Engineering Commons^™

Role Of Primary Freeboard On Staged Combustion Of Hardwood Pellets In A Fixed Bed Combustor, Awais Junejo, Yasir Al-Abdeli, Jacobo Porteiro

Research outputs 2022 to 2026

In staged fixed bed biomass combustion, primary air is supplied beneath the fuel bed with secondary air then provided above in the freeboard region. For fixed bed configurations, the freeboard is further divided into a primary freeboard length (LI), which is upstream of the secondary air and a secondary freeboard length (LII), measured from the secondary air all the way to the exhaust port. Despite extensive research into fixed bed configurations, no work has been successfully completed that resolves the effects of changing LI on fuel conversion, both in the fuel bed and within the freeboard of batch-type biomass combustors. …

Integrating Temperature Dependence Into A Microstructure-Sensitive Fatigue Model For Titanium Alloys, Jared Michael Darius

Masters Theses

This work seeks to integrate temperature dependence into a microstructure-sensitive fatigue model for titanium alloys produced by both extrusion and electron beam melting (EBM) additive manufacturing, revising and enhancing the MultiStage Fatigue (MSF) model as the foundational model framework. Traditional fatigue modeling has required design engineers to conservatively use a lower-bound estimate of fatigue life predictions given a statistically significant spread of experimental data that can span up to two or sometimes three orders of magnitude for a given test condition. This variation in fatigue data has since been accounted for with the advent of the MSF model, linking individual …

Temperature Effect On The Mechanical Properties Of Steel Fiber Reinforced Ultra-High-Performance Concrete, Jenny Bernadette Gomes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The contemporary innovation in concrete technology is ultra-high-performance concrete (UHPC). In this work, mechanical properties of UHPC are studied at ambient terrestrial temperature conditions. Specimens are prepared under laboratory environments maintaining the temperature of -25°C, -5°C, 15°C, 35°C, and 55°C. A freeze thaw chamber is utilized to condition the specimens at specified temperatures. Compressive strength, flexural strength, toughness, and modulus of elasticity are determined under varying temperature and steel fiber volume content. The results indicate that both temperature and steel fibers have effect on the mechanical properties of UHPC. The flexural and compressive strength show an opposite trend of strength …

Synthesis And Polymerization Processes Of 1-Chlorine-3- Piperidine -2-Propylmethacrylate Monomer, N U. Pulatova, O S. Maksumova, Izabela Barszczewska Rybarek

Technical science and innovation

An amino alcohol was synthesized on the basis of piperidine and epichlorohydrin. The esterification reaction of methacrylic acids with the obtained amino alcohol was studied. In order to identify optimal synthesis conditions, the influence of temperature, reaction duration and ratio of reactive reagents was investigated. The processes of obtaining unsaturated esters by esterification reactions with 1-chlorine-3-piperidine-2-propanol and acrylic-, methacrylic acids have been studied. The effect of monomer concentration on the rate of polymerization reaction and the yield of polymer formation was studied . The radical polymerization of a new monomer with a piperidine cycle in the presence of a nitrogen-containing …

Reducing The Impact Of Heavy-Weight Cars On The Deformation Of Asphalt Concrete Coatings, I.S Sodiqov, A.M Qoraboyev, F.B. Ashurov

The Scientific Journal of Vehicles and Roads

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Multiscale Investigation Of Thixotropy In Soft Clays, Jing Peng

Doctoral Dissertations

Fine-grained clay particles of <2 >µm in size are ubiquitous in soils and sedimentary rocks. Due to their platy shape, high aspect ratio, and surface charges, clay particles play a dominant role in controlling the mechanical properties of those fine-grained geomaterials such as soft clays and shales. In physics and engineering, some materials show that the strength and stiffness increases with time even if the boundary conditions remain unchanged (e.g., no change in pressure, temperature, or composition), and such a phenomenon is called thixotropy. It is generally agreed that the principle of thixotropy of wet clays is complex. For a closed, …

Application Of Methods Of Intermittent Ventilation Of Industrial Premises Using A Digital Data Transmission System, Yuriy Shipulin, Abdullayev Temur, Jamolidin Usmanov, Shahnoza Ergasheva

Chemical Technology, Control and Management

The article is devoted to topical applied issues, the application of methods of intermittent ventilation of industrial buildings using a digital data transmission system. The requirements for the parameters of the environment are determined, which include: composition, purity, temperature, air humidity, the content of positive and negative ions, the presence of fields of various origins (thermal, optical, biological, gas, and electromagnetic). The authors of the article argue that some of the listed parameters can be supported by ventilation and air conditioning (SCA) systems.

