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Zinc oxide (ZnO) is a compound with versatile applications. The compound can be synthesized in multiple sizes and shapes. The actual final product shape or morphology depends largely on the solvent used. The understanding of the actual interaction amongst the solvent and solute molecules is a very promising way to predict the shape of ZnO. Further, the operating conditions used during synthesis of ZnO also influence the final size of the product. This review paper specifically focuses on synthesis of zinc oxide through solvothermal synthesis with salt of zinc oxide with single solvent and with different operating conditions. The literature on effect of mixture of solvents is also reported in one of the subsections. The aim of this review is to understand the actual interaction amongst single salt and solvent without presence of any other compound in it. The presence of more than one compound in solvent or mixture of solvent increases the complexity of the problem. Therefore, there is a need to focus on this specific collection of literature to understand the basics, while future studies can be devoted to more complex studies. This review covers the effect of solvents like alcohols, alkanes, glycols, ring compounds and water on zinc salt. Also, it reports the effect of operating parameters like effect of precursor, temperature and time based on the available literature. [ABSTRACT FROM AUTHOR]

Copyright of MAS Journal of Applied Sciences is the property of MAS Journal of Applied Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, we consider the existence and multiplicity of normalized solutions for critical Choquard equations involving logarithmic nonlinearity in the Heisenberg group. Under suitable assumptions, combined with the truncation technique, the concentration‐compactness principle, and the genus theory, we obtain the existence and multiplicity of the normalized solutions in the Lp$$ {L}^p $$‐subcritical case. As far as we know, the result of the paper is completely new in the Euclidean case. [ABSTRACT FROM AUTHOR]

The treatment of shoulder instability in patients with subcritical glenoid bone loss poses a difficult problem for surgeons as new evidence supports a higher failure rate when a standard arthroscopic Bankart repair is used. The purpose of this study was to compare a conjoint tendon transfer (soft-tissue Bristow) to an open Bankart repair in a cadaveric instability model of 10% glenoid bone loss. Eight cadaveric shoulders were tested using a custom testing system that allows for a 6-degree-of-freedom positioning of the glenohumeral joint. The rotator cuff muscles were loaded to simulate physiologic muscle conditions. Four conditions were tested: (1) intact, (2) Bankart lesion with 10% bone loss, (3) conjoint tendon transfer, and (4) open Bankart repair. Range of motion, glenohumeral kinematics, and anterior-inferior translation at 60° of external rotation with 20 N, 30 N, and 40 N were measured in the scapular and coronal planes. Glenohumeral joint translational stiffness was calculated as the linear fit of the translational force-displacement curve. Force to anterior-inferior dislocation was also measured in the coronal plane. Repeated measures analysis of variance with a Bonferroni correction was used for statistical analysis. A Bankart lesion with 10% bone loss increased the range of motion in both the scapular (P =.001) and coronal planes (P =.001). The conjoint tendon transfer had a minimal effect on the range of motion (vs. intact P =.019,.002), but the Bankart repair decreased the range of motion to intact (P =.9,.4). There was a significant decrease in glenohumeral joint translational stiffness for the Bankart lesion compared with intact in the coronal plane (P =.021). The conjoint tendon transfer significantly increased stiffness in the scapular plane (P =.034), and the Bankart repair increased stiffness in the coronal plane (P =.037) compared with the Bankart lesion. The conjoint tendon transfer shifted the humeral head posteriorly at 60° and 90° of external rotation in the scapular plane. The Bankart repair shifted the head posteriorly in maximum external rotation in the coronal plane. There was no significant difference in force to dislocation between the Bankart repair (75.8 ± 6.6 N) and the conjoint tendon transfer (66.5 ± 4.4 N) (P =.151). In the setting of subcritical bone loss, both the open Bankart repair and conjoint tendon transfer are biomechanically viable options for the treatment of anterior shoulder instability; further studies are needed to extrapolate these data to the clinical setting. [ABSTRACT FROM AUTHOR]

Copyright of Klimatizacija, Grejanje, Hladjenje (KGH) is the property of Union of Mechanical & Electrotechnical Engineers & Technicians of Serbia (SMEITS) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Jilin University (Science Edition) / Jilin Daxue Xuebao (Lixue Ban) is the property of Zhongguo Xue shu qi Kan (Guang Pan Ban) Dian zi Za zhi She and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper is concerned with the multiplicity results to a class of p$$ p $$‐Kirchhoff type elliptic equation with the homogeneous Neumann boundary conditions by the abstract linking lemma due to Brézis and Nirenberg. We obtain the twofold results in subcritical and critical cases, which is a meaningful addition and completeness to the known results about Kirchhoff equation. At the same time, this paper also gives a method to deal with p$$ p $$‐Laplacian, Kirchhoff equation, and some Kirchhoff type equation in a unified variational framework. [ABSTRACT FROM AUTHOR]

