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This paper studies the constrained two-dimensional non-guillotine cutting problem with defects, in which a set of items of a specific size is cut from a large rectangular sheet with defective areas, with the number of each type of cut item cannot exceed a specified quantity. The objective is to maximise the total value of the cut items. We propose a decomposition approach to address the problem. The process involves decomposing the original problem into a master problem and a subproblem. The master problem is formulated as a one-dimensional contiguous bin packing problem, while the subproblem is an x-Check problem to identify a two-dimensional packing that does not lead to any overlap. The x-Check problem is effectively addressed by using an integer linear programming model. When the x-Check problem proves infeasible, cuts are added to the master problem, and the iteration is repeated until the x-Check finds a feasible solution. Furthermore, we introduce several novel techniques, including valid inequalities, preprocessing techniques, and lifting the cut methods to improve the performance of the algorithm. Extensive computational results show that our method can quickly find the optimal solution for the 5450 instances in the literature. [ABSTRACT FROM AUTHOR]

In additive manufacturing processes such as laser powder bed fusion, the build orientation and packing of components affect the required support structures, the number of parts in each build, and the surface roughness of the printed parts, among other factors. Maximising the packing density while minimising the build height can increase effective machine utilisation and decrease per-part cost. Yet, the build layout optimisation problem is highly nonlinear and difficult to solve using human intuition, so a systematic algorithm approach is required. Here, we present and demonstrate a voxel-based analysis method with Bayesian optimisation for determining component build orientation in additive manufacturing. We introduce selected case studies incorporating exemplary process attributes of laser powder bed fusion, including the determination of orientation and packing configurations based on support removal and tool-accessibility constraints. [ABSTRACT FROM AUTHOR]

Packing soft rectangular objects in an optimized convex container is considered. Each soft rectangle can be freely translated and rotated, has a fixed area, and its dimensions can vary in certain limits. The convex container may have prohibited zones where allocation of the objects is not allowed. The soft rectangles must be arranged completely inside the container; mutual intersection and overlapping with prohibited zones is not allowed. The objective is to minimize a certain metric characteristic of the container. The corresponding nonlinear mathematical problem is formulated using the phi-function technique to present non-overlapping and containment conditions. A model-based heuristic is proposed to find reasonable solutions to the problem. Numerical results are provided for triangular, circular, and scaled polygonal containers to validate the model and demonstrate the proposed approach's efficiency. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the degradation of Congo red and Rhodamine B dyes in synthetic wastewater by ozonation and study the parameters that influence the efficiencies of color removal such as concentration of pollutants, gas flow rate, time of reaction, and the pH of solution. Congo red dye and Rhodamine B dye were selected as model pollutants. ozonation process of these dyes was carried out in a continuous reactor with a diameter of 8 cm and length of 25 cm. It was observed that over 85% of Congo red and 95% of Rhodamine B could be removed at 90 min for both dyes. and when using the H2O2 (0.5, 1, 1.5) ml for Rhodamine B and Cong Red at 90 min the decolorization efficiency in natural pH was 93%, 95%, 96%, 84%, 89%, and 94% respectively. When used the packing the decolorization efficiency changed from 77% to 82% for Rhodamine B and from 53% to 63% for Congo Red. Higher color removal could be achieved when ozonation was carried out in an alkaline condition (pH 10) for Congo Red and an acidic condition (pH 1.5) for Rhodamine B. The ozonation of dyes was dominant at room temperature and atmospheric pressure. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article explores the potential applications of virtual reality (VR) in robotic packing processes. The experiments were conducted in RobotStudio, utilising digital twins of actual stations situated within the Robotics Laboratory of the Military University of Technology. The authors present an algorithm for designing stations and implementing VR in the programming and modification of robot movement paths. Tests were conducted with robot programmers and technicians, demonstrating the validity of using VR technology as an effective bridge between offline programming on a computer and online programming at a real workstation.

The article presents the results of metallographic analysis of blacksmithing items, found during excavations at the Podgory V settlement, located on the Samara Bend. The materials of the 1999-2001 excavations are represented by items and sets (including burials ones) belonging to the period from the Early Iron Age to the Middle Ages. The most representative materials are related to the Imenkovo culture of the IV–VII centuries. The sample of ferrous metal artifacts subjected to metallographic study amounted to 21 pieces: knives, awls, sickle, arrowhead, earring with a polyhedron, fixing ring, fire lighter and plate. The metallographic collection included rod-shaped objects, some of which were identified as semi-finished products (metal raw material). It was found that the main material for most of the items was low carbon steel. Packing of blanks was often used and local cementation was applied. The share of heat-treated products is high, signs of high-temperature forging were recorded. The revealed characteristics of forgings from Podgory Vsetlement, in general, correspond to the level of development and technological appearance of East European early medieval ironworking. However, there were also found such features that distinguish the “Podgory” sample from the archaeometallographic collections of other Middle Volga sites of the Early Middle Ages. The peculiarity manifested itself in the use of the characteristic twisting technique of two- or multilayer blanks.

