scholarly journals Synthesis of high quality 2D carbide MXene flakes using a highly purified MAX precursor for ink applications

2021 ◽  
Author(s):  
Shi-Hyun Seok ◽  
Seungjun Choo ◽  
Jinsung Kwak ◽  
Hyejin Ju ◽  
Ju-Hyoung Han ◽  
...  

A method of pelletizing raw materials was used to tackle unwarranted variations in MXene products depending on the parent MAX phases, manufacturing techniques, and preparation parameters, enabling a direct painting process on various surfaces for ink applications.

Author(s):  
I. A. Ilina ◽  
I. A. Machneva ◽  
E. S. Bakun

  The article is devoted to the study of the chemical composition, physical and thermal-pfysical characteristics of damp apple pomaces and the identifying patterns of influence of drying temperature the functional composition and gel-forming ability of pectin. The research is aimed at obtaining initial data for the subsequent calculation of the main technological, hydro-mechanical, thermal, structural and economic characteristics of devices for drying the plant raw materials, ensuring the environmental safety and high quality of pectin-containing raw materials, the reducing heat and energy costs. As a result of the study of the thermal characteristics of apple pomaces, the critical points (temperature conductivity – 16.5 x 10-8 m2/s, thermal conductivity – 0.28 W/m K, heat capacity – 1627 j/(kg K)) at a humidity of 56 % are determined, which characterizing the transition from the extraction of weakly bound moisture to the extraction of moisture with strong bonds (colloidal, adsorption). It was found that the pomaces obtained from apples of late ripening have a higher content of solids (21-23 %), soluble pectin and protopectin (2.5-4.5 %). Dried pomaces obtained from apple varieties of late ripening contain up to 25 % pectin, which allow us to recommend them as a source of raw materials for the production of pectin. The optimum modes of preliminary washing of raw materials are offered, allowing to the remove the ballast substances as much as possible. It is established that when the drying temperature increases, the destructive processes are catalyzed: the strength of the pectin jelly and the uronide component and the degree of pectin esterification are reduced. The optimum drying temperature of damp apple pomaces is 80 0C, at which the quality of pectin extracted from the dried raw materials is maintained as much as possible. It is shown that the most effective for the pectin production is a fraction with a particle size of 3-5 mm, which allow us to extract up to 71 % of pectin from raw materials.


Physics ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 320-351
Author(s):  
Serge Nagorny

Recent progress in Cs2HfCl6 (CHC) crystal production achieved within the last five years is presented. Various aspects have been analyzed, including the chemical purity of raw materials, purification methods, optimization of the growth and thermal conditions, crystal characterization, defect structure, and internal radioactive background. Large volume, crack-free, and high quality CHC crystals with an ultimate scintillating performance were produced as a result of such extensive research and development (R & D) program. For example, the CHC crystal sample with dimensions ∅23 × 30 mm3 demonstrates energy resolution of 3.2% FWHM at 662 keV, the relative light output at the level of 30,000 ph/MeV and excellent linearity down to 20 keV. Additionally, this material exhibits excellent pulse shape discrimination ability and low internal background of less than 1 Bq/kg. Furthermore, attempts to produce a high quality CHC crystal resulted in research on this material optimization by constitution of either alkali ions (Cs to Tl), or main element (Hf to Zr), or halogen ions (Cl to Br, I, or their mixture in different ratio), as well as doping with various active ions (Te4+, Ce3+, Eu3+, etc.). This leads to a range of new established scintillating materials, such as Tl2HfCl6, Tl2ZrCl6, Cs2HfCl4Br2, Cs2HfCl3Br3, Cs2ZrCl6, and Cs2HfI6. To exploit the whole potential of these compounds, detailed studies of the material’s fundamental properties, and understanding of the variety of the luminescence mechanisms are required. This will help to understand the origin of the high light yield and possible paths to further extend it. Perspectives of CHC crystals and related materials as detectors for rare nuclear processes are also discussed.


