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We investigate the reorientation dynamics of four octanol isomers with very different characteristics regarding the formation of hydrogen-bonded structures by means of photon-correlation spectroscopy (PCS) and broadband dielectric spectroscopy. PCS is largely insensitive to orientational cross-correlations and straightforwardly probes the α-process dynamics, thus allowing us to disentangle the complex dielectric relaxation spectra. The analysis reveals an additional dielectric relaxation contribution on time scales between the structural α-process and the Debye process. In line with nuclear magnetic resonance results from the literature and recent findings from rheology experiments, we attribute this intermediate contribution to the dielectric signature of the O–H bond reorientation. Due to being incorporated into hydrogen-bonded suprastructures, the O–H bond dynamically decouples from the rest of the molecule. The relative relaxation strength of the resulting intermediate contribution depends on the respective position of the hydroxy group within the molecule and seems to vanish at sufficiently high temperatures, i.e., exactly when the overall tendency to form hydrogen bonded structures decreases. Furthermore, the fact that different octanol isomers share the same dipole density allows us to perform an in-depth analysis of how dipolar cross-correlations appear in dielectric loss spectra. We find that dipolar cross-correlations are not solely manifested by the presence of the slow Debye process but also scale the relaxation strength of the self-correlation contribution depending on the Kirkwood factor. [ABSTRACT FROM AUTHOR]

Neural precursor cells (NPCs) that persist in the postnatal/adult subventricular zone (SVZ) express connexins that form hemichannels and gap junctions. Gap junctional communication plays a role in NPC proliferation and differentiation during development, but its relevance on postnatal age remains to be elucidated. In this work we aimed to evaluate the effect of the blockade of gap junctional communication on proliferation and cell fate of NPCs obtained from the SVZ of postnatal rats. NPCs were isolated and expanded in culture as neurospheres. Electron microscopy revealed the existence of gap junctions among neurosphere cells. Treatment of cultures with octanol, a broad-spectrum gap junction blocker, or with Gap27, a specific blocker for gap junctions formed by connexin43, produced a significant decrease in bromodeoxyuridine incorporation. Octanol treatment also exerted a dose-dependent antiproliferative effect on glioblastoma cells. To analyze possible actions on NPC fate, cells were seeded in the absence of mitogens. Treatment with octanol led to an increase in the percentage of astrocytes and oligodendrocyte precursors, whereas the percentage of neurons remained unchanged. Gap27 treatment, in contrast, did not modify the differentiation pattern of SVZ NPCs. Our results indicate that general blockade of gap junctions with octanol induces significant effects on the behavior of postnatal SVZ NPCs, by reducing proliferation and promoting glial differentiation. [ABSTRACT FROM AUTHOR]

The octanol/water partition coefficient P (logP) is a hydrophobicity index and is one of the determining factors for the pharmacokinetics of orally administered substances because it influences membrane permeability. To illustrate the wide-ranging variety of compounds in the chemical space, a two-dimensional data plot consisting of 25 blocks was previously proposed based on a substance’s in silico chemical descriptors. The logP values of approximately 200 diverse chemicals (test plus reference compounds covering all 25 blocks of the chemical space) were estimated experimentally using retention times in reverse-phase liquid chromatography; these values were compared with those of authentic reference compounds with established logP values (available for 17 of 60 reference substances in the Organization for Economic Co-operation and Development Test Guideline 117). The logP values of 140 of 165 chemicals successfully estimated using four different mobile phase conditions (pH 2, 4, 7, and 10 for molecular forms) correlated significantly with those calculated using the in silico packages ChemDraw and ACD/Percepta (r > 0.72). Although substances that neighbored authentic compounds in the chemical space had precisely correlated logP values estimated experimentally and in silico, some compounds that were more distant from authentic substances showed lower logP values than those estimated in silico. These results indicate that additional authentic reference materials with wider ranging chemical diversity and their logP values from reverse-phase liquid chromatography should be included in the international test guidance to promote simple and reliable estimation of octanol/water partition coefficients, which are important determinant factors for the pharmacokinetics of general chemicals. [ABSTRACT FROM AUTHOR]

Spinel ferrites, ZnFe2O4, MnFe2O4, and ZnMnFe2O4, were synthesized using the sol–gel method and thoroughly investigated for their potential as catalytic and magnetic materials. Experiments unveiled that ZnMnFe2O4 exhibited excellent catalytic and magnetic properties, whereas the Density Functional Theory (DFT) calculations provided insight into the excellent performance of ZnMnFe2O4 compared with ZnFe2O4 and MnFe2O4. The catalytic efficiencies of the synthesized spinel ferrites were evaluated against a model reaction, i.e., the gas-phase oxidation of octanol to a corresponding aldehyde, utilizing molecular oxygen as an oxidant. The results indicated that the order of catalytic activity was ZnMnFe2O4 > MnFe2O4 > ZnFe2O4. The reaction was found to follow Langmuir Hinshelwood's mechanism for dissociative adsorption of molecular oxygen. Owing to their superb catalytic and magnetic properties, mixed ferrites can be extended to a variety of organic transformation reactions. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl carboxylic and sulfonic acids (PFCAs and PFSAs, respectively) have low acid dissociation constant values and are, therefore, deprotonated under most experimental and environmental conditions. Hence, the anionic species dominate their partitioning between water and organic phases, including octanol and phospholipid bilayers which are often used as model systems for environmental and biological matrices. However, data for solvent–water (SW) and membrane–water partition coefficients of the anion species are only available for a few per‐ and polyfluoroalkyl substances (PFAS). In the present study, an equation is derived using a Born‐Haber cycle that relates the partition coefficients of the anions to those of the corresponding neutral species. It is shown via a thermodynamic analysis that for carboxylic acids (CAs), PFCAs, and PFSAs, the log of the solvent–water partition coefficient of the anion, log KSW(A−), is linearly related to the log of the solvent–water partition coefficient of the neutral acid, log KSW(HA), with a unity slope and a solvent‐dependent but solute‐independent intercept within a PFAS (or CA) family. This finding provides a method for estimating the partition coefficients of PFCAs and PFSAs anions using the partition coefficients of the neutral species, which can be reliably predicted using quantum chemical methods. In addition, we have found that the neutral octanol–water partition coefficient, log KOW, is linearly correlated to the neutral membrane–water partition coefficient, log KMW; therefore, log KOW, being a much easier property to estimate and/or measure, can be used to predict the neutral log KMW. Application of this approach to KOW and KMW for PFCAs and PFSAs demonstrates the utility of this methodology for evaluating reported experimental data and extending anion property data for chain lengths that are unavailable. Environ Toxicol Chem 2023;42:2317–2328. © 2023 SETAC [ABSTRACT FROM AUTHOR]

