Design and Microwave-Assisted Synthesis of TiO2-Lanthanides Systems and Evaluation of Photocatalytic Activity under UV-LED Light Irradiation

The TiO2-Eu and TiO2-La systems were successfully synthesized using the microwave method. Based on the results of X-ray diffraction analysis, it was found that regardless of the analyzed systems, two crystal structures were noted for the obtained samples: anatase and rutile. The analysis, such as XPS and EDS, proved that the doped lanthanum and europium nano-particles are present only on the TiO2 surface without disturbing the crystal lattice. In the synthesized systems, there were no significant changes in the bandgap energy. Moreover, all the obtained systems were characterized by high thermal stability. One of the key objectives of the work, and a scientific novelty, was the introduction of UV-LED lamps into the metronidazole photo-oxidation pathway. The results of the photo-oxidation study showed that the obtained TiO2 systems doped with selected lanthanides (Eu or La) show high efficiency in the removal of metronidazole, and at the same consuming nearly 10 times less electricity compared to conventional UV lamps (high-pressure mercury lamp). Liquid-chromatography mass-spectrometry (LC-MS) analysis of an intermediate solution showed the presence of fragments of the degraded molecule by m/z 114, 83, and 60, prompting the formulation of a plausible photodegradation pathway for metronidazole.

Induction Motor PI Observer with Reduced-Order Integrating Unit

This article presents an innovative induction motor state observer designed to reconstruct magnetic fluxes and the angular speed of an induction motor for speed sensorless control system applications such as field-oriented control (FOC). This observer is an intermediate solution between the proportional observer and the classical proportional-integral (PI) observer with respect to which the order of the integrating unit is reduced. Additional modifications of the observer’s structure have been implemented to ensure stability and to improve its functional properties. As a result, two versions of the observer structure were produced and experimentally tested using a sensorless FOC control system. Both structures resulted in correct control system operation for a wide range of angular speeds, including low speed ranges.

Intermediate class of warm pseudoscalar inflation

High dissipative regime of warm pseudoscalar inflation model (Kamali in Phys Rev D 100:043520, arXiv:1901.01897 [gr-qc], 2019) with an approximately constant value of dissipation parameter Q is studied. Intermediate solution of the scale-factor related to the accelerated expansion of the Universe which is rolled out by observational data in the context of standard (cold) model of inflation is used. There is a region of free parameters phase-space of the model which is interestingly compatible with recent observational data. It is discussed that the model is also compatible with the swampland criteria in a broad range of parameters phase-space and TCC in a limited area of parameters.

First Deployment of Motorized Casing Reamer Shoe in Abu Dhabi Offshore

The paper will describe a novel approach of deploying casing through a problematic open hole. It involves a drillable hydraulic motorized casing reamer shoe that can rotate freely without aid of pumping, but once resistance is encountered, pump pressure can then be applied to engage the drive mechanism inside the tool. Thus it will turn into a high-speed reaming shoe that delivers sufficient reaming action. A market research was done to find a quick intermediate solution to tackle difficulty in deploying casing down to section TD. A turbine based motorized reamer shoe was then selected to encounter the challenge with some risk mitigation in place. The first deployment was run in the well where it was identified as a challenging well context and had experienced casing being held up in the first run. Despite the fact that a wiper trip has smoothened the hole condition, the parameters that were captured during the running, the finger printing, the cementing job, and the drilling out of the shoe had ticked some boxes to evaluate the suitability of the technology implementation in the field. Moreover, the lessons learned from the first run itself has also led to further testing and modification of the tool design/setup itself. The detailed analysis and operation feedback from casing running job and subsequent operation will be beneficial to provide other operators in assessing the minimum requirement and suitability of this technology utilization to overcome the drilling challenge.

Guided Visibility Sampling++

Visibility computation is a common problem in the field of computer graphics. Examples include occlusion culling, where parts of the scene are culled away, or global illumination simulations, which are based on the mutual visibility of pairs of points to calculate lighting. In this paper, an aggressive from-region visibility technique called Guided Visibility Sampling++ (GVS++) is presented. The proposed technique improves the Guided Visibility Sampling algorithm through improved sampling strategies, thus achieving low error rates on various scenes, and being over four orders of magnitude faster than the original CPU-based Guided Visibility Sampling implementation. We present sampling strategies that adaptively compute sample locations and use ray casting to determine a set of triangles visible from a flat or volumetric rectangular region in space. This set is called a potentially visible set (PVS). Based on initial random sampling, subsequent exploration phases progressively grow an intermediate solution. A termination criterion is used to terminate the PVS search. A modern implementation using the Vulkan graphics API and RTX ray tracing is discussed. Furthermore, we show optimizations that allow for an implementation that is over 20 times faster than a naive implementation.

