Cellular Configuration Research Articles

Cellular manufacturing system design using grouping efficacy-based genetic algorithm

This paper presents an algorithm for the design of manufacturing cells and part families. This algorithm is suitable for arriving at a good block diagonal structure for a cellular manufacturing design problem with part machine incidence matrix as input. The objective of this algorithm is the maximisation of grouping efficacy (GE), which is one of the most widely used measures of quality for cellular configurations. Assignment of machines to cells is using genetic algorithm, and part assignment heuristic is based on an effective customised rule. A comparison of the proposed algorithm is made with seven other methods of cell formation by taking 36 problems from the literature and found that the proposed algorithm is performing much better than the others. Finally, the algorithm is extended to form configurations with good GE when there are alternative routes.

Cellular-local Algorithm for Localizing and Estimating Changes in Binary Images

In this paper we consider the problem of detection of changes and estimation of the degree of these changes in a dynamically changing binary image. The authors introduce the numerical characteristic degree of change areas in dynamically changing binary images, based on the Jaccard similarity coefficient. To calculate this characteristic the authors developed an original architecture of a two-dimensional cellular automaton with the diffusion dynamics. We establish that cellular automaton configurations converge to a stationary configuration. The stationary configuration of a cellular automaton defines the desired characteristics for each area in dynamically changing binary images. The result can be presented as a grayscale image, that greatly facilitates the visual analysis of the dynamics of changes in dynamically changing binary images. The suggested approach can be used to detect and numerically estimate changes in the case when a number of brightness gradation comprises more than two values.

The alpha1,3GalT knockout/alpha1,2FucT transgenic pig does not appear to have an advantage over the alpha1,3GalT knockout pig with respect to glycolipid reactivity with human serum antibodies

The human H-transferase (α2FucT) was introduced in Gal-negative pigs to produce pig organs not only free from Gal-antigens, but also in which the uncapped N-acetyllactosamine precursor had been transformed into non-xenogenic blood group H type 2 compounds. This work is the first descriptive analysis of glycolipids from the GalT-KO/FucT-TG pig. The aim was to investigate the cell membrane antigens in GalT-KO/FucT-TG tissues to explore its efficacy as an organ donor. Also, detailed knowledge on the correlation between the cellular glycosyltransferase configuration and the resulting carbohydrate phenotype expression is valuable from a basic glycobiological perspective. Neutral and acidic glycolipids from GalT-KO/FucT-TG small intestine were compared with glycolipids from two wildtype and two GalT-KO pig intestines. Glycolipid reactivity was tested on thin layer chromatography plates using chemical reagents, antibodies, lectins, and human serum. Structural characterization of neutral glycolipids was performed by LC-ESI/MS and proton NMR spectroscopy. Characterization of the glycolipid expression in GalT-KO/FucT-TG intestine showed absence of Gal antigens and decreased/unchanged levels of the N-acetyllactosamine precursor and the blood group H type 2 expression, when compared with the wildtype. The reactivity of human serum antibodies to GalT-KO/FucT-TG derived glycolipids was similar or slightly elevated when compared with GalT-KO glycolipids. Results from LC-ESI/MS and proton NMR spectroscopy revealed no established neutral xenogenic antigens in the GalT-KO/FucT-TG pig, and could thus not explain the immunologic reactivity to human serum antibodies. The antibody binding to acidic glycolipids is most likely to be explained by the abundance of N-glycolylneuraminic acid epitopes in pig tissues. Six neutral complex biantennary glycolipids with blood group H type 1, 2, Lewis(x) and Lewis(y) determinants were found, of which three were identified in this work for the first time. One of these was a nonaglycosylceramide with blood group H type 2 and lactosyl determinants linked to a lactotetraosyl core, and the other two were decaglycosylceramides with blood group H type 1 and H type 2 determinants linked to a neolactotetraosyl core, and Lewis(x) and blood group H type 1 determinants on a lactotetraosyl core, respectively. Lipid-linked carbohydrate antigens in the GalT-KO/FucT-TG pig intestine showed no or minor qualitative difference when compared with GalT-KO pigs. The GalT-KO/FucT-TG pig did not appear to have an advantage over the GalT-KO pig with respect to reactivity with human antibodies from a xenotransplantation perspective.

