Gas Law Research Articles

Programmable intratumoral drug delivery to breast cancer using wireless bioelectronic device with electrochemical actuation

ABSTRACT Objective Breast cancer is a global health concern that demands attention. In our contribution to addressing this disease, our study focuses on investigating a wireless micro-device for intratumoral drug delivery, utilizing electrochemical actuation. Microdevices have emerged as a promising approach in this field due to their ability to enable controlled injections in various applications. Methods Our study is conducted within a computational framework, employing models that simulate the behavior of the microdevice and drug discharge based on the principles of the ideal gas law. Furthermore, the distribution of the drug within the tissue is simulated, considering both diffusion and convection mechanisms. To predict the therapeutic response, a pharmacodynamic model is utilized, considering the chemotherapeutic effects and cell proliferation. Results The findings demonstrate that an effective current of 3 mA, along with an initial gas volume equal to the drug volume in the microdevice, optimizes drug delivery. Microdevices with multiple injection capabilities exhibit enhanced therapeutic efficacy, effectively suppressing cell proliferation. Additionally, tumors with lower microvascular density experience higher drug concentrations in the extracellular space, resulting in significant cell death in hypoxic regions. Conclusions Achieving an efficient therapeutic response involves considering both the characteristics of the tumor microenvironment and the frequency of injections within a specific time frame.

On the ideal gas law for crowds with high pressure

Active particle systems, such as human crowds, are out of equilibrium posing a significant challenge in identifying a suitable equation of state. However, several previous observations suggest that a crowd’s speed distribution may conform to a two-dimensional Maxwell–Boltzmann distribution under certain yet-to-be-determined conditions. Our research uncovers that the divergence between the fluctuation velocity magnitude’s probability density function and its best 2D Maxwell–Boltzmann fit diminishes in a power-law fashion with decreasing collision time scale between individuals. These findings are robustly supported by both experimental data and simulations with diverse boundary conditions and force potentials. The equilibrium characteristics of crowds are interpreted through a canonical ensemble framework. Furthermore, we show that high pressure indicates equilibrium characteristics in human crowds. Remarkably, we reveal the ideal gas law for human crowds without resorting to any behavior assumption. We demonstrate the predictive capability of the ideal gas law on both observational and modeling data. Our research highlights a new pathway to explore and validate traditional thermodynamic quantities and laws in the setting of high-pressure human crowds, advancing our understanding of active matter systems.

Application of Flue Gas Foam-Assisted Steam Flooding in Complex and Difficult-to-Produce Heavy Oil Reservoirs.

In order to study the mechanism of improving recovery efficiency of complex difficult-to-recover heavy oil reservoirs and explain the interaction and migration law of flue gas, foam, and steam, this paper designed the experiment of flue gas influence on heavy oil flow and the experiment of flue gas foam displacement in complex difficult-to-recover heavy oil model. The results show that the flue gas has expansion and an energy enhancement effect. Moreover, the interfacial tension of heavy oil can be reduced, and the higher the CO2 content in flue gas, the more beneficial it is to reduce the interfacial tension. When there is an interlayer in the reservoir, the gas can form a "puncture" in the interlayer, which provides a channel for the subsequent upward expansion of steam, so that the upper part of the interlayer can be used to expand the steam sweep range. The main mechanism of improving heavy oil recovery with flue gas foam is that the foam regulates fluid mobility and improves the thermal sweep efficiency of steam. In addition, the injected foam can emulsify with heavy oil, reduce the viscosity of heavy oil, and improve the fluidity of heavy oil. Finally, the maximum oil production rate increased from 1.809 to 2.455 g/min, and the recovery rate increased from 44.3 to 68.8%.

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.

