bluuebunny/crossref_metadata_2025 huggingface dataset:
A Retrospective Study on the Hazards of the Carbon Dioxide Laser Plume
Authors: Lobraico Rocco V. , Schifano Michael J. , Brader Kevin R.
Published: August 2012

Recent experimental studies of airborne contaminants found in the carbon dioxide laser plume have raised questions as to the potential danger of serious viral transmission during laser procedures. These concerns originated from a study of the human papilloma wart virus that reported intact strands of the DNA virus in the laser plume during the ablation of verrucae with the carbon dioxide laser. However, the study did not demonstrate the viability of such viral remnants. Such viability is difficult to demonstrate due to the strict species specificity of the papilloma virus, thus precluding the possibility of transinfection of an animal model with human papilloma DNA. We have therefore conducted a retrospective study to explore both the incidence of acquired lesions among laser users and also the details predisposing to the development of such lesions. Although a small percentage of our respondents reported acquired lesions, the role of the laser plume as the primary source of such lesions is unlikely. It is our opinion that the majority of reported lesions were acquired through direct contact, and proper sterile technique would significantly reduce the transmission of human papilloma virus during therapeutic procedures.
New Materials: Non-Equilibrium Synthesis by Laser
Authors: Mazumder J. , Sircar S. , Ribaudo C. , Kar A.
Published: August 2012

Synthesis of nonequilibrium phases provides an opportunity to engineer new materials with novel properties. The technique of laser surface modification (LSM) provides a unique means of synthesizing novel non-equilibrium materials by taking advantage of the inherent rapid heating and cooling rate of the process. LSM can be used to obtain specific surface properties significantly different from bulk properties. Also, by depositing multiple layers by LSM, nonequilibrium materials with specific properties can also be synthesized in near net shape. This approach is now pursued for various applications, including aerospace engine and structural components for high temperature service and wear and corrosion resistant components for chemical and engineering industries. This paper describes a synthesis of Ni-Al-Cr-Hf alloys with extended solid solution of Hf by laser cladding techniques. A 10 kW CW CO2 laser with mixed powder feed was used for the cladding process. Microstructural studies reveal the formation of dendrites with about 11–14 wt % Hf along with eutectic structure in the interdendritic zones. Isothermal oxidation tests revealed improved oxidation resistance at 1200°C compared to conventional nickel superalloys. A mathematical model is also reported for the prediction of the effect of laser process parameters on non-equilibrium phase diagram.
High Performance Laser Triangulation Ranging
Authors: Penney C. Murray , Thomas Brad
Published: August 2012

Laser triangulation ranging can provide data rates to at least 10,000 points per second, with resolution on the order of one thousandth of an inch, while observing strongly uncooperative targets through hostile environments. Data rate has been increased to greater than 100,000 points per second for applications requiring high resolution 3-D maps of extended uncooperative surfaces. One successful approach to these applications is described. Also, several optical and engineering characteristics affecting present performance levels are examined. These characteristics include range resolution, the number of distinct range points that can be measured to high accuracy, dynamic range requirements, light economy, and environmental tolerance.
Laser Welding of Plastics in Low and High Gravity Environments
Authors: Mueller R. E. , Duley W. W. , MacLean S. , Garneau M. , Tryggvason B. , Evans W. F. J.
Published: August 2012

Initial results of a series of laser processing experiments performed under the micro-gravity conditions supplied by NASA's KC-135 aircraft are presented. Weld morphologies of polypropylene and polyethylene were obtained under both hyper- and hypo-gravity conditions. Differences in keyhole shape and weld spiking morphology are observed.
Laser System for Dulling Work Roll by Q-Switched Nd:YAG Laser
Authors: Minamida K. , Suehiro J. , Toshimitu T. , Kawamoto T.
Published: August 2012

A new dulling system for the work rolls used to roughen the surface of cold-rolled steel sheet has been developed. Such sheets are used in various products, such as outer panels of automobiles, and decorative outer plates of electric appliances. In this process, several pulsed laser beams generated by Q-switched Nd:YAG lasers produce small craters with rims around them. This process includes a longitudinal scanning system within the laser processing head and a rotation system for the work roll; consequently, the surface of the dulled roll consists of innumerable small craters. The main features of the system consist of: (1) a special way of controlling RF power applied to the acousto-optic modulator for the Q-switching to change the peak power, pulse duration, and low level CW power to fit the dulling condition, (2) a method to combine two or more pulse beams to control the profile of dulling craters. Immediate advantages of this process are: (1) timesaving (very high repetition rate of pulses by Q-switching), (2) stable operation (without a mechanical chopper which is usually used with a CO2 laser to make pulsed beam), and (3) cost-saving. This newly developed system is effectively applied to the production of cold-rolled steel sheets.
The Clinical Status of Low Energy Laser Therapy in 1989
Authors: Basford Jeffrey R.
Published: August 2012

Low energy laser therapy has gained varying acceptance as a treatment for a broad range of soft tissue, musculoskeletal and neurological conditions. A controversial, but surprisingly large body of research with cell cultures suggests that laser irradiation can nondestructively alter cellular processes. Unfortunately, animal and human studies are often contradictory and difficult to evaluate due to differing study designs. As a result, the clinical effectiveness of low energy laser therapy remains debatable. Nevertheless, the findings are intriguing and deserve further investigation.
Composition and Microstructure of Laser Beam Welds between Dissimilar Metals
Authors: Kujanpää V. P. , Helin J. P. , Moisio T. J. I. , Bruck G. J.
Published: August 2012

