scholarly journals Research of the biostability of organic bases of paints for wood

2021 ◽  
pp. 11-18
Author(s):  
Sergii Guzii ◽  
Ihar Bazhelka ◽  
Anastasiya Kanavalava
Keyword(s):  
Aspergillus Niger ◽  
Epoxy Resin ◽  
Organic Film ◽  
Minimum Level ◽  
Time Intervals ◽  
Mycelium Growth ◽  
Organic Bases ◽  
Subsequent Time ◽  
Film Forming ◽  
Lesion Level

The biostability of organic film-formers of paints and varnishes intended for staining wood to the action of the fungus Aspergillus niger was studied. It was found that in Sabouraud's environment on days 7, 14 and 21 from the beginning of infection, the epoxy hardener is characterized by the minimum level of damage, respectively, 1, 1.6 and 2.4 points; alkyd film former has 2 points, and in subsequent time intervals 3.7 points; epoxy resin on day 7 is characterized by a lesion level of 1.7 points, on the following days of exposure – 4 points; pentaphthalic film former, respectively, 2.7, 3.7 and 4 points. According to the degree of resistance in the Sabouraud environment, organic film-formers of wood paints can be ranked as follows: epoxy (hardener)>alkyd>epoxy resin>pentaphthalic>organosilicon. It is shown that in the environment of Czapek on 7, 14 and 21 days from the beginning of infection, the minimum level of damage is characterized by an epoxy hardener, respectively, 2, 2.3 and 3 points; pentaphthalic film former, respectively, 2 and 3 points; alkyd film former, respectively, 2.4, 3.7 and 4 points; epoxy resin on day 7 is characterized by a lesion level of 3 points, on the following days of exposure – 4 points. According to the degree of resistance in the environment of Czapek, organic film-forming agents for wood paints can be ranked as follows: epoxy (hardener)>pentaphthalic>alkyd>epoxy resin>organosilicon. Organosilicon film-formers were most intensively affected by the fungus both 7 days after exposure and at a later time, reaching the maximum values of the lesions – 4 points. During the test period, no zones of mycelium growth inhibition were observed in the studied organic bases

New surface treatment techniques to minimize copper alloy leaching in drinking water

2012 ◽  
Vol 7 (4) ◽  
Author(s):  
Norikazu Sugaya
Keyword(s):  
Surface Treatment ◽  
Raw Materials ◽  
Organic Film ◽  
Forming Process ◽  
Mixed Acid ◽  
Treatment Techniques ◽  
Acid Washing ◽  
Washing Process ◽  
Film Forming ◽  
Materials Used

This new surface treatment is simple and easy as well as low in cost. The processes can even be performed by hand. Pharmaceutical raw materials used for the surface treatment, such as hydrochloric acid and nitric acid used in a mixed acid washing process and vegetable oil used in an organic film forming process, are easily obtained in many countries.

scholarly journals Usefulness of Imaging Response Assessment after Irreversible Electroporation of Localized Pancreatic Cancer—Results from a Prospective Cohort

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2862
Author(s):  
Rasmus V. Flak ◽  
Rune V. Fisker ◽  
Niels H. Bruun ◽  
Mogens T. Stender ◽  
Ole Thorlacius-Ussing ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Irreversible Electroporation ◽  
Response Assessment ◽  
Time Intervals ◽  
Patient Level ◽  
Positron Emission ◽  
Included Patient ◽  
Before And After ◽  
Lesion Level ◽  
Level Analysis

(1) Background: Irreversible electroporation (IRE) is a nonthermal ablation technique that is being studied in nonmetastatic pancreatic cancer (PC). Most published studies use imaging outcomes as an efficacy endpoint, but imaging interpretation can be difficult and has yet to be correlated with survival. The aim of this study was to examine the correlation of imaging endpoints with survival in a cohort of IRE-treated PC patients. (2) Methods: Several imaging endpoints were examined before and after IRE on 18F-fluorodeoxyglucose positron emission tomography (PET) with computed tomography. Separate analyses were performed at the patient and lesion levels. Mortality rate (MR) ratios for imaging endpoints after IRE were estimated. (3) Results: Forty-one patients were included. Patient-level analysis revealed that progressive disease (PD), as defined by RECIST 1.1, is correlated with a higher MR at all time intervals, but PD, as defined by EORTC PET response criteria, is only correlated with the MR in the longest interval. No correlation was found between PD, as defined by RECIST, and the MR in the lesion-level analysis. (4) Conclusions: Patient-level PD, as defined by RECIST, was correlated with poorer survival after IRE ablation, whereas no correlations were observed in the lesion-level analyses. Several promising lesion-level outcomes were identified.

