Chemical Engineering Commons^™

In Vitro Models For The Study Of Liver Biology And Diseases: Advances And Limitations, Savneet Kaur, Srivatsan Kidambi, Martí Ortega-Ribera, Le Thi Thanh Thuy, Natalia Nieto, Victoria C. Cogger, Wei-Fen Xie, Frank Tacke, Jordi Gracia-Sancho

Department of Chemical and Biomolecular Engineering: Faculty Publications

In vitro models of liver (patho)physiology, new technologies, and experimental approaches are progressing rapidly. Based on cell lines, induced pluripotent stem cells or primary cells derived from mouse or human liver as well as whole tissue (slices), such in vitro single- and multicellular models, including complex microfluidic organ-on-a-chip systems, provide tools to functionally understand mechanisms of liver health and disease. The International Society of Hepatic Sinusoidal Research (ISHSR) commissioned this working group to review the currently available in vitro liver models and describe the advantages and disadvantages of each in the context of evaluating their use for the study of …

Genetic Code Expansion In Pseudomonas Putida Kt2440, Xinyuan He, Tian Gao, Yan Chen, Kun Liu, Jiantao Guo, Wei Niu

Department of Chemical and Biomolecular Engineering: Faculty Publications

Pseudomonas putida KT2440 is an emerging microbial chassis for bio-based chemical production from renewable feedstocks and environmental bioremediation. However, tools for studying, engineering, and modulating protein complexes and biosynthetic enzymes in this organism are largely underdeveloped. Genetic code expansion for the incorporation of unnatural amino acids (unAAs) into proteins can advance such efforts and, furthermore, enable additional controls of biological processes of the strain. In this work, we established the orthogonality of two widely used archaeal tRNA synthetase and tRNA pairs in KT2440. Following the optimization of decoding systems, four unAAs were incorporated into proteins in response to a UAG …

Ab Initio Insight Into The Electrolysis Of Water On Basal And Edge (Fullerene C20) Surfaces Of 4 Å Single-Walled Carbon Nanotubes, Zhen Jiang, Nadia N. Intan, Qiong Yang

Department of Chemical and Biomolecular Engineering: Faculty Publications

The extreme surface reactivity of 4 Å single-walled carbon nanotubes (SWCNTs) makes for a very promising catalytic material, however, controlling it experimentally has been found to be challenging. Here, we employ ab initio calculations to investigate the extent of surface reactivity and functionalization of 4 Å SWCNTs. We study the kinetics of water dissociation and adsorption on the surface of 4 Å SWCNTs with three different configurations: armchair (3,3), chiral (4,2) and zigzag (5,0). We reveal that out of three different configurations of 4 Å SWCNTs, the surface of tube (5,0) is the most reactive due to its small HOMO–LUMO …

Correlating The Macrostructural Variations Of An Ion Gel With Its Carbon Dioxide Sorption Capacity, Tung Nguyen,, Mona Bavarian, Siamak Nejati

Department of Chemical and Biomolecular Engineering: Faculty Publications

We report on a direct correlation between the macroscale structural variations and the gas sorption capacities of an ion gel. Here, we chose 1-ethyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide ([Emim][TF₂N]) and poly(vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP) as the ionic liquid and host polymer, respectively. The CO₂ sorption in the thin films of the IL-polymer was measured using the gravimetric method. The results of our experiment showed that the trend in CO₂ uptake of these mixtures was nonlinearly correlated with the content of IL. Here, we highlight that the variations in the molecular structure of the polymers were the main reason behind …

Electrophilic Aldehyde 4-Hydroxy-2-Nonenal Mediated Signaling And Mitochondrial Dysfunction, Sudha Sharma, Papori Sharma, Tara Bailey, Susmita Bhattarai, Utsab Subedi, Chloe Miller, Hosne Ara, Srivatsan Kidambi, Hong Sun, Manikandan Panchatcharam, Sumitra Miriyala

