The Experts below are selected from a list of 69 Experts worldwide ranked by ideXlab platform

Stuart M Phillips - One of the best experts on this subject based on the ideXlab platform.

  • Resistance exercise and appropriate nutrition to counteract muscle wasting and promote muscle hypertrophy.
    Current Opinion in Clinical Nutrition and Metabolic Care, 2010
    Co-Authors: Elisa I. Glover, Stuart M Phillips
    Abstract:

    Purpose of reviewLoss of skeletal muscle mass is a common feature of a number of clinical scenarios including limb Casting, Bed rest, and various disorders such as HIV-AIDS, sepsis, cancer cachexia, heart failure, and uremia. Commonly, muscle disuse (hypodynamia) is the sole reason, or a large part,

  • Resistance exercise and appropriate nutrition to counteract muscle wasting and promote muscle hypertrophy
    Current Opinion in Clinical Nutrition and Metabolic Care, 2010
    Co-Authors: Elisa I. Glover, Stuart M Phillips
    Abstract:

    PURPOSE OF REVIEW: Loss of skeletal muscle mass is a common feature of a number of clinical scenarios including limb Casting, Bed rest, and various disorders such as HIV-AIDS, sepsis, cancer cachexia, heart failure, and uremia. Commonly, muscle disuse (hypodynamia) is the sole reason, or a large part, of why muscle mass is lost. The reduction in strength, or dynapenia, that accompanies these conditions is also a function of the degree of hypodynamia and is related to muscle loss.\n\nRECENT FINDINGS: The major and consistent finding in a number of human-based models of muscle wasting is a decline in the synthesis of new muscle proteins both in the postabsorptive and fed states. Thus, countermeasures are best suited to those that augment muscle protein synthesis and not those that attempt to counteract proteolysis. Our main thesis is that retention of muscle mass in wasting conditions will be achieved to the greatest extent by focussing on increased muscle use with moderate-to-high resistance loads as the primary countermeasure with a secondary countermeasure being to provide adequate nutritional support. Either intervention alone will alleviate some part of hypodynamia-induced muscle mass loss and dynapenia; however, together nutrition and muscular contraction will result in greater mitigation of muscle loss.\n\nSUMMARY: Advances in our understanding of hypodynamia-induced muscle loss, a condition common to almost all syndromes of muscle wasting, has led to a focus on reduced basal and feeding-induced elevations in protein synthesis. Countermeasures for wasting should focus on stimulating anabolism rather than alleviating catabolism.

Elisa I. Glover - One of the best experts on this subject based on the ideXlab platform.

  • Resistance exercise and appropriate nutrition to counteract muscle wasting and promote muscle hypertrophy.
    Current Opinion in Clinical Nutrition and Metabolic Care, 2010
    Co-Authors: Elisa I. Glover, Stuart M Phillips
    Abstract:

    Purpose of reviewLoss of skeletal muscle mass is a common feature of a number of clinical scenarios including limb Casting, Bed rest, and various disorders such as HIV-AIDS, sepsis, cancer cachexia, heart failure, and uremia. Commonly, muscle disuse (hypodynamia) is the sole reason, or a large part,

  • Resistance exercise and appropriate nutrition to counteract muscle wasting and promote muscle hypertrophy
    Current Opinion in Clinical Nutrition and Metabolic Care, 2010
    Co-Authors: Elisa I. Glover, Stuart M Phillips
    Abstract:

    PURPOSE OF REVIEW: Loss of skeletal muscle mass is a common feature of a number of clinical scenarios including limb Casting, Bed rest, and various disorders such as HIV-AIDS, sepsis, cancer cachexia, heart failure, and uremia. Commonly, muscle disuse (hypodynamia) is the sole reason, or a large part, of why muscle mass is lost. The reduction in strength, or dynapenia, that accompanies these conditions is also a function of the degree of hypodynamia and is related to muscle loss.\n\nRECENT FINDINGS: The major and consistent finding in a number of human-based models of muscle wasting is a decline in the synthesis of new muscle proteins both in the postabsorptive and fed states. Thus, countermeasures are best suited to those that augment muscle protein synthesis and not those that attempt to counteract proteolysis. Our main thesis is that retention of muscle mass in wasting conditions will be achieved to the greatest extent by focussing on increased muscle use with moderate-to-high resistance loads as the primary countermeasure with a secondary countermeasure being to provide adequate nutritional support. Either intervention alone will alleviate some part of hypodynamia-induced muscle mass loss and dynapenia; however, together nutrition and muscular contraction will result in greater mitigation of muscle loss.\n\nSUMMARY: Advances in our understanding of hypodynamia-induced muscle loss, a condition common to almost all syndromes of muscle wasting, has led to a focus on reduced basal and feeding-induced elevations in protein synthesis. Countermeasures for wasting should focus on stimulating anabolism rather than alleviating catabolism.

B. Terry Beck - One of the best experts on this subject based on the ideXlab platform.

  • Transfer Length Characterization of Entire Crosstie Plant Casting Bed Using Continuously Traversing Dual-Camera Non-Contact Optical Strain Sensors
    2017 Joint Rail Conference, 2017
    Co-Authors: B. Terry Beck, Aaron A. Robertson, Robert J. Peterman, Kyle A. Riding, John Wu
    Abstract:

    Transfer length has been identified as a key diagnostic parameter for evaluating the load bearing capability of prestressed concrete railroad crossties. Furthermore, it has been proposed for use as a valuable quality control parameter. However, until quite recently the capability to easily and accurately measure transfer length has been limited primarily to a laboratory setting. This is especially true for measurements made in the harsh environment of a tie manufacturing plant. The development of portable non-contact optical strain sensors has opened the door to rapid in-plant transfer length measurement. The measurement capability of these devices has been repeatedly demonstrated not only in the laboratory, but more importantly also through actual testing at multiple tie manufacturing plants. The latest version of the automated Laser-Speckle Imaging (LSI) system developed by the authors offers improved optical resolution of longitudinal surface strain, with the ability to resolve longitudinal prestressed concrete crosstie surface strain without time-consuming special surface preparation. The new system is also capable of making measurements of strain in a real-time “on-the-fly” manner over the entire distance range of interest on the tie associated with transfer length development. This faster capability to capture the strain profile with high resolution makes this new technology very beneficial for field testing and in-plant diagnostics applications. It has been demonstrated to be capable of resolving minor differences in longitudinal surface strain profiles associated with ties even in adjacent cavities. As a logical next step toward eventual implementation of transfer length as a quality control parameter, it is important to evaluate the expected variation of transfer length during the tie manufacturing process. This paper presents the results of extensive in-plant assessment of transfer length in an attempt to characterize experimentally the in-plant manufacturing variations that can occur in practice. To the best of the authors’ knowledge, this is the first time extensive real-time measurements to this extent have been attempted in an actual tie manufacturing plant with the expressed purpose of statistically characterizing the variations in transfer length that take place over an entire Casting Bed. A sampling of transfer lengths from well over 50 ties was determined during the manufacturing process (corresponding to over 100 transfer length measurements). The sampled tie measurement locations were distributed at different “form” locations along the Casting Bed, and included samplings of ties from several different “cavities” within a given form. The entire Bed was 45 forms in length, each form having 6 tie cavities, for a total Bed size of 270 ties. The statistical distribution of overall transfer length measurement results is presented, along with what may be typical variations in strain profile and resulting transfer length as a result of variations that took place in the manufacturing process. The overall range of transfer length observed, along with an investigation of possible bias due to position within the Casting Bed, and apparent variations of transfer length within a given form, are identified and discussed.