An austenitic stainless steel AISI 304 and a low-carbon steel 1018 were laser welded in the vertical-up position to form a dissimilar metal joint, by varying the laser beam alignment, gap between the base metals, and filler metal (AISI 309). The welds were inspected visually and by optical microscopy, and composition profiles were measured using electron probe microanalysis. It was found that the laser welding produces a fairly inhomogeneous structure in the weld. This is revealed by both the microstructure and the composition profile. The average dilution was found to vary as a systematic function of laser beam alignment. Undesirable levels of dilution were identified as well as ranges of dilution which would provide acceptable weld metal properties.
Fatigue Strength of Laser-Welded Lap Joints
Authors: Albright Charles E. , Hsu Chris , Lund R. Olan
Published: August 2012

This investigation demonstrates that weld pattern selection can significantly increase fatigue strength in laser-welded lap joints. The study included evaluations of the effects of weld pattern, plate thickness, intersheet gap width and joint prebending on fatigue strength. All joints were tested in simple lap tensile shear. A weld pattern with multiple short welds parallel to the loading direction, and located within a band transverse to the loading direction, exhibited a fatigue strength 1.8 times higher (about 10 times longer fatigue life) than a simple transverse weld. Increasing plate thickness greatly reduced fatigue strength, while prebending and intersheet gap had no significant effect on joint fatigue strength.
Cutting of Al-Alloys Using High-Pressure Coaxial Nozzle
Authors: Biermann B. , Biermann S. , Bergmann H. W.
Published: August 2012

Aluminum alloys are used extensively in aerospace structures because of their high strength-to-weight characteristics. Unfortunately, these alloys are difficult to cut by laser processing. This behavior stems from: 1) their affinity for atmospheric gases, 2) their tendency to form high melting point reaction products and 3) the marked difference between their solidus and liquidus temperatures, which leads to formation of a mushy zone during cutting. This paper describes the results of a program directed toward improving CO2-laser cutting performance in aluminum alloys by optimization of cutting parameters. Tests were conducted with three gas-assist nozzle types: 1) a conventional coaxial nozzle, 2) a ring (annular) nozzle and 3) a high-pressure (to 15 bar) coaxial nozzle. The free flow field of the high-pressure nozzle was examined by schlieren photography. Micro and macro geometrical aspects of the cutting edge were examined using a test piece designed to provide information on cutting accuracy. Mechanical and corrosion tests of laser-cut samples were made and showed that postcutting heat treatment is required to restore tensile strength and avoid pitting corrosion in the heat-affected zone (HAZ) adjacent to the cut edge.
Schmidt-Cassegrain Optics For Laser Doppler Velocimetry Applications
Authors: Dunagan Stephen E.
Published: August 2012

A procedure is identified for adapting Schmidt-Cassegrain telescope optics to perform the laser beam focusing and scattered light collection tasks associated with dual-beam laser Doppler velocimetry. A generic, aperture-normalized system is analyzed using ray-tracing and Gaussian beam propagation analysis methods. Two relatively simple modification approaches are identified, each of which provides probe volume imaging performance near the diffraction limit. Similar modifications may be configured for laser beam focusing and provide small, high-intensity beam waists near the paraxial focus. The predicted performance of the generic modified telescope system exceeds that of similar large-aperture lens designs. Performance parameters including resolution limit and beam waist size and location were confirmed experimentally.
Two-Color Particle-Imaging Velocimetry
Authors: Goss Larry P. , Post Michael E. , Trump Darryl D. , Sarka Benjamin
Published: August 2012

A novel experimental method for determining two-dimensional velocity flowfields has been developed. The technique, two-color particle-imaging velocimetry (PIV), is similar to existing PIV techniques except that two different-color laser sources are used to form the light sheets required for exposing the position of particles in a seeded flowfield. A green-colored laser sheet (formed by a doubled Nd:YAG laser) and a red-colored laser sheet (formed by an Nd.YAG-pumped dye laser) are employed sequentially to expose the particle positions, which are recorded on 35 mm color film. Analysis of the resulting images involves digitizing the exposed film with color filters to separate the green- and red-particle image fields and processing the digitized images with velocity-displacement software. The two-color PIV technique has the advantage that direction, as well as particle displacement, is uniquely determined because the green-particle image occurs before the red one by a known time increment. Velocity measurements utilizing the two-color PIV technique on a propane jet diffusion flame have been made and are discussed.
Welding Zinc-Coated Steel with a Laser and the Properties of the Weldment
Authors: Akhter Rehan , Steen W. M. , Watkins K. G.
Published: August 2012

This paper discusses the lap welding of zinc-coated mild steel sheet using a laser. This process is of great interest to the manufacturers of cars, washing machines and other components made from sheet steel and subject to corrosion. Conventional and high-energy density welding of this material results in explosive ejection of the zinc vapor and an unsatisfactory weld. Several techniques are presented for the removal of the zinc from the interface or the control of the zinc vapors. Of the processes discussed in the paper the use of a gap between the sheets to vent the zinc vapor is shown to produce satisfactory welds. The resulting welds made both by this gap technique and by welding uncoated material were tested for fatigue, impact resistance, mechanical strength, hardness and corrosion resistance to salt solutions. The welds were made using a variety of lasers and the comparison in performance of these lasers is presented.
Mo Conductor Forming Technique with Laser Chemical Vapor Deposition (CVD)
Authors: Sano Shyuzo , Hongo Mikio , Mizukoshi Katsuro , Kamimura Takashi
Published: August 2012

