In this research, the performance of ultrasonic pulse velocity (UPV) in concrete is examined as a nondestructive experiment in order to estimate mechanical (compressive and tensile strength) and durability (water absorption) properties of fiber-reinforced self-compacted concrete For this purpose 11 mixture designs containing 3 types of fibers (steel: 0.1, 0.2, 0.3 and 0.4 percent by volume, Pol...

ABSTRACT: In the paper a transformational impact force reconstruction method is presented, which features a one-point strain measurement in a mechanical transducer. To determine the spectral transmittance of a section of the mechanical transducer necessary in the reconstruction process, strain waves propagating in the transducer are used: the incident, and the first reflected one, created by th...

The tooth is an ectodermal organ that arises from a tooth germ under the regulation of reciprocal epithelial-mesenchymal interactions. Tooth morphogenesis occurs in the tooth-forming field as a result of reaction-diffusion waves of specific gene expression patterns. Here, we developed a novel mechanical ligation method for splitting tooth germs to artificially regulate the molecules that contro...

We provide a completely quantum-mechanical derivation of the spectrum of gravitational waves produced in any inflationary cosmology. The gravitational waves result from a sequence of Bogoliubov transformations between creation and annihilation operators defined in de Sitter space and in radiation-and matter-dominated Robertson-Walker spacetimes. We discuss how the results depend on the initial ...

Soft structures with rationally designed architectures capable of large, nonlinear deformation present opportunities for unprecedented, highly tunable devices and machines. However, the highly dissipative nature of soft materials intrinsically limits or prevents certain functions, such as the propagation of mechanical signals. Here we present an architected soft system composed of elastomeric b...

Sound is detected and converted into electrical signals within the ear. The cochlea not only acts as a passive detector of sound, however, but can also produce tones itself. These otoacoustic emissions are a striking manifestation of the cochlea's mechanical active process. A controversy remains of how these mechanical signals propagate back to the middle ear, from which they are emitted as sou...

We present a method for the control of waves based on inverse multiple scattering theory. Conceived as generalization concept metagrating, we call metaclusters to finite set scatterers whose position and properties are obtained by design once have defined their response some external incident field. The particular focus is designing passive that do not require an source energy. applied propagat...

sugar, which can be extracted from sugar cane and sugar beet, is one of the most important ingredients of food. conducting more research to increase the extraction efficiency of sugar is necessary due to high production of sugar beet and its numerous processing units in northern khorasan province. in this research, the effect of temperature, time and the frequency of ultrasonic waves on mechani...

Electrogastrography (EGG) appears to be useful method to evaluate the gastric motility as noninvasive approach. However, it is not known what EGG means. The aim of this study is to make clear the meanings of electrical activity recorded dy EGG for gastric motility. EGG recorded by cutaneous electrodes was compared to gastric electromyogram recorded by serosal electrodes and gastric mechanical a...