Department of Chemical and Biomolecular Engineering: Faculty Publications

Reactive oxygen species (ROS), a by-product of aerobic life, are highly reactive molecules with unpaired electrons. The excess of ROS leads to oxidative stress, instigating the peroxidation of polyunsaturated fatty acids (PUFA) in the lipid membrane through a free radical chain reaction and the formation of the most bioactive aldehyde, known as 4-hydroxynonenal (4-HNE). 4-HNE functions as a signaling molecule and toxic product and acts mainly by forming covalent adducts with nucleophilic functional groups in proteins, nucleic acids, and lipids. The mitochondria have been implicated as a site for 4-HNE generation and adduction. Several studies clarified how 4-HNE affects the …

Fabricating 3-Dimensional Human Brown Adipose Microtissues For Transplantation Studies, Ou Wang, Li Han, Haishuang Lin, Mingmei Tian, Shuyang Zhang, Bin Duan, Soonkyu Chung, Chi Zhang, Xiaojun Lian, Yong Wang, Yuguo Lei

Department of Chemical and Biomolecular Engineering: Faculty Publications

Transplanting cell cultured brown adipocytes (BAs) represents a promising approach to prevent and treat obesity (OB) and its associated metabolic disorders, including type 2 diabetes mellitus (T2DM). However, transplanted BAs have a very low survival rate in vivo. The enzymatic dissociation during the harvest of fully differentiated BAs also loses significant cells. There is a critical need for novel methods that can avoid cell death during cell preparation, transplantation, and in vivo. Here, we reported that preparing BAs as injectable microtissues could overcome the problem. We found that 3D culture promoted BA differentiation and UCP-1 expression, and the optimal initial …

Nonordered Dendritic Mesoporous Silica Nanoparticles As Promising Platforms For Advanced Methods Of Diagnosis And Therapies, S. Malekmohammadi, Riaz Ur Rehman Mohammed, H. Samadian, A. Zarebkohan, A. García-Fernández, G. R. Kokil, F. Sharifi, J. Esmaeili, M. Bhia, M. Razavi, M. Bodaghi, T. Kumeria, R. Martínez-Máñez

Department of Chemical and Biomolecular Engineering: Faculty Publications

Dendritic mesoporous silica nanoparticles (DMSNs) are a new generation of porous materials that have gained great attention compared to other mesoporous silicas due to attractive properties, including straightforward synthesis methods, modular surface chemistry, high surface area, tunable pore size, chemical inertness, particle size distribution, excellent biocompatibility, biodegradability, and high pore volume compared with conventional mesoporous materials. The last years have witnessed a blooming growth of the extensive utilization of DMSNs as an efficient platform in a broad spectrum of biomedical and industrial applications, such as catalysis, energy harvesting, biosensing, drug/gene delivery, imaging, theranostics, and tissue engineering. DMSNs are considered great …

Exploring The Metabolic Landscape Of Pancreatic Ductal Adenocarcinoma Cells Using Genome-Scale Metabolic Modeling, Mohammad Mazharul Islam, Andrea Goertzen, Pankaj K. Singh, Rajib Saha

Department of Chemical and Biomolecular Engineering: Faculty Publications

Pancreatic ductal adenocarcinoma (PDAC) is a major research focus because of its poor therapy response and dismal prognosis. PDAC cells adapt their metabolism to the surrounding environment, often relying on diverse nutrient sources. Because traditional experimental techniques appear exhaustive to find a viable therapeutic strategy, a highly curated and omics-informed PDAC genome-scale metabolic model was reconstructed using patient-specific transcriptomics data. From the model-predictions, several new metabolic functions were explored as potential therapeutic targets in addition to the known metabolic hallmarks of PDAC. Significant downregulation in the peroxisomal beta oxidation pathway, flux modulation in the carnitine shuttle system, and upregulation in …

