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An economic model generally describes the mechanisms used to generate revenue from a business. If it fails to generate income, its failure is inevitable. Therefore, decisions regarding missions are not based solely on technical specifications; economic profitability is also a crucial factor in decision-making and is a primary consideration for commercial investments. This consideration becomes particularly important in high-cost, long-duration projects, such as space missions, where the return on investment and economic justification are more complex. Lunar mining projects are no exception and require a comprehensive financial and technical feasibility assessment approach.To analyze the economic feasibility of any project, it is essential to evaluate its economic model. This paper conducts an economic valuation of lunar mining, focusing on materials available on the Moon, using fuzzy analysis and sensitivity analysis to identify suitable materials for exploitation. The materials are categorized into oxides, metals, and fuels. Using an appropriate economic model for space mining, the study evaluates the economic potential of selling these materials on Earth.Based on the economic feasibility analysis, each group identifies SiO₂, Mg, and helium-3 (3He) as high-priority materials. SiO₂ and Mg are expected to be profitable in conservative scenarios with increased mission duration and frequency. In optimistic scenarios, all three materials could be profitable. Ultimately, SiO₂ is selected as the target material for lunar mining.

Study Design Observational study. Purpose Investigation of factors related to proximal junctional kyphosis (PJK) and device failure in patients with early-onset scoliosis. Overview of Literature The use of growth-friendly devices, such as traditional dual growing rod (TDGR) for the treatment of early-onset scoliosis (EOS), may be associated with important complications, including PJK and device failure. Methods Thirty-five patients with EOS and treated with TDGR from 2014 to 2021 with a minimum follow-up of 2 years were retrospectively evaluated. Potential risk factors, including demographic factors, disease etiology, radiological measurements, and surgical characteristics, were assessed. Results PJK was observed in 19 patients (54.3%), and seven patients (20%) had device failure. PJK was significantly associated with global final kyphosis change (p=0.012). No significant correlation was found between the rod angle contour, type of implant, connector design, and the risk of PJK or device failure. Conclusions Treatment of EOS with TDGR is associated with high rates of complications, particularly PJK and device failure. The device type may not correlate with the risk of PJK and device failure. The progression of thoracic kyphosis during multiple distractions is an important risk factor for PJK.

This paper presents design, analytical modeling and optimization of a 55 watts, 3000 rpm surface mounted permanent magnet (SPM) machine with cubical permanent magnets (PMs) for the cooling fan application. First, the size/dimensions of the motor are laid out at the design stage to meet the specifications (e.g., rated power, speed) of the target application. Next, general performance characteristics of the designed machine are analytically predicted using a two-dimensional (2-D) hybrid analytical model. The hybrid model is composed of (i) solving Maxwell equations on a hypothetical slotless structure, and (ii) virtual magnetizing current to account for the stator slotting effects. Due to the lack of cylindrical symmetry of the given structure with cubical-shape PMs, the PM region is divided into a number of smaller segments and the calculations are carried out discretely per PM segment as opposed to the standard practice of considering the entire PM region as one subdomain. Next, the machine structure is optimized simultaneously mitigate the torque ripple and boost the torque density. The laboratory prototype of the motor is fabricated and tested to further validate the analytical model as well as the functionality of the designed motor.

Abstract The authors present a new design of a PM‐assisted synchronous reluctance motor (PM‐SynRM) with uneven air‐gap length to improve the power factor and enhance the torque production capability. The rotor structure is modified to properly shift rotor magnetic poles and therefore (i) increases the back‐EMF and the electromagnetic torque, (ii) allows electromagnetic torque and reluctance torque components peak near the same current phase angle. The proposed solution is simple, does not require changing the arrangement of magnets and/or flux barriers and is applicable to all types of PM‐SynRMs. Sensitivity analysis is carried out to determine the extent of which the proposed magnetic pole shifting may impact the resultant torque profile. To assess the level of success, the electromagnetic characteristics of the proposed design (e.g. torque, power factor, and back‐EMF) are compared against the baseline structure under the same operating conditions. For verification purposes, Finite Element simulation results are validated via a series of analytical calculations and experimental measurements, and supported with detailed theoretical discussion.

