Infrared transmission and emission spectroscopic study of selected Chinese palygorskites

Infrared and infrared emission spectroscopy were used to analyze the difference in structure and thermal behavior of two Chinese palygorskites. The position of the main bands identified in the infrared spectra of the palygorskites studied is similar for these two Chinese samples, but there are some differences in their intensity, which is significant. This discrepancy is attributed to various geological environments in different regions and the existence of impurities. The infrared emission spectra clearly show the structural changes and dehydroxylation of the palygorskites when the temperature is raised. The dehydration of the palygorskites is followed by the loss of intensity of the OH stretching vibration bands in the region 3600-3200 cm-1. Dehydroxylation is followed by the decrease in intensity in the bands between 3700 and 3550 cm-1. Dehydration of pure palygorskite was completed by 600 °C. Partial loss of coordinated water was observed at 400 °C. Infrared emission spectroscopy is an effective method to determine the stability of the mineral.

Room ventilation and the risk of airborne infection transmission in three health care settings within a large teaching hospital

Background: Room ventilation is a key determinant of airborne disease transmission. Despite this, ventilation guidelines in hospitals are not founded on robust scientific evidence related to prevention of airborne transmission. Methods: We sought to assess the effect of ventilation rates on influenza, tuberculosis (TB) and rhinovirus infection risk within three distinct rooms in a major urban hospital; a Lung Function Laboratory, Emergency Department (ED) Negative-pressure Isolation Room and an Outpatient Consultation Room were investigated. Air exchange rate measurements were performed in each room using CO2 as a tracer. Gammaitoni and Nucci’s model was employed to estimate infection risk. Results: Current outdoor air exchange rates in the Lung Function Laboratory and ED Isolation Room limited infection risks to between 0.1 and 3.6%. Influenza risk for individuals entering an Outpatient Consultation Room after an infectious individual departed ranged from 3.6 to 20.7%, depending on the duration for which each person occupied the room. Conclusions: Given the absence of definitive ventilation guidelines for hospitals, air exchange measurements combined with modelling afford a useful means of assessing, on a case-by-case basis, the suitability of room ventilation at preventing airborne disease transmission.

The risk of airborne influenza transmission in passenger cars

Travel in passenger cars is a ubiquitous aspect of the daily activities of many people. During the 2009 influenza A (H1N1) pandemic a case of probable transmission during car travel was reported in Australia, to which spread via the airborne route may have contributed. However, there are no data to indicate the likely risks of such events, and how they may vary and be mitigated. To address this knowledge gap, we estimated the risk of airborne influenza transmission in two cars (1989 model and 2005 model) by employing ventilation measurements and a variation of the Wells-Riley model. Results suggested that infection risk can be reduced by not recirculating air; however, estimated risk ranged from 59 to 99.9% for a 90 min trip when air was recirculated in the newer vehicle. These results have implications for interrupting in-car transmission of other illnesses spread by the airborne route.

Transit line passenger transmission and productiveness under high load conditions

Deterministic transit capacity analysis applies to planning, design and operational management of urban transit systems. The Transit Capacity and Quality of Service Manual (1) and Vuchic (2, 3) enable transit performance to be quantified and assessed using transit capacity and productive capacity. This paper further defines important productive performance measures of an individual transit service and transit line. Transit work (p-km) captures the transit task performed over distance. Passenger transmission (p-km/h) captures the passenger task delivered by service at speed. Transit productiveness (p-km/h) captures transit work performed over time. These measures are useful to operators in understanding their services’ or systems’ capabilities and passenger quality of service. This paper accounts for variability in utilized demand by passengers along a line and high passenger load conditions where passenger pass-up delay occurs. A hypothetical case study of an individual bus service’s operation demonstrates the usefulness of passenger transmission in comparing existing and growth scenarios. A hypothetical case study of a bus line’s operation during a peak hour window demonstrates the theory’s usefulness in examining the contribution of individual services to line productive performance. Scenarios may be assessed using this theory to benchmark or compare lines and segments, conditions, or consider improvements.

