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Biological Engineering Commons™

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2010

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Articles 31 - 40 of 40

Full-Text Articles in Biological Engineering

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 Jan 2010

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

Department of Agricultural and Biological Systems Engineering: Faculty 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 Jan 2010

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

Department of Agricultural and Biological Systems Engineering: Faculty 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 …


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 Jan 2010

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

Department of Agricultural and Biological Systems Engineering: Faculty 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 …


Modeling Changes In Biomass Composition During Microwave-Based Alkali Pretreatment Of Switchgrass, Deepak R. Keshwani, Jay J. Cheng Jan 2010

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

Department of Agricultural and Biological Systems Engineering: Faculty 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 minutes. The kinetic modeling approach for lignin …


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 Jan 2010

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

Department of Agricultural and Biological Systems Engineering: Faculty 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- …


Cytocompatible Cross-Linking Of Electrospun Zein Fibers For The Development Of Water-Stable Tissue Engineering Scaffolds, Quiran Jiang, Narendra Reddy, Yiqi Yang Jan 2010

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

Department of Agricultural and Biological Systems Engineering: Faculty 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, …


Microwave-Based Alkali Pretreatment Of Switchgrass And Coastal Bermudagrass For Bioethanol Production, Deepak R. Keshwani, Jay J. Cheng Jan 2010

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

Department of Agricultural and Biological Systems Engineering: Faculty 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 minutes. 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 xylose. …


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 Jan 2010

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

Department of Agricultural and Biological Systems Engineering: Faculty 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 …


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 Jan 2010

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

Department of Agricultural and Biological Systems Engineering: Faculty Publications

We compared daily net radiation (Rn) estimates from 19 methods with the ASCE‐EWRI Rn 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 Rn method, were then evaluated against Rn 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 (Rnl). All methods use …


Robust Dynamic Balance Of Ap-1 Transcription Factors In A Neuronal Gene Regulatory Network., Gregory M Miller, Babatunde A Ogunnaike, James S Schwaber, Rajanikanth Vadigepalli Jan 2010

Robust Dynamic Balance Of Ap-1 Transcription Factors In A Neuronal Gene Regulatory Network., Gregory M Miller, Babatunde A Ogunnaike, James S Schwaber, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: The octapeptide Angiotensin II is a key hormone that acts via its receptor AT1R in the brainstem to modulate the blood pressure control circuits and thus plays a central role in the cardiac and respiratory homeostasis. This modulation occurs via activation of a complex network of signaling proteins and transcription factors, leading to changes in levels of key genes and proteins. AT1R initiated activity in the nucleus tractus solitarius (NTS), which regulates blood pressure, has been the subject of extensive molecular analysis. But the adaptive network interactions in the NTS response to AT1R, plausibly related to the development of …