A reduction in resistivity and an improvement in reliability of Mo conductors formed by laser CVD from Mo(CO)6 gas have been achieved using laser annealing. By establishing a standard of 10 μ Ω • cm, the reduction in resistivity was analyzed by AES (Auger Electron Spectrometry) and XRD (X-ray Diffractometry) methods. Reliability has been confirmed by the stability of resistance when subjected to a heat cycle of −50 – 150°C for more than 70 times.
Precision Limits of the Estimation of the Parameters of Förster Models of Fluorescence Waveforms
Authors: Dowell L. Jonathan
Published: August 2012

The author examined the precision of maximum-likelihood-derived, nonlinear least-squared-error algorithms that are suitable for laboratory implementation and that estimate the parameters of Förster models of fluorescence. The estimation precision for these parameters is limited by inherent noise in the fluorescence-waveform measurement. This paper examines the Förster model and its recent applications and discusses parameter estimations for models of energy transfer by different wavefunction interactions. It presents the results of Monte Carlo simulation studies of noise-limited parameter-estimation precision and presents waveform-measurement strategies, based on optimal observation times and sequential parameter estimation, that can reduce parameter-estimation error. This investigation is part of ongoing research in thermal metrology using the temperature-dependent laser-induced-fluorescence lifetime of rare-earth-doped ceramic phosphors. This work combines parameter-estimation concepts from electrical engineering with waveform-description theories from solid-state physics. The results are applicable to laser applications, fluorescence physics and chemistry, and metrology because the precise description of fluorescence is important in each of these fields. The results also provide an example of applied parameter-estimation theory.
Safety of Medical Excimer Lasers with an Emphasis on Compressed Gases
Authors: Sliney David H. , Clapham Terrance N.
Published: August 2012

Excimer lasers which emit short ultraviolet radiation (UVR) are currently being used in experimental and developmental surgical applications. Although UVR exposure is possible, it is not normal in laser angioplasty (cardiovascular surgery) and is insignificant in photokera-toplasty (ophthalmic surgery). However, significant potential hazards exist with the use of excimer laser gases such as fluorine and HCI. Stringent safeguards for handling and use are required when these gases are employed in a clinical setting. Recommended safety measures are provided.
The Protective Characteristics of Polycarbonate Lenses Against CO2 Laser Radiation
Authors: Sliney David H. , Sparks Shawn D. , Wood Rodney L.
Published: August 2012

The vulnerability of plastic laser eye protection used with Class 4 CW lasers was studied using a high-power industrial laser to produce 4 by 4 cm burn zones. Since a CW (or repetitively pulsed) laser beam can burn through such eye protectors, this potential is of concern to Laser Safety Officers (LSOs) prescribing laser eye protectors and transparent barriers for use around both the 10 to 80-W CO2 lasers used in surgery as well as multi-kilowatt industrial CO2 lasers. Polycarbonate filters are shown to have superior resistance to burn through, and thresholds for protective lens burn-through in 3–10 s are provided. It is recommended that LSOs consider polycarbonate transparent impact safety lenses to have a protective optical density (OD) of 4.
Tutorial Guide: Laser Measurement Techniques Guide For Hazard Evaluation. Part 1
Authors: Lyon Terry
Published: August 2012

A tutorial guide is presented to provide uniform guidance when performing radiometric measurements upon laser systems to perform a hazard evaluation. This guide was requested by and presented to the Department of Defense (DOD) Laser System Safety Working Group (LSSWG) to serve as a standardized method when performing hazard evaluations primarily upon tactical and training military laser systems including laser rangefinders and designators. Technical information is provided in detail to select a suitable detector, preform radiometric measurements, assess laser system pointing errors, calculate laser protective eyewear optical density, calculate beam divergence, and predict peak beam irradiances or radiant exposures at any distance from the laser. The guide identifies the primary health and safety consultants within DOD who are responsible to evaluate the potential hazards from military laser systems. This guide is intended to serve less experienced personnel by pointing out some common measurement errors and detector limitations which can lead to erroneous results. The guide also directs the reader to review the requirements of MIL-STD-1425A when a military laser system has been exempted from the requirements of the federal regulation for laser products, 21 CFR 1040. This guide was intended to facilitate acceptance of laser hazard evaluations performed by other services and to aid planners of joint service laser exercises.
Real-Time Fast Fourier Transform Analysis of Acoustic Emission during CO2 Laser Welding of Materials
Authors: Mao Y-L. , Kinsman G. , Duley W. W.
Published: August 2012

Real-time fast Fourier transform (FFT) analysis of acoustic emission has been developed for monitoring laser welding processes. Significant differences in acoustic emission have been observed in conduction and keyhole processing regimes. The amplitude fluctuation of acoustic emission becomes intensified in the transition from conduction welding to keyhole welding. The integrated FFT power spectrum emission has been correlated to laser power, welding speed, and focusing parameters. These results suggest a simple way of monitoring the welding process. A simplified physical model has been developed to explain the fluctuation frequency. The predictions of this model are found to be in good agreement with experimental data.
Laser Light Scattering in Biomedical Diagnostics and Therapy
Authors: Tuchin Valery V.
Published: August 2012

