Form Of Braids Research Articles

Writing through … from … to … underneath … over … in between … negotiating the force field of the unworded in the braided thesis mode

Words aloud the page, aloud the dab and dash of a pen, the swish of wrist, the nib is avatar, the ink is silent virus, moldwarp burrowing along, just beneath the surface, there I am, trying to slip between the nib and that which would be scratched out from my fingers, hand and arm. Trying to eke the groove of thought, its carve through language skin. Creative and critical writing hold in tension between them a force field that is essentially implicit and unworded. It is here that my practice-based and theoretical research, concerned with how a contemporary poetic practice might thematically and artistically engage with the unsaid and the unsayable, seeks to play. My focus is on apophasis, the rhetoric of denial and negation, which since classical times has been a means of using language to deal with what lies beyond language. Taking a braided form, this paper reflects on the process and experience of producing a blended thesis in order to explore, through an apophatic lens, the implications of collapsing the distance between creative and critical modes to write into and out of the force field of un-wordedness.

A century of channel change caused by flow augmentation on Sixth Water Creek and Diamond Fork River, Utah, USA

AbstractThe Diamond Fork River in central Utah, USA experienced extreme flow augmentation via transbasin flows. Beginning in 1916, irrigation water was delivered through a tributary, Sixth Water Creek, with daily summer flows regularly exceeding a 500‐year flood at the point of introduction. Flows were dramatically reduced by management action in 2004 but with mandated minimum flows. We examined the geomorphic response of Sixth Water and Diamond Fork using aerial imagery, lidar, topographic cross sections, and sediment transport measurements. River channel response varied with valley confinement and with position in the watershed, which determined the magnitude of augmented flow relative to natural floods and the amount of sediment supply. Confined, steep sections of Sixth Water incised many meters into bedrock, whereas partially confined and unconfined sections developed a braided form even under conditions of general incision. With the removal of flow augmentation, smaller natural floods on Sixth Water are unable to transport bed material and the channel remains static. On the alluvial lower Diamond Fork, a lower slope, upstream sediment supply, and larger natural floods produced a dynamic shifting channel that widened in response to natural floods. After flow augmentation, a coarsened bed is partially mobile and channel narrowing appears to be limited by artificial baseflow, which prevent vegetation establishment in the channel.

Identification of mechanical properties of a braided alfa stem (Stipa tenacissima L.) by an inverse method

The aging of buildings and structures, accompanied by an increase in the prices of conventional building materials, has pushed the scientific community to explore new techniques and materials to rehabilitate existing buildings. Rehabilitation aims to extend the service life of a structure while maintaining its strength and stability. Among these techniques, composite materials based on synthetic fibers, such as carbon fibers, have been developed. However, materials with low carbon footprints that are bio-sourced and eco-friendly are of interest to the scientific community. The use of Alfa plant natural stems in a braided form is the focus of this study. This study is the first to use geometric shapes to improve the performance of a natural fiber-reinforced composite. Epoxy was used as the matrix, which is the material used most often in composite designed for reinforced concrete structures. This study aims to determine the equivalent mechanical properties of the Alfa braided stem using the reverse method. Test specimens of the epoxy/Alfa composites were manufactured and tested on a tensile machine. The epoxy was tested, and its properties were determined. Subsequently, a finite element numerical model of the specimen was constructed, and the properties of the braided Alfa stem were varied until identical results were obtained. The mechanical properties of the Alfa braided stem were thus identified. The results showed that the braided Alfa stem had a stiffness modulus of 23.243 GPa.

Brunnian braids over the 2-sphere and Artin combed form

Finding homotopy group of spheres is an old open problem in topology. Berrick et al. derive in [A. J. Berrick, F. Cohen, Y. L. Wong and J. Wu, Configurations, braids, and homotopy groups, J. Amer. Math. Soc. 19 (2006)] an exact sequence that relates Brunnian braids to homotopy groups of spheres. We give an interpretation of this exact sequence based on the combed form for braids over the sphere developed in [R. Gillette and J. V. Buskirk, The word problem and consequences for the braid groups and mapping class groups of the two-sphere, Trans. Amer. Math. Soc. 131 (1968) 277–296] with the aim of helping one to visualize the sequence and to do calculations based on it.

