Research Development on Sodium-Ion Batteries

The Transmission Control Protocol.

In Software Defined Networking (SDN) the control plane is physically separate from the forwarding plane. Control software programs the forwarding plane (e.g., switches and routers) using an open interface, such as OpenFlow. This paper aims to overcomes two limitations in current switching chips and the OpenFlow protocol: i) current hardware switches are quite rigid, allowing ``Match-Action'' processing on only a fixed set of fields, and ii) the OpenFlow specification only defines a limited repertoire of packet processing actions. We propose the RMT (reconfigurable match tables) model, a new RISC-inspired pipelined architecture for switching chips, and we identify the essential minimal set of action primitives to specify how headers are processed in hardware. RMT allows the forwarding plane to be changed in the field without modifying hardware. As in OpenFlow, the programmer can specify multiple match tables of arbitrary width and depth, subject only to an overall resource limit, with each table configurable for matching on arbitrary fields. However, RMT allows the programmer to modify all header fields much more comprehensively than in OpenFlow. Our paper describes the design of a 64 port by 10 Gb/s switch chip implementing the RMT model. Our concrete design demonstrates, contrary to concerns within the community, that flexible OpenFlow hardware switch implementations are feasible at almost no additional cost or power.

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Forwarding metamorphosis: fast programmable match-action processing in hardware for SDN

We report a study of self-assembled beta-pleated sheets in B. mori silk fibroin films using thermal analysis and infrared spectroscopy. B. mori silk fibroin may stand as an exemplar of fibrous proteins containing crystalline beta-sheets. Materials were prepared from concentrated solutions (2−5 wt % fibroin in water) and then dried to achieve a less ordered state without beta-sheets. Crystallization of beta-pleated sheets was effected either by heating the films above the glass transition temperature (Tg) and holding isothermally or by exposure to methanol. The fractions of secondary structural components including random coils, alpha-helices, beta-pleated sheets, turns, and side chains were evaluated using Fourier self-deconvolution (FSD) of the infrared absorbance spectra. The silk fibroin films were studied thermally using temperature-modulated differential scanning calorimetry (TMDSC) to obtain the reversing heat capacity. The increment of the reversing heat capacity ΔCp0(Tg) at the glass transition fo...

/pdf/determining-beta-sheet-crystallinity-in-fibrous-proteins-by-2aov4wvj48.pdf

Determining Beta Sheet Crystallinity in Fibrous Proteins by Thermal Analysis and Infrared Spectroscopy

PLA composites: From production to properties

Since the introduction of the 10 GbE standard in 2002, the ability of general purpose processors to efficiently process network traffic with common protocols such as TCP/IP has been revisited and critically evaluated. However, recent commercially available processors such as Intelreg Coretrade 2 Duo Processor introduce microarchitectural enhancements that could significantly influence the approach to accelerating network processing. We examine the network performance of a real platform containing Intelreg Coretrade micro-architecture based processors, the role of coherency and a prototype implementation of direct cache placement (direct cache access or DCA) of inbound network traffic. We observe that a substantial portion of the time relates to the inefficiency of I/O specific coherence protocols in the platform. We demonstrate that a relatively, low complexity implementation of DCA called 'Prefetch Hint' provides a 15 to 43% speed-up to receive-side processing across a range of I/O sizes and present a detailed characterization of the benefits.

/pdf/impact-of-cache-coherence-protocols-on-the-processing-of-2dlaq8qurp.pdf

Impact of Cache Coherence Protocols on the Processing of Network Traffic

Cellulose nanocrystals (CNCs) using different polymorphs of cellulose were fabricated from raw bamboo pulp through alkali treatment followed by acid hydrolysis. The effect of CNC polymorphs, namely CNC I, CNC II and CNC:I → II (CNC II from cellulose I), on morphology, crystal structure, degree of hydrogen bonding and thermal stability were studied. These polymorphs were dispersed in polylactic acid (PLA) films using a casting evaporation approach and their effect on the structural, thermal, mechanical and barrier properties of the PLA were investigated. The CNC polymorphs differ significantly in their reinforcement capability and ability to form percolated networks. Incorporation of CNC II and CNC:I → II significantly improved the Young's modulus of composites (by ∼72%). However, their elongation at break significantly decreased compared to CNC I, due to high hydroxyl functionality, which forms an entangled hydrogen bonded network within the polymer matrix, leading to improvement in mechanical as well as barrier properties. The theoretically calculated moduli of composites using Halpin–Kardos, Cox–Krenchel and Ouali models showed good agreement for CNC I, CNC II and CNC:I → II, albeit at higher aspect ratio. All three CNCs showed the ability to form percolated networks, the occurrence and stability of which varied with the type of polymorph. Therefore, the current study provides an insight towards selection of appropriate polymorphs for fabrication of CNC reinforced high performance poly (lactic acid) based bionanocomposites.

