Partial Disassembly Research Articles

Energy consumption and profit-oriented disassembly line balancing for waste electrical and electronic equipment

The quantity of waste electrical and electronic equipment (WEEE) is very large. WEEE not only occupies resources, but also easily pollutes the environment. The disassembly line is the most efficient way to address large-scale WEEE. How to improve disassembly profit and reduce energy consumption has become a significant and challenging research topic. However, the existing literature only considers the completely normal disassembly mode, ignoring the uncertainties such as corrosion and deformation of parts, and the evaluation system of the disassembly line cannot take into account both economic benefits and environmental impacts. Therefore, this paper introduces the destructive disassembly mode into the disassembly line and proposes a partial destructive disassembly line balancing model. The model aims to comprehensively optimize the number of stations, smoothness index, energy consumption, and disassembly profit. To obtain high-quality disassembly schemes, an improved genetic algorithm based on task precedence relationship is developed. Finally, the proposed model and method are applied to an engineering example of a television disassembly line. The performance of the proposed method is verified by comparing it with ant colony optimization, particle swarm optimization, artificial bee colony, and simulated annealing. The analysis of the disassembly schemes shows that the partial destructive mode can improve the disassembly profit and reduce energy consumption.

Partial disassembly line balancing under uncertainty: robust optimisation models and an improved migrating birds optimisation algorithm

A partial disassembly line balancing problem under uncertainty is studied in this paper, which concerns the allocation of a sequence of tasks to workstations such that the overall profit is maximised. We consider the processing time uncertainty and develop robust solutions to accommodate it. The problem is formulated as a non-linear robust integer program, which is then converted into an equivalent linear program. Due to the intractability of such problems, the exact algorithms are only applicable to small-scale instances. We develop an improved migrating birds optimisation algorithm. Two enhancement techniques are proposed. The first one finds the optimal number of tasks to be performed for each sequence rather than random selection used in the literature; while the second one exploits the specific problem structure to construct effective neighbourhoods. The numerical results show the strong performance of our proposal compared to CPLEX and the improved gravitational search algorithm (IGSA), especially for large-scale problems. Moreover, the enhancement due to the proposed techniques is obvious across all instances considered.

Albumin-driven disassembly of lipidic nanoparticles: the specific case of the squalene-adenosine nanodrug.

In the field of nanomedicine, nanostructured nanoparticles (NPs) made of self-assembling prodrugs emerged in the recent years with promising properties. In particular, squalene-based drug nanoparticles have already shown their efficiency through in vivo experiments. However, a complete pattern of their stability and interactions in the blood stream is still lacking. In this work we assess the behavior of squalene-adenosine (SQAd) nanoparticles - whose neuroprotective effect has already been demonstrated in murine models - in the presence of fetal bovine serum (FBS) and of bovine serum albumin (BSA), the main protein of blood plasma. Extensive physicochemical characterizations were performed using Small Angle Neutron Scattering (SANS), cryogenic transmission electron microscopy (Cryo-TEM), circular dichroism (CD), steady-state fluorescence spectroscopy (SSFS) and isothermal titration calorimetry (ITC) as well as in silico by means of ensemble docking simulations with human serum albumin (HSA). Significant changes in the colloidal stability of the nanoparticles in the presence of serum albumin were observed. SANS, CD and SSFS analyses demonstrated an interaction between SQAd and BSA, with a partial disassembly of the nanoparticles in the presence of BSA and the formation of a complex between SQAd and BSA. The interaction free energy of SQAd nanoparticles with BSA derived from ITC experiments, is about -8 kcal mol-1 which is further supported in silico by ensemble docking simulations. Overall, our results show that serum albumin partially disassembles SQAd nanoparticles by extracting individual SQAd monomers from them. As a consequence, the SQAd nanoparticles would act as a circulating reservoir in the blood stream. The approach developed in this study could be extended to other soft organic nanoparticles.

Coordination tailoring of water-labile 3D MOFs to fabricate ultrathin 2D MOF nanosheets.

A novel coordination tailoring top-down delamination strategy involving the controllable partial disassembly of water-labile 3D MOFs has been explored to fabricate ultrathin 2D MOF nanosheets, and it exhibits many advantages such as green, convenience and high efficiency. Accordingly, 2D ultrathin MOF nanosheets with a two-fold interpenetrated architecture have been rapidly obtained from a 3D pillar-layered MOF, and they show distinguished fluorescence responses to different solvents.

Single-cell ATP detection and content analyses in electrostimulus-induced apoptosis using functionalized glass nanopipettes.