Compression Ignition (CI) engine is one of the vital powertrains which are used for heavy-duty commercial purposes because of their better fuel economy and high torque reserve. However, the use of diesel increases several harmful pollutants such as unburnt hydrocarbons, carbon monoxide, smoke, etc. Thus, finding an alternative fuel is necessary as it decreases pollution and also diesel is a non-renewable resource. The main aim of this work is to study the influence of diesel-octanol blends on the performance and emission characteristics of a CI engine. Octanol fuel was mixed with diesel in various proportions to obtain five blends and named as D90OCT10, D80OCT20, D70OCT30, D60OCT40 and D50OCT50. These blends are tested on a 5.9 kW four-stroke, single-cylinder diesel engine and the obtained results are compared with a neat diesel fuel at all the loads. It can be seen that the diesel-octanol blends showed an increase in brake thermal efficiency (BTE) compared to a diesel fuel. The HC and CO emissions can be seen to be reduced, while the NOX and smoke emissions are found to be higher than the diesel. The blends like D80OCT20 and D70OCT30 showed better results than D90OCT10, D60OCT40 and D50OCT50 blends with BTE of 28.13% and 29.56% respectively. Upon analysing the emissions, NOX was found to be high for D80OCT20 and D70OCT30 blends. This is attributed to the high in-cylinder temperature and pressure generated during fuel combustion. The presence of oxygen in the octanol helped in achieving more complete combustion. Due to this, the diesel-octanol blends showed superior performance and lower emission than diesel. [ABSTRACT FROM AUTHOR]

The current literature reports a few papers regarding the prediction of heat release rate of a diesel engine fuelled with n-octanol blends using numerical methods. To address this gap, the main objective of the presented study is to derive correlations for estimating the variation in heat release rate of a diesel engine fuelled with diesel fuel and diesel fuelbiodiesel- n-octanol blends. For this purpose, three different ternary blends were prepared by varying the n-octanol concentration to 6% (OCT6), 8% (OCT8), and 10% (OCT10) by volume. The estimation of heat release rate was accomplished using the least-squares regression (sine, piecewise, and rational equations) and the function approximation (Padé approximation) methods. The ignition delay and peak heat release rate increased by 3.8462%, 5.9501% for OCT6; 7.6923%, 3.7125% for OCT8; and 8.9744%, 3.0755% for OCT10, respectively, compared to diesel fuel. The peak cylinder pressure of OCT6 and OCT8 was observed to be higher by 2.4378% and 1.3982%, respectively, whereas that of OCT10 was found to be lower by 1.9458%, compared to diesel fuel. Compared to the others, the suggested rational equation qualitatively and quantitatively achieved the best correlation with all experimental heat release rate data measured by both the author and some other authors. [ABSTRACT FROM AUTHOR]

ATP, as a paracrine signalling molecule, induces intracellular Ca2+ elevation via the activation of purinergic receptors on the surface of glia-like cochlear supporting cells. These cells, including the Deiters' cells (DCs), are also coupled by gap junctions that allow the propagation of intercellular Ca2+ waves via diffusion of Ca2+ mobilising second messenger IP3 between neighbouring cells. We have compared the ATP-evoked Ca2+ transients and the effect of two different gap junction (GJ) blockers (octanol and carbenoxolone, CBX) on the Ca2+ transients in DCs located in the apical and middle turns of the hemicochlea preparation of BALB/c mice (P14–19). Octanol had no effect on Ca2+ signalling, while CBX inhibited the ATP response, more prominently in the middle turn. Based on astrocyte models and using our experimental results, we successfully simulated the Ca2+ dynamics in DCs in different cochlear regions. The mathematical model reliably described the Ca2+ transients in the DCs and suggested that the tonotopical differences could originate from differences in purinoceptor and Ca2+ pump expressions and in IP3–Ca2+ release mechanisms. The cochlear turn-dependent effect of CBX might be the result of the differing connexin isoform composition of GJs along the tonotopic axis. The contribution of IP3-mediated Ca2+ signalling inhibition by CBX cannot be excluded. [ABSTRACT FROM AUTHOR]