In this paper, we present a new class of linear fractional differential operators that are based on classical Gaussian hypergeometric functions. Then, we utilize the new operators and the concept of differential subordination to construct a convex set of analytic functions. Moreover, through an examination of a certain operator, we establish several notable results related to differential subordination. In addition, we derive inclusion relation results by employing Briot–Bouquet differential subordinations. We also introduce a perspective study for developing subordination results using Gaussian hypergeometric functions and provide certain properties for further research in complex dynamical systems.

In this paper, by using Poisson distribution probability, some characteristics of analytic multivalent q-symmetric starlike and q-symmetric convex functions of order η are examined. Then, by utilizing the Poisson distribution and the concept of the q-analogue Salagean integral operator, the p-valent convergence polynomial was introduced. Furthermore, a number of subclasses of analytic symmetric p-valent functions linked to novel polynomials are also deduced. After that, specific coefficient constraints are determined and symmetric δ,q-neighborhoods for p-valent functions are defined. In relation to symmetric δ,q-neighborhoods of q-symmetric p-valent functions formed by Poisson distributions, this paper presents new inclusion results. In addition, a detailed discussion of certain q-symmetric inequalities of analytic functions with negative coefficients is also provided.

In this paper, we employ a q-Noor integral operator to perform a q-analogue of certain fractional integral operator defined on an open unit disc. Then, we make use of the Hadamard convolution product to discuss several related results. Also, we derive a class of convex functions by utilizing the q-fractional integral operator and apply the inspired presented theory of the differential subordination, to geometrically explore the most popular differential subordination properties of the aforementioned operator. In addition, we discuss an exciting inclusion for the given convex class of functions. Over and above, we investigate the q-fractional integral operator and obtain some applications for the differential subordination.

Improving the use of platinum in propane dehydrogenation catalysts is a crucial aspect to increasing the efficiency and sustainability of propylene production. A known and practiced strategy involves incorporating more abundant metals in supported platinum catalysts, increasing its activity and stability while decreasing the overall loading. Here, using colloidal techniques to control the size and composition of the active phase, we show that Pt/Cu alloy nanoparticles supported on alumina (Pt/Cu/Al 2 O 3 ) displayed elevated rates for propane dehydrogenation at low temperature compared to a monometallic Pt/Al 2 O 3 catalyst. We demonstrate that the enhanced catalytic activity is correlated with a higher surface Cu content and formation of a Pt-rich core and Cu-rich shell that isolates Pt sites and increases their intrinsic activity. However, rates declined on stream because of dynamic metal diffusion processes that led to a more uniform alloy structure. This transformation was only partially inhibited by adding excess hydrogen to the feed stream. Instead, cobalt was introduced to provide trimetallic Pt/Cu/Co catalysts with stabilized surface structure and stable activity and higher rates than the original Pt/Cu system. The structure-activity relationship insights in this work offer improved knowledge of propane dehydrogenation catalyst development featuring reduced Pt loadings and notable thermal stability for propylene production.

Chronic kidney disease-associated pruritus (CKD-aP) represents a common distressing problem in patients with end-stage renal disease. This study aimed to assess the efficacy and safety of omega-3 supplementation in the treatment of CKD-aP. MEDLINE/PubMed, Cochrane Central Register of Controlled Trials, Web of Science, ProQuest, and Scopus databases were searched systematically for articles published from inception until May 21, 2024. Outcomes were pruritus severity at the end of the study or its change from baseline (primary) and intervention-related adverse effects (secondary). Results were pooled as standardized mean difference (SMD) and risk ratio (RR) for numeric and dichotomous outcomes, respectively, along with their 95% confidence intervals (CIs). Eight studies were included. Treatment with omega-3 fatty acids showed a significantly lower severity of CKD-aP at the end of treatment (pooled SMD (95% CI) = -1.03 (-1.85, -0.22), p = 0.024) and changed from baseline (pooled SMD (95% CI) = -0.93 (-1.57, -0.28), p = 0.014). Omega-3 supplementation reduced the risk of CKD-aP (pooled RR (95% CI) = 0.68 (0.12, 3.81), p = 0.661). Omega-3 fatty acid supplementation appears to be a promising effective and safe treatment for CKD-aP. However, the included studies had several limitations that warrant further high-quality studies to elucidate its effect and investigate the causes of non-response in patients who did not improve., Competing Interests: Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Alqahtani et al.)

