Direct Method Research Articles

Proposed automated contrast-enhanced microscopical method for evaluating air void structure in compacted asphalt concrete mixtures

There is no direct, less expensive, and practical method to measure the interconnectivity and parameters of air voids in asphalt mixtures other than the total air void volume calculated traditionally using bulk and maximum theoretical specific gravities. Unlike the conventional method, this paper proposes a method that is suitable for advanced applications and studies, such as for the evaluation of air void distribution and air void gradient to model and simulate long-term aging, predict top-down fatigue cracking, evaluate the effectiveness of compaction of thick lifts, and satisfy the representative volume element (RVE) requirements (a homogenous and representative specimen) for performance tests. Developing the proposed compact asphalt evaluation method included modifying the sample preparation methods and analysis from the American Society of Testing & Materials (ASTM), C457 Method C, and recently applied in the analyses of two independent studies at the Federal Highway Administration (FHWA). The first study was focused on checking the air void distribution within the small specimen for dynamic modulus and uniaxial cyclic fatigue tests using AASHTO TP 132 and TP 133, respectively. Results of air void analyses conducted on the interior and exterior sides of several slices sawn from different compacted asphalt mixtures consistently showed that the air void contents on the external sides are higher than on the interior. The second study was to evaluate whether the thicker-than-typical lift thickness to nominal maximum aggregate (NMAS) ratio was causing any top-to-bottom air void gradient in the pavement. Results showed that air void sizes and contents are consistently higher along the top ends of all the cores, and the total air void contents measured using the new method on several specimens from the field were comparable with the indirectly calculated air void percent with up to ± 0.4 percent random error. Overall, the new method is practical to apply to larger-size samples and is a tool that both agencies and contractors can use for confirming in situ void uniformity. Its application can support innovations and improve performance in asphalt pavement construction.

Imaging of Isolated Exosomes by Correlative Microscopy.

Correlative microscopy is a sophisticated imaging technique that combines optical and electron microscopes, with the most common approach being the integration of light microscopy and electron microscopy, known as correlative light and electron microscopy (CLEM). While CLEM provides a comprehensive view of biological samples, it presents a significant challenge in sample preparation due to the distinct processes involved in each technique. Striking a balance between these methods is crucial. Despite numerous approaches, achieving seamless imaging with CLEM remains a complex task. Exosomes, nanovesicles ranging from 30 to 150 nm in size, are enclosed by a lipid bilayer and released by various cell types. Visualizing exosomes poses difficulties due to their small size and minimal electric charge. However, imaging exosomes at high resolution offers a direct method to understand their morphology and functions. In this study, we evaluated exosome imaging with CLEM using a combination of confocal, transmission electron microscope, and scanning electron microscope (SEM). In addition, we conducted a comparative analysis of these two techniques, evaluating their suitability and efficiency in imaging nanoscale structures. In this study, we found that confocal-SEM correlation is more applicable for imaging exosomes. Moreover, we observed that exosomes were found in clusters in confocal-SEM correlation.

Achieving highly accurate cavity thickness measurements in fabric compaction

The compaction of a fabric reinforcement in a Universal Testing Machine (UTM) allows to determine the achievable fiber volume fraction across a wide range of pressures, a valuable information for composite manufacturing. As seen in the first international compressibility benchmark, inaccuracies in the fabric stack thickness measurement, the approach to compliance correction and the non-parallelism between compaction plates resulted in highly inaccurate compression curves. In this paper, the different variability sources affecting indirect thickness methods, based on the machine displacement, and direct methods with laser sensors are presented and its impact on the accuracy is estimated. In conclusion, both thickness measurement methods produced similar results; however, the thickness measured by direct methods experienced more variability due to minor changes in the rig’s displacement or the orientations between plates, combined with other sources of variability such as external interferences or vibrations from the compaction plate which led to variations in measurement precision throughout the tests.

On the optical soliton solutions to the fractional complex structured (1+1)-dimensional perturbed gerdjikov-ivanov equation

In this work, we examine the complex structured Fractional Perturbed Gerdjikov-Ivanov equation (FPGIE), which describes the propagation of optical pulses with perturbation effects. This model finds applications in optical fibers, especially in photonic crystal fibers. We are discovered novel and unique optical soliton solutions using the modified Extended Direct Algebraic Method (mEDAM), which has never been used with this model previously. As a result, a hierarchy of traveling wave solutions including singular kink, periodic, solitary kink, and rogue-shaped soliton solutions, etc., are derived. Some obtained solutions are discussed graphically based on numerical values of some parameters related to the solution. The results add new and unique soliton types to the model and demonstrate how they interact and impact the system’s overall dynamics.