The description of special features of laser light interaction with biotissues, such as the skin, eye and dental tissues etc., with respect to laser diagnostics and therapy methods development is done. Optical models of transparent and turbid biotissues are analyzed. The role of static and dynamic light scattering in the light dosimetry, tissue heating, and receiving information of biotissue optical parameters, its structure, movements, and vibrations is considered.
Crystallographic and structural characterization of heterometallic platinum compounds. Part II. Heterobinuclear Pt compounds with Pt⋯M (M = transition or lantanide metal) > 3.0 Å
Authors: Melnik Milan , Sprusansky Ondrej , Holloway Clive
Published: August 2012

This review covers almost two hundred and twenty heterobinuclear platinum compounds in which Pt⋯M separation is over 3.0 Å. The M is a transition metal (Cu, Ag, Au, Ti, V, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni and Pd). There is an example of a lanthanide, Yb and a actinide, U. The Pt atom has oxidation numbers 0, +2 and +4. The Pt coordination geometries include trigonal planar Pt(0); square planar Pt(II); trigonal bipyramidal, and pseudo octahedral Pt(IV), with the most frequent being square planar. The most common ligands for Pt are P and C donor atoms, as well as a chlorine atom. The Pt — Ag distance of 3.002(1) Å is the shortest found in this series. There are examples which contain two crystallographically independent molecules, which differ mostly by degree of distortion and even one unique example, which contains eight such molecules. These are examples of distortion isomerism. Factors affecting bond lengths and angles are discussed and some ambiguities in coordination polyhedral are outlined.
The minimal displacement problem in the space l
∞
Authors: Bolibok Krzysztof
Published: August 2012

We give a lower bound for the minimal displacement characteristic in the space l
∞.
Improved hydrothermal synthesis of MoS2 sheathed carbon nanotubes
Authors: Robles-Nuñez Jaciel , Chiñas-Castillo Fernando , Sanchez-Rubio Manuel , Lara-Romero Javier , Huirache-Acuña Rafael , Jimenez-Sandoval Sergio , Alonso-Nuñez Gabriel
Published: August 2012

MoS2 sheathed carbon nanotubes have been successfully synthesized using a hydrothermal route under controlled conditions. The resultant material was studied by XRD, EDS, HRTEM, and Raman spectroscopy. Advantages of the preparation presented here compared to other methods are: a) lower reaction temperature, b) high yield of sheathed nanotubes including ends and full body, c) simple process with non-toxic materials, and d) no damage inflicted to nanotubes.
Quantitative analysis of two adulterants in Cynanchum stauntonii by near-infrared spectroscopy combined with multi-variate calibrations
Authors: Dong Wen-Jiang , Ni Yong-Nian , Kokot Serge
Published: August 2012

Authentication of traditional Chinese medicines (TCMs) has become important because they can be adulterated with relatively cheap herbal medicines similar in appearance. Detection of such adulterated samples is needed because their presence is likely to reduce the pharmacological potency of the original TCM and, in the worst cases, the samples may be harmful. The aim of this study was to develop a rapid near-infrared spectroscopy (NIRS) analytical method which was supported by multi-variate calibration, e.g. partial least squares regression (PLSR) and radial basis function artificial neural networks (RBF-ANN), in order to quantify the TCM and the adulterants. In this work, Cynanchum stauntonii (CS), a commonly used TCM, in mixtures with one or two adulterants — two morphological types of TCM, Cynanchum atrati (CA) and Cynanchum paniculati (CP), were determined using NIR reflectance spectroscopy. The three sample sets, CS adulterated with CA or CP, and CS with both CA and CP, were measured in the range of 800–2500 nm. Both PLSR and RBF-ANN calibration models provided satisfactory results, even at an adulteration level of 5 mass %, but the RBF-ANN models with better root mean square error of prediction (RMSEP) values for CS, CA, and CP arguably performed better. Consequently, this work demonstrates that the NIR method of sampling complex mixtures of similar substances such as CS adulterated by CA and/or CP is capable of producing data suitable for the quantitative analysis of mixtures consisting of the original TCM adulterated by one or two similar substances, provided the spectral data are interrogated by multi-variate methods of data analysis such as PLS or RBF-ANN.
Determination of pK a of benzoic acid- and p-aminobenzoic acid-modified platinum surfaces by electrochemical and contact angle measurements
Authors: Tekin-Celebi Secil , Solak Ali , Ustundag Zafer , Demirci Serkan
Published: August 2012

Acidity constant values of benzoic acid (BA)-modified platinum electrode (Pt-BA) and p-aminobenzoic acid (pABA)-modified platinum electrode (Pt-NHBA) surfaces were determined using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and contact angle measurements (CAM). Diazonium tetrafluoroborate salt reduction and pABA oxidation reactions were used to prepare (Pt-BA) and (Pt-NHBA) surfaces, respectively. Both surfaces exhibited pH dependence with [Fe(CN)6]3−/4− redox probe solutions at different pH; this allowed us to estimate the surface pK a values. Acidity constants for Pt-BA surface were found to be pK a (3.09 ± 0.25), (4.89 ± 0.11), and (3.91 ± 0.54) by CV, EIS, and CAM techniques, respectively, while the values for Pt-NHBA surface were pK a (3.16 ± 0.45), (4.24 ± 0.40), and (5.64 ± 0.12). The Pt-BA surface pK a values were lower in CV and CAM measurements relative to the bulk solution of BA, while a higher value was observed in EIS for Pt-BA surface. The pK a values determined for Pt-NHBA surface via both CV and EIS were lower than the bulk value; however, the result obtained from CAM was one unit higher than pK a of bulk pABA.
Palladium-catalysed Claisen rearrangement of 6-allyloxypurines
Authors: Koukal Petr , Dvořáková Hana , Dvořák Dalimil , Tobrman Tomáš
Published: August 2012