Effects of Accelerated Aging Period of Time at 180°C on Tensile Property of Plain Woven Fabric/Epoxy Resin Laminated Composites

2012 ◽  
Vol 182-183 ◽  
pp. 76-79 ◽  
Author(s):  
Lei Lei Song ◽  
Quan Rong Liu ◽  
Jia Lu Li
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Epoxy Resin ◽  
Laminated Composites ◽  
Accelerated Aging ◽  
Woven Fabric ◽  
Accelerated Ageing ◽  
Time Intervals ◽  
Composite Samples

In this paper, carbon fiber reinforced resin matrix composites were produced by stacking eight pieces of carbon fiber woven plain fabric and subjected to accelerated ageing. Accelerated ageing was carried out in oven at 180°C for three different time intervals (60 hours, 120 hours and 180 hours). The influence of different ageing time intervals at 180°C on tensile properties of laminated composites was examined, compared with the composites without aging. The appearance and damage forms of these laminated composites were investigated. The results revealed that the tensile strength of the laminates declined significantly after long term accelerated aging at 180°C. The average tensile strengths of composite samples aged 60 hours, 120 hours, and 180 hours period of time at 180°C are 80.36%, 79.82%, 76.57% of average tensile strength of composite samples without aging, respectively. The high temperature accelerated aging makes the resin macromolecular structure in the composites changed, and then the adhesive force between fiber bundles and resin declines rapidly which result in the tensile strength of composites aged decrease. This research provides a useful reference for long term durability of laminated/epoxy resin composites.

On a Certain Class of Expanding Systems

2010 ◽  
Vol 17 (2) ◽  
pp. 299-306
Author(s):  
Adam Żuchowski
Keyword(s):  
Transfer Function ◽  
Input Signal ◽  
Initial Conditions ◽  
System Optimization ◽  
Gain Coefficient ◽  
Time Intervals ◽  
System Parameters ◽  
Linear Dynamic ◽  
Subsequent Time ◽  
Input Signals

On a Certain Class of Expanding Systems The interesting properties of a class of expanding systems are discussed. The operation of the considered systems can be described as follows: the input signal is processed by a linear dynamic converter in subsequent time intervals, each of them is equal to Ti. Processing starts at the moments n · Ti, always after zeroing of converter initial conditions. For smooth input signals and a given transfer function of the converter one can suitably choose Ti and the gain coefficient in order to realize the postulated linear operations on input signals, which is quite different comparing it to the operation realized by the converter. The errors of postulated operations are mainly caused by non-smooth components of the input signal. The principles for choice of system parameters and rules for system optimization are presented in the paper. The referring examples are attached too.

scholarly journals Resistance of Aspergillus niger Tiegh. to the effect of amide anesthetics

2021 ◽  
Vol 10 (1) ◽  
pp. 86-91
Author(s):  
Vadim Aleksandrovich Isaichkin ◽  
Ekaterina Sergeevna Selezneva ◽  
Evgeniy Sergeevich Korchikov
Keyword(s):  
Aspergillus Niger ◽  
Adaptive Response ◽  
Genetic Information ◽  
Low Dose ◽  
Wide Distribution ◽  
High Dose ◽  
Mycelium Growth ◽  
Direct Exposure ◽  
Anesthetic Solution ◽  
Series Of Experiments

The wide distribution of Aspergillus in nature is determined by their ability to adapt in the conditions of development of anthropogenic biocoenoses. Micromycetes survive due to rapid growth, intensive reproduction and labile metabolism, causing various kinds of damage to the substrates on which they were due to certain circumstances. However, it is noted that in the process of adaptation, many Aspergillus change physiologically, i.e. without changing the genetic information and heredity of this organism. These features of Aspergillus make them indispensable in model experiments allowing to assess the effects of xenobiotics even in micro doses and the ability to adapt to them. In this regard, it is interesting to investigate anesthetics widely used in surgery. Some of them have shown antibacterial activity, but their antifungal activity remains unknown. The authors investigated the ability of Aspergillus niger Tiegh. to adapt to the effects of certain amide anesthetics: lidocaine, ropivacaine and bupivacaine. Two series of experiments were carried out. In the first one the effect of anesthetics was investigated at concentrations of 0,001; 0,01 and 0,1 mg/ml per growth, number of colonies and sizes of spores and conidiophores; in the second one A. niger Tiegh. spores from a culture grown in a environment containing an anesthetic solution at a concentration of 0,001 mg/ml were germinated on nutrient medium with anesthetics at a concentration of 1 mg/ml. It was discovered that anesthetics affect differently the germination of spores and the formation of colonies of A. niger Tiegh. The maximum toxicity was shown by ropivacaine, significantly reducing the number of colonies, the minimum by bupivacaine. It was discovered that ropivacaine and bupivacaine inhibit mycelium growth more than lidocaine. All investigated anesthetics at selected concentrations do not affect reliably the size of spores and conidiophores. The study of preadaptation caused by a low dose of anesthetics showed that the number of colonies in preadapted cultures after exposure at a high dose of 1 mg/ml significantly increased compared to direct exposure at a dose of 1 mg/ml. It can be argued that the observed changes in the number of colonies are an adaptive response of A. niger Tiegh. to the action of anesthetics. The diameter of colonies after preadaptation was significantly less than with direct exposure at a dose of 1 mg/ml (p 0,05), that is we observe the effect of cumulation. Possible mechanisms of the observed effect, including hormesis, are discussed.