It is shown that when the controlled parameters are limited to a multidimensional area, the SCA control …

Concrete Maturity Method Applied To Rapid-Setting Calcium-Sulfoaluminate (Csa) Concretes For Pavement Repair Under Different Ambient Temperatures, Ryan Nicholas Langford

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With more and more people using roadways the need for fast and efficient repair work is becoming increasingly important. Lane closures impede traffic flow and result in congestion. To further limit the amount of time lane closures are needed for repair work, calcium sulfoaluminate (CSA) cement concrete has become an increasing popular construction material for its ability to reach adequate strength requirements within four hours. Because of this accelerated repair time, advanced testing methods are needed to verify that the replaced concrete does indeed meet or exceed the minimum compressive strength requirements.

The maturity method is one test used to …

Aggregation Dynamics Of Bulk Nanoparticle Haloing Systems And The Influence Of Non-Ambient Temperatures., Marzieh Moradi

Electronic Theses and Dissertations

One of the methods of assembling colloids into 3D crystal structures is through the use of nanoparticle haloing. Nanoparticle haloing is a stabilization mechanism in binary particle suspensions possessing both a size and charge asymmetry, with which the nanoparticles aid in the bulk suspension’s stability. By altering the volume fractions of nanoparticles, it is possible to control the effective repulsion between the microparticles. Understanding the colloidal interactions and aggregate crystallinity as a function of nanoparticle concentration, temperature, and time are key challenges in developing future materials and designing crystalized 3D colloidal systems. In this study, we investigated the effect of …

Using Single-Molecule Dna Flow-Stretching Experiments To See The Effects Of Temperature And Viscosity, Fatema Tuz Zohra

Theses and Dissertations

Deoxyribonucleic acid (DNA) is a highly charged long and semi-flexible polymer of which length is much longer than cell dimensions at least by 1,000-folds. A long linear DNA turns into a crumpled structure to fit into a tiny cell volume by the process known as DNA compaction. In nature, DNA fits into the volume of the cell using DNA compaction by packaging genome material. Various types of protein are involved in DNA compaction. To experiment with various proteins as DNA compaction agents, DNA needs to be stretched out. In our thesis, the effect of temperature and buffer viscosity on DNA …

Interrelation Of Thermal Stimulation With Haptic Perception, Emotion, And Memory, Mehdi Hojatmadani

USF Tampa Graduate Theses and Dissertations

Haptics is an interdisciplinary field of science that deals with how humans perceive and respond to different sensory cues perceived through touch. Thermal haptics as a branch deals with how humans perceive the temperature sensation and respond to that. The process in which thermal perception occurs is well known to researchers. What seems missing in the literature is how temperature interacts or sometimes intervenes in other physiological and psychological aspects of our lives. In this research, a series of studies are presented where the main focus was how temperature and brain interact with each other to impede or enhance our …

Experimental Investigation And Prediction Of Long-Term Effect Of Sustained Load And Harsh Environment On Fiber-Reinforced Polymer Composites, Amir Hussain Idrisi

Dissertations

In this dissertation the durability of thermoset composites was investigated under sustained load. Two thermoset composites, E-glass/epoxy and E-glass/polyurethane were immersed in seawater under sustained load (10%, 15%, 20%, 25% of failure load) and varying temperature (23°C to 95°C) for the period of 15 months. Mechanical, physical and thermal properties were experimentally investigated. The effects of temperature, moisture, and immersion time on the deterioration of the composite material were studied for both composites. It was observed that the weight of the samples increased with the immersion time and temperature for both the composites. The highest increase in weight of the …

Improving The Accuracy Of Measuring The Volume And Mass Of Liquid Product In Horizontal Cylindrical Tanks, Nodirbek Rustambekovich Yusupbekov, Azamat Alijonovich Yusupov, Bobir Alisher Ogli Boronov

Chemical Technology, Control and Management

The article is devoted to improving the accuracy of the system for measuring and controlling the level of liquid materials in horizontal cylindrical tanks. The task of ensuring continuous accurate control of the level, volume and mass of petroleum products, taking into account the shape of the bottom of the tank, is set. In order to improve the accuracy of the measuring device, a laser rangefinder is installed, which allows you to determine the distance from the tank lid to the point of the surface level of the liquid product and calculate the volume of the liquid material by determining …

