Multiple Stop Research Articles

Classification, main types of structures and purpose of capillary means to ensure fuel perfection

The flight of a spacecraft is characterized by the alternation of active sections of the trajectory, when the propulsion system is operating, and passive sections, in which the liquid components of the fuel in the tanks are under the influence of microgravity and, as a result, various disturbing factors (actions: aerodynamic forces, solar wind, internal gravitational forces, disturbances from the engines of the orientation and stabilization system, etc.) can occupy any position in them. At the same time, the situation is not ruled out when the gas phase can get into the flow line, which in the future can lead to a failure to restart the propulsion system and an emergency end of the mission. Therefore, an almost obligatory element of the systems for storing and supplying liquid rocket fuel components of the propulsion system of a spacecraft is the means of ensuring fuel continuity, the main criterion for the perfection of which is the amount of residual fuel components that cannot be produced due to a violation of the fluid continuity at the inlet to the propulsion system. The design of the fuel continuity means is directly determined by the internal geometry of the tank and the characteristics of the pneumohydraulic system of the spacecraft. A significant complication of the design of the fuel continuity means occurs in the presence of several factors that are present when a spacecraft performs a flight task: multiple launch and stop of the propulsion system, performing complex maneuvers under conditions of multidirectional external force impulses, which is just inherent in spacecraft. The position uncertainty and heterogeneity of the boundaries between the boost gas and fuel components at the time of launching the propulsion system require additional measures to prevent premature gas breakthrough into the flow line with its subsequent entry into the propulsion system. Therefore, over more than five decades, fuel continuity tools have been developed, the operation of which is based on various principles. At the same time, capillary-type fuel continuity means are most widely used. During this time, the basic physical principles of the behavior of a liquid under the action of capillary forces under weightless conditions were studied, the main types of designs of means for ensuring fuel continuity were determined, and the range of tasks they solved was described.

Investigating the impact of stop network designs on DRT operation

Modern on-demand mobility concepts have the potential to drive the mobility transition. Increasing attention is being paid to DRT (Demand Responsive Transportation) services that enable the bundling of trips with the help of dynamic routing algorithms. Many providers use a stop-based operating concept for this purpose. The transport between so-called virtual stops promises a higher fraction of shared trips and shorter vehicle detours. The aim of this paper is to investigate multiple stop network designs and their impacts on the efficiency of the operation. For this purpose, three stop network generation approaches were derived from literature and applied to the simulation environment MATSim. A scenario in the city center of Berlin is simulated, where all inner car trips are replaced by DRT. Comparing the stop network design against a door-to-door service, the results suggest a trade-off between a reduction of vehicle kilometers (up to 18%) and increased walking distances (up to 250 meters on average).

Recombination hotspots in Neurospora crassa controlled by idiomorphic sequences and meiotic silencing.

Genes regulating recombination in specific chromosomal intervals of Neurospora crassa were described in the 1960s, but the mechanism is still unknown. For each of the rec-1, rec-2, and rec-3 genes, a single copy of the putative dominant allele, for example, rec-2SL found in St Lawrence OR74 A wild type, reduces recombination in chromosomal regions specific to that gene. However, when we sequenced the recessive allele, rec-2LG (derived from the Lindegren 1A wild type), we found that a 10 kb region in rec-2SL strains was replaced by a 2.7 kb unrelated sequence, making the "alleles" idiomorphs. When we introduced sad-1, a mutant lacking the RNA-dependent RNA polymerase that silences unpaired coding regions during meiosis into crosses heterozygous rec-2SL/rec-2LG, it increased recombination, indicating that meiotic silencing of a gene promoting recombination is responsible for dominant suppression of recombination. Consistent with this, mutation of rec-2LG by Repeat-Induced Point mutation generated an allele with multiple stop codons in the predicted rec-2 gene, which does not promote recombination and is recessive to rec-2LG. Sad-1 also relieves suppression of recombination in relevant target regions, in crosses heterozygous for rec-1 alleles and in crosses heterozygous for rec-3 alleles. We conclude that for all 3 known rec genes, 1 allele appears dominant only because meiotic silencing prevents the product of the active, "recessive," allele from stimulating recombination during meiosis. In addition, the proposed amino acid sequence of REC-2 suggests that regulation of recombination in Neurospora differs from any currently known mechanism.