The Kauffman bracket skein module of the handlebody of genus 2 via braids

In this paper we present two new bases, [Formula: see text] and [Formula: see text], for the Kauffman bracket skein module of the handlebody of genus 2 [Formula: see text], KBSM[Formula: see text]. We start from the well-known Przytycki-basis of KBSM[Formula: see text], [Formula: see text], and using the technique of parting we present elements in [Formula: see text] in open braid form. We define an ordering relation on an augmented set [Formula: see text] consisting of monomials of all different “loopings” in [Formula: see text], that contains the sets [Formula: see text], [Formula: see text] and [Formula: see text] as proper subsets. Using the Kauffman bracket skein relation we relate [Formula: see text] to the sets [Formula: see text] and [Formula: see text] via a lower triangular infinite matrix with invertible elements in the diagonal. The basis [Formula: see text] is an intermediate step in order to reach at elements in [Formula: see text] that have no crossings on the level of braids, and in that sense, [Formula: see text] is a more natural basis of KBSM[Formula: see text]. Moreover, this basis is appropriate in order to compute Kauffman bracket skein modules of closed–connected–oriented (c.c.o.) 3-manifolds [Formula: see text] that are obtained from [Formula: see text] by surgery, since isotopy moves in [Formula: see text] are naturally described by elements in [Formula: see text].

Twine selection is essential for successful hatchery cultivation of Saccharina latissima, seeded with either meiospores or juvenile sporophytes

The predominant method used for the cultivation of European kelp involves seeding onto twine spools. The selection of a suitable twine is essential. In four experiments, synthetic and natural polymer twines were seeded with either meiospore or juvenile sporophytes of Saccharina latissima. Development was monitored over both the hatchery and outplanting phase at an experiment seaweed farm, Scotland, UK. Twisted twine seeded with meiospores gave 37 ± 21% higher biomass yield than the braided form, despite 46 ± 10% lower sporophyte density during the hatchery period. Twisted twine was also more favourable when sporophyte seeding, increasing juvenile retention by 140%. Three-month-old sporophytes had 50% weaker bioadhesion on polyamide (PA), polyester (PES) and polypropylene (PP) compared to polyvinyl alcohol (PVA). This was reflected in 11–24% higher biomass on PVA following outplanting. However, if the twine surface was treated by corona discharge before seeding, PA, PES and PP achieved an equivalent biomass to PVA. Jute and sisal twine had a toxic effect on the development of meiospores. In contrast, seeding with sporophytes was successful onto jute and sisal, but bioadhesion was weak. Finally, cotton was moderately toxic to meiospores but also had a bioadhesion strength and biomass yield comparable to PVA. We conclude that PVA and corona-treated synthetic twines are excellent for either meiospore or sporophyte seeding. Cotton is a very promising biodegradable twine, although further research is needed to optimise its physical structure. We also conclude that results during the hatchery period do not predict the success of seeded twine following outplanting.

The HOMFLY polynomial of links in closed braid form

We provide a new proof of Jaeger’s formula expressing the HOMFLY polynomial of a link presented in closed braid form, replacing the original representation theoretic proof with an easy combinatorial and geometric argument. Using new variants of Jaeger’s result we provide a direct and elementary proof of the fact that the braid index of a link that has an n-string closed braid diagram that is also reduced and alternating, is exactly n. Until now this fact was only known as a consequence of a result due to Murasugi on fibered links that are star products of elementary torus links and of the fact that alternating braids are fibered.

Prediction of Passive Intermodulation on Mesh Reflector Antenna Using Collaborative Simulation: Multiscale Equivalent Method and Nonlinear Model

We propose a collaborative simulation method for evaluation of passive intermodulation (PIM) on mesh reflector antenna. The electric field on the surface of reflector can be simulated exactly and conveniently by the multiscale equivalent method and finite-element method solver. Meanwhile, the coefficients in the nonlinear model of PIM characteristic on mesh structure are determined from the experimental results on mesh reflector sample, so that the PIM of mesh reflector antenna with the same braided form and working conditions can be calculated using the same nonlinear model. In simulation, the PIM calculations of mesh reflector samples based on the actual woven form and with dimensions of $0.25 \times 0.25\,\,\text{m}^{2}$ at C-band and Ku-band have been established, indicating basically consistent to the measured results and validating the effectiveness of this method. Moreover, the PIM prediction of a mesh reflector antenna with the same woven structure is also given. These results show that this method can be utilized to predict PIM level of the mesh reflector antenna under conditions of the precise PIM measurement of mesh reflector sample, also providing reference for designing the low PIM microwave components.

