Particle-Size-Dependent Anticorrosion Performance of the Si3N4-Nanoparticle-Incorporated Electroless Ni-P Coating

Electroless Nickel–Phosphorus (Ni-P) coating is recognized mostly for its outstanding corrosion and wear-resistant behavior. The intrinsic corrosion and wear-resistant properties of Ni-P-based coating could be further upgraded by incorporating appropriate second-phase additive particles into the coating matrix. However, such properties of the Ni-P-based coating greatly rely on the surface and microstructural evolution arising with the co-deposition of the additive particles. In this study, submicron Si3N4 (average size ~200 nm) and nano Si3N4 (average size ~20 nm) particles were incorporated while depositing a Ni-P alloy in a low-carbon steel substrate to develop the Ni-P-Si3N4 composites through the electroless coating method. The 20 nm Si3N4-incorporated composite coating constituted fewer defects such as cavities and micropores on the surface, but such defects significantly appeared on the surface of the composite after the incorporation of 200 nm Si3N4 nanoparticles. Subsequently, the composite Ni-P-Si3N4, developed with the co-deposition of 20 nm nanoparticles, is enriched with enhanced anticorrosion characteristics compared with the composite developed with 200 nm nanoparticles. The enhancement of anticorrosion behavior was attributed mainly to the Si3N4 nanoparticles that covered the substantial volume of the coating and led to inhibit the formation of corrosion active sites such as defects and metallic Ni phase.

Effects of dry particle coating with nano- and microparticles on early compressive strength of portland cement pastes

It is known that nano-and microparticles have been very popular in recent years since their advantages. However, due to the very small size of such materials, they have very high tendency to agglomeration particularly for nanoparticles. Therefore, it is critical that they are properly distributed in the system to which they are added. This paper investigated the effects of dry particle coating with nano-and microparticles to solve the agglomeration problem. For a clear evaluation, paste samples were preferred to detemine the compressive strength. Nano-SiO2 and nano-CaCO3, micro-CaCO3 and micro-SiO2, also known as silica fume, were selected as particulate additives. It was studied by the addition of various percentages (0.3, 0.7, 1, 2, 3 and 5%) of nano-and microparticles in cementitious systems, replacing cement by weight with and without dry particle coating. Dry particle coating was made by using a high-speed paddle mixer. Portland cement and additive particles were mixed at 1500 rpm for 30 seconds in high-speed powder mixer designed for this purpose. The 3-day compressive strength of the cement-based samples to which particles were added at the specified rates was determined and the effect of the dry particle coating on the early strength was investigated. According to the results, it was observed that the production of paste with the dry particle coating technique gave higher compressive strength compared to the production of paste directly in early period. Especially with dry particle coating, compressive strength increased more than 100% in paste samples containing 0.3% nano-SiO2 compared to direct addition without coating.

Experimental Investigation on Turbulent Flow Deviation in a Gas-Particle Corner-Injected Flow

An experimental model of a corner-injected flow is built to investigate the turbulent flow behavior by employing the PIV technique. The influences of the ideal tangential circle, the additive particles and the initial gas mass flux on the corner-injected flow are analyzed systematically. To be specific, the flow deviation, the velocity profile, the vortex evolution and the turbulent flow development are discussed quantitatively. The influences of the increasing ideal tangential circle on the turbulent jet deviation are shortened gradually, and the impinging circles are obviously narrowed with the injection of particles. The gas-particle corner-injected flow can obtain a good rotation when the ideal tangential circle is 0.25 times the width of the impinging chamber. The momentum decay of the corner-injected flow diminishes with the increasing ideal tangential circle and the decreasing initial gas velocity. The rotation strength of the vortex is more affected by the injection of laden particles, while the angular distortion enhances when increasing the ideal tangential circle. The increasing initial gas mass flux plays a dominant role in the development of the corner-injected flow, secondly the increasing ideal tangential circle, and last the injection of particles. All these findings can provide theoretical support in the design of a corner-fired furnace.

