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As the demand for sustainable and environmentally conscious practices continues to grow, recycled plastics have become increasingly popular for plastics manufacturers. However, reprocessing these materials can result in inconsistencies in both process and product quality, leading to a loss in mechanical properties. To address this issue, this work investigates the injection molding of recycled and virgin polypropylene (PP). Using a multi-cavity hot runner mold, correlations between processing parameters, such as melt temperature, mold temperature, pack pressure, soak time, and mechanical properties, were systematically investigated. A multivariate analysis approach was used to model the variables for each material. Results indicated significant correlations between processing, mechanical properties, and morphology. In particular, for the PP, the melt temperature affected the formation of [beta]-crystals and their transition to [alpha]-crystals upon tensile testing. Different morphology was observed for the recycled polypropylene (rPP), in which crystallization was affected by polyethylene (PE) contamination. The results discuss the injection molding polymer, structure, and properties, relationship providing an approach to understanding and optimizing the mechanical properties of rPP. Highlights * Polyethylene contamination in polypropylene significantly influences crystallinity. * Recycling contamination reduces the polypropylene's ability to form (3 crystals. * Virgin polypropylene mechanical properties can be tailored through processing conditions. * Recycled polypropylene mechanical properties suffer at higher temperatures and residence times. * Polypropylene [alpha]/[beta] morphologies can be visualized after mechanical testing. KEYWORDS crystallization, hot runner injection molding, recycled polypropylene, 1 | INTRODUCTION Injection molding's ability to mass produce complex parts cost-effectively allowed plastics to become one of the most widely used materials, with injection molding contributing 33% of all [...]

Toluene and other fuel hydrocarbons are commonly found in association with radionuclides at numerous US Department of Energy sites, frequently occurring together with Cr(VI) and other heavy metals. In this study, the extremely radiation-resistant bacterium Deinococcus radiodurans, which naturally reduces Cr(VI) to the less mobile and less toxic Cr(III), was engineered for complete toluene degradation by cloned expression of tod and xyl genes of Pseudomonas putida. The recombinant Tod/Xyl strain showed incorporation of carbon from 14C-labelled toluene into cellular macromolecules and carbon dioxide, in the absence or presence of chronic ionizing radiation. The engineered bacteria were able to oxidize toluene under both minimal and complex nutrient conditions, and recombinant cells reduced Cr(VI) in sediment microcosms. As such, the Tod/Xyl strain could provide a model for examining the reduction of metals coupled to organic contaminant oxidation in aerobic radionuclide-contaminated sediments.

The article examines the impact of World Trade Organization's trade rules on corporate taxes for United States and European Union member states.

MerR, the metalloregulator of the bacterial mercury resistance (mer) operon, binds Hg(II) with high affinity. To study the mechanism of metal-induced activation, a small protein was previously engineered embodying in a single polypeptide the metal-binding domain (MBD) ordinarily formed between two monomers of MerR. Here the physiological and biochemical properties of MBD expressed on the cell surface or in the cytosol were examined, to better understand the environments in which specific metal binding can occur with this small derivative. Over 20 000 surface copies of MBD were expressed per Escherichia coli cell, with metal stoichiometries of 1.0 Hg(II) per MBD monomer. Cells expressing MBD on their surface in rich medium bound 6-1-fold more Hg(II) than those not expressing MBD. Although in nature cells use the entire mer operon to detoxify mercury, it was interesting to note that cells expressing only MBD survived Hg(II) challenge and recovered more quickly than cells without MBD. Cell-surface-expressed MBD bound Hg(II) preferentially even in the presence of a 22-fold molar excess of Zn(II) and when exposed to equimolar Cd(II) in addition. MBD expressed in the cystosol also afforded improved survival from Hg(II) exposure for E. coli and for the completely unrelated bacterium Deinococcus radiodurans.

