Linear filtering with fractional Brownian motion in the signal and observation processes

Integral equations for the mean-square estimate are obtained for the linear filtering problem, in which the noise generating the signal is a fractional Brownian motion with Hurst index h∈(3/4,1) and the noise in the observation process includes a fractional Brownian motion as well as a Wiener process. AMS subject classifications: 93E11, 60G20, 60G35

The Role of the Liver X Receptor (LXR) in the Fetal Programming of Hepatic Gluconeogenesis

Chronic diseases such as type 2 diabetes and the Metabolic Syndrome create enormous burdens on society. Epidemiological studies now strongly implicate intrauterine growth restriction (IUGR) for increasing the risk of developing chronic diseases later on in life. However, the molecular mechanisms underlying how IUGR leads to the increased susceptibility to these metabolic diseases in adulthood is not well understood. The Liver-X-Receptor (LXR) is a nuclear receptor involved in cholesterol, glucose, and lipid metabolism. LXR acts to decrease gluconeogenesis through repression of glucose-6-phosphatase(G6Pase), phosphoenolpyruvate carboxykinase(PEPCK), and 11β-hydroxysteroid dehydrogenase type-1(11β-HSD1). Using a well-characterized model of maternal protein restriction in rats, this study attempts to elucidate the role of LXR in the long-term programming of impaired glucose homeostasis. It was discovered that altered expression of LXR during the gestational and neonatal period predisposes the fetus to impaired glucose tolerance in adult life through LXR-mediated activation of the gluconeogenic genes G6Pase, PEPCK, and 11β-HSD1

Possible Used Fuel Management Options For A Single Reactor Utility

Used nuclear fuel generated by the operation of Nuclear Power Plants (NPP) needs to be managed in a safe, responsible and effective way. Whereas utilities managing several NPP can implement large scale used fuel management operations, a single reactor utility will chose solutions adapted for relatively low amount of used fuel. There are currently two different approaches for managing used fuel: Open fuel cycle, or “once-through” strategy, where used fuel is considered to be waste and disposed of after wet or dry interim storage following in-reactor use; Closed fuel cycle, or “recycling” strategy, where used fuel is considered as valuable material as it mainly contains reusable uranium and plutonium and thus recycled; such strategy can be implemented directly after in-reactor use without interim storage step and can also be put in place after interim storage; by treating used fuel, 96% of the nuclear material is recovered and recycled as Mixed OXide (MOX) fuel and Enriched Reprocessed Uranium (ERU) fuel; the remaining 4% of non-recyclable material, as well as cladding and structural elements of fuel assemblies, are packaged for final disposal. In addition, long term interim storage of used fuel has been retained by some states until decision is made for one or the other of the two available options, keeping in mind that interim storage, even long term, is a waiting solution and not a sustainable one. For all options, disposal is the final radioactive waste management step: either direct disposal of used fuel or disposal of final residual waste remaining after used fuel treatment. The purpose of the paper is to present the possible used fuel management options for a single reactor utility, clarifying advantages and drawbacks of each of them according to following criteria: safety, security, sustainable development, environment protection, non-proliferation, public acceptance, economy

Per os infectivity of white spot syndrome virus (WSSV) in white-legged shrimp (Litopenaeus vannamei) and role of peritrophic membrane

As earlier observations on peroral infectivity of WSSV in white-legged shrimp are conflicting, here, a standardized peroral intubation technique was used to examine (i) the role of the physical composition of the viral inoculum and (ii) the barrier function of the PM. In a first experiment, the infectivity of a WSSV stock was compared by determining the SID50 by intramuscular injection, peroral inoculation or via feeding. The following titers were obtained: 108.77 SID50/g by intramuscular injection, 10(1.23) SID50/g by peroral inoculation and 100.73 SID50/g by feeding. These results demonstrated that 10(7.54)-10(8.03) infectious virus is needed to infect shrimp by peroral inoculation and via feeding. Next, it was examined if damage of the PM may increase the susceptibility for WSSV by peroral route. The infectivity of a virus stock was tested upon peroral inoculation of shrimp with and without removal of the PM and compared with the infectivity upon intramuscular inoculation. The virus titers obtained upon intramuscular injection and peroral inoculation of shrimp with and without PM were 10(8.63), 10(1.13) and 10(1.53) SID50/mL, respectively. This experiment confirmed the need of 10(7.1)-10(7.5) infectious virus to infect shrimp via peroral route and showed that the removal of the PM slightly but not significantly (p > 0.05) facilitated the infection of shrimp. This study indicated that WSSV contaminated feed is poorly infectious via peroral route, whereas it is highly infectious when injected into shrimp. The PM plays a minor role as internal barrier of shrimp against WSSV infection

Micro-simulation of Car Drivers’ Movements at Parking Lots

AbstractDrivers’ movements across or within parking facilities contribute to various problems, i.e., congestion, safety, and environmental effects. Micro-simulation can help to increase the understanding of drivers’ movements and their effects on parking management. This study aims to develop a multi agent-based simulation tool to demonstrate its capability of studying driver movements across parking lots. The program was constructed using the multi-agent modeling environment NetLogo. The developed simulation tool allows to adjust features of the parking facilities. Additionally, vehicle travel time and parking occupancy indicators were integrated to investigate the efficiency of the parking