Estimation of the Born data in inverse scattering of layered media

The first term in the Born series, as we call the Born data, is linear with the scatterers. Here we present a scheme to map the total field data to the Born data in layered media using only the single-input single-output (SISO) setup. This nonlinear mapping is based on the reduced order model (ROM) approach, which constructs ROMs of the original wave operator. Normally, the construction of ROMs requires multi-input multi-output data. By introducing fictitious sensors, we estimate the Born data with SISO data in layered media. We give a simple way of using the time-domain Green’s function to estimate the received data for other fictitious sensors without calculating the complicated Sommerfeld integral. The resulting Born data contains only the single-scattering component, which can be helpful for many imaging applications. A numerical example is given incorporating the direct imaging back-propagation method. It validates the linearity of the Born data by providing an artifact-free image without the optimization process.

Research on thermal deformation of cylinder bore with orthogonal experiment method of aluminum alloy cylinder block in diesel engine

Using aluminum alloy materials provides an efficient and direct method for achieving engine weight reduction. In this study, a thermo-mechanical coupling simulation model of the diesel engine was established to investigate the deformation of cylinder bores in both cast iron and aluminum alloy cylinder blocks. The reliability of the simulation model is validated by the temperature field test of the cast iron cylinder. Four evaluation indexes, namely average roundness, cylindricity, coaxiality, and light leakage, were used to assess the deformation of the cylinder bore. The results indicate that the temperature is the primary factor contributing to the deformation in both cast iron and aluminum alloy cylinder bores. Under thermo-assembly condition, the average roundness, cylindricity, coaxiality, and light leakage rate of aluminum alloy cylinder bore were observed to be higher by 36.71 %, 12.69 %, 14.77 %, and 18.85 %, respectively, compared to those of cast iron cylinder bore. To decrease the deformation of the cylinder bore, the orthogonal experiment method was used to study the three factors affecting the heat dissipation of the water jacket. It was discovered that extending the water jacket extends upward was the most effective way to reduce the temperature of the cylinder block. By selecting the optimal combination scheme for simulation calculations, an optimized cylinder temperature of 162 °C, with the maximum deformation of the cylinder bore decreasing by 13.64 %. Additionally, the average roundness, cylindricity, coaxiality, and light leakage rate of the cylinder bore showed reductions of 17.48 %, 21.8 %, 23.00 %, and 14.10 %, respectively, when compared to the original aluminum alloy cylinder block.

Generation and Characterization of a Human Neuronal In Vitro Model for Rett Syndrome Using a Direct Reprogramming Method.

Rett Syndrome (RTT) is a severe neurodevelopmental disorder, afflicting 1 in 10,000 female births. It is caused by mutations in the X-linked methyl-CpG-binding protein gene (MECP2), which encodes for the global transcriptional regulator methyl CpG binding protein 2 (MeCP2). As human brain samples of RTT patients are scarce and cannot be used for downstream studies, there is a pressing need for in vitro modeling of pathological neuronal changes. In this study, we use a direct reprogramming method for the generation of neuronal cells from MeCP2-deficient and wild-type human dermal fibroblasts using two episomal plasmids encoding the transcription factors SOX2 and PAX6. We demonstrated that the obtained neurons exhibit a typical neuronal morphology and express the appropriate marker proteins. RNA-sequencing confirmed neuronal identity of the obtained MeCP2-deficient and wild-type neurons. Furthermore, these MeCP2-deficient neurons reflect the pathophysiology of RTT in vitro, with diminished dendritic arborization and hyperacetylation of histone H3 and H4. Treatment with MeCP2, tethered to the cell penetrating peptide TAT, ameliorated hyperacetylation of H4K16 in MeCP2-deficient neurons, which strengthens the RTT relevance of this cell model. We generated a neuronal model based on direct reprogramming derived from patient fibroblasts, providing a powerful tool to study disease mechanisms and investigating novel treatment options for RTT.

