Weeklong improved colour contrasts sensitivity after single 670 nm exposures associated with enhanced mitochondrial function

Mitochondrial decline in ageing robs cells of ATP. However, animal studies show that long wavelength exposure (650–900 nm) over weeks partially restores ATP and improves function. The likely mechanism is via long wavelengths reducing nanoscopic interfacial water viscosity around ATP rota pumps, improving their efficiency. Recently, repeated 670 nm exposures have been used on the aged human retina, which has high-energy demands and significant mitochondrial and functional decline, to improve vision. We show here that single 3 min 670 nm exposures, at much lower energies than previously used, are sufficient to significantly improve for 1 week cone mediated colour contrast thresholds (detection) in ageing populations (37–70 years) to levels associated with younger subjects. But light needs to be delivered at specific times. In environments with artificial lighting humans are rarely dark-adapted, hence cone function becomes critical. This intervention, demonstrated to improve aged mitochondrial function can be applied to enhance colour vision in old age.

Application of Gene Expression Programming (GEP) in Modeling Hydrocarbon Recovery in WAG Injection Process

Water alternating gas (WAG) injection has been successfully applied as a tertiary recovery technique. Forecasting WAG flooding performance using fast and robust models is of great importance to attain a better understanding of the process, optimize the operational conditions, and avoid high-cost blind tests in laboratory or pilot scales. In this study, we introduce a novel correlation to determine the performance of the near-miscible WAG flooding in strongly water-wet sandstones. We conduct dimensional analysis with Buckingham’s π theorem technique to generate dimensionless numbers using eight key parameters. Seven dimensionless numbers are employed as the input variables of the desired correlation for predicting the recovery factor of a near-miscible WAG injection. A verified mathematical model is used to generate the required training and testing data for the development of the correlation using a gene expression programming (GEP) algorithm. The provided data points are then separated into two subsets: training (67%) to develop the model and testing (33%) to assess the models’ capability. Conducting error analysis, statistical measures and graphical illustrations are provided to assess the effectiveness of the introduced model. The statistical analysis shows that the developed GEP-based correlation can generate target data with high precision such that the training phase leads to R2 = 92.85% and MSE = 1.38 × 10−3 and R2 = 91.93% and MSE = 4.30 × 10−3 are attained for the testing phase. The relative importance of the input dimensionless groups is also determined. According to the sensitivity analysis, decreasing the oil–water capillary number results in a significant reduction in RF in all cycles. Increasing the magnitudes of oil to gas viscosity ratio and oil to water viscosity ratio lowers the RF of each cycle. It is found that oil to gas viscosity ratio has a higher impact on RF value compared to oil to water viscosity ratio due to a higher viscosity gap between the gas and oil phases. It is expected that the GEP, as a fast and reliable tool, will be useful to find vital variables including relative permeability in complex transport phenomena such as three-phase flow in porous media.

Fast Upscaling of Polymer Flood Simulations Using Fractional Flow and Scaled Mobilities

We introduce a pseudoisation method to upscale polymer flooding in order to capture the flow behaviour of fine scale models. This method is also designed to improve the predictability of pressure profiles during this process. This method controls the numerical dispersion of coarse grid models so that we are able to reproduce the flow behaviour of the fine scale model. To upscale polymer flooding, three levels of analysis are required such that we need to honour (a) the fractional flow solution, (b) the water and oil mobility and (c) appropriate upscaling of single phase flow. The outcome from this analysis is that a single pseudo relative permeability set that honours the modification that polymer applies to water viscosity modification without explicitly changing it. The shape of relative permeability can be chosen to honour the fractional flow solution of the fine scale using the analytical solution. This can result in a monotonic pseudo relative permeability set and we call it the Fractional-Flow method. To capture the pressure profile as well, individual relative permeability curves must be chosen appropriately for each phase to ensure the correct total mobility. For polymer flooding, changes to the water relative permeability included the changes to water viscosity implicitly thus avoiding the need for inclusion of a polymer solute. We call this type of upscaling as Fractional-Flow-Mobility control method. Numerical solution of the upscaled models, obtained using this method, were validated against fine scale models for 1D homogenous model and as well as 3D models with randomly distributed permeability for various geological realisations. The recovery factor and water cut matched the fine scale model very well. The pressure profile was reasonably predictable using the Fractional-Flow-Mobility control method. Both Fractional-Flow and Fractional-flow-Mobility control methods can be calculated in advance without running a fine scale model where the analysis is based on analytical solution even though produced a non-monotonic pseudo relative permeability curve. It simplified the polymer model so that it is much easier and faster to simulate. It offers the opportunity to quickly predict oil and water phase behaviour.