Physics-informed discrete element modeling for the bandgap engineering of cylinder chains

We propose an efficient method to build a simple discrete element model (DEM) that accurately simulates the oscillation of a continuum beam. The DEM is based on the Timoshenko beam theory of slender cylindrical members and their corresponding wave dynamics in assembly. This physics-informed DEM accounts for multiple vibration modes of the constituting beam elements in wide frequency ranges. We construct various DEMs mimicking cylinder chains and compare their wave dynamics with those measured in experiments to validate the proposed method. Furthermore, we construct a graded woodpile chain of slender cylinders. We experimentally and numerically investigate the frequency bandgaps of the system and demonstrate the possibility of constructing a wide bandgap by consecutively superposing multiple stop bands generated from cylinders of various lengths. This system is highly efficient in blocking propagating waves by leveraging the vibration isolation effect stemming from the local resonance of the cylinders. The proposed DEM method can be useful for investigating and designing complex vibration systems in an efficient and accurate manner. Moreover, the design approach of manipulating the frequency bandgap can be exploited for developing vibration filters and impact mitigation devices.

Combustion behavior of electrically controlled solid propellant with tungsten additive

In recent times, there is a growing interest in utilizing the controllable solid propellant combustion that facilitates multiple start and stop bits of the electrically controlled solid propellant (ECSP) combustion at will. This paper is an attempt to understand the effect of tungsten metal additive in the ECSP. The tungsten metal powder (1 μm size) is blended with the lithium perchlorate (LP) and polyvinyl alcohol (PVA) along with other ingredients. LP and PVA form the baseline composition, and metal content is added between 5 and 15% by weight. Thermal analysis of the ECSP samples were conducted at 5 °C/min utilizing differential scanning calorimetry (DSC) and thermogravimetry (TGA) in the temperature range of 30 °C–600 °C, and the results showed that the dominant exothermic peaks occur around 260 °C. High speed imaging facilitates in understanding the combustion characteristics of the ECSP samples. The ignition is achieved by applying 300 V DC supply across the molybdenum electrodes. ECSP combustion can be divided into two distinct phases of burning that can be designated as the transient burning and the steady phase burning. It is found that the burning rate was 38.2% faster for 15%-metalized ECSP than 5%-metalized. In addition, multi-wavelength pyrometry was used to obtain the average flame temperature, and it was observed that the flame temperature was 9% lower for 15%-metalized than 5%-metalized. Hence, this study enunciates the burning characteristics of tungsten based ECSP and helps in realizing the potential use of tungsten as a metal additive in the ECSP for micro thrust generation.

Genome and Transcriptome Analyses Facilitate Genetic Control of Wohlfahrtia magnifica, a Myiasis-Causing Flesh Fly.

Myiasis caused by Wohlfahrtia magnifica is a widespread parasitic infestation in mammals. The infested host suffers from damage as the developing larvae feed on its tissues. For the control of myiasis infestation, genetic methods have been shown to be effective and promising as an alternative to insecticides. Combining genome, isoform sequencing (Iso-Seq), and RNA sequencing (RNA-seq) data, we isolated and characterized two sex-determination genes, W. magnifica transformer (Wmtra) and W. magnifica transformer2 (Wmtra2), whose orthologs in a number of insect pests have been utilized to develop genetic control approaches. Wmtra transcripts are sex-specifically spliced; only the female transcript encodes a full-length functional protein, while the male transcript encodes a truncated and non-functional polypeptide due to the presence of the male-specific exon containing multiple in-frame stop codons. The existence of five predicted TRA/TRA2 binding sites in the male-specific exon and the surrounding intron of Wmtra, as well as the presence of an RNA-recognition motif in WmTRA2 may suggest the auto-regulation of Wmtra by its own protein interacting with WmTRA2. This results in the skipping of the male-specific exon and translation of the full-length functional protein only in females. Our comparative study in dipteran species showed that both the WmTRA and WmTRA2 proteins exhibit a high degree of similarity to their orthologs in the myiasis-causing blow flies. Additionally, transcriptome profiling performed between adult females and adult males reported 657 upregulated and 365 downregulated genes. Functional analysis showed that among upregulated genes those related to meiosis and mitosis Gene Ontology (GO) terms were enriched, while, among downregulated genes, those related to muscle cell development and aerobic metabolic processes were enriched. Among the female-biased gene set, we detected five candidate genes, vasa (vas), nanos (nanos), bicoid (bcd), Bicaudal C (BicC), and innexin5 (inx5). The promoters of these genes may be able to upregulate Cas9 expression in the germline in Cas9-based homing gene drive systems as established in some flies and mosquitoes. The isolation and characterization of these genes is an important step toward the development of genetic control programs against W. magnifica infestation.

