Periodica Polytechnica Chemical Engineering最新文献_第10页

Flame Protection Technologies for Wood: Developing and Testing for Fire of Timbers with a Flame-retardant Coating Based on the Epoxy-amine Composite Modified by Copper(II) Hexafluorosilicate 木材防火技术:六氟硅酸铜(II)改性环氧胺复合材料阻燃涂料的研制与木材防火性能试验

IF 1.3 4区工程技术

Periodica Polytechnica Chemical Engineering Pub Date : 2022-01-24 DOI: 10.3311/ppch.19050

B. Mykhalichko, H. Lavrenyuk

{"title":"Flame Protection Technologies for Wood: Developing and Testing for Fire of Timbers with a Flame-retardant Coating Based on the Epoxy-amine Composite Modified by Copper(II) Hexafluorosilicate","authors":"B. Mykhalichko, H. Lavrenyuk","doi":"10.3311/ppch.19050","DOIUrl":"https://doi.org/10.3311/ppch.19050","url":null,"abstract":"A new type of fire-retardant coating for wood based on epoxy-amine composites modified with copper(II) hexafluorosilicate has been developed. To optimize the composition of the fire-retardant coating, the values of ignition and self-ignition temperatures, the combustibility group indices and the smoke generation coefficient of the developed epoxy-amine composites were used. It was found that the values of the ignition and self-ignition temperatures of epoxy-amine composites containing a flame retardant are higher than those of composites without it, by 15–34 °C and 25–58 °C, respectively. Compared to unmodified epoxy-amine composites, CuSiF6-modified epoxy-amine composites have 204–327 °C lower values of the maximum temperature of combustion gases and 7.8–10.4% less mass loss during combustion. It is shown that modified epoxy-amine composites with an optimized composition are classified as hardly combustible materials with moderate smoke-forming ability. Based on the results of experimental studies, the technological mode of coating the wood was chosen. The developed epoxy-amine composite with reduced combustibility has been used as a fire-retardant coating for wooden structures. Testing for fire showed that developed coating belongs the first group of fire protection efficiency, which ensures reliable fire protection of wood. In contrast, the coatings based on epoxy-amine composites without a flame retardant do not provide fire protection of wood at all.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"52 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78138573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Effect of N,N'-Dicyclohexyl Terephthalic Dihydrazide on the Crystallization and Properties of Isotactic Polypropylene N,N'-二环己基对苯二甲酸二肼对等规聚丙烯结晶及性能的影响

IF 1.3 4区工程技术

Periodica Polytechnica Chemical Engineering Pub Date : 2022-01-24 DOI: 10.3311/ppch.19074

F. Horváth, Levente Bihari, A. Menyhárd

{"title":"Effect of N,N'-Dicyclohexyl Terephthalic Dihydrazide on the Crystallization and Properties of Isotactic Polypropylene","authors":"F. Horváth, Levente Bihari, A. Menyhárd","doi":"10.3311/ppch.19074","DOIUrl":"https://doi.org/10.3311/ppch.19074","url":null,"abstract":"Application of nucleating agents is a common way to manipulate the structure and properties of crystalline polymers. Our goal was to synthesize N,N'-dicyclohexyl terephthalic dihydrazide (DCTDH) and study it from the viewpoint of applicability as a nucleating agent for isotactic polypropylene (iPP). We used differential scanning calorimetry to investigate the efficiency of DCTDH in samples containing the nucleating agent in a wide concentration range. We used polarized light microscopy to study the crystalline morphology developed in the presence of this nucleating agent. To characterize the mechanical properties of the nucleated samples, we performed tensile and impact tests on injection molded specimens. DCTDH proved to be a non-soluble α-nucleating agent in iPP, with a saturation concentration around 300 ppm. The nucleating agent has a significant effect on the crystalline structure of iPP, microspherulitic structure forms in its presence. Owing to the different structure, a considerable change in the mechanical properties is observable: with increasing nucleating agent content the tensile modulus increases, while impact resistance has a maximum value around 300 ppm nucleating agent content.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"39 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75190279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Preparation of Veterinary Premix with Dual Active Ingredients in Granular Form 颗粒状双活性成分兽用预混料的制备