A glass nanopipette functionalized with ATP-responsive gold nanoparticle assemblies was developed for ATP detection in single-cells and used for analysing the content change of ATP during electrostimulus (ES)-induced apoptosis. The variation of ATP content in single normal cells and cancer cells during apoptosis was detected by the method.

Nanoassembly of Oligopeptides and DNA Mimics the Sequential Disassembly of a Spherical Virus

AbstractProtein subunits of a low aspect ratio (width over length) with stimuli‐responsiveness are hallmark building blocks of spherical viruses. The interaction of these repeating subunits enables hierarchical assembly for genome packaging and sequential disassembly for optimal genome release. Here, we mimicked these features and constructed a functional spherical artificial virus. The rationally designed 22‐amino acid peptide containing pH‐sensitive histidines and aromatic residues self‐assembled into homogenous nanodiscs of a low aspect ratio (≈7×7×4 nm). In the presence of DNA, the inter‐nanodisc interactions drove the formation of a viral capsid‐like structure enclosing DNA in the interior. This artificial virus roughly 50 nm in diameter underwent partial disassembly in response to acidic pH. The resulting intermediate with lowered DNA‐binding affinity continued to protect DNA from nuclease digestion. Such nanostructures, which mimic the intricate morphology and the intracellular transformation of spherical viruses, can be useful for constructing synthetic gene delivery vehicles, as evidenced by their efficient transgene expression.

Nanoassembly of Oligopeptides and DNA Mimics the Sequential Disassembly of a Spherical Virus.

Protein subunits of a low aspect ratio (width over length) with stimuli-responsiveness are hallmark building blocks of spherical viruses. The interaction of these repeating subunits enables hierarchical assembly for genome packaging and sequential disassembly for optimal genome release. Here, we mimicked these features and constructed a functional spherical artificial virus. The rationally designed 22-amino acid peptide containing pH-sensitive histidines and aromatic residues self-assembled into homogenous nanodiscs of a low aspect ratio (≈7×7×4 nm). In the presence of DNA, the inter-nanodisc interactions drove the formation of a viral capsid-like structure enclosing DNA in the interior. This artificial virus roughly 50 nm in diameter underwent partial disassembly in response to acidic pH. The resulting intermediate with lowered DNA-binding affinity continued to protect DNA from nuclease digestion. Such nanostructures, which mimic the intricate morphology and the intracellular transformation of spherical viruses, can be useful for constructing synthetic gene delivery vehicles, as evidenced by their efficient transgene expression.

Partial disassembly line balancing for energy consumption and profit under uncertainty

Abstract The disassembly line is one of the most important ways to handle large quantities of waste electrical and electronic equipment efficiently. The disassembly line balancing is to assign disassembly tasks to each workstation reasonably while satisfying various constraints, which is one of the challenging topics in recent years. Considering the uncertainty, environmental protection and economic benefits of disassembly, this paper establishes a stochastic partial disassembly line balancing model that comprehensively evaluates the number of workstations, workload smoothness, energy consumption, and disassembly profit. In order to obtain high-quality feasible solutions, a new multi-objective discrete flower pollination algorithm is proposed. The method establishes four heuristic rules, discrete operations, and multi-objective processing methods combined with the characteristics of the problem. The effectiveness and application ability of the proposed model and method are verified by a disassembly example of a waste printer, and various disassembly schemes are obtained, which can provide guidance for decision makers to construct disassembly lines.

Cellulases and pectinases act together on the development of articulated laticifers in Ficus montana and Maclura tinctoria (Moraceae).

The presence of articulated laticifers in the Moraceae family was recently discovered, which means that the location of pectinase and cellulase activities must be of great importance for their growth. Thus, the present study aimed to determine the role of these enzymes in the laticifer growth in Ficus montana and Maclura tinctoria. Reproductive meristems were collected and fixed in Karnovsky. Pectinase and cellulase labeling was performed in part of the samples, while another part was processed for usual TEM analyses. Pectinase and cellulase activities were detected in the vacuole and close to the middle lamella in both species. The presence of cellulases in the laticifers supports their articulated origin. Therefore, the occurrence of pectinase and cellulase activity in the laticifers points out that these enzymes could act in the dissolution of the transverse walls and in the processes of intrusive growth (through the dissolution of the middle lamella) and cell elongation (through the partial disassembly of components of the wall making it more plastic). Both enzymes are synthesized in the endoplasmic reticulum and transported to the cell wall by exocytosis or stored in the vacuole. The species studied showed a diverse subcellular composition, which is probably related to the species and not to the laticifer type (they present the same type) and to the composition of the latex (they show similar latex composition). We conclude that the presence of pectinases and cellulases can be used as a diagnostic condition for the laticifer types (articulated vs. non-articulated).

