An Experimental Study on Mechanical Properties of Self Compacting Concrete by using Fiber Reinforcement

The invention of Self Compacting Concrete has been tremendous and continuing growth in the working area over the past decade, culminating in its widespread usage in today’s reality. It outperforms regular cement in application and completion, cost, work reserve funds, and solidity. The addition of strands enhances its qualities, particularly those related to SCC’s post- break behaviour. The goal is to investigate the strength properties of SCC when mixed with various types of strands. Different strand types and filament speeds are among the variables studied. The essential characteristics of SCC, including strength, break energy, sturdiness, and sorptivity, must be controlled. The hydrated design and security development between fiber and blend will be examined using an electron microscope to examine the tiny building of several mixes. 12mm cut glass fiber, carbon fiber, and basalt fiber will be used in the request, as they have been for quite some time. 0.0 percent, 0.1 percent, 0.15 percent, 0.2 percent, 0.25 percent, and 0.3 percent of strands are removed based on volume. The request is broken down into two parts. The first half involves creating a planned blend for SCC of a detailed assessment, such as M30. The second half involves adding filaments such as glass, basalt, and carbon strands to the SCC blends and evaluating and verifying their plastic and hardened properties. The experiment demonstrates a modest improvement in SCC aspects by adding strands of various types and altering the volume. Carbon fiber is the most improved in the more challenging state, followed by Basalt fiber and Glass fiber, and the least improved in the plastic state due to its high-water absorption. Glass fiber fared better in the plastic state. Basalt fiber fared better in the present study regarding cost, appropriate amount, and overall viability.

An Experimental Study on Mechanical Properties of Self Compacting Concrete by using Fiber Reinforcement

The invention of Self Compacting Concrete has been tremendous and continuing growth in the working area over the past decade, culminating in its widespread usage in today's reality. It outperforms regular cement in application and completion,cost, work reserve funds, and solidity. The addition of strands enhances its qualities, particularly those related to SCC's post- break behaviour. The goal is to investigate the strength properties of SCC when mixed with various types of strands. Different strand types and filament speeds are among the variables studied. The essential characteristics of SCC, including strength, break energy, sturdiness, and sorptivity, must be controlled. The hydrated design and security development between fiber and blend will be examined using an electron microscope to examine the tiny building of several mixes. 12mm cut glass fiber, carbon fiber, and basalt fiber will be used in the request, as they have been for quite some time. 0.0 percent, 0.1 percent, 0.15 percent, 0.2 percent, 0.25 percent, and 0.3 percent of strands are removed based on volume. The request is broken down into two parts. The first half involves creating a planned blend for SCC of a detailed assessment, such as M30. The second half involves adding filaments such as glass, basalt, and carbon strands to the SCC blends and evaluating and verifying their plastic and hardened properties. The experiment demonstrates a modest improvement in SCC aspects by adding strands of various types and altering the volume. Carbon fiber is the most improved in the more challenging state, followed by Basalt fiber and Glass fiber, and the least improved in the plastic state due to its high-water absorption. Glass fiber fared better in the plastic state. Basalt fiber fared better in the present study regarding cost, appropriate amount, and overall viability

Compensatory bellows oscillations as a corrugated shell with liquid inside

The paper deals with a relevant problem of shipbuilding, i.e. calculation of free and forced vibrations of pipeline compensatory bellows. These devices are used to reduce the vibration load caused by ship power machines. When analyzing the vibrations of the compensatory bellows, it is necessary to take into account the liquid contained in the bellows. In this work, the design model of the bellows is represented by a corrugated elastic shell as a material surface with five degrees of freedom. A variant of the classical theory of shells, built on the basis of Lagrangian mechanics, is used. The influence of the liquid is taken into account by two models. First, the liquid is considered to be ideal and incompressible and is considered through the attached mass to the shell. The shell is replaced by a cylindrical surface with a radius in the middle line of the corrugation. To account for the influence of the frequency of bellows oscillations on the attached inertia of the liquid in the calculation we also used the acoustic approximation; and derived a formula for a generalized attached mass of the ideal compressible liquid. The equations of the bellows oscillations under the periodic loading are obtained. The problem has been solved by the finite difference method. The values of natural frequencies of free vibrations are obtained for the compensatory bellows from the corrosion-resistant heat-resistant steel. It is shown that by taking account of the liquid, we significantly change the natural frequencies of the bellows. With high-frequency vibrations it is necessary to take into account the compressibility of the liquid. The problem of the forced vibrations of the bellows caused by a displacement of its end face by the harmonic law is solved. The internal forces and moments are determined, as well as occurring stresses by Mises criterion in the bellows. We found the critical value of the end face displacement at a frequency of 50 Hz, at which the bellows goes into a plastic state.

