Mechanical Engineering Commons^™

Simulation And Prototyping Of A Knee Assistive Device For Improved Gait Function, Khemwutta Pornpipatsakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to develop a knee-assistive device while walking. The research was separated into two sections: the gait support simulation in MATLAB and the prototype of the device. Data on body part positions and ground reaction force were collected from three adult Thai participants walking at a speed of 1.5 m/s to calculate knee moment. The simulation section provides support moments during walking using machine learning and artificial stiffness control strategy (MLASCS), composed of the kNN model and the instantaneous artificial stiffness per body mass (IASPB) equations. The MLASCS was used to determine the proper amount of support moment …

Modeling Of Patient-Specific Periaortic Mechanics And Pulmonary Artery Hemodynamics Based On Phase-Contrast Magnetic Resonance Imaging Sequences., Johane H. Bracamonte

Theses and Dissertations

Inverse modeling in cardiovascular medicine is a collection of methodologies that can provide non-invasive patient-specific estimations of clinical risk factors using medical imaging as inputs. Its incorporation into clinical practice has the potential to improve diagnosis and treatment planning with low associated risks and costs.

Herein, three different phase contrast magnetic resonance imaging (MRI) modalities were implemented as input data, displacement encoding with stimulated echoes (DENSE MRI) applied, and time-resolved velocity encoding phase-contrast MRI, in 1D and 3D, applied to pulmonary artery (PA) hemodynamics.

A model to account for the effect of periaortic interactions due to static and dynamic structures …

Branched Chain Amino Acid Strain State Monitoring With Raman Spectroscopy And Plasmonic Bowtie Nanoantenna Devices For Early Disease Detection, Caroline A. Campbell

Theses and Dissertations

This work centers on the development and the down-selection of nano-manufactured devices to be used in conjunction with Raman spectroscopy for probing a branched chain amino acid. The nano-manufactured devices integrate plasmonic nanoantennas for the purpose of amplifying molecular fingerprints, which are otherwise difficult to detect, through Surface Enhanced Raman Spectroscopy (SERS). Plasmonic nanostructures can be utilized for a variety of biomedical and biochemical applications to detect the characteristic fingerprint provided by Raman Spectroscopy. The nano-manufactured devices create an electric field that amplifies minute perturbations and raises the signal above background noise. This may provide a deeper understanding of signal …

Development And Optimization Of A Low Volume Air-Jet Dry Powder Inhaler (Dpi) Platform For The Delivery Of High Dose Aerosolized Powder To Infants, Connor Howe

Theses and Dissertations

The goal of this research project was to develop an infant air-jet dry powder inhaler (DPI) platform for high-efficiency nose-to-lung (N2L) aerosol administration to infants through optimization of individual system components followed by expansion of the system to higher doses and different formulations using a new approach. Primary challenges associated with aerosol delivery to infants using the N2L route include the extremely narrow extrathoracic airways, short inspiratory times (~0.2 sec), low safe airway pressure (H₂O), and very low volumes of air (~10 mL) available to form the aerosol. The infant air-jet DPI system was comprised of three main …

Hybridization From Guest-Host Interactions Reduces The Thermal Conductivity Of Metal-Organic Frameworks, Mallory E. Decoster, Hasan Babaei, Sangeun S. Jung, Zeinab M. Hassan, John T. Gaskins, Ashutosh Giri, Emma M. Tiernan, John A. Tomko, Helmut Baumgart, Pamela M. Norris, Alan J.H. Mcgaughey, Christopher E. Wilmer, Engelbert Redel, Gaurav Giri, Patrick E. Hopkins

Electrical & Computer Engineering Faculty Publications

We experimentally and theoretically investigate the thermal conductivity and mechanical properties of polycrystalline HKUST-1 metal–organic frameworks (MOFs) infiltrated with three guest molecules: tetracyanoquinodimethane (TCNQ), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), and (cyclohexane-1,4-diylidene)dimalononitrile (H4-TCNQ). This allows for modification of the interaction strength between the guest and host, presenting an opportunity to study the fundamental atomic scale mechanisms of how guest molecules impact the thermal conductivity of large unit cell porous crystals. The thermal conductivities of the guest@MOF systems decrease significantly, by on average a factor of 4, for all infiltrated samples as compared to the uninfiltrated, pristine HKUST-1. This reduction in thermal conductivity goes in …