Molecular-Level Control Over Ionic Conduction And Ionic Current Direction By Designing Macrocycle-Based Ionomers, Shyambo Chatterjee, Ehsan Zamani, Seefat Farzin, Iman Evazzade, Oghenetega Allen Obewhere, Tyler James Johnson, Vitaly Alexandrov, Shudipto Konika Dishari

Department of Chemical and Biomolecular Engineering: Faculty Publications

Poor ionic conductivity of the catalyst-binding, submicrometer- thick ionomer layers in energy conversion and storage devices is a huge challenge. However, ionomers are rarely designed keeping in mind the specific issues associated with nanoconfinement. Here, we designed nature-inspired ionomers (calix-2) having hollow, macrocyclic, calix[4]arene-based repeat units with precise, sub-nanometer diameter. In ≤100 nm-thick films, the in-plane proton conductivity of calix-2 was up to 8 times higher than the current benchmark ionomer Nafion at 85% relative humidity (RH), while it was 1−2 orders of magnitude higher than Nafion at 20−25% RH. Confocal laser scanning microscopy and other synthetic techniques allowed us …

Protocol To Engineer Nanofilms Embedded Lipid Nanoparticles For Controlled And Targeted Drug Delivery (Nectar), Rashi Porwal, Stephen L. Hayward, Srivatsan Kidambi

Department of Chemical and Biomolecular Engineering: Faculty Publications

We present a protocol to engineer a substrate-mediated delivery platform comprising hyaluronic acid-coated lipid nanoparticles (HALNPs) embedded into polyelectrolyte multilayer (PEM) films. This platform allows controlled spatiotemporal release of lipid nanoparticles (LNP) by embedding them within the polyelectrolyte multilayer films matrix. HALNP conjugate with antibodies also adds the ability for targeted delivery. The use of LNP enables this platform to encapsulate both hydrophobic and hydrophilic drugs. This platform can easily be reproduced and utilized for various biomedical drug delivery applications. For complete details on the use and execution of this protocol, please refer to Hayward et al. (2015, 2016a, 2016b), …

Substrate Delivery Of Embedded Liposomes, Srivatsan Kidambi, Stephen L. Hayward

Department of Chemical and Biomolecular Engineering: Faculty Publications

This invention relates to compositions useful for localized and sustained release of therapeutic agents, and more particularly to functionalized liposomes embedded in a poly electrolyte multilayer. Methods of preparing the compositions, methods of treating diseases, devices, and pharmaceutical compositions comprising the compositions are also provided.

Complete Modeling Of The Chondrogenic Environment Under Continuous Low-Intensity Ultrasound, Heather Newell

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Articular cartilage is an avascular tissue that requires therapeutic intervention methods. This work answers the following: determine transducer operation to optimize the bioeffects; calculate the magnitude of pressure exerted on chondrocytes at an injury site; and confirm the theoretical findings by an animal model.

Earlier work has shown that cellular response to US is maximized at the resonance frequency of the cells. Resonance frequencies were calculated for chondrocytes in various layers. The latter configuration closest resembles in vivo conditions and the resonance occurred at 3.8±0.3 ������. The 3D model of US propagation in a rabbit knee was constructed from MRIs …

Expedited Pcr With Stirring, Hendrik Viljoen

Department of Chemical and Biomolecular Engineering: Faculty Publications

Disclosed are an apparatus and methods for rapid amplification of nucleic acids. More particularly, the present dis closure relates to an apparatus for mixing a reaction solution during amplification of nucleic acids and to methods for amplifying nucleic acids. Also disclosed are methods for lysing cells in a sample and amplifying nucleic acids.

