Syntactic Composition Research Articles

Fishing line artificial muscle reinforced composite for impact mitigation and on-demand damage healing

In this study, a fishing line artificial muscle reinforced syntactic foam composite was investigated. About 3.5 vol.% of polymer artificial muscle was woven into a two-dimensional grid skeleton and embedded into a syntactic foam matrix. The grid-stiffened syntactic foam composite was designed to be able to repeatedly heal cracks on-demand. Short thermoplastic fibers were also dispersed into the foam matrix both as reinforcement and as a healing agent. The composite panel was repeatedly impacted, bending fractured, and healed as per the biomimetic close-then-heal strategy. It is found that the composite panel responds to impact quasi-statically. The impact- and bending-induced macroscopic cracks can be repeatedly healed with high healing efficiency, under both free and clamped boundary conditions. Contrary to most healing systems, the healing efficiency within the damage–healing cycles in this study increases as the damage-healing cycle increases. Because the artificial muscle is made of low-cost and high-strength fishing line, it is envisioned that the composite panel developed in this study may be a viable alternative core for healable lightweight composite sandwich structures at competitive cost.

Adjective conjunction as a window into the LATL’s contribution to conceptual combination

Though a large literature implicates the left anterior temporal lobe (LATL) for combinatory operations, recent MEG studies have suggested that it is specifically involved in the composition of complex concepts, rather than syntactic or semantic composition in a more general sense. To further specify the computational contribution of the LATL, we tested whether LATL effects as observed in MEG require a situation in which features combine to form a single coherent entity representation or whether the relevant computation simply requires the attribution of features to a set but not necessarily to the same members of the set. Under the former hypothesis, the LATL would be sensitive to the number of features added to the representation of a single entity whereas under the latter account, LATL activity would reflect the total number of features integrated across different members of a set. To test this, we employed conjunctions of two adjectives whose lexical semantics were varied such that they either allowed or disallowed the attribution of their denoted properties to the same members of a set, i.e., the properties were either compatible or incompatible. The compatible properties resulted in so-called intersective and the incompatible in so-called collective readings. Our results show that the LATL tracks the number of features attributed to an individual as opposed to the number of features attributed to a set. Interestingly, the reverse pattern was found in the right ATL, demonstrating that although this region often shows parallel effects to the LATL, its functional contribution is clearly distinct.

Effects of ageing on mechanical properties of stiffened syntactic foam core sandwich composites for marine applications

Foam core based sandwich composite materials are extensively used in marine sectors because of its high strength and stiffness to weight ratios. The structural materials used for marine applications should possess good damage tolerance capability. Hence, it is essential that these materials shall be tested for their residual mechanical properties when exposed to marine environment. In the present work, syntactic foam is prepared by uniform mixing of dry fly ash cenosphere and phenolic resin in equal proportions. Syntactic foam is further stiffened by integrating it with honeycomb structure during manufacturing. Sandwich composites are developed with core of syntactic foam (with and without honeycomb structure) and face skins of glass/epoxy composite. Sandwich coupons are prepared in two batches; one being subjected to ageing in natural sea water and other under accelerated environment. Both aged and unaged coupons are subjected to mechanical tests to determine their residual properties under compression, flexure, and low-velocity impact as per ASTM standards. Results showed that the moisture absorption is significant up to about 60 days beyond which it is marginal. The saturation level was attained for an immersion period of about one year, at which the material exhibited significant damage, at the interfacial regions of core-skin, cenosphere-phenolic resin, and fiber-matrix. Ageing of sandwich composites under sea water and accelerated environment has shown detrimental effect on their mechanical properties. However, the extent of degradation in properties due to ageing can be reduced by the incorporation of resin impregnated honeycomb structure in syntactic foam. Microscopic features of aged coupons are also investigated to predict mode of damage due to ageing.

