Transfer Measurements (transfer + measurement)

Distribution by Scientific Domains

Selected Abstracts

A study of best practices in training transfer and proposed model of transfer

Lisa A. Burke
Data were gathered from a sample of training professionals of an American Society of Training and Development (ASTD) chapter in the southern United States regarding best practices for supporting training transfer. Content analysis techniques, based on a rigorous methodology proposed by Insch, Moore, & Murphy (1997), were used to analyze the rich data. Findings suggest that interventions for bolstering training transfer are best carried out in the work context and design and delivery phase, take place after training or during, and involve trainers and supervisors. Activities garnering top attention from trainers as best practices include (starting with most frequently reported) supervisory support activities, coaching, opportunities to perform, interactive training activities, transfer measurement, and job-relevant training. Several new transfer variables also emerged from the data, indicating existing transfer models can be further refined. Ultimately, we propose a refined model of transfer to extend human resource development (HRD) theory in the area of transfer. [source]

Techniques for oxygen transfer measurement in bioreactors: a review

S Suresh
Abstract Oxygen is the most essential requirement for aerobic bioprocesses. The microbial growth in a bioreactor depends upon the oxygen transfer rate (OTR). The OTR is widely used to study the growth behavior of microbial and plant cell cultures. The mass transfer coefficient (kLa) determines the magnitude of the OTR. There are many techniques for measuring oxygen concentration and OTR in bioreactors. Zirconia, electrochemical, infrared, ultrasonic and laser cells are used to measure oxygen concentration in the liquid medium. Optical sensors are better alternatives to measure oxygen concentration in small bioreactors. Sulfite oxidation and gassing-out methods with a Clark-type electrode have been used for OTR measurements in bioreactors. Many new novel techniques have evolved recently for intermittent and continuous online measurement of OTR/kLa in various types of bioreactors. The present paper gives an overview of various measurement techniques and their limitations and/or suitability for measurement of OTR/kLa in various kinds of bioreactors, especially small bioreactors. Copyright © 2009 Society of Chemical Industry [source]

pH-insensitive glucose indicators

Jared R. Garrett
Abstract There is an urgent need for developing a biosensor that can real-time and noninvasively determine glucose concentration within living cells. In our previous study, we have engineered a glucose indicator protein (GIP) that can provide continuous glucose monitoring through a conformation change-induced Förster resonance-energy transfer measurement. Because of the pH-sensitivity of the fluorescent proteins used in the GIP construction, the GIP made from these fluorescent proteins is less tolerant to a pH change, especially to the acidic environment. It has been well documented that intracellular pH does not always remain the same, and it fluctuates in metabolism and other cellular activities and also differs between cellular compartments. To address these issues, we developed a GIP that can tolerate to pH change. This GIP was constructed by flanking a glucose binding protein with a cyan fluorescent protein and a pH-insensitive yellow fluorescent protein. Our experimental results indicated that the new GIP is more tolerant to pH change. The glucose response of this new GIP kept almost unchanged from pH 7.3 to 5.3, suggesting its capability of tolerating to acidic environment. This capability is desirable for intracellular glucose measurement. [source]

Heat transfer and fluid flow characteristics in a swirling impinging jet

Mamoru Senda
Abstract An experimental study on heat transfer and fluid flow has been carried out for a swirling round impinging jet. A thermosensitive liquid crystal sheet was used for the heat transfer measurements and the three velocity components were measured with LDV in the stagnation region for cases where the Swirl number Sw = 0.0, 0.22, and 0.45 at the Reynolds number Re = 8100. The formation of recirculation flow due to a swirl near the impinging wall was found to deteriorate the heat transfer coefficient in the stagnation region and results in a more uniform distribution of the Nusselt number with an increasing Swirl number. The heat transfer mechanism of the swirling impinging jet is discussed based on the flow characteristics of the mean velocities and turbulence quantities. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(5): 324,335, 2005; Published online in Wiley InterScience (www.interscience. DOI 10.1002/htj.20068 [source]

Applications of time-resolved resonance energy transfer measurements in studies of the molecular crowding effect,

