Field oven used to cook up alternative to cotton defoliation
ASAE member Paul Funk, pfunk@nmsu.edu, USDA-ARS
Baking cotton plants with blasts of air at 121-177°C (250-350°F) could provide a fast-acting alternative to chemical defoliants that has the added benefit of toasting insects responsible for sticky, hard-to-process cotton.
The heat treatment recipe from scientists with the USDA’s Southwestern Cotton Ginning Research Laboratory in Mesilla Park, N.M., calls for a tractor-pulled oven with enclosed propane burner and motor-driven fan.
 Engineering technicians Tye Lightfoot (l), Billy Armijo, and tractor driver Orlando Morales test drive a portable oven in cotton fields at New Mexico State University's Leyendecker Plant Science Research Center near Las Cruces. Heat treatment may provide an alternative to traditional defoliation. (Photo by Paul Funk, courtesy of Southwestern Cotton Ginning Research Lab) |
“The cotton leaf is only a few cells thick, so this process cooks the leaves within 24 hours,” says Paul Funk, an agricultural engineer with the Agricultural Research Service lab at New Mexico State University (NMSU).
In 2002, crews treated fields at NMSU’s Leyendecker Plant Science Research Center to pinpoint an optimal temperature for heat treatment. Control plots were treated with conventional defoliants that allow farmers to harvest the highest percentage of mature cotton in one pass through the field.
Defoliants stop leaf growth, open bolls, and cause leaf drop. But heat treatment leaves some foliage on, so scientists are testing fiber in ginning and textile research labs to make sure it gets clean enough.
If so, heat offers a new option for organic production and hard-to-defoliate Pima cotton. Another plus: heat kills the aphids and whiteflies that contaminate cotton with sugary waste.
“The cost per acre is roughly equal between propane and defoliant, but the ground rig is more expensive to operate because of labor costs,” Funk says. “A self-propelled machine could be the next step if it’s feasible and economical.”
| Pigs like it hot, but not
too hot ASAE member Victor van Wagenberg, A.V.van.Wagenberg@pv.agro.nl, Research Institute for Animal Husbandry The majority of pigs in Europe and North America spend their entire lifetime indoors. To supply the animals with fresh air and thermal comfort, the room in which they live is provided with a ventilation and heating system. The climate around the pigs, the Animal Occupied Zone (AOZ), needs to meet the animals’ demands. Pigs kept in a too hot or too cold AOZ have reduced welfare and performance. It is in the interest of the pigs and the farmer to optimize the climate in the AOZ.
The Research Institute for Animal Husbandry in the Netherlands has developed a new ventilation system for pig rooms. In rooms with the new ventilation system, fresh air flows through underground air channels and enters the room close to the animals with very low air velocities. The result is a good fresh air supply in the AOZ, effective ventilation, and energy savings. The climate in all pens is equal, and controlling the climate in the AOZ is improved. The effect of this ventilation system on animal behavior and animal performance is currently being studied. |
Fiber optic sensor detects glutamate
Jenna Rickus, rickus@ecn.purdue.edu, Purdue University
Many food components are biologically active molecules. For example, the amino acid glutamate doesn’t just make your cheese taste good; it also functions in your brain to help you taste the cheese. Glutamate is one of the major signaling molecules used by neurons to communicate with one another.
One approach to measuring biological molecules in food is to mimic the detection strategies of cells. Cells utilize proteins including receptors and enzymes as “detectors.” These proteins selectively bind molecules and report their presence to the cell. A neuron detects the glutamate released by another neuron through a receptor protein on its cell surface. Biosensors can be constructed by incorporating the protein detection systems of cells into engineered devices.
Jenna Rickus, assistant professor in the Agricultural and Biological Engineering Department at Purdue University, uses the metabolic enzyme used by cells to produce and degrade glutamate to detect glutamate. The enzyme reaction produces a fluorescent molecule that can be measured by its interaction with light. By immobilizing the enzyme on the tip of an optical fiber, remote detection of glutamate is possible by shining laser light down the fiber and measuring fluorescence production.
