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1

Framework for additive manufacturing workflow in the marine industry: Practical case study of ordering 3D printed parts from a design office

Sawa Agnieszka

Zeszyty Naukowe Politechniki Morskiej w Szczecinie

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2025

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nr 83 (155)

51--62

EN

Additive manufacturing technology, a relatively new and dynamically evolving field, is increasingly used in a variety of manufacturing applications. On ships operated for a long period of time, where some parts are no longer manufactured, additive technology offers a forward-looking solution for the rapid and efficient reproduction of necessary components. This paper proposes a standardized operational workflow for managing requests and orders for 3D-printed components in the maritime industry, designed to address the unique challenges faced by vessels operating in remote locations. A case study involving the reconstruction of a fastening component within the control cabinet of a ship’s safety and RPM switch unit system demonstrates the practicality of this approach. The part is successfully reproduced using a standardized workflow, which began with the collection of photographs and measurements from the ship’s crew. This data enabled the creation of a precise 3D model and the subsequent production of 180 components made from PET-G material, selected for its durability and suitability for the intended application. The standardized workflow developed in this study minimized errors, reduced processing times, and ensured that the reproduced part met operational requirements. By establishing a scalable and adaptable framework for communication between the ship’s crew, engineers, and manufacturing facilities, the workflow highlights the transformative capability of additive technologies as a practical solution for the immediate needs of modern shipping operations.

2

Use of graphene oxide as an active layer on a tapered fibre for detection of volatile liquid vapours : ammonium hydroxide, trimethyl phosphate, and 1,4-thioxane

Krawczyk Julian, Korec-Kosturek Joanna, Kosturek Rafał, Jakubowska Iwona, Pakuła Anna, Djas Małgorzata, Kowiorski Krystian, Stasiewicz Karol A.

Opto-Electronics Review

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2025

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Vol. 33, No. 2

art. no. e154305

EN

This paper investigates the application of a G-Flake graphene oxide (GO) layer as an innovative coating material for optical fibre tapers, enhancing the sensor sensitivity to various volatile liquid vapours. The results confirm that this combination is effective because the formation of a monolayer of adsorbed gas alters light propagation in the tapered optical fibre. These changes are detectable across a broad wavelength spectrum, ranging from visible to infrared. In this study, three volatile liquids - trimethyl phosphate (TMP), 1,4-thioxane (THX), and ammonium hydroxide (NH₄OH) - were tested using pure THX and TMP without dilution, while NH₄OH was applied as a 25% solution. The gases used in the research simulate chemical warfare agents, such as sulphur mustard and sarin. The authors used the differential method to analyse the results, which revealed the formation of characteristic peak pairs around a wavelength of 795 nm. The peak heights and the distance between them varied over time in response to exposure to the selected vapours. Additionally, the amplitude of the transmitted power changes linearly in the first 30-45 min, with the highest power change rate observed for TMP (0.026 dBm/min at 789.2 nm). The greatest contrast between maximum and minimum power levels was observed for TMP, reaching 4.45 dBm. An approach was presented that demonstrates how a tapered fibre covered with GO can be used as the basis for developing a low-cost gas and vapour sensor.

3

Enhancing mobility with knee orthoses: Design considerations and patient needs through case study

Kahtan Yassr Y., Kubba Ammar Issam, Hasan Hala Salman, Ismail Mahmud Rasheed, Mohammed Noor B.