Orbit design and attitude control of diffractive sail and validation with solar polar mission

Liquid crystal diffractive sails can generate controllable tangential radiation pressures, which have advantages in the Solar Polar Imager mission (SPI). This paper proposes a composite diffractive sail design consisting of an ideal passive diffraction grating sail and liquid crystal polarization gratings (LCPGs). The main diffractive grating sail generates thrust for orbital transfer with a sun-facing attitude. An optimal 3.8-year transfer trajectory is obtained by an improved direct method. Small-area LCPGs distributed around the edge are used for three-axis attitude control. The LCPGs can continuously modulate the force and torque by controlling the applied voltage based on the electro-optical characteristic of liquid crystal materials. A control strategy, including an adaptive attitude-tracking PD controller and a control allocation method, is designed to track the attitude profile generated by the transfer trajectory. Finally, the attitude-orbit coupling dynamics are used to simulate the whole process, and the results show that orbital insertion errors are minor.

An Extension to Direct Method of Clarkson and Kruskal and Painlev$$\acute{e}$$ Analysis for the System of Variable Coefficient Nonlinear Partial Differential Equations

An Extension to Direct Method of Clarkson and Kruskal and Painlev$$\acute{e}$$ Analysis for the System of Variable Coefficient Nonlinear Partial Differential Equations

Formulation and Evaluation of Herbal Antioxidant Tablets of Urtica Dioica Extract

This study explores the formulation and assessment of herbal antioxidant tablets derived from Urtica dioica (stinging nettle) extracts for arthritis and osteoarthritis treatment. Various extraction methods were compared, revealing that 100% dehydrated ethanol at 45 degrees Celsius for four hours in a Soxhlet apparatus resulted in an 89% phenolic extraction. Although ethyl acetate yielded the highest phenolic extract (187%), its toxicity led to the selection of ethanol for further extraction. The Folin-Ciocalteu method determined the total phenolic content. The DPPH assay demonstrated positive antioxidant activity of the Urtica dioica ethanolic extract, with an IC50 value of 37.5761201 μg/mL, compared to the standard ascorbic acid with an IC50 value of 21.23506 μg/ml. Herbal tablets were formulated using the direct compression method. The findings highlight the potential of Urtica dioica extracts as effective herbal antioxidants for arthritis and osteoarthritis treatment. This research enhances our understanding of natural remedies and their therapeutic applications. Future investigations should delve into the clinical efficacy and safety of these herbal antioxidant tablets, paving the way for their potential integration into clinical settings. This study contributes valuable insights into the development of alternative therapies for managing arthritic conditions, emphasizing the importance of exploring nature's remedies in healthcare.

A frost ice formation method of horizontal axis wind turbine blade based on polynomial fitting

In this paper, a new direct calculation method of frost ice shape on the blade surface of horizontal axis wind turbine is proposed. Using linear interpolation algorithm, the airfoil ice shape obtained by LEWICE 2D software or ice wind tunnel experiment was fitted with equidistant step length in the first and fourth quadrants and equidistant step length in the second and third quadrants. The key point coordinates of ice shapes on cross-sections along the span-wise were mapped into lagging and flapping surfaces through the mathematical dimension reduction, respectively. The polynomial fitting was used to deal with ice projection points of multiple sections in lagging and flapping surfaces, and then the blade’s frost ice shape was obtained. By calculating the sum of squared residuals of the polar diameter at the same polar angle, the errors between experimental and airfoil frost shape fitting methods, experimental and FENSAP, and blade frost shape formation methods and FENSAP were analyzed. The results show that the new method is in good agreement with the ice shape of FENSAP simulation results and experimental results. The residual sum of squares is small. This method makes the analysis of frost ice morphology of wind turbine blades do not need to consider interdisciplinary. The calculation process is simple and reliable.

PERANCANGAN SISTEM INFORMASI PELAYANAN ADMINISTRASI PENDUDUK PADA KELURAHAN LEMBANGSARI

The smallest government agency at village level is the sub-district office, which is an agency that processes population data, especially in the process of making Family Cards (KK), Birth Certificates, Death Certificates, Immigrant Certificates and Moving Certificates. To be able to improve population data collection and its reports to higher agencies, namely sub-districts, steps are needed to develop a data management system. The aim of this research is to analyze the running system and design a computerized information system. The data collection methods used in this research are direct observation, interviews, literature, and analysis methods and system design using UML. The administrative service system in Lembangsari sub-district still uses ledgers to input data for letters that have been created. Searching for the letter file to be created is still experiencing difficulties due to the accumulation of files. Mail files that have been created are prone to being lost. Therefore, a follow-up information system that utilizes information technology will help collect data on the population of a sub-district, especially in the process of collecting population data, Family Cards (KK), Birth Certificates, Death Certificates, Immigrant Certificates and Moving Certificates to be more effective and efficient.

