Results 231 to 240 of about 1,391,504 (276)

Affine encryption technique based on quadratic function

Informatics and Mathematical Methods in Simulation
Affine ciphers originated in ancient times. However, despite the advent of modern cryptographic standards, they are still relevant in cryptography.
М.M. Kasianchuk, М.P. Holembiovskyi
semanticscholar   +1 more source

Affinity chromatography of fibroblast growth factors on substituted polystyrene

Journal of Chromatography B: Biomedical Sciences and Applications, 1990
The heparin-binding growth factors aFGF and bFGF (acidic and basic fibroblast growth factor) from crude bovine brain extract were co-eluted with purified [125I]aFGF and/or [125I]bFGF as tracers from heparin-Sepharose and from several insoluble substituted polystyrenes used as stationary phases in low-pressure affinity chromatography. The ability of the
M A, Dourges, D, Gulino, J, Courty, J, Badet, D, Barritault, J, Jozefonvicz   +5 more
openaire   +2 more sources

Electron affinities of aza-substituted polycyclic aromatic hydrocarbons

Canadian Journal of Chemistry, 1989
Electron affinities for aza-substituted polycyclic aromatics were determined from measurements of electron transfer equilibria in the dilute gas phase with a pulsed electron high pressure mass spectrometer (PHPMS). These are (in kcal/mol): quinazoline (12.7), quinoxaline (15.8), cinnoline (16.0), acridine (20.3), benzo[c]cinnoline (20.6), pyrido[2,3-b]
Glen W. Dillow, P. Kebarle
openaire   +1 more source

Substructural Abstract Syntax with Variable Binding and Single-Variable Substitution

Logic in Computer Science
We develop a unified categorical theory of substructural abstract syntax with variable binding and single-variable (capture-avoiding) substitution. This is done for the gamut of context structural rules given by exchange (linear theory) with weakening ...
Marcelo Fiore, Sanjiv Ranchod
semanticscholar   +1 more source

Multiple RGB Images Security based on Substitution–Permutation Network over the Residue Classes of Eisenstein Integer Z[Ω]π

European Journal of Pure and Applied Mathematics
This paper presents a multiple RGB image encryption scheme that utilizes a pair of 8×8 S-boxes constructed over the residue classes of Eisenstein integers Z[Ω]π, implemented within a three-stage Substitution–Permutation Network (SPN) architecture.
Maha Alammari, Muhammad Sajjad, Mushtaq K. Abdalrahem, Robinson Julian Serna   +3 more
semanticscholar   +1 more source

Novel substituted pyrrolidines are high affinity histamine H3 receptor antagonists

Bioorganic & Medicinal Chemistry Letters, 2010
Pre-clinical characterization of novel substituted pyrrolidines that are high affinity histamine H(3) receptor antagonists is described. These compounds efficiently penetrate the CNS and occupy the histamine H(3) receptor in rat brain following oral administration. One compound, (2S,4R)-1-[2-(4-cyclobutyl-[1,4]diazepane-1-carbonyl)-4-(3-fluoro-phenoxy)-
Emily M, Stocking, Leah, Aluisio, John R, Atack, Pascal, Bonaventure, Nicholas I, Carruthers, Christine, Dugovic, Anita, Everson, Ian, Fraser, Xiaohui, Jiang, Perry, Leung, Brian, Lord, Kiev S, Ly, Kirsten L, Morton, Diane, Nepomuceno, Chandravadan R, Shah, Jonathan, Shelton, Akinola, Soyode-Johnson, Michael A, Letavic   +17 more
openaire   +2 more sources

Proposal of dynamic algorithms combining a substitution layer and a key addition layer for block ciphers using SHA3-256

ICT Research
In recent years, one research direction that has garnered significant attention from scientists is enhancing the security of SPN block ciphers against strong cryptanalysis attacks through dynamic methods.
Tran Thi Luong
semanticscholar   +1 more source

A Secure Image Encryption Scheme Based on Two-Layer Substitution Permutation Network(SPN) with Multi-Scale Processing

2025 1st International Conference on Radio Frequency Communication and Networks (RFCoN)
The encryption of digital images requires specialized cryptographic techniques due to their unique characteristics, such as strong pixel correlation, high data redundancy and large storage requirements.
Gnanapriya B, P. L, Viyola Roshni A X B, Jayabal Rajamohan, S. Priya   +4 more
semanticscholar   +1 more source

Electrophile affinity and positional selectivity in electrophilic substitution reactions of N-substituted pyrroles

Russian Chemical Bulletin, 2011
In terms of the density functional theory (DFT) using B3LYP/6-31G(d) method with full geometry optimization, gas-phase quantum chemical calculations were performed for σ-complexes formed upon the attack of electrophiles E (E = H+, Me+, Me3Si+, Br+, NO2 +, MeCO+, SO3) on α- and β-positions of furan, thiophene, selenophene, pyrrole, and N-substituted ...
L. I. Belen’kii, N. D. Chuvylkin, I. D. Nesterov   +2 more
openaire   +1 more source

The Proton Affinity of Some Substituted Naphtalenes

Journal of physical organic chemistry, 1999
The absolute proton affinity (PA) pertaining aromatic carbons of the monosubstituted naphtalenes involving CH3, OH, CHO, NO2 and Cl substituents is calculated at the MP2(fc)/6-31G**//HF/6-31G* + ZPVE(HF/6-31G*) level of theory. Increments corresponding to unsubstituted positions within the naphtalene skeleton are estimated.
Eckert-Maksić, Mirjana, Antol, Ivana, Klessinger, Martin, Maksić, Zvonimir B.   +3 more
openaire   +2 more sources