6-Allyloxypurines readily undergo palladium-catalysed Claisen rearrangement under mild conditions affording N 1-substituted hypoxanthines. In contrast with the previously reported protocol, the Claisen rearrangement can be performed using Pd(PPh3)4 or Pd(dba)2/dppf in dry THF at 60°C. The reaction can accommodate variously substituted allyl fragments to position N 1 of the hypoxanthine skeleton with high yields. Retention of the double bond configuration during rearrangement was observed.
Fifty Years of Post-Colonial Mapping in Nigeria: An Overview
Authors: Uluocha Nnabugwu
Published: August 2012

Since achieving political independence from Great Britain in 1960, Nigeria has assumed full responsibility for the mapping of her territories. Fifty years on, the country has made some progress in mapping; this progress has not met all mapping needs, but it has advanced into the realm of the geospatial sciences. Digital systems linked to satellite observations and aerial surveys have been developed. There remains a gap between the demand for and the supply of maps and allied products in Nigeria. In the early part of the period under study (1960–2010), many mapping projects initiated in Nigeria became moribund, while some did not get off the ground at all. Consequently, like most African countries, Nigeria still lacks basic maps needed for judicious resource planning, development, and management. Instability coupled with lack of a well-established mapping policy, shortage of funding, and successive governments' failure to integrate mapping into national development has affected mapping in the country. The national development process has thus far not fostered the growth of a rich mapping culture. Nigeria, like many other countries in Africa, needs a national geospatial data infrastructure (NGDI), a robust mapping policy, improved funding of mapping programs, and strong cartographic institutions. If vigorously pursued, those measures will surely revolutionize the state of mapping in Nigeria and the rest of Africa.
Considering Risk Locations When Defining Perturbation Zones for Geomasking
Authors: Lu Yongmei , Yorke Charles , Zhan F. Benjamin
Published: August 2012

Geomasking techniques are commonly used to mask the true location information of cases by introducing noise into location data. This study seeks to improve the spatially adaptive random perturbation (SARP) geomasking method by using the actual distribution of the residential addresses (or “risk location”) rather than the people (or “risk population”) to define a perturbation zone. The procedure used in the study also employs a “donut-shaped” perturbation zone, rather than the traditional “pancake-shaped” zone, when displacing a case. The effectiveness of the proposed geomasking methods is assessed in terms of their potential to control for location re-engineering and their ability to maintain the point patterns embedded in the real distribution. The authors conclude that SARP geomasking using the distribution of actual street addresses protects privacy more effectively than geomasking based on population size; the different SARP techniques do not significantly change the clustering patterns on a global level, but the geomasked data tend to be more clustered than the real case distribution.
Electronic Principles of Hydrogen Incorporation and Dynamics in Metal Hydrides
Authors: Ivanović Nenad , Novaković Nikola , Radisavljević Ivana , Matović Ljiljana , Grbović Novaković Jasmina
Published: August 2012

An approach to various metal hydrides based on electronic principles is presented. The effective medium theory (EMT) is used to illustrate fundamental aspects of metal-hydrogen interaction and clarify the most important processes taking place during the interaction. The elaboration is extended using the numerous existing results of experiment and calculations, as well as using some new material. In particular, the absorption/desorption of H in the Mg/MgH2 system is analyzed in detail, and all relevant initial structures and processes explained. Reasons for the high stability and slow sorption in this system are noted, and possible solutions proposed. The role of the transition-metal impurities in MgH2 is briefly discussed, and some interesting phenomena, observed in complex intermetallic compounds, are mentioned. The principle mechanism governing the Li-amide/imide transformation is also discussed. Latterly, some perspectives for the metal-hydrides investigation from the electronic point of view are elucidated.
A Practical Protection Coordination Strategy Applied to Secondary and Facility Microgrids
Authors: Jin Dae-Geun , Choi Jong-Chan , Won Dong-Jun , Lee Hak-Ju , Chae Woo-Kyu , Park Jung-Sung
Published: August 2012

In a conventional distribution system, protection algorithms are designed to operate on a unidirectional high fault-current level. In a microgrid, a fault current from distributed generation (DG) may bring about a relay malfunction because of the bidirectional and relatively small fault current. Therefore, the conventional protection scheme is not applicable to microgrids and a new protection method must be developed. In this paper, two protection coordination algorithms which can be applied for facility and secondary microgrids are proposed, respectively. The proposed protection algorithms eliminate faults not by the EMS signal but by directional relays. Moreover, this makes the algorithms flexible regardless of the types and numbers of DG. The proposed protection algorithms were simulated at the KEPCO RI Microgrid Demonstration Site.
Performance of Thermosyphon Solar Water Heaters in Series
Authors: Liu Yi-Mei , Chung Kung-Ming , Chang Keh-Chin , Lee Tsong-Sheng
Published: August 2012

