Appropriating,Reclaiming and Inventing Identity Through Architecture

Local received knowledge once ensured buildings had a strong connection with their environment and the surrounding community. With rapid urbanisation and the professionalisation of design and construction, architects working internationally with a finely attuned sensibility to place and context have been able to take up the baton and take the opportunity to develop notions of locality and identity. For the last two decades, the Aga Khan Award for Architecture has been recognising the contribution of design teams that have been responsible for producing exceptional architecture for Islamic communities worldwide. Here, the award scheme's director, Farrokh Derakshani , defines some key treatments of identity in architecture.     

Effect of adverse geological condition on TBM operation in Ghomroud tunnel conveyance project

With the planned length of 36 km, Ghomroud tunnel is one of the longest tunnels under construction in central Iran. About half or 18 km of this tunnel was excavated by a double shield TBM. Several adverse geological conditions encountered, consisting of ground squeezing and face collapse, hindering TBM performance, and caused several TBM stoppages and jamming. This paper presents the impact of ground conditions on machine performance based on the information obtained from field observations and geotechnical site investigations. As built geological conditions are described while the method and results of tunnel convergence measurements and their impacts on tunneling operation is examined. Based on the detail study of the available geological information and tunnel convergence measurements, it was evident that the existence of weak structures in rock mass resulted in high rate of the convergence, which was the dominant factor in the TBM jamming. Since it was not possible to make observation and measurements of geological parameters when working in a lined tunnel built by a shielded machine, an attempt was made to correlate TBM operational parameters and ground convergence. The preliminary result of the analysis has indicated a good correlation among machine’s operational parameters and tunnel convergence. If the system is fully developed, these parameters can be used as an indicator of the potential for high rates of convergence. An early warning on ground convergence is essential for taking precautionary measures to avoid TBM from getting jammed by squeezing ground.     

An Efficient SQUID NDE Defect Detection Approach by?Using?an?Adaptive?Finite-Element?Modeling

Incorporating the finite-element method for the modeling of the SQUID NDE response to a predefined defect pattern, an adaptive algorithm has been developed for the reconstruction of unknown defects using an optimization algorithm for updating of the forward problem. The defect reconstruction algorithm starts with an initial estimation for the defect pattern. Then the forward problem is solved and the obtained field pattern is compared with the measured signal from the SQUID NDE system. The result is used by an optimization algorithm to update the defect structure to be incorporated in the FEM forward problem for the next iteration. Since the mentioned model based inverse algorithm normally consumes a lot of computational resources, the number of iterations plays an important role in the determination of the total response convergence time. Consequently, different optimization algorithms have been applied and their performances are compared. In this work by incorporating an efficient forward model and using the stochastic and deterministic optimization algorithms for defect updating we have investigated their performance on the inversion of the SQUID NDE signal and also their ability to defect reconstruction in the noisy environment.     

Study of the tip mass and interaction force effects on the frequency response and mode shapes of the AFM cantilever

The vibrational characteristics of an atomic force microscope (AFM) cantilever beam play a key role in dynamic mode of the atomic force microscope. As the oscillating AFM cantilever tip approaches the sample, the tip–sample interaction force influences the cantilever dynamics. In this paper, we present a detailed theoretical analysis of the frequency response and mode shape behavior of a cantilever beam in the dynamic mode subject to changes in the tip mass and the interaction regime between the AFM cantilever system and the sample. We consider a distributed parameter model for AFM and use Euler–Bernoulli method to derive an expression for AFM characteristics equation contains tip mass and interaction force terms. We study the frequency response of AFM cantilever under variations of interaction force between AFM tip and sample. Also, we investigate the effect of tip mass on the frequency response and also the quality factor and spring constant of each eigenmodes of AFM micro-cantilever. In addition, the mode shape analysis of AFM cantilever under variations of tip mass and interaction force is investigated. This will incorporate the presentation of explicit analytical expressions and numerical analysis. The results show that by considering the tip mass, the resonance frequencies of the cantilever are decreased. Also, the tip mass has a significant effect on the mode shape of the higher eigenmodes of the AFM cantilever. Moreover, tip mass affects the quality factor and spring constant of each modes.     

The HARPSS process for fabrication of precision MEMS inertial sensors

The high aspect-ratio combined poly- and single-crystal silicon micromachining technology (HARPSS) and its application to fabrication of precision MEMS inertial sensors are presented. HARPSS is a single wafer, all silicon, front-side release process which is capable of producing 10–100's of microns thick, electrically isolated, 3-D poly- and single-crystalline silicon microstructures with various size air-gaps ranging from sub-micron to tens of microns. High aspect-ratio (>50:1) polysilicon structures are created by refilling 100's of microns deep trenches with polysilicon deposited over a sacrificial oxide layer. This technology provides features required for precision micromachined inertial sensors. The all-silicon feature of this technology improves long term stability and temperature sensitivity while fabrication of large area, vertical electrodes with sub-micron gap spacing will increase the sensitivity by orders of magnitude.     

Inadvertently high dialysate magnesium causing weakness and nausea in hemodialysis patients

As maintenance hemodialysis patients are exposed to large quantities of dialysis water, any contamination of it might be reflected in plasma levels. We present a series of cases due to such a contamination. Six maintenance hemodialysis patients dialyzing at the same peripheral hemodialysis facility presented to us over a short period of time with symptoms mimicking inadequate dialysis. Their blood urea and creatinine levels were not very high, but all the patients had hypermagnesemia [serum Mg levels = 1.8 (±0.3) mmol/L]. Except for one patient who had cardiac arrest at presentation, all patients improved after undergoing hemodialysis at our center [serum Mg at discharge = 0.86 (±0.01) mmol/L]. The origin of hypermagnesemia was traced to dialysis water contamination with magnesium due to inadequate maintenance of the water treatment system. Corrective measures improved the quality of water, and no further cases were reported from that center. Proper maintenance and periodic checks of the quality of water are central to the outcomes of maintenance hemodialysis patients.     

A neural network-based method for coverage measurement of shot-peened panels

Neural Computing and Applications - Shot peening is a cold metal working process to improve the material strength, reduce corrosion fatigue and prevent fracture. Measuring the coverage level is an...     

Design approach of the ARIES-AT power core and vacuum vessel cost assessment

The complexity of fusion power plants require the integration of many diverse and important system requirements to achieve a design approach that is viewed as a commercially viable electric plant. The ARIES-AT power core design builds upon a history of fusion power core designs that evolve along with physics and engineering advances. The baseline design point is optimized for maximum performance and minimum capital cost based upon the ARIES systems code results, along with physics and engineering analyses. The ARIES-AT power core is designed to be quick and easily maintainable to achieve high plant availability. A key element to achieve the high availability is the integration of the core elements with the design of the vacuum vessel. The vacuum vessel design is developed in more detail to assure the key assembly and maintenance features could be realized at an affordable cost.