En los últimos años, la industria del envasado ha comenzado a tomar conciencia sobre el impacto ambiental de los materiales utilizados en sus productos. El creciente interés de los consumidores por opciones más ecológicas ha llevado a la industria a enfocarse en la investigación y el desarrollo de alternativas que no solo sean más sostenibles, sino que mantengan y mejoren las características del producto, garantizando una mayor duración y seguridad alimentaria. Este artículo explora cómo algunos residuos biológicos provenientes de la cadena agrícola y agroindustrial, combinados con agentes antimicrobianos pueden ser aprovechados para crear empaques biodegradables, activos e inteligentes. Estos empaques no solo mejoran la calidad de los alimentos, sino que también ofrecen propiedades de barrera que ayudan a preservar su inocuidad hasta llegar al consumidor final.

The Colored bin packing problem (CBPP) is a generalization of the Bin packing problem (BPP). The CBPP consists of packing a set of items, each with a weight and a color, in bins of limited capacity, minimizing the number of used bins and satisfying the constraint that two items of the same color cannot be packed side by side in the same bin. In this article, we proposed an adaptation of BPP heuristics and new heuristics for the CBPP. Moreover, we propose a set of fast neighborhood search algorithms for CBPP. These neighborhoods are applied in a meta-heuristic approach based on the Variable neighborhood search (VNS) and a matheuristic approach that combines linear programming with the meta-heuristics VNS and Greedy randomized adaptive search (GRASP). The results indicate that our matheuristic is superior to VNS and that both approaches can find near-optimal solutions for a large number of instances, even for those with many items. [ABSTRACT FROM AUTHOR]

Based on the packing density of cross-polytopes in R n , more than 50 years ago Golomb and Welch proved that the packing density of Lee spheres in Z n must be strictly smaller than 1 provided that the radius r of the Lee sphere is large enough compared with n, which implies that there is no perfect Lee code for the corresponding parameters r and n. In this paper, we investigate the lattice packing density of Lee spheres with fixed radius r for infinitely many n. First we present a method to verify the nonexistence of the second densest lattice packing of Lee spheres of radius 2. Second, we consider the constructions of lattice packings with density δ n → 2 r (2 r + 1) r ! as n → ∞ . When r = 2 , the packing density can be improved to δ n → 2 3 as n → ∞ . [ABSTRACT FROM AUTHOR]

Injection molding is a crucial manufacturing technology for producing complex, high-quality parts at scale, making it essential in various industries, including consumer electronics and automotive sectors. However, a lack of understanding about how injection parameters impact common defects like sink marks, short shots, and warpage often limits the widespread adoption of injection molding. This research aims to bridge this gap by providing a comprehensive digital simulation of the injection molding process within a complex mold cavity. Utilizing Moldex3D and the Finite Volume Method (FVM), this study characterizes essential material properties–viscosity, specific heat, density, and thermal conductivity–and examines the effects of gate location and part design on minimizing weld lines and warpage. The FVM involves dividing the computational domain into a finite number of small control volumes. This method is particularly well-suited for handling complex geometries and flow conditions, facilitating detailed and accurate simulations. This study employs Moldex3D, a leading simulation software in the field of injection molding, to demonstrate the use of CAE for design verification and process innovation. Moldex3D’s advanced capabilities make it an ideal tool for simulating injection molding processes, helping improve the quality of parts and contributing to the overall advancement of molding skills in the industry. The simulations revealed optimal gate locations that significantly improved filling patterns, reduced warpage by 50%, and minimized weld lines, thereby enhancing overall part quality. Key contributions of this research include the identification of critical flow characteristics, the reduction of defect-prone regions, and the enhancement of plastic component rigidity. This study provides valuable insights into optimizing injection molding processes, offering a pathway to improved efficiency and part quality in advanced manufacturing. [ABSTRACT FROM AUTHOR]

Copyright of Problems of Mechatronics. Armament, Aviation, Safety Engineering / Problemy Mechatroniki. Uzbrojenie, lotnictwo, Inżynieria Bezpieczeństwa is the property of Index Copernicus International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper studies the constrained two-dimensional guillotine cutting problem with defects, whose objective is to cut a subset of given items from a defective sheet such that the profit of selected items is maximised. The guillotine cut constraint, which requires each cut must go through one side of the sheet to the opposite side, is considered. We solve this problem via a recursive dynamic programming approach. A set of upper bounds is proposed to keep the promising nodes. The normal points and raster points are extended to reduce the number of vertical and horizontal cuts by considering the effect of the defect. The experiment results show that our approach can solve most of the instances in the literature and outperforms existing approaches. [ABSTRACT FROM AUTHOR]

The Tree Packing Conjecture (TPC) by Gyárfás states that any set of trees \(T_2,\dots,T_{n-1}, T_n\) such that \(T_i\) has \(i\) vertices pack into \(K_n\). The conjecture is true for bounded degree trees, but in general, it is widely open. Bollobás proposed a weakening of TPC which states that \(k\) largest trees pack. The latter is true if none tree is a star, but in general, it is known only for \(k=5\). In this paper we prove, among other results, that seven largest trees pack.

This paper explores methods to improve the sustainability of packing artworks, focusing on soft wrapping of framed paintings. In 2022, the UK Museums and Heritage Sustainable Packing Group was formed. The research described in this paper focuses on one aspect of the group's activity: seeking to find materials and methods which reduce environmental burdens and comply with conservation standards for soft wrapping two-dimensional artworks for short journeys between display, storage locations and conservators' studios. The project investigated the physical qualities of recycled content polyethylene (PE), bioplastics and paper-based alternatives, along with common barrier materials such as virgin PE sheet and Bubble Wrap®, to form comparative datasets. Each material's environmental impact, potential for reuse, interaction with artworks and ability to maintain adequate buffering against environmental changes during transport was researched. Alternative methods were also explored to reduce the quantity of sealing tape and promote its reversibility and reuse. The environmental impacts of the materials were assessed by sustainability specialists at the University of Manchester's Sustainable Materials Innovation Hub. Reusable and recycled content films offered the most promising alternatives to the PE wrapping most used at present. The use of a tying method, eliminating the need for adhesive tape, also showed potential for further investigation. The low-cost testing methodology should be refined to better control the variables and allow for more repeatable testing, but these preliminary results will help to refine future research directions. [ABSTRACT FROM AUTHOR]

2,4-Difluoronitrobenzene has been reacted with a linker diamine (ethylenediamine or propylenediamine) and butylamine, in either order, to give new molecular building blocks for porous supramolecular networks. Two structures were established by X-ray single crystal structure determinations. The propylenediamine structure displays small pores, which may be due to the longer and more flexible linker in the structure. [ABSTRACT FROM AUTHOR]

Copyright of Agroindustrial Science is the property of Agroindustrial Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Tree Packing Conjecture (TPC) by Gyárfás states that any set of trees T2,...,n-1, Tn Ti has i vertices pack into Kn. The conjecture is true for bounded degree trees, but in general, it is widely open. Bollobás proposed a weakening of TPC which states that k largest trees pack. The latter is true if none tree is a star, but in general, it is known only for k = 5. In this paper we prove, among other results, that seven largest trees pack. [ABSTRACT FROM AUTHOR]

Any collection of non-blocking cubes, whose total volume does not exceed 1/3, can be packed into the unit cube. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the presence of residual Plus Moist HS-W (PM), a novel calcium alginate packing material, during the initial postoperative visit following endoscopic sinus surgery. The research aims to identify factors that influence the quantity of remaining PM. A retrospective review of medical records was conducted for patients who underwent middle meatus packing with PM. A total of fifty-two patients (representing 92 sides of paranasal sinuses) were included in the analysis. The remaining PM was classified as follows: absent (0) in 41 out of 92 cases, minimal (1) in 22 out of 92 cases, moderate (2) in 15 out of 92 cases, and substantial (3) in 14 out of 92 cases. Notably, all three patients who underwent Draf III surgery exhibited a significant amount of PM during their initial visit, with two patients classified as grade 2 and one patient as grade 3. Other factors investigated were found to be unrelated to the persistence of PM. Removal of all PM was achieved effortlessly using suction under flexible endoscopy. This study highlights the efficacy of PM in post-endoscopic sinus surgery care. It is important to limit an amount of PM, particularly in Draf III procedures. [ABSTRACT FROM AUTHOR]

To solve the problem of high oxygen content in the deoxygenated pregnant liquid after long-term use of the deoxygenation tower in the zinc powder replacement process, this paper mainly conducts a series of studies on the packing types and loading methods of the deoxygenation tower in a gold smelting plant. Through in-depth comparison and analysis of multiple process indicators such as deoxygenation rate, replacement of barren liquid, and grade of gold mud, it was found that using polypropylene Pall Ring packing instead of plastic point wave packing can significantly alleviate the problem of clogging of gaps after calcium deposition of the packing, improve the deoxygenation performance of the deoxygenation tower, significantly reduce zine powder consumption, lower the grade of precious metals in replacement barren liquid, and improve the grade of gold mud. The improvement of packing has extended the service life of the deoxygenation tower, reduced the interference of base metal elements on the gold mud smelting process, and achieved significant economic benefits. [ABSTRACT FROM AUTHOR]

