235 results match your criteria: "Bourns College of Engineering[Affiliation]"

Chemical speciation, including polycyclic aromatic hydrocarbons (PAHs), and toxicity of particles emitted from meat cooking operations.

Sci Total Environ

August 2018

University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA 92507, USA; Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA 92521, USA. Electronic address:

We assessed the chemical properties and oxidative stress of particulate matter (PM) emissions from underfired charbroiled meat operations with and without the use of aftertreatment control technologies. Cooking emissions concentrations showed a strong dependence on the control technology utilized, with all emission rates showing decreases with the control technologies compared to the baseline testing. The organic acids profile was dominated by the saturated nonanoic, myristic, palmitic, and stearic acids, and the unsaturated oleic, elaidic, and palmitoleic acids.

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Currently, major biofuel crops are also food crops that demand fertile soils and good-quality water. Jerusalem artichoke (Helianthus tuberosus, Asteraceae) produces high tonnage of tubers that are rich in sugars, mainly in the form of inulin. In this study, plants of the cultivar "White Fuseau" grown under five salinity levels were evaluated for tuber yield.

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Gas-phase kinetics modifies the CCN activity of a biogenic SOA.

Phys Chem Chem Phys

February 2018

Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA 92521, USA.

Our current knowledge of cloud condensation nuclei (CCN) activity and the hygroscopicity of secondary organic aerosol (SOA) depends on the particle size and composition, explicitly, the thermodynamic properties of the aerosol solute and subsequent interactions with water. Here, we examine the CCN activation of 3 SOA systems (2 biogenic single precursor and 1 mixed precursor SOA system) in relation to gas-phase decay. Specifically, the relationship between time, gas-phase precursor decay and CCN activity of 100 nm SOA is studied.

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Gasoline Particulate Filters as an Effective Tool to Reduce Particulate and Polycyclic Aromatic Hydrocarbon Emissions from Gasoline Direct Injection (GDI) Vehicles: A Case Study with Two GDI Vehicles.

Environ Sci Technol

March 2018

Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT) , University of California, 1084 Columbia Avenue , Riverside , California 92507 , United States.

We assessed the gaseous, particulate, and genotoxic pollutants from two current technology gasoline direct injection vehicles when tested in their original configuration and with a catalyzed gasoline particulate filter (GPF). Testing was conducted over the LA92 and US06 Supplemental Federal Test Procedure (US06) driving cycles on typical California E10 fuel. The use of a GPF did not show any fuel economy and carbon dioxide (CO) emission penalties, while the emissions of total hydrocarbons (THC), carbon monoxide (CO), and nitrogen oxides (NOx) were generally reduced.

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Deactivation of Cellulase at the Air-Liquid Interface Is the Main Cause of Incomplete Cellulose Conversion at Low Enzyme Loadings.

Sci Rep

January 2018

Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California Riverside, 900 University Ave, Riverside, CA, 92521, USA.

Amphiphilic additives such as bovine serum albumin (BSA) and Tween have been used to improve cellulose hydrolysis by cellulases. However, there has been a lack of clarity to explain their mechanism of action in enzymatic hydrolysis of pure or low-lignin cellulosic substrates. In this work, a commercial Trichoderma reesei enzyme preparation and the amphiphilic additives BSA and Tween 20 were applied for hydrolysis of pure Avicel cellulose.

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A microfluidic thermometer: Precise temperature measurements in microliter- and nanoliter-scale volumes.

PLoS One

January 2018

Department of Bioengineering, Bourns College of Engineering, University of California Riverside, Riverside, CA 92521, United States of America.

Measuring the temperature of a sample is a fundamental need in many biological and chemical processes. When the volume of the sample is on the microliter or nanoliter scale (e.g.

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Background: natural variants have been shown to realize a broad range of sugar yields during saccharification, however, the structural features responsible for higher sugar release from natural variants are not clear. In addition, the sugar release patterns resulting from digestion with two distinct biological systems, fungal enzymes and , have yet to be evaluated and compared. This study evaluates the effect of structural features of three natural variant lines, which includes the line BESC standard, with respect to the overall process of sugar release for two different biological systems.

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Background: Consolidated bioprocessing (CBP) by anaerobes, such as which combine enzyme production, hydrolysis, and fermentation are promising alternatives to historical economic challenges of using fungal enzymes for biological conversion of lignocellulosic biomass. However, limited research has integrated CBP with real pretreated biomass, and understanding how pretreatment impacts subsequent deconstruction by CBP vs. fungal enzymes can provide valuable insights into CBP and suggest other novel biomass deconstruction strategies.

