Equivalent Solid Material Model For Bcc Lattice Cell Structures Involving Vertical And Horizontal Struts, Tahseen A. Alwattar, Ahsan Mian

Mechanical and Materials Engineering Faculty Publications

In this study, a body-centered cubic (BCC) lattice unit cell occupied inside a frame structure to create a so-called “InsideBCC” is considered. The equivalent quasi-isotropic properties required to describe the material behavior of the InsideBCC unit cell are equivalent Young’s modulus ( E e ) , equivalent shear modulus ( G e ) , and equivalent Poisson’s ratio ( ν e ) . The finite element analysis (FEA) based computational approach is used to simulate and calculate the mechanical responses of InsideBCC unit cell, which are the mechanical responses of the equivalent solid. Two separates finite element models are then …

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Creating Library Learning Spaces That Support Twenty-First Century Pedagogy And Student Learning, Deborah Lynn Christoffersen Jun 2020

Creating Library Learning Spaces That Support Twenty-First Century Pedagogy And Student Learning, Deborah Lynn Christoffersen

Theses and Dissertations

University libraries struggle to keep up with rapidly changing technology and the associated change in teaching strategy. Most administrators and librarians are often not trained to assess space needs and struggle to reassign library spaces for non-traditional library use. As such, they often embark on expensive and time-consuming feasibility studies, using (typically) hard-earned monies to complete the research or to pilot a new space. What academic research library administrators and staff lack is an analysis tool for discovering and planning needed renovations and improvements in aging library facilities. The purpose of this research project was to determine how students use …

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Constitutive Model Of Lateral Unloading Creep Of Soft Soil Under Excess Pore Water Pressure, Wei Huang, Kejun Wen, Xiaojia Deng, Junjie Li, Zhijian Jiang, Yang Li, Lin Li, Farshad Amini Jun 2020

Constitutive Model Of Lateral Unloading Creep Of Soft Soil Under Excess Pore Water Pressure, Wei Huang, Kejun Wen, Xiaojia Deng, Junjie Li, Zhijian Jiang, Yang Li, Lin Li, Farshad Amini

Civil and Architectural Engineering Faculty Research

Presented in this paper is a study on the lateral unloading creep tests under different excess pore water pressures. The marine sedimentary soft soil in Shenzhen, China, was selected in this study. The results show that the excess pore water pressure plays a significant role in enhancing the unloading creep of soft soil. Higher excess pore water pressure brings more obvious creep deformation of soft soil and lower ultimate failure load. Meanwhile, the viscoelastic and the viscoplastic modulus of soft soil were found to exponentially decline with creep time. A modified merchant model and a combined model of the modified …

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Design Of A 7-Mhz Portable Direct Conversion Transceiver With Digitally Controlled Keying, Abram Morphew Jun 2020

Design Of A 7-Mhz Portable Direct Conversion Transceiver With Digitally Controlled Keying, Abram Morphew

Dissertations and Theses

This thesis outlines the design of a portable direct conversion transceiver system for the 7-MHz (or 40m) band. This band is popular due to its propagation characteristics which allow for world-wide communication with very low power. The transceiver utilizes a crystal-stabilized local oscillator optimized for frequency agility, low power consumption, and an optimal drive level of +7 dBm. A low power 8-bit microcontroller acts as an interface for either a straight key providing manual Morse code operation or digital logic control from a personal computer. It also acts as a side tone oscillator providing audio feedback to the operator during …

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Investigation The Nonlinear Optical Properties Of Silver Nanoparticles Using Femtosecond Laser, Al Aboud Wahed Al-Isawi, M. H. Mezher, Ali Z. Ghazi Zahid, Heba Abdul Jaleel Alasady, S. T. Yousif, Maitham Al-Alyawy, W. Y. Chong, R. Zakaria, Sahbudin Shaari, Ali H. Mezher, Hala Musawy, Saad H. Al-Isawi, Afyaa H. Muzher, Jaber K. Taher, A. R. Jaber, A. Q. Latef, B. S. Saleh Jun 2020

Investigation The Nonlinear Optical Properties Of Silver Nanoparticles Using Femtosecond Laser, Al Aboud Wahed Al-Isawi, M. H. Mezher, Ali Z. Ghazi Zahid, Heba Abdul Jaleel Alasady, S. T. Yousif, Maitham Al-Alyawy, W. Y. Chong, R. Zakaria, Sahbudin Shaari, Ali H. Mezher, Hala Musawy, Saad H. Al-Isawi, Afyaa H. Muzher, Jaber K. Taher, A. R. Jaber, A. Q. Latef, B. S. Saleh