  • Performance of a Continuously Traversing 2-Camera Non-Contact Optical Strain Sensor for In-Plant Assessment of Prestressed Concrete Railroad Crosstie Transfer Length
    2016 Joint Rail Conference, 2016
    Co-Authors: B. Terry Beck, Aaron A. Robertson, Robert J. Peterman, Chih-hang John Wu
    Abstract:

    Accurate knowledge of transfer length has been shown to be crucial to the goal of maintaining continuous production quality in the modern manufacture of prestressed concrete railroad ties. Traditional manual laboratory methods, such as the conventional Whittemore method which requires the use of emBedded reference points, are clearly not suitable for production operation or for use in reliable production quality-control.This paper presents the results of another advance in the development of automated transfer length measurement systems for practical in-plant operation. The new device offers a significant improvement over the previously successful automated Laser-Speckle Imaging (LSI) system developed by the authors. The earlier automated LSI strain measurement system has been modified to provide significantly improved optical resolution of longitudinal surface strain, with the ability to resolve longitudinal prestressed concrete crosstie surface strain without time-consuming special surface preparation. More importantly, the new system is also capable of making measurements of strain in a real-time “on-the-fly” manner over the entire distance range of interest on the tie associated with transfer length development. It features both a “jog” mode of operation, similar to its predecessor in which measurements of longitudinal surface strain are automatically captured in arbitrary spatial increments over the entire range of the computer-controlled traverse, and an “on-the-fly” mode in which measurements of longitudinal surface strain are captured without the need for stopping at each measurement location. This latter mode offers the potential of a much faster capture of the strain profile and should prove to be very beneficial for field testing and in-plant diagnostic applications.The performance of this new system is first demonstrated using a new calibrated step-wise uniform strain field setup which has been developed specifically for verification of this and other automated transfer length measurement systems. This verification system produces a calibrated step change in surface deflection, effectively subjecting the automated strain measurement system to an ideal step change in longitudinal strain for a given gauge length. In addition, the new automated system is demonstrated by conducting measurements of longitudinal surface strain on prestressed concrete crossties in a manufacturing plant. For this latter experimental in-plant testing, strain measurements using the new system are also compared directly with those from the recently introduced 6-camera transfer length measurement system, as well as with the traditional Whittemore gauge measurements. The agreement between these independent measurement systems is remarkable, and it is shown to even be possible to discern differences in strain profile and associated transfer length between adjacent crossties within a given Casting Bed. This new automated and high-resolution device should provide a very convenient and fast diagnostic tool for the manufacturer to quickly identify the need to modify production (e.g., concrete mix) if transfer length specifications fall out of desired range.Copyright © 2016 by ASME

  • Experimental Investigation of the Influence of Surface Contaminants on the Transfer Length of Smooth and Indented Prestressing Reinforcements Used in the Manufacture of Concrete Railroad Ties
    2015 Joint Rail Conference, 2015
    Co-Authors: B. Terry Beck, Robert J. Peterman, Chih-hang John Wu, Steve Mattson
    Abstract:

    It has been hypothesized that surface contaminants, such as lubricants on prestressing wires or strands, influence the resulting transfer length. However, until recently, the extent of this possible influence has only been speculation, as has been the relative influence on wire in comparison to strand. With the recent development of the ability to rapidly assess transfer length using new non-contact optical methods, it is now possible to explore hypothetical scenarios such as this with nearly real-time capability in the manufacturing plant.This paper presents a recent attempt to determine the effect of lubricating oil on the transfer length of ties, by conducting nearly real-time in-plant transfer length measurements using a newly developed prototype multi-camera non-contact transfer length measurement system. The testing was conducted on prismatic concrete turnout ties manufactured at the Nortrak plant in Cheyenne, Wyoming. Two different types of turnout ties were investigated, one containing indented 5.32-mm-diameter wire reinforcement and the other containing 3/8-in.-diameter 7-wire strand. These ties were located near the end of the Casting Bed. Prior to Casting, one end of the form was sprayed with a generic lubricant, literally saturating the prestressing wires or strands. The ties were then cast and de-tensioned following the normal manufacturing process. This clearly represented a highly worst-case scenario for the influence of surface contaminants.Measurements were made using the new multi-camera system, providing a detailed profile of surface strain over several feet along each end of the last three ties in the Casting Beds (one for strand and one for wire) — the last tie being the one subjected to the application of oil prior to Casting. Hence, the influence of oil application on adjacent ties was also revealed by these tests. For the tie end with strand reinforcement subjected to oil soaking, the maximum compressive strain only reached about 400 microstrain, far below the nominal average maximum strain level of approximately 1000 microstrain. In fact, the associated transfer length for the oil-soaked end could not be definitively measured because the strain level never achieved the plateau level of strain. In contrast, the tie end with oil-soaked indented wire exhibited a significant increase in transfer length; however, the transfer length remained well below the distance to the rail seat. From these worst-case tests, one can conclude that smooth strand is potentially highly influenced by lubricating oils, whereas the influence on indented wire is likely small by comparison.Copyright © 2015 by ASME