The heat transfer characteristics of evaporative condensers in an R744 air conditioning system were evaluated using the numerical and the experimental methods. Two configurations of condensers were studied: Case 1 with five layers of tubes and Case 2 with eight layers of tubes. In order to evaluate the heat transfer characteristics, the temperature field, the phase change, the pressure distribution, and thermodynamic parameters were considered. For Case 2, it indicated the capability of R744 condensation from the superheated status to the liquified status by analyzing the outlet temperature of the condenser changed from 28.7 °C to 30.3 °C with a change in condensation pressure from 72.6 bar to 68.5 bar. In this study, R744 mass flow rate increases from 14.34 kg/h to 46.08 kg/h, and the pressure drop also increases from 0.23 bar to 0.47 bar for the simulation and 0.4 bar to 0.5 bar for the experiment, respectively. The results indicate that the five-layer configuration causes a higher pressure drop and lower COP than those obtained from the eight-layer one (splitting into two sets for smaller pressure drop). Furthermore, the evaporative condensers using mini tubes that are flooded in the cooling water tank are suitable for the subcritical R744 air conditioning system. In addition, the results obtained from the experimental data are in good agreement with those obtained from the numerical results, with a deviation of less than 5%. [ABSTRACT FROM AUTHOR]

We prove the existence of a solution for an equation where the nonlinearity is singular at zero, namely - Δ u = (- u - β + f (u)) χ { u > 0 } in Ω ⊂ R 2 with Dirichlet boundary condition. The function f grows exponentially, which can be subcritical or critical with respect to the Trudinger–Moser embedding. We examine the functional I ϵ corresponding to the ϵ -perturbed equation - Δ u + g ϵ (u) = f (u) , where g ϵ tends pointwisely to u - β as ϵ → 0 + . We show that I ϵ possesses a critical point u ϵ in H 0 1 (Ω) , which converges to a genuine nontrivial nonnegative solution of the original problem as ϵ → 0 . We also address the problem with f(u) replaced by λ f (u) , when the parameter λ > 0 is sufficiently large. We give examples. [ABSTRACT FROM AUTHOR]

For a solution u to the Navier-Stokes equations in spatial dimension n ≥ 3 which blows up at a finite time T > 0, we prove the blowup estimate || u(t)||. Bsp+εp,q (Rn) ≥,ε,(pv qv 2) (T-t)-ε/2 for all ε Є [1, 2) and p, q Є [1, n/2-ε), where sp := 1 + n/p is the scaling-critical regularity, is the cutoff function used to define the Littlewood--Paley projections. For ε = 2, we prove the same type of estimate but only for q = 1: || u(t)||. Bsp+εp,q (Rn) ≥,ε,(pv qv 2)) (T-t)-1 for all p Є [1,∞). Under the additional restriction that p, q Є [1, 2] and n = 3, these blowup estimates are implied by those first proved by Robinson, Sadowski, and Silva [J. Math. Phys., 53 (2012), 115618] for p = q = 2 in the case ε Є (1, 2), and by McCormick et al. [SIAM J. Math. Anal., 48 (2016), pp. 2119--2132] for p = 2 in the cases (ε, q) =(1, 2) and (ε, q) =(2, 1). [ABSTRACT FROM AUTHOR]

The accurate calculation of pressurized water reactor burned fuel neutron source intensity plays a significant role in the subcritical reactivity measurement. The calculation methods of both spontaneous fission source and (α, n) neutron source were researched in this paper. There were multiple sources of alpha particle in reactor core, including 238Pu, 239Pu, 240Pu, 241Am, 242Cm, 244Cm, etc. Among these sources, the dominant source was coming from 242Cm decay. 242Cm approximation method as well as ratio fitting method were proposed for obtaining (α, n) neutron source intensity. In 242Cm approximation method, all alpha particle sources were neglected with the exception of 242Cm. The ORIGEN code was used to analyze the ratio of (α, n) to the spontaneous fission neutron of 242Cm for different enrichment assemblies at different shutdown time. It is found that the ratio of (α, n) to the spontaneous fission neutron of 242Cm is fixed around 0.191. Therefore, the neutron number density of spontaneous fission neutron is multiplied by the factor of 0-191 to obtain (α, n) neutron source intensity due to 242Cm decay. On account of neglecting all (α, n) neutron source intensity with the exception of 242Cm, it is foreseeable that 242Cm approximation method would underestimate (α, n) neutron source intensity. In ratio fitting method, the ratio of (α, n) to the total neutron source intensity was analyzed. It is found that the ratio of (α, n) to the total neutron source intensity is linearly related to the burunp when the burnup is greater than 20 000 MW·d/tU. Therefore, two fitting methods were proposed to obtain the ratio of (α, n) to the total neutron source intensity. The polynomial fitting method was used with burnup less than 20 000 MW·d/tU, on the other hand, the liner fitting method was adopted with burnup greater than 20 000 MW·d/tU. Based on the in-house core design code package, the burned fuel neutron source calculation module was developed. In order to account for reactor core space effect and burnup history effect, the micro-depletion correction method in core design code package was used to obtain accurate number densities of actinide nuclides. The developed module was verified by calculating fuel assembly examples. Comparing with the reference code, the maximum errors of total source intensity is about 5% provided by both 242Cm approximation method and ratio fitting method. With the developed burned fuel neutron source intensity calculation module, both radial and axial distributions of burned fuel neutron source intensity in the reactor core are obtained. These distributions are of significant importance to ex-core detector signal measurements. The work in this paper is an important technology support for subcritical rod worth measurement development.

