Biological metal oxide composite transport layers cast from green solvents for boosting light harvesting response of organic photovoltaic cells indoors

Organic solar cells with biological metal oxide electron transport layers ETLs , consisting of a ZnO compact layer covered by a thin DNA layer, both of which deposited with green solvents water or water alcohols mixtures are presented for application under low intensity indoor lighting. Under white LED lamp 200, 400 lx , photovoltaic cells with P3HT PC70BM polymer semiconductor blends delivered an average maximum power density MPD of 8.7 amp; 956;W cm amp; 8722;2, corresponding to a power conversion efficiency, PCE, of 8.56 PCE of best cell was 8.74 . The ZnO DNA bilayer boosted efficiency by 68 and 13 in relative terms compared to cells made with DNA only and ZnO only ETLs at 400 lx. Photovoltaic cells with ZnO DNA composite ETLs based on PTB7 PC70BM blends, that absorb a broader range of the indoor lighting spectrum, delivered MPDs of 16.2 amp; 956;W cm amp; 8722;2 with an estimated average PCE of 14.3 best cell efficiency of 15.8 at 400 lx. The best efficiencies for cells fabricated on flexible plastic substrates were 11.9 at 400 lx. This is the first report in which polymer photovoltaics incorporating biological materials have shown to increment performance at these low light levels and work very efficiently under indoor artificial light illumination. The finding can be useful for the production of more bio compatible photovoltaics as well as bio sensing devices based on organic semiconductor

Capacitance spectroscopy of thin film formamidinium lead iodide based perovskite solar cells

This work concerns the interpretation of capacitance spectroscopy results in perovskite based solar cells. Based on the deep level transient spectroscopy and admittance spectroscopy results, we present arguments that the observable signals in perovskite based solar cells come from anion migration rather than being a response from deep trap energy levels. The ion migration parameters, such as activation energy and ion concentration, are calculated and compared to theoretical values for different migration paths of ions in perovskites. Those parameters evolve with time, reflecting in the degradation of the cells, which we propose to link with a change in the anion migration path in perovskit

Changing Attitudes towards Hepatitis B among Asian Americans: From Saving Face to Getting Serious

Background: Asian Americans have the highest prevalence of hepatitis B virus (HBV) in the US. The San Francisco Hep B Free (SFHBF) campaign aimed to increase awareness and access to HBV education and services among Asian Americans in San Francisco. Purpose: We sought to examine attitudes and knowledge among Asian Americans regarding HBV at baseline (2009) and benefits of the SFHBF outreach campaign four years later (2013). Methods: Four focus groups were conducted (n=45) in 2009, followed by in-depth interviews (n=40) in 2013. Results: In 2009, many participants were misinformed about HBV symptoms and transmission. They also reported stigma associated with HBV, which hindered Asian Americans from discussing the disease and seeking services. The 2013 interviews revealed that SFHBF had contributed towards awareness of HBV screenings and vaccinations, and also instilled acute seriousness that HBV could affect them directly. Conclusion: The in-depth interviews conducted in 2013 illustrated that there was less concern about “saving face,” but a shift to a level of seriousness associated with HBV. Future efforts among Asian Americans should continue to focus on self-efficacy regarding HBV prevention, including screening and vaccination

Performance of edible cactus (Opuntiaficus-indica) in saline environments

Edible cactus [Opuntiaficus-indica (L.) Mill.] has been used as fruit, vegetable, forage and wide range of commercial purposes in arid regions. It has high efficiency to produce biomass per unit water use due to specialized photosynthetic mechanism. Owing to its tolerance to low input and adverse conditions, it has ample scope for introduction and cultivation in arid and saline parts of world. A field experiment was conducted to standardise planting techniques and irrigation requirements of cactus at Hisar (Haryana) during 2008-2010. Cactus clones 1270, 1271, 1280 and 1287 were planted on ridges, flat beds and furrows with no irrigation, irrigations at one month and two months interval using saline ground water. Raised bed plantations resulted in better survival and plant height. The survival was higher without irrigation but the plant height was higher with monthly irrigation. Clone 1270 sprouted earliest and highest survival was recorded in clone 1271. To assess salinity and alkalinity tolerance, clone 1280, was planted at Karnal. Three soil salinity (ECe) levels and four pH levels were maintained along with no fertilizer, NPK and FYM. This clone was found to tolerate moderate salinity (52 mM) but sensitive to pH and had negligible growth at pH 9.8. Application of NPK and FYM helped in mitigating the effects of salt stress. Raised bed planting was advantageous and once established, Opuntia can sustain saline groundwater irrigation for optimum growth and production