Increased Water Viscosity Enhances Water Intake and Reduces Risk of Calcium Oxalate Stone Formation in Cats

The purpose of this study is to determine if water with increased viscosity results in increased water intake, thus lowering the risk of urolithiasis in cats. Twelve healthy adult cats were fed pre-trial standard dry maintenance food for 1 week and then randomized into two groups for the study phase. The cats continued to receive the same food but were provided either control (deionized) water or viscous (1% methylcellulose) water for two months and then switched to the other water type for two months in a cross-over study design with repeated measures. Complete blood counts, serum chemistry profiles, and urinalysis were performed at the initiation of the study and again at 1, 2, 3, and 4 months. Daily water consumption and energy intake for each cat were recorded. Body weights were assessed weekly. Cats consuming 1% methylcellulose water with increased viscosity had increased water intake (p < 0.001; 25% and 21% higher at 28 and 56 days, respectively). Increased consumption of water resulted in lower urine specific gravity (p = 0.04), serum creatinine (p = 0.02), and blood urea nitrogen (p = 0.002) concentrations (without changing serum albumin, glucose, and calcium concentrations or serum osmolality) and decreased urine calcium concentration (p = 0.01) compared with cats consuming control water. In addition, the increased water intake increased (p = 0.05) resistance to oxalate crystal formation.

Phase-Field Simulation of Imbibition for the Matrix-Fracture of Tight Oil Reservoirs Considering Temperature Change

Injection water temperature is often different from that of the reservoir during water injection development in the tight reservoir. Temperature change causes different fluid properties and oil-water interface properties, which further affects the imbibition process. In this paper, a matrix-fracture non-isothermal oil-water imbibition flow model in tight reservoirs is established and solved by the finite element method based on the phase-field method. The ideal inhomogeneous rock structure model was used to study the influence of a single factor on the imbibition. The actual rock structure model was used to study the influence of temperature. The mechanism of temperature influence in the process of imbibition is studied from the micro-level. It is found that the imbibition of matrix-fracture is a process in which the water enters the matrix along with the small pores, and the oil is driven into the macropores and then into the fractures. Temperature affects the imbibition process by changing the oil-water contact angle, oil-water interfacial tension, and oil-water viscosity ratio. Reducing oil-water contact angle and oil-water viscosity ratio and increasing oil-water interfacial tension are conducive to the imbibition process. The increase in injection water temperature is usually beneficial to the occurrence of the imbibition. Moreover, the actual core structure imbibition degree is often lower than that of the ideal core structure. The inhomogeneous distribution of rock particles has a significant influence on imbibition. This study provides microscale theoretical support for seeking reasonable injection velocity, pressure gradient, injection temperature, and well-shutting time in the field process. It provides a reference for the formulation of field process parameters.

Minireview: Formulasi Obat Kumur Ekstrak Daun Ketul (Bidens pilosa)

Abstract— Ketul (Bidens pilosa L) is weed plant that has antibacterial properties. The potential of this plant has not been developed yet in Indonesia. We conducted a literature study about this plant use for herbal mouthwash. The purposes of this study were to determine components of Ketul leaf with antibacterial activity, to know the extraction solvent, to determine the method for antibacterial activity, and to predict the characteristics and components of herbal mouthwash formula. The results showed that Ketul leaf contains tannins, cardiac glycosides, saponins, alkaloids, flavonoids, and terpenoids which could inhibit the growth of various bacteria, including Streptococcus mutans. Hence the mouthwash is predicted to have antibacterial activity. The safe extraction solvent widely used was 70-80% ethanol. The Ketul leaf extract has the potential to be applied in herbal mouthwash formula. Other characteristic can be adjusted to meet the requirements as herbal mouthwash, which are pH between 5-7, the viscosity value near water viscosity value (1cP), stable during storage, and color is brownish yellow. Some common additives were added in mouthwash to improve the flavors and taste, such as sorbitol, tween-80, peppermint oil, and sodium benzoate. Keywords: antibacterial activity, solvent, Streptococcus mutans, weed Abstrak— Ketul (Bidens pilosa L) merupakan tumbuhan gulma yang memiliki aktivitas antibakteri. Potensi tumbuhan ini belum banyak dikembangkan di Indonesia. Pada tulisan ini telah dilakukan kajian pustaka pemanfaatan Ketul untuk obat kumur herbal. Tujuan kajian ini adalah untuk mengetahui komponen ekstrak daun Ketul yang berkhasiat antibakteri, mengetahui pelarut ekstraksi, metode penentuan aktivitas antibakteri obat kumur, dan prediksi karakteristik dan komponen obat kumur herbal daun Ketul. Hasil penelusuran pustaka menunjukkan bahwa daun Ketul mengandung tannin, glikosida jantung, saponin, alkaloid, flavonoid, dan terpenoid, yang dapat menghambat pertumbuhan berbagai bakteri, termasuk Streptococcus mutans sehingga obat kumur kemungkinan memiliki aktivitas antibakteri. Pelarut aman yang banyak digunakan untuk ekstraksi komponen fitokimia tersebut adalah etanol 70-80%. Penentuan daya antibakteri dapat dilakukan menggunakan metode difusi agar atau pengenceran. Ekstrak daun Ketul berpotensi digunakan dalam formula obat kumur herbal. Selain potensi antibakterinya, karakteristik lainnya dapat diatur untuk memenuhi syarat formula obat kumur herbal yaitu pH berkisar 5-7, nilai viskositas mendekati nilai viskositas air (1cP), stabilitas dapat tetap terjaga selama penyimpanan dan kemungkinan obat kumur berwarna kuning kecoklatan. Beberapa bahan tambahan, seperti sorbitol, tween-80, peppermint oil, dan natrium benzoate, merupakan bahan tambahan yang aman dan umum digunakan untuk menambah cita rasa dan stabilitas formula obat kumur herbal ekstrak daun Ketul. Kata kunci: aktivitas antibakteri, gulma, pelarut, Streptococcus mutans