On a smooth bounded domain we study the Trudinger-Moser functional Eα(u)≔∫Ω(eαu2−1)dx,u∈H1(Ω){E}_{\alpha }\left(u):= \mathop{\int }\limits_{\Omega }({e}^{\alpha {u}^{2}}-1){\rm{d}}x,\hspace{1.0em}u\in {H}^{1}\left(\Omega ) for α∈(0,2π)\alpha \in \left(0,2\pi ) and its restriction Eα∣Σλ{E}_{\alpha }{| }_{{\Sigma }_{\lambda }}, where Σλ≔u∈H1(Ω)∣∫Ω(∣∇u∣2+λu2)dx=1{\Sigma }_{\lambda }:= \left\{u\in {H}^{1}\left(\Omega )| {\int }_{\Omega }(| \nabla u{| }^{2}+\lambda {u}^{2}){\rm{d}}x=1\right\} for λ>0\lambda \gt 0. By applying the asymptotic analysis and the variational method, we obtain asymptotic behavior of critical points of Eα∣Σλ{E}_{\alpha }{| }_{{\Sigma }_{\lambda }} both as λ→0\lambda \to 0 and as λ→+∞\lambda \to +\infty . In particular, we prove that when α\alpha is sufficiently small, maximizers for supu∈ΣλEα(u){\sup }_{u\in {\Sigma }_{\lambda }}{E}_{\alpha }\left(u) tend to 0 in C(Ω¯)C\left(\overline{\Omega }) as λ→+∞\lambda \to +\infty .

A feasibility study of a subcritical fission-fusion hybrid reactor using lead-lithium eutectic as a coolant and minor actinides (MAs) as fuel is presented. Such a reactor could support the fission community by transmuting MAs and the fusion community by breeding tritium. The feasibility of such a reactor for the burnup of MAs is assessed in terms of burnup performance, tritium breeding, and safety characteristics. Tandem mirrors are a promising neutron source technology, and a deuterium-tritium tandem mirror is considered here for the neutron source with power Psource = 1.13 MW assumed for scoping purposes. Subcritical reactivities from keff = 0.9800 to keff = 0.9950 were considered, representing the initial reference for subcritical reactivity and the assessed upper limit, respectively. Stability analyses indicated the reactivity would be stable under perturbations of fuel, coolant, and inlet temperatures, with a positive reactivity insertion expected during reactor shutdown. This k e f f range corresponded to nuclear heating values of 150 to 650 MW and mass burn rates of 53 to 216 kg/year. The upper mass burn rate limit would require 1110 reactor years with a capacity factor of 0.9 to fission the global supply of MAs and could offset the annual U.S. MA production with eight reactors. Tritium breeding was assessed for keff = 0.9800 and 3.795% 6Li enrichment in the coolant, and a tritium breeding ratio of 1.602 ± 0.017 was tallied, suggesting the reactor could, without elevated 6Li enrichment, produce tritium to both sustain operation and supply tritium for other fusion devices. Time-series modeling of fuel burnup was conducted for a four-batch loading scheme and three different fuel residence times at keff = 0.9800, which showed system performance would drop with burnup, and that the rate of this drop was lower for longer fuel residence times, motivating a means of reactivity control. Last, changes in fuel composition with burnup were assessed for relative concentrations of MAs, transmutation products, and fission products. The breeding of plutonium in the blanket was calculated and found to be of minimal proliferation concern. [ABSTRACT FROM AUTHOR]

General expressions for statistical entropy analysis of vapor-compression refrigeration cycles are given. An open-source software for statistical entropy analysis of vapor-compression refrigeration cycles has been developed. Using the statistical entropy analysis method, two different refrigeration cycles that use an ejector as an expansion device were compared with 5 other cycles in which throttle valves are used as expansion devices. Calculations were made for two temperature levels: medium-temperature and low-temperature. Energy consumption levels are shown to depend on the cycle used and the boiling. The results showed the expedience and prospects of use of ejectors as expansion devices not only in transcritical, but also in subcritical refrigeration cycles. [ABSTRACT FROM AUTHOR]

If our expectations are to have a future with the resources provided by the earth, the recycling of plastics has become one of the most important topics that, as humans, we must deal with. Among the technologies developed for treating this issue is the hydrothermal liquefaction (HTL) method. In this review, subcritical and supercritical hydrothermal processes are presented. Experimental methods and product yields are disclosed and discussed. Subcritical conditions have previously been used to depolymerize synthetic polymers containing heteroatoms, such as bisphenol-A-based epoxy resin (Epoxy), polyamide 6 (PA6), polyamide 6/6 (PA66), polyethylene terephthalate (PET), polycarbonate (PC), and polyurethane (PU). This type of polymer can be broken down using this low-temperature, low-pressure method because it has heteroatoms that are easy to break down. To depolymerize polyolefins like polyethylene (PE) and polypropylene (PP), derivatives and mixtures, formed by long hydrocarbon chains, supercritical water conditions (> 374 °C; > 23 MPa) seem to be required. These requirements make the procedure quite expensive. The review showed that a new method that uses pressures between 2.5 and 30 MPa, temperatures above 400 °C, and residence times of 20 to 60 min, named low-pressure hydrothermal liquefaction (LP-HTL), can be used to handle this type of polyolefin hydrocarbon. This review describes the conditions needed to handle this problematic type of feedstock and, in a certain way, the possible utilization of such technology for treating more complex waste mixtures.

