Engineering Commons^™

Modeling Heat Transfer During Cooling Of Ready-To-Eat Meat And Poultry Products Using Three-Dimensional Finite Element Analysis And Web-Based Simulation, Jihan F. Cepeda Jimenez

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

The meat industry is required to comply with processing performance standards for preventing the growth of foodborne pathogens in products. These performance standards, established by the United States Department of Agriculture - Food Safety and Inspection Service (USDA-FSIS) require a reduction of Salmonella spp (lethality standard) and limit the growth of sporeforming bacteria (stabilization standard) in certain processed meat products. In general, strategies used to comply with these standards are associated with thermal processing. Meat processors have difficulties complying with these performance standards. Moreover, thermal processing deviations are an issue in the meat industry that generate uncertainty regarding the safety …

Development Of An Integrated Soil Properties Mapping System, Rajveer S. Dhillon

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

One of the main goals of precision agriculture (PA) is to define spatial variability in soil properties within an agricultural field to make decisions that can maximize profitability and reduce negative environmental impact. Various soil sensor systems have been developed over the years to map soil properties on-the-go. In this study, an Integrated Soil Mapping System (ISMS) was developed to predict soil water content, soil organic matter, and soil mechanical resistance on-the-go using a capacitance moisture sensor, an optical sensor, and a load cell sensor respectively. These sensors were mounted on the ISMS for acquiring three different data layers at …

Identification Of Holocarboxylase Synthetase Chromatin Binding Sites In Human Mammary Cell Lines Using The Damid Technology, Dipika Singh

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

Holocarboxylase synthetase (HCS) is a chromatin protein that is essential for mediating the covalent binding of biotin to histones. Biotinylation of histones plays crucial roles in the repression of genes and repeats in the human genome. The objective of this project was to determine genomic binding sites of holocarboxylase synthetase (HCS) in the human chromatin of breast cell lines using an antibody independent technology. We tested the feasibility of DNA adenine methyltransferase identification (DamID) technology to map HCS binding sites in human mammary cell lines. Full-length HCS was fused to Dam for subsequent transfection into breast cancer (MCF-7) and normal …

Hydraulic Conductivity, Infiltration, And Runoff From No-Till And Tilled Cropland, Jessica H. Deck

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

Infiltration and runoff are important processes that affect the efficiency of center pivot irrigation systems. No-till planting systems potentially influence the hydraulic properties of soils and the soil surface conditions. The result of long-term use of no-till could be higher infiltration and lower runoff from rainfall and irrigation.

This potential was investigated in Nebraska on two center pivot irrigated sites; Fillmore County and Phelps County, one furrow irrigated site; South Central Agriculture Laboratory (SCAL), and one dryland site; Rogers Farm. Paired treatments were used at each location, one that was no-till planted and one that used two to three operations …

Removal Of Low Density Sediments By Vegetative Filters, Brent M. Hall

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

The use of vegetative filter strips (VFS) is a longstanding best management practice for the removal of sediment and other pollutants from overland flow. Many attempts have been made to model the effectiveness of a VFS based upon soil, vegetation, and sediment properties, and also upon flow conditions, but little work has been done to investigate the reliability of the existing models when considering sediments, such as microbial pathogens, that have a lower density than the mineral sediments used for development of the models. The objectives of this study were to: 1) quantify the ability of a VFS to remove …

The Other Gulf Oil Crisis - In Southwest Asia, Adam Liska

Biological Systems Engineering: Papers and Publications

The oil spill in the Gulf of Mexico is a rude reminder of the risks inherent in an economy dependent upon petroleum. But there's a quieter crisis in the other gulf - the Persian Gulf - that should call Americans' attention to the even more severe consequences of relying upon imported oil. The costs of using the military to protect the transport of oil from the most turbulent part of the world should convince our country's policymakers to increase investments in researching and developing affordable, American-made clean-burning alternative fuels. But, first, we have to understand the real causes, costs and …

Evaluation Of Ethanol And Water Introduction Via Fumigation On Efficiency And Emissions Of A Compression Ignition Engine Using An Atomization Technique, Grant S. Janousek

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

Performance of a diesel engine, equipped for ethanol and water fumigation, was studied. The method implemented allowed for non-destructive introduction of liquids in advance of the turbocharger. Engine torque, speed, emission components, diesel and ethanol fuel rates were recorded and analyzed for each mixture of inputs. Based on the results of the study, thermal efficiency was not significantly different from the baseline diesel performance when using several ethanol and water mixtures. On the other hand, ethanol fumigation caused a significant reduction in NOx emissions and an increase in HC and CO emissions. No significant changes in CO2 or O2 occurred.