Cascade Bowl Multicavity Structure for In Situ Surface-Enhanced Raman Scattering Detection of Organic Gas Molecules.

With the increasing emphasis on atmospheric environmental protection, it is crucial to find an efficient, direct, and accurate method to identify pollutant species in the atmosphere. To solve this problem, we designed and prepared the cascade multicavity (CMC) structure composed with silver nanoparticles (Ag NPs) as a surface-enhanced Raman scattering (SERS) substrate with favorable light transmittance and flexibility. The multicavity structure distributed on the surface introducing the homogeneous connecting holes endows the structure to more fully utilize the incident light while slowing the gas movement rate. Theoretical and experimental results have demonstrated that the Ag NPs/cascade multicavity (Ag-CMC) SERS substrate is a highly sensitive SERS substrate that can be used for in situ detection of gases under non-perpendicularly incident laser irradiation or bending of the substrate. We believe that the SERS substrate can provide a more efficient and feasible way for in situ detection of gaseous pollutants.

Transformation of Elliptic Curve Discrete Logarithm Problem to QUBO Using Direct Method in Quantum Annealing Applications

This paper investigates how to reduce the elliptic curve discrete logarithm problem over prime fields to the quadratic unconstrained binary optimization (QUBO) problem in order to obtain as few logical qubits as possible. In the best case scenario, if n is the bitlength of a characteristic of prime field Fp, approximately 3n³ logical qubits are required for such a reduction in the Edwards curve case. We present a practical attack on an elliptic curve discrete logarithm problem over the 3-bit prime field F7 for an elliptic curve with the subgroup of order 8. We solved this problem using the D-Wave Advantage QPU. To the best of the authors' knowledge, no one has made, so far, a practical attack on the elliptic curve discrete logarithm over a prime field using the direct quantum method.

Solution to the schrödinger equation for bound states of polar molecules using shallow neural networks

The time independent Schrödinger equation can be solved analytically in very few cases. This is why scientists rely on approximate numerical methods. One that is yet to be a part of the everyday toolbox for physicists are neural networks. With it, it is possible to calculate eigenfunctions and the energy spectra of bound states. A double exponential central potential is used to describe the interaction between two electric dipoles that form through van der Waals interactions. These systems can be important when the electric dipoles are very large and differ from covalent, ionic, and other kinds of bonds, as is the case of the monomers M−C60, where M=Cs,Li or other alkali metals. Based in statistical physics, it has been shown that a dimer can be formed through a spontaneous and exothermic reaction. The ground state and the first two excited states of this system were calculated, also the solutions and their associated energies were plotted. The result for the ground state is compared to the shooting method and the direct variational method. The numerical value of the ground states obtained suggests that the dimers can be dissociated by electromagnetic waves with wavelengths in the far infrared regime, very close to microwaves.

Economic optimal control of source-storage collaboration based on wind power forecasting for transient frequency regulation

Under the dual crisis of climate and energy, clean energy has been rapidly developing, and the wind penetration of power systems has been continuously improving, which has brought much attention to the frequency safety of the power grid. This paper discusses two types of transient frequency regulation (TFR) scenarios with source-storage collaboration, where wind power and energy storage are used as auxiliary TFR resource. First, a distributed ultra-short-term wind power forecasting (WPF) method is proposed to facilitate the TFR resource planning of system operators. Second, a bi-level optimal control strategy is developed, aiming for the lowest TFR cost. According to the TFR power demand at the station level, the TFR powers of wind turbines, battery energy storage units, and conventional thermo-synchronous generators are dynamically allocated by using the accelerated alternating direction method of multipliers algorithm at the unit level. Finally, a case study is conducted to validate the effectiveness of the proposed WPF method and control strategy. Simulation results show that the WPF method ensures good prediction accuracy and qualification rate, and the control strategy effectively optimizes the economy of TFR.

Robust multi-view learning via M-estimator joint sparse representation

Recently, multi-view learning has achieved extraordinary success in many research areas such as pattern recognition and data mining. Most existing multi-view methods mainly focus on exploring the correlation information between different views and their performance may severely degrade in the presence of heavy noises and outliers. In this paper, we put forward a robust multi-view joint sparse representation (RMJSR) method for multi-view learning. Firstly, we design a novel multi-view Cauchy estimator based loss function originating from robust statistics to address complex noises and outliers in reality. Based on this, we leverage the ℓ1,q norm to enhance our model by encouraging the learned representation of multiple views to share the same sparsity pattern. Secondly, to explore the optimal solution for the RMJSR model, we devise an effective optimization algorithm based on the half-quadratic (HQ) theory and the alternating direction method of multipliers (ADMM) framework. Thirdly, we provide the theoretical guarantee for revealing the theoretical condition for the success of the proposed method. Further, we have also provided extensive analysis of the proposed method, including the optimality condition, convergence analysis, and complexity analysis. Extensive experimental results validate the effectiveness and robustness of the proposed method in comparison with state-of-the-art competitors. The source code is available at https://github.com/Huyutao7/RMJSRC.

