DuPont (China)

Bifacial modules now represent a growing percentage of the PV module market due to their higher output power and more effective use of the available light for photovoltaic conversion. Initial adoption of double glass module constructions has raised concerns related to increased module weight and potential failure mechanisms. The introduction of transparent backsheets has provided an alternative that brings advantages including lighter weight, established manufacturing processes and established field performance. In this paper we discuss the development of a transparent backsheet based on Tedlar® polyvinylfuoride films. The long-term durability of these transparent backsheets and the stability of key backsheet properties is reviewed. The performance of these backsheet in accelerated module testing is also discussed.

With the introduction of new materials, processes and structures for PV modules, the assessment of module durability to the multiple stresses in the outdoor environment has become a critical part of new product evaluation. We have developed test methodologies which evaluate the durability of PV modules to temperature, humidity, UV from the front and back of the module, and mechanical stresses related to temperature cycles and snow/wind loads. Test sequences have been developed to reduce the overall test timing and evaluate new module structures including bifacial modules. These tests are predictive of backsheet outer layer failure, backsheet inner layer and encapsulant delamination. Total test time is reduced from 8.2 months to <5 months.

Objective:To compare the clinical efficacy and safety of oil gauze silver dressing and silver ions dressing on diabetic ulcers in elderly outpatients.Methods:Twenty-two patients with Type-2 diabetic foot ulcers were included in the study conducted at Yantai Yuhuangding Hospital between April 2013 and April 2014. At the time of enrolment they were divided into the silver ions and oil gauze silver groups based on the order of admission. Dressings were changed twice weekly until the ulcer had healed. Clinical efficacy measures were healing outcomes and speed of healing. Adverse events were recorded.Results:The silver ions and oil gauze silver groups were comparable at baseline (P>0.05). Before treatment, the fasting blood glucose (FBG) and two hour postprandial blood glucose (2h PBG) levels were 6.88±0.50 mmol /L and 15.55±2.47 mmol/L in the oil gauze silver group, and 6.93±0.41 mmol/L and 15.23±2.58 mmol/L in the silver ions group, respectively. After treatment, the FBG and 2h PBG levels were 6.82±0.32 mmol/L and 8.67±0.86 mmol/L in the oil gauze silver group, and 6.85±0.27 mmol/L and 8.83 ± 0.61 mmol/L in the silver ions group, respectively. The healing time of foot ulcers was 23.8±2.7 days in the silver ions group and 15.8±2.5 days in the oil gauze silver group (P<0.05).Conclusion:Oil gauze silver dressings for diabetic foot ulcers were associated with favorable clinical outcomes compared with silver ion dressings, especially with respect to ulcer healing speed.

Head smut, caused by the fungus Sphacelotheca reiliana (Kühn) Clint, is a devastating threat to maize production. In this study, QTL mapping of head smut resistance was performed using a recombinant inbred line (RIL) population from a cross between a resistant line “QI319” and a susceptible line “Huangzaosi” (HZS) with a genetic map constructed from genotyping-by-sequencing (GBS) data and composed of 1638 bin markers. Two head smut resistance QTL were identified, located on Chromosome 2 (q2.09HR) and Chromosome 5 (q5.03HR), q2.09HR is co-localized with a previously reported QTL for head smut resistance, and the effect of q5.03HR has been validated in backcross populations. It was also observed that pyramiding the resistant alleles of both QTL enhanced the level of resistance to head smut. A genome-wide association study (GWAS) using 277 diverse inbred lines was processed to validate the mapped QTL and to identify additional head smut resistance associations. A total of 58 associated SNPs were detected, which were distributed in 31 independent regions. SNPs with significant association to head smut resistance were detected within the q2.09HR and q5.03HR regions, confirming the linkage mapping results. It was also observed that both additive and epistastic effects determine the genetic architecture of head smut resistance in maize. As shown in this study, the combined strategy of linkage mapping and association analysis is a powerful approach in QTL dissection for disease resistance in maize.

Matching accelerated test results to field observations is an important objective in the photovoltaic industry. We continue to develop test methods to strengthen correlations. We have previously reported good correlation of FTIR spectra between accelerated tests and field measurements. The availability of portable FTIR spectrometers has made measurement in the field convenient and reliable. Recently, nano-indentation has shown promise to correlate changes in backsheet mechanical properties. A precisely shaped stylus is pressed into a sample, load vs displacement recorded and mechanical properties of interest calculated in a nondestructive test. This test can be done on full size modules, allowing area variations in mechanical properties to be recorded. Finally, we will discuss optical profilometry. In this technique a white light interferogram of a surface is Fourier transformed to produce a three-dimensional image. Height differences from 1 nm to 5 mm can be detected over an area of a few cm. This technique can be used on minimodules, and is useful to determine crack and defect dimensions. Results will be presented correlating accelerated tests with fielded modules covering spectroscopic, mechanical, and morphological changes.

Poly(trimethylene terephthalate) (PTT) which combines properties of polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), is used in everyday products such as apparel and carpet. DuPont has successfully developed a renewably sourced building block, bio‐based 1,3‐propanediol (PDO), through industrial bio‐technology using glucose as the raw material. This green technology has significantly promoted the commercialization of PTT and its development activities. In DuPont's China R&amp;D center, an industrial polymer technology platform has been established to serve the local China market with PTT manufacturing and application support. This platform explores new industrial applications for and modifications to PTT, such as expansion of the application space into engineering polymers (EP), development of fire retardancy, melt viscosity regulation for PTT fiber spinning and the use of PTT in nanocomposite preparations.

Solution based textured ZnO film significantly improves efficiency of thin film silicon solar cells due to its light trapping effect.

Abstract Polyamides are high polymers that contain the amide repeat linkage in the polymer backbone. Some common terms used with polyamides are nylon, aramid, and polyphthalamide. Nylon is defined as any polyamide having less than 85% of the amide group directly connected to two aromatic groups. Aramid is a polyamide having 85% or more of the amide groups directly connected to two aromatic groups. Polyphthalamide is a polyamide in which the residues of terephthalic acid or a combination comprise at least 55 mol% of the dicarboxylic acid portion of two repeating units in the polymer chain. This article is a general overview of polyamides, with emphasis on technology developed since 1980. There is an extensive coverage of properties including chemical reactions. Manufacturing for most of the important polyamides is discussed. Commercial polyamides incorporate three classes of additives: endcappers; branching agents; and chain couplers. Because of economic advantages and governmental regulations, there has been a substantial increase in recycling of the starting materials for polyamides and energy, most often as steam.