Search

In the present study, nickel and copper fast diffusion in silicon is investigated in the framework of the cBΩ thermodynamic model, which connects point defect parameters with the bulk elastic and expansion properties. All the calculated point defect thermodynamic properties (activation Gibbs free energy, activation enthalpy, activation entropy, and activation volume) exhibit temperature dependence due to the non-linear anharmonic behavior of the isothermal bulk modulus of Si. Calculated activation enthalpies (0.15–0.16 eV for Ni and 0.17–0.19 eV for Cu) are in agreement with the reported experimental results. Small values of calculated activation volumes for both dopants (∼4% of the mean atomic volume) are consistent with the interstitial diffusion of Ni and Cu in Si. [ABSTRACT FROM AUTHOR]

Interactions between a protein and a ligand are often accompanied by a redistribution of the population of thermally accessible conformations. This dynamic response of the protein's functional energy landscape enables a protein to modulate binding affinities and control binding sensitivity to ligand concentration. In this paper, we investigate the structural origins of binding affinity and allosteric cooperativity of binding two Ca2+ ions to each domain of Calmodulin (CaM) through simulations of a simple coarse-grained model. In this model, the protein's conformational transitions between open and closed conformational ensembles are simulated explicitly and ligand binding and unbinding are treated implicitly within the grand canonical ensemble. Ligand binding is cooperative because the binding sites are coupled through a shift in the dominant conformational ensemble upon binding. The classic Monod-Wyman-Changeux model of allostery with appropriate binding free energies to the open and closed ensembles accurately describes the simulated binding thermodynamics. The simulations predict that the two domains of CaM have distinct binding affinity and cooperativity. In particular, the C-terminal domain binds Ca2+ with higher affinity and greater cooperativity than the N-terminal domain. From a structural point of view, the affinity of an individual binding loop depends sensitively on the loop's structural compatibility with the ligand in the bound ensemble, as well as the conformational flexibility of the binding site in the unbound ensemble. [ABSTRACT FROM AUTHOR]

Insertion of a solute into a vessel comprising biopolymers is a fundamental function in a biological system. The entropy originating from the translational displacement of solvent particles plays an essential role in the insertion. Here we study the dynamics of entropic insertion of a large spherical solute into a cylindrical vessel. The solute and the vessel are immersed in small spheres forming the solvent. We develop a theoretical method formulated using the Fokker-Planck equation. The spatial distribution of solute-vessel entropic potential, which is calculated by the three-dimensional integral equation theory combined with rigid-body models, serves as input data. The key quantity analyzed is the density of the probability of finding the solute at any position at any time. It is found that the solute is inserted along the central axis of the vessel cavity and trapped at a position where the entropic potential takes a local minimum value. The solute keeps being trapped without touching the vessel inner surface. In a significantly long time τ, the solute transfers to the position in contact with the vessel bottom possessing the global potential minimum along the central axis. As the solute size increases, τ becomes remarkably longer. We also discuss the relevance of our result to the functional expression of a chaperonin/cochaperonin in the assistance of protein folding. [ABSTRACT FROM AUTHOR]

Calmodulin (CaM) is a ubiquitous Ca2+-binding protein consisting of two structurally similar domains with distinct stabilities, binding affinities, and flexibilities. We present coarse grained simulations that suggest that the mechanism for the domain's allosteric transitions between the open and closed conformations depends on subtle differences in the folded state topology of the two domains. Throughout a wide temperature range, the simulated transition mechanism of the N-terminal domain (nCaM) follows a two-state transition mechanism while domain opening in the C-terminal domain (cCaM) involves unfolding and refolding of the tertiary structure. The appearance of the unfolded intermediate occurs at a higher temperature in nCaM than it does in cCaM consistent with nCaM's higher thermal stability. Under approximate physiological conditions, the simulated unfolded state population of cCaM accounts for 10% of the population with nearly all of the sampled transitions (approximately 95%) unfolding and refolding during the conformational change. Transient unfolding significantly slows the domain opening and closing rates of cCaM, which can potentially influence its Ca2+-binding mechanism. [ABSTRACT FROM AUTHOR]

