scholarly journals Compression Characteristics of Solid Wastes as Backfill Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Meng Li ◽  
Jixiong Zhang ◽  
Rui Gao
Keyword(s):  
Large Diameter ◽  
Testing Machine ◽  
Deformation Modulus ◽  
Compression Tests ◽  
Initial Portion ◽  
Filling Materials ◽  
Backfill Materials ◽  
Material Testing Machine ◽  
Compression Characteristics ◽  
The Relationship

A self-made large-diameter compression steel chamber and a SANS material testing machine were chosen to perform a series of compression tests in order to fully understand the compression characteristics of differently graded filling gangue samples. The relationship between the stress-deformation modulus and stress-compression degree was analyzed comparatively. The results showed that, during compression, the deformation modulus of gangue grew linearly with stress, the overall relationship between stress and compression degree was approximately nonlinear, and the deformation of gangue was rather large during the initial portion of the test. Gangue sample mixed with Talbot Formula provides the best deformation resistance capacity, followed by fully graded and single-graded gangue samples. For applications, with adjustment of the gradation of filling materials and optimal design of compacting equipment, surface subsidence may be better controlled.

scholarly journals Objective Method for Measuring Firmness of Iceberg Lettuce

HortScience ◽  
2000 ◽  
Vol 35 (5) ◽  
pp. 894-897 ◽  
Author(s):  
R. Andrew Schofield ◽  
Jennifer R. DeEll ◽  
Dennis P. Murr
Keyword(s):  
Human Error ◽  
Testing Machine ◽  
Predictive Ability ◽  
Compression Tests ◽  
Load Range ◽  
Iceberg Lettuce ◽  
Quadratic Response Surface ◽  
Quadratic Response ◽  
Leaf Distribution ◽  
The Relationship

Traditional hand compression firmness scores of iceberg lettuce (Lactuca sativa L.) heads were compared with force-deformation data collected from parallel-plate compression tests conducted with a universal testing machine. Sample deformation was measured over a load range of 30 to 40 N. A quadratic response surface best described the relationship between hand firmness scores (1 to 5 scale) and three measurements of sample deformation (mm). Sample deformation was as precise as hand compression in measuring lettuce firmness, and it provided improved reproducibility by eliminating much of the human error. Although adequate for most firm heads, the predictive ability of the statistical model was weak for soft heads (when the hand firmness score was <2), and for heads with inconsistencies in firmness because of uneven leaf distribution. The minimum sample size required to determine accurately the mean firmness score (±0.5 units) of a population of harvested lettuce was ≈20 heads. This may be a disadvantage, since sampling one head requires ≈1.5 minutes. Overall, the instrument-based method measures lettuce firmness as precisely as the hand compression method, and provides a standardized, objective measurement for postharvest researchers when exchanging or reporting firmness data.

Warm Lateral Extrusion of Magnesium Wrought Alloy by Using Multi-Axes Material Testing Machine

2005 ◽  
Vol 488-489 ◽  
pp. 487-490 ◽  
Author(s):  
Kanichi Hatsukano ◽  
Kunio Matsuzaki ◽  
Toru Shimizu ◽  
Kichitaro Shinozaki
Keyword(s):  
Room Temperature ◽  
Elevated Temperatures ◽  
Testing Machine ◽  
Material Testing ◽  
Extrusion Temperature ◽  
Compression Tests ◽  
Lateral Extrusion ◽  
Cylindrical Billet ◽  
Cylinder Compression ◽  
Material Testing Machine

The Formability of magnesium wrought alloys, AZ61 and AZ31 were investigated . First, the cylinder compression tests were carried out at room temperature and elevated temperatures. Then, the possibility of applying the warm lateral extrusion of the AZ61 and AZ31 alloys were examined under several conditions by using the multi-axes material testing machine. A cylindrical billet coated with molybdenum disulfide lubricant was set in the horizontal die cavity and the billet was heated up to the extrusion temperature, and then extruded laterally under the two horizontally advancing punches. Furthermore, lateral extrusion with counteracting pressure on the end of branches by using two punches methods was tried to reduce the extrusion temperature and sound products was obtained around 190°C.

Interface Structure of Be/HR-1Stainless Steel by Vacuum Diffusion Bonding

2011 ◽  
Vol 314-316 ◽  
pp. 968-971
Author(s):  
Hui Li ◽  
Shang Qi Zhou ◽  
Ji Lan Kong
Keyword(s):  
Stainless Steel ◽  
Diffusion Bonding ◽  
Testing Machine ◽  
Interface Structure ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Composition And Structure ◽  
Material Testing Machine ◽  
The Relationship

