Effect of Seed Orientation, Acid Delinting, Moisture Level, and Sample Type on Cottonseed Fracture Resistance

2019 ◽  
Vol 62 (4) ◽  
pp. 1045-1053
Author(s):  
Michael K. Dowd ◽  
Roji Manandhar ◽  
Christopher D. Delhom
Keyword(s):  
Fracture Resistance ◽  
Compressive Force ◽  
Cottonseed Oil ◽  
Sample Type ◽  
Seed Sample ◽  
Roller Mill ◽  
Seed Damage ◽  
Damage Seed ◽  
Tensile Tester ◽  
Environmental Relative Humidity

Abstract. Cottonseed damage during processing is a growing concern for cotton ginners and cottonseed oil processors. A test to evaluate the durability of seed samples would be beneficial to breeders and ginners to help reduce problems associated with seed damage. Toward this goal, cottonseed fracture resistance was studied with a tensile tester fitted with an adapter to apply compressive force. Seeds cracked with more compressive force when oriented vertically in the tester than when oriented horizontally. Seeds had a greater fracture resistance when they were drier. Even differences in environmental relative humidity (35% to 65%) were enough to affect the testing, indicating that cottonseed requires conditioning to obtain consistent results. Treating the seed with sulfuric acid to remove surface linters did not affect the seed’s tendency to fracture, but significant differences were discernible among seed samples with different genetic backgrounds and production histories. Because several individual seeds needed to be tested to achieve representative results, the compressive fracture resistance may not be the most convenient tool for determining the potential for seed damage during processing. A better test might be some form of mechanical damaging device (e.g., a shaker or roller mill) that would allow faster analysis of a representative seed sample. Keywords: Cottonseed, Ginning, Seed damage, Seed fracture resistance.

scholarly journals Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth Restored with Resin Fiber Post and Stainless Steel Post: An In Vitro Study

2015 ◽  
Vol 03 (02) ◽  
pp. 080-084
Author(s):  
Vijay Singh ◽  
Poonam Bogra ◽  
Saurabh Gupta ◽  
Navneet Kukreja ◽  
Neha Gupta
Keyword(s):  
Stainless Steel ◽  
Fracture Resistance ◽  
Testing Machine ◽  
Compressive Force ◽  
Control Group ◽  
Fiber Post ◽  
Endodontically Treated Teeth ◽  
Group I ◽  
Significant Difference

AbstractFracture resistance of endodontically treated teeth restored with post. Aims: This study aims to compare the fracture resistance of endodontically treated teeth restored with resin fiber and stainless steel post. Commercially available prefabricated resin fiber post(Dentsply Maillefer Easy Post), prefabricated stainless steel post(Coltene/Whaledent Parapost) were used. Methods and Material: Forty five maxillary central incisors were obturated and divided into 3 groups: Control Group (Group I) without any post (n = 15), Resin Fiber Post Group (Group II) (n = 15) and Stainless Steel Post Group (Group III) (n = 15). In all Groups except control group, post space was prepared; a post was cemented, and a core build-up was provided. All the specimens were subjected to compressive force under a universal testing machine until fracture. Statistical analysis used: The results were analyzed using the variable analysis test (ANOVA). Results: One-way analysis of variance revealed significant difference among test groups. The control group demonstrated highest fracture resistance (925.2183 N), followed by the resin fiber post group (486.7265 N) and stainless steel post group (423.539N). Conclusions: Teeth restored with resin fiber post showed higher fracture resistance values than prefabricated stainless steel post.

scholarly journals Fracture Resistance in Non-Vital Teeth: Absence of Interproximal Ferrule and Influence of Preparation Depth in CAD/CAM Endocrown Overlays—An In Vitro Study

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 436
Author(s):  
Lucía Barallat ◽  
María Arregui ◽  
Sandra Fernandez-Villar ◽  
Blanca Paniagua ◽  
Andrés Pascual-La Rocca
Keyword(s):  
Fracture Strength ◽  
Fracture Resistance ◽  
Testing Machine ◽  
Compressive Force ◽  
Ample Evidence ◽  
Alveolar Crest ◽  
Cad Cam ◽  
Group A ◽  
Group B ◽  
Group D

