scholarly journals Sod Tensile Strength, Handling Quality, and Their Interrelationship for 39 Bermudagrasses

2021 ◽  
pp. 1-6
Author(s):  
Lakshmy Gopinath ◽  
Dennis L. Martin ◽  
Justin Quetone Moss ◽  
Yanqi Wu ◽  
Shuhao Yu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Linear Relationship ◽  
Field Method ◽  
Harvest Date ◽  
Strong Positive Correlation ◽  
Quantitative Parameter ◽  
Slow Recovery ◽  
Cultivar Selection ◽  
Handling Quality ◽  
Qualitative Parameter

Suitable tensile strength is essential for sod harvest, transport, and installation. Thirty-nine bermudagrass (Cynodon sp.) entries were evaluated for sod handling quality (SHQ) and sod tensile strength (STS) during 2014–15. The SHQ (a discontinuous qualitative parameter) was evaluated using a 1 to 5 scale with 1 = complete pad separation during handling and 5 = no cracking or separation in the sod pad with excellent quality. The STS (a quantitative parameter) was determined using the force required to shear/separate the sod pad. Sod harvests were conducted at 14, 22, and 24 months after planting (MAP). The entry, harvest date, and their interaction affected STS and SHQ. Entries OKC 1302 and 12-TSB-1 had greater STS than ‘Patriot’ but less STS than ‘Latitude 36’, ‘Tifway’, ‘Astro’, and ‘TifGrand’. The seeded entry PST-R6T9S had the lowest STS and SHQ. The overall mean STS and SHQ were lowest at 22 MAP, which could be attributed to the slow recovery of the entries after Winter 2014. A strong positive correlation (r = 0.92) between STS and SHQ suggests that SHQ can be used as a rapid field method to estimate suitability for sod harvest. A predictive linear relationship between overall STS and overall SHQ (r2 = 0.85) found predicted STS values of 8.5, 22.6, 36.8, and 51.0 kg⋅dm–2 for overall mean SHQ ratings of 2, 3, 4, and 5, respectively. The results of this work will help sod producers in cultivar selection and will aid breeders in making commercialization decisions.

scholarly journals A study of tensile strength of fractured rock mass by phase field method in DEAL.II with local refinement technique

2020 ◽  
Vol 71 (7) ◽  
pp. 737-745
Author(s):  
Dang Hong Lam
Keyword(s):  
Tensile Strength ◽  
Rock Mass ◽  
Phase Field ◽  
Fractured Rock ◽  
Mechanical Energy ◽  
Field Method ◽  
Phase Field Method ◽  
Small Scale ◽  
Local Refinement ◽  
Fractured Rock Mass

Cracking propagation in elastic and porous media is still challenge topics in mechanical, energy, and environmental engineering. In this paper, the phase field method will be used to model the cracking propagation at the small scale for elastic media. This method is doing well in DEAL.II with the help of local refinement technique which allows studying the tensile strength of fractured rock mass behavior without prior knowledge of cracking propagation path and reduction of computational consumption. This implementation is applied to model a fractured rock mass in which a plenty of explicit fractures are distributed though total energy released by Griffith's criterion. Through these applications, we demonstrate and highlight the performance of the phase field method with local refinement technique in modeling crack propagation as well as investigate the tensile strength of fractured rock mass dependency its crack orientation

Relationship between alternate bearing and apical bud development in cranberry (Vaccinium macrocarpon)

Botany ◽  
2019 ◽  
Vol 97 (2) ◽  
pp. 101-111 ◽  
Author(s):  
Jenny L. Bolivar-Medina ◽  
Juan E. Zalapa ◽  
Amaya Atucha ◽  
Sara E. Patterson
Keyword(s):  
Growth Rates ◽  
Management Practices ◽  
Vaccinium Macrocarpon ◽  
Strong Positive Correlation ◽  
Alternate Bearing ◽  
Apical Bud ◽  
Apical Buds ◽  
Cultivar Selection ◽  
One Year

Similar to other woody crops, cranberry (Vaccinium macrocarpon Ait.) exhibits alternate bearing or a tendency to produce heavier yields one year, followed by lighter yields the next year. Unfortunately, despite the occurrence in many fruit crops, this trait is not well understood. The variable differentiation of floral initials in cranberry uprights is a distinguishing characteristic associated with alternate bearing. This study evaluates bud morphology and the presence of floral initials through characterization of longitudinal sections of apical buds from vegetative and fruiting uprights of alternate and non-alternate bearing genotypes. Our results reveal that differentiation of floral initials in fruiting uprights only occurs in non-alternate bearing genotypes and after initiation in vegetative uprights. In addition, a strong positive correlation was found between the increase of bud width and the presence of floral initials. Lastly, uprights from the alternate bearing genotype exhibited significantly faster growth rates of the reproductive buds compared with the vegetative buds. In summary, our study shows marked differences in timing and growth rates of floral initials between uprights of the two genotypes, suggesting a possible correlation with resource allocation during the growth season, and thus could contribute to cultivar selection and management practices.