Immobilization of proteins into a fiber optic sensor can be challenging because the delicate proteins are not always compatible with the harsh usage requirements of the final sensor. One way to protect the protein is to encapsulate it in a proteinfriendly porous glass using a room temperature synthesis method known as sol-gel. After encapsulation the protein remains active as a detector and has added protection resulting in a more rugged device. In addition, the glass is transparent and does not interfere with the fluorescence signal carried by the optical fiber.
This type of fiber optic sensor could be used for a wide variety of applications, from measuring glutamate in foods to studying glutamate signals in the brain.
This work was conducted at the University of California, Los Angeles, under the direction of Bruce Dunn and Allan J. Tobin.
| Exploring chicken eating
habits for enhanced well-being ASAE members Kelly Persyn, kpersyn@iastate.edu, and Hongwei Xin, hxin@iastate.edu, Iowa State University, and Richard Gates, gates@bae.uky.edu, University of Kentucky Understanding feeding characteristics of animals is of fundamental value to engineering design and management strategies for enhanced well-being and production efficiency. White Leghorn laying hens have a high tendency of feather pecking and cannibalism. Beak trimming has been a management practice used by the U.S. poultry industry to prevent such cannibalism. However, beak trimming may temporarily or permanently alter the feeding behavior of the birds, which may need to be considered in the engineering design or management schemes (e.g., number of birds per feeder or per feed-line space, and time allocation in a mealtime feeding scheme). The same may be said about stocking density of caged layers – another topic on bird welfare that is drawing much attention among both the production and consumer industries.
The first study examined the comparative feeding behaviors of laying hens with or without beak trimming and revealed intriguing results. A second study is in progress that quantifies feeding behavior of pullets with or without beak trimming, especially during the period subsequent to beak trimming at 7 days of age. In addition to the feeding behavior parameters mentioned above, the magnitude of pecking force for both groups will be examined. This result may help reveal the degree and duration of chronic pain that may be associated with eating after beak trimming. The approach may also be used as a non-invasive means to quantify animal welfare. |
Beer flavor monitored by biosensor technology
ASAE member John Sheppard, john.sheppard@mcgill.ca, McGill University
Ever tasted beer that seemed slightly “off,” characterized by a butterscotch- like flavor? If you have, it was mostly likely due to a natural compound, called diacetyl, produced by yeast during beer fermentation.
With the ability to detect levels below 0.1 parts per million, our taste buds are extremely sensitive to diacetyl, and therefore, brewers try to ensure that almost all of the diacetyl is eliminated during the maturation process. Although, given the appropriate conditions, the yeast themselves will metabolize the diacetyl into compounds that do not affect flavor, it is often difficult to predict the rate at which the desired reduction in diacetyl will occur.
 Biosensors measure levels of diacetyl produced by yeast during beer fermentation. |
Biosensors utilize biochemical reactions to determine the presence of specific compounds, offering the food industry a new rapid type of monitoring device with high sensitivity. This particular biosensor is configured in a kit form that includes all the necessary materials to obtain results within minutes by following a few simple steps.
The measurement is based on the fact that the enzymatic reduction of diacetyl requires the cofactor nicotinamide adenine dinucleotide phosphate (NADPH). Therefore, changes in NADPH concentration can be used as a direct indication of the amount of diacetyl reacted. This information can be translated into the sample’s initial diacetyl concentration according to the reaction kinetics and the kit’s design parameters. Furthermore, NADPH is easily and accurately monitored by the absorbance of UV light.
