As laying hen housing styles change throughout Iowa to meet legislative and consumer demands, drying of manure can be economically expensive and energy intensive. With about 50% of total electricity consumption and about 60% of annual electricity costs attributed to manure drying, this represents an opportunity for producers to decrease production costs while reducing electrical grid strain. To understand current practices and potential opportunities, survey data were collected from 34 Iowa egg producers in fall 2020, representing egg-laying (n = 50), breeding (n = 30), and rearing (n = 20) facilities. Average (+/- SD) reported number of weekly manure removal events was 2.2 +/- 0.50 for all housing styles with 2.4 +/- 0.09 for cage-free aviaries and 2.2 +/- 0.58 for conventional cage. Reported daily manure blower operation was 14.2 +/- 11.0 h/d for all facilities, with cage-free aviaries operating blowers for 10.0 +/- 11.8 h/d while conventional cage houses operated blowers for 15.1 +/- 10.8 h/d. On a per thousand bird basis, reported overall energy usage was 10.1 kWh per day, 308 kWh per month, and 3.7 MWh per year. Energy costs per thousand birds were US$0.81 per day, US$25 per month, and US$296 per year. Respondents from 16 facilities reported their facility did not have smart meters (i.e., monitoring voltage, current, power factor, and energy consumption), while 10 reported smart meter usage and 5 reported they were unsure. Managers were no more likely to be aware of facility peak demand or track peak demand regardless of whether the facility had a smart meter (aware: P = 0.09; track: P = 0.26). Interestingly, all 21 respondents reported being aware of peak demand incentives; however, only 9 (43%) respondents indicated their facilities participate in these incentives. These results provide a characterization of manure drying practices and energy usage in Iowa egg production facilities. There are opportunities to impact the manure drying process through control strategies that optimize blower energy based on environmental conditions, target manure moisture content, and peak demand periods.

Learning objects originally developed for use in online learning environments can also be used to enhance face-to-face instruction. This study examined the learning impacts of online learning objects packaged into modules and used in different contexts for undergraduate education offered on campus at three institutions. A multi-case study approach was used, examining learning impacts across a variety of course subjects, course levels (introductory and advanced undergraduate), student levels (undergraduate and graduate), and instructional goals (i.e., replacement for lecture, remediation). A repeated measures design was used, with learning data collected prior to viewing the online module, after completion of the module, and at the end of the semester. The study provided a broad examination of ways that online modules are typically used in a college classroom, as well as measured learning effectiveness based on different instructional purpose and usage contexts. Results showed the effectiveness of the modules in serving as a substitute for classroom lecture, remediation of course prerequisite material, introduction to content with follow-up lab practice, and review for final exams. In each of these cases, the use of the modules resulted in significant learning increases, as well as retention of the learning until the end of the semester.

This article charts the progress of CenUSA Bioenergy, a USDA-NIFA-AFRI coordinated agricultural project focused on the North Central region of the US. CenUSA’s vision is to develop a regional system for producing fuels and other products from perennial grass crops grown on marginally productive land or land that is otherwise unsuitable for annual cropping. This article focuses on contributions CenUSA has made to nine primary systems needed to make this vision a reality: feedstock improvement; feedstock production on marginal land; feedstock logistics; modeling system performance; feedstock conversion into biofuels and other products; marketing; health and safety; education, and outreach. The final section, Future Perspectives, sets forth a roadmap of additional research, technology development and education required to realize commercialization.

