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1.
The voluminous utilization and application of plate and frame heat exchangers (PFHE) in many industries has accelerated the consumer and designer both to optimize exchanger total cost. Over the last few years, several old and new generation algorithms were employed and exploited to optimize PFHE cost. This study explores the application and performance of three new-generation algorithms Big Bang-Big Crunch (BBBC), Grey Wolf Optimizer (GWO), and Water Evaporation Optimization (WEO) in designing optimally PFHE. Besides, this study also compares the performance of three well-established old generations algorithms namely genetic algorithm (genetics and natural selection), particle swarm optimization (animals behaviour), and differential evolution (population-based) with the above three new algorithms in the optimization of PFHE.Seven design factors are chosen for PFHE optimization: exchanger length on hot and cold sides, height and thickness of fin, length of the fin-strip, fin frequency, and the number of hot side layers. The applicability of the suggested algorithms is assessed using a case study based on published research. Though DE performs the best in this study of design optimization concerning total cost and computational time, the three new-generation meta-heuristic algorithms BBBC, GWO, and WEO also provide the novel scope of application in heat exchanger design optimization and successfully finding the cost of the heat exchanger. According to this study, capital costs increase by 19.5% for BBBC, 24% for GWO, and 7.6% for GWO, but operational costs fall by 9.5% for BBBC and GWO when compared to the best performing algorithm (DE). On the other hand, WEO shows an increase of 32.6% in operational costs. Aside from that, a full analysis of the computing time for each algorithm is also provided. The DE has the quickest run time of 0.09 ?s, while the PSO takes the longest at 33.97 ?s. The rest of the algorithms have nearly identical values. As a result, a good comparison is established in this study, offering an excellent platform for designers and customers to make selections. Additionally, the three new generations algorithms mentioned here were not used earlier for optimization of PFHE and the comparative study illustrates that each of them possesses eat potential for cost optimization and also solving other complex problems. 相似文献
2.
Akhil Kumar Singh Dr. Mohammad Usman Dr. Giuseppe Sciortino Prof. Dr. Eugenio Garribba Prof. Dr. Sankar Prasad Rath 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(43):10098-10110
Metallophilic interactions between closed-shell metal ions are becoming a popular tool for a variety of applications related to high-end materials. Heavier d8 transition-metal ions are also considered to have a closed shell and can be involved in such interactions. There is no systematic investigation so far to estimate the structure and energy characteristics of metallophilic interactions in AgII/AgII (d9/d9), AgIII/AgIII (d8/d8), and mixed-valent AgII/AgIII (d9/d8) complexes, which have been demonstrated in the present study. Both interporphyrinic and intermetallic interactions were investigated on stepwise oxidation by using a rigid ethene-bridged cis silver(II) porphyrin dimer and the results compared with those for highly flexible ethane-bridged analogues. By controlling the nature of chemical oxidants and their stoichiometry, both 1e and 2e oxidations were done stepwise to generate AgII/AgIII mixed-valent and AgIII/AgIII porphyrin dimers, respectively. Unlike all other ethene-bridged metalloporphyrin dimers reported earlier, in which 2e oxidation stabilizes only the trans form, such an oxidation of silver(II) porphyrin dimer stabilizes only the cis form because of the metallophilic interaction. Besides silver(II) ⋅⋅⋅ silver(II) interactions in cis silver(II) porphyrin dimer, stepwise oxidations also enabled us to achieve various hitherto-unknown silver(II) ⋅⋅⋅ silver(III) and silver(III) ⋅⋅⋅ silver(III) interactions, which thereby allow significant modulation of their structure and properties. The strength of Ag ⋅⋅⋅ Ag interaction follows the order AgII/AgII (d9/d9)<AgII/AgIII (d9/d8)<AgIII/AgIII (d8/d8). Single-crystal XRD, X-ray photoelectron spectroscopy (XPS), 1H NMR and EPR spectroscopy, and variable-temperature magnetic investigations revealed various oxidation states of silver and metallophilic interactions, which are also well supported by computational analysis. 相似文献
3.
Reduction of ketone 3 derived from (R)-2,3-cyclohexylideneglyceraldehyde 1 with some common hydrides took place with syn-selectivity. The resulting major product 4a has been exploited as a common chiral template to prepare both enantiomers Ia,b of disparlure. 相似文献
4.
Akhil Ranjan 《Proceedings Mathematical Sciences》2000,110(1):27-34
In this paper we give a proof of Lichnerowicz conjecture for compact simply connected manifolds which is intrinsic in the
sense that it avoids thenice embeddings into eigenspaces of the Laplacian. Even if one wants to use these embeddings, this paper gives a more streamlined proof.