The rotating normal form of braids is regular

Defined on Birman–Ko–Lee monoids, the rotating normal form has strong connections with the Dehornoy's braid ordering. It can be seen as a process for selecting between all the representative words of a Birman–Ko–Lee braid a particular one, called rotating word. In this paper we construct, for all n⩾2, a finite-state automaton which recognizes rotating words on n strands, proving that the rotating normal form is regular. As a consequence we obtain the regularity of a σ-definite normal form defined on the whole braid group.

Differential Regulation of Hedgehog and Parathyroid Signaling in Mulberry and Nonmulberry Silk Fibroin Textile Braids.

Even after several decades of research, the most optimal source of silk for promoting osteogenesis in situ is still a subject of debate. A major gap in existing knowledge is role of underlying signaling mechanisms in both the mulberry and nonmulberry silk species that leads to the development of differential levels of osteogenesis. In our previous study, we elucidated the role of Wnt/β-catenin signaling for promoting superior osteogenic differentiation in nonmulberry silk braids in the presence of TGF-β and pro-osteogenic supplements. Here, we provide a comparative osteogenic analysis of the two most popular silk species (mulberry and nonmulberry silk), in the form of silk braids prepared from natively spun fibers, by conducting detailed gene expression profiling using 25 different osteogenic markers, followed by further validation by immunohistochemistry. Our study provides novel insights into the direct regulatory role of nonmulberry silk fibroin braids on hedgehog and parathyroid signaling pathways in controlling osteogenic differentiation of cultured human fetal osteoblasts (hFOBs), a phenomenon not very evident in the mulberry silk textile braids. Although both silk braids enabled adequate cellular attachment, proliferation, and extracellular collagen matrix formation, superior expression of osteogenic markers (ALP, VDR, Runx2), matrix proteins (Col1A2, OPN), and signaling molecules (GLI1, GLI2, Shh) with characteristic terminal osteocytic phenotype could only be observed in nonmulberry silk. Therefore, our study provided detailed insights into the development of engineered bone to be a prospective tissue equivalent with potential to provide the essential instructive elements for activating physiological pathways of bone differentiation. Such engineered constructs have potential for use as an in vitro model for drug testing and as scaffolds for bone regeneration strategies.

PRESENTATIONS AND REPRESENTATIONS OF SURFACE SINGULAR BRAID MONOIDS

The surface singular braid monoid corresponds to marked graph diagrams of knotted surfaces in braid form. In a quest to resolve linearity problem for this monoid, we will show that if it is defined on at least two or at least three strands, then its two or respectively three dimensional representations are not faithful. We will also derive new presentations for the surface singular braid monoid, one with reduced the number of defining relations, and the other with reduced the number of its singular generators. We include surface singular braid formulations of all knotted surfaces in Yoshikawa's table.

The relaxation normal form of braids is regular

Braids can be represented geometrically as laminations of punctured disks. The geometric complexity of a braid is the minimal complexity of a lamination that represents it, and tight laminations are representatives of minimal complexity. These laminations give rise to a normal form of braids, via a relaxation algorithm. We study here this relaxation algorithm and the associated normal form. We prove that this normal form is regular and prefix-closed. We provide an effective construction of a deterministic automaton that recognizes this normal form.

The 2-braid group and Garside normal form

We investigate the relation between the Garside normal form for positive braids and the 2-braid group defined by Rouquier. Inspired by work of Brav and Thomas we show that the Garside normal form is encoded in the action of the 2-braid group on a certain categorified left cell module. This allows us to deduce the faithfulness of the 2-braid group in finite type. We also give a new proof of Paris’ theorem that the canonical map from the generalized braid monoid to its braid group is injective in arbitrary type.

From Precambrian Iron-Formation to Terraforming Mars: The JIMES Expedition to Santorini

ABSTRACTThe iron embayments at Santorini, Greece, have long been considered by geologists to be the most useful modern environment for understanding variables related to precipitation of Precambrian iron-formation. To help understand the rock record, the embayments were studied almost monthly for a year to assess seasonal variations in iron bacteria and diatoms along with mineralogy, weather, water chemistry, and ecology. Unidentified red rods dominated and accounted for most ferrihydrite production. Diatom abundance was seasonal, including Parlibellus delognei which produces molecular oxygen within iron-coated sheaths. The gross structures of the microbial iron precipitates were in the form of rods, spheres, and braids. Speculations resulting from our observations suggest that life's origin could have been intimately related to chemical/physical processes occurring where volcanic sources discharged iron through highly porous siliceous substrates and into the primitive ocean. The diverse community also provides a potentially useful ecosystem for Mars terraforming experiments.