We investigate which terms in Reduced-Dimensionality Semiclassical Transition State Theory (RD SCTST) contribute most significantly in rate constant calculations of hydrogen extraction and exchange reactions of hydrocarbons.We also investigate the importance of deep tunneling corrections to the theory. In addition, we introduce a novel formulation of the theory in Jacobi coordinates. For the reactions of H atoms with methane, ethane, and cyclopropane, we find that a one-dimensional (1-D) version of the theory without deep tunneling corrections compares well with 2-D SCTST results and accurate quantum scattering results. For the "heavy-light-heavy" H atom exchange reaction between CH3 and CH4, deep tunneling corrections are needed to yield 1-D results that compare well with 2-D results. The finding that accurate rate constants can be obtained from derivatives of the potential along only one dimension further validates RD SCTST as a computationally efficient yet accurate rate constant theory. [ABSTRACT FROM AUTHOR]

Fundamental understanding of mass transport in solids as a function of temperature is crucial to applications in various all-solid-state ionic devices, including fuel cells, sensors, and batteries. Commonly, electrical properties have been investigated at various temperatures and the activation energy computed from the slope of the Arrhenius plot. Changes in the activation energy as a function of chemical composition induced by chemical substitution/doping are used as a tool to understand defects and transport phenomena in solids. Meyer and Neldel found that the energy of activation can appear in the pre-exponential factor, A, in a manner that cancels the traditional activation energy factor in the Arrhenius equation at a certain transition temperature. This pre-exponential activation energy is manifested as an entropy and designated as the entropy of activation and the phenomenon is called as the Meyer-Neldel rule (MNR). Entropy of activation has been associated with the stochastic nature of the barrier heights, which is then reflected in the randomness of the jump frequency of the charge carriers. Many of the theoretical approaches developed to study this phenomenon utilize a Boltzmann distribution of the barrier heights; we have used a classical Bose-Einstein (BE) distribution in which, at the transition temperature, a large number of very low-energy barriers appear as a "condensate" minimizing the role of the activation energy. The advantage of using the BE statistics over the Boltzmann statistics lies in the fact that the former naturally contains a transition temperature. Using this model, we have further analyzed the entropy of several Li-stuffed garnet-type solid electrolytes, which are being considered for all-solid-state Li batteries and as well as several other fast ion-conducting solids. [ABSTRACT FROM AUTHOR]

Insertion and release of a solute into and from a vessel comprising biopolymers is a fundamental function in a biological system. A typical example is found in a multidrug efflux transporter. 'Multidrug efflux' signifies that solutes such as drug molecules with diverse properties can be handled. In our view, the mechanism of the multidrug efflux is not chemically specific but rather has to be based on a physical factor. In earlier works, we showed that the spatial distribution of the solute-vessel potential of mean force (PMF) induced by the solvent plays imperative roles in the insertion/release process. The PMF can be decomposed into the energetic and entropic components. The entropic component, which originates from the translational displacement of solvent molecules, is rather insensitive to the solute-solvent and vessel inner surface-solvent affinities. This feature is not shared with the energetic component. When the vessel inner surface is neither solvophobic nor solvophilic, the solvents within the vessel cavity and in the bulk offer almost the same environment to any solute with solvophobicity or solvophilicity, and the energetic component becomes much smaller than the entropic component (i.e., the latter predominates over the former). Our idea is that the multidrug efflux can be realized if the insertion/release process is accomplished by the entropic component exhibiting the insensitivity to the solute properties. However, we have recently argued that the entropic release of the solute is not feasible as long as the vessel geometry is fixed. Here we consider a model of TolC, a cylindrical vessel possessing an entrance at one end and an exit at the other end for the solute. The spatial distribution of the PMF is calculated by employing the three-dimensional integral equation theory with rigid-body models in which the constituents interact only through hard-body potentials. Since the behavior of these models is purely entropic in origin, our analysis is focused on the entropic component. We show that the entropically inserted solute can be released by a continuous variation of the vessel geometry which forms a time-dependent entropic force continuing to accelerate the solute motion to the exit. Solutes with a wide range of sizes are entropically released using the same vessel-geometry variation. The results obtained are fairly general and also applicable to the efflux pump protein AcrB and ATP-binding cassette transporter. [ABSTRACT FROM AUTHOR]