Numerical and Experimental Study on Preheating Burner Characteristics for Peak Shaving

With the proportion of renewable energy power in the electricity market gradually increasing, coal-fired power is transforming from primary to basic power, with it providing peak and frequency shaving. However, most current methods for peaking below 50% load have been applied industrially, sacrificing the efficiency of the unit. This is not in line with the goals of energy conservation and emission reduction. Therefore, this study proposes a new preheating-based peaking method. This study experimentally and simulatively explores the flow characteristics, pyrolysis gas law, and NOx emission characteristics of a preheating burner at 40–100% load. The results show that the burner has a significant preheating effect, producing high-temperature char and large amounts of pyrolysis gas. As the load decreases, the burner exit temperature increases, whereas the airflow stiffness decreases. There is little variation in the pyrolysis gas concentration between 40% and 100% loads. The NOx concentration at the burner outlet increases and the reduction efficiency decreases with decreasing load. At 40% load, NOx emissions are 91.53 mg/Nm3 and the reduction efficiency reaches 95.9%. Therefore, preheating is an economical, stable, and low-NOx-emission-peaking method. This study provides theoretical guidance for the application of preheating burners for the 40–100% load peaking of coal-fired units.

A Study of a Two-Phase Heat Transfer Mechanism in a Vertical Sintering Cooling Furnace

In order to explore the law of gas–solid countercurrent cooling heat transfer in a vertical sinter cooling furnace at a high temperature, based on the Euler model and the local non-thermodynamic equilibrium theory, an exergy efficiency model was built to evaluate the heat transfer process in the vertical sinter cooling furnace with different parameter changes. It was found that the inlet temperature of cooling air and sinter inlet temperature are the main factors affecting the temperature field and gas–solid heat transfer characteristics in the furnace. Under the conditions of each parameter, the cooling air temperature presents a radial “M” shape distribution. The axial cooling section is the most intense area of gas–solid heat transfer, and this part has the best heat transfer effect. When the inlet temperature of cooling air and the inlet temperature of sinter increase, the outlet temperature of sinter and the outlet temperature of cooling air increase. When the sinter equivalent diameter increases, the cooling air outlet temperature decreases gradually, while the sinter outlet temperature increases gradually. When the diameter and height of the cooling section increase, respectively, the outlet temperature of the sinter decreases and the outlet temperature of the cooling air increases. Based on dimensional analysis, the heat transfer correlation formula suitable for certain test conditions is obtained.

Estimating The Exploration And Production (E&P) Industry's Rig Contract Business Owner

According to Article 33 of the 1945 Structure, oil and gas have the potential to greatly influence state and revenue generation sources, thereby realizing societal welfare and economic prosperity. For this reason, oil and gas have a crucial and strategic position among natural resources. As a result, a specialized work group for exploration and production (E&P) was established through the enactment of Oil and Gas Law Number 22, 2001. This organization is in charge of supervising all exploration and production-related operations. In accordance with Presidential Regulation No. 12, 2021, Procedural Instruction 007, 2017, exploration and production builders carry out the rig procurement procedure to rig providers builders with their proposal Owner Estimate's worth. There are conflicting interpretations and discrepancies in the Owner Estimate instruction problem for upstream exploration and production (E&P). Concerns pertaining to areas of law positivism that Owner Estimate provides may or may not be secret in the process. It allows for collusion during the purchasing procedure. Normative juridical analysis is used in the research to make Owner Estimates of Value and to cover regulation. Therefore, in order to achieve conformity with the agreement principle and legal certainty, it is required to alter the President's Regulation and the Summary of Procedural Instruction. In order for the specialized work group for exploration and production (E&P), the E&P builders, and the rig providers to execute upstream business flawlessly and optimally to support communal welfare, the regulation's evaluation will support legal clarity, ability, and persuasiveness.

Brazil’s New Gas Law: Analysis, Implications, and Remuneration of Gas Processing Plants with Non-Discriminatory Access to Customers

Brazil will increasingly rely on the availability of natural gas as new discoveries in the Pre-Salt portion are explored. Currently, a substantial amount of the gas produced associated with oil is reinjected (60,84 million m³/day in 2021, according to the Ministry of Mines and Energy), with the lack of structure being one of the factors for this non-energy purpose. The New Gas Law proposes to fill this gap by stimulating investments in infrastructure. In this sense, market opening has the potential to promote the rupture of natural monopolies by providing access to infrastructure, including Natural Gas Processing Plants (NGPP). This units, in addition to conditioning the gas for sale, allow the recovery of higher molecular weight fractions, or (Natural Gas Liquid). However, the instructions for this access required by the government are insufficient for issues related to the NGL recovery efficiency of these units, as well the method of remuneration arising from the NGL production capacity. It is proposed in this paper to include a processing tariff, based on static simulation of available technological routes. Comparison of energy spent and NGL recovery efficiency will allow to formulate the gas price, unfolding from the price of the molecule.