Water-soluble spin probes were obtained from reduction-resistant sterically shielded pyrrolidine nitroxides by forming a 4,5-dicarboxy-1H-1,2,3-triazole fragment in the side chain by the Huisgen reaction of the azido group with acetylenedicarboxylic acid ester followed by hydrolysis. For the synthesized radicals, the reduction rate constants by ascorbate and the partition coefficient in an octanol—water system were determined. [ABSTRACT FROM AUTHOR]

Understanding the volatile profile of melon is an ever increasingly important task for breeders for enhancing their flavour component. For this purpose, F1 progeny and parental lines were analysed using headspace‐solid phase microextraction gas chromatography–mass spectrometry‐based analysis. Diallel analysis showed that most of the investigated compounds were controlled via non‐additive genetic effects with general combining ability to specific combining ability ratios of less than 0.4. High heterosis results were observed in alcohols such as ethanol and octanol in both rind and mesocarp samples and benzylalcohol in the rind. It was also noted that the ester‐based compounds with high heterosis values in mesocarp samples differed from those with heterosis in rind samples. These observations further emphasize the non‐additive control of these compounds. It can be concluded that non‐additive genetic control is strongly governing the genetic profile within the studied progeny. This finding indicated that dudaim lines as a valuable genetic material enhanced the volatile profile of odourless commercial types of ameri and inodorus melon. [ABSTRACT FROM AUTHOR]

In this work, solvent extraction of In(III) from sulfate solutions by using mixtures of D2EHPA with octyl alcohol and octanoic acid was investigated. The introduction of the additives into the organic phase was shown to lead to an antagonistic effect thus facilitating efficient indium stripping from the loaded organic phase. The antagonistic effect is significantly higher in the D2EHPA (HR) and octyl alcohol (HA) mixtures. The formation of stable associates between D2EHPA and HA leads to a decrease in the extraction efficiency of indium. In the presence of alcohol, almost complete stripping of indium from a D2EHPA loaded phase can be achieved to produce a strip liquor containing>33.0 g/L In. Based on the analysis of the extraction data and by using nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy of the organic phases, it was concluded that indium extraction with D2EHPA in octyl alcohol is due to the formation of the extracted compound InR3. The equilibrium constant (logK) for indium extraction with solutions of D2EHPA in octyl alcohol was found to be − 0.12 ± 0.05. Extraction systems containing D2EHPA and octyl alcohol can be used to recover indium from various industrial solutions, in particular from the solutions derived from lead-zinc production and from liquid crystal display panel wastes. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) with long alkyl substituents are amphiphilic, which leads to a bicontinuous liquid structure. The strongly interacting anionic and cationic head groups form a long range charge network, with the hydrocarbon tails forming a nonpolar domain. Such nonpolar domains have been shown to dissolve a variety of neutral organic solvents. In mixtures of ILs with solvents the neutral organic molecules residing in the nonpolar domains experience different environments and friction from the charged cations and anions. Thus, the neutral molecules diffuse much faster than predicted by hydrodynamic scaling using the average viscosity of the mixture. In this work, we report studies on the structure and transport properties of mixtures of 1-octanol with the IL trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide ( P 6,6,6,14 + / NTf 2 − ). The majority of the atom fraction in the P 6,6,6,14 + cation comprises four hydrocarbon substituents. The unique amphiphilic nature of ILs with the P 6,6,6,14 + cation makes 1-octanol fully miscible with the IL at ambient temperatures. X-ray scattering experiments show that the IL structure persists in the mixtures for 1-octanol mole fractions as large as xoct = 0.90. The self-diffusion coefficients of the three molecular species in the mixtures were measured by NMR experiments. The self-diffusion of the P 6,6,6,14 + cation is well described by the Stokes–Einstein equation, while the diffusivity of the NTf 2 − anion is slightly lower than the hydrodynamic prediction. The measured diffusivities of octanol in these mixtures are 1.3–4 times higher than the hydrodynamic predictions. [ABSTRACT FROM AUTHOR]

We report a striking anomaly in the pressure dependent Debye-relaxation time of the branched monohydroxy alcohol 2-butyl-1-octanol. Evidence of a crossover from slower to faster than exponential pressure dependency was obtained at different temperatures via high pressure broadband dielectric spectroscopy. At the same time, viscosity measurements reveal similar behavior in the viscosity, respectively, the structural relaxation time, indicating a similar origin of the phenomena. [ABSTRACT FROM AUTHOR]

Blind predictions of octanol/water partition coefficients and pKa at 298.15 K for 22 drug-like compounds were made for the SAMPL7 challenge. Octanol/water partition coefficients were predicted from solvation free energies computed using electronic structure calculations with the SM12, SM8 and SMD solvation models. Within these calculations we compared the use of gas- and solution-phase optimized geometries of the solute. Based on these calculations we found that in general the use of solution phase-optimized geometries increases the affinity of the solutes for water as compared to octanol, with the use of gas-phase optimized geometries resulting in the better agreement with experiment. The pKa is computed using the direct approach, scaled solvent-accessible surface model, and the inclusion of an explicit water molecule, where the latter two methods have previously been shown to offer improved predictions as compared to the direct approach. We find that the use of an explicit water molecule provides superior predictions, and that the predicted macroscopic pKa is sensitive to the employed microstates. [ABSTRACT FROM AUTHOR]

