Physical Basis Research Articles

Hypobaric type oxygenators - physics and physiology.

Brain injury is still a serious complication after cardiac surgery. Gaseous microemboli (GME) are known to contribute to both short and longer-term brain injury after cardiac surgery. Hypobaric and novel dual-chamber oxygenators use the physical behaviors and properties of gases to reduce GME. The aim of this review was to present the basic physics of the gases, the mechanism in which the hypobaric and dual-chamber oxygenators reduce GME, their technical performance, the preclinical studies, and future directions. The gas laws are reviewed as an aid to understanding the mechanisms of action of oxygenators. Hypobaric-type oxygenators employ a high oxygen, no nitrogen environment creating a steep concentration gradient of nitrogen out of the blood and into the oxygenator, reducing the risk of GMEs forming. Adequately powered clinical studies have never been carried out with a hypobaric or dual-chamber oxygenator. These are required before such technology can be recommended for widespread clinical use.

Enhancement of superconductivity by organic flexible substrates in NbSe2 thin flakes

The regulation of superconductivity is of great significance in basic physics and device applications. Typically superconductivity can be tuned by chemical doping, gate voltage, and pressure. The interaction between superconductivity and substrates in low-dimensional systems is concerned in recent years, but a systematic and in-depth investigation is still lacking. Here we report a systematic study concerning the influence of substrates on the performance of superconductivity in NbSe2 thin flakes. It is found that the superconducting critical temperature Tc can be enhanced when the organic flexible substrates are adopted, as compared with that using the inorganic rigid substrates. Such an enhancement is more distinct under the applied magnetic fields. The analysis combined with Raman scattering experiments shows that the improvement of superconductivity is closely related to the softening of E2g1 phonon mode, pointing out the most possible mechanism for the effect of substrates on superconductivity. Meanwhile, the involvement of organic substrate also enhances the wave number of the charge-density-wave related soft mode.

An improved axisymmetric interfacial lattice Boltzmann flux solver for large-density-ratio multiphase flows

In this paper, an improved axisymmetric interfacial lattice Boltzmann flux solver abandoning the previous predictor-corrector scheme is proposed. Unlike the previous model starting from the two-dimensional standard lattice Boltzmann method (LBM), the present method is developed using the axisymmetric LBM, which directly incorporates the axisymmetric effects into the distribution functions. As a result, the proposed solver does not need the corrector step involving complicated space derivatives. It makes this method simpler and more computationally efficient. In the present solver, the resultant governing equation is globally resolved by the finite volume method, while the fluxes are reconstructed by local application of the axisymmetric LBM. Therefore, the inconsistency between the local reconstruction and the global governing equation can be eliminated because the global equation can be strictly derived from the axisymmetric LBM, which holds stronger physical basis than the previous method. Numerical experiments about the interface capturing and the multiphase flows are conducted to test the proposed model. Results show that the present method is superior to the fractional step solver in terms of the accuracy, stability, and computational efficiency. In addition, this solver has the capacity of simulating large-density-ratio and complex interfacial change.

Development of the TALUBA Model to Increase Science, Islam, and Local Wisdom and Instill Taluba Character

This research aimed to create TALUBA learning model-assisted modules that enhance three different forms of literacy. These were the literacy of science, Islam, and indigenous wisdom. The other was to maintain honorable character. The South Kalimantan people's local characters, especially Baiman (faithful), Bauntung (fortunate), and Batuah (dignified), are known as the taluba (three ‘ba’) characters. Using the ADDIE design, this study was a research and development project. Twenty-eight students studying work and energy in Basic Physics served as the research sample. The study instruments were the validation sheets, observation sheets, test questions, and questionnaires. Tests, observations, and surveys were the methods utilized to acquire data. The Aiken formula, N-Gain, mean, and percentage were employed in the data analysis. With a value of 0.92-1.00, learning models and modules were known to be valid based on the data analysis results. In the very good category, the average application of the learning model by lecturers was 4.85, while for students, it was 4.30. According to the test findings, the N-gains for literacy in scientific, Islamic, and local wisdom were 0.93, 0.92, and 0.94 in the high group, respectively. The very good category's average taluba character was 4.61. Additionally, there was a good reaction from students to the learning models and modules. This suggests that the proposed TALUBA learning model is appropriate for lecture use.

