Static Fluid Research Articles

Existence and stability of static spherical fluid shells in a Schwarzschild-Rindler–anti–de Sitter metric

We demonstrate the existence of static stable spherical fluid shells in the Schwarzschild-Rindler-anti-de Sitter (SRAdS) spacetime where $ds^2 = f(r)dt^{2} -\frac{dr^{2}}{f(r)}-r^{2}(d\theta ^2 +\sin ^2 \theta d\phi ^2)$ with $f(r) = 1 -\frac{2Gm}{r} + 2 b r -\frac{\Lambda}{3}r^2$. This is an alternative to the well known gravastar geometry where the stability emerges due to the combination of the repulsive forces of the interior de Sitter space with the attractive forces of the exterior Schwarzschild spacetime. In the SRAdS spacetime the repulsion that leads to stability of the shell comes from a negative Rindler term while the Schwarzschild and anti-de Sitter terms are attractive. We demonstrate the existence of such stable spherical shells for three shell fluid equations of state: vacuum shell ($p=-\sigma$), stiff matter shell ($p=\sigma$) and dust shell ($p=0$) where $p$ is the shell pressure and $\sigma$ is the shell surface density. We also identify the metric parameter conditions that need to be satisfied for shell stability in each case. The vacuum stable shell solution in the SRAdS spacetime is consistent with previous studies by two of the authors that demonstrated the existence sf stable spherical scalar field domain walls in the SRAdS spacetime.

PENINGKATAN KETERAMPILAN BERPIKIR KRITIS PESERTA DIDIK MELALUI PENERAPAN PENDEKATAN SAINTIFIK

This study aims to determine the effect of applying a scientific approach to improve students' critical thinking skills on static fluid material at SMA Mujahidin Pontianak. The research method used was Pre-Experimental with One Group Pre-test Post-test design. The data collection tool used was in the form of questions, namely 8 questions in multiple choice form. This study involved 25 students of class XI IPA 2 as a sample selected by random sampling technique. The results showed that the average gain score for critical thinking skills was 0.3 in the moderate category. This research is expected to be used as an alternative remediation activity for students in order to improve critical thinking skills

A conservative level set method for N-phase flows with a free-energy-based surface tension model

We introduce the N-phase Conservative Level Set Free-Energy-based Surface Tension model (NCLS-FEST) for multiphase flow (N≥3). The model minimizes numerical overlaps of fluids and voids between fluids that are found in the standard Conservative Level Set (CLS) method for three fluid phases. The key differences between NCLS-FEST and CLS methods are the multiphase compression-diffusion equation to ensure conservation, an interface with constant width, a physical solution with minimal overlaps and voids between phases at each time step, and a free-energy-based surface tension model. We demonstrate that the NCLS-FEST method has accurate results for N-phase fluid flows involving complicated geometrical configurations, including triple lines in the liquid lens problem for three and four fluid phases, with accurate conservation of mass. Additionally, we show that the NCLS-FEST method can be extended to N-phase fluid-solid flow, where the solid phase is modeled by a static fluid phase.

Effect of resistive heating on incessantly poignant thin needle in magnetohydrodynamic Sakiadis hybrid nanofluid

The flow and energy transport of water-ethylene glycol (EG) based Ti-Cu hybrid nanofluid due to incessantly poignant needle in magnetohydrodynamic Sakiadis flow with resistive heating is investigated. We scrutinized the flow and heat transfer of the Blasius and free stream flows. The governing Partial Differential Equations are transformed as Ordinary Differential Equations using suitable similarities and resolved numerically using RK (Runge-Kutta) based shooting procedure. Numerical and graphical outcomes are explored and examined for the drive, thermal transport, surface friction and local Nusselt number of various pertinent parameters. It is originate that the flow and thermal boundary layer of Blasius and Sakiadis flows are not equal. The rate of energy transport is high in moving needle in the static fluid when equated with the fixed needle in dynamic fluid. It is also established that the rate of heat transfer in Ti-Cu/EG-water hybrid nanofluid is more than water-EG/Ti nanofluid.