Jules Bouis (1822-1886) was a French pharmacist that made a detailed study of castor oil. With the help of heat and distillation he separated and prepared a variety of compounds, such as œnantol, ricinolamide, ricinelaidic, caprylic, phosphocaprylic, and sebacic acids, ricinelaidine, caprylic alcohol, caprylene, capryl halides, sulfocaprylates, and capril amine. He also provided a detailed description of the physical and chemical properties of these compounds. Bouis analyzed the phenomena of solidification and fusion, particularly of fatty materials, and proposed a new method for their best determination based on covering the bulb of the thermometer with a thin layer of the material being tested. He explained the changes in the values of these parameters, when repeating the fusion-solidification cycle, as caused by a change in the structure of the solid phase. He gave a detailed tabulation of the variation of these parameters with the composition of a fatty mixture. Bouis studied the action of chlorine on mercury(I) cyanide in the dark and under the influence of sunlight and discovered a new derivative of formula C8N4Cl8,C4Cl6, methylene chloromesitate, and the existence of several cyanogene chlorides. Bouis studied the action of hydrogen on wrought iron and steel and found that it always generated ammonia from the outer layer of the metal and that steel contained much less nitrogen than wrought iron. This treatment transformed wrought iron into a very crystalline and fragile material that did not keep magnetism. [ABSTRACT FROM AUTHOR]

We present a systematic, top-down, thermodynamic parametrization scheme for dissipative particle dynamics (DPD) using water-octanol partition coefficients, supplemented by water-octanol phase equilibria and pure liquid phase density data.We demonstrate the feasibility of computing the required partition coefficients in DPD using brute-force simulation, within an adaptive semi-automatic staged optimization scheme. We test the methodology by fitting to experimental partition coefficient data for twenty one small molecules in five classes comprising alcohols and poly-alcohols, amines, ethers and simple aromatics, and alkanes (i.e., hexane). Finally, we illustrate the transferability of a subset of the determined parameters by calculating the critical micelle concentrations and mean aggregation numbers of selected alkyl ethoxylate surfactants, in good agreement with reported experimental values. [ABSTRACT FROM AUTHOR]

Efficient drug discovery is based on a concerted effort in optimizing bioactivity and compound properties such as lipophilicity, and is guided by efficiency metrics that reflect both aspects. While conformation–activity relationships and ligand conformational control are known strategies to improve bioactivity, the use of conformer‐specific lipophilicities (logp) is much less explored. Here we show how conformer‐specific logp values can be obtained from knowledge of the macroscopic logP value, and of the equilibrium constants between the individual species in water and in octanol. This is illustrated with fluorinated amide rotamers, with integration of rotamer 19F NMR signals as a facile, direct method to obtain logp values. The difference between logp and logP optimization is highlighted, giving rise to a novel avenue for lipophilicity control in drug discovery. [ABSTRACT FROM AUTHOR]

Efficient drug discovery is based on a concerted effort in optimizing bioactivity and compound properties such as lipophilicity, and is guided by efficiency metrics that reflect both aspects. While conformation–activity relationships and ligand conformational control are known strategies to improve bioactivity, the use of conformer‐specific lipophilicities (logp) is much less explored. Here we show how conformer‐specific logp values can be obtained from knowledge of the macroscopic logP value, and of the equilibrium constants between the individual species in water and in octanol. This is illustrated with fluorinated amide rotamers, with integration of rotamer 19F NMR signals as a facile, direct method to obtain logp values. The difference between logp and logP optimization is highlighted, giving rise to a novel avenue for lipophilicity control in drug discovery. [ABSTRACT FROM AUTHOR]

• The adhesion ability of different octanol solutions and the wrap angle of coal dust on the droplet surface were studied. • The wetting ability of different solutions was studied. • The surface energy difference between coal dust and octanol solution was studied. Using the high-speed motion acquisition system, we studied the adhesion ability and wetting ability of coal dust under the effect of four octanol solutions. The adhesion ability followed the order: 2-Octanol > 4-Octanol > 1-Octanol > 3-Octanol. The wrap angle of coal dust on the octanol surface exhibited an increasing trend with the rise in coal proportion of dust. The observed behavior was substantiated by the interaction force, ascertained through molecular dynamic simulations. The interaction force between coal dust and 3-Octanol was the smallest leading to the weakest adhesion ability by the 3-Octanol solution. The contact angle of octanol solution droplet at the coal dust surface under the same octanol concentration was investigated to follow the order: 2-Octanol > 4-Octanol > 1-Octanol > 3-Octanol. The wetting velocity decreased as the coal proportion of dust increased. The wetting ability followed the order: 2-Octanol < 4-Octanol < 1-Octanol < 3-Octanol. The surface energy of dust increased as the coal proportion decreased. The dedusting efficient under the effect of octanols depended on the difference in surface energy between the coal dust and the octanol solution. The greater the Δ γ (difference between the surface energy of the dust and solution), the weaker the adhesion ability, and the stronger the wetting ability. The findings of our study can offer valuable insights for the development of dedusting reagent design. [ABSTRACT FROM AUTHOR]

In the present work, a series of experiments were designed and conducted to prepare biodiesel from cottonseed oil and to blend it with octanol. The thermal and mass transfer characteristics of the biodiesel were further improved by adding functionalized multi-walled carbon nanotubes (MWCNTs). The performance of the engine with the blended fuel was analyzed through characterization and measurement of the gas emissions from the engine. Four blends of cottonseed oil (B20, B40, B60, and B100) were prepared initially, and each blend was added with octanol additive of 5%, 10%, and 15% together with 3% of functionalized MWCNTs by mass. The performance analysis showed that B20 with 5%, 10%, and 15% octanol represented relatively lower brake specific fuel consumption relative to all test fuels. Likewise, the addition of MWCNT nanoparticle further stabilized the rate of fuel consumption and brake thermal efficiency. It was also identified that at larger values of diesel and biodiesel blends, the performance and also the quantity of gas emission were the same. [ABSTRACT FROM AUTHOR]

