• Journal of Powder Materials
• /
• v.18 no.6
• /
• pp.510-516
• /
• 2011

In the present study, potassium and caesium doped Ag/$Al_2O_3$ catalysts were synthesized by simple wet impregnation method and evaluated for selective catalytic reduction (SCR) of NOx using methane. TEM analysis and diffraction patterns demonstrated the finely dispersed Ag particles. BET surface measurements reveal that the prepared materials have moderate to high surface area and the metal amount found from ICP analysis was well matching with the theoretical loadings. The synthesized K-Ag/$Al_2O_3$ and Cs-Ag/$Al_2O_3$ catalysts exhibited a promotional effect on deNOx activity in the presence of $SO_2$ and $H_2O$. The long-term isothermal studies at $550^{\circ}C$ under oxygen rich condition showed the superior catalytic properties of the both alkali promoted samples. The crucial catalytic properties of materials are attributed to NO adsorption properties detected by the NO TPD.

• Advances in materials Research
• /
• v.3 no.4
• /
• pp.227-232
• /
• 2014

$Ce^{4+}$, $Eu^{3+}$, $Tb^{3+}$ co-doped $Ca_3Si_3O_8F_2$ phosphor was synthesized via solid state reaction method using $CaF_2$, $CaCO_3$ and $SiO_2$ as raw materials for the host and $Eu_2O_3$, $CeO_2$, and $Tb_4O_7$ as activators. The luminescent properties of the phosphor was analysed by spectrofluorophotometer at room temperature. The effect of excitation wavelengths on the luminescent properties of the phosphor i.e. under near-ultraviolet (nUV) and visible excitations was investigated. The emission peaks of $Ce^{4+}$, $Eu^{3+}$, $Tb^{3+}$ co-doped $Ca_3Si_3O_8F_2$ phosphor lays at 480(blue band), 550(green band) and 611nm (red band) under 380nm excitation wavelength, attributed to the $Ce^{4+}$ ion, $Tb^{3+}$ ion and $Eu^{3+}$ ions respectively. The results reveal that the phosphor emits white light upon nUV (380nm) / visible (465nm) illumination, and a red light upon 395nm / 535nm illumination. RE ions doped $Ca_3Si_3O_8F_2$ is a promising white light phosphor for LEDs. The emission colours can be seen using Commission international de l'eclairage (CIE) co-ordinates. A single host phosphor emitting different colours under different excitations indicates that it is a potential phosphor having applications in many fields.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.11
• /
• pp.1686-1694
• /
• 2019

Objective: Lignin plays a relevant role in the inhibition of cell wall (CW) structural carbohydrate degradation. Thus, obtaining accurate estimates of the lignin content in tropical plants is important in order to properly characterize the mechanism of lignin action on CW degradation. Comparing conflicting results between the different methods available for commercial use will bring insight on the subject. This way, providing data to better understand the relationship between lignin concentration and implications with tropical forage degradation. Methods: Five grass species, Brachiaria brizantha cv $Marand{\acute{u}}$, Brachiaria brizantha cv $Xara{\acute{e}}s$(MG-5), Panicum maximum cv Mombaça, Pennisetum purpureum cv Cameroon, and Pennisetum purpureum cv Napier, were harvested at five maturity stages. Acid detergent lignin (ADL), Klason lignin (KL), acetyl bromide lignin (ABL), and permanganate lignin (PerL) were measured on all species. Lignin concentration was correlated with in vitro degradability. Results: Highly significant effects for maturity, lignin method and their interaction on lignin content were observed. The ADL, KL and ABL methods had similar negative correlations with degradability. The PerL method failed to reliably estimate the degradability of tropical grasses, possibly due to interference of other substances potentially soluble in the $KMnO_4$ solution. Conclusion: ADL and KL methods use strong acid ($H_2SO_4$) and require determination of ash and N content in the lignin residues, therefore, increasing time and cost of analysis. The ABL method has no need for such corrections and is a fast and a convenient method for determination of total lignin content in plants, thus, it may be a good option for routine laboratory analysis.

• Economic and Environmental Geology
• /
• v.48 no.2
• /
• pp.169-175
• /
• 2015

Silver production in Peru was 118 Moz in 2013, which was $3^{rd}$ ranked in the world. Silver production mines which were ranked from $1^{st}$ to $5^{th}$ in Peru in 2013 were Antamina(16.7 Moz), Uchuchacua(12 Moz), Pallancata(7.6 Moz), Anim$\acute{o}$n(7 Moz), and Arcata(5.4 Moz). Total reported silver resources in Peru is about 7,012 Moz, and resources from the belts of Miocene epithermal deposits and the belts of Miocene skarn, replacement and vein deposits are 4,812 Moz, which corresponds to 69% of total resources. There are 14 ongoing projects which will be developed to the production stage from 2014 to 2019. Through these projects, silver production in Peru is expected to be 148 Moz in 2017.

