Compression Behaviors of Parallel Bamboo Strand Lumber Under Static Loading

In order to investigate the influence of length and compression directions upon behaviour of parallel bamboo strand lumber(PBSL)specimens,240 axial compression tests have been performed.With three similar one different typical failure modes,the mechanical performance for PBSL specimens under compression parallel to grain and perpendicular to grain are different as a whole.From the point of the characteristic values,the compression strength parallel to grain is 2.1 times of the compression strength perpendicular to grain.The elastic modulus for compression parallel to grain is 3.64 times of the compression strength perpendicular to grain.While the compression ratios along two compression directions are equal to each other.The bigger Poisson ratios for one typical side surface is 3.93 times of that for another typical side surface for PBSL specimens under compression perpendicular to grain,and the bigger value is equal to that for PBSL specimens under compression parallel to grain.Length can influence the mechanical properties of the PBSL specimens.The size 50 mm×50 mm×100 mm should be good choice for the standard or code to measure the compression strength.PBSL materials have better ductility under compression parallel to grain than that under compression perpendicular to grain.Stress-strain relationship models were proposed for PBSL specimens under compression parallel to grain and perpendicular to grain,respectively.These proposed models gave a good agreement with the test results.

Mechanical Properties and Stress Strain Relationship Models for Bamboo Scrimber

In order to investigate the basic mechanical properties and stress strain relationship model for bamboo scrimber manufactured based on a new technique,a large quantities of experiments have been carried out.Based on the analysis of the test results,the following conclusions can be drawn.Two main typical failure modes were classified for bamboo scrimber specimens both under tension parallel to grain and tension perpendicular to grain.Brittle failure happened for all tensile tests.The slope values for the elastic stages have bigger discreteness compared with those for the specimens under tensile parallel to grain.The failure modes for bamboo scrimber specimens under compression parallel to grain could be divided into four.Only one main failure mode happened both for the bending specimens and the shear specimens.With the COV values of 28.64 and 25.72 respectively,the values for the strength and elastic modulus under tensile perpendicular to grain have the largest discreteness for bamboo scrimber.From the point of CHV values,the relationship among the mechanical parameters for bamboo scrimber were proposed based on the test results.Compared with other green building materials,bamboo scrimber manufactured based on a new technique has better mechanical performance and could be used in construction area.Three stress strain relationship models which are four-linear model,quadratic function model,and cubic function model were proposed for bamboo scrimber specimens manufactured based on a new technique.The latter two models gives better prediction for stress strain relationship in elastic plastic stage.

Review on Connections for Original Bamboo Structures

Bamboo is a green construction material in line with sustainable development strategies.The use of raw bamboo in architecture has existed since ancient times.In the long development years of original bamboo buildings,many areas in the world gradually formed unique bamboo buildings,which have become an important local cultural feature.For building structures,joints are the key to ensure structural load transfer.Because of hollow and thin-walled material property of bamboo,the connection in raw bamboo buildings has always been a major difficulty and problem in the application of bamboo,which seriously hinders the development of original bamboo structures.In order to promote the use of raw bamboo,two traditional connection methods in raw bamboo structures are described in this paper firstly,with the advantages and disadvantages of the two methods pointed out.Also,research progress on four categories of raw bamboo building joints is described namely,bolt joints,steel member joints,filler reinforced joints and other types of joints.This work can provide a reference for future research and engineering applications.

Study on the Adhesive for the Production of High Strength Four Layer Composite Corrugated Board

In order to study of adhesive which is applicable to the production of high strength four layer composite corrugated board,the composite corrugated medium was respectively coated with cassava starch adhesive,environmental-friendly modified water glass binder,CP-88 starch adhesive,polyvinyl alcohol adhesive and polyvinyl acetate adhesive,then the edgewise crush resistance and flat crush resistance contrast experiment on produced corrugated board samples was tested.The experiment results demonstrated that the produced corrugated board with environmental-friendly modified water glass binder had high edgewise crush resistance,general flat crush resistance and more economic,so the environmental-friendly modified water glass binder can be used for the production of high strength four layer composite corrugated board.

Identification and functional analysis of shared gene signatures between systemic lupus erythematosus and Sjogren's syndrome

Background:Systemic lupus erythematosus(SLE)is an autoimmune disease that can affect multiple systems.Sjogren's syndrome(SS)is an autoimmune disease that may be primary SS(pSS)or occur together with other autoimmune diseases,including SLE.This study aimed to explore the shared gene signatures in SLE and pSS.Methods:Gene expression data sets of SLE(GSE50772 and GSE81622)and pSS(GSE84844 and GSE48378)were obtained and analyzed for differentially expressed genes(DEGs)in peripheral blood mononuclear cells(PBMCs).A protein–protein interaction(PPI)network was constructed.Gene ontology(GO)and KEGG pathway enrichment analysis were carried out for the DEGs.Results:We screened 232 and 110 DEGs from the SLE and pSS data sets,respectively.We found 32 shared DEGs,which were all upregulated in patients compared with controls.Among these 32 DEGs,11 genes showed a more than twofold change in all data sets(IFI27,IFI44L,RSAD2,IFIT1,IFI44,USP18,IFI6,HERC5,EPSTI1,OAS1,and OAS3).PPI analysis showed that 29 genes interacted with each other.GO analysis showed that these 32 shared DEGs were mainly enriched in biological processes associated with the type Ⅰ interferon signaling pathway,defense response to viruses,response to viruses,negative regulation of viral genome replication,and the immune response.Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that these 32 DEGs were related to virus infection.Conclusion:This study showed that alterations to biological processes associated with the response to virus infection play critical roles in both SLE and pSS.