Investigating performance, reliability and safety parameters of photovoltaic module inverter: Test results and compliances with the standards

Reliability, safety and quality requirements for a new type of photovoltaic module inverter have been identified and its performance has been evaluated for prototypes. The laboratory tests have to show whether the so-called second generation photovoltaic module inverter can comply with the expectations and where improvements are still necessary. Afterwards, the test results have been compared with the internationals standards.     

Femtosecond Chemical Dynamics in Solution: Photodissociation of I3-

We report a study of the UV photolysis of I₃⁻ in alcohol solutions, using femtosecond time-resolved transient transmission experiments. We interpret our results to indicate that photoexcitation leads to direct formation, within 300 fs, of diiodide ions which are vibrating coherently. The time scales for vibrational dephasing, vibrational relaxation, and reorientation of the fragment ions are 400 fs, 4 ps, and 5 ps, respectively. UV transient transmission experiments were conducted in order to characterize the time scales for recombination. Recombination takes place on several time scales. A fast component is assigned to primary recombination, followed by vibrational relaxation on the ground state of I₃⁻. The prominence of this recombination route is found to be strongly dependent on the solvent. Finally, time domain quantum simulation techniques are employed in order to gain insight into the nature of the nascent diiodide vibrational distribution, and to introduce a semiquantitative model for the stage of bond fission for isolated ions.     

A non-periodic Fourier method for solution of the classical wave equation

A Fourier method solution for the classical wave equation which overcomes the difficulty of the periodicity of the trigonometric functions is presented.     

Imaging Mass Spectrometry of a Coral Microbe Interaction with Fungi

Fungal infections are increasing worldwide, including in the aquatic environment. Microbiota that coexist with marine life can provide protection against fungal infections by secretion of metabolites with antifungal properties. Our laboratory has developed mass spectrometric methodologies with the goal of improving our functional understanding of microbial metabolites and guiding the discovery process of anti-infective agents from natural sources. GA40, a Bacillus amyloliquefaciens strain isolated from an octocoral in Panama, displayed antifungal activity against various terrestrial and marine fungal strains. Using matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS), the molecular species produced by this microbe were visualized in a side-by-side interaction with two representative fungal strains, Aspergillus fumigatus and Aspergillus niger. The visualization was performed directly on the agar without the need for extraction. By evaluating the spatial distributions, relative intensities and m/z values of GA40 secreted metabolites in the fungal interactions and singly grown control colonies, we obtained insight into the antifungal activity of secreted metabolites. Annotation of GA40 metabolites observed in MALDI-IMS was facilitated by MS/MS networking analysis, a mass spectrometric technique that clusters metabolites with similar MS/MS fragmentation patterns. This analysis established that the predominant GA40 metabolites belong to the iturin family. In a fungal inhibition assay of A. fumigatus, the GA40 iturin metabolites were found to be responsible for the antifungal properties of this Bacillus strain.     

Internet content regulation: what method?

The law and regulation of electronic communications in the United States (Us) is fragmented, overlapping, and controversial, with overarching First Amendment limitations for government action directed toward content. Because the law was written for “legacy” systems of telecommunications without regard for the present convergence of the industry and media, there are different laws, different administrative oversight, and sometimes conflicting legislative policies depending on the delivery mechanism and media. Because of this complexity, this article focuses on content regulation of internet communications broadly defined, how it impacts providers of telecommunications, and conversely how the private actions of providers impact content regulation. We begin with a discussion of the First Amendment to the United States Constitution, as it is essential to an understanding of the limitations to federal regulation. Then, federal statutory attempts to regulate internet content are examined followed by a discussion of the applicable administrative law. The last section of the article describes how private entities have filled in the gap in the absence of government regulation by private terms of use, and in conclusion compares this approach to other regulatory mechanisms.     

Attributions, vulnerability, and psychological adjustment: The case of breast cancer.

Hypothesized that psychological adjustment would be positively associated with breast cancer victims' perceptions of invulnerability to a recurrence of cancer and that victims' causal attributions for cancer (e.g., self-blame, birth control pills, sexually demanding husband) would influence adjustment to the extent that the attributions contributed to or detracted from perceived invulnerability. A path model was developed based on the proposed association between invulnerability and adjustment, and attributions were tested for whether they directly or indirectly influenced adjustment. Responses from intensive interviews of 42 breast cancer victims (aged 23–81 yrs) who had undergone mastectomies within 2 yrs prior to being interviewed were used to test the path model. Ss were also administered the Beck Depression Inventory and another measure to assess emotional response to breast cancer at Ss' present stage of adjustment. Results support the hypothesized positive association between perceived invulnerability and adjustment and show that the relationships between specific attributions and adjustment were mediated by vulnerability beliefs. Follow-up data may be useful in ascertaining the role played by cognitions in the biological progression of cancer. (52 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Erythrocyte–Platelet Hybrid Membrane Coating for Enhanced Nanoparticle Functionalization

Cell‐membrane‐coated nanoparticles have recently been studied extensively for their biological compatibility, retention of cellular properties, and adaptability to a variety of therapeutic and imaging applications. This class of nanoparticles, which has been fabricated with a variety of cell membrane coatings, including those derived from red blood cells (RBCs), platelets, white blood cells, cancer cells, and bacteria, exhibit properties that are characteristic of the source cell. In this study, a new type of biological coating is created by fusing membrane material from two different cells, providing a facile method for further enhancing nanoparticle functionality. As a proof of concept, the development of dual‐membrane‐coated nanoparticles from the fused RBC membrane and platelet membrane is demonstrated. The resulting particles, termed RBC–platelet hybrid membrane‐coated nanoparticles ([RBC‐P]NPs), are thoroughly characterized, and it is shown that they carry properties of both source cells. Further, the [RBC‐P]NP platform exhibits long circulation and suitability for further in vivo exploration. The reported strategy opens the door for the creation of biocompatible, custom‐tailored biomimetic nanoparticles with varying hybrid functionalities, which may be used to overcome the limitations of current nanoparticle‐based therapeutic and imaging platforms.     

Factorial validity of problematic Internet use scales

There exists a number of multidimensional measurement scales for problematic Internet use (PIU) with varying factor structures. This study reviews the factor analytic techniques used to develop these measures and discusses their implications for the factorial validity, particularly discriminant validity, of these PIU scales. To further illustrate these points, we reformulate the four-factor Online Cognition Scale into a more parsimonious two-factor measure (i.e., dependency and distraction) and demonstrate its factorial validity as well as robustness across student and working adult samples. Contributions of this research are discussed.     

Hand-arm vibration syndrome (HAVS) and musculoskeletal symptoms in the neck and the upper limbs in professional drivers of terrain vehicles--a cross sectional study

This study compares the prevalence of symptoms of Hand-arm vibration syndrome (HAVS) and musculoskeletal symptoms in the neck and the upper limbs, between professional drivers of terrain vehicles and a referent group. 769 male professional drivers of forest machines, snowmobiles, snowgroomers and reindeer herders and 296 randomly selected male referents completed a questionnaire about symptoms of HAVS and musculoskeletal symptoms in the neck and the upper limbs. They also gave information about their lifetime exposure duration driving terrain vehicles and their nicotine use. Prevalence odds ratios (POR) were determined and adjusted for age and nicotine use. Results show that there is a relation between exposure to driving terrain vehicles and some of the symptoms of HAVS (POR: 1.2–6.1). Increased odds of musculoskeletal symptoms in neck, shoulders and wrists were also found (POR 1.2–6.4), and it seemed to be related to the cumulative exposure time.