Highly thermally responsive hybrid in-fiber slab waveguide grating structure with a plastic core and a silica cladding

A 1.2(height)×125(depth)×500(length) micro-slot was engraved along a fiber Bragg grating by chemically assisted femtosecond laser processing. By filling epoxy and UV-curing, waveguide with plastic-core and silica-cladding was created, presenting high thermal responding coefficient of 211pm/°C.

Highly thermally responsive hybrid in-fiber sSlab waveguide grating structure with a plastic core and a silica cladding

A 1.2(height)×125(depth)×500(length) micro-slot was engraved along a fiber Bragg grating by chemically assisted femtosecond laser processing. By filling epoxy and UV-curing, waveguide with plastic-core and silica-cladding was created, presenting high thermal responding coefficient of 211pm/°C.

Effect of anisotropy on elastic moduli measured by nanoindentation in human tibial cortical bone

Many biological materials are known to be anisotropic. In particular, microstructural components of biological materials may grow in a preferred direction, giving rise to anisotropy in the microstructure. Nanoindentation has been shown to be an effective technique for determining the mechanical properties of microstructures as small as a few microns. However, the effects of anisotropy on the properties measured by nanoindentation have not been fully addressed. This study presents a method to account for the effects of anisotropy on elastic properties measured by nanoindentation. This method is used to correlate elastic properties determined from earlier nanoindentation experiments and from earlier ultrasonic velocity measurements in human tibial cortical bone. Also presented is a procedure to determine anisotropic elastic moduli from indentation measurements in multiple directions. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res.

Elastic and plastic properties of Mo3Si measured by nanoindentation

Single crystal Mo3Si specimens were grown and tested at room temperature using established nanoindentation techniques at various crystallographic orientations. The indentation modulus and hardness were obtained for loads that were large enough to determine bulk properties, yet small enough to avoid cracking in the specimens. From the indentation modulus results, anisotropic elastic constants were determined. As load was initially increased to approximately 1.5 mN, the hardness exhibited a sudden drop that corresponded to a jump in displacement. The resolved shear stress that was determined from initial yielding was 10-15% of the shear modulus, but 3 to 4 times the value obtained from the bulk hardness. Non-contact atomic force microscopy images in the vicinity of indents revealed features consistent with {100}(010) slip.

Acousto-optic modulation in a microstructured plastic optical fibre Bragg grating

The present work addresses the control of the mPOF Bragg grating spectrum properties through acousto-optic modulation. For the first time, the interaction of a flexural acoustic wave, generated by longitudinal excitation of different frequencies, with the Bragg grating will be presented. Also it will be demonstrated the quasi linear relationship between PZT load and maximum reflected power/ 3dB bandwidth of the reflected spectrum.

Microstructure-based inherent anisotropy of asphalt mixtures

Asphalt mixtures have been demonstrated to be anisotropic materials in both laboratory and field tests. The anisotropy of asphalt mixtures consists of inherent anisotropy and stress-induced anisotropy. In previous work, the inherent anisotropy of asphalt mixtures was quantified by using only the inclination angles of the coarse aggregate particles in the asphalt mixtures. However, the inclination of fine aggregates also has a contribution to the inherent anisotropy. Moreover, the contribution to the inherent anisotropy of each aggregate may not be the same as in the previous work but will depend on the size, orientation, and sphericity of the aggregate particle. This paper quantifies the internal microstructure of the aggregates in asphalt mixtures by using an aggregate-related geometric parameter, the vector magnitude. The original formulation of the vector magnitude, which addresses only the orientation of coarse aggregates, is modified to account for not only the coarse aggregate orientation, but also the size, orientation, and sphericity of coarse and fine aggregates. This formulation is applied to cylindrical lab-mixed lab-compacted asphalt mixture specimens varying in asphalt binder type, air void content, and aging period. The vertical modulus and the horizontal modulus are also measured by using nondestructive tests. A relationship between the modified vector magnitude and the modulus ratio of the vertical modulus to the horizontal modulus is developed to quantify the influence of the inherent microstructure of the aggregates on the anisotropy of the mixtures. The modulus ratio is found to depend solely on the aggregate characteristics including the inclination angle, size, and sphericity, and it is independent of the asphalt binder type, air void content, and aging period. The inclination angle, itself, proves to be insufficient to quantify the inherent anisotropy of the asphalt mixtures. © 2011 American Society of Civil Engineers.