Aerogel-filled metals: a syntactic cellular material

A new filler material is presented and tested to produce light-weight aluminium alloy composites: the pore space between nano-structured silica-aerogel granulates is infiltrated with Al-alloy melts. Since these filler materials have vanishing density (100 kg m−3), they need not to be removed from the final cast product. Their shape, size and volume fraction determine the materials' properties. Different methods were used to prepare metal-aerogel syntactic foam composites: centrifugal casting, squeeze and suction casting. The last method gave the best results, using an Al–11Si melt. We produced circular and rectangular bars up to 500-mm length. The composite material has a density of around 900 kg m−3, a yield stress of 8 MPa and absorbs 8 kJ kg−1 mechanical energy.

Mechanical behavior of pure Al and Al–Mg syntactic foam composites containing glass cenospheres

Glass cenospheres were used as space holders for making aluminum matrix syntactic foams by pressure infiltration technique. The mechanical properties and failure behavior of cenospheres/Al syntactic foams with pure Al and Al–Mg alloys were investigated in the present work. The failure behavior of cenospheres in two syntactic foams was similar. However, the mechanical behavior of these two syntactic foams was different. Under compression process, the cenospheres/pure Al showed discontinuous shear band and drum shape, while cenospheres/Al–Mg exhibited continuous shear band and was divided by main shear zone. At the tensile state, the cenospheres in pure Al matrix syntactic foam debonded from the matrix, while the cenospheres in Al–Mg matrix syntactic foam was well-bonded and appeared to lamellar tearing. It is suggested that the difference of mechanical deformation behavior could be attributed to the matrix ductility and the forming of interfacial reaction product MgAl2O4 coatings.

Data characterizing tensile behavior of cenosphere/HDPE syntactic foam.

The data set presented is related to the tensile behavior of cenosphere reinforced high density polyethylene syntactic foam composites “Processing of cenosphere/HDPE syntactic foams using an industrial scale polymer injection molding machine” (Bharath et al., 2016) [1]. The focus of the work is on determining the feasibility of using an industrial scale polymer injection molding (PIM) machine for fabricating syntactic foams. The fabricated syntactic foams are investigated for microstructure and tensile properties. The data presented in this article is related to optimization of the PIM process for syntactic foam manufacture, equations and procedures to develop theoretical estimates for properties of cenospheres, and microstructure of syntactic foams before and after failure. Included dataset contains values obtained from the theoretical model.

An Automated Summarization Assessment Algorithm for Identifying Summarizing Strategies.

BackgroundSummarization is a process to select important information from a source text. Summarizing strategies are the core cognitive processes in summarization activity. Since summarization can be important as a tool to improve comprehension, it has attracted interest of teachers for teaching summary writing through direct instruction. To do this, they need to review and assess the students' summaries and these tasks are very time-consuming. Thus, a computer-assisted assessment can be used to help teachers to conduct this task more effectively.Design/ResultsThis paper aims to propose an algorithm based on the combination of semantic relations between words and their syntactic composition to identify summarizing strategies employed by students in summary writing. An innovative aspect of our algorithm lies in its ability to identify summarizing strategies at the syntactic and semantic levels. The efficiency of the algorithm is measured in terms of Precision, Recall and F-measure. We then implemented the algorithm for the automated summarization assessment system that can be used to identify the summarizing strategies used by students in summary writing.

Simplified syntactic web service composition for flaw less propagation

Simplified syntactic web service composition for flaw less propagation

Connectivity in left-dislocation and the composition of the left periphery

This paper proposes a crosslinguistically uniform analysis of Left-dislocation constructions, according to which left-dislocated XPs are elliptical sentence fragments surfacing in linear juxtaposition to their host clause. The analysis is shown to provide a principled solution toCinque’s Paradox: dislocated XPs are extra-sentential constituents akin to parentheticals while behaving in certain respects as having moved to their surface position from within the host clause, in apparent violation of the boundaries of “sentence grammar” as typically defined. The solution in terms of deletion and endorphoric linkage undermines templatic analyses of the ‘cartographic’ tradition, showing that in at least some cases the “sentential periphery” reflects not syntactic composition but juxtaposition in discourse.

