Magneto-Optic Spectroscopy and Near-Field Optical Coupling in Nanoparticle Composite Materials

The Faraday rotation spectrum of composites containing magnetite nanoparticles is found to be dependent on the interparticle spacing of the constituent nanoparticles. The composite materials are prepared by combining chemicallysynthesized Fe3O4 (magnetite) nanoparticles (8 nm diameter) and poly(methylmethacrylate) (PMMA). Composites are made containing a range of nanoparticle concentrations. The peak of the main spectral feature depends on nanoparticle concentration; this peak is observed to shift from approximately 470 nm for (dilute composites) to 560 nm (concentrated). A theory is presented based on the dipole approximation which accounts for optical coupling between magnetite particles. Qualitative correlations between theoretical calculations and experimental data suggest the shifts in spectral peak position depend on both interparticle distance and geometrical configuration

Resistive Exercise Device

An exercise device 10 is particularly well suited for use in low gravity environments, and includes a frame 12 with plurality of resistance elements 30,82 supported in parallel on the frame. A load transfer member 20 is moveable relative to the frame for transferring the applied force to the free end of each captured resistance element. Load selection template 14 is removably secured both to the load transfer member, and a plurality of capture mechanisms engage the free end of corresponding resistance elements. The force applying mechanism 53 may be a handle, harness or other user interface for applying a force to move the load transfer member

Measurement Of Optical Properties Of Soot Using Cavity Ring-Down Spectroscopy And Integrating Nephelometry

Since black carbon and brown carbon are among the greatest contributors to radiative forcing (black carbon being second only to carbon dioxide), this work focuses on the laboratory measurement of their optical properties using cavity ring-down spectroscopy (CRDS) and integrating nephelometry. Water soluble soot is collected using an impinger and cascade impactor by burning different fuel types to mimic ambient aerosols dominant in regions where biomass burning is the main source of aerosols. Using an optical parametric oscillator (OPO) as a light source, we are able to measure extinction and scattering over a wide range of wavelengths. A correction factor is calculated using a method by Anderson and Ogren to reconcile scattering from the nephelometer to extinction from the CRDS. The extinction-minus-scattering method is then used to determine absorption. Purely scattering polystyrene latex (PSL) spheres of known sizes (100 – 700 nm) are used in the lab to calibrate the system for this study. Measurements of optical properties of soot collected from different fuel sources at different stages of burning are reported

Participatory Planning and Procedural Protections: The Case for Deeper Public Participation in Urban Redevelopment

For decades legal and planning commentators have advocated a deeper and more meaningful level of public participation in urban revitalization efforts. The result of such advocacy has increased the use of public participation as a criterion for awarding federal redevelopment funds but has had little impact on participatory requirements in state redevelopment law. This article explores the theoretical arguments in favor of increased public participation in the redevelopment context and finds that there is an overemphasis on direct democracy arguments and the “empowerment” theory, a concept that belies simple definition. This article explores the intrinsic and instrumental benefits of public participation and finds that participatory planning is beneficial as a legitimizing form of deliberation in governance, but only when used as a supplement to, rather than a replacement for politically accountable legislative authorities. This understanding of the role of participatory planning provides a more convincing rhetorical and normative regime that justifies the difficulties that arise when granting greater resident control of redevelopment and further legitimizes the planning process in a way that is legally cognizable by courts reviewing urban redevelopment plans. As a result, this article describes the need for more robust procedural legal rights that would allow low-income residents to resist redevelopment in those instances where the goals of participatory planning are not attained due to government corruption or inattention to public input. This new rhetorical and normative regime is tested against actual urban redevelopment planning methods used in Camden, New Jersey and East St. Louis, Illinois. This article suggests specific changes to state redevelopment laws that would enshrine deeper public participation values and concludes with an eye towards the additional research and advocacy necessary for achieving those changes

Exercise Device Would Exert Selectable Constant Resistance

An apparatus called the resistive exercise device (RED) has been proposed to satisfy a requirement for exercise equipment aboard the International Space Station (ISS) that could passively exert a selectable constant load on both the outward and return strokes. The RED could be used alone; alternatively, the RED could be used in combination with another apparatus called the treadmill with vibration isolation and stabilization (TVIS), in which case the combination would be called the subject load device (SLD). The basic RED would be a passive device, but it could incorporate an electric motor to provide eccentric augmentation (augmentation to make the load during inward movement greater than the load during outward movement). The RED concept represents a unique approach to providing a constant but selectable resistive load for exercise for the maintenance and development of muscles. Going beyond the original ISS application, the RED could be used on Earth as resistive weight training equipment. The advantage of the RED over conventional weight-lifting equipment is that it could be made portable and lightweight

Larval ecology of benthic marine invertebrates at Signy Island, Antarctica

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN011138 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Magnesium oxide doping reduces acoustic wave attenuation in lithium metatantalate and lithium metaniobate crystals

Single crystals of lithium metatantalate and lithium metaniobate, grown from melts having different stoichiometries and different amounts of magnesium oxide, show that doping lowers temperature-independent portion of attenuation of acoustic waves. Doped crystals possess optical properties well suited for electro-optical and photoelastic applications

Mechanical vibration transmission characteristics of the left ventricle: Implications with regard to auscultation and phonocardiography

Systolic-diastolic phasic alteration of left ventricular mechanical vibration transmissibility was studied in an open chest canine preparation. A continuous vibratory tone was applied to the base of the heart, and a miniature heart surface vibration sensor applied to the epicardium near the ventricular apex. This allowed the detection of the percent of the vibration that was transmitted from source to sensor. These data were compared with those from intracardiac phonocardiograms obtained using a micromanometer-tipped catheter. It was found that in systole, the ventricle transmitted a vibratory tone from the cardiac base to the apex so that it was readily detected by the heart surface sensor. In marked contrast, during diastole the relaxed ventricle failed almost completely to transmit the vibration to the apical position. When the dog experienced heart failure during hypoxia, the ventricular diastolic vibration transmissibility was found to equal or exceed that of the systolic phase

Integrated management of white mold in soybean

Sclerotinia sclerotiorum, the causal agent for white mold (Sclerotinia stem rot), is a devastating soybean fungal pathogen. In 2006, white mold ranked in the top 10 yield reducing diseases of soybean and was estimated to account for over 2 billion metric tonnes of yield loss world-wide (1). In the United States, soybean losses in 2009 reached an estimated 59 million bushels due to white mold, which cost producers ~$560 million (2, 3). Disease control is limited due to the lack of complete resistance in commercial cultivars and an incomplete understanding of resistance mechanisms (3). Further investigation of white mold resistance mechanisms in soybean and subsequent resistance evaluations of soybean germplasm would improve commercially available resistance

Investigation of Substituted-Benzene Dopants for Charge Exchange Ionization of Nonpolar Compounds by Atmospheric Pressure Photoionization

Atmospheric pressure photoionization (APPI) using a dopant enables both polar and nonpolar compounds to be analyzed by LC/MS. To date, the charge exchange ionization pathway utilized for nonpolar compounds has only been efficient under restrictive conditions, mainly because the usual charge exchange reagent ions—the dopant photoions themselves—tend to be consumed in proton transfer reactions with solvent and/or dopant neutrals. This research aims to elucidate the factors affecting the reactivities of substituted-benzene dopant ions; another, overriding, objective is to discover new dopants for better implementing charge exchange ionization in reversed-phase LC/MS applications. The desirable properties for a charge exchange dopant include low reactivity of its photoions with solvent and dopant neutrals and high ionization energy (IE). Reactivity tests were performed for diverse substituted-benzene compounds, with substituents ranging from strongly electron withdrawing (EW) to strongly electron donating (ED). The results indicate that both the tendency of a dopant's photoions to be lost through proton transfer reactions and its IE depend on the electron donating/withdrawing properties of its substituent(s): ED groups decrease reactivity and IE, while EW groups increase reactivity and IE. Exceptions to the reactivity trend for dopants with ED groups occur when the substituent is itself acidic. All told, the desirable properties for a charge exchange dopant tend towards mutual exclusivity. Of the singly-substituted benzenes tested, chloro- and bromobenzene provide the best compromise between low reactivity and high IE. Several fluoroanisoles, with counteracting EW and ED groups, may also provide improved performance relative to the established dopants