Nitrogen Effect on Growth-Related Parameters and Evaluation of Portulaca oleracea as a Phytoremediation Species in a Cr(VI)-Spiked Soil

In a pot experiment, we assessed the potential of purslane (Portulaca oleracea) as a phytoremediation species in Cr(VI)-contaminated soils. We focused on the evaluation of phytotoxic Cr(VI) effects at concentrations reaching 150 mg Cr(VI) kg−1 and the possible stress amelioration effect of nitrogen on Cr(VI)-stressed plants. Treatments were T-0 (control), T-1 (25 mg Cr(VI) kg−1), T-2 = 50 mg kg−1, T-3 = 100 mg kg−1, and T-4 = 150 mg kg−1. We measured Cr(VI) concentration in aerial and root tissues, a series of parameters related to photosynthesis and plant growth, phosphorus aerial plant tissue content, and we also calculated indices (ratios) related to leaf growth and above ground tissue water content. Cr(VI) almost exclusively was found in root tissues; all physiological and growth parameters studied were severely affected and plants selectively accumulated phosphorus in aerial plant tissues with increasing Cr(VI) soil concentrations. On the other hand, N amendment resulted in improved plant features in some of the measured parameters: chlorophyll index was improved with added N at T-2, plant height was significantly higher at T-0, T-1, and T-2, and aerial dry weight and leaf area was higher at T-0; these effects indicate that added N did increase P. oleracea potential to ameliorate Cr(VI) toxic effects. We conclude that purslane showed a potential as a possible species to be successfully introduced to Cr(VI)-laden soils, but more research is certainly necessary.

Protection of Zr Alloy under High-Temperature Air Oxidation: A Multilayer Coating Approach

Metallic Cr and multilayer CrN/Cr coatings with a thickness of 2.5 µm were deposited onto E110 alloy by magnetron sputtering. Oxidation tests in air were performed at 1100 °C for 10–40 min. The gravimetric measurements showed better protective properties of multilayer CrN/Cr coatings in comparison with metallic Cr coating. Multilayer coating prevented fast Cr–Zr inter-diffusion by the formation of a ZrN layer beneath the coating. The appearance of ZrN is caused by interaction with nitrogen formed from the decomposition of CrN to Cr2N phases. Optical microscopy revealed a residual Cr layer for the multilayer CrN (0.25 µm)/Cr (0.25 µm) coating for all the oxidation periods. Additional in situ X-ray diffraction (XRD) studies of coated alloy during linear heating up to 1400 °C showed that the formation of the Cr2Zr phase in the case of multilayer coatings occurred at a higher (~150 °C) temperature compared to metallic Cr. Multilayer coatings can decrease the nitrogen effect for Zr alloy oxidation. Uniform and thinner oxide layers of Zr alloy were observed when the multilayer coatings were applied. The highest oxidation resistance belonged to the CrN/Cr coating with a multilayer step of 0.25 µm.

Nitrogen effect on the growth and yield contributing characters of Binadhan-19

The experiment was conducted at the BINA sub-station, Rahmatpur, Barishal, during the period from April 2020 to August 2020 to investigate the effect of nitrogen on the yield of transplant Aus rice cv. Binadhan-19. The experiment comprised four levels of nitrogen viz (a) N0 (zero nitrogen), (b) N1 (90 kg N/ha), (c) N2 (110 kg N/ha) and (d) N3 (130 kg N/ha). Nitrogen fertilizer was applied at two splits. The experiment was laid out in a randomized complete block design with three replications. Results revealed that plant height, effective tiller, non-effective tiller, flag leaf length, filled gran, unfilled grain and 1000 grain weight were increased with increasing nitrogen doses till 110 kg N ha-1. Furthermore, the highest grain weight was recorded in 110 kg N ha-1 due to superior performance of yield contributing characters of BInadhan-19. A positive correlation was found between grain yield and total dry matter production. The experimental results concluded that 110 kg N ha-1 would be the best dose for higher gain yield in Binadhan-19 in aus season.

Quantifying the nitrogen effect on CO2 capture using isoporous network polymers

The impact of nitrogen atoms on CO2 binding was evaluated for two isostructural porous bisimidazole-linked polymers (BILPs), which serendipitously had identical surface areas and pore size distributions, a very rare observation.