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71.
72.
Eylem Dizman Tomak Mark Hughes Umit C. Yildiz Hannu Viitanen 《Journal of Materials Science》2011,46(3):598-607
The aim of the study was to screen any possible synergistic effect available with combination of plant oils and boron compounds to decrease boron leaching and improve thermal degradation of wood by means of dual treatment. In order to reduce the leachability of boron compounds, sapwood of beech and Scots pine samples were treated with oils to create a hydrophobic layer on the wood cells that may prevent water uptake. Increase (%) of boron retained in double-treated samples after leaching was approximately 20% compared to boron-treated samples without oil. The most promising results on boron leaching obtained in the case of using waste and sunflower oil. Thermogravimetric residues were increased by the higher loading of boron compounds in double-treated samples. Spectra of FTIR-Photoacoustic spectrometer showed some deformation of lignin and cellulose followed by degradation of hemicelluloses of treated wood samples due to heat effect at 160 °C. 相似文献
73.
Surface modification of Scots pine: the effect of process parameters on the through thickness density profile 总被引:2,自引:0,他引:2
Lauri Rautkari Kristiina Laine Nick Laflin Mark Hughes 《Journal of Materials Science》2011,46(14):4780-4786
This study evaluated the significance of different process parameters (press temperature, closing time, holding time, moisture content and compression ratio) on solid wood surface densification and its effect on the density profile generated in Scots pine sapwood. Changes in the microstructure of the wood were also evaluated microscopically. The results showed that with a shorter closing time, densification occurred closer to the sample surface than with an extended closing time. At a compression temperature of 150 °C, the vertical density profile exhibited a sharp peak in density that was close to the wood surface. A higher temperature of 200 °C resulted in a slightly broader density peak that was less intense and further from the surface. A holding time of 10 min resulted in the wood compressing to a slightly greater extent than when using a holding time of 1 min. Higher moisture content led to more extensive deformation. The results indicate that surface modification by densification is a viable method of enhancing wood properties. 相似文献
74.
It is demonstrated that for an isolated Mode I planar crack embedded in an infinite body, the stress intensity factor along the crack front is a function independent of the elastic constants. 相似文献
75.
Mark J.Schulz 《材料科学技术学报》2012,28(3):261-267
The corrosion behavior of pure Mg,AZ31,and AZ91D were evaluated in various in vitro and in vivo environments to investigate the potential application of these metals as biodegradable implant materials.DC polarization tests and immersion tests were performed in different simulated body solutions,such as distilled(DI) water,simulated body fluid(SBF) and phosphate buffered solution(PBS).Mg/Mg alloys were also implanted in different places in a mouse for in vivo weight loss and biocompatibility investigations.The in vivo subcutis bio-corrosion rate was lower than the corrosion rate for all of the in vitro simulated corrosive environments.The Mg/Mg alloys were biocompatible based on histology results for the liver,heart,kidney,skin and lung of the mouse during the two months implantation.Optical microscopy and scanning electron microscopy were carried out to investigate the morphology and topography of Mg/Mg alloys after immersion testing and implantation to understand the corrosion mechanisms. 相似文献
76.
Yingping Huang Ross McMurran Mark Amor-Segan Gunwant Dhadyalla R. Peter Jones Peter Bennett Alexandros Mouzakitis Jan Kieloch 《The International Journal of Advanced Manufacturing Technology》2010,51(1-4):233-246
A current premium vehicle is implemented with a variety of information, entertainment, and communication functions, which are generally referred as an infotainment system. During vehicle development, testing of the infotainment system at an overall level is conventionally carried out manually by an expert who can observe at a customer level. This approach has significant limitations with regard to test coverage and effectiveness due to the complexity of the system functions and human’s capability. Hence, it is highly demanded by car manufacturers for an automated infotainment testing system, which replicates a human expert encompassing relevant sensory modalities relating to control (i.e., touch) and observation (i.e., sight and sound) of the system under test. This paper describes the design, development, and evaluation of such a system that consists of simulation of vehicle network, vision-based inspection, automated navigation of features, random cranking waveform generation, sound detection, and test automation. The system developed is able to: stimulate a vehicle system across a wide variety of initialisation conditions, exercise each function, check for system responses, and record failure situations for post-testing analysis. 相似文献
77.
Mark Livingston Nick Bailey Ade Kearns 《Journal of Housing and the Built Environment》2010,25(4):409-427
Those living in deprived areas may have a greater reliance on the neighbourhood as a setting for social activity. However, the reduced quality of deprived neighbourhoods may make attachment in such places less likely. Other factors, like high turnover and social mix, may also act to reduce an individual’s attachment in these neighbourhoods. Using qualitative methods, this study examines both emotional and functional attachment to deprived neighbourhoods, specifically considering the impact of high turnover and of social mix. Social mix is broadly defined, including but not limited to ethnic and tenure mix. Many respondents reported strong emotional attachments to their communities, with the presence of strong social networks and a sense of security the most important contributing factors. Functional attachments and attachments to the physical environment were weak or absent. High turnover in deprived areas was found to reduce place attachment by undermining social networks, lowering social interaction, and eroding trust and feelings of security. There was little evidence that social mix in any dimension reduced attachment significantly. However, high residential turnover and a rapidly changing (ethnic) mix in one area had led to increased anxieties and reduced attachments. The research shows that rather than systemic factors being dominant, place attachment in deprived areas is very context dependent (e.g. in terms of where the neighbourhood is located in relation to others). For an individual, also experiential, historical and personal factors are strong determinants of attachment. 相似文献
78.
79.
Changsheng Wu Peng Jiang Wei Li Hengyu Guo Jie Wang Jie Chen Mark R. Prausnitz Zhong Lin Wang 《Advanced functional materials》2020,30(3)
Transdermal drug delivery (TDD) systems with feedback control have attracted extensive research and clinical interest owing to their unique advantages of convenience, self‐administration, and safety. Here, a self‐powered wearable iontophoretic TDD system that can be driven and regulated by the energy harvested from biomechanical motions is proposed for closed‐loop motion detection and therapy. A wearable triboelectric nanogenerator (TENG) is used as the motion sensor and energy harvester that can convert biomechanical motions into electricity for iontophoresis without stored‐energy power sources, while a hydrogel‐based soft patch with side‐by‐side electrodes is designed to enable noninvasive iontophoretic TDD. Proof‐of‐concept experiments on pig skin with dyes as model drugs successfully demonstrate the feasibility of the proposed system. This work not only extends the application of TENG in the biomedical field, but may also provide a cost‐effective solution for noninvasive, electrically assisted TDD with closed‐loop sensing and treatment. 相似文献
80.
Bernette M. Oosterlaken Yifei Xu Mark M. J. van Rijt Marina Pilz da Cunha Gilles H. Timmermans Michael G. Debije Heiner Friedrich Albertus P. H. J. Schenning Nico A. J. M. Sommerdijk 《Advanced functional materials》2020,30(6)
In this work, a nanohybrid material based on a freestanding polymeric liquid crystal network capable of postmodification via cation exchange to tune birefringence is proposed. The smectic liquid crystal films can be infiltrated with a variety of cations, thereby changing the refractive indices (ne and no) and the effective birefringence (Δn) of the nanohybrid material, with reversible cation infiltration occurring within minutes. Birefringence could be tuned between values of 0.06 and 0.19, depending on the cation infiltrated into the network. Upon infiltration, a decrease in the smectic layer spacing is found with layer contraction independent of the induced change in birefringence. Potential applications are in the field of specialty optical devices, such as flexible, retunable reflective filters. 相似文献