First Report on Post-harvest management of black mold of onion by eugenol

Black mold of onion caused by Aspergillus niger is a serious and prevalent postharvest disease of onion. This problem drastically reduces the quality and marketability of onion bulbs. Conventional fungicides employed to con-trol A. niger contamination posed negative impact on human health and en-vironment and highlighted the need to discover ecofriendly management practices. In the present study we attempted to explore the use of eugenol for the management of black mold of onion. Eugenol may exhibit differ-ences in antifungal activity in liquid state and in volatile phase. Hence, we developed and validated a new method, conical flask- paper cone method to study the antifungal activity of vapour phase disinfectants. This method was found to be precise, reproducible, sensitive and accurate with inter-assay R.S.D < 10%, intra-assay R.S.D <5% and R2>0.99. Conical flask- paper cone method was further utilized to determine the minimum inhibitory concen-tration of eugenol against A. niger. We observed that 0.03355 μl / cm3 eu-genol caused invitro and invivo inhibition of A. niger. Onion bulbs that were stored by eugenol fumigation, prior inoculated by A. niger, did not develop black mold symptoms and maintained high sensory acceptability. Microscop-ic observations revealed that eugenol fumigation resulted in inhibition of spore germination, coagulation of cytoplasm, formation of large vesicles and shrinkage of A. niger mycelium. In conclusion, our study showed for the first time that eugenol fumigation significantly controlled black mold incidence during storage and maintained post harvest quality and sensory acceptance. This study also introduced a new method for evaluating antifungal activity of volatile compounds.

Amine-Substituent Induced Highly Selective and Rapid “Turn-on” Detection of Carcinogenic 1,4-Dioxane from Purely Aqueous and Vapour phase with Novel Post-Synthetically Modified d10-MOFs

Herein, an amine decorated Cd(II) metal-organic framework (MOF) with uninodal 6-c topology was synthesized as a suitable platform for facile post-synthetic modification (PSM). The as-synthesized parent d10-MOF (1) with free...

Stability of pyrolysis condensates during their high-temperature treatment

As part of a project dealing with the material use of waste plastics processed by pyrolysis, a method for the purification of primary pyrolysis gas at temperatures above the dew point of condensing components was proposed. In order to avoid the loss of liquid products, two procedures have been proposed to study this issue. The first procedure consists in separating the pyrolysis condensate from permanent gases and its subsequent evaporation and introduction into a high-temperature reactor where the purification takes place. The second procedure used the same equipment, but the pyrolyser was connected in series with a high temperature reactor by a heated tube. The function of the device is demonstrated on a pair of pure polymers, namely highdensity polyethylene and polypropylene. In practice, however, the device is used for testing waste plastics. The mass balance of liquid, gaseous and solid products of pyrolysis and subsequent vapour phase conduction through a high-tem-perature reactor was supplemented by data from chromatographic analysis. Experiments have shown that the separation of pyrolysis and subsequent evaporation of the condensate in an independent reactor causes the formation of an undesirable amount of fine aerosol (mist). Pyrolysis without any subsequent high-temperature step produced 85–90 % condensate. The inclusion of a separate high-temperature reactor reduced the yield of condensate to 44.5–47.5 %, at the expense of the above-mentioned mist. Its conver-sion back to liquid is difficult and makes the process inefficient for industry. In tests with the series-connected pyrolyser and the high-temperature reactor, the situation was significantly better. 68.5–73.5 % of condensate was obtained in this case. In addition to the formation of mist, the conduction of steam of condensing components through the high-temperature reactor also caused a slight change in the composition of the liquids obtained. There was a decrease in the proportion of C21–C29 hydrocarbons in products and, conversely, an increase in the concentration of C5–C15 hydrocarbons. Besides verifying a suitable approach to the high-temperature processing of pyrolysis products, the experiments showed that changing a single subparameter (in this case the separation of the two reactors) significantly altered the results of the experiments. During laboratory simulation of industrial processes, it is important not to approach simplifications, but to copy all conditions as much as possible.

Risk assessment and remediation of NAPL contaminated soil and groundwater

The presence of water-immiscible organic liquids—commonly called non-aqueous phase liquids or NAPLs—in soils and groundwater, is a worldwide environmental problem. Typical examples of NAPLs include: petroleum products, organic solvents and organic liquid waste from laboratories and industry. The molecular components of NAPLs present in soils, rocks and groundwater are readily transferred to the vapour and aqueous phases. The extent to which they do this is determined by their solubility (which is quite limited) and vapour pressure (which can be quite high). These molecular components, once dispersed in the vapour phase or dissolved in the aqueous phase, can provide a long-term source of harm to biotic receptors. The object of this lecture text is to examine how we can assess the degree of harm using quantitative risk assessment and how NAPL contaminated environments can be restored through the use of chemical, biological and physical remediation technologies. Graphical abstract

Application of geophysical and hydrogeological analyses to predict water and hydrocarbon entry to the T5 Tunnel, west Iran

The Garmsiri Project, including the 4.5 km long T5 Tunnel, is under construction in western Iran. The T5 tunnel passes through the NW-SE trending Emam Hasan Anticline (EHA), perpendicular to the fold axis. The fold is mainly composed of the marlstone and argillaceous limestone layers of Cretaceous to Miocene age, incorporating the Pabdeh-Gurpi Formation, karst limestone of the Asmari Formation, and marlstone and gypsum of the Gachsaran Formation. There was a risk of water entry into the tunnel since it was constructed below the regional groundwater table elevation. In addition the entry of hydrocarbons, in either liquid or vapour phase, to the tunnel was possible due to the presence of numerous active bitumen mines in the vicinity of the anticline. To predict the risk of water or hydrocarbon entry geological and hydrogeological analyses together with the Audio Magnetotelluric (AMT) method were applied. Based on the field works, resistivity and geological cross sections were provided along the tunnel path. Several boreholes were drilled along the tunnel route and watertable elevation, Rock Quality Designation (RQD) and permeability values were measured. To determine a broad range of features related to the anticline, 55 AMT stations were positioned along the tunnel route. Dimensionality analysis confirmed 2D dimensionality of the AMT transfer functions, which allowed to apply the 2D bimodal inversion using a non-linear conjugate gradient algorithm. Integration of the geological and hydrogeological data with the resistivity model resulted in a more detailed geological section along the tunnel, including watertable elevation and identification of highly conductive zones in which bitumen migrated. It was predicted that water entry would be observed through the Asmari Formation and also that elevated H2S concentrations would be encountered during drilling in the anomalous conductive zones. Monitoring results and field observations gained during the tunnel construction were compared by the predictions.

Separation of AlN layers from silicon substrates by KOH etching

In this work, the AlN/Si(111) epitaxial structures grown consistently by plasma assisted molecular beam epitaxy (PA MBE) and hydride vapour phase epitaxy (HVPE) methods were studied. The PA MBE AlN buffer layers were synthesized via coalescence overgrowth of self-catalyzed AlN nanocolumns on Si(111) substrates and were used as templates for further HVPE growth of thick AlN layer. It was shown that described approaches can be used to obtain AlN layers with sufficiently smooth morphology. It was found that HVPE AlN inherited crystallographic polarity of the AlN layer grown by PA MBE. It was demonstrated that the etching of such AlN/Si(111) epitaxial structures results in partial separation of the AlN epilayers from the Si(111) substrate and allows to form suspended structures. Moreover, the avoidance of surface damage and backside overetching was achieved by use thin Cr film as surface protective coating and by increasing the layer thickness accordingly.