201,119 research outputs found
Performance-based seismic design of a modular pipe-rack
No full textAimed at demonstrating the benefits of using a robust PBD (performance-based design) framework in the engineering construction
industry, the seismic analysis of a typical pipe-rack module is presented in this paper, comparing prescriptive and performancebased
approaches. The case-study steel frame is 6 m long, 8 m wide and 10 m tall, and is representative of this type of structures
in the oil and gas industry. The hazard analysis is used to select a representative set of recorded accelerograms for increasing
values of the seismic intensity measure (IM), chosen as the spectral ordinate at the fundamental period of vibration of the structure. Nonlinear time-history analyses are carried out with the commercial software SAP2000 to establish the fragility curves relevant to the pipe rack. The process is automated through MATLAB coding and a range of EDPs (engineering demand parameters) are statistically characterised, namely internal forces, deformations and absolute accelerations, which in turn are associated with various DMs (damage measures)
Performance-based seismic design of a modular pipe-rack
No full textAimed at demonstrating the benefits of using a robust PBD (performance-based design) framework in the engineering construction
industry, the seismic analysis of a typical pipe-rack module is presented in this paper, comparing prescriptive and performancebased
approaches. The case-study steel frame is 6 m long, 8 m wide and 10 m tall, and is representative of this type of structures
in the oil and gas industry. The hazard analysis is used to select a representative set of recorded accelerograms for increasing
values of the seismic intensity measure (IM), chosen as the spectral ordinate at the fundamental period of vibration of the structure. Nonlinear time-history analyses are carried out with the commercial software SAP2000 to establish the fragility curves relevant to the pipe rack. The process is automated through MATLAB coding and a range of EDPs (engineering demand parameters) are statistically characterised, namely internal forces, deformations and absolute accelerations, which in turn are associated with various DMs (damage measures)
Optimal Storage Rack Design for a 3-dimensional Compact AS/RS
No full textIn this paper, we consider a newly-designed compact three-dimensional automated storage and retrieval system (AS/RS). The system consists of an automated crane taking care of movements in the horizontal and vertical direction. A gravity conveying mechanism takes care of the depth movement. Our research objective is to analyze the system performance and optimally dimension of the system. We estimate the crane’s expected travel time for single-command cycles. From the expected travel time, we calculate the optimal ratio between three dimensions that minimizes the travel time for a random storage strategy. In addition, we derive an approximate closed-form travel time expression for dual command cycles. Finally, we illustrate the findings of the study by a practical example.AS/RS;Warehousing;Order Picking;Travel Time Model;Compact Storage Rack Design
Receptor for activated C kinase-1 facilitates protein kinase C-dependent phosphorylation and functional modulation of GABA(A) receptors with the activation of G-protein-coupled receptors
No full textGABA(A) receptors are the principal sites of fast synaptic inhibition in the brain. These receptors are hetero-pentamers that can be assembled from a number of subunit classes: alpha(1-6), beta(1-3), gamma(1-3), delta(1), epsilon, theta, and pi, but the majority of receptor subtypes is believed, however, to be composed of alpha, beta, and gamma2 subunits. A major mechanism for modulating GABA(A) receptor function occurs via the phosphorylation of residues within the intracellular domains of receptor subunits by a range of serine/ threonine and tyrosine kinases. However, how protein kinases are targeted to these receptors to facilitate functional modulation remains unknown. Here we demonstrate that the receptor for activated C kinase (RACK-1) and protein kinase C (PKC) bind to distinct sites on GABA(A) receptor beta subunits. Although RACK-1 is not essential for PKC binding to GABAA receptor beta subunits, it enhances the phosphorylation of serine 409, a residue critical for the phospho-dependent modulation of GABA(A) receptor function in the beta1 subunit by anchored PKC. Furthermore, RACK-1 also enhances GABA(A) receptor functional modulation in neurons by a PKC-dependent signaling pathway with the activation of muscarinic acetylcholine receptors (mAChRs). This PKC-dependent modulation of neuronal GABAA receptors was mirrored by an increase in the phosphorylation of GABA(A) receptor beta subunits with the activation of mAChRs.Our results suggest a central role for RACK-1 in potentiating PKC-dependent phosphorylation and functional modulation of GABA(A) receptors. Therefore, RACK-1 will enhance functional cross talk between GABA(A) receptors and G-protein-coupled receptors and therefore may have profound effects on neuronal excitability
rack
No full textrack nA hair comb.A hair comb.PRINTED ITEM DNE-citG. M. Story July 1956Used IUsed IUsed
rack
No full textrack nn. A comb for the hair.n. A comb for the hair.PRINTED ITEMG. M. Story July 1959Used IUsed IUsed
The influence of support conditions on short- and long-term track behaviour
No full textRailway track support conditions are known to deeply affect the dynamic performance of vehicle-track interaction, influencing the state of the track system both in the short and in the long term. Exactly how much and how is not precisely understood and the notion of track stiffness, although thought to be a key parameter of the track quality, is currently not being monitored systematically. This paper seeks to analyse the influence on the ballast behaviour of track vertical stiffness and especially its spatial non-uniformity, using available experimental data measured at different sites. Mathematical models are developed and the effectiveness of applying under sleeper pads is also investigated. Finally, an iterative procedure based on Guerin’s settlement law is used to take into account the long-term behaviour of the ballast. Such models can help to understand mitigation solutions as well as predicting track quality evolution over time
rack ?n / rack sticks
No full textrack ntwo long sticks which are bolted to the _bunk_ of a sled for hauling pulpwoodPRINTED ITEMrack n ? WKG. M. Story JAN 7 1988Used I and SupUsed I and SupWithdraw
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