Multi-channel THz perfect absorber using graphene-based Fibonacci photonic crystals

A graphene-based multi-channel THz perfect absorber is proposed in this paper. The absorber consists of a graphene layer, a Fibonacci quasi-periodic layer, a spacer, and a substrate. We demonstrate that the structure we proposed can lead to multi-channel perfect THz absorption because of the graphene surface plasmon polaritons and multiple photonic stop bands in this structure. The multi-channel working frequencies and absorption peaks can be flexibly tuned by controlling the incidence angle, size of component materials, and Fermi energy. Moreover, by adjusting the Fibonacci quasi-period orders of the structure, the number of working channels can be flexibly expanded without reoptimizing the structure size. Moreover, by adjusting the Fibonacci quasi-period orders of the structure, the number of working channels can be flexibly expanded without reoptimizing the structure size. Using existing technology, our design scheme is easy to realize, which will be helpful to promote the development and application of novel tunable optoelectronic devices.

Gene editing in the nematode parasite Nippostrongylus brasiliensis using extracellular vesicles to deliver active Cas9/guide RNA complexes

Despite recent advances, animal-parasitic nematodes have thus far been largely refractory to genetic manipulation. We describe here a new approach providing proof of principle that CRISPR/Cas9-mediated gene editing of parasitic nematodes is achievable using vesicular stomatitis virus glycoprotein-pseudotyped extracellular vesicles for the delivery of Cas9-single guide ribonucleoprotein complexes. We demonstrate that extracellular vesicle-delivered ribonucleoproteins can be used to disrupt a secreted deoxyribonuclease in Nippostrogylus brasiliensis. Introduction of a repair template encoding multiple stop codons led to measurable reduction in expression of the targeted gene. Altered transcripts corresponding to the edited locus were detected by RT-PCR, demonstrating that vesicles can access cells of tissues actively expressing the gene of interest. These data provide evidence that this technique can be employed for targeted gene editing in N. brasiliensis, making this species genetically tractable for the first time, although further refinement will be necessary for routine and robust interrogation of gene function.

A Qualitative Study to Explore the Employment Experiences and Perspectives of Women Living with Multiple Sclerosis in the UK

Employment is a key determinant of health, yet up to 80% of individuals with multiple sclerosis stop work within 15 years of diagnosis. The unpredictable nature of MS, both on a daily basis, and longer term means that maintaining employment can be difficult. Multiple sclerosis affects women disproportionately (> 60% of cases) and they often experience greater workplace challenges, yet few studies explore this. This study aimed to deepen understanding of the employment experiences and perspectives of women with multiple sclerosis to help inform future policy developments and care. A descriptive phenomenological approach was used involving thematic analysis from fourteen in-depth semi-structured interviews (data collected 2020). The inclusion criteria were adult women diagnosed with multiple sclerosis living in the UK who have current or previous experiences of employment. Seven themes were identified: Multiple sclerosis symptoms, workplace support, adjustments in the workplace, prioritisation of employment, making compromises, time and informal networks. These themes offer a descriptive account of the participant’s experiences of work, how they experience their multiple sclerosis in relation to employment and some of the constraints and enablers to work. The findings highlight the importance of both individual and broader socio-environmental factors to successful employment outcomes. Tailored community support for these women, such as that provided by nurses, was considered central. There is a need for better collaboration at a policy level between government departments and for more research into women with chronic conditions, to further explore the relationship between different variables.

Low-valent tungsten redox catalysis enables controlled isomerization and carbonylative functionalization of alkenes.

The controlled isomerization and functionalization of alkenes is a cornerstone achievement in organometallic catalysis that is now widely used throughout industry. In particular, the addition of CO and H2 to an alkene, also known as the oxo-process, is used in the production of linear aldehydes from crude alkene feedstocks. In these catalytic reactions, isomerization is governed by thermodynamics, giving rise to functionalization at the most stable alkylmetal species. Despite the ubiquitous industrial applications of tandem alkene isomerization/functionalization reactions, selective functionalization at internal positions has remained largely unexplored. Here we report that the simple W(0) precatalyst W(CO)6 catalyses the isomerization of alkenes to unactivated internal positions and subsequent hydrocarbonylation with CO. The six- to seven-coordinate geometry changes that are characteristic of the W(0)/W(II) redox cycle and the conformationally flexible directing group are key factors in allowing isomerization to take place over multiple positions and stop at a defined unactivated internal site that is primed for in situ functionalization.

