Composted Municipal Waste and Fertilizer Effects on Soils and Sugarcane.

Application of composted municipal waste to agricultural lands has potential benefits to improve soil fertility and crop yield. It may lead to accumulation of heavy metals within soils and leaching of nutrients and heavy metals into the ground water. The objectives of this study were to investigate: (1) the effects of composted municipal waste and fertilizer on soil chemical properties and sugarcane elemental uptake and yield; and (2) the leachability of elements in compost amended soils. Results of three field experiments from a Baldwin silty clay loam and a Memphis silt loam showed that compost application at $\ge$33.6 Mg/ha increased soil nutrients, organic matter, and pH. Compost application also increased the Cu, Zn, Cd, and Pb for the Baldwin soil and Cu for the Memphis soil. The increased metal concentrations were much lower than toxic levels. Plant tissue and sugar juice data demonstrated that compost was beneficial for sugarcane growth and there was no heavy metal accumulation. Yield data indicate that compost application at $\ge$134.4 Mg/ha can produce plant cane and sugar yields equivalent to those obtained by applying inorganic fertilizer (179 kg N, 101 kg \rm P\sb2O\sb5, 134 kg K\sb2O, and 27 kg S per hectare) on a Baldwin soil. The correlation analysis between extracted trace metals in soils and plant tissue digests showed that the increased heavy metals did not reflect the amounts taken up by sugarcane. This indicates that the DTPA method of soil metal extraction is a questionable index for the bioavailability of trace metals in compost amended soils. Leaching experiments using soil columns showed that nutrient and heavy metal concentrations in leachate increased with increasing compost rate, but decreased with time. Concentrations of NO\sb3-N, SO\sb4-S, and Cl\sp- were higher than the primary or secondary drinking water standards during the first 2 wk. But, heavy metals concentrations were lower than the primary or secondary drinking water standards throughout the leaching period except for Mn. These results suggest that there is a potential contamination of groundwater with the nutrients following compost application, but contamination of groundwater with heavy metals should be negligible

Essays on technology and international trade

The three essays contained in this dissertation are about technology and international trade. The first essay examines optimal intellectual property rights (IPR) protection in developing countries, while the other two estimate product quality at the sectoral level for a panel of twelve manufacturing sectors in twenty OECD countries using a novel approach and relate import competition and R&D investment to the growth of sectoral product quality. Chapter 2 is motivated by the work of Acemoglu and Zilibotti (2001), who argue that the technologies developed in the North are not appropriate for the needs of the South, due to a ``technology-skill mismatch\u27\u27 problem. Chapter 2 tries to solve this problem by putting forward a sector-differentiated IPR protection for developing countries. Specifically, in autarky, the IPR protection in the low-skill intensive sector of the South should be greater than its high-skill intensive sector. However, the greater protection for the low-skill intensive sector is not necessary when free trade in the final good is allowed between the North and South. This implies that international trade can help the South solve the technology-skill mismatch problem. In Chapter 3, I estimate product quality at the sector level for twenty OECD countries based on a gravity equation derived from a quality-heterogeneity model of trade. I find that the estimated quality levels vary substantially across countries and over time, and as in Hallak and Schott (2011), there is a positive correlation between countries\u27 product quality and their per-capita income that is declining over time. Lastly, the quality gap between rich and poor countries is more pronounced in capital- and skill-intensive sectors. Using quality estimates from Chapter 3, the fourth chapter investigates the contributions of import competition and R&D investment to the growth of sectoral product quality. I find that import competition leads to substantial quality upgrading, confirming the findings of Amiti and Khandelwal (2013). I also find that both R&D and human capital can facilitate quality upgrading by increasing the absorptive capacity of developing countries, corroborating the results of Fisher-Vanden and Terry (2009)

Fast catheter segmentation and tracking based on x-ray fluoroscopic and echocardiographic modalities for catheter-based cardiac minimally invasive interventions