Novel Ni-Mg-Al-Ca catalyst for enhanced hydrogen production for the pyrolysis-gasification of a biomass/plastic mixture

A Ni-Mg-Al-Ca catalyst was prepared by a co-precipitation method for hydrogen production from polymeric materials. The prepared catalyst was designed for both the steam cracking of hydrocarbons and for the in situ absorption of CO2 via enhancement of the water-gas shift reaction. The influence of Ca content in the catalyst and catalyst calcination temperature in relation to the pyrolysis-gasification of a wood sawdust/polypropylene mixture was investigated. The highest hydrogen yield of 39.6molH2/g Ni with H2/CO ratio of 1.90 was obtained in the presence of the Ca containing catalyst of molar ratio Ni:Mg:Al:Ca=1:1:1:4, calcined at 500°C. In addition, thermogravimetric and morphology analyses of the reacted catalysts revealed that Ca introduction into the Ni-Mg-Al catalyst prevented the deposition of filamentous carbon on the catalyst surface. Furthermore, all metals were well dispersed in the catalyst after the pyrolysis-gasification process with 20-30nm of NiO sized particles observed after the gasification without significant aggregation.

Controlling the properties of microstructured plastic optical fiber Bragg gratings using acousto-optic excitation

A fine control of the mPOF Bragg grating spectrum properties, such as maximum reflected power and 3dB bandwidth, through acousto-optic modulation (AOM) using flexural regime is presented. A numerical comparison of the strain field along mPOFBG - AOM and the similar structure with SMFBG-AOM was presented, showing that the strain field amplitude is higher along the mPOFBG due to its smaller mechanical stiffness. The obtained results can be used in the development of fine-tuned optical filters using low voltage sources and low frequency regimes, to obtain tunable optical filters and to control the shape of the spectrum. Studies of the behavior in different gratings (such as phase shifted and long period gratings) for photonic applications, such as tunable notch filters or tunable cavities, are in progress. It can potentially be applied on tunable optical filters for POF transmission. © 2012 IEEE.

Az SAP-rendszer fejlesztése egy műanyag-feldolgozó vállalatnál (Development of SAP system in a plastic manufacturing company)

Az SAP-rendszernek a kontrollingszervezetek működésére gyakorolt pozitív hatása nem titok. A visszacsatolás lehetőségének biztosításával alkalom nyílik a szervezetek tevékenységének követésére, ellenőrzésére, felülbírálására. A logisztika mint az egész vállalatot átszövő rendszer, működésének nyomon követése is létfontosságúvá vált, hiszen összetettségéből kifolyólag jellegzetességei, színvonala az egész rendszerre hatást gyakorol. A logisztikai rendszer és folyamatainak figyelemmel kísérésére a logisztikai kontrollingrendszer nyújt megoldást, visszacsatolási pontjain keresztül. A műanyag-feldolgozó vállalat esetében a szervezeti SAP-rendszer logisztikai kontrollingterületének fejlesztésétől várják a szervezeti hatékonyság emelkedését és a jobb színvonal elérését. _____ Positive effect of the SAP system on the operation of controlling organisations has not been a secret. Opportunity of the feedback will be possible to track, control, override operation of the organisations. The logistic controlling system provides a solution through feedback points for monitoring the logistic system and processes. In the case of plastics manufacturing company the increasing of organisational efficiency and achievement of a better standard is anticipated from development of logistic controlling area of the organisational SAP system.