摘要 :
We analyze the effect of a small inclination on the well-studied problem of two-dimensional binary fluid convection in a horizontally extended closed rectangular box with a negative separation ratio, heated from below. The horizon...
展开
We analyze the effect of a small inclination on the well-studied problem of two-dimensional binary fluid convection in a horizontally extended closed rectangular box with a negative separation ratio, heated from below. The horizontal component of gravity generates a shear flow that replaces the motionless conduction state when inclination is not present. This large-scale flow interacts with the convective currents resulting from the vertical component of gravity. For very small inclinations the primary bifurcation of this flow is a Hopf bifurcation that gives rise to chevrons and blinking states similar to those obtained with no inclination. For larger but still small inclinations this bifurcation disappears and is superseded by a fold bifurcation of the large-scale flow. The convecton branches, i.e., branches of spatially localized states consisting of counterrotating rolls, are strongly affected, with the snaking bifurcation diagram present in the noninclined system destroyed already at small inclinations. For slightly larger but still small inclinations we obtain small-amplitude localized states consisting of corotating rolls that evolve continuously when the primary large-scale flow is continued in the Rayleigh number. These localized states lie on a solution branch with very complex behavior strongly dependent on the values of the system parameters. In addition, several disconnected branches connecting solutions in the form of corotating rolls, counterrotating rolls, and mixed corotating and counterrotating states are also obtained.
收起
摘要 :
We shall derive some basic properties of matrices over a regular incline. We discuss the regularity for matrices over an incline in terms of full row space, full column space and full space factorization. We shall provide an algor...
展开
We shall derive some basic properties of matrices over a regular incline. We discuss the regularity for matrices over an incline in terms of full row space, full column space and full space factorization. We shall provide an algorithm for a regularity of a matrix over an incline whose elements are not linearly ordered.
收起
摘要 :
ASTM C143/C143M-15a, Standard Test Method for Slump of Hydraulic-Cement Concrete, states that the slump test is to be conducted on a level work surface. However, the standard does not provide a method for determining if a work sur...
展开
ASTM C143/C143M-15a, Standard Test Method for Slump of Hydraulic-Cement Concrete, states that the slump test is to be conducted on a level work surface. However, the standard does not provide a method for determining if a work surface is level, a tolerance for levelness, or guidance on what to do in the event that a work surface is not level. More importantly, field technicians need to know at what angle(s) and slump(s), if any, an inclined work surface will significantly influence the measured slump. A study at Valparaiso University included 114 simultaneous measures of slump on a horizontal and separate inclined work surface. This study indicates that inclination angles greater than 6 degrees will influence the outcome of a slump test for slumps of 5 to 7 in. (127 to 179 mm). There is no evidence of concrete "leaning over" for lower inclinations or slumps. At high angles and high slumps, the fluidity of the concrete negates any influence of the inclination. Consequently, it is recommended that ASTM Committee C09.60 on Fresh Concrete Testing add language to C143 requiring the slump test to be conducted on a work surface with an inclination less than 6 degrees, which equates to a 1:9.5 gradient and 10.5 % slope, regardless of the slump of the concrete.
收起
摘要 :
The long-term results of high tibial osteotomy (HTO) depend mainly on postoperative alignment. However, under- or overcorrection can occur during and after surgery. Biomechanically, excessive overcorrection after HTO can potential...
展开
The long-term results of high tibial osteotomy (HTO) depend mainly on postoperative alignment. However, under- or overcorrection can occur during and after surgery. Biomechanically, excessive overcorrection after HTO can potentially lead to unfavorable knee kinematics and increased shear stress at the joint surface. Fine tuning of the medial soft tissue during open wedge HTO is necessary for a satisfactory limb alignment.
收起
摘要 :
A design-oriented analytical model able to evaluate the shear capacity of reinforced concrete (RC) beams strengthened with fiber-reinforced polymer (FRP) sheets or strips oriented in any direction is proposed. The formulation of t...
展开
A design-oriented analytical model able to evaluate the shear capacity of reinforced concrete (RC) beams strengthened with fiber-reinforced polymer (FRP) sheets or strips oriented in any direction is proposed. The formulation of the model is based on the variable-inclination stress-field approach, aiming to extend the provisions of current European standards to beams strengthened in shear using FRP. The main novelty of the model lies in taking into account the possible different inclination of steel stirrup and FRP reinforcement in determining the orientation of a compressed concrete stress field, and in shear strength evaluation, overcoming the approximation of the known models with variable inclination of the concrete strut in the assessment of concrete strut capacity, in which the value that has to be assigned to the shear reinforcement direction is not defined, that is, either that of the steel stirrup or the external FRP reinforcement. The proposed model is able to take into account different steel stirrup and external FRP shear reinforcement orientation in assessing the reduction of the steel transverse reinforcement efficiency due to the brittle failure of the composite and also as a function of the effective composite to yielding steel strain ratio. Moreover, regarding the former aspect, a simplified approximate procedure is proposed for solving the drawbacks related to verifying compressed concrete strength in the suggested method of application of code models for RC beams strengthened by means of FRP reinforcement inclined with a different slope from the pre-existing steel stirrup. Complete and U-shaped schemes are considered. The effectiveness of the proposed model adopting different relations for assessment of the FRP effective strains proposed in the literature is investigated, differentiating them by shape of the cross section and by the possible presence of fiber-anchoring devices. The shear capacity predicted by the model and those obtained using international codes and literature models are compared against the experimental results, proving that the proposed model is the most effective in predicting the shear strength when considering specimens having steel stirrups and FRP shear reinforcement arranged with different inclinations.