3D BrainCV: Simultaneous visualization and analysis of cells and capillaries in a whole mouse brain with one-micron voxel resolution

Systematic cellular and vascular configurations are essential for understanding fundamental brain anatomy and metabolism. We demonstrated a 3D brainwide cellular and vascular (called 3D BrainCV) visualization and quantitative protocol for a whole mouse brain. We developed a modified Nissl staining method that quickly labeled the cells and blood vessels simultaneously in an entire mouse brain. Terabytes 3D datasets of the whole mouse brains, with unprecedented details of both individual cells and blood vessels, including capillaries, were simultaneously imaged at 1-μm voxel resolution using micro-optical sectioning tomography (MOST). For quantitative analysis, we proposed an automatic image-processing pipeline to perform brainwide vectorization and analysis of cells and blood vessels. Six representative brain regions from the cortex to the deep, including FrA, M1, PMBSF, V1, striatum, and amygdala, and six parameters, including cell number density, vascular length density, fractional vascular volume, distance from the cells to the nearest microvessel, microvascular length density, and fractional microvascular volume, had been quantitatively analyzed. The results showed that the proximity of cells to blood vessels was linearly correlated with vascular length density, rather than the cell number density. The 3D BrainCV made overall snapshots of the detailed picture of the whole brain architecture, which could be beneficial for the state comparison of the developing and diseased brain.

Finite element investigation on deflection of cellular beams with various configurations

The effect of the cellular beam configuration on the deflection has been investigated by using the three-dimensional finite element analysis of 408 cellular beams. Cross-section dimension, beam slenderness, opening size and opening spacing are found to affect the stiffness of the analytical load-deflection curve. The parametric study of the FE stiffness and normalized stiffness is conducted. The stress distribution of the finite element (FE) model reveals the strut stress in the web-post contributes to the increasing deflection in addition to the regular bending deflection. The deformation of the web-post and the relative movement between the upper and lower tee-sections due to strut stress is the main reason of the additional deflection in the cellular beams. The effect of the strut stress is found to be significant for the deflection of the short-span beams but less for the long-span beams. To convert the theoretical bending deflection to be the overall deflection, the calibrating coefficient function is established by using the empirical study. The function is formulated in terms of the slenderness, spacing and cross section ratio. The deflection prediction is useful to check serviceability condition for the design purpose.

A nonlinear auxetic structural vibration damper with metal rubber particles

The work describes the mechanical performance of a metal rubber particles (MRP) damper design based on an auxetic (negative Poisson’s ratio) cellular configuration. The auxetic damper configuration is constituted by an anti-tetrachiral honeycomb, where the cylinders are filled with the MRP material. The MRP samples have been subjected to quasi-static loading to measure the stiffness and loss factor from the static hysteresis curve. A parametric experimental analysis has been carried out to investigate the effect of relative density and filling percentage on the static performance of the MRP, and to identify design guidelines for best use of MRP devices. An experimental assessment of the integrated auxetic-MRP damper concept has been provided through static and dynamic force response techniques.

SILICOMB PEEK Kirigami cellular structures: mechanical response and energy dissipation through zero and negative stiffness

The work describes the manufacturing, testing and parametric analysis of cellular structures exhibiting zero Poisson’s ratio-type behaviour, together with zero and negative stiffness effects. The cellular structures are produced in flat panels and curved configurations, using a combination of rapid prototyping techniques and Kirigami (Origami and cutting) procedures for PEEK (Polyether Ether Ketone) thermoplastic composites. The curved cellular configurations show remarkable large deformation behaviours, with zero and negative stiffness regimes depending also on the strain rate applied. These unusual stiffness characteristics lead to a large increase of energy absorption during cyclic tests.

Cytotoxicity of titanium dioxide nanoparticles in rat neuroglia cells

Aim: To find the cytotoxicity of titanium dioxide nanoparticles (nano-TiO2) posed to neuroglia cells.Methods: This study tested the inhibiting effect of different sized nano-TiO2 on the cell survival rate for rat astrocytes in vitro and in vivo and pathological analysis was also done to evaluate its effect; IL-1β, TNF-α and IL-10 of rat brain tissue was also examined.Results: In vitro examination, the inhibiting effect of nano-TiO2 on the cell survival rate, was significantly enhanced dose dependently. There were also obvious changes in cellular configuration, such as sparse arrangement, increscent cell spaces, increasing intracellular particles and decreasing cellular transparency. When rats were exposed to nano-TiO2 of 10 and 20 nm in diameter in 1.0 and 10.0 mg kg−1, the concentrations IL-1β, TNF-α and IL-10 in brain tissue increased with the dose of nano-TiO2. Pathological observation indicated that the blood–brain barrier was destroyed and resulted in brain tissue necrosis, inflammation and cellular oedema.Conclusions: Nano-TiO2 is toxic to rat neuroglia cells. This toxicity may be related to particle size and the mechanism may be associated with its induction inflammation.

An Enhanced Difference Method for Multi-objective Model of Cellular Base Station Antenna Configurations

In this paper, we propose a fine-grained grid-based multi-objective model which aims at optimizing base station antennas' configurations, such as transmit power, antenna tilt and antenna azimuth, in order to upgrading network performance in cellular networks. As the model is non-convex, non-smooth and discrete and computationally expensive, we use decomposition method to solve the MOP problem. We mainly focus on addressing the scalarized sub-problem after decomposition. For the scalarized sub-problem, we propose an enhanced difference method. First, difference of each component is calculated, which provides the guidance of optimization. Then an OPSO is applied to search the optimal step length. The method is applied to GSM network optimization on an area in Beijing. The effect of the application shows that proposed method has a good performance, and is effective/efficient to solve mobile network optimization problems.