Favipiravir (Fav) has become a well-known drug for medication of patients by appearance of COVID-19. Heterocyclic structure and connected peptide group could make changes for Fav yielding different features from those required features. Therefore, it is indeed a challenging task to prepare a Fav compound with specific features of desired function. In this work, existence of eight Fav structures by tautomeric formations and peptide group rotations were obtained using density functional theory (DFT) optimization calculations. Gas phase, octanol solution, and water solution were employed to show impact of solution on features of Fav besides obtaining partition coefficients (LogP) for Fav compounds. Significant impacts of solutions were seen on features of Fav with the obtained LogP order: Fav-7 > Fav-8 > Fav-4 > Fav-3 > Fav-2 > Fav-5 > Fav-1 > Fav-6. As a consequence, internal changes yielded significant impacts on features of Fav affirming its carful medication of COVID-19 patients. [ABSTRACT FROM AUTHOR]

Blind predictions of octanol/water partition coefficients at 298.15 K for 22 drug-like compounds were made for the SAMPL7 challenge. The octanol/water partition coefficients were predicted using solvation free energies computed using molecular dynamics simulations, wherein we considered the use of both pure and water-saturated 1-octanol to model the octanol-rich phase. Water and 1-octanol were modeled using TIP4P and TrAPPE-UA, respectively, which have been shown to well reproduce the experimental mutual solubility, and the solutes were modeled using GAFF. After the close of the SAMPL7 challenge, we additionally made predictions using TIP4P/2005 water. We found that the predictions were sensitive to the choice of water force field. However, the effect of water in the octanol-rich phase was found to be even more significant and non-negligible. The effect of inclusion of water was additionally sensitive to the chemical structure of the solute. [ABSTRACT FROM AUTHOR]

In an overview, the relationships between activity, property, and chemical structure of the anthracycline derivatives, as topoisomerase II enzyme inhibitors, were studied in pairs. These analogs were investigated in three categories with known half-maximal inhibitory concentration (IC50), known octanol/water partition coefficient (logP), and both IC50 and logP unknown values. The QSAR and QSPR models were developed on analogs of the first and second groups, respectively. LogP was related to calculated pIC50 ((pIC50)calc) surprisingly (R2 = 0.929, Q2LOO = 0.910, RMSE = 0.235, F = 157.511). External verification was performed through comparing calculated logP (logPcalc) with three programs using 77 analogs out of the training and test sets. In application domain of the model, the suggested model had the highest correlation with ClogP method (R = 0.744) and this was better than the correlation between milogP–ClogP (R = 0.724), AlogP–ClogP (R = 0.662), and AlogP–milogP (R = 0.691). Furthermore, in the case of analogs possessing a long carbon chain substitution (nc ≥ 3), estimation methods had a significant error in calculation logP, while our suggested model provides more accurate results. The proposed algorithm can be useful in primary screening among anthracycline derivatives to select potent drug candidates. [ABSTRACT FROM AUTHOR]

Octanol–water partition coefficients (log Kow) are widely used in pharmaceutical and environmental chemistry to assess the lipophilicity of compounds. Traditionally log Kow is determined using a shake-flask method that uses milliliters of sample and solvent and requires hours for preparation, extraction, and analysis. Here, we report an automated system for rapid log Kow determination for an array of compounds using slug flow nanoextraction (SFNE) enabled by a microfluidic chip. In the method, an autosampler is used to introduce 1 μL of sample into a microfluidic device that segments the injected volume into a series of 4 nL slugs that are each paired to an adjacent octanol slug. Each octanol–water phase pair is compartmentalized by an immiscible fluorous carrier fluid. During flow, rapid extraction occurs at each octanol–water interface. The resulting linear array of slugs flows into an online UV absorbance detector that is used to determine concentrations in the phases, allowing the log Kow to be measured. The microfluidic device allows toggling between two-phase "aqueous plug" generation (aqueous sample separated by fluorous carrier fluid) and three-phase "phase pair" generation. In this way, online calibration for detection in the aqueous phase can be achieved. The method is applied to determining log Kow for a panel of seven pharmaceutical compounds, including complete calibration curves, at three different pHs in under 2 h using 5 μL of extraction standard and 2.9 μL of octanol per extraction standard analyzed. [ABSTRACT FROM AUTHOR]

In this paper, the effects of octanol on the spray characteristics of biodiesel are investigated. Four kinds of blends fuel are used to explore the variation of spray tip penetration, spray cone angle, spray area, and spray tip velocity under different injection pressure and environmental pressure conditions. In addition, this article also uses the experimental data to verify the model of Hiroyasu and Arai. The results showed that with the increase in octanol proportion, the spray tip penetration decreased at first and then increased while the spray cone angle and the peak tip velocity increased at first and then decreased. Only the spray area increased gradually. Among various fuels, the blended fuel with 30% octanol has the longest spray tip penetration and the largest spray area, while the blended fuel with 20% octanol has the largest spray cone angle. The prediction data of the Hiroyasu and Arai model is greater than the experimental data. Therefore, this article revises the model by introducing the density term, viscosity term, and the correction factor. Compared with the Hiroyasu and Arai model, the modified spray model is in good agreement with the experimental data and is more suitable for predicting the macroscopic spray characteristics of the blended fuel under high injection pressure. [ABSTRACT FROM AUTHOR]

