FIELD INSTRUMENTATIONS AND NUMERICAL ANALYSIS OF GEOSYNTHETIC REINFORCED SOIL – INTEGRATED BRIDGE SYSTEM (GRS-IBS)

Geosynthetic reinforced soil (GRS) is a special soil with geosynthetic fabric closely stacked in layers as soil stabilization and considered an alternative design method to the conventional bridge support technology. In this research study, a field case study of Maree Michel bridge, which is located in Route LA 91 Vermilion Parish in Louisiana, was instrumented with six different types of instrumentations to monitor the performance of GRS-IBS bridge abutment and to develop 2D and 3D finite element models. The instrumentations include Shape Acceleration Array (SAA), earth pressure cells, strain gauges, piezometers, and thermocouples. Additionally, surveying was conducted at the bridge surface upon the completion of the construction. Two and three-dimensional finite elements (FE) computer program PLAXIS 2016 was chosen to model the GRS abutment. First, the FE simulation is performed for the case study, in which the FE models were verified using the results of field monitoring program. A comprehensive parametric study was then conducted to evaluate the effect of different design variables on the performance of the GRS-IBS. Based on the results of parametric study, the relationship between the reinforcement spacing and the reinforcement strength on the behavior of the GRS-IBS performance was evaluated. The results indicated that the reinforcement spacing has a higher impact than the reinforcement strength on the performance of GRS-IBS for a reinforcement spacing equal or greater than 0.2 m (8 in.), and similar impact for reinforcement spacing less than 0.2 m (8 in.). An analytical model was developed to calculate the required tensile strength of GRS-IBS abutment based on the composite behavior of the closely reinforcement soil. The equations were verified by using field measurements and by the results of the finite element (FE) method of analysis. The results of the analytical model were also compared with the current design procedure adopted by the Federal Highway Administration (FHWA). Finally, the FE analysis demonstrated that the possible potential failure envelope of the GRS-IBS abutment was found to be a combination of a punching shear failure at the top and Rankine failure surface at the bottom, in which the failure envelope is developed under the inner edge of the footing and extending vertically downward to intersect with the Rankine active failure surface

Screening for Novel Inhibitors of Alpha-Ynuclein Seeded Nucleation-Dependent Aggregation and Toxicity as a Potential Therapeutic Strategy for Parkinson’s Disease

α-Synuclein aggregation is the key pathogenic event in several important neurological disorders including Parkinson’s Disease, dementia with Lewy bodies and multiple system atrophy, giving rise to a distinct group of neurodegenerative diseases known as synucleinopathies. Although the molecular basis of α – syn toxicity is mediated by a nucleation-dependent aggregation process. To elucidate the structural basis of α-synuclein mediated toxicity, we developed various methods to prepare different α-synuclein species of a defined size and morphology distribution, and we investigated their toxicity in different human dopaminergic cell lines. We observed that crude α-synuclein oligomers preparations, containing both monomeric and heterogeneous mixtures of α-synuclein oligomers, were the most toxic species. The toxicity of α-synuclein aggregates was directly linked to the presence of the monomeric α-synuclein, and strongly dependent on its ability in seeded nucleation-dependent aggregation converting into amyloid fibrils. Therefore any effort to identify compounds that could inhibit or even reverse the aggregation process should assess the effect of the potential inhibitors on the seeded aggregation of α-synuclein, among others. We screened thirty Chinese herbal medicinal compounds for their effect on α-synuclein aggregation, seeded polymerization and toxicity by employing biophysical, biochemical and cell-culture-based techniques. Among the screened compounds, only ginsenoside Rbl, salvianolic acid B, dihydromyricetin and gallic acid were shown to be strong inhibitors of α-syn fibrillation, seeded aggregation ant toxicity. Our results showed that gallic acid, ginsenoside Rb1 and salvianolic acid B inhibit α-synuclein fibrillation by binding and stabilizing the structure of the soluble, non-toxic oligomers, which are devoid of β-sheet content. In contrast, dihydromyricetin was found to be able to bind both oligomeric and monomeric species of α-synuclein. In the case of gallic acid, the inhibition of α-synuclein fibrillation is related to the compound’s hydroxyl moieties whose number and position on the phenyl ring were proven to be significant for the process of inhibition, as indicated by the structure activity relationship data obtained from fourteen structurally similar benzoic acid derivatives. Overall, the compounds identified herein may represent the starting point for designing new molecules that could be utilized as drugs for the treatment of Parkinson’s Disease and related disorders