As a byproduct, we get a simple criterion for a polynomial to be a Jacobi polynomial. 相似文献
5.
6.
Hyun-Shik Yun Hongkyun Lee Young-Tae Park Min-Kyu Ji Akhil N. Kabra Chung Jeon Byong-Hun Jeon Jaeyoung Choi 《Applied biochemistry and biotechnology》2014,173(8):2054-2064
Microalgae were selected and isolated from acid mine drainage in order to find microalgae species which could be cultivated in low pH condition. In the present investigation, 30 microalgae were isolated from ten locations of acid mine drainage in South Korea. Four microalgae were selected based on their growth rate, morphology, and identified as strains of KGE1, KGE3, KGE4, and KGE7. The dry biomass of microalgae species ranged between 1 and 2 g L?1 after 21 days of cultivation. The growth kinetics of microalgae was well described by logistic growth model. Among these, KGE7 has the highest biomass production (2.05?±?0.35 g L?1), lipid productivity (0.82?±?0.14 g L?1), and C16–C18 fatty acid contents (97.6 %). These results suggest that Scenedesmus sp. KGE 7 can be utilized for biodiesel production based on its high biomass and lipid productivity. 相似文献
7.
Akhil R Chakravarty Pattubala A. N. Anreddy Bidyut K. Santra Anitha M. Thomas 《Journal of Chemical Sciences》2002,114(4):391-401
Redox active mononuclear and binuclear copper(II) complexes have been prepared and structurally characterized. The complexes have planar N-donor heterocyclic bases like 1,10-phenanthroline
(phen), dipyridoquinoxaline (dpq) and dipyridophenazine (dppz) ligands that are suitable for intercalation to B-DNA. Complexes
studied for nuclease activity have the formulations [Cu(dpq)2(H2O)] (ClO4)2.H2O (1), [CuL(H2O)2(μ-ox)](ClO4)2 (L = bpy,2; phen,3; dpq,4; and dppz,5) and [Cu(L)(salgly)] (L = bpy,6; phen,7; dpq,8; and dppz,9), where salgly is a tridentate Schiff base obtained from the condensation of glycine and salicylaldehyde. The dpq complexes
are efficient DNA binding and cleavage active species. The dppz complexes show good binding ability but poor nuclease activity.
The cleavage activity of thebis-dpq complex is significantly higher than thebis-phen complex of copper(II). The nuclease activity is found to be dependent on the intercalating nature of the complex and
on the redox potential of the copper(II)/copper(I) couple. The ancillary ligand plays a significant role in binding and cleavage
activity. 相似文献
8.
Huynh Le Thanh Nguyen Tran Thi Thuy Dung Nguyen Hoang Hai Au Nguyen Thi Thu Trang Tran Van Man Grag Akhil Le My Loan Phung 《Journal of Solid State Electrochemistry》2018,22(7):2247-2254
Journal of Solid State Electrochemistry - Olivine LiFePO4 (LFP) is a promising cathode material for high-rated lithium-ion batteries. However, olivine faced a severe disadvantage of low... 相似文献
9.
Akhil R. Chakravarty F.Albert Cotton Derek A. Tocher Joanne H. Tocher 《Polyhedron》1985,4(8):1475-1478
Electrochemical studies on a new class of diruthenium(II,III) compounds were done. The complexes having a polar arrangement of ligands across the diruthenium unit in Ru2Cl(hp)4(Hhp), Ru2Cl(chp)4 and Ru2Cl(PhNpy)4 where Hhp, Hchp and PhNHpy are 2-hydroxypyridine, 6-chloro-2-hydroxypyridine, and 2-anilinopyridine, respectively, undergo two or more oxidations and reductions. The metal centered reductions in the range of +0.1 to ?0.75 V and oxidations in the range +0.5 to +1.2 V are discussed and compared with diruthenium carboxylato and amidato complexes. 相似文献
10.
Vimalraj V Vijayalakshmi S Umayaparvathi S Krishnan AR 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,78(2):670-675
The Fourier transform infrared spectra, 1H NMR and 13C NMR spectra of 2-furoic hydrazide have been recorded. Optimized geometry, frequency and intensity of the vibrational bands of 2-furoic hydrazide were obtained by the density functional theory (DFT) and ab initio levels of theory and also 1H NMR, 13C NMR chemical shifts were calculated using 6-31G+(d,p) basis sets. The theoretical values were compared with experimental values. 相似文献