收起
摘要 :
Heat and mass transfer between air and falling desiccant film is investigated for inclined parallel and counter flow configurations. Two different configurations are proposed and parametrically analyzed. Effect of inclination angl...
展开
Heat and mass transfer between air and falling desiccant film is investigated for inclined parallel and counter flow configurations. Two different configurations are proposed and parametrically analyzed. Effect of inclination angle is examined to study enhancements in dehumidification and cooling processes of the air and regeneration of liquid desiccant in terms of pertinent parameters. Cu-ultrafine particles are also added to the desiccant film to investigate the enhancement in heat and mass transfer between the air and the desiccant film. The pertinent parameters are air and desiccant Reynolds numbers, inlet conditions for both air and liquid desiccant, Cu-ultrafine particles volume fraction, and thermal dispersion. It is shown that inclination angle plays a significant role in enhancing the dehumidification, cooling, and regeneration processes.
收起
摘要 :
An idempotent semiring is called an incline if it satisfies the identity 1 + x = x. The class of inclines is a variety of semirings with the variety of c-semirings as a subvariety. Let A~* be the free monoid on an alphabet A, and ...
展开
An idempotent semiring is called an incline if it satisfies the identity 1 + x = x. The class of inclines is a variety of semirings with the variety of c-semirings as a subvariety. Let A~* be the free monoid on an alphabet A, and let ≤h be the embedding order on A~*. Then, as the algebra of independent subsets of the ordered monoid (A~*, ≤h), the set H(A) of hyper codes on A forms a free incline. Furthermore, some subsets H_C(A) and H_(mic)(A) of H(A) can be constructed as a free c-semiring and a free multiplicatively idempotent c-semiring, respectively.
收起
摘要 :
The motion characteristics of mineral particles in a modified fluidized bed (mFB) with inclined plates have been studied both theoretically and experimentally. A particulate sedimentation model is built on the fluidization superfi...
展开
The motion characteristics of mineral particles in a modified fluidized bed (mFB) with inclined plates have been studied both theoretically and experimentally. A particulate sedimentation model is built on the fluidization superficial velocity, terminal settling velocity, the device dimensions, the particle properties, and the volume fraction of the particulate suspensions in the inclined channel, which is to describe the motion behavior of particles in mono-disperse suspensions. The experimental particles are a mixture of silica and sand particles with the sizes in the range of 425 - 710 mu m and 710 - 880 mu m, respectively. Further, the model is extended to describe bi-disperse suspensions. The experimental system is established to be consistent with the theoretical arrangements, aiming to provide more accurate measurements. Specifically, the prediction results are in good agreement with the experimental data with the absolute deviation less than 11%. The results showed that the average solid volume fraction in the inclined channel fluctuates slightly for a given total solid inventory. The theoretical model is of certain practical significance for applications of this system to the classification, separation, and desliming of minerals.
收起
摘要 :
The motion characteristics of mineral particles in a modified fluidized bed (mFB) with inclined plates have been studied both theoretically and experimentally. A particulate sedimentation model is built on the fluidization superfi...
展开
The motion characteristics of mineral particles in a modified fluidized bed (mFB) with inclined plates have been studied both theoretically and experimentally. A particulate sedimentation model is built on the fluidization superficial velocity, terminal settling velocity, the device dimensions, the particle properties, and the volume fraction of the particulate suspensions in the inclined channel, which is to describe the motion behavior of particles in mono-disperse suspensions. The experimental particles are a mixture of silica and sand particles with the sizes in the range of 425 - 710 μm and 710 - 880 μm, respectively. Further, the model is extended to describe bi-disperse suspensions. The experimental system is established to be consistent with the theoretical arrangements, aiming to provide more accurate measurements. Specifically, the prediction results are in good agreement with the experimental data with the absolute deviation less than 11%. The results showed that the average solid volume fraction in the inclined channel fluctuates slightly for a given total solid inventory. The theoretical model is of certain practical significance for applications of this system to the classification, separation, and desliming of minerals.
收起
原文获取