MaMADS2 repression in banana fruits modifies hormone synthesis and signalling pathways prior to climacteric stage

Background: While the role of ethylene in fruit ripening has been widely studied, the contributions of additional plant hormones are less clear. Here we examined the interactions between the transcription factor MaMADS2-box which plays a major role in banana fruit ripening and hormonal regulation. Specifically, we used MaMADS2 repressed lines in transcriptome and hormonal analyses throughout ripening and assessed hormone and gene expression perturbations as compared to wild-type (WT) control fruit. Results: Our analyses revealed major differences in hormones levels and in expression of hormone synthesis and signaling genes mediated by MaMADS2 especially in preclimacteric pulp. Genes encoding ethylene biosynthesis enzymes had lower expression in the pulp of the repressed lines, consistent with reduced ethylene production. Generally, the expression of other hormone (auxin, gibberellins, abscisic acid, jasmonic acid and salicylic acid) response pathway genes were down regulated in the WT pulp prior to ripening, but remained high in MaMADS2 repressed lines. Hormone levels of abscisic acid were also higher, however, active gibberellin levels were lower and auxin levels were similar with MaMADS2 repression as compared to WT. Although abscisic level was higher in MaMADS2 repression, exogenous abscisic acid shortened the time to ethylene production and increased MaMADS2 mRNA accumulation in WT. Exogenous ethylene did not influence abscisic acid level. CRE - a cytokinin receptor, increased its expression during maturation in WT and was lower especially at prebreaker in the repressed line and zeatin level was lower at mature green of the repressed line in comparison to WT. Conclusions: In addition to previously reported effects of MaMADS2 on ethylene, this transcription factor also influences other plant hormones, particularly at the pre-climacteric stage. The cytokinin pathway may play a previously unanticipated role via MaMADS2 in banana ripening. Finally, abscisic acid enhances MaMADS2 expression to promote ripening, but the transcription factor in turn auto inhibits ABA synthesis and signaling. Together, these results demonstrate a complex interaction of plant hormones and banana fruit ripening mediated by MaMADS2

Stability Assessment of p i n Perovskite Photovoltaic Mini Modules Utilizing Different Top Metal Electrodes

Long term stability is one of the major challenges for p i n type perovskite solar modules PSMs . Here, we demonstrate the fabrication of fully laser patterned series interconnected p i n perovskite mini modules, in which either single Cu or Ag layers are compared with Cu Au metal bilayer top electrodes. According to the scanning electron microscopy measurements, we found that Cu or Ag top electrodes often exhibit flaking of the metal upon P3 top contact removal laser patterning. For Cu Au bilayer top electrodes, metal flaking may cause intermittent short circuits between interconnected sub cells during operation, resulting in fluctuations in the maximum power point MPP . Here, we demonstrate Cu Au metal bilayer based PSMs with an efficiency of 18.9 on an active area of 2.2 cm2 under continuous 1 sun illumination. This work highlights the importance of optimizing the top contact composition to tackle the operational stability of mini modules, and could help to improve the feasibility of large area module deployment for the commercialization of perovskite photovoltaic

Encapsulation and outdoor testing of Perovskite Solar Cells comparing industrially relevant process with a simplified lab procedure

