A gated recurrent unit model to predict Poisson’s ratio using deep learning

Static Poisson’s ratio(vs)is crucial for determining geomechanical properties in petroleum applications,namely sand production.Some models have been used to predict vs;however,the published models were limited to specific data ranges with an average absolute percentage relative error(AAPRE)of more than 10%.The published gated recurrent unit(GRU)models do not consider trend analysis to show physical behaviors.In this study,we aim to develop a GRU model using trend analysis and three inputs for predicting n s based on a broad range of data,n s(value of 0.1627-0.4492),bulk formation density(RHOB)(0.315-2.994 g/mL),compressional time(DTc)(44.43-186.9 μs/ft),and shear time(DTs)(72.9-341.2μ s/ft).The GRU model was evaluated using different approaches,including statistical error an-alyses.The GRU model showed the proper trends,and the model data ranges were wider than previous ones.The GRU model has the largest correlation coefficient(R)of 0.967 and the lowest AAPRE,average percent relative error(APRE),root mean square error(RMSE),and standard deviation(SD)of 3.228%,1.054%,4.389,and 0.013,respectively,compared to other models.The GRU model has a high accuracy for the different datasets:training,validation,testing,and the whole datasets with R and AAPRE values were 0.981 and 2.601%,0.966 and 3.274%,0.967 and 3.228%,and 0.977 and 2.861%,respectively.The group error analyses of all inputs show that the GRU model has less than 5% AAPRE for all input ranges,which is superior to other models that have different AAPRE values of more than 10% at various ranges of inputs.

The Impact of Clay Loading on the Relative Intercalation of Poly(Vinyl Alcohol)-Clay Composites

Polymer clay nanocomposites (PCN) materials are industrially applied because of their unique properties. However many of their physical and chemical properties have not been determined. The formed structures of polymer/clay nanocomposite depend on the nature of interactions between polymer chains and clay platelets. According to the possible modes of interactions between polymer matrix and clay sheets, these nanocomposites can be classified into: intercalated, flocculated and exfoliated nanocomposites. In this work, the morphology of the nanocomposite was studied using X-ray diffraction (XRD) and nanoscaning electron microscopy (NSEM). XRD and NSEM measurements confirmed the intercalation between poly(vinyl alcohol) chains and cloisite®20A sheets. Because of the intercalation between the clay platelets and the PVA chains, as the clay concentration increases as the band intensities in FT-IR spectra increase. On the other hand, the XRD did not provide clear shift of any of the clay peaks for PVA/cloisite® 10A nanocomposites and confirm the non-intercalation between PVA matrix and cloisite®10A platelets. The relative intercalation (RI) of PVA/Cloisite®20A nanocomposites declined with increase in the clay loadings. In contrast, for PVA/Cloisite®10A, RI values slightly increased with increasing the clay loading.

Adsorption of CO₂on Polyethyleneimine 10k—<i>Mesoporous silica</i>Sorbent: XPS and TGA Studies

A CO2 solid sorbent based on polyethyleneimine 10k (PEI-10k) impregnated into mesoporous silica (MPS) foam was synthesized and utilized to capture CO2 at temperatures ranged from 65°C to 95°C. The calculated nitrogen and carbon contents in the bulk of the PEI-10k/MPS sorbent were similar to the XPS results measured on the surface of the foam, suggesting that the PEI was homo-geneously distributed throughout the MPS support. After CO2 adsorptionthe N 1s peak was broadened and could be resolved into two components: a high binding energy component (~401 eV) and a lower binding energy one (396 eV), respectively. The former nitrogen states are consistent with a protonated amine, presumably, due to carbamate formation. The lower binding energy component (~396 eV) could possibly be due to strongly chemisorbed CO2. The maximum sorption capacity was about 4 mmole CO2/g sorbent at 85°C and 1 bar. This capacity was doubled by raising the CO2 pressure to 24.95 bars. The adsorption results can be described by a Langmuir adsorption isotherm.

Catalytic evaluation of promoted CeO_2-ZrO_2 by transition, alkali, and alkaline-earth metal oxides for diesel soot oxidation

Series of mixed metal oxides were synthesized by gel-combustion method and their catalytic activities for soot oxidation were investigated. The catalysts were M-Ce-Zr （M = Mn, Cu, Fe, K, Ba, Sr）, and χK-20Mn-Ce-Zr （χ= 0, 5, 10, 20）, they were characterized by XRD, SEM, TPR and BET surface area techniques. The results of soot temperature programmed oxidation （TPO） in an O2 oxidizing atmosphere indicate that K-Ce-Zr has the highest catalytic activity for soot oxidation under loose contact condition, due to enhancement of the soot and catalyst contacts. On the other hand, under a tight contact condition, Mn-Ce-Zr and Cu-Ce-Zr nano-composites have high activities for soot oxidation and lower the soot TPO peak temperatures by about 280 and 270℃, respectively, as compared to non-catalytic soot oxidation. Furthermore, the addition of up to 10 wt.% potassium oxides into Mn-Ce-Zr increases its catalytic activity and further reduces the soot TPO peak temperature by about 40℃ under loose contact condition.