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We consider the following Kirchhoff-type problem in an unbounded exterior domain $\Omega\subset\mathbb{R}^{3}$ : (*) \begin{align} \left\{ \begin{array}{ll} -\left(a+b\displaystyle{\int}_{\Omega}|\nabla u|^{2}\,{\rm d}x\right)\triangle u+\lambda u=f(u), & x\in\Omega,\\ \\ u=0, & x\in\partial \Omega,\\ \end{array}\right. \end{align} where a  > 0, $b\geq0$ , and λ  > 0 are constants, $\partial\Omega\neq\emptyset$ , $\mathbb{R}^{3}\backslash\Omega$ is bounded, $u\in H_{0}^{1}(\Omega)$ , and $f\in C^1(\mathbb{R},\mathbb{R})$ is subcritical and superlinear near infinity. Under some mild conditions, we prove that if \begin{equation*}-\Delta u+\lambda u=f(u), \qquad x\in \mathbb R^3 \end{equation*} has only finite number of positive solutions in $H^1(\mathbb R^3)$ and the diameter of the hole $\mathbb R^3\setminus \Omega$ is small enough, then the problem (*) admits a positive solution. Same conclusion holds true if Ω is fixed and λ  > 0 is small. To our best knowledge, there is no similar result published in the literature concerning the existence of positive solutions to the above Kirchhoff equation in exterior domains. [ABSTRACT FROM AUTHOR]

Prediction of brittle fracture of amorphous oxide glasses continues to be a challenge due to the existence of multiple fracture mechanisms that vary with loading conditions. To address this challenge, we present a model for all three regimes of crack growth in glasses. Regimes I and III are controlled by Arrhenius processes while regime II is transport controlled along with a simple Arrhenius model for viscoelastic stress relaxation. Through dimensional arguments and physical reasoning, we propose a single mechanism which underlies both regime III subcritical crack growth and near-crack-tip viscoelastic relaxation. By combining the subcritical crack growth and viscoelastic models we obtain a prediction for a threshold stress intensity, Kth, below which stresses around the crack relax faster than it propagates. For stress intensity KI

The heat transfer characteristics of evaporative condensers in an R744 air conditioning system were evaluated using the numerical and the experimental methods. Two configurations of condensers were studied: Case 1 with five layers of tubes and Case 2 with eight layers of tubes. In order to evaluate the heat transfer characteristics, the temperature field, the phase change, the pressure distribution, and thermodynamic parameters were considered. For Case 2, it indicated the capability of R744 condensation from the superheated status to the liquified status by analyzing the outlet temperature of the condenser changed from 28.7 °C to 30.3 °C with a change in condensation pressure from 72.6 bar to 68.5 bar. In this study, R744 mass flow rate increases from 14.34 kg/h to 46.08 kg/h, and the pressure drop also increases from 0.23 bar to 0.47 bar for the simulation and 0.4 bar to 0.5 bar for the experiment, respectively. The results indicate that the five-layer configuration causes a higher pressure drop and lower COP than those obtained from the eight-layer one (splitting into two sets for smaller pressure drop). Furthermore, the evaporative condensers using mini tubes that are flooded in the cooling water tank are suitable for the subcritical R744 air conditioning system. In addition, the results obtained from the experimental data are in good agreement with those obtained from the numerical results, with a deviation of less than 5%.

Chokes are very vital components of the producing system used to regulate flow and mitigate undesirable release of hydrocarbons to the environment from downhole. Basically, there are two types of chokes, the surface and subsurface chokes. The surface chokes are designed to operate at critical flow where pressure perturbations downstream are not transmitted upstream whereas the subsurface chokes are designed to operate at subcritical conditions where pressure perturbations downstream are transmitted upstream. This work focused on the development of a model for predicting surface choke performance using an Excel Solver-non-linear gradient reduction technique. With this solver, new sets of constants were developed for an existing choke performance model that was selected amongst several other correlations. Comparison of this model with the selected model and other existing models shows that the model from this study is most accurate in predicting choke performance. Statistical parameters were also used to ascertain the goodness of fit and agreement with existing models and the results show very good agreement. [ABSTRACT FROM AUTHOR]