This study evaluated the effectiveness of ozone to reduce the presence of fungi in stored high-moisture maize. Maize at moisture contents of 18, 22 and 26% (wet basis) were treated with air having ozone concentrations of 0, 50, 500, 1000 and 15,000 ppm for 1 h at a flow rate of 0.5 L min(-1). After treatment, maize samples were surface disinfected and fungal species - Aspergillus, Cladosporium, Curvularia, Fusarium, Mucor, Penicillium, and Rhizopus - enumerated in the samples. The response to grain moisture content varied with fungal species. The average fungal infections per 100 kernels of maize for the non-ozone treated samples was 14.0 for Aspergillus, 0.6 for Cladosporium, 0.9 for Curvularia, 28.6 for Fusarium, 11.6 for Mucor, 56.9 for Penicillium, and 3.2 for Rhizopus. Ozone at the median concentrations - 500 and 1000 ppm - was most effective in reducing the presence of Aspergillus (p < 0.0001), Fusarium (p < 0.0001) and Mucor (p < 0.0001). Penicillium infections decreased with ozone concentrations of 1000 and 15,000 ppm (p < 0.0001). An ozone concentration of 15,000 ppm was necessary to reduce Rhizopus infection (p < 0.001). Ozone is capable of penetrating the surface of maize kernels to reduce fungal infections during storage. Ozonation of high-moisture maize is likely most effective in controlling the activity of Aspergillus and Fusarium due to their relatively high occurrence of infection on non-ozone treated maize and the observed reduction in their presence at lower ozone treatment concentrations. (C) 2013 Elsevier Ltd. All rights reserved.

BACKGROUND:A variety of methods have been developed for estimating lignin concentration within plant materials. The objective of this study was to compare the lignin concentrations produced by six methods on a diverse population of forage and biomass materials and to examine the relationship between these concentrations and the portions of these materials that are available for utilisation by livestock or for ethanol conversion.RESULTS:Several methods produced lignin concentrations that were highly correlated with the digestibility of the forages, but there were few relationships between these methods and the available carbohydrate of the biomass materials. The use of Na₂SO₃ during preparation of residues for hydrolysis resulted in reduced lignin concentrations and decreased correlation with digestibility of forage materials, particularly the warm-season grasses.CONCLUSION:There were several methods that were well suited for predicting the digestible portion of forage materials, with the acid detergent lignin and Klason lignin method giving the highest correlation across the three types of forage. The continued use of Na₂SO₃ during preparation of Van Soest fibres needs to be evaluated owing to its ability to reduce lignin concentrations and effectiveness in predicting the utilisation of feedstuffs and feedstocks. Because there was little correlation between the lignin concentration and the biomass materials, there is a need to examine alternative or develop new methods to estimate lignin concentrations that may be used to predict the availability of carbohydrates for ethanol conversion.

Near-infrared reflectance spectroscopy (NIRS) has been used extensively in the forage industry for rapid measurement of forage constituents and could be useful for determining quality of biomass feedstocks at the point of delivery. In previous work, we developed an assay that partitions feedstock carbohydrates based on their availability to be converted to fermentable sugars, including non-structural carbohydrates (C N), biochemically available carbohydrates (C B) with an associated first-order availability rate constant (k B), and unavailable carbohydrates (C U ). Additional quality parameters measured included neutral detergent lignin (NDL), total available carbohydrates (C A), and total carbohydrates (C T). We evaluated the variability of biomass quality parameters in a set of corn stover samples and developed calibration equations for determining parameter values using NIRS. Fifty-two corn stover samples harvested in Iowa and Wisconsin in 2005 and 2006 were analyzed using a high-throughput assay for determining feedstock quality for biochemical conversion. Non-structural carbohydrates ranged from 84 to 155 g kg−1 dry matter (DM); C B ranged from 354 to 557 g kg−1 DM; k B ranged from 0.199 to 0.330 h−1; C A ranged from 463 to 699 g kg−1 DM, and NDL ranged from 32 to 74 g kg−1 DM. Significant differences (P < 0.0001) among samples were observed for all parameters, except k B. Near-infrared reflectance spectroscopy calibration equations were developed for C N, C B, C A, C U , C T, and NDL. It was not possible to generate a meaningful calibration equation for k B. There is significant variability within the corn stover population for several key quality-related carbohydrate and lignin constituents which can be predicted reliably using NIRS.

Published literature has shown conflicting results regarding the effects of magnetic fields on the fermentation kinetics or cellular growth of various Saccharomyces cerevisiae strains. Here, two sets of experiments were conducted to characterize the role of magnetic fields on cell growth and ethanol production during fermentation. The first experiment was completed for 25 h at a 2% dextrose loading rate under influence of homogeneous and non-homogeneous static magnetic fields on the order of 100 and 200 mT, respectively. The second experiment was completed for 30 h at a 6% dextrose loading rate under the influence of a non-homogeneous static magnetic field on the order of 200 mT. It was found that homogeneous magnetic fields have no significant effect on the yeast cell growth, while non-homogeneous static magnetic fields produced an increase (~ 8% over the control) in peak ethanol concentration with 2% dextrose loading.