Improper pesticide handling is the main cause of contamination of the environment in agricultural systems. This could be caused by leakage of spraying liquid, leftovers, and inappropriate washing of spraying equipment. This study assessed the ability of suggested biomixture modules for remediate repetitive cycles of high chlorpyrifos doses. In three consecutive treatments, four tested modules were contaminated with 160 µg g -1 chlorpyrifos. Chlorpyrifos residues, dehydrogenase activity, and microbial respiration were continuously monitored for 22 weeks. Six bacterial consortia were isolated at the end of the experiment from four treated modules (B +3 , BF +3 , S +3 , and SF +3 ) and two from untreated modules (B and S). The isolated consortium efficiency in degrading chlorpyrifos was studied. The results revealed that the best chlorpyrifos removal efficiency was achieved when using the stimulated biomixture module (BF) recorded 98%, 100%, and 89%, at the end of three chlorpyrifos treatments, respectively. Such removal efficiency was compatible with the biological activity results of the tested modules: dehydrogenase activity and microbial respiration. There was no difference in the efficiency among the S, B, and BF +3 consortia. The results presented here demonstrate that the combination of vermicompost, wheat straw, soil, and NPK (stimulated biomixture module) can successfully reduce the risk of a point source of pesticide pollution., (© 2024. The Author(s).)

Tailoring nanoscale catalysts to targeted applications is a vital component in reducing the carbon footprint of industrial processes; however, understanding and controlling the nanostructure influence on catalysts is challenging. Molybdenum disulfide (MoS 2 ), a transition metal dichalcogenide (TMD) material, is a popular example of a nonplatinum-group-metal catalyst with tunable nanoscale properties. Doping with transition metal atoms, such as cobalt, is one method of enhancing its catalytic properties. However, the location and influence of dopant atoms on catalyst behavior are poorly understood. To investigate this knowledge gap, we studied the influence of Co dopants in MoS 2 nanosheets on catalytic hydrodesulfurization (HDS) through a well-controlled, ligand-directed, tunable colloidal doping approach. X-ray absorption spectroscopy and density functional theory calculations revealed the nonmonotonous relationship between dopant concentration, location, and activity in HDS. Catalyst activity peaked at 21% Co:Mo as Co saturates the edge sites and begins basal plane doping. While Co prefers to dope the edges over basal sites, basal Co atoms are demonstrably more catalytically active than edge Co. These findings provide insight into the hydrogenolysis behavior of doped TMDs and can be extended to other TMD materials., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Vanadium redox flow batteries (VRFBs) have emerged as promising solutions for stationary grid energy storage due to their high efficiency, scalability, safety, near room-temperature operation conditions, and the ability to independently size power and energy capacities. The performance of VRFBs heavily relies on the redox couple reactions of V 2+ /V 3+ and VO 2+ /VO 2 + on carbon electrodes. Therefore, a thorough understanding of the surface functionality of carbon electrodes and their propensity for degradation during electrochemical cycles is crucial for designing VRFBs with extended lifespans. In this study, we present a coupled experimental-theoretical approach based on carbon K edge X-ray absorption spectroscopy (XAS) to characterize carbon electrodes prepared under different conditions and identify relevant functional groups that contribute to unique spectroscopic features. Atomic models were created to represent functional groups, such as hydroxyl, carboxyl, methyl, and aldehyde, bonded to carbon atoms in either sp 2 or sp 3 environments. The interactions between functionalized carbon and various solvated vanadium complexes were modeled using density functional theory. A library of carbon K-edge XAS spectra was generated for distinct carbon atoms in different functional groups, both before and after interacting with solvated vanadium complexes. We demonstrate how these simulated spectra can be used to deconvolve ex situ experimental spectra measured from carbon electrodes and to track changes in the electrode composition following immersion in different electrolytes or extended cycling within a functional VRFB. By doing so, we identify the active species present on the carbon electrodes, which play a crucial role in determining their electrochemical performance.