Perovskite solar cells PSCs have shown great potential for next generation photovoltaics. One of the main barriers to their commercial use is their poor long term stability under ambient conditions and, in particular, their sensitivity to moisture and oxygen. Therefore, several encapsulation strategies are being developed in an attempt to improve the stability of PSCs in a humid environment. The lack of common testing procedures makes the comparison of encapsulation strategies challenging. In this paper, we optimized and investigated two common encapsulation strategies lamination based glass glass encapsulation for outdoor operation and commercial use COM and a simple glue based encapsulation mostly utilized for laboratory research purposes LAB . We compare both approaches and evaluate their effectiveness to impede humidity ingress under three different testing conditions on shelf storage at 21 C and 30 relative humidity RH ISOS D1 , damp heat exposure at 85 C and 85 RH ISOS D3 , and outdoor operational stability continuously monitoring device performance for 10 months under maximum power point tracking on a roof top test site in Berlin, Germany ISOS O3 . LAB encapsulation of perovskite devices consists of glue and a cover glass and can be performed at ambient temperature, in an inert environment without the need for complex equipment. This glue based encapsulation procedure allowed PSCs to retain more than 93 of their conversion efficiency after 1566 h of storage in ambient atmosphere and, therefore, is sufficient and suitable as an interim encapsulation for cell transport or short term experiments outside an inert atmosphere. However, this simple encapsulation does not pass the IEC 61215 damp heat test and hence results in a high probability of fast degradation of the cells under outdoor conditions. The COM encapsulation procedure requires the use of a vacuum laminator and the cells to be able to withstand a short period of air exposure and at least 20 min at elevated temperatures in our case, 150 C . This encapsulation method enabled the cells to pass the IEC 61215 damp heat test and even to retain over 95 of their initial efficiency after 1566 h in a damp heat chamber. Above all, passing the damp heat test for COM encapsulated devices translates to devices fully retaining their initial efficiency for the full duration of the outdoor test gt;10 months . To the best of the authors knowledge, this is one of the longest outdoor stability demonstrations for PSCs published to date. We stress that both encapsulation approaches described in this work are useful for the scientific community as they fulfill different purposes the COM for the realization of prototypes for long term real condition validation and, ultimately, commercialization of perovskite solar cells and the LAB procedure to enable testing and carrying out experiments on perovskite solar cells under noninert condition

PCR and Omics Based Techniques to Study the Diversity, Ecology and Biology of Anaerobic Fungi:Insights, Challenges, and Opportunities

Anaerobic fungi (phylum Neocallimastigomycota) are common inhabitants of the digestive tract of mammalian herbivores, and in the rumen, can account for up to 20% of the microbial biomass. Anaerobic fungi play a primary role in the degradation of lignocellulosic plant material. They also have a syntrophic interaction with methanogenic archaea, which increases their fiber degradation activity. To date, nine anaerobic fungal genera have been described, with further novel taxonomic groupings known to exist based on culture-independent molecular surveys. However, the true extent of their diversity may be even more extensively underestimated as anaerobic fungi continue being discovered in yet unexplored gut and non-gut environments. Additionally many studies are now known to have used primers that provide incomplete coverage of the Neocallimastigomycota. For ecological studies the internal transcribed spacer 1 region (ITS1) has been the taxonomic marker of choice, but due to various limitations the large subunit rRNA (LSU) is now being increasingly used. How the continued expansion of our knowledge regarding anaerobic fungal diversity will impact on our understanding of their biology and ecological role remains unclear; particularly as it is becoming apparent that anaerobic fungi display niche differentiation. As a consequence, there is a need to move beyond the broad generalization of anaerobic fungi as fiber-degraders, and explore the fundamental differences that underpin their ability to exist in distinct ecological niches. Application of genomics, transcriptomics, proteomics and metabolomics to their study in pure/mixed cultures and environmental samples will be invaluable in this process. To date the genomes and transcriptomes of several characterized anaerobic fungal isolates have been successfully generated. In contrast, the application of proteomics and metabolomics to anaerobic fungal analysis is still in its infancy. A central problem for all analyses, however, is the limited functional annotation of anaerobic fungal sequence data. There is therefore an urgent need to expand information held within publicly available reference databases. Once this challenge is overcome, along with improved sample collection and extraction, the application of these techniques will be key in furthering our understanding of the ecological role and impact of anaerobic fungi in the wide range of environments they inhabit