Research outputs 2014 to 2021

© 2020 Published under licence by IOP Publishing Ltd. In this research, the fabrication of silver nanoparticles and experimental nonlinear response (NLO). The fabrication of the silver nanoparticles has been done using E-Beam evaporation on a glass substrate (Ag-NPs) and investigation of their nonlinear optical response (NLO). The silver nanoparticles was evaluated by optical spectrum (UV-Vis) that shows localized surface Plasmon band at 375 nm. The experiment shows the nonlinear absorption and nonlinear refraction effect of silver nanoparticles, the silver nanoparticles is analysed by Z-Scan technique using a femtoseconds laser with 800 nm wavelength. The result shows the nonlinear absorption …

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Retention Of Swine Slurry Constituents In Soil And Crop Residue As Affected By Setback Distance, John E. Gilley, Shannon L. Bartelt-Hunt, Kent M. Eskridge, Xu Li, Amy M. Schmidt, Daniel D. Snow Jun 2020

Retention Of Swine Slurry Constituents In Soil And Crop Residue As Affected By Setback Distance, John E. Gilley, Shannon L. Bartelt-Hunt, Kent M. Eskridge, Xu Li, Amy M. Schmidt, Daniel D. Snow

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Setbacks are prescribed distances from surface waters within which manure application is not allowed. Little information is available concerning the retention of swine slurry constituents in soil and crop residue materials within setback areas. This study was conducted to measure the retention of selected constituents within a setback area following the upslope application of swine slurry and the introduction of simulated rainfall. The no-till cropland site had a slope gradient of 4.9% and a mean winter wheat residue cover of 7.73 Mg ha−1 . Soil and vegetative samples were collected on 3.7 m wide by 23.2 m long plots with …

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Conversion Of Self-Contained Breathing Apparatus Mask To Open Source Powered Air-Purifying Particulate Respirator For Fire Fighter Covid-19 Response, Benjamin R. Hubbard, Joshua M. Pearce Jun 2020

Conversion Of Self-Contained Breathing Apparatus Mask To Open Source Powered Air-Purifying Particulate Respirator For Fire Fighter Covid-19 Response, Benjamin R. Hubbard, Joshua M. Pearce

Michigan Tech Publications, Part 1

To assist firefighters and other first responders to use their existing equipment for respiration during the COVID-19 pandemic without using single-use, low-supply, masks, this study outlines an open source kit to convert a 3M-manufactured Scott Safety self-contained breathing apparatus (SCBA) into a powered air-purifying particulate respirator (PAPR). The open source PAPR can be fabricated with a low-cost 3-D printer and widely available components for less than $150, replacing commercial conversion kits saving 85% or full-fledged proprietary PAPRs saving over 90%. The parametric designs allow for adaptation to other core components and can be custom fit specifically to fire-fighter equipment, including …

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An Agent-Based Decision Support Framework For Suas Deployment In Small Infantry Units, Carsten Douglas Christensen Jun 2020

An Agent-Based Decision Support Framework For Suas Deployment In Small Infantry Units, Carsten Douglas Christensen

Theses and Dissertations

Small unmanned aircraft systems (sUAS) will become a disruptive force on the modern battlefield. In recent years, sUAS size and cost have decreased while their capability has increased. They have forced a reconsideration of the air superiority paradigm held since the First World War. Perhaps their most attractive, and worrisome, feature is the huge range of combat roles that they might fulfill. The presence of sUAS on future battlefields is certain, but the role they will play and their impact on those battlefields are not. This work presents a decision support framework for sUAS deployment in small infantry units. The …

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Exploratory Analysis Of Recent Trends In School Travel Mode Choices In The U.S., Abhay Lidbe, Xiaobing Li, Emmanuel Kofi Adanu, Shashi Nambisan, Steven Jones Jun 2020

Exploratory Analysis Of Recent Trends In School Travel Mode Choices In The U.S., Abhay Lidbe, Xiaobing Li, Emmanuel Kofi Adanu, Shashi Nambisan, Steven Jones

Civil and Environmental Engineering and Construction Faculty Research

The study explores the recent trends in school travel using the 2017 National Household Travel Survey data. The study also investigates the exogenous factors affecting the school travel mode choice using random parameters multinomial logit (RPMNL) model. The results indicate that urban school trips range between 3 and 5 miles, whereas, average rural trips are longer than 6 miles. School commute times are higher among lower-income households. Further, the share of school bus and auto has declined while that of walking and biking has increased in 2017. This change is significant among high school students. Like other studies, the findings …