The development of pre-service teachers’ argumentation self-efficacy through argumentation-based chemistry instruction

This research aimed to examine the impact of argumentation-based chemistry instruction on the argumentation self-efficacy of pre-service teachers' (PSTs’) and their perceptions regarding the effectiveness of this instruction on their argumentation self-efficacy. This exploratory study involved a cohort of PSTs who actively participated in a series of argumentation-based chemistry activities facilitated by their classroom teacher over an 11-week period, with each activity spanning 1 or 2 weeks. The introduction of argumentation preceded the exploration of chemistry topics, including heat and temperature, gas laws, physical and chemical change, solubility, distinctive properties of matter, chemical reactions, and acids-bases. Data sources comprised the self-efficacy scale for argumentation, the evaluation of instruction for enhancing self-efficacy survey, and semi-structured interviews. The findings revealed an increase in PSTs' self-efficacy for argumentation after 11 weeks of argumentation-based chemistry instruction. These results suggest that PSTs can significantly enhance their self-efficacy for argumentation when provided with instruction tailored to incorporate argumentation principles.

Experimental simulation study on gas flow field in combined goaf during the transition period of coal pillar-free working face relocation

Regarding the gas disaster caused by the complex ventilation system and the changeable flow field in the combined goaf during the transition period of the coal pillar-free working face, the self-designed physical simulation test bench for the combined goaf of coal pillar-free mining was used to compare and analyze the distribution law of wind pressure, gas, and oxygen concentration field in the combined goaf during the moving period of the working face and the normal mining period. The results show that during the relocation period, the gas concentration in the stope will always be slightly higher than that in the normal mining period, and the existing air leakage channel will lead to complex air flow in the combined goaf, which is easy to cause gas explosion accidents. The formation conditions, judgment principles, and judgment methods of the dangerous area of gas explosion coupling disaster in goaf are analyzed. By changing the air distribution ratio of the main and auxiliary air intake roadways, it is concluded that the explosion area will form an “L”-shaped explosion zone in the goaf, and the area of gas explosion disaster area during the relocation period will be larger than that the normal mining period. According to the size of the gas explosion area, the optimal air distribution ratio of the main and auxiliary air intake roadway during the transition period of the working face relocation and the normal mining period is 2:1. Under this air distribution ratio, the gas explosion area is the smallest, which is 132 284 and 113 534 mm2, respectively. The research results are of great significance to reveal the mechanism of gas disaster induced by goaf during the transition period of coal pillar-free relocation.

Numerical Simulation Study on the Movement Law of Gas in Fractured Space during Coal Mining

Numerical Simulation Study on the Movement Law of Gas in Fractured Space during Coal Mining

Numerical simulation study on the movement law of gas in fractured space during coal mining

Numerical simulation study on the movement law of gas in fractured space during coal mining

Global warming impact of fluorinated gases in ophthalmic surgeries at a tertiary eye center in India.

Global warming is one of the greatest health threats of the 21 st century. The ophthalmic sector contributes to the emission of greenhouse gases, thus altering the natural environment. There is currently no data on global emissions of fluorinated gases in ophthalmic surgery. This retrospective study from 2017 to 2021 aims to report the carbon dioxide (CO 2 ) equivalence of sulfur hexafluoride (SF 6 ), hexafluoroethane (C 2 F 6 ), and octafluoropropane (C 3 F 8 ) at a tertiary eye center. Data collected from 1842 surgical procedures that used injections of fluorinated gases were analyzed. Environmental impact (global warming potential over 100 years) was calculated by converting milliliters to grams by using modified ideal gas law at standard temperature and pressure for the canisters and then to their CO 2 equivalence. Though 70% of surgeries used C 3 F 8 , the least greenhouse effect causing fluorinated gas, the total carbon emission was 1.4 metric tons. The most common indication was macular hole surgery (36.86%). This study paves a step toward analyzing the problem statement, thus awakening us to contemplate options to make ophthalmic surgeries greener.

Measuring whole body inert gas wash-out.