Seasonal variation in in vitro methane production of two perennial ryegrass cultivars

2003 ◽  
Vol 2003 ◽  
pp. 158-158
Author(s):  
D. K. Lovett ◽  
A. Bortolozzo ◽  
D. McGilloway ◽  
F. P. O’Mara
Keyword(s):  
Seasonal Variation ◽  
Perennial Ryegrass ◽  
Methane Production ◽  
Heading Date ◽  
Harvest Date ◽  
Cultivar Selection

Previous studies have identified small but significant differences in in vitro methane (CH4) production between perennial ryegrass cultivars harvested pre-heading date. This raises the possibility that enteric CH4 production could be reduced through cultivar selection. The aim of this study was to assess the effect of harvest date on in vitro CH4 output of two cultivars previously identified as having a high and low methanogenic potential (Lovett et al., 2003).

scholarly journals Impact of the Enzyme Charge on the Production and Morphological Features of Cellulose Nanofibrils

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3238
Author(s):  
Sergio Henríquez-Gallegos ◽  
Gregory Albornoz-Palma ◽  
Andrea Andrade ◽  
Carolina Soto ◽  
Miguel Pereira
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cell Wall ◽  
Aspect Ratio ◽  
Linear Relationship ◽  
Mechanical Treatment ◽  
Essential Role ◽  
Cellulose Nanofibrils ◽  
Degree Of Polymerization ◽  
Cnf Films

The available research does not allow specific relationships to be established between the applied enzymatic-mechanical treatment, the degree of polymerization, and the characteristics of the cellulose nanofibrils (CNFs) produced. This work aims to establish specific relationships between the intensity of enzymatic treatment, the degree of polymerization of the cellulose, the morphology of CNFs, and the tensile strength of the CNF films. It is determined that the decrease in the degree of polymerization plays an essential role in the fibrillation processes of the cell wall to produce CNFs and that there is a linear relationship between the degree of polymerization and the length of CNFs, which is independent of the type of enzyme, enzyme charge, and intensity of the applied mechanical treatment. In addition, it is determined that the percentage of the decrease in the degree of polymerization of CNFs due to mechanical treatment is irrespective of the applied enzyme charge. Finally, it is shown that the aspect ratio is a good indicator of the efficiency of the fibrillation process, and is directly related to the mechanical properties of CNF films.

scholarly journals Softwood kraft pulp fines: application and impact on specific refining energy and strength properties

Cellulose ◽  
2020 ◽  
Vol 27 (17) ◽  
pp. 10359-10367
Author(s):  
Daniel Mandlez ◽  
Lukas Zangl-Jagiello ◽  
Rene Eckhart ◽  
Wolfgang Bauer
Keyword(s):  
Tensile Strength ◽  
Linear Relationship ◽  
Apparent Density ◽  
Kraft Pulp ◽  
Strength Properties ◽  
Air Permeability ◽  
Research Interest ◽  
Paper Properties ◽  
Softwood Kraft Pulp ◽  
Breaking Length

AbstractAlong with the emergence of micro and nanofibrillated celluloses and their application in papermaking, the influence of the so called fines fraction of pulps on both process and product properties has received increasing research interest in recent years. Several researchers have experimented with primary and/or secondary pulp fines to assess their effects on paper properties with not always consistent results. Our work focuses on the targeted application of the primary fines fraction of an unbleached softwood kraft pulp. The primary fines are separated from the pulp to be subsequently added to achieve blends of $$5\%, 9\%$$ 5 % , 9 % and $$12\%$$ 12 % primary fines content. These blends were then refined in a PFI mill to evaluate the effect of the primary fines on refining as well as on paper properties of hand sheets prepared from these pulps. It is shown that the addition of primary fines enhances tensile strength in the unrefined and slightly refined state, while the maximum tensile strength of the highly refined reference pulp is not increased. A slightly increased dewatering resistance (Schopper Riegler) at comparable air permeability (Gurley) for a given tensile strength was also observed. The linear relationship between tensile index and apparent sheet density seems to be affected in the unrefined and slightly refined state where the breaking length of the fines enriched samples is higher for a given apparent density.