Investigation of the hydrogen adsorbed density inside the pores of MOF-5 from path integral grand canonical Monte Carlo at supercritical and subcritical temperature

We examine the high density limit of the adsorption isotherms of hydrogen on MOF-5. The isotherms are calculated using quantum GCMC simulations over the pressure range： 0-150 atm （1 atm = 1.01325 ~ 105 Pa） in the subcritical and supercritical state at 30, 50, 77, 113, 196 and 296 K. The fluid phase density in the pores for each temper- ature is calculated and shown to reach values higher than normal liquid density. The fluid phase density obtained at 30 K is observed to correspond to a highly compressed liquid. The radial distribution function of the adsorbed phase at 30 and 50 K are calculated. The adsorption isotherms are compared with available experimental data at 30, 50, 77 and 298 K.

Photo-stability of CsPbBr_3 perovskite quantum dots for optoelectronic application

Due to their superior photoluminescence(PL)quantum yield(QY) and tunable optical band gap,all-inorganic CsPbBr_3 perovskite quantum dots(QDs) have attracted intensive attention for the application in solar cells,light emitting diodes(LED),photodetectors and laser devices.In this scenario,the stability of such materials becomes a critical factor to be revealed.We hereby investigated the long-term stability of as-synthesized CsPbBr_3 QDs suspended in toluene at various environmental conditions.We found light illumination would induce drastic photo-degradation of CsPbBr_3 QDs.The steady-state spectroscopy,transmission electron microscopy(TEM),and X-ray diffraction(XRD)verified that CsPbBr_3 QDs tend to aggregate to form larger particles under continuous light soaking.In addition,decreasing PL QY of the QDs during light soaking indicates the formation of trap sites.Our work reveals that the main origin of instability in CsPbBr_3 QDs and provides reference to engineer such QDs towards optimal device application.

Advancement and new perspectives of using formulated reactive amine blends for post-combustion carbon dioxide (CO_(2)) capture technologies

Chemical absorption using amine-based solvents have proven to be the most studied,as well as the most reliable and efficient technology for capturing carbon dioxide(CO_(2))from exhaust gas streams and synthesis gas in all combustion and industrial processes.The application of single amine-based solvents especially the very reactive monoethanolamine(MEA)is associated with a parasitic energy demand for solvent regeneration.Since regeneration energy accounts for up to threeequarters of the plant operating cost,efforts in its reduction have prompted the idea of using blended amine solvents.This review paper highlights the success achieved in blending amine solvents and the recent and future technologies aimed at increasing the overall volumetric mass transfer coefficient,absorption rate,cyclic capacity and greatly minimizing both degradation and the energy for solvent regeneration.The importance of amine biodegradability(BOD)and low ecotoxicity as well as low amine volatility is also highlighted.Costs and energy penalty indices that influences the capital and operating costs of CO_(2) capture process was also highlighted.A new experimental method for simultaneously estimating amine cost,degradation rate,regeneration energy and reclaiming energy is also proposed in this review paper.

Enhancement of photovoltaic performance by two-step dissolution processed photoactive blend in polymer solar cells

We reported enhanced performance of polymer solar cells, based on poly(3-hexylthiophene):[6,6]-phenylC_(61)-butyric acid methyl ester(P3HT:PC_(61)BM) and polythieno[3,4-b]-thiophene-co-benzodithiophene:[6,6]-phenylC_(71)-butyric acid methyl ester(PTB7:PC_(71)BM) photovoltaic systems, by a two-step dissolution treatment of photoactive blends. Optical and morphological characterization revealed that the composition of the ordered polymer and donor/acceptor phase structure in the photoactive layer can be optimized using a two-step dissolution treatment. In addition, time-resolved photoluminescence indicated that exciton dissociation efficiency could be increased using this method. Current density-voltage(J-V) measurements showed that power conversion efficiencies(PCE) of the two-step dissolution treated devices were higher than those of one-step treated devices by 24% and 8% for P3HT:PC61BM and PTB7:PC_(71)BM systems, respectively. Therefore, this two-step dissolution treatment further optimizes the performance of polymer solar cells.

Effect of the degree of template removal from mesoporous silicate materials on their adsorption of heavy oil from aqueous solution

The key aim of this study is to evaluate the adsorption of heavy oil from aqueous solutions with different oil contents over mesoporous silicate materials having different surfactant template contents. The meso- porous silicate materials have been synthesized from tetraethylorthosilicate as a silica precursor and cetyltri- methylammonium bromide as a template using the sol-gel technique. Four samples were prepared by （1） totally removing the template using the calcination process, （2） partially removing the template via ethanol extraction, （3） partially removing the template via water extraction, and （4） keeping the template as synthesized, respectively. These four samples have been characterized using X-ray diffraction, nitrogen adsorption, thermal gravimetric ana- lysis and Fourier transformed infrared. The effect of the degree of template removal of these mesoporous materials for the oil removal has been investigated. The oil removal is inversely proportional to the surfactant content in the mesoporous material, being highest for the calcined sample but lowest for the as-synthesized sample. The kinetic of oil adsorption over the calcined material has been also studied and the data obtained fit well a second-order model.