Effective scraping in a scraped surface heat exchanger: some fluid flow analysis

An outline of mathematical models that have been used to understand the behaviour of scraped surface heat exchangers is presented. In particular the problem of the wear of the blades is considered. A simple model, exploiting known behaviour of viscous flow in corners and in wedges, and accounting for the forces on the blade is derived and solutions generated. The results shows initial rapid wear but that the wear rate goes to zero

Detection of embryo mortality and hatch using thermal differences among incubated chicken eggs

Accurate diagnosis of both the stage of embryonic mortality and the hatch process in incubated eggs is a fundamental component in troubleshooting and hatchery management. However, traditional methods disturb incubation, destroy egg samples, risk contamination, are time and labour-intensive and require specialist knowledge and training. Therefore, a new method to accurately detect embryonic mortality and hatching time would be of significant interest for the poultry industry if it could be done quickly, cheaply and be fully integrated into the process. In this study we have continuously measured individual eggshell temperatures and the corresponding micro-environmental air temperatures throughout the 21 days of incubation using standard low-cost temperature sensors. Moreover, we have quantified the thermal interaction between eggs and air by calculating thermal profile changes (temperature drop time, drop length and drop magnitude) that allowed us to detect four categories of egg status (infertile/early death, middle death, late death and hatch) during incubation. A decision tree induction classification model accurately (93.3%) predicted the status of 105 sampled eggs in comparison to the classical hatch residue breakout analyses. With this study we have provided a major contribution to the optimisation of incubation processes by introducing an alternative method for the currently practiced hatch residue breakout analyses.status: publishe

Conceptualizing Equity in the Implementation of California Education Finance Reform

We examine how district administrators’ conceptions of equity relate to the implementation of finance reform. We use sensemaking theory and four views of equity—libertarian, liberal, democratic liberal, and transformative—to guide a case study of two districts, finding evidence of two conceptions of equity: (1) greater resources for students with greater needs and (2) equal distribution of resources for all students. One district demonstrated an organization-wide belief in the first conception, whereas the other conveyed individual-level understandings of both conceptions. These beliefs were mirrored in resource allocation decisions and informed by districts’ student demographics, organizational identities, and perceptions of adequacy

Heat and fluid flow in a scraped-surface heat exchanger containing a fluid with temperature-dependent viscosity

Scraped-surface heat exchangers (SSHEs) are extensively used in a wide variety of industrial settings where the continuous processing of fluids and fluid-like materials is involved. The steady non-isothermal flow of a Newtonian fluid with temperature-dependent viscosity in a narrow-gap SSHE when a constant temperature difference is imposed across the gap between the rotor and the stator is investigated. The mathematical model is formulated and the exact analytical solutions for the heat and fluid flow of a fluid with a general dependence of viscosity on temperature for a general blade shape are obtained. These solutions are then presented for the specific case of an exponential dependence of viscosity on temperature. Asymptotic methods are employed to investigate the behaviour of the solutions in several special limiting geometries and in the limits of weak and strong thermoviscosity. In particular, in the limit of strong thermoviscosity (i.e., strong heating or cooling and/or strong dependence of viscosity on temperature) the transverse and axial velocities become uniform in the bulk of the flow with boundary layers forming either just below the blade and just below the stationary upper wall or just above the blade and just above the moving lower wall. Results are presented for the most realistic case of a linear blade which illustrate the effect of varying the thermoviscosity of the fluid and the geometry of the SSHE on the flow

A comparison of block and semi-parametric bootstrap methods for variance estimation in spatial statistics

Efron (1979) introduced the bootstrap method for independent data but it cannot be easily applied to spatial data because of their dependency. For spatial data that are correlated in terms of their locations in the underlying space the moving block bootstrap method is usually used to estimate the precision measures of the estimators. The precision of the moving block bootstrap estimators is related to the block size which is difficult to select. In the moving block bootstrap method also the variance estimator is underestimated. In this paper, first the semi-parametric bootstrap is used to estimate the precision measures of estimators in spatial data analysis. In the semi-parametric bootstrap method, we use the estimation of the spatial correlation structure. Then, we compare the semi-parametric bootstrap with a moving block bootstrap for variance estimation of estimators in a simulation study. Finally, we use the semi-parametric bootstrap to analyze the coal-ash data

The Multiwavelength Survey By Yale-Chile (MUSYC) Wide K-Band Imaging, Photometric Catalogs, Clustering, And Physical Properties Of Galaxies At Z Similar To 2

