Chemical Engineering Commons^™

Polylactic Acid (Pla) Containing Talc Microparticles And Amorphous Polyhydroxyalkanoates (Aphas) For Improved Barrier And Mechanical Properties In Food Packaging, Mohammed Alfaifi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Polylactic acid (PLA) is a biobased and compostable polymer that is increasingly being used as an alternative to petroleum-based, non-biodegradable polymers for single-use food packaging due to its environmental benefits. It is also commercially available in large quantities, and it can be processed like polyethylene. However, it has a higher water-vapor permeability (WVP) as compared to polyolefins and polyethylene terephthalate that are the incumbent materials. This results in a competitive disadvantage in employing PLA for packaging baked goods since the shelf life of the food is likely to be reduced. In the past, barrier properties of PLA were improved by …

Economic Profitability Of Sustainable Buildings Industry, Mohanad Ibrahim Altuma, Hanadi Abdulridha Lateef, Ayad Abdulkhaleq Al-Yousuf

Al-Esraa University College Journal for Engineering Sciences

The increasing global awareness of the Earth's deteriorating condition and the unpredictable effects of climate change has given rise to worldwide phenomena that impact several elements like the economy, agricultural security, water availability, and energy supplies. Buildings contribute significantly to the generation of greenhouse gases, as well as the disposal of pollutants and energy consumption. Therefore, they play a crucial role in addressing environmental issues.

Although sustainable buildings are widely acknowledged as a potential advancement, professionals in the property market still believe that the upfront costs of creating sustainable buildings are significantly higher than those of conventional buildings. This view …

Designing A Visual Control Framework Based On Feature Point Analysis To Guide Robots In Uncharted Areas, Isam Sadiq Rasham Al-Ghadhbawi

Al-Esraa University College Journal for Engineering Sciences

Image processing may be made more accurate and efficient with the use of optical processing technologies. In order to make better design judgments early in the package design process, visual packaging art simulation aims to swiftly develop realistic packaging effects. Conventional simulation techniques frequently yield findings that are neither realistic or detailed, and they also take a lot of time and human resources. Optical processing-based machine vision technology can fully utilize computer vision and image processing techniques to simulate package designs accurately and efficiently. This research proposes a foundation for machine vision technologies based on image optical processing. Real package …

Machine-Learning-Assisted Design Of Deep Eutectic Solvents Based On Uncovered Hydrogen Bond Patterns, Usman Lame Abbas, Yuxuan Zhang, Joseph Tapia, Md Selim, Jin Chen, Jian Shi, Qing Shao

Markey Cancer Center Faculty Publications

Non-ionic deep eutectic solvents (DESs) are non-ionic designer solvents with various applications in catalysis, extraction, carbon capture, and pharmaceuticals. However, discovering new DES candidates is challenging due to a lack of efficient tools that accurately predict DES formation. The search for DES relies heavily on intuition or trial-and-error processes, leading to low success rates or missed opportuni- ties. Recognizing that hydrogen bonds (HBs) play a central role in DES formation, we aim to identify HB features that distinguish DES from non-DES systems and use them to develop machine learning (ML) models to discover new DES systems. We first analyze the …

Mathematical Modeling Of Coupled Heat And Mass Transfer In Metal-Hydride Hydrogen Storage Systems, Muhammad Hasnain

College of Graduate Studies: Theses & Dissertations

As a promising clean energy carrier hydrogen has recently gained significant interest, but its efficient and safe storage is a major challenge. Compared to the gaseous state and liquid state, metal hydrides (MH) offer a potentially more effective storage approach for hydrogen. However, the main challenge in this approach is the low thermal conductivity of the MH bed that leads to low heat transfer and ultimately to higher charging and discharging times. The purpose of this work is to develop an in-house comprehensive heat and mass transfer model for hydrogen sorption in MH reactors to simulate the dynamic behavior of …

Extrusion-Based Additive Manufacturing Of Magnetic Heat Exchange Structures For Caloric Applications, Vaibhav Sharma

Theses and Dissertations

Currently, the commercial building sector accounts for 18% of total U.S. end-use energy consumption, of which almost a third was from on-site combustion of fossil fuels for space and water heating. Magnetic heat pumping (MHP) technology is an energy-efficient, sustainable, environmentally-friendly alternative to conventional vapor-compression cooling technology. Several MHP designs today are predicted to be highly energy efficient, on condition that suitable working materials can be developed. This materials challenge has proven to be daunting due to issues associated with intricate synthesis/post-processing protocols and complications related to shaping the mostly brittle magnetocaloric alloys into thin-walled channeled regenerator structures to facilitate …

