Effect Of Loading Method Research Articles

Effect of loading method on selective hydrogenation of chloronitrobenzenes over amorphous Ni–B/CNTs catalysts

Carbon nanotubes (CNTs)-supported amorphous Ni–B catalysts were prepared by selectively depositing Ni–B particles inside or outside the CNTs (Ni–B-in/CNTs or Ni–B-out/CNTs). Hydrogenation of chloronitrobenzenes was carried out to test how the Ni–B particle-loading method over the CNTs affected the catalytic performance. Compared with the Ni–B-out/CNTs, the Ni–B-in/CNTs, because of the nanospace limitation inside the CNTs, restricted the size and aggregative behavior of the Ni–B particles better, and formed an amorphous Ni–B alloy with high thermal stability. The Ni–B-in/CNTs exhibited a much higher catalytic activity for hydrogenation of chloronitrobenzenes than the Ni–B-out/CNTs.

Physicochemical properties of Cu loaded onto core–shell Al-MCM-41: Effect of loading methods

Copper species in the structure of Cu/core–shell Al-MCM-41 catalysts prepared by different techniques of Cu loading including substitution, ion-exchange, and impregnation methods were characterized by using temperature-programmed reduction, surface area and porosity analyzer, diffuse reflectance UV–vis-near-infrared spectroscopy, Fourier transforms infrared spectroscopy. Cu2+ in tetrahedral coordination was mostly found from the substitution method. However, from this method CuO was formed from the excess solution of copper nitrate trapped within pores of Al-MCM-41. For the ion-exchange method, only Cu2+ ions were detected. On the other hand, for the impregnation method with high copper loading, the observed copper species was CuO crystals, while with low copper loading both CuO and Cu2+ ions were detected. The acidity of catalysts was also studied by NH3-TPD. It was found that the distinction of copper species in the structure had an effect on Brønsted acid of pre- and post-reduction catalysts, especially in the impregnation method. This study reveals a perspective in the fundamental understanding of copper species-based catalysis.

The effect of the loading method and cross-head speed on resin–dentin microshear bond strength

This study compared the effect of different loading methods and cross­head speeds on resin–dentin microshear bond strength (μSBS) using two etch­and­rinse adhesive systems. Sixty molar teeth had their dentin surfaces exposed and were randomly distributed into 12 groups (n=5), according to a combination of the factors: loading methods (orthodontic-looped wire and chisel systems), cross-head speed (0.5, 1.0 and 5.0mm/min) and adhesive system (Adper Single Bond 2 and XP Bond). Five tygon tubes were positioned over each sample, filled with composite resin and photoactivated. After 24h, they were tested. The data were analyzed with a two-way ANOVA and Tukey test (α=0.05). The µSBS of the adhesives was higher with the chisel methods, compared to the orthodontic-looped wire (p<0.05). The cross-head speed was only significant for the chisel (p<0.05). The evaluated test variables affect the µSBS for both adhesives and therefore should be standardized; however the loading method proved to have the most effect on μSBS values.

Selective hydroisomerization of n-dodecane over platinum supported on SAPO-11

Effects of loading method and amount of platinum on the hydroisomerization of n-dodecane were investigated. Platinum was supported on SAPO-11 by incipient wetness, ion exchange, or atomic layer deposition. Characterization of catalysts was carried out using N2 adsorption, XRD, NH-TPD, TPR, and pyridine-IR. The dispersion of the Pt (IE 0.2)/SAPO-11 and the Pt (ALD 0.6)/SAPO-11 are 0.65 and 0.59, respectively, which are much higher than those of the catalysts prepared by incipient wetness method. The Pt(IW)/SAPO-11 catalyst exhibited the best isomerization activity in the hydroisomerization of n-dodecane, which is attributed to the highest reducibility.