• Journal of Advanced Marine Engineering and Technology
• /
• v.23 no.4
• /
• pp.462-472
• /
• 1999

De-NOx facility using Selective Catalytic Reduction method is the most widely applied one that removes NOx from flue gas emitted from combustion facility such as boiler for power generation engine incinerator etc. Reductant $NH_3\;or\;NH_4OH$ is sprayed into flue gas to convert NOx into $H_2O$ and $N_2.$ Good mixing between flue gas and $NH_3$ is the most important factor to increase reduction in catalytic layer and to reduce unreacted NH3 slip. Therefore the development of mixer device for mixing effect is one of the important part for SCR facility. Objectives of this study are to investigate the relation between flow and concentration field by observation at the wake of delta-wing type mixer. At the first stage qualitative measurement of flow field is conducted by flow visualization using laser light sheet in lab. scale wind tunnel. Also we have conducted the quantitative analysis by comparing flow field measurement using LDV with numerical simulation. On the basis of qualitative and quantitative analysis we investigate the dis-tribution of flow and concentration in flow model facility. The results of an experimental and compu-tational examination of the vortex structures shed from delta wing type vortex generator having $40^{\circ}$ angle of attack are presented, The effects of vortex structure on the gas mixing is discussed, too.

• Journal of The Korean Astronomical Society
• /
• v.37 no.4
• /
• pp.269-272
• /
• 2004

We present the first results of a wide field survey for planetary nebulae throughout M31 undertaken at the KPNO 0.9m telescope with the Mosaic camera. So far, images in [O III]$\lambda$5007 and its continuum filter have been analyzed. Our survey appears to be at least $90\%$ complete to about 2 mag below the peak of the planetary nebula luminosity function. Over 900 planetary nebulae candidates have been found within a 12 square degree area.

• The Korean Society of Law and Medicine
• /
• v.15 no.2
• /
• pp.367-397
• /
• 2014

Dans le contentieux m$\acute{e}$dical, il est difficile de prouver l'existence d'un lien de causalit$\acute{e}$ entre la faute m$\acute{e}$dicale et les pr$\acute{e}$judices subis par la victime. R$\acute{e}$partir bien de façon raisonnable la charge de la preuve du lien causal est alors une des questions pr$\acute{e}$occup$\acute{e}$es par la doctrine cor$\acute{e}$enne. La Cour supr$\hat{e}$me cor$\acute{e}$enne semble toutefois facilliter l'indemnisation des victimes dans les cas o$\grave{u}$ la responsabilit$\acute{e}$ du m$\acute{e}$decin a ${\acute{e}}t{\acute{e}}$ mise en cause, et cela en admettant des fois une solution op$\acute{e}$rant un renversement de la charge de la preuve du lien causal. Une telle attitude a ${\acute{e}}t{\acute{e}}$ m$\hat{e}$me affirm$\acute{e}$e dans un arr$\hat{e}$t rendu r$\acute{e}$cemment en cas de dommage caus$\acute{e}$ par le fait du produit de sant$\acute{e}$, notamment pour le cas de contamination virale par voie de transfusion. La Cour a $\acute{e}$galement reconnu que l'action se pr$\acute{e}$scrit $\grave{a}$ partir du moment de la consolidation du pr$\acute{e}$judice. Aux termes de cette $\acute{e}$tude, on pourra constater que le juge français reconna$\hat{i}$t aussi l'assouplissement de la charge de la preuve du lien de causalit$\acute{e}$ en mati$\acute{e}$re d'action m$\acute{e}$dicale. Il faudra toutefois souligner que le ph$\acute{e}$nom$\acute{e}$ne ne soit pas g$\acute{e}$n$\acute{e}$ralis$\acute{e}$ en droit français, d'autant plus que la pr$\acute{e}$somption de l'existence de la causalit$\acute{e}$ en la mati$\grave{e}$re a $\acute{e}$t$\acute{e}$ admise de mani$\grave{e}$re restrictive par la l$\acute{e}$gislation sp$\acute{e}$cifique. Tel $\acute{e}$tait notamment le cas pour les accidents de la contamination par le virus du sida ou de l'h$\acute{e}$patite C survenus apr$\grave{e}$s la transfusion. En d$\acute{e}$finitive, on peut dire qu'en droit français, le principe est maintenu en cas de manquement $\grave{a}$ une obligation de r$\acute{e}$sultat n$\acute{e}$e du contrat m$\acute{e}$dical, tandis que la Cour de cassation admet parfois en mati$\grave{e}$re de droit commun de la responsabilit$\acute{e}$ contractuelle la pr$\acute{e}$somption de causalit$\acute{e}$ en cas d'inex$\acute{e}$cution des obligations de r$\acute{e}$sultat. En fait, la pr$\acute{e}$somption de causalit$\acute{e}$ dans le contentieux m$\acute{e}$dical pourra mener les m$\acute{e}$decins $\grave{a}$ se diriger vers les traitements d$\acute{e}$fensifs. Cette situation peut m$\hat{e}$me conduire $\grave{a}$ emp$\hat{e}$cher le d$\acute{e}$veloppement de la science m$\acute{e}$dicale, enfin $\grave{a}$ une situation d$\acute{e}$savantageuse aux patients. Il y a alors lieu de se m$\acute{e}$fier des int$\acute{e}$r$\hat{e}$ts d$\acute{e}$s$\acute{e}$quilibr$\acute{e}$s entre le m$\acute{e}$decin et le patient. De ce point de vue, on peut estimer que le droit français donne des suggestions aux juristes cor$\acute{e}$ens dans la recherche des solutions plus ad$\acute{e}$quates en ce qui concerne la charge de la preuve du lien causal en mati$\acute{e}$re de responsabilit$\acute{e}$ m$\acute{e}$dicale.