Incompatible Deformation Model of Rocks with Defects around a Thick-Walled Cylinder

Before the excavation of underground engineering, joints, fissures, and voids already exist in the rock—that is, there are defects in the rock. Due to the existence of these defects, the rock produces plastic deformation, which can lead to incompatible deformation. Therefore, the classic continuum theory cannot accurately describe the deformation of the rock. In this paper, a relationship between the strain tensor and metric tensor was studied by analyzing the three states of elastic plastic deformation, and the elasto-plastic incompatible model was built. Additionally, the stress and deformation of a thick-walled cylinder under hydrostatic pressure was investigated by using a finite element program written in the FORTRAN language. The results show that the plastic strain is associated with not only deviator stress but also the distribution of defects (represented by the incompatible parameter R). With the value of R increasing, the defects in the rock increased, but the elastic plastic stiffness matrix decreased. Thus, as more rock enters the plastic state, the deformation of the surrounding rock is enlarged.

Restructuring insight: An integrative review of insight in problem-solving, meditation, psychotherapy, delusions and psychedelics

Occasionally a solution arrives as a sudden understanding - an insight. Insight has been considered as an “extra” ingredient of creative thinking and problem-solving. Here we propose that insight is a central process in seemingly distinct areas of research. Drawing on literature from a variety of fields, we show that besides being a common topic in problem-solving literature, insight is also a core component in psychotherapy, essential for some forms of meditation, a key process underlying the emergence of primary delusions in schizophrenia, and a factor that drives the positive outcomes of psychedelic therapy. Our goal is to bridge these different views and research traditions. In each case, we discuss the prerequisites and consequences of insight. We examine evidence for common prerequisites of insight experiences, comprising a tension within knowledge structures and a plastic state of mind. We discuss a framework for explaining insight across these fields and highlight the clinical relevance of studying insight. This integrative review provides a better understanding of insight, a central feature of our minds.

Mechanical Properties of Lightweight Foamed Concrete Reinforced with Raw Mesocarp Fibre

Lightweight foamed concrete (LFC) is recognised for its high flowability, minimal utilization of aggregates and superior heat insulation properties. LFC is excellent under compression but poor in tensile stress, as it produces multiple microcracks. LFC cannot withstand the tensile stress induced by applied forces without additional reinforcing elements. Hence, this study was conducted to examine the potential utilisation of oil palm mesocarp fibre (OPMF) reinforced LFC in terms of its mechanical properties. Two densities, 600kg/m3 and 1200kg/m3, were cast and tested with six different percentages of OPMF, which were 0.15%, 0.30%, 0.45% and 0.60%. The parameters evaluated were compressive strength, flexural strength and tensile strength. The results revealed that the inclusion of 0.45% of OPMF in LFC helps to give the best results for the compressive strength, flexural strength and splitting tensile strength. The OPMF facilitated to evade the promulgation of cracks in the plastic state in the cement matrix when the load was applied

Calculation of the elasticplastic deformation of a solid body by multidimensional nodal method of characteristics

Описан многомерный узловой метод характеристик, предназначенный для численного расчета упругопластической деформации твердого тела в рамках модели Прандтля-Рейса с уравнением состояния небаротропного типа. В качестве критерия перехода из упругого в пластическое состояние применялось условие текучести Мизеса. Рассмотренный численный метод базируется на координатном расщеплении исходной системы уравнений на ряд одномерных подсистем с последующим их интегрированием с помощью одномерного узлового метода характеристик. Метод использован для расчета ряда одно- и двумерных модельных задач A multidimensional nodal method of characteristics is described. The method is designed to numerically calculate the elastoplastic deformation of a solid body within the Prandtl-Reis model with the non-barotropic state equation. The Mises flow condition was used as a criterion for the transition from an elastic to a plastic state. The considered numerical method is based on the coordinate splitting of the original system of equations into a number of one-dimensional subsystems. Then the resulting equations were integrated using a one-dimensional nodal method of characteristics. The proposed method allows calculating a number of one- and two-dimensional model problems. The results of calculations that employ the multidimensional node method of characteristics were compared with data calculated using the Godunov hybrid method in the framework of a model that did not take into account the contribution of potential elastic compression energy to the total energy of the medium. There are some discrepancies in the calculation results that occur at high speeds of interaction of the aluminum striker with the barrier, exceeding 500 m/s, which are associated with omission of the potential energy due to the elastic compression of the solid within the original Prandtl-Reis model

