Structural analysis of plate-type fuel assemblies and development of a non-destructive method to assess their integrity

This work is concerned with the structural behaviour and the integrity of parallel plate-type nuclear fuel assemblies. A plate-type assembly consists of several thin plates mounted in a box-like structure and is subjected to a coolant flow that can result in a considerable drag force. A finite element model of an assembly is presented to study the sensitivity of the natural frequencies to the stiffness of the plates' junctions. It is shown that the shift in the natural frequencies of the torsional modes can be used to check the global integrity of the fuel assembly while the local natural frequencies of the inner plates can be used to estimate the maximum drag force they can resist. Finally a non-destructive method is developed to assess the resistance of the inner plates to bear an applied load. Extensive computational and experimental results are presented to prove the applicability of the method presented. © 2013 Elsevier B.V. All rights reserved.

The structure and function of neurons with variable nonlinear transfer function

One novel neuron with variable nonlinear transfer function is firstly proposed, It could also be called as subsection transfer function neuron. With different transfer function components, by virtue of multi-thresholded, the variable transfer function neuron switch on among different nonlinear excitated state. And the comparison of output's transfer characteristics between it and single-thresholded neuron will be illustrated, with some practical application experiments on Bi-level logic operation, at last the simple comparison with conventional BP, RBF, and even DBF NN is taken to expect the development foreground on the variable neuron.. The novel nonlinear transfer function neuron could implement the random nonlinear mapping relationship between input layer and output layer, which could make variable transfer function neuron have one much wider applications on lots of reseach realm such as function approximation pattern recognition data compress and so on.

Effect of a step quantum well structure and an electric-field on the Rashba spin splitting

Spin splitting of conduction subbands in Al_(0.3)Ga_(0.7)As/GaAs/Al_xGa_(1-x)As/Al_(0.3)Ga_(0.7)As step quantum wells induced by interface and electric field related Rashba effects is investigated theoretically by the method of finite difference. The dependence of the spin splitting on the electric field and the well structure, which is controlled by the well width and the step width, is investigated in detail. Without an external electric field, the spin splitting is induced by an in terface related Rashba term due to the built-in structure inversion asymmetry. Applying the external electric field to the step QW, the Rashba effect can be enhanced or weakened, depending on the well structure as well as the direction and the magnitude of the electric field. The spin splitting is mainly controlled by the interface related Rashba term under a negative and a stronger positive electric field, and the contribution of the electric field related Rashba term dominates in a small range of a weaker positive electric field.A method to determine the interface parameter is proposed.The results show that the step QWs might be used as spin switches.

Studies on hybridization effects of different geographic populations of Chlamys farreri - II. The medium-term growth and development of Chlamys farreri populations from China and Russia and their reciprocal crosses

Based on the research of juvenile (2, 3, 4 months) growth and survival of three populations of two different geographic areas in Chlamys farreri from Russian and China and their F, hybrids derived from Chinese cultural population (CC) female x Russian population (RW) male, Chinese wild population (CW) female x Russian population (RW) male, Russian population (RW) female x Chinese wild population (CW) the study of the medium-term (6, 8, 10, 12 months) growth and development of Chlamys farreri was carried out. The four determined results indicated that there existed different extent heterosis (3% similar to 52 %) for the growth in three types of F-1 hybrids, and the offspring derived from CC female X Rmale had a stronger heterosis among the crosses at the medium-term; the uptrend among traits are wet weight > shell width > shell length > shell height, Chinese cultural population could be recognized as excellent parent, and seasonal variations influence very much on the daily increment and growth rate of each trait of Chlamys farreri and it is only able to survive and could barely grow in winter (6 similar to 8 months), but grows fast in temperate season (10similar to12 months).