Study Of The Rheological Properties Of The Suspension Formed During The Production Of Caustic Soda By The Lime Method, Aktam Ulashovich Erkaev, Dildora Tursunova

Chemical Technology, Control and Management

The process of obtaining sodium hydroxide - caustic soda by conversion of soda ash with lime milk in the presence of natural mirabilite - has been investigated. The influence of temperature, Na₂CO₃: Na₂SO₄ ratio, concentration of lime milk and duration of the conversion process on this process was studied by identifying their optimal values. The study of the rheological properties of the reaction pulp showed that it is mobile and well filtered, which makes it possible to obtain rapidly settling large crystals of Na₂CO₃·2Na₂SO₄, Na …

Cellulose Biodegradability And Its Impact On Enhanced Biological Phosphorus Removal, Moustafa Ibrahim Elbahrawi

Electronic Thesis and Dissertation Repository

Cellulose from toilet paper contributes approximately one third of the influent organic suspended solids (TSS) to wastewater treatment plants and is a key target for resources recovery. Cellulose recovery is beneficial as it reduces the required energy for treatment and biosolids treatment cost. Hence, understanding the hydrolysis of cellulose in wastewater which is mainly affected by temperature and the solids retention time (SRT), is a major key to determine the optimum location for its recovery. In order to assess the impact of temperature and SRT on cellulose degradation, this study investigated the biological aerobic degradation of cellulose in four laboratory-scale …

Development Of Preparations Based On Local Components For Dust Suppression On Quarry Roads, Olikulov Fakhriyor, Mukhiddinov Bakhоdir, Vapoev Khusniddin, Zhurayev Shokhruh

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the work is to develop dust-collecting preparations based on local raw materials for the suppression of man-made dust formed on quarry paths. For this purpose, 4 types of the drug were created in the laboratory on the basis of domestic raw materials for dust suppression. The dependence of the viscosity and density of the created preparations on the concentration of components and temperature is studied. For the preparation of the solution of the created drug, a semi-industrial installation is created, which presents the general view and the process of preparing the solution. The spray of the prepared …

Synthesis And Spectroscopic Study Of Complex Compounds Of Mn(Ii), Co(Ii), Ni(Ii), Cu(Ii) And Zn(Ii) Acetates With 2-Aminobenzimidazole, Gapurova Lobar, Kadirova Shakhnoza, Rakhmonоva Dilnoza, Olimova Manzura

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the work is to develop a synthesis procedure and obtain new complex compounds of transition metal acetates with 2-aminobenzimidazole (L), to study the composition and structure of the synthesized compounds by elemental, thermal, X-ray phase analysis and IR spectroscopy. A procedure for the synthesis of new complex compounds of Mn(II), Cо(II), Ni(II), Cu(II) and Zn acetates with 2-aminobenzimidazole was developed and the composition and structure of the synthesized complex compounds were studied using modern physicochemical methods. Coordination competing donor centers, electronic and geometric structures of the ligand molecule were studied on the basis of a quantum-chemical calculation …

Research Of Focl Parameters In The Range Of Positive Temperatures, Dilmurod Davronbekov, Zafar Khakimov

Bulletin of TUIT: Management and Communication Technologies

This article studies the parameters of fiber-optic communication lines (FOCL) in the temperature range. For research, a climatic unit has been developed that allows a wide temperature range for testing (from -90°C to + 90°C) and an experimental complex for investigating the stability of optical parameters of a fiber-optic cable with temperature changes in the range from + 18°C to + 76°C. A technology of sequential switching of optical fibers of a fiber-optic cable by means of welding is proposed, thanks to which the constructive problem of placing a long optical fiber in a limited volume of a heat chamber …

Impact Of Number Of Solar Cells In Parallel/Series And Temperature On Junction Capacitance, Zhigang Zhao, Chunjie Zhang, Gao Pu, Hutang Sang, Xiaoqian Li

Journal of System Simulation

Abstract: The study to the dynamic parameters of the photovoltaic cell is of crucial importance for the design of the corresponding afterward stage controller in the photovoltaic power generation system. Beginning with the analysis to physical mechanism of the photovoltaic cell, more accurate equivalent formulation of the junction voltage and bias voltage of the photovoltaic cells /module/array was deduced, and the explicit formulation between the bias voltage and output voltage was received by using the Lambert W function based on equivalent series resistance and the saturation current. The formulation was adopted which combined the engineering mathematics model and intrinsic carrier …

