Methodology for Designing and Evaluating Chemical Systems for Improved Oil Recovery

The purpose of this research was to demonstrate the methodology for development of high performance chemical systems for improved oil recovery (IOR). Previous studies have shown that high performing surfactant formulations can be quickly identified and optimized by assessing the microemulsion phase behavior and aqueous phase homogeneity. Similarly, in this research, extensive phase behavior assessments were performed for many combinations of chemical slug components that included various surfactants, co-surfactants, co-solvents, alkali and polymers. Methodical planning, preparation, execution, observations and recording of phase behavior experiments and results enabled selection of the best performing chemical components and their concentrations were optimized. A total of five formulations showed good microemulsion phase behavior but only three passed the aqueous stability requirement. These three formulations were then evaluated in core floods. Out of the three formulations, one consistently gave high residual oil recovery ranging between 86%-91% at reservoir temperature with both soft brine (NaCl only) and synthetic formation brine. Synthetic formation brine for Trembley contained a high concentration of divalent cations in addition to monovalent yet it had a minimal effect on oil recovery, proving that the formulation was robust at even high salinity contrast with formation brine. The formulation was therefore recommended for further studies on limestone cores. Pressures across the sandstone cores and its subsections, and effluent's microemulsion and aqueous phase properties were utilized to explain the performance of formulations and oil displacement process in the sandstone cores. Corefloods showed that slug size, surfactant concentration, salinity and viscosity of chemical systems were important chemical flood design parameters that also impacted the oil recovery

Multiple Sequence Alignment Menggunakan Nature-Inspired Metaheuristic Algorithms

Multiple sequence alignment adalah proses dasar yang sering dibutuhkan dalam mengolah beberapa sequence yang berhubungan dengan bioinformatika. Apabila multiple sequence alignment telah selesai dikerjakan, maka dapat dilakukan analisis-analisis lain yang lebih jauh, seperti analisis filogenetik atau prediksi struktur protein. Banyaknya kegunaan dari multiple sequence alignment mengakibatkannya menjadi salah satu permasalahan yang banyak diteliti. Banyak algoritma-algoritma metaheuristic yang berdasar pada kejadian-kejadian alami, yang biasa disebut dengan nature-inspired metaheuristic algorithms. Beberapa algoritma baru dalam nature-inspired metaheuristic algorithms yang dianggap cukup efisien antara lain adalah firefly algorithm, cuckoo search, dan flower pollination algorithm. Dalam penelitian ini dipaparkan modified Needleman-Wunsch alignment. Didapatkan hasil bahwa modified Needleman-Wunsch alignment adalah metode yang cukup bagus. Modified Needleman-Wunsch alignment tersebut digunakan untuk membentuk solusi awal dari firefly algorithm, cuckoo search, dan flower pollination algorithm. Didapatkan hasil bahwa firefly algorithm, cuckoo search, dan flower pollination algorithm dapat menghasilkan solusi-solusi baru yang lebih baik. Secara keseluruhan, firefly algorithm adalah algoritma yang terbaik dari tiga algoritma tersebut dalam segi skor alignment, namun membutuhkan waktu komputasi yang lebih besar. ======================================================================================== Multiple sequence alignment is a fundamental tool that often needed to process bioinformatic sequences. If multiple sequence alignment is completed, we can process other further analysis, such as phylogenetic analysis or protein structure prediction. The versatility of multiple sequence alignment led it to be the one of the problems that studied continously. Many metaheuristic algorithms are based on natural events, with the so called nature-inspired metaheuristic algorithms. Algorithms in nature-inspired metaheuristic algorithms that considered to be good are firefly algorithm, cuckoo search, and flower pollination algorithm. In this research, we propose modified Needleman-Wunsch alignment. The results show that modified Needleman-Wunsch alignment is a good method. Modified Needleman-Wunsch alignment is used to create initial solution of firefly algorithm, cuckoo search, and flower pollination algorithm. The results show that firefly algorithm, cuckoo search, and flower pollination algorithm can produce new better solution. Overall, firefly algorithm is the best algorithm among the others in alignment score, but need large computation time

Instantaneous Flood Events Data Analyses in Northern Pakistan

In large watersheds of Pakistan, a proper flood intensity assessment is a most important concern for many water management applications. The present study investigates the possible best-fit probability distributions technique of uttermost flood events using more than 30 years data (except Mastuj Bridge station) from 15 stream flow stations in northern Pakistan, operated and maintained by Surface Water Hydrology Project (SWHP), WAPDA. Different statistical distribution model, were used to estimate design floods for risk planning and the design of important civil infrastructure. Method of moments was used for estimation of parameters of selective distributions. Four goodness-of-fit statistics test K, A2, χ2 and Root mean square error (RMSE) were applied to evaluate the most appropriate probability distribution. P3, LP3, GEV, and LN were determined best fit distribution model. Among the eight-probability distribution’s P3 fitted 33.3% of the stations, LP3 also fitted 33.3% of the stations, GEV fitted 26.7% of the stations and LN fitted 6.7% of the stations. The more practical result for peak flood were calculated for recurrence intervals of 5-year, 25-year, 50-year, 100-year, 500-year and 1000-years respectively. In future before planning and designing any project such as Hydropower, irrigation systems, Dike, flood disaster assessment and management at Indus and adjacent rivers, P3, LP3, GEV and LN distributions results should be considered more reliable on these locations

