Biogenic Organic Carbon Compounds in Air and Rain

Rainwater quality has not been an issue of concern until recent decades of increasing urbanization and industrialization. Therefore, the role of biogenic contamination sources has been always underestimated as generally, anthropogenic contaminants are thought to be responsible for rainwater quality deterioration. This study aims to find the sources and reasons of biogenic VOC emission into the air and their changes in the air. Also, transfer of biogenic VOCs into the rainwater and their abundance have been investigated. The effects of these biogenic VOCs on rainwater quality have been studied by sampling of two rain events in the University of Massachusetts in Amherst. Key water quality parameters such as UV/VIS absorbance, DOC, SUVA, chlorine residual and DBPs formation potentials have been measured and analyzed. The results show a number of high concentrations of DOC and DBP formation potentials in rainwater samples suggesting that although rainwater is still the highest quality of drinking water, but it may have some quality issues especially in terms of DBPs formation potentials that can be caused mainly by the emission of biogenic VOCs

FUTURE HYDROLOGICAL FAILURE PROBABILITY OF DAMS IN NEW ENGLAND UNDER LAND USE AND CLIMATE CHANGE

Floods lead to the overtopping of dams which is the main cause of dam failures and can result in significant loss of lives and property. This study investigates how the hydrological failure probability of dams in New England may change with future changes in climate and land use. Non-stationarity of future precipitation caused by the anthropogenic climate change and altered watershed concentration times caused by anthropogenic alterations such as urbanization, industrialization or deforestation can impact the mechanisms of runoff production and transfer. This can potentially change the frequency, magnitude, or duration of floods. Therefore, due to different flood patterns and consequently different hydrological failure probability, dams in New England likely have very different future risk levels. As hydrological failure probability indicators, the magnitude and frequency, and duration of floods exceeding a threshold are used to determine the variability of hydrological failure probability. Aside from the historical measured and gridded climate and land use data, this study uses one high temporal- and spatial-resolution, dynamically downscaled climate change projection and 29 statistically downscaled climate change projections as well as four land use projections from “The New England Landscape Futures Project”. Results show that basin response in New England during high-flow events has not significantly changed during recent decades in spite of recent changes in climate and runoff generation mechanisms. Also, dammed basins with higher storage capacity are found to have a decrease in basin response and flood peaks while there is not enough evidence the significance of urban development on high-flow events in New England. It is likely that dams in New England experience higher levels of hydrological failure probability. This is because compared to historical data, future floods are likely to increase in magnitude and frequency, but they are not likely to last longer. Also, the results show more accentuated increase in the frequency compared to the magnitude of future floods. This study will help dam owners and state regulators plan for more resilient dam operations and more rigorous dam maintenance and account for the future risk associated with the approximately 15,000 dams in New England

LMI-Based Reset Unknown Input Observer for State Estimation of Linear Uncertain Systems

This paper proposes a novel kind of Unknown Input Observer (UIO) called Reset Unknown Input Observer (R-UIO) for state estimation of linear systems in the presence of disturbance using Linear Matrix Inequality (LMI) techniques. In R-UIO, the states of the observer are reset to the after-reset value based on an appropriate reset law in order to decrease the $L_2$ norm and settling time of estimation error. It is shown that the application of the reset theory to the UIOs in the LTI framework can significantly improve the transient response of the observer. Moreover, the devised approach can be applied to both SISO and MIMO systems. Furthermore, the stability and convergence analysis of the devised R-UIO is addressed. Finally, the efficiency of the proposed method is demonstrated by simulation results

Machine Learning Methods in Individual Migration Behavior

Machine learning is described as “a field of computer science that gives a machine the ability to learn”. In fact, machine learning is considered as a sub branch of Artificial Intelligence(AI). In recent years the rise of big data and cloud computing gives AI expert and specifically machine learning expert to dive deeply in data and extract knowledge from it by using machine learning algorithms. In this paper we try to introduce the basic concepts of machine learning algorithms including supervised learning, unsupervised learning and reinforcement learning and its usage in different applications. We describe specifically how to use machine learning in migration process modeling and focus on an approach for migration description, that is based on one of machine learning methods, the decision tree algorithm. We apply this method for the description of the economic behavior of an individual in the question of continuing his work in Russia based on the panel data and the data from the sociological survey. The accuracy of our estimation using decision tree is 67 percent for this specific task. All in all, the main objective of this paper is to introduce the important aspects of machine learning and its usages in the state-of-the-art technologies

