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2014

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Articles 361 - 390 of 12299

Full-Text Articles in Physical Sciences and Mathematics

Comparing Disease Prevalence In Hard Corals At Four Different Reefs Near The Island Of Narganá In The Guna Yala Comarca Of Panamá, Connor Hinton Dec 2014

Comparing Disease Prevalence In Hard Corals At Four Different Reefs Near The Island Of Narganá In The Guna Yala Comarca Of Panamá, Connor Hinton

Independent Study Project (ISP) Collection

Coral reefs harbor much of the world’s known marine biodiversity. For a number of reasons, coral reefs are becoming increasingly threatened. Large portions of the world’s reefs have already been lost, and the number of degrading reefs is constantly on the rise. One cause for the destruction of coral reefs are coral diseases, ultimately causing coral mortality. With the death of corals, a key species is lost, endangering the entire reef ecosystem. Documenting the presence of such diseases could be useful in assessing current reef health and ameliorating the growing threat of coral diseases. In this project, 18 40m2 belt …


Scale-Up Methodology For Bench-Scale Slurry Photocatalytic Reactors Using Combined Irradiation And Kinetic Modelling, Patricio J. Valades Pelayo Dec 2014

Scale-Up Methodology For Bench-Scale Slurry Photocatalytic Reactors Using Combined Irradiation And Kinetic Modelling, Patricio J. Valades Pelayo

Electronic Thesis and Dissertation Repository

The present study focuses on developing a predictive methodology to scale-up a slurry annular photoreactor using a TiO2 Degussa P25 from the bench-scale to a pilot-plant scale. The bench-scale photoreactor is a Photo-CREC-Water II, a 2.65 L internally-irradiated slurry annular photocatalytic reactor. The pilot-plant scale photoreactor is a Photo-CREC Water Solar Simulator, a 9.8 L pilot-plant photoreactor, externally irradiated by eight lamps.

The adopted methodology allows the independent validation of radiative and kinetic models avoiding cross-correlation issues. The proposed approach involves two Monte Carlo methods, to model the Radiative Transfer Equation (RTE) inside each photoreactor. With this end, a …


Odd-Even Effects In Charge Transport Across N-Alkanethiolate-Based Sams, Mostafa Baghbanzadeh, Felice C. Simeone, Carleen M. Bowers, Kung Ching Liao, Martin Thuo, Mahdi Baghbanzadeh, Michael S. Miller, Tricia Breen Carmichael, George M. Whitesides Dec 2014

Odd-Even Effects In Charge Transport Across N-Alkanethiolate-Based Sams, Mostafa Baghbanzadeh, Felice C. Simeone, Carleen M. Bowers, Kung Ching Liao, Martin Thuo, Mahdi Baghbanzadeh, Michael S. Miller, Tricia Breen Carmichael, George M. Whitesides

Chemistry and Biochemistry Publications

This paper compares rates of charge transport across self-assembled monolayers (SAMs) of n-alkanethiolates having odd and even numbers of carbon atoms (nodd and neven) using junctions with the structure MTS/SAM//Ga2O3/EGaIn (M = Au or Ag). Measurements of current density, J(V), across SAMs of n-alkanethiolates on AuTS and AgTS demonstrated a statistically significant odd-even effect on AuTS, but not on AgTS, that could be detected using this technique. Statistical analysis showed the values of tunneling current density across SAMs of n-alkanethiolates on AuTS with nodd and neven belonging to two separate sets, and while there is a significant difference between the …


The Potentials And Challenges Of Big Data In Public Health, Rena N. Vithiatharan Dec 2014

The Potentials And Challenges Of Big Data In Public Health, Rena N. Vithiatharan

Australian eHealth Informatics and Security Conference

The potential to use big data sources for public health increases with the broadening availability of data and improved methods of analysis. Whilst there are some well-known examples of the opportunistic use of big data, such as GoogleFlu, public health has not yet realised the full potential of such data sources. A literature review was undertaken to identify the potential of such data collections to impact public health, and to identify what challenges are currently limiting this potential. The potential include improved real-time analysis, research and development and genome studies. However, challenges listed are poor universal standardisation and classification, privacy …


Big Data In Healthcare: What Is It Used For?, Rebecca Hermon, Patricia A H Williams Dec 2014