Biologically inspired water purification through selective transport

Biologically inspired systems based on cellular mechanics demonstrate the ability to selectively transport ions across a bilayer membrane. These systems may be observed in nature in plant roots, which remove select nutrients from the surrounding soil against significant concentration gradients. Using biomimetic principles in the design of tailored active materials allows for the development of selective membranes for capturing and filtering targeted ions. Combining this biomimetic transport system with a method for reclaiming the captured ions will allow for increased removal potential. To illustrate this concept, a device for removing nutrients from waterways to aid in reducing eutrophication is outlined and discussed. Presented is a feasibility study of various cellular configurations designed for this purpose, focusing on maximizing nutrient uptake. The results enable a better understanding of the benefits and obstacles when developing these cellularly inspired systems.

Resource allocation with multicell processing, interference cancelation and backhaul rate constraint in single carrier FDMA systems

We consider a cellular system where base stations (BSs) cooperate to receive data from mobile terminals (MTs) using single carrier frequency division multiple access (SC-FDMA). This yields a distributed multiantenna system, with corresponding multicell processing gain. Moreover, the exchange of information among BSs is limited due to the rate constraint on the backhaul network. A first contribution of the paper is a scheduler of the signals shared among BSs on the backhaul with the objective of maximizing the SC-FDMA system sum rate. A greedy algorithm is proposed as a viable solution of the problem. A fundamental feature of the scheduler is that BSs may share received signals only within a subset of the subcarriers of each SC-FDMA block. As a further contribution of the paper, to increase the system sum rate, we also consider interference cancelation, where BSs detect some messages without cooperation, and transmit on the backhaul a suitable linear combination of received and detected signals. The scheduling problem is suitably modified to take into account interference cancelation, thus selecting the MTs for which detection occurs before sharing the signal on the backhaul. Numerical results for typical cellular configurations are presented.

Deployable auxetic shape memory alloy cellular antenna demonstrator: design, manufacturing and modal testing

This work describes the design, manufacturing and testing of a deployable antenna for deep-space missions based on a hybrid honeycomb truss made of shape memory alloy (SMA). The deployable characteristics are enhanced by the equivalent auxetic (negative Poisson’s ratio) behaviour of the cellular configuration. Specific emphasis is placed on the modal analysis techniques used to test the lightweight SMA structure.

Reducing Setup Time in Manufacturing Cells in a JIT Environment

Setup time is a major issue in Just-in-time environments. Even with a cellular manufacturing configuration, reduction of setup time is not fully insured and needs to be explicitly targeted. We have introduced a mathematical programming model which would reduce sequence-dependent setup time in manufacturing cells. Since the BIP model is NP hard, a solution approach based on a Genetic Algorithm has been improvised.

Single Cell Time-resolved Quorum Responses Reveal Dependence on Cell Density and Configuration

Bacterial communication via quorum sensing has been extensively investigated in recent years. Bacteria communicate in a complex manner through the production, release, and reception of diffusible low molecular weight chemical signaling molecules. Much work has focused on understanding the basic mechanisms of quorum sensing. As more and more bacteria grow resistant to conventional antibiotics, the development of drugs that do not kill bacteria but instead interrupt their communication is of increasing interest. This study presents a method for analyzing bacterial communication by investigating single cell responses. Most conventional analysis methods for bacterial communication are based on the averaged response from many bacteria, masking how individual cells respond to their immediate environment. We applied a fiber-optic microarray to record cellular communication from single cells. Single cell quorum sensing systems have previously been employed, but the highly ordered array reported here is an improvement because it allows us to simultaneously investigate cellular communication in many different environments with known cellular densities and configurations. We employed this method to detect how genes under quorum regulation are induced or repressed over time on the single cell level and to determine whether cellular density and configuration are indicative of the single cell temporal patterns of gene expression.

A Gradient Cellular Core for Aeroengine Fan Blades Based on Auxetic Configurations

In this study, gradient cellular centresymmetric auxetic configurations are evaluated as potential cores for aeroengine fan blades, and optimized to reduce the dynamic response for the first three fundamental modes. Auxetic (negative Poisson’s ratio) re-entrant cellular beams are modeled, manufactured, and tested to assess their natural frequencies and mode shapes. Gradient versions of these beams with a varying internal cell angle are then designed to be incorporated as fillers in a baseline fan blade model. The optimized configurations of the gradient core lead to a substantial decrease of the mass of the fan blade, reduction of the dynamic modal displacements, and a lowering of the first three natural frequencies within the admissible frequency bandwidth.

