Interior Point Methods for Linear Optimization is a comprehensive, thorough textbook on interior point methods (IPMs). The era of IPMs was initiated by N. Karmarkar's 1984 paper, which triggered ...turbulent research and reshaped almost all areas of optimization theory and computational practice. This book gives a comprehensive review of the main results of more than a decade of IPM research. Numerous exercises are provided to aid in understanding the material.
Metals usually exist in the form of polycrystalline solids, which are thermodynamically unstable because of the presence of disordered grain boundaries. Grain boundaries tend to be eliminated through ...coarsening when heated or by transforming into metastable amorphous states when the grains are small enough. Through experiments and molecular dynamics simulations, we discovered a different type of metastable state for extremely fine-grained polycrystalline pure copper. After we reduced grain sizes to a few nanometers with straining, the grain boundaries in the polycrystals evolved into three-dimensional minimal-interface structures constrained by twin boundary networks. This polycrystalline structure that underlies what we call a Schwarz crystal is stable against grain coarsening, even when close to the equilibrium melting point. The polycrystalline samples also exhibit a strength in the vicinity of the theoretical value.
In this paper, an iterative algorithm is introduced to solve the split common fixed point problem for asymptotically nonexpansive mappings in Hilbert spaces. The iterative algorithm presented in this ...paper is shown to possess strong convergence for the split common fixed point problem of asymptotically nonexpansive mappings although the mappings do not have semi-compactness. Our results improve and develop previous methods for solving the split common fixed point problem. MSC: 47H09, 47J25.
•The physical properties of the bio-jet fuel can be adjusted by controlling the CC coupling conditions.•The alkane with spiro ring structure has the low freezing point.•W/O microemulsion formed by ...the NaOH solution and cyclohexane favors the aldol condensation.•The density of the jet fuel is 0.869 g·ml−1 and the freezing point is lower than −60℃.
Production of jet fuel with high performance is attractive in the field of biomass utilization. This paper provides a way to controllably produce renewable jet fuel with high-density and low-freezing point by the condensation of biomass-derived cyclopentanone and followed hydrodeoxygenation. It is found that the freezing point of the jet fuel decreased rapidly with the increase of the content of spirocyclic alkane and the density increased gradually with content of tricyclic alkane. And the composition of jet fuel can be adjusted by controlling the reaction conditions of cyclopentanone condensation. At 30 °C and 3 h, the precursors of jet fuel were prepared by condensation of cyclopentanone over NaOH catalyst and the final obtained HDO products were comprised of 54.56% bicyclopentane, 31.88% tricyclic alkane and 13.56% spirocyclic alkane. The density of the jet fuel was 0.869 g·ml−1 and the freezing point was less than −60 °C. These parameters are obviously superior to that of commercial Jet-A.
Conventional polymerization for the synthesis of carbon nitride usually generates amorphous heptazine‐based melon with an abundance of undesired structural defects, which function as charge carrier ...recombination centers to decrease the photocatalytic efficiency. Herein, a fully condensed poly (triazine imide) crystal with extended π‐conjugation and deficient structure defects was obtained by conducting the polycondensation in a mild molten salt of LiCl/NaCl. The melting point of the binary LiCl/NaCl system is around 550 °C, which substantially restrain the depolymerization of triazine units and extend the π‐conjugation. The optimized polymeric carbon nitride crystal exhibits a high apparent quantum efficiency of 12 % (λ=365 nm) for hydrogen production by one‐step excitation overall water splitting, owing to the efficient exciton dissociation and the subsequent fast transfer of charge carriers.
A fully condensed poly (triazine imide) crystal, which features extended π‐conjugation and deficient structural defects, decorated with Pt and CoOx as redox cocatalysts efficiently drives the one‐step excitation overall water splitting for H2 and O2 production with a record apparent quantum efficiency of 12 % at 365 nm.
Conductive fibers have received considerable interest due to their potential applications in the flexible electronics field. Fabricating a conductive fiber that can realize fast deformation with ...stretchability for multifunctional applications is still highly appealing. Here, we present a deformable conductive fiber (DCF) fabricated by injecting liquid metal (LM) into a hollow thermoplastic polyurethane (TPU) fiber; the DCF can be shaped into a 2D or 3D shape by an electrothermal method at the thermoplastic transition point of TPU. Combined with the solid-liquid phase transition characteristics of the LM at its melting point, the DCF exhibits a variable shape memory feature at two transition points. We have demonstrated that the double-torsional DCF and the helical DCF can act as a capacitive sensor and an inductive sensor, respectively, and they have both been used for human motion monitoring. In addition, the helical DCF can also act as a stretchable electrode with excellent electrical properties (resistance change <2%) under a maximal mechanical strain of 3300%. Overall, the DCF presents great potential for applications in human motion monitoring, soft robotics and smart electronic textiles.
