Aging of Plant Tissue and Stress-Strain Curves, Modulus of Elasticity and Specific Gravity of Plant Tissues

1945 ◽  
Vol 48 (2) ◽  
pp. 186 ◽  
Author(s):  
Otto Treitel
Weed Science ◽  
2013 ◽  
Vol 61 (1) ◽  
pp. 63-67 ◽  
Author(s):  
R. Bradley Lindenmayer ◽  
Scott J. Nissen ◽  
Philip P. Westra ◽  
Dale L. Shaner ◽  
Galen Brunk

Field bindweed is extremely susceptible to aminocyclopyrachlor compared to other weed species. Laboratory studies were conducted to determine if absorption, translocation, and metabolism of aminocyclopyrachlor in field bindweed differs from other, less susceptible species. Field bindweed plants were treated with 3.3 kBq14C-aminocyclopyrachlor by spotting a single leaf mid-way up the stem with 10 µl of herbicide solution. Plants were then harvested at set intervals over 192 h after treatment (HAT). Aminocyclopyrachlor absorption reached a maximum of 48.3% of the applied radioactivity by 48 HAT. A translocation pattern of herbicide movement from the treated leaf into other plant tissues emerged, revealing a nearly equal aminocyclopyrachlor distribution between the treated leaf, aboveground tissue, and belowground tissue of 13, 14, and 14% of the applied radioactivity by 192 HAT. Over the time-course, no soluble aminocyclopyrachlor metabolites were observed, but there was an increase in radioactivity recovered bound in the nonsoluble fraction. These results suggest that aminocyclopyrachlor has greater translocation to belowground plant tissue in field bindweed compared with results from other studies with other herbicides and other weed species, which could explain the increased level of control observed in the field. The lack of soluble metabolites also suggests that very little metabolism occurred over the 192 h time course.


2020 ◽  
Vol 10 (5) ◽  
pp. 6220-6223
Author(s):  
A. H. Bhutto ◽  
G. S. Bhurgri ◽  
S. Zardari ◽  
M. A. Zardari ◽  
B. A. Memon ◽  
...  

The settlement calculation of a multi-story building is a challenging task due to the variation of soil properties and the use of an appropriate constitutive model for the reliable representation of soils’ stress-strain behaviors. In this study, the settlement response of a multi-story building was calculated with the simple Mohr-Coulomb Model (MCM) and the Hardening Soil Model (HSM). The effect of soil modulus of elasticity using both models was investigated on the overall settlement response of the building. Results indicated that MCM overestimated immediate settlement in a range of 50 to 65% compared to HSM. The settlement response of the building calculated with both models was within the allowable range. The results of this study can be helpful for geotechnical engineers working on reliable predictions of the settlement of multi-story buildings.


2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Teuku Rihayat ◽  
Noor Mustafa ◽  
Saari Mustapha

This study investigates the effect of filler content on mechanical properties for polypropylene. There are  synthesis clay and  un-synthesis clay  used  as  filler  content. Different ratio  of  clay  was  d  in polypropylene to study which ratio have a better mechanical properties. The tensile test was carried out using INSTRON5565 and the maximum stress, strain, and modulus of elasticity observed. Results of the study showed that polypropylene/clay nanocomposite has a higher maximum stress compare to pure polypropylene and un-synthesis clay have a lowest. Besides that modulus of elasticity of specimen calculated and finds that it increased with increment filler content and strain did not affect by filler. The conclusion is synthesis clay filled into polypropylene will having a better material.Keywords: Nanocomposite, polypropylene, synthesis clay.


1986 ◽  
Vol 69 (1) ◽  
pp. 162-166
Author(s):  
Khaja Khaleeluddin ◽  
Linda Bradford

Abstract Total nonstructural carbohydrates (TNC) in plant tissue are underestimated by single enzyme (a-amylase or glucoamylase) extraction and overestimated by mild acid hydrolysis. A combination of glucoamylase and mycolase degraded starch completely to glucose at 60°C and pH 4.9. This dual enzyme extraction procedure was effective in determining TNC in plant tissues that do not accumulate fructosans. The reducing sugar (mainly glucose and/or fructose) extracts produced by enzymatic digestion of plant tissue were clarified with barium hydroxide and zinc sulfate solutions and analyzed by the Shaffer-Somogyi copperiodometric titration method. The dual enzyme method hydrolyzed pure starch derived from corn, wheat, and potato, and potato-soluble starch to about 100% glucose, whereas mycolase only yielded about 88% hydrolysis. Although corn starch was completely hydrolyzed in 2 h by the dual enzyme method, plant tissues required at least 24 h hydrolysis for maximum TNC values. Lead acetate precipitation of the protein in the dual enzyme extracts interfered with the copper-iodometric titration. Gelatinization of starch in plant tissue by autoclaving gave higher TNC values than heating on a hot plate for 5 min. The Schaffer-Somogyi copper iodometric titration method could be used to measure/or define the activity of certain enzymes.


Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2801 ◽  
Author(s):  
Ayman El-Zohairy ◽  
Hunter Hammontree ◽  
Eddie Oh ◽  
Perry Moler

Concrete is one of the most common and versatile construction materials and has been used under a wide range of environmental conditions. Temperature is one of them, which significantly affects the performance of concrete, and therefore, a careful evaluation of the effect of temperature on concrete cannot be overemphasized. In this study, an overview of the temperature effect on the compressive behavior of plain hardened concrete is experimentally provided. Concrete cylinders were prepared, cured, and stored under different temperature conditions to be tested under compression. The stress–strain curve, mode of failure, compressive strength, ultimate strain, and modulus of elasticity of concrete were evaluated between the ages of 7 and 90 days. The experimental results were used to propose constitutive models to predict the mechanical properties of concrete under the effect of temperature. Moreover, previous constitutive models were examined to capture the stress–strain relationships of concrete under the effect of temperature. Based on the experimental data and the proposed models, concrete lost 10–20% of its original compressive strength when heated to 100 °C and 30–40% at 260 °C. The previous constitutive models for stress–strain relationships of concrete at normal temperatures can be used to capture these relationships under the effect of temperature by using the compressive strength, ultimate strain, and modulus of elasticity affected by temperature. The effect of temperature on the modulus of elasticity of concrete was considered in the ACI 318-14 equation by using the compressive strength affected by temperature and the results showed good agreement with the experimental data.


2019 ◽  
Vol 66 (2) ◽  
pp. 191-201
Author(s):  
Rapeepan Kantavichai ◽  
Eric C Turnblom ◽  
Eini C Lowell

Abstract This study aimed to investigate the effects of juvenile spacing (precommercial thinning), thinning, and fertilization on Douglas-fir butt log (first 4.9 m) and second log (4.9–10 m) quality attributes: juvenile wood percentage, heartwood percentage, rings per inch, specific gravity, and modulus of elasticity. A 41-year-old, 36.6 m site index Douglas-fir stand in western Oregon, USA was selected as the first stand to explore. Nine common silviculture pathway treatments of juvenile spacing, thinning, and fertilization were applied to independent 0.404-hectare plots. Ninety-nine trees were felled and disks cut at five heights along the stem. Wood properties were measured and calculated from the disks for log quality attributes. There was no effect of silvicultural treatments on log heartwood percentage, but significant effects on other log quality attributes were observed. Juvenile wood percentage and rings per inch declined with stand density control and fertilization treatment. Responses to thinning and fertilization in log specific gravity depend on juvenile spacing. Also, thinning and juvenile spacing were shown to have impacts on log modulus of elasticity.


1976 ◽  
Vol 56 (1) ◽  
pp. 133-137 ◽  
Author(s):  
G. M. WARD

Symptoms of sulphur deficiency and toxicity on greenhouse tomatoes (Lycopersicon esculentum Mill.) and cucumbers (Cucumis sativis L.) were produced experimentally in sand culture and are described in detail. The principal morphological effect was a general depression of growth and fruit production. A S content of less than 0.25% in any plant tissue was associated with severe deficiency. The distribution of S in various plant tissues is shown.


1984 ◽  
Vol 116 (9) ◽  
pp. 1277-1279 ◽  
Author(s):  
Arthur E. Weis

Plant galls are growth deformities developed under the influence of parasitic insects. The process of differentiation of normal plant tissue into gall tissue has been examined by many authors (Kostoff and Kendall 1929; Rohfristch 1977; see also Mani 1964) but less effort has been made to study the effects of the gallmaker on plant tissues outside the vicinity of active gall formation. Negative effects on the overall growth of the host plant can be expected because the gall acts as an energy and nutrient sink (Palct 1972; Hartnett and Abrahamson 1979), which can cause abnormal patterns of resource allocation among plant organs.


2014 ◽  
Vol 912-914 ◽  
pp. 247-250 ◽  
Author(s):  
Diego Henrique de Almeida ◽  
Raquel Schmitt Cavalheiro ◽  
Fabiane Salles Ferro ◽  
Tiago Hendrigo de Almeida ◽  
André Luis Christoforo ◽  
...  

Schizolobium amazonicum is being much used in Brazil for several purposes because, besides being a native Brazilian wood specie, has important features such as low density and small incidence of natural defects. At this point, researches with the purpose of obtaining further knowledge of their properties are being conducted to better targeting their use. The aim of this research is to evaluate the modulus of elasticity of structural size pieces of Schizolobium amazonicum wood using the technique of transverse vibration. Tests were carried out using 30 pieces (standard moisture content 12%) with sizes of 3 cm x 15 cm x 2.5 m. The average value of elastic modulus determined for lumber of Schizolobium amazonicum was interesting to its low specific gravity.


Sign in / Sign up

Export Citation Format

Share Document