scholarly journals Six-Year Evaluation of Circular Root Barriers on Two Tree Species

2009 ◽  
Vol 35 (1) ◽  
pp. 41-46
Author(s):  
Dennis Pittenger ◽  
Donald Hodel
Keyword(s):  
Surface Soil ◽  
Low Cost ◽  
Large Diameter ◽  
Tree Roots ◽  
Reduced Height ◽  
Root Barriers ◽  
Small Roots ◽  
Root Barrier ◽  
Ficus Microcarpa ◽  
Height Increase

The influence of four circular root barriers on surface root development and tree growth was evaluated on Liquidambar styraciflua (American sweetgum) and Ficus microcarpa (Indian laurel fig) in southern California, U.S. Six years after installation, root barriers had reduced the total number of roots growing in the surface 15 cm (6 in) of soil and nearly eliminated large (diameter 5 cm [2 in] or greater) surface tree roots within a 120 cm (48 in) radius of the trunk. Various sizes and types of low-cost noncommercial barriers, including a container-grown tree’s nursery container with the bottom removed, were equally effective in reducing the number of large-diameter surface roots. However, roots grew below barriers and returned to the surface soil when soil texture, bulk density, and water content were near optimum for root growth at the bottom of the barrier. Many small roots 1.25 cm (0.5 in) £ diameter less than 2.5 cm (0.5 in £ diameter to less than 1 in) were found growing in the upper 15 cm (6 in) of soil just beyond barriers within 18 to 60 cm (7 to 24 in) of the trunk. No barrier treatment reduced the number of small roots of either species beyond 60 cm (24 in) radius from the trunk. Keeping pavement at least 120 cm (48 in) away from trees would be as effective as a root barrier in reducing the possibility of damage from large surface roots. A #15 nursery container serving as a root barrier reduced caliper increase of both species, whereas this treatment and the DeepRoot® barrier treatment reduced height increase of Liquidambar.

scholarly journals Comparison of Methods to Reduce Sidewalk Damage from Tree Roots

2008 ◽  
Vol 34 (3) ◽  
pp. 179-183
Author(s):  
E. Thomas Smiley
Keyword(s):  
North Carolina ◽  
Research Laboratory ◽  
Long Term Effects ◽  
Tree Roots ◽  
Platanus Acerifolia ◽  
Tree Diameter ◽  
Plane Trees ◽  
Root Barriers ◽  
Root Barrier

Tree roots growing under sidewalks are known to crack or lift pavement often creating a tripping hazard for pedestrians. This experiment was conducted to determine the long-term effects of below- and alongside-pavement treatments on tree root development and sidewalk damage. London, U.K. plane trees (Platanus × acerifolia) were planted next to sidewalks at the Bartlett Tree Research Laboratory in Charlotte, North Carolina, U.S., in 1996. Treatments installed at the time of planting were: DeepRoot Universal Tree Root Barrier (UB18-2), vertical polyethylene sheet, gravel, Foamular® 150 extruded polystyrene, and a structural soil. The sidewalks and soil beneath them were removed in 2006. Minimal sidewalk lifting or cracking was associated with the DeepRoot barrier, gravel, and foam treatments. Vertical root barriers and foam resulted in fewer and deeper roots under the pavement. Treatments had no impact on tree diameter growth.

Water transport in European Beech roots (<5mm) under drought in the south of Lower Saxony

2021 ◽  
Author(s):  
Eva Messinger ◽  
Heinz Coners ◽  
Dietrich Hertel ◽  
Christoph Leuschner
Keyword(s):  
Soil Moisture ◽  
Water Transport ◽  
Water Uptake ◽  
Sap Flow ◽  
Climate Models ◽  
European Beech ◽  
Root Surface Area ◽  
Lower Saxony ◽  
Tree Roots ◽  
Small Roots