Unraveling the multiplex folding of nucleosome chains in higher order chromatin.

The DNA of eukaryotic chromatin and chromosomes is repeatedly supercoiled around histone octamers forming 'beads-on-a-string' chains of nucleosomes. The extent of nucleosome chain folding and DNA accessibility vary between different functional and epigenetic states of nuclear chromatin and change dramatically upon cell differentiation, but the molecular mechanisms that direct 3D folding of the nucleosome chain in vivo are still enigmatic. Recent advances in cell imaging and chromosome capture techniques have radically challenged the established paradigm of regular and hierarchical chromatin fibers by highlighting irregular chromatin organization and the importance of the nuclear skeletal structures hoisting the nucleosome chains. Here, we argue that, by analyzing individual structural elements of the nucleosome chain - nucleosome spacing, linker DNA conformations, internucleosomal interactions, and nucleosome chain flexibility - and integrating these elements in multiplex 3D structural models, we can predict the features of the multiplex chromatin folding assemblies underlying distinct developmental and epigenetic states in living cells. Furthermore, partial disassembly of the nuclear structures suspending chromatin fibers may reveal the intrinsic mechanisms of nucleosome chain folding. These mechanisms and structures are expected to provide molecular cues to modify chromatin structure and functions related to developmental and disease processes.

A multi-objective discrete flower pollination algorithm for stochastic two-sided partial disassembly line balancing problem

Two-sided production line can utilize both the left and right stations to increase the productivity of large-sized products. For the disassembly of large-sized waste products such as cars and buses, the two-sided layout is introduced into the disassembly line. This paper constructs a mathematical model of the stochastic two-sided partial disassembly line balancing with multi-objective, multi-constraint and uncertainty. The aim is to optimize the number of stations, workload smoothness, energy consumption and profit of the production line simultaneously. A multi-objective discrete flower pollination algorithm based on Pareto dominance relations is proposed as the optimization method of the problem. In order to improve the quality of initial solutions, four heuristic rules combining the characteristics of the problem are designed. The effectiveness of the heuristic rules and the superiority of the proposed algorithm are verified by solving a set of test problems, and the application capabilities of the proposed model and method have also been verified.

D-Tryptophan governs biofilm formation rates and bacterial interaction in P. mendocina and S. aureus

Biofilm genesis by Pseudomonasand Staphylococcus sp is associated with biofouling in natural settings. D-Tryptophan (D-Trp) inhibits bacterial biofilms and have been proposed for biofouling control applications. In this study, D-Trp significantly inhibited Pseudomonas mendocina and Staphylococcus aureuscell attachment (biofilm formation) rates on polystyrene96-well microtiter plates in comparison with L-Tryptophan (L-Trp) and mixtures of D-/L-Tryptophan (D-/L-Trp). Theinhibitory effect was greater on P. mendocina,where the rate of cell adherence was declined to 8.79105cells/h from8.09106cells/h (control) inP. mendocina.InS. aureusit was declined to 4.29107cells/h from 9.29107cells/h(control) at 1 mM concentration. It hindered the intracellular communication and adherence in both the strains, as con-firmed by SEM and real time PCR analysis. Addition of D-Trp to preformed biofilms also caused partial disassembly. Intraand interbacterial aggregation were decreased subsequently upon treatment with D-Trp. It repressed the genes involved incell-cell communication, which could be responsible for the diminished biofilm formation of the selected strains. HenceD-Tryptophan has proved to be an effective strategy to control biofilm and may support in the development of surfacecoating technologies.

Modeling and optimization of multi-objective partial disassembly line balancing problem considering hazard and profit

With the improvement of environmental awareness, green manufacturing has been highly concerned by manufacturers and environmental organizations. In particular, for the increasing number of waste electrical and electronic equipment, disassembly as an important content of green manufacturing can reduce environmental impacts and save natural resources. The traditional complete disassembly mode only focuses on disassembly efficiency, which cannot satisfy the needs of environmental protection and economic development. Therefore, this paper establishes an evaluation system of partial disassembly line to balance environmental impacts and economic benefits. In this model, all hazardous tasks must be disassembled, and the benefit indicators of disassembly lines, including the number of workstations, workload smoothness and disassembly profit, are optimized simultaneously. To obtain satisfactory disassembly schemes, a new multi-objective genetic simulated annealing algorithm is proposed. The effectiveness and superiority of the proposed method are verified by a series of test examples. Moreover, a variety of disassembly schemes are presented in a practical disassembly case. All the schemes implement the disassembly of all hazardous tasks, while the average disassembly profit of the proposed method is 23.93%, 9.14% and 15.57% higher than that of other three comparison methods. Experimental results show that the proposed mode and method can not only reduce the environmental impacts, but also improve the economic efficiency indicators of disassembly lines.

