Achievements of Truss Models for Reinforced Concrete Structures

Achievements are presented for truss models of RC structures developed in previous years: 1. Two constitutive models, biaxial and triaxial, are based on regular trusses, with bars obeying nonlinear uniaxial σ-ε laws of material under simulation;both models have been compared with test results and show a dependence of Poisson ratio on curvature of σ-ε law. 2. A truss finite element has been used in the nonlinear static and dynamic analysis of plane RC frames;it has been compared with test results and describes, in a simple way, the formation of plastic hinges. 3. Thanks to the very simple geometry of a truss, the equilibrium equations can be easily written and the stiffness matrix can be easily updated, both with respect to the deformed truss, within each step of a static incremental loading or within each time step of a dynamic analysis, so that to take into account geometric nonlinearities. So the confinement of a RC column is interpreted as a structural stability effect of concrete. And a significant role of the transverse reinforcement is revealed, that of preventing, by its close spacing and sufficient amount, the buckling of inner longitudinal concrete struts, which would lead to a global instability of the RC column. 4. The proposed truss model is statically indeterminate, so it exhibits some features, which are not met by the “strut-and-tie” model.

Hierarchical microstructures with high spatial frequency laser induced periodic surface structures possessing different orientations created by femtosecond laser ablation of silicon in liquids

High spatial frequency laser induced periodic surface structures(HSFLs)on silicon substrates are often developed on flat surfaces at low fluences near ablation threshold of 0.1 J/cm2,seldom on microstructures or microgrooves at relatively higher fluences above 1 J/cm^2.This work aims to enrich the variety of HSFLs-containing hierarchical microstructures,by femtosecond laser(pulse duration:457 fs,wavelength:1045 nm,and repetition rate:100 kHz)in liquids(water and acetone)at laser fluence of 1.7 J/cm^2.The period of Si-HSFLs in the range of 110–200 nm is independent of the scanning speeds(0.1,0.5,1 and 2 mm/s),line intervals(5,15 and 20μm)of scanning lines and scanning directions(perpendicular or parallel to light polarization direction).It is interestingly found that besides normal HSFLs whose orientations are perpendicular to the direction of light polarization,both clockwise or anticlockwise randomly tilted HSFLs with a maximal deviation angle of 50°as compared to those of normal HSFLSs are found on the microstructures with height gradients.Raman spectra and SEM characterization jointly clarify that surface melting and nanocapillary waves play important roles in the formation of Si-HSFLs.The fact that no HSFLs are produced by laser ablation in air indicates that moderate melting facilitated with ultrafast liquid cooling is beneficial for the formation of HSFLs by LALs.On the basis of our findings and previous reports,a synergistic formation mechanism for HSFLs at high fluence was proposed and discussed,including thermal melting with the concomitance of ultrafast cooling in liquids,transformation of the molten layers into ripples and nanotips by surface plasmon polaritons(SPP)and second-harmonic generation(SHG),and modulation of Si-HSFLs direction by both nanocapillary waves and the localized electric field coming from the excited large Si particles.

Lipid-Protein Microinclusions in the Morphological Structures of Organelle Membranes Studied by Fluorescent Confocal Microscopy

Peculiar properties of morphological structures of organelle membranes were studied by fluorescent confocal microscopy. The list of objects in our experiments was represented by mitochondria, chloroplasts and vacuoles. During this study, identification of lipid microinclusions having the form of such lipid-protein structural microformations as lipid-protein microdomains, vesicles and membrane tubular structures (cytoplasmic transvacuolar strands and nanotubes) located in organelle membranes or bound up with them was conducted. Such membrane probes as laurdan, DPH, ANS and bis-ANS were used. Comparison of fluorescence intensity of these membrane probes was conducted. This investigation of the morphological properties of lipid-protein structural microformations was accompanied with analysis of 1) the phase state and 2) dynamics of microviscosity variations in the membrane elements of isolated plant cell organelles. Distributions of laurdan fluorescence generalized polarization (GP) values for the membrane on the whole and for the intensively fluorescing membrane segments were obtained. It was discovered that the microviscosity of intensively fluorescing membrane segments essentially differed from the microviscosity of the rest part of the membrane. In conclusion, some results of the study of peculiar properties of lipid-protein structural microformations related to the structure of organelle membranes and the discoveries made in this investigation are discussed.