Advanced Synthesis And Rational Design Of Support Structures For Nobel Metal Heterogeneous Catalysis: Towards Enhanced Activity And Continuous Processes, Brian R. Clark

Theses and Dissertations

The field of catalysis has a wide-ranging impact. Our group has identified the constant need for improved catalytic activity in high-impact applications such as hydrosilylation and cross-coupling reactions. For these reactions, precious metal catalysts often exhibit markedly better performance than their counterparts, but they can be a significant process cost that decreases overall economic efficiencies. To address this challenge, we explored support structures that can enhance catalytic activity at low metal loadings and improve precious metal recovery through simple filtration. We found that a platinum on graphene nanoplatelet catalyst (PtGNP) synthesized via strong electrostatic adsorption with microwave irradiation (SEA-MW) exhibits …

Synthesis Of Lithium Nickel Cobalt Manganese Oxide (Ncm) Cathodes For Lithium-Ion Batteries, Jethrine H. Mugumya

Theses and Dissertations

There are various ways to produce lithium nickel manganese cobalt oxide (NCM) based cathodes for lithium-ion batteries, among them; co-precipitation synthesis carried out in tank-based reactors followed by lithiation is commonly employed because of its cost-effectiveness and scalability. Although it is the preferred synthesis method, it has several issues and challenges. Discussed in this dissertation are some of these issues as well as potential solutions. Physical and chemical properties of the co-precipitation product such as yield, particle size, morphology, and tap density, depend on various reaction parameters, which include pH, chelating agents, metal salt concentrations, and stirring speed. In the …

Supported Metal Nanoparticle Synthesis: Precursor Deposition And Agglomeration At Support Surfaces, Edward H. Chandler Jr.

Theses and Dissertations

Catalysis is a critical component of the chemical manufacturing industry. For example, it has been estimated to be essential to more than 90% of the major industrial processes developed during the middle years of the 20^th century.¹ Heterogeneously supported transition metal catalysts in particular have many benefits such as easy separability from the reaction mixture and high thermal stability. One method of synthesizing these is wet impregnation, wherein a metal solution is brought into contact with an oxide- or carbon-based powder. Given optimal environmental conditions, a metal will adhere to the surface through electrostatic means in a process …

Hydrogen Production From Microbial Electrolysis Cells Powered With Microbial Fuel Cells, Dina Aboelela

Biochemical Engineering

No abstract provided.

Synthesis Of Carbon Nanomaterials From Sale Gas Using Nimo/Mgo Catalyst, Ahsan Khan

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aims to convert greenhouse gases into valuable nanomaterials as a sustainable way to capture and utilize carbon. It examines the synthesis of carbon nanotubes (CNTs) from a methane-ethane mixture (sale gas) with CO₂ added in different reactor setups. A NiMo/MgO catalyst was used to enhance CNT growth. Nickel and molybdenum act as active sites, facilitating to break carbon bonds and supporting CNT formation. The addition of CO₂ promotes dry reforming, which enhances syngas production and influences CNT properties. Factors like gas composition, CO₂ presence, and reactor type affect CNT structure and yield. Extended reaction times improved graphitization, creating …

Change Of Metal Oxidation State At High Temperature, Impact Of Temperature And Reactive Gases, Yegor Nikitin

Dissertations and Theses

The fundamental understanding of gas-solid reactions enables a wide range of applications to be developed and improved. Specifically, the use of metal-based materials is critical to ensuring robust, safe, and long-term operations. For example, in power systems where boilers are used to generate steam for heat or electricity generation the use of stainless metal alloys is critical to allow high quality steam to be produced in a very harsh environment. Alternatively, in catalysis, the use of metal doped heterogeneous catalysts are essential in achieving selectivity and conversion performance for chemical synthesis to emissions abatement. Typically, these metal alloys must withstand …

Nanoparticle Stabilized Interfaces And Their Effect On Foam Stability, Nicole T. Donovan

Dissertations and Theses

No abstract provided.

The Racial Disparities Of The Gamma-Secretase/Notch Pathway And Inhibition In Triple Negative Breast Cancer, Jobin Joseph

Dissertations and Theses

Triple Negative Breast Cancer (TNBC) continues to be a formidable challenge in oncology, characterized by its aggressive phenotype and limited treatment options. Alarming racial disparities in TNBC outcomes persist, with underrepresented populations experiencing disproportionately higher rates of mortality and poorer prognoses. This master's thesis aims to delve into the molecular intricacies that contribute to these disparities, with a specific focus on gamma secretase activity, a key regulator of cellular processes.