We present a deformable conductive fiber composed of a hollow TPU fiber filled with liquid metal, which can realize fast shape transformation by electrothermal heating, for multifunctional applications.
The dense matching of pairs is the basis of advanced image processing applications, such as 3D reconstruction and simultaneous localisation and mapping (SLAM). However, it is difficult to obtain ...efficient dense matching results in wide baseline image pairs due to various conditions. For this reason, the authors propose a dense matching method for wide baseline images based on an equal proportion of triangulation. Firstly, this Letter proves the mathematical property of equal proportion of triangulation affine transformation, and then builds a triangulation based on the set of sparse matching points. By using this property, the positions of equal proportion points in the corresponding triangulation of the two images to be matched are calculated, respectively. Secondly, to eliminate the points and obtain the inner point set, these proportional points are used to check the similarity of the matching triangle regions. Finally, the inner point set is used to calculate the positions of the dense matching points as the final dense matching result. The experimental results verified the validity and accuracy of the proposed method and this method is suitable for tilt photography, multispectral and multidate remote sensing image dense registration, and more.
Review of drop impact on heated walls Liang, Gangtao; Mudawar, Issam
International journal of heat and mass transfer,
March 2017, 2017-03-00, 20170301, Letnik:
106
Journal Article
Recenzirano
•Drop impact is reviewed in terms of heat transfer mechanisms and predictive tools.•It is segregated into film evaporation, nucleate, transition and film boiling.•Inconsistencies are found regarding ...impact process and ensuing heat transfer.•Recommendations are provided for future research.
This paper provides a comprehensive review of published literatures concerning the fluid mechanics and heat transfer mechanisms of liquid drop impact on a heated wall. The review is divided into four parts, each centered on one of the main heat transfer regimes: film evaporation, nucleate boiling, transition boiling, and film boiling. Each of these regimes is discussed in detail in terms of available depictions of drop deformation and/or breakup, proposed heat transfer mechanisms, predictive correlations and/or models. It is shown that understanding the underlying physics for each heat transfer regime is highly dependent on the experimental methods that investigators have adopted, and broadness of available databases in terms of liquid type, drop size and momentum, impact angle, and wall material and surface roughness. Despite significant advances in experimental, theoretical and computational research in understanding the interfacial behavior of the drop from the moment of impact, there are many inconsistencies concerning some of the most important aspects of the impact process and ensuing heat transfer, especially in regards to critical heat flux, transition boiling, and the Leidenfrost point. This review is concluded with recommendations concerning future work that is needed to address poorly understood and/or contradictory issues.
Polyethylene furanoate (PEF) represents a promising renewable resource-based bioplastic as replacement for fossil-based polyethylene terephthalate (PET) with improved material properties. However, ...the synthesis of PEF through conventional polycondensation remains challenging, since the time-intensive reaction leads to degradation and undesired discolouration of the product. Here we show the successful rapid synthesis of bottle-grade PEF via ring-opening polymerisation (ROP) from cyclic PEF oligomers within minutes, thereby avoiding degradation and discolouration. The melting point of such mixture of cyclic oligomers lies around 370 °C, well above the degradation temperature of PEF (~329 °C). This challenge can be overcome, exploiting the self-plasticising effect of the forming polymer itself (which melts around 220 °C) by initiation in the presence of a high boiling, yet removable, and inert liquid plasticiser. This concept yields polymer grades required for bottle applications (M
> 30 kg mol
, conversion > 95%, colour-free products), and can be extended to other diffusion-limited polymer systems.
This report present the results of the EURAMET inter-comparison carried out to compare the calibration of thermocouples from 419,527 °C (freezing point of Zn) up to 1492 °C (melting point of the Pd-C ...eutectic). This inter-comparison is intended to be used to support the calibration and measurement capabilities (CMCs) of the participants in the calibration of thermocouples.
The comparison was organized in three loops with nineteen participating laboratories and it allowed the performance of the measurement either in fixed points and/or by comparison. The method used to analyse the results of the comparison was the generalized weighted mean that takes into account the full covariance matrix that includes correlations between the participants which have similar traceability sources and between measurements performed by the same laboratory (i.e. the pilots that performed measurements at the beginning and at the end of each loop and the measurements performed by the same laboratory in fixed points and by comparison at the same calibration point).
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Final Report
. Note that this text is that which appears in Appendix B of the BIPM key comparison database
kcdb.bipm.org/
.
The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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