Robert J. Peterman - One of the best experts on this subject based on the ideXlab platform.

  • Transfer Length Characterization of Entire Crosstie Plant Casting Bed Using Continuously Traversing Dual-Camera Non-Contact Optical Strain Sensors
    2017 Joint Rail Conference, 2017
    Co-Authors: B. Terry Beck, Aaron A. Robertson, Robert J. Peterman, Kyle A. Riding, John Wu
    Abstract:

    Transfer length has been identified as a key diagnostic parameter for evaluating the load bearing capability of prestressed concrete railroad crossties. Furthermore, it has been proposed for use as a valuable quality control parameter. However, until quite recently the capability to easily and accurately measure transfer length has been limited primarily to a laboratory setting. This is especially true for measurements made in the harsh environment of a tie manufacturing plant. The development of portable non-contact optical strain sensors has opened the door to rapid in-plant transfer length measurement. The measurement capability of these devices has been repeatedly demonstrated not only in the laboratory, but more importantly also through actual testing at multiple tie manufacturing plants. The latest version of the automated Laser-Speckle Imaging (LSI) system developed by the authors offers improved optical resolution of longitudinal surface strain, with the ability to resolve longitudinal prestressed concrete crosstie surface strain without time-consuming special surface preparation. The new system is also capable of making measurements of strain in a real-time “on-the-fly” manner over the entire distance range of interest on the tie associated with transfer length development. This faster capability to capture the strain profile with high resolution makes this new technology very beneficial for field testing and in-plant diagnostics applications. It has been demonstrated to be capable of resolving minor differences in longitudinal surface strain profiles associated with ties even in adjacent cavities. As a logical next step toward eventual implementation of transfer length as a quality control parameter, it is important to evaluate the expected variation of transfer length during the tie manufacturing process. This paper presents the results of extensive in-plant assessment of transfer length in an attempt to characterize experimentally the in-plant manufacturing variations that can occur in practice. To the best of the authors’ knowledge, this is the first time extensive real-time measurements to this extent have been attempted in an actual tie manufacturing plant with the expressed purpose of statistically characterizing the variations in transfer length that take place over an entire Casting Bed. A sampling of transfer lengths from well over 50 ties was determined during the manufacturing process (corresponding to over 100 transfer length measurements). The sampled tie measurement locations were distributed at different “form” locations along the Casting Bed, and included samplings of ties from several different “cavities” within a given form. The entire Bed was 45 forms in length, each form having 6 tie cavities, for a total Bed size of 270 ties. The statistical distribution of overall transfer length measurement results is presented, along with what may be typical variations in strain profile and resulting transfer length as a result of variations that took place in the manufacturing process. The overall range of transfer length observed, along with an investigation of possible bias due to position within the Casting Bed, and apparent variations of transfer length within a given form, are identified and discussed.