There is ample evidence to support the use of endocrowns to restore endodontic teeth. However, the influence of the position of the interproximal margins on fracture strength has not yet been studied. The aim was to determine the relationship between the apicocoronal position of the interproximal restorative margins and fracture resistance in nonvital teeth restored with CAD/CAM endocrown overlays. Forty extracted human maxillary premolars were prepared for endocrown overlay restorations without ferrule on the interproximal aspects and classified according to the position of the interproximal restoration margins in relation to the alveolar crest: 2 mm (group A), 1 mm (group B), 0.5 mm (group C), and 0 mm (group D). Fracture strength was measured using a universal testing machine applying a compressive force to the longitudinal tooth axis. Group A had a mean fracture resistance of 859.61 (±267.951) N, group B 1053.9 (±333.985) N, group C 1124.6 (±291.172) N, and group D 780.67 (±183.269) N, with statistical differences between groups. Group C had the highest values for fracture strength compared to the other groups (p < 0.05). The location of the interproximal margins appears to influence the fracture resistance of CAD/CAM endocrown overlays. A distance of 0.5 mm between the interproximal margin and the alveolar crest was associated with increased fracture resistance.

Vibration Analysis of a Vertical Roller Mill: Modeling and Validation

2014 ◽  
Author(s):  
Engin H. Çopur ◽  
Metin U. Salamci ◽  
Selahattin Gülbeyaz
Keyword(s):  
Mathematical Model ◽  
Vibration Analysis ◽  
Compressive Force ◽  
Vibration Characteristics ◽  
Physical Parameters ◽  
Roller Mill ◽  
Vibration Tests ◽  
Working Parameters ◽  
The Mathematical Model ◽  
Vertical Roller

In this paper, vibration characteristics of a Vertical Roller Mill (VRM) are studied by using physical parameters of an operating VRM. The mathematical model is derived and simulated for a set of working parameters. Mechanical properties of the grinding material and the physical properties of the mechanical construction are used in the vibration model in order to obtain more realistic results. Simulation results are presented which give critical frequencies of the VRM. The effects of the hydraulic compressive force to the vibration characteristics are investigated. The effects of the material feeding rate (which affects the mineral thickness to be grinded) to the vibration characteristics are also simulated. In order to validate the mathematical model, a set of experimental vibration tests are performed on the VRM. Vibrations are measured during the run-down procedure of the VRM in order to determine natural frequencies of the mill as well as excitation frequencies of the system. The measurements showed the validity of the proposed mathematical model for the vibration analysis of the VRM.

scholarly journals SOME EFFECTS OF BARLEY GRASS SEED ON YOUNG SHEEP

1975 ◽  
pp. 59-65
Author(s):  
M.J. Hartley
Keyword(s):  
Weight Gain ◽  
Rapid Growth ◽  
Adult Sheep ◽  
Grass Seed ◽  
Beneficial Effects ◽  
Seed Damage ◽  
Damage Seed ◽  
Loss Of Weight

Studies were made of the effects of barley grass on young sheep. Up to 8 kg per lamb loss of weight gain during summer has been shown to be due (to barley grass seed damage. Seed in the eyes caused the most rapid growth check but irritation to nostrils, mouth, and skin all contributed. Lambs were affected far more than adult sheep and differences between breeds of sheep were sufficient to consider change of breed where barley grass was troublesome. The beneficial effects and disadvantages of herbicide conmtrol are discussed in relation to density of barley grass infestation.

Modeling the Fracture Resistance of Sunflower Seed and Its Kernel as a Function of Moisture Content, Variety, Size and Loading Orientation

2011 ◽  
Vol 7 (3) ◽  
Author(s):  
R. Khodabakhshian ◽  
Bagher Emadi ◽  
Mohammad Hossein Abbaspour Fard ◽  
Mohammad Hossein Saiedirad
Keyword(s):  
Moisture Content ◽  
Fracture Resistance ◽  
Sunflower Seed ◽  
Compressive Force ◽  
Rupture Force ◽  
Sunflower Seeds ◽  
Absorbed Energy ◽  
Vertical Orientation ◽  
Horizontal Orientation ◽  
Opposite Trend

