Recent Development in Electricity Price Forecasting Based on Computational Intelligence Techniques in Deregulated Power Market

The development of artificial intelligence (AI) based techniques for electricity price forecasting (EPF) provides essential information to electricity market participants and managers because of its greater handling capability of complex input and output relationships. Therefore, this research investigates and analyzes the performance of different optimization methods in the training phase of artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) for the accuracy enhancement of EPF. In this work, a multi-objective optimization-based feature selection technique with the capability of eliminating non-linear and interacting features is implemented to create an efficient day-ahead price forecasting. In the beginning, the multi-objective binary backtracking search algorithm (MOBBSA)-based feature selection technique is used to examine various combinations of input variables to choose the suitable feature subsets, which minimizes, simultaneously, both the number of features and the estimation error. In the later phase, the selected features are transferred into the machine learning-based techniques to map the input variables to the output in order to forecast the electricity price. Furthermore, to increase the forecasting accuracy, a backtracking search algorithm (BSA) is applied as an efficient evolutionary search algorithm in the learning procedure of the ANFIS approach. The performance of the forecasting methods for the Queensland power market in the year 2018, which is well-known as the most competitive market in the world, is investigated and compared to show the superiority of the proposed methods over other selected methods.© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

Ektopowy zespół Cushinga u pacjentów z nowotworem śródpiersia lub płuc — doniesienie z ośrodka trzeciego stopnia referencyjności w Iranie

Introduction: Ectopic Cushing`s syndrome (ECS) secondary to neuroendocrine tumours (NETs) of the lung and mediastinum are rarely encountered. In this study, we present our experience in Iran on 15 patients with ECS secondary to lung and mediastinal tumours over a period of 27 years. Material and methods: Since 1985, 15 patients with ECS secondary to lung and mediastinal tumours have been diagnosed and prospectively followed by the endocrinology team of Taleghani Hospital, Tehran, Iran. The clinical signs and symptoms, laboratory findings, radiological features, immunohistochemical characteristics, management strategies and outcome data are here presented. Results: There were six women and nine men, aged 26–70 years, all presenting with typical features of Cushing’s syndrome. Based on histopathologic evaluations, four patients had small cell lung cancer (SCLC) and seven patients had pulmonary NETs, one patient had a thymic NET, and one case was diagnosed as a lung tumourlet. The mean ± SD serum cortisol, 24h urine free cortisol and plasma ACTH were 47.2 ± 20.5 μg/dL, 2,702 ± 5,439 μg/day, and 220 ± 147 pg/mL, respectively. Pulmonary lesions ranged in diameter from 1.1 to 4 cm (mean 1.9 ± 1.1 cm). One patient had a 10 cm mediastinal mass. The duration of follow up in these cases was between one month and seven years (mean 29.9 ± 27.5 months). The four patients with SCLC died within three months of diagnosis. Conclusion: Our data demonstrates the protean clinical and laboratory manifestations of ECS secondary to lung and mediastinal tumours, the problems encountered in diagnosis, and the need for a multidisciplinary approach. This study confirms other series from Western Europe and North America that, unlike the SCLC patients who show a poor outlook, ECS secondary to lung carcinoids has a more favourable prognosis. Wstep: Ektopowy zespół Cushinga (ectopic Cushing`s syndrome, ECS), który rozwija się u pacjentów mających nowotwory neuroendokrynne (neuroendocrine tumours, NET) śródpiersia lub płuc, jest zaburzeniem rzadko spotykanym. Niniejsza publikacja przedstawia doświadczenia autorów z ośrodka w Iranie, którzy w okresie 27 lat prowadzili 15 pacjentów z zespołem Cushinga wtórnym do nowotworów śródpiersia lub płuc. Materiał i metody: W okresie od 1985 zespół endokrynologów ze szpitala Taleghani Hospital w Teheranie zidentyfikował i prowadził w sposób prospektywny 15 pacjentów z objawami ECS uwarunkowanymi obecnością nowotworów śródpiersia lub płuc. Niniejsza publikacja przedstawia obraz kliniczny i objawy podmiotowe, wyniki badań laboratoryjnych i radiologicznych oraz badań immunohistochemicznych materiału tkankowegoz guzów nowotworowych, a także informacje na temat wdrożonego leczenia i jego wyników. Wyniki: W badanej grupie znalazło się 6 kobiet i 9 mężczyzn, w wieku 26–70 lat. U wszystkich pacjentów stwierdzono typowe cechy kliniczne zespołu Cushinga. Na podstawie badań histopatologicznych wycinków z guzów nowotworowych postawiono rozpoznanie drobnokomórkowego raka płuca (SCLC, small cell lung cancer) u 4 pacjentów, neuroendokrynnego nowotworu płuca (NET) bliżej nieokreślonego typu u 7 pacjentów, NET grasicy u jednej osoby oraz rozpoznanie zmiany typu tumorlet w płucu u jednej osoby. Średnie stężenie kortyzolu w surowicy ( ± odchylenie standardowe) wyniosło 47,2 ± 20,5 μg/dl, stężenie wolnego kortyzolu w moczu ze zbiórki dobowej 2.702 ± 5.439 μg/dobę, a stężenie ACTH w osoczu 220 ± 147 pg/ml. Zmiany nowotworowe w płucach miały wielkość od 1,1 do 4 cm (średni wymiar guza 1,9 ± 1,1 cm). Guz śródpiersia (u jednej osoby) miał średnicę 10 cm. Czas obserwacji wyniósł od 1 miesiąca do 7 lat (średnia 29,9 ± 27,5 miesięcy). Czterech chorych na SCLC zmarło w okresie do 3 miesięcy od postawienia rozpoznania. Wnioski: Przedstawione dane wskazują na różnorodność obrazu klinicznego i danych laboratoryjnych u pacjentów z objawami ECS w przebiegu choroby nowotworowej śródpiersia lub płuc. Konstelacja ta wymaga więc wielospecjalistycznej opieki już od momentu wdrożenia postępowania diagnostycznego. Przedstawione wyniki są zbieżne z danymi z publikacji pochodzących z Europy Zachodniej i Stanów Zjednoczonych i wskazują na stosunkowo korzystne rokowanie u pacjentów mających objawy ECS w związku z rakowiakiem płuca, w przeciwieństwie do pacjentów mających zmiany typu SCLC