Supercritical hydraulically controlled overflow of Antarctic Bottom Water from the Weddell Sea has been observed in the Orkney Passage during field measurements in February 2022. The Orkney Passage is the main pathway for the densest layer of Antarctic Bottom Water flow from the Weddell Sea to the Scotia Sea. The bottom current overflows the sill across the passage and flows down from the crest of the sill at 3600 m deeper than 4000 m. The descending flow accelerates because of the difference in the height of the sill and its foot. An estimate of the Froude number of this flow was greater than unity. Near the foot of the slope the kinetic energy of the flow becomes insufficient to continue moving in this regime. The flow slows down, and strong mixing and warming of the bottom water occurs due to the exchange with the surrounding waters. This hydrodynamic phenomenon is called supercritical hydraulically controlled flow. However, the flow of bottom water continues further and eventually fills the abyssal depths of the Atlantic. [ABSTRACT FROM AUTHOR]

Soybean oil deodorizer distillates (SODD), a by-product of soybean oil refining, primarily comprised of free fatty acids (FFA, 40.62–51.23 wt%), acyglycerides (22–25 wt%), and unsaponifiable matter (19.81–42.23 wt%), was explored as a potential feedstock for the synthesis of fatty acid methyl ester under subcritical conditions. Oil mixtures of linoleic acid and soybean oil were used as models to investigate the effects of reactor loading (RL = 25, 50, 90%), solvent-to-fatty acid ratio (SFR = 0.15–1.5 mL/g), mixing (0, 300 rpm), temperature (30–245 °C), and reaction time under non-isothermal and isothermal conditions. In addition, water and acetic acid were used as additives to investigate their effect on the reaction. Under favorable reaction conditions of 90% RL, SFR of 0.5 mL/g, and reacted non-isothermally to 245 °C and held for 100 min with stirring, high conversions or yields (87–89%) could be achieved when using SODDs having different total fatty acid content (59.37–77.42 wt%). The effect of unsaponifiable matter in significant quantities and some simple strategies to overcome possible limitations in the use of such feedstock were also looked into. The presence of high FFA allows (trans)esterification to be carried out under subcritical conditions without the need of adding a catalyst. [Display omitted] [ABSTRACT FROM AUTHOR]

Tung oil is an important dry grease. In order to overcome the deficiencies of traditional processes in oil production, the preparation of tung oil was carried out by the butane-subcritical method. A response surface optimization experiment was carried out based on Design-Expert software, and the best process parameters were obtained. The extraction temperature was 42.98 °C, the extraction time was 43.77 min, the particle size of the raw material was 38.88 mesh, and the oil yield of tung oil under this condition reached 67.437%. The fatty acid composition of tung oil was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS): the content of α-oleostearic acid was 74.99%, linoleic acid content was 8.83%, oleic acid content was 7.42%, palmitic acid content was 2.02%, and stearic acid content was 4.35%. Through the analysis of the oil sample obtained, five indicators showed that the process of obtaining oil products met the requirements of the national standard. By simulating the subcritical n-butane/tung oil dissolution equilibrium model, the miscible dynamic equilibrium of tung oil in subcritical n-butane was studied at temperatures in the range of 35–50 °C and an equilibrium time of 40 min, and the kinetic equations of oil extraction at different temperatures were obtained, with a coefficient of determination (R2) greater than 0.99. The oil extraction rate was up to 67.12 ± 0.05% under optimal extraction conditions through the optimization of univariate and response surface experimental design. Using 1stOpt data processing software, the data of tung oil extraction rate at different times were fitted, and it was found that the Patricelli model accurately elucidated the kinetic process of tung oil extraction through subcritical n-butane, with R2 greater than 0.99. [ABSTRACT FROM AUTHOR]

A low-temperature hydrothermal synthesis technique was employed as a medium to produce ceria−zirconia mixed oxides particles at temperatures of 200–300 °C and pressure of 10 MPa in a batch process. At these conditions, the average crystallite sizes of ceria−zirconia mixed oxides increased slightly with increasing reaction temperature when the feed solution containing ceria and zirconia with a ratio of 1:1 was fed. SEM images illustrated that the morphologies of the ceria−zirconia mixed oxides particles were spherical and spherical−like with a diameter of around 100 nm. The EDX spectrum indicated that the signal corresponding to the ceria and the zirconia elements at 5 and 2 keV, respectively, were strongly detected in the products. The XRD pattern revealed that the mixed metal oxides particle products that comprised of cerium and zirconium oxides particles with cubic and monoclinic structures, respectively, were affected by their molar content in the feed solution.