Using Neural Networks to Predict Secondary Structure for Protein Folding

Protein Secondary Structure Prediction (PSSP) is considered as one of the major challenging tasks in bioinformatics, so many solutions have been proposed to solve that problem via trying to achieve more accurate prediction results. The goal of this paper is to develop and implement an intelligent based system to predict secondary structure of a protein from its primary amino acid sequence by using five models of Neural Network (NN). These models are Feed Forward Neural Network (FNN), Learning Vector Quantization (LVQ), Probabilistic Neural Network (PNN), Convolutional Neural Network (CNN), and CNN Fine Tuning for PSSP. To evaluate our approaches two datasets have been used. The first one contains 114 protein samples, and the second one contains 1845 protein samples.

Mapping theme trends and knowledge structures for human neural stem cells:a quantitative and co-word biclustering analysis for the 2013-2018 period

Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends and knowledge structures for human neural stem cells have not yet been studied bibliometrically.In this study,we retrieved 2742 articles from the PubMed database from 2013 to 2018 using "Neural Stem Cells" as the retrieval word.Co-word analysis was conducted to statistically quantify the characteristics and popular themes of human neural stem cell-related studies.Bibliographic data matrices were generated with the Bibliographic Item Co-Occurrence Matrix Builder.We identified 78 high-frequency Medical Subject Heading(MeSH)terms.A visual matrix was built with the repeated bisection method in gCLUTO software.A social network analysis network was generated with Ucinet 6.0 software and GraphPad Prism 5 software.The analyses demonstrated that in the 6-year period,hot topics were clustered into five categories.As suggested by the constructed strategic diagram,studies related to cytology and physiology were well-developed,whereas those related to neural stem cell applications,tissue engineering,metabolism and cell signaling,and neural stem cell pathology and virology remained immature.Neural stem cell therapy for stroke and Parkinson’s disease,the genetics of microRNAs and brain neoplasms,as well as neuroprotective agents,Zika virus,Notch receptor,neural crest and embryonic stem cells were identified as emerging hot spots.These undeveloped themes and popular topics are potential points of focus for new studies on human neural stem cells.

Predictions of Electronic, Transport, and Structural Properties of Magnesium Sulfide (MgS) in the Rocksalt Structure

We report results from ab-initio, self-consistent density functional theory (DFT) calculations of electronic, transport and bulk properties of rock salt magnesium sulfide (MgS). In the absence of experimental data on these properties, except for the bulk modulus, these results are predictions. Our calculations utilized the Ceperley and Alder local density approximation (LDA) potential and the linear combination of Gaussian orbitals (LCGO). The key difference between our computations and other previous ab-initio DFT ones stems from our use of successively larger basis sets, in consecutive, self-consistent calculations, to attain the ground state of the material. We predicted an indirect (Γ-X) band gap of 3.278 eV for a room temperature lattice constant of 5.200Å. We obtained a predicted low temperature indirect (Γ-X) band gap of 3.512 eV, using the equilibrium lattice constant of 5.183Å. We found a theoretical value of 79.76 GPa for the bulk modulus;it agrees very well with the experimental finding of 78 ±3.7 GPa.

Geologic-Geophysical Indicators of the Deep Structure of Zones of Geothermal Anomalies for Allocation of Channels of the Deep Heat and Mass Transfer

On the basis of the analysis of field thermogeochemical data along abnormal zones of a thermal stream in the Bukhara-Khiva, oil-and-gas region of the Turan (Tegermen, Chagakul, Shimoly Alat, Beshtepa) was succeeded to obtain important data on a deep structure of sites. Data of gas-chemical and geothermal observations show about confinedness of abnormal concentration of methane to zones of the increased values of the temperature field the measured values of temperatures (Tegermen Square and others). On geoelectric section mines 2-D of inversion of the MT-field depth of 4000 m are lower, among very high-resistance the chemogenic and carbonate deposits of the Paleozoic is traced the subvertical carrying-out abnormal zone. This zone is identified as the channel of a deep heat and mass transfer with which hydrocarbon (HC) deposits are connected. It is shown that electro-investigation when using a geophysical complex can and has to become “advancing” at exploration by oil and gas.