A study on the effect of loading methods (central and two-point) on the bending properties of panel products

Investigations were carried out to study the effect of loading methods viz. central and two-point loading on bending properties of panel products made from wood and bamboo viz. plywood, bamboo mat board (BMB) and bamboo mat veneer composite (BMVC). Panel products of different thicknesses were tested under central and two-point bending for evaluating modulus of rupture (MoR) and modulus of elasticity (MoE). The results revealed that there is a reduction of 3–6% in MoE and increase of 6–10% in MoR values for plywood, whereas a reduction of 8–12% in MoE and increase of 6–10% in MoR values for BMVC was observed, when tested by using two-point loading as compared to central loading method of bending test. Whereas, two-point loading test method is not relevant for flexible panel products like BMB and the values of MoR and MoE obtained by central and two-point loading test methods are not comparable.

모래지반에서 재하방법이 반복수평하중을 받는 말뚝의 거동에 미치는 영향

The behavior of laterally cyclic loaded piles is affected by the magnitude and number of cycles of cyclic lateral loads as well as loading method (1-way or 2-way loading). In this study, calibration chamber tests were carried out to investigate the effects of loading method of cyclic lateral loads on the behavior of piles driven into sand. Results of the chamber tests show that the permanent lateral displacement of 1-way cyclic loaded piles is developed in the same direction as the first loading, whereas that of 2-way cyclic loaded piles is developed in the reverse direction of the first loading. 1-way cyclic lateral loads cause a decrease of the ultimate lateral load capacity of piles, and 2-way cyclic lateral loads cause an increase of the ultimate lateral load capacity of piles. The change of ultimate lateral load capacity with loading method of cyclic lateral loads increases with increasing number of cycles. It is also observed that the 1-way cyclic loads generate greater maximum bending moment than 2-way cyclic loads for piles in cyclic loading step and generates smaller maximum bending moment for piles in the ultimate state. It can be attributed to the difference in compaction degree of the soil around the piles with loading method of cyclic lateral loads. In addition, it is founded that 1-way and 2-way cyclic lateral loads cause a decrease in the maximum bending moment of piles in the ultimate state compared with that of piles subjected to only monotonic loads.

Meso–macroporous monolithic CuO–CeO 2/γ/α-Al 2O 3 catalysts for CO preferential oxidation in hydrogen-rich gas: Effect of loading methods

Meso–macroporous alumina supported CuO–CeO 2 catalysts were prepared by citrate, urea combustion and impregnation methods. The effect of loading methods on the microstructure of the catalysts, the interaction between copper and ceria and the catalytic performance for preferential oxidation of CO in hydrogen-rich gases was investigated. The prepared monolithic catalysts were characterized by using techniques of N 2 adsorption and desorption, SEM, XRD, HRTEM and TPR. The results showed that the loading methods markedly influenced the catalyst structure and the catalytic performance. The citrate and urea combustion methods favored the formation of the interaction between copper and ceria. Compared with the urea combustion method, the citrate method led to smaller ceria particles on the alumina support. The meso–macroporous monolithic catalysts prepared by the citrate method maintained the structural characteristics of the highly active CuO–CeO 2 catalysts, and showed good catalytic performance in CO preferential oxidation in the simulated reformate gases containing water and CO 2.

Favorable recycling photocatalyst TiO 2/CFA: Effects of loading method on the structural property and photocatalytic activity

In order to more easily separate TiO 2 photocatalyst from the treated wastewater, TiO 2 was immobilized on the surface of coal fly ash by employing three kinds of approaches, sol–gel procedure, ambient hydrolysis procedure and hybrid slurry procedure. The effects of loading method on the structural property of TiO 2-coated coal fly ash (TiO 2/CFA), such as morphology, crystal structure, porous property and ultraviolet-visible absorption were investigated, and the photocatalytic activity of TiO 2/CFA was evaluated by the photocatalytic depigmentation and mineralization of methyl orange solution. The results show that TiO 2/CFA particles are easy to precipitate and recover from water. The hybrid slurry procedure is a more proper method to immobilize TiO 2 on coal fly ash than the other two procedures because the TiO 2/CFA sample prepared by hybrid slurry procedure exhibits higher photocatalytic activity and better repeatability.