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 6

108--120

EN

Knee orthoses are critical in many conditions from pain due to arthritis to knee instability during sports. However, there are very serious challenges regarding usability, comfort, and aesthetics in designing knee orthoses. This paper takes a design approach for the knee orthosis specifically targeted toward arthritis patients and young athletes. From these requirements, it became imperative to have a lightweight, skin-friendly device capable of providing real-time feedback through embedded sensors. A bi-modal methodology was adopted: theoretically, the leg and spring fixtures were modeled in SOLIDWORKS to compute muscle forces with and without the use of orthosis; experimentally, three sets of springs and a brace were manufactured and tested. Kinematic and kinetic data were captured using the G-Walk system; EMG measurements were used to evaluate upper leg muscle activity in controlled tests. This study compared knee braces with spring wires of diameters 1.6 mm, 2.0 mm, and 2.25 mm against an unbraced condition during the Squat Jump Test performed with the G-Walk system. All braced conditions reduced dynamic performance; flight height, center of mass, and average concentric speed was reduced by up to 15%, 20%, and 40% respectively. Kinetic analysis indicated stable takeoff force, lower impact force by 10%, and coupled reduction of eccentric phase rate by 80% with increase in concentric phase by 300%. Increased brace stiffness resulted in lower Quadriceps and Patella forces; EMG data indicated the 2.0 mm brace as providing the optimal balance. Some discrepancies were noted against theoretical models.

4

Analizator PYLoX 3 – antidotum na trudności wynikające ze zmiany normy PN-G-04037

Kubańska Anna, Kryca Marek, Dziubiński Jarosław

Napędy i Sterowanie

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2024

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R. 26, nr 9

32--35

PL

Październik 2023 roku przyniósł polskiemu górnictwu zmianę jednej z ważniejszych norm obowiązujących w tym sektorze – normy PN-G-04037 dotyczącej zabezpieczenia przeciwwybuchowego zakładów górniczych. Jedną z głównych zmian, które wprowadza najnowsze wydanie normy, jest liczba prób wymaganych do pobrania w poszczególnych obszarach wyrobisk. [...] Podstawową metodą analizy zawartości części niepalnych jest metoda spalania. Jest ona pracochłonna (ważenie próbki przed i po spaleniu z bardzo dużą dokładnością, przygotowanie naważki, obliczenia) i energochłonna z uwagi na duże zużycie energii przez piece muflowe...

5

On a Unified Form of Fractional Volterra-type Integro-Differential Equations and its applications

Pandey Shared Chander, Chaudhary Kaushalya

Journal of Mathematics and Applications

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2024

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Vol. 47

61--89

EN

In the present article, an extension for the family of Volterra-type integro-differential equations, involving a generalization of Hilfer fractional derivative with the Lorenzo-Hartley’s G-function (LHGF) in the kernel, is proposed. A compact and computable solution of the considered family of integro-differential equations is established in terms of an infinite series of LHGF. Further, certain known and new special cases of the proposed family are also established. Furthermore, some examples of the integro-differential equation are also discussed. Moreover, from the application point of view, generalized fractional free-electron laser equations involving the Caputo and the Riemann-Liouville fractional derivatives are also determined. Finally, the graphical illustrations for the solutions of the studied generalized fractional free-electron laser equations are demonstrated.

6

Calculating G-code for CNC machine using the Mamdani fuzzy logic inference system

Kalandyk Dawid, Kwiatkowski Bogdan, Mazur Damian

Archives of Control Sciences

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2024

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Vol. 34, No. 3

501--511

EN

The widespread desire to automate the CNC machine control process and optimize it is leading to the development of new algorithms. The article presents both a novel approach to this task based on a fuzzy decision-making system as well as an evaluation of the proposed solution on a large database containing data from multiple machining processes and a comparison with the Reference Points Realization Optimization (RPRO) algorithm used in industry. In addition to achieving the intended accuracy of the machining process, the presented system is also easily interpretable for the expert operating the machine. It is also possible to manipulate the presented system easily and shape it according to specific needs.

7

Near-field multiple‑blast resistance of G-HPC sandwich walls incorporated with metallic tube core

Yuan Pengcheng, Xu Shenchun, Yang Ting, Zhou Yun, Shao Ruizhe, Su Yu, Wu Chengqing

