Exchange of polycyclic aromatic hydrocarbons across the air-water interface in the Bohai and Yellow Seas

In this study, air and surface seawater samples collected from the Bohai (BS) and Yellow Seas (YS) in May 2012 were determined exchange of PAHs, especially of low-molecular-weight (LMW) PAHs (three- and four-ring PAHs) at the air-water interface. Net volatilization fluxes of LMW PAHs were 266-1454 ng/m(2)/d and decreased with distance from the coast, indicating that these PAHs transported from coastal runoff were potential contributors to the atmosphere in the BS and YS. Moreover, LMW PAHs were enriched in the dissolved phase compared with those in the particulate phase in the water column, possibly suggesting that the volatilized LMW PAHs were directly derived from wastewater discharge or petroleum pollution rather than released from contaminated sediments. The air-sea exchange fluxes of the three-ring PAHs were 2- to 20-fold higher than their atmospheric deposition fluxes in the BS and YS. The input to and output from the water reached equilibrium for four-ring PAHs. Differently, five- and six-ring PAHs were introduced into the marine environment primarily through dry and wet deposition, indicating that the water column was still a sink of these PAHs from the surrounding atmosphere. (C) 2016 Elsevier Ltd. All rights reserved

On the Methods for Explaining Polarization of Private and Unobservable Opinions: An opinion-behavior co-evolutionary approach

Polarized opinions are everywhere. From opposite attitudes towards Hawaiian pizza to the partisan divide in theUnited States, we have experienced enough opinion polarization in recent years. Sadly, it is usually a sign of follow-up criticism when people start to talk about "opinion polarization". The term, which should neutrally describe a widespread social phenomenon, has been proven to be associated with different dismaying outcomes, ranging from hostility to civil wars. Given its harmful consequence, few would doubt the urgent need for a solution to this long-lasting issue, and such a solution requires a deep understanding of opinion polarization in real-life situations. The urgent need has motivated remarkable research efforts in the past few decades. Especially in the domain of computational sociology, a considerable amount of opinion dynamics models have been proposed to explain opinion polarization from microscopic mechanisms that govern interactions between individuals. A common feature of these models, which probably results from their roots in statistic physics, is that opinions are observable and can be directly affected by other opinions just like a "spin" in the famous Ising model. However, opinions in real life are of fundamental difference from "spin" in the sense that it is by nature private and unobservable, whose expression, transmission, and inference largely depend on observable behaviors: even if people are allowed to verbally exchange opinions, how these opinions are translated into words and how these words are inferred by both parties still play a critical role in the dynamics of opinions. Thereby, we could put forward a thesis (which we did, literally) that there is a fundamental discrepancy between opinion polarization in the literature and opinion polarization in real-life situations that would deteriorate our trust in these models, let alone the solutions generated accordingly.Transport and Logistic

Learning opinions by observing actions: Simulation of opinion dynamics using an action-opinion inference model

Opinion dynamics models are based on the implicit assumption that people can observe the opinions of others directly, and update their own opinions based on the observation. This assumption significantly reduces the complexity of the process of learning opinions, but seems to be rather unrealistic. Instead, we argue that the opinion itself is unobservable, and that people attempt to infer the opinions of others by observing and interpreting their actions. Building on the notion of Bayesian learning, we introduce an action-opinion inference model (AOI model); this model describes and predicts opinion dynamics where actions are governed by underlying opinions, and each agent changes her opinion according to her inference of others’ opinions from their actions. We study different action-opinion relations in the framework of the AOI model, and show how opinion dynamics are determined by the relations between opinions and actions. We also show that the well-known voter model can be formulated as being a special case of the AOI model when adopting a bijective action-opinion relation. Furthermore, we show that a so-called inclusive opinion, which is congruent with more than one action (in contrast with an exclusive opinion which is only congruent with one action), plays a special role in the dynamic process of opinion spreading. Specifically, the system containing an inclusive opinion always ends up with a full consensus of an exclusive opinion that is incompatible with the inclusive opinion, or with a mixed state of other opinions, including the inclusive opinion itself. A mathematical solution is given for some simple action-opinion relations to help better understand and interpret the simulation results. Finally, the AOI model is compared with the constrained voter model and the language competition model; several avenues for further research are discussed at the end of the paper.Transport and Logistic

An experimental study of vertical greenery systems for window shading for energy saving in summer

Past studies have demonstrated the remarkable energy-saving effect of vertical greenery systems. The vast majority of these works focus on opaque building walls. While external shadings on windows are more effective than these on walls. Inspired by the climbing plants (vines) raised outside windows by residents, the present study proposed the design of movable green window shading systems (MGWSS) that can shade beam solar radiation but allows soft daylighting. On the basis of simplified MGWSS models, experiments were conducted in summer to evaluate the shading performance with three plant species. First, the energy-saving effect and climatic data were measured for test rooms with west-facing windows. The results indicated that the presence of green shading reduced the impact of solar radiation on the cooling energy consumption with the correlation coefficients from 0.94 to 0.61. Then, the shading coefficient, which is a key parameter for energy saving, was measured by a new technique using photovoltaic panels. The correlation between the coverage rate and the surface-averaged shading coefficient was established. The results showed that when the coverage rate of the MGWSS with Dishcloth gourd was 80%, the shading coefficient was 0.28, and the cooling energy consumption and heat flux transferred through the window glass were reduced by 11.5% and 64.8%, respectively. The shading characteristic was investigated using the instantaneous data. It found that stronger ambient solar radiation resulted in better shading performance (lower shading coefficient). For a west-facing window, the best shading performance was found at oblique solar incidence angles.Accepted Author ManuscriptHistory & Complexit