Learning basic physics in Pharmacy Study Program with systems thinking skills needed by pharmacy students

This research is a preliminary study aimed at analyzing the methods of teaching basic physics applied in the pharmacy program, as well as its implications for the relevance of physics concepts in pharmacy courses and the development of students' system thinking skills. A cross-sectional survey method was used, employing a structured questionnaire based on the Likert scale, involving physics course instructors from private and public universities. The research findings indicate that, although basic physics has significant potential in contributing to the development of the system thinking skills required by pharmacy graduates, challenges in integrating physics concepts with pharmacy courses still exist. The pharmacy curriculum's focus on pharmaceutical and health aspects may overlook students' understanding of basic physics. Therefore, the importance of developing teaching methods and physics laboratory practices that are appropriate for the pharmacy context becomes clearer. This research concluded that there is a need for the development of more suitable learning methods for basic physics courses in the pharmacy program, with an emphasis on developing system thinking skills crucial in the field of health, and the integration of pharmacy laboratories as a learning support. This is expected to enhance the understanding of physics concepts in the pharmacy context and build relevant system thinking skills for graduates of the pharmacy program.

Comparative Analysis Accuracy ID3 Algorithm and C4.5 Algorithm in Selection of Candidates Basic Physics Laboratory Assistant

Basic Physics Laboratory is one of the supporting laboratories at Gunadarma University. Each practical activity in the laboratory is supervised by respective assistants. Therefore, a support system is needed as a basis for decision-making in determining assistant candidates. This decision-making process is processed using data mining techniques, specifically classification algorithms. The criteria or attributes used in the decision-making process include written test scores, practical test scores, presentation scores, equipment usage abilities, and interviews. The classification algorithms used in this research are ID3 and C4.5 algorithms. The tools used to implement these algorithms are RapidMiner Studio 9.10. These algorithms will generate decision trees that can be used as decision support. The aim of this research is to conduct an accuracy comparison analysis for the ID3 and C4.5 algorithms. The highest accuracy obtained will be used as a reference for determining whether assistant candidates are accepted or not. The accuracy results show that the C4.5 algorithm has the highest accuracy, precision, and recall compared to the ID3 algorithm. The determination of the highest value is done using the k-fold cross-validation model for values 2, 4, 6, 8, and 10. The C4.5 algorithm has the highest accuracy of 96.67% at k-fold value = 2.

Case Method in The Problem-Based Learning Model to Increase Student Participation in The Basic Physics Course

Today's lecture activities require more active learning. However, lecture activities in Basic Physics courses often always focus on the lecturer. This research analyzes the application of the case method in increasing student participation in the Basic Physics I course. This research is a 2 cycle of classroom action research applied to the Basic Physics I course in the 2023/2024 academic year. The research design uses a spiral model by Kemmis and McTaggart. The research results showed that there was an increase in student activity scores in cycle 1 and cycle 2, namely 38.86% (poor category) to 69.14 (fair category).

XÂY DỰNG BỘ TÌNH HUỐNG DẠY - HỌC MỘT SỐ NỘI DUNG TRONG MODULE S1.4 THEO CHƯƠNG TRÌNH ĐÀO TẠO DỰA TRÊN NĂNG LỰC CỦA TRƯỜNG ĐẠI HỌC Y HÀ NỘI

In this study, applying the theories on case-based learning, we have built a new set of 30 case studies used in teaching and learning for some contents of Module S1.4: Physical basis of life activities and applications in medicine according to the competency-based training program of Hanoi Medical University. A set of 30 case studies accompanied by 150 multiple choice questions (MCQ) is designed to suit each corresponding teaching method such as Lectures (LEC), Seminar (SEM), and Team Based Learning (TBL). The feedback from students shows that 97.1% of students agreed that the content of the cases is suitable with the goals and content of each corresponding lesson; 95.3% of students said that the situations all have a clinical context, promoting the attractiveness of the lesson. The content of the set of situations in the topic is completely new and has been built and used by lecturers of Medical Physics, Hanoi Medical University in teaching students of Hanoi Medical University recently.

Co-doped BaFe2As2 Josephson junction fabricated with a focused helium ion beam

Josephson junction plays a key role not only in studying the basic physics of unconventional iron-based superconductors but also in realizing practical application of thin-film based devices, therefore the preparation of high-quality iron pnictide Josephson junctions is of great importance. In this work, we have successfully fabricated Josephson junctions from Co-doped BaFe2As2 thin films using a direct junction fabrication technique which utilizes high energy focused helium ion beam (FHIB). The electrical transport properties were investigated for junctions fabricated with various He+ irradiation doses. The junctions show sharp superconducting transition around 24 K with a narrow transition width of 2.5 K, and a dose correlated foot-structure resistance which corresponds to the effective tuning of junction properties by He+ irradiation. Significant J c suppression by more than two orders of magnitude can be achieved by increasing the He+ irradiation dose, which is advantageous for the realization of low noise ion pnictide thin film devices. Clear Shapiro steps are observed under 10 GHz microwave irradiation. The above results demonstrate the successful fabrication of high quality and controllable Co-doped BaFe2As2 Josephson junction with high reproducibility using the FHIB technique, laying the foundation for future investigating the mechanism of iron-based superconductors, and also the further implementation in various superconducting electronic devices.