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Nappe Oscillations On Free-Overfall Structures, Data From Laboratory Experiments, Maurine Lodomez, Blake Tullis, Pierre Archambeau, Vasileios Kitsikoudis, Michel Pirotton, Benjamin Dewals, Sébastien Erpicum Jun 2020

Nappe Oscillations On Free-Overfall Structures, Data From Laboratory Experiments, Maurine Lodomez, Blake Tullis, Pierre Archambeau, Vasileios Kitsikoudis, Michel Pirotton, Benjamin Dewals, Sébastien Erpicum

Publications

This paper presents a dataset obtained from fifty-two laboratory experiments of nappe oscillations on free overfall structures. Data were collected on two complementary experimental setups, each consisting of a linear weir model. The dataset covers test configurations involving varied geometric parameters (i.e. weir crest shape, weir width, fall height and nappe confinement) and inflow discharges. The following experimental data were produced: assessment of nappe oscillation occurrence and associated frequencies. The later measurements were performed using characterization techniques (image and sound analysis) developed for this research. Reuse of the collected data will support efforts to improve the understanding of the physical …

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Quantifying The Conditioning Period For Geogrid-Reinforced Aggregate Base Materials Through Cyclic Loading, Chad Derrick Vickery Jun 2020

Quantifying The Conditioning Period For Geogrid-Reinforced Aggregate Base Materials Through Cyclic Loading, Chad Derrick Vickery

Theses and Dissertations

Geogrid reinforcement can improve the performance of pavements by stiffening the aggregate base material and decreasing pavement deformations. Understanding the effects of cyclic loading on the modulus of geogrid-reinforced base materials would help engineers better anticipate actual increases in the modulus of aggregate base materials under given traffic loads. The objective of this laboratory research was to investigate the effects of cyclic loading on the resilient modulus, the modulus to peak axial stress, the elastic modulus, and the modulus at 2 percent strain of geogrid-reinforced aggregate base materials. The scope of the research included two aggregate base materials (Wells Draw …

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Impacts Of Changing The Transit Signal Priority Requesting Threshold On Bus Performance And General Traffic: A Sensitivity Analysis, Michael Harmon Sheffield Jun 2020

Impacts Of Changing The Transit Signal Priority Requesting Threshold On Bus Performance And General Traffic: A Sensitivity Analysis, Michael Harmon Sheffield

Theses and Dissertations

A sensitivity analysis was performed on the transit signal priority (TSP) requesting threshold to evaluate its impact on bus performance and general traffic. Two distinct bus routes were evaluated to determine the optimal requesting threshold that would balance the positive impacts on bus performance with the negative impacts on general traffic. Route 217, a conventional bus route, and the Utah Valley Express (UVX), a bus rapid transit line, utilize a dedicated short-range communication (DSRC)-based TSP system as part of their normal, day-to-day operations. Using field-generated data exclusively, bus performance and general traffic were evaluated over a 7-month period from February …

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Study Of Recombinant Protein Fractions From The Bombyx Mori And Pichia Pastoris Using "Native Page" Method, Abdurhakhmanov Aloliddin, Sasmakov Sobirdjan, Khasanov Shuhrat, Ashirov Оybek Jun 2020

Study Of Recombinant Protein Fractions From The Bombyx Mori And Pichia Pastoris Using "Native Page" Method, Abdurhakhmanov Aloliddin, Sasmakov Sobirdjan, Khasanov Shuhrat, Ashirov Оybek

CHEMISTRY AND CHEMICAL ENGINEERING

We have studied the recombinant protein fractions of ̴ 24-34 kDa obtained from Bombyx mori - silkworm larvae and yeast Pichia pastoris. Fractions, containing the recombinant proteins by gel-electrophoresis using the “Native PAGE” method, which allows for differentiation of proteins according to their natural (surface) charge and conformational properties were studied. The results showed that the recombinant protein fraction from Bombyx mori (̴ 34 kDa) consisted of four components and fraction from Pichia pastoris (̴ 24 kDa) consisted one component. The most optimal conditions for the “Native PAGE”- the main gel: Tris HCl (pH-8.8) 244 mM, Bis-Acrylamide 10%, TEMED 0.08%, …

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Pressure-Compensated Temperature Control In Rectification Column, Norkobilov Adham, Turakulov Zafar, Kamolov Azizbek, Talipov Hojiakbar Jun 2020

Pressure-Compensated Temperature Control In Rectification Column, Norkobilov Adham, Turakulov Zafar, Kamolov Azizbek, Talipov Hojiakbar