Description of students' science process skills on density material

Physics is one of the subjects related to various scientific concepts in which some of its applications can be found in everyday life. Thus in the learning of physics required special skills, namely science process skills. Science process skills have two categories, basic science process skills, and integration science processes. The researcher conducted research that aims to measure the ability of students' science process skills on static fluid material by using an observation sheet that matches the indicators of science process skills. The research method used is a mixed-method (mix methods) while the design used is sequential explanatory, which combines quantitative and qualitative research in a sequence using the quantitative method and then the quantitative method. From the results of interviews and observations, it can be seen that the science process skills of students at Adhyaksa 1 Junior High School in Jambi are classified as good.

THE APPLICATION OF MODEL PROBLEM BASED LEARNING (PBL) AGAINST STUDENT RESULTS IN SENIOR HIGH SCHOOL 11 SAMARINDA

This study aims to determine the increase in student learning outcomes of class XI IPA 1 senior high school 11 Samarinda after applying the PBL model to the Static Fluid material and to find out student responses about the application of the PBL model in static fluid learning. The research used One Group Pretest-Posttest Design method on Static Fluid material. The technique used was purposive sampling with the sample of this study were 35 students of class XI IPA 1 senior high school 11 Samarinda. The instruments used were written questions and questionnaires. Based on the results of the study showed that the average N-Gain was 0.69. The results of the t-test calculation showed that a significant level of learning outcomes and students' responses to PBL was in a good category or criteria.

Description of Physics Problem-solving in the Topic of Static Fluid: Case Study of Physics Education in Halu Oleo University

Good physics teaching in secondary schools and colleges emphasize problem-solving. Although students are effective in conventional tests of problem-solving, there is evidence that they have little or no comprehension of basic concepts. There are two (2) reasons that justify the claim that solving plays a broad role in the physics curriculum at most levels of education, namely problem solving can facilitate students learning physics and physics can assist students in developing the skills needed to solve problems in the real world. This study aims to provide a description of the physics problem-solving ability of Halu Oleo university physics education students on static fluid material. This type of research is a quantitative descriptive study with research subjects in 4 classes of physics education students at Halu Oleo University. The research instrument and data collection made in the form of problem-solving essay test questions given to 120 students from 4 classes. The material of the investigation took one of the topics, namely static fluid. The problem-solving assessment consists of a useful description, physics approach, specific application of physics, mathematical procedures, logical progression adopted from the research of Docktor et al. 2016. The results of the analysis found that in the four classes that were tested on conceptual problem-solving tests, the average of all students were in the useful description category. In other words, students could only translate and organize information from problems into appropriate and useful representations, and summarize the essence of the information provided symbolically, visually and in writing. As for the category of physics approach, specific application of physics, mathematical procedures, logical progression that are in the low category are still weak.

Research and Improvement of Calculation Method of Flow Pressure in Mechanical Recovery Wells

This paper takes the flow pressure of oil recovery wells in polymer flooding blocks in the past two years as the research data, and conducts field test research based on the analysis of test principles and technical indicators of the equipment. By taking the oil wells at the actual static pressure measurement points as the research object, the author compares the flow pressure of the static fluid with that calculated by the low-pressure test data management and analysis software so as to analyze the rationality and data modification method of the formula. By giving full play to the role of the data of the flow pressure and working liquid level in the dynamic analysis and development program preparation, this paper formulates a reasonable working system for mechanical recovery wells, thereby helping to ensure the sustainable and stable production of oil fields.The low-pressure test team is responsible for the test of the indicator diagram and working liquid level of the oil well in the polymer flooding block. Comprehensive data such as the indicator diagram, working liquid level, depth of the middle layer, pump depth, depth of pump inlet, and casing pressure, as well as comprehensive water cut are imported into the data management and analysis software, which are used to calculate the flow pressure of the oil wells.