Effect of loading method on the fracture mechanics of two layered all-ceramic restorative systems

Objective The aim of this research was to evaluate both the fracture and impact strength of two core veneered all-ceramic systems and to reveal whether the speed of loading affects fracture mechanism. Methods The absorbed energy by IPSEmpress-Eris crowns and Cercon-Ceram S crowns in a fracture strength test was compared by the energy absorbed in an impact strength test. The principles of fractography were used to identify fracture origin and dimensions and to calculate the stress at failure. Finite element analysis (FEA) was used to rationalize the results. Results For the IPSEmpress 2-Eris crowns, there was a significant difference in the energy absorbed for the fracture test and the impact test, where for the Cercon-Ceram S, there was no significant difference. Despite the high strength of the zirconia cores there was no significant difference in the energy absorbed between the two systems in the impact strength test. The dominant mode of failure of layered all-ceramic restorations under occlusal loading is cone cracking in the veneering ceramic. Significance It was concluded that to exploit the high strength of the zirconia cores the strength of the veneering ceramic has to improve as delamination and cone cracking of the veneer are the most expected failure modes.

ULTIMATE STRENGTH OF T-SHAPED AND CROSS-SHAPED SOCKET JOINTS BETWEEN STEEL BEAM AND CONCRETE-FILLED STEEL TUBULAR COLUMN

The authors have proposed an equation for estimating the ultimate strength of T-shaped socket joints. However, the effect of cyclic loading and external diagphragms, applicability to the cross-shaped joint and other issues must be verified. Therefore, the static loading tests by using the T-shaped joint specimens were carried out in order to investigate the effects of loading method and the diaphragm. Monotonic static loading tests by using the cross-shaped joint specimens were also carried out. The test results indicate that the loading method and the diaphragm affect the ultimate strength, and that the application of the proposed method to the cross-shaped joint is promising.

The ineffective loading process of the embryo transfer catheter alters implantation and pregnancy rates

The ineffective loading process of the embryo transfer catheter alters implantation and pregnancy rates

Failure Behavior of Wood (Japanese cypress) under Combined Axial Force and Torque. Effects of Loading Method and Loading Path.

Mechanical behavior of wood subjected to normal-shear combined stress conditions was examined. Wood specimens of rectangular bars of Japanese cypress were cut into those whose long axis coincided with the longitudinal direction. These specimens were loaded and twisted in and around the long axis, respectively, according to the following two loading methods, that is, the proportional deformation loading method and the initially constant loading method which has two loading paths. The obtained results are summarized as follows : (1) When the torsional moment was applied to the specimen slightly, the obtained failure strength tended to be measured larger than the pure normal strength. (2) The failure loci of whole testing data could be expressed by the ellipse formula. (3) The failure loci seemed not to be influenced by the loading method and loading path, although the failure mode seemed to be influenced by the loading path.

Influence of loading method and stocking density during transport on meat and dry-cured ham quality in pigs with different halothane genotypes

The effect of loading method and stocking density in transit on meat and dry-cured ham quality was investigated in pigs with different halothane genotypes. A total of 507 Italian heavy pigs, supplied by two farms, were loaded by ramp or lift and transported unmixed for 35–55 min to the abattoir at a stocking density of either <0.4 or >0.6m 2 per 100 kg pigs. After overnight lairage in separate pens with free access to water, the pigs were slaughtered. Halothane genotype was assessed post mortem. Four hundred and thirty-nine pigs had a homozygous dominant (NN) genotype and 68 pigs were heterozygous (Nn). Carcass skin damage, meat quality traits and ham curing parameters were evaluated. Loading method and stocking density showed a negligible effect on meat and dry-cured ham quality while the predominant factor affecting these was the halothane genotype. Nn pigs produced meat with a faster rate of pH fall and lower water holding capacity as well as ham with higher weight losses in salting and greater incidence of defects in the dry-cured product. There were insignificant interactions between halothane genotype and loading method or stocking density. Overall, irrespective of pre-slaughter treatment, the Nn pigs were less suitable for the production of high quality products such as dry-cured ham.