Understanding the stress state before and after an earthquake is essential to study how stress on faults evolves during the seismic cycle. This study integrates wellbore failure analysis, laboratory experiments, and edge dislocation model to study the stress state before and after the Chi‐Chi earthquake. The post‐earthquake in‐situ stress state observed along boreholes of the Taiwan Chelungpu‐fault Drilling Project (TCDP) is heterogeneous due to lithological variations. Along the borehole, we observe that drilling‐induced tensile fractures are only present in sandstones, whereas breakouts are mostly present in silt‐rich rocks. Laboratory experiments on TCDP cores also show that tensile and compressive strength are weaker in sandstones than in silt‐rich rocks. These observations imply that both maximum and minimum horizontal principal stresses are higher in silt‐rich intervals. Extended leak‐off tests in the TCDP borehole also show lower minimum horizontal stress in sand‐rich intervals, consistent with the above observations. We combine these observations to estimate a profile of stress magnitudes along the well which explains the variability of stress states found in previous studies. The stress heterogeneity we observed underlines the importance of acknowledging the spatial scale that the stress data represent. We then use an edge dislocation model constrained by GPS surface displacements obtained during Chi‐Chi earthquake to calculate the coseismic stress changes. Our inferred pre‐earthquake stress magnitudes, obtained by subtracting the coseismic stress change from the post‐earthquake stress, suggest subcritical stress state before the earthquake despite the large displacements observed during the Chi‐Chi earthquake in the region where TCDP encountered the fault. Plain Language Summary: Stress in the Earth's crust defines the forces acting on faults which drive earthquakes. Therefore, tracking how stress accumulates due to plate motion and is released due to fault slip have been a central topic in the study of earthquake mechanics and associated seismic hazard. Previous studies which analyzed data collected from Taiwan Chelungpu‐fault Drilling Project (TCDP), drilled after the 1999 Chi‐Chi earthquake, show that the post‐earthquake stress inferred from those studies is inconsistent with each other. This study reviewed previous measurements, conducted laboratory experiments, and analyzed borehole data to revisit the stress state after the Chi‐Chi earthquake. We show that stress state varies along the TCDP borehole due to lithology and fault‐related changes in mechanical properties, which explains why past studies indicated significant variability. We also estimated the pre‐earthquake stress before the Chi‐Chi earthquake to understand stress conditions leading to the rupture. We calculated the stress change caused by the Chi‐Chi earthquake and subtract it from the post‐earthquake stress to obtain the pre‐earthquake stress. Our pre‐earthquake stress estimate suggests that the stress before the Chi‐Chi earthquake was low in magnitude compared to the frictional strength of rocks. Key Points: We obtain a near‐continuous stress profile which captures the lithology‐dependent and fault‐related stress variation along the boreholesVariability in stress states reported from previous studies is explained by stress variations caused by lithological variationsThe estimated pre‐earthquake stress profile indicates subcritical stress state within the Chelungpu fault zone prior to the earthquake [ABSTRACT FROM AUTHOR]

This study examined the accuracy of a Lagrangian scheme for simulating both the motion and wall impaction of neutrally buoyant inertial spheres (8.85 ≤ St ≤ 18.04) moving in the subcritical regime (Re = 10,972 and 22,366) of flows past a circular cylinder. The accuracy of the eddy-resolving simulations of the flow field was verified based on available data at nearly comparable flow conditions. The accuracy of the particle tracking scheme was verified with respect to corresponding experimental data in a laboratory flume. Particle dispersion en route to the circular cylinder is mostly driven by the flow disturbance from the particle injector tube. The trends in collision rates are largely explained by the rate of particle entertainment into the boundary layer around the cylinder and the inertial condition of the spheres in this proximity region—both of which can be better assessed by post-processing of the numerical outcomes. The primary incentive to undertake this work was the need for validating a particle-based method for quantifying the hydraulic stressors leading to bodily damage of fish passing flows influenced by hydraulic infrastructure. [ABSTRACT FROM AUTHOR]

Based upon the method of moving spheres, we establish some Liouville-type results of a weighted elliptic equation. For subcritical nonlinearity, we prove non-existence result on the entire space. For supercritical nonlinearity, we obtain non-existence on bounded star-shaped domains. Meanwhile, a regularity result is also obtained. [ABSTRACT FROM AUTHOR]

Utilization of subsurface reservoirs, including fluid extraction/injection, can induce stress changes and modify in‐situ chemical equilibrium causing subcritical fracturing and deformation. Here, we show that chemical complexation reactions at the newly created fracture surfaces within the crack tip limit fracturing during consolidation of granular calcite assemblages. Previously, we showed that analogous chemical complexation reactions can increase in‐situ fracture toughness in pre‐fractured single crystal calcite. To test the chemical complexation effect under subsurface conditions, we consolidated samples under increasing hydrostatic pressure to induce widespread intergranular fracturing in the presence of fluid containing common anions. Measured consolidation, acoustic emissions, and microfracturing demonstrate that deformation correlates with complexation affinity for calcium in calcite and aqueous anions. We observed that deformation is lowest in the presence of strongly complexing anions (e.g., sulphate), provided sufficient anion diffusion rates. This understanding is important for predicting reservoir effective strength in the presence of complex aqueous fluids. Plain Language Summary: The current study identifies chemical reactions at the crack tip of calcite that control the extent of fracturing during consolidation. Calcite is one of the most abundant minerals in the Earth's crust; however, the chemical mechanisms that could promote or arrest crack growth in calcite are poorly understood. Microscopic cracks in individual calcite grains could affect reservoir‐scale processes such as deformation and subsidence. Here, we show that chemical reactions at the crack tips of calcite define fracturing behavior and, therefore, consolidation at pressures typical for geologic formations. Key Points: We examined how the formation of surface complexes affects fracture‐driven consolidation in granular assemblages of calciteMore fracturing and faster consolidation of calcite grain packs are observed in fluids containing anions with weak affinity for calciumStrongly complexing anions can effectively shield crack tips from hydrolysis reaction and modify deformation rates and total strains [ABSTRACT FROM AUTHOR]