Study on physio-chemical properties of plasma polymerization in C2H2/N2 plasma and their impact on COL X

Nitrogen-containing plasma polymerization is of considerable interest for tissue engineering due to their properties on cell adhesion and mesenchymal stem cells (MSCs) response. In this study, low-pressure RF plasma of acetylene and nitrogen was used to deposit nitrogen-containing plasma polymerized coatings on several substrates. Deposition kinetics and surface characteristics of coatings were investigated in terms of RF power and gas flow ratio. OES was used to monitor the plasma process and investigate the relation between the film structure and plasma species. Presence of several bonds and low concentration of amine functional groups were determined using FTIR and Colorimetric methods. Contact angle goniometry results indicated about 30% increase in surface hydrophilicity. Stability of coatings in air and two different liquid environments was examined by repeating surface free energy measurements. Deposited films exhibited acceptable stability during the storage duration. Surface roughness measured by AFM was found to decrease with growing concentration of nitrogen. The deposition rate increased with increasing RF power and decreased with growing concentration of nitrogen. Zeta potential measurements of coatings revealed the negative potential on the surface of the thin films. Temporary suppression of collagen X in the presence of plasma coatings was confirmed by RT-PCR results

Runoff Coefficients of High-flow Events in Undisturbed New England Basins

The New England region in the Northeast U.S. receives high annual precipitation as rain and snow, which results in floods that endanger people and infrastructure. Owing to the complexity of hydrologic systems, increases in the frequency and intensity of large precipitation events do not always translate into increases in surface runoff measured as event flow at the basin outlet. However, recent studies have recognized positive trends in the frequency and magnitude of high-flow events in New England. For high-flow events of equal or greater than 2-year daily runoff, the runoff coefficients, or the fraction of precipitation converted into surface runoff during an event, were determined for 28 undisturbed New England basins with natural flow conditions. Results indicated that runoff coefficients increase in magnitude and variability with distance from the Atlantic coast toward the north and west. The average runoff coefficient of high-flow events across all basins is 0.90, while there exist many high-flow events with runoff coefficients greater than one. Also, runoff coefficients were generally stationary showing that flood events in undisturbed basins have remained proportional to precipitation inputs, despite increases in extreme precipitation, possibly due to shifts in evapotranspiration, snowpack, and soil moisture. Flood management efforts should continue to focus on large springtime precipitation events, which generate the highest runoff coefficients. Finally, this study can serve as a reference point for future exploration of the flood susceptibility of basins with anthropogenic alterations like dam construction or land use change

Fertility outcomes subsequent to medical and surgical treatment for ectopic pregnancy: A retrospective cohort study in Iran

Background: Ectopic pregnancy (EP) and its treatment methods may affect subsequent fertility outcomes. Objective: To compare methotrexate (MTX), laparoscopic salpingostomy, and salpingectomy methods of EP treatment and their effects on fertility outcomes. Materials and Methods: This retrospective cohort study was performed on women receiving a definitive diagnosis of tubular EP from 2014 to 2017 at Arash Medical Center, Tehran, Iran. In total, 194 women were studied, of which 64 were treated with MTX, 52 underwent salpingostomy, and 78 underwent salpingectomy, depending on their clinical status. Basic information, obstetrics history, and major outcomes of the treatment after an 18-month follow-up, including recurrence of EP, miscarriage, and successful intrauterine pregnancy (IUP), were recorded and variables were compared among the three groups. Results: There was no significant difference in fertility outcomes among the three groups. Among the studied variables, predictors of successful IUP after EP treatment were multiparity (Hazard Ratio (HR): 1.37; 95%CI: 1.06-1.77), no history of miscarriage (HR: 2.37; 95%CI: 1.01-5.56), and a higher number of live births (HR: 1.54; 95%CI: 1.01- 2.37). On the other hand, predictors of EP recurrence included nulliparity (HR: 1.61; 95%CI: 1.02-2.53) and a lower number of live births (HR: 3.84; 95%CI: 1.43-10.98). The effect of other factors, including the utilized therapeutic modalities, was not statistically significant. Conclusion: The current study results demonstrated that after an 18-month follow-up, fertility outcomes, including recurrence of EP and successful IUP, were not significantly different among the subjects with EP treated with MTX, salpingostomy, or salpingectomy. Further studies with long-term follow-ups are recommended. Key words: Ectopic pregnancy, Fertility, Methotrexate, Salpingostomy, Salpingectomy