Quantifying inert gas wash-out is crucial to understanding the pathophysiology of decompression sickness. In this study, we developed a portable closed-circuit device for measuring inert gas wash-out and validated its precision and accuracy both with and without human subjects. We developed an exhalate monitor with sensors for volume, temperature, water vapor and oxygen. Inert gas volume was extrapolated from these inputs using the ideal gas law. The device's ability to detect volume differences while connected to a breathing machine was analysed by injecting a given gas volume eight times. One hundred and seventy-two coupled before-and-after measurements were then compared with a paired t-test. Drift in measured inert gas volume during unlabored breathing was evaluated in three subjects at rest using multilevel linear regression. A quasi-experimental cross-over study with the same subjects was conducted to evaluate the device's ability to detect inert gas changes in relation to diving interventions and simulate power. The difference between the injected volume (1,996 ml) and the device's measured volume (1,986 ml) was -10 ml. The 95% confidence interval (CI) for the measured volume was 1,969 to 2,003 ml. Mean drift during a 43 min period of unlaboured breathing was -19 ml, (95% CI, -37 to -1). Our power simulation, based on a cross-over study design, determined a sample size of two subjects to detect a true mean difference of total inert gas wash-out volume of 100 ml. We present a portable device with acceptable precision and accuracy to measure inert gas wash-out differences that may be physiologically relevant in the pathophysiology of decompression sickness.

DETERMINATION OF SEVERAL IMPORTANT PARAMETERS OF HOLLOW ELECTRODES ABNORMAL GLOW DISCHARGE PLASMA UNDER THE INFLUENCE OF MAGNETIC FIELD AT DIFFERENT GAS PRESSURES

This paper investigates the impact of an axial magnetic field on several plasma parameters of hollow electrode argon abnormal glow discharge. The discharge is generated by applying a DC voltage ranging from 0-6KV. By varying the pressure and magnetic field strength (0-25mT), the plasma potential, frequency, and degree of ionization were measured. The plasma potential, frequency, and degree of ionization were evaluated using spectroscopic measurements of the electron temperature and density. The results of the experiment show that the plasma potential decreases as the magnetic field strength increases, while the plasma frequency increases for lower pressure but reaches a constant value for higher pressure due to the increasing number of excitation collisions among the plasma-charged particles. The degree of ionization, determined using the ideal gas law, shows a near-linear relationship with the axial magnetic field at both low and high pressure.

New Model for Coal Gas Diffusion Based on the Fractal Tree-Like Bifurcation Network Structure.

To investigate the nonstationary diffusion and transport law of gas in coal, an innovative fractal diffusion model based on fractal theory and a treelike bifurcation network under different diffusion modes were built. In addition, the quantitative relationships among the diffusion coefficient, temperature, pressure, and structural parameters were determined. The model considers the effect of pore tortuosity and connectivity on gas diffusion, which renders it more realistic than the previously presented single-pore diffusion models. Moreover, each parameter in the model has a definite physical meaning and does not contain any empirical constants. The applicability of the new model was verified by experimental data and other model. Subsequently, a sensitivity analysis of the gas diffusion coefficient was performed to study the effect of the microstructural parameters on gas diffusion. Finally, the dispersion degree of the diffusion coefficients at different temperatures and pressures was analyzed to determine the main influencing factors of gas diffusion at different diffusion stages in coal and study their evolution. The results show that the gas diffusion state is more sensitive to pressure variations. The diffusion behavior of gases in coal-based porous media is more influenced by the temperature and pressure at the beginning of the diffusion process.

Experimental study on the desorption law and diffusion kinetic characteristics of gas in raw coal and tectonic coal

To better reveal the nature of gas flow in raw coal and tectonic coal composite seams during gas extraction, experiments on the gas desorption and diffusion kinetic characteristics of raw coal and tectonic coal under different gas adsorption equilibrium pressures were carried out. Meanwhile, the applicability of Airey empirical formula was analysed, and the unipore model and bidisperse model were used to fit the experimental results and calculate the diffusion coefficient. The results show that the initial gas desorption rate and gas desorption volume of raw coal are much smaller than those of tectonic coal at the initial stage of gas desorption; at the later stage, the gas desorption rate of tectonic coal decays rapidly and the ultimate gas desorption volume tends to a stable value, however, the gas desorption rate of raw coal decays slowly and the ultimate gas desorption volume continues to increase. Airey empirical formula has some limitations in characterizing the gas desorption law in coal and is more suitable for fracture-rich “block” coal, but for the tectonic coal, the fitted ultimate gas desorption volume has a significant error from the actual one. The unipore model is suitable for describing some specific periods in the initial stage of the gas desorption process of raw coal, and the bidisperse model makes up for the defects of the unipore model and can accurately describe the gas diffusion law of tectonic coal. The study provides a theoretical basis for the scientific planning of coal and coalbed methane mining.