Two experiments were conducted to determine the effect of ozone treatment on controlling deterioration of high-moisture maize under extreme and moderate environmental conditions experienced during harvest. In the first experiment, 0.77-kg maize samples held at 22% moisture content were treated with ozone at 0.08, 0.16, 0.31, 0.62, 0.94, 1.25 and 1.56 mg kg maize−1 min−1 (60–1120 ppm ozone in air during application) for periods of 5 or 24 h, with an additional treatment of 1.56 mg min−1 repeated every 3 d, and stored at 32 °C for 9 d under continuous aeration. Ozone treatment decreased dry matter loss compared to the control, but not to a level that would likely justify ozone treatment at the rates and treatment times used. In the second experiment, 2.43-kg maize samples held at 26% moisture content were treated with ozonation rates of 0.25, 0.5, 1, and 2 mg kg maize−1 min−1 (1090–8680 ppm ozone during application) for 24 h, stored at 15.5 °C for 30 d and passively aerated every 3 d. Additional ozone treatments at the 2 mg kg maize−1 min−1 rate were applied for 1 h on 3-, 6-, and 12-d intervals throughout the experiment. Single ozone treatments of 1 and 2 mg kg maize−1 min−1 were equally effective, reducing dry matter loss by 1.3 percentage points compared to the control after 30 d of storage. Repeat treatments at 2 mg kg maize−1 min−1 did not reduce dry matter loss compared to the single treatment.

16 Introduction 19 Materials and Methods 23 Results 30 Discussion 32 Acknowledgements 36 References 36 Chapter 3. Carbohydrate availability model for determining lignocellulosic biomass feedstock quality 49 Abstract 49 Introduction 52 Theory 54 Materials and Methods 57 Results and Discussion 61 Acknowledgements 65 References 65 Chapter 4. High-throughput assay for screening biomass feedstocks for biochemical conversion to fuels 7449 Introduction 52 Theory 54 Materials and Methods 57 Results and Discussion 61 Acknowledgements 65 References 65 Chapter 4. High-throughput assay for screening biomass feedstocks for biochemical conversion to fuels 74 Abstract 74 Introduction 77 Materials and Methods 80 Results and Discussion 87 Acknowledgements 90 References 9174 Introduction 77 Materials and Methods 80 Results and Discussion 87 Acknowledgements 90 References 91

We have developed a relatively simple simultaneous saccharification and fermentation (SSF) technique to determine the ethanol production potential for large sets of biomass samples. The technique is based on soaking approximately 0.5 grams of a biomass sample in aqueous ammonia at room temperature and at atmospheric pressure for 24 h, then fermenting with Saccharomyces cerevisiae D(5)A for 24 h using Spezyme CP, for enzymatic hydrolysis of structural polysaccharides. We have tested the technique on a set of corn stover samples representing much of the genetic variability in the commercial corn hybrid population. The samples were weighed into modified Ankom filter bags (F57) before soaking to avoid biomass loss during the process. Fermentation samples were analyzed for ethanol after 24 h by HPLC. Percentages of theoretical maximum ethanol yields of the samples ranged between 44.9 and 73%. We observed that percentages of theoretical maximum ethanol yields were highly correlated (r(2)=0.90) with acid detergent lignin concentration while a low correlation was observed between cellulose concentration and ethanol yield. Near infrared spectra of corn stover samples were also examined. The coefficient of determination (r(2)) from regression of predicted versus measured percent theoretical maximum ethanol yield was 0.96. This result suggests that using NIRS is a promising method for predicting ethanol yield, but larger calibration sets are necessary for obtaining improved accuracy for larger sample populations. We conclude that the developed SSF technique could be applied to large numbers of biomass samples to rapidly estimate ethanol yields and to compare different biomass samples in terms of ethanol yields.

