The OCaml programming language finds application across diverse domains, including systems programming, web development, scientific computing, formal verification, and symbolic mathematics. OCaml is a memory-safe prog...
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The OCaml programming language finds application across diverse domains, including systems programming, web development, scientific computing, formal verification, and symbolic mathematics. OCaml is a memory-safe programming language that uses a garbage collector (GC) to free unreachable memory. It features a low-latency, high-performance GC, tuned for functional programming. The GC has two generations-a minor heap collected using a copying collector and a major heap collected using an incremental mark-and-sweep collector. Alongside the intricacies of an efficient GC design, OCaml compiler uses efficient object representations for some object classes, such as interior pointers for supporting mutually recursive functions, which further complicates the GC design. The GC is a critical component of the OCaml runtime system, and its correctness is essential for the safety of OCaml programs. In this paper, we propose a strategy for crafting a correct, proof-oriented GC from scratch, designed to evolve over time with additional language features. Our approach neatly separates abstract GC correctness from OCaml-specific GC correctness, offering the ability to integrate further GC optimizations, while preserving core abstract GC correctness. As an initial step to demonstrate the viability of our approach, we have developed a verified stop-the-world mark-and-sweep GC for OCaml. The approach is fully mechanized in f* and its low-level subset Low*. We use the KaRaMel compiler to compile Low* to C, and integrate the verified GC with the OCaml runtime. Our GC is evaluated against off-the-shelf OCaml GC and Boehm-Demers-Weiser conservative GC, and the experimental results show that verified OCaml GC is competitive with the standard OCaml GC.
The cellular-Lindel & ouml;f property is a common generalization of the Lindel & ouml;f property and the countable chain condition that was introduced by Bella and Spadaro [Monatsh. Math. 186 (2018), pp. 345-3...
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The cellular-Lindel & ouml;f property is a common generalization of the Lindel & ouml;f property and the countable chain condition that was introduced by Bella and Spadaro [Monatsh. Math. 186 (2018), pp. 345-353]. We solve two questions of Alas, Gutierrez-Dom & imath;nguez and Wilson [Acta Math. Hungar. 167 (2022), pp 548-560] by constructing consistent examples of a normal almost cellular-Lindel & ouml;f space which is neither cellular-Lindel & ouml;f nor weakly Lindel & ouml;f and a Tychonoff cellular-Lindel & ouml;f space of Lindel & ouml;f degree co1 and uncountable weak Lindel & ouml;f degree for closed sets. We also construct a ZfC example of a space for which both the almost cellular-Lindel & ouml;f property and normality are undetermined in ZfC.
Although the work of G.f.C. Griss is commonly understood as a program of negationless mathematics, close examination of Griss's work suggests a more fundamental feature is its executability, a requirement that men...
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Although the work of G.f.C. Griss is commonly understood as a program of negationless mathematics, close examination of Griss's work suggests a more fundamental feature is its executability, a requirement that mental constructions are possible only if corresponding mental activity can be actively carried out. Emphasizing executability reveals that Griss's arguments against negation leave open several types of negation-including D. Nelson's strong negation-as compatible with Griss's intuitionism. Reinterpreting Griss's program as one of executable mathematics, we iteratively develop a pair of bilateral constructive logics and argue for their adequacy as accounts of the propositional basis of Griss's work. We conclude by observing connexive features exhibited by the two bilateral logics and by investigating the difficulties connexive principles reveal for the development of executable mathematics.
The minimum (S/f)min and maximum (S/f)max solvent-to-feed ratios with their respective number of stages are essential in designing countercurrent solvent extraction processes, as they define the operating limits of th...
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The minimum (S/f)min and maximum (S/f)max solvent-to-feed ratios with their respective number of stages are essential in designing countercurrent solvent extraction processes, as they define the operating limits of the separation task. The (S/f)min is typically asso-ciated with an infinite number of stages, and the common state-of-the-art method to graphically determine it for ternary systems depends on finding the limiting tie line that passes through a known feed composition. However, the method applicability ceases when solute concentration in the feed is high enough so that no limiting tie lines exist anymore. This work comes to extend for the first time the said method beyond its validity region to cover feed compositions for which it fails. To support the presented theory, rigorous simulations are performed that clearly show the typical asymptotic behavior at infinite stages when the graphical (S/f)min is approached. for (S/f)max, although it is as-sociated in literature with one required stage, it is not clear how this applies and whether the term "stage" is even applicable. By discussing it from different perspectives, this work shows how the corresponding minimum stages can be obtained and that they can be different from one. The latter is also supported by simulations.(c) 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
In this paper, we presented a numerical study of a CdS/Sb2Se3 mono junction solar cell (SC) using the SC Capacitive Simulator (SCAPS-1D). We validated an experimental work using a variety of Sb2Se3 experimental parame...
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In this paper, we presented a numerical study of a CdS/Sb2Se3 mono junction solar cell (SC) using the SC Capacitive Simulator (SCAPS-1D). We validated an experimental work using a variety of Sb2Se3 experimental parameters, and the results showed excellent agreement between numerical and experimental J-V curves, yielding a PCE of 7.54%.To continue, we analyzed the impact of Sb2Se3 thin layer thickness, charge carrier concentration, bulk defect density, and interface defect (CdS/Sb2Se3) on solar cell characteristics. With the optimum Sb2Se3 layer thickness of 1.2 mu m, carrier concentration of 10(15) cm(-3), bulk defect of 10(13) cm(-3), and CdS/Sb2Se3 interface defect densities of 10(10) cm(-2), we were able to attain an efficiency of 16.62%, Jsc = 35.38 mA/cm(2), Voc = 0.66 V, and ff = 70.33%. finally, we investigated the insertion effect of n-GaAs (ETL) and P+-CuO HTL (BSf) on Sb2Se3 solar cell efficiency. The novel ITO/n-CdS/n-GaAs/p-Sb2Se3/p(+)-CuO HTL/Au heterostructure achieved a huge efficiency of 19.60%.