The Boltzmann distribution in gravity field

The air is comprised of innumerable particles. In the atmosphere, the particles are mostly gas molecules, including nitrogen, oxygen, and hydrogen, extending in the air in a gravitational field caused by Earth. With thermal statistics, there are methods to calculate and observe some microscopic properties of this group of particles. This essay aims to disclose the density distribution of gas particles in the air from different altitudes and at different speeds. All the calculations have proceeded on the approximately ideal circumstance with some corrections. The calculation and observation method is based on ideal gas law and rudimentary Boltzmann distribution using knowledge of thermal dynamics and thermal statistics. At the end of the main body of this essay, the final formula is given with graphs created in Matlab providing more ocular illustrations. These parameters are mostly composed of physical fundamental constants and do not require information from a database.

An Adsorption-Desorption Heat Engine for Power Generation from Waste Heat

According to the United States Department of Energy, waste heat recovery would allow up to a 20% reduction in greenhouse gases (GHG) emission. Most of the waste energy is discharged as a low-grade heat at temperatures less than 250°C. Therefore, the development of new technologies and the enhancement of existing ones to convert low-grade heat into electrical or mechanical energy are of great importance. The working principle of adsorption-desorption heat pumps with cyclic switching between adsorption and desorption is adapted in the proposed heat engine to generate electrical power from low-temperature heat. Thermodynamic analysis of the heat engine cycle is carried out for the pair adsorbant-adsorbent: CO<sub>2</sub>-activated carbon. Its efficiencies are calculated accepting the ideal gas law and an adsorption-desorption equilibrium at the key points of the cycle. The cycle consists of two isochores and two isotherms like the Stirling engine, but at the same temperature range and without heat regeneration, its thermal efficiency (work per heat supplied) can reach 11.3% vs. 5.0% and specific work 50.7 vs. 3.55 in the latter. The proposed unit has thermal efficiency in the range of Organic Rankine Cycle units and can be utilized in small-scale applications up to 40kWe, where manufacturing cost of turbines or expanders for ORCs increases dramatically. Accounting for quality (temperature) of utilized heat, the proposed cycle’s exergy efficiency, <em>ζ<sub>ex</sub></em> = 34.5% approaches that of water-steam Rankine cycles utilizing natural gas or coal combustion.

CO Diffusion Study and Spatial and Temporal Variation Modeling during the Construction Period of the Plateau Railroad Tunnel.

In order to investigate the diffusion law of CO gas in the vicinity of the tunnel boring face of the plateau long tunnel, to improve the efficiency of tunnel smoke exhaust, and to derive the spatial-temporal variation model of CO concentration for predicting the concentration of CO at different times and in different cross sections under specific environments, a CO diffusion model of a tunnel in Yunnan was established by using Ansys Fluent Fluid Simulation Software, and the CO transport characteristics under different conditions were simulated by taking the ventilation time, wind speed, and location of the air ducts as the influencing factors. The results show that the wind flows from the mouth of the wind pipe after the wind speed decreases, the diffusion area increases and arrives at the face of the direction of the rebound in the jet stream of new wind, and the return wind under the joint action of the vortex produced obviously, to reach the wind pipe mouth after the tunnel wind flow field, basically tends to stabilize. When the wind pipe mouth was arranged in the arch waist, 20 m away from the boring face, the inlet wind speed was 9 m/s and the ventilation time was 30 min; the CO concentration in the tunnel was reduced to below the maximum allowable concentration value. Moreover, the concentration of CO in the tunnel at the moment of 15 min of ventilation has a nonlinear positive correlation with the change of distance L from the boring face, while at the cross section of the air outlet of the wind pipe L = 20 m, the ventilation time is from 1 to 30 min and the concentration of CO at the cross section has a nonlinear decreasing trend with the ventilation time, which can be deduced according to the different space-time change models.