441 research outputs found
Teaching/ Learning Experiences: Meanings Constructed by Participants ini a Degree Completion Program for Adult Students
The purpose of this study was to explore the meaning that teachers and their adult students construct of their classroom experiences and to see how those meanings impact the teaching/ learning process. Because of the multiple factors affecting an educational experience, this study took the view that this should be explored in a holistic way. Most educational research focuses on the teacher\u27s perspective, with students and their learning considered as the result of the educational process. In order to more fully understand what is occurring in classrooms and what students are actually learning, it is important to ascertain student perceptions of their learning, and it\u27s relative value to them.
This was a case study done in the naturalistic, ethnographic mode. The adult learners in one cohort of a non-traditional degree completion program were interviewed as to their understanding of what was occurring in class, what they were learning, and what aspects of their experience were important to them. Three specific course modules of this program were used as the basis of the student interviews. In addition, the teachers for each of these modules were interviewed to obtain their understanding of what was occurring in the classroom and what they perceived the students were learning. These sets of interviews were then compared to see what common understandings were revealed by both teachers and students.
The key aspects that these adults students understood and perceived as importants to their classroom experience and to their learning were 1) their relationship to the teacher, 2) their relationship to the other students in the cohort, and 3) their own personal life issues or concerns; and least important was 4) content or subject matter. The teachers similarly perceived the relationship that they developed with their students as important and essential to encouraging growth and change in their students. With this emphasis on relationships, these results suggest that when designing learning experiences for adult students that affective and cognitive issues need to be taken into consideration. In addition, the impact of the cohort and the teacher on individual student learning needs to be examined more fully
Torsional Rigidity of Rectangular Wood Composite Materials
The torsional rigidity of wood members is necessary for predicting lateral torsional buckling of laterally unsupported beams, and is useful for estimating the stiffness of two-way floor systems and the natural frequency for wood floors. Current estimations of torsional rigidity of composite wood materials are based upon elastic constant ratios of solid wood. Recently published work has found differences in the elastic constant ratios of solid wood versus structural composite lumber (SCL) materials. These differences in elastic properties may indicate differences in torsional rigidity. Rectangular sections of solid-sawn lumber and various SCL materials were tested to determine values of torsional rigidity. Torsional rigidity of solid-sawn lumber was significantly different (
Chemically Tunable Formation of Different Discrete, Oligomeric, and Polymeric Self‐Assembled Structures from Digold Metallotweezers
Digold metallotweezers whose complex supramolecular landscape is controlled by adding a series of metal cations are described. The metallotweezers have a strong tendency to form interesting supramolecular structures on addition of Tl+, Ag+, and Cu+. The choice of the cation can be used to direct the formation of a designated molecular architecture. The addition of thallium facilitates the formation of a self‐aggregated duplex structure in which the cation occupies the cavity of the dimer. The same type of structure is formed when Cu+ is added, and the resulting duplex inclusion complex shows interesting vapochromic properties. This copper‐encapsulating system evolves in solution to a 1D helical supramolecular polymer showing multiple aurophilic and Au⋅⋅⋅Cu interactions, in which the copper cation is bound to several alkynyl ligands of the tweezer. The addition of a small amount of silver cations to the digold tweezer yields a similar type of inclusion dimer complex, but adding an excess of the cation produces new discrete molecules presumably exhibiting multiple Au⋅⋅⋅Au, Au⋅⋅⋅Ag, and Ag⋅⋅⋅Ag metallophilic interactions. The differences in the supramolecular structures formed are ascribed to the different tendencies of the metal cations to exhibit interactions with the gold atoms and to coordinate to the alkynyl ligands of the tweezer
The effect of gelatin bloom strength on dry extruded pet food and injection molded treats
Master of ScienceDepartment of Grain Science and IndustryGreg AldrichPet food is a $23 billion industry that continues to grow. Owners continue to humanize their pets and their dietary needs, thus the pet food industry tends to mirror human dietary trends. Currently, pet food is trending towards higher levels of protein, thus lower levels of starch. Decreasing starch, one of the main structure forming ingredients in extruded foods, creates issues in terms of lower rates of expansion and decreased kibble durability. Consumers tend to dislike ingredients that do not serve a dual nutritional purpose; therefore gelatin may be a plausible binding ingredient for high protein pet foods.
Gelatin is a pure protein derived from collagen and is sold as a dry, odorless, tasteless powder. High-bloom gelatins find numerous uses in the human food as a stabilizer, foaming agent, and capsule base among other uses. Low-bloom gelatin may find a value-adding opportunity as a nutritional binder in the pet food market.