ANALISIS PERSEPSI MAHASISWA TERHADAP PENGGUNAAN SUMBER BELAJAR DALAM KURIKULUM MERDEKA DI FAKULTAS ILMU PENDIDIKAN

Artikel ini mengulas evaluasi mengenai bagaimana mahasiswa menilai penggunaan sumber belajar dalam penerapan Kurikulum Merdeka di Fakultas Ilmu Pendidikan. Kurikulum Merdeka merupakan suatu pendekatan inovatif dalam pendidikan tinggi yang menitikberatkan pada memberikan fleksibilitas dan otonomi kepada mahasiswa dalam pemilihan sumber belajar mereka. Tujuan penelitian ini adalah untuk memahami bagaimana mahasiswa menafsirkan penggunaan sumber belajar dalam kerangka Kurikulum Merdeka, sejauh mana penggunaan sumber belajar ini memengaruhi proses pembelajaran mereka, dan dampaknya terhadap pencapaian kompetensi. Data penelitian dikumpulkan melalui survei dan wawancara dengan mahasiswa dari berbagai program studi di Fakultas Ilmu Pendidikan. Hasil analisis data mengungkapkan beragam persepsi yang dimiliki oleh mahasiswa terkait penggunaan sumber belajar dalam Kurikulum Merdeka, termasuk tantangan dan manfaat yang mereka alami. Dalam kesimpulan, artikel ini membahas implikasi temuan tersebut terhadap implementasi Kurikulum Merdeka dan memberikan rekomendasi untuk meningkatkan penggunaan sumber belajar dalam pendidikan tinggi yang lebih adaptif dan responsif

SALSA: A Sequential Alternating Least Squares Approximation Method For MIMO Channel Estimation

In this paper, we consider the channel estimation problem in sub-6 GHz uplink wideband MIMO-OFDM communication systems, where a user equipment with a fully-digital beamforming structure is communicating with a base station having a hybrid analog-digital beamforming structure. A novel channel estimation method called Sequential Alternating Least Squares Approximation (SALSA) is proposed by exploiting a hidden tensor structure in the uplink measurement matrix. Specifically, by showing that any MIMO channel matrix can be approximately decomposed into a summation of R factor matrices having a Kronecker structure, the uplink measurement matrix can be reshaped into a 3-way tensor admitting a Tucker decomposition. Exploiting the tensor structure, the MIMO channel matrix is estimated sequentially using an alternating least squares method. Detailed simulation results are provided showing the effectiveness of the proposed SALSA method as compared to the classical least squares method

Advanced Modeling of Lubricated Interfaces in General Curvilinear Grids

Tackling fluid-flow problems involving intricate surface geometries has been the catalyst for a plethora of numerical investigations aimed at accommodating curved complex boundaries. An example is the application of body-fitted curvilinear coordinate transformation, where the one-to-one correspondence of grid points from the physical to the computational domain is achieved. In lubricated interfaces, such conversion is challenging due to the complex governing equations in the mapped-grid, the numerical instabilities exhibited by their non-linearities and the severity of operating conditions. The present contribution proposes a Reynolds-based, finite volume fluid-structure interaction (FSI) framework for solving thermal elastohydrodynamic lubrication (TEHL) problems mapped onto non-orthogonal curvilinear grids in the computational domain. We demonstrate how the strong conservation form of the pertinent governing equations can be expressed in three-dimensional curvilinear grids and discretised using finite volume method to ensure fluid-flow conservation and enforce mass-conserving cavitation conditions. Numerical and experimental benchmarks showcase the robustness and versatility of the proposed framework to simulate a diverse range of lubrication problems, hence achieving a predictive computational tool that would enable a shift towards tribology-aware design

