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Kisich K.O.,National Jewish Medical and Research Center | Higgins M.P.,National Jewish Medical and Research Center | Park I.,National Jewish Medical and Research Center | Cape S.P.,Cooperative Institute for Research in Environmental science CIRES | And 7 more authors.
Vaccine | Year: 2011

A stable and high potency dry powder measles vaccine with a particle size distribution suitable for inhalation was manufactured by CO2-Assisted Nebulization with a Bubble Dryer® (CAN-BD) process from bulk liquid Edmonston-Zagreb live attenuated measles virus vaccine supplied by the Serum Institute of India. A novel dry powder inhaler, the PuffHaler® was adapted for use in evaluating the utility of cotton rats to study the vaccine deposition, vaccine virus replication, and immune response following inhalation of the dry powder measles vaccine. Vaccine deposition in the lungs of cotton rats and subsequent viral replication was detected by measles-specific RT-PCR, and viral replication was confined to the lungs. Inhalation delivery resulted in an immune response comparable to that following injection. The cotton rat model is useful for evaluating new measles vaccine formulations and delivery devices. © 2010 Elsevier Ltd.

Tuchscherer R.,Datum Engineers Inc. | Birrcher D.,International Bridge Technologies Inc. | Huizinga M.,Thornton Tomasetti | Bayrak O.,Environmental and Architectural engineering
ACI Structural Journal | Year: 2010

The purpose of the testing program described in this paper was to evaluate the benefits of triaxial confinement that occurs when the loaded area of a strut-and-tie model (STM) is surrounded by concrete on all sides. To achieve this goal, five full-scale beams were fabricated and tested at the Ferguson Structural Engineering Laboratory in Austin, TX. Specimens were tested with a span-depth ratio (a/A) of 1.85. Two ends of each beam were tested, resulting in a total of 10 tests. Eight tests were conducted on beams with a 21 × 42 in. (530 × 1070 mm) cross section, and two tests were conducted on beams with a 36 × 48 in. (910 × 1220 mm) cross section. The primary experimental variables were the size of the load- and support-bearing plates and the amount of web reinforcement. Based on the results of the testing program, it is recommended that the permissible nodal stresses of an STM be increased for nodes triaxially confined by concrete. Copyright © 2010, American Concrete Institute. All rights reserved.

Garber D.B.,Florida International University | Gallardo J.M.,Technological University of Panama | Bayrak O.,Environmental and Architectural engineering
ACI Structural Journal | Year: 2016

A comprehensive experimental database containing 237 specimens from 27 different research studies was assembled during a larger research effort undertaken at the University of Texas at Austin to investigate three different short-term loss and four different longterm loss estimation procedures. The assembled database was filtered to eliminate specimens with incomplete information or those not adequately representing those found in the field (as a result of either being too small or overstressed at release). The specimens contained within this filtered database offered a diversity of characteristics well representative of beams found in bridges. This database was used to evaluate several different short-and longterm loss estimation procedures. The results of these evaluations can help to aid the designer in selection of an appropriate procedure for estimating prestress loss. © 2016, American Concrete Institute. All rights reserved.

Varney J.C.,Huitt Zollars Inc. | Brown M.D.,WDP and Associates | Bayrak O.,Environmental and Architectural engineering | Poston R.W.,WDP and Associates
ACI Structural Journal | Year: 2011

The performance of improperly constructed beams is of particular concern in the repair of concrete structures. Not only is there uncertainty about the actual as-built strength and what measures may improve capacity, but also the presence of improper structural details may lead to litigation concerning what structural repairs are really necessary to restore perceived loss of strength. For the specific case of shear, there is value in knowing a reasonable and safe approximation of the shear capacity of improperly detailed beams. To study the effect of improperly anchored stirrups on the shear strength of reinforced concrete beams, four 13 × 24 in. (330 ×610 mm) reinforced concrete sections were fabricated with varying proper and improper shear reinforcement details and loaded to failure. Current ACI 318 and AASHTO LRFD code provisions were used to compare the resulting failure loads from tests with calculated nominal capacities. The experimental results suggest that reinforcement anchorage, as tested, has no significant effect on the shear capacity of a reinforced concrete section. © 2011, American Concrete Institute. All rights reserved.

Hovell C.,T.Y. Lin International | Avendano A.,Technological University of Panama | Bayrak O.,Environmental and Architectural engineering | Jirsa J.,University of Texas at Austin
ACI Structural Journal | Year: 2014

Ten 54 in. (1372 mm) deep U-beam test specimens were fabricated and load-tested in shear. The first five specimens were built following existing standard designs, with variables including reinforcement type and number of prestressing strands. All of these test specimens failed near the support, along the interface between the bottom flange and the web of the beam, at shear loads significantly below the calculated shear capacity. The shear force at failure did not vary with reinforcement or prestressing levels. The second five test specimens were designed to increase the capacity of the bottom flange-to-web interface. Three of the specimens contained significantly more reinforcement crossing the bottom flange-to-web interface near beam end and/or a longer end block than the first group of beams. These specimens failed in typical web-shear failure modes at loads well in excess of the calculated shear capacity, with no signs of distress at the bottom flange-to-web interface. © 2014, American Concrete Institute.

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