Sheets of branched poly(lactic acid) obtained by one-step reactive extrusion–calendering process: physical aging and fracture behavior

The architectural modifications of a linear poly(D,L-Lactide) acid (PD,L-LA) commercial grade were induced by a one-step reactive extrusion–calendering process using a styrene-glycidyl acrylate copolymer as reactive agent. The melt degradation was counteracted by chain extension and branching reactions, leading to a stabilization of the melt properties and an increase in the molecular weight. For such modified samples [poly(lactic acid) (PLA)-reactive extrusion (REX)], the rate of physical aging at 30 °C was investigated during 1 week in order to simulate industrial storage conditions. Fracture behavior of “de-aged” and “controlled aged” (1 week) samples was investigated using the essential work of fracture (EWF) methodology and the critical tip opening displacement at the crack propagation onset, respectively. These analyses were complemented by digital image correlation analysis and inspection of the fractured surfaces by scanning electronic microscopy. As a result of the architectural modifications, the entanglement network density was increased. Those accounted for a slight decrease in the physical aging rate. Under uniaxial loading, aged reactive extrusion (REX) samples exhibited multiple crazing, leading to a slight increase in strain at break. Nevertheless, as a result of a similar dynamic environment of the entangled polymer coils, de-aged REX samples disclosed similar mechanical properties as compared to their neat counterparts. Regarding de-aged samples, the EWF analysis revealed no changes in the work required for the onset of crack propagation. However, the energy consumed up to the onset of crack propagation of aged PLA-REX samples decreased due to an apparently decreased network extensibility, promoting a premature craze–crack transition.     

Studies on phospholipid biosynthesis in hepatocytes from alcoholic rats by using radiolabeled exogenous precursors

We have studied the synthesis of phospholipids in hepatocytes isolated from chronically ethanol-treated rats by using isotopically labelled serine, ethanolamine, and choline as exogenous precursors. Our results demonstrate that ethanol induces specific effects on the biosynthesis of phosphatidyl-ethanolamine and phosphatidylcholinevia CDP-derivatives and also on the synthesis of phosphatidylserinevia the Ca⁺⁺-dependent base-exchange reaction. Thus, the synthesis of phosphatidylethanolamine from [³-H]ethanolamine and the incorporation of [³H]serine into phosphatidylserine were clearly higher in hepatocytes from ethanol-treated rats compared to controls. The synthesis of phosphatidylcholine from [methyl-¹⁴C] choline, on the other hand, decreased markedly, suggesting a specific inhibition of cholinephosphotransferase activity. We have also demonstrated that the phosphatidylcholine levels are markedly decreased in hepatocytes isolated from chronically ethanol-treated rats as a consequence of the lower phosphatidylcholine biosynthesis. The decrease in the incorporation of radioactivity from choline to betaine, which we also found, is interpreted as being the result of a higher use of betaine as methyl donor instead of methionine to maintain the hepaticS-adenosylmethionine levels in chronic alcoholism.     

Maize and pigeon pea sole crop and intercrop nutrient response functions for Tanzania

The development of ecological circular agriculture has been highly encouraged by the Chinese government to recycle agricultural wastes, reduce mineral fertilizer input, and protect the environment. Biogas slurry, a byproduct of biogas engineering developed in rural areas of China, could be used as N fertilizer for crop growth. The field experiments were conducted in 2014 and 2015 to study the plant growth responses and environmental impacts of applying biogas slurry to two-season Zizania aquatica Turcz. growth. The potential factors that restrict the rational use of biogas slurry were also clarified. Mineral N fertilizer can be completely or partly substituted by N fertilizer from biogas slurry to satisfy Z. aquatica plant growth. It was not at the cost of sacrificing yield, dry matter accumulation, N accumulation and physiological N use efficiency in the above-ground parts. However, the growth inhibition occurs when the N quantity in biogas slurry was 2 or 2.7 times higher than that of mineral N fertilizer. Vitamin C in non-shell swollen culms (as edible part) of Z. aquatica significantly increased after biogas slurry application. Biogas slurry application substantially increased the N concentrations, i.e., total N, NH₄ ⁺–N, and NO₃ ^?–N in floodwater and delayed the time to reach national discharge standards. However, biogas slurry application did not affect the N concentrations in percolating water compared with the treatment with mineral N fertilizer only. Applying biogass slurry did not generate potential pollution risks by trace elements (Cu, Zn, Pb, Cr, Cd, As, and Hg) in the non-shell swollen culm and soil, and did not increase the nitrate content in non-shell swollen culm. We found the NH₄ ⁺–N concentration in biogas slurry can account for 77–93% of total N and reflects the N level in biogas slurry to a great degree. Semi-quantitative color-based colorimetric methods possessing simple and fast characteristics should be developed to determine the NH₄ ⁺–N concentration with the purpose of promoting reasonable use of biogas slurry in area of crop cultivation. Otherwise, excessive use of biogas slurry can adversely affect crops and increase environmental risks.     