Big Data In Healthcare: What Is It Used For?, Rebecca Hermon, Patricia A H Williams

Australian eHealth Informatics and Security Conference

Big data analytics is a growth area with the potential to provide useful insight in healthcare. Whilst many dimensions of big data still present issues in its use and adoption, such as managing the volume, variety, velocity, veracity, and value, the accuracy, integrity, and semantic interpretation are of greater concern in clinical application. However, such challenges have not deterred the use and exploration of big data as an evidence source in healthcare. This drives the need to investigate healthcare information to control and reduce the burgeoning cost of healthcare, as well as to seek evidence to improve patient outcomes. Whilst …


Byod In Ehealth: Herding Cats And Stable Doors, Or A Catastrophe Waiting To Happen?, Krishnun Sansurooh, Patricia A H Williams Dec 2014

Byod In Ehealth: Herding Cats And Stable Doors, Or A Catastrophe Waiting To Happen?, Krishnun Sansurooh, Patricia A H Williams

Australian eHealth Informatics and Security Conference

The use of personal devices in the work environment has crossed the boundaries of work and socially related tasks. With cyber criminals seriously targeting healthcare for medical identity theft, the lack of control of new technologies within healthcare networks becomes an increasing vulnerability. The prolific adoption of personal mobile devices in the healthcare environment requires a proactive approach to the management of Bring Your Own Device (BYOD). This paper analysed the current state of the problem and the challenges that this creates in an environment that has stringent privacy and security requirements. The discourse demonstrates that the issue is not …


3rd Australian Ehealth Informatics And Security Conference, 2014, Edith Cowan University: Conference Details, Security Research Institute, Edith Cowan University Dec 2014

3rd Australian Ehealth Informatics And Security Conference, 2014, Edith Cowan University: Conference Details, Security Research Institute, Edith Cowan University

Australian eHealth Informatics and Security Conference

No abstract provided.


Customising Doctor-Nurse Communications, Brian Cusack, Dave Parry Dec 2014

Customising Doctor-Nurse Communications, Brian Cusack, Dave Parry

Australian eHealth Informatics and Security Conference

Doctor-Nurse communications are critical for patient safety and workflow effectiveness. Our research question was: What further improvements can be made to current communication systems? A variety of mobile and land based communication systems have been used and experimented with. In the study, the pager was found to be most common and more recent attempts to provide broadband capability with systems such as the iBeep. We built an alternative information system using Android phones and a software application that was customised by feedback from the medical professionals. The trial in five wards with 22 doctors and 170 nurses over one month …


Managing Wireless Security Risks In Medical Services, Brian Cusack, Akar Kyaw Dec 2014

Managing Wireless Security Risks In Medical Services, Brian Cusack, Akar Kyaw

Australian eHealth Informatics and Security Conference

Medical systems are designed for a range of end users from different professional skill groups and people who carry the devices in and on their bodies. Open, accurate, and efficient communication is the priority for medical systems and consequently strong protection costs are traded against the utility benefits for open systems. In this paper we assess the vulnerabilities created by the professional and end user expectations, and theorise ways to mitigate wireless security vulnerabilities. The benefits of wireless medical services are great in terms of efficiencies, mobility, and information management. These benefits may be realised by treating the vulnerabilities and …


Security Of Electronic Health Records In A Resource Limited Setting: The Case Of Smart-Care Electronic Health Record In Zambia, Keith Mweebo Dec 2014

Security Of Electronic Health Records In A Resource Limited Setting: The Case Of Smart-Care Electronic Health Record In Zambia, Keith Mweebo

Australian eHealth Informatics and Security Conference

This paper presents a case study of security issues related to the operationalization of smart-care, an electronic medical record (EMR) used to manage Human Immunodeficiency Virus (HIV) health information in Zambia. The aim of the smart-care program is to link up services and improve access to health information, by providing a reliable way to collect, store, retrieve and analyse health data in a secure way. As health professionals gain improved access to patient health information electronically, there is need to ensure this information is secured, and that patient privacy and confidentiality is maintained. During the initial stages of the program …


Avoiding Epic Fails: Software And Standards Directions To Increase Clinical Safety, Patricia A H Williams, Vincent B. Mccauley Dec 2014

Avoiding Epic Fails: Software And Standards Directions To Increase Clinical Safety, Patricia A H Williams, Vincent B. Mccauley

Australian eHealth Informatics and Security Conference

No abstract provided.


