Combination Of Infiltration Research Articles

Microstructure and mechanical properties of W-WC/Fe composite fiber-reinforced Fe matrix composite prepared by combination of infiltration and in-situ solid phase diffusion

To overcome the strength-toughness inversion relationship in steel/Fe matrix composites, a novel W-WC/Fe composite fiber-reinforced Fe matrix composite ((W-WC/Fe)f-IMC) with exceptional strength and toughness was fabricated by an in-situ fabrication method combining infiltration and in-situ solid-phase diffusion. The (W-WC/Fe)f-IMC consists of aligned W-WC/Fe composite fibers embedded in an Fe matrix. The W-WC/Fe composite fiber exhibits a characteristic core-shell structure on its cross section, with a resilient metal W fiber serving as the core and a robust annular WC-Fe layer acting as the shell. Due to the inward-outward growth and the gradient microstructure of the WC-Fe layer, the interface bonding strength between the W fiber/WC-Fe layer and the WC-Fe layer/matrix remains excellent. As a result, the (W-WC/Fe)f-IMC achieves an exceptional fracture strain of 35.5 ± 1.3 %, while maintaining high yield strength of 701 ± 16 MPa and ultimate compression strength of 1100 ± 18 MPa, surpassing those of cast Fe, which had values of 26.9 ± 1.1 %, 365 ± 20 MPa, and 834 ± 15 MPa, respectively. The simultaneous enhancement of the strength and toughness in (W-WC/Fe)f-IMC can be primarily attributed to the synergistic coupling effect between the high strength W-WC/Fe composite fibers and the tough matrix. The strategy proposed in this study holds promise as a method to alleviate the trade-off between strength and ductility in steel/Fe matrix composites.

A review of groundwater in high mountain environments

AbstractMountain water resources are of particular importance for downstream populations but are threatened by decreasing water storage in snowpack and glaciers. Groundwater contribution to mountain streamflow, once assumed to be relatively small, is now understood to represent an important water source to streams. This review presents an overview of research on groundwater in high mountain environments (As classified by Meybeck et al. (2001) as very high, high, and mid‐altitude mountains). Coarse geomorphic units, like talus, alluvium, and moraines, are important stores and conduits for high mountain groundwater. Bedrock aquifers contribute to catchment streamflow through shallow, weathered bedrock but also to higher order streams and central valley aquifers through deep fracture flow and mountain‐block recharge. Tracer and water balance studies have shown that groundwater contributes substantially to streamflow in many high mountain catchments, particularly during low‐flow periods. The percentage of streamflow attributable to groundwater varies greatly through time and between watersheds depending on the geology, topography, climate, and spatial scale. Recharge to high mountain aquifers is spatially variable and comes from a combination of infiltration from rain, snowmelt, and glacier melt, as well as concentrated recharge beneath losing streams, or through fractures and swallow holes. Recent advances suggest that high mountain groundwater may provide some resilience—at least temporarily—to climate‐driven glacier and snowpack recession. A paucity of field data and the heterogeneity of alpine landscapes remain important challenges, but new data sources, tracers, and modeling methods continue to expand our understanding of high mountain groundwater flow.This article is categorized under: Science of Water > Hydrological Processes Science of Water > Water and Environmental Change Science of Water > Methods