Experimental Study Of Wall Bounded Harbor Seal Whisker Inspired Pin Geometries, Anish Prasad, Mark Ricklick

Publications

Conventional cylindrical/elliptical pins are one of the most widely used geometries in convection cooling systems and are used in the internal cooling of gas turbine blades and other applications, as they promote better heat transfer at the expense of large pressure losses and unsteadiness in the flow. The need to reduce pressure drop and maintain the heat transfer rates are a pressing requirement for a variety of industries to improve their cooling efficiency. One such prominent field of research is conducted in optimizing the design of pin geometries. In this study, a harbor seal whisker inspired geometry is being studied …

Magneto-Exothermic Catalytic Chemical Reaction Along A Curved Surface, Muhammad Ashraf, Uzma Ahmad, Saqib Zia, Rama S. R. Gorla, Amnah S. Al-Johani, Ilyas Khan, Mulugeta Andualem

Faculty Publications

In the current study, the physical behavior of the boundary layer flows along a curved surface owing exothermic catalytic chemical reaction, and the magnetic field is investigated. The mathematical model comprised of a part of momentum, energy, and mass equations, which are solved using a finite difference method along with primitive variable formulation. Numerical solutions, using the method of quantitative differentiation, are made with the appropriate choice of dimensionless parameters. Analysis of the results obtained shows that the field temperature and flow of fluids are strongly influenced by the combined effects of catalytic chemical reactions and the magnetic field. The …

Prolonged Exposure To Microgravity Increases Susceptibility To Traumatic Brain Injury, Ryan Baskerville

UNF Graduate Theses and Dissertations

With the prospect of semi-permanent and permanent habitable fixtures on the moon and Mars, the complications associated with long-term exposure to microgravity should be investigated exhaustively. Spaceflight Associated Neuro-Ocular Syndrome (SANS), a group of neurological and ocular effects resulting from prolonged exposure to microgravity, is characterized by significant fluid shifts into the cranium, namely cerebrospinal fluid and blood, and an upward shift of the brain relative to the skull. This syndrome, along with its immediate effects on visual acuity, cognitive ability, and motor function are recognized by NASA, but its effects on susceptibility to traumatic brain injury have yet to …

An Analysis Of Thermal Comfort Perception In Cal Poly's Math & Science Building, Pouria Ali Fariborzi

Master's Theses

Since Americans, on average, spend approximately 90% of their time indoors according to the EPA, it is crucial to provide room occupants with the best, most comfortable, and healthiest possible environment, which is known as Indoor Environmental Quality (IEQ). This thesis aims to identify how we can provide comfortable learning environments to improve student success. To determine the best possible environment for occupants, a model of the Math & Science Building was developed, validated, and modified using DesignBuilder. In addition, we compared thermal comfort surveys to actual measured conditions for some classrooms. Analysis indicates that students prefer a cooler thermal …

Cool Thermal Energy Storage: Water And Ice To Alternative Phase Change Materials, Sandra K. S. Boetcher

Publications

Cool thermal energy storage has a long history dating back to ancient times with modern developments beginning in the mid-nineteenth century where blocks of ice were cut from frozen lakes for cooling applications. Today, the prevalent mode of thermal energy storage is the utilization of ice tanks in commercial buildings for peak shaving and load shifting. In this chapter, a summary of different types of water/ice thermal energy storage systems is provided; an overview of alternative phase change materials for use in cool thermal energy storage is given; and alternative phase change material thermal energy systems, their implementation, challenges, and …

A Vacuum-Driven Distillation Technology Of Aqueous Solutions And Mixtures, Guo Guangyu

Dissertations

Distillation of aqueous solutions and aqueous mixtures has vast industrial applications, including desalination, wastewater treatment, and fruit juice concentration. Currently, two major distillation technologies are adopted in the industry, membrane separation and thermal distillation. However, both of them face certain inevitable drawbacks. Membrane separation has disadvantages as relying on high-grade energy, requiring membrane, fouling problem, narrow treatment range, limited scalability, and vibrating and noisy operating conditions. Traditional thermal distillation technologies can avoid above concerns but has other shortcomings, such as relatively low energy efficiency and yield rate, complicated and bulky system structure, and scaling problem.

