Hybrid process for heterogeneous surface bonding

Non-destructive elemental analysis of prehistoric potsherds in the southern Ryukyu Islands, Japan: Consideration of the pottery surface processing technique in the boundary region between the Japanese Jōmon and Neolithic Taiwan

Polycarbonate (PC) and Acrylonitrile Butadiene Styrene (ABS) were welded by a combination of a diode laser and a CNC machining center. Laser beam delivered through the transparent PC and was absorbed in an opaque ABS. Polymers were melted and joined by absorbed and conducted heat. Experiments were carried out by varying working distance from 44mm to 50mm for the focus spot diameter control, laser input power from 10W to 25W, and scanning speed from 100 to 400mm/min. The weld bead and cross-section were analyzed for weld quality, and tensile results were presented through the joint force measurement. With focus distance at 48mm, laser power with 20W, and welding speed at 300mm/min, experimental results showed the best welding quality which bead size was measured to be 3.75mm. The shear strength at the given condition was <TEX>$22.8N/mm^2$</TEX>. Considering tensile strength of ABS is <TEX>$43N/mm^2$</TEX>, shear strength was sufficient to hold two materials. A single process was possible in a CNC machining system, surface processing, hole machining and welding. As a result, the process cycle time was reduced to 25%. Compared to a typical process, specimens were fabricated in a single process, with high precision.

On the characterization of heterogeneous surfaces through the dual site–bond model

&amp;lt;p&amp;gt;Earth System Models (ESMs) traditionally operate at large horizontal resolutions, on the order of 100km, which can obscure the effects of smaller scale heterogeneity. The literature, as well as work in the Coupling of Land and Atmospheric Subgrid Parameterizations (CLASP) project, indicates that surface heterogeneity, particularly in surface fluxes, has important implications for not only surface processes but atmospheric processes as well. Previous work using large-eddy simulation (LES) shows that spatial variability in surface heating can produce significant secondary circulations that are closely related to the type and scale of heterogeneity and are not currently captured by single column sub-grid atmospheric parameterizations used in ESMs.. This presentation aims to address this persistent weakness by using a multi-column approach, where two single column models, one over a high sensible heat flux portion of a climate gridcell domain and another over a low sensible heat flux portion, are coupled through a modeled secondary circulation.&amp;amp;#160;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;To accomplish this task, we run the Cloud Layers Unified By Binomials (CLUBB) standalone single column model over a 100 km box centered at the Southern Great Plains site in Oklahoma for a variety of surface and atmospheric conditions both as a single column model, and with two coupled columns. Results are also compared to LESs that use a homogeneous surface flux field and LESs that use realistic, high resolution surface flux fields. Initial results focus on liquid water path (LWP) response to added heterogeneity for 43 day long simulations. We observed qualitatively similar responses in LWP as a result of accounting for heterogeneity induced secondary circulations in both LES and multi-column CLUBB as well as indications of clear trends in response based on the atmospheric conditions. This work indicates that a multi-column setup has significant promise for modeling the impacts of heterogeneity induced secondary circulations for application in ESMs at a fraction of the computational expense of LES. Continuing work expands this analysis to cover a wider variety of surface and atmospheric conditions, determine when multi column CLUBB has significant sensitivities to heterogeneity induced secondary circulations, and explore avenues for further simplification of the model setup.&amp;lt;/p&amp;gt;

High-resolution satellite imagery raises new prospects for detailed study of the Greenland ice sheet (GrIS) surface processes and ice discharge. However, dramatic spatiotemporal variability of ice surface reflectance and features poses significant challenges for registration of satellite imagery. This study proposes a new feature-based registration method to register high-resolution panchromatic images of the ice sheet ablation zone. Its idea is to use relatively stable supraglacial rivers as tie points for automated image registration. A first demonstration is made using WorldView-1/2/3 panchromatic images (spatial resolution 0.5 m) as follows: first, supraglacial rivers are delineated using spectral analysis, nonlocal means denoising, Gabor filtering, and path opening. Next, buffer and overlay tools are combined to generate an area of interest and eliminate tie point outliers, yielding subset of high-confidence tie points for registration. Finally, a coherent point drift algorithm is applied to match these tie points and implement registration. Results show that the proposed method demonstrates good performance, despite a heterogeneous ice surface background that complicates river delineation. Accuracy of image registration negatively correlates with seasonal spatiotemporal variability of supraglacial river patterns, suggesting that for the best results, repeat images and time-adaptive techniques should be used. For time-stable meltwater channels, however, the method offers a novel, automated way to register high-resolution satellite imagery of the GrIS ablation zone. Well-registered ice surface high-resolution images reveal that short-term (1-2 week) variations in surface melting rate affect channel morphology (drainage densities and channel widths) significantly, whereas a signal from background advection by flowing ice is not apparent.

