Terrain modeling and path selection by an autonomous Martian exploratory vehicle

Computerized simulation of terrain sensing and modeling for unmanned surface vehicle on Mars surfac

Assessment of an in vitro whole cigarette smoke exposure system: The Borgwaldt RM20S 8-syringe smoking machine

<p>Abstract</p> <p>Background</p> <p>There have been many recent developments of <it>in vitro </it>cigarette smoke systems closely replicating <it>in vivo </it>exposures. The Borgwaldt RM20S smoking machine (RM20S) enables the serial dilution and delivery of cigarette smoke to exposure chambers for <it>in vitro </it>analyses. In this study we have demonstrated reliability and robustness testing of the RM20S in delivering smoke to <it>in vitro </it>cultures using an in-house designed whole smoke exposure chamber.</p> <p>Results</p> <p>The syringe precision and accuracy of smoke dose generated by the RM20S was assessed using a methane gas standard and resulted in a repeatability error of ≤9%. Differential electrical mobility particle spectrometry (DMS) measured smoke particles generated from reference 3R4F cigarettes at points along the RM20S. 53% ± 5.9% of particles by mass reached the chamber, the remainder deposited in the syringe or connecting tubing and ~16% deposited in the chamber. Spectrofluorometric quantification of particle deposition within chambers indicated a positive correlation between smoke concentration and particle deposition. <it>In vitro </it>air-liquid interface (ALI) cultures (H292 lung epithelial cells), exposed to whole smoke (1:60 dilution (smoke:air, equivalent to ~5 μg/cm²)) demonstrated uniform smoke delivery within the chamber.</p> <p>Conclusions</p> <p>These results suggest this smoke exposure system is a reliable and repeatable method of generating and exposing ALI <it>in vitro </it>cultures to cigarette smoke. This system will enable the evaluation of future tobacco products and individual components of cigarette smoke and may be used as an alternative <it>in vitro </it>tool for evaluating other aerosols and gaseous mixtures such as air pollutants, inhaled pharmaceuticals and cosmetics.</p

Status report on emerging photovoltaics

\ua9 2023 Society of Photo-Optical Instrumentation Engineers (SPIE).This report provides a snapshot of emerging photovoltaic (PV) technologies. It consists of concise contributions from experts in a wide range of fields including silicon, thin film, III-V, perovskite, organic, and dye-sensitized PVs. Strategies for exceeding the detailed balance limit and for light managing are presented, followed by a section detailing key applications and commercialization pathways. A section on sustainability then discusses the need for minimization of the environmental footprint in PV manufacturing and recycling. The report concludes with a perspective based on broad survey questions presented to the contributing authors regarding the needs and future evolution of PV

Is the Bankruptcy Code an Adequate Mechanism for Resolving the Distress of Systemically Important Institutions?

The President and members of Congress are considering proposals that would give the government broad authority to rescue financial institutions whose failure might threaten market stability. These systemically important institutions include bank and insurance holding companies, investment banks, and other large, highly leveraged, and interconnected entities that are not currently subject to federal resolution authority. Interest in these proposals stems from the credit crisis, particularly the bankruptcy of Lehman Brothers. That bankruptcy, according to some observers, caused massive destabilization in credit markets for two reasons. First, market participants were surprised that the government would permit a massive market player to undergo a costly Chapter 11 proceeding. A very different policy had been applied to other systemically important institutions such as Bear Steams, Fannie Mae, and Freddie Mac. Second, the bankruptcy filing triggered fire sales of Lehman assets. Fire sales were harmful to other non-distressed institutions that held similar assets, which suddenly plummeted in value. They were also harmful to any institution holding Lehman\u27s commercial paper, which functioned as a store of value for entities such as the Primary Reserve Fund. Fire sales destroyed Lehman\u27s ability to honor these claims. Lehman\u27s experience and the various bailouts (of AIG, Bear Steams, and other distressed institutions) have produced two kinds of policy proposals. One calls for wholesale reform, including creation of a systemic risk regulator with authority to seize and stabilize systemically important institutions. Another is more modest and calls for targeted amendments to the Bankruptcy Code and greater government monitoring of market risks. This approach would retain bankruptcy as the principal mechanism for resolving distress at non-bank institutions, systemically important or not. Put differently, current debates hinge on one question: is the Bankruptcy Code an adequate mechanism for resolving the distress of systemically important institutions? One view says no, and advances wholesale reform. Another view says yes, with some adjustments. This Essay evaluates these competing views: Section II discusses the current structure of the Bankruptcy Code and its limited ability to protect markets from failing systemically important institutions. Section III outlines policy responses. In Section IV, I conclude that the Code is indeed inadequate for dealing with failures of systemically important institutions. A systemic risk regulator is needed because a judicially administered process cannot move with sufficient speed and expertise in response to rapidly changing economic conditions

NRC photometer design for the realization of a luminous intensity scale

NRC publication: Ye

A Spectrum Injection-Based Approach for Malware Prevention in UHF RFID Systems

Radio frequency identification (RFID) is a technology that uses electromagnetic waves (EMW) to send, process, and store data by using a built-in integrated circuit and antenna. However, its susceptibility to malware attacks poses a threat to data privacy and system performance. Thus, there is a need to develop techniques to protect RFID systems from malware injection and improve efficiency through spectrum optimization. An approach for improving the efficiency and data privacy of RFID systems operating in the ultra-high frequency (UHF) band is proposed for multiple data rates of 160, 256, 320, and 640 kbps. Firstly, a method is introduced for reconstructing regular data in a malware-free RFID system with optimized spectrum usage, which reaches up to 50&#x0025; of the total spectrum and improves efficiency. Secondly, a spectrum injection-based approach (SIBA) is proposed by incorporating a bandpass filtering (BPF) technique to inject the missing spectrum of regular data with a portion of the malware-injected data spectrum. This approach results in faster and more precise data reconstruction with higher accuracy and overcomes the malware. A noise reduction technique based on BPF is also proposed to reduce the noise effects and enhance the accuracy of data reconstruction at different signal-to-noise ratio (SNR) levels. This technique is evaluated through extensive analysis with various metrics such as reconstruction accuracy, robustness to noise, bandwidth utilization factor (BUF), and computational complexity, making it suitable for resource-constrained environmental settings. These approaches address the challenges of malware injection and spectrum optimization, resulting in more efficient and secure RFID systems

Strategies In Learning Fluid Mechanics: A literature Review

One of the broad and intricate subfields of physics is fluid mechanics. Learning techniques for students are an essential component of learning fluid mechanics because they increase their motivation to learn, enhance learning outcomes, and encourage active participation in class. An overview of the prior research was highlighted in this publication, and several fluid mechanics learning methodologies were looked at in this review. The study found that the majority of students performed well in group settings, particularly when fluid mechanics principles are used in practical settings, which is the most successful teaching method. The studies that were reviewed in this literature review demonstrated that offering students team-based experiential learning is the best way to inspire them to learn fluid mechanics and to recognize the value of doing so. Therefore, by developing ideas and putting them into practice through active exploration, students learn more