2013 ◽  
Vol 116 (1) ◽  
pp. 125-141 ◽  
Author(s):  
Manoj Dora ◽  
Dirk Van Goubergen ◽  
Maneesh Kumar ◽  
Adrienn Molnar ◽  
Xavier Gellynck

Purpose – Recent literature emphasizes the application of lean manufacturing practices to food processing industries in order to improve operational efficiency and productivity. Only a very limited number of studies have focused on the implementation of lean manufacturing practices within small and medium-sized enterprises (SMEs) operating in the food sector. The majority of these studies used the case study method and concentrated on individual lean manufacturing techniques geared towards resolving efficiency issues. This paper aims to analyze the status of the lean manufacturing practices and their benefits and barriers among European food processing SMEs. Design/methodology/approach – A structured questionnaire was developed to collect data. A total of 35 SMEs' representatives, mostly CEOs and operations managers, participated in the survey. The study investigated the role of two control variables in lean implementation: size of the company and country of origin. Findings – The findings show that lean manufacturing practice deployment in food processing SMEs is generally low and still evolving. However, some lean manufacturing practices are more prevalent than others; e.g. flow, pull and statistical process control are not widely used by the food processing SMEs, whereas total productive maintenance, employee involvement, and customer association are more widespread. The key barriers encountered by food SMEs in the implementation of lean manufacturing practices result from the special characteristics of the food sector, such as highly perishable products, complicated processing, extremely variable raw materials, recipes and unpredictable demand. In addition, lack of knowledge and resources makes it difficult for food processing SMEs to embark on the lean journey. Originality/value – The gap in the literature regarding the application of lean manufacturing in the food sector is identified and addressed in this study. The originality of this paper lies in analyzing the current status of the use of lean manufacturing practices among food SMEs in Europe and identifying potential barriers.


Archaeometry ◽  
2011 ◽  
Vol 53 (2) ◽  
pp. 364-386 ◽  
Author(s):  
ROSSELLA ARLETTI ◽  
GIOVANNA VEZZALINI ◽  
CESARE FIORI ◽  
MARIANGELA VANDINI

2013 ◽  
Vol 787 ◽  
pp. 382-387
Author(s):  
Li Zhou ◽  
Yuan Kui Ding ◽  
Pai Feng Luo

A facile low-cost non-vacuum process for fabrication of high quality CuInSe2(CIS) films is described, which indicates a promising way for the application in thin film solar cells. First, citrate-capped Cu11In9alloy nanoparticles are synthesized by hot-injection method after a system research on the different reaction time and Cu-In ratio of the raw materials. From the TEM and XRD results, we can see that uniform spherical nanoparticles with dominant Cu11In9phase and less particle-to-particle agglomeration are successfully achieved in this study. Then, employing spray and RTP selenization process, high quality CIS films with dense and big grains are obtained, which show the single chalcopyrite structure and the preferred (112) orientation. An energy band gap about 1.01 eV is measured through the absorption spectroscopy measurement in our work.


2021 ◽  
Vol 1028 ◽  
pp. 365-370
Author(s):  
Diba G Auliya ◽  
Soni Setiadji ◽  
Zulfi Mofa Agasa ◽  
Fitrilawati ◽  
Norman Syakir ◽  
...  

Polydimethylsiloxane (PDMS) has been widely used as a vitreous humour substitution in vitreoretinal surgery. Due to its limited availability and increasing domestic needs, the price of PDMS in Indonesia became very expensive. Previously, we reported the synthesized of PDMS from a high grade of monomer of 98% of Octamethylcyclotetrasiloxane (D4) and found that all PDMS samples produced high quality samples similar to that of commercial one. However, by considering the ease of obtaining raw materials and also the production costs, the synthesis of PDMS using monomer which easy to be found in Indonesia and low production costs is needed to be developed. Here, we reported the synthesis of PDMS using low grade of 96% of D4 in order to produce high quality of PDMS with low viscosity that can be used for vitreous humous substitution in vitreoretinal surgery. PDMS samples with low viscosity value of 0.94-1.35 Pa.s have been successfully synthesized from low grade of D4 and MM using ring-opening polymerization method. The yields of PDMS resulted in this research were in the range between 67.27% and 76.26%. From FTIR spectroscopy, it is found that all synthesized samples have structure and functional groups similar to PDMS using high grade of monomer of 98% Octamethylcyclotetrasiloxane (D4). From refractometer and surfgauge measurements, all samples have refractive index in the range of 1,4034-1,4040 and the value surface tension was 21 m.N/m.