The aim of this work was to develop a mathematical model describing the evolution of rupture force, absorbed energy and deformation at rupture point. The models exploit the theory of the mechanical behavior of sunflower seeds and its kernel with moisture content, variety, size and loading orientation. The proposed models have been tested on three common Iranian varieties of sunflower seeds and their kernels namely Azargol, Shahroodi and Fandoghi. The results showed that rupture forces for both sunflower seed and kernel decreased with increasing moisture content, while in both loading orientations and for all varieties and size categories, the absorbed energy and deformation at rupture point increased as moisture content increased. The required compressive forces in both orientations, to initiate sunflower seed hulls rupture were higher (30.06 – 117.46 N) than those required to rupture the kernels (11.64 – 39.98 N). The seeds required lower dehulling compressive force when loaded under horizontal orientation than vertical orientation. However, an opposite trend was observed for the kernels. The deformation of kernels was substantially higher (1.92 – 2.90 mm) than the seeds (0.47 – 1.66 mm) for all variables.

scholarly journals The Influence of Different Obturation Systems on the Fracture Resistance of Endodontically Treated Roots. An in Vitro Study

2017 ◽  
Vol 20 (1) ◽  
pp. 6
Author(s):  
Mazen Doumani ◽  
Saleem Abdulrab ◽  
Abdulaziz Samran ◽  
Ahmed Doumani ◽  
Kinda Layous ◽  
...  
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Compressive Force ◽  
In Vitro Study ◽  
Study Groups ◽  
Control Group ◽  
Endodontically Treated Teeth ◽  
Gutta Percha ◽  
Group 2

<p><strong>Objective: </strong>This study aimed to compare the fracture resistance of endodontically treated roots filled by different obturation systems. <strong>Material and methods: </strong>Ninety-six upper central incisors were used and decoronated, retaining 12 mm of the roots. On the basis of obturation systems, the roots were divided into 4 groups (n=24): Group1 (COGR): control group (unprepared, unfilled), Group 2 (AVGR): ActiV GP points/ActiV GP sealer, Group3 (GPGR): Gutta percha points/AH plus sealer, and Group4 (GAGR): Gutta percha points/ActiV GP sealer. The last three groups were obturated with the single cone technique. The roots were then stored in 100% relative humidity at 37 °C for 2 weeks. A vertical compressive force was exerted with a universal testing machine until a fracture occurred. Data were statistically analyzed with one-way ANOVA. <strong>Results</strong><strong>:</strong> Mean (SD) failure loads for groups ranged from 920.51 ± 210.37 to 1113.44 ± 489.42 N. The fracture resistance between the different study groups indicated no statistical difference. <strong>Conclusions:</strong> ActiV GP system did not exert a significant effect on the fracture resistance of endodontically treated teeth.</p>

scholarly journals In Vitro Comparative Analysis of Fracture Resistance of Lithium Disilicate Endocrown and Prefabricated Zirconium Crown in Pulpotomized Primary Molars

2019 ◽  
Vol 7 (23) ◽  
pp. 4094-4100
Author(s):  
Yasmine El Makawi ◽  
Nagwa Khattab
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Compressive Force ◽  
Lithium Disilicate ◽  
Resin Cement ◽  
Primary Molars ◽  
Second Primary ◽  
Post Hoc ◽  
Ceramic Restorations

AIM: This study aimed to evaluate the effect of lithium disilicate endocrowns compared to prefabricated zirconia crown used for restoring pulpotomized primary molars, on their Fracture Resistance and to compare the loads to failure these different ceramic restorations with previously reported posterior occlusal forces. METHODS: Twenty mandibular left second primary molars were randomly distributed into two groups (n = 10 in each group) the zirconia Crown (Nusmile zr.) Group (G1) and the lithium disilicate (IPS e.max Press) Endocrown Group (G2). In all groups pulpotomy procedure was done before preparation then each sample was prepared based on their allocated restoration, both zirconia crown (Nusmile zr.) and endocrown (IPS e.max Press) were cemented by dual-cure resin cement. All samples were loaded to failure using a universal testing machine (Instron, USA), and the compressive force was applied. The data were analysed using one-way (ANOVA) and Tukey’s post hoc significance difference tests. Differences were considered significant at (p< 0.05). RESULTS: Group zirconia crown (G1) showed significantly higher fracture strength than Group (G2) lithium disilicate endocrown (p < 0.05). CONCLUSION: The zirconia crown showed higher fracture resistance than lithium disilicate endocrown. However, both tested zirconia crown and lithium disilicate endocrown withstood the application of axial occlusal forces greater than the reference values for posterior occlusal loads.

