AbstractIn this paper, some exact solutions of the stochastic generalized nonlinear shallow water wave equation are investigated. This equation is important in fluid mechanics’ fields since it can ...model the propagation of disturbances in water and other incompressible fluids. Opposite to what is usually considered in the literature, the two dispersion coefficients of the nonlinear terms are considered dependent random quantities as a more realistic case. The modified extended-tanh function (METF) method is combined with the random variable transformation (RVT) technique to get full probabilistic solutions of the problem via computing the probability density functions (PDFs) of the solution processes. Based on the probability density function, any statistical moment of the solution can be evaluated. Through two different applications for the input random variables (dispersion coefficients), my findings are applied efficiently. Finally, numerical results are presented graphically along the spatial dimension at a certain wave speed and time. The obtained results ratify that the proposed technique is efficient and powerful for obtaining analytical probabilistic solutions for the problem.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Novel catalytic materials are highly demanded to perform a variety of catalytic organic reactions. MOFs combine the benefits of heterogeneous catalysis like easy post reaction separation, catalyst ...reusability, high stability and homogeneous catalysis such as high efficiency, selectivity, controllability and mild reaction conditions. The possible organization of active centers like metallic nodes, organic linkers, and their chemical synthetic functionalization on the nanoscale shows potential to build up MOFs particularly modified for catalytic challenges. In this review, we have summarized the recent research progress in heterogeneous catalysis by MOFs and their catalytic behavior in various organic reactions, highlighting the key features of MOFs as catalysts based on the active sites in the framework. Examples of their post functionalization, inclusion of active guest species and metal nanoparticles have been discussed. Finally, the use of MOFs as catalysts for asymmetric heterogeneous catalysis and stability of MOFs has been presented as separate sections.
Novel catalytic materials are highly demanded to perform a variety of catalytic organic reactions.
Robotic control in a continuous action space has long been a challenging topic. This is especially true when controlling robots to solve compound tasks, as both basic skills and compound skills need ...to be learned. In this paper, we propose a hierarchical deep reinforcement learning algorithm to learn basic skills and compound skills simultaneously. In the proposed algorithm, compound skills and basic skills are learned by two levels of hierarchy. In the first level of hierarchy, each basic skill is handled by its own actor, overseen by a shared basic critic. Then, in the second level of hierarchy, compound skills are learned by a meta critic by reusing basic skills. The proposed algorithm was evaluated on a Pioneer 3AT robot in three different navigation scenarios with fully observable tasks. The simulations were built in Gazebo 2 in a robot operating system Indigo environment. The results show that the proposed algorithm can learn both high performance basic skills and compound skills through the same learning process. The compound skills learned outperform those learned by a discrete action space deep reinforcement learning algorithm.
Surfactant flooding is an important technique used in enhanced oil recovery to reduce the amount of oil in pore space of matrix rock. Surfactants are injected to mobilize residual oil by lowering the ...interfacial tension between oil and water and/or by the wettability alteration from oil-wet to water-wet. A large number of cationic, anionic, non-ionic, and amphoteric surfactants have been investigated on a laboratory scale under different conditions of temperature and salinity. Selection of the appropriate surfactant is a challenging task, and surfactants have to be evaluated by a series of screening techniques. Different types of surfactants along with their limitations are reviewed with particular emphasis on the phase behavior, adsorption, interfacial tension, and structure–property relationship. Factors affecting the phase behavior, interfacial tension, and wettability alteration are also discussed. Field applications of surfactants for chemical enhanced oil recovery in carbonate and sandstone reservoirs are also reviewed. Finally, some recent trends and future challenges in surfactant enhanced oil recovery are outlined. Field studies show that most of the surfactant flooding has been conducted in low-temperature and low-salinity sandstone reservoirs. However, high-temperature and high-salinity carbonate reservoirs are still challenging for implementation of surfactant flooding.
New well-designed materials are highly demanded with the prospect of versatile properties, offering successful applications as alternates to conventional materials. Major new insights into ...metal-organic self-assembled structures assisting biochemical purposes have recently emerged. Metal-organic polyhedral cages are highlighted as new research materials to be used for therapeutic, sensing and imaging, purposes
etc
. This tutorial review covers achievements in the biochemical applications of these multinuclear complexes. Examples of their ability to aid the ionic transport, biomolecular sensing, imaging, and drug delivery are presented.
New well-designed materials are highly demanded with the prospect of versatile properties, offering successful applications as alternates to conventional materials.
This study addresses the imperative to comprehend gravity shifts resulting from groundwater storage (GWS) variations in the Arabian Peninsula. Despite the critical importance of water resource ...sustainability and its relationship with gravity, limited research emphasizes the need for expanded exploration. The investigation explores the impact of GWS extraction on the gravity field, utilizing Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) data in addition to validation using the WaterGAP Global Hydrology Model (WGHM). Spanning April 2002 to June 2023, this study predicts GWS trends over the next decade using the Seasonal Autoregressive Integrated Moving Average (SARIMA) model. The comprehensive time-series analysis reveals a significant GRACE-derived groundwater storage (GWS) trend of approximately −4.90 ± 0.32 mm/year during the study period. This trend has a notable impact on the gravity anomaly (GA) values, as observed through the decomposition analysis. The projected GWS indicates a depletion rate of 14.51 km3/year over the next decade. The correlation between GWS and GA is substantial at 0.80, while the GA and rainfall correlation is negligible due to low precipitation rates. Employing multiple linear regression explains 80.61% of the variance in gravity anomaly due to GWS, precipitation, and evapotranspiration. This study investigates climate change factors—precipitation, temperature, and evapotranspiration—providing a holistic understanding of the forces shaping GWS variations. Precipitation and evapotranspiration exhibit nearly equal values, limiting GWS replenishment opportunities. This research holds significance in studying extensive GWS withdrawal in the Arabian Peninsula, particularly concerning crust mass stability.