X-ray fluoroscopy and echocardiography imaging (ultrasound, US) are two imaging modalities that are widely used in cardiac catheterization. For these modalities, a fast, accurate and stable algorithm for the detection and tracking of catheters is required to allow clinicians to observe the catheter location in real-time. Currently X-ray fluoroscopy is routinely used as the standard modality in catheter ablation interventions. However, it lacks the ability to visualize soft tissue and uses harmful radiation. US does not have these limitations but often contains acoustic artifacts and has a small field of view. These make the detection and tracking of the catheter in US very challenging. The first contribution in this thesis is a framework which combines Kalman filter and discrete optimization for multiple catheter segmentation and tracking in X-ray images. Kalman filter is used to identify the whole catheter from a single point detected on the catheter in the first frame of a sequence of x-ray images. An energy-based formulation is developed that can be used to track the catheters in the following frames. We also propose a discrete optimization for minimizing the energy function in each frame of the X-ray image sequence. Our approach is robust to tangential motion of the catheter and combines the tubular and salient feature measurements into a single robust and efficient framework. The second contribution is an algorithm for catheter extraction in 3D ultrasound images based on (a) the registration between the X-ray and ultrasound images and (b) the segmentation of the catheter in X-ray images. The search space for the catheter extraction in the ultrasound images is constrained to lie on or close to a curved surface in the ultrasound volume. The curved surface corresponds to the back-projection of the extracted catheter from the X-ray image to the ultrasound volume. Blob-like features are detected in the US images and organized in a graphical model. The extracted catheter is modelled as the optimal path in this graphical model. Both contributions allow the use of ultrasound imaging for the improved visualization of soft tissue. However, X-ray imaging is still required for each ultrasound frame and the amount of X-ray exposure has not been reduced. The final contribution in this thesis is a system that can track the catheter in ultrasound volumes automatically without the need for X-ray imaging during the tracking. Instead X-ray imaging is only required for the system initialization and for recovery from tracking failures. This allows a significant reduction in the amount of X-ray exposure for patient and clinicians.Open Acces

Maxwell-Hydrodynamic Model for Simulating Nonlinear Terahertz Generation from Plasmonic Metasurfaces

The interaction between the electromagnetic field and plasmonic nanostructures leads to both the strong linear response and inherent nonlinear behavior. In this paper, a time-domain hydrodynamic model for describing the motion of electrons in plasmonic nanostructures is presented, in which both surface and bulk contributions of nonlinearity are considered. A coupled Maxwell-hydrodynamic system capturing full-wave physics and free electron dynamics is numerically solved with the parallel finite-difference time-domain (FDTD) method. The validation of the proposed method is presented to simulate linear and nonlinear responses from a plasmonic metasurface. The linear response is compared with the Drude dispersion model and the nonlinear terahertz emission from a difference-frequency generation process is validated with theoretical analyses. The proposed scheme is fundamentally important to design nonlinear plasmonic nanodevices, especially for efficient and broadband THz emitters.Comment: 8 pages, 7 figures, IEEE Journal on Multiscale and Multiphysics Computational Techniques, 201

Quantitative particle approximations of stochastic 2D Navier-Stokes equation

In this article, we investigate an interacting particle system featuring random intensities, individual noise, and environmental noise, commonly referred to as stochastic point vortex model. The model serves as an approximation for the stochastic 2-dimensional Navier-Stokes equation. We establish a quantitative mean-field convergence for the stochastic 2-dimensional Navier-Stokes equation in the form of relative entropy. To address challenges posed by environmental noise, random intensities, and singular kernel, we compare relative entropy for conditional distributions, employing technology of disintegration and the relative entropy method developed by Jabin and Wang in [JW18].Comment: 51 page

The Quantitative Analysis on the Individual Characteristics of Urban Residents and Their Sport Consumption Motivation

AbstractUsing the questionnaire, mathematical statistics and entropy measurement methods, the quantitative relationship between the individual characteristics urban residents and their sports consumption motivation are studied. The results show that the most main sports consumption motivation of urban residents is fitness motivation and social motivation. Urban residents of different gender, age, education and income levels are different in regulating psychological motivation, rational consumption motivation and seeking common motivation

A Study on the Government Subsidies for CR Express Based on Dynamic Games of Incomplete Information

CHINA RAILWAY Express (CR express) refers to the international container train running in the East Asian Economic Circle and the developed European Economic Circle, and it is an important link in the development of “The Belt and Road”. However, as CR Express is still in the early stages of development, it is still on the way to fully market-oriented operations, and also has some problems such as high overall transportation cost, disorderly competition and other issues. From the perspective of government subsidies, this paper by searching the relationship in incomplete information dynamic game between local government and local relevant enterprises, gets the optimal subsidy amount for the government to obtain the maximum social benefit. The results can provide a reference for the government to formulate a reasonable subsidy policy and for the CR express to realize market-oriented