  • Performance of a Continuously Traversing 2-Camera Non-Contact Optical Strain Sensor for In-Plant Assessment of Prestressed Concrete Railroad Crosstie Transfer Length
    2016 Joint Rail Conference, 2016
    Co-Authors: B. Terry Beck, Aaron A. Robertson, Robert J. Peterman, Chih-hang John Wu
    Abstract:

    Accurate knowledge of transfer length has been shown to be crucial to the goal of maintaining continuous production quality in the modern manufacture of prestressed concrete railroad ties. Traditional manual laboratory methods, such as the conventional Whittemore method which requires the use of emBedded reference points, are clearly not suitable for production operation or for use in reliable production quality-control.This paper presents the results of another advance in the development of automated transfer length measurement systems for practical in-plant operation. The new device offers a significant improvement over the previously successful automated Laser-Speckle Imaging (LSI) system developed by the authors. The earlier automated LSI strain measurement system has been modified to provide significantly improved optical resolution of longitudinal surface strain, with the ability to resolve longitudinal prestressed concrete crosstie surface strain without time-consuming special surface preparation. More importantly, the new system is also capable of making measurements of strain in a real-time “on-the-fly” manner over the entire distance range of interest on the tie associated with transfer length development. It features both a “jog” mode of operation, similar to its predecessor in which measurements of longitudinal surface strain are automatically captured in arbitrary spatial increments over the entire range of the computer-controlled traverse, and an “on-the-fly” mode in which measurements of longitudinal surface strain are captured without the need for stopping at each measurement location. This latter mode offers the potential of a much faster capture of the strain profile and should prove to be very beneficial for field testing and in-plant diagnostic applications.The performance of this new system is first demonstrated using a new calibrated step-wise uniform strain field setup which has been developed specifically for verification of this and other automated transfer length measurement systems. This verification system produces a calibrated step change in surface deflection, effectively subjecting the automated strain measurement system to an ideal step change in longitudinal strain for a given gauge length. In addition, the new automated system is demonstrated by conducting measurements of longitudinal surface strain on prestressed concrete crossties in a manufacturing plant. For this latter experimental in-plant testing, strain measurements using the new system are also compared directly with those from the recently introduced 6-camera transfer length measurement system, as well as with the traditional Whittemore gauge measurements. The agreement between these independent measurement systems is remarkable, and it is shown to even be possible to discern differences in strain profile and associated transfer length between adjacent crossties within a given Casting Bed. This new automated and high-resolution device should provide a very convenient and fast diagnostic tool for the manufacturer to quickly identify the need to modify production (e.g., concrete mix) if transfer length specifications fall out of desired range.Copyright © 2016 by ASME

  • Experimental Investigation of the Influence of Surface Contaminants on the Transfer Length of Smooth and Indented Prestressing Reinforcements Used in the Manufacture of Concrete Railroad Ties
    2015 Joint Rail Conference, 2015
    Co-Authors: B. Terry Beck, Robert J. Peterman, Chih-hang John Wu, Steve Mattson
    Abstract:

    It has been hypothesized that surface contaminants, such as lubricants on prestressing wires or strands, influence the resulting transfer length. However, until recently, the extent of this possible influence has only been speculation, as has been the relative influence on wire in comparison to strand. With the recent development of the ability to rapidly assess transfer length using new non-contact optical methods, it is now possible to explore hypothetical scenarios such as this with nearly real-time capability in the manufacturing plant.This paper presents a recent attempt to determine the effect of lubricating oil on the transfer length of ties, by conducting nearly real-time in-plant transfer length measurements using a newly developed prototype multi-camera non-contact transfer length measurement system. The testing was conducted on prismatic concrete turnout ties manufactured at the Nortrak plant in Cheyenne, Wyoming. Two different types of turnout ties were investigated, one containing indented 5.32-mm-diameter wire reinforcement and the other containing 3/8-in.-diameter 7-wire strand. These ties were located near the end of the Casting Bed. Prior to Casting, one end of the form was sprayed with a generic lubricant, literally saturating the prestressing wires or strands. The ties were then cast and de-tensioned following the normal manufacturing process. This clearly represented a highly worst-case scenario for the influence of surface contaminants.Measurements were made using the new multi-camera system, providing a detailed profile of surface strain over several feet along each end of the last three ties in the Casting Beds (one for strand and one for wire) — the last tie being the one subjected to the application of oil prior to Casting. Hence, the influence of oil application on adjacent ties was also revealed by these tests. For the tie end with strand reinforcement subjected to oil soaking, the maximum compressive strain only reached about 400 microstrain, far below the nominal average maximum strain level of approximately 1000 microstrain. In fact, the associated transfer length for the oil-soaked end could not be definitively measured because the strain level never achieved the plateau level of strain. In contrast, the tie end with oil-soaked indented wire exhibited a significant increase in transfer length; however, the transfer length remained well below the distance to the rail seat. From these worst-case tests, one can conclude that smooth strand is potentially highly influenced by lubricating oils, whereas the influence on indented wire is likely small by comparison.Copyright © 2015 by ASME