Kazuo Ishiguro acknowledges the fallibility of the human condition, and herein lies the therapeutic core of his novels. The current study proposes a theoretical approach to Ishiguro's second novel (1989) from an interdisciplinary perspective on the main character's narrative. In the first part, Henry James' interpretation of literature applies to Masuji Ono's totalitarian views to link fiction to real life. The second part discusses the relativity of choices and decisions based on transgenerational ethics as presented in Strauss and Howe's Fourth Turning Theory. The third part focuses on Ono's narrative unreliability as a form of confabulation. Since Ono's recollections often clash with what his family can remember about certain events, the painter may be suffering from the false memory effect as a form of healing old trauma. The last subchapter explains the concept of 'mono no aware' from a scientific perspective. The Japanese understanding of the 'pathos of things' is reflected in the second law of thermodynamics, which stipulates that universal disorder will always increase. While young Ono refuses to accept the floating world, old Ono seeks to make peace with the transitory nature of existence, which is equivalent to accepting the entropy of the Universe. [ABSTRACT FROM AUTHOR]

The aims of this study were firstly to compare the similarity in upper-body muscle activation between the bench press and push-up at similar loads, and secondly to establish a 1-RM prediction equation between the two exercises based upon the load-velocity relationship. Twenty resistance-trained male athletes (age 22.5 ± 5.24 years, body mass 83.7 ± 10.7 kg, body height 1.80 ± 0.06 m) performed push-ups and bench presses with four different loads. Push-ups were performed without a weight vest and with a 10-20-30 kg weight vest. Bench presses were performed at 50-80% of athletes' assumed 1 repetition max (1-RM) in 10 kg steps, while a linear encoder measured performance during the exercises. A load-velocity relationship was established as a product of the load and velocity for the push-up and bench press per participant and the equation was used to establish a predicted 1-RM. Mean muscle activation of eight upper body muscles was recorded for each exercise and each load. The main findings of this study demonstrate an extremely large association between the predicted 1-RM loads performed with the push-up and bench press (r = 0.93) in experienced resistance trained men. Furthermore, most muscles showed similar activations between the two exercises with the different loads except the deltoid and biceps brachii muscles. It may be concluded that it is possible to predict a cross-over 1-RM between the two exercises based upon the load-velocity relationship in each exercise, and that training push-ups largely targets the same muscles as the bench press except the deltoid and biceps muscles. For coaches and athletes, the use of this method is a low cost and time-effective alternative for standard 1-RM bench press testing to predict maximal upper body strength. [ABSTRACT FROM AUTHOR]

Physicochemical parameters, total phenols contents (TPC), and oxidative stabilities at 120–160 °C were evaluated for two monovarietal (Arbequina and Cobrançosa cultivars, cvs.) and one blend extra‐virgin olive oil, confirming the label quality grade and allowing grouping them according to the different TPC (TPC = 88 ± 7, 112 ± 6 and 144 ± 4 mg CAE/kg, for cv. Arbequina, blend and cv. Cobrançosa oils, respectively). The lipid oxidation rate increased with the decrease of the TPC, being Cobrançosa oils (higher TPC) more thermally stable. Kinetic‐thermodynamic parameters were determined using the activated complex/transition‐state theory and the values did not significantly differ for Cobrançosa and blend oils, which had the highest TPC, suggesting a hypothetically threshold saturation of the beneficial effect. Cobrançosa oils had a significant more negative temperature coefficient, higher temperature acceleration factor, greater activation energy and frequency factor, higher positive enthalpy of activation, lower negative entropy of activation, and greater positive Gibbs free energy of activation, probably due to the higher TPC. The results confirmed that lipid oxidation was a nonspontaneous, endothermic, and endergonic process with activated formed complexes structurally more ordered than the reactants. A negative deviation from the Arrhenius behavior was observed for all oils being the super‐Arrhenius behavior more marked for Arbequina oils that had the lowest TPC. Finally, the kinetic‐thermodynamic parameters allowed classifying oils according to the binomial olive cultivar/total phenols level, being the temperature acceleration factor and the Gibbs free energy of activation at 160 °C the most powerful discriminating parameters. [ABSTRACT FROM AUTHOR]

The rate of hydrolysis of hydrolysis of ethyl benzoate were measured volumetric over the temperature range of 200c to 400c.in water-methanol mixture at different composition. The different solvation in initial and transition state is due to decrease in rate with varying the composition of mixture. The influence of solvent on reaction rate was examined in term of activation parameter. The increase in values of DG* and simultaneous depletion in values of DH* and DS* with solvent composition reveals that the reaction is Enthalpy domination and Entropy controlled. The value of iso-kinetic temperature is less than 300 shows the weak interaction between solvent and solute.