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 2

art. no. e75, 2024

EN

Multiple-blast loading induced in one explosion case more significantly threatens the safety of engineering structures, compared with single-blast loading. This study first proposed a novel sandwich wall based on the steel wire mesh (SWM) geopolymer based high-performance concrete (G-HPC) slab and metallic tube core (MTC) to mitigate the threat induced by the multiple-blast loading. The dynamic responses and failure mechanism of the sandwich wall was investigated by field blast tests and numerical simulations. The damage to the sandwich wall under different multiple-blast scenes was estimated in detail. The effect of parameters including the spacing of the steel tubes and the thickness of the front/rear slab was also investigated by numerical simulations. The experimental results showed that the sandwich walls could still maintain the integrity, indicating an excellent multiple-blast resistance. The numerical results illustrated that the front slabs could directly resist the multiple-blast loading and the metallic tube core could further mitigate the blast wave propagation. The parametric analysis indicated that the increase in the thickness of the rear slab improves the multiple-blast resistance of the sandwich wall.

8

Determination of Design Limitations of Curved Profiles Manufactured by Robotics Non-Planar Additive Manufacturing

Štefčák Pavol, Gajdoš Ivan, Slota Ján, Varga Jozef, Kimáková Zuzana, Vrabel Marek

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no. 3

92--98

EN

The emerging trend of employing 4 or more axes multi-purpose and gantry industrial robots in large format additive manufacturing presents numerous opportunities as well as challenges. The capacity to handle substantial material quantities and rapidly produce prototypes, jigs, and final products of considerable dimensions necessitates the formulation of a well-suited production strategy. This involves setting production parameters to minimize material consumption and production time, considering the limitations of the utilized technologies, and ensuring the final product's quality. While slicers are commonly employed for establishing manufacturing strategies and production parameters, most additive manufacturing slicers are optimized for planar 3 axes 3D printing. This limitation hinders their ability to generate non-planar and freeform toolpaths. To overcome this constraint, this paper delves into the utilization of parametric modelling as a potent tool in the realm of non-planar additive manufacturing. It explores the possibilities offered by Rhinoceros Grasshopper software in designing toolpath strategies and fabricating non-planar layers. The paper addresses the associated challenges and limitations of parametric modelling, including computational complexity and the requirement for specialized software and expertise. It emphasizes the crucial need to strike a balance between design complexity and manufacturability to ensure the successful implementation of non-planar additive manufacturing processes.

9

Wpływ sposobu przechowywania filamentu ABS, PLA, PET-G na właściwości wyrobów wytwarzanych przyrostowo metodą FDM

Góralski Błażej, Siergiej Joanna

Zarządzanie Przedsiębiorstwem

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2023

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Vol. 26, nr 1

7--11

EN

The subject of the article is the influence of filament moisture on the quality of products manufactured using the additive method using the Fused Deposition Modelling (FDM) method. Three types of thermoplastic polymers were tested: ABS, PLA and PET-G. The polymers were stored in environments with different humidity. The moisture content of the filament was determined as the water content in the material expressed as a percentage by weight. To obtain the expected humidity of the samples, they were conditioned for 7 days in tightly closed containers with constant humidity of 40%, 60% and 80%. After the sample conditioning process was completed, they were removed from the container and subjected to further tests. The influence of filament humidity on selected properties of manufactured products is presented, such as: surface quality of the obtained samples, tensile strength and dimensional repeatability. To sum up, the method of storing the filament affects the moisture content of the filament. The humidity of the filament, in turn, affects the quality of products manufactured using the FDM method, including: on: mechanical properties, dimensional stability, Surface appearance. Therefore, it is important in what conditions the filament is stored before the production process begins.

10

Fractional stochastic differential equations driven by G-Brownian motion with delays

Saci Akram, Redjil Amel, Boutabia Hacene, Kebiri Omar

Probability and Mathematical Statistics

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2023

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Vol. 43, Fasc. 1

1--21

EN

This paper consists of two parts. In part I, existence and uniqueness of solution for fractional stochastic differential equations driven by G-Brownian motion with delays (G-FSDEs for short) is established. In part II, the averaging principle for this type of equations is given. We prove under some assumptions that the solution of G-FSDE can be approximated by solution of its averaged stochastic system in the sense of mean square.