Transverse shear modulus of SILICOMB cellular structures

This work describes the transverse shear stiffness properties of a novel honeycomb with zero Poisson’s ratio. The cellular configuration is simulated using a series of finite element models representing full-scale and representative unit cells of the honeycomb topology. The models are benchmarked against experimental results from pure shear and 3-point bending ASTM tests. The benchmarked models are used to perform a parametric study of the shear moduli ( G 13 and G 23) against the geometry of the unit cell and the gauge thickness of the honeycomb panels. The shear stiffness maps obtained allow comparison of the SILICOMB configuration against classical centresymmetric and rectangular honeycomb topologies.

In Vitro Study and Biocompatibility of Calcined Mesoporous Silica Microparticles in Mouse Lung

We report on the pneumatocyte structure and function of mouse lung specimens exposed in vitro to two calcined mesoporous silica particles, MCM41-cal (spheres, ∼300 to 1000 nm in diameter) and SBA15-cal (irregular rods averaging ∼500 nm in diameter and ∼1000 nm in length). These mesoporous silica particles are in consideration for potential medical application as delivery vehicles for genes, drugs, and bio-imagers. In the study, lung specimens (about 10 mg each) were excised from male Balb/c mice, immediately immersed in Krebs-Henseleit buffer, ice-cold, and continuously gassed with O(2):CO(2) (95:5). The samples were incubated at 37°C in the same buffer with and without 200 μg/mL MCM41-cal or SBA15-cal for 5-14 h. The tissues were then rinsed thoroughly and processed for light and electron microscopy. Normal alveolar morphology was evident in all the studied specimens. There was no significant difference in the number of apoptotic cells between the treated and untreated samples. Despite their relatively large sizes, the particles were abundantly present in pneumocytes, macrophages, endothelial cells, fibroblasts, and interstitium. They were seen in different areas of the cytoplasm, suggesting intracellular movements. Their presence did not appear to disturb cellular configuration or micro-organelles. Due to their rigidity and surface charges, some were firmly attached to (indenting) the nuclear membrane. The rate of respiration (cellular mitochondrial O(2) consumption, in μM O(2)/min/mg) in specimens exposed to 200 μg/mL particles for up to 12 h was the same as untreated specimens. These findings confirm "reasonable" bioavailability and biocompatibility of calcined mesoporous silicas with mouse lung within at least 5-14 h of exposure time.

Effects of strain rate on dislocation for TA15 alloy during hot compressive deformation

The effects of strain rate on the dislocation type and dislocation configure of TA15 alloy were investigated. The experimental results show that the operating dislocation type changes from \( \bar c \) type to \( \bar c \) and \( \bar a + \bar c \) type with increasing strain rate under the deformation condition of 900 °C, 60% strain. Under the condition of 900 °C, 60% strain and 0.001/s strain rate, lots of orientate dislocation cellular configurations and sub-grains, many dislocations pile up before sub boundary. When the strain rate increases to 0.1/s, some dislocations exhibit curved and dislocation tangles and pile-ups can be found, suggesting more dislocations and much stronger interactions among dislocations.

Evaluation of cellular manufacturing configurations in dynamic conditions using simulation

This paper investigates the performance of classical cellular manufacturing systems compared to other two systems proposed in literature: fractal cells and remainder cells. This paper proposes three strategies to control a cellular manufacturing system with remainder cell and how to configure and control a fractal manufacturing system. The performance measures of the manufacturing systems are analyzed when several unforeseen events occur as: machine breakdowns, production mix changes, demand fluctuations, and processing time variability. A simulation environment developed by Arena® package was used to investigate the three manufacturing system configurations. The performance measures investigated are: throughput, throughput times of the parts, work in process, manufacturing utilization, and due date performance (tardiness). The simulation results show how the fractal and remainder cells can be a valid alternative to cellular manufacturing systems in a very dynamic environment.

Numerical Analysis on Static Mechanical Properties of the Periodic Multilayer Lattice Material

Lattice material is a typical periodic structural material, and the gaps of the lattice material are often used to carry filling materials. In order to satisfy the load-carrying requirements of a certain multifunction/structure integrated composite material, four different 3D periodic multilayer lattice materials were proposed in this paper, such as the square, the quadrate, the tetrahedron and the hexagon. The BEAM189 element in ANSYS was adopted to predict their static mechanical properties, and the Mises strength criterion was taken as the failure criterion. Based on the solution of FEM, the axial stress and displacement of the top surface were obtained. The results indicated that adopting the relative stiffness and the load-mass ratio as the overall assessment is effective to evaluate the overall bearing capacity of the multilayer lattice materials. Given the same cross-section size of the cellular configuration, the hexagon multilayer lattice material shows the relatively optimal overall bearing capacity in the four configurations, while the tetrahedron configuration performs the worst.