Walter White "aka" Heisenberg. La aparición de un icono cultural*

The fan ar t phenomenon created around the TV series Breaking Bad , issued by AMC between 2008 and 2013, has generated a set of icons of its protagonist, Walter White, played by actor Bryan Cranston. The icons discussed in this paper keep a isography, a set of constant elements in their syntactic composition, and a clear homeomorphism in their functionality to the matrix text from which they arise. The interest of this work focuses on the description of both its features and functions and its emergence until its conversion into what might be called a cultural icon .

Data characterizing flexural properties of Al/Al2O3 syntactic foam core metal matrix sandwich.

Microstructural observations and flexural property datasets are provided for aluminum alloy matrix syntactic foam core sandwich composites. The tests are conducted in three-point bending configuration. The data supplied includes methods used for conducting microscopy and mechanical testing. Raw load–displacement data, which is used to plot stress–strain graphs, obtained during the flexural test is also included. Images from a DSLR camera are stitched together to form a detailed failure sequencing video. Failure of specimens is captured in sequential images using a digital camera. These images are stitched together to develop a video for visualization of failure mechanisms. Calculations are also included for a theoretical model that is used to estimate the flexural properties of the syntactic foam core sandwich.

Query-based multi-documents summarization using linguistic knowledge and content word expansion

In this paper, a query-based summarization method, which uses a combination of semantic relations between words and their syntactic composition, to extract meaningful sentences from document sets is introduced. The problem with current statistical methods is that they fail to capture the meaning when comparing a sentence and a user query; hence there is often a conflict between the extracted sentences and users' requirements. However, this particular method can improve the quality of document summaries because it is able to avoid extracting a sentence whose similarity with the query is high but whose meaning is different. The method is executed by computing the semantic and syntactic similarity of the sentence-to-sentence and sentence-to-query. To reduce redundancy in summary, this method uses the greedy algorithm to impose diversity penalty on the sentences. In addition, the proposed method expands the words in both the query and the sentences to tackle the problem of information limit. It bridges the lexical gaps for semantically similar contexts that are expressed using different wording. The experimental results display that the proposed method is able to improve performance compared with the participating systems in DUC 2006. The experimental results also showed that the proposed method demonstrates better performance as compared to other existing techniques on DUC 2005 and DUC 2006 datasets.

PDLK: Plagiarism detection using linguistic knowledge

Plagiarism is described as the reuse of someone else's previous ideas, work or even words without sufficient attribution to the source. This paper presents a method to detect external plagiarism using the integration of semantic relations between words and their syntactic composition. The problem with the available methods is that they fail to capture the meaning in comparison between a source document sentence and a suspicious document sentence, when two sentences have same surface text (the words are the same) or they are a paraphrase of each other. Therefore it causes inaccurate or unnecessary matching results. However, this method can improve the performance of plagiarism detection because it is able to avoid selecting the source text sentence whose similarity with suspicious text sentence is high but its meaning is different. It is executed by computing the semantic and syntactic similarity of the sentence-to-sentence. Besides, the proposed method expands the words in sentences to tackle the problem of information limit. It bridges the lexical gaps for semantically similar contexts that are expressed in a different wording. This method is also capable to identify various kinds of plagiarism such as the exact copied text, paraphrasing, transformation of sentences and changing of word structure in the sentences. As a result, the experimental results have displayed that the proposed method is able to improve the performance compared with the participating systems in PAN-PC-11. The experimental results also displayed that the proposed method demonstrates better performance as compared to other existing techniques on PAN-PC-10 and PAN-PC-11 datasets.