We present K-band imaging of two similar to 30' x 30' fields covered by the Multiwavelength Survey by Yale-Chile (MUSYC) Wide NIR Survey. The SDSS 1030+05 and Cast 1255 fields were imaged with the Infrared Side Port Imager (ISPI) on the 4 m Blanco telescope at the Cerro Tololo Inter-American Observatory (CTIO) to a 5 sigma point-source limiting depth of K similar to 20 (Vega). Combining these data with the MUSYC optical UBVRIz imaging, we created multiband K-selected source catalogs for both fields. These catalogs, together with the MUSYC K-band catalog of the Extended Chandra Deep Field South (ECDF-S) field, were used to select K 20 BzK galaxies over an area of 0.71 deg(2). This is the largest area ever surveyed for BzK galaxies. We present number counts, redshift distributions, and stellar masses for our sample of 3261 BzK galaxies (2502 star-forming [sBzK] and 759 passively evolving [pBzK]), as well as reddening and star formation rate estimates for the star-forming BzK systems. We also present two-point angular correlation functions and spatial correlation lengths for both sBzK and pBzK galaxies and show that previous estimates of the correlation function of these galaxies were affected by cosmic variance due to the small areas surveyed. We have measured correlation lengths r(0) of 8.89 +/- 2.03 and 10.82 +/- 1.72 Mpc for sBzK and pBzK galaxies, respectively. This is the first reported measurement of the spatial correlation function of passive BzK galaxies. In the Lambda CDM scenario of galaxy formation, these correlation lengths at z similar to 2 translate into minimum masses of similar to 4 x 10(12) and similar to 9 x 10(12) M(circle dot) for the dark matter halos hosting sBzK and pBzK galaxies, respectively. The clustering properties of the galaxies in our sample are consistent with their being the descendants of bright Lyman break galaxies at z similar to 3, and the progenitors of present-day > 1L* galaxies.Astronom

Institutional Learning in Technical Projects: Horticulture Technology R&D Systems in India

This paper demonstrates the way in which institutional learning has been adopted by a post-harvest technology research project in India to cope with the institutional constraints associated with various public agencies, as well as to help formulate broader lessons for institutional reform in horticultural R&D systems. The case study presents an institutional history of public and private efforts to assist farmers from the Vijaya Association of Fruit and Vegetable Growers’ Cooperative Societies of Andhra Pradesh to produce and sell export quality mangoes. Problems in the relationships between stakeholders reveal the need to see technology transfer in a much more holistic light than is conventionally understood

Choice, connections, challenges, and continuation: Motivation in language awakening practice

An individual’s motivation to learn their language is what spurs them to put in effort and then sustain that effort over the long term. For language awakening practitioners, motivation may be crucial for facing the unique difficulties that come from learning a language that has become dormant. In this chapter, we look at the motivations that inspire and sustain practitioners who are awakening their languages. Co-author Taylor-Adams highlights the experiences described in interviews with practitioners working on four Indigenous languages of North America and presents an analysis of textual data from the Global Survey of Revitalization Efforts (Pérez Báez et al., 2019). Co-author Hall reflects on her experience awakening her heritage language, Nuu-wee-ya’ (Oregon Dene). By combining interview, survey, and ethnographic data and using an Indigenous-framed methodology for interpreting these data (Wilson, 2008), this chapter illustrates 1) the unique challenges of awakening a language, 2) the persistence and effort that practitioners put into the work, and 3) the centrality of community and relationships in L2 motivation for awakening languages. La motivación de un individuo por aprender su lengua es lo que le lleva a entregarse al esfuerzo y mantenerlo a largo plazo. Para los que laboran por el despertar de una lengua, la motivación puede ser crucial para enfrentarse a las dificultades únicas que emergen al aprender una lengua después de un periodo en que ha estado dormida. En este capítulo, vemos las motivaciones que inspiran y mantienen la entereza de quienes laboran por el despertar de su lengua. La co-autora Taylor-Adams resalta las experiencias descritas en entrevistas con individuos trabajando con cuatro lenguas indígenas de Norteamérica y presenta un análisis de datos textuales de la Encuesta Global de Esfuerzos de Revitalización (Pérez Báez et al., 2019). La co-autora Hall piensa sobre su experiencia al despertar su lengua de herencia, Nuu-wee-ya’ (Oregon Dene). Al combinar datos de entrevistas, de la encuesta, y datos etnográficos, una metodología dentro de un marco conceptual indígena para interpretar estos datos (Wilson, 2008), este capítulo ilustra 1) los retos únicos del despertar de una lengua, 2) la perseverancia y esfuerzo de los participantes, y 3) la centralidad de la comunidad y de las relaciones en la motivación para el aprendizaje L2 de lenguas que están siendo despertadas

Impact of culture towards disaster risk reduction

Number of natural disasters has risen sharply worldwide making the risk of disasters a global concern. These disasters have created significant losses and damages to humans, economy and society. Despite the losses and damages created by disasters, some individuals and communities do not attached much significance to natural disasters. Risk perception towards a disaster not only depends on the danger it could create but also the behaviour of the communities and individuals that is governed by their culture. Within this context, this study examines the relationship between culture and disaster risk reduction (DRR). A comprehensive literature review is used for the study to evaluate culture, its components and to analyse a series of case studies related to disaster risk. It was evident from the study that in some situations, culture has become a factor for the survival of the communities from disasters where as in some situations culture has acted as a barrier for effective DRR activities. The study suggests community based DRR activities as a mechanism to integrate with culture to effectively manage disaster risk

Anti-Nirvana: crime, culture and instrumentalism in the age of insecurity

‘Anti-Nirvana’ explores the relationship between consumer culture, media and criminal motivations. It has appeared consistently on the list of the top-ten most-read articles in this award-winning international journal, and it mounts a serious neo-Freudian challenge to the predominant naturalistic notion of ‘resistance’ at the heart of liberal criminology and media studies. It is also cited in the Oxford Handbook of Criminology and other criminology texts as a persuasive argument in support of the theory that criminality amongst young people is strongly linked to the acquisitive values of consumerism and the images of possessive individualism that dominate mass media