INFLUENCE OF OIL PALM SPIKELETS FIBRE ON MECHANICAL PROPERTIES OF LIGHTWEIGHT FOAMED CONCRETE

As issues related to sustainable construction in Malaysia gains more importance, research on the utilization of waste by products especially from oil palm in concrete is vigorously implemented. Utilization of different parts of oil palm fibres in lightweight foamed concrete have garnered positive outcomes in terms of conservation of natural resources, lessening of environmental problem and can improve concrete's durability and mechanical properties. Lightweight foamed concrete (LFC) is well-known as a low-density concrete with a wide range of applications. It is good in compression but poor under flexural load, as it produces multiple microcracks and cannot withstand the additional stress induced by applied forces without supplementary reinforcing elements. Hence this study was performed to examine the potential use of oil palm spikelets fibre (OPSF) in LFC in order to improve its engineering properties. LFC specimens were strengthened with OPSF fibre at different percentages of 0.15%, 0.30%, 0.45%, and 0.60%. LFC density of 1000 kg/m3 was prepared with a constant cement-to-sand ratio of 1:1.5, and cement-to-water ratio of 0.45. The parameters that had been evaluated were flexural strength, compressive strength and splitting tensile strength. The results revealed that the addition of 0.45% of OPSF fibre gave the best compressive, bending and splitting tensile strengths result. OPSF fibre in LFC aided to evade the promulgation of cracks in the plastic state in the cementitious matrix.

The plasticity of pancreatic cancer stem cells: implications in therapeutic resistance

The ever-growing perception of cancer stem cells (CSCs) as a plastic state rather than a hardwired defined entity has evolved our understanding of the functional and biological plasticity of these elusive components in malignancies. Pancreatic cancer (PC), based on its biological features and clinical evolution, is a prototypical example of a CSC-driven disease. Since the discovery of pancreatic CSCs (PCSCs) in 2007, evidence has unraveled their control over many facets of the natural history of PC, including primary tumor growth, metastatic progression, disease recurrence, and acquired drug resistance. Consequently, the current near-ubiquitous treatment regimens for PC using aggressive cytotoxic agents, aimed at ‘‘tumor debulking’’ rather than eradication of CSCs, have proven ineffective in providing clinically convincing improvements in patients with this dreadful disease. Herein, we review the key hallmarks as well as the intrinsic and extrinsic resistance mechanisms of CSCs that mediate treatment failure in PC and enlist the potential CSC-targeting ‘natural agents’ that are gaining popularity in recent years. A better understanding of the molecular and functional landscape of PCSC-intrinsic evasion of chemotherapeutic drugs offers a facile opportunity for treating PC, an intractable cancer with a grim prognosis and in dire need of effective therapeutic advances.

Systematic Review Based on the Study of Elastic-Plastic Transition Stresses

A systematic review based upon the study of elastic-plastic transition stresses. A worthwhile work about the analysis of elastic-plastic transition stresses in different rotating materials by varying different parameters is discussed. In the case of compressible material, the strain rates have a maximum value at the internal surface. It has been observed that radial stress has a higher value at the internal surface of the rotating disc made of incompressible material as compared to circumferential stress with thermal effect and this value of radial stress further increases. With the increase of angular speed, the value of radial stress further increases as compared to the case with no thermal effect. The magnitude of the stresses and pressure reduce with the variation of thickness needed for a fully plastic state. At the inner surface, the effect of heat increases stress for compressible material. The thickness and density parameters decrease the value of angular speed at the internal surface of the rotating disc of compressible material as well as incompressible materials. The radial and the hoop stress, both decrease with the increased value of temperature at the Elastic-Plastic stage, but with the reverse result obtained for a fully Plastic state.