CHEMISTRY AND CHEMICAL ENGINEERING

The focus of this work is to study the control of a rectification column (RC) for separating n-butane (nC4) and n-pentane (nC5) mixtures. Two control structures based on conventional temperature control (TC) and pressure-compensated control (PTC) structures are studied and compared using Aspentech software. The control performance of TC and PTC are investigated in terms of the control of component purities in both distillate and bottoms streams, under various disturbances in feed and pressure conditions. Due to pressure compensation, PTC is superior to TC in terms of purity and impurity control under disturbances in feed and pressure conditions. Accordingly, simulation …

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Research Of Kinetic Characteristics Of The Process Of Decomposition Of Zinc Concentrate With Hydrochloric Acid, Rosilov Mansur, Deng Tianlong, Usmanov Ilham, Samadiy Murodjon Jun 2020

Research Of Kinetic Characteristics Of The Process Of Decomposition Of Zinc Concentrate With Hydrochloric Acid, Rosilov Mansur, Deng Tianlong, Usmanov Ilham, Samadiy Murodjon

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study was the theoretical justification of the kinetic characteristics of the process of producing zinc chloride from zinc concentrate of the Khandiza deposit. For this, the effect of temperature and duration of the process of autoclave zinc extraction in a 28% hydrochloric acid solution was studied at a ratio of Zn: HCI = 1:1.1. Variable parameters were the temperature of 70, 80 and 90 °C and the duration of the leaching process of 6, 8 and 10 hours. The optimal parameters for the production of zinc chloride were determined.

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The Study Of The Component Composition Of The Reaction Mixture Containing Formaldehyde Reaction Products, Hurramov Lochinbek, Alimukhamedova Nozima, Adilov Ravshan, Alimukhamedov Muzafar Jun 2020

The Study Of The Component Composition Of The Reaction Mixture Containing Formaldehyde Reaction Products, Hurramov Lochinbek, Alimukhamedova Nozima, Adilov Ravshan, Alimukhamedov Muzafar

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is to study the effect of the conditions of the reaction of monoethanolamine (Meol) with formaldehyde (FD) on the composition of the reaction mixture. Interaction of monoethanolamine with formaldehyde leads to the formation of N,N’,N”-tris(β-oxyethyl) hexahydro-S-triazine or N,N-bisoxazolidine. The type of final product was determined by the conditions of the reaction and the molar ratio of aminoalcohol:formaldehyde. The chromatogram of the vacuum-distilled final product obtained at the molar ratio of monoethanolamine:formaldehyde=1:1 shows on an individual compound with a retention time of 4.173 s. With increase in the molar ratio of monoethanolamine:formaldehyde=1: 2, the final product …

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Obtaining Microcrystalline Cellulose From Melon Crops And Studying Its Structure, Umarova Vasila, Mardonov Asror, Khamdamova Dilnoza, Akmalova Guzal Jun 2020

Obtaining Microcrystalline Cellulose From Melon Crops And Studying Its Structure, Umarova Vasila, Mardonov Asror, Khamdamova Dilnoza, Akmalova Guzal

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study was to obtain microcrystalline cellulose from gourds. Cellulose was isolated from the stems of watermelon and pumpkin by acid and alkaline heat treatment. Microcrystalline cellulose was obtained from cellulose by hydrolysis. Cellulose was hydrolyzed in a mixture of sulfuric acid and hydrogen peroxide. The optical parameters of the microcrystalline cellulose sample, ash content, bulk density, water swelling, and moisture sorption were determined. The structural features of the obtained microcrystalline cellulose were studied by IR spectroscopy. The functional groups present under various conditions for the production of microcrystalline cellulose were determined. The influence of the duration …

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Radiopaque Activity Of Iodine Containing Methylene-Bis-Carbamate, Baltabaev Ubaydulla, Djuraev Abdukahhor, Abduvakilov Jahongir, Abdullaeva Matluba Jun 2020

Radiopaque Activity Of Iodine Containing Methylene-Bis-Carbamate, Baltabaev Ubaydulla, Djuraev Abdukahhor, Abduvakilov Jahongir, Abdullaeva Matluba

CHEMISTRY AND CHEMICAL ENGINEERING

Considering that many derivatives of bis carbamates have different biological activity, it was intuitive to produce a targeted synthesis of new derivatives of bis carbamates by the interaction of hexamethylene diisocyanate with 3,5-diode-4-hydroxybenzoic acid and 2,4,6-triiodophenol (1: 2 mol, respectively) in freshly distilled dry pyridine at 95-110 оC for 6 hours, the corresponding derivatives were obtained - methylene bis carbamates. Experimental studies have been conducted to identify the acute toxicity and radiopaque properties of the synthesized new N, -hexamethylene bis (2,6-diode-4-carboxyphenylcarbamate).

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