Experimental investigation of the effect of Vitagnus plant extract on enhanced oil recovery process using interfacial tension (IFT) reduction and wettability alteration mechanisms

© 2020, The Author(s). Surfactant flooding is a chemical enhanced oil recovery (cEOR) process wherein anionic, cationic, non-ionic, and amphoteric surfactants are injected into oil reservoirs to produce more hydrocarbon. These chemical and industrial agents might cause some economic and environmental challenges. Recently, injection of natural surfactants, as new environmentally friendly EOR agents, for improving oil recovery has been proposed by researchers. In this study, the extract of Vitagnus, a natural surfactant, was used to minimize the interfacial tension (IFT) and alter the rock wettability towards the strong water-wet system, thereby improving the oil recovery from the carbonate rock The conductivity, pH, and turbidity measurements were undertaken to identify the critical micelle concentration (CMC) of the surfactant solutions prepared by mixing 500, 1000, 2000, 3000, 4000, 5000, 6000, and 7000 ppm of the Vitagnus extract and distilled water. The obtained experimental results reveal that the optimum CMC value of the used surfactant was 3000 ppm. At this CMC value, the IFT reduced from 29.5 to 5.28 mN/m, and the contact angle of the oil droplet on the surface of the carbonate rock decreased from 114° to 29°. Accordingly, during the tertiary process, oil recovery was improved from 44% to 54.6% OOIP (original oil in place) by injecting 2.25 PVs of the VIT3000 surfactant containing 3000 ppm of the plant extract

Economic and productivity evaluation of different horizontal drilling scenarios: Middle East oil fields as case study

Development of high-density oil and gas fields presents a great challenge to the energy industry due to the low productivity of individual wells and their high drilling cost. We thus compared the productivity, associated costs and economical revenues gained from two field development scenarios, with multilateral and horizontal drilling, to evaluate the optimal drilling and completion conditions in a giant heavy oil reservoir in the Middle East. Well path design was identified as one of the most complex parameters depending on the well-testing results, field production and reservoir simulation data. The fishbone well of four branches with a length of 300 m each and 30° deviation from the main hole was identified to be drilled and completed using open-hole sidetrack as the best approach. The fishbone structure raised production by 393%, while drilling cost only increased by 130% compared with a conventional horizontal well

Insight into nano-chemical enhanced oil recovery from carbonate reservoirs using environmentally friendly nanomaterials

