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901.
Forough Nasuhipur Zarrin Ghasemi Aziz Shahrisa Nasser Arsalani 《Journal of heterocyclic chemistry》2023,60(1):106-115
In this work, a one-pot three-component reaction of ninhydrin, primary amines, and 1,3-dicarbonyl compounds was investigated under various conditions to synthesis of diverse derivatives of dihydroindeno[1,2-b]pyrroles. Catalyst-free conditions in EtOH under ultrasound irradiation (45% of amplitude) were selected as a novel and efficient method for synthesis of these fused structures. The reactivity of different primary amines was then investigated for steric and electronic effects. Two examples of difunctional structures were also synthesized by using of 1,4-diaminobenzene under optimum conditions with high yields. The structure of all products was characterized by spectroscopic methods and elemental analysis. 相似文献
902.
Shahid Aziz Faheem Akhter Hidayat Hussain Jiguo Liu Huijiao Yan Li Cui Qixu Chen Wei Cheng Daijie Wang Xiao Wang 《Journal of separation science》2023,46(20):2300306
Bergenia ciliata (haw.) Sternb, the renowned pharmaceutical plant in Jammu and Kashmir of Pakistan, is widely applied in treating different illnesses including diabetes, diarrhea, and vomiting. This work employed an efficient one-step inner-recycling counter-current chromatography for preparative separating and purifying compounds with similar partition coefficients from the rhizome of Bergenia ciliate (haw.). Five compounds, including quercetin rhamnodiglucoside ( 1 ), quercetin-3-O-rutinoside ( 2 ), bergenine ( 3 ), kaempferol ( 4 ), and palmatic acid ( 5 ), were successfully separated using the optimized biphasic solvent system that contained ter-butylmetylether/n-butanol/acetonitrile/water (2:2:1:5, v/v) with the purities over 98%. Mass spectrometry and nuclear magnetic resonance were conducted for structural identification. As a result, our proposed strategy might be applied in separating compounds with similar partition coefficients, which was advantageous with regard to the less solvent and time consumption, and the increased number of theoretical plates. 相似文献
903.
Salman Khalil Umar Muhammad Modibbo Ather Aziz Rain Irfan Ali 《Journal of Nonlinear Modeling and Analysis》2023,5(2):311-324
The methods of multiple criteria decision-making (MCDM) are increasingly becoming the most desired tools for making daily decisions in various fields of human endeavors. Staff employment in any sector requires a thorough evaluation of the applicant before selection to ensure effective and efficient service delivery. Besides, healthcare is one of the most complicated organizations dealing with human lives. This paper has developed a staff selection model considering a fuzzy environment by using the technique for order preference similar to the ideal solution (TOPSIS) method. For the delivery and promotion of quality healthcare systems, medical staff selection is crucial to the system. Therefore, the study evaluates medical staff by using the expert''s linguistic judgement under the criteria of skill, experience and ability to respond to a problem. The expert''s vagueness in judgments has been represented by using fuzzy triangular numbers. The study determines the closeness coefficient, the measures of separation and the ideal solutions of the TOPSIS method. The most appropriate medical staff are ranked and selected based on the available criteria. The Fuzzy-TOPSIS method is simple and can help other organizations achieve proper ranking, evaluation and selection of qualified candidates, as it takes imprecise information into account. 相似文献
904.
905.
906.
Amin Al-Fakih Zakaria Mohamed Nor Shaik Inayath Basha M. Nasiruzzaman Shaikh Shamsad Ahmad Mohammed A. Al-Osta Md. Abdul Aziz 《Chemical record (New York, N.Y.)》2023,23(5):e202300039
The disposal of red mud (RM), a waste material generated by the aluminum industry, remains a global environmental concern because of its high alkalinity and smaller particle size, which have the potential to pollute air, soil, and water. Recently, efforts have been made to develop a strategy for reusing industrial byproducts, such as RM, and turning waste into value-added products. The use of RM as (i) a supplementary cementitious material for construction and building materials, such as cement, concrete, bricks, ceramics, and geopolymers, and (ii) a catalyst is discussed in this review. Furthermore, the physical, chemical, mineralogical, structural, and thermal properties of RM, as well as its environmental impact, are also discussed in this review. It is possible to conclude that using RM in catalysis, cement, and construction industries is the most efficient way to recycle this byproduct on a large scale. However, the low cementitious properties of RM can be attributed to a reduction in the fresh and mechanical properties of composites incorporating RM. On the other hand, RM can be used as an efficient active catalyst to synthesize organic molecules and reduce air pollution, which not only makes use of solid waste but also lowers the price of the catalyst. The review provides basic information on the characterization of RM and its suitability in various applications, paving the way for more advanced research on the sustainable disposal of RM waste. Future research perspectives on the utilization of RM are also addressed. 相似文献
907.
Suzan I. Aziz Zaghloul E. Kandeel Mona M. Husein Salem El Gohary Eiman I. Abou El Maged 《Heteroatom Chemistry》1995,6(4):319-323
A new route for the synthesis of 3H-1,2,4-triazolo[1,5-a]pyridines 7a–j , 12a , b , and 17a , b utilizing the reaction of the hydrazones of cyanoethanoic acid hydrazide 3a , b with ylidene malononitriles 2a–e , malononitrile, and 3-aminocrotononitrile is described. 相似文献