• CO 2 GSHP vapor-compression cycle w/ liquid-line/suction-line heat exchanger (LLSL-HX). • Experimentally tested in cooling mode in an environmental chamber. • The COP ranged (7.3 to 2.4) for entering liquid temperature (10 to 39) °C. • An exergy analysis showed the compressor had the largest defect. • LLSL-HX gave small benefit to transcritical cycle and penalized subcritical cycle. A prototype CO 2 ground-source heat pump (GSHP), i.e. a water-to-air heat pump designed to couple with a ground heat exchanger, was tested in cooling mode per ISO standard 13256-1 to provide experimental data for assessing and improving CO 2 -based GSHPs. The GSHP consisted of a vapor-compression cycle with a liquid-line/suction-line heat exchanger (LLSL-HX). The system operated in a subcritical cycle for antifreeze entering liquid temperature (ELT) ≤ 25 °C and a transcritical cycle for ELT > 25 °C. The 'Standard' condition metrics were: coefficient of performance (COP) 4.14, total capacity 6690 W, sensible capacity 5400 W, and sensible-heat ratio (SHR) 0.81. The 'Part-load' performance was: COP 4.92, total capacity 7240 W, sensible capacity 5640 W, and SHR 0.78. The GSHP was also tested at additional ELTs ranging (10 to 39) °C, where COP ranged (7.3 to 2.4). Compressor efficiency correlations were shown for these and 118 additional tests. The LLSL-HX was estimated to reduce COP by (0 to 2)% for ELTs ranging (10 to 25) °C, and increase COP by (0 to 5)% for ELTs ranging (30 to 39) °C. At the 'Standard' condition the major exergy defects were compressor 0.32, ground heat exchanger 0.19, condenser 0.11, evaporator 0.11, EEV 0.07, pump 0.07, and fan 0.04. The exergy defects were sensitive to ELT, though the compressor was always the largest. Estimated performance of the cycle without the LLSL-HX showed for ELT (10 to 39) °C the HX reduced the EEV throttling defect by (0 to 0.08) and compressor defect by (0 to 0.015), but increased the condenser/gas-cooler defect by (0 to 0.06). [ABSTRACT FROM AUTHOR]

We consider the Cauchy problem for the inhomogeneous nonlinear Schrödinger (INLS) equation iut + Δ u = x -b f(u), u(0) =0 ∈ HS (ℝn), where 0 < s < min {n, n/2 + 1}, 0 < b > min {2, n - s, 1 + n-2s/2} and f (u) is a nonlinear function that behaves like λ u σu with λ ∈ ℂ and σ > 0. We prove that the Cauchy problem of the INLS equation is globally well-posed in HS (ℝn) if the initial data is sufficiently small and σ0 < σ < σS, where σ0 = 4 -- 2b/n and σS = 4 -- 2b/n -- 2s if s < n/2, σS = ∞ if s ≥ n/2. Our global well-posedness result improves the one of Guzmán [Nonlinear Anal. Real World Appl. 37 (2017), 249-286] by extending the validity of s and b. In addition, we also have the small data scattering result. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the Cauchy problem of the subcritical semilinear generalized Tricomi equations with dimension n ≥ 3. Under the assumption that the initial data are smooth and compactly supported, the Cauchy problem is shown to be locally well‐posed and the lower bound estimate of the lifespan is established. We also obtain the upper bound of the lifespan with the same scale; hence, the sharp lifespan is determined. The proof is based on the improved versions of the weighted Strichartz estimates. [ABSTRACT FROM AUTHOR]

In addition to the conventional fixed-source method, the iterative k-source (IKS) method is another Monte Carlo algorithm used for solving fixed-source problems. In contrast to the fixed-source method, the IKS method iterates the fission sources for each generation, which is similar to the k -eigenvalue calculation. The IKS method does not require following long-chain fission reactions until the end, even for a nearly critical subcritical system. The source-multiplication factor, k s , which is supposed to be less than unity, is calculated for each cycle. However, k s occasionally or frequently exceeds unity in a nearly critical system owing to statistical fluctuations, in which case the result of the IKS method is biased. To eliminate this bias, the frequency at which k s exceeds unity should be minimized by increasing the source size per cycle. As demonstrated in this study, the computational efficiency of the IKS method is three to ten times that of the conventional fixed-source method. • Iterative k-source method is a quite different algorithm for fixed-source problems. • Ratio of fixed sources to fissions is obtained in each cycle from multiplication. • In a nearly critical system, the ratio often becomes zero, resulting in bias. • The source per cycle must be large to prevent the bias. [ABSTRACT FROM AUTHOR]

We prove existence of two solutions for an elliptic equation with exponential growth on a bounded domain. The first solution is obtained by an approximation scheme together with a fixed point theorem. The second solution is found by variational methods, and its expression is given by the sum of the first solution by other adequate function. The nonlinearities may have subcritical, critical or supercritical exponential growth. [ABSTRACT FROM AUTHOR]