Exploring size effects in copper-chromium-zirconium using indentation techniques and in-situ micro-pillar compression

The influence of microstructure on the mechanical properties of materials has been the focus of research over several decades, with various attempts made to characterize this size effect numerically, e.g. the Hall-Petch relationship. This behaviour is overlaid with an extrinsic size dependence that scales with the testing technique used, whereby the smaller the sampled volume the stronger the material appears to behave. Considering the growing trend towards miniaturised mechanical testing, particularly in the electronics industry and nuclear community, both forms of the size effect need to be fully understood in order to achieve engineering-relevant results. In particular, knowing how the two contribute cumulatively in different material systems is non-trivial and requires further investigation. Please click Additional Files below to see the full abstract

Possible Used Fuel Management Options For A Single Reactor Utility

Used nuclear fuel generated by the operation of Nuclear Power Plants (NPP) needs to be managed in a safe, responsible and effective way. Whereas utilities managing several NPP can implement large scale used fuel management operations, a single reactor utility will chose solutions adapted for relatively low amount of used fuel. There are currently two different approaches for managing used fuel: Open fuel cycle, or “once-through” strategy, where used fuel is considered to be waste and disposed of after wet or dry interim storage following in-reactor use; Closed fuel cycle, or “recycling” strategy, where used fuel is considered as valuable material as it mainly contains reusable uranium and plutonium and thus recycled; such strategy can be implemented directly after in-reactor use without interim storage step and can also be put in place after interim storage; by treating used fuel, 96% of the nuclear material is recovered and recycled as Mixed OXide (MOX) fuel and Enriched Reprocessed Uranium (ERU) fuel; the remaining 4% of non-recyclable material, as well as cladding and structural elements of fuel assemblies, are packaged for final disposal. In addition, long term interim storage of used fuel has been retained by some states until decision is made for one or the other of the two available options, keeping in mind that interim storage, even long term, is a waiting solution and not a sustainable one. For all options, disposal is the final radioactive waste management step: either direct disposal of used fuel or disposal of final residual waste remaining after used fuel treatment. The purpose of the paper is to present the possible used fuel management options for a single reactor utility, clarifying advantages and drawbacks of each of them according to following criteria: safety, security, sustainable development, environment protection, non-proliferation, public acceptance, economy

A PC based time domain reflectometer for space station cable fault isolation

Significant problems are faced by astronauts on orbit in the Space Station when trying to locate electrical faults in multi-segment avionics and communication cables. These problems necessitate the development of an automated portable device that will detect and locate cable faults using the pulse-echo technique known as Time Domain Reflectometry. A breadboard time domain reflectometer (TDR) circuit board was designed and developed at the NASA-JSC. The TDR board works in conjunction with a GRiD lap-top computer to automate the fault detection and isolation process. A software program was written to automatically display the nature and location of any possible faults. The breadboard system can isolate open circuit and short circuit faults within two feet in a typical space station cable configuration. Follow-on efforts planned for 1994 will produce a compact, portable prototype Space Station TDR capable of automated switching in multi-conductor cables for high fidelity evaluation. This device has many possible commercial applications, including commercial and military aircraft avionics, cable TV, telephone, communication, information and computer network systems. This paper describes the principle of time domain reflectometry and the methodology for on-orbit avionics utility distribution system repair, utilizing the newly developed device called the Space Station Time Domain Reflectometer (SSTDR)

Virtual Reality and Creativity: Lessons Learned from a Luminaire Design Project

Current research in design education showed that experiencing virtual reality (VR) in learning led to higher creativity in students. However, some studies showed only a partial impact of VR on student creativity. Using video data analysis (VDA), the authors examined a half-an-hour excerpt of the recorded VR learning experience from a previous study on interior design students (n=13). The authors sought an explanation for the partial impacts of VR on students’ creativity via observing and interpreting one participant’s (a) interaction with VR and (b) the context of the virtual environment. VDA analysis results indicated that the implemented VR technology was intuitive for a fundamental learner yet required time and practice to gain advanced skills. Exploration time was also necessary for students to fully demonstrate the novel, resolution, and style aspects of creativity in their works. The implication is that the partial impact of VR on creativity found in the previous study might be due to the constraints of time and expertise of students (i.e., learn and explore), not VR technology per se. Educators and institutions wishing to include VR in their curricula should allow students ample time and access to VR applications and headsets to practice and sharpen their expertise

The smallest macroscale tensile test - a model to describe constrained flow at the microscale

This work addresses the strain response and plastic flow behavior of grain boundary or interface containing materials during small scale mechanical testing. We introduce a set of geometric criteria allowing us to constrain a sample to obtain macroscopic-like flow behavior on a microscale test, as shown in Figure 1. Furthermore, the featured parameter, the blocked volume ratio, provided a new description of plasticity of microscale tensile samples in a constrained volume due to external interfaces such as coating and grain boundaries. The proposed description was experimentally validated with different Ni-based materials and different constraints (grain boundary and coating interfaces). The developed theory would open new research avenues in establishing the connection between microscale response to bulk properties as follows: Please click Additional Files below to see the full abstract