This project proposes an innovative …

Electro-Chemo-Mechanics Of The Interfaces In 2d-3d Heterostructure Electrodes, Vidushi Sharma

Dissertations

Unique heterostructure electrodes comprising two-dimensional (2D) materials and bulk three dimensional (3D) high-performance active electrodes are recently synthesized and experimentally tested for their electrochemical performance in metal-ion batteries. Such electrodes exhibit long cycle life while they also retain high-capacity inherent to the active electrode. The role of 2D material is to provide a supportive mesh that allows buffer space for volume expansions upon ion intercalation in the active material and establishes a continuous electronic contact. Therefore, the binding strength between both materials is crucial for the success of such electrodes. Furthermore, battery cycles may bring about phase transformations in the …

Energy Planning Model Design For Forecasting The Final Energy Consumption Using Artificial Neural Networks, Haidy Eissa

Theses and Dissertations

“Energy Trilemma” has recently received an increasing concern among policy makers. The trilemma conceptual framework is based on three main dimensions: environmental sustainability, energy equity, and energy security. Energy security reflects a nation’s capability to meet current and future energy demand. Rational energy planning is thus a fundamental aspect to articulate energy policies. The energy system is huge and complex, accordingly in order to guarantee the availability of energy supply, it is necessary to implement strategies on the consumption side. Energy modeling is a tool that helps policy makers and researchers understand the fluctuations in the energy system. Over the …

Numerical Investigation On The Effect Of Spectral Radiative Heat Transfer Within An Ablative Material, Raghava S. C. Davuluri, Rui Fu, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

The spectral radiative heat flux could impact the material response. In order to evaluate it, a coupling scheme between KATS - MR and P1 approximation model of radiation transfer equation (RTE) is constructed and used. A Band model is developed that divides the spectral domain into small bands of unequal widths. Two verification studies are conducted: one by comparing the simulation computed by the Band model with pure conduction results and the other by comparing with similar models of RTE. The comparative results from the verification studies indicate that the Band model is computationally efficient and can be used to …

Research Of Physical And Mechanical Properties Of Babbits Filled In Sliding Bearings, K G. Gaparov

Scientific-technical journal

The article presents the results of research of physical and mechanical properties of babbites prepared from scrap and wastes poured into sliding bearings. The development of the technology of recycling scrap and babbites waste is aimed at optimizing the parameters of the technology of cleaning and melting babbites for reuse of so-called secondary babbites.

Solution-Processed Flexible Broadband Zno Photodetector Modified By Ag Nanoparticles, N. P. Klochko, K. S. Klepikova, I. V. Khrypunova, V. R. Kopach, I. I. Tyukhov, S. I. Petrushenko, S. V. Dukarov, V. M. Sukhov, M. V. Kirichenko, A. L. Khrypunova

Faculty Research, Scholarly, and Creative Activity

In this work, we present flexible broadband photodetectors (PDs) fabricated by a deposition of nanostructured zinc oxide (ZnO) films on polyimide (PI) substrates by using cheap and scalable aqueous method Successive Ionic Layer Adsorption and Reaction (SILAR). In order to increase the long-wavelength absorption of the nanostructured ZnO layer, we created its intrinsic defects, including oxygen vacancies by post-treatment at 300 °C in vacuum and thus the light-sensitive material ZnO/PI was obtained. Then we applied silver nanoparticles (Ag NPs) from a silver sol onto a nanostructured ZnO film, which were visualized using SEM in the form of spheres up to …

Mathematical Model Of The Efficiency Of Investments Aimed In The Implementation Of Water-Saving Technologies