Molecular structure and expression patterns of flounder (Paralichthys olivaceus) Myf-5, a myogenic regulatory factor

Myf-5, a member of the myogenic regulatory factors (MRF), has been shown to be expressed in muscle precursors in early stage zebrafish embryos. The MRFs, including MyoD, Myf-5, Myogenin and MR-F4, belong to the basic Helix-Loop-Helix transcription factors that contain a conserved basic Helix-Loop-Helix (bHLH) domain. To better understand the role of Myf-5 in the development of fish muscles, we have isolated the Myf-5 genomic sequence and cDNA from Flounder (Paralichthys olivaceus), and analyzed its structures and patterns of expression. Promoter analysis identified several putative transcription factor binding sites such as an E-box, NF-Y sites that might confer muscle-specific expression. Myf-5 transcripts were first detected in the paraxial mesoderm that gives rise to slow muscles. During somitogenesis, Myf-5 expression was found in developing somites. Myf-5 expression decreased gradually in somites in the anterior region, but remained strong in the newly formed somites. In the hatching stage, the expression was also detected in other muscle cells such as head muscle and fin muscle. In the growing fish, RT-PCR results showed that Myf-5 was expressed in the skeletal muscle and intestine. (c) 2006 Elsevier Inc. All rights reserved.

Structure and Interpretation of Computer Programs

"The Structure and Interpretation of Computer Programs" is the entry-level subject in Computer Science at the Massachusetts Institute of Technology. It is required of all students at MIT who major in Electrical Engineering or in Computer Science, as one fourth of the "common core curriculum," which also includes two subjects on circuits and linear systems and a subject on the design of digital systems. We have been involved in the development of this subject since 1978, and we have taught this material in its present form since the fall of 1980 to approximately 600 students each year. Most of these students have had little or no prior formal training in computation, although most have played with computers a bit and a few have had extensive programming or hardware design experience. Our design of this introductory Computer Science subject reflects two major concerns. First we want to establish the idea that a computer language is not just a way of getting a computer to perform operations, but rather that it is a novel formal medium for expressing ideas about methodology. Thus, programs must be written for people to read, and only incidentally for machines to execute. Secondly, we believe that the essential material to be addressed by a subject at this level, is not the syntax of particular programming language constructs, nor clever algorithms for computing particular functions of efficiently, not even the mathematical analysis of algorithms and the foundations of computing, but rather the techniques used to control the intellectual complexity of large software systems.

The Limitations of Law in promoting synergy between environment and development policies in developing countries

Journal of Energy and Natural Resources Law, 24(4) pp.574-606 RAE2008

The effects of ageing and exercise on skeletal muscle structure and function

Musculoskeletal ageing is associated with profound morphological and functional changes that increase fall risk and disease incidence and is characterised by age-related reductions in motor unit number and atrophy of muscle fibres, particularly type II fibres. Decrements in functional strength and power are relatively modest until the 6th decade, after which the rate of loss exponentially accelerates, particularly beyond the 8th decade of life. Physical activity is a therapeutic modality that can significantly attenuate age-related decline. The underlying signature of ageing, as manifested by perturbed redox homeostasis, leads to a blunting of acute and chronic redox regulated exercise adaptations. Impaired redox regulated exercise adaptations are mechanistically related to altered exercise-induced reactive oxygen and nitrogen species generation and a resultant failure to properly activate redox regulated signaling cascades. Despite the aforementioned specific impairment in redox signaling, exercise induces a plethora of beneficial effects, irrespective of age. There is, therefore, strong evidence for promoting regular physical exercise, especially progressive resistance training as a lifelong habitual practice.

Irish Times coverage of Irish relief and development nongovernmental organisations, legitimacy and accountability, 1994-2009: analysis and implications for the role of nongovernmental organisations

The overall aim of this study was to investigate the extent to which and ways in which Irish relief and development nongovernmental organisations (NGOs) were linked with the concepts of legitimacy and accountability in Irish Times newspaper coverage between 1994 and 2009. This research was based on a quantitative content analysis of 215 Irish Times articles and the results were analysed using statistical methods. Key findings of the research included that NGO accountability received significantly more coverage than NGO legitimacy, "principal-agent" approaches to NGO accountability received significantly more coverage than "stakeholder" approaches to NGO accountability, and questioning of NGOs based on either their accountability or legitimacy was very limited. It is suggested that these findings may indicate both a failure by Irish NGOs to promote "development literacy" and global solidarity among the Irish public, and a limited degree of "development literacy" and global solidarity among the Irish public.