Optical Characterization And Distribution Of Chromophoric Dissolved Organic Matter (Cdom) In Soil Porewater From A Salt Marsh Ecosystem, Catherine D. Clark, Paige Aiona, Jason K. Keller, Warren J. De Bruyn Dec 2014

Optical Characterization And Distribution Of Chromophoric Dissolved Organic Matter (Cdom) In Soil Porewater From A Salt Marsh Ecosystem, Catherine D. Clark, Paige Aiona, Jason K. Keller, Warren J. De Bruyn

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

To characterize chromophoric dissolved organic matter (CDOM) in marsh porewaters and its contribution as a carbon source, optical properties (absorbance, fluorescence indices, 3-dimensional excitation-emission matrices [EEMs]) of soil porewater and surface water were measured in a southern Californian salt marsh. Absorption coefficients and fluorescence intensities were higher in porewater than in overlying surface waters, consistent with higher CDOM concentration at depth. Humic-type peaks A and C were observed in EEMs in all samples, and peak M was observed in surface waters and shallow porewater to -5 cm depth. Fluorescence:absorbance (flu:abs) ratios and spectral slopes (S) decreased across the surface interface, …


A Partner-Matching Framework For Social Activity Communities, Chunyu Ai, Wei Zhong, Mingyuan Yan, Feng Gu Dec 2014

A Partner-Matching Framework For Social Activity Communities, Chunyu Ai, Wei Zhong, Mingyuan Yan, Feng Gu

Publications and Research

A lot of daily activities require more than one person to participate and collaborate with each other; however, for many people, it is not easy to find good partners to engage in activities with one another. With the rapid growth of social network applications, more and more people get used to creating connections with people on the social network. Therefore, designing social network framework for partner-matching is significant in helping people to easily find good partners. In this paper, we proposed a framework which can match partners for an active community. In order to improve the matching performance, all users …


Hf Accelerated Electron Fluxes, Spectra, And Ionization, Herbert C. Carlson, Joseph B. Jensen Dec 2014

Hf Accelerated Electron Fluxes, Spectra, And Ionization, Herbert C. Carlson, Joseph B. Jensen

All Physics Faculty Publications

Wave particle interactions, an essential aspect of laboratory, terrestrial,and astrophysical plasmas, have been studied for decades by transmitting high power HF radio waves into Earth’s weakly ionized space plasma, to use it as a laboratory without walls. Application to HF electron acceleration remains an active area of research (Gurevich, 2007) today. HF electron acceleration studies began when plasma line observations proved (Carlson et al, 1982) that high power HF radio wave-excited processes accelerated electrons not to ~ eV, but instead to - 100 times thermal energy (10s of eV), as a consequence of inelastic collision effects on electron transport. Gurevich …


A Study Of Fe3O4 Magnetic Nanoparticle Rf Heating In Gellan Gum Polymer Under Various Experimental Conditions For Potential Application In Drug Delivery, Gabriel Marcus Dec 2014

A Study Of Fe3O4 Magnetic Nanoparticle Rf Heating In Gellan Gum Polymer Under Various Experimental Conditions For Potential Application In Drug Delivery, Gabriel Marcus

USF Tampa Graduate Theses and Dissertations

Magnetic nanoparticles (MNPs) have found use in a wide variety of biomedical applications including hyperthermia, imaging and drug delivery. Certain physical properties, such as the ability to generate heat in response to an alternating magnetic field, make these structures ideal for such purposes. This study's objective was to elucidate the mechanisms primarily responsible for RF MNP heating and determine how such processes affect polymer solutions that might be useful in drug delivery. 15-20 nm magnetite (Fe3O4) nanoparticles at 0.2% and 0.5% concentrations were heated with RF fields of different strengths (200 Oe, 400 Oe and 600 …


Access To Hiv Prevention And Care For Hiv-Exposed And Hiv-Infected Children: A Qualitative Study In Rural And Urban Mozambique, Caroline De Schacht, Carlota Lucas, Caterina Mboa, Michelle Gill, Eugenia Macasse, Stelio A. Dimande, Emily A. Bobrow, Laura Guay Dec 2014