Effect of Different Carbon Materials on the Conductivity of Epoxy Resin Conductive Coatings

2021 ◽  
Vol 1020 ◽  
pp. 164-169
Author(s):  
Guang Zhao Li ◽  
La Jun Feng ◽  
Zhe Zhai ◽  
Fang Fang Wang
Keyword(s):  
Epoxy Resin ◽  
Electrostatic Force ◽  
Theory Model ◽  
Epoxy Coating ◽  
Conductive Coatings ◽  
Conductive Coating ◽  
Multi Walled Carbon Nanotube ◽  
Film Forming ◽  
Conductive Mechanism ◽  
Conductive Particles

In this work, the conductive coating was prepared by electrostatic spraying with graphene and Multi-walled carbon nanotube (MWCNTs) as conductive medium and epoxy resin powder as film-forming material, in order to solve the pro·blem of high content and uneven dispersity of conductive particles in conductive coatings prepared by brushing method. The resistance of the coating was measured by four probe method, the dispersity of conductive particles in the coating was analyzed by scanning electron microscope (SEM), and the conductive mechanism of the coating was analyzed by percolation theory model. The results show that the conductive particles can be dispersed evenly in the whole coating by electrostatic force. Meanwhile, the electrostatic force can also stretch the conductive particles in the coating along the direction of the thickness of that. The flake graphene is vertically arranged in the coating, and the curled MWCNTs forms the conductive network of "island-bridge" structure. The conductive particles laped each other to form a conductive path, which greatly reduced the content of conductive particles. The seepage threshold of graphene conductive coating was only 1.5 wt.%, which lower than that of the MWCNTs conductive coating, which is 3 wt.%. The resistance of epoxy coating containing with 0.5 wt.% graphene is 3397 Ω·m, and that of epoxy coating containing with 0.5 wt.% MWCNTs is 1049 Ω·m.

scholarly journals Dynamic Ochratoxin A Production by Strains of Aspergillus niger Intended Used in Food Industry of China

Toxins ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 122
Author(s):  
Xiaomin Han ◽  
Hongru Jiang ◽  
Fengqin Li
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Wheat Bran ◽  
High Performance ◽  
Food Industry ◽  
Time Intervals ◽  
Culture Substrate ◽  
Industrial Strains

Thirty strains of Aspergillus niger, including 27 intended used in the food industry of China, were studied for their ochratoxin A (OTA) production on the three natural substrates—corn, rice, and wheat bran—at different time intervals by high-performance liquid chromatography. It was found that the frequencies of OTA for the studied 27 industrial strains ranged from 14.8% (4/27) at day 28 to 25.9% (7/27) at day 7 on corn, 14.8% (4/27) at day 7 to 33.3% (9/27) at day 21 on rice, and 22.2% (6/27) at day 7, 14, and 28 to 44.4% (12/27) at day 21 on wheat bran, respectively. The average concentrations of OTA produced by the studied 27 industrial strains ranged from 5.1 μg/kg at day 28 to 8.7 μg/kg at day 21 on corn, 4.2 μg/kg at day 7 to 17.9 μg/kg at day 14 on rice, and 4.5 μg/kg at day 7 to 7.2 μg/kg at day 21 on wheat bran, respectively. Furthermore, the OTA production in the studied 27 industrial strains of A.niger was strongly associated with their function (or application), culture substrate, and time. The saccharifying enzyme producers produced higher levels of OTA, compared with the organic acid producers, the tannase producers, and the β-galactosidase producer, while concentration differences were also observed in OTA production among strains of A.niger with the same application. In a word, some strains of A.niger intended used in the Chinese food industry indeed have the capability of producing OTA, elevating the risks to food safety associated with their use.

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