Prediction Of Long-Term Physical Properties Of Low Density Polyethylene (Ldpe)Cable Insulation Materials By Artificial Neural Network Modeling Approach Underenvironmental Constraints, Ferhat Slimani, Abdallah Hedir, Mustapha Moudoud, Ali̇ Durmuş, Mounir Amir, Mohamed Megherbi

Turkish Journal of Electrical Engineering and Computer Sciences

This study quantifies long-term physical properties of low density polyethylene (LDPE) cables insulations exposed to environmental constraints such as UV radiation and temperature via both experimental measurements and mathematical modeling approach. For this purpose, tensile test and electrical breakdown test were carried out to determine elongation at break, tensile strength, and dielectric strength of unaged and aged specimens, respectively. Experimental results showed that both UV and temperature exposures affected the LDPE properties, significantly. A supervised artificial neural network (ANN) trained by the Levenberg?Marquardt algorithm was designed for predicting the long-term characteristics of specimens and also for minimizing the experimental procedures. …

Fluid Dynamic Analysis Over Turbulent Flows, Bryce Mcguire, Tevin James, Dareon Medley

NSF REU: Propulsion, Aerodynamics, and Controls of Aerial Vehicles

The purpose of this research is to run CFDs (Computational Fluid Dynamics) with several type of objects that consist of the following: 90-Degree Pipe, Combustors, Scramjets, Scramjets with Fuel Injectors, and Airfoils. The sole reasoning is to get a clear understanding of the mechanisms that are ran through by using the computational software called: ANSYS. With this, it will aid into running fluid flows through these objects to observe the desirable variables such as: Velocity, Temperature, Pressure, Total Pressure, Total Temperature, Eddy Viscosity, Turbulence Kinetic Energy, Turbulence Eddy Dissipation, etc.

Investigation Of The Moisture Binding Forms In Plant Raw Materials And Thermal Characteristics Determination, Tojiniso Raxmanova, Shaxnoza Sultanova, Jasur Safarov, Esra Capanoglu

Technical science and innovation

In this article, the forms of moisture connection and the thermal characteristics of plant materials are studied. Rosehip and hawthorn fruits were chosen as the object of research. In the heat analyzer, a decrease in the mass of the product and an increase in temperature were found when the temperature was controlled in a certain gas environment. The curves of the dependence of the dog rose and hawthorn samples on the mass and temperature are given. DTA-1/10 galvanometer sensitivity; sensitivity of the DTG-1/5 galvanometer; the maximum heating temperature is 300° С and the rate of change of the furnace heating …

Effect Of Temperature On Early‐Age Properties Of Self‐Consolidating Concrete Equivalent Mortar, Nima Farzadnia, Jing Pan, Kamal Khayat, Eric Wirquin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, the effect of ambient temperature during casting on fresh properties, hydration kinetics, and early‐age compressive strength of self-consolidating concrete (SCC) was evaluated. Concrete equivalent mortars (CEMs) with water‐to‐binder ratios of 0.41 and 0.45 were cast based on SCC mixture designs for building and infrastructure construction and precast applications. The CEMs were prepared at temperatures ranging from 8 to 36°C. Superplasticizer (SP) and air‐entraining agent (AEA) demand were evaluated for the CEM mixtures made with different supplementary cementing material (SCM) and limestone filler types. Test results showed that the ambient temperature can significantly affect the SP and AEA …

Specific Features Of Optical Fiber Cable Operation During Tension And Change Of Ambient Temperature, Dilmurod Davronbekov, Zafar Khakimov

Bulletin of TUIT: Management and Communication Technologies

This article examines the effect of longitudinal and thermoelastic deformation of an optical module on the technological reserve of an optical fiber. Analytical expressions are given for determining the lower limit of the technological margin of an optical fiber for various types of fiber-optic cable section along the axis.