Should dualists locate the physical basis of experience in the head?

Dualism holds that experiences are non-physical states that exist alongside physical states. Dualism leads to the postulation of psychophysical laws that generate experiences by operating on certain sorts of physical states. What sorts of physical states? To the limited extent that dualists have addressed this question, they have tended to favor a brain-based approach that locates the physical basis of experience in the head. In contrast, this paper develops an argument for a form of dualism on which experience has a physical basis that reaches out into the world. Specifically, the argument uses a puzzle about spatial experience to support a theory I call tracking dualism. On tracking dualism, a psychophysical law generates experiences by operating on complex physical states that involve both brain states and tracking relations that they bear to features of the environment. To develop the argument, I discuss tracking dualism alongside its more familiar physicalist counterpart, the tracking intentionalist theory associated with Dretske, Lycan, and Tye. I conclude by outlining a tracking dualist research agenda.

Physical bases of the short-term forecast of earthquakes

Physical bases of the short-term forecast of earthquakes

A 3D time-dependent backward erosion piping model

Backward erosion piping (BEP) is a failure mechanism of hydraulic structures like dams and levees on cohesionless foundations subjected to seepage flows. This article models the time-dependent development of BEP using numerical simulation of the erosion process. A 3-dimensional finite element equilibrium BEP model is extended with a formulation for the sediment transport rate. The model is compared to and calibrated with small- and large-scale experiments. Finally, a large set of simulations is analyzed to study the effects of factors such as grain size, scale (seepage length) and overloading on the rate of pipe progression. The results show that the development of BEP in the small-scale experiments is predicted well. Challenges remain for the prediction at larger scales, as calibration and validation is hard due to limited large-scale experiments with sufficiently accurate measurements. The results show that the progression rate increases with grain size and degree of overloading and decreases with seepage length, which is consistent with experimental observations. The model results provide a better physical basis for incorporating time-dependent development in the risk assessment and design of levees.

Magnetic resonance relaxometry in assessment of morphological properties of brain gliomas: state of the art

Magnetic resonance (MR) relaxometry, or measurement of tissue magnetic relaxation properties, is a technology intended to quantitatively depict the physical basis of structural MR imaging. This review is devoted to perspective directions of studies and application of MR relaxometry in brain glioma preoperative and pretherapeutic diagnosis. The current data advocate for emerging capabilities of relaxometry in glioma grading (despite possible overlap between different grades) and differentiating between gliomas and tumors of other origin. Some studies showed features of relaxometric values within the perifocal infiltrative edema zone possibly related to glioma infiltrative growth. We separately reviewed the works aimed at searching for the most aggressive and malignant foci in glioma tissue and extremely useful for tumor biopsy or removal. No less important are capabilities of relaxometry in radiogenomics, first of all, in IDH status prediction. The relaxometric method possesses perspective in multiparametric brain glioma diagnostics.

Renormalization scheme factorization of one-loop Fierz identities

We present a proof of the factorization of renormalization scheme in one-loop-corrected Fierz identities. This scheme factorization facilitates the simultaneous transformation of operator basis and renormalization scheme using only relations between physical operators; the evanescent operators in the respective bases may be chosen entirely independently of each other. The relations between evanescent operators in the two bases is automatically accounted for by the corrected Fierz identities. We illustrate the utility of this result with a two-loop anomalous dimension matrix computation using the Naive-Dimensional Regularization scheme, which is then transformed via one-loop Fierz identities to the known result in the literature given in a different basis and calculated in the Larin scheme. Additionally, we reproduce results from the literature of basis transformations involving the rotation of evanescent operators into the physical basis using our method, without the need to explicitly compute one-loop matrix elements of evanescent operators.

