A mathematical model was developed for the purpose of predicting the fate and transport of down‐the‐drain household chemicals in septic systems. The model was tested with field data collected from a typical septic system located near Cambridge, Ontario, Canada. Model simulations were in good agreement with field data for the laundry detergent builders tartrate monosuccinate (TMS) and tartrate dissuccinate (TDS). The model was also independently verified with phosphate data collected from the study site. A sensitivity analysis showed little change in model predictions when the distribution coefficient and biodegradation rate constants were varied by 10%. Results from this study support that this model is satisfactory as a screening level tool for predicting the fate and transport of household chemicals in septic systems.
It is demonstrated by numerical modeling that spectrally dispersed compound pumping diodes and low-loss pumping chamber reduced the temperature dependence of the output energy of quasi-continuous wave diode-pumped Nd:YAG lasers considerably. Several compound diodes with different spectral profiles were tested for pumping. The laser energy was calculated as a function of diode temperature from -30°C to 60°C. When a compound diode with a flat-top spectrum was used for pumping, the mean laser energy was 83% of the maximum energy of a Nd:YAG laser pumped by a diode with a narrow bandwidth. In addition, a compound diode with three emission lines was tested for pumping. When the wavelength gap between the adjacent emission lines of the pumping diode was in the range of 3-10 nm, the mean energy of the Nd:YAG laser became similar to that of a Nd:YAG laser pumped by a diode with a flat-top spectrum.
[Purpose] To determine the correlations of differences in the income level with the presence of metabolic syndrome (MetS), energy intake, and physical activity across Korean elderly populations.[Methods] We obtained data from 2,139 elderly individuals (aged >65 years) based on the Korea National Health and Nutrition Examination Survey (KNHANES) (2016‒2018). We analyzed the levels of physical activity (PA) and energy intake using the survey data. Moreover, we analyzed the differences in energy intake and PA levels according to the income level and MetS.[Results] Compared with the non-MetS group, the MetS group displayed significantly higher levels of waist circumference (p=0.000), triglycerides (p=0.000), systolic blood pressure (p=0.000), diastolic blood pressure (p=0.016), and fasting blood glucose (p=0.000) for both high and low income levels. However, the level of high-density lipoprotein cholesterol was significantly lower in the MetS group than that in the non-MetS group (p=0.000). The level of smoking in non-MetS men was significantly higher than that in MetS men across all participants (p=0.047). Except carbohydrate intake, the total energy intake (p=0.022), fat intake (p=0.009), and protein intake (p=0.005) were significantly lower in the MetS group than those in the non-MetS group for high income levels. We obtained similar results for low income levels. The two-way analysis of variance (ANOVA) did not identify an interaction between the income level and the presence of MetS; however, the total energy, i.e., the level of total energy intake, was significantly lower in participants with low income levels than in those with high income levels. For high income levels, transport PA (p=0.002), vigorous recreational PA (p=0.001), moderate recreational PA (p=0.001), and total PA (p=0.000) were significantly lower in the MetS group than those in the non-MetS group. For low income levels, moderate occupational PA (p=0.012), transport PA (p=0.018), and total PA ((p=0.000) were significantly lower in the MetS group than those in the non-MetS group. The total PA, i.e., the level of energy consumption, was significantly lower in the elderly with low income levels than in those with high income levels.[Conclusion] Regardless of the income level, the elderly with MetS exhibited low levels of energy intake and PA, compared with those without MetS. In addition, regardless of the presence of MetS, the elderly with low income levels exhibited lesser energy intake and PA. These findings implied the need for balanced nutrient intake and increased participation in PA as well as education and program development to prevent MetS in the elderly.
Light emitting d iode (LED) pumped solid-state lasers were designed. Several solid state materials such as Nd:YA G, Nd :glass, Ti:sapphire, and solid dye were studied. To pump efficiently with LEDs, various types of reflectors were tested. Absorption of rays from arrays of LEDs by solid gain med iu m was calculated and then the calculated data was transferred to co mmercial cavity analysis software. The lasing characteristics such as lasing thresholds, thermal lens, and slope efficiencies were estimated. Introducti onSolid State lasers have been pumped by flash lamps, laser d iode, or other lasers. There are large heat generation and short life time problems when pumped with flash lamps. Laser diode is expensive and it should be protected from humidity, static electricity and dust. These problems have been addressed numerous times over the past decades. In this work, an alternative pump source light emitting diode (LED) was considered. The LEDs were suggested as pump source about 40 years ago. At that time, LEDs had low electric to optical power conversion efficiency [ 1,2] and to obtain laser light, several experimental technics were tried [1][2][3][4]. However, due to low output power of LEDs, the study using LEDs had been rare. Recently, LEDs wh ich have high power output are developed rapidly. Also it has low cost. LED application such as pumping laser is considered here [5]. Calculation and ResultFor the LED pu mped solid-state laser design, we used commercial ray tracing software (ZEMAX) and laser cavity analysis software (LASCA D). The co mbined calcu lation of the software enabled to us to evaluate numerically the laser output performance, totally absorbed LED beam, and the absorbed energy profile inside laser crystal. In the calculation, Nd:YA G, Nd:Glass, solid dye, and Ti:Sapphire solid rods were considered as LED pumped gain media. For precise calculat ion, experimentally measured output power and wavelength of the wh ite and the blue LEDs, which were co mmercially available (S42180 and B42180, Seoul semiconductor), were considered. The output powers were 0.31 W fo r the wh ite LED and 0.46 W for the blue LED. Figure 1 shows the picture of devised LED pumped laser. To pu mp laser crystal efficiently, four LED bars surrounded laser crystal symmetrically. In ZEMAX code, the absorbed LED power inside laser crystal was calculated with help of measured relative strength of emitted spectra fro m LEDs. The absorbed LED power was calculated and it was imported to LASCAD for analysis of thermal effect and laser output power. Figure 2(a) and 2(b ) show the calculated output powers as a function of absorbed white and blue LED power. The optimal output coupler reflectivity was optimized fo r each laser crystal and cavity loss was set as 0.02. We assumed the total maximu m LED output power of 200 W. Fro m the calculation, the absorption efficiency of Nd:YA G, solid dye, Nd :Glass and Ti:Sapphire were 6%, 24% 8%OSA/ SumSession 2011 Tu40-1
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