Finite Element Modelling And Exergy Analysis Of A Solar Thermal Hollow Fiber Vacuum Membrane Distillation System, Benjamin Shuldes

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

A finite element model was developed to investigate the performance of a vacuum membrane distillation module under various operating conditions and membrane parameters. Porosity, tortuosity, pore diameter, membrane thickness, and fiber length were varied along with feed temperature, velocity, and flow configuration. In all cases, boundary layer polarization phenomena were seen to inhibit the performance of the module. At certain conditions, for a 7.5 cm fiber, the reduction in permeate flux from 65 LMH (Liter/m²/h) at the inlet to below 45 LMH at the outlet of the fibers was observed. In most cases, salt concentration polarization was the …

Metabolic Modeling And Omics-Integrative Analysis Of Single And Multi-Organism Systems: Discovery And Redesign, Mohammad Mazharul Islam

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Computations and modeling have emerged as indispensable tools that drive the process of understanding, discovery, and redesign of biological systems. With the accelerating pace of genome sequencing and annotation information generation, the development of computational pipelines for the rapid reconstruction of high-quality genome-scale metabolic networks has received significant attention. These models provide a rich tapestry for computational tools to quantitatively assess the metabolic phenotypes for various systems-level studies and to develop engineering interventions at the DNA, RNA, or enzymatic level by careful tuning in the biophysical modeling frameworks. in silico genome-scale metabolic modeling algorithms based on the concept of optimization, …

Creation And Application Of Various Tools For The Reconstruction, Curation, And Analysis Of Genome-Scale Models Of Metabolism, Wheaton L. Schroeder

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Systems biology uses mathematics tools, modeling, and analysis for holistic understanding and design of biological systems, allowing the investigation of metabolism and the generation of actionable hypotheses based on model analyses. Detailed here are several systems biology tools for model reconstruction, curation, analysis, and application through synthetic biology. The first, OptFill, is a holistic (whole model) and conservative (minimizing change) tool to aid in genome-scale model (GSM) reconstructions by filling metabolic gaps caused by lack of system knowledge. This is accomplished through Mixed Integer Linear Programming (MILP), one step of which may also be independently used as an additional curation …

Exploration Of The Sludge Biodiesel Pathway, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Wastewater sludge is an overlooked source of fat, oil, and grease (FOG) that could be converted into biodiesel. The United States produces about 8 million tons of sludge per year. The disposal cost for this amount of sludge is about 2 billion US dollars. The widespread availability and low cost of sludge compared to other biodiesel raw materials make it an economical choice for a renewable fuel. Using sludge as a raw material can produce 25 to 30 mg per gram of fatty acid methyl ester (FAME); the main component of biodiesel. Sludge biodiesel has the potential of transforming a …

Quantitative Pcr Of Small Nucleic Acids: Size Matters, Jay Min Lim, Rahul Tevatia, Ravi Saraf

Department of Chemical and Biomolecular Engineering: Faculty Publications

Quantitative dysregulation in small nucleic acids (NA), such as microRNA (miRNA), extracted from minimally invasive biopsies, such as, blood, stool, urine, nose, throat, are promising biomarker for diseases diagnosis and management. We quantify the effect of the extra step of poly(A) ligation for cDNA synthesis and small size of the NA on the limit of quantification (LOQ) of quantitative PCR (qPCR), the gold standard to measure copy number. It was discovered that for small NA, the cycle threshold, Ct that is proportional to −log[c], where [c] is the concentration of the target NA exhibits a sharp transition. The results indicate …

Investigating The Effect Of E30 Fuel On Long Term Vehicle Performance, Adaptability And Economic Feasibility, Adil Alsiyabi, Seth Stroh, Rajib Saha

Department of Chemical and Biomolecular Engineering: Faculty Publications

Due to the drawbacks associated with the use of petroleum derived fuels, the use of more sustainable fuel sources has garnered increasing attention in several sectors including road transportation. However, the transition away from gasoline is often hindered by the inability of currently operating vehicles to efficiently run under alternative fuels. Therefore, the logical short-term alternative is to transition to clean fuel sources including higher-ethanol fuel blends that are compatible with current fuel systems and spark-ignition engines. In this work, the long-term adaptability and economic feasibility of non-flex vehicles to consume a 30% ethanol (E30) fuel blend was investigated. Sixteen …

