Processing and phase separation of LSMO-based multiferroic composite ceramics

In this paper, the effect of processing conditions on phase separation and crystal structure of (x) La_0.625Sr_0.375MnO₃–(1 − x) LuMnO₃ composite system was studied by XRD and SEM. The results confirm that there is a solid solution of monoclinic phase of space group P112₁/a in this system, i.e. (La_0.625Sr_0.375)_x Lu_1−xMnO₃ is formed for x = 0.980–1.0. For 0 < x ≤ 0.975, the immiscibility region shows clear separation of both La-rich and Lu-rich phases. The optimal preparation conditions were found for this system: sintering at 1250 and 1350 °C for samples of monoclinic La-rich phase and for the immiscibility region, respectively.     

A study of Pb vacancies and Pb-O vacancy pairs in doped Pb0.85Sr0.15 (Zr0.55Ti0.45)O3 ceramics by positron annihilation

Positron annihilation spectroscopy has been used to study the formation and complex of Pb and O vacancies in polycrystalline Pb_0.85Sr_0.15(Zr_0.55Ti_0.45)O₃(PSZT) ceramics with various amounts of Mn and (Sb, Nb) dopants, fabricated from mixed-oxide powders. The results suggest that the positron may be trapped by V_Pb vacancies and V_Pb-V_o pairs in PSZT with characteristic lifetimes of 305±6 and 379±15 ps, respectively. Doped Mn^3+/2+ ions are assumed to substitute for (Zr, Ti)⁴⁺ in the perovskite (ABO₃) lattice and V_o vacancies were created for charge compensation. V_Pb vacancies were generated when partial Sb³⁺ entered the Pb²⁺ site or certain amounts of Sb⁵⁺ occupied the B site. Impurity ions serving as acceptors or donors significantly affect the conduction process and dielectric and piezoelectric behaviour which could be accounted for by the defect structures of PSZT seen by the positron.     

Integrated production planning and control system for a panelized home prefabrication facility using simulation and RFID

The construction industry is adopting off-site construction for its superior quality, short cycle time, and minimal environmental impact. Among the different off-site construction methods, panelized construction follows a manufacturing approach where houses are built in smaller panels in an assembly line. Due to the complex and unique nature of the home building process, existing manufacturing concepts such as automated production planning and control system are not applicable to the panelized home production facility. This paper utilizes radio frequency identification (RFID) technology, data mining, and simulation-based optimization to develop a production planning and control system for a panelized home production facility. The RFID system is used to automatically collect the production data; however, the RFID data in this study contains considerable noise. Thus, it is crucial to extract the relevant data from the raw data. A RANSAC model is developed for this purpose to automatically clean the RFID data and then use it to build the simulation model, which is then integrated with an optimization algorithm to generate the production schedule and real-time performance monitoring. The proposed framework cleans the noisy RFID data to extract records that represent a steady flow of assembly line. These clean records are then used to build PDFs that are required to develop discrete event simulation model that can help managers to capture an almost real-time snapshot of the production of the assembly line as well as automatically optimize the production schedule. The proposed system is implemented and validated in a panelized wall production facility operated by ACQBUILT Inc., a prefabricated home builder in Edmonton, Canada.     

Performance analysis of simulation-based optimization of construction projects using High Performance Computing

The complexity and uncertain nature of bridge construction projects require simulation for analyzing and planning these projects. On the other hand, optimization can be used to address the inverse relationship between the cost and time of a project and to find a proper trade-off between these two key elements. In addition, the large number of resources required in large-scale bridge construction projects results in a very large search space. Therefore, there is a need for using parallel computing to reduce the computational time of the simulation-based optimization problem. Another problem in this area is that most of the construction simulation tools need an integration platform to be combined with optimization techniques. To alleviate these limitations, an integrated simulation-based optimization framework is developed within one High Performance Computing (HPC) platform, and its performance is analyzed by carrying out a case study. A master-slave (or global) parallel Genetic Algorithm (GA) is used to decrease the computation time and to efficiently use the full capacity of the computer. In addition, sensitivity analysis is applied to identify the promising configuration for GA and the best number of cores used in parallel and to analyze the impact of GA parameters on the overall performance of the simulation-based optimization model. Using NSGA-ΙΙ as the optimization algorithm resulted in better near-optimal solutions compared to those of fast-messy GA. Moreover, performing the proposed framework on multiple nodes using the cluster system led to 31% saving in the computation time on average. Furthermore, the GA was tuned using sensitivity analyses, which resulted in the selection of the best parameters of the GA.     