Many chemical methods have been developed to favor a particular product in transformations of compounds that have two or more reactive sites. We explored a different approach to site selectivity using vibrational strong coupling (VSC) between a reactant and the vacuum field of a microfluidic optical cavity. Specifically, we studied the reactivity of a compound bearing two possible silyl bond cleavage sites—Si–C and Si–O, respectively—as a function of VSC of three distinct vibrational modes in the dark.The results show that VSC can indeed tilt the reactivity landscape to favor one product over the other.Thermodynamic parameters reveal the presence of a large activation barrier and substantial changes to the activation entropy, confirming the modified chemical landscape under strong coupling. [ABSTRACT FROM AUTHOR]

Abstract The mixture of choline chloride and ethyleneglycol ((1:3) on the molar scale) is first characterized using density, viscosimetry and refractive index measurements, in the temperature range 20–45°C, with controlled amounts of water. Thermodynamic parameters such as the activation entropy, enthalpy and Gibbs energy for the viscous flow are deduced from the data and show that the solvent is highly structured. A protocol to disperse in this solvent 10 nm maghemite nanoparticles previously synthesized in water is described. The good quality of the dispersion is assessed by visual observations, optical microscopy, small angle X-ray scattering (SAXS), magnetization measurements, viscosimetry, and light scattering. The results lead to the description of a local viscosity around the particles, lower than the macroscopic one, that could be the result of the solvent segregation with ethyleneglycol being mostly present in the close vicinity of the particles. Highlights • The complex solvent made of a mixture of ethylene glycol-choline chlorine is characterized (viscosity and density). • The influence of water is examined. • The Eyring model for the molecular flow shows high associativity (H-bonds). • Stable dispersions of magnetic nanoparticles (MNPs) were dispersed in this solvent. • The local viscosity around the NPs is lower than the bulk one. [ABSTRACT FROM AUTHOR]

High-entropy alloys (HEAs) are an emerging class of advanced structural alloys under extensive research; yet, the properties of the liquid states of these materials, which are relevant to their processing, have been far less explored. In this work, we utilize ab initio molecular dynamics simulations to investigate the melt properties of a representative HEA—the Cantor alloy—and its derivatives: CrMnFeCoNi, CrFeCoNi, and CrCoNi. The atomic dynamics of these melts at various temperatures are investigated, specifically to analyze their electronic and atomic structures, including charge transfer, pair distribution functions, and short-range order. Results are compared with existing information for the liquids of metallic glasses, which also typically contain multiple principal elements, but retain the amorphous state under moderate to fast cooling rates. The present results provide insights into the structural and bonding factors favoring solidification to single-phase solid solutions in HEAs. [ABSTRACT FROM AUTHOR]

We consider backreacted AdS5 × S5 coupled with Nf massless avors introduced by D7-branes at nonzero temperature. The backreacted geometry is in the Veneziano limit. The temperature of this system is related to the event horizon at rh. Dividing one of the spatial directions into a line segment with length l, we will calculate the holographic entanglement entropy (HEE) between the two subspaces. We study the behavior near the event horizon, and nally nd that there exists con nement/decon nement phase transition phenomenon near the horizon since the difference between the entanglement entropy of the connected minimal surface and the disconnected one changes sign. [ABSTRACT FROM AUTHOR]

The thermodynamic parameters Eact, ΔH≠, ΔS≠, and ΔG≠ for various processes involving antioxidants were calculated using literature kinetic data (k, T). The ΔG≠ values of the antioxidants' processes vary in the range 91.27-116.46 kJmol-1 at 310 K. The similarity of the ΔG≠ values (for all of the antioxidants studied) is supported to be an indication that a common mechanism in the above antioxidant processes may be taking place. A value of about 10-30 kJmol-1 is the activation energy for the diffusion of reactants depending on the reaction and the medium. The energy 92 kJmol-1 is needed for the excitation of O2 from the ground to the first excited state (¹Δg, singlet oxygen). We suggest the same role of the oxidative stress and specifically of singlet oxygen to the processes of antioxidants as in the processes of proteinaceous diseases. We therefore suggest a competition between the various antioxidants and the proteins of proteinaceous diseases in capturing singlet oxygen's empty π* orbital. The concentration of the antioxidants could be a crucial factor for the competition. Also, the structures of the antioxidant molecules play a significant role since the various structures have a different number of regions of high electron density. [ABSTRACT FROM AUTHOR]