11

Expectation properties of generalized order statistics based on the Gompertz-G family of distributions

Alharbi Yousef F., Fawzy Mohamad A., Athar Haseeb

Operations Research and Decisions

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2023

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Vol. 33, No. 4

1--14

EN

Gompertz-G family of distributions has been considered. The moment properties of generalized order statistics were studied and characterization results have been presented. Further, several examples and special cases were discussed. The results can be applied to many known distributions included in this family.

12

Some results of homogeneous expansions for a class of biholomorphic mappings defined on a Reinhardt domain in ℂn

Sima Xiaoying, Tu Zhenhan, Xiong Liangpeng

Demonstratio Mathematica

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2023

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Vol. 56, nr 1

art. no. 20220242

EN

Let S*γ,A,B(D) be the usual class of g -starlike functions of complex order γ in the unit disk D={ζ∈C:∣ζ∣<1} , where g(ζ)=(1+Aζ)∕(1+Bζ) , with γ∈C\{0},−1 ≤A < B ≤1,ζ∈D. First, we obtain the bounds of all the coefficients of homogeneous expansions for the functions f∈S*γ,A,B(D) when ζ=0 is a zero of order k+1 of f(ζ)−ζ . Second, we generalize this result to several complex variables by considering the corresponding biholomorphic mappings defined in a bounded complete Reinhardt domain. These main theorems unify and extend many known results.

13

Dynamical property of hyperspace on uniform space

Ji Zhanjiang

Demonstratio Mathematica

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2023

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Vol. 56, nr 1

art. no. 20230264

EN

First, we introduce the concepts of equicontinuity, expansivity , ergodic shadowing property, and chain transitivity in uniform space. Second, we study the dynamical properties of equicontinuity, expansivity , ergodic shadowing property, and chain transitivity in the hyperspace of uniform space. Let (X,μ) be a uniform space, (C(X),Cμ) be a hyperspace of (X,μ) , and ƒ:X→X be uniformly continuous. By using the relationship between original space and hyperspace, we obtain the following results: (a) the map ƒ is equicontinous if and only if the induced map Cƒ is equicontinous; (b) if the induced map Cƒ is expansive, then the map f is expansive; (c) if the induced map Cƒ has ergodic shadowing property, then the map f has ergodic shadowing property; (d) if the induced map Cƒ is chain transitive, then the map ƒ is chain transitive. In addition, we also study the topological conjugate invariance of (G,h) -shadowing property in metric G - space and prove that the map S has (G,h) -shadowing property if and only if the map T has (G,h) -shadowing property. These results generalize the conclusions of equicontinuity, expansivity, ergodic shadowing property, and chain transitivity in hyperspace.

14

Convergence analysis of M-iteration for 𝒢-nonexpansive mappings with directed graphs applicable in image deblurring and signal recovering problems

Chairatsiripong Chonjaroen, Yambangwai Damrongsak, Thianwan Tanakit

Demonstratio Mathematica

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2023

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Vol. 56, nr 1

art. no. 20220234

EN

In this article, weak and strong convergence theorems of the M-iteration method for 𝒢-nonexpansive mapping in a uniformly convex Banach space with a directed graph were established. Moreover, weak convergence theorem without making use of Opial’s condition is proved. The rate of convergence between the M-iteration and some other iteration processes in the literature was also compared. Specifically, our main result shows that the M-iteration converges faster than the Noor and SP iterations. Finally, the numerical examples to compare convergence behavior of the M-iteration with the three-step Noor iteration and the SP-iteration were given. As application, some numerical experiments in real-world problems were provided, focused on image deblurring and signal recovering problems.