Uncertainty Of A Manometric Method For Determining The Humidity Of Fibrous Materials, O.Sh. Khakimov, N.Sh. Muminov, J.A. Hamidov

Chemical Technology, Control and Management

A manometric method for determining the moisture content of fibrous materials is considered. The scheme and principle of operation of the device. A formula is given for calculating the moisture content of a material. It is emphasized that the two-chamber manometric method for determining the moisture content of materials is an indirect measurement. To determine the measurement result and its uncertainty, it is necessary to justify and choose one of the appropriate methods for determining the measurement results and assess their uncertainty - the linearization method or the reduction method. The main sources of uncertainty are identified. The pairwise correlation …

Enhancing The Visibility Of Vernier Effect In A Tri-Microfiber Coupler Fiber Loop Interferometer For Ultrasensitive Refractive Index And Temperature Sensing, Fangfang Wei, Dejun Liu, Zhe Wang, Zhuochen Wang, Gerald Farrell, Qiang Wu, Gang-Ding Peng, Yuliya Semenova

Articles

In this paper a Vernier effect based sensor is analyzed and demonstrated experimentally in a tri-microfiber coupler (Tri-MFC) and polarization-maintaining fiber (PMF) loop interferometer (Tri-MFC-PMF) to provide ultrasensitive refractive index and temperature sensing. The main novelty of this work is an analysis of parameters of the proposed Tri-MFC-PMF with the objective of determining the conditions leading to a strong Vernier effect. It has been identified by simulation that the Vernier effect is a primary factor in the design of Tri-MFC-PMF loop sensing structure for sensitivity enhancement. It is furthermore demonstrated experimentally that enhancing the visibility of the Vernier spectrum in …

Influence Of Technological Parameters On The Chemical Composition Of Calcium Polyphosphates From Phosphorites Central Kyzylkum, Ulugberdieva Ziyada, Khujamberdiev Sherzod, Mirzakulov Kholtura, Usmanov Ilkham

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the research was to study the effect of temperature, the ratio of P2O5EPA:P2O5PRM and the duration of calcination on the content of various forms of P2O5 in calcium polyphosphate. The effect of calcination temperature from 150 to 300 °C, the ratio of P2O5EPA:P2O5FRM from 2,15 to 4,50 and the duration of the process from 20 to 120 minutes on the changes in various forms of P2O5 were studied. It was shown that with increasing temperature to 200-250 °C the content of the total (ortho + poly) assimilable form of Р2О5 increases and then decreases, passing through a …

Study On Creep Characteristics Of Claystone Under Thermo-Hydro- Mechanical Coupling, Wei-Zhong Chen, Fan-Fan Li, Jiang Lei, Hong-Dan Yu, Yong-Shang Ma

Rock and Soil Mechanics

As an alternative medium for the underground disposal of radioactive waste, claystone will be in the complex conditions of thermo-hydro-mechanical coupling for a long time. In order to study the long-term stability of surrounding rocks, a series of heating-cooling drainage creep tests on claystone was carried out under different confining pressures and deviatoric stresses, and the following conclusions were drawn. The rise of temperature will increase the creep rate of claystone, and extend the time of decay creep stage. But during the cooling process, the samples mainly experience shrinkage deformation without obvious creep deformation being observed. The decrease of confining …

The Effect Of High Efficiency Building Technologies And Pv Generation On The Energy Profiles For Typical Us Residences, Evan S. Jones, Rosemary E. Alden, Huangjie Gong, Andrew G. Frye, Donald G. Colliver, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

The penetrations of high efficiency technologies and photovoltaic (PV) generation are increasing in the residential sector. Technologies such as improved insulation and efficient HVAC systems significantly affect the energy profile of a house. This effect varies due to climate characteristics, i.e. temperature, solar radiation, relative humidity, and wind speeds. The effect of other technologies, such as efficient water heaters, lighting, or kitchen appliances, is mainly governed by human behavior, which may be represented by a schedule. This paper studies the performance of both climate-influenced and scheduled household devices among different levels of efficiency through combined computational and experimental methods. Three …

Simulation Research On Influence Of Blood Flow On Heating During Hifu Treatment, Suqin Dai, Shengyou Qian, Yaosheng Gui, Xiao Sheng

Journal of System Simulation

Abstract: When blood vessel exists in the tumor tissue, and its boundary portion close to the vessel will be strongly influenced by the cooling effect of the blood vessel. This influence will lead to the incomplete cancer treatment. To study the influence of blood flow on heating towards the above situation, concave spherical transducer was used as the heat source, and sound intensity distribution was obtained by Rayleigh integral. Pennes equation was solved with finite difference method, then the dose distribution was calculated to determine the thermal damage degree of tissue using quantitative relationship between the heating time and temperature. …