On the evaluation of metal-corrosion inhibitor interactions by adsorption isotherms

Among the key problems in atmospheric and hydrologic sciences are the modeling of the interaction between the atmosphere and land surface hydrology while also quantifying the surface/subsurface hydrologic flow processes both in vertical and lateral directions, and modeling the heterogeneity in surface and subsurface hydrologic processes. Meanwhile, in standard water resources engineering practice, the planning and management of the water resources is performed over the geographical region of a watershed. To address these issues, a model of coupled atmospheric-hydrologic processes at the watershed scale, the Watershed Environmental Hydrology Hydro-Climate Model (WEHY-HCM), has been developed. The atmospheric model PSU/NCAR MM5 (Fifth Generation Mesoscale Model) was coupled to the watershed hydrology model WEHY through the atmospheric boundary layer to form the WEHY-HCM. The WEHY-HCM is especially useful for producing nonexistent atmospheric data as input to the modeling of surface and subsurface hy...

Land surface heterogeneity and its effects on surface processes have been a concern to hydrologists and climate scientists for the past several decades. The contrast between the fine spatial scales at which heterogeneity is significant (1 km and finer) and the coarser scales at which most climate simulations with land surface models are generated (hundreds of kilometers) remains a challenge, especially when incorporating land surface and subsurface lateral fluxes of mass. In this study, long-term observational land surface forcings and derived solar radiation were used to force high-resolution land surface model simulations over the Arkansas–Red River basin in the Southern Great Plains region of the United States. The most unique aspect of these simulations is the fine space (1 km2) and time (hourly) resolutions within the model relative to the total simulation period (51 yr) and domain size (575 000 km2). Runoff simulations were validated at the subbasin scale (600–10 000 km2) and were found to be in good agreement with observed discharge from several unregulated subbasins within the system. A hydroclimatological approach was used to assess simulated annual evapotranspiration for all subbasins. Simulated evapotranspiration values at the subbasin scale agree well with predictions from a simple one-parameter empirical model developed in this study according to Budyko’s concept of “geographical zonality.” The empirical model was further extended to predict runoff and evapotranspiration sensitivity to precipitation variability, and good agreement with computed statistics was also found. Both the empirical model and simulation results demonstrate that precipitation variability was amplified in the simulated runoff. The finescale at which the study is performed allows analysis of various aspects of the hydrologic cycle in the system including general trends in precipitation, runoff, and evapotranspiration, their spatial distribution, and the relationship between precipitation anomalies and runoff and soil water storage anomalies at the subbasin scale.

A new multi-user hybrid surface and bulk micromachining process on silicon-on-insulator (SOI) wafers is discussed. This 13-mask process consists of a doped polysilicon layer for electrical connection and non-critical structures and a single crystal silicon (SCS) layer for excellent optical and mechanical properties in the critical MEMS design. There are 7 masks for doping and etching of the SCS layer. The flexibility and versatility of this process allows for microsystems designs such as actuators, optical gratings, and dimples/anchors on the SCS layer. The MEMS devices fabricated and tested in this paper include thermal actuators, hinges, latches, optical switches, mirrors, and waveguides.

Estimates of the hydrological budget in the Walnut River Watershed (WRW; ∼5000 km2) of southern Kansas were made with a parameterized subgrid-scale surface (PASS) model for the period 1996–2002. With its subgrid-scale distribution scheme, the PASS model couples surface meteorological observations with satellite remote sensing data to update root-zone available moisture and to simulate surface evapotranspiration rates at high resolution over extended areas. The PASS model is observationally driven, making use of extensive parameterizations of surface properties and processes. Heterogeneities in surface conditions are spatially resolved to an extent determined primarily by the satellite data pixel size. The purpose of modeling the spatial and interannual variability of water budget components at the regional scale is to evaluate the PASS model's ability to bridge a large grid cell of a climate model with its subgrid-scale variation. Modeled results indicate that annual total evapotranspiration at the WRW is about 66%–88% of annual precipitation—reasonable values for southeastern Kansas—and that it varies spatially and temporally. Seasonal distribution of precipitation plays an important role in evapotranspiration estimates. Comparison of modeled runoff with stream gauge measurements demonstrated close agreement and verified the accuracy of modeled evapotranspiration at the regional scale. In situ measurements of energy fluxes compare favorably with the modeled values for corresponding grid cells, and measured surface soil moisture corresponds with modeled root-zone available moisture in terms of temporal variability despite very heterogeneous surface conditions. With its ability to couple remote sensing data with surface meteorology data and its computational efficiency, PASS is easily used for modeling surface hydrological components over an extended region and in real time. Thus, it can fill a gap in evaluations of climate model output using limited field observations.