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Background: Hydrothermal pretreatment using liquid hot water (LHW) is capable of substantially reducing the cell wall recalcitrance of lignocellulosic biomass. It enhances the saccharification of polysaccharides, particularly cellulose, into glucose with relatively low capital required. Due to the close association with biomass recalcitrance, the structural change of the components of lignocellulosic materials during the pretreatment is crucial to understand pretreatment chemistry and advance the bio-economy.

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In the shadow of a burgeoning biomass-to-fuels industry, biological conversion of lignocellulose to fermentable sugars in a cost-effective manner is key to the success of second-generation and advanced biofuel production. For the effective comparison of one cellulase preparation to another, cellulase assays are typically carried out with one or more engineered cellulase formulations or natural exoproteomes of known performance serving as positive controls. When these formulations have unknown composition, as is the case with several widely used commercial products, it becomes impossible to compare or reproduce work done today to work done in the future, where, for example, such preparations may not be available.

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Characterizing emission rates of regulated pollutants from model year 2012+ heavy-duty diesel vehicles equipped with DPF and SCR systems.

Sci Total Environ

April 2018

Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA 92507, United States; Bourns College of Engineering - Center for Environmental Research and Technology (CE-CERT), University of California, Riverside, CA 92507, United States. Electronic address:

The regulated emissions of five 2012 and newer, low-mileage, heavy-duty Class 8 diesel trucks equipped with diesel particulate filters (DPFs) and selective catalytic reduction (SCR) systems were evaluated over test cycles representing urban, highway, and stop-and-go driving on a chassis dynamometer. NOx emissions over the Urban Dynamometer Driving Schedule (UDDS) ranged from 0.495 to 1.

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Our prior work provides evidence that visual feedback distortion drives an implicit adaptation; a gradual distortion of visual representation of step length modulated subjects' step lengths away from symmetry. To further explore the effect of the visual feedback distortion on unconscious change in step symmetry, we investigated whether such adaptation would occur even in the presence of altered limb mechanics by adding mass to one side of the leg. 26 subjects performed three 8-min trials (weight only, weight plus visual feedback, and weight plus visual feedback distortion) of treadmill walking.

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Overcoming factors limiting high-solids fermentation of lignocellulosic biomass to ethanol.

Proc Natl Acad Sci U S A

October 2017

Department of Bioengineering, Bourns College of Engineering, University of California, Riverside, CA 92507;

Simultaneous saccharification and fermentation (SSF) of solid biomass can reduce the complexity and improve the economics of lignocellulosic ethanol production by consolidating process steps and reducing end-product inhibition of enzymes compared with separate hydrolysis and fermentation (SHF). However, a long-standing limitation of SSF has been too low ethanol yields at the high-solids loading of biomass needed during fermentation to realize sufficiently high ethanol titers favorable for more economical ethanol recovery. Here, we illustrate how competing factors that limit ethanol yields during high-solids fermentations are overcome by integrating newly developed cosolvent-enhanced lignocellulosic fractionation (CELF) pretreatment with SSF.

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Capillary-Force-Assisted Clean-Stamp Transfer of Two-Dimensional Materials.

Nano Lett

November 2017

Department of Electrical and Computer Engineering, ‡Department of Chemical and Environmental Engineering, §Department of Physics, and ∥Material Science and Engineering Program, Bourns College of Engineering, University of California, Riverside, California 92521, United States.

A simple and clean method of transferring two-dimensional (2D) materials plays a critical role in the fabrication of 2D electronics, particularly the heterostructure devices based on the artificial vertical stacking of various 2D crystals. Currently, clean transfer techniques rely on sacrificial layers or bulky crystal flakes (e.g.

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Despite continuing efforts to reduce foodborne pathogen contamination of fresh produce, significant outbreaks continue to occur. Identification of appropriate surrogates for foodborne pathogens facilitates relevant research to identify reservoirs and amplifiers of these contaminants in production and processing environments. Therefore, the objective of this study was to identify environmental Escherichia coli isolates from manures (poultry, swine and dairy) and surface water sources with properties similar to those of the produce associated foodborne pathogens E.

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Simultaneously reducing CO and particulate exposures via fractional recirculation of vehicle cabin air.

Atmos Environ (1994)

July 2017

Spokane Research Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Spokane, WA, USA.

Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO levels in the cabin.

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AESOP: A Python Library for Investigating Electrostatics in Protein Interactions.

Biophys J

May 2017

Department of Bioengineering, Bourns College of Engineering, University of California, Riverside, California. Electronic address:

Electric fields often play a role in guiding the association of protein complexes. Such interactions can be further engineered to accelerate complex association, resulting in protein systems with increased productivity. This is especially true for enzymes where reaction rates are typically diffusion limited.

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Use of Brevibacillus choshinensis for the production of biologically active brain-derived neurotrophic factor (BDNF).