Be and HR-I stainless steel with AgCu28 as an interlayer was diffusion bonded by hot pressing，The microstructure，distribution of composition and phase，mechanical properties of the joints were analyzed using scanning electron microscopy(SEM)，scanning auger microspectroy(SAM)，x-ray diffraction(XRD) and material testing machine，and the relationship between composition and structure and properties，and the effect of interlayer materials AgCu28 alloy were also discussed．The results show that good joint can be obtained using AgCu28 alloy as an interlayer material，because it can reduce the mutual diffusion between beryllium and stainless steel elements，the formation of brittle intermetallic compounds between beryllium and stainless steel elements are avoided effectively to improve the diffusion bonding strength and properties．

Experimental Research on Relationship of Load and Displacement of Universal Testing Machine

2011 ◽  
Vol 250-253 ◽  
pp. 1582-1587 ◽  
Author(s):  
Jiang Xu ◽  
Li Feng Lu ◽  
Hong Wei Yang ◽  
Jin Neng Wang ◽  
Yuan Zhang
Keyword(s):  
Cyclic Loading ◽  
Testing Machine ◽  
Pressure Head ◽  
Material Testing ◽  
Pressure Plate ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
Material Testing Machine ◽  
Relationship Of ◽  
The Relationship

The related components of material testing machine (e.g., pressure plate, pressure head, compression bar, etc.) produce distortion in the experiment. It is obviously irrational to use the stroke to replace the specimen displacement, which can’t be measured directly by the extensometer in the destructive test. Therefore, the evolution of specimen displacement, machine displacement and stroke of 45 steel, duralumin alloy and sandstone was analyzed under uniaxial monotonic loading and uniaxial cyclic loading. The results show that the deformation of the related components of universal testing machine, which increases/decreases along with the increase/ decrease of load, can’t be ignored. And there is a good one-to-one correspondence between the machine displacement and the load. It also has nothing to do with the types of specimen materials and the experiments. The relationship of machine displacement and the load can be used to determine the specimen displacement indirectly.

scholarly journals Experimental studies on the transformation from firn to ice in the wet-snow zone of temperate glaciers

1997 ◽  
Vol 24 ◽  
pp. 181-185 ◽  
Author(s):  
Katsuhisa Kawashima ◽  
Tomomi Yamada
Keyword(s):  
Experimental Studies ◽  
Ice Formation ◽  
Compression Tests ◽  
Densification Rate ◽  
Overburden Pressure ◽  
Proportionality Constant ◽  
Wet Snow ◽  
Water Saturated ◽  
The Relationship ◽  
Good Agreement

The densification of water-saturated firn, which had formed just above the firn-ice transition in the wet-snow zone of temperate glaciers, was investigated by compression tests under pressures ranging from 0.036 to 0.173 MPa, with special reference to the relationship between densification rate, time and pressure. At each test, the logarithm of the densification rate was proportional to the logarithm of the time, and its proportionality constant increased exponentially with increasing pressure. The time necessary for ice formation in the firn aquifer was calculated using the empirical formula obtained from the tests. Consequently, the necessary time decreased exponentially as the pressure increased, which shows that the transformation from firn in ice can be completed within the period when the firn aquifer exists, if the overburden pressure acting on the water-saturated firn is above 0.12–0.14 MPa. This critical value of pressure was in good agreement with the overburden pressure obtained from depth–density curves of temperate glaciers. It was concluded that the depth of firn–ice transition was self-balanced by the overburden pressure to result in the concentration between 20 and 30 m.

scholarly journals Resistance to Fracture of Dental Roots Obturated with Different Materials

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Berkan Celikten ◽  
Ceren Feriha Uzuntas ◽  
Kamran Gulsahi
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Negative Control Group ◽  
Positive Control ◽  
Negative Control ◽  
Positive Control Group ◽  
Control Group ◽  
Root Canal Filling ◽  
Filling Materials ◽  
Group 2

The aim of this study was to compare the vertical fracture resistance of roots obturated with different root canal filling materials and sealers. Crowns of 55 extracted mandibular premolar teeth were removed to provide root lengths of 13 mm. Five roots were saved as negative control group (canals unprepared and unfilled). Fifty root canals were instrumented and then five roots were saved as positive control group (canals prepared but unfilled). The remaining 45 roots were randomly divided into three experimental groups (n=15root/group) and obturated with the following procedures: in group 1, glass ionomer-based sealer and cone (ActiV GP obturation system); in group 2, bioceramic sealer and cone (EndoSequence BC obturation system); and in group 3, roots were filled with bioceramic sealer and cone (Smartpaste bio obturation system). All specimens were tested in a universal testing machine for measuring fracture resistance. For each root, the force at the time of fracture was recorded in Newtons. The statistical analysis was performed by using Kruskal-Wallis and post hoc test. There were no significant differences between the three experimental groups. The fracture values of three experimental and negative control groups were significantly higher than the positive control group. Within the limitations of this study, all materials increased the fracture resistance of instrumented roots.

scholarly journals Formation conditions and mechanical properties of aggregates produced in tephra–water–snow flows