Large scale green production of poly(oxymethylene) dimethyl ethers(DMM n ) would be crucial if the diesel-DMM n blends were applied to tackle the worldwide formidable air pollution by particulate matter. Kinetics studies are of great significance among the core challenges for understanding the reaction principles and process design. Kinetic model was developed for the production of DMM n from methylal and trioxane with sulfonic acid-functionalized ionic liquid as catalyst. Reversible reactions of propagation-depolymerization were simultaneously considered with non-equal rate constants for complex sequential reactions. The kinetic model proposed showed good accuracy and consistency for both forward and backward reactions. Activation energies E p were in the range of 35.7 to 39.6 kJ mol −1 for DMM n propagation reactions and 50.8 to 54.7 kJ mol −1 for DMM n decomposition, with the difference of −15.1 kJ mol −1 determined by Arrhenius equation. Entropy of activation, determined by Eyring-Polanyi equation, could make a significant contribution to the Gibbs energy barrier in the DMM n propagation/decomposition. It is interesting that the Schulz-Flory type distribution still could be maintained even the calculated rate constants increased with DMM n chain length. [ABSTRACT FROM AUTHOR]

The rheological properties of nitrocellulose solutions in cyclohexanone in the presence of phthalic and 4-nitrophthalic diester plasticizers were studied by rotational viscometry to reveal a behavior similar to that of Newtonian fluids. The activation parameters of the viscous flow regime were calculated. An influence of nitroplasticizers and dibutyl phthalate on the rheology of nitrocellulose was established. The influence of plasticizers on the mechanical properties of nitrocellulose films was discussed. [ABSTRACT FROM AUTHOR]

Reaction rates of toluene disproportionation (A) and cumene cracking (B) normalized by the number of Brønsted acid sites were analyzed on aluminosilicates. The activation entropy showed linear and compensatory relationship against the activation enthalpy. The slope of entropy-enthalpy plot was in the order of (B) > (A) > small alkane cracking, whereas the intercept on the horizontal axis was in the order of propane and isobutane cracking > linear C4–8 alkanes and iso-pentane cracking > (A) > (B). The former is consistent with the bulkiness of reactant, while the latter is consistent with intrinsic difficulty of formation of intermediate cations. [ABSTRACT FROM AUTHOR]

Transmetalation between Pd(Br)(PhA)(PCyp3)2 (Ph = phenyl, Cyp = cyclopentyl) and Cu(CaHMePhB)(NHC) (NHC = 1,3-bis(2,6-diisopropylphenyl)-imidazolidin-2-ylidene) is an important elementary step in recently reported catalytic cross-coupling reaction by Pd/Cu cooperative system. DFT study discloses that the transmetalation occurs with inversion of the stereochemistry of the CaHMePhB group. In its transition state, the CaHMePhB group has almost planar structure around the Ca atom. That planar geometry is stabilized by conjugation between the π* orbital of the PhB and the 2p orbital of the Ca. Another important factor is activation entropy (ΔS°‡); retention transmetalation occurs through Br-bridging transition state, which is less flexible than that of the inversion transmetalation because of the Br-bridging structure, leading to a smaller activation entropy in the retention transition state than in the inversion transition state. For CaHMeEt group, transmetalation occurs in a retention manner. In the planar CaHMeEt group of the inversion transition state, the Ca 2p orbital cannot find a conjugation partner because of the absence of π-electron system in the CaHMeEt. Transmetalation of CaHMe(CH=CH2) occurs in a retention manner because the vinyl π* is less effective for the conjugation with the Ca 2p because of its higher orbital energy than the Ph π*. The introduction of electronwithdrawing substituent on the PhB is favorable for inversion transmetalation. These results suggest that the stereochemistry of the Ca atom in transmetalation can be controlled by electronic effect of the CaHMeR (R = phenyl, vinyl, or alkyl) and sizes of the substituent and ligand. [ABSTRACT FROM AUTHOR]

Effects of Cu, Mn, Al, Ti, Mo on generalized stacking fault energies, Rice-criterion ductilities, and twinabilities of CoCrFeNi-based face-centered cubic high entropy alloys were investigated using density functional theory calculations. The calculated barrier energies and twinnabilities revealed that the addition of Ti or Mo increased the tendency of dislocation glide and deformation twinning, while addition of Mn, Cu and relatively high amount of Al facilitated dislocation gliding and martensitic transformation. Low amount of Al resulted in only dislocation gliding. Furthermore, the addition of Mn and Cu increased the calculated Rice-criterion ductility while other elements decreased it. [ABSTRACT FROM AUTHOR]