DEFINITING AND ITS GEOLOGIC MEANING OF SOUTH-NORTH TREND FAULTED STRUCTURE BELT IN QIANGTANG BASIN, NORTH PART OF TIBET

There were more expounding to north—west (west) trend fault and north\|east trend fault within Qiangtang Basin, North Part of Tibet, in the past literature. With increasing of geophysical exploration data, nearly east\|west trend structure began to be taken note to. Since the year of 1995, by a synthetic study to geophysical and geological data, that south\|north trend faulted structures are well developed. These structures should be paid much more attention to, because they have important theoretical meaning and practical significance.1 Spreading of south\|north faulted structure belt According to different geological and geophysical data, the six larger scale nearly south\|north faulted structure belt could be distinguished within the scope of east longitude 84°～96° and near Qiangtang Basin. The actual location of the six belts are nearly located in the west of the six meridian of east longitude 85°,87°,89°,91°,93°,95° or located near these meridian. The six south\|north faulted structure belts spread in the same interval with near 2° longitude interval. The more clear and much more significance of south\|north trend faulted structure belts are the two S—N trend faulted structure belts of east longitude 87° and 89°. There are S—N trend faulted structure belts in the west of east longitude 83°,81°, or near the longitudes. The structure belts spreading features,manifestation,geological function and its importance, and inter texture and structure are not exactly so same. The structure belts all different degree caused different region of geological structure or gravity field and magnetic field. There is different scale near S—N trend faulted structure belt between the belts.

Dynamic Analysis of Soil Structure Interaction Effect on Multi Story RC Frame

In this study dynamic analysis of Soil Structure Interaction (SSI) effect on multi story reinforced concrete (RC) frame founded on soft soil (flexible base) is made and compared with fixed base. Two model 2D RC frames with 7 and 12 story are selected for analysis. Winkler Spring and half space direct method models are used for flexible base for the frames founded on two types of soft soils with shear velocity Vs < 150 m/s Asper Seismic Codes of Chinese GB50011-2010 Soil IV and Ethiopian ES8-2015 soil D. The frames are subjected to strong ground motion matched to response spectrums of soft soil of Chinese GB50011-2010 and Ethiopian ES8-2015 for linear time history analysis. The dynamic analysis result shows Spring and Fixed base mass participation 90% reaches in 2 or 3 modes but in direct method 11 to 30 modes for story 12 and 7 respectively. However, both flexible base models have bigger fundamental period of vibration and inter story drift but smaller base shear than fixed base. In addition, within the flexible base models the inter-story drift, second order effect (P-Δ) and Story shear distribution are different along the height of frames. The spring model shows larger Story drift and second order effect (P-Δ) at the bottom of Story for both soft soils types. On the other hand, half space direct method model indicates value reverse to spring model;it gives bigger Story drift and P-Δ effect in the top stories than fixed base. Finally, this study concludes that base shear reduction due to SSI may not be always beneficial. Because the gravity load is constant in both fixed and flexible bases that cause bigger P-Δ effect at the bottom stories due to increase, inter story drift and decrease story shear in flexible base.