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Hirofumi Niiya ◽  
Kenichi Oda ◽  
Daisuke Tsuji ◽  
Hiroaki Katsuragi
Keyword(s):  
Mechanical Properties ◽  
Mixing Time ◽  
Testing Machine ◽  
Small Scale ◽  
Scaling Analysis ◽  
Compression Tests ◽  
Ice Slurry ◽  
Experimental Conditions ◽  
Formation Conditions ◽  
Snow And Ice

Abstract The formation of aggregates consisting of snow, water, and tephra has been reported in small-scale experiments on three-phase flows containing tephra, water, and snow, representing lahars triggered by snowmelt. Such aggregates reduce the mobility of mud flow. However, the formation mechanism of such aggregates under various conditions has not been investigated. To elucidate the formation conditions and mechanical properties of the aggregates, we performed mixing experiments with materials on a rotating table and compression tests on the resulting aggregates with a universal testing machine in a low-temperature room at $$0\,^{\circ }\text {C}$$ 0 ∘ C . From experiments with varying component ratios of the mixture and tephra diameter, the following results were obtained: (i) the aggregate grew rapidly and reached maturity after a mixing time of 5 min; (ii) the mass of aggregates increased with snow concentration, exhibiting an approximately linear relationship; (iii) single aggregates with large mass formed at lower and higher tephra concentrations, whereas multiple aggregates with smaller mass were observed at intermediate concentrations; (iv) the shape of the aggregate satisfied the similarity law for an ellipsoid; (v) the compressive mechanical behavior could be modeled by an empirical nonlinear model. The obtained mechanical properties of the aggregates were independent of the experimental conditions; (vi) scaling analysis based on the Reynolds number and the strength of the aggregates showed that the aggregates cannot form in ice-slurry lahars. Our findings suggest that low-speed lahars containing snow and ice are likely to generate aggregates, but snow and ice in the ice-slurry lahars are dispersed without such aggregates.

scholarly journals Pressure Sensor System for Customized Scoliosis Braces

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1153
Author(s):  
Franz Konstantin Fuss ◽  
Asliza Ahmad ◽  
Adin Ming Tan ◽  
Rizal Razman ◽  
Yehuda Weizman
Keyword(s):  
Pressure Sensor ◽  
Testing Machine ◽  
Force Plate ◽  
Cost Effective ◽  
Mobile Systems ◽  
Sensor System ◽  
Closed Cell ◽  
Hard Shell ◽  
Energy Absorbers ◽  
Material Testing Machine

Hard-shell thoracolumbar sacral orthoses (TLSOs) are used for treating idiopathic scoliosis, a deformation of the spine with a sideways curvature. The pressure required inside the TLSO for ideal corrective results remains unclear. Retrofitting TLSOs with commercially available pressure measurement systems is expensive and can only be performed in a laboratory. The aim of this study was to develop a cost-effective but accurate pressure sensor system for TLSOs. The sensor was built from a piezoresistive polymer, placed between two closed-cell foam liners, and evaluated with a material testing machine. Because foams are energy absorbers, the pressure-conductance curve was affected by hysteresis. The sensor was calibrated on a force plate with the transitions from loading to unloading used to establish the calibration curve. The root mean square error was 12% on average within the required pressure range of 0.01–0.13 MPa. The sensor reacted to the changing pressure during breathing and different activities when tested underneath a chest belt at different tensions. The peak pressure reached 0.135 MPa. The sensor was further tested inside the scoliosis brace during different activities. The measured pressure was 0.014–0.124 MPa. The results from this study enable cheaper and mobile systems to be used for clinical studies on the comfort and pressure of braces during daily activities.

A Laboratory Scale Equipment to Relieve Force and Pressure in Cold Extrusion of Lead Hollow Components

2008 ◽  
Vol 367 ◽  
pp. 137-144 ◽  
Author(s):  
Luigino Filice ◽  
Francesco Gagliardi ◽  
Fabrizio Micari
Keyword(s):  
Numerical Analysis ◽  
Testing Machine ◽  
Load Cell ◽  
Numerical Code ◽  
Cold Extrusion ◽  
Compression Tests ◽  
Local Pressure ◽  
Total Load ◽  
Pure Lead ◽  
Good Surface

Nowadays, many researchers are involved in studies aimed to the explanation of some peculiar aspects regarding manufacturing processes. In this paper, an experimental campaign was carried out in order to reproduce tube extrusion starting from a cylindrical billet. In particular, the development of a proper equipment is presented: the aim was to measure both the total load, by using the testing machine load cell, and the local pressure value on the porthole. The latter task was carried out performing a proper system based on the use of a small load-cell. The tube was extruded with a good surface quality and the external area does not show any welding line evidence. Pure Lead was used for the experimental analysis; this material was chosen due to its high ductility which allows to carry out the process at room temperature. The material was characterized by compression tests at different strain rates and the obtained material law was used to perform a numerical analysis using SFTC Deform 3D numerical code. The Numerical analysis was carried out to show both the advantages and drawbacks of the modern FE codes when extrusion processes are investigated.

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