Densification of network base stations is indispensable to achieve the stringent Quality of Service (QoS) requirements of future mobile networks. However, with a dense deployment of transmitters, ...interference management becomes an arduous task. To solve this issue, exploring radically new network architectures with intelligent coordination and cooperation capabilities is crucial. This survey paper investigates the emerging user-centric cell-free massive Multiple-input multiple-output (MIMO) network architecture that sets a foundation for future mobile networks. Such networks use a dense deployment of distributed units (DUs) to serve users; the crucial difference from the traditional cellular paradigm is that a specific serving cluster of DUs is defined for each user. This framework provides macro diversity, power efficiency, interference management, and robust connectivity. Most importantly, the user-centric approach eliminates cell edges, thus contributing to uniform coverage and performance for users across the network area. We present here a guide to the key challenges facing the deployment of this network scheme and contemplate the solutions being proposed for the main bottlenecks facing cell-free communications. Specifically, we survey the literature targeting the fronthaul, then we scan the details of the channel estimation required, resource allocation, delay, and scalability issues. Furthermore, we highlight some technologies that can provide a management platform for this scheme such as distributed software-defined network (SDN). Our article serves as a check point that delineates the current status and indicates future directions for this area in a comprehensive manner.
Introduction
Surgical closure of sinus venosus atrial septal defect (SVASD) is the standard management. A safe and effective transcatheter approach will be an attractive option.
Objectives
To assess ...the feasibility and long‐term safety of transcatheter closure of SVASD with anomalous pulmonary venous drainage.
Patients and methods
From July 2011 to October 2013, four patients with large SVASD and anomalous right upper pulmonary venous (RUPV) drainage underwent transcatheter closure of their defects at Ibn‐Albitar Center for Cardiac Surgery, Baghdad, Iraq. Two patients with superior vena cava (SVC)‐type SVASD underwent closure using covered Cheatham‐Platinum (CP) stents with no need for septal occluder. The other two patients had large RA‐type SVASD who underwent closure using covered CP stents only in one patient and stents and device in the other one. An angiogram in the RUPV during balloon inflation in the SVC was done to ensure that the RUPV drains back to the left atrium. The covered CP stent was mounted and hand crimped onto Z‐Med™ or BIB‐balloon catheters and deployed in the desired location under transesophageal echocardiography guidance.
Results
The two patients with SVC‐type SVASD underwent successful closure using two overlapping covered CP stents implanted in the SVC, thus creating total septation between the SVC and the RUPV. The RA‐type SVASD patients underwent closure using two overlapping covered CP stents. One with mild to moderate residual shunt that completely disappeared at 12 months follow‐up after implantation of a second 45 mm CP stent. A significant residual shunt in the second patient was closed successfully using a PFO device.
Conclusion
Transcatheter closure of SVASD through SVC stent insertion with or without subsequent device implantation is feasible and effective.
Hydroxytyrosol (HYT) is one of the main alcoholic compounds of the olive leaves extract (OLE), which is known for its beneficial effects. This study aimed to investigate the effectiveness of olive ...leaves extract standardized with 25% hydroxytyrosol (OLES-25%HYT) in treatment of induced ulcerative colitis. Three groups of albino rats, were divided as following, group 1 (normal control), group 2 (induced ulcerative colitis and untreated) and group 3 (induced ulcerative colitis and treated with OLES-25%HYT). Colonic tissue samples were collected from all studied groups, the antioxidant activity for malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), myeloperoxidase (MPO) and nitric oxide (NO) were performed. The expression of pro-inflammatory cytokines, the apoptotic gene Bax and the anti-apoptotic gene Bcl2 was obtained in colon tissue to evaluate the OLES-25%HYT effect on ulcerative colitis. OLES-25%HYT showed effectiveness on reduction of mortality rate and disease activity index (DAI). Also, reduced oxidative stress and inflammation in colon tissue, OLES-25%HYT showed a significant reduction in colon MDA, MPO and NO levels and a significant elevation in SOD, CAT and GPX levels and cause down regulation of pro-inflammatory cytokines. Also, the apoptotic gene Bax downregulated and the anti-apoptotic gene Bcl2 upregulated as a result of the treatment compared to untreated induced ulcerative colitis group. OLES-25%HYT showed intestinal anti-inflammatory, antioxidants and anti-apoptotic effects in experimental models of ulcerative colitis.
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•Ulcerative colitis consider one of the major inflammatory bowel disease.•Hydroxytyrosol is a phenolic alcohol, with wide range of biological effects•Hydroxytyrosol ameliorate oxidative biomarkers in ulcerative colitis•Hydroxytyrosol reduce inflammatory biomarkers in ulcerative colitis
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