The test is sensitive to below 0.05 parts per million of diacetyl and in comparison to the traditional method, gas chromatography, is much less expensive and faster.
| New products made from microwave-treated
wood ASAE member Graham Brodie, grahamb@unimelb.edu.au, University of Melbourne The drying, strength, durability, dimensional stability, machining, and treatment characteristics of timber are quite variable. In spite of this, many people prefer the natural appearance of wood in favor of the many extensively modified wood-based products currently available on the market. Microwave wood modification overcomes much of this natural variability by making the wood permeable. This technique assists the drying processes without the associated defects of bow, twist, checking, and collapse. It also facilitates treatment with preservatives and resins.
Extensive wood modification results in a product called Torgvin as shown above. This product is being investigated for its thermal and acoustic insulation properties. Another product called Vintorg is produced from Torgvin by impregnating the microwave-expanded crosssection with resin followed by pressing and curing. Vintorg has strength and stability properties similar to laminated veneer lumber but maintains the natural appearance of wood. Two of the many useful features of Vintorg are the ability to use low-grade materials (such as the core wood of radiata pine or Douglas fir heartwood) and the use of insecticidal resins, which reduces the prospects of termite and borer attack. |
Optical imaging for early cancer detection
Gang Yao, yaog@missouri.edu, University of Missouri
Early detection of cancer saves thousands of lives each year. Five-year survival rates for many patients whose cancers are caught early range from 80 to 90 percent.
In the fight against this disease, a University of Missouri biological engineering researcher is developing a device that uses a near-infrared laser to perform optical biopsies in the early detection of cancer and other diseases.
“Early detection is very important in fighting cancer,” says researcher Gang “Gary” Yao. “We want to develop a reliable diagnostic tool for biomedical applications. Hopefully, patients could be screened for such diseases as skin cancer, osteoarthritis, and cardiovascular problems.”
Diagnostic tools such as CAT scans, X-rays, or ultrasound are not always sensitive to tumors in their early stages, he says.
 Gang Yao is developing a device that uses a near-infrared laser to perform optical biopsies. (University of Missouri photo by Jim Curley) |
One reason for this is that the rapid growth of tumor cells leads to both large blood volume and blood deoxygenation. On the cellular level, cancer cells also have larger nuclei than healthy cells and display different light scattering properties. Those changes can be detected optically.
A problem faced by optical detection is the scattering of light within the tissue. Multiple scattered light in the tissue causes loss of the spatial information that is critical for medical imaging. To correct the problem, Yao uses optical coherence tomography. This technique uses the laser’s coherent property to detect light from a specified place inside the tissue.
A laser is directed at a patient’s tissue samples, and the back-scattered light is collected and combined with a reference beam. The resulting “beat” signal to the reference beam can be detected with high sensitivity.
Y ao is building a bench model of a high spatial resolution imaging device with an advanced signal processing algorithm to compare imaging results of cancerous and healthy cells with imaging results obtained by more conventional methods.
Optical biopsies can be used at the surface of tissues or internally with endoscopes. Such technology should lead to inexpensive, more powerful diagnostic and less invasive tools, he says.
| Soy heating oil possible
alternative ASAE members Aaron Deckard, addeckar@purdue.edu and Harry Gibson, gibson@ecn.purdue.edu, Purdue University Staying warm crosses people’s minds when the coldest part of winter approaches. Americans burn nearly 27.6 billion liters (7.3 billion gallons) of heating oil to stay warm in their homes each year, but the cost of petroleum heating oil is historically unstable, and environmental concerns are associated with home heating. The USDA has channeled funds through the United Soybean Board to help researchers in agricultural and biological engineering at Purdue University investigate the use of soybean oil as a clean and cost-effective heating fuel alternative in certain areas of the U.S. heating fuel market.
More testing of storage stability, nozzle performance, and overall system efficiency continues with hopes of finding a blend that substantially reduces the sulfur and NOx emissions caused by petroleum heating oil that can have long-term negative effects on both the environment and the furnace components. The other goal for soy heating oil is to make oil heat more cost comparable to other space heating methods by using the soybean oil component as a stable price buffer to the current price fluctuations being seen in the petroleum fuel industry. |