Effects of Composite Coatings Functionalized with Material Additives Applied on Textile Materials for Cut Resistant Protective Gloves

The objective of the present work was to evaluate the effects of different types of particles added to a polymer paste applied onto a textile carrier on the cut resistance of the resulting material. Knitted aramid textile samples were coated in laboratory conditions using a polymer paste that was functionalized with 12 types of reinforcing particles of different chemical compositions and size fractions. Cut resistance was tested in accordance with the standard EN ISO 13997:1999 and the results were subjected to statistical analysis. The effects of additive particles on the microstructure of the polymeric layer were assessed by means of scanning electron microscopy. The type and size of the particles affected the cut resistance of the functionalized knitted fabric. They were also found to change the morphology of the porous structure. Composite coatings containing the smallest additive particles exhibited the best cut resistance properties.

Additive particles, prosodic structure and focus sensitivity in Hungarian

The main aim of this article is to investigate the prosody-information structure interface in the analysis of the Hungarian additive particle is ‘also, too’. We present a prosodic study of narratives, collected through guided elicitation, and provide a prosodic basis for a focus-based analysis of is. Standard formal semantic approaches to the interpretation of additive particles regard additive particles as focus sensitive, hence the associate of the particle is focal and the focus interpretation (in terms of alternatives) is a significant part in its semantics. This view is considered crosslinguistically valid, although the discussion mostly concerns English. In Hungarian, the focus sensitivity of the additive particle is not directly transparent and needs more elaboration. In the relevant literature, the issue of focus marking with respect to the additive particle is has been insufficiently studied or merely stipulated. In this article, we argue for the importance of a more elaborate study of the prosody-information structure interface in the analysis of Hungarian additive particles. Accordingly, we provide data and its analysis to support our core argument and claims. Our study contributes to the overall understanding and analysis of is and to the general claims about focus marking and focus types in Hungarian. We aim to complement the standard semantic analyses by providing a prosodic analysis supporting the focus-sensitive analysis of is instead of merely stipulating an association with focus. On a more general level, we show that the various readings of additive particles can be explained by taking the prosodic patterns of the relevant constructions into account.

Pengaruh Fraksi Berat Serbuk Alumina Terhadap Porositas Busa Aluminium Hasil Injeksi Gas

Aluminum foam is a very interesting material to develop. This material is a material that has a combination of characteristics between physical and mechanical properties such as high stiffness and low density. There are several processes for making aluminum foam that have been developed, either through the liquid, solid, or gas phases. And of these various processes, the process of making aluminum foam through the liquid phase by using the gas injection method is the simplest and cheapest process. The principle of the process of making aluminum foam with this method is that bubbles are produced from the process of blowing the gas into the aluminum liquid in which there are additive particles that function as a bubble stabilizer. These stable bubbles will become pores after the aluminum liquid solidifies. This research will discuss the effect of the weight fraction of alumina powder with an average size of 5.77 μm added to liquid aluminum on the macro-pore structure in the form of shape and size as well as the spread of the resulting pores. And the result is that the optimal weight fraction of adding alumina powder is 15%, where the resulting pores have a more homogeneous and evenly shaped and sized.

Additive Linking in L2 French Discourse by German Learners: Syntactic Embedding and Intonation Patterns

This study deals with the expression of additive linking in L2 French by adult German learners with two proficiency levels (advanced vs. intermediate). We examine whether crosslinguistic influences are observed in three domains: the frequency and type of additive expressions in discourse, the syntactic integration of additive particles in the utterance and the prosodic contour associated with them. A total of 70 participants (20 French native speakers, 20 German native speakers and 30 German learners of L2 French) performed an oral narrative task elicited via a video clip presenting abundant additive contexts. Our results show that advanced German learners did not experience an L1 transfer in any of the domains analyzed, but instead they show a learner-specific tendency to overmark the contrastive status of the relevant entities in discourse. Yet traces of crosslinguistic influence are visible in intermediate learners’ choice and frequency of additive means, as well as the preferred position of the particles. All learners seem to have quickly discarded the possibility to mark scope by prosody, in contrast to what they do in their L1. We discuss these findings in the light of the L2 acquisition of cohesive devices in discourse and their interactions with different linguistic levels.