PEMERIKSAAN STATIC FLUID MAGNETIC RESONANCE UROGRAPHY PADA ANAK DENGAN DUGAAN OBSTRUKSI TRAKTUS URINARIUS

Background : Static fluid Magnetic Resonance Urography (MRU) treats the urinary tract as a static column of fluid, using one of a variety of T2-weighted sequences that exploit the long T2 relaxation time of urine. It does not require the excretion of contrast material and is therefore useful for demonstrating the collecting system and ureter of an obstructed urinary tract. Static fluid MRU provides good morphology visualization and multiplanar three-dimensional reconstruction capability.
 Aim of study : To display the excellence of static fluid MRU in visualization of dilatated urinary tract segments in pediatric cases with suspectedurinary obstruction.
 Methods : Nine pediatric patients with suspected obstructive uropathy (as suggested by ultrasound) were included in this case study. The examinations were performed with 1.5T MR scanners using static fluid T2-weighted MRU sequence. Ultrasound examinations were done forall patients. Voiding cystourethrogram was done for 3 patients.
 Results : Eight studied patients had dilated collecting systems. Static fluid MRU can provide detailed structural assessment of dilatatedcollecting systems. It was superior to ultrasound in evaluation of obstructive double collecting system, ureteral ectopia, ureteral obstructionand massive hydroureteronephrosis.

A ANALISIS TINGKAT PEMAHAMAN PESERTA DIDIK YANG DIAJARKAN DENGAN METODE EKSPERIMEN DENGAN MENGGUNAKAN MODEL PEMBELAJARAN DISCOVERY LEARNING DI KELAS XI MIA SMA SWASTA HOSANA MEDAN TP. 2019/2020

This research was conducted with the aim to improve cognitive, affective and psychomotor understanding of SMA Swasta Hosana Medan students in Class XI MIA odd semester of the 2019/2020 academic year with the subject of elasticity and static fluid with experimental methods using discovery learning models. This research is a classroom action research, which was conducted using two cycles using a total sample. Each class is taught with different teaching material, in the first cycle the teaching material presented is elasticity and in the second cycle the teaching material is static fluid. Each cycle is evaluated, reflected and improved in the hope of achieving cognitive, affective and psychomotor learning indicators for students. From the evaluation results obtained an average cognitive value for cycle I of 70.24 and cycle II of 78.10 with a gain <g> = 0.26 low criteria, and the results of the t test, obtained t count 3.13> t table 1.684 means there is influence. The average affective cycle I was 80.20 while the second cycle was 84.22 with a gain <g> = 0.20 in the low category, and the results of the t test were obtained by t arithmetic 6.203> t table 1.684, meaning that there was an improvement effect of the cycle I to cycle II. For the psychomotor assessment results, the average value of the first cycle was 71.90 while the second cycle was 77.78, and the gain <g> = 0.21 was in the low category, and from the results of the t test, t count was 7.83> t table 1.684 there is an improvement in the results from cycle I to cycle II. Thus the level of understanding of SMA Swasta Hosana Medan students in class XI MIA increases if taught by the experimental method using discovery learning models for the subject matter of elasticity and static fluid in the 2019/2020 academic year.

The effectiveness of local wisdom-based static fluid modules in the wetlands environment

This study aims to describe the effectiveness of static fluid module based on local wisdom in the wetlands environment. This study is a research and development study and uses the 4D model modified. The effectiveness of the module is measured using a learning outcome test. The subjects of this study were sixty grade XI students from two public high schools in Banjarmasin city. The result of the analysis showed that the effectiveness of teaching materials have a medium category. The result indicates that the static fluid module based on local wisdom in the wetland environment is effective so that they can be used in the learning process in the classroom, at the high school level.

Beyond moments: relativistic lattice Boltzmann methods for radiative transport in computational astrophysics

ABSTRACT We present a new method for the numerical solution of the radiative-transfer equation (RTE) in multidimensional scenarios commonly encountered in computational astrophysics. The method is based on the direct solution of the Boltzmann equation via an extension of the lattice Boltzmann (LB) equation and allows to model the evolution of the radiation field as it interacts with a background fluid, via absorption, emission, and scattering. As a first application of this method, we restrict our attention to a frequency independent (‘grey’) formulation within a special-relativistic framework, which can be employed also for classical computational astrophysics. For a number of standard tests that consider the performance of the method in optically thin, optically thick, and intermediate regimes with a static fluid, we show the ability of the LB method to produce accurate and convergent results matching the analytic solutions. We also contrast the LB method with commonly employed moment-based schemes for the solution of the RTE, such as the M1 scheme. In this way, we are able to highlight that the LB method provides the correct solution for both non-trivial free-streaming scenarios and the intermediate optical-depth regime, for which the M1 method either fails or provides inaccurate solutions. When coupling to a dynamical fluid, on the other hand, we present the first self-consistent solution of the RTE with LB methods within a relativistic-hydrodynamic scenario. Finally, we show that besides providing more accurate results in all regimes, the LB method features smaller or comparable computational costs compared to the M1 scheme.