SENSITIVITY ANALYSIS FOR POLYMER INJECTION TO IMPROVE HEAVY OIL RECOVERY – SMALL-SCALE SIMULATION STUDY

Polymer flooding has been widely used for enhancing oil recovery, due to the growing number of successful applications around the world. The process aims to increase water viscosity and, thus, decrease the water/oil mobility ratio, thereby improving sweep efficiency. The understanding of the physical mechanisms involved in this enhanced oil recovery process allows us to forecast the application potential of polymer flooding. This work aims to assess physical phenomena associated with heavy oil recovery through polymer flooding using 1D small-scale simulation models. We evaluate the influence of different levels of adsorption, accessible pore volume, residual resistance factor, and polymer concentration on the results and compare their magnitude effect on the results. The models used in this study were built using data from previous lab work and literature. For each one of the mentioned parameters, this work compares the histories of water cut, cumulative water-oil ratio, average pressure, and oil recovery factor. Additionally, water saturation, water viscosity, and water mobility profile were determined for specific periods of the flooding process. The sensitivity analyses showed that high levels of adsorption influence the polymer loss of the advance front, delaying oil recovery. Low values of accessible pore volume lead to a slightly faster polymer breakthrough and oil recovery anticipation. A high residual resistance factor increases the average pressure and improves oil recovery. Higher polymer concentration enhances the displacement efficiency and enhances the recovery factor.

CFD simulation of HPAM EOR solutions mechanical degradation by restrictions in turbulent flow

Polymer flooding is a widely used enhanced oil recovery (EOR) technology. The purpose of the polymer is to increase water viscosity to improve reservoir sweep efficiency. However, mechanical elements of the polymer injection facilities may impact the viscosity of the polymer negatively, decreasing it drastically. Mechanical degradation of the polymer occurs in case of flow restrictions with abrupt diameter changes in valves and control systems. Such flow restrictions may induce mechanical stresses along the polymer chain, which can result in its rupture. In this research, physical experiments and numerical simulations using CFD (Computational Fluid Dynamics) were used to propose a model for estimating the mechanical degradation for the flow of polymer solutions. This technique involves the calculation of velocity gradients, pressure drawdown, and polymer degradation of the fluid through geometry restriction. The simulations were validated through polymer injection experiments. The results show that with the greater volumetric flow and lower effective diameters, there is more mechanical degradation due to polymer shearing; nonetheless, this depends on the rheology properties inherent in each polymer in an aqueous solution. This method is suitable to estimate the mechanical degradation of the polymer solution in flooding facilities and accessories. Further, the results obtained could enhance the use of the polymer, calculating its actual mechanical degradation, minimizing it, or using it to support the development of new accessories.

Copolymer Based on Polyglycerol-Acrylate-Lactate as Potential Water Viscosifier and Surfactant for Enhanced Oil Recovery

Polymer and surfactant flooding are widely applied processes in enhanced oil recovery (EOR) in which viscous polymers or surfactants aqueous solutions are introduced in oil reservoirs to rise the recovery of the remaining oil. In this regard, one of the challenges of EOR practices is the use of efficient but low-cost viscosifier and surfactant polymers. This work is aimed at synthesizing a polyglycerol derived from the biodegradable and nontoxic monomer, glycerol, and evaluating the effect of its copolymerization on rheological and interfacial properties, which were tested in water and brine for the former and in the water/oil system for the last properties. The copolymers were synthesized using a polyglycerol backbone, acrylic acid, lactic acid, and oleic acid. The chemical structure of copolymers was characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TG), and differential scanning calorimetry (DSC). The viscosity and the interfacial tension (IFT) of polymeric solutions were tested. Thus, the viscosity and surface performance of the prepared polymer solutions in distilled water and brine were analyzed according to the structure of the synthesized polymers. The results showed that the synthesized polymers modified water viscosity and surface tension between water and oil. The developed polymers could be candidates for applications in enhanced oil recovery and related applications.