A novel simple procedure to consider seismic soil structure interaction effects in 2D models

A method is proposed to estimate the seismic soil-structure-interaction （SSI） effects for use in engineering practice. It is applicable to 2D structures subjected to vertically incident shear waves supported by homogenous half-spaces. The method is attractive since it keeps the simplicity of the spectral approach, overcomes some of the difficulties and inaccuracies of existing classical techniques and yet it considers a physically consistent excitation. This level of simplicity is achieved through a response spectra modification factor that can be applied to the free-field 5%-damped response spectra to yield design spectral ordinates that take into account the scattered motions introduced by the interaction effects. The modification factor is representative of the Transfer Function （TF） between the structural relative displacements and the free- field motion, which is described in terms of its maximum amplitude and associated frequency. Expressions to compute the modification factor by practicing engineers are proposed based upon a parametric study using 576 cases representative of actual structures. The method is tested in 10 cases spanning a wide range of common fundamental vibration periods.

Recent developments in seismically isolated buildings in Japan

The Building Standard Law of Japan and related Enforcement Order and Notifications have been substantially revised since the year 2000 to introduce a performance-based regulatory and deregulation system for building control systems. Up to then,time-history analyses were mandatory for isolated buildings and had to be specially approved by the Minster of the Ministry of Construction (MOC).Simplified design procedures based on the equivalent linear method for seismically isolated buildings have been issued as'Notification 2009-Structnral calculation procedure for buildings with seismic isolation'from MOC,and are now integrated into the Ministry of Land,Infrastructure,and Transportation (MLIT).Along with Notification 2009,'Notification 1446 of year 2000-Standard for specifications and test methods for seismic isolation devices'was also issued.Buildings with heights equal to or less than 60m and that are designed according to these Notifications,including base isolated buildings,only need approval from local building officials,and no longer require the special approval of the Minister of MLIT.This paper summarizes:1) some statistics related to buildings with seismic isolation completed up to the end of 2001; 2) simplified design procedures required by Notification 2009 of year 2000;and 3) performance of seismic isolation devices required by Notification 1446 of year 2000.

The forced activation of asexual conidiation in Aspergillus niger simplifies bioproduction

Aspergillus niger is an efficient cell factory for organic acids production,particularly l-malic acid,through genetic manipulation.However,the traditional method of collecting A.niger spores for inoculation is labor-intensive and resource-consuming.In our study,we used the CRISPR-Cas9 system to replace the promoter of brlA,a key gene in Aspergillus conidiation,with a xylose-inducible promoter xylP in l-malic acid-producing A.niger strain RG0095,generating strain brlAxylP.When induced with xylose in submerged liquid culture,brlAxylP exhibited significant upregulation of conidiation-related genes.This induction allowed us to easily collect an abundance of brlAxylP spores(>7.1×106/mL)in liquid xylose medium.Significantly,the submerged conidiation approach preserves the substantial potential of A.niger as a foundational cellular platform for the biosynthesis of organic acids,including but not limited to l-malic acid.In summary,our study offers a simplified submerged conidiation strategy to streamline the preparation stage and reduce labor and material costs for industrial organic acid production using Aspergillus species.