Appl Microbiol Biotechnol

July 2017

Department of Chemical Engineering and Materials Science, Michigan State University, 428 S. Shaw Lane, Room 2100, Engineering Building, East Lansing, MI, 48824-1226, USA.

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family critical for neuronal cell survival and differentiation, with therapeutic potential for the treatment of neurological disorders and spinal cord injuries. The production of recombinant, bioactive BDNF is not practical in most traditional microbial expression systems because of the inability of the host to correctly form the characteristic cystine-knot fold of BDNF. Here, we investigated Brevibacillus choshinensis as a suitable expression host for bioactive BDNF expression, evaluating the effects of medium type (2SY and TM), temperature (25 and 30 °C), and culture time (48-120 h).

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Effects of Partial Absence of Visual Feedback Information on Gait Symmetry.

Appl Psychophysiol Biofeedback

June 2017

Department of Biomedical Engineering, The Gordon and Jill Bourns College of Engineering, California Baptist University, 8432 Magnolia Avenue, Riverside, CA, 92504, USA.

The incorporation of real-time visual feedback during gait rehabilitation can improve the efficacy of training. Our prior work demonstrated that the imposed distortion of simple visual feedback information of step lengths entails an unintentional adaptive process in the subjects' spatial gait pattern, thereby suggesting the important role of implicit learning in the context of gait rehabilitation that employs visual feedback. The purpose of this study was to investigate whether the removal of a portion of visual feedback information-after it had initially been provided-had any impact on gait symmetry.

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Impact of biodiesel on regulated and unregulated emissions, and redox and proinflammatory properties of PM emitted from heavy-duty vehicles.

Sci Total Environ

April 2017

University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA 92507, USA; Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA 92521, USA.

The emissions and the potential health effects of particulate matter (PM) were assessed from two heavy-duty trucks with and without emission control aftertreatment systems when operating on CARB ultra-low sulfur diesel (ULSD) and three different biodiesel blends. The CARB ULSD was blended with soy-based biodiesel, animal fat biodiesel, and waste cooking oil biodiesel at 50vol%. Testing was conducted over the EPA Urban Dynamometer Driving Schedule (UDDS) in triplicate for both trucks.

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Detailed Analysis of Criteria and Particle Emissions from a Very Large Crude Carrier Using a Novel ECA Fuel.

Environ Sci Technol

February 2017

Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States.

Ocean going vessels (OGVs) operating within emission control areas (ECA) are required to use fuels with ≤0.1 wt % sulfur. Up to now only distillate fuels could meet the sulfur limits.

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Will Aerosol Hygroscopicity Change with Biodiesel, Renewable Diesel Fuels and Emission Control Technologies?

Environ Sci Technol

February 2017

Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States.

The use of biodiesel and renewable diesel fuels in compression ignition engines and aftertreatment technologies may affect vehicle exhaust emissions. In this study two 2012 light-duty vehicles equipped with direct injection diesel engines, diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) were tested on a chassis dynamometer. One vehicle was tested over the Federal Test Procedure (FTP) cycle on seven biodiesel and renewable diesel fuel blends.

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Traffic emissions are associated with the elevation of health risks of people living close to highways. Roadside vegetation barriers have the potential of reducing these risks by decreasing near-road air pollution concentrations. However, while we understand the mechanisms that determine the mitigation caused by solid barriers, we still have questions about how vegetative barriers affect dispersion.

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The Community model for near-PORT applications (C-PORT) is a screening tool with an intended purpose of calculating differences in annual averaged concentration patterns and relative contributions of various source categories over the spatial domain within about 10 km of the port. C-PORT can inform decision-makers and concerned citizens about local air quality due to mobile source emissions related to commercial port activities. It allows users to visualize and evaluate different planning scenarios, helping them identify the best alternatives for making long-term decisions that protect community health and sustainability.

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Effects of dilute acid and flowthrough pretreatments and BSA supplementation on enzymatic deconstruction of poplar by cellulase and xylanase.

Carbohydr Polym

February 2017

Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California Riverside, 900 University Ave, Riverside, CA 92521, USA; Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, 1084 Columbia Ave, Riverside, CA 92507, USA; BioEnergy Science Center (BESC), Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831, USA. Electronic address:

To help understand factors controlling the recalcitrance of lignocellulosic biomass to deconstruction to sugars, poplar was pretreated with liquid hot water (LHW) and extremely dilute acid (EDA) at 140°C and 180°C in batch and flowthrough reactors. The resulting solids were then subjected to enzymatic hydrolysis by eight combinations of cellulase, xylanase, and bovine serum albumin (BSA). Co-addition of xylanase to cellulase resulted in up to 11 percentage points higher overall sugar yield than their sequential addition.

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