Study on drying rate in contact drying with flexible screen

The moisture contents (MC) of popular veneers were tested in Composition Board Laboratory of Northeast Forestry University by contact drying with flexible screen. The influence factors considered included temperature, initial moisture contents (IMC), and veneer thickness. Veneer-drying laws under different hot press conditions were analyzed. The results showed that the drying rate increased with temperature rising. 160°C was considered to be more efficient than 140°C and 180°C because excessive high temperature has no significant contribution to drying rate. IMC had significant effect on drying rate. The veneer with high IMC had a higher drying rate at above fiber saturation point (FSP) and a lower drying rate at below FSP, compared to the veneer with low IMC. Average drying rate also varied with thickness in power law.

Emission and drying kinetics of paper mill sludge during contact drying process

The emission and contact drying kinetics of the paper mill sludge (PMS) were studied through experiments carried out in a paddle dryer. To get a better understanding of its drying mechanism, a penetration model developed by Tsotsas and Schlünder (1986) was used to simulate the drying kinetics of the PMS. The result indicated that this kinetics could be divided into three phases: pasty, lumpy and granular phases, and could be successfully simulated by the penetration model as the related sludge parameters were integrated into the model. The emission rate curves of the volatile compounds (VCs) were interrelated to the drying rate curve of the PMS, especially for volatile fatty acids (VFAs) and ammonia in this study.

Comparison of the effects of first and second generation silicone hydrogel contact lens wear on tear film osmolarity

AIM:To compare the effects of first and second generation silicone hydrogel(SiH) contact lens wear on tear film osmolarity.METHODS:The healthy subjects who have never used contact lenses before were enrolled in the study.Tear film osmolarity values of 16 eyes(group 1) who wore first generation SiH contact lenses were compared with those of 18 eyes(group 2) who wore second generation SiH contact lenses after three months follow-up.RESULTS:Beforecontactlenswear,tearfilmosmolarity of groups 1 and 2 were 305.02±49.08 milliosmole(mOsm) and 284.66±30.18mOsm,respectively.After three months of contact lens wear,osmolarity values were found 317.74±60.23mOsm in group 1 and 298.40±37.77mOsm in group 2.Although osmolarity values for both groups of SiH contact lens wear after three months periods were slightly higher than before the contact lens wear,the difference was not statistically significant. CONCLUSION:Contact lens wear may cause evaporation from the tear film and can increase tear film osmolarity leading to symptoms of dry eye disease.In the current study,there is a tendency to increase tear film osmolarity for both groups of SiH contact lens wear,but the difference is not statistically significant.

Local grid refinement in multigrid method for point contact problems of polycrystalline anisotropic material under dry and lubricated conditions

Predicting rolling bearing fatigue life requires knowledge of the three-dimensional(3D)stress fields in the roller and raceway near the lubricated contact.Owing to the increasingly severe operating conditions,the effect of localized features such as surface roughness,subsurface inclusions,and even the crystallographic structure of the material becomes important.Achieving such detail requires(locally)extremely dense gridding in simulations,which in 3D is a major challenge.Multigrid techniques have been demonstrated to be capable of solving such problems.In this study,multigrid techniques are shown to further increase the efficiency of the solution by exploiting local grid refinement while maintaining the simplicity of a uniform discretization.This is achieved by employing increasingly finer grids only locally,where the highest resolution is required.Results are presented for dry contact and elastohydrodynamically lubricated contact cases,circular as well as elliptic,with varying crystallographic structure,and with surface roughness.The results show that the developed algorithm is very well suited for detailed analysis,with also excellent prospects for computational diagnostics involving actual material crystallographic structure from electron backscatter diffraction measurements.

Chevron-type graphene nanoribbons with a reduced energy band gap:Solution synthesis,scanning tunneling microscopy and electrical characterization

Graphene nanoribbons(GNRs)attract a growing interest due to their tunable physical properties and promise for device applications.A variety of atomically precise GNRs have recently been synthesized by on-surface and solution approaches.While on-surface GNRs can be conveniently visualized by scanning tunneling microscopy(STM),and their electronic structure can be probed by scanning tunneling spectroscopy(STS),such characterization remains a great challenge for the solution-synthesized GNRs.Here,we report solution synthesis and detailed STM/STS characterization of atomically precise GNRs with a meandering shape that are structurally related to chevron GNRs but have a reduced energy band gap.The ribbons were synthesized by Ni0-mediated Yamamoto polymerization of specially designed molecular precursors using triflates as the leaving groups and oxidative cyclodehydrogenation of the resulting polymers using Scholl reaction.The ribbons were deposited onto III-V semiconducting InAs(110)substrates by a dry contact transfer technique.High-resolution STM/STS characterization not only confirmed the GNR geometry,but also revealed details of electronic structure including energy states,electronic band gap,as well as the spatial distribution of the local density of states.The experimental STS band gap of GNRs is about 2 eV,which is very close to 2.35 eV predicted by the density functional theory simulations with GW correction,indicating a weak screening effect of InAs(110)substrate.Furthermore,several aspects of GNR-InAs(110)substrate interactions were also probed and analyzed,including GNR tunable transparency,alignment to the substrate,and manipulations of GNR position by the STM tip.The weak interaction between the GNRs and the InAs(110)surface makes InAs(110)an ideal substrate for investigating the intrinsic properties of GNRs.Because of the reduced energy band gap of these ribbons,the GNR thin films exhibit appreciably high electrical conductivity and on/off ratios of about 10 in field-effect transistor measurements,suggesting their promise for device applications.