IF 1.3 4区工程技术

Periodica Polytechnica Chemical Engineering Pub Date : 2022-01-18 DOI: 10.3311/ppch.18703

Andrea Fodor-Kardos, A. Ujhidy, G. Nagy, B. Gyetvai, J. Tóth

引用次数: 0

Assessment of Water Quality in the Molnár János Cave – Budapest, Hungary Molnár János洞穴的水质评价-布达佩斯，匈牙利

IF 1.3 4区工程技术

Periodica Polytechnica Chemical Engineering Pub Date : 2022-01-05 DOI: 10.3311/ppch.18969

Mariana Menoncin, Miklós Murai, Péter Szombathy, D. Szieberth

引用次数: 0

In–Vitro Antibacterial and Antifungal Efficacy of Greenly Fabricated Senna alata Leaf Extract Silver Nanoparticles and Silver Nanoparticle-Cream Blend 绿色合成番泻叶提取物纳米银颗粒和纳米银颗粒-乳膏混合物的体外抗菌和抗真菌效果

IF 1.3 4区工程技术

Periodica Polytechnica Chemical Engineering Pub Date : 2022-01-03 DOI: 10.3311/ppch.18271

B. Adebayo-Tayo, S. Borode, S. Alao

{"title":"In–Vitro Antibacterial and Antifungal Efficacy of Greenly Fabricated Senna alata Leaf Extract Silver Nanoparticles and Silver Nanoparticle-Cream Blend","authors":"B. Adebayo-Tayo, S. Borode, S. Alao","doi":"10.3311/ppch.18271","DOIUrl":"https://doi.org/10.3311/ppch.18271","url":null,"abstract":"Nanoparticles biosynthesis has been extensively studied for its biomedical applications. In this study, the in-vitro antibacterial and antifungal activity of greenly fabricated silver nanoparticles (NPs) from Senna alata leaf extract (SaAgNPs) and silver nanoparticle cream blend (SaAgNPs-cream blend) were investigated. The SaAgNPs were characterized using UV-visible spectrophotometry, FTIR, SEM, TGA, DLS, EDX, and XRD. The presence of surface plasmon band around 500 nm indicates AgNPs formation and functional groups such as alkenes, carboxylic acids, and alkyl aryl ether responsible for capping and stabilization of the nanoparticles. The SaAgNPs were spherical and 1.00 µm in size; TGA shows the formation of stable SaAgNPs, DLS shows 1.8 % intensity with 1905 nm average diameter and a polydispersity index of 0.595. EDX analysis confirmed the formation of pure silver nanoparticles. SaAgNPs supported the production of cosmetically acceptable SaAgNPs-cream blend with appropriate pH and viscosity. SaAgNPs and the SaAgNPs cream-blends had antibacterial activity against all and some of the test bacterial and fungal isolates. SaAgNPs had the highest activity against Pseudomonas aeruginosa 27853, Rhizopus sp. and Candida tropicalis with a zone of 16 mm and 30 mm. The cream-blends had activity against 68.75 % and 75 % of the test bacteria and fungi with the highest activity against Streptococcus epidermidis B (7.0 mm) and Candida albicans B (8.0 mm). In conclusion, the crude Senna alata leaf extracts, the bio-fabrication SaAgNPs and SaAgNPs-cream blend have antibacterial antifungal potentials which can be effectively utilized for the control of pathogenic bacteria and fungi.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"350 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82589282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Testing the Fit of Regression Models Estimated with Extremely Small Samples: Application in Pharmaceutical Stability Studies 极小样本估计回归模型的拟合检验:在药物稳定性研究中的应用

IF 1.3 4区工程技术

Periodica Polytechnica Chemical Engineering Pub Date : 2022-01-03 DOI: 10.3311/ppch.18793