2021 ◽  
pp. 88-96
Author(s):  
N. Spodyniuk ◽  
◽  
L. Horbachenko ◽  

The constant development of the country's agricultural sector allows the production of biofuels, such as fuel pellets, from agricultural waste - straw, corn and sunflower husks. However, the transportation of fuel pellets is quite energy consuming. The process of loading and unloading, transportation over long distances requires complex mechanized equipment. The use of a pneumatic conveyor for grain reloading will allow to provide high-quality transportation of fuel pellets. The aim of the article was to investigate the operation of the pneumatic conveyor for overloading fuel pellets, to determine the optimal indicators that affect the productivity of the pneumatic conveyor. Since fuel pellets, as raw materials, are structurally similar to cereals, a study of the pneumatic grain conveyor PTZ-25 was conducted. The dependence of the productivity of the pneumatic conveyor on the lifting height h, m and the length of the pipelines L, m was obtained. The obtained results showed that by reducing the length of the pipelines by four times and the lifting height by half, the productivity of the pneumatic conveyor will increase by 1.15 times. Key words: fuel pellets, pneumatic conveyor, productivity


Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 488 ◽  
Author(s):  
Shiyong Zhang ◽  
Jia Li ◽  
Qin Qin ◽  
Wei Liu ◽  
Chao Bian ◽  
...  

Naturally derived toxins from animals are good raw materials for drug development. As a representative venomous teleost, Chinese yellow catfish (Pelteobagrus fulvidraco) can provide valuable resources for studies on toxin genes. Its venom glands are located in the pectoral and dorsal fins. Although with such interesting biologic traits and great value in economy, Chinese yellow catfish is still lacking a sequenced genome. Here, we report a high-quality genome assembly of Chinese yellow catfish using a combination of next-generation Illumina and third-generation PacBio sequencing platforms. The final assembly reached 714 Mb, with a contig N50 of 970 kb and a scaffold N50 of 3.65 Mb, respectively. We also annotated 21,562 protein-coding genes, in which 97.59% were assigned at least one functional annotation. Based on the genome sequence, we analyzed toxin genes in Chinese yellow catfish. Finally, we identified 207 toxin genes and classified them into three major groups. Interestingly, we also expanded a previously reported sex-related region (to ≈6 Mb) in the achieved genome assembly, and localized two important toxin genes within this region. In summary, we assembled a high-quality genome of Chinese yellow catfish and performed high-throughput identification of toxin genes from a genomic view. Therefore, the limited number of toxin sequences in public databases will be remarkably improved once we integrate multi-omics data from more and more sequenced species.


2015 ◽  
Vol 4 (4) ◽  
pp. 59-71
Author(s):  
Sergey Nikolaevich Korenevskiy ◽  
Andrey Sergeevich Kizilov

The article presents a brief synthesis of the results deal with the study of ceramics Maikop-novosvobodnaya community using the method of a. a. Bobrinsky and use of the microscope with 12 times magnification. it sets out ideas about raw materials, methods of construction, surface treatment. especially emphasized the problem of the use by the ancient potters of rotary devices. For the first time about such vessels were noted in the work of a. a. Bobrinsky and r. M. Munchaev in 1966, for example, vessels with a flat bottom. at present a series of examples of traces deal with use of rotary devices has expanded. in the article by a. s. Kizilov shows the simulation of the vessel of the Maikop culture and fixation of the traces of its turn without a fixed axis of rotation and with a non-fixed environment of rotation. as a result, the actual doing of those and other traces that prove the use of Maikop potters rotary devices with a fixed axis of rotation in the manufacture of vessels not only flat, but round bottom too.


Author(s):  
В. И. Завьялов ◽  
Н. Н. Терехова

Получить полноценную характеристику производственной культуры Древней Руси невозможно без изучения роли сельского ремесла. Многофакторный анализ археометаллографических данных позволил сделать вывод о том, что сельское ремесленное производство представляло гораздо более сложное явление, чем виделось ранее. Древнерусское село не только служило поставщиком сырья в городские ремесленные центры и производило простую в технологическом отношении продукцию, но и воспринимало технологические инновации. Сельские мастера сами могли производить качественные кузнечные изделия и снабжали ими ближайшую округу. It is not possible to obtain full characteristics of the Medieval Russia production culture without examining the role of rural crafts. Multivariate analysis of archaeometallographic data made it possible to conclude that rural crafts were a much more sophisticated phenomenon than previously thought. A village in Medieval Russia not only supplied raw materials to craft centers and manufactured technologically simple products but also adopted technological innovations. Rural craftsmen were able to produce high-quality blacksmith products and supplied them to the nearby population.


Sign in / Sign up

Export Citation Format

Share Document