• Restorative Dentistry and Endodontics
• /
• v.42 no.2
• /
• pp.105-110
• /
• 2017

Objectives: This study investigated the cleaning ability of ultrasonically activated irrigation (UAI) and a novel activation system with reciprocating motion (EC, EasyClean, Easy Equipamentos $Odontol\acute{o}gicos$) when used with a relatively new chelating agent (QMix, Dentsply). In addition, the effect of QMix solution when used for a shorter (1 minute) and a longer application time (3 minutes) was investigated. Materials and Methods: Fifty permanent human teeth were prepared with K3 rotary system and 6% sodium hypochlorite. Samples were randomly assigned to five groups (n = 10) according to the final irrigation protocol: G1, negative control (distilled water); G2, positive control (QMix 1 minute); G3, QMix 1 minute/UAI; G4, QMix 1 minute/EC; G5, QMix 3 minutes. Subsequently the teeth were prepared and three photomicrographs were obtained in each root third of root walls, by scanning electron microscopy. Two blinded and pre-calibrated examiners evaluated the images using a four-category scoring system. Data were statistically analyzed using Kruskal-Wallis and Dunn tests (p < 0.05). Results: There were differences among groups (p < 0.05). UAI showed better cleaning ability than EC (p < 0.05). There were improvements when QMix was used with auxiliary devices in comparison with conventional irrigation (p < 0.05). Conventional irrigation for 3 minutes presented significantly better results than its use for 1 minute (p < 0.05). Conclusions: QMix should be used for 1 minute when it is used with UAI, since this final irrigation protocol showed the best performance and also allowed clinical optimization of this procedure.

• Journal of the Korean Chemical Society
• /
• v.45 no.4
• /
• pp.312-317
• /
• 2001

7'-Aldehyde-nucleosides analogue (2a, 2c) were synthesized from 6-N-benzoyl-2',3'-O-isopropylideneadenosine and uridine. The condensation of 2 with ethoxycarbonylmethylene Wittig reagent produced the adenosine and uridine analogues containing extended conjugated diene and ethoxycarbonyl group, ethyl-1',5',6',7',8'-pentadeoxy-1'-(adenin-9-yl)-$\beta$-D-ribo-nona-5'(E),7'(E)-dienofuranuronate (4b) and ethyl-1'. 5',6',7',8'-pentadeoxy-1'-(uracil-1-yl)-$\beta$-D-ribo-nona-5'(E),7'-(E)-dienofuranuronate (4c). 9-[8',8'-dibromo-5',6',7',8' -tetradeoxy-$\beta$-D-ribo-octa-5'(E),7'(E)-diene]nucleosides (6b, 6c) were also prepared from 2 with similar method.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.42 no.6
• /
• pp.352-357
• /
• 2016

Objectives: This study aimed to evaluate the stability of prosthetic screws from three types of craniofacial prostheses retention systems (bar-clip, ball/O-ring, and magnet) when submitted to mechanical cycling. Materials and Methods: Twelve models of acrylic resin were used with implants placed 20 mm from each other and separated into three groups: (1) bar-clip (Sistema INP, São Paulo, Brazil), (2) ball/O-ring (Sistema INP), and (3) magnet (Metalmag, São Paulo, Brazil), with four samples in each group. Each sample underwent a mechanical cycling removal and insertion test (f=0.5 Hz) to determine the torque and the detorque values of the retention screws. A servo-hydraulic MTS machine (810-Flextest 40; MTS Systems, Eden Prairie, MN, USA) was used to perform the cycling with 2.5 mm and a displacement of 10 mm/s. The screws of the retention systems received an initial torque of 30 Ncm and the torque values required for loosening the screw values were obtained in three cycles (1,080, 2,160, and 3,240). The screws were retorqued to 30 Ncm before each new cycle. Results: The sample was composed of 24 screws grouped as follows: bar-clip (n=8), ball/O-ring (n=8), and magnet (n=8). There were significant differences between the groups, with greater detorque values observed in the ball/O-ring group when compared to the bar-clip and magnet groups for the first cycle. However, the detorque value was greater in the bar-clip group for the second cycle. Conclusion: The results of this study indicate that all prosthetic screws will loosen slightly after an initial tightening torque, also the bar-clip retention system demonstrated greater loosening of the screws when compared with ball/O-ring and magnet retention systems.