Flexural Study of Lightweight Concrete Beams casted of Oil Palm Shell (OPS) Aggregates

This study's main goal is to investigate the potential applications of OPS aggregate in the manufacturing of concrete. This helps to preserve natural resources in addition to addressing the problem of how to get rid of OPS trash. For this study, twelve under-reinforced concrete beams were made and tested. The reinforcing ratios of these beams varied, from 0.52% to 3.90%.  The paper presents data related to several important aspects of the beams' behavior, including Information about how the beams deflected under load, Details about when and how cracks formed in the beams, Measures of how much the beams could deform before failure, Information on how the beams rotated at their ends during testing. The flexural behaviour of reinforced OPS concrete beams and other regular reinforced concrete beams was compared in the study. The experimental results and the current industry Codes of practice were found to be reasonably well aligned. Notably, beams with low reinforcement ratios satisfied every serviceability standard listed in BS 8110, proving that they were appropriate for real-world uses

Statistical Review Evaluation of 5G Antenna Design Models from a Pragmatic Perspective under Multi-Domain Application Scenarios

Antenna design for the 5G spectrum requires analysis of contextual frequency bands, design of miniaturization techniques, gain improvement models, polarization techniques, standard radiation pattern designs, metamaterial integration, and substrate selection. Most of these models also vary in terms of qualitative & and quantitative parameters, which include forward gain levels, reverse gain, frequency response, substrate types, antenna shape, feeding levels, etc. Due to such a wide variety in performance, it is ambiguous for researchers to identify the optimum models for their application-specific use cases. This ambiguity results in validating these models on multiple simulation tools, which increases design delays and the cost of deployments. To reduce this ambiguity, a survey of recently proposed antenna design models is discussed in this text. This discussion recommended that polarization optimization and gain maximization are the major impact factors that must be considered while designing antennas. It is also recommended that collocated microstrip slot antennas, fully planar dual-polarized broadband antennas, and real-time deployments of combined slot antenna pairs with wide-band decoupling are very advantageous. Based on this discussion, researchers will be able to identify optimal performance-specific models for different applications. This discussion also compares underlying models in terms of their quantitative parameters, which include forward gain levels, bandwidth, complexity of deployment, scalability, and cost metrics. Upon referring to this comparison, researchers will be able to identify the optimum models for their performance-specific use cases. This review also formulates a novel Antenna Design Rank Metric (ADRM) that combines the evaluated parameters, thereby allowing readers to identify antenna design models that are optimized for multiple parameters and can be used for large-scale 5G communication scenarios

Ultrasound-modulated optical microscopy for ex-vivo imaging of scattering biological tissue

Ultrasound-modulated optical microscopy (UOM) based on a long-cavity confocal Fabry-Perot interferometer (CFPI) [J.Biomed.Opt. 13(5), 0504046, (2008)] is used for real time detection of multiply scattered light modulated by high frequency (30 MHz) ultrasound pulses propagating in an optically strongly scattering medium. In this article, we use this microscope to study the dependence of ultrasound-modulated optical signals on the optical absorption of objects embedded about 3 mm deep in tissue mimicking phantoms. These results demonstrate that the dependence is nearly linear. Most importantly, we imaged blood vasculature and melanin in highly scattering tissue samples from a mouse and a rat. Thus UOM can be used to study the morphology of blood vasculature and blood-associated functional parameters, such as oxygen saturation

Towards very high resolution imaging in ultrasound-modulated optical tomography of biological tissues

We explored the possibility of applying very high ultrasound frequencies to achieve very high resolution in ultrasound-modulated optical tomography of soft biological tissues. The ultrasound-modulated coherent light that traversed the scattering biological tissue was detected by a long-cavity and a large etendue confocal Fabry- Perot interferometer. We used various focused ultrasound transducers of 15 MHz, 30 MHz, and 50 MHz to obtain two dimensional images of optically absorbing objects positioned at a few millimeters depth below the surface of both optically scattering phantoms and soft biological tissue samples. This technology is complementary to other imaging technologies, such as confocal microscopy and optical-coherence tomography, and has potential for broad biomedical applications

Towards very high resolution imaging in ultrasound-modulated optical tomography of biological tissues

We explored the possibility of applying very high ultrasound frequencies to achieve very high resolution in ultrasound-modulated optical tomography of soft biological tissues. The ultrasound-modulated coherent light that traversed the scattering biological tissue was detected by a long-cavity and a large etendue confocal Fabry- Perot interferometer. We used various focused ultrasound transducers of 15 MHz, 30 MHz, and 50 MHz to obtain two dimensional images of optically absorbing objects positioned at a few millimeters depth below the surface of both optically scattering phantoms and soft biological tissue samples. This technology is complementary to other imaging technologies, such as confocal microscopy and optical-coherence tomography, and has potential for broad biomedical applications

Imaging optically scattering objects with ultrasound-modulated optical tomography

We show the feasibility of imaging objects having different optical scattering coefficients relative to the surrounding scattering medium using ultrasound-modulated optical tomography (UOT). While the spatial resolution depends on ultrasound parameters, the image contrast depends on the difference in scattering coefficient between the object and the surrounding medium. Experimental measurements obtained with a CCD-based speckle contrast detection scheme are in agreement with Monte Carlo simulations and analytical calculations. This study complements previous UOT experiments that demonstrated optical absorption contrast

Optical phantoms for ultrasound-modulated optical tomography

Optical phantoms are widely used for simulating optical properties of biological tissues. Their accurate design and fabrication are important factors in validating and designing biomedical systems. We discuss fabrication and measurement of optical phantoms in ultrasound-modulated optical tomography. The optical properties of the phantoms are measured by an oblique-incidence diffuse reflectance spectrometer, which can accurately measure the wavelength-dependent absorption and reduced scattering coefficients of optical phantoms. In addition, the acoustic properties of the phantoms are discussed