Automatic computation for optimum height planning of apartment buildings to improve solar access

The objective of this study is to suggest a mathematical model and an optimal algorithm for determining the height of apartment buildings to satisfy the solar rights of survey buildings or survey housing units. The objective is also to develop an automatic computation model for the optimum height of apartment buildings and then to clarify the performance and expected effects. To accomplish the objective of this study, the following procedures were followed:

(1)

The necessity of the height planning of obstruction buildings to satisfy the solar rights of survey buildings or survey housing units is demonstrated by analyzing through a literature review the recent trend of disputes related to solar rights and to examining the social requirements in terms of solar rights. In addition, the necessity of the automatic computation system for height planning of apartment buildings is demonstrated and a suitable analysis method for this system is chosen by investigating the characteristics of analysis methods for solar rights assessment.

(2)

A case study on the process of height planning of apartment buildings will be briefly described and the problems occurring in this process will then be examined carefully.

(3)

To develop an automatic computation model for height planning of apartment buildings, geometrical elements forming apartment buildings are defined by analyzing the geometrical characteristics of apartment buildings. In addition, design factors and regulations required in height planning of apartment buildings are investigated. Based on this knowledge, the methodology and mathematical algorithm to adjust the height of apartment buildings by automatic computation are suggested and probable problems and the ways to resolve these problems are discussed. Finally, the methodology and algorithm for the optimization are suggested.

(4)

Based on the suggested methodology and mathematical algorithm, the automatic computation model for optimum height of apartment buildings is developed and the developed system is verified through the application of some cases. The effects of the suggested model are then demonstrated quantitatively and qualitatively.

     

Enzyme kinetic measurements using a droplet-based microfluidic system with a concentration gradient

In this paper, we propose a microfluidic device that is capable of generating a concentration gradient followed by parallel droplet formation within channels with a simple T-junction geometry. Linear concentration gradient profiles can be obtained based on fluid diffusion under laminar flow. Optimized conditions for generating a linear concentration gradient and parallel droplet formation were investigated using fluorescent dye. The concentration gradient profile under diffusive mixing was dominated by the flow rate at sample inlets, while parallel droplet formation was affected by the channel geometry at both the inlet and outlet. The microfluidic device was experimentally characterized using optimal layout and operating conditions selected through a design process. Furthermore, in situ enzyme kinetic measurements of the β-galactosidase-catalyzed hydrolysis of resorufin-β-d-galactopyranoside were performed to demonstrate the application potential of our simple, time-effective, and low sample volume microfluidic device. We expect that, in addition to enzyme kinetics, drug screening and clinical diagnostic tests can be rapidly and accurately performed using this droplet-based microfluidic system.     

Torsional Stiffness of Prestressing Tendons in Double-T Beams

When a prestressed double-T beam is subjected to torsion, a pair of prestressing tendons resists torsional rotation because of the restoring action of the displaced prestressing tendons. A comprehensive formulation to account for the torsional restoring action of double-T beams is presented, based on Vlasov’s hypothesis of considering warping displacement in an open-section. The deformation energies of prestressing tendons and reinforcing bars are calculated based on the deformed geometry to obtain the total potential energy. A two-noded beam element with seven degrees of freedom per node approximates an axial displacement, two translations, two flexural, and one torsional rotations, and a warping displacement to derive the finite-element equilibrium equations by minimizing the potential energy function. The role of prestressing forces of the tendons on the torsional resistance and the limitations of the traditional transformed section approach are addressed when it is applied to torsional problems. As a numerical example, an existing three-span continuous double-T beam is analyzed, and the bimoment and angle of twist are compared to those calculated using conventional three-dimensional finite-element analysis and the analytical solution of governing differential equations.     

Cocatalyst‐Free Photocatalysts for Efficient Visible‐Light‐Induced H2 Production: Porous Assemblies of CdS Quantum Dots and Layered Titanate Nanosheets

Highly efficient, visible‐light‐induced H₂ generation can be achieved without the help of a Pt cocatalyst by new hybrid photocatalysts, in which CdS quantum dots (QDs) (particle size ≈2.5 nm) are incorporated in the porous assembly of sub‐nanometer‐thick layered titanate nanosheets. Due to the very‐limited crystal dimension of component semiconductors, the electronic structure of CdS QDs is strongly coupled with that of the layered titanate nanosheets, leading to an efficient electron transfer between them and the enhancement of the CdS photostability. As a consequence of the promoted electron transfer, the photoluminescence of CdS QDs is nearly quenched after hybridization, indicating the almost‐suppression of electron‐hole recombination. These Pt‐cocatalyst‐free, CdS‐layered titanate nanohybrids show much‐higher photocatalytic activity for H₂ production than the precursor CdS QDs and layered titanate, which is due to the increased lifetime of the electrons and holes, the decrease of the bandgap energy, and the expansion of the surface area upon hybridization. The observed photocatalytic efficiency of these Pt‐free hybrids (≈1.0 mmol g^?1 h^?1) is much greater than reported values of other Pt‐free CdS‐TiO₂ systems. This finding highlights the validity of 2D semiconductor nanosheets as effective building blocks for exploring efficient visible‐light‐active photocatalysts for H₂ production.     