Emerging structures and dynamic mechanisms ofγ-secretase for Alzheimer’s disease

γ-Secretase,called“the proteasome of the membrane,”is a membrane-embedded protease complex that cleaves 150+peptide substrates with central roles in biology and medicine,including amyloid precursor protein and the Notch family of cell-surface receptors.Mutations inγ-secretase and amyloid precursor protein lead to early-onset familial Alzheimer’s disease.γ-Secretase has thus served as a critical drug target for treating familial Alzheimer’s disease and the more common late-onset Alzheimer’s disease as well.However,critical gaps remain in understanding the mechanisms of processive proteolysis of substrates,the effects of familial Alzheimer’s disease mutations,and allosteric modulation of substrate cleavage byγ-secretase.In this review,we focus on recent studies of structural dynamic mechanisms ofγ-secretase.Different mechanisms,including the“Fit-Stay-Trim,”“Sliding-Unwinding,”and“Tilting-Unwinding,”have been proposed for substrate proteolysis of amyloid precursor protein byγ-secretase based on all-atom molecular dynamics simulations.While an incorrect registry of the Notch1 substrate was identified in the cryo-electron microscopy structure of Notch1-boundγ-secretase,molecular dynamics simulations on a resolved model of Notch1-boundγ-secretase that was reconstructed using the amyloid precursor protein-boundγ-secretase as a template successfully capturedγ-secretase activation for proper cleavages of both wildtype and mutant Notch,being consistent with biochemical experimental findings.The approach could be potentially applied to decipher the processing mechanisms of various substrates byγ-secretase.In addition,controversy over the effects of familial Alzheimer’s disease mutations,particularly the issue of whether they stabilize or destabilizeγ-secretase-substrate complexes,is discussed.Finally,an outlook is provided for future studies ofγ-secretase,including pathways of substrate binding and product release,effects of modulators on familial Alzheimer’s disease mutations of theγ-secretase-substrate complexes.Comprehensive understanding of the functional mechanisms ofγ-secretase will greatly facilitate the rational design of effective drug molecules for treating familial Alzheimer’s disease and perhaps Alzheimer’s disease in general.

Crustal density structure of the southern segment of the Liaocheng-Lankao fault, China

The 1:200,000 middle-large scale Bouguer gravity anomaly data covering the southern segment of the Liaocheng-Lankao fault(SLLF)and its vicinity are analyzed with two methods.First,the Bouguer gravity anomaly data are decomposed by two-dimensional(2 D)wavelet to make the family of multi-scale modes correspond with density structure at different depths.Second,a two and half dimension(2.5 D)human-computer interaction inversion of the Bouguer gravity anomaly data are conducted with the constraints provided by two deep seismic sounding profiles(DSS1 and DSS2)crossing the study area to get the crustal density profiles.Based on the integrated study,we can draw the following conclusions:1)SLLF appears to be a deep fault with almost vertical dipping and rooted into the uppermost mantle;2)In the middle to upper crust SLLF shows an clear turning patterns and segmentation features;3)In the study area the epicentral distributions of the precisely re-located small earthquakes and the historical large earthquakes have a good correspondence with the turning patterns and segmentation features of SLLF;and 4)The results of the horizontal slices from 2 D wavelet decomposition show that there are significant differences in the density structure on the two sides of the fault.A well-defined concave structure with low density exists in the upper crust of the Dongming Depression on the west side of the fault,with the concave center being estimated at a depth of about 8 km.In contrast,the upper crust on the east side presents a relative thinner pattern in depth with a bit higher density.Meanwhile,the low-density structure in the middle crust underneath the fault is presumably caused by the uplift of the upper mantle materials and their intrusion along the deep rupture system.This paper clarified the inconsistency of fault system and epicenters of small earthquakes from upper to lower crust.The results indicated that the fault system plays an important governing role to the seismicity in this area.

From Highly Structured E-Infinity Rings and Transfinite Maximally Symmetric Manifolds to the Dark Energy Density of the Cosmos

Starting from well established results in pure mathematics, mainly transfinite set theory, E-infinity algebra over operads, fuzzy manifolds and fuzzy Lie symmetry groups, we construct an exact Weyl scaling for the highly structured E-infinity rings corresponding to E-infinity theory of high energy physics. The final result is an exact expression for the energy density of the cosmos which agrees with previous analysis as well as accurate cosmological measurements and observations, such as COBE, WMAP and Planck. The paper is partially intended as a vivid demonstration of the power of pure mathematics in physics and cosmology.

Ecological Structure and Prediction Equations for Estimating Tree Age, and Dendometric Parameters of <i>Acacia senegal</i>in the Senegalese Semi-Arid Zone—Ferlo