Erratum to: Early emergence of the FtsH proteases involved in photosystem II repair

The verb ‚make“ was used instead of ‚form“ in the following sentence. Instead of A phylogenetic analysis of over 6000 FtsH protease sequences revealed that there are three major groups of FtsH proteases originating from gene duplication events in the last common ancestor of bacteria, and that the FtsH proteases involved in PSII repair make a distinct clade branching out before the divergence of FtsH proteases found in all groups of anoxygenic phototrophic bacteria. It should read A phylogenetic analysis of over 6000 FtsH protease sequences revealed that there are three major groups of FtsH proteases originating from gene duplication events in the last common ancestor of bacteria, and that the FtsH proteases involved in PSII repair form a distinct clade branching out before the divergence of FtsH proteases found in all groups of anoxygenic phototrophic bacteria. The word ‚photosynthetic“ was omitted in the following sentence: Instead of We conclude that the phylogeny of FtsH proteases is consistent with an early origin of water oxidation chemistry. It should read We conclude that the phylogeny of FtsH proteases is consistent with an early origin of photosynthetic water oxidation chemistry. The words ‚reactions“ and ‚for“ were used mistakenly in the following paragraph: Instead of Oxygenic photosynthetic electron transport from water to NADP+ requires the participation of two functionally distinct reactions centers (RCs) acting in series: photosystem II (PSII, a Type II RC containing quinone electron acceptors) and photosystem I (PSI, a Type I RC containing redox-active iron-sulphur clusters). Early ideas on for the emergence of oxygenic photosynthesis focused on the evolution of PSI and PSII from pre-existing RCs found in anoxygenic photosynthetic bacteria (Nitschke and Rutherford 1991) and the horizontal transfer of genes encoding chlorophyll biosynthetic enzymes and RC proteins (Hohmann-Marriott and Blankenship 2011, Fischer et al. 2016). It should read Oxygenic photosynthetic electron transport from water to NADP+ requires the participation of two functionally distinct reaction centers (RCs) acting in series: photosystem II (PSII, a Type II RC containing quinone electron acceptors) and photosystem I (PSI, a Type I RC containing redox-active iron-sulphur clusters). Early ideas on the emergence of oxygenic photosynthesis focused on the evolution of PSI and PSII from pre-existing RCs found in anoxygenic photosynthetic bacteria (Nitschke and Rutherford 1991) and the horizontal transfer of genes encoding chlorophyll biosynthetic enzymes and RC proteins (Hohmann-Marriott and Blankenship 2011, Fischer et al. 2016). The word ‚other“ was missing in the following sentence: Instead of Possible evolutionary constraints include the need to maintain protein quality control in the multiple membrane compartments found in cyanobacteria, chloroplasts, and mitochondria and the fact that oxygenic photosynthesis is associated with the production of singlet oxygen and ROS (reactive oxygen species), leading to protein damage, particularly in the thylakoid membrane which houses the photosynthetic apparatus. It should read Possible evolutionary constraints include the need to maintain protein quality control in the multiple membrane compartments found in cyanobacteria, chloroplasts and mitochondria and the fact that oxygenic photosynthesis is associated with the production of singlet oxygen and other ROS (reactive oxygen species), leading to protein damage, particularly in the thylakoid membrane which houses the photosynthetic apparatus. The word ‚of“ was mistakenly used instead of ‚to“ in the following sentence: Instead of Recognition of damaged D1 by cyanobacterial FtsH complexes is thought to be mediated by partial disassembly of damaged PSII (Krynicka et al. 2015) and binding of the N-terminal tail of D1 (Komenda et al. 2007). It should read Recognition of damaged D1 by cyanobacterial FtsH complexes is thought to be mediated by partial disassembly of damaged PSII (Krynicka et al. 2015) and binding to the N-terminal tail of D1 (Komenda et al. 2007).