A recent study [C. Gainaru, R. Figuli, T. Hecksher, B. Jakobsen, J. C. Dyre, M. Wilhelm, and R. Böhmer, Phys. Rev. Lett. 112, 098301 (2014)] of two supercooled monohydroxy alcohols close to the glass-transition temperature showed that the Debye peak, thus far mainly observed in the electrical response, also has a mechanical signature. In this work, we apply broadband shear-mechanical spectroscopy to a systematic series of octanol structural isomers, x-methyl-3-heptanol (with x ranging from 2 to 6). We find that the characteristics of the mechanical signature overall follow the systematic behavior observed in dielectric spectroscopy. However, the influence from the molecular structure is strikingly small in mechanics (compared to roughly a factor 100 increase in dielectric strength) and one isomer clearly does not conform to the general ordering. Finally, the mechanical data surprisingly indicate that the size of the supramolecular structures responsible for the Debye process is nearly unchanged in the series. [ABSTRACT FROM AUTHOR]

BiOBr nanospheres grown in situ on lamellar Ti3C2 were synthesised in an octanol solvothermal system to obtain BiOBr/Ti3C2 heterojunction composites with high visible photocatalytic activity (OBT). The composition, crystal structure and morphology of OBT were characterised using X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. The photoelectrochemical properties of OBT were tested via UV-vis diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy and transient photocurrents. Results showed that the BiOBr prepared with octanol demonstrates loose nanospheres with a diameter of approximately 2 μm and clear characteristic peak intensity of the (110) crystal plane. Compared with pure-phase BiOBr and BiOBr/Ti3C2 heterojunction synthesis with an ethylene glycol solvothermal method (EBT), the increased visible-light response threshold of the OBT band gap and the significantly enhanced photogenerated current density of OBT effectively improve the oxidation efficiency of the aromatic ring structure. The rhodamine B degradation rate of OBT is approximately 10% higher than that of EBT. Trapping agent experiments confirmed the dominant role of ˙O2− in OBT photocatalytic processes. The results of this study can provide a basis for the analysis of the photocatalytic mechanism of OBT. [ABSTRACT FROM AUTHOR]

In this present study, the emissions and performance characteristics of four-stroke, single-cylinder, water-cooled, diesel engine fueled with different blends of Rice bran biodiesel and octanol blends i.e. RBD100, RBD90O10 (10% Volume of octanol dispersed in RBD100) and RBD80O20 (20% Volume of octanol dispersed in RBD100) at 1800 rpm for compression ratio 17.5:1 were investigated. The transesterification process was used for biodiesel production with the presence of the alkaline catalyst (KOH) and methanol. The optimum biodiesel yield was found to be 88%. The fuel properties of the blends were found to be within the ASTM limits. Experimental results revealed that BTE increased and BSFC decreased with octanol addition to rice bran biodiesel. Furthermore, the diesel engine fueled with octanol and biodiesel blends reduced the NOx, Smoke, HC, CO emission due to the higher latent heat of vaporization and improved chemical properties. [ABSTRACT FROM AUTHOR]

It is well established that many mono-hydroxy alcohols show an extra relaxation process of the Debye type in addition to the signatures of primary and secondary structural relaxations, which is observed only in dielectric spectroscopy and related techniques. In order to gain further insight into the nature of this Debye peak, we study the linear and nonlinear dielectric behavior of a series of isomeric octyl alcohols and of mixtures of n-propanol with one of the octanols. These samples display systematic variations of the Debye peak intensity and concomitant changes in the Kirkwood correlation factor gK from 0.1 to 4, indicative of different equilibrium constants, Kc/r, that characterize the populations of non-polar ring and polar open chain structures. For cases where Kc/r is not too far from unity, we find that a high electric field shifts Kc/r towards more chains, and that the accompanying change in the end-to-end vector of hydrogen-bond connected structures occurs on the Debye time scale. The results suggest that gK is correlated with the spectral separation of the Debye and primary structural peaks, as both features depend on steric hindrance of chain flexibility or bond rotation barriers and on average chain lengths. Based on the complex dynamics of supercooled mono-hydroxy alcohols with three relaxation peaks that cover many orders of magnitude in frequency, it is argued that a frequency dependent gK may be required for assessing the average orientational correlations within hydrogen-bonded structures correctly. [ABSTRACT FROM AUTHOR]

Power spectra are a powerful tool provided by two-dimensional correlation analysis. However, this tool is seldom used in practice. This work shows selected examples of using of the power spectra for the study of various kinds of samples with the aim to promote more common use of this tool. By examination of the power spectrum of specific sample, one can estimate the sensitivity of different molecular fragments on a given perturbation. Determination of the power spectra for smaller data subsets provides information on the dynamics of perturbation-induced spectral changes. If the experimental spectra of different samples in the same perturbation window are recorded, the comparison of the power spectra yields information on differences in the sensitivity of various samples on common perturbation. This possibility is particularly useful for studies of the spectra-structure correlations, interactions, and molecular dynamics. A comparison of the power spectra obtained by using different reference spectra provides information on the nature of spectral changes at different wavenumbers. [ABSTRACT FROM AUTHOR]