Peter Hyndman - One of the best experts on this subject based on the ideXlab platform.

  • New Iron Cove Bridge, Sydney - Part of the Inner West Busway Project
    2020
    Co-Authors: Irene Scott, Iain Hespe, Peter Hyndman
    Abstract:

    In October 2007 the RTA awarded Baulderstone, Hyder Consulting and Manidis Roberts the Alliance contract to design and construct the Inner West Busway at Rozelle. Austress Freyssinet was engaged under a sub-alliance agreement. The project is currently under construction and is due for completion in 2011. The Inner West Busway Project objective was to provide a bus lane and tidal flow arrangement and a new duplicated Iron Cove Bridge. The New Iron Cove Bridge consists of eight incrementally launched box girder spans, with three approach spans of Super-tee girders, providing a total combined bridge length of 480m. The bridge structure and associated temporary works had several significant constraints including the location of services (sewer, disused sluice tunnel) in the Casting Bed area, heritage items, constrained horizontal alignment and a reduced area for a Casting Bed due to the proximity to the existing road. An innovative design and construction solution overcame technical and geometric challenges, which include the following: 1) The Casting Bed is located in front of the abutment, rather than behind. 2) Pier 1 is incorporated in the Casting Bed. 3) The launching pier is an elevated structure, which required bracing back to the Casting Bed to reduce the horizontal loads and movements. 4) The box girder is being launched over permanent pot bearings. 5) The horizontal alignment changes on Pier 2 with a tighter radius while the centreline radius of the box girder remains constant, which impacts the cantilever lengths of the box girder, and necessitates transverse posttensioning.

  • Inner West Busway: new Iron Cove Bridge
    2011
    Co-Authors: Peter Hyndman, Iain Hespe
    Abstract:

    The new Iron Cove Bridge is part of the recently completed Inner West Busway Project along Victoria Rd in Sydney, which was delivered as an alliance contract by the Bridge to Bay Alliance. The alliance team partners are the RTA, Baulderstone, Hyder Consulting and Manidis Roberts and sub alliance partners Freyssinet. The bridge is a 480m long hybrid structure comprising eight spans of single box girder superstructure, with three approach spans of super-t girders tying into the existing Victoria Rd approaches. The construction methods include incremental launch for the main spans of the new Iron Cove Bridge. This paper outlines the progression from concept to completion for the design and construction solution reached by the team to enable the New Iron Cove Bridge to be incrementally launched in a constrained location and describes the design features for the superstructure and substructure. In particular the paper addresses the unusual launching procedure that had the Casting Bed located in front of the new abutment, the launch pier in front of the Casting Bed and the detailing required to control the deflections and rotations during launch for the critical locations of the segment construction joints. Incorporated in the launching sequence was the launch nose that was erected and launched with the first segment from the rear of the launching Bed. The launch process was a critical factor in the project program and a cycle time of 6 days was achieved for segment launch through the use of a high early strength concrete mix, concrete maturity testing and prefabrication of reinforcement in a jig adjacent the Casting Bed. The result of the techniques adopted for the Iron Cove Bridge Design and Construction was that the bridge was completed to a tight program that saw the project opening ahead of schedule.