Microscopic Flow Observation of Photopolymer by UV-Laser Beam Exposure

Microscopic flow of liquid photopolylner around the cured polymer was observed during laser exposure. The maximum velocity was about 4 mm/s. The temperature raised by reaction heat, causes the density of liquid photopolymer to vary, resulting in this flow. This flow causes the nearby cured strands to sway and it decreases the accuracy of SL model.Mechanical Engineerin

The Neurophysiological Implications of an Atypical Slow Negative Potential in Short Interval CNV Paradigm

We recorded a slow negative potential from Cz (10/20 method) in 49 healthy students (12 male, 37 female, mean age 19.1) by a short interstumulus interval CNV paradigm. The interstimulus interval was 2 or 3 seconds, the warning stimulus presented at random or regular interval at 0.2 Hz. An atypical negative variation with two separated negative peaks was recorded in 26.0-30.6% trials regardless of interstimulus interval or modality of warning stimulus presentation, while a typical CNV was recorded in 32.0-59.2% of trials. No apparent negative variation was recorded in 14.3-18.4% in 2 seconds interstimulus interval, and 28-38% in 3 seconds interstimulus interval, showing that 2 seconds interval is better to get stable CNV recording than 3 seconds interval. The first negative wave of the atypical negative variation was 692-799msec in duration, but frequently prolonged to 1000msec or more in 3 seconds interval. It usually had negative peak around 900-1100msec, but sometimes around 1500msec. This features are different from any reported negative components of CNV. The second negative wave began 800-1200msec before second stimulus, and had its peak just before second stimulus, showing common features with readiness potential. The appearance of CNV was unsatble in the students in which the atypical negative variation was recorded in regular, 2 seconds intersitimulus interval, and the amplitude of slow vertex response and pattern reversal visual evoked potential was lower in thses students than in the students in which a typical CNV was recorded more than 3 times in total 4 times of trials. These findings indicate that the atypical variation observed in this study is due to a lowered arousal level or cortical neuronal activity, rather than a separated appearance of different components of CNV.CNVの記録条件を検討する目的で、健康若年成人49名（男12、女37）を対象にS(1)-S(2)+Rパラダイムを用いてCNVを記録した。S(1)-S(2)間隔2秒のほうが3秒よりも安定してCNVが記録されたが、刺激間隔とは無関係に26～30％の試行で二峰性の陰性変動をもつ非定型な緩電位が記録された。この緩電位は同一被検者でも出現性が一貫せず、個体差よりも被検者の状態に依存していた。二峰性陰性波のうち、後期成分は準備電位に対応するものと思われたが、前期成分はS(1)後900～1100msecにピークをもつ陰性波で、これまで報告されたCNVの要素波とは対応しなかった。また、この非定型CNVを示す被検者ではCNV出現が不安定で、SVRおよびパターンVEPの振幅が低い傾向があり、試行時の被検者の覚醒水準低下よるものではないかと考えられた

Effect of increasing salinity on biogas production in waste landfills with leachate recirculation: A lab-scale model study

AbstractThe effects of salinity on anaerobic waste degradation and microbial communities were investigated, in order to propose an appropriate leachate recirculation process in a waste landfill in a tropical region. A salt concentration of 21mScm−1 of electrical conductivity (EC) did not affect waste degradation, but a salt concentration of 35mScm−1 of EC inhibited CH4 generation. A higher salt concentration of 80mScm−1 of EC inhibited not only CH4 and CO2 generation, but also degradation of organic compounds. The bacterial and archaeal community compositions were affected by high salinity. High salinity can exert selective pressure on bacterial communities, resulting in a change in bacterial community structure. Ammonium caused strong, dominant inhibition of biogas production in the salt concentration range of this study. Quality control, especially of ammonium levels, will be essential for the promotion of waste biodegradation in landfills with leachate recirculation

Redox Imbalance Induced by Contact Sensitizers Triggers the Maturation of Dendritic Cells

Although p38 mitogen-activated protein kinases (MAPK) play a crucial role in the activation of monocyte-derived dendritic cells (MoDC) by contact sensitizers, the upstream signals of p38 MAPK remain undetermined. To examine whether sensitizers induce redox or oxidative stress in dendritic cells (DC), which subsequently stimulate p38 MAPK, we measured the ratio of the oxidized (GSSG) versus reduced (GSH) form of cellular glutathione in MoDC stimulated with five sensitizers including NiCl2 and 2,4-dinitrochlorobenzene (DNCB) and three non-sensitizers including sodium dodecyl sulfate using colorimetric assays. All the sensitizers, but none of the non-sensitizers at sublethal concentration, reduced the GSH/GSSG ratio, which was accompanied by phosphorylation of p38 MAPK. Treatment with the antioxidant, N-acetyl-L-cysteine, which suppressed the reduction of the GSH/GSSG ratio, abrogated both the phosphorylation of p38 MAPK and the augmentation of CD86 expression. A similar response pattern was observed in THP-1 macrophage-monocyte cells. Unexpectedly, however, formaldehyde (HCHO) reduced the GSH/GSSG ratio in MoDC, but not in THP-1. This finding, in conjunction with the observation that DNCB and NiCl2 reduced the GSH/GSSG ratio at different kinetics, indicated that the sensitizers reduced the GSH/GSSG ratio by a different mechanism. These data suggest that the GSH/GSSG imbalance plays a crucial role in triggering DC maturation by sensitizers

The unusual case of plastic deformation and high dislocation densities with the cold sintering of the piezoelectric ceramic K0.5Na0.5NbO3

K0.5Na0.5NbO3 (KNN) can be readily densified using the cold sintering process, but despite observing high relative permittivity, the ferroelectric hysteresis is strongly suppressed along with a major suppression in the all-important piezoelectric properties. In this study, KNN is fabricated using a NaOH+KOH transient flux under a uniaxial pressure of 400 MPa and heating to 300 °C for 2 h to drive densification to 93% theoretical. It is only after a secondary heat treatment that we observe improvements of the ferroelectric hysteresis and piezoelectric properties. From a detailed structural-property-processing study using analytical transmission electron microscopy (TEM), X-ray line broadening and high field dielectric characterization methodologies we conclude that there is an unusual in-situ plastic deformation process that takes place in addition to the densification under the cold sintering process. High densities of dislocations within grains were observed that lead to multiple pinning sites that impact both the intrinsic and extrinsic contributions to the high field dielectric and piezoelectric properties. Annealing significantly reduced the dislocation density in the highly defective crystallites, observed directly from the TEM and from the sharpening of the X-ray diffraction peaks, resulting in piezoelectric and ferroelectric properties that approached those of conventionally sintered KNN