Campanula is one of the largest genus of the Campanulaceae family, represented by approximately 115 species in Turkey and is spread through Iran-Turan, Eastern Mediterranean and Mediterranean phytogeographical regions. The aim of the current study was to determine some morphological features, phenological characteristics and leaf-flower volatile components of Campanula rapunculus var. rapunculus collected in different sites of Uludag Mountain (Bursa). The average plant height was calculated as 37.21 cm, number of corolla was 2.4, the length of the corolla was 2.0 cm, calyx lobe length was 1.36 cm, leaf width was 1.7 cm and leaf length was 4.31 cm. Considering phenological features, it was measured that the first flowering ends in May, full flowering ends in June and late flowering ends in late July. A total of 32 different volatile components were detected in Campanula rapunculus. With the aid of gas chromatographymass spectroscopy (GC-MS) of volatile components by solid phase microextraction technique (SPME), 3-Methylbutanal (10.87%), cis-3-Hexene-1-ol (9.85%) and 3-Octanol (9.62%) were identified as major components. In addition to its medicinal benefits, studies on Campanula genus, considered as food and ornamental plants, should be increased and its value should be revealed. [ABSTRACT FROM AUTHOR]

Accurately computing partition coefficients is a pivotal part of drug discovery. Specifically, octanol–water partition coefficients can provide information into hydrophobicity of drug-like molecules, as well as a de facto representation of membrane permeability. However, one challenge facing the computation of partition coefficients is the need to encapsulate various microscopic environments. These include areas of largely bulk solvent (i.e., either water or octanol) or regions where octanol is saturated with water or areas of higher salt concentration. Also, tautomeric effects require consideration. Thus, we present a Boltzmann weighting approach that incorporates transfer free energies across varying microscopic media, as well as varying tautomeric state, to compute partition coefficients in the SAMPL6 challenge. [ABSTRACT FROM AUTHOR]

Design of metal oxide nanoparticles is a key study for obtaining high-functional materials with tunable properties. For that purpose, great progress on chemical methods for controlling the growth of nanoparticles during the synthesis has been made. However, an important challenge faced by this field of study is to completely understand the crystallization process and the chemical pathways during the syntheses that use growth-controlling agents. In this study, the synthesis of ZrO2 was conducted by a solvothermal methodology using three different organic solvents (oleic acid, benzyl alcohol and octyl alcohol) and adjusting the Zr precursor concentration, aiming to control the ZrO2 nanocrystal growth and obtain single-phase nanocrystalline particles. X-ray diffraction and Raman spectroscopy experiments indicated the formation of pure monoclinic, cubic and tetragonal ZrO2 nanocrystals for the syntheses using oleic acid, benzyl alcohol and octyl alcohol as solvents with precursor concentrations of 0.25, 0.50 and 0.50 mol L−1, respectively. Transmission electron microscopy was used to analyze the nanocrystal structure and to assess the crystal size distribution. Infrared and solid-state 13C nuclear magnetic resonance spectroscopy confirmed the presence of the organic ligands chemically bonded to the surface of the nanocrystals. Thermogravimetric analysis indicated an increasing ratio of ligand molecules/surface area as the acidity of the solvent increased. With the observations from this study, the solvent pKa value, the chemical structure and the type of coordination of the capping agents are ascribed as responsible for promoting different growth pathways, allowing pure crystalline phase zirconium oxide nanocrystals to be obtained. [ABSTRACT FROM AUTHOR]

Solubility of sulfadiazine (SD), sulfamerazine (SMR) and sulfamethazine (SMT) in cosolvent mixtures octanol+methanol was investigated to 278.15 K, 298.15 and 313.15 K. In all cases, the lowest solubility of each drug was obtained in pure octanol at 278.15 K. The maximum solubility depends on the polarity of the drug, thus SMR and SMT reached their maximum solubility in cosolvent mixtures methanol-rich. The solution thermodynamic functions were calculated from the experimental solubility data, using the van't Hoff and Gibbs equations, following the approach proposed by Krug et al. The enthalpy of solution is positive in all cases, which is an indication of the endothermic process with a marked entropic favor. Theoretical solubility and mean lethal concentration were calculated using the Abraham model. [ABSTRACT FROM AUTHOR]

Owing to its chemical and pharmacological significances, the efficacy of reactive separation of protocatechuic acid (0.001–0.01 kmol m−3) from aqueous stream by means of tri-n-octylamine (TOA), di-2-ethylhexyl phosphoric acid (D2EHPA) as well as tri-n-butyl phosphate (TBP) in octanol has been investigated, in terms of extraction efficiency, loading ratio, equilibrium complexation constants, and distribution coefficients. Extraction ability was obtained in the order TOA (91.2%) > TBP (88.64%) > D2EHPA (86.43%). In all cases, 1:1 protocatechuic acid:extractant complex is obtained. Further, diffusion coefficients, number of stages for extraction systems, and relative basicity model were used for relating the efficacy. [ABSTRACT FROM AUTHOR]

