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Abstract An experimental study was performed to investigate pyrolysis products, char morphology, and reactivity of char derived from large wood cylinders. Wood samples with various sizes (i.e. sawdust with particle size

To review the effectiveness and safety of chemical ablation using ethanol or OK-432 for the treatment of TGDCs (thyroglossal duct cysts).MEDLINE and EMBASE databases were searched up to May 29, 2020, to identify studies reporting the safety and efficacy of chemical ablation using ethanol or OK-432 for the treatment of TGDCs. The search query consisted of synonyms of thyroglossal duct cysts and ethanol or OK-432 ablation. The pooled success and complication rates were calculated using the inverse variance method to calculate weights, and pooled proportions were determined using the DerSimonian-Laird random-effects method.Seven original articles including a total of 129 patients were included. The efficacy of chemical ablation was acceptable, with a pooled success rate of 70% (95% CI, 47-86%). The pooled success rate of ethanol ablation was superior to that of OK-432 ablation, although with equivocal statistical significance (84% vs. 51%, p = 0.055). Repeat ethanol ablation achieved a pooled success rate of 47% (95% CI, 24-71%). The chemical ablation procedures were safe, with a pooled major complication rate of 0.9% (95% CI, 0.1-5.8%).Chemical ablation using ethanol or OK-432 for the treatment of TGDCs had acceptable success and low complication rates, and repeat treatment after initial failure was also feasible. In addition, it is an inexpensive and simple procedure and could therefore be considered a first-line treatment for TGDCs.• The efficacy of chemical ablation using ethanol or OK-432 was acceptable, with a pooled success rate of 70% (95% CI, 47-86%). The pooled success rate of ethanol ablation was superior to that of OK-432 ablation, although with equivocal statistical significance (84% vs. 51%, p = 0.055). • Repeat ethanol ablation was also feasible, with a pooled success rate of 47% (95% CI, 24-71%). • The chemical ablation procedures were safe, with a pooled major complication rate of 0.9% (95% CI, 0.1-5.8%).

Abstract The processing of citrus fruits leaves massive by-products. Those by-products which are considered as wastes contain a wide range of healthy bioactive compounds where carotenoids are among of them. This work aimed to study the optimum supercritical carbon dioxide (SC-CO 2 ) extraction conditions for maximization of carotenoid content and antioxidant activity for citrus by-products, using response surface methodology so that those by-products can not only be valorized effectively but also to reduce disposal problems. The effects of pressure, temperature, and mixing ratio (citrus peel-to-citrus seed mass ratio) on the recovery of carotenoids and antioxidant activity were studied. A second-order polynomial model showed a suitable fitting of the experimental values regarding the carotenoid content (R 2 = 0.9974, p 2 = 0.9919, p 2 = 0.9885, p −1 oil for carotenoid content, 0.762 mg cm −3 for DPPH, and 1.220 mg cm −3 for ABTS assay. The predicted and the experimental values were well in agreement, thus affirming the adequacy and validity of the predicted models. Overall, the combination of citrus by-products could yield the oils with good bio-activity and this could be a new valorization method.

MG Si can be effectively refined using a fractional melting process. The efficiency of fractional melting depends on two parameters, the heating rate and the wetness. Generally, the heating rate should be slow to ensure impurity diffusion and, in order to perfectly separate the liquid from the solid/liquid mixture, there should not be higher wetness. Many MG Si metal impurities exhibit retrograde solubility. The metal impurity behaviors with retrograde solubility were studied during the FM process. The change of the microstructure during the process was also studied with a SEM and an EPMA. Due to the retrograde behavior, slow heating below the maximum solubility temperature was not necessary to refine MG Si. For the FM process, the operating temperature range to refine MG Si should be carefully selected considering the behavior of major metal impurities in the mushy zone.

Abstract The effect of water vapor addition on the electrochemical oxygen reduction was investigated for the interfaces between fluorite-type oxide-ion conductors (YSZ, ceria) and various types of electrodes at the temperature range 750–1100 K in air. The interface conductivity of YSZ electrolyte/gold electrode at open circuit condition increased when a slight amount of water vapor was added to air at T = 865 K. However, the interface conductivity of YSZ/platinum decreased during a long-term exposure in humid atmospheres. The improvement was correlated to the enhancement of oxygen exchange through water molecules, and the degradation is probably due to the blocking of oxygen molecule migration by the adsorbed water molecules.

A new method is presented for calculating the nose curves and critical loading conditions of power systems. The nose curve (PV curve), which donates the relationship between total load and system voltages, is calculated by a new approach based on the homotopy continuation method. The critical loading condition, which might be called the bifurcation point, is also calculated precisely as the final point of the nose curve. This method does not require an exhausting cut-and-try process or a rough-approximation process. It is based on the conventional Newton-Raphson load flow calculation, but it overcomes the numerical difficulties associated with the singularity of the Jacobian matrix. The results of applying the proposed method to the IEEE 118-bus system and to other large practical systems (e.g., a 496-bus system) verify its robustness and feasibility. >

Abstract Particle image velocimetry (PIV) measurements of the flow patterns in a pressurized heavy water reactor (PHWR) were made in a 1/4 scaled-down model of the Canadian deuterium uranium (CANDU) reactor. Archimedes’ number (Ar) was introduced to evaluate the dynamic similarities between the isothermal (Ar = 0) and heating conditions. Small and large PIV fields of view were used to measure the overall flow field. Flow patterns were analyzed by measuring the spatial velocity distributions and the impingement positions of the inlet jet. The momentum-dominated flow patterns were measured under isothermal conditions (Ar = 0). The impingement position bias increased as Ar increased due to buoyancy effects. The overall moderator circulation characteristics were explored for various Ar values up to 0.157.

Abstract This study aims to analyze the cavitating flow inside the nozzle and the spray characteristics near the nozzle tip according to the needle positions and orifice inlet roundness through experimental analysis. To simulate the needle movement during fuel injection by the injector, six needle positions were used. The upper and lower positions of the needle were assumed to be the positions where the needle was fully opened and just before being fully closed. The length-to-width ratio of the nozzle was 2.0, and the nozzle was made in two dimensions for convenience of visualization. The inside of the nozzle was visualized by the shadow graphic visualization technique, and the image was acquired using a high-speed camera. The cavitating flow inside the nozzle and the spray characteristics near the nozzle tip were analyzed using the self-developed image processing code. The experimental results show that cavitating flow characteristics such as cavitation length and cavitation width and external flow characteristics such as spray angle were influenced by the shape of the orifice inlet and needle positions. In addition, when the cavitating flow became the hydraulic flip, the phenomenon in which the spray angle was bent like a bow was examined. This phenomenon occurred frequently as the volume fraction of hydraulic flip at the tip of the nozzle became larger than a certain level. In addition, when the cavitating flow became the hydraulic flip, the phenomenon in which the spray angle was bent like a bow was examined. In addition, we discussed the negative effects that occurring when the same phenomenon in an actual injector.