Nutrients transport in the bare urban redeveloped soil system during runoff process

Stormwater pollution in redeveloped soils mixed with construction wastes imposes a serious impact to receiving waters. The transport and distribution of rainfall water and nutrients in the surface-flow and subsurface-flow (including side-flow and down-flow) of bare redeveloped soil runoff system were determined. Results indicated that the flow patterns and pollutants transport of surface-flow were different from those in subsurface-flow. The flowrate of surface-flow increased at the beginning and reached to a stable state, and then disappeared immediately after the rainfall stopped. While the flow rate of subsurface-flow was persisted and decreased gradually artery the rainfall. Most of the pollutants were carried in the surface-flow, which directly results in polluting the surface-receiving waters. And the pollutants distribution percent in side-flow was higher than that in down-flow. Results obtained in this study will provide information for the management of stormwater pollution in the bare redeveloped soil mixed with construction wastes.     

Prenatal Exposure to Lipopolysaccharide Results in Myocardial Fibrosis in Rat Offspring

The epigenetic plasticity hypothesis indicates that exposure during pregnancy may cause adult-onset disorders, including hypertension, myocardial infarction and heart failure. Moreover, myocardial fibrosis coincides with hypertension, myocardial infarction and heart failure. This study was designed to investigate the effects of prenatal exposure to lipopolysaccharide (LPS) on myocardial fibrosis. The result showed that at six and 16 weeks of age, the LPS-treated offspring exhibited increased collagen synthesis, an elevated cardiac index (CI), higher mRNA levels of TIMP-2 and TGFβ and a reduced mRNA level of MMP2. The protein levels corresponded to the mRNA levels. The offspring that were prenatally treated with pyrrolidine dithiocarbamic acid (PDTC), an inhibitor of NF-κB, displayed improvements in the CI and in collagen synthesis. Moreover, PDTC ameliorated the expression of cytokines and proteins associated with myocardial fibrosis. The results showed that maternal inflammation can induce myocardial fibrosis in offspring during aging accompanied by an imbalance of TIMP-2/MMP2 and TGFβ expression.     

Microwave-Assisted Synthesis of Glutathione-Capped CdTe/CdSe Near-Infrared Quantum Dots for Cell Imaging

These glutathione (GSH)-conjugated CdTe/CdSe core/shell quantum dot (QD) nanoparticles in aqueous solution were synthesized using a microwave-assisted approach. The prepared type II core/shell QD nanoparticles were characterized by UV–Vis absorption, photoluminescence (PL) spectroscopy, X-ray powder diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM). Results revealed that the QD nanoparticles exhibited good dispersity, a uniform size distribution and tunable fluorescence emission in the near-infrared (NIR) region. In addition, these nanoparticles exhibited good biocompatibility and photoluminescence in cell imaging. In particular, this type of core/shell NIR QDs may have potential applications in molecular imaging.     

Anti-TMV Activity of Malformin A1, a Cyclic Penta-Peptide Produced by an Endophytic Fungus Aspergillus tubingensis FJBJ11

Plant-associated microorganisms are known to produce a variety of metabolites with novel structures and interesting biological activities. An endophytic fungus FJBJ11, isolated from the plant tissue of Brucea javanica (L.) Merr. (Simaroubaceae), was proven to be significantly effective in producing metabolites with anti-Tobacco mosaic virus (TMV) activities. The isolate was identified as Aspergillus tubingensis FJBJ11 based on morphological characteristics and ITS sequence. Bioassay-guided isolation led to the identification of a cycli penta-peptide, malformin A₁, along with two cyclic dipeptides, cyclo (Gly-l-Pro) and cyclo (Ala-Leu). Malformin A₁ showed potent inhibitory effect against the infection and replication of TMV with IC₅₀ values of 19.7 and 45.4 μg·mL⁻¹, as tested using local lesion assay and leaf-disc method, respectively. The results indicated the potential use of malformin A₁ as a leading compound or a promising candidate of new viricide.     

Gene Overexpression and RNA Silencing Tools for the Genetic Manipulation of the S-(+)-Abscisic Acid Producing Ascomycete Botrytis cinerea

The phytopathogenic ascomycete Botrytis cinerea produces several secondary metabolites that have biotechnical significance and has been particularly used for S-(+)-abscisic acid production at the industrial scale. To manipulate the expression levels of specific secondary metabolite biosynthetic genes of B. cinerea with Agrobacterium tumefaciens-mediated transformation system, two expression vectors (pCBh1 and pCBg1 with different selection markers) and one RNA silencing vector, pCBSilent1, were developed with the In-Fusion assembly method. Both expression vectors were highly effective in constitutively expressing eGFP, and pCBSilent1 effectively silenced the eGFP gene in B. cinerea. Bcaba4, a gene suggested to participate in ABA biosynthesis in B. cinerea, was then targeted for gene overexpression and RNA silencing with these reverse genetic tools. The overexpression of bcaba4 dramatically induced ABA formation in the B. cinerea wild type strain Bc-6, and the gene silencing of bcaba4 significantly reduced ABA-production in an ABA-producing B. cinerea strain.