The ionizing radiation (IR) dose that yields 20% survival ([D.sub.20]) of Shewanella oneidensis MR-1 is lower by factors of 20 and 200 than those for Escherichia coli and Deinococcus radiodurans, respectively. Transcriptome analysis was used to identify the genes of MR-1 responding to 40 Gy ([D.sub.20]). We observed the induction of 170 genes and repression of 87 genes in MR-1 during a 1-h recovery period after irradiation. The genomic response of MR-1 to IR is very similar to its response to UV radiation (254 nm), which included induction of systems involved in DNA repair and prophage synthesis and the absence of differential regulation of tricarboxylic acid cycle activity, which occurs in IR-irradiated D. radiodurans. Furthermore, strong induction of genes encoding antioxidant enzymes in MR-1 was observed. DNA damage may not be the principal cause of high sensitivity to IR, considering that MR-1 carries genes encoding a complex set of DNA repair systems and 40 Gy IR induces less than one double-strand break in its genome. Instead, a combination of oxidative stress, protein damage, and prophage-mediated cell lysis during irradiation and recovery might underlie this organism's great sensitivity to IR.

Deinococcus radiodurans R1 (DEIRA) is a bacterium best known for its extreme resistance to the lethal effects of ionizing radiation, but the molecular mechanisms underlying this phenotype remain poorly understood. To define the repertoire of DEIRA genes responding to acute irradiation (15 kGy), transcriptome dynamics were examined in cells representing early, middle, and late phases of recovery by using DNA microarrays covering [approximately equal to] 94% of its predicted genes. At least at one time point during DEIRA recovery, 832 genes (28% of the genome) were induced and 451 genes (15%) were repressed 2-fold or more. The expression patterns of the majority of the induced genes resemble the previously characterized expression profile of recA after irradiation. DEIRA recA, which is central to genomic restoration after irradiation, is substantially up-regulated on DNA damage (early phase) and down-regulated before the onset of exponential growth (late phase). Many other genes were expressed later in recovery, displaying a growth-related pattern of induction. Genes induced in the early phase of recovery included those involved in DNA replication, repair, and recombination, cell wall metabolism, cellular transport, and many encoding uncharacterized proteins. Collectively, the microarray data suggest that DEIRA cells efficiently coordinate their recovery by a complex network, within which both DNA repair and metabolic functions play critical roles. Components of this network include a predicted distinct ATP-dependent DNA ligase and metabolic pathway switching that could prevent additional genomic damage elicited by metabolism-induced free radicals.

Understanding biological systems and the roles of their constituents is facilitated by the ability to make quantitative, sensitive, and comprehensive measurements of how their proteome changes, e.g., in response to environmental perturbations. To this end, we have developed a high-throughput methodology to characterize an organism's dynamic proteome based on the combination of global enzymatic digestion, high-resolution liquid chromatographic separations, and analysis by Fourier transform ion cyclotron resonance mass spectrometry. The peptides produced serve as accurate mass tags for the proteins and have been used to identify with high confidence >61% of the predicted proteome for the ionizing radiation-resistant bacterium Deinococcus radiodurans. This fraction represents the broadest proteome coverage for any organism to date and includes 715 proteins previously annotated as either hypothetical or conserved hypothetical.

Research has been conducted on the Deinococcus radiodurans RecA protein important for the radiation resistance of this organism. The cloning of this protein and its expression in Escherichia coli have been carried out and the results indicate the existence of the sharp contrast between D. radiodurans and E. coli RecA proteins.

Results demonstrate that the genome sequence of Clostridium acetobutylicum accounts for majority of the genes involved in solvent-production. It consists of a 3.94-megabase chromosome and a 192-kilobase megaplasmid and exhibits both genome conservation and organization to that displayed by Bacillus subtilis.

The genomic analysis in Deinococcus radiodurans reveal that the bacterium has developed protective features to resist extreme radiation and desiccation resistance in terms of specific superfamily of enzymes and proteins. Data also point out to the occurrence of numerous nucleotide repeats in the genome that are involved in stress resistance.

Research has been conducted on the radiation-resistance microorganism Deinococcus radiodurans. Nutritional constituents that restore D. radiodurans growth have been identified.