Actively homogenizing fluid distribution and slug length of liquid-liquid segmented flow in parallelized microchannels

Liquid-liquid segmented flow offers the unique characteristics of high heat and mass transfer combined with a narrow residence time distribution and thus shows great potential in process intensification of biphasic applications. Capacity increase of this technology can only be achieved by numbering-up, if scale-related advantages are to be preserved. This implies homogeneous residence times and volume flows in all parallel channels. Conventionally this is achieved by static fluid distribution concepts with high pressure drops. This contribution develops a microfluidic valve based on temperature-controlled viscosity adjustments. It can be used to actively compensate for manufacturing tolerances in parallelized micro reactors and thus requires a lower pressure drop than static distribution concepts to achieve a homogeneous fluid distribution. The distributor concept is combined with sensors and actuators for flow patterns and an automated parallelization concept for homogenizing flow patterns of liquid-liquid slug flows in micro channels is presented.

Numerical simulation on structural dynamics of 5 MW wind turbine

Considering the rigid-flexible coupling system of 5 MW wind turbine, the static pressure, fluid temperature, Mach number, vorticity, shear stress and velocity distribution of tower flange are obtained under the combined action of wind shear and fluctuating wind. The dynamic response of rigid-flexible coupling structure is studied by the combined action of the whole vibration and local vibration of 5 MW wind turbine. Through the analysis of dynamic parameter change curve, the improvement measures of tower structure are put forward, and the dynamic response of the structure before and after improvement is compared. The superiority of the improved structure is expounded, so as to provide reference basis for engineering application.

Stability and horizon formation during dissipative collapse

We investigate the role played by density inhomogeneities and dissipation on the final outcome of collapse of a self-gravitating sphere. By imposing a perturbative scheme on the thermodynamical variables and gravitational potentials we track the evolution of the collapse process starting off with an initially static perfect fluid sphere which is shear-free. The collapsing core dissipates energy in the form of a radial heat flux with the exterior spacetime being filled with a superposition of null energy and an anisotropic string distribution. The ensuing dynamical process slowly evolves into a shear-like regime with contributions from the heat flux and density fluctuations. We show that the anisotropy due to the presence of the strings drives the stellar fluid towards instability with this effect being enhanced by the density inhomogeneity. An interesting and novel consequence of this collapse is the earlier formation of the horizon.

Singularities in quantum corrected space-times

In this paper we consider a static and regular fluid generating a locally spherically symmetric and time-independent space-time and calculate the leading quantum corrections to the metric to first order in curvature. Starting from a singularity free classical solution of general relativity, we show that singularities can be introduced in the curvature invariants by quantum gravitational corrections calculated using an effective field theory approach to quantum gravity. We identify non-trivial conditions that ensure that curvature invariants remain singularity free to leading order in the curvature expansion of the effective action.

Identifitacion of Students' Misconceptions in Static Fluid

This study aimed to identify students’ misconceptions in static fluid covering Archimedes’ Principle and hydrostatic pressure. The used-instruments were of 10 multiple choice questions supported by reasons for answers. The method used in this research was giving the exercise in the form of questions to 32 students of XI class who had received subject matter of Archimedes’ Principle and hydrostatic pressure at middle and high school levels. The results of the students’ answers were then analyzed and presented qualitatively and quantitatively. Based on the analysis of students’ answers obtained 16 types of misconceptions in static fluid. In comprehending Archimedes' Principle, most students experienced difficulties in determining the state of floating, sinking and determining magnitude of buoyancy of objects in a fluid. While on hydrostatic pressure topic, most students found it difficult to determine the amount of hydrostatic pressure at a point in the fluid.