Enhanced Anthocyanin Extraction From Red Cabbage Using Pulsed Electric Field Processing, Tanya K. Gachovska, David A. Cassada, Jeyamkondan Subbiah, Milford Hanna, Harshavardhan Thippareddi, Daniel D. Snow

Biological Systems Engineering: Papers and Publications

This study was conducted to evaluate the effect of pulsed electric field (PEF) treatment on anthocyanin extraction from red cabbage using water as a solvent. Mashed cabbage was placed in a batch treatment chamber and subjected to PEF (2.5 kV/cm electric field strength; 15 μs pulse width and 50 pulses, specific energy 15.63 J/g). Extracted anthocyanin concentrations (16 to 889 μg/mL) were determined using HPLC. Heat and light stabilities of the control and PEF-treated samples, having approximately the same initial concentrations, were studied. PEF treatments enhanced total anthocyanin extraction in water from red cabbage by 2.15 times with a higher …

Securing Foreign Oil: A Case For Including Military Operations In The Climate Change Impact Of Fuels, Adam J. Liska, Richard K. Perrin

Biological Systems Engineering: Papers and Publications

Military operations are major industrial activities that use massive amounts of fuel and materials that significantly contribute to climate change. In this article, we assert that military activity to protect international oil trade is a direct production component for importing foreign oil— as necessary for imports as are pipelines and supertankers—and therefore the greenhouse gas (GHG) emissions from that military activity are relevant to U.S. fuel policies related to climate change. Military security for protection of global maritime petroleum distribution is part of the acquisition process, but in addition, recent Middle Eastern wars may also be related to securing petroleum …

Ultrasound Transient Shear Wave Elasticity Imaging For Tendon Tissue, Pengfei Song

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

Degeneration of tendon tissue is a common cause of tendon dysfunction with the symptoms of repeated episodes of pain and palpable increase of tendon thickness. Tendon mechanical properties are directly related to its physiological composition and the structural organization of the interior collagen fibers which could be altered by tendon degeneration due to overuse or injury. Thus, measuring mechanical properties of tendon tissue may represent a quantitative measurement of pain, reduced function, and tissue health. Ultrasound elasticity imaging has been developed in the last two decades and has proved to be a promising tool for tissue elasticity imaging. To date, …

Uncertainty In Indirect Land Use Change Emissions In The Life Cycle Of Biofuels: Implications For Legislation, Adam Liska

Adam Liska Papers

Current EPA life cycle analysis (LCA) of greenhouse gas (GHG) emissions from corn-ethanol will be the foundation for regulations for advanced biofuels. It appears regulatory policies that include emissions from indirect land use change (and other indirect emissions) in the biofuel life cycle are moving faster than the underlying science; there is no comparable scientific study that approaches the complexity in methods currently used by the EPA. There is substantial uncertainty in quantifying direct and indirect emissions from fuels, as evidenced by conflicting results from state and federal regulators and from within the scientific community. If indirect emissions from land …

Controlling Nonviral Gene Delivery Through The Cell-Biomaterial Interface, Beth A. Duensing

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

Controlling Nonviral Gene Delivery through the Cell-Biomaterial Interface
Beth Ann Duensing, M.S. University of Nebraska, 2010
Adviser: Angela Pannier