Periodicity In The Electrochemical Dissolution Of Transition Metals, Florian D. Speck, Alexandra Zagalskaya, Vitaly Alexandrov, Serhiy Cherevko

Department of Chemical and Biomolecular Engineering: Faculty Publications

Extensive research efforts are currently dedicated to the search for new electrocatalyst materials in which expensive and rare noble metals are replaced with cheaper and more abundant transition metals. Recently, numerous alloys, oxides, and composites with such metals have been identified as highly active electrocatalysts through the use of high-throughput screening methods with the help of activity descriptors. Up to this point, stability has lacked such descriptors. Hence, we elucidate the role of intrinsic metal/oxide properties on the corrosion behavior of representative 3d, 4d, and 5d transition metals. Electrochemical dissolution of nine transition metals is quantified using online inductively coupled …

Optimizing Membrane Distillation With Solar Thermal Collectors, Andrew Mason, Ben Shulders, Siamak Nejati

UCARE: Research Products

With rising human populations, the demand for freshwater is an ever-growing problem. One emerging technology to combat this problem is membrane distillation (MD). MD has several advantages for water desalination including 100% rejection of solute (salt, heavy metals, etc.) and mergeability with other affordable energy sources (solar heat, electric resistance, etc.) However, at the moment the specific energy consumption (SEC) of MD is very high due to low water production rates and large energy inputs to heat water. In a solar‐assisted design for MD, the high cost of solar collectors (~$200/m2) inhibits the low cost of water production in comparison …

Development Of Novel Catalysts For Hydrogen Gas Production From Biomass Compounds, Boanerges Bamaca

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Hydrothermal biomass gasification technologies (sub- and supercritical water gasification and aqueous-phase reforming) have considerable economic, environmental, and technical advantages over other energy-extensive technologies (e.g. natural gas reforming) for hydrogen gas production. However, lack of economically feasible and highly active catalysts is a main challenge that impedes upscaling of these technologies for hydrogen gas production.

The goal of this study was to develop innovative, economically feasible and active heterogeneous supported metal catalysts for hydrothermal processes for producing hydrogen gas from biomass-derived compounds. Because of its stable structure and chemical inertness, graphene was used as catalyst support. Graphene supported metal catalysts were …

Upgrading Cracking Waste To Rubber Precursors Via Oxidative Dehydrogenation, Andrew Mason, Delaney Franck, Firdvas Nasimov, Lindsey Jarema, Gitau Wambugu

Department of Chemical and Biomolecular Engineering: Funded Proposals

To: Dr. Yasar Demirel, Professor, University of Nebraska-Lincoln

As the result of process changes within an ethylene cracking plant, the amount of a C4 byproduct waste stream has significantly increased (Fabiano, Nedwick 1999). A system of extractive distillation and catalytic oxidative dehydrogenation can be used to add value to this C4 waste stream by producing high purity 1,3-Butadiene, an important rubber precursor. 1,3-Butadiene is a critical component of multiple consumer goods, including automobile tires and synthetic rubber and has a steadily increasing demand, reaching 10 million metric tons in 2012 (Biddy, Scarlata, Kinchin, 2016). The simulation assumes a feed flow …

Nanomechanical Characterization Of Fuel Cell Ionomers, Jackson Goddard

UCARE: Research Products

Energy sustainability can be achieved by improving and adopting clean energy technologies, and a better nanoscale understanding of ionomer-catalyst layers could lead to increased efficiency of proton exchange membrane fuel cells. Samples of Nafion ( Perfluorosulfonic acid ionomer) and PFIA (Perfluoroimide acid ionomer) of varying film thickness were prepared and then studied using contact resonance force microscopy. It was determined that storage and loss modulus increase as relative humidity increases and ionomer film thickness goes below 100 nm. Furthermore, in this specific study, the similar storage and loss modulus of Nafion and PFIA could be attributed to similar backbone structure …