15

Boundedness of G-Fractional Commutators with G-BMO functions

Elman Ibrahimov, Jafarova Ar. Saadat

Commentationes Mathematicae

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2023

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Vol. 61, No. 1/2

1--14

EN

In this paper we study (Lp,λ,ω p , Lp,λ,ωq )-boundedness of commutators of the Gegenbauer fractional integral Jα G and fractional maximal operator Mα G generated by Gegenbauer differential operator Gλ

16

Evaluation of the Influence of the Cooling Method Used During Grinding on the Operating Properties of Ceramic Grinding Wheels Made with Different Abrasives

Stachurski Wojciech, Dębkowski Ryszard, Rosik Radosław, Święcik Robert, Pawłowski Witold

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no. 3

1--18

EN

This article presents the results of a study of the performance characteristics of ceramic grinding wheels during peripheral grinding of flat surfaces carried out using different methods of supplying cooling and lubricating fluid (coolant). In the study, T1 type grinding wheels were used, differing in the type of abrasive used in their construction. The abrasive consisted of mixtures with different volume percentages of: 1) grains of conventional white electro-corundum, 2) grains of submicrocrystalline sintered corundum produced by sol-gel technology, 3) microcrystalline sintered ceramic grains with RECERAMAX™ RT microclasters from RECKEL. Specimens made of 145Cr6 tool steel (60±1 HRC) were ground using coolant feeding by flood method and MQL (Minimum Quantity Lubrication) method. During the study, the components of grinding force (Fn, Ft), radial loss of the grinding wheel and roughness of the ground surface were measured, which made it possible to determine the volumetric wear of the grinding wheel Vs, the total grinding power P, and then calculate the grinding indicators G and Ks. The obtained values of the G index indicate that, regardless of the type of grinding wheel used, a higher relative grinding efficiency was obtained during grinding with the delivery of coolant by the MQL method. The highest values of this index were obtained in the case of the grinding process carried out with a grinding wheel containing RECERAMAX™ RT abrasive. The Ks index confirmed the best performance of the mentioned grinding wheel. Since its value also depends on the total grinding power P and the surface roughness parameter Ra, the grinding process carried out with this grinding wheel is additionally characterized by a better quality of the obtained surface and lower energy consumption.

17

Asymptotic analysis of a closed G-network of unreliable nodes

Rusilko Tatiana

Journal of Applied Mathematics and Computational Mechanics

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2022

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Vol. 21, nr 2

91--102

EN

A closed exponential queueing G-network of unreliable multi-server nodes was studied under the asymptotic assumption of a large number of customers. The process of changing the number of functional servers in network nodes was considered as the birth-death process. The process of changing the number of customers at the nodes was considered as a continuous-state Markov process. It was proved that its probability density function satisfies the Fokker-Planck-Kolmogorov equation. The system of differential equations for the first-order and second-order moments of this process was derived. This allows us to predict the expectation, the variance and the pairwise correlation of the number of customers in the G-network nodes both in the transient and steady state.

18

Introduction to Probabilistic Concurrent Systems

Abbes Samy

Fundamenta Informaticae

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2022

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vol. 187, nr 2-4

71--102

EN

The first part of the paper is an introduction to the theory of probabilistic concurrent systems under a partial order semantics. Key definitions and results are given and illustrated on examples. The second part includes contributions. We introduce deterministic concurrent systems as a subclass of concurrent systems. Deterministic concurrent system are “locally commutative” concurrent systems. We prove that irreducible and deterministic concurrent systems have a unique probabilistic dynamics, and we characterize these systems by means of their combinatorial properties.

19

Characterizations of quasi-metric and G-metric completeness involving w-distances and fixed points

Karapınar Erdal, Romaguera Salvador, Tirado Pedro

Demonstratio Mathematica

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2022

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Vol. 55, nr 1

939--951

EN

Involving w-distances we prove a fixed point theorem of Caristi-type in the realm of (non-necessarily T1) quasi-metric spaces. With the help of this result, a characterization of quasi-metric completeness is obtained. Our approach allows us to retrieve several key examples occurring in various fields of mathematics and computer science and that are modeled as non- T1 quasi-metric spaces. As an application, we deduce a characterization of complete G -metric spaces in terms of a weak version of Caristi’s theorem that involves a G-metric version of w-distances.

20

Throwback

Gambarelli Gianfranco

Control and Cybernetics

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2022

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Vol. 51, No. 2

125--130

EN

With this short composition, I’d like to share with you a few events of my scientific life.