Syntactic foam core metal matrix sandwich composite: Compressive properties and strain rate effects

The present work is the first attempt to study metal matrix syntactic foam core sandwich composites. The sandwich is studied for microstructure and compressive properties at quasi-static and high strain rates. Under quasi-static compressive conditions, specimens were tested in the flatwise and edgewise orientations. The compressive strength, yield strength and plateau stress were higher in the flatwise orientation. Furthermore, both orientations for the sandwich composites showed a higher specific compressive strength and specific yield strength than the foam core alone. Failure initiated in the particles in the flatwise orientation, but in the carbon fabrics in the edgewise orientation. The results show that the fabric had a reinforcing effect under quasi-static conditions. The high strain rate (HSR) characterization was conducted in the strain rate range 525–845s−1 using a split-Hopkinson pressure bar set-up equipped with a high speed image acquisition system. Within this strain rate range, the compressive strength of the sandwich is similar to that of the syntactic foam core alone. Upon review, the syntactic foam core metal matrix sandwich outperforms most of the syntactic foams in terms of energy absorption and compressive strength at comparable density levels.

Compressive Properties of Syntactic Foam Reinforced by Warp-knitted Spacer Fabric

Syntactic foam composites are widely used as aviation, construction and marine materials because of their high specific strength, specific modulus, damage tolerance and low moisture absorption. The present work aimed to investigate the compression behaviours of syntactic foam reinforced by warp knitted spacer fabric (SF-WKSF). Eight kinds of SF-WKSF samples were produced with warp knitted spacer fabrics of various surface layer structures and parameters including inclination-angle, fineness of spacer yarns, different microballoons types as well as contents. The compression tests were carried out on aMTS material testing system and the compression properties of SF-WKSF were analyzed based on the experimental compressive stress-strain curves and modulus values. It was indicated that the SF-WKSF made with preferable spacer fabric showed higher compressive modulus and yield strength values compared to neat syntactic foam (NSF). The results also demonstrated that all the parameters had significant effects on the compression performances of SF-WKSF. The composites could gain better anti-compression capacities by selecting larger inclination-angle, coarser spacer yarn, denser surface layer structure, higher microballoon density and higher S60HS microballoon contents.

Investigation of the breakdown process of syntactic foam under lightning impulse stress at liquid nitrogen temperature

In superconducting components for electrical power distribution networks liquid nitrogen (LN2) based insulation systems are commonly used. LN2 has a cooling and an insulating function simultaneously. One disadvantage of these insulation systems is the bubble formation within LN2 due to heat losses of the current carrying conductor, which reduces the dielectric strength of the insulation system drastically. An alternative is a solid insulation system where LN2 mainly takes a cooling function. This paper focuses on syntactic foam as a solid insulation system for superconducting power components. Syntactic foam is a composite material consisting of a polymeric matrix and embedded hollow microspheres. Both epoxy resin and unsaturated polyester resin serve as matrix material. The hollow microspheres’ sheath is made from glass or ceramic. Various syntactic foam compositions generated from the mentioned materials are investigated regarding their dielectric strengths under lightning impulse voltage stresses at liquid nitrogen temperatures (LNT). In addition to the experiments, numerical field simulations are carried out to understand the process of breakdown within syntactic foam.

Automatic summarization assessment through a combination of semantic and syntactic information for intelligent educational systems

Summary writing is a process for creating a short version of a source text. It can be used as a measure of understanding. As grading students’ summaries is a very time-consuming task, computer-assisted assessment can help teachers perform the grading more effectively. Several techniques, such as BLEU, ROUGE, N-gram co-occurrence, Latent Semantic Analysis (LSA), LSA_Ngram and LSA_ERB, have been proposed to support the automatic assessment of students’ summaries. Since these techniques are more suitable for long texts, their performance is not satisfactory for the evaluation of short summaries. This paper proposes a specialized method that works well in assessing short summaries. Our proposed method integrates the semantic relations between words, and their syntactic composition. As a result, the proposed method is able to obtain high accuracy and improve the performance compared with the current techniques. Experiments have displayed that it is to be preferred over the existing techniques. A summary evaluation system based on the proposed method has also been developed.