Citrus limon (lemon) possesses immunoregulatory, antioxidant, and lipid-lowering effects. Our previous study showed that lemon fermented products (LfP) which were lemon fermented with Lactobacillus OPC1 had the abilit...
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Citrus limon (lemon) possesses immunoregulatory, antioxidant, and lipid-lowering effects. Our previous study showed that lemon fermented products (LfP) which were lemon fermented with Lactobacillus OPC1 had the ability to avert obesity. However, the LfP effects on the pathway of lipid metabolism by gut microbiota were still unclear. This study was aimed to investigate the LfP effects on liver lipid metabolism and gut microbiota in a rat model of obesity caused by a high-calorie diet. LfP effectively reduced the total triglyceride (49.7%) and total cholesterol (53.3%) contents of the liver. Additionally, the mRNA levels of genes related to triglyceride metabolism (SREBP-1c, PPAR gamma, and ACC), cholesterol metabolism (HMG-CoA reductase, ACAT, and LCAT), and lipid beta-oxidation (PPAR alpha, and CPT-1) were regulated by LfP. furthermore, LfP reduced the ratio offirmicutes/Bacteroidetes and enhanced the ratio offirmicutes Clostridia. Overall, these findings suggested that LfP might use as a potential dietary supplement for preventing obesity by modulating the lipid metabolism and improving the gut microbiota.
Antioxidant properties of essential oils (EOs) depend on environmental, genetic and other factors. We hypothesized that the EOs of rosemary (Rosmarinus officinalis), lavender (Lavendula sublepoidota) and ferulago cont...
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Antioxidant properties of essential oils (EOs) depend on environmental, genetic and other factors. We hypothesized that the EOs of rosemary (Rosmarinus officinalis), lavender (Lavendula sublepoidota) and ferulago contracta may be affected by distillation methods. This study investigated the effects of hydrodistillation (HD) and steam distillation (SD) on bioactive compounds yield, total phenol content (TPC), total flavonoid content (TfC), and antioxidant property of rosemary, lavender and f. contracta EOs. Results showed that the yield of EO in SD was significantly higher than HD (p < 0.05). Thumbnail (11.28%;10.71%) and Eucalyptol (9.48%;12.58%) in rosemary EO, Eucalyptol (25.9%;22.7), Borneol (12.43%;14.09%) and Camphor (9.61%;5.76%) in lavender EO, and Thumbnail (15.37%;9.98%), bornyl ester (13.42%;14.32%), trans-beta-Ocimene (11.52%;6.78%) and Limonene (8.93%;3.34%) (in HD and SD respectively) known as the principal components in f. contracta. In rosemary, f. contracta and lavender EOs TfC, TPC, and antioxidant activity obtained by SD significantly higher than HD method (p < 0.05). Among the distillation methods studied, SD was the best method for the EO extraction while keeping the highest yield, TPC, TfC and antioxidant activity. Overall, the findings revealed that the type of distillation has a substantial impact on the EO performance, composition, and antioxidant capability.
This paper studies the stability for impulsive dynamical networks (IDN) where different nodes may have different impulse time sequences. By deriving the conditions of global uniform exponential stability for zero-orde...
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This paper studies the stability for impulsive dynamical networks (IDN) where different nodes may have different impulse time sequences. By deriving the conditions of global uniform exponential stability for zero-order delayed systems, the criteria of stability for IDN are established. The stability results for IDN are then used to design event-triggered impulsive control (ETIC) for stabilization of continuous-time dynamical networks (CDN). In every node of CDN, three levels of event-triggering conditions are set for ETIC. The ex-ponential stabilization of CDN is shown to be achieved by the designed ETIC and it also shows that the ETIC is robust w.r.t. time-delays. Moreover, a non-instantaneous ETIC (NI-ETIC) is proposed for the stabilization of CDN. Three examples with numerical simulations are given to show that the designed ETIC has lower impulse frequency and cost of control than the classic time-triggered impulsive control. It is also shown that the discontinuity and the instantanity of ETIC are improved by the NI-ETIC.(c) 2023 Elsevier Inc. All rights reserved.
It has been shown that for obtaining hydrophobic coatings, it is reasonable to use fluoroalkylalkoxysilanes (fASs) with a longer fluoroalkyl chain than fAS-19, so that the f/Si molar ratio exceeds 5-6. It is proposed ...
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It has been shown that for obtaining hydrophobic coatings, it is reasonable to use fluoroalkylalkoxysilanes (fASs) with a longer fluoroalkyl chain than fAS-19, so that the f/Si molar ratio exceeds 5-6. It is proposed to purposefully change not only the chain length of oligomers, but also the structure of solutions from dilute colloidal solutions to structured gels, with the f/Si ratio being controlled. In the case of polycondensation of investigated fluoroalkylalkoxysilanes on a hydroxylated surface, a strong silicone framework is formed, which is chemically bonded to the surface and to fluoroalkyl chains oriented perpendicular to it.
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