Cell-biomaterial interactions and the corresponding cellular behaviors are poorly understood. Therefore, in this study, the ability of biomaterial surface properties to control nonviral gene delivery was investigated through surface chemistry and protein adsorption and subsequently correlated to cellular behaviors controlled by cell-biomaterial interactions. Self-assembled monolayers (SAMs) of alkanethiols on gold were used as model biomaterials to investigate the effect of surface properties on nonviral gene transfer to cells adhered to these surfaces. SAMs presenting terminal CH₃, OH, COO^{- …}

Life Cycle Greenhouse Gas Emissions From Biofuels: Variability, Uncertainty, And Steps Toward Accurate Regulation, Adam J. Liska, Bruce E. Dale

Adam Liska Papers

a)Variability in life cycle greenhouse gas (GHG) emissions from corn-ethanol:
biorefineries
cropping systems
co-product feeding to livestock

b) EPA regulation of life cycle GHG emissions from biofuels & use of life cycle analysis (LCA):
uncertainties & inaccuracies
indirect effects

c) Building accurate knowledge infrastructure, theory, and research teams for accurate LCA methods for biofuels

Preferential Flow Effects On Subsurface Contaminant Transport In Alluvial Floodplains, Derek M. Heeren, Ron B. Miller, Garey A. Fox, Daniel E. Storm, Todd Halihan, Chad J. Penn

Biological Systems Engineering: Papers and Publications

For sorbing contaminants, transport from upland areas to surface water systems is typically considered to be due to surface runoff, with negligible input from subsurface transport assumed. However, certain conditions can lead to an environment where subsurface transport to streams may be significant. The Ozark region, including parts of Oklahoma, Arkansas, and Missouri, is one such environment, characterized by cherty, gravelly soils and gravel bed streams. Previous research identified a preferential flow path (PFP) at an Ozark floodplain along the Barren Fork Creek in northeastern Oklahoma and demonstrated that even a sorbing contaminant, i.e., phosphorus, can be transported in significant …

Heating Performance Assessment Of Domestic Microwave Ovens, Krishnamoorthy Pitchai, Sohan Birla, Jeyamkondan Subbiah, David D. Jones

Department of Biological Systems Engineering: Conference Presentations and White Papers

Due to inherent nature of standing wave patterns of microwaves inside a cavity and dielectric properties of different components in a food, microwave heating leaves non-uniform distribution of energy inside the food volumetrically. Achieving heating uniformity plays critical role in improving the safety of microwave heated products. In this paper, we present a method for assessing heating uniformity within domestic microwave ovens. A custom designed container
was used to assess heating uniformity of a range of microwave ovens using IR camera. The study suggested that the best place to place food in a microwave oven is not at center but …

Effect Of Magnetron Frequency On Heating Pattern In Domestic Oven, Sohan Birla, Krishnamoorthy Pitchai, Jeyamkondan Subbiah, David D. Jones

Department of Biological Systems Engineering: Conference Presentations and White Papers

In this study a computer model was developed to simulate microwave heating of a model food with a range of magnetron frequencies. The range was decided upon performing the frequency spectrum analysis of microwave leakage from the microwave oven. Simulation results showed that the magnetron input as sinusoidal frequency from 2.44 GHz to 2.48 GHz generates different heating profiles. The simulated heating profiles were compared with experimental heating profiles obtained by using an IR camera. None of simulations with individual frequency exactly matches with experimental temperature profile. The closet match between simulated and observed temperature profiles was found with 2.46 …

Cytocompatible Cross-Linking Of Electrospun Zein Fibers For The Development Of Water-Stable Tissue Engineering Scaffolds, Quiran Jiang, Narendra Reddy, Yiqi Yang

Biological Systems Engineering: Papers and Publications

This paper reports a new method of cross-linking electrospun zein fibers using citric acid as a non-toxic cross-linker to enhance the water stability and cytocompatibility of zein fibers for tissue engineering and other medical applications. The electrospun structure has many advantages over other types of structures and protein-based biomaterials possess unique properties preferred for tissue engineering and other medical applications. However, ultrafine fiber matrices developed from proteins have poor mechanical properties and morphological stability in the aqueous environments required for medical applications. Efforts have been made to improve the water stability of electrospun protein scaffolds using cross-linking and other approaches, …