The Kembs project: environmental integration of a large existing hydropower scheme

The environment was a major issue for the Kembs relicensing process on the upper Rhin River. Since 1932, Kembs dam derives water from the Rhine River to the "Grand Canal d'Alsace" (GCA) which is equipped with four hydropower plants (max. diverted flow: 1400 m3/s, 630 MW, 3760 GWh/y). The Old Rhine River downstream of the dam is 50 km long and has been strongly affected by works (dikes) since the 19th century for flood protection and navigation, and then by the construction of the dam. Successive engineering works induced morphological simplification and stabilization of the channel pattern from a formerly braided form to a single incised channel, generating ecological alterations. As the Kembs hydroelectric scheme concerns three countries (France, Germany and Switzerland) with various regulations and views on how to manage with environment, EDF undertook an integrated environmental approach instead of a strict "impact/mitigation" balance that took 10 years to develop. Therefore, the project simultaneously acts on complementary compartments of the aquatic, riparian and terrestrial environment, to benefit from the synergies that exist between them ; a new powerplant (8,5 MW, 28 GWh/y) is built to limit the energetic losses and to ensure various functions thereby increasing the overall environmental gain.

In Memoriam: Slavik Jablan 1952–2015

After a long and brave battle with a serious illness, our dear friend and colleague Slavik Jablan passed away on 26 February 2015. [...]

Steam gasification of multiwire LiYCY type electrical cable

Original, non-separated pieces of the LiYCY cable (with multilayer metal/plastic (copper/PVC) structure) were gasified by steam in an excess at atmospheric pressure. Conversion of the gaseous stream was enhanced by catalytic bed of original granulated material, prepared from aluminosilicate (local clay) and calcium carbonate. In the process metal (Cu) preserved unchanged form of cords and braids and was quantitatively separated (49 % of original mass of the cable). Non-metal components (51 % of original mass of the cable) were converted to a slightly sintered non-metallic powder (3.3 % of original mass of the cable) and gaseous phase. Condensation of steam facilitated elimination of tars and oils as well as hydrochloride from the gas. It was estimated that only 5 % of carbon (from the cable components) was retained in the cooling/condensing line, mostly as water non-soluble phases. Efficiency of absorption of hydrochloride by catalytic bed and aqueous condensate was almost the same (but only 50 % of estimated total chlorine quantity was finally balanced).

Feature: Deserting the Narrative Line: Teaching the Braided Form

This essay describes an approach to teaching the braided essay, highlighting the rewards and difficulties.

Experimental Study on River Channel's Formation and Change Process of on the Surface of Delta Deposition

Experimental study on river channels formation and change process with two different constant flows 2.45L/s and 4.9L/s that which come from mountains and into delta depositions surface, based on sediment supply 15.72kg/h at the water inlet. After 964h experiment, research on the study shows as follows: with 2.45L/s flow, on the surface of delta depositions forming process the channel appears as straight, braided, micro-bend and meandering form. The first formation processes of delta deposition are straight and braided river which appeared alternately every 50h on the surface. When time goes on the delta get longer and braided streams branch of the shunt decrease gradually, that made the channel appeared with slightly curved form. Combined with that flexural radius gets bigger because of the outer bank erosion of slightly curved channel backed off, finally the meandering channels presented. With 4.9L/s flow, the formation processes gave priority of braided river, which appeared every 15h cycle, following the aggravate of eroding in floodplain and scouring in main channel, the river pool board-shallow comes with the main-flow swing, the channel existed as slightly curved form, and appears two sides of deposition. Finally analysis and research the channel cross-section morphological and longitudinal slope. In conclusion, the delta depositions surface channel existed as micro-bend of no branch with single strands, under the constantly water and sediment conditions.

THE BRESSAUD NORMAL FORM OF BRAIDS THROUGH WORD REWRITE SYSTEMS

We introduce a nondeterministic rewrite system which is conjectured to converge to the Bressaud normal form of braids as presented in [X. Bressaud, A normal form for braids, J. Knot Theory Ramifications17(6) (2008) 697–732]. We prove the conjecture for 3-strand braids.