The development of equations to predict tree height, crown diameter, crown depth from stem diameter of a tree species enables arborists, researchers, and urban forest managers to model costs and benefits, analyze alternative management scenarios, and determine the best management practices for sustainable forests. The objective of this study was to develop regression prediction models for tree age, tree height, crown diameter, crown ratio and crown depth for A. senegal growing in Ferlo, in the northern Senegal. Four plantations of different years old (ISRA, 10 years old plantations, Ndodj, 8 years old plantations, Boulal, 5 years old plantations and Déali, 4 years old plantations) were selected. The following dendometric variables: crown height, crown diameter, stem diameter at the breast height, stem basal diameter (at 0.30 m) and the height from the tree base to first branch were measured on a total of 489 trees. The results suggested that the ecological structure of the different year old A. Senegal plantation revealed a bell-shaped form with left dissymmetric distribution indicating a predominance of individuals with small diameter at breast height. Allometry study of A. Senegal showed highly significant positive correlations (p = 0.00) between stem diameter at breast height, stem basal diameter, tree height, crown diameter and crown depth. Positive correlations were also found between crown diameter, tree height and crown height. Prediction models derived from these relationships can be used to estimate the tree height, stem diameter at breast height and crown depth from crown diameter with greater precision. As for A. Senegal age estimation, the established model is not strong as it can explain only 49.1% of the age variation.

General Structure Physics of an Aerial Remote Sensing Platform and Its Systemic Accuracy Criterion

Accuracy is a key factor in high-resolution remote sensing and photogrammetry. The factors that affect accuracy are imaging system errors and data processing errors. Due to the complexity of aerial camera errors, this paper focuses on the design of digital aerial camera systems and the means to reduce system error and data processing inefficiencies. There are many kinds of digital aerial camera systems at present;however, these systems lack a unified physical model, which ultimately leads to more complicated designs and multi-camera modes. Such a system is complex and costly, as it is easily affected by factors such as vibration and temperature. Thus, the installed accuracy can only reach the millimeter level. Here, we describe a unified physical structure for a digital aerial camera that imitates an out-of-field multi-charge-coupled device (CCD), an in-field multi-CCD, and once-imaging and twice-imaging digital camera systems. This model is referred to as the variable baseline-height ratio spatiotemporal model. The variable ratio allows the opto-mechanical spatial parameters to be linked with height accuracy, thus providing a connection to the surface elevation. The twice-imaging digital camera prototype system and the wideband limb imaging spectrometer provide a transformation prototype from the current multi-rigid once-imaging aerial camera to a single rigid structure. Thus, our research lays a theoretical foundation and prototype references for the construction and industrialization of digital aerial systems.

Three-Dimensional Thermo-Elastic-Plastic Finite Element Method Modeling for Predicting Weld-Induced Residual Stresses and Distortions in Steel Stiffened-Plate Structures

The objective of the present paper is to develop nonlinear finite element method models for predicting the weld-induced initial deflection and residual stress of plating in steel stiffened-plate structures. For this purpose, three-dimensional thermo-elastic-plastic finite element method computations are performed with varying plate thickness and weld bead length (leg length) in welded plate panels, the latter being associated with weld heat input. The finite element models are verified by a comparison with experimental database which was obtained by the authors in separate studies with full scale measurements. It is concluded that the nonlinear finite element method models developed in the present paper are very accurate in terms of predicting the weld-induced initial imperfections of steel stiffened plate structures. Details of the numerical computations together with test database are documented.

Considering for the blanket structure scheme of HCCB DEMO

For the solid blanket concept of helium cooled ceramic breeder (HCCB) demonstration fusion power plant (DEMO), a feasible blanket structure with configuration 2×X is proposed as considering relatively low temperature limit of neutron multiplier beryllium pebbles. Based on that, preliminary design for the typical blanket module of HCCB DEMO has been carried out and verified by thermal-hydraulic analysis and structural analysis. Furthermore, the specific relationship of maximum temperature depended on the surface heating of blanket key part first wall (FW) is also analyzed.