Enhanced Codon-Anticodon Interaction at In-Frame UAG Stop Codon Improves the Efficiency of Non-Natural Amino Acid Mutagenesis.

The introduction of non-natural amino acids into proteins through the stop codon readthrough methodology has been used to design proteins for diverse applications. However, this method suffers from low yields of the modified protein, as the suppressor tRNA that recognizes the stop codon is unable to compete effectively with release factor 1 (RF1), which terminates translation. We reasoned that a suppressor tRNA with improved interaction with the UAG stop codon on the mRNA will be able to compete more effectively with RF1. To test this idea, we inserted two 2,6-diaminopurine (D) units in the tRNA anticodon stem loop, including one at the third position of the tRNA anticodon. The modified suppressor tRNA could potentially form additional H-bonds between the N2-exocyclic amine of D and the C2 carbonyl group of uracil, thereby enhancing mRNA-tRNA interaction and/or altering tRNA conformation. The stronger interaction at the codon-anticodon interface resulted in improved UAG decoding efficiency and a higher yield of the modified protein containing a non-natural amino acid at multiple sites. Our findings are consistent with the importance of hydrogen bonding and tRNA conformation at the tRNA-mRNA duplex interface during in-frame UAG suppression, which improves protein translation at multiple UAG stop sites. This work provides valuable inputs toward improved non-natural amino acid mutagenesis for creating designer proteins.

Actively tuning of transverse wave band gaps in hybrid sandwich beam metamaterials with shunted piezoelectric array and inertial amplification mechanism

In this paper, a tunable sandwich beam metamaterial is designed by implementing a hybrid project composed of the piezoelectric shunted array technique and the inertial amplification mechanism. Concerned with the shunted piezoelectric constitutive relation, the kinematic analysis of added mechanism and the transverse motion of base structure, a theoretical model is established to estimate the band gap characteristics of the sandwich beam lined with pyramidal truss cores using the transfer matrix method, whose accuracy is further validated by the finite element simulations. Numerical results show that multiple stop bands are generated at low frequencies owing to the mechanisms of electromechanical resonance, amplifying inertia and mechanical resonance, certainly enhancing the level of vibration suppression. Subsequently, a comprehensive parametric analysis is conducted to investigate the influences of the shunting circuits and attached mechanism on the attenuation diagrams. It is demonstrated that the hybrid sandwich lattice can offer more tunable space to acquire ultra-broad band gaps. Furthermore, based on the design potential, the amplitudes and bandwidths of the attenuation region are maximized by operating an optimization study. Such advanced attenuation performance can be applied for a wide range of engineering applications.

Radiometric analysis of digitized Z-scope records in archival radar sounding film

AbstractThe earliest airborne geophysical campaigns over Antarctica and Greenland in the 1960s and 1970s collected ice penetrating radar data on 35 mm optical film. Early subglacial topographic and englacial stratigraphic analyses of these data were foundational to the field of radioglaciology. Recent efforts to digitize and release these data have resulted in geometric and ice-thickness analysis that constrain subsurface change over multiple decades but stop short of radiometric interpretation. The primary challenge for radiometric analysis is the poorly-characterized compression applied to Z-scope records and the sparse sampling of A-scope records. Here, we demonstrate the information richness and radiometric interpretability of Z-scope records. Z-scope pixels have uncalibrated fast-time, slow-time, and intensity scales. We develop approaches for mapping each of these scales to physical units (microseconds, seconds, and signal to noise ratio). We then demonstrate the application of this calibration and analysis approach to a flight in the interior of East Antarctica with subglacial lakes and to a reflight of an East Antarctic ice shelf that was observed by both archival and modern radar. These results demonstrate the potential use of Z-scope signals to extend the baseline of radiometric observations of the subsurface by decades.

Sequence Diversity, Locus Structure, and Evolutionary History of the SpTransformer Genes in the Sea Urchin Genome.