The General Agreement on Tariffs and Trade has advocated the use of tariffs as opposed to non-tariff barriers to promote trade liberalisation in trading goods. Tariffs are seen as more easily manipulated through lower rates and multilateral reductions. Tariffs on industrial goods have declined to only 6.3% during the Uruguay Round in 1988 from some 40% in 1947. The use of non-tariff barriers, which are more difficult to account for, must be closely observed, especially in the traders such as the European Union, Japan, the US, and Canada, to prevent the loss of ground gained in tariff reduction.

The issue of taxation remains to be an important determinant in the successful implementation of multilateral agreement on investment (MAI). Provisions of the MAI should not serve as obstacles in the implementation of bilateral tax treaties network to achieve its goal towards the promotion and protection of foreign direct investments (FDI). Taxation also has to be addressed by the non-discrimination provisions of the MAI in order to prevent the exploitation of existing international tax laws that may result in the undermining of FDI.

The ability of Deinococcus radiodurans R1 to repair severe damage to its DNA, without mutagenesis or lethality, is dependent on recA. The process of recombinational DNA repair during the first few hours is distinct from that occurring over the next 24 hours. Initially, the repair occurs to the same degree in both MD424 recA(super +) and MD431 recA cells. At a later stage, DNA fragments in the former continue to enlarge while the process stops in the latter. This suggests the presence of a different mode of repair at early times rather than one that is solely recA-dependent.

Expression of the Shigella (S) flexneri recA gene in recA-defective Deinococcus (D) radiodurans does not result in the alleviation of the D. radiodurans recA phenotype. The absence of phenotype complementation despite S. flexneri accumulation in D radiodurans indicates a fundamental difference in the mode of action of the S. flexneri RecA protein and that of D. radiodurans RecA, making them unable to function when introduced into the the other species.

The resistance of the bacterium Deinococcus radiodurans to ionizing radiation may be the result of a process of chromosomal recombination that is dependent upon the recA gene and mediated by DNA double-strand breaks. Following irradiation of chromosomes in the cells, which causes DNA fragmentation, there may have been up to 175 crossovers per chromosome being repaired. Details of the recombination processes are discussed.

There are concerns that governments may utilize tax measures or expenditures as alternative measures to protect their local industries to counter the provisions of the General Agreement of Tariffs and Trade. Tax measures can be used as non-tariff protectionist measures. These measures, however, are very difficult to evaluate due to their lack of transparency and they provide benefits through tax deductions instead of direct subsidies. It was suggested that countries should promote transparency in their tax laws so that budgetary effects of tax concessions can be evaluated.

Experimental studies of DNA repair in Deinococcus radiodurans show that cell repair of plasmid DNA damaged by high irradiation is similar to that of chromosomal DNA repair. There is extensive recombination among plasmids during repair, the study of which serves as a model for understanding the repair mechanisms in the chromosome. The capacity of the D. radiodurans to withstand high doses of radiation aids these studies.

Gene mutations and plasmid construction studies reveal that the gene recA, belonging to the genus family of Deinococcus radiodurans R1, repairs plasmid DNA damages due to ionizing radiation exposure by a mechanism homologous to chromosomal DNA repair. All viable cells retain a heterologous plasmid without drug selection. Plasmid repair is pronounced in recA cells.

INTRODUCTION As the European Community (EC) dismantles impediments to the establishment and functioning of a single internal market and perhaps moves toward greater economic and monetary union, it will have [...]

The effect of the Cape Breton Investment Tax Credit (CBITC) on manufacturing employment and productivity in Cape Breton show that although CBITC increased productivity of labor due to capital infusion, the efficiency of the total factors of productivity remains unaffected. It is concluded that the CBITC does not lead to improved efficiency in Cape Breton manufacturing.

This paper sets up an aggregated general equilibrium simulation model of a closed economy to study the steady-state effects of alternative tax systems on saving, capital accumulation, and economic welfare. The three systems compared are a progressive income tax, a progressive general consumption tax, where all saving is tax-deductible, and a hybrid system, where households are free to allocate their saving between deductible and non-deductible forms. It is concluded that a switch to the latter system from a progressive income tax yields significantly higher welfare gains than a switch to a progressive consumption tax.