Inducing Increased Bioplastic Production In R. Palustris Cga009, Cameron Gilley, Dylan Hoppner, Brandi J. Brown

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

PHA’s (polyhydroxyalkanoates) are important bio polymers in different industries such as petroleum, medicine, and nano technology. In the microorganisms in which they are produced, they serve as an energy storage material by storing both carbon and usable electrons. This is useful in environments where the organisms are nutrient starved. PHA’s have a practical use especially in the medical field as bio-plastics because they are biodegradable and bio-compatible. Rhodopseudomonas. palustris, a common soil bacterium, is notable for its uncommon metabolic flexibility. Its diverse metabolism means that it can fix CO 2 and grow on many lignin based monomers in both aerobic …

Fabrication Of Composite Membranes For Solar-Thermal Desalination, Andrew Mason, Mahdi Mohammadighaleni, Siamak Nejati

UCARE: Research Products

With rising human populations, the demand for freshwater is an ever-growing problem. One emerging technology to combat this problem is membrane distillation (MD). MD has several advantages for water desalination such as:

•100% rejection of solute (salt, heavy metals, etc.) •Mergeable with other affordable energy sources (solar heat, electric resistance, etc.)

However, at the moment the specific energy consumption (SEC) of MD is very high due to low water production rates and large energy inputs to heat water. In a solar-assisted design for MD, the high cost of solar collectors (~$200/m2) inhibits low cost of water production in comparison to …

Evaluation Of The Embedded Environmental Impacts Of The Sanitary Sewer System Using Life Cycle Assessment, Kimberly Law

UCARE: Research Products

This study identifies the overall impact that the installation and construction phase of sanitary sewer systems have on the environment. Construction data on sanitary sewer systems from small Nebraska communities was collected and compared to the operating phase of the sanitary sewer. The operating phase is the energy required for the lift station. Analyzing sanitary sewers during their entire life cycle involved the raw materials, infrastructure construction, installation, operation of the system, and maintenance.

Wastewater treatment systems are meant to reduce the negative impact that humans have on the environment. The purpose of the system is to treat and disinfect …

Pharmaceutical Manufacturing In The 21st Century: Identification And Analysis Of Key Elements, Robert N. Mills

Honors Program: Senior Projects (Public)

The availability of quality pharmaceutical products impacts the lives of the global population on a daily basis. The importance of product availability and quality within pharmaceutical manufacturing requires that quality systems put into place are capable of accurately and robustly capturing the quality compliance, or lack thereof, of the various stages of production. This review intends to analyze current expert-recommended best practices within key elements of a pharmaceutical manufacturing quality control system and provide recommendations throughout. The quality elements discussed include Quality by Design method validation, necessary equipment determination, and equipment qualification, followed by documentation control and data flow.

Wastewater Treatment Fatty Acids For Biodiesel Production, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Wastewater scum is the thick oily substance that floats on top of the primary and secondary tanks within a wastewater treatment plant. Scum has a 30% to 60% lipid content making it an excellent resource for the biodiesel industry. Also the use of scum would reduce the cost of current management practices such as landfill disposal or incineration. In this article there is an overview of lipid byproducts currently being produced at wastewater treatment plants today. This is followed by a presentation showing a full length process for turning wastewater scum into biodiesel raw material.

Feasibility Analysis Of Adipic Acid Production, Serpil Unlu

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Adipic acid is an essential intermediate chemical feedstock for the production of nylon-6,6; hence it is valuable from an industrial perspective. Currently, commercial adipic acid production includes a combination of two stages. The first stage produces a mixture of cyclohexanone and cyclohexanol called ‘’KA oil” derived from cyclohexane. In the second stage, KA oil is reacted with nitric acid to produce adipic acid. The second stage generates excess N₂O emission, which is considered as 310 times more potent than CO₂. Renewable feedstocks that can be converted to value-added chemicals offer significant potential for the necessary transition …