Tuberculosis infection in children with negative reactions to the diaskintest

Variants of the course of tuberculosis infection in 54 children from two to 14 years old, negatively reacting to a sample with an allergen tuberculosis recombinant (Diaskintest) were analyzed. There were 3 groups: 1st – 27 children infected with Mycobacterium tuberculosis (MBT), 50. 0% of cases; 2nd – 16 children with newly diagnosed residual post-tuberculosis changes (OPTI), 29. 6% of cases; 3rd group – 11 patients with active tuberculosis, 20. 4% of cases.
 Methods of examination: intradermal Mantoux test with 2TE and Diaskintest, according to the testimony of a number of patients in vitro tests: QuantiFERON test (QFT), – SPOT test.TV, multispiral computed tomography, bacteriological, molecular genetic methods of investigation on MBT. The method of mass tuberculin diagnostics revealed 70. 4 ± 8. 8% of children of the 1st group, 93. 8 ± 4. 7% of the 2nd group and 54. 6 ± 15. 0% of children of the 3rd group. The duration of infection with MBT in children was different and was less than 1 year in children of the 1st and 2nd groups – 51. 9 ± 9. 6% and 43. 8 ± 12. 4% of cases, respectively, which was significantly more frequent than in patients of the 3rd group (18. 2 ± 11. 6% of cases). Tuberculosis disease occurred in the form of complicated forms of the primary period-in 45. 5 ± 15. 0 % of cases, uncomplicated forms – in 27. 3 ± 3. 4% of cases, generalized lesions – in 27. 3 ± 13. 4% of cases. Diagnosis of a specific lesion occurred equally in the manifest phases of inflammation: infiltration, infiltration and decay (45. 5 ± 15. 0% of cases), and in the phase of ongoing reverse development (incomplete calcination – in 45. 5 ± 15. 0% of cases), one child had a combination of infiltration and calcination phases (9. 1 ± 8. 7% of cases). Residual posttuberculosis changes in children of group 2 were more often formed in the form of calcifications in the organs of the thoracic cavity – in 87. 5% of cases, in 12. 5 ± 8. 3% of patients OPTI was formed by the formation of seals.
 Conclusion: in children with negative reactions to the Diaskintest requires individual comprehensive diagnosis of tuberculosis infection.

Storm Water Management of Low Impact Development in Urban Areas Based on SWMM

LID (low impact development) is the storm management technique designed for controlling runoff in urban areas, which can be used to solve urban flooding disasters. Taking Sucheng District of Suqian City, Jiangsu Province, China as an example, this project used SWMM (storm water management model) to study the effect of four different types of LID scenarios (① no LID technique, ② LID technique based on infiltration, ③ LID technique based on water storage, ④ LID technique based on the combination of infiltration and water storage) on urban flooding under different rainfall patterns. For the whole study area, the results show that infiltration facilities have the greater reduction rate of surface runoff compared with storage facilities. The combined model (infiltration + storage) works best in the reduction of peak flow and flood volume, with the maximum reduction rate of peak flow (32.5%), and the maximum reduction rate of flood volume (31.8%). For local nodes, infiltration facilities and water storage facilities have different effects. Infiltration facilities significantly reduce runoff of node 47, the reduction rate of ponding time ranges from 73.1% to 54.5%, while water storage facilities have no effects on it. Storage facilities significantly reduce runoff of node 52, the reduction rate of ponding time is 100%, while infiltration facilities have no effects on it. Under all the LID designs, runoff reduction gradually increases with the increasing rainfall amount, and peak reduction becomes stable when rainfall amount reaches about 81.8 mm. In general, the combined model (infiltration + storage) performs better than any other scenarios in runoff reduction. The research shows that LID facilities can greatly mitigate flood, thus the urban flooding disasters caused by extreme rainstorms can be prevented.

COMPARISON OF ONSITE INFILTRATION AND CONSTANT RATE INFUSION FOR POSTOPERATIVE ANALGESIA IN DOGS WITH MAMMARY TUMORS UNDERGOING BILATERAL RADICAL MASTECTOMY AND OVARIOHYSTERECTOMY

Analgesia of the wide surgical excision region in surgeries such as bilateral radical mastectomy plays an important role in postoperative care. Opioids are effective in alleviating pain; however, they are sometimes difficult to obtain in most local veterinary hospitals. The objective of this research was to compare the efficacies of (1) onsite infiltration analgesia with lidocaine and bupivacaine (group I, [Formula: see text]) and intravenous injection with buprenorphine and (2) constant rate infusions (CRIs) of fentanyl and ketamine (group II, [Formula: see text]) for postoperative analgesia after bilateral radical mastectomy and ovariohysterectomy in dogs with mammary tumors. The results showed that a combination of infiltration with lidocaine and bupivacaine and intravenous injection with buprenorphine was as effective as CRIs of fentanyl and ketamine. Infiltration analgesia with lidocaine and bupivacaine may be an option for analgesia in dogs undergoing bilateral mastectomy and ovariohysterectomy and may help reducing pure [Formula: see text]-opioid requirements.