Studies of albedo over urban/rural surface are important to better understand the land surface process in the ABL(atmospheric boundary layer). Urban landscape is the most heterogeneous surface that strongly influences the structure and development of the ABL. In this paper, the directional hemispherical reflectance (black-sky albedo, BSA), the bihemispherical reflectance (white-sky albedo, WSA) and the actual albedo (blue-sky albedo, A) are retrieved from the MODIS BRDF/albedo product (MOD43B1) for three broadbands (0.3- 0.7μm, 0.7-5.0μm, 0.3-5.0μm) in the Changjiang Delta of China. Particular attention is directed to examine the difference of surface albedos over urban and rural areas. The seasonal and spatial variations are investigated. Validation has also been done against field observation and showed that the albedo from MODIS is less than the observed. Albedo in visible broadband (0.3-0.7μm) over urban area is larger than that over rural area, but is less in near infrared broadband (0.7-5.0μm). For the total short broadbrand, it is difficult to reach qualitative conclusion because of urban complexity. The correlations of albedos and NDVI are strongly influenced by the spectral band and land cover. They are positive for the visible and the total broadbands, but negative for the near infrared in same season.

Studies on land surface processes using remote sensing data gains importance in the context of Geosphere Biosphere Programme. Present study addresses the applicability of split‐window method, in a tropical environment for mapping of surface temperature over heterogeneous surface from satellite data. The accuracy of the method is about +2.2°K, which is reasonable value taking into account the atmospheric attenuation in tropical environment. An attempt has been made to derive emissivity from normalized difference vegetation index (NDVI) by taking into account the fraction of vegetation cover of each pixel, which is determined by satellite data. The emissivity values estimated from satellite data found to be in reasonable agreement with an estimated error of less than 1%. The results of the study indicate the potential use of NDVI as a modulating parameter in the land surface temperature estimation from satellite data.

A surface slicing planning method based on the K-means clustering algorithm and improved fruit fly optimization algorithm (FOA) is proposed to address the efficiency problem in the surface processing of special shaped workpieces. The NURBS surface reconstruction is performed on the complex surface of the selected workpiece, and the K-means clustering algorithm with the curvature-distance factor is used to subdivide the surface, and the FOA with the hopping strategy is used to plan the optimal connection path for each subdivision with different starting points. This improves the local search capability of the FOA by improving the mixing of different classes that occurs when the surface is subdivided. Finally, the proposed method is demonstrated to be effective for surface slicing by simulating the slicing plan on the constructed heterogeneous workpiece surface, and the shortest connectivity paths are obtained for different starting points.

Aggregation of area-averaged evapotranspiration over the Ejina Oasis based on a flux matrix and footprint analysis

ABSTRACTThis work focused in the evaluation of Oreochromis niloticus fish scales (FS) as biosorbent material in the removal of Zn from a synthetic effluent based on automotive battery industry effluent and, further, a hybrid neutralization/biosorption process, aiming at a high-quality treated effluent, by a cooperative use of dolomite and FS. For this, a physicochemical and morphological characterization (i.e. SEM–EDX, FTIR, XRD, and TXRF) was performed, which helped to clarify a great heterogeneity of active sites (phosphate, carbonate, amide, and hydroxyl) on the biosorbent; also the inorganic constituents (apatites) leaching from the FS was identified. Biosorption results pointed out to a pH-dependent process due to changes in the functional group’s anionic character (i.e. electrostatic interactions), where an initial pH = 3 favored the Zn uptake. Kinetic and equilibrium studies confirmed the heterogeneous surface and cooperative sorption, wherein experimental data were described by Generalized Elovich kinetic model and the favorable isotherm profile by Langmuir–Freundlich isotherm ( = 15.38 mg g–1 and ). Speciation diagram of Zn species along with the leached species demonstrated that, for the studied pH range, the biosorption was the most likely phenomena rather than precipitation. Finally, the hybrid neutralization/biosorption process showed great potential since both the Zn concentration levels and the pH reached the legislation standards (CZn = 4 mg L–1; pH = 5). Hence, based on the characterization and biosorption results, a comprehensive evaluation of the involved mechanisms in such complex system helped to verify the prospective of FS biosorbent for the Zn treatment from solution, in both individual and hybrid processes.