Parents' experiences of child growth and development concerns: an interpretative phenomenological analysis

Background: Assessing child growth and development is complex. Delayed identification of growth or developmental problems until school entry has health, educational and social consequences for children and families. Health care professionals (HCPs), including Public Health Nurses work with parents to elicit and attend to their growth and development concerns. It is known that parents have concerns about their children’s growth and development which are not expressed in a timely manner. Measuring parental concern has not been fully effective to date and little is known about parents’ experiences of expressing concerns. Aim: To understand how parents make sense of child growth or development concerns. Method: The study was qualitative using Interpretative Phenomenological Analysis (IPA). A purposeful sample of 15 parents of pre-school children referred by their PHN to second tier services was used. Data were collected by semi-structured interviews. NVivo version 10 was used for data management purposes and IPA for analysis. Findings: Findings yielded two contextual themes which captured how parents described The Concern – ‘telling it as it is’ and their experiences of being Referred on. Four superordinate themes were found which encapsulated the Uncertainty – ‘a little bit not sure’ of parents as they made sense of the child’s growth and development problems. They were influenced by Parental Knowledge – ‘being and getting in the know’ which aided their sense-making before being prompted by Triggers to action. Parents then described Getting the child’s problem checked out as they went to express their concerns to HCPs. Conclusion and Implications: Parental expression of concerns about their child is a complex process that may not be readily understood by HCPs. A key implication of findings is to reappraise how parental concern is elicited and attended to in order to promote early referral and intervention of children who may have growth and development problems.

Investigation of population genetic structure and mating system in the ant Pheidole pallidula

The origin of eusociality in haplo-diploid organisms such as Hymenoptera has been mostly explained by kin selection. However, several studies have uncovered decreased relatedness values within colonies, resulting primarily from multiple queen matings (polyandry) and/or from the presence of more than one functional queen (polygyny). Here, we report on the use of microsatellite data for the investigation of sociogenetic parameters, such as relatedness, and levels of polygyny and polyandry, in the ant Pheidole pallidula. We demonstrate, through analysis of mother-offspring combinations and the use of direct sperm typing, that each queen is inseminated by a single male. The inbreeding coefficient within colonies and the levels of relatedness between the queens and their mate are not significantly different from zero, indicating that matings occur between unrelated individuals. Analyses of worker genotypes demonstrate that 38% of the colonies are polygynous with 2-4 functional queens, and suggest the existence of reproductive skew, i.e. unequal respective contribution of queens to reproduction. Finally, our analyses indicate that colonies are genetically differentiated and form a population exhibiting significant isolation-by-distance, suggesting that some colonies originate through budding.

Magnetic Resonance Imaging Biomarkers of Renal Structure and Function

The kidney's major role in filtration depends on its high blood flow, concentrating mechanisms, and biochemical activation. The kidney's greatest strengths also lead to vulnerability for drug-induced nephrotoxicity and other renal injuries. The current standard to diagnose renal injuries is with a percutaneous renal biopsy, which can be biased and insufficient. In one particular case, biopsy of a kidney with renal cell carcinoma can actually initiate metastasis. Tools that are sensitive and specific to detect renal disease early are essential, especially noninvasive diagnostic imaging. While other imaging modalities (ultrasound and x-ray/CT) have their unique advantages and disadvantages, MRI has superb soft tissue contrast without ionizing radiation. More importantly, there is a richness of contrast mechanisms in MRI that has yet to be explored and applied to study renal disease.