Spatiotemporal dynamics of wetted soils across a polar desert landscape

AbstractLiquid water is scarce across the landscape of the McMurdo Dry Valleys (MDV), Antarctica, a 3800 km2ice-free region, and is chiefly associated with soils that are adjacent to streams and lakes (i.e. wetted margins) during the annual thaw season. However, isolated wetted soils have been observed at locations distal from water bodies. The source of water for the isolated patches of wet soil is potentially generated by a combination of infiltration from melting snowpacks, melting of pore ice at the ice table, and melting of buried segregation ice formed during winter freezing. High resolution remote sensing data gathered several times per summer in the MDV region were used to determine the spatial and temporal distribution of wet soils. The spatial consistency with which the wet soils occurred was assessed for the 2009–10 to 2011–12 summers. The remote sensing analyses reveal that cumulative area and number of wet soil patches varies among summers. The 2010–11 summer provided the most wetted soil area (10.21 km2) and 2009–10 covered the least (5.38 km2). These data suggest that wet soils are a significant component of the MDV cold desert land system and may become more prevalent as regional climate changes.

Development and Demonstration of a GIS-Based Cumulative Effectiveness Approach to Buffer Design and Evaluation

A methodology for incorporating site-specific landscape characteristics into vegetated stream buffer design has been developed. This methodology consists of calculations within a geographic information system format, and applies a sequential accumulation of the contribution of individual pixels of buffer width to overall performance. A demonstration of the application of the methodology to a watershed expecting development is presented here and implications for decision making are discussed. Information layers derived from landscape data layers and used in buffer-performance calculations are displayed. Specific calculations performed in the demonstration are buffer delineation, with implications related to the potential impact of variable versus fixed width buffers, to the impact of assumptions with respect to the type of sediment needing to be settled out, and to the need to mandate wider buffer widths adjacent to lower order streams. Sediment-trapping efficiency calculations can be used to set performance standards and assess the viability of certain criteria in terms of areas potentially available for buffers. The reduction in peak discharges of storm-water runoff (through some combination of infiltration and detention) is becoming a surrogate water-quality parameter for non-point-source pollution in recent total maximum daily load determinations. Infiltration-volume estimation can be used in assessing the feasibility of such a surrogate approach.

Water tracks and permafrost in Taylor Valley, Antarctica: Extensive and shallow groundwater connectivity in a cold desert ecosystem

Water tracks are zones of high soil moisture that route water downslope over the ice table in polar environments. We present physical, hydrological, and geochemical evidence collected in Taylor Valley, McMurdo Dry Valleys, Antarctica, which suggests that previously unexplored water tracks are a significant component of this cold desert land system and constitute the major flow path in a cryptic hydrological system. Geological, geochemical, and hydrological analyses show that the water tracks are generated by a combination of infiltration from melting snowpacks, melting of pore ice at the ice table beneath the water tracks, and melting of buried segregation ice formed during winter freezing. The water tracks are enriched in solutes derived from chemical weathering of sediments as well as from dissolution of soil salts. The water tracks empty into ice-covered lakes, such as Lake Hoare, resulting in the interfingering of shallow groundwater solutions and glacier-derived stream water, adding complexity to the geochemical profile. Approximately four orders of magnitude less water is delivered to Lake Hoare by any given water track than is delivered by surface runoff from stream flow; however, the solute delivery to Lake Hoare by water tracks equals or may exceed the mass of solutes delivered from stream flow, making water tracks significant geochemical pathways. Additionally, solute transport is two orders of magnitude faster in water tracks than in adjacent dry or damp soil, making water tracks “salt superhighways” in the Antarctic cold desert. Accordingly, water tracks represent a new geological pathway that distributes water, energy, and nutrients in Antarctic Dry Valley, cold desert, soil ecosystems, providing hydrological and geochemical connectivity at the hillslope scale.