More than a single thermosyphon solar water heater may be employed in applications when considerable hot water consumption is required. In this experimental investigation, eight typical Taiwanese solar water heaters were connected in series. Degree of temperature stratification and thermosyphon flow rate in a horizontal tank were evaluated. The system was tested under no-load, intermittent and continuous load conditions. Results showed that there was stratification in tanks under the no-load condition. Temperature stratification also redeveloped after the draw-off. Analysis of thermal performance of the system was conducted for each condition.
Towards Annotopia—Enabling the Semantic Interoperability of Web-Based Annotations
Authors: Hunter Jane , Gerber Anna
Published: August 2012

This paper describes the results of a collaborative effort that has reconciled the Open Annotation Collaboration (OAC) ontology and the Annotation Ontology (AO) to produce a merged data model [the Open Annotation (OA) data model] to describe Web-based annotations—and hence facilitate the discovery, sharing and re-use of such annotations. Using a number of case studies that include digital scholarly editing, 3D museum artifacts and sensor data streams, we evaluate the OA model’s capabilities. We also describe our implementation of an online annotation server that supports the storage, search and retrieval of OA-compliant annotations across multiple applications and disciplines. Finally we discuss outstanding problem issues associated with the OA ontology, and the impact that certain design decisions have had on the efficient storage, indexing, search and retrieval of complex structured annotations.
Assessing Disaster Preparedness among Latino Migrant and Seasonal Farmworkers in Eastern North Carolina
Authors: Burke Sloane , Bethel Jeffrey W. , Britt Amber Foreman
Published: August 2012

Natural disasters including hurricanes, floods, earthquakes, tornadoes, and fires often involve substantial physical and mental impacts on affected populations and thus are public health priorities. Limited research shows that vulnerable populations such as the low-income, socially isolated migrant and seasonal farmworkers (MSFW) are particularly susceptible to the effects of natural disasters. This research project assessed the awareness, perceived risk, and practices regarding disaster preparedness and response resources and identified barriers to utilization of community and government services during or after a natural disaster among Latino MSFWs’ and their families. Qualitative (N = 21) focus groups (3) and quantitative (N = 57) survey methodology was implemented with Latino MSFWs temporarily residing in rural eastern North Carolina to assess perceived and actual risk for natural disasters. Hurricanes were a top concern among the sample population, many participants shared they lacked proper resources for an emergency (no emergency kit in the house, no evacuation plan, no home internet, a lack of knowledge of what should be included in an emergency kit, etc.). Transportation and language were found to be additional barriers. Emergency broadcasts in Spanish and text message alerts were identified by the population to be helpful for disaster alerts. FEMA, American Red Cross, local schools and the migrant clinic were trusted places for assistance and information. In summary, tailored materials, emergency alerts, text messages, and news coverage concerning disaster threats should be provided in the population’s native language and when feasible delivered in a culturally appropriate mechanism such as “charlas” (talks) and brochures.
Risky Play and Children’s Safety: Balancing Priorities for Optimal Child Development
Authors: Brussoni Mariana , Olsen Lise L. , Pike Ian , Sleet David A.
Published: August 2012

Injury prevention plays a key role in keeping children safe, but emerging research suggests that imposing too many restrictions on children’s outdoor risky play hinders their development. We explore the relationship between child development, play, and conceptions of risk taking with the aim of informing child injury prevention. Generational trends indicate children’s diminishing engagement in outdoor play is influenced by parental and societal concerns. We outline the importance of play as a necessary ingredient for healthy child development and review the evidence for arguments supporting the need for outdoor risky play, including: (1) children have a natural propensity towards risky play; and, (2) keeping children safe involves letting them take and manage risks. Literature from many disciplines supports the notion that safety efforts should be balanced with opportunities for child development through outdoor risky play. New avenues for investigation and action are emerging seeking optimal strategies for keeping children “as safe as necessary,” not “as safe as possible.” This paradigm shift represents a potential for epistemological growth as well as cross-disciplinary collaboration to foster optimal child development while preserving children’s safety.
Synthesis, Structure Optimization and Antifungal Screening of Novel Tetrazole Ring Bearing Acyl-Hydrazones
Authors: Malik Maqsood Ahmad , Al-Thabaiti Shaeel Ahmed , Malik Manzoor A.
Published: August 2012

Azoles are generally fungistatic, and resistance to fluconazole is emerging in several fungal pathogens. In an attempt to find novel azole antifungal agents with improved activity, a series of tetrazole ring bearing acylhydrazone derivatives were synthesized and screened for their in vitro antifungal activity. The mechanism of their antifungal activity was assessed by studying their effect on the plasma membrane using flow cytometry and determination of the levels of ergosterol, a fungal-specific sterol. Propidium iodide rapidly penetrated a majority of yeast cells when they were treated with the synthesized compounds at concentrations just above MIC, implying that fungicidal activity resulted from extensive lesions of the plasma membrane. Target compounds also caused a considerable reduction in the amount of ergosterol. The results also showed that the presence and position of different substituents on the phenyl ring of the acylhydrazone pendant seem to play a role on the antifungal activity as well as in deciding the fungistatic and fungicidal nature of the compounds.
Neuroprotective Effects of Erucin against 6-Hydroxydopamine-Induced Oxidative Damage in a Dopaminergic-like Neuroblastoma Cell Line
Authors: Tarozzi Andrea , Morroni Fabiana , Bolondi Cecilia , Sita Giulia , Hrelia Patrizia , Djemil Alice , Cantelli-Forti Giorgio
Published: August 2012

