Understanding flow-system dynamics of underground coal mine complexes is essential to designing in-situ remediation. Such
complexes can be studied by applying time series analysis to the precipitation series and well and mine discharge hydrographs.
The Corning mine complex discharges acid mine drainage into Sunday Creek in Ohio, USA. Analysis of the Corning discharge shows
that the aquifer has a short (9 days) response time and has little capacity for long-term storage. A time lag of 3–4 days
occurs between precipitation and discharge, which corresponds to pressure pulse propagation displacing stored mine water,
rather than actual advective flow of water. A gradual decline in hydraulic head is observed from the unsaturated recharge
area to the fully flooded discharge area. All well hydrographs show a similar seasonal trend, with mine water levels peaking
in early summer, and reaching their lowest levels in early fall, consistent with seasonal recharge patterns. A relatively
isolated and fully saturated portion of the mine is sensitive to diurnal barometric pressure, as is typical of confined aquifers,
with well water level declining as pressure increases. Other portions of the mine behave as unconfined aquifers, insensitive
to barometric pressures. The results also demonstrate the important spatial heterogeneity of the aquifer and indicate that
the mine does not behave as a single pool. 相似文献
Recent large foodborne outbreaks caused by Salmonella enterica serovars have been associated with consumption of foods with high fat content and reduced water activity, even though their ingredients usually undergo pasteurization. The present study was focused on the heat tolerance of Salmonella enterica serovars Agona, Enteritidis, and Typhimurium in peanut butter. The Salmonella serovars in the peanut butter were resistant to heat, and even at a temperature as high as 90 degrees C only 3.2-log reduction in CFU was observed. The obtained thermal inactivation curves were upwardly concave, indicating rapid death at the beginning (10 min) followed by lower death rates and an asymptotic tail. The curves fitted the nonlinear Weibull model with beta parameters < 1, indicating that the remaining cells have a lower probability of dying. beta at 70 degrees C (0.40 +/- 0.04) was significantly lower than beta at 80 degrees C (0.73 +/- 0.19) and 90 degrees C (0.69 +/- 0.17). Very little decrease in the viable population (less than 2-log decrease) was noted in cultures that were exposed to a second thermal treatment. Peanut butter is a highly concentrated colloidal suspension of lipid and water in a peanut meal phase. We hypothesized that differences in the local environments of the bacteria, with respect to fat content or water activity, explained the observed distribution and high portion of surviving cells (0.1%, independent of the initial cell number). These results demonstrate that thermal treatments are inadequate to consistently destroy Salmonella in highly contaminated peanut butter and that the pasteurization process cannot be improved significantly by longer treatment or higher temperatures. 相似文献
The kinetics of the methane dry (CO2) reforming over the SmCoO3 was investigated in the temperature ranged 973–1073 K by varying the CH4 and CO2 partial pressures. Based on detailed study of the reaction mechanism, a mechanistic model is proposed from which a kinetic model is derived. The mechanistic pattern assumes adsorption of CH4 on reduced Co, followed by methane cracking and carbon deposition. CO2 reacts with Sm2O3 to form Sm2O2CO3 and the oxycarbonates react with carbon to produce CO. The power law and Langmuir–Hinshelwood kinetic model which is established on this mechanism were able to forecast the kinetic results. 相似文献
Theoretical and empirical analyses suggest that affective features of dyadic communication bear importantly on relationship satisfaction. A circumplex model that originated in research on the structure of affect was first replicated using data from premarital problem-solving discussions. Negativity, Positivity, and Disengagement emerged as the 3 primary factors. Multiple regression analyses, controlling for premarital relationship satisfaction, showed affective Disengagement at premarriage to be negatively associated with marital satisfaction at 18 (n?=?84) and 30 (n?=?72) mo after marriage. Negativity of premarital affective expression correlated negatively with premarital satisfaction (n?=?88) but not with postmarital satisfaction. Two variables formed by combining affect factors contributed to the prediction of 30-mo marital satisfaction. Elements associated with current marital satisfaction appear to differ from those associated with later marital satisfaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
The main objective of this research effort was to study whether microencapsulation could be a viable alternative to obtain probiotic orange or peach juices. In order to be considered probiotic food, probiotic bacteria must be present in sufficient viable numbers to promote a benefit to the host. The survival and viability of Lactobacillus paracasei L26 in juices over 50?days of storage at 5°C was assessed, evaluating the potential use of encapsulated cells in alginate microcapsules. L. paracasei L26 demonstrated good viability in both orange and peach juices despite the low pH values of both juices. Microencapsulation in alginate, with or without double coating, revealed to be suitable to protect L. paracasei L26 since viable cells were approximately 9 log cfu/g after 50?days of storage at 5°C. In general, the probiotic fruit juices showed a decrease in pH during storage. Glucose and fructose contents as well as citric acid contents decreased during storage, whereas an increase in formic acid was observed. The outcome of this study points to L. paracasei L26 as having promising potential, especially in an encapsulated form, as functional supplements in fruit juices without dairy ingredients due to their tolerance in an acidic environment over 50?days of storage at 5°C. Further studies are warranted to prove the functionality of juices with encapsulated probiotic strains. 相似文献
