Effects of Wood Drying Schedules on Fluid Flow in Paulownia Wood

Effects of three drying schedules on fluid flow were studied in the sapwood and heartwood of Paulownia wood (Paulownia fortunei). Boards with a commercial thickness of 5 cm were randomly dried to a final moisture content of 8 ± 2% using a mild (T₆E₃), a moderate (T₆E₄), and a severe (T₇E₄) drying schedule. Permeability measurement was carried out when specimens reached the final moisture content. Results showed a significant difference in the specific gas permeability as well as liquid permeability of the boards dried under the three drying schedules. Furthermore, a significant difference was observed in the gas permeability of sapwood and heartwood, dried under the different schedules, but not much significant difference was seen in the liquid permeability between sapwood and heartwood. T₆E₃ had the highest liquid permeability; furthermore, it was reported to have resulted in the lowest warping and most homogeneous moisture profile. This mild schedule is therefore recommended for commercial drying of Paulownia wood when further preservation and impregnation processes are planned for the dried boards. In the meantime, it is concluded that the age and drying schedule have significant effects on the formation of tyloses, significantly affecting gas and liquid permeability in Paulownia wood.     

Evaluation of Dispersive Liquid–Liquid Microextraction–HPLC–UV for Determination of Deoxynivalenol (DON) in Wheat Flour

A fast and simple method for the extraction of deoxynivalenol (DON) from wheat flour using dispersive liquid–liquid microextraction (DLLME) followed by high-performance liquid chromatography–UV detection has been developed and compared with immunoaffinity column cleanup (IAC) process. The influence of several important parameters on the extraction efficacy was studied. Under optimized conditions, a linear calibration curve was obtained in the range of 50–1,000 μg/L. Average recoveries of DON from spiked wheat samples at levels of 500 μg/kg for DLLME and IAC ranged from 72.9?±?1.6 and 85.5?±?3.1, respectively. A good correlation was found for spiked samples between DLLME and IAC methods. The limit of detection was 125 and 50 μg/kg for DLLME and IAC method, respectively. Advantages of DLLME method with respect to the IAC have been pointed out.     

System‐level reliability sensitivity analysis by using weighted average simulation method

In addition to reliability analysis, investigation of the uncertainties' effect on the safety of structures can be regarded as one of the great concerns in engineering fields. The present study provides an efficient perturbation‐based reliability sensitivity analysis approach based on weighted average simulation method (WASM) to attain uncertainties effects on the structures safety. Without asking additional samplings and/or requiring to function derivation (that is necessary in score function method), the proposed approach simultaneously uses the finite difference and weight flexibility feature of WASM to estimate the parameter sensitivities of a reliability problem. The proposed method has also been successfully applied to the improved version of WASM to obtain reliability based sensitivity results with very few samples. The accuracy and efficiency of the proposed method is examined by solving five analytical and engineering examples with highly nonlinear performance functions and system‐level reliability problems. For each example, results are compared with those obtained by Monte Carlo simulation and common reliability methods. It is shown that the method is capable of solving real world system‐level engineering problems efficiently and accurately.     

Strain-induced disorder-order crystalline phase transition in nylon 6 and its miscible blends

This study deals with the structural modifications of a polyamide 6 (PA6) and a miscible blend of this PA6 with an amorphous semi-aromatic copolyamide (PA6/aPA) under tensile drawing. By combining X-ray diffraction and FTIR spectroscopy, the crystalline phase transitions have been investigated as a function of drawing temperature and strain for both systems. A mechanically induced β-α transition has been clearly identified for PA6 at 100 °C and above, whereas the PA6/aPA blend undergoes the same evolution at 130 °C. These threshold temperatures are very close to the upper limit of the glass-rubber transition of the two systems. This is evidence that the amorphous chain mobility plays a major role on the reorganization capability of the crystalline phase towards its stable form. Further discussion is made regarding the physical origin of this phenomenon.     

MOSAICA: A web-2.0 based system for the preservation and presentation of cultural heritage

The question of how to present cultural heritage resources in a way that attracts potential users is becoming important in our ever-changing world. This paper describes MOSAICA system – a web 2.0-based toolbox, dedicated for the preservation and presentation of cultural heritage. This paper also describes an evaluation study that examined MOSAICA system’s usability and social impact. Online questionnaires and semi-structured interviews were administered among users from Israel, France, and Poland. Findings indicated positive views related to MOSAICA’s usage in terms of knowledge gain, ease of use, and attractiveness. Findings also indicated that learning about the stories, customs, and traditions of diverse cultures, via hypertext narratives, may enhance positive dispositions toward open-mindedness, in general, and non-judgmental views, in specific. MOSAICA system provides a generic framework for users, of any culture and religion, to actively engage in preserving their heritage via activities such as investigation, exploration, and storytelling.     

Use of perfused isolated muscle, as studied by (31)P NMR, to investigate metabolism and post-mortem changes

An experimental system was designed to study as independently as possible the effects of various in-vivo or post-mortem factors susceptible to influence muscle metabolism. This system was made up of an NMR probe, a physiological stimulator, a perfusion system and a force monitoring device. Rabbit muscles were isolated and perfused with bovine red cells, then put into the NMR probe to follow the evolution of pH and phosphorylated compounds. It was possible to keep muscle metabolism stable for 2 h. Death was simulated by stopping the perfusion which allowed post-mortem changes to be followed. The effects of adrenaline perfusion or of a 5 s tetanus on some traits of metabolism and on changes following muscle death were studied. Tetanus immediately before perfusion was stopped accelerated changes in pH and in phosphocreatine and ATP contents; adrenaline perfusion during 30 min before perfusion was stopped had little effect on these traits.     