This paper presents a three-dimensional numerical modeling of a PEM fuel cell with tree-like flow field channels. Four different tree-like configurations are considered for the study based on a statistical analysis of the veins of the leaves of different trees. The number of bifurcations of the vein and their inclination are considered as parameters for the characterization. Four different configurations are the most recurrent, corresponding to one level of bifurcation at 37° and 74° and two levels of bifurcation at 37° and 74°. The model considers a complete solution of the mass, momentum, energy, and electrochemical equations. An entropy generation analysis is developed as a post processing once the solution of the models is obtained. Because new geometries for the channel configuration in the bipolar plates are introduced, special attention is considered for the entropy generation due to mass flow. Results indicate that the configuration with two levels of bifurcation at 37° is efficient at removing water from the cathode channels, resulting in a good current density production. In addition, a better performance of the PEM fuel cell (higher current density production and lower entropy production) is obtained by increasing the number of bifurcations. [ABSTRACT FROM AUTHOR]

The release of NO by [Fe(NO)(Et2NpyS4)], where (Et2NpyS4)2− = 2,6-bis(2-mercaptophenylthiomethyl)-4-substituted pyridine(2-), has been studied in the absence and presence of a trapping agent. The results show that [Fe(NO)(Et2NpyS4)] releases NO spontaneously in solution with a slow rate,k-NO = 1.7 × 10−4s−1at 23 °C, in a reversible reaction. NO release becomes faster when the reaction intermediate [Fe(Et2 NpyS4)] was trapped by CO, thereby preventing the back reaction. The release of NO was studied as a function of CO concentration and temperature. The reported activation parameters, especially the positive activation entropy values for the release of NO, favor the operation of a dissociative interchange (Id) mechanism. Thus, [Fe(NO)(Et2NpyS4)] can serve as a NO deliverer. [ABSTRACT FROM PUBLISHER]

This paper researches on methods of the color image segmentation method of Lingwu long jujubes based on the maximum entropy to achieve the accuracy of image segmentation and improve accuracy of machine recognition. According to law between the color of Lingwu long jujubes and characteristic of environment, starting from the hue information, this paper is first to explore the difference between the hue of Lingwu long jujubes and the environment which it lives and then use maximum entropy to segment image. It finds optimal threshold by mathematical criterion judging the accuracy of image segmentation. The method of pre-processing of image is mean filter firstly. Then, it extracts hue information of true color image and uses maximum entropy for image segmentation, judging accuracy of image segmentation by segmentation area whether it is in accordance with the 3σ principle. Mathematical morphology is used for smoothing image and eliminating small holes. Finally, segmented image will be obtained through labeling the image by using methods of labeled image and using characteristic parameters for extracting feature. By comparing the segmentation effect with artificial method of the 30 Lingwu long jujubes images, it proves that the color image segmentation method of Lingwu long jujubes based on the maximum entropy has good effect to extract the object region. The accuracy of segmentation rate is up to 89.60%. The time that the algorithm run is 1.3132 s. [ABSTRACT FROM AUTHOR]

The change of zero order entropy is studied over different strategies of grammar production rule selection. The two major rules are distinguished: transformations leaving the message size intact and substitution functions changing the message size. Relations for zero order entropy changes were derived for both cases and conditions under which the entropy decreases were described. In this article, several different greedy strategies reducing zero order entropy, as well as message sizes are summarized, and the new strategy MinEnt is proposed. The resulting evolution of the zero order entropy is compared with a strategy of selecting the most frequent digram used in the Re-Pair algorithm. [ABSTRACT FROM AUTHOR]

Oxidation is one of the most important industrial reactions as it yields useful products. Literature survey indicates the use of several organic oxidants for the oxidation of alcohols to the corresponding carbonyl compounds but inorganic oxidants have rarely been used. Further, the kinetic and thermodynamic aspects of oxidation of perfumery alcohols have not been investigated. In this paper, we report the kinetic studies of oxidation of acyclic primary perfumery alcohols, Nerol, Citronellol and Geraniol, to aldehydes using K2S2O8 and KIO4 in acidic medium. The oxidation was carried out under first order kinetic conditions with respect to the inorganic oxidants. The progress of reaction was monitored by iodometric estimation of the unreacted oxidants at regular time interval during the course of the reaction. The reaction was found to be independent of ionic strength (μ).The thermodynamic activation parameters have been determined from the variation of oxidation rate with temperature. Suitable reactionmechanism have been suggested for the oxidation of perfumery alcohols. [ABSTRACT FROM AUTHOR]