Swine manure contains a host of chemical and biological constituents which make it desirable for amending lignocellulosic biomass in storage for year round processing in a biorefinery. Application of swine manure in an integrated biomass storage and conversion system was investigated to determine the potential for improved conversion of corn stover to organic acids and soluble carbohydrates during ensiling. Corn stover-swine manure mixtures were prepared containing swine manure at rates of 0%, 15%, 30% 45%, and 60% while simultaneously being adjusted to 65% moisture on a wet basis and ensiled for 0, 1, 7, and 21 days. Samples were analyzed for pH, dry matter, water-soluble carbohydrates, and organic acids. All treatments, with the exception of the 60% manure substrate, produced a pH less than 4.5, which is sufficient for stable storage. Water-soluble carbohydrates were highest in the control treatment, producing a level of 3.0% DM at day 21. Lactic acid production was unaffected by the rate of manure, with a concentration of 2.8% DM reached at day 21. Acetic acid production was improved with the manure substrates. Manure amendment rates of 30%, 45%, and 60% produced the highest acetic acid concentration of 1.8% DM Treatments of 0%, 15%, 30%, and 45% swine manure would be acceptable substrates for use in this system; however, if preservation of fermentable carbohydrates is a higher priority than organic acid production, then the pure corn stover substrate would be the most appropriate material to use.

Current methods for characterization of lignocellulosic biomass feedstocks for biological conversion are dominated by compositional analysis and digestibility/ fermentation tests; however, both these groups of laboratory methods have their respective advantages and disadvantages. The purpose of this paper is to develop a wet-chemistry assay for determination of lignocellulosic biomass quality that combines both compositional analysis and fermentation methods. This assay also should not require expensive or highly specialized laboratory equipment and should be able to be adapted for high throughput applications, such as near infrared reflectance spectroscopy (NIRS).

Kenaf is an annual fiber crop adaptable to a wide range of climates and soil types. This study investigated the use of kenaf core fiber as a feedstock for enzyme-enhanced fermentation. Triplicate kenaf core fiber samples were treated with enzymes having cellulase:hemicellulase activity ratios of 0:1, 0.015:1, 0.45:1, and 2.54:1 at a rate of 5010IU/kg dry matter hemicellulase activity, vacuum-sealed, and incubated at 37°C for 21d. Samples were analyzed for pH, water soluble carbohydrates, organic acids, and hemicellulose and cellulose concentrations. All treatments produced a pH less than 4.0, which is sufficient for stable storage. Treatments with 2.54:1 and 0.45:1 produced the highest water soluble carbohydrate and lactic acid concentrations. Enzymes with no or low cellulase activity produced results similar to the control. Utilizing enzyme mixtures with high cellulase activity is an effective pretreatment method for ensiled kenaf core fiber.

Iodoform, an iodine-containing compound used in antiseptic applications, has been foundto be effective at selectivity inhibiting certain microbial populations. Application of iodoform in ahybrid fermentation system was investigated to determine the potential for increased lactic acidproduction by inhibiting undesirable microbes which can metabolize lactic acid. Iodoform treatmentrates of 0, 0.03, 0.06, 0.11, and 0.23 g/kg dry matter (DM) were applied to a swine manure-cornstover substrate, containing 60 % manure, adjusted to 65 % moisture on a wet basis and ensiled for0, 1, 7, and 21 days. A hemicellulase-cellulase enzyme mixture was also applied to all samples at a rate of 5 and 12.5 IU/g DM of hemicellulase and cellulase activity, respectively. Samples wereanalyzed for pH, water soluble carbohydrates, and organic acids. A substantial decrease in pH wasobserved in all treatments, but none of the treatments reached a pH of 4.5, which is sufficient forstable storage of corn stover biomass at 65 % moisture. Lactic and acetic acid production wasincreased with application of iodoform at 0.23 g/kg DM. Iodoform was also found to inhibit butyricfermentation, with a rate of 0.23 g/kg DM determined to be appropriate. Overall, iodoform canimprove fermentation in the biomass ensilage conversion system by improving lactic acid productionand inhibiting butyric fermentation.