Weires N.A.,Boise State University |
Johnston A.,Boise State University |
Warner D.L.,Boise State University |
McCormick M.M.,U S Customs and Border Protection |
And 2 more authors.
Journal of Chemical Education | Year: 2011
Distillation is a ubiquitous technique in the undergraduate organic chemistry curriculum; the technique dates back to ca. 3500 B.C.E. With the emergence of green chemistry in the 1990s, the importance of emphasizing responsible waste management practices for future scientists is paramount. Combining the practice of distillation with the message that waste generation should be minimized conveys green concepts from the beginning of the student's experience in the lab. In this experiment, acetone waste collected from the cleaning of student glassware is purified by fractional distillation. The purity of the resulting distillate is determined by refractive index and density calculation. The distilled acetone is of sufficient purity (∼88%) that students can reuse it to wash glassware, collect the waste, and add it to a communal still that is operated by the instructor or support personnel. Students learn how to set up and perform a fractional distillation experiment, learn how to test the distillate for purity by refractive index and density, and are exposed to the value of recycling materials for reuse. The communal distillation apparatus provides an ongoing source of purified acetone for students to use throughout the remainder of the term. © 2011 The American Chemical Society and Division of Chemical Education, Inc.
Gerde J.R.,U S Customs and Border Protection |
Christens-Barry W.A.,Equipoise Imaging LLC
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010
Analysis of footwear under the Harmonized Tariff Schedule of the United States (HTSUS) is partly based on identifying the boundary ("parting line") between the "external surface area upper" (ESAU) and the sample's sole. Often, that boundary is obscured. We establish the parting line as the curved intersection between the sample outer surface and its insole surface. The outer surface is determined by discrete point cloud coordinates obtained using a laser scanner. The insole surface is defined by point cloud data, obtained using a touch probe device-a coordinate measuring machine (CMM). Because these point cloud data sets do not overlap spatially, a polynomial surface is fitted to the insole data and extended to intersect a mesh fitted to the outer surface point cloud. This line of intersection defines the ESAU boundary, permitting further fractional area calculations to proceed. The defined parting line location is sensitive to the polynomial used to fit experimental data. Extrapolation to the intersection with the ESAU can heighten this sensitivity. We discuss a methodology for transforming these data into a common reference frame. Three scenarios are considered: measurement error in point cloud coordinates, from fitting a polynomial surface to a point cloud then extrapolating beyond the data set, and error from reference frame transformation. These error sources can influence calculated surface areas. We describe experiments to assess error magnitude, the sensitivity of calculated results on these errors, and minimizing error impact on calculated quantities. Ultimately, we must ensure that statistical error from these procedures is minimized and within acceptance criteria. © 2010 Copyright SPIE - The International Society for Optical Engineering.
Bett-Garber K.L.,U.S. Department of Agriculture |
Greene J.L.,Kraft Foods Inc. |
Lamikanra O.,Frito Lay |
Ingram D.A.,U S Customs and Border Protection |
Watson M.A.,U.S. Department of Agriculture
Journal of Food Quality | Year: 2011
Consistent storage temperature of 2-5C for fresh-cut produce is difficult to maintain throughout distribution. This study determined the effects of temperature changes on the sensory quality of fresh-cut cantaloupe. Cantaloupe was processed, packaged and stored for 7 days. Samples were maintained at 4 and 10C (controls) or transferred from 4 to 10C after 24 or 48h. Descriptive sensory analysis was used to evaluate aroma, flavor and texture after days 2, 5 and 7 of storage. Respiration and weight loss were monitored. Aroma and flavor were affected by temperature treatments. Texture was affected a little by temperature changes. Fruity/melon aroma and flavor, citrus aroma and sweet aromatic flavor were negatively affected by temperature changes compared to control treatments. Musty and rancid/painty flavors and bitter increased due to temperature changes. Respiration and moisture loss were affected more by storage at 10C than temperature change. Temperature increases during storage of fresh-cut fruit decreases product quality. 2011 Wiley Periodicals, Inc. Published 2011. This article is a US Government work and is in the public domain in the USA.
Ma-Ham A.,U S Customs and Border Protection |
Ma-Ham A.,Pacific Northwest National Laboratory |
Wu H.,Pacific Northwest National Laboratory |
Wang J.,Pacific Northwest National Laboratory |
And 3 more authors.
Journal of Materials Chemistry | Year: 2011
This paper describes the preparation and optimization of the analytical properties of the protein based drug delivery platform apoferritin. In biological systems, the protein cage ferritin is used to store iron and to keep it from building to toxic levels in cells. When the iron atoms are removed from ferritin, apoferritin is formed. In this study, daunomycin, an anthracycline antibiotic drug that has been used for specific types of cancer treatment such as acute myeloid leukemia and acute lymphocytic leukemia, was encapsulated within the protein cage for drug delivery. Daunomycin slows or stops the growth of cancer cells by binding with the cell's DNA. The model for daunomycin-DNA complex binding mechanism is intercalation, where daunomycin binds with approximately every 3 base pairs causing a local unwinding, but a negligible distortion of the helical conformation. The binding affinity for free DNA is higher than that of structured DNA in cells. Upon binding with DNA the fluorescence intensity of daunomycin decreases. We used apoferritin's ability to disassemble and reassemble under pH control to load the therapeutic compound daunomycin. The combination of a modifiable interior and exterior surface and the passable hydrophobic and hydrophilic channels through the cage allows the containment or attachment of both insoluble and soluble drugs for delivery. At experimental pH 5 conditions the interaction between the apoferritin interior cage and daunomycin is weak making it difficult to encapsulate the drug effectively within the protein cage. The incorporation of poly-l-aspartic acid (PLAA), a polypeptide and biodegradable material that does not increase the toxicity of the drug delivery system and is negatively charged at pH 5.0, into the drug delivery system resulted in a substantial improvement in the drug encapsulation. The binding properties of free daunomycin with DNA were compared to the newly synthesized apoferritin protein based drug delivery system. Encapsulation of the daunomycin within the apoferritin protein cage had little effect upon the intrinsic binding constant, Ki, or the exclusion parameter n as compared to the free daunomycin model. The study resulted in the design and optimization of a unique protein based drug delivery platform using the protein cage apoferritin for potential therapeutic administration of the anti-cancer agent daunomycin. © 2011 The Royal Society of Chemistry.
Gerde J.R.,U S Customs and Border Protection |
Christens-Barry W.A.,Equipoise Imaging LLC
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011
In a project to meet requirements for CBP Laboratory analysis of footwear under the Harmonized Tariff Schedule of the United States (HTSUS), a hybrid metrology system comprising both optical and touch probe devices has been assembled. A unique requirement must be met: To identify the interface-typically obscured in samples of concern-of the "external surface area upper" (ESAU) and the sole without physically destroying the sample. The sample outer surface is determined by discrete point cloud coordinates obtained using laser scanner optical measurements. Measurements from the optically inaccessible insole region are obtained using a coordinate measuring machine (CMM). That surface similarly is defined by point cloud data. Mathematically, the individual CMM and scanner data sets are transformed into a single, common reference frame. Custom software then fits a polynomial surface to the insole data and extends it to intersect the mesh fitted to the outer surface point cloud. This line of intersection defines the required ESAU boundary, thus permitting further fractional area calculations to determine the percentage of materials present. With a draft method in place, and first-level method validation underway, we examine the transformation of the two dissimilar data sets into the single, common reference frame. We also will consider the six previously-identified potential error factors versus the method process. This paper reports our on-going work and discusses our findings to date. © 2011 SPIE.