• Octanol and Pentanol improve hydrous ethanol/diesel blending stability. • TGA performed for D100, Pentanol, Octanol, ethanol, Pe10E10D80, and Oc10E10D80. • Engine combustion, performance, and exhaust emissions were tested. • The Oc10E10D80 and Pe10E10D80 have a higher total heat release compared to D100. • Smoke, NO x , CO and CO 2 emissions reduced by 73%, 33%, 83%, and 56%, respectively. Pentanol and Octanol are strong candidates to improve the blending stability of hydrous ethanol and diesel. Most of the available studies are limited to the stability assessment and properties characterization without combustion evaluation. In this study, the impact of ternary blends of pentanol/hydrous ethanol/diesel (Pe10E10D80) and octanol/hydrous ethanol/diesel (Oc10E10D80) on CI engine combustion and performance are investigated. The fuel characteristics are measured, and a thermogravimetric analysis is performed. A set of experiments are performed on a CI engine at a wide range of operating conditions. The experiments report that the peak cylinder pressures for Pe10E10D80 and Oc10E10D80 are lower than that of D100. The rate of heat release (RoHR) at premixed combustion phase is diminished but enhanced for diffusion combustion zone. Ignition delay and combustion duration increased for ternary blends. The BSEC and bsfc for Oc10E10D80 is lower than D100, but both for Pe10E10D80 are higher than D100. The BTE of Oc10E10D80 is higher than D100, but Pe10E10D80 has lower BTE. The smoke, NO x , CO and CO 2 emissions are reduced by 73%, 33%, 83%, and 56%, respectively. Pentanol and octanol addition to hydrous ethanol/diesel blend achieves better blending stability with improved engine performance and reduced emissions. [ABSTRACT FROM AUTHOR]

The near and midinfrared spectra of 1-octanol (and 2-octanol) have been measured along the liquid-gas coexistence curve from room temperature up to the critical point and in the supercritical domain along the isotherm T=385 °C (and T=365 °C) above the critical point of both 1-octanol and 2-octanol for pressure ranging from 0.5 up to 15 MPa. The density values of SC 1- and 2-octanol have been estimated by analysing the near infrared (NIR) spectra in the 3va(CH) region. A quantitative analysis of the absorption band associated with the OH stretching vibration [v(OH)] and its first and second overtones [2v(OH) and 3v(OH)] was carried out in order to estimate the percentage of “free” OH groups in both alcohols in the whole thermodynamic domain investigated here. Very consistent results have been obtained from the independent analysis of these three different absorption bands which gave us a good confidence in the degree of hydrogen bonding reported here for 1- and 2-octanol. Thus, the percentage of free OH groups which is around 5% in liquid 1-octanol under ambient conditions strongly increase up to 70%-80% at a temperature of about 340 °C. Then, in the supercritical domain, upon a decrease of the density from 0.4 to 0.1 g cm-3, the fraction of free hydroxyl groups is nearly constant presenting a plateaulike regime around 80%. As the density decreases again, this plateau regime is followed by a further increase of Xnb which reaches a value of 96% for the system in the gaseous phase (0.01 g cm-3; P=0.45 MPa). Finally, it comes out from this study that the percentage of free OH groups is always greater in 2-octanol than in 1-octanol at the same density. [ABSTRACT FROM AUTHOR]

The prominent Debye-type but non-Arrhenius dielectric relaxation is a feature common to many monohydroxy alcohols in their liquid state. Although this exponential process is often considered to reflect the primary structural relaxation, only a faster, smaller, and nonexponential relaxation peak correlates with viscous flow and mechanical relaxation. We provide dielectric relaxation data for 2-methyl-1-butanol, 2-ethyl-1-hexanol, and 3,7-dimethyl-1-octanol across ten decades in time. Based on these and previous results, we show that there exists a variety of dielectric to mechanical relaxation time ratios in the viscous regime, but a universal value of 100 for that ratio appears to evolve in the high temperature limit. The temperature dependence for both the relaxation time and strength of the Debye peak differs from the typical behavior of structural dynamics in terms of the α process. The implications of these findings for rationalizing the Debye-type dielectric process of hydrogen-bonded liquids are discussed.© 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The adsorption of 1-octanol at the free water surface has been investigated by Monte Carlo computer simulation. Six different systems, built up by an aqueous and a vapor phase, the latter also containing various number of octanol molecules, have been simulated. The number of the octanol molecules has been chosen in such a way that the octanol surface density varies in a broad range, between 0.27 and 7.83 μmol/m2 in the six systems simulated. For reference, the interfacial system containing bulk liquid octanol in the apolar phase has also been simulated. The results have shown that the formation of hydrogen bonds between the interfacial water and adsorbed octanol molecules is of key importance in determining the properties of the adsorbed layer. At low octanol surface concentration values all the octanol molecules are strongly (i.e., by hydrogen bonds) bound to the aqueous phase, whereas their interaction with each other is negligibly small. Hence, they are preferentially oriented in such a way that their own binding energy (and thus their own free energy) is minimized. In this preferred orientation the O–H bond of the octanol molecule points flatly toward the aqueous phase, declining by about 30° from the interfacial plane, irrespectively from whether the octanol molecule is the H-donor or the H-acceptor partner in the hydrogen bond. Hence, in its preferred orientation the octanol molecule can form at least two low energy hydrogen bonds with water: one as a H-donor and another one as a H-acceptor. Moreover, the preferred orientation of the hydrogen bonded water partners is close to one of the two preferred interfacial water alignments, in which the plane of the water molecule is parallel with the interface. When increasing the octanol surface density, the water surface gets saturated with hydrogen bonded octanols, and hence any further octanol molecule can just simply condense to the layer of the adsorbed octanols. The surface density value at which this saturation occurs is estimated to be about 1.7 μmol/m2. Above this surface density value the hydrogen bonded octanols and their water partners are oriented in such a way that the number of the water–octanol hydrogen bonds is maximized. Hence, the preferred alignment of the O...O axes of these hydrogen bonds is perpendicular to the interface. This orientation is far from the optimal alignment of the individual octanol molecules, which is also reflected in the observed fact that, unlike in the case of many other adsorbents, the average molecular binding energy of the adsorbed octanol molecules increases (i.e., becomes less negative) with increasing octanol surface density. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]