Darren H. Jarboe

Biofilm-based algal cultivation systems

Biofilm-based algal cultivation has received increased attention as a potential platform for algal production and other applications such as wastewater treatment. Algal biofilm cultivation systems represent an alternative to the suspension-based systems that have yet to become economically viable. One major advantage of algal biofilm systems is that algae can be simply harvested through scraping and thus avoid the expensive harvesting procedures used in suspension-based harvesting such as flocculation and centrifugation. In recent years, an assortment of algal biofilm systems have been developed with various design configurations and biomass production capacities. This review summarizes the state of the art of different algal biofilm systems in terms of their design and operation. Perspectives for future research needs are also discussed to provide guidance for further development of these unique cultivation systems.

Grain Residuals and Time Requirements for Combine Cleaning

Emerging identity-preserved grain markets depend on avoidance of commingling grain at harvest. Knowledge of where grain resides in a combine, cleaning labor requirements, and resulting purity levels would assist producers. Measurements were made of grain and other material residing in different areas of rotary- and cylinder-type combines in replicated clean-outs during corn and soybean harvest and also in preliminary clean-outs during oat harvest. Concentration of the prior (i.e. commingled) grain was measured in the first grain harvested of the subsequent crop. Total material remaining in the combine ranged from 84 to 186 lb, 61% of which was whole grain. The greatest amounts of corn and soybean material (17 to 74 lb) were found in the grain tank and rock trap. Intermediate amounts were found in the head or feederhouse, elevators, and at times the cylinder/rotor (soybeans), the unloading auger (soybeans, oats), and rear axle/chopper area. The least amounts were found in the cleaning shoe and straw walkers (cylinder-type machine). Time spent to clean the combine varied from about two hours to seven hours. Cleaning the head, grain tank, threshing rotor/cylinder, and cleaning shoe required more time than other areas. Immediately after cleaning, small amounts of prior (commingled) grain and foreign material, 0.2 to 2.5 lb, were found in the first bushel of subsequent grain harvested. Following clean-outs, commingled grain levels dropped below 0.5% after 20 bu were harvested. Over 14 lb of wheat were found during the first clean-out of a combine following 50 ac of oat harvest (no physical clean-out prior to oat harvest).

An example of commercializing biobased coatings and binders

Commercialization of emerging biobased technologies delivers new functionality and value to manufacturers and customers. Navigating this process can be difficult and value extraction from the technology elusive. A biobased coatings and binders example will be used to demonstrate: (1) the development of an initial research, development, and commercialization plan; (2) the influence and importance of industry partners throughout the project; and (3) the use of licensing and other methods to create value.

Essential Elements for Producer Participation in Biomass Markets

Opportunities for agricultural producers to provide lignocellulosic feedstocks to manufacturers of biobased products such as ethanol, butanol, and fine chemicals are emerging. When evaluating such biomass market opportunities, several factors must be considered (e.g., sustainability, possible harvest delays, labor availability, initial investment, risk). The primary objective of this study was to develop rigorous constructs defining the essential elements for producer participation in biomass markets. In this paper, we report the results and analysis of a mail survey of 2,250 Iowa producers farming 50 acres or more. The survey instrument was developed using relevant items to assess essential elements for producer participation in biomass markets. Semantic Differential Scales (rating from one to seven with polar opposites as scale anchors) were used and the Dillman Protocol was followed. Producers returned 885 surveys, 645 of which were complete, for a response rate of 28.7%. Exploratory factor analysis was used to analyze the survey data and group survey items into multi-item constructs.

Student Perspectives on a New Biomass Production Module for Fundamentals of Biorenewable Resources

In 2007, a USDA Higher Education Challenge Grant funded the creation of a Virtual Education Center (VEC) for Biorenewable Resources at three partner land-grant institutions. Three new courses are taught through the VEC, each using multiple instructors and exchanges of video lectures between sites. The most heavily subscribed of these is a graduate survey type course entitled Fundamentals of Biorenewable Resources. In this paper, we report on student survey results for the biomass production module, which covered the production of corn, soybean, hay and forage, and short rotation woody crops, as well as biotechnology basics. The survey was administered using WebCT and SurveyMonkey in spring 2010. The survey instrument gathered student perspectives on the module content and delivery, and student learning. Quantitative and qualitative data were collected and analyzed.

Impact of Two Course Content Delivery Systems on Student Learning

In 2007, a USDA Higher Education Challenge Grant funded the creation of a Virtual Education Center (VEC) for Biorenewable Resources at three partner land grant institutions. Three new courses are taught through the VEC, each using multiple instructors and exchanges of video lectures between sites. The most heavily subscribed of these is a graduate survey course entitled Fundamentals of Biorenewable Resources. In this paper, we report on comparisons of two online delivery methods used in the fundamentals course: 1) a standard video lecture using a tablet computer, and 2) a self-contained menu-driven autotutorial presentations (MDAP) delivered via Adobe Flash. In both cases, the module covered production of corn, soybean, hay and forage, and short rotation woody crops, as well as biotechnology basics. The two versions contained nearly identical academic content. The module was taught during weeks 9 to 11 of the course, allowing students to be sorted based on prior course performance to ensure the two groups were academically similar. Student performance data from the course were collected through WebCT assessments (quizzes and an exam) in spring 2010 and statistical analysis was used to determine student learning differences.

Effects of Full, Abbreviated, and No Clean-Outs on Commingled Grain during Combine Harvest

Growers of identity-preserved crops desire to keep grain separate throughout the production process. Earlier research has demonstrated that some locations in a combine such as cleaning and threshing areas harbor relatively smaller amounts of grain, but require relatively large amounts of time to clean. Omitting clean-out in some areas and flushing residual grain with new grain in the first grain tank full may lower commingled grain concentration to acceptable levels for some customers.