Effect of a Two Piece Scalloped Implant Design on Interproximal Bone Apposition/Retention - A Pilot Study in Rabbits

The aim of the study was to evaluate the effect of an experimental two piece scalloped implant design with a scalloped elliptical coronal part and an HA surface treatment on the bone to implant contact percentage in comparison to a commercially available HA treated implant. The possibility of bone apposition / retention along the exposed coronal scalloped part and the effect of the presence of a junction on the bone to implant contact percentage and bone apposition / retention were analyzed. 10 rabbits were included in the study with each rabbit receiving one control implant in one tibia and one experimental implant (experimental implant) in the other. Rabbits were divided in two groups: Group one: consisted of 6 rabbits. The experimental implants were placed with all second scalloped part (4mm) above the existing bone level compared to the control implant that received a 3mm healing abutment placed above the existing bone level. No membrane or grafting material was used and the periosteam and tissue were sutured over the implants. Group two: Consisted of 4 rabbits. The experimental implants were placed with only the scalloped platform (2mm) above the existing bone level compared to the control implants that received a cover screw. No membrane or grafting material was used and the periosteam and tissue were sutured over the implants. Sites were allowed to heal for 27days after which the animals were sacrificed and gross samples were prepared and sent for histomorphometric analysis. BIC% was measured twice for each group, once from the top of the implant to the inferior border of the superior cortical plane and the second over the whole length of the implant. The effect of the presence of a junction between the implant parts and the level of the junction in relation to bone apposition was evaluated. There was no statistically significant difference between the BIC% of the implants and the control implants in both groups one and two, however the bone was better adapted along the second scalloped part of the experimental implant than around the healing abutment of the control implant. It was also possible to gain bone apposition / retention around the second part of the experimental implant and beyond the existing native bone level provided that space can be maintained; it was consistent up to 2mm above the native bone level. The presence of a junction between part one and part two had no effect on bone apposition / retention

HUBUNGAN MINDSET TERHADAP MOTIVASI BELAJAR PESERTA DIDIK SEKOLAH DASAR DI DEPOK

This study aims to determine the relationship between mindset and learning motivationelementary school students and find out the obstacles to learning motivation and look for thesolution. The type of research used in this research is quantitative research.The population in this study was grade V and grade VI elementary school in Depok with the number of samples is 112 students for the academic year 2022/2023. Data collection techniques that used are questionnaires and observations. From the calculation results obtained a correlation test of 0.570 which is in the medium interval. This shows that the relationship between mindset and learning motivation. The obstacles come from students who less motivated when learning in class and outside the classroom. The solution is awareness of students, conducted training for teachers and parents, teachers foster motivation students by creating a pleasant atmosphere, linking learning with everyday life

Recovery under Side Constraints

This paper addresses sparse signal reconstruction under various types of structural side constraints with applications in multi-antenna systems. Side constraints may result from prior information on the measurement system and the sparse signal structure. They may involve the structure of the sensing matrix, the structure of the non-zero support values, the temporal structure of the sparse representationvector, and the nonlinear measurement structure. First, we demonstrate how a priori information in form of structural side constraints influence recovery guarantees (null space properties) using L1-minimization. Furthermore, for constant modulus signals, signals with row-, block- and rank-sparsity, as well as non-circular signals, we illustrate how structural prior information can be used to devise efficient algorithms with improved recovery performance and reduced computational complexity. Finally, we address the measurement system design for linear and nonlinear measurements of sparse signals. Moreover, we discuss the linear mixing matrix design based on coherence minimization. Then we extend our focus to nonlinear measurement systems where we design parallel optimization algorithms to efficiently compute stationary points in the sparse phase retrieval problem with and without dictionary learning