Concordance of dynamic fractional inequalities interconnected on time scales

In this work, we present an extension of dynamic reverse Minkowski’s inequality by using the time scale Riemann–Liouville type fractional integrals. By using the definitions of delta and nabla time scales Riemann–Liouville type fractional integral operators, we find other general dynamic fractional inequalities. Our findings unify and extend some continuous, discrete and quantum analogues.Publisher's Versio

Reconciliation of discrete and continuous versions of some dynamic inequalities synthesized on time scale calculus

summary:The aim of this paper is to synthesize discrete and continuous versions of some dynamic inequalities such as Radon's Inequality, Bergström's Inequality, Schlömilch's Inequality and Rogers-Hölder's Inequality on time scales in comprehensive form

Molecular Simulations of the Ribosome and Associated Translation Factors

The ribosome is a macromolecular complex which is responsible for protein synthesis in all living cells according to their transcribed genetic information. Using X-ray crystallography and, more recently, cryo-electron microscopy (cryo-EM), the structure of the ribosome was resolved at atomic resolution in many functional and conformational states. Molecular dynamics simulations have added information on dynamics and energetics to the available structural information, thereby have bridged the gap to the kinetics obtained from single-molecule and bulk experiments. Here, we review recent computational studies that brought notable insights into ribosomal structure and function.Comment: 11 pages, 3 figures, to be published in Current Opinion in Structural Biolog

Optimization of Gigabit Passive Optical Network (GPON) Devices Replacement Interval

Entering the industrial era that is increasingly advanced and growing, reliable internet connection becomes a very important foundation for every business. Internet connection failure or downtime will be the obstacle and causes much loss both for businessman and for internet provider company. This research aims to find a solution on how to minimize internet connection failure. One of the various methods that can be used to overcome the problem is called preventive maintenance. This research is chosen to determine how far the role of preventive maintenance in reducing the risk of connection failure due to device failure. Several tools that used in this research, such as statistical distribution to determine the pattern of device failure, and mathematical formula to calculate the estimated duration of the downtime occurs based on the time of preventive maintenance was applied. From that calculation, it can be concluded the optimal time to apply preventive maintenance to minimize downtime duration. The results reveal that a decreasing downtime value happens when preventive maintenance is applied at the optimal age of the device. EI8E - 8FE Electrical Interface Card kit was reduced by 8.01% with an optimal age of 21.82 days. GTGH - 16 Port GPON Line Card devices were reduced by 5.46% with an optimal age of 16.69 days. EMTPDP-DC Power Board devices are reduced by 0.1% with an optimal age of 53 days. The GPON MSVG - Control & Switching Card device is reduced by 4.38% with an optimal age of 32.28 days. MTPD - Power Supply equipment is reduced by 1.2% with an optimal age of 92.35 days. The ETC8B - 8E1 / T1 CES Card device was reduced by 0.84% with an optimal age of 41.23 days

Energy, Emissions and the Economy: Empirical Analysis from Pakistan

It is now an established fact that the most important environmental problem of our era is global warming.1 The rising quantity of worldwide carbon dioxide (CO2) emissions seems to be escalating this problem. As the emissions generally result from consumption of fossil fuels, decreasing energy spending seems to be the direct way of handling the emissions problem. However, because of the possible negative impacts on economic growth, cutting the energy utilisation is likely to be the “less preferred road”. Moreover, if the Environmental Kuznets Curve (EKC) hypothesis applies to the emissions and income link, economic growth by itself may become a solution to the problem of environmental degradation [Rothman and de Bruyn (1998)]. Coondoo and Dinda (2002), however, argue that both developing and developed economies must sacrifice economic growth. Still, countries may opt for different policies to fight global environmental problems, mainly depending on the type of relationship between CO2 emissions, income, and energy consumption over the long run [Soytas and Sari (2006)]. Hence, the emissions-energy-income nexus needs to be studied carefully and in detail for every economy, but more so for the developing countries. In this paper, we investigate the relationship between energy consumption, CO2 emissions and the economy in Pakistan from a long run perspective, in a multivariate framework controlling for gross fixed capital, labour and exports by employing ARDL bounds testing approach

Risk assessment of failure of outdoor high voltage polluted insulators under combined stresses near shoreline

The aim of this paper is to investigate the various effects of climate conditions on outdoor insulators in coastal areas as a result of saline contamination under acidic and normal cold fog, determining significant electrical and physico-chemical changes on the insulator surface and considering the effect of discharge current, electric field distribution and surface roughness. To replicate similar conditions near the shoreline, experimental investigations have been carried out on insulation materials with the combined application of saline contamination and acidic or normal cold fog. The test samples included silicone rubber (SiR), ethylene propylene diene monomer (EPDM) and high-density polyethylene (HDPE), which were used as reference. The materials are of the same composition as those used in real-life outdoor high voltage insulators. All samples were aged separately in an environmental chamber for 150 h for various saline contaminations combined with acidic and normal cold fog, and were generated by means of the adopted experimental setup. This analysis represented conditions similar to those existing near the shoreline exposed to saline and acid spray during winter and early spring. Electric field and discharge current along polymeric samples were examined under acidic and normal cold fog. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopic (SEM) were used to probe the physico-chemical changes on the samples surface and investigate the hydrophobicity recovery property after aging tests. Finally, a comparative study was carried out on polymeric samples before and after being exposed to the acidic and normal cold fog based on the results obtained from the experiment. Research data may provide references for the better prediction of surface degradation as well as for the better material coating and design of external insulation