747 research outputs found
DesignTracking: Track and Replay BIM-based Design Process
Among different phases of the life cycle of a building or facility, design is
of the utmost importance to ensure safety, efficiency and sustainability of the
building or facility. How to control and improve design quality and efficiency
has been explored for years, and more studies emerged with the popularization
of Building Information Modelling (BIM). However, most of them focused on the
extraction of design behaviors, while paying less attention to how a design is
formed. Therefore, this study proposes an approach to tracking and replaying
the BIM-based design process by integrating data logging and 4D visualization
techniques. First of all, potential design behaviors and procedures are
analyzed and extracted by observing how a designer designs a BIM model.
Meanwhile, the required data for logging design process is defined and a
relevant method to collect these data is developed based on the APIs of BIM
software. Then, strategies on how to visualize different design procedures are
designed and implemented via 4D visualization. Finally, a prototype system is
developed based on Autodesk Revit and validated through a case study. Result
shows that the proposed approach enables intuitively and interactively review
of the design process, and makes it easier to understand design behaviors and
even identify potential pitfalls, thus improving the design efficiency and
quality
Synergistic Effect of Trehalose and Saccharose Pretreatment on Maintenance of Lyophilized Human Red Blood Cell Quality
Purpose: To investigate the synergistic effect of trehalose and saccharose pretreatment on maintenance of lyophilized human red blood cell (RBC) quality.Methods: RBCs were pre-treated with trehalose and saccharose, and then lyophilized and re-hydrated. Prior to lyophilization and after re hydration, RBC parameters, RBC counts, total hemoglobin concentration, mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), comprehensive deformation index, hemolysis ratio and phosphatidylserine (PS) expression, were determined using a hematology analyzer, an RBC deformation instrument, a spectrophotometer and a flow cytometer, respectively. Superoxide dismutase (SOD), glucose-6-phosphate dehydrogenase (G-6-PD), and adenosine triphosphatase (ATPase) activities were determined using kits for SOD, ATPase, and G-6- PD assay, respectively.Results: After lyophilization-rehydration, RBC counts and total hemoglobin recovery rates, deformability, and RBC SOD, ATPase, and G-6-PD activities were significantly decreased by 47.24 – 74.65 % (p < 0.01), compared with the normal group. RBC osmotic fragility and PS expression on the outer surface of the RBC membrane were significantly increased by 168.53 and 629.30 % (p < 0.01), respectively, compared with the normal group. RBC MCH and MCV values were not significantly affected by lyophilization rehydration (p > 0.05). Trehalose and saccharose pretreatment significantly reversed the effects of lyophilization-rehydration on these RBC parameters by approximately 13.16 – 211.11 % (p < 0.01), compared with the control group. The combined effects were synergistic.Conclusion: Trehalose and saccharose pretreatment synergistically enhances maintenance of lyophilized RBC quality.Keywords: Trehalose, Saccharose, Lyophilization, Red blood cell, Hematological parameter
catena-Poly[[diaquanickel(II)]-μ-7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylato]
In the crystal structure of the title compound, [Ni(C8H8O5)(H2O)2]n, the NiII cation is in a Jahn–Teller-distorted octahedral coordination environment binding to two O atoms from water molecules, the bridging O atom of the bicycloheptane unit, two carboxylate O atoms from different carboxylate groups and one carboxylate O atom from a symmetry-related bridging ligand. The crystal structure is made up from layers propagating parallel to the bc plane
Hypersonic wave wall flow based on gas kinetic method
The transition of hypersonic boundary layer can lead to a several-fold
increase in surface heat flux and skin friction for the aircraft, significantly
impacting its flight performance. The corrugated wall, as a passive control
method for boundary layer flow, also serves as a type of wall microstructure,
making its study on the local rarefaction effect of considerable engineering
significance. In this study, we employed the conservative discrete unified gas
dynamic scheme and utilized a domain-wide numerical simulation method.
Initially, we simulated the hypersonic flat plate flow with different depths of
corrugated walls under the conditions of incoming flow Mach number of 6 and
Reynolds number of . Subsequently, we investigated the effects of
corrugated walls, including flat plate corrugated walls and wedge corrugated
walls, under varying Reynolds numbers for an incoming flow Mach number of 6,
and discussed the impact of local rarefaction effect of corrugated walls under
different Reynolds numbers. By using the local Knudsen number as the criterion,
we found that under these conditions, the occurrence of local rarefaction
effect near the corrugated wall due to consecutive failures does not take place
when the incoming Reynolds number reaches or .
However, when the incoming Reynolds number drops to , the local
rarefaction effect near the corrugated wall becomes evident, with the
appearance of non-equilibrium effects in translational and rotational
temperatures of molecules. This phenomenon becomes more pronounced as the
Reynolds number decreases further
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