Access To Hiv Prevention And Care For Hiv-Exposed And Hiv-Infected Children: A Qualitative Study In Rural And Urban Mozambique, Caroline De Schacht, Carlota Lucas, Caterina Mboa, Michelle Gill, Eugenia Macasse, Stelio A. Dimande, Emily A. Bobrow, Laura Guay

Epidemiology Faculty Publications

Background Follow-up of HIV-exposed children for the delivery of prevention of mother-to-child transmission services and for early diagnosis and treatment of HIV infection is critical to their survival. Despite efforts, uptake of postnatal care for these children remains low in many subSaharan African countries. Methods A qualitative study was conducted in three provinces in Mozambique to identify motivators and barriers to improve uptake of and retention in HIV prevention, care and treatment services for HIV-exposed and HIV-infected children. Participant recommendations were also gathered. Individual interviews (n=79) and focus group discussions (n=32) were conducted with parents/caregivers, grandmothers, community leaders and health …


Fresh: Fair And Efficient Slot Configuration And Scheduling For Hadoop Clusters, Jiayin Wang, Yi Yao, Ying Mao, Bo Sheng, Ningfang Mi Dec 2014

Fresh: Fair And Efficient Slot Configuration And Scheduling For Hadoop Clusters, Jiayin Wang, Yi Yao, Ying Mao, Bo Sheng, Ningfang Mi

Department of Computer Science Faculty Scholarship and Creative Works

Hadoop is an emerging framework for parallel big data processing. While becoming popular, Hadoop is too complex for regular users to fully understand all the system parameters and tune them appropriately. Especially when processing a batch of jobs, default Hadoop setting may cause inefficient resource utilization and unnecessarily prolong the execution time. This paper considers an extremely important setting of slot configuration which by default is fixed and static. We proposed an enhanced Hadoop system called FRESH which can derive the best slot setting, dynamically configure slots, and appropriately assign tasks to the available slots. The experimental results show that …


Evaluating The Progress Of A Mangrove Reforestation Project On Isla Galeta, Colon, Abigail Hope Outterson Dec 2014

Evaluating The Progress Of A Mangrove Reforestation Project On Isla Galeta, Colon, Abigail Hope Outterson

Independent Study Project (ISP) Collection

Just off the Atlantic coast of Panama, a dynamic and self-renewing ecosystem takes advantage of the tropical climate and swampy conditions. Guarding Punta Galeta’s shores since before it was a U.S. navy base in the 1930’s, mangroves that have persisted here for centuries now draw scientists and tourists alike from all over the world to the Smithsonian Tropical Research Center. Once viewed as unproductive, distasteful environments, mangroves are increasingly recognized worldwide as critical habitat for endangered and commercially significant species, as well as for their ecological and aesthetic value. Uniquely adapted to survive in saline environments, mangroves combine methods of …


On The Data Of Images, Lori Ziegelmeier Dec 2014

On The Data Of Images, Lori Ziegelmeier

Lori Beth Ziegelmeier

No abstract provided.


Health Professionals’ Roles In Animal Agriculture, Climate Change, And Human Health, Aysha Z. Akhtar, Michael Greger, Hope Ferdowsian, Erica Frank Dec 2014

Health Professionals’ Roles In Animal Agriculture, Climate Change, And Human Health, Aysha Z. Akhtar, Michael Greger, Hope Ferdowsian, Erica Frank

Michael Greger, MD, FACLM

What we eat is rapidly becoming an issue of global concern. With food shortages, the rise in chronic disease, and global warming, the impact of our dietary choices seems more relevant today than ever. Globally, a transition is taking place toward greater consumption of foods of animal origin, in lieu of plantbased diets. With this transition comes intensification of animal agriculture that in turn is associated with the emergence of zoonotic infectious diseases, environmental degradation, and the epidemics of chronic disease and obesity. Health professionals should be aware of these trends and consider them as they promote healthier and more …


An Abstract View On Modularity In Knowledge Representation, Yuliya Lierler, Miroslaw Truszczyński Dec 2014

An Abstract View On Modularity In Knowledge Representation, Yuliya Lierler, Miroslaw Truszczyński