The generation of large immune gene families is often driven by evolutionary pressure exerted on host genomes by their pathogens, which has been described as the immunological arms race. The SpTransformer (SpTrf) gene family from the California purple sea urchin, Strongylocentrotus purpuratus, is upregulated upon immune challenge and encodes the SpTrf proteins that interact with pathogens during an immune response. Native SpTrf proteins bind both bacteria and yeast, and augment phagocytosis of a marine Vibrio, while a recombinant SpTrf protein (rSpTrf-E1) binds a subset of pathogens and a range of pathogen associated molecular patterns. In the sequenced sea urchin genome, there are four SpTrf gene clusters for a total of 17 genes. Here, we report an in-depth analysis of these genes to understand the sequence complexities of this family, its genomic structure, and to derive a putative evolutionary history for the formation of the gene clusters. We report a detailed characterization of gene structure including the intron type and UTRs with conserved transcriptional start sites, the start codon and multiple stop codons, and locations of polyadenylation signals. Phylogenetic and percent mismatch analyses of the genes and the intergenic regions allowed us to predict the last common ancestral SpTrf gene and a theoretical evolutionary history of the gene family. The appearance of the gene clusters from the theoretical ancestral gene may have been driven by multiple duplication and deletion events of regions containing SpTrf genes. Duplications and ectopic insertion events, indels, and point mutations in the exons likely resulted in the extant genes and family structure. This theoretical evolutionary history is consistent with the involvement of these genes in the arms race in responses to pathogens and suggests that the diversification of these genes and their encoded proteins have been selected for based on the survival benefits of pathogen binding and host protection.

Multiple band gaps for efficient wave attenuation by inertial amplification in periodic functionally graded beams

With the purpose of obtaining complete stop bands which allow one isolate both longitudinal and transverse vibrations in functionally graded beams, this paper adopts the inertial amplification mechanisms via attaching them on the base beam whose material properties are described by the power-law function to study the nature of propagation and attenuation characteristics. The dynamic model of the inertial amplification mechanism is developed to capture inertial forces when the coupled axial-bending deformation is present in the base structure. By employing the principle of the virtual work and the Bloch theory, a discrete formulation is presented to exploit the complex band diagram. Numerical analyses show that multiple stop bands whose attenuation performances are comparable to that of resonance gaps can be obtained, demonstrating the efficiency on suppressing wave propagation over a wide frequency band, which is helpful to expand the range of engineering applications with functionally graded materials for vibration and sound reduction. Furthermore, the effects of the geometrical characteristics of attached substructure, power-law index and material damping are investigated.

Optimization of connection architectures and mass distributions for metamaterials with multiple resonators

Metamaterials with multiple resonators have been widely investigated for the purpose of generating multiple stop bands or broadening the attenuation bandwidth. The multiple resonators could be connected end to end in a line, namely, in-series connection, or connected individually to the host structures, namely, in-parallel connection. This paper investigates the influence of the resonator connection methodology on the frequency response functions of metamaterial beams with multiple resonators and exhibits an approach for optimizing their resonator distribution over the structure. The receptance functions of metamaterial beams with various resonator connection architectures are calculated by a transfer matrix model, which is verified through finite element model results. It is demonstrated that resonator interconnection architectures have a great impact on the global dynamic properties of metamaterials. An optimization strategy is subsequently proposed to find out the optimal resonator connection architectures and mass distributions that could minimize the maximal receptance functions in targeted single and multiple frequency ranges. The objective functions within single targeted frequency ranges are solved by the adoption of the genetic algorithm method. The weighted sum method is used to gain an optimal solution for multi-frequency range optimization. The metamaterial beams with optimal resonator connection methods and mass distributions demonstrate greatly enhanced vibration attenuation at frequencies of interest compared with other beams. The work is expected to provide the necessary theoretical basis and incentive for future researchers working on the design of metamaterials with extended, tuned, and optimized stop bands.

Does alcohol cue inhibitory control training survive a context shift?

Inhibitory control training (ICT) is a novel psychological intervention that aims to improve inhibitory control in response to alcohol-related cues through associative learning. Laboratory studies have demonstrated reductions in alcohol consumption following ICT compared with control/sham training, but it is unclear if these effects are robust to a change of context. In a preregistered study, we examined whether the effects of ICT would survive a context shift from a neutral context to a seminaturalistic bar setting. In a mixed design, 60 heavy drinkers (40 female) were randomly allocated to receive either ICT or control/sham training in a neutral laboratory over 2 sessions. We developed a novel variation of ICT that used multiple stop signals to establish direct stimulus–stop associations. The effects of ICT/control were measured once in the same context and once following a shift to a novel (alcohol-related) context. Our dependent variables were ad libitum alcohol consumption following training, change in inhibitory control processes, and change in alcohol value. ICT did not reduce alcohol consumption in either context compared with the control group. Furthermore, we demonstrated no effects of ICT on inhibitory control processes or alcohol value. Bayesian analyses demonstrated overall support for the null hypotheses. This study failed to find any effects of ICT on alcohol consumption or candidate psychological mechanisms. These findings illustrate the difficulty in training alcohol-inhibition associations and add to a growing body of literature suggesting that ICT holds little evidential value as a psychological intervention for alcohol use disorders.