Effect of Loading Method on Compression Testing of Composite Materials

Compression testing methods for composite materials usually employ either shear loading or end loading to apply the compressive load to the specimen. The effect of both loading methods on compression testing of unidirectional composite materials was studied. A combined loading scheme, i.e., the compression specimen was subjected to a combined end and shear loading, was also investigated. The stress distributions within a compression specimen subjected to each of these three different loadings were studied using a three-dimensional finite element analysis. It was found that the shear loading method yielded the most severe stress concentration at the tab tip of the specimen, while the end loading yielded a high shear stress concentration at the loading end of the specimen. The combined loading method was found to be a good compromise to reduce the stress concentration at both the tab tip and the loading end of the specimen, when compared to the shear loading and the end loading methods, respectively. The effect of loading method on a thick-section compression specimen was also analyzed. The end loading method was found to be superior to the shear loading method. The analytical results were also correlated with available experimental data. End crushing of the end-loaded specimen is often experimentally observed, due to the high stress concentration at the end of the specimen as predicted in the present study. However, if the end crushing problem can be overcome, available experimental results show that the end loading method generally yields slightly higher compressive strengths for unidirectional composites than the shear loading method. This agrees with the present analytical results, the end loading method yielding less stress concentration at the tab tip.

ＤＳＣＡによる岩石内微小き裂の評価

In the first part of this study, strains under hydrostatic pressure in an elastic and isotropic body containing a number of penny-shaped microcracks were theoretically investigated to clarify the physical meaning of the parameters used in Differential Strain Curve Analysis (DSCA) and then, a new parameter was proposed to reduce the effects of anisotropy in the intrinsic linear compressibility on the evaluation of crack density.In the second part of this study, the effects of loading methods were experimentally investigated first and the results in the third loading cycle were proposed to be used to evaluate microcracks in rock. Then the parameters characterizing microcracks were determined for some rocks by DSCA. The results showed that better reproducibility was obtained by the new parameter, (Δβ/βl) I, and that microcracks in a soft and porous sedimentary rock can be evaluated by DSCA if the maximum pressure is chosen so that the pressure does not cause new microfracturing in the rock.

On the single fibre pull-out problem: effect of loading method

The loading method in single fibre pull-out experiments would influence the stress distributions in the constituents which, in turn, determine the fibre debond and frictional pull-out stresses. The difference in these stresses for three loading conditions (i.e. the fixed matrix bottom, fixed fibre and matrix bottom and the restrained matrix top conditions) has been identified in a newly-developed analytical model that is based on a fracture mechanics approach. It is shown that the restrained matrix top condition induces a lower initial debond, maximum debond and frictional pull-out stresses compared with the fixed bottom conditions. This is explained by the observation that the potential energy release rate calculated for a given external stress with respect to incremental debond crack propogation is always higher, thereby allowing easy debonding, for the restrained top loading condition. After complete debonding, the interfacial frictional shear stress is significantly lower for the restrained top condition, requiring a low external stress to overcome the interfacial friction for fibre pull-out. The difference in the debond and pull-out stresses increases with increasing embedded fibre length and decreases with increasing ratio of matrix to fibre radii (or fibre volume fraction). A systematic way of evaluating the difference in theoretical predictions against experiments is also presented.

12. Effects of loading method on triaxial test results: R. Lundgren, J.K. Mitchell and J.H. Wilson.J. soil Mech. Fndns Div ASCE94 (2), 407–419 (Mar. 1968)

12. Effects of loading method on triaxial test results: R. Lundgren, J.K. Mitchell and J.H. Wilson.J. soil Mech. Fndns Div ASCE94 (2), 407–419 (Mar. 1968)

2056 鉄筋コンクリート梁に対する曲げと剪断の加力方式(構造)

2056 鉄筋コンクリート梁に対する曲げと剪断の加力方式(構造)