Yuliya Lierler

Modularity is an essential aspect of knowledge representation and reasoning theory and practice. It has received substantial attention. We introduce model-based modular systems, an abstract framework for modular knowledge representation formalisms, similar in scope to multi-context systems but employing a simpler information-flow mechanism. We establish the precise relationship between the two frameworks, showing that they can simulate each other. We demonstrate that recently introduced modular knowledge representation formalisms integrating logic programming with satisfiability and, more generally, with constraint satisfaction can be cast as modular systems in our sense. These results show that our formalism offers a simple unifying framework for …


U.S. Drought Monitor, December 2, 2014, Anthony Artusa Dec 2014

U.S. Drought Monitor, December 2, 2014, Anthony Artusa

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 2, 2014 (12/2/14) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


Nucleation At The Contact Line Observed On Nanotextured Surfaces, C W. Gurganus, J. C. Charnawskas, A. B. Kostinski, R. A. Shaw Dec 2014

Nucleation At The Contact Line Observed On Nanotextured Surfaces, C W. Gurganus, J. C. Charnawskas, A. B. Kostinski, R. A. Shaw

Department of Physics Publications

It has been conjectured that roughness plays a role in surface nucleation, the tendency for freezing to begin preferentially at the liquid-gas interface. Using high speed imaging, we sought evidence for freezing at the contact line on catalyst substrates with imposed characteristic length scales (texture). Length scales consistent with the critical nucleus size and with δ∼τ/σ, where τ is a relevant line tension and σ is the surface tension, range from nanometers to micrometers. It is found that nanoscale texture causes a shift in the nucleation of ice in supercooled water to the three-phase contact line, while microscale texture does …


Vimos Ultra-Deep Survey (Vuds): Witnessing The Assembly Of A Massive Cluster At Z~3.3, B.C. Lemaux, O. Cucciati, L.A.M. Tasca, O. Le Fevre, G. Zamorani, P. Cassata, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, R. Thomas, E. Vanzella, E. Zucca, R. Amorin, S. Bardelli, P. Capak, L.P. Cassara, M. Castellano, A. Cimatti, J.G. Cuby, S. De La Torre, A. Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, C. Moreau, S. Paltani, B. Ribeiro, M. Salvato, D. Schaerer, M Scodeggio, V. Sommariva, M. Talia, Y. Taniguchi, L. Tresse, D. Vergani, P.W. Wang, S. Charlot, T. Contini, S. Fotopoulou, R.R. Gal, D.D. Kocevski, C. Lopez-Sanjuan, L.M. Lubin, Y. Mellier, T. Sadibekova, N. Scoville Dec 2014

Vimos Ultra-Deep Survey (Vuds): Witnessing The Assembly Of A Massive Cluster At Z~3.3, B.C. Lemaux, O. Cucciati, L.A.M. Tasca, O. Le Fevre, G. Zamorani, P. Cassata, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, R. Thomas, E. Vanzella, E. Zucca, R. Amorin, S. Bardelli, P. Capak, L.P. Cassara, M. Castellano, A. Cimatti, J.G. Cuby, S. De La Torre, A. Durkalec, A. Fontana, Mauro Giavalisco, A. Grazian, N.P. Hathi, O. Ilbert, C. Moreau, S. Paltani, B. Ribeiro, M. Salvato, D. Schaerer, M Scodeggio, V. Sommariva, M. Talia, Y. Taniguchi, L. Tresse, D. Vergani, P.W. Wang, S. Charlot, T. Contini, S. Fotopoulou, R.R. Gal, D.D. Kocevski, C. Lopez-Sanjuan, L.M. Lubin, Y. Mellier, T. Sadibekova, N. Scoville

Mauro Giavalisco

Using new spectroscopic observations obtained as part of the VIMOS Ultra-Deep Survey (VUDS), we performed a systematic search for overdense environments in the early universe (z> 2) and report here on the discovery of Cl J0227-0421, a massive protocluster at z = 3.29. This protocluster is characterized by both the large overdensity of spectroscopically confirmed members, δgal = 10.5 ± 2.8, and a significant overdensity in photometric redshift members. The halo mass of this protocluster is estimated by a variety of methods to be ~3 × 1014ℳ⊙ at z ~ 3.3, which, evolved to z = 0 results in a …


Polynomials With Prescribed Bad Primes, David P. Roberts Dec 2014

Polynomials With Prescribed Bad Primes, David P. Roberts

Mathematics Publications

We tabulate polynomials in ℚ[t] with a given factorization partition, bad reduction entirely within a given set of primes, and satisfying auxiliary conditions associated to 0, 1, and ∞. We explain how these polynomials are of particular interest because of their role in the construction of nonsolvable number fields of arbitrarily large degree and bounded ramification.