Varda Ittah
Abstract The native structures of many globular proteins are only weakly stabilized and form in solution ensembles of multiple conformers. The energy differences between the conformers are assumed to be small. This is the case of flexible multidomain proteins where domain motions were observed. High concentrations of inert macrosolute, which create a crowded or confined environment, can cause shifts of the distribution of the conformers of such proteins towards the more compact structures. This effect may also promote compact structures in partially folded proteins. Time-resolved dynamic non-radiative excitation energy transfer (tr-RET) is suitable for detection of either subtle or major changes in distributions of intramolecular distances in protein molecules in solutions. Two experiments were performed which demonstrated the applicability of tr-RET for detection of the effect of macrosolutes on the conformational ensembles of flexible states of protein molecules. The distribution of distances between residues 203 and 169 in the CORE domain of E. coli adenylate kinase (AK) in the denatured state was determined in the presence of high concentrations of dextran 40. A significant shift of the mean of the distribution was observed without reduction of its width. This was interpreted as a shift to compact structure without change of the degree of disorder of the chain. In a second experiment the distribution of the distance between residues 55 and 169 in AK, which spans the cleft between the CORE and the AMPbind domains, was monitored. No clear effect of high concentrations of dextran 40 was found. These experiments show the strength of the application of tr-RET in investigation of changes in the sub-states of flexible conformations of globular protein. Networks of pairs of labeled sites can be prepared and tr-RET experiments can be performed in order to search for the segments of the protein molecules, which respond to the presence of inert macromolecules in their environment. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Annual assessment spirometry, plethysmography, and gas transfer in cystic fibrosis: Do they predict death or transplantation

FRCPCH, Mark Rosenthal MD
Abstract Aim The long- and short-term prognostic value of pediatric spirometry, plethysmography, and gas transfer measurements in cystic fibrosis (CF) were assessed. Methods Two hundred ninety-eight children with CF and ,4 annual assessment lung function measurements at a single institution were analyzed in mid childhood. Long-term outcome was death or lung transplantation (D/T) before 2007. Short-term outcome was forced expired volume in one second (FEV1) z -score 1 year after the previous lung function measurements. Results 26/298 had a D/T outcome at median 19.5 years. A zFEV1,<,,2 aged 8 years had a positive predictive value of 67% (sensitivity 67%) for D/T in those homozygous for ,F508 but zFEV1 at older ages and all genotypes was unhelpful. The ratio of residual volume to total lung capacity z -score could also predict a few D/T individuals when zFEV1 was normal in mid childhood. Most other lung function measurements were not helpful. Matching D/T with alive groups for year of birth left prognostic utility unchanged. Only current zFEV1 could significantly predict zFEV1 1 year hence (56% variability explained, P,<,0.00001); no other lung function, gender, age or nutrition factor was significant. Conclusion The value of routine plethysmography and gas transfer measurements in CF is questionable in CF management. Detecting abnormal spirometry even at age 8 years may be too late to affect long-term outcome. Pediatr Pulmonol. 2008; 43:945,952. © 2008 Wiley-Liss, Inc. [source]

A new photobioreactor for continuous microalgal production in hatcheries based on external-loop airlift and swirling flow

Karine Loubière
Abstract This study deals with the scale of a new photobioreactor for continuous microalgal production in hatcheries. The combination of the state-of-art with the constraints inherent to hatcheries has turned the design into a closed, artificially illuminated and external-loop airlift configuration based on a succession of elementary modules, each one being composed of two transparent vertical interconnected columns. The liquid circulation is ensured pneumatically (air injections) with respect to a swirling motion (tangential inlets). A single module of the whole photobioreactor was built-up to scale its geometry (diameter and length) and to optimize its design (air sparger, tangential inlets). The volumetric productivities were predicted by modeling radiative transfer and growth of Isochrysis affinis galbana (clone Tahiti). The hydrodynamics of the liquid phase was modeled in terms of global flow behavior (circulation and mixing times, Péclet number) and of swirling motion decay along the column (Particle Image Velocimetry). The aeration performances were determined by overall volumetric mass transfer measurements. Continuous cultures of Isochrysis affinis galbana (clone Tahiti) were run in two geometrical configurations, generating either an axial or a swirling flow. Lastly, the definitive options of design are presented as well as a 120-L prototype, currently implemented in a French mollusk hatchery and commercialized. Biotechnol. Bioeng. 2009;102: 132,147. © 2008 Wiley Periodicals, Inc. [source]

Aeration of Large Size Tanks by a Surface Agitator

R. Sardeing
Abstract A new device has been developed in order to achieve urban or industrial wastewater biological treatment. It has been designed specially for lagoon applications to oxygenate and mix with the same apparatus. The goal is both to achieve a high gas flooding rate and to reach a maximal depth with the bubble plume. Mass transfer measurements have allowed us to choose the most appropriate geometry. Considering the application of the device and the possible use of low-pressure O2 produced on-site, the agitation system is located close to the liquid surface and is composed of a gas-inducing turbine. The role of propellers in addition to the gas-inducing turbine, as well as the use of baffles and a shell, have been experimentally studied. Numerical simulations (CFD) of the whole apparatus in single-phase flow have been used to study the influence of the stator part of the geometry. [source]