The research methodology encompasses a multi-faceted approach, amalgamating clinical data analysis with extensive in vitro and in vivo experimentation. The study employs cutting-edge molecular profiling techniques and gene expression analysis …

Alkaline Potassium Polyacrylate Electrolytes For Rechargeable Zinc-Manganese Dioxide Batteries, Jungsang Cho

Dissertations and Theses

Zinc (Zn)–manganese dioxide (MnO₂) rechargeable batteries have high specific theoretical capacity as well as being environmentally friendly, intrinsically safe and low-cost. Liquid electrolytes, such as potassium hydroxide (KOH), are historically used in these batteries; however, many failure mechanisms of the Zn–MnO₂ battery chemistry result from the use of liquid electrolytes, including the formation of electrochemically inactive compounds and shape change of Zn electrodes during charge and discharge cycling. This led to incorporation of an alkaline polymer electrolyte as an alternative to the liquid KOH electrolyte in Zn-MnO₂ rechargeable batteries, with the aim of making them non-spillable …

Surface Activity At The Air-Water Interface And Self-Stratification Of Silica Nanoparticles Functionalized With Tri-Methoxy Poly(Ethylene Glycol) Silane, Hyeongoo Jung

Dissertations and Theses

Aggregated silica nanoparticles (SNPs) have been functionalized with tri-methoxy poly(ethylene glycol) silane (mPEG silane), end-capped with a methyl group. This functionalization imparts surface activity at the air-water interface due to the hydrophobic nature of the end-capped methyl group. To determine the surface coverage of silane on the particle surface, solution-state ¹H-NMR spectroscopy was utilized for characterization, and surface tension measurements were conducted to assess their tension-lowering ability. Solutions containing 10 wt% of the functionalized SNPs reduced the quasi-static surface tension to approximately 53 mN/m, regardless of the amount of reacted mPEG silane. However, the quantification of mPEG silane influenced …

Hydrodynamics Of Drops And Particles Driven By Marangoni And Diffusiophoretic Forces, Subramaniam Chembai Ganesh

Dissertations and Theses

This study investigates the hydrodynamics of particles and drops driven by forces generated by an asymmetrical physical and chemical surrounding environment. In the first part, a novel colloidal motor design driven by surface tension forces is proposed, utilizing an active Janus particle encapsulated in an immiscible liquid drop to form a compound drop/particle. Marangoni forces induced by asymmetric solute adsorption at the liquid-liquid interface of the drop propels the compound system. The propulsion speeds of the motor are analyzed for various relative sizes and configurations of the Janus particle and the encapsulating drop and the effects of varying the transport …

Molecular Origins Of Phase Stability In Phase-Change Nano-Emulsions For Thermal Energy Storage By Nmr Spectroscopy, Jungeun Park

Dissertations and Theses

Phase change materials (PCMs) are latent heat storage materials that can store or release thermal energy during phase transitions. Organic PCM nano-emulsions are formed by emulsifying oil in water in the presence of surfactants, enhancing thermal conductivity and pumpability. However, PCMs nano-emulsions can become unstable due to repeated thermal cycling and shear in heat transfer systems.

To better understand the molecular origins of phase instability in PCMs nano-emulsions, liquid-state nuclear magnetic resonance (NMR) measurements were applied to a model PCM nano-emulsion. Quantitative ¹H single-pulse NMR measurements established the liquid fraction of oil within nano-emulsions as a function of temperature, …

Understand The Structure-Water-Responsive Relationship By Engineering Silk Materials, Yeojin Jung

Dissertations and Theses

Water-responsive (WR) materials mechanically swell and shrink in response to changes in relative humidity, and they have demonstrated the capability to exert higher actuation energy than conventional actuators and artificial muscles. As a result, WR materials have recently gained attention as potential high-energy actuating components for engineering applications. Despite the growing interest in this emerging category of WR materials, the fundamental WR mechanism of their significant performance is still not fully understood, limiting the ability to rationally design engineered systems. This dissertation presents three approaches for understanding the water-responsiveness of materials by engineering Bombyx (B.) mori silkworm silk protein. First, …

The Effect Of Nanoconfined Liquid Properties On The Water-Responsive Behavior Of Bacterial Cell Walls, Seungri Kim

Dissertations and Theses

Water-responsive (WR) materials have the ability to mechanically swell and shrink in response to changes in relative humidity (RH). These WR materials are used by many biological systems to perform essential tasks; for example, pinecones use WR materials to release their seeds in dry environments, and wheat awns open and close to propel seeds into the soil, driven by daily RH changes. The WR actuation of some biomaterials is extremely powerful, for example Bacillus subtilis cell walls display record-high actuation energy and power densities of 72 MJ m^-3 and 9.1 MW m^-3, surpassing those of all existing …