Velocity measurements of a dilute particulate suspension over and through a porous medium model

We experimentally examine pressure-driven flows of 1%, 3%, and 5% dilute suspensions over and through a porous media model. The flow of non-colloidal, non-Brownian suspensions of rigid and spherical particles suspended in a Newtonian fluid is considered at very low Reynolds numbers. The model of porous media consists of square arrays of rods oriented across the flow in a rectangular channel. Systematic experiments using high-spatial-resolution planar particle image velocimetry (PIV) and index-matching techniques are conducted to accurately measure the velocity measurements of both very dilute and solvent flows inside and on top of the porous media model. We found that for 1%, 3%, and 5% dilute suspensions the fully-developed velocity profile inside the free-flow region are well predicted by the exact solution derived from coupling the Navier-Stokes equation within the free flow-region and the volume-averaged Navier Stokes (VANS) equation for the porous media. We further analyze the velocity and shear rate at the suspension-porous interface and compare these data with those of pure suspending fluid and the related analytical solutions. The exact solution is used to define parameters necessary to calculate key values to analyze the porous media/fluid interaction such as Darcy velocity, penetration depth, and fractional ratios of the mass flow rate. These parameters are comparable between the solvent, dilute suspensions, and exact solution. However, we found clear effects between the solvent and the suspensions which shows different physical phenomenon occurring when particles are introduced into a flow moving over and through a porous media.Comment: 38 pages, 10 figure

Dual-Polarized Reconfigurable Intelligent Surface Assisted Broad Beamforming

A reconfigurable intelligent surface (RIS) consists of a large number of low-cost elements that can control the propagation environment seen from a transmitter by intelligently applying phase shifts to impinging signals before reflection. This paper studies an RIS-assisted communication system where a transmitter wants to transmit a common signal to many users residing in a wide angular area. To cover this sector uniformly, the RIS needs to radiate a broad beam with a spatially flat array factor, instead of a narrow beam as normally considered. To achieve this, we propose to use a dual-polarized RIS consisting of elements with orthogonal polarizations and show that the RIS can produce a broad beam if the phase shift configuration vectors in the two polarizations form a so-called Golay complementary sequence pair. By utilizing their properties, we also present a method for constructing configuration for large RISs from smaller ones, while preserving the broad radiation pattern of the smaller RIS. The numerical results corroborate the mathematical analyses and highlight the greatly improved coverage properties.Comment: This letter has been accepted for publication in IEEE Communications Letter

Senyapan Dalam Ujaran Isyana Dan Cindercella Pada Video Talkshow “Metal” Di Youtube

Penelitian ini merupakan penelitian terhadap fenomena senyapan dalam produksi ujaran Isyana dan Cindercella dalam talkshow ringan “Metal” di youtube. Metode yang digunakan yaitu metode kualitatif deskriptif dengan tujuan untuk mendeskripsikan temuan dari hasil analisis terhadap fenomena senyapan dalam produksi ujaran Isayana dan Cindercella di dalam video tersebut seperti jenis senyapan, distribusi senyapan, dan penyebab senyapan. Hasilnya ditemukan dua jenis senyapan di dalam video tersebut yaitu senyapan diam dan senyapan terisi yang meliputi senyapan yang terisi dengan bunyi, kata, pengulangan, dan kombinasi pengulangan. Distribusi senyapan semuanya berada di posisi tengah klausa. Ada pun penyebab terjadinya senyapan yaitu: (1) pengambilan napas, (2) pencarian kosakata yang tepat, (3) gugup, (4) lupa pada kosakata tertentu, (5) koreksi dari penutur, (6) keraguan, dan (7) penekanan pada kata tertentu

Development of Viral Vectors for Use in Cardiovascular Gene Therapy

Cardiovascular disease represents the most common cause of mortality in the developed world but, despite two decades of promising pre-clinical research and numerous clinical trials, cardiovascular gene transfer has so far failed to demonstrate convincing benefits in the clinical setting. In this review we discuss the various targets which may be suitable for cardiovascular gene therapy and the viral vectors which have to date shown the most potential for clinical use. We conclude with a summary of the current state of clinical cardiovascular gene therapy and the key trials which are ongoing

Healthier Living with MS:The Key Role of Self-Efficacy and Emotion Regulation

ObjectivesUnderstanding distress and quality of life (QOL) is important in improving the lives of people with multiple sclerosis (MS), and investigating their antecedents is very important. The present study aimed to examine the role of multiple sclerosis self-efficacy and difficulties in emotion regulation in predicting distress and QOL in people with MS. Also, this study compared types of MS (RRMS, PPMS, and SPMS) in terms of MS self-efficacy, difficulties in emotion regulation, distress, and QOL.MethodsThis study included 122 people with three types of MS (RRMS=33, PPMS=62, and SPMS=25). Data were collected by the use of four scales: Quality of Life (QOL), Psychological Distress (DASS), Difficulties in Emotion Regulation (DERS), and Multiple Sclerosis Self-Efficacy (MSSE). Pearson's correlation, path analysis, MANOVA, and Tukey's post hoc test were used for data analysis.ResultsFindings indicated MS self-efficacy had negative and significant effects on difficulties in emotion regulation and distress and had a positive and significant effect on QOL. Difficulties in emotion regulation had a negative and significant effect on QOL and a positive and significant effect on distress. Also, the indirect effect (through difficulties in emotion regulation) of MS self-efficacy on distress and QOL was significant. In addition, the comparisons showed that differences between RRMS and SPMS in terms of MS self-efficacy and distress were significant.ConclusionsSelf-efficacy and emotion regulation are key components in improving the life (reducing distress and increasing QOL) of people with MS, although it depends to some extent on the type of MS disease