Oxidative stress (OS) contributes to the cascade leading to the dysfunction or death of dopaminergic neurons during Parkinson’s disease (PD). A strategy to prevent the OS of dopaminergic neurons may be the use of phytochemicals as inducers of endogenous antioxidants and phase 2 enzymes. In this study, we demonstrated that treatment of the dopaminergic-like neuroblastoma SH-SY5Y cell line with isothiocyanate erucin (ER), a compound of cruciferous vegetables, resulted in significant increases of both total glutathione (GSH) levels and total antioxidant capacity at the cytosolic level. The increase of GSH levels was associated with an increase in the resistance of SH-SY5Y cells to neuronal death, in terms of apoptosis, induced by 6-hydroxydopamine (6-OHDA). The pretreatment of SH-SY5Y cells with ER was also shown to prevent the redox status impairment, in terms of intracellular ROS and O2•− formation, and loss of mitochondrial membrane potential, early events that are initiators of the apoptotic process, induced by 6-OHDA. Last, the antiapoptotic and antioxidant effects of ER were abolished by buthionine sulfoximine, supporting the main role of GSH in the neuroprotective effects recorded by ER. These results suggest that ER may prevent the oxidative damage induced by 6-OHDA.
Graphene Nanoplatelets as Novel Reinforcement Filler in Poly(lactic acid)/Epoxidized Palm Oil Green Nanocomposites: Mechanical Properties
Authors: Chieng Buong Woei , Ibrahim Nor Azowa , Wan Yunus Wan Md Zin , Hussein Mohd Zobir , Silverajah V. S. Giita
Published: August 2012

Graphene nanoplatelet (xGnP) was investigated as a novel reinforcement filler in mechanical properties for poly(lactic acid) (PLA)/epoxidized palm oil (EPO) blend. PLA/EPO/xGnP green nanocomposites were successfully prepared by melt blending method. PLA/EPO reinforced with xGnP resulted in an increase of up to 26.5% and 60.6% in the tensile strength and elongation at break of the nanocomposites respectively, compared to PLA/EPO blend. XRD pattern showed the presence of peak around 26.5° in PLA/EPO nanocomposites which corresponds to characteristic peak of graphene nanoplatelets. However, incorporation of xGnP has no effect on the flexural strength and modulus. Impact strength of PLA/5 wt% EPO improved by 73.6% with the presence of 0.5 wt% xGnP loading. Mechanical properties of PLA were greatly improved by the addition of a small amount of graphene nanoplatelets ( < 1 wt%).
Training for Defense? From Stochastic Traits to Synchrony in Giant Honey Bees (Apis dorsata)
Authors: Weihmann Frank , Hoetzl Thomas , Kastberger Gerald
Published: August 2012

In Giant Honey Bees, abdomen flipping happens in a variety of contexts. It can be either synchronous or cascaded, such as in the collective defense traits of shimmering and rearing-up, or it can happen as single-agent behavior. Abdomen flipping is also involved in flickering behavior, which occurs regularly under quiescent colony state displaying singular or collective traits, with stochastic, and (semi-) synchronized properties. It presumably acts via visual, mechanoceptive, and pheromonal pathways and its goals are still unknown. This study questions whether flickering is preliminary to shimmering which is subject of the fs (flickering-shimmering)-transition hypothesis? We tested the respective prediction that trigger sites (ts) at the nest surface (where shimmering waves had been generated) show higher flickering activity than the alternative non-trigger sites (nts). We measured the flickering activity of ts- and nts-surface bees from two experimental nests, before and after the colony had been aroused by a dummy wasp. Arousal increased rate and intensity of the flickering activity of both ts- and nts cohorts (P < 0.05), whereby the flickering intensity of ts-bees were higher than that of nts-bees (P < 0.05). Under arousal, the colonies also increased the number of flickering-active ts- and nts-cohorts (P < 0.05). This provides evidence that cohorts which are specialist at launching shimmering waves are found across the quiescent nest zone. It also proves that arousal may reinforce the responsiveness of quiescent curtain bees for participating in shimmering, practically by recruiting additional trigger site bees for expanding repetition of rate and intensity of shimmering waves. This finding confirms the fs-transition hypothesis and constitutes evidence that flickering is part of a basal colony-intrinsic information system. Furthermore, the findings disprove that the muscle activity associated with flickering would heat up the surface bees. Hence, surface bees are not actively contributing to thermoregulation.
Novel Pyranopyrazoles: Synthesis and Theoretical Studies
Authors: Al-Amiery Ahmed A. , Al-Bayati Redah I. , Saed Fouad M. , Ali Wassan B. , Kadhum Abdul Amir H. , Mohamad Abu Bakar
Published: August 2012

A series of pyranopyrazoles, namely, 7-(2-aminoethyl)-3,4-dimethyl-1-phenyl-1H-pyrazolo[3,4-b]pyridin-6(7H)-one (2), (Z)-3,4-dimethyl-1-(4-((4-nitrobenzylidene)amino)phenyl)pyrano[2,3-c]pyrazol-6(1H)-one (5), 1-(4-(3,4-dimethyl-6-oxopyrano[2,3-c]pyrazol-1(6H)-yl)phenyl)-3-(naphthalen-1-yl)urea (6), (Z)-ethyl 4-((3,4-dimethyl-6-oxo-1,6-dihydropyrano[2,3-c]pyrazol-5-yl)diazenyl)benzoate (8) and 3,4-dimethyl-N-(naphthalen-1-yl)-6-oxopyrano[2,3-c]pyrazole-1(6H)-carboxamide (9) were synthesized and characterized by means of their UV-VIS, FT-IR, 1H-NMR and 13C-NMR spectral data. Density Functional Theory calculations of the synthesized pyranopyrazoles were performed using molecular structures with optimized geometries. Molecular orbital calculations have provided detail description of the orbitals, including spatial characteristics, nodal patterns, and the contributions of individual atoms.
Hsp90 Inhibitors and the Reduction of Anti-Cancer Drug Resistance by Non-Genetic and Genetic Mechanisms
Authors: Lu Xiangyi , Wang Luan , Ruden Douglas M.
Published: August 2012

In this review, we focus on how inhibitors of Hsp90 can help prevent the resistance to anti-cancer drugs by synergistically increasing their cancer killing abilities and thereby allowing them to function at much lower concentrations than normally used. Hsp90 helps to fold numerous client proteins, such as Akt, Raf, Src, chromatin-modifying proteins, nuclear hormone receptors, and kinetochore assembly proteins. We discuss four mechanisms by which Hsp90 inhibitors can potentially synergize with anti-cancer drugs: by making a drug-resistant protein that is a client for Hsp90 more sensitive to the drug, by increasing chromosomal aneuploidy and the effectiveness of DNA-damaging drugs, by inhibiting Trithorax proteins which trimethylate histone 3 at lysine 4 (H3K4me3) and thereby decreasing expression of tumor promoter genes, and by interacting with the negative elongation factor (NELF) complex in tumors. We also explain how the evolutionary capacitor function of Hsp90 can be exploited with inhibitors of Hsp90 by exposing new protein variants that can be targeted with other drugs, thereby opening new avenues of combination drug therapy to treat cancer. We believe that inhibition of these processes can increase the efficacy of Hsp90 inhibitors with other anti-cancer drugs.
Effects of Roof Pitch on Air Flow and Heating Load of Sealed and Vented Attics for Gable-Roof Residential Buildings
Authors: Wang Shimin , Shen Zhigang
Published: August 2012

Pitch value is an important consideration in residential gable roof design and construction. However, how roof pitch, coupled with air flows in attic space, affects the energy performance of building attics has been barely investigated. In this paper, a 2D unsteady computational fluid dynamics (CFD) model is employed to investigate the effects of roof pitch on air flow and heating load of both sealed and vented attics for gable-roof residential buildings. The simulation results show that air flow in the sealed attics is steady and asymmetric, while that in the vented attics is a combination of an essentially symmetric base flow and a periodically oscillating flow. For both the sealed and vented attic cases, the heating load is found to increase with the roof pitch, and the heat transfer of turbulent air flow in attic space can be satisfactorily correlated by a simple relationship between appropriately defined Nusselt number and Rayleigh number.
Urban Vulnerability in Bantul District, Indonesia—Towards Safer and Sustainable Development
Authors: Hizbaron Dyah R. , Baiquni Muhammad , Sartohadi Junun , Rijanta R.
Published: August 2012

Assuring safer and sustainable development in seismic prone areas requires predictive measurements, i.e., hazard, vulnerability and risk assessment. This research aims to assess urban vulnerability due to seismic hazard through a risk based spatial plan. The idea is to indicate current and future potential losses due to specified hazards with given spatial and temporal units. Herein, urban vulnerability refers to the classic separation between social and physical vulnerability assessments. The research area covers six sub-districts in Bantul, Indonesia. It experienced 6.2 Mw earthquakes on May, 27th, 2006 and suffered a death toll of 5700, economic losses of up to 3.1 billion US$ and damage to nearly 80% of a 508 km2 area. The research area experienced the following regional issues: (1) seismic hazard; (2) rapid land conversion and (3) domination of low-income group. This research employs spatial multi criteria evaluations (SMCE) for social vulnerability (SMCE-SV) and for physical vulnerability (SMCE-PV). The research reveals that (1) SMCE-SV and SMCE-PV are empirically possible to indicate the urban vulnerability indices; and (2) integrating the urban vulnerability assessment into a spatial plan requires strategic, technical, substantial and procedural integration. In summary, without adequate knowledge and political support, any manifestation towards safer and sustainable development will remain meager and haphazard.
Sixteen novel microsatellite markers developed for Dendrocalamus sinicus (Poaceae), the strongest woody bamboo in the world
Authors: Dong Yu‐Ran , Zhang Zhi‐Rong , Yang Han‐Qi
Published: August 2012

• Premise of the study: Microsatellite primers were developed in the strongest and most economically important bamboo species, Dendrocalamus sinicus, to investigate its genetic variability.

• Methods and Results: Using the Fast Isolation by AFLP of Sequences COntaining Repeats (FIASCO) protocol, 16 polymorphic primer sets were identified within 24 individuals from two geographic locations. The number of alleles per locus ranged from two to four, with a mean of 2.6. The observed and expected heterozygosities varied from 0 to 1.000 and from 0.311 to 0.754, respectively. The cross‐amplification of the 16 primer pairs was tested in four other Dendrocalamus species, and nine to 13 (56.3–81.3%) primer pairs were successfully amplified.

• Conclusions: These markers will be useful for studies on the genetic diversity of D. sinicus, which may facilitate conservation of this species.