Effect of cellulose nanocrystal polymorphs on mechanical, barrier and thermal properties of poly(lactic acid) based bionanocomposites

Thermally recyclable polylactic acid/cellulose nanocrystal films through reactive extrusion process

This article reports the fabrication of poly (3-hydroxybutyrate) (PHB)/cellulose nanocrystal (CNC) based nanobiocomposite films with improved gas barrier and migration properties for food packaging applications. Acid hydrolysis of cellulose pulp from bamboo (Bambusabalcooa) yields CNCs with diameter of 15–20 nm and length of 400–600 nm. Evaluation of d-spacing using XRD indicates intercalation of PHB matrix with CNC at optimum loadings of 2 wt%. Overall migration values in presence of both polar and nonpolar food simulants are found within standard limits. After migration studies on PHB/CNC films, significant decrease in crystallization temperature (by 15°C) is observed, with subsequent presence of multiple melting peaks. The oxygen transmission rate (OTR) decreases significantly (by ∼65%), even at low CNC (∼2 wt%) loadings. Permeation activation energy (calculated from Arrhenius equation) and barrier properties, such as solubility and diffusivity, improved (decreased by ∼57 and 17%, respectively) with loading fractions (∼2 wt%) due to the hydrogen bonded interaction of PHB with CNCs as well as tortuous path provided towards oxygen permeation. POLYM. ENG. SCI., 55:2388–2395, 2015. © 2015 Society of Plastics Engineers

Poly (3‐hydroxybutyrate)/cellulose nanocrystal films for food packaging applications: Barrier and migration studies

This paper reports a single-step co-precipitation method for the fabrication of magnetic cellulose nanocrystals (MGCNCs) with high iron oxide nanoparticle content (∼51 wt % loading) adsorbed onto cellulose nanocrystals (CNCs). X-ray diffraction (XRD), Fourier transform infrared (FTIR), and Raman spectroscopic studies confirmed that the hydroxyl groups on the surface of CNCs (derived from the bamboo pulp) acted as anchor points for the adsorption of Fe3O4 nanoparticles. The fabricated MGCNCs have a high magnetic moment, which is utilized to orient the magnetoresponsive nanofillers in parallel or perpendicular orientations inside the polylactic acid (PLA) matrix. Magnetic-field-assisted directional alignment of MGCNCs led to the incorporation of anisotropic mechanical, thermal, and electrical properties in the fabricated PLA-MGCNC nanocomposites. Thermomechanical studies showed significant improvement in the elastic modulus and glass-transition temperature for the magnetically oriented samples. Differential scanning calorimetry (DSC) and XRD studies confirmed that the alignment of MGCNCs led to the improvement in the percentage crystallinity and, with the absence of the cold-crystallization phenomenon, finds a potential application in polymer processing in the presence of magnetic field. The tensile strength and percentage elongation for the parallel-oriented samples improved by ∼70 and 240%, respectively, and for perpendicular-oriented samples, by ∼58 and 172%, respectively, in comparison to the unoriented samples. Furthermore, its anisotropically induced electrical and magnetic properties are desirable for fabricating self-biased electronics products. We also demonstrate that the fabricated anisotropic PLA-MGCNC nanocomposites could be laminated into films with the incorporation of directionally tunable mechanical properties. Therefore, the current study provides a novel noninvasive approach of orienting nontoxic bioderived CNCs in the presence of low magnetic fields, with potential applications in the manufacturing of three-dimensional composites with microstructural features comparable to biological materials for high-performance engineering applications.

Magnetic Cellulose Nanocrystal Based Anisotropic Polylactic Acid Nanocomposite Films: Influence on Electrical, Magnetic, Thermal, and Mechanical Properties

Amit Kumar

Papers

Impact of Cache Coherence Protocols on the Processing of Network Traffic

Effect of cellulose nanocrystal polymorphs on mechanical, barrier and thermal properties of poly(lactic acid) based bionanocomposites

Thermally recyclable polylactic acid/cellulose nanocrystal films through reactive extrusion process

Poly (3‐hydroxybutyrate)/cellulose nanocrystal films for food packaging applications: Barrier and migration studies

Magnetic Cellulose Nanocrystal Based Anisotropic Polylactic Acid Nanocomposite Films: Influence on Electrical, Magnetic, Thermal, and Mechanical Properties