CRUST AND UPPER STRUCTURE OF QINGHAI-TIBET PLATEAU AND ITS ADJACENT REGIONS FROM SURFACE WAVEFORM INVERSION

In this paper,218 long period Rayleigh wave records from 7 seismic station of CDSN are selected.We applied a partitioned waveform inversion to these data in order to construct a 3\|D model of shear velocity down to 400km depth in the crust and upper mantle of Qinghai\|Tibet plateau and Its Adjacent Regions (22°～44°N,70°～110°E).The first step of the waveform inversion used involved the matching of the waveforms of fundamental and highermost Ravleigh waves with waveforms synthesized from stratified models;in the second stage,the 3\|D model was constructed by solve linear constrains equation. The major structural features inferred from the surface waveform inversions can be summarized as follows:(1) There is a great contrast between surface waveform through Qinghai—Thibet plateau and the others.Main frequency of the former is lower than the latter, which indicate the crust depth of Qinghai—Tibet plateau is deeper than the others. In addition,the amplitude of about 30s period and 50s period is lower than both sides,which implied these exist lower velocity layer at about 25km depth and about 50km depth in Qinghai—Tibet plateau Crust.The former is common,the latter was argued because resolution of most method can not prove it.

Stand Structure, Diversity and Regeneration Status of Woody Species in Open and Exclosed Dry Woodland Sites around <i>Molapo</i>Farming Areas of the Okavango Delta, Northeastern Botswana

Stand structure, diversity and regeneration status of woody species were investigated in open and exclosed dry woodland sites in Island Safari, Shorobe and Xobe, northeastern Botswana. A total of 105, 111 and 130 quadrats, measuring 20 × 20 m each, were laid down along parallel line transects in the three sites, respectively, to collect data. A total of 47 species, representing 16 families and 24 genera, were recorded in the study sites. Of these, 33 species representing 13 families and 20 genera, 41 species representing 15 families and 23 genera and 27 species representing 10 families and 14 genera were encountered in Island Safari, Shorobe and Xobe, respectively. The most diverse family was Fabaceae followed by Combretaceae and Tiliaceae at all the three sites. The most diverse genus was Acacia, followed by Combretum and Grewia. The diversity of woody species in the study sites were 2.18, 2.15 and 1.5 in Shorobe, Island Safari and Xobe, respectively, while their corresponding evenness values were 0.6, 0.6 and 0.5, respectively. The mean densities of the woody species encountered in Island Safari, Shorobe and Xobe were 2629, 4271 and 2745 individuals ha&#451, respectively. The five densest species were Colophospermum mopane, Dichrostachys cinerea, Acacia tortilis, Philenoptera violacea and Terminalia prunioides in Island Safari, C. mopane, A. tortilis, A. erioloba, P. violacea and D. cinerea in Shorobe and Acacia mellifera, A. tortilis, P. nelsii, A. luederitzii and A. erubescens in Xobe. The highest important value index values were exhibited by C. mopane, D. cinerea, A. tortilis, P. violacea and T. prunioides in Island Safari, C. mopane, A. erioloba, A. tortilis, P. violacea and C. imberbe in Shorobe, and A. mellifera, A. tortilis, P. nelsii and A. luederitzii in Xobe. The alarming result was the fact that 71%, 80% and 85% of the woody species recorded in Island Safari, Shorobe and Xobe, respectively, exhibited hampered regeneration and, thus, unhealthy population structures. Therefore, there is an urgent need to address the observed unhealthy population structures of the woody species through investigation of the major causes of their hampered regeneration, and also designing measures that will facilitate natural and artificial regeneration of these species at the three study sites.

Determining relative block structure rating for rock erodibility evaluation in the case of non-orthogonal joint sets

The most commonly used method for assessing the hydraulic erodibility of rock is Annandale's method.This method is based on a correlation between the erosive force of flowing water and the capacity of rock resistance. This capacity is evaluated using Kirsten's index, which was initially developed to evaluate the excavatability of earth materials. For rocky material, this index is determined according to certain geomechanical factors related to intact rock and rock mass, such as compressive strength of intact rock, rock block size, discontinuity shear strength and relative block structure. To quantify the relative block structure, Kirsten(1982) developed a mathematical expression that accounts for the shape and orientation of the blocks relative to the direction of flow. Kirsten's initial concept for assessing the relative block structure considers that the geological formation is mainly fractured by two joint sets forming an orthogonally fractured system. An adjusted concept is proposed to determine the relative block structure when the fractured system is non-orthogonal where the angle between the planes of the two joint sets is greater or less than 90°. An analysis of the proposed relative block structure rating shows that considering a non-orthogonally fractured system has a significant effect on Kirsten's index and, as a consequence, on the assessment of the hydraulic erodibility of rock.