A multidimensional data model using the fuzzy model based on the semantic translation

With the rapid development of Web 2.0 sites such as Blogs and Wikis users are encouraged to express opinions about certain products, services or social topics over the web. There is a method for aggregating these opinions, called Opinion Aggregation, which is made up of four steps: Collect, Identify, Classify and Aggregate. In this paper, we present a new conceptual multidimensional data model based on the Fuzzy Model based on the Semantic Translation to solve the Aggregate step of an Opinion Aggregation architecture, which allows exploiting the measure values resulting from integrating heterogeneous information (including unstructured data such as free texts) by means of traditional Business Intelligence tools. We also present an entire Opinion Aggregation architecture that includes the Aggregate step and solves the rest of steps (Collect, Identify and Classify) by means an Extraction, Transformation and Loading process. This architecture has been implemented in an Oracle Relational Database Management System. We have applied it to integrate heterogeneous data extracted from certain high end hotels websites, and we show a case study using the collected data during several years in the websites of high end hotels located in Granada (Spain). With this integrated information, the Data Warehouse user can make several analyses with the benefit of an easy linguistic interpretability and a high precision by means of interactive tools such as the dashboards.     

Effect of blanching and hygroscopic coating on quality of fresh cut carrots (Daucus carota var. chantenay) during storage

The effect of blanching at low temperatures (solution 1% acid citric, 50 degrees C for 30 seconds) and the application of glycerol as humectant (3% p/p, 20 seconds) to preserve the quality of fresh-cut carrots (Daucus carota) were studied as individual or combined treatments. Four treatments were evaluated: a control by dipping samples for 30 seconds in distilled water (T1); blanching (T2); glycerol application (T3); and blanching plus glycerol application (T4). Total carotenoids content, color, soluble solids and weight loss were monitored during storage. Results showed no differences between treatments in carotenoids content (p > 0.10) and soluble solids (p > 0.05). However, differences were observed between treatments in weight loss (p < 0.05) and color change (p < 0.05). Blanched samples (T2 and T4) showed small changes in orange color intensity compared to treatments T1 and T3 (p < 0.05).     

Tight binding of the antitumor drug ditercalinium to quadruplex DNA

The structural selectivity of the DNA-binding antitumor drug ditercalinium was investigated by competition dialysis with a series of nineteen different DNA substrates. The 7H-pyridocarbazole dimer was found to bind to double-stranded DNA with a preference for GC-rich species but can in addition form stable complexes with triplex and quadruplex structures. The preferential interaction of the drug with four-stranded DNA structures was independently confirmed by electrospray mass spectrometry and a detailed analysis of the binding reaction was performed by surface plasmon resonance (SPR) spectroscopy. The BIAcore SPR study showed that the kinetic parameters for the interaction of ditercalinium with the human telomeric quadruplex sequence are comparable to those measured with a duplex sequence. Slow association and dissociation were observed with both the quadruplex and duplex structures. The newly discovered preferential binding of ditercalinium to the antiparallel quadruplex sequence d(AG(3)[T(2)AG(3)](3)) provides new perspectives for the design of drugs that can bind to human telomeres.     

Space‐time ring‐TCM codes with CPM based on the decomposed model for transmission over Rayleigh fading channels

Space–time (ST) coding is a proved technique for achieving high data rates in 3G mobile systems that combines coding, modulation and multiple transmitters and receivers. A novel algorithm is proposed for ST ring trellis‐coded modulation (ST‐RTCM) systems with continuous‐phase modulation (CPM) when the channel coefficients are known to the receiver. This algorithm is based on the CPM decomposed model, which exploits the memory properties of this modulation method, resulting in a straightforward implementation of joint ST coding and CPM, which is particularly suitable for ring codes. This new scheme is used to investigate the performance of the delay diversity code with CPM over slow Rayleigh fading channels, in particular with MSK which is one of the most widely used modulation methods of continuous phase. Furthermore, a feedback version of delay diversity allowed by the decomposition is tested in 1REC and 1RC systems. This feedback configuration is seen to provide good results for low signal‐to‐noise ratios. Simulations results are also provided for multilevel ST‐RTCM codes that achieve a higher throughput than MSK‐coded systems. Additionally the serial concatenation of an outer Reed–Solomon code with an ST‐RTCM code is shown, this combination further reduces the error probability and achieves even more reliable communications. Copyright © 2005 John Wiley & Sons, Ltd.     

Solutions to Industrial Engineering problems using integrated software environments

The development of word processing systems and the spreadsheet environment marked the beginning of the professional computing movement. For the first time, programs were available that were both highly functional and highly usable, even by non-computer people. The next group of “hot” programs in the business market were “integrated” packages providing a combination of word processing, spreadsheet, database, graphics, and telecommunications. Unfortunately, these integrated packages have not displaced such single purpose programs as Lotus 1-2-3, dBase and WordPerfect as the dominant forces in desktop computing. Integrated packages are generally perceived as complex, cumbersome, and difficult to master. An important point to note, however, is that high proficiency is not necessary; successful users of commercial software seldom know or use more that 40% of a programs functionality.

This paper addresses the use of integrated software packages to solve Industrial Engineering problems. More specifically, examples are presented demonstrating the use of Ashton Tate's Framework II to solve production and operations management problems. Sample applications include forecasting, after tax economic analysis, and data storage and retrieval, demonstrating the advantages of linking word processing, spreadsheets, and databases.     

Self-timed Manchester chain carry propagate adder

The authors present a self-timed adder that uses two Manchester chains to propagate carries in a two-rail code. With the inclusion of buffers in the chains, the adder met the timing conditions typical of an asynchronous design based on the `bundled-data, bounded-delay' model and is significantly faster than self-timed adders with restoring logic and similar complexity