Optical Packet and Burst-Switched Networks

In order to address poor bandwidth-utilization in circuit-switched WRONs, various techniques for optical packet-switching (OPS) have been explored, but needing complex technologies, such as real-time header extraction/insertion, packet alignment, etc. An intermediate solution between the WRONs and OPS networks – the optical burst-switched (OBS) network – has been explored, where several packets are clubbed together at ingress nodes to form optical bursts, which are transmitted with the headers sent as control packets ahead of each bursts. With this prior resource-reservation scheme at en-route nodes before burst arrivals, OBS networks overcome the challenges of OPS networks, while improving bandwidth utilization as compared to WRONs. We first present the node architectures, followed by header-processing schemes and switch designs for OPS networks. Next we present the basic concepts of OBS networking and describe the necessary network protocols, including burst assembly scheme, just enough time (JET) signaling, resource-reservation and routing schemes. (145 words)

A fixed-point approach for decaying solutions of difference equations

A boundary value problem associated with the difference equation with advanced argument * Δ ( a n Φ ( Δ x n ) ) + b n Φ ( x n + p ) = 0 , n ≥ 1 is presented, where Φ ( u ) = | u | α sgn u , α > 0, p is a positive integer and the sequences a , b , are positive. We deal with a particular type of decaying solution of (*), that is the so-called intermediate solution (see below for the definition). In particular, we prove the existence of this type of solution for (*) by reducing it to a suitable boundary value problem associated with a difference equation without deviating argument. Our approach is based on a fixed-point result for difference equations, which originates from existing ones stated in the continuous case. Some examples and suggestions for future research complete the paper. This article is part of the theme issue ‘Topological degree and fixed point theories in differential and difference equations’.

A Model for Creating Interactive eBooks for eLearning

In recent decades, electronic books have revolutionized the publishing world. In this sense, an area of application is education, where electronic books can be used as educational resources to implement learning strategies about content and in eLearning environments. For this, it is necessary to introduce interactive elements in the electronic books that turn the reader into an active actor in the reading process. However, ebooks have a limitation regarding their creation process. In this sense, the tools can be user-oriented or programmer-oriented. The former are intuitive to use and have user-friendly interfaces, but they offer a reduced number of functionalities to add to books. The second are aimed at programmers, allowing for the implementation of any functionality, but limiting the number of content creators who can use them. The main motivation of this work is to propose an intermediate solution that offers a wide number of functionalities while not requiring deep programming knowledge to use them. In this sense, the solution of this article is novel since it proposes the use of extensible markup language (XML) documents to specify the structure of the electronic book in such a way that its processing will lead to the electronic book.

Initial tightening of a cylinder head assembly on a marine engine block

When attaching the cylinder head to the engine block, to internal combustion engines, the force with which the mounting screws are tightened is of particular importance (in case of too tight a tightening the screws may break, and in the case of too small tightening the fluid may leave the container due to removal. the flanges one to the other). In the case of slow, high-power engines, the engine block is individual, containing a single cylinder shirt. The intermediate solution of the engine block for a group of cylinders is also used. The two-stroke engine chops are more strongly heat demanded, due to the doubling of the number of cycles in the unit of time, respectively by combustion processes in the unit of time. Requesting the cylinder head bolts and other components of the assembly by force due to the pressure developed during the process of gas exchange and combustion in the engine cylinders is a demand with a pulsating character.

Critical Tension: Sufficiency and Parsimony in QCA

The main objective of the qualitative comparative analysis is to find solutions that display sufficient configurations of causal conditions leading to the presence of an outcome. These solutions should be less complex than the original observed configurations, as parsimonious as possible, without sacrificing the sufficiency requirement. Sufficiency and parsimony are two requirements that act in opposition, and an optimal solution is one that accommodates both. There are different search strategies that lead to different types of solutions, with an ongoing debate about which solution type is closest to the true, underlying causal structure. This article presents the different logics behind each simplification system in order to explain how and why they lead to different results and introduces the concept of “robust sufficiency” to clear the debate. It analyses the correctness ratios for the different solution type and provides an improved set of procedures to measure correctness that captures the best features from each system. Out of the competition between the conservative and the parsimonious search strategies, the intermediate solution emerges as the best hybrid that is suitable for causal analysis, outperforming the parsimonious solution in recovering a known (even parsimonious) causal structure.