Profit-oriented partial disassembly line design: dealing with hazardous parts and task processing times uncertainty

This paper addresses the problem of profit-oriented disassembly line design and balancing considering partial disassembly, presence of hazardous parts and uncertainty of task processing times. Few papers have studied the stochastic disassembly line balancing problem and existing approaches have focused on heuristic and metaheuristic methods. Most existing work has concentrated on complete disassembly where task times are assumed to be normal random variables and where AND/OR graphs are not considered. The objective of this paper is the design of a serial line that obtains the maximum revenue and then balances the workload under uncertainty. The processing time of a disassembly task is assumed to be a random variable with any known probability distribution. An AND/OR graph is used to model the precedence relationships among tasks. Stochastic programming models and exact-based solution approaches combining the L-shaped algorithm and Monte Carlo sampling techniques are proposed. The relevance and applicability of the proposed models and solution methods are shown by solving efficiently a set of disassembly problem instances from the literature.

Multi-objective Optimization for Partial Disassembly Line Balancing with Goaldriven Discrete Cuckoo Search

Multi-objective Optimization for Partial Disassembly Line Balancing with Goaldriven Discrete Cuckoo Search

Modeling and Optimizing for Multi-objective Partial Disassembly Line Balancing Problem

Modeling and Optimizing for Multi-objective Partial Disassembly Line Balancing Problem

Partial/Parallel Disassembly Sequence Planning for Complex Products

Disassembly is a very important step in recycling and maintenance, particularly for energy saving. However, disassembly sequence planning (DSP) is a challenging combinatorial optimization problem due to complex constraints of many products. This paper considers partial and parallel disassembly sequence planning for solving the degrees-of-freedom in modular product design, considering disassembly time, cost, and energy consumption. An automatic self-decomposed disassembly precedence matrix (DPM) is designed to generate partial/parallel disassembly sequence for reducing complexity and improving efficiency. A Tabu search-based hyper heuristic algorithm with exponentially decreasing diversity management strategy is proposed. Compared with the low-level heuristics, the proposed algorithm is more efficient in terms of exploration ability and improving energy benefits (EBs). The comparison results of three different disassembly strategies prove that the partial/parallel disassembly has a great advantage in reducing disassembly time, and improving EBs and disassembly profit (DP).

Nanostructured Phthalocyanine Assemblies with Protein-Driven Switchable Photoactivities for Biophotonic Imaging and Therapy.

Switchable phototheranostic nanomaterials are of particular interest for specific biosensing, high-quality imaging, and targeted therapy in the field of precision nanomedicine. Here, we develop a "one-for-all" nanomaterial that self-assembles from flexible and versatile phthalocyanine building blocks. The nanostructured phthalocyanine assemblies (NanoPcTBs) display intrinsically unique photothermal and photoacoustic properties. Fluorescence and reactive oxygen species generation can be triggered depending on a targeted, protein-induced, partial disassembly mechanism, which creates opportunities for low-background fluorescence imaging and activatable photodynamic therapy. In vitro evaluations indicate that NanoPcTB has a high selectivity for biotin receptor-positive cancer cells (e.g., A549) compared to biotin receptor-negative cells (e.g., WI38-VA13) and permits a combined photodynamic and photothermal therapeutic effect. Following systemic administration, the NanoPcTBs accumulate in A549 tumors of xenograft-bearing mice, and laser irradiation clearly induces the inhibition of tumor growth.

Structural insights into the light-driven auto-assembly process of the water-oxidizing Mn4CaO5-cluster in photosystem II.

In plants, algae and cyanobacteria, Photosystem II (PSII) catalyzes the light-driven splitting of water at a protein-bound Mn4CaO5-cluster, the water-oxidizing complex (WOC). In the photosynthetic organisms, the light-driven formation of the WOC from dissolved metal ions is a key process because it is essential in both initial activation and continuous repair of PSII. Structural information is required for understanding of this chaperone-free metal-cluster assembly. For the first time, we obtained a structure of PSII from Thermosynechococcus elongatus without the Mn4CaO5-cluster. Surprisingly, cluster-removal leaves the positions of all coordinating amino acid residues and most nearby water molecules largely unaffected, resulting in a pre-organized ligand shell for kinetically competent and error-free photo-assembly of the Mn4CaO5-cluster. First experiments initiating (i) partial disassembly and (ii) partial re-assembly after complete depletion of the Mn4CaO5-cluster agree with a specific bi-manganese cluster, likely a di-µ-oxo bridged pair of Mn(III) ions, as an assembly intermediate.