Máté Mihalovits, S. Kemény

{"title":"Testing the Fit of Regression Models Estimated with Extremely Small Samples: Application in Pharmaceutical Stability Studies","authors":"Máté Mihalovits, S. Kemény","doi":"10.3311/ppch.18793","DOIUrl":"https://doi.org/10.3311/ppch.18793","url":null,"abstract":"Pharmaceutical stability studies are conducted to estimate the shelf life, i.e. the period during which the drug product maintains its identity and stability. In the evaluation of process, regression curve is fitted on the data obtained during the study and the shelf life is determined using the fitted curve. The evaluation process suggested by ICH considers only the case of the true relationship between the measured attribute and time being linear. However, no method is suggested for the practitioner to decide if the linear model is appropriate for their dataset. This is a major problem, as a falsely selected model may distort the estimated shelf life to a great extent, resulting in unreliable quality control. The difficulty of model misspecification detection in stability studies is that very few observations are available. The conventional methods applied for model verification might not be appropriate or efficient due to the small sample size. In this paper, this problem is addressed and some developed methods are proposed to detect model misspecification. The methods can be applied for any process where the regression estimation is performed on independent small samples. Besides stability studies, frequently performed construction of single calibration curves for an analytical measurement is another case where the methods may be applied. It is shown that our methods are statistically appropriate and some of them have high efficiency in the detection of model misspecification when applied in simulated situations which resemble pre-approval and post-approval stability studies.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"243 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76574982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Applicability of Neural Networks for the Fermentation of Propionic Acid by Propionibacterium acidipropionici 神经网络在丙酸丙酸杆菌发酵丙酸中的适用性

IF 1.3 4区工程技术

Periodica Polytechnica Chemical Engineering Pub Date : 2021-11-23 DOI: 10.3311/ppch.18283

Aladár Vidra, Á. Németh

引用次数: 1

Improving the Performance of Microbial Fuel Cells with Modified Carbon Aerogel Based Cathode Catalysts 用改性碳气凝胶基阴极催化剂改善微生物燃料电池性能

IF 1.3 4区工程技术

Periodica Polytechnica Chemical Engineering Pub Date : 2021-11-19 DOI: 10.3311/ppch.18854

B. Lóránt, K. László, G. Tardy

{"title":"Improving the Performance of Microbial Fuel Cells with Modified Carbon Aerogel Based Cathode Catalysts","authors":"B. Lóránt, K. László, G. Tardy","doi":"10.3311/ppch.18854","DOIUrl":"https://doi.org/10.3311/ppch.18854","url":null,"abstract":"Microbial fuel cells (MFCs) are capable of converting the chemical energy of biodegradable organic matter directly into electricity, thus they can be applied in various fields: waste elimination, biosensor industry and production of renewable energy. In this study, the efficiency of noble metal free carbon aerogel based cathode catalysts was investigated and compared to plain glassy carbon cloth without catalyst (CC ) and platinum containing carbon powder catalyst ( PtC ) in H-type MFCs. Surface extension by carbon aerogel (CA ) enhanced the maximum power density by 34 % compared to CC, to 14.1 W m−3. With nitrogen doped carbon aerogel (NCA) the performance was further increased to 15.7 W m−3. Co-doping the resorcinol-melamine-formaldehyde based aerogel with graphene oxide (GNCA) resulted in an additional power increase of 70 %, indicating that the electrocatalytic activity of NCAs can be considerably improved by co-doping with graphene oxide. Although the performance of GNCA remained below that of PtC (50.2 W m−3) in our investigations, it can be concluded that GNCA based coatings may provide a noble metal free, and therefore competitive and sustainable alternatives for cathode catalysis in MFC based technologies.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"263 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79041115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Pressurized Liquid Extraction of Hemp Residue and Purification of the Extract with Liquid-Liquid Extraction 大麻渣的加压萃取及液-液萃取纯化

IF 1.3 4区工程技术

Periodica Polytechnica Chemical Engineering Pub Date : 2021-11-19 DOI: 10.3311/ppch.18456

J. Béri, Sara Nagy, Ádám Kolay Kovács, E. Vági, E. Székely

引用次数: 4

Assessment on Performance-properties of Asymmetric Nanofiltration Membranes from Polyethersulfone/n-Methyl-2-pyrrolidone/water Blends with Poly(vinyl pyrrolidone) as Additive 以聚乙烯基吡咯烷酮为添加剂的聚醚砜/n-甲基-2-吡咯烷酮/水共混物纳滤膜性能评价

IF 1.3 4区工程技术

Periodica Polytechnica Chemical Engineering Pub Date : 2021-11-11 DOI: 10.3311/ppch.18357

Sabariah Rozali, Nurul Hannan Mohd Safari, Abdul Rahman Hassan, M. Ahmad, R. Yunus

引用次数: 4