&lt;p&gt;Climate models predict hotter and dryer summers in Germany, with longer periods of extreme droughts like in summer 2018. How does this affect the water uptake and transport in tree roots growing in the top- and subsoil?&lt;/p&gt;&lt;p&gt;In summer 2018 and 2019 we measured the water transport in fine roots (&lt;5mm) of European Beech on tertiary sand and triassic sandstone up to 2 m depth. We adapted the well-established HRM technique to enable measurements of very small sap flow rates in small roots. Thus, we measured the water transport as a temperature ratio of a stretching heat pulse.&lt;/p&gt;&lt;p&gt;Relating sap flow to root surface area, root depth, anatomy, soil moisture, and VPD allows for interesting insights in tree water uptake rates: Where are the limits of drought intensity and duration, for water uptake and recovery of small roots? Are there differences in the function of top- and subsoil roots? Are roots specialized for water transport or nutrient uptake? The investigated data gives a first hint on how the water transport in Beech roots differs with changes in the soil moisture and VPD under changing climate.&lt;/p&gt;

scholarly journals Basic Materials Studies of Lanthanide Halide Scintillators

2007 ◽  
Vol 1038 ◽  
Author(s):  
F. P. Doty ◽  
Douglas McGregor ◽  
Mark Harrison ◽  
Kip Findley ◽  
Raulf Polichar ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Materials Science ◽  
Low Cost ◽  
Large Diameter ◽  
Scale Up ◽  
Chemical Properties ◽  
Anisotropic Plasticity ◽  
Ongoing Work ◽  
Perfect Cleavage ◽  
Physical And Chemical

AbstractCerium and lanthanum tribromides and trichlorides form isomorphous alloys with the hexagonal UCl3 type structure, and have been shown to exhibit high luminosity and proportional response, making them attractive alternatives for room temperature gamma ray spectroscopy. However the fundamental physical and chemical properties of this system introduce challenges for material processing, scale-up, and detector fabrication. In particular, low fracture stress and perfect cleavage along prismatic planes cause profuse cracking during and after crystal growth, impeding efforts to scale this system for production of low cost, large diameter spectrometers. We have reported progress on basic materials science of the lanthanide halides. Studies to date have included thermomechanical and thermogravimetric analyses, hygroscopicity, yield strength, and fracture toughness. The observed mechanical properties pose challenging problems for material production and post processing; therefore, understanding mechanical behavior is key to fabricating large single crystals, and engineering of robust detectors and systems. Analysis of the symmetry and crystal structure of this system, including identification of densely-packed and electrically neutral planes with slip and cleavage, and comparison of relative formation and propagation energies for proposed slip systems, suggest possible mechanisms for deformation and crack initiation under stress. The low c/a ratio and low symmetry relative to traditional scintillators indicate limited and highly anisotropic plasticity cause redistribution of residual process stress to cleavage planes, initiating fracture. Ongoing work to develop fracture resistant lanthanide halides is presented.

Targeting Low Cost and Value-Added Rehabilitation of Large Diameter Sewers

2009 ◽  
Vol 2009 (2) ◽  
pp. 518-522
Author(s):  
J. Morgan ◽  
J. Trypus ◽  
S. Fairfax ◽  
E. Haenlein
Keyword(s):  
Low Cost ◽  
Large Diameter ◽  
Value Added

Rectangular Microlens Array Having High Sag for Multi Chip LED Packaging

2006 ◽  
Vol 326-328 ◽  
pp. 1491-1494 ◽  
Author(s):  
Won Kyu Jeung ◽  
Chang Hyun Lim ◽  
Tae Hoon Kim ◽  
Seog Moon Choi
Keyword(s):  
Mass Production ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Large Diameter ◽  
Optical Loss ◽  
Microlens Array ◽  
Wafer Level ◽  
Rectangular Shape ◽  
Replication Method ◽  
Optical Extraction

A novel rectangular shape microlens array having high sag for solid-state lighting is presented. The rectangular shape of proposed microlens can maximize the fill factor of silicon based light-emitting-diode (LED) packaging and minimize the optical loss through the reduction of unnecessary reflection at the same time. Microlens, which has high sag, over 3 75 μm and large diameter, over 3 mm can enormously enhance output optical extraction eff iciency. Moreover wafer level packaging technology is adopted to improve the aligning accu racy and mass production of LED packaging. This wafer level microlens array can be direc tly fabricated on LED packaging using replication method. It has many advantages in optica l properties, low cost, high aligning accuracy, and mass production.