Four extrusion experiments were performed to test this hypothesis. Experiment 1 compared gelatin at 0%, 5%, 10%, and 15% inclusion and 15% gelatin at 3 different extruder screw speeds. Results showed a decrease in expansion but an increase in hardness and pellet durability index (PDI); however there may have been inadequate preconditioning. It was unclear whether the decrease in expansion or presence of gelatin improved product durability. Experiment 2 analyzed two levels of gelatin, 0% and 10%, under two extruder screw speeds, 300 rpm and 500 rpm, and two hydration ratios, 17% and 28%. In this experiment, there were no differences in density, expansion, hardness, or PDI. This indicated that preconditioning was more ideal and may indicate gelatin does not decrease product expansion. Experiment 3 analyzed two levels of gelatin, 0% and 10%, at two target densities, low and high. Results indicated that gelatin created a more expanded product when processed under similar conditions as a control formula. Experiment 4 analyzed different strengths of gelatin to determine if the low-bloom gelatin experiments were repeatable with more conventional strength gelatins. Treatments were a control with no gelatin, and a 100 bloom, 175 bloom, and 250 bloom gelatin. Results showed increased gelatin strength increased product expansion, likely through a foaming effect. However, durability declined with mid- and high-bloom gelatins; thus, low-bloom gelatin may be the most promising to improve product characteristics and preserve durability.
Two additional experiments were performed in order to explore gelatin bloom strength in injection molded treat processing. A lab-scale experiment was performed to optimize an initial formula. Tensile strength, strain at break, Young’s Modulus, puncture force, and peaks were measured. It was determined that equal parts gelatin, gluten, and glycerin were most ideal for further testing purposes. Determination of gelatin bloom strength effects with three bloom strength gelatins were used to produce beadlets on a pilot-scale twin-screw extruded and production model injection molding system. Differences were noted between treatments; wherein high bloom gelatin created a softer, more stretchy treat and low bloom gelatin created a tougher, more rubbery treat.
Low-bloom gelatin may find use as a nutritional binder in high protein pet foods and may be an alternative to high-bloom gelatin in injection molded dental treats
Multistimuli Response Micro- and Nanolayers of a Coordination Polymer Based on Cu2I2 Chains Linked by 2-Aminopyrazine
This is the peer reviewed version of the following article: Conesa‐Egea, J., Gallardo‐Martínez, J., Delgado, S., Martínez, J. I., Gonzalez‐Platas, J., Fernández‐Moreira, V., ... & Amo‐Ochoa, P. Multistimuli Response Micro‐and Nanolayers of a Coordination Polymer Based on Cu2I2 Chains Linked by 2‐Aminopyrazine. Small 13.33 (2017): 1700965 , which has been published in final form at https://doi.org/10.1002/smll.201700965. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionA nonporous laminar coordination polymer of formula [Cu2I2(2-aminopyrazine)]n is prepared by direct reaction between CuI and 2-aminopyrazine, two industrially available building blocks. The fine tuning of the reaction conditions allows obtaining [Cu2I2(2-aminopyrazine)]n in micrometric and nanometric sizes with same structure and composition. Interestingly, both materials show similar reversible thermo- and pressure-luminescent response as well as reversible electrical response to volatile organic solvents such as acetic acid. X-ray diffraction studies under different conditions, temperatures and pressures, in combination with theoretical calculations allow rationalizing the physical properties of this compound and its changes under physical stimuli. Thus, the emission dramatically increases when lowering the temperature, while an enhancement of the pressure produces a decrease in the emission intensity. These observations emerge as a direct consequence of the high structural flexibility of the Cu2I2 chains which undergo a contraction in Cu-Cu distances as far as temperature decreases or pressure increases. However, the strong structural changes observed under high pressure lead to an unexpected effect that produces a less effective Cu-Cu orbital overlapping that justifies the decrease in the intensity emission. This work shows the high potential of materials based on Cu2I2 chains for new applicationsThe authors thank financial support from the Spanish Ministerio de Economía y Competitividad (MAT2013-46502-C2-2P, MAT2016-77608-C3-1-P, MAT2016-75883-C2-2-P, MAT2010-20843-C02-01, MAT2016-75586-C4-4-P, CTQ2016-75816-C2-1P), also thank the scientific computing center (CCC) of the Autonoma University of Madrid for their time. J.I.M. acknowledges the financial support by the Ramón y Cajal Program of MINECO (Grant RYC-2015-17730) and the EU via the ERC-Synergy Program (Grant ERC-2013-SYG-610256 NANOCOSMOS
The Use of an Embedded Librarian to Enhance Student Information Literacy Skills: A Pilot Study