Hiding opinions by minimizing disclosed information: an obfuscation-based opinion dynamics model

In the field of opinion dynamics, the hiding of opinions is routinely modeled as staying silent. However, staying silent is not always feasible. In situations where opinions are indirectly expressed by one’s observable actions, people may however try to hide their opinions via a more complex and intelligent strategy called obfuscation, which minimizes the information disclosed to others. This study proposes a formal opinion dynamics model to study the hitherto unexplored effect of obfuscation on public opinion formation based on the recently developed Action-Opinion Inference Model. For illustration purposes, we use our model to simulate two cases with different levels of complexity, highlighting that the effect of obfuscation largely depends on the subtle relations between actions and opinions.Transport and LogisticsEnergy & Industr

A Practical Real Gas Model in CFD

Polynomial functions are generated to describe real gas properties in computational fluid dynamics (CFD). Two-variable relative least square fitting is applied. In this way the real gas model can be generated fast and easily and the computational time requested is small and precision of the function can be easily adjusted. In this paper this kind of real-gas model is implemented for toluene and super sonic stator nozzle is calculated. The obtained results are compared to the measured ones

Study of Influence of Operating Parameters on Braking Distance

Stopping distance includes driver thinking distance and braking distance. Braking distance is one of the basic standards for road design and maintenance practices. Adequate tire–pavement skid resistance plays a significant role in reducing braking distance and consequently enhancing road safety. With technology such as the antilock braking system, the friction force is maximized by applying the brakes repeatedly, in an on-and-off pattern, such that the braking distance is shortened. Several studies have shown the effect that some parameters, such as water film thickness, tire inflation pressure, and wheel load, have on braking distance. Less discussed is the effect of slip ratio, temperature, and pavement surface characteristics. Measuring the braking distance in the field is energy-consuming and time-consuming, and there are uncertainties in the environmental conditions as well. General approaches to calculating braking distance are based on basic mechanics principles. To the authors’ knowledge, a model that can simulate the whole braking process is not available. The presented study proposes a way to predict braking distance by means of finite element modeling only. A model that can include the effect of parameters such as temperature, slip ratio, and pavement surface characteristics on the braking distance is introduced.Accepted Author ManuscriptPavement Engineerin

Together alone: a group-based polarization measurement

The growing polarization of our societies and economies has been extensively studied in various disciplines and is subject to public controversy. Yet, measuring polarization is hampered by the discrepancy between how polarization is conceptualized and measured. For instance, the notion of group, especially groups that are identified based on similarities between individuals, is key to conceptualizing polarization but is usually neglected when measuring polarization. To address the issue, this paper presents a new polarization measurement based on a grouping method called “Equal Size Binary Grouping” (ESBG) for both uni- and multi-dimensional discrete data, which satisfies a range of desired properties. Inspired by techniques of clustering, ESBG divides the population into two groups of equal sizes based on similarities between individuals, while overcoming certain theoretical and practical problems afflicting other grouping methods, such as discontinuity and contradiction of reasoning. Our new polarization measurement and the grouping method are illustrated by applying them to a two-dimensional synthetic data set. By means of a so-called “squeezing-and-moving” framework, we show that our measurement is closely related to bipolarization and could help stimulate further empirical research.Transport and LogisticsEnergy & Industr

Non-intrusive Reliability Analysis of Multi-layered Slopes in Spatially Variable Soils

Stochastic finite element method and random finite element method can provide rigorous tools for slope reliability analysis incorporating spatial variability of soil properties. However, both of them are difficult to be applied into practice due to the modification of finite-element codes and the low efficiency, respectively. To address these problems, this paper develops a more practical approach called non-intrusive stochastic finite element method (NISFEM) for slope reliability analysis in spatially variable soils. In the NISFEM, the random fields of spatially variable soils are generated using Karhunen-Loeve expansion, and the safety factor of slope stability is calculated using commercial finite-element package. After that, the Hermite polynomial chaos expansion is used to express the safety factor explicitly for slope reliability analysis. In addition, this paper suggests an easy dimension reduction technique to further improve the efficiency of NISFEM, namely, to adopt a relatively small truncated ratio in Karhunen-Loeve expansion. The proposed method is illustrated and verified using a multi-layered soil slope example. Through the sensitivity study, it is found that the vertical spatial variability affects the slope failure probability and the sensitivity of uncertain soil properties significantly

23.7 A BJT-Based Temperature Sensor with ±0.1 C(3σ) Inaccuracy from -55°C to 125°C and a 0.85pJ.K²Resolution FoM Using Continuous-Time Readout

BJT-based temperature sensors are widely used due to their high accuracy over a wide temperature range with a low-cost 1-point trim. Although resistor-based sensors can achieve better energy efficiency, they typically require a 2-point trim to achieve comparable accuracy, while thermal-diffusivity based sensors achieve superior accuracy at the cost of energy efficiency [1]. This paper presents a BJT-based temperature sensor that achieves both excellent accuracy and energy efficiency. To avoid the kTfC noise limitations of conventional discrete-time (OT) readout schemes [2], [3], it employs a compact continuous-time (CT) front-end. Component mismatch, which often limits the accuracy of CT front-ends [4], [5], is mitigated by a combination of dynamic element matching (OEM) and a low-cost resistor-ratio self-calibration scheme. As a result, the sensor achieves a resolution FoM of 0.85textpJcdotK 2, and a competitive inaccuracy of pm 0.1 circC (3sigma) from -55 circC tO 125 circC after a 1-point trim. This makes it 4times more energy-efficient than state-of-the-art BJT-based sensors with similar accuracy [2], [4], [5].Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic