Effects of Acculturation and Generational Status on Ethnocultural and Psychosocial Adaptation of Mexican-American Adolescents

The extent to which acculturation and generational status affect the ethnocultural and psychosocial adaptation of Mexican-American adolescents was investigated. Participants were classified into acculturation and generational status levels from scores on the Acculturation Rating Scale for Mexican-Americans-Revised (ARSMA-II) and the dependent variable was measured using the Psychosocial Adaptation for Cultural and Contextual Correspondence-Research Version (PACCC-RV). Mexican-American adolescents with lower acculturation levels and more recent residence in the United States perceived they were ethnoculturally different from others in their environment especially in regards to communication difficulties. Similar to previous studies, acculturation and generational status appear to be measuring similar dimensions

Improved Models of Cable-to-Post Attachments for High-Tension Cable Barriers

Computer simulation models were developed to analyze and evaluate a new cable-to-post attachment for high-tension cable barriers. The models replicated the performance of a keyway bolt currently used in the design of a high-tension cable median barrier being developed at the Midwest Roadside Safety Facility. Component tests of the keyway bolts were simulated and compared to the component test results. Accurate friction, fracture strain, and stress-strain material properties were determined for a solid element model of the keyway bolt by applying actual load curve measured from the test to a simulated pull cable. By simulating the material properties of the solid element keyway bolt in bending, torsion, and tension of a rod, load curves were developed for a simplified beam element model of the keyway bolt as well. When material properties were finalized, the solid and beam element models of the keyway bolt were inserted in bogie test models and simulated again. By analyzing the bogie testing results, it was determined that due to the very small size of the keyway bolt and potential contact difficulties, solid element models of the keyway bolt may be impractical for full-scale simulation purposes. However, the beam element models were determined to be advantageous and had a very small computational cost in comparison

A GaAs metalorganic vapor phase epitaxy growth process o reduce Ge out-diffusion from the Ge substrate

A barrier based on GaAs for controlling the Ge out diffusion has been developed by metalorganic vapor phase epitaxy. It is based on a thin GaAs layer (50 nm) grown at a low temperature (≈500 °C) on top of a predeposition layer, showing that GaAs prevents the Ge diffusing when it is grown at a low temperature. Additionally, two different predeposition monolayers have been compared, concluding that when the Ga is deposited first, the diffusions across the GaAsGe heterointerface decrease

Field-aligned current associated with low-latitude plasma blobs as observed by the CHAMP satellite

Here we give two examples of low-latitude plasma blobs accompanied by linearly polarized perpendicular magnetic deflections which imply that associated field-aligned currents (FACs) have a 2-D sheet structure located at the blob walls. The estimated FAC density is of the order of 0.1 μA/m<sup>2</sup>. The direction of magnetic deflections points westward of the magnetic meridian and there is a linear correlation between perpendicular and parallel variations. All these properties are similar to those of equatorial plasma bubbles (EPBs). According to CHAMP observations from August 2000 to July 2004, blobs show except for these two good examples no clear signatures of 2-D FAC sheets at the walls. Generally, perpendicular magnetic deflections inside blobs are weaker than inside EPBs on average. Our results are consistent with existing theories: if a blob exists, (1) a significant part of EPB FAC will be closed through it, exhibiting similar perpendicular magnetic deflection inside EPBs and blobs, (2) the FAC closure through blobs leads to smaller perpendicular magnetic deflection at its poleward/downward side, and (3) superposition of different FAC elements might result in a complex magnetic signature around blobs

Silver and Gold Nanoparticles Alter Cathepsin Activity In vitro

Nanomaterials are being incorporated into many biological applications for use as therapeutics, sensors, or labels. Silver nanomaterials are being utilized for biological implants and wound dressings as an antiviral material, whereas gold nanomaterials are being used as biological labels or sensors due to their surface properties and biocompatibility. Cytotoxicity data of these materials are becoming more prevalent; however, little research has been performed to understand how the introduction of these materials into cells affects cellular processes. Here, we demonstrate the impact that silver and gold nanoparticles have on cathepsin activity in vitro. Cathepsins are important cellular proteases that are imperative for proper immune system function. We have selected to examine gold and silver nanoparticles due to the increased use of these materials in biological applications. This manuscript depicts how both of these types of nanomaterials affect cathepsin activity, which could impact the host's immune system and its ability to respond to pathogens. Cathepsin B activity decreases in a dose-dependent manner with all nanoparticles tested. Alternatively, the impact of nanoparticles on cathepsin L activity depends greatly on the type and size of the material

MGS Dynamic Deflections and Working Widths at Lower Speeds

The Midwest Guardrail System (MGS) has been full-scale crash tested in many configurations, including installations adjacent to slopes, with different types of wood posts, with and without blockouts, for culvert and bridge applications, and at high flare rates. Although the performance of the MGS and the dynamic deflection and working width of the barrier have been examined, little is known about the dynamic deflection and working width of the MGS when impacted at lower speeds. The MGS is a relatively low-cost barrier, and the Test Level 3 (TL-3) version could be installed for TL-2 and TL-1 applications. The barrier is expected to capture or redirect errant vehicles impacting at speeds less than or equal to those used for crash testing according to TL-3of the Manual for Assessing Safety Hardware (MASH). Accurate dynamic deflections and working widths of the MGS when impacted at lower speeds are critical for the safe placement of guardrail to reduce the likelihood of vehicle impact with a shielded hazard in the Zone of Intrusion (ZOI) for use on level terrain and in combination with curbs. LS-DYNA computer simulation models of a 2007 Chevrolet Silverado impacting both a tangent MGS and MGS in combination with a curb at a 6-ft 3-in. (1.9-m) post spacing (i.e., standard post spacing) were calibrated against previous crash tests. Then, the model was simulated with two lower speeds and at five impact locations with a conservative soil model to determine the maximum dynamic deflection and working width of the system at TL-1 and TL-2 impact conditions of MASH

Influence of GaInP ordering on the electronic quality of concentrator solar cells

The ordering phenomenon produces a reduction in the band gap of the GaInP material. Though a drawback for many optoelectronic applications, ordering can be used as an additional degree of material and device engineering freedom. The performance of the record efficiency GaInP/GaAs/Ge multijunction solar cells depends on the quality and design of the GaInP top cell, which can be affected also by ordering. The tradeoff existing between band gap and minority carrier properties, and the possibility of creating a back surface field (BSF) structure based on an order–disorder GaInP heterostructure makes the study of the ordering appealing for solar cell applications. In this work, the ordering dependency with the growth conditions and substrate orientation is studied. The results obtained are presented to enrich and extend the data available in the literature. Then the properties of order–disorder GaInP heterostructures are assessed by using them as BSF in GaInP concentrator solar cells. The external quantum efficiency (EQE) shows a good behavior of these BSF layers, but unexpectedly poor electronic quality in the active layers. Although the exact origin of this problem remains to be known, it is attributed to traps introduced by the ordered/disordered domains matrix or growth native defects. EQE measurements with bias light show a recovery of the minority carrier properties, presumably due to the saturation of the traps

Structural investigation of MOVPE-Grown GaAs on Ge by X-ray techniques

The selection of appropriate characterisation methodologies is vital for analysing and comprehending the sources of defects and their influence on the properties of heteroepitaxially grown III-V layers. In this work we investigate the structural properties of GaAs layers grown by Metal-Organic Vapour Phase Epitaxy (MOVPE) on Ge substrates – (100) with 6⁰ offset towards – under various growth conditions. Synchrotron X-ray topography (SXRT) is employed to investigate the nature of extended linear defects formed in GaAs epilayers. Other X-ray techniques, such as reciprocal space mapping (RSM) and triple axis ω-scans of (00l)-reflections (l = 2, 4, 6) are used to quantify the degree of relaxation and presence of antiphase domains (APDs) in the GaAs crystals. The surface roughness is found to be closely related to the size of APDs formed at the GaAs/Ge heterointerface, as confirmed by X-ray diffraction (XRD), as well as atomic force microscopy (AFM), and transmission electron microscopy (TEM)

Structural investigation of MOVPE-Grown GaAs on Ge by X-ray techniques

The selection of appropriate characterisation methodologies is vital for analysing and comprehending the sources of defects and their influence on the properties of heteroepitaxially grown III-V layers. In this work we investigate the structural properties of GaAs layers grown by Metal-Organic Vapour Phase Epitaxy (MOVPE) on Ge substrates – (100) with 6⁰ offset towards – under various growth conditions. Synchrotron X-ray topography (SXRT) is employed to investigate the nature of extended linear defects formed in GaAs epilayers. Other X-ray techniques, such as reciprocal space mapping (RSM) and triple axis ω-scans of (00l)-reflections (l = 2, 4, 6) are used to quantify the degree of relaxation and presence of antiphase domains (APDs) in the GaAs crystals. The surface roughness is found to be closely related to the size of APDs formed at the GaAs/Ge heterointerface, as confirmed by X-ray diffraction (XRD), as well as atomic force microscopy (AFM), and transmission electron microscopy (TEM)