scholarly journals Modern high-resistance alloy steel used in railway transport

2017 ◽  
Vol 171 (4) ◽  
pp. 250-254
Author(s):  
Włodzimierz STAWECKI ◽  
Maciej BAJERLEIN ◽  
Paweł DASZKIEWICZ

The article presents an overview of modern steel used in rail transport. Directions for the development of materials, technologies and constructions used in the manufacture of rail vehicles are, on the one hand, determined by the technical and economic requirements of industry and, on the other, by the continued emphasis of environmentalists on reducing fuel consumption and CO2 emissions. This generates innovation in the use of modern materials, processing methods and new design solutions and results in reduced vehicle weight. More bold forecasts today show that at the current pace of technology development, in the near future the mass of the vehicle will reduce by an average of 30%. Observing the trends and pace of rail transport development, it can be predicted that existing restrictions on the use of modern materials, such as high prices, technological conditions and difficult automation of large-scale production, can be predicted.

2015 ◽  
Vol 719-720 ◽  
pp. 123-126
Author(s):  
Jin Sun ◽  
Qing Zhong Xue ◽  
Yong Gang Du ◽  
Fu Jun Xia ◽  
Qi Kai Guo

Porous graphene is a collection of graphene-related materials which exhibits properties distinct from those of graphene, and it has widespread potential applications in various fields. Several approaches have been developed to produce porous graphene. However, the large-scale production of porous graphene nanosheets still remains a great challenge. Moreover, the costs of some methods are prohibitive for its commercial production and the processes are too complicated and time-consuming. In this work, we propose a simple and green method by which graphene nanosheets can be etched by sodium hydroxide under autogenous pressure at 180 °C. The morphologies and surface elements of the porous graphene nanosheets and sizes of pores were characterized. It is demonstrated that the one-step etching of graphene nanosheets is an effective method to obtain large-scale porous graphene nanosheets with high and uniform porosity. The pores in the porous graphene nanosheets were 6 nm depth (the same as the thickness of the graphene nanosheets) and 30-50 nm width.


Africa ◽  
1943 ◽  
Vol 14 (4) ◽  
pp. 170-176 ◽  
Author(s):  
Theresa Cahan

Opening ParagraphThere is a tendency in some quarters to regard secondary industries as a panacea for all the economic ills of tropical Africa. It would be well at this initial stage to sound a note of warning. In the past, the industrialization of agricultural countries has had two results: one good, one bad. On the one hand, the establishment in a country of labour-saving machinery and large-scale production in place of the old laborious method of making things by hand has led to a rise in the general standard of living within the country in terms of real incomes. On the other hand, the drift of workers to the towns and the herding together of large numbers of people in factories resulted in the sum of social evils associated with the ‘dark satanic mills’: overcrowding, sweated labour, destitution, unemployment, and many more. The problem for tropical Africa to-day is to combine the maximum of the first and good effect with a minimum of the second evil.


2020 ◽  
Vol 28 (1) ◽  
pp. 15-29
Author(s):  
Patrícia Fernandes ◽  
Andreia Amaral ◽  
Belén Colavolpe ◽  
Daniela Balonas ◽  
Maria Serra ◽  
...  

Nowadays there is a great demand for chestnut rootstocks with improved resistance to Phytophthora cinnamomi, the causing agent of ink disease/root rot. The majority of genotypes that are being commercialized and used in the new plantations, were selected from the breeding programs of the XX century. The climate scenarios have been changing throughout the years, therefore the selection of new genotypes, better adapted to the current conditions of soil and climate, together with an effective and expedite production system, are essential to fulfill the needs of the market on better propagation materials. The INIAV’s chestnut breeding program, established in 2006, aims the improvement of resistance of chestnut to biotic stresses. By taking advantage of micropropagation, this program developed a pipeline to produce new hybrid varieties with improved resistance to P. cinnamomi. Micropropagation helps to overcome the recalcitrance that chestnut tissues present to traditional clonal propagation techniques. This work describes the pipeline of production of these hybrids and characterizes the plants from in vitro to ex vitro conditions. The pipeline allows the development of healthy plants capable of robust and continuous growth in ex vitro conditions. Nowadays these hybrids are being multiplied in a large scale production system, to be released to the market in the near future.


2017 ◽  
Vol 171 (4) ◽  
pp. 145-149
Author(s):  
Włodzimierz STAWECKI ◽  
Jerzy MERKISZ ◽  
Maciej BAJERLEIN ◽  
Pawel DASZKIEWICZ

The article presents an overview of modern plastics for use in rail vehicles. The analysis of plastics and composites in the constructional aspect was analyzed. The trends in the development of polymer materials, technologies and constructions used in the manufacture of vehicles, on the one hand, are determined by the technical and economic requirements of industry and, on the other, by the continued emphasis on reducing fuel consumption and CO2 emissions. Further development will be subject to pre-impregnation techniques, particularly in the form of different types of reinforcement. Full use of the advantages of reinforced polymer materials in vehicle production will only be achieved when further optimization of the resin properties and development of automation will result in the widespread use of composite components in series production. Observing the trends and pace of development, it is possible to predict that there are still restrictions on the use of polymeric materials in the transport sector, such as relatively high prices, technological constraints and the hindering automation of large-scale production. Modern construction and material solutions, in particular those using reinforced plastics, are primarily designed to reduce vehicle weight and have better noise and vibration damping properties. Rail vehicles are becoming more environmentally friendly at the time and travel comfort is higher.