This pilot study explored an embedded librarian (EL) intervention to enhance occupational therapy student information literacy skills development. The EL provided computer laboratory and in-class instruction, online presence in the classroom website, and extensive office hours to assist students in the identification of information needed, determination of how and where to find scholarly information needed, and assessment and utilization of information retrieved to meet assignment requirements. Participants were 46 third-year (junior) occupational therapy students. Three tools were used to assess skills pre and post intervention: the Student Assessment of Information Literacy Skills, the Student Perception of Literacy Skills-Q (SPIL-Q), and database tracking of frequency, kind (in-person versus email), and topic (citation formatting, database search term development, etc.) of student visits. These were analyzed via percentage of change and compared with course grade via Pearson r correlation tests. Results: Students showed limited improvement on the quantitative SAILS test (2%), but 31% (n=14) perceived increase in overall information literacy skills on the SPIL-Q, particularly in finding information needed for assignments. Correlation analyses revealed a moderate, positive correlation (r = .600, p \u3c .05) between those who made in-person inquiries to the EL related to defining the need for information and overall course grade. Responses to the question of why students accessed/did not access the librarian outside of class were grouped into general themes. Results suggest occupational therapy educators and students might benefit from explicit instruction and in-person modeling of identification of information needed and database search techniques to locate best evidence for practice decisions and to emphasize this as a lifelong requirement of client-centered care
Investigation of structure-directing interactions within copper(i)thiocyanate complexes through X-ray analyses and non-covalent interaction (NCI) theoretical approach
Herein, we reported the synthesis of copperIJI) thiocyanate complexes with ortho-pyridinyl carbohydrazones containing a thiophene (L1) or a furyl ring (L2) as a mixture of two different crystals for each compound, linkage isomers of C1N, [CuIJNCS)IJL1)PPh3] and C1S, [Cu(SCN)(L1)PPh3], for L1, whereas monomeric and polymeric structures C2N, [Cu(NCS)(L2)PPh3], and C2P, [–(NCS)Cu(L2)–]n, for L2. Crystallographic information and theoretical calculations, mainly noncovalent interaction reduced density gradient (NCI-RDG) analyses, were pursued to generate a profound understanding of the structure-directing interactions in these complexes. The supramolecular assemblies are first driven by cooperative π⋯π interactions and hydrogen bonds followed by CH⋯π, S⋯S and S⋯π linkages. In the case of the linkage isomers, intermolecular interactions may have a significant role in the formation of the less stable S-bound isomer C1S
Molecular Catalysts with Intramolecular Re-O Bond for Electrochemical Reduction of Carbon Dioxide
Creosote Treatment Effect On Hardwood Glulam Beam Properties
Flexure tests were conducted to determine the effect of creosote treatment on the performance of Combination A northern red oak, yellow poplar, and red maple glued-laminated (glulam) beams. This testing was conducted in accordance with ASTM D198-84 (ASTM 1987a), and the beams were fabricated in accordance with AITC 119-85 (AITC 1986), ANSI/AITC 190.1-83(AITC 1983b), and AITC 200-83 (AITC 1983a). Shear tests were also conducted on samples taken from the beams to determine the glueline shear strength and percent wood failure (WF).There was no significant difference (P < 0.05) between the modulus of rupture (MOR) of creosote-treated and untreated northern red oak beams. However, the MORs of the creosote-treated red maple and yellow poplar beams were significantly (P < 0.05) higher than those for untreated beams. There was no significant difference (P < 0.05) between the treated and untreated apparent modulus of elasticity (MOE) of each species. Therefore, the post-fabrication creosote treatment process from 145.92 to 215.76 kg/m3 (9.11 to 13.47 pcf) average weight retention did not adversely affect the strength (MOR) or stiffness (MOE) of northern red oak, red maple, and yellow poplar Combination A glulam beams.Glueline shear strengths for treated and untreated specimens of each species met or exceeded minimum performance criteria in AITC 200-83. Creosote treatment significantly (P < 0.05) increased glueline shear strength of red maple, but had no effect on the shear strength of red oak and yellow poplar specimens. Mean percentage wood failure of treated shear specimens was significantly (P < 0.05) greater than of untreated specimens in each species. Mean percentage wood failures of red oak and yellow poplar gluelines exceeded AITC 200-83 performance criteria; percentage wood failure of untreated (48%) and treated (59%) red maple shear specimens did not meet AITC 200-83 performance criteria
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