Investigating artificial groundwater recharge to ensure the water supply to the city of Graz

Being Austria's fourth largest water-supply company, the Grazer Stadtwerke AG., has ensured the successful water-supply of the Styrian capital with 250.000 inhabitants for many years. The average daily water demand of the area amounts to about 50,000 m3. Approximately 30 % of the total demand is covered by the bulk water supply from the Zentral Wasser Versorgung Hochschwab Süd. The waterworks Friesach and Andritz, which cover the additional 70 % of the water demand, operate by means of artificial groundwater recharge plants where horizontal filter wells serve as drawing shafts. The groundwater recharge systems serve to increase the productivity of the aquifer and to reduce the share of the infiltration from the Mur River. Protection areas have been identified to ensure that the water quality of the aquifer stay at optimal levels. The protection areas are divided into zones indicating various restrictions for usage and planning. Two respective streams serve as the source for the water recharge plants. Different infiltration systems are utilised. Each of the various artificial groundwater recharge systems displays specific advantages and disadvantages in terms of operation as well as maintenance. In order to secure a sustainable drinking water supply the recharge capacity will be increased. Within an experimental setting different mixtures of top soils are investigated with respect to infiltration and retention rates and compared to the characteristics of the existing basins. It can be shown that the current operating sand basin with more than 90% grains in the range between 0.063 and 6.3 mm represents the best combination of infiltration and retention rates. In future experiments the performance of alternative grain size distributions as well as planting the top soil will be tested. Additionally, in order to optimize the additional groundwater recharge structures the composition of the subsurface water regarding its origin is statistically analyzed.

Hydrostatic consolidation of commingled fibre composites

A molten hybrid-yarn composite is modelled as a continuum. Constitutive equations governing hydrostatic consolidation are formulated, based on a two-phase continuum mechanical framework developed in a recent paper [Larsson R, Wysocki M, Toll S. Process-modelling of composites using two-phase porous media theory. European Journal of Mechanics-A 2004;23:15–36]. The fibre bundles are assumed to be completely surrounded by resin, thus subjected to hydrostatic pressure. To model the infiltration of resin into the fibre bundles, we introduce a compressible solid phase consisting of fibres plus intra-fibre void. The compression of the solid phase is caused by a combination of infiltration and elastic compression of the fibre bundles. The models are micromechanical, and all parameters have a clear physical meaning and are measurable in principle. Using parameter values out of the literature and estimated from micrographs, the number of adjustable parameters may be brought down to one: a spring constant for the fibre bundle elasticity. Consolidation experiments are performed, where a tool is closed to a prescribed compression and then held fixed, while the pressure is monitored over time. The predicted and measured pressure traces are in good agreement.

Melt-infiltration processing of TiC/Ni3Al composites

A simple melt-infiltration processing route has been developed for the fabrication of TiC/Ni3Al ceramic/intermetallic composites, which involves a combination of infiltration and subsequent liquid phase sintering. For Ni3Al contents from 8 to 25 vol. %, densities in excess of 98% of theoretical are readily obtained when processing at 1450 °C. TiC and Ni3Al are the only phases detected in the densified materials. Ni3Al ductility is retained after processing, leading to the possibility of ductile phase toughened TiC composites for elevated temperature applications (up to ∼1100 °C).

Increasing high temperature oxidation and corrosion resistance of graphite and carbon-fiber-reinforced carbon by deposition of a low pressure chemically vapor-deposited silicon carbide coating

This paper describes a process to protect graphite and carbon-fiber-reinforced carbon (CFRC) against high temperature oxidation and corrosion while maintaining thermal shock properties by a combination of infiltration and deposition into and/or onto the products' surface. Coating parameters and morphologies are discussed. Through research and continuing product development, it is possible to reduce greatly the rates of oxidation and corrosion of graphite or CFRC by the use of low pressure chemical vapor deposition of SiC and multilayer techniques. A β-SiC (111) coating alone or in combination with a multilayer treatment can be produced in large-scale reactors to achieve enhanced oxidation and corrosion resistance while not eliminating the thermal shock properties.