Fracture Resistance of Remaining Buccal Cusps in Maxillary Premolar Ceramic Onlay Restorations

2020 ◽  
Vol 45 (6) ◽  
pp. 624-631
Author(s):  
I Thainimit ◽  
P Totiam ◽  
K Wayakanon
Keyword(s):  
Computer Aided Design ◽  
Fracture Resistance ◽  
Compressive Load ◽  
Compressive Force ◽  
Resin Cement ◽  
Tooth Structure ◽  
Partial Coverage ◽  
Cad Cam ◽  
Maxillary Premolars ◽  
One Year

Clinical Relevance Preparation designs for bondable partial coverage restorations are varied. As little as 1 mm of thickness of a remaining buccal cusp can be kept when restoring maxillary premolars with bondable partial coverage restorations. SUMMARY Indirect partial coverage restorations have become increasingly popular in recent years as new and improved adhesive materials have been developed. These restorations can preserve substantial amounts of tooth structure. However, there are some aspects of indirect partial coverage restorations for which no clear protocol exists. This study investigated the minimal thickness of the nonfunctional cusp that must be left in a bondable ceramic partial coverage restoration in order to resist compressive force. Ninety sound human maxillary premolar teeth were obtained and used in one of the following three ways. Ten of the sound teeth were used as a control without further preparation. Forty other sound teeth had cavities designed and were tested as “unrestored teeth.” The remaining 40 sound teeth received not only cavities but also restoration and were tested as “restored teeth.” Both the restored group and the unrestored group were prepared either with an overlay or with varying buccal cusp thicknesses of 1, 2, or 3 mm. In total, there were nine experimental groups with 10 in each group (n=10). The prepared teeth were digitally scanned, and the restorations were designed and fabricated from IPS e.max computer-aided design (CAD) software using a CAD/CAM machine (CEREC MC XL, Dentsply Sirona, Bensheim, Germany). The restorations were cemented with resin cement (Panavia V5). All samples underwent thermocycling and dynamic fatigue simulating approximately one year of actual use. All the teeth were then subjected to compressive load until the point of fracture, and the mode of each fracture was analyzed. Results show that the fracture resistance of the restored groups was significantly higher than the nonrestored groups (p&lt;0.001) and the sound teeth (p&lt;0.05). Crucially, this study determined that 1 mm of remaining buccal cusp thickness in bondable partial coverage restorations for maxillary premolars is sufficient to withstand normal use of the tooth without breakage.

Failure Stress Estimation of Table Liner for Vertical Roller Mill

2007 ◽  
Vol 345-346 ◽  
pp. 457-460
Author(s):  
Dong Woo Lee ◽  
Seok Swoo Cho ◽  
Won Sik Joo
Keyword(s):  
Fatigue Failure ◽  
Structural Design ◽  
Raw Materials ◽  
Compressive Force ◽  
Design Guidelines ◽  
Roller Mill ◽  
Design Life ◽  
Hydraulic Cylinders ◽  
Stress Estimation ◽  
Vertical Roller

A roller mill is composed of several rollers, rotational table liners, hydraulic cylinders and raw materials are ground between the rollers and the table with the assistance with a shearing and compressive force. It has been reported that an unexpected fatigue failure occurred in a table liner in the course of grinding portland cement. It is subjected to the cyclic bending stress by the rollers load and the centrifugal force by the table rotation and fractures at the edge of grinding path of outer roller. It demands design life 4×107 cycles but has fatigue life 4×106 ~ 8×106 cycles. The purpose of this study is to reveal the failure mechanism of the table liner occurring in the grinding operation of roller mill and to show the structural design guidelines for reducing the fatigue failure.

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