The use of nanoparticles (NPs) in enhanced oil recovery (EOR) processes is very effective in reducing the interfacial tension (IFT) and surface tension (ST) and altering the wettability of reservoir rocks. The main purpose of this study was to use the newly synthesized nanocomposites (KCl / SiO2 / Xanthan NCs) in EOR applications. Several analytical techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM) were applied to confirm the validity of the synthesized NCs. From the synthesized NCs, nanofluids were prepared at different concentrations of 100-2000 ppm and characterized using electrical conductivity, IFT, and ST measurements. From the obtained results, it can be observed that 1000 ppm is the optimal concentration of the synthesized NCs that had the best performance in EOR applications. The nanofluid with 1000 ppm KCl / SiO2 / Xanthan NCs enabled reducing the IFT and ST from 33 and 70 to 29 and 40 mN/m, respectively. However, the contact angle was highly decreased under the influence of the same nanofluid to 41° and the oil recovery improved by an extra 17.05 % OOIP. To sum up, KCl / SiO2 / Xanthan NCs proved highly effective in altering the wettability of rocks from oil-wet to water-wet and increasing the cumulative oil production

Synergistic efficiency of zinc oxide/montmorillonite nanocomposites and a new derived saponin in liquid/liquid/solid interface-included systems: Application in nanotechnology-assisted enhanced oil recovery

Oil production faces challenges such as limited oil production from carbonate reservoirs, high oil production costs, and environmental issues. Chemical flooding as an enhanced oil recovery (EOR) method (CEOR) can increase oil production by the use of chemical additives such as surfactants into the reservoirs. Surfactants can increase oil recovery by interfacial tension (IFT) reduction and alteration of the rock wettability from oil-wet to water-wet. The synthesis of chemicals such as synthetic surfactants is usually costly and harmful to the environment. To solve these problems, many researchers have oriented on the use of natural surfactants instead of synthetic ones within the CEOR process. A new approach to increase the efficiency of CEOR is the synergizing of the chemical additives with nanoparticles as a hybrid fluid, which is known as the nanotechnology-assisted EOR method. In this research, a natural surfactant derived from Cyclamen persicum (CP) plant was extracted, and its performance was optimized with the zinc oxide/montmorillonite (ZnO/MMT) nanocomposite in a synergistic usage. At the optimum concentration of the surfactant, the measurements of the IFT and the contact angle show 57.78 and 61.58 % optimizations, respectively. Also, in the presence of NaCl, the performance of CP is improved. IFT and contact angle measurements were also conducted for ZnO/MMT nanofluids and CP-ZnO/MMT as hybrid nanofluids. Results indicate that ZnO/MMT nanocomposites can alter the wettability of the carbonate rock to the water-wet state. Also, the CP-ZnO/MMT hybrid nanofluid shows a good potential in both IFT reduction and altering wettability from oil-wet to water-wet. Finally, to investigate the effects of solutions on increasing oil recovery factor (RF), the optimum concentrations of the surfactant, nanocomposite, and hybrid solutions were selected for dynamic core flooding experiments, and improvements showed oil RF increases of 8.2, 6, and 13 %, respectively

Investigating the effect of [C8Py][Cl] and [C18Py][Cl] ionic liquids on the water/oil interfacial tension by considering Taguchi method

Capillary and interfacial forces are of great influences of trapping hydrocarbon in porous media after primary and secondary recovery processes. The trapped crude oil in the reservoir can be mobilized and produced by reducing these forces. Thus, surfactant flooding, as a main enhanced oil recovery (EOR) method, is usually applied to reduce the interfacial tension (IFT) of crude oil–water system in porous medium and improves the oil recovery. This study focused on the effect of [C8Py][Cl] and [C18Py][Cl] ionic liquids (ILs), as a new family of surfactant, in combination with various salts including sodium chloride, potassium chloride, magnesium sulfate and potassium sulfate on IFT reduction. EOR injection solutions were prepared from mixing the ILs at different concentrations of 100, 250, 500 and 1000 ppm with the salts ranging from 500 to 80,000 ppm. Obtained results showed that the minimum IFT value from both ILs was achieved when the concentration of the ILs was about 1000 g/mL, and the concentrations of KCl, K2SO4, MgSO4 and NaCl were 1000, 2000, 500 and 80,000 ppm, respectively. The minimum IFTs were achieved when NaCl and ILs concentrations were the maximum and MgSO4 concentration was the minimum