STR-922: IMPACT OF SLENDERNESS ON THE SEISMIC RESPONSE OF ROCKING FRAMES IN ONTARIO NUCLEAR POWER PLANTS

Canadian Nuclear Power Plants (NPPs) are located on the eastern side of the North American continent, with the majority of them in Ontario. The Design Basis Earthquake (DBE), based on West Coast records, is prescribed in the Canadian nuclear standards. Seismic Probabilistic Risk Assessment studies of the existing plants consider time histories obtained from the latest research on the East Coast earthquakes as seismic input to the analysis. Although Canadian standards are silent about rocking response of unanchored objects, various industry guidelines and the standard ASCE 43-05 prescribe methodologies in this regard. Applications of a rocking frame in a NPP may vary from squat piers supporting a heavy rigid object to a slender masonry frame consisting of two concrete block walls and a rigid diaphragm on top. The methods of analysis prevalent in the nuclear industry recommend obtaining the response of an individual pier of a rocking frame, rather than an equivalent pier representing the rocking frame. Methods of obtaining an equivalent pier, whose response is the same as that of a rocking frame, have been detailed in the literature where it has been emphasized that rocking frames are more stable than an individual rocking pier. However, it is noticed that the response of rocking frames is influenced by their slenderness and also by the boundary condition at the contact between the piers and the top mass. The support boundary conditions are bounded by two extremes: the full top width of a pier, or a point support at its top center. This paper compares the equivalent block parameters of rocking frames for these two extreme boundary conditions. Also, it presents the seismic response of a slender rocking frame subjected to earthquake records compatible with the DBE spectra of Ontario NPPs, as well as spectra used in risk analysis

A methodology for solving single-model, stochastic assembly line balancing problem

Cataloged from PDF version of article.In this paper, a methodology is developed to solve the single-model, stochastic assembly line balancing problem for the objective of minimizing the total labor cost and the expected incompletion cost arising from tasks not completed within the prescribed cycle time. The methodology is based on determining an initial DP based solution and its improvement using a branch-and-bound procedure which uses an approximate solution instead of a lower bound for fathoming nodes. Detailed experimentation shows the superiority of this method over the most promising one from the literature. # 1999 Elsevier Science Ltd. All rights reserved

Set-up saving schemes for printed circuit boards assembly

Focusing on a basic printed circuit board (PCB) assembly line configuration characterized by very long set-up times, we examine two scheduling methods that can significantly reduce the set-up. Both methods -the Grouped Set-Up (GSU) method that has been recently introduced in the literature and the Sequence Dependent Scheduling (SDS) method, which has not been studied in this context -are based on component commonality among PCB types. Using the typical traditional scheduling method as a benchmark, the GSU and the SDS methods are compared in terms of three performance measures: line throughput, average work-in-process (WIP) inventory level, and implementation complexity. Guidelines for selecting the most appropriate method for a given production environment are proposed. The analysis is illustrated using real data from a typical production line

Group set-up for printed circuit board assembly

The current practice in the assembly of electronic components on printed circuit boards (PCBs) is serial production. a process characterized by very long set-up times. However, with the advent of efficient on-line process information .. new production control methods are now possible. This paper proposes a different production method, called the group set-up (GSU) method, which can significantly reduce set-up times. The traditional and the GSU production methods are compared, and it is shown that the GSU always performs better than the traditional method in terms of total production flow (throughput) and labour time However, the traditional method performs better than the GSU in terms of work in process (WIP) inventory; and in some cases, in terms of makespan (lead time). A detailed analysis for a small number of PCBs is presented

Factors Affecting the Development of Workforce Versatility

Among all strategies supporting the firms' flexibility and agility, the development of human resources versatility holds a promising place. This article presents an investigation of the factors affecting the development of this flexibility lever, related to the problem of planning and scheduling industrial activities, taking into account two dimensions of flexibility: the modulation of working time, which provides the company with fluctuating work capacities, and the versatility of operators: for all the multi-skilled workers, we adopt a dynamic vision of their competences. Therefore, this model takes into account the evolution of their skills over time, depending on how much they were put in practice in previous periods. The model was solved by using an approach relying on genetic algorithm that used an indirect encoding to build the chromosome genotype, and then a serial scheduling scheme is adopted to build the solution

Toxoplasma and Plasmodium protein kinases: roles in invasion and host cell remodelling

Some apicomplexan parasites have evolved distinct protein kinase families to modulate host cell structure and function. Toxoplasma gondii rhoptry protein kinases and pseudokinases are involved in virulence and modulation of host cell signalling. The proteome of Plasmodium falciparum contains a family of putative kinases called FIKKs, some of which are exported to the host red blood cell and might play a role in erythrocyte remodelling. In this review we will discuss kinases known to be critical for host cell invasion, intracellular growth and egress, focusing on (i) calcium-dependent protein kinases and (ii) the secreted kinases that are unique to Toxoplasma (rhoptry protein kinases and pseudokinases) and Plasmodium (FIKKs)

Quantitative response of wheat to sowing dates and irrigation regimes using ceres-wheat model

An experiment was conducted at Punjab Agricultural University, Ludhiana during 2014–15 and 2015–16, keeping four sowing dates {25th Oct (D1), 10th Nov (D2), 25th Nov (D3) and 10th Dec (D4)} in main plots and five irrigation schedules {irrigation at 15 (FC15), 25 (FC25), 35 (FC35) and 45 (FC45) % depletion of soil moisture from field capacity (FC) and a conventional practice} in sub plots. The objective of the study was to evaluate the performance of CERES-Wheat model for simulating yield and water use under varying planting and soil moisture regimes. The simulated and observed grain yield was higher in D1, with irrigation applied at FC15 as compared to all other sowing date and irrigation regime combinations. Simulated grain yield decreased by 19% with delay in sowing from 25th October to 10th December because of 8% reduction in simulated crop evapotranspiration. Simulated evapotranspiration decreased by 16%, wheat grain yield by 23% and water productivity by 15% in drip irrigation at 45% depletion from field capacity as compared to drip irrigation at 15% of field capacity. It was further revealed that the model performed well in simulating the phenology, water use and yield of wheat

GAPDH controls extracellular vesicle biogenesis and enhances the therapeutic potential of EV mediated siRNA delivery to the brain.

Extracellular vesicles (EVs) are biological nanoparticles with important roles in intercellular communication, and potential as drug delivery vehicles. Here we demonstrate a role for the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in EV assembly and secretion. We observe high levels of GAPDH binding to the outer surface of EVs via a phosphatidylserine binding motif (G58), which promotes extensive EV clustering. Further studies in a Drosophila EV biogenesis model reveal that GAPDH is required for the normal generation of intraluminal vesicles in endosomal compartments, and promotes vesicle clustering. Fusion of the GAPDH-derived G58 peptide to dsRNA-binding motifs enables highly efficient loading of small interfering RNA (siRNA) onto the EV surface. Such vesicles efficiently deliver siRNA to multiple anatomical regions of the brain in a Huntington's disease mouse model after systemic injection, resulting in silencing of the huntingtin gene in different regions of the brain