The focus of this work is to advance preclinical imaging tools to study the structure and function of the renal system. Studies were conducted in normal and disease models to understand general renal physiology as well as pathophysiology. This dissertation is separated into two parts--the first is the identification of renal architecture with ex vivo MRI; the second is the characterization of renal dynamics and function with in vivo MRI. High resolution ex vivo imaging provided several opportunities including: 1) identification of fine renal structures, 2) implementation of different contrast mechanisms with several pulse sequences and reconstruction methods, 3) development of image-processing tools to extract regions and structures, and 4) understanding of the nephron structures that create MR contrast and that are important for renal physiology. The ex vivo studies allowed for understanding and translation to in vivo studies. While the structure of this dissertation is organized by individual projects, the goal is singular: to develop magnetic resonance imaging biomarkers for renal system.

The work presented here includes three ex vivo studies and two in vivo studies:

1) Magnetic resonance histology of age-related nephropathy in sprague dawley.

2) Quantitative susceptibility mapping of kidney inflammation and fibrosis in type 1 angiotensin receptor-deficient mice.

3) Susceptibility tensor imaging of the kidney and its microstructural underpinnings.

4) 4D MRI of renal function in the developing mouse.

5) 4D MRI of polycystic kidneys in rapamycin treated Glis3-deficient mice.

Cultural life scripts structure recall from autobiographical memory.

Three classes of evidence demonstrate the existence of life scripts, or culturally shared representations of the timing of major transitional life events. First, a reanalysis of earlier studies on age norms shows an increase in the number of transitional events between the ages of 15 and 30 years, and these events are associated with narrower age ranges and more positive emotion than events outside this period. Second, 1,485 Danes estimated how old hypothetical centenarians were when they had been happiest, saddest, most afraid, most in love, and had their most important and most traumatic experiences. Only the number of positive events showed an increase between the ages of 15 and 30 years. Third, undergraduates generated seven important events that were likely to occur in the life of a newborn. Pleasantness and whether events were expected to occur between the ages of 15 and 30 years predicted how frequently events were recorded. Life scripts provide an alternative explanation of the reminiscence bump. Emphasis is on culture, not individuals.

Adaptive intervention design in mobile health: Intervention design and development in the Cell Phone Intervention for You trial.

BACKGROUND/AIMS: The obesity epidemic has spread to young adults, and obesity is a significant risk factor for cardiovascular disease. The prominence and increasing functionality of mobile phones may provide an opportunity to deliver longitudinal and scalable weight management interventions in young adults. The aim of this article is to describe the design and development of the intervention tested in the Cell Phone Intervention for You study and to highlight the importance of adaptive intervention design that made it possible. The Cell Phone Intervention for You study was a National Heart, Lung, and Blood Institute-sponsored, controlled, 24-month randomized clinical trial comparing two active interventions to a usual-care control group. Participants were 365 overweight or obese (body mass index≥25 kg/m2) young adults. METHODS: Both active interventions were designed based on social cognitive theory and incorporated techniques for behavioral self-management and motivational enhancement. Initial intervention development occurred during a 1-year formative phase utilizing focus groups and iterative, participatory design. During the intervention testing, adaptive intervention design, where an intervention is updated or extended throughout a trial while assuring the delivery of exactly the same intervention to each cohort, was employed. The adaptive intervention design strategy distributed technical work and allowed introduction of novel components in phases intended to help promote and sustain participant engagement. Adaptive intervention design was made possible by exploiting the mobile phone's remote data capabilities so that adoption of particular application components could be continuously monitored and components subsequently added or updated remotely. RESULTS: The cell phone intervention was delivered almost entirely via cell phone and was always-present, proactive, and interactive-providing passive and active reminders, frequent opportunities for knowledge dissemination, and multiple tools for self-tracking and receiving tailored feedback. The intervention changed over 2 years to promote and sustain engagement. The personal coaching intervention, alternatively, was primarily personal coaching with trained coaches based on a proven intervention, enhanced with a mobile application, but where all interactions with the technology were participant-initiated. CONCLUSION: The complexity and length of the technology-based randomized clinical trial created challenges in engagement and technology adaptation, which were generally discovered using novel remote monitoring technology and addressed using the adaptive intervention design. Investigators should plan to develop tools and procedures that explicitly support continuous remote monitoring of interventions to support adaptive intervention design in long-term, technology-based studies, as well as developing the interventions themselves.