Transit line passenger transmission and productiveness under high load conditions : presentation

Transit Capacity Analysis critical to urban system Planning Design, Operation Productive Performance Analysis not so well detailed This study extends TRB’s & Vuchic’s work in this area

UWB antenna array for wireless transmission along corridors

A 2-element elliptical patch antenna array with a bi-directional radiation pattern has been developed for ultra wideband indoor wireless communications. The array is constructed by means of feeding two omni-directional elliptical patch elements with a 3-section hybrid power divider. Experimental results show that the array has a stable radiation pattern and low return loss over a broad bandwidth of 64% (3.1 - 6 GHz).

Using approximate Bayesian computation to estimate transmission rates of nosocomial pathogens

In this paper, we apply a simulation based approach for estimating transmission rates of nosocomial pathogens. In particular, the objective is to infer the transmission rate between colonised health-care practitioners and uncolonised patients (and vice versa) solely from routinely collected incidence data. The method, using approximate Bayesian computation, is substantially less computer intensive and easier to implement than likelihood-based approaches we refer to here. We find through replacing the likelihood with a comparison of an efficient summary statistic between observed and simulated data that little is lost in the precision of estimated transmission rates. Furthermore, we investigate the impact of incorporating uncertainty in previously fixed parameters on the precision of the estimated transmission rates.

Socio-environmental variability and Barmah Forest virus disease transmission : a review of epidemiological evidence and future prospects

Barmah Forest Virus (BFV) disease is the most rapidly emerging mosquito-borne disease in Australia. BFV transmission depends on factors such as climate, virus, vector and the human population. However, the impact of climatic and social factors on BFV remains to be determined. This paper provided an overview of current research and discusses the future research directions on the BFV transmission. These research findings could be regarded as an impetus towards BFV prevention and control strategies.

Analysis of the damping properties of high-transmission-ratio Cycloidal drives

Cycloidal drives are widely used in today’s industries for drives where large reduction ratios are required. Drive-train dynamics plays an important role in their design. This paper presents a new methodology for assessing damping characteristics of Cycloidal drives and compares the natural frequencies obtained from experiments and theoretical/numerical calculations using Fast-Fourier-Transforms.

Impact of wind power development on transmission planning at Midwest ISO

The Midwest Independent Transmission System Operator (MISO) has experienced significant amounts of wind power development within the last decade. The MISO footprint spans the majority of the upper Midwest region of the country, from the Dakotas to Indiana and as far east as Michigan. These areas have a rich wind energy resource. States in the MISO footprint have passed laws or set goals that require load serving entities to supply a portion of their load using renewable energy. In order to meet these requirements, significant investments are needed to build the transmission infrastructure necessary to deliver the power from these often remote wind energy resources to the load centers. This paper presents some of the transmission planning related work done at MISO which was largely influenced by current and future needs for increased wind power generation in the footprint. Specifically, topics covered are generator interconnection, long-term planning coordination, and cost-allocation for new transmission lines.

Long term transmission planning to meet renewable energy targets in Australia

Australia is rich in renewable energy resources such as wind, solar and geothermal. Geographical diversity of these renewable resources combined with developing climate change policies poses a great challenge for the long term interconnection planning. Intermittency of wind and solar potentially driving the development of new transmission lines bring additional complexity to power system operations and planning. This paper provides an overview of generation and transmission planning studies in Australia to meet 20% renewable energy target by 2020. Appraisal of the effectiveness of dispersed energy storage, non schedulable peaking plants, wide area controls and demand management techniques to aid the penetration of renewables is presented in this paper

Could BFFB mode breath aerosol play a role in H5N1 transmission?

Recent findings concerning exhaled aerosol size distributions and the regions in the respiratory tract in which they are generated could have significant implications for human to human spread of lower respiratory tract-specific infections. Even in healthy people, measurable quantities of aerosol are routinely generated from the Lower Respiratory Tract (LRT) during breathing(1-3). We have found that there at least three modes in the exhaled aerosol size distribution of healthy adults(4) (see Figure 1). These modes each have a characteristic size and arise from different parts of the respiratory tract. The respiratory bronchioles produce aerosol during breathing, the larynx during speech and the oral cavity also during speech. The model of the resulting droplet size distribution is therefore called the Bronchial Laryngeal Oral (B.L.O.) tri-modal model of expired aerosol.