Hydraulic traits were studied in temperate, woody evergreens in a high-elevation heath community to test for trade-offs between the delivery of water to canopies at rates sufficient to sustain photosynthesis and protection against disruption to vascular transport caused by freeze-thaw-induced embolism. Freeze-thaw-induced loss in hydraulic conductivity was studied in relation to xylem anatomy, ...

Preliminary note The aim of the investigation was to compare and unveil efficiency of electro-hydraulic control (EHR) system to mechanical three point hitch regulation in mouldboard ploughing. Increase of working velocity and three point hitch automatic regulation activity decreased depth of ploughing at both regulation systems but electro-hydraulic system done it more accurately since deviatio...

Spatial gradients in mangrove tree height in barrier islands of Belize are associated with nutrient deficiency and sustained flooding in the absence of a salinity gradient. While nutrient deficiency is likely to affect many parameters, here we show that addition of phosphorus (P) to dwarf mangroves stimulated increases in diameters of xylem vessels, area of conductive xylem tissue and leaf area...

The aim of this study was to compare ex vivo filtration rate (hydraulic conductance) in human dentin discs mechanically treated with diamond and carbide burs of different grain size with or without acid etching. Method: 60 healthy third molars, recently extracted from patients aged 18-30 years, were cleaned, disinfected (0.1% thymol) and embedded in epoxy resin blocks. Dentin discs were obtaine...

A four- to seven-fold enhancement of leaf hydraulic conductance by light has been reported in three temperate tree species. The enhancement occurs in the liquid-flow pathway between the petiole and the site of water evaporation. The enhancement occurs within 1 h, and dissipates in darkness over a period of 1 to 10 h depending on species. Here we report light-induced enhancement of leaf hydrauli...

The hydraulic resistance was measured on internodal cells of Chara corollina and Nitellopsis obtusa using the method of transcellular osmosis described by KAMIYA and TAzAwA in 1956. The transcellular hydraulic resistances of N. obtusa and C. corollina are 2.63 and 1.11 pm -I sPa, resepectively. These values correspond to osmotic permeability coefficients (P os) of 102.6 and 243.1 flm s I, respe...

soil hydraulic properties are key soil physical characteristics that are required to conduct soil and water related studies such as irrigation and drainage. in this study, three indirect methods: inverse modeling, pedo-transfer function, and the semi-physical method of arya et al., were compared in a sandy loam soil to estimate soil moisture retention and unsaturated hydraulic conductivity curv...

Angiosperm and coniferous tree species utilize a continuum of hydraulic strategies. Hydraulic safety margins (defined as differences between naturally occurring xylem pressures and pressures that would cause hydraulic dysfunction, or differences between pressures resulting in loss of hydraulic function in adjacent organs (e.g., stems vs. leaves) tend to be much greater in conifers than angiospe...

1.0 Introduction Hydraulic fracturing, the process of initiation and propagation of a crack by pumping fluid at relatively high flow rates and pressures, is one of several techniques for creating cracks in rock. Fractures in the earth's crust are desired for a variety of reasons, including enhanced oil and gas recovery, re-injection of drilling or other environmentally sensitive wastes, measure...

In this paper, we describe a hydraulic system design and vehicle dynamic modeling for development of tire roller traction, an essential aspect in the system analysis of tire rollers. Generally, tire rollers are one of the most useful types of machines employed in road construction, technically applied to many construction fields. We also conceptualize a new hydraulic and driving system as well ...