2006 ◽  
Vol 78 (9) ◽  
pp. 1703-1713 ◽  
Author(s):  
Morinobu Endo ◽  
Takuya Hayashi ◽  
Yoong-Ahm Kim

Carbon nanotubes consisting of a rolled graphene layer built from sp2 units have attracted the imagination of scientists as 1D macromolecules. Here, we will describe the recent progress on selective synthesis of various carbon nanotubes through the judicious control of synthetic conditions and their practical applications of these carbon nanotubes in the fields of electrochemical systems, nanocomposites, and medical devices. It is envisaged that carbon nanotubes will play an important role in the development of nanotechnology in the near future.


2021 ◽  
Author(s):  
Dimitra Makarouni ◽  
Christos Kordulis ◽  
Vassilis Dourtoglou

AbstractApplication of a novel “zeolite catalyst–solvent” system for the sustainable one-step synthesis of the terpenoid manoyl oxide, the potential precursor of forskolin and ambrox. Manoyl oxide high-yield and large-scale production over a zeolite catalyst has been infeasible so far, while this system results in 90% yields at 135 °C and atmospheric pressure. Substrate-controlled methodology is used to achieve selectivity. Solvent-driven catalysis is shown, as the activation energy barrier decreases in the presence of appropriate solvents, being 62.7 and 93.46 kJmol−1 for a glyme-type solvent and dodecane, respectively. Finally, catalyst acidity is key parameter for the process. Graphic Abstract


1993 ◽  
Vol 32 (1) ◽  
pp. 129-131
Author(s):  
Naureen Talha

The literature on female labour in Third World countries has become quite extensive. India, being comparatively more advanced industrially, and in view of its size and population, presents a pictures of multiplicity of problems which face the female labour market. However, the author has also included Mexico in this analytical study. It is interesting to see the characteristics of developing industrialisation in two different societies: the Indian society, which is conservative, and the Mexican society, which is progressive. In the first chapter of the book, the author explains that he is not concerned with the process of industrialisation and female labour employed at different levels of work, but that he is interested in forms of production and women's employment in large-scale production, petty commodity production, marginal small production, and self-employment in the informal sector. It is only by analysis of these forms that the picture of females having a lower status is understood in its social and political setting.


2018 ◽  
Vol 15 (4) ◽  
pp. 572-575 ◽  
Author(s):  
Ponnusamy Kannan ◽  
Samuel I.D. Presley ◽  
Pallikondaperumal Shanmugasundaram ◽  
Nagapillai Prakash ◽  
Deivanayagam Easwaramoorthy

Aim and Objective: Itopride is a prokinetic agent used for treating conditions like non-ulcer dyspepsia. Itopride is administered as its hydrochloride salt. Trimethobenzamide is used for treating nausea and vomiting and administered as its hydrochloride salt. The aim is to develop a novel and environmental friendly method for large-scale production of itopride and trimethobenzamide. Materials and Methods: Itopride and trimethobenzamide can be prepared from a common intermediate 4- (dimethylaminoethoxy) benzyl amine. The intermediate is prepared from one pot synthesis using Phyrdroxybenzaldehye and zinc dust and further reaction of the intermediate with substituted methoxy benzoic acid along with boric acid and PEG gives itopride and trimethobenzamide. Results: The intermediate 4-(dimethylaminoethoxy) benzylamine is prepared by treating p-hydroxybenzaldehyde and 2-dimethylaminoethyl chloride. The aldehyde formed is treated with hydroxylamine hydrochloride. The intermediate is confirmed by NMR and the purity is analysed by HPLC. Conclusion: Both itopride and trimethobenzamide were successfully synthesized by this method. The developed method is environmental friendly, economical for large-scale production with good yield and purity.


Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 241
Author(s):  
Shaden A. M. Khalifa ◽  
Eslam S. Shedid ◽  
Essa M. Saied ◽  
Amir Reza Jassbi ◽  
Fatemeh H. Jamebozorgi ◽  
...  

Cyanobacteria are photosynthetic prokaryotic organisms which represent a significant source of novel, bioactive, secondary metabolites, and they are also considered an abundant source of bioactive compounds/drugs, such as dolastatin, cryptophycin 1, curacin toyocamycin, phytoalexin, cyanovirin-N and phycocyanin. Some of these compounds have displayed promising results in successful Phase I, II, III and IV clinical trials. Additionally, the cyanobacterial compounds applied to medical research have demonstrated an exciting future with great potential to be developed into new medicines. Most of these compounds have exhibited strong pharmacological activities, including neurotoxicity, cytotoxicity and antiviral activity against HCMV, HSV-1, HHV-6 and HIV-1, so these metabolites could be promising candidates for COVID-19 treatment. Therefore, the effective large-scale production of natural marine products through synthesis is important for resolving the existing issues associated with chemical isolation, including small yields, and may be necessary to better investigate their biological activities. Herein, we highlight the total synthesized and stereochemical determinations of the cyanobacterial bioactive compounds. Furthermore, this review primarily focuses on the biotechnological applications of cyanobacteria, including applications as cosmetics, food supplements, and the nanobiotechnological applications of cyanobacterial bioactive compounds in potential medicinal applications for various human diseases are discussed.


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