Laser Diode Induced Lighting Modules

Laser diodes have the potential of becoming the light engines of future lighting technology since they have negligible efficiency droop factor, unlike light emitting diodes. This study demonstrates the possibility of laser diodes coupled to phosphor targets being used as a solid state lighting system with high power applications. It was revealed that white light emitting modules with efficiency of up to 217 lumens per watt based on laser diodes can currently be made and upon further development of laser diode technology and relevant phosphor materials there is room for further improvements. The report also demonstrates the ability of this technology to produce a tailored emission spectrum for a given specific requirement. Two test lamp prototypes were made using laser diodes and phosphor targets and their emission characteristics were investigatedBrunel University London & EPSRC grant No. EP/K504208/

Validation of a laboratory method for evaluating dynamic properties of reconstructed equine racetrack surfaces.

BackgroundRacetrack surface is a risk factor for racehorse injuries and fatalities. Current research indicates that race surface mechanical properties may be influenced by material composition, moisture content, temperature, and maintenance. Race surface mechanical testing in a controlled laboratory setting would allow for objective evaluation of dynamic properties of surface and factors that affect surface behavior.ObjectiveTo develop a method for reconstruction of race surfaces in the laboratory and validate the method by comparison with racetrack measurements of dynamic surface properties.MethodsTrack-testing device (TTD) impact tests were conducted to simulate equine hoof impact on dirt and synthetic race surfaces; tests were performed both in situ (racetrack) and using laboratory reconstructions of harvested surface materials. Clegg Hammer in situ measurements were used to guide surface reconstruction in the laboratory. Dynamic surface properties were compared between in situ and laboratory settings. Relationships between racetrack TTD and Clegg Hammer measurements were analyzed using stepwise multiple linear regression.ResultsMost dynamic surface property setting differences (racetrack-laboratory) were small relative to surface material type differences (dirt-synthetic). Clegg Hammer measurements were more strongly correlated with TTD measurements on the synthetic surface than the dirt surface. On the dirt surface, Clegg Hammer decelerations were negatively correlated with TTD forces.ConclusionsLaboratory reconstruction of racetrack surfaces guided by Clegg Hammer measurements yielded TTD impact measurements similar to in situ values. The negative correlation between TTD and Clegg Hammer measurements confirms the importance of instrument mass when drawing conclusions from testing results. Lighter impact devices may be less appropriate for assessing dynamic surface properties compared to testing equipment designed to simulate hoof impact (TTD).Potential relevanceDynamic impact properties of race surfaces can be evaluated in a laboratory setting, allowing for further study of factors affecting surface behavior under controlled conditions

STUDIES ON HIBISCUS CANNABINUS, HIBISCUS SABDARIFFA, AND CANNABINUS SATIVA PULP TO BE A SUBSTITUTE FOR SOFTWOOD PULP- PART 2: SAS-AQ AND NSSC-AQ DELIGNIFICATION PROCESSES

Hibiscus cannabinus, Cannabis sativa, and Hibiscus sabdariffa, fast growing productive annual plants, could provide fiber necessary to partially alleviate the world’s fiber deficit. The present study aimed at producing high yield pulp and the best mechanical strength properties with minimum impact on environment by SAS-AQ, and NSSC-AQ pulping processes. A total alkali of 13% (as Na2O), an alkali ratio of 0.80, and a Na2SO3 charge 11.70% (as Na2O) were found optimum to reduce maximum kappa number. A lower kappa number and good strength properties were achieved by increasing total alkali and Na2SO3 charge. SAS-AQ pulps showed good response towards CEHH bleaching. The NSSC-AQ pulping was conducted at a total alkali charge of 8% (as Na2O) by varying the ratio of sulphite-to-carbonate (100:0-0:100), and cooking time (60-120 min) at 1600C. A ratio of sulphite-to-carbonate 60:40 was suitable for corrugating medium (cooking time 60 min), while a ratio of sulphite-to-carbonate 70:30 showed better strength properties (longer cooking time)

Black hole Attack Prevention in VANET

The past decade has witnessed the emergence of Vehicular Ad-hoc Networks (VANETs), from the well-known Mobile Ad Hoc Networks (MANETs) in wireless communications. VANETs are self-organizing networks established among vehicles equipped with communication facilities. In VANETs vehicles are equipped with On Board Unit (OBU) through which they are capable of organizing themselves, by discovering their neighbor vehicles and capable to communicate with Infrastructure nodes equipped with Road Side Unit (RSU) for finding optimal path, Service based Information as well as other sensible Information for safe Transportation over the wireless medium. Recently, VANETs have been getting greater attention as more applications are depending on them. Researchers have tried to propose various Protocols, Approaches and methodologies that will improve the Quality, Efficiency, Authenticity and Integrity of different services of VANETs. Many of the applications require a high level of security. Thus, the main challenge is to protect VANETs from different security attacks. VANETs use the open wireless medium to communicate which makes it easy for an attacker to impose his attacks by Manipulating, Sniffing, and blocking the different packets. In VANETs all the nodes can act as routers for the data packets and there is no clear line of defence where it is possible to place a firewall. The main concern is how to provide best security in VANET without any negotiating with performance & reliability.The objective of this work is to check feasibility of using infrastructure based vehicular communication for detecting and preventing Blackhole Attacks. In this paper we proposed three different approaches for Blackhole attack prevention. We analyze performance of the proposed approaches for different scenario by generating heterogeneous traffic environment. With the proposed approaches we get the reduction in Packet Loss of up to 79.6971%

The impact of COVID-19 on the practice of Oral and Maxillofacial Pathology in the United States and Canada

Background: The COVID-19 pandemic has significantly disrupted the delivery of healthcare, including oral healthcare services. The restrictions imposed for mitigating spread of the virus forced dental practitioners to adopt significant changes in their workflow pattern. The aim of this study was to investigate the impact of the pandemic on the practice of oral and maxillofacial pathology in two countries in regard to educational activities, and clinical and diagnostic pathology services

Information Theoretic Approach to Design of Emergency Response Systems

Emergency response information systems provide critical support to the disaster management. Despite of the growing interest in this area, the existing research is scanty. A significant limitation is the lack of sound theoretical foundations for emergency management and the information system development. In this paper, the authors adapt Information Theory to explore the theoretical underpinnings of emergency response and discuss the general system design issues

Data Model Development for Fire Related Extreme Events - An Activity Theory and Semiotics Approach

Post analyses of major extreme events reveal that information sharing is critical for an effective emergency response. The lack of consistent data standards in the current emergency management practice however serves only to hinder efficient critical information flow among the incident responders. In this paper, we adopt a theory driven approach to develop a XML-based data model that prescribes a comprehensive set of data standards for fire related extreme events to better address the challenges of information interoperability. The data model development is guided by third generation Activity Theory and semiotics theories for requirement analyses. The model validation is achieved using a RFC-like process typical in standards development. This paper applies the standards to the real case of a fire incident scenario. Further, it complies with the national leading initiatives in emergency standards (National Information Exchange Model)

Perceived Risk and Resilience in the Face of Natural Disasters: A Study of Hospital

Though hospital information systems have been extensively studied as a technology and there is now a growing body of literature in the area of infrastructure interdependencies, the dependencies of civil and built infrastructure on the health care information infrastructure (HII) is understudied. In particular, there is no study to our knowledge that addresses the issue of Hospital Information Infrastructure in the context of disasters. This study explores how an organization’s information systems infrastructure is affected by disasters and examines the relationship between organizational resilience and information infrastructure effectiveness by using conceptual model