RESUMEN
Performance of solar PV diminishes with the increase in temperature of the solar modules. Therefore, to further facilitate the reduction in cost of photovoltaic energy, new approaches to limit module temperature increase in natural ambient conditions should be explored. Thus far only approaches based at the individual panel level have been investigated, while the more complex, systems approach remains unexplored. Here, we perform the first wind tunnel scaled solar farm experiments to investigate the potential for temperature reduction through system-level flow enhancement. The percentage of solar irradiance converted into electric power depends upon module efficiency, typically less than 20%. The remaining 80% of solar irradiance is converted into heat, and thus improved heat removal becomes an important factor in increasing performance. Here, We investigate the impact of module inclination on system-level flow and the convective heat transfer coefficient. Results indicate that significant changes in the convective heat transfer coefficient are possible, based on wind direction, wind speed, and module inclination. We show that 30-45% increases in convection are possible through an array-flow informed approach to layout design, leading to a potential overall power increase of ~5% and decrease of solar panel degradation by +0.3%/year. The proposed method promises to augment performance without abandoning current PV panel designs, allowing for practical adoption into the existing industry. Previous models demonstrating the sensitivity to convection are validated through the wind tunnel results, and a new conceptual framework is provided that can lead to new means of solar PV array optimization.
RESUMEN
Peptides are used as reagents both for basic research and diagnostic purposes. Therefore, there is a need for novel methods for the design of peptide molecules with a particular specific physiochemical profile. The properties of the peptides are governed by the nature of amino acids constituting the peptide. There is a lack of a web server or tools which could predict all the possible combinations of the peptides generated because of the combinations of amino acids based on the physiochemical properties. We have developed a peptide combination generator (PepCoGen), a web server for generating all the possible combinations of peptides by varying the amino acids having similar physiochemical properties at a particular position. It also predicts other properties of the peptides including molecular weight, charge, solubility, hydrophobic plot, and isoelectric point, and random three-dimensional models for each generated combination.
RESUMEN
A key challenge in nursing education is how to teach the students clinical competencies effectively and to provide opportunities for practicing the fundamental nursing skills safely. The purpose of this study was to examine the competency scores of practicing a clinical skill and the satisfaction level of nursing students on three instructional methods using an action research: the online self-paced interactive video learning, demonstration-only method, and a video demonstration in class. Participants were both male and female nursing students enrolled in the Foundations of Nursing Course (N = 26, 6 males and 20 females; mean age = 19.42 ± 0.50) and were evaluated at precycle, postcycle 1, and postcycle 2. Each cycle of inquiry was planned to address the problems quickly and efficiently through four steps: planning, acting, observing, and reflecting. A triangulation technique was employed for data collection using a competency skill evaluation checklist, a satisfaction questionnaire, and a focus group feedback questionnaire. A video was developed in the researcher's college pertaining to the practical skills. Each research cycle was successively built up on one another using the reflections and feedback from the students based on the previous cycle. The competency skills at various cycles did not demonstrate significant differences between three instructional methods, whereas satisfaction score was the highest with the online self-paced interactive video demonstration. Online video learning use as a supplement in nursing instruction is well supported and offers a promising alternative in teaching clinical skill compared with other teaching strategies. However, more rigorous studies are required to get further empirical evidence in replacing the demonstration method, for teaching nursing practical skill and in improving students' learning ability and competence.
RESUMEN
The purpose of the present study was to investigate the antimicrobial effects of functionalized polyanilines (fPANIs) against stationary phase cells and biofilms of Pseudomonas aeruginosa and Staphylococcus aureus using homopolymer of sulfanilic acid (poly-SO3H) as a model. The chemically synthesized poly-SO3H was characterized using Fourier Transform Infra-Red (FTIR) and Ultraviolet-Visible (UV-Vis) spectroscopies. The molecular weight (Mw) and elemental analysis of homopolymer poly-SO3H were also examined. We found that poly-SO3H was bactericidal against stationary phase cells of P. aeruginosa and S. aureus at a concentration of 20 mgml(-1). Surprisingly, we discovered that the same concentration (20 mgml(-1)) of poly-SO3H significantly disrupted and killed bacterial cells present in pre-established forty-eight hour static biofilms of these organisms, as shown by crystal violet and bacterial live/dead fluorescence staining assays. In support of these data, poly-SO3H extensively diminished the expression of bacterial genes related to biofilm formation in stationary phase cells of P. aeruginosa, and seemed to greatly reduce the amount of the quorum sensing molecule N-(3-oxododecanoyl)-l-homoserine lactone (3OC12-HSL) able to be recovered from biofilms of this organism. Furthermore, we found that poly-SO3H was able to effectively penetrate and kill cells in biofilms formed by the P. aeruginosa (AESIII) isolate derived from the sputum of a cystic fibrosis patient. Taken together, the results of the present study emphasise the broad antimicrobial activities of fPANI, and suggest that they could be developed further and used in some novel ways to construct medical devices and/or industrial equipment that are refractory to colonization by biofilm-forming bacteria.