Testing Fuel Efficiency Of Tractors With Both Continuously Variable And Standard Geared Transmissions, Christopher N. Howard

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

A John Deere 8295R IVT tractor with a continuously variable transmission (CVT) and a John Deere 8295R PowerShift (PST) tractor (Waterloo, Iowa) with a standard geared transmission (GT) were tested for fuel consumption at three different travel speeds with six different load levels applied per speed. The JD 8295R PST tractor was tested both at full throttle (FT) and shifted up two gears and throttled back (SUTB) to achieve the same travel speed as at full throttle conditions. The three speeds tested corresponded to the maximum speeds achieved in 6th, 8th and 10th gear for the JD 8295R PST tractor …

Sodium Hydroxide Pretreatment And Enzymatic Hydrolysis Of Coastal Bermuda Grass, Ziyu Wang, Deepak R. Keshwani, Arthur P. Redding, Jay J. Cheng

Biological Systems Engineering: Papers and Publications

Coastal Bermuda grass was pretreated with NaOH at concentrations from 0.5% to 3% (w/v) for a residence time from 15 to 90 min at 121 °C. The pretreatments were evaluated based on total lignin removal and production of total reducing sugars, glucose and xylose from enzymatic hydrolysis of the pretreated biomass. Up to 86% lignin removal was observed. The optimal NaOH pretreatment conditions at 121 °C for total reducing sugars production as well as glucose and xylose yields are 15 min and 0.75% NaOH. Under these optimal pretreatment conditions, total reducing sugars yield was about 71% of the theoretical maximum, …

Dual-Stage Sugar Substitution In Strawberries With A Stevia-Based Sweetener, Juan Garcia-Noguera, Curtis L. Weller, Francisca I. P. Oliveira, Sueli Rodrigues, Fabiano A. N. Fernandes

Biological Systems Engineering: Papers and Publications

The present study introduces and analyzes a new process denominated dual-stage sugar substitution (D3S). This process aims to induce sugar substitution in strawberries. In a first stage, high-calorie sugars (sucrose, fructose and glucose) are partially removed from the fruit samples and in a second stage, low-calorie sugar (stevioside and rebaudioside) is incorporated to the fruit to maintain its sweetness. The process was evaluated by studying the use of ultrasound application in one or both stages of the D3S process. Best performance of the process was obtained by subjecting the fruit samples to ultrasound in the sugar removal stage followed by …

Microwave-Based Alkali Pretreatment Of Switchgrass And Coastal Bermudagrass For Bioethanol Production, Deepak R. Keshwani, Jay J. Cheng

Biological Systems Engineering: Papers and Publications

Switchgrass and coastal bermudagrass are promising lignocellulosic feedstocks for bioethanol production. However, pretreatment of lignocelluloses is required to improve production of fermentable sugars from enzymatic hydrolysis. Microwave- based alkali pretreatment of switchgrass and coastal bermudagrass was investigated in this study. Pretreatments were carried out by immersing the biomass in dilute alkali reagents and exposing the slurry to microwave radiation at 250 W for residence times ranging from 5 to 20 min. Simons’ stain method was used to quantify changes in biomass porosity as a result of the pretreatment. Pretreatments were evaluated based on yields of total reducing sugars, glucose, and …

Ultrasound-Assisted Osmotic Dehydration Of Strawberries: Effect Of Pretreatment Time And Ultrasonic Frequency, Juan Garcia-Noguera, Francisca I. P. Oliveira, Maria Izabel Gallão, Curtis L. Weller, Sueli Rodrigues, Fabiano A. N. Fernandes

Biological Systems Engineering: Papers and Publications

Pretreatment of fruits prior to drying has shown success in reducing drying time and costs. In this work, ultrasound-assisted osmotic dehydration has been implemented as a method to increase water diffusivity and reduce drying time in strawberries. Strawberry halves were immersed in distilled water and in two different concentrations of sucrose solutions while pretreatment time and ultrasonic frequency levels were varied to determine their effect on drying time, water loss, and soluble solids gain. A microscopic analysis was carried out to evaluate the formation of microchannels and other changes to the fruit tissue structure. Greater sucrose concentration used in ultrasound- …