Pengaruh Model Pembelajaran CCM CCA Terhadap Kemampuan Pemecahan Masalah Fluida Statis Peserta Didik

This research is a Pre-experimental research with One Group Pretest-Posttest Design. This study aims to describe the students 'problem solving abilities during the learning process and determine the effect of CCM CCA learning models on problem solving skills and mastery of students' static fluid concepts . The study population was all students of class XI MIPA SMAN 4 Praya with a sampling technique using purposive sampling . The research sample was students in the three classes that were used as experimental classes that were given treatment in the form of learning using the CCM CCA learning model . Problem solving skills are obtained during the learning process by using LKPD which is equipped with problem solving ability instruments. The instrument used for problem-solving abilities uses test instruments in the form of test descriptions. Problem solving ability is measured by problem description. The conclusions obtained, namely 1) the level of problem-solving ability when the learning process is included in the medium category, 2) the CCM CCA learning model influences the ability of problem solving and mastery of students' static fluid concepts. DOI: 10.29408/kpj.v4i1.2089

The Feasibility of Student Worksheet based on Collaborative Creativity to Improve Students Creative Thinking Skill

This study aims to describe the feasibility of the student worksheet based on collaborative creativity to improve creative thinking skills on static fluid material in terms of validity, practicality, and effectiveness. This type of research is a type of development research by the ADDIE model with one group pre-test post-test experimental design method. The trial subjects were 107 students from class XI-MIPA 1, XI-MIPA 3, and XI-MIPA 4 in SMAN 1 Sumberrejo. The instruments used were validation instruments, observation instruments for the practicalities of the student worksheet, test instruments, and questionnaires to measure the student worksheet's effectiveness. The results showed that the validity of the student worksheet was included in the very valid category. In terms of the implementation of learning and student activities, the student worksheet practicality criteria are in the excellent category. The student worksheet's effectiveness criteria, based on test results, are in the medium category, and students' responses are very effective. Thus, the student worksheet that has been developed can improve creative thinking skills in learning the physics of static fluid material.

Diminishing Depth to Water in Cambrian-Ordovician Arbuckle Group Disposal Wells in Kansas

Industrial and municipal wastewater and oilfield brines have been disposed of into the Cambrian-Ordovician Arbuckle Group for decades in Kansas and nearby states in the midcontinent United States. The industrial and municipal wastewater disposal wells (designated Class I disposal wells) are regulated by the Kansas Department of Health and Environment. The oilfield brines are disposed of in Class II disposal wells, which are regulated by the Kansas Corporation Commission. Annual testing of formation pressure and static fluid levels in Class I wells compose a body of data that is useful in monitoring movement of water and fill-up of Arbuckle disposal zones. In western Kansas, the depth to water in wells penetrating the Arbuckle can be several hundred to more than a thousand feet (305 m) below ground surface, but in parts of southern and southeastern Kansas, the depth to water locally can be less than 100 ft (31 m). Furthermore, most Class I wells indicate Arbuckle fluid levels in central and south-central Kansas are rising ~10 ft (~3 m) annually, suggesting that at current disposal rates, the Arbuckle may lose its capacity to accept wastewater under gravity flow in parts of the state in the next few decades, principally south-central and southeastern Kansas along the Oklahoma state line. At present in parts of six Kansas counties along the Oklahoma state line, low-density (~1.0 g/cc or slightly greater density) wastewater in a wellbore does not have a sufficient hydrostatic head by gravity alone to force its way into the more dense resident Arbuckle formation water.
 In general, Arbuckle formation water flows west to east in Kansas. Arbuckle disposal wells in Kansas collectively dispose of ~800,000,000 barrels (~127,000,000 m3) of wastewater per year, although some of this is recycled from Arbuckle oil production. Declines in oil price since mid-2014 have resulted in less oilfield disposal in the Arbuckle since 2015. The number of Class I wells recording annual fluid rises have also declined since 2015, as has the median of their annual change in static fluid level, but overall, more Class I wells are still recording fluid rises. There is a poor correlation between changes in fluid levels in Class I wells and the volume of fluid disposed in them annually, thereby indicating that more regional characteristics may control water movement in the Arbuckle. More monitoring wells are needed to better understand the movement of water in the deep subsurface and to anticipate any potential problems that may occur with reduced disposal capacity and possible migration of fluids through unplugged or improperly plugged older wells.