Methodology for Analysis of Installation of a Steel Lazy Wave Riser

2004 ◽  
Author(s):  
Marcio M. Mourelle ◽  
Marcos Queija de Siqueira ◽  
Gabriela Grisolia de Avila ◽  
Ana Lucia F. Lima Torres
Keyword(s):  
Failure Modes ◽  
Feasible Solution ◽  
Low Cost ◽  
Large Diameter ◽  
Petroleum Industry ◽  
Computer Code ◽  
Cost Increase ◽  
Limited Length ◽  
Operational Phase ◽  
Configuration Changes

The Petroleum Industry has been looking for a configuration for large diameter steel risers, which can be used either at FPSO’s or Semi Submersible Platforms. An interesting option with a low cost increase is the lazy-wave configuration, which is obtained by the addition of buoyancy modules along a limited length of the riser, close to its touch down area. The steel lazy-wave riser is usually checked for the standard failure modes in the operational phase. The present work shows that it is also necessary in the early stages of design, to define an installation procedure in order to assure configuration feasibility, as high stresses develop at riser hog and sag areas as a function of buoyancy modules installation. Riser configuration changes during the installation process demands managing top angle, launched length and distances between the platform and the installation vessel. The limitations of the installation’s equipment have to be taken into account as well. The methodology for the riser analysis in obtaining a feasible solution is outlined. The riser analysis is performed using the Petrobras in-house computer code, ANFLEX and considers a real application scenario for study.

Observation of Cracks Originating from Transition Area in Induction-Heated S45C Shaft under Rotating Bending Fatigue

2020 ◽  
Vol 832 ◽  
pp. 3-9
Author(s):  
Koshiro Mizobe ◽  
Masayuki Matsushita ◽  
Takuya Shibukawa ◽  
Katsuyuki Kida
Keyword(s):  
Induction Heating ◽  
Low Cost ◽  
Large Diameter ◽  
Low Carbon Steel ◽  
Fatigue Tests ◽  
Low Carbon ◽  
Bending Fatigue ◽  
Transition Area ◽  
Rotating Bending Fatigue ◽  
Rotating Bending

Low carbon steel is one of the most common steels used in industry because of its low cost. If more strength is required, it can be strengthened by induction heating which is also a low-cost method. In order to investigate the effect of induction heating on large diameter shafts, we performed rolling bending fatigue tests using 10 mm diameter specimens. We found that TRO cracks originating from the boundary between the soft and hard layers governed the fatigue fracture of the shafts.

scholarly journals Large Dimension and Low-Cost Fe-SMA Rods

2019 ◽  
Vol 271 ◽  
pp. 01005
Author(s):  
Hande Ozcan ◽  
Ji Ma ◽  
Jeremy E. Schaffer ◽  
Ibrahim Karaman
Keyword(s):  
Grain Growth ◽  
Single Phase ◽  
Electron Backscatter Diffraction ◽  
Low Cost ◽  
Large Diameter ◽  
Heat Treatments ◽  
Two Phase ◽  
Electron Backscatter ◽  
Bamboo Structure ◽  
Backscatter Diffraction

The effects on sample size on abnormal grain growth in inexpensive FeMnAlNi shape memory alloy (SMAs) wires and rod were investigated. It was shown that repeated heat treatments between single phase (bcc) and two phase (bcc + fcc) region resulted in abnormal grains with bamboo structure both in small sized wires and large diameter rods. Microstructural features were investigated using electron backscatter diffraction (EBSD) and it was found that 0.5 mm wires possess strong [011] texture whereas, large diameter rods have random texture after grain growth heat treatments.

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