scholarly journals Off-Axial Tensile Properties of Precontraint PVDF Coated Polyester Fabrics under Different Tensile Rates

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Lanlan Zhang
Keyword(s):  
Tensile Strength ◽  
Linear Relationship ◽  
Failure Modes ◽  
Tensile Tests ◽  
Woven Fabrics ◽  
Uniaxial Tensile ◽  
Fracture Mechanisms ◽  
Axial Angle ◽  
Axial Tensile ◽  
Research Objects

Two types of Precontraint PVDF coated polyester are taken as the research objects. A series of uniaxial tensile tests were carried out to study the tensile performances of the specimens in eleven in-plane directions including 0°, 5°, 15°, 25°, 35°, 45°, 55°, 65°, 75°, 85°, and 90°, and six tensile rates (10 mm/min, 25 mm/min, 50 mm/min, 100 mm/min, 200 mm/min, and 500 mm/min) were also considered. The corresponding failure modes and fracture mechanisms were discussed, and the relationships between tensile strength and strain at break and tensile rate and off-axial angles were obtained. Results show that the Precontraint PVDF coated woven fabrics are typically anisotropic. With off-axial angle increasing, the tensile strength decreases while the strain at break increases. Three failure modes can be observed, including failure of yarns pulled out, yarns fracture, and mixture failure. With tensile rate increasing, the tensile strength increases slightly while the strain at break decreases. The tensile strength and strain at break show good linear relationship with tensile rate’s logarithm.

A novel method for evaluation of biofilm tensile strength resisting erosion

1999 ◽  
Vol 39 (7) ◽  
pp. 261-268 ◽  
Author(s):  
Akiyoshi Ohashi ◽  
Takashi Koyama ◽  
Kazuaki Syutsubo ◽  
Hideki Harada
Keyword(s):  
Tensile Strength ◽  
Tensile Test ◽  
Strong Positive Correlation ◽  
Test Device ◽  
Elastic Coefficient ◽  
Physiological Properties ◽  
Different Types ◽  
Similar Range ◽  
Novel Method ◽  
Biofilm Development

A novel methodology is proposed in this study to evaluate the tensile strength of biofilms by using a newly developed tensile test device. Three different types of biofilms were prepared for tensile test: Run 1 biofilm was aerobically cultivated on glucose, and Run 2 and Run 3 biofilms were denitrifying biofilms grown on glucose and on methanol, respectively, as a sole carbon source. Each of three biofilms was formed on the outer surfaces of tygon-made tubes (diameter 4.76 mm) submerged in a rectangular open-channel reactor. The results demonstrated that the tensile strengths of three different biofilms had a tendency to increase with the biofilm development over a period of 50 days of reactor operation and eventually reached a similar range, approximately 500 to 1000 Pa, independent of biofilm types or cultivation conditions. An elastic coefficient of the biofilm was determined by assuming that a biofilm behaves as an elastic material during the tensile test. A strong positive correlation was found between the elastic coefficient and the tensile strength. However, the behavior of extracellular biopolymer (ECP) content and the biofilm density were not dependent on the tensile strength. Scanning electron microscope (SEM) observations also suggested that the biofilm structural properties such as elastic coefficient are more determinative factors for the tensile strength than are the biofilm physiological properties such as ECP content.

A study of tensile strength of fractured rock mass by phase field method in DEAL.II with local refinement technique

2020 ◽  
Vol 71 (7) ◽  
pp. 737-745
Author(s):  
DANG Hong-Lam
Keyword(s):  
Tensile Strength ◽  
Rock Mass ◽  
Phase Field ◽  
Fractured Rock ◽  
Mechanical Energy ◽  
Field Method ◽  
Phase Field Method ◽  
Small Scale ◽  
Local Refinement ◽  
Fractured Rock Mass

Cracking propagation in elastic and porous media is still challenge topics in mechanical, energy, and environmental engineering. In this paper, the phase field method will be used to model the cracking propagation at the small scale for elastic media. This method is doing well in DEAL.II with the help of local refinement technique which allows studying the tensile strength of fractured rock mass behavior without prior knowledge of cracking propagation path and reduction of computational consumption. This implementation is applied to model a fractured rock mass in which a plenty of explicit fractures are distributed though total energy released by Griffith's criterion. Through these applications, we demonstrate and highlight the performance of the phase field method with local refinement technique in modeling crack propagation as well as investigate the tensile strength of fractured rock mass dependency its crack orientation

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