Collective Motion of Conducting Filaments in Pt/n‐Type TiO2/p‐Type NiO/Pt Stacked Resistance Switching Memory

Filamentary resistance switching (RS) is one of the more obvious and useful phenomena in the family of RS mechanisms. In filamentary RS, the long reset switching time and substantially large power consumption are the critical obstacles for microelectronic applications. In this study, an innovative solution to overcome this reset problem is suggested by stacking n‐type TiO₂ and p‐type NiO films. Interestingly, in this stacked structure, the region where filament rupture and rejuvenation occurs could be arbitrarily controlled to be at any location between the interface with the metal electrode and the TiO₂/NiO interface by using an appropriate switching sequence. This collective motion behavior of conducting filaments can be practically used to reduce reset switching time from ～100 μs to ～150 ns, with an extremely high off/on resistance ratio of ～10⁶.     

Nanoparticle Arrays: Sub‐Nanometer Level Size Tuning of a Monodisperse Nanoparticle Array Via Block Copolymer Lithography (Adv. Funct. Mater. 2/2011)

The fabrication and catalytic application of a size‐tunable monodisperse nanoparticle array enabled by block copolymer lithography is demonstrated. Highly uniform vertical cylinder nanodomains are achieved in poly(styrene‐block‐4‐vinylpyridine) (PS‐b‐P4VP) diblock copolymer thin‐films by solvent annealing. The prominent diffusion of the anionic metal complexes into the protonated P4VP cylinder nanodomains occurs through specific electrostatic interactions in a weakly acidic aqueous solution. This well‐defined diffusion with nanoscale confinement enables preparation of the laterally ordered monodisperse nanoparticle array with sub‐nanometer level precise size tuning. The controlled growth of monodisperse nanoparticle arrays is proven by their catalytic use for vertical carbon nanotube (CNT) growth via plasma enhanced chemical vapor deposition (PECVD). Since the size of the catalyst particles is the decisive parameter for the diameters and wall‐numbers of CNTs, the highly selective growth of double‐walled or triple‐walled CNTs could be accomplished using monodisperse nanoparticle arrays.     

A Mussel Adhesive Protein Fused with the BC Domain of Protein A is a Functional Linker Material that Efficiently Immobilizes Antibodies onto Diverse Surfaces

The efficient immobilization of antibodies onto solid surfaces is vital for the sensitivity and specificity of various immunoassays and immunosensors. A novel linker protein, BC‐MAP, is designed and produced in Escherichia coli by genetically fusing mussel adhesive protein (MAP) with two domains (B and C) of protein A (antibody‐binding protein) for efficient antibody immobilization on diverse surfaces. Through direct surface‐coating analyses, it is found that BC‐MAP successfully coats diverse surfaces including glass, polymers, and metals, but the BC domain alone does not. Importantly, antibodies are efficiently immobilized on BC‐MAP‐coated surfaces, and the immobilized antibodies interact selectively with their corresponding antigen. Quartz‐crystal‐microbalance analyses show that BC‐MAP has excellent antibody‐binding ability compared to that of BC protein on gold surfaces. These results demonstrate that the MAP domain, with uniquely strong underwater adhesive properties, plays a role in the direct and efficient coating of BC‐MAP molecules onto diverse surfaces that lack additional surface treatment, and the BC domain of BC‐MAP contributes to the selective and oriented immobilization of antibodies on BC‐MAP‐coated surfaces. Thus, the BC‐MAP fusion protein could be a valuable novel linker material for the facile and efficient immobilization of antibodies onto diverse solid supports.     

Tristate Memory Using Ferroelectric–Insulator–Semiconductor Heterojunctions for 50% Increased Data Storage

Ferroelectric random‐access memory (FeRAM) is considered to be one of the best candidates for universal memory. However, difficult scaling of the memory cell size has hindered the realization of high density FeRAM. Given that size scaling is inherently limited by the complicated crystal structure and processing of ferroelectric materials, the highly stable and step‐wise three memory state of one cell can be another pathway to high‐density FeRAM. A feasible structure and actual operation of a tristate memory function for high‐density FeRAM is presented that uses stacked ferroelectric Pb(Zr,Ti)O₃/insulating Al₂O₃/semiconducting ZnO layers with Pt top and bottom electrodes. The complicated electrical responses of the stacked structure to external stimuli are well understood based on the separated trapping of the compensating charges at the Pb(Zr,Ti)O₃/Al₂O₃ and Al₂O₃/ZnO interfaces and the discrete dissipation of the trapped charges during polarization switching in one direction. This unique function of the structure induces three discrete charge states that can be used to increase the memory density by 50% compared to conventional FeRAM at a given cell size.     

Development of a qualitative evaluation framework for performance shaping factors (PSFs) in advanced MCR HRA

Human reliability analysis (HRA) is performed as part of the probabilistic risk assessment to identify and quantify human actions and the associated impacts on structures, systems, and components of complex facilities. In performing HRA, conditions that influence human performance have been analyzed in terms of several context factors. These context factors, which are called performance shaping factors (PSFs) are used to adjust the basic human error probability (BHEP), and PSFs have been derived in various ways depending on the HRA methods used.