Using A Vision Sensor System For Performance Testing Of Satellite-Based Tractor Auto-Guidance, Dwight Easterly, Viacheslav I. Adamchuk, Michael F. Kocher, Roger M. Hoy

Biological Systems Engineering: Papers and Publications

A vision sensing system for the measurement of auto-guidance pass-to-pass and long-term errors was implemented to test the steering performance of tractors equipped with auto-guidance systems. The developed test system consisted of an optical machine vision sensor rigidly mounted on the rear of the tested tractor. The center of the drawbar hitch pin point was used as the reference from which to measure the deviation of the tractor’s actual travel path from its desired path. The system was built and calibrated to a measurement accuracy of better than 2 mm. To evaluate the sensor, two auto-guidance systems equipped with RTK-level …

Testing Fuel Efficiency Of A Tractor With A Continuously Variable Transmission, Bart A. Coffman, Michael F. Kocher, Viacheslav I. Adamchuk, Roger M. Hoy, Erin E. Blankenship

Biological Systems Engineering: Papers and Publications

A John Deere 8530 IVT tractor (Waterloo, Iowa) with a continuously variable transmission (CVT) that could be operated in automatic (CVT) or manual (fixed gear ratio) mode was tested for fuel consumption at a setpoint travel speed of 9 km·h^‐1 with 17 different drawbar loads. Linear regression analysis results showed that with the throttle set to maximum in both transmission modes, operating the tractor with the transmission in the automatic mode was more fuel efficient than operating with the transmission in the manual mode when the drawbar power was approximately 78%, or less, of maximum power. When load transition …

Testing Of Rtk-Level Satellite-Based Tractor Auto-Guidance Using A Visual Sensor System, Dwight Easterly, Viacheslav I. Adamchuk, Roger M. Hoy, Michael F. Kocher

Biological Systems Engineering: Papers and Publications

The use of satellite-based positioning has advanced considerably in the world of agriculture, providing a range of technical solutions that include the automated steering of tractors and self-propelled machinery. With the development of auto-guidance systems comes the need to evaluate their performance. Given that current precision and accuracy claims are relatively small in magnitude, it is imperative there be a testing system capable of detecting errors with ten times greater accuracy-- possibly as little as a few millimeters. A visual sensor was adopted to achieve this level of measurement resolution. The sensor was used to determine the cross-track error estimates …

Modeling Changes In Biomass Composition During Microwave-Based Alkali Pretreatment Of Switchgrass, Deepak R. Keshwani, Jay J. Cheng

Biological Systems Engineering: Papers and Publications

This study used two different approaches to model changes in biomass composition during microwave-based pretreatment of switchgrass: kinetic modeling using a time-dependent rate coefficient, and a Mamdani-type fuzzy inference system. In both modeling approaches, the dielectric loss tangent of the alkali reagent and pretreatment time were used as predictors for changes in amounts of lignin, cellulose, and xylan during the pretreatment. Training and testing data sets for development and validation of the models were obtained from pretreatment experiments conducted using 1–3% w/v NaOH (sodium hydroxide) and pretreatment times ranging from 5 to 20 min. The kinetic modeling approach for lignin …

Net Radiation Dynamics: Performance Of 20 Daily Net Radiation Models As Related To Model Structure And Intricacy In Two Climates, Suat Irmak, Denis Mutiibwa, José O. Payero

Biological Systems Engineering: Papers and Publications

We compared daily net radiation (R_n) estimates from 19 methods with the ASCE‐EWRI R_n estimates in two climates: Clay Center, Nebraska (sub‐humid) and Davis, California (semi‐arid) for the calendar year. The performances of all 20 methods, including the ASCE‐EWRI R_n method, were then evaluated against R_n data measured over a non‐stressed maize canopy during two growing seasons in 2005 and 2006 at Clay Center. Methods differ in terms of inputs, structure, and equation intricacy. Most methods differ in estimating the cloudiness factor, emissivity (α), and calculating net longwave radiation (R_nl). All methods use …