In this study, large band gap zinc oxide nanoparticles (ZnO-NPs) were prepared by a facile, cost-effective, and eco-friendly co-precipitation method in aqueous solutions. Trisodium citrate was employed as a green and bio-safe complexing agent for zinc ions without using ammonia and/or any organic solution. The annealing effect on crystal structure, morphology, particle size, composition, UV absorption, and fluorescence (FL) properties of the synthesized ZnO-NPs was evaluated using various techniques. The UV–Visible absorption spectra of the ZnO-NPs showed a strong absorption peak in the UV-C region with a wide band gap energy of 4.2–4.4 eV. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) images demonstrated fine spherical particles with approximate diameters of 20–50 nm. The average hydrodynamic diameter and zeta potential values of the as-prepared and the annealed ZnO-NPs in deionized water were 28.2 nm, ? 32.4 mV, 38.9 nm, and ? 16.1 mV, respectively. The FL and UV–Visible results illustrated that the annealing could considerably influence the emission and absorption spectra of the samples in the UV region. The FL and EDX results revealed that the annealing affects the composition, defect points, and states population in the crystal structure of the ZnO-NPs. Practical experiments of exposing the samples to UV radiation and the FL measurements indicated that the ZnO-NPs were sensitive to the excitation wavelengths, therefore, they have potential application in fabricating various types of UV sensors and filters (blockers), as well as photocatalytic activities.
Oxidative stress is both the cause and consequence of impaired functional homeostasis characterizing human aging. The worsening efficiency of stress response with age represents a health risk and leads to the onset and accrual of major age-related diseases. In contrast, centenarians seem to have evolved conservative stress response mechanisms, probably derived from a combination of a diet rich in natural antioxidants, an active lifestyle and a favorable genetic background, particularly rich in genetic variants able to counteract the stress overload at the level of both nuclear and mitochondrial DNA. The integration of these factors could allow centenarians to maintain moderate levels of free radicals that exert beneficial signaling and modulator effects on cellular metabolism. Considering the hot debate on the efficacy of antioxidant supplementation in promoting healthy aging, in this review we gathered the existing information regarding genetic variability and lifestyle factors which potentially modulate the stress response at old age. Evidence reported here suggests that the integration of lifestyle factors (moderate physical activity and healthy nutrition) and genetic background could shift the balance in favor of the antioxidant cellular machinery by activating appropriate defense mechanisms in response to exceeding external and internal stress levels, and thus possibly achieving the prospect of living a longer life. 相似文献
Bubble size distribution (BSD) is relevant to the design of gas–liquid systems, as it determines the interfacial area available in heat and mass transfer processes. Although data on BSD in stirred aerated tanks are available, a systematic comparison of alternative modeling functions for these data is lacking. In this work, BSDs obtained in air–water dispersions in a stirred aerated tank with a Rushton turbine and BSDs available in the literature for similar systems were modeled by 14 empirical probability density functions (PDFs). It was found that both the distribution of Nukiyama–Tanasawa with three adjustable parameters and the Rosin–Rammler distribution with two adjustable parameters reasonably fit original and literature BSDs. It is also concluded that it is possible to correlate the PDF parameters with the power dissipated by the agitator in the liquid phase, allowing the BSD to be modeled with only two parameters in a range of dissipated power from 0.5 to 2.3?kW/m3. BSDs thus modeled provide good predictions of average bubble size. 相似文献
We have discovered the sirtuin-rearranging ligands (SirReals) as a novel class of highly potent and selective inhibitors of the NAD+-dependent lysine deacetylase sirtuin 2 (Sirt2). In previous studies, conjugation of a SirReal with a ligand for the E3 ubiquitin ligase cereblon to form a so-called proteolysis-targeting chimera (PROTAC) enabled small-molecule-induced degradation of Sirt2. Herein, we report the structure-based development of a chloroalkylated SirReal that induces the degradation of Sirt2 mediated by Halo-tagged E3 ubiquitin ligases. Using this orthogonal approach for Sirt2 degradation, we show that other E3 ligases than cereblon, such as the E3 ubiquitin ligase parkin, can also be harnessed for small-molecule-induced Sirt2 degradation, thereby emphasizing the great potential of parkin to be used as an E3 ligase for new PROTACs approaches. Thus, our study provides new insights into targeted protein degradation in general and Sirt2 degradation in particular. 相似文献