Irrigation and Melioration

In Uzbekistan, research work is being carried out aimed at improving the economic mechanisms for the introduction of water-saving technologies for irrigating agricultural crops. At the same time, the issues related to the analysis of the effectiveness of the use of water-saving technologies when irrigating cotton, the development of mathematical methods for assessing the effectiveness of investments, as well as their introduction into practice have not been sufficiently studied. This article provides a mathematical model of the efficiency of investments aimed at introducing water-saving technologies. The results of a numerical experiment of a mathematical model show that the introduction of …

Efficient Use Of Water Resources In The Basins Of Small Rivers, F. Gapparov, M.F. Gafforova

Irrigation and Melioration

The article provides a recommendation for the efficient use of water resources in the basins of small foothill rivers. The research was carried out on the example of the Govasay river basin located in the northern part of the Fergana Valley. The efficiency factor of the canal has been determined and a technical assessment has been given for the management of water resources in the river basin; the efficiency of the canal is 65-75%. A program for the operational management of water resources in The Govasay river basin and a GIS map of water consumers in the Govasay river basin …

Model Of Groundwater Level Control Using Horizontal Drainage, A. Arifjanov, M. Otaxonov, Z. Abdulkhaev

Irrigation and Melioration

The article describes the main factors affecting the rise in the level of groundwater in the city of Fergana and ways to eliminate them. Currently, in order to reduce the negative impact of rising groundwater levels on the environment, crops, buildings and structures, as well as underground utilities, it is proposed to design horizontal drainage in urban areas and a mathematical model has been developed for changing the groundwater level. For this, long-term data from observation wells were analyzed and the hydraulic parameters of horizontal drainage were selected taking into account the hydrogeology of the area. Taking into account the …

Results Of Proximate Analysis Of Energy Use Of Municipal Solid Waste, N.N. Abduganiev

Irrigation and Melioration

In the modern industrialized world, various raw materials are processed and used for human consumption. While some of the raw materials are converted into the desired product, the rest is thrown into the environment as waste. It is known that solid waste is a type of biomass that is formed in the course of human life. The article presents the results of a preliminary analysis of studies on the use of solid waste energy in the Urta-Chirchik district of the Tashkent region. Sorting results showed that the total volume of municipal solid waste in the district consists mainly of wood …

Shredding Of Cotton Stalks Under The Action Of Toothpicks In A Combined Unit, B. Khudayarov, U. Kuziev, B. Sarimsakov, М. Kholbutaev

Irrigation and Melioration

The article presents materials devoted to the justification of the parameters of the crown-wheel of the combined aggreagate. The technological process of work and the design of the working part, which is crushed by crushing cotton stalks, without breaking them, laying them on the movement of the unit, has been substantiated and developed. The optimal parameters of the crown-wheel and the tooth are determined by solving the regression equations that determine the optimal values of the vertical load on the teeth and its working quality. The results of theoretical and experimental research show that the amount of crushing of cotton …

Influence Of Electrophysical Methods On The Processes Of Root Formation Of Grapes, N.M. Markayev

Irrigation and Melioration

The article describes the possibilities of electrophysical processing before planting cuttings during vegetative cultivation of grape seedlings. The processes of root formation in cuttings using the electrophysical method in the article Acceleration of the process of root formation in cuttings of black raisins, treated at 71 V/m and an electric field strength of 15 hours, and an increase in the viability, quality, growth and survival of rooted seedlings up to 16.67-34% Presented the results of experiments on the increase and methods of electrotechnological processing of grape cuttings. The result of the study is the analysis and results of the processes …

Conditions, Criteria And Principles For Creating An Agri-Cultural Land Market In Uzbekistan, A.R. Nurnazarov

Irrigation and Melioration

The article analyzes the prerequisites for creating a market for agricultural land in the Republic of Uzbekistan, special attention is paid to land reform, land degradation (reduction of the bonitet score from 60 in 1991 to 50 or more at present, pasture degradation by 20-30%) and increase in economic from their use, the role of land rent in payments for land. 6 basic principles for creating a land market have been established and systematized, the relationship between X-rays and water in the irrigated farming zone, the role of the market in increasing the efficiency and effectiveness of the use of …

Economic Assessment Of The Effect Of Family Income On Students' Disciplines, Sh.A. Muratov