Ensemble Prediction And Data Assimilation For Operational Hydrology, Dong-Jun Seo, Yuqiong Liu, Hamid Moradkhani, Albrecht Weerts Dec 2014

Ensemble Prediction And Data Assimilation For Operational Hydrology, Dong-Jun Seo, Yuqiong Liu, Hamid Moradkhani, Albrecht Weerts

Civil and Environmental Engineering Faculty Publications and Presentations

This special section in the Journal of Hydrology will discuss the need for advancing hydrologic ensemble prediction and DA.


Earthquake And Tsunami Forecasts: Relation Of Slow Slip Events To Subsequent Earthquake Rupture, Timothy H. Dixon, Yan Jiang, Rocco Malservisi, Robert Mccaffrey, Nicholas Voss, Marino Protti, Victor Gonzalez Dec 2014

Earthquake And Tsunami Forecasts: Relation Of Slow Slip Events To Subsequent Earthquake Rupture, Timothy H. Dixon, Yan Jiang, Rocco Malservisi, Robert Mccaffrey, Nicholas Voss, Marino Protti, Victor Gonzalez

Geology Faculty Publications and Presentations

The 5 September 2012 Mw 7.6 earthquake on the Costa Rica subduction plate boundary followed a 62-y interseismic period. High-precision GPS recorded numerous slow slip events (SSEs) in the decade leading up to the earthquake, both up-dip and down-dip of seismic rupture. Deeper SSEs were larger than shallower ones and, if characteristic of the interseismic period, release most locking down-dip of the earthquake, limiting down-dip rupture and earthquake magnitude. Shallower SSEs were smaller, accounting for some but not all interseismic locking. One SSE occurred several months before the earthquake, but changes in Mohr–Coulomb failure stress were probably too small to …


Parweb: A Front-End Interface For Cluster Computing., Jacob Potter Dec 2014

Parweb: A Front-End Interface For Cluster Computing., Jacob Potter

Honors Theses

The High Performance Computational Science Laboratory at Western Michigan University operates a cluster of systems for use by students, professors, and professional researchers. Currently users that want to access the cluster, known as “Thor”, require knowledge of the Unix/Linux command line. They also require knowledge of operating a piece of software known as TORQUE to correctly achieve results from the High Performance Computing Lab.

The Web User Interface Framework for High Performance Cluster Computing alleviates the need for intimate knowledge of a command line interface, and replaces the current interaction interface with a more user friendly and graphical oriented system. …


Vehicle Base Station, Emad William Saad, John L. Vian, Matthew A. Vavrina, Jared A. Nisbett, Donald C. Wunsch Dec 2014

Vehicle Base Station, Emad William Saad, John L. Vian, Matthew A. Vavrina, Jared A. Nisbett, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

A system to load and unload material from a vehicle comprises a vehicle base station and an assembly to autonomously load and unload material from the vehicle.


Charge On Luminous Bodies Resembling Natural Ball Lightning Produced Via Electrical Arcs Through Lump Silicon, Christina L. Porter, Galen P. Miley, David J. Griffiths, Erik J. Sánchez Dec 2014

Charge On Luminous Bodies Resembling Natural Ball Lightning Produced Via Electrical Arcs Through Lump Silicon, Christina L. Porter, Galen P. Miley, David J. Griffiths, Erik J. Sánchez

Physics Faculty Publications and Presentations

A phenomenon resembling natural ball lightning can be produced via electrical arcing through silicon. We use lump silicon instead of silicon wafers to achieve higher production rates and larger, longer-lived luminous balls than previously reported. The luminous balls consist of a silicon core surrounded by a porous network of loosely bound silicon dioxide nanoparticles. We find that the balls carry a small net charge on the order of 10−12 C and propose that the nanoparticles are electrostatically bound to the core due to this charge.