Eurocode-compliant system-level reliability analyses of trussed portal frames under climatic loads

Eurocode 3 provides Geometrically and Materially Nonlinear Analysis with Imperfections-method (GMNIA) in which the entire structure can be designed in system-level. In GMNIA, reliability of structural system is verified by using a system safety factor which is obtained in Eurocode 3 based on numerical or experimental capacity test results. Unfortunately, such test results are scarcely published in the literature thus complicating the determination of the factor for a design engineer. In the so-called Direct Design Method, however, system safety factors are provided in advance for the design engineer by system-level reliability studies. This study determines the Eurocode-compliant GMNIA system safety factor for Warren truss portal frames by using the approach of the Direct Design Method. Advanced numerical models are utilized to perform Monte Carlo-simulations for entire structural systems. These simulations provide statistical distributions of system resistances which are employed in the First-Order Reliability Method to derive the system safety factors. Studied structures are made of S700 cold-formed hollow sections. Various system geometries, system configurations and load combinations consisting of snow and wind loads are investigated and a suitable system safety factor is proposed for the ultimate limit state design of Warren truss portal frames. The proposed system safety factor is applied in a practical comparison in which Warren system is designed both by the conventional Eurocode 3 method and GMNIA. This comparison reveals that GMNIA has a remarkable potential to offer reduced material consumption in design compared to the conventional method.

Preparation of gallic acid-polydimethylsiloxane codeposited carbon fibers to improve interfacial properties of epoxy composites

A novel method, drawing inspiration from the chemistry principle observed in mussels, has been recently developed to augment the wettability and adherence of carbon fibers (CFs) within epoxy resin matrix. This technique entails the concurrent application of gallic acid and aminopropyl double terminated polydimethylsiloxane on CF surfaces via a direct method. Advanced analytical techniques like scanning electron microscopy, X-ray diffraction, infrared and Raman spectroscopy, along with X-ray photoelectron spectroscopy, confirmed the effective simultaneous deposition of these agents, possibly via Michael addition or Schiff base reactions. Incorporation of these treated fibers into epoxy composites resulted in notable performance enhancements. The composites with gallic acid and polydimethylsiloxane modified fibers exhibited up to 14%, 13%, and 27% improvements in interlaminar shear strength, flexural modulus, and flexural strength, respectively, compared to their counterpart with untreated fibers. These results indicate that combining gallic acid and polydimethylsiloxane on CFs is a potent approach to boost the interface qualities of CF-reinforced epoxy resin composites.

The CDK Inhibitor Dinaciclib Improves Cisplatin Response in Nonseminomatous Testicular Cancer: A Preclinical Study.

Most patients with testicular germ cell tumors (GCTs) are treated with cisplatin (CP)-based chemotherapy. However, some of them may develop CP resistance and therefore represent a clinical challenge. Cyclin-dependent kinase 5 (CDK5) is involved in chemotherapy resistance in different types of cancer. Here, we investigated the possible role of CDK5 and other CDKs targeted by dinaciclib in nonseminoma cell models (both CP-sensitive and CP-resistant), evaluating the potential of the CDK inhibitor dinaciclib as a single/combined agent for the treatment of advanced/metastatic testicular cancer (TC). The effects of dinaciclib and CP on sensitive and resistant NT2/D1 and NCCIT cell viability and proliferation were evaluated using MTT assays and direct count methods. Flow cytometry cell-cycle analysis was performed. The protein expression was assessed via Western blotting. The in vivo experiments were conducted in zebrafish embryos xenografted with TC cells. Among all the CDKs analyzed, CDK5 protein expression was significantly higher in CP-resistant models. Dinaciclib reduced the cell viability and proliferation in each cell model, inducing changes in cell-cycle distribution. In drug combination experiments, dinaciclib enhances the CP effect both in vitro and in the zebrafish model. Dinaciclib, when combined with CP, could be useful for improving nonseminoma TC response to CP.