Irrigation and Melioration

The importance of higher education in scientific research, its role in poverty reduction and population growth has been studied theoretically. Also, when using the data of social surveys conducted by 538 respondents (students) studying in higher education institutions, they were awarded the Order of the logistics regulator in the economic assessment of the factors influencing the rate of mastery of disciplines. Factors influencing the acquisition of subjects by students: the main income of the family comes from non-farm (69,9 %), sex (52,2 %), studying at a higher education institution on a state grant (108,8 %), the student's course of study …

Innovative Rotor Casing And Leveling Apron For Combined Tillage Machine, A.A. Akhmetov, L.B. Muratov

Irrigation and Melioration

Investigations of the design of a combined machine equipped with an innovative casing and a leveler apron are presented, and the parameters of the leveler apron are substantiated. It was experimentally established that when the height of the drawing prism is exceeded by more than 200 mm, due to the falling of the crumbling part of the soil onto the rotor, the soil is thrown forward in the direction of the machine. Therefore, to eliminate soil waste, it is necessary either to reduce the height of the drag prism, or to increase the distance between the rotor and the leveling …

Ensuring The Uniformity Of Movement Of The Working Bodies Of The Machine For Processing Ridges In The Depth Of Travel, А. Tukhtakuziev, K.G. Abdulkhaev

Irrigation and Melioration

The article theoretically investigates the issue of identifying ways to ensure the deepening of the working bodies of the machine for processing ridges to a given processing depth and its required uniformity of stroke. The research results show that the deepening of the working bodies of the ridges processing machine to a given processing depth and its required uniformity is provided mainly due to the correct choice of the vertical distance from its reference plane to the lower connection points. The novelty of the conducted research lies in the fact that an analytical dependence has been obtained that allows us …

Develepment Of Land Market In Eastern European Countries And Experience For Uzbekistan, A.R. Nurnazarov

Irrigation and Melioration

The article examines the experience of the formation of the agricultural land market in Eastern European countries since the 90 s of the twentieth century, the problems and features of its devel-opment, the impact of the land market on the economies of countries. Particular attention is paid to the transformation of land ownership, methods of land privatization, land pricing, restrictions on land purchase, regulation of land relations in market conditions, issues of granting the right to pur-chase land to foreign individuals and legal entities, requirements for land owners for the presence of a special agricultural education or 3-5 years of …

The Developmet Of Competences Via Techniques For Enhancing Esp (English For Specific Purposes) Vocabulary Of Learners, G. Eshchanova

Irrigation and Melioration

In the article a recent trend in higher education is ESP (English for Specific Purposes) courses is discussed. These courses are designed around students’ needs based on their field of study. The goal is to strengthen students’ proficiency and help them to get ready to cope with everyday situations and deal with professionals in many fields such as: engineering, medicine, education and IT. There are many training sessions organized by international experts whose goal is to train local teachers to teach these courses successfully. In order to develop an ability to learn new vocabulary, for both general English and technical …

Development Of Girls’ Sports, A.R. Khodjanov, V.V. Mahmudov

Irrigation and Melioration

The article addresses current issues of higher education, taking into account its specifics. She has been providing appropriate advice on improving girls' physical well-being. The use of opportunities and qualities has an impact on the creation of comfortable conditions for female athletes. For girls involved in sports, the creation of impressive quality and possible conditions is considered. As a result, the girls-athletes of our institute took 2-3 places in the district and city qualifying rounds of chess, table tennis and won a ticket to the republican stage. At the republican stage, 2 female students of our team took 4th place …

The Imrovement Of Esp Teaching Via Methodical Provision At Technical Institution: Specializm-Oriented English Via Agriculture, G. Eshchanova, U. Nullaev

Irrigation and Melioration

In the given article the ways that ESP combines subject matter and English language teaching is discussed. This approach can be highly motivating for students because students are able to apply what they learn in their English classes to their main field of study, whether it be law, computing, business, tourism, etc. Being able to use the vocabulary and structures that they learn in a meaningful context reinforces what is taught and increases their motivation. Nevertheless, ESP concentrates more on language in context than on teaching grammar and language structures. Additionally, the ways of teaching English in ESL classes and …