Electric field induced switching of the fluorescence of single semiconductor quantum rods

The exceptional fluorescence properties of single CdSe quantum rods (QRs) arising from internal and external electric fields are studied. Reversible external field induced switching of the emission in single QRs is reported for the first time. This effect was correlated with local field induced emission intensity reduction and newly observed darkening mechanism. Bimodal spectral jumps under a zero field were also observed and assigned to charged exciton emission, a phenomenon that was likewise directly controlled through an external field. These phenomena point to the use of single QRs as spectrally tunable charge sensitive fluorophores with polarized emission in fluorescence tagging and optical switching applications.     

Effects of partial left ventriculectomy on left ventricular performance in patients with nonischemic dilated cardiomyopathy

OBJECTIVES: This study sought to assess the effects of partial left ventriculectomy (PLV) on left ventricular (LV) performance in a series of consecutive patients with nonischemic dilated cardiomyopathy. BACKGROUND: Reduction of LV systolic function in patients with heart failure is associated with an increase of LV volume and alteration of its shape. Recently, PLV, a novel surgical procedure, was proposed as a treatment option to alter this process in patients with dilated cardiomyopathy. METHODS: We studied 19 patients with severely symptomatic nonischemic dilated cardiomyopathy, before and 13+/-3 days after surgery, and 12 controls. Single-plane left ventriculography with simultaneous measurements of femoral artery pressure was performed during right heart pacing. RESULTS: The LV end-diastolic and end-systolic volume indexes decreased after PLV (from 169 to 102 ml/m2, and from 127 to 60 ml/m2, respectively, p < 0.0001 for both). Despite a decrease in LV mass index (from 162 to 137 g/m2, p < 0.0001), there was a significant decrease in LV circumferential end-systolic and end-diastolic stresses (from 277 to 159 g/cm2, p < 0.0001 and from 79 to 39 g/cm2, p = 0.0014, respectively). Ejection fraction improved (from 24% to 41%, p < 0.0001); the stroke work index remained unchanged. CONCLUSIONS: The PLV improves LV performance by a dramatic reduction of ventricular end-systolic and end-diastolic stresses. Further studies are needed to assess whether this effect is sustained during long-term follow-up and to define the role of PLV in the treatment of patients with dilated cardiomyopathy.     

Two new cases of liver angiosarcoma: history and perspectives of liver angiosarcoma among plastic industry workers

In this report of two new cases of liver angiosarcoma (ASL) among plastic industry workers, the authors present the history and perspectives of this problem. The first cases of ASL have been registered since 1974, and in 1984, the European register of angiosarcoma was founded. In this register, 11 cases of ASL and one case of haemangiopericytoma have been registered from Croatia, all from a single plastics plant near Split. Two new cases of ASL (in retired autoclave cleaners, who were exposed to a concentration of 500-1000 ppm vinyl chloride monomer (VCM) during the working process) in the same plant are represented. They were detected with combined techniques of ASL detection, and both are still alive. The diagnoses have been histologically confirmed: one of them was surgically treated with segmental liver resection. The appearance of new cases of ASL confirms the perspective presented in the last report by the same authors.     

Synthesis and calcium channel modulating effects of isopropyl 1,4-dihydro-2,6-dimethyl-3-nitro-4-(thienyl)-5-pyridinecarboxylates

A group of racemic isopropyl 1,4-dihydro-2,6-dimethyl-3-nitro-4-(thienyl)-5-pyridinecarboxylates++ + 7a-f were prepared using a modified Hantzsch reaction that involved the condensation of a thienylcarboxaldehyde 4a-f with isopropyl 3-aminocrotonate 5 and nitroacetone 6. In vitro calcium channel antagonist activities were determined using a guinea pig ileum longitudinal smooth muscle (GPILSM) assay. Compounds 7a-f exhibited weaker calcium channel antagonist activity (IC50 = 10(-5) to 10(-7) M range) than the reference drug nifedipine (IC50 = 1.43 x 10(-8) M). The point of attachment of the C-4 thienyl ring system was a determinant of antagonist activity [3-thienyl (7b) > 2-thienyl (7a)]. A 5-substituent in the 2-thienyl moiety influenced antagonist activity where the potency order was 5-bromo-2-thienyl 7f > or = 5-methyl-2-thienyl 7c > 2-thienyl 7a. Although the 5-methyl-2-thienyl 7c and 3-methyl-2-thienyl 7d isomers are equipotent antagonists, the 5-bromo-2-thienyl compound 7f appears to be marginally more active than the 4-bromo-2-thienyl isomer 7e. The 2-thienyl compound 7a, unlike the 3-thienyl isomer 7b, exhibited an agonist effect on GPILSM in the absence of the muscarinic agonist carbachol. Effects of the 2-thienyl 7a and 3-thienyl 7b isomers on the magnitude of calcium current were determined in guinea pig ventricular myocytes with voltage clamp techniques. Results showed that 2-thienyl 7a inhibited calcium current (antagonist) when voltage steps were made from a potential of -40 mV. However, when voltage steps were made from -60 mV, 7a enhanced calcium current (agonist). The 3-thienyl isomer 7b had little, if any, effect on calcium current.