Effect of freeze–thaw cycles on the macrostructure and failure mechanisms of fiber-reinforced clay using industrial computed tomography

Freeze–thaw cycling is a critical issue in cold-climate engineering because these cycles impact the mechanical properties of soils due to the translocation of water and ice at temperatures near 0 °C. Reinforcement methods have been developed to decrease these adverse effects, including the use of polypropylene (PP) fibers. However, few macrostructural investigations have been able to demonstrate the underlying physical basis for their effectiveness. This study used computed tomography (CT) images of clay samples reinforced with 2% PP fibers and subjected to unconfined compression and Brazilian tests before and after up to 10 closed-system freeze–thaw cycles (FTCs). Significant effects of the FTCs on soil structure include a reduction in macropores and an increase in mesopores. The addition of PP fibers reduces this change in the number of macropores from 28% to 18% following 10 FTCs. Unreinforced samples also show more localized propagation of shear/tensile cracks during tests than reinforced samples as a result of having a higher failure strength and ductility. The bridging effect of fibers, deviation of the failure path, and formation of microcracks around fibers are clearly illustrated in the CT images. This study provides significant insights relevant to engineering design in cold regions.

Nanoscale Vector Magnetic Sensing with Current‐Driven Stochastic Nanomagnet

AbstractDetection of vector magnetic fields at nanoscale dimensions is critical in applications ranging from basic material science and fundamental physics to information storage and medical diagnostics. So far, nanoscale vector magnetic field sensing is achieved solely by exploiting a single nitrogen‐vacancy (NV) center in a diamond, by evaluating the Zeeman splitting of NV spin qubits by using the technique of an optically‐detected magnetic resonance. This protocol requires a complex optical setup and expensive detection systems to detect the photoluminescence light, which may limit miniaturization and scalability. Here, a simple approach with all‐electric operation to sensing a vector magnetic field at 200 × 200 nm2 dimensions is experimentally demonstrated, by monitoring a stochastic nanomagnet's transition probability from a metastable state, excited by a driving current due to spin‐orbit torque, to a settled state.

Perbandingan Pemahaman Konsep Fisika Dasar Berdasarkan Jalur Masuk Mahasiswa Departemen Pendidikan Fisika

Students' understanding of Basic Physics concepts regarding Kinematics has different levels of understanding according to the entry route. This research aims to determine the comparison of understanding of Basic Physics concepts regarding Kinematics based on student entry points at the Department of Physics Education. The type of research used is experimental research. The sample used was 34 undergraduate students majoring in Physics Education who were chosen randomly. The research instrument used was a questionnaire with four multiple choice questions. Data collection techniques use Google Forms which are shared in class groups. The data obtained were analyzed using CRI (Certainty of Response Index) and Analysis of Variance (ANOVA). The research results show that there are differences in understanding of Basic Physics concepts based on entry route

Advances in 3D bioprinting for regenerative medicine applications

Abstract Biofabrication techniques allow for the construction of biocompatible and biofunctional structures composed from biomaterials, cells and biomolecules. Bioprinting is an emerging 3D printing method which utilizes biomaterial-based mixtures with cells and other biological constituents into printable suspensions known as bioinks. Coupled with automated design protocols and based on different modes for droplet deposition, 3D bioprinters are able to fabricate hydrogel-based objects with specific architecture and geometrical properties, providing the necessary environment that promotes cell growth and directs cell differentiation towards application-related lineages. For the preparation of such bioinks, various water-soluble biomaterials have been employed, including natural and synthetic biopolymers, and inorganic materials. Bioprinted constructs are considered to be one of the most promising avenues in regenerative medicine due to their native organ biomimicry. For a successful application, the bioprinted constructs should meet particular criteria such as optimal biological response, mechanical properties similar to the target tissue, high levels of reproducibility and printing fidelity, but also increased upscaling capability. In this review, we highlight the most recent advances in bioprinting, focusing on the regeneration of various tissues including bone, cartilage, cardiovascular, neural, skin and other organs such as liver, kidney, pancreas and lungs. We discuss the rapidly developing co-culture bioprinting systems used to resemble the complexity of tissues and organs and the crosstalk between various cell populations towards regeneration. Moreover, we report on the basic physical principles governing 3D bioprinting, and the ideal bioink properties based on the biomaterials’ regenerative potential. We examine and critically discuss the present status of 3D bioprinting regarding its applicability and current limitations that need to be overcome to establish it at the forefront of artificial organ production and transplantation.

The physical basis and damage mechanism of blast injuries

The physical basis and damage mechanism of blast injuries

Research of the semiconductor sensors based on anomal photovoltaic effect with highly sensitive parameters of the deformation

Optical parameters of thin polycrystalline semiconductor films during deformation (t, n, 𝜆, R, T 𝑣a, 𝜑 𝜎) changes. An optical elastic effect has been created. Its physical basis is that deformation affects the shape of the zonal diagram by changing the crystal lattice constants. This condition gives rise to various optical and other electronic phenomena in semiconductor thin films .