Phenolic‐epoxy matrix curable by click chemistry—synthesis, curing, and syntactic foam composite properties

ABSTRACTAlkyne functional phenolic resin was cured by azide functional epoxy resins making use of alkyne‐azide click reaction. For this, propargylated novolac (PN) was reacted with bisphenol A bisazide (BABA) and azido hydroxy propyloxy novolac (AHPN) leading to triazole‐linked phenolic‐epoxy networks. The click cure reaction was initiated at 40–65°C in presence of Cu2I2. Glass transition temperature (Tg) of the cured networks varied from 70°C to 75°C in the case of BABA‐PN and 75°C to 80°C in the case of AHPN‐PN. DSC and rheological studies revealed a single stage curing pattern for both the systems. The cured BABA‐PN and AHPN‐PN blends showed mass loss above 300°C because of decomposition of the triazole rings and the novolac backbone. Silica fiber‐reinforced syntactic foam composites derived from these resins possessed comparable mechanical properties and superior impact resistance vis‐a‐vis their phenolic resin analogues. The mechanical properties could be tuned by regulating the reactant stoichiometry. These low temperature addition curable resins are suited for light weight polymer composite for related applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41254.

MEG evidence for conceptual combination but not numeral quantification in the left anterior temporal lobe during language production.

The left anterior temporal lobe (LATL) has risen as a leading candidate for a brain locus of composition in language; yet the computational details of its function are unknown. Although most literature discusses it as a combinatory region in very general terms, it has also been proposed to reflect the more specific function of conceptual combination, which in the classic use of this term mainly pertains to the combination of open class words with obvious conceptual contributions. We aimed to distinguish between these two possibilities by contrasting plural nouns in contexts where they were either preceded by a color modifier (“red cups”), eliciting conceptual combination, or by a number word (“two cups”), eliciting numeral quantification but no conceptual combination. This contrast was chosen because within a production task, it allows the manipulation of composition type while keeping the physical stimulus constant: a display of two red cups can be named as “two cups” or “red cups” depending on the task instruction. These utterances were compared to productions of two-word number and color lists, intended as non-combinatory control conditions. Magnetoencephalography activity was recorded during the planning for production, prior to motion artifacts. As expected on the basis of comprehension studies, color modification elicited increased LATL activity as compared to color lists, demonstrating that this basic combinatory effect is strongly crossmodal. However, numeral quantification did not elicit a parallel effect, suggesting that the function of the LATL is (i) semantic and not syntactic (given that both color modification and numeral quantification involve syntactic composition) and (ii) corresponds more closely to the classical psychological notion of conceptual combination as opposed to a more general semantic combinatory function.

Investigation of the Dielectric Strength of Syntactic Foam at 77 K under DC Stress

Liquid nitrogen (LN2) based electrical insulation systems for superconducting equipment of electrical power distribution networks are state of the art. Since LN2 is a cryogenic liquid it has some disadvantages when used as insulation. This paper deals with syntactic foam as an alternative insulation system for superconducting apparatus. Syntactic foam is a composite material consisting of a polymeric matrix and embedded hollow microspheres with diameters of several 10 μp?. As hollow microspheres are gas-filled, using those as filling material features significant reductions of the relative permittivity and of the thermal contraction due to cooling the material to liquid nitrogen temperature (LNT, T = 77 K). In this study both an epoxy resin (ER) and an unsaturated polyester resin (UPR) serve as matrix material. The hollow microspheres used in this investigation are made of untreated and silanized glass. The results of measurements of the dielectric DC strength show, that the dielectric strength of all investigated syntactic foam compositions are significantly higher at LNT compared to ambient temperature (AT). Furthermore, the effect of a higher dielectric strength of syntactic foam with silanized glass spheres at ambient temperature vanishes at LNT. Hence, the dielectric strength at LNT is unaffected by silanization of glass microspheres.