We establish the uniqueness of positive radial solutions of {Δu + ƒ(u) = 0, x ∈ A u(x) = 0 x ∈ ∂ A (P) where A := Aa,b = {x ∈ Rn : a < |x| < b}, 0 < a < b ≤ ∞. We assume that the nonlinearity ƒ ∈ C[0,∞) ∩ C1 (0,∞) is such that ƒ(0) = 0 and satisfies some convexity and growth conditions, and either ƒ(s) > 0 for all s > 0, or has one zero at B > 0, is non positive and not identically 0 in (0,B) and it is positive in (B,∞). [ABSTRACT FROM AUTHOR]

In order to enrich the stability and bifurcation theory of the three dimensional chaotic systems, taking a quadratic truncate unfolding system with the triple singularity equilibrium as the research subject, the existence of the equilibrium, the stability and the bifurcation of the system near the equilibrium under different parametric conditions are studied. Using the method of mathematical analysis, the existence of the real roots of the corresponding characteristic equation under the different parametric conditions is analyzed, and the local manifolds of the equilibrium are gotten, then the possible bifurcations are guessed. The parametric conditions under which the equilibrium is saddle-focus are analyzed carefully by the Cardan formula. Moreover, the conditions of codimension-one Hopf bifucation and the prerequisites of the supercritical and subcritical Hopf bifurcation are found by computation. The results show that the system has abundant stability and bifurcation, and can also supply theorical support for the proof of the existence of the homoclinic or heteroclinic loop connecting saddle-focus and the Silnikov's chaos. This method can be extended to study the other higher nonlinear systems.

Amphoteric aminophenol compounds have diverse synthetic and industrial use due to their multi-functional chemical reactivity. In this study, the synthesis of amphoteric flavonoid compounds via chemical modification with sub- and supercritical ammonia was explored. Both product formation and degree of amination of both catechin and condensed tannins were dependent on the processing conditions employed. Applying subcritical ammonia conditions produced ammonium ion formation and polymerization of these flavonoids. Under these conditions, ammonium group hydrogen-bonding was determined at the flavonoid B-ring catechol group and characterized by the δNH4+ bending at 1400 cm−1 in FTIR spectra. In contrast, using supercritical ammonia conditions (150 °C, 115 bar) led to formation of the desired amine-substituted products. Characterization of the aminated catechin and tannin products confirmed hydroxyls of the flavanyl A-ring were substituted to –NH2. FTIR established C-NH2 bond formation (1550, 1250 cm−1) with %N and NMR indicating stoichiometric substitutions of hydroxyl groups at the C5 and C7 flavonoid A-ring positions. Moreover, under supercritical ammonia conditions, there was a reduced tendency for the undesired base-catalysed autocondensation observed at lower temperatures and pressures. [ABSTRACT FROM AUTHOR]

Spatially localized two-dimensional spot patterns occur for a wide variety of two component reaction-diffusion systems in the singular limit of a large diffusivity ratio. Such localized, far-from-equilibrium patterns are known to exhibit a wide range of different instabilities such as breathing oscillations, spot annihilation, and spot self-replication behavior. Prior numerical simulations of the Schnakenberg and Brusselator systems have suggested that a localized peanut-shaped linear instability of a localized spot is the mechanism initiating a fully nonlinear spot self-replication event. From a development and implementation of a weakly nonlinear theory for shape deformations of a localized spot, it is shown through a normal form amplitude equation that a peanut-shaped linear instability of a steadystate spot solution is always subcritical for both the Schnakenberg and Brusselator reaction-diffusion systems. The weakly nonlinear theory is validated by using the global bifurcation software pde2path [H. Uecker, D. Wetzel, and J. D. Rademacher, Numer. Math. Theory Methods Appl., 7 (2014), pp. 58{106] to numerically compute an unstable, non-radially symmetric, steady-state spot solution branch that originates from a symmetry-breaking bifurcation point. [ABSTRACT FROM AUTHOR]

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A fundamental understanding and simulation of fuel atomization, phase transition, and mixing are among the topics researchers have struggled with for decades. One of the reasons for this is that the accurate, robust, and efficient simulation of fuel jets remains a challenge. In this paper, a tabulated multi-component real-fluid model (RFM) is proposed to overcome most of the limitations and to make real-fluid simulations affordable. Essentially, a fully compressible two-phase flow and a diffuse interface approach are used for the RFM model, which were implemented in the CONVERGE solver. PISO and SIMPLE numerical schemes were modified to account for a highly coupled real-fluid tabulation approach. These new RFM model and numerical schemes were applied to the simulation of different fundamental 1-D, 2-D, and 3-D test cases to better understand the structure of subcritical and transcritical liquid–gas interfaces and to reveal the hydro-thermodynamic characteristics of multicomponent jet mixing. The simulation of a classical cryogenic injection of liquid nitrogen coaxially with a hot hydrogen jet is performed using thermodynamic tables generated by two different equations of state: Peng–Robinson (PR) and Soave–Redlich–Kwong (SRK). The numerical results are finally compared with available experimental data and published numerical studies with satisfactory agreement.