High temperatures have dramatic negative effects on interconnect performance. In a bus, whenever the state transitions from "0" to "1", or "0" to "1", joule heating causes the temperature to rise. A low-power error-correcting cooling (LPECC) code, introduced in Chee et al. (IEEE Trans Inf Theory 64:3062–3085, 2018), is a coding scheme which can be used to control the peak temperature, the average power consumption of on-chip buses and error-correction for the transmitted information, simultaneously. In this paper, we show upper bounds and some lower bounds of LPECC codes by some combinatorial configurations, and also present several families of optimal LPECC codes. [ABSTRACT FROM AUTHOR]

The review and comparative analysis of known literature approaches and methods for predicting the packing density of binary powder systems are carried out. A theoretical model is proposed for a binary mixture to provide the spline approximation of calculated and research data with an appropriate accuracy. The model parameters are physical values, whose comparison for different binary systems makes it possible to estimate both the effect of a method of their formation on the packing density and the degree of adequacy to real powder materials for the available theoretical models. [ABSTRACT FROM AUTHOR]

This article compares two types of external ear canal packing options, Spongostan and Silastic, for endoscopic ear surgery. The study found that there was no statistically significant difference in post-operative healing outcomes between the two dressings. Both dressings were considered viable options for endoscopic ear surgery. The study aimed to fill a gap in the literature regarding packing options for this type of surgery. However, the study has limitations and further research is needed to determine the optimal timing of leaving the Spongostan dressing in place. [Extracted from the article]

In a graph G : = (V (G) , E (G)) , a subset M of the vertex set V (G) is a module (or interval, clan) of G if every vertex outside M is adjacent to all or none of M. The empty set, the singleton sets, and the full set of vertices are trivial modules. The graph G is indecomposable (or prime) if all its modules are trivial. If G is indecomposable, we say that an edge e of G is a removable edge if G − e is indecomposable (here G − e : = (V (G) , E (G) − { e })). The graph G is said to be unstable if it has no removable edges. For a positive integer k , the k th power G k of a graph G is the graph obtained from G by adding an edge between all pairs of vertices of G with distance at most k. A graph G of order n (i.e., | V (G) | = n) is said to be p -placeable into G k , if G k contains p edge-disjoint copies of G. In this paper, we answer a question, suggested by Boudabbous in a personal communication, concerning unstable graphs and packing into their fifth power as follows: First, we give a characterization of the unstable graphs which is deduced from the results given by Ehrenfeucht, Harju and Rozenberg (the theory of 2 -structures: a framework for decomposition and transformation of graphs). Second, we prove that every unstable graph G is 2 -placeable into G 5 . [ABSTRACT FROM AUTHOR]

An i-packing in a graph G is a set of vertices that are pairwise at distance more than i. A packing colouring of G is a partition X = {X1, X2,... , Xk } of V(G) such that each colour class Xi is an i-packing. The minimum order k of a packing colouring is called the packing chromatic number of G, denoted by χρ(G). In this paper we investigate the existence of trees T for which there is only one packing colouring using χρ(T) colours. For the case χρ(T) = 3, we completely characterise all such trees. As a by-product we obtain sets of uniquely 3-χρ-packable trees with monotone χρ-colouring and non-monotone χρ-colouring respectively. [ABSTRACT FROM AUTHOR]

In the MAXSPACE problem, given a set of ads A, one wants to place a subset A′ ⊆ A into K slots B1, ..., BK of size L. Each ad Ai ∈ A has sizesi and frequencywi. A schedule is feasible if the total size of ads in any slot is at most L, and each ad Ai ∈ A′ appears in exactly wi slots. The goal is to find a feasible schedule that maximizes the space occupied in all slots. We introduce MAXSPACE-RDWV, a MAXSPACE generalization with release dates, deadlines, variable frequency, and generalized profit. In MAXSPACE-RDWV each ad Ai has a release date ri ≥ 1, a deadline di ≥ ri, a profit vi that may not be related with si and lower and upper bounds wmini and wmaxi for frequency. In this problem, an ad may only appear in a slot Bj with ri ≤ j ≤ di, and the goal is to find a feasible schedule that maximizes the sum of values of scheduled ads. This paper presents some algorithms based on meta-heuristics GRASP, VNS, and Tabu Search for MAXSPACE and MAXSPACE-RDWV. We compare our proposed algorithms with Hybrid-GA proposed by Kumar et al. [Eur. J. Oper. Res. 173 (2006) 1067–1089]. We also created a version of Hybrid-GA for MAXSPACE-RDWV and compared it with our meta-heuristics. Some meta-heuristics like VNS and GRASP+VNS have better results than Hybrid-GA for both problems. In our heuristics, we apply a technique that alternates between maximizing and minimizing the fullness of slots to obtain better solutions. We also applied a data structure called BIT to the neighborhood computation in MAXSPACE-RDWV and showed that this enabled our algorithms to run more iterations. [ABSTRACT FROM AUTHOR]