Expression of enzymes for 3'-phosphoadenosine-5'-phosphosulfate (PAPS) biosynthesis and their preparation for PAPS synthesis and regeneration.

The synthesis of sulfated polysaccharides involves the sulfation of simpler polysaccharide substrates, through the action sulfotransferases using the cofactor, 3'-phosphoadenosine-5'-phosphosulfate (PAPS). Three enzymes are essential for the in vitro synthesis of PAPS, namely, pyrophosphatase (PPA), adenosine 5'-phosphosulfate kinase (APSK), and ATP sulfurylase (ATPS). The optimized enzyme expression ratio and effect on PAPS synthesis were evaluated using ePathBrick, a novel synthetic biology tool that assemble multiple genes in a single vector. The introduction of multiple promoters and stop codons at different location enable the bacterial system to fine tune expression level of the genes inserted. Recombinant vectors expressing PPA (U39393.1), ATPS (CP021243.1), and PPA (CP047127.1) were used for fermentations and resulted in volumetric yields of 400-1380 mg/L with accumulation of 34-66% in the soluble fraction. The enzymes from soluble fraction, without any further purification, were used for PAPS synthesis. The PAPS was used for the chemoenzymatic synthesis of a heparan sulfate polysaccharide and coupled with a PAPS-ASTIV regeneration system. ASTIV catalyzes the regeneration of PAPS. A recombinant vector expressing the enzyme ASTIV (from Rattus norvegicus) was used for fermentations and resulted in volumetric yield of 1153 mg/L enzyme with accumulation of 48% in the soluble fraction. In conclusion, we have successfully utilized a metabolic engineering approach to optimize the overall PAPS synthesis productivity. In addition, we have demonstrated that the ePathBrick system could be applied towards study and improvement of enzymatic synthesis conditions. In parallel, we have successfully demonstrated an autoinduction microbial fermentation towards the production of mammalian enzyme (ASTIV). KEY POINTS : • ePathBrick used to optimize expression levels of enzymes. • Protocols have been used for the production of recombinant enzymes. • High cell density fed-batch fermentations with high yields of soluble enzymes. • Robust fermentation protocol successfully transferred to contract manufacturing and research facilities.

Integrated optimization of train stop planning and timetabling for commuter railways with an extended adaptive large neighborhood search metaheuristic approach

Train stop plans and timetables play key roles in railway operation. Previous research has demonstrated that their integration can significantly improve the quality of a train timetable, especially for commuter railways with flexible service frequencies and multiple stop plans. However, solving the dilemma of the mathematical tractability and practicality of the model is still an open challenge. To obtain a high-quality timetable and simultaneously consider more realistic conditions, an integrated combination optimization model of both train stop plans and timetables under time-dependent passenger demand is proposed in this article. More realistic conditions, such as no predefined schedule, a variable total number of trains and oversaturation, are taken into account. The problem is modeled as a mixed-integer nonlinear programming problem (MINLP) to optimize passenger travel efficiency and mainly consists of (1) the total waiting time at stations, (2) the delay time for trains due to a train stop, and (3) the minimization of the total train running time. An extended adaptive large-scale neighborhood search (ALNS) algorithm is developed to solve the problem. A numerical experiment is designed to test the validity of the model and the algorithm. Then, the integrated approach is applied in a real-world case. The results show that the proposed approach can simultaneously reduce the passenger total waiting time and delay time as well as the train running time within a short computation time and demonstrate the effectiveness of the model and the approach.

Phononic band gaps by inertial amplification mechanisms in periodic composite sandwich beam with lattice truss cores

In order to acquire multiple and wider stop bands in periodic sandwich lattice, this work applies the inertial amplification mechanisms to the composite sandwich beam with pyramidal truss cores and presents a theoretical study on the wave propagation characteristics of the proposed sandwich lattice. An analytical model based on the plane wave expansion method and the Galerkin method is developed to investigate the dispersion relation of transverse waves propagating through the sandwich beam, whose validity is verified by the numerical simulations of spatial decaying performance predicted by the finite element method. Numerical results of complex band structures show that the proposed sandwich beam can obtain multiple stop bands and possess much wider bandwidth. Employing the developed model, the effects of varying attached substructure, the layout of truss members and the material damping on the attenuation performance are discussed to show the flexibility and to obtain thorough understanding of the system.