Physical Chemistry

Electron Spin-Echo Envelope Modulation (ESEEM) signals attributed to axial water bound to Cu +2 have been detected and analyzed in Cu(II)-doped 17 O-water enriched potassium zinc sulfate hexahydrate (tutton salt) crystals. The magnetic field orientation dependences of low frequency modulations were measured to fit hyperfine and quadrupole coupling tensors of a 17 O (I=5/2) nucleus. The hyperfine tensor (A xx , A yy , A zz : 0.13, 0.23, -3.81 MHz) exhibits almost axial symmetry with the largest value directed normal to the metal equatorial plane in the host structure. Comparisons with quantum chemical calculations position this nucleus about 2.3 Å from the copper. The isotropic coupling (-1.15 MHz) is small and reflects the weak axial water interaction with a d x2-y2 unshared orbital of copper. The 17 O-water quadrupole interaction parameters (e 2 qQ/h = 6.4 MHz and η =0.93) are close to the average of those found in a variety of solid hydrates. In addition, the coupling tensor directions correlate very closely with the O8 water geometry, with the maximum quadrupole direction 3º from the water plane normal, and its minimum coupling about 2º from the H-H direction. In almost all previous magnetic resonance 17 O-water studies, the quadrupole tensor orientation was based on theoretical considerations. This work represents one of the few experimental confirmations of its principal axis frame. When Cu 2+ dopes into Tutton salt, a Jahn-Teller distortion interchanges the relative long and intermediate metal O7 and O8 bond lengths of the zinc host. Therefore, only those unit cells containing the impurity conform to the pure copper tutton structure. This study provides further support for this model. Moreover, coupling interactions from distant H 2 17 O such as in the present case have important implications in studies of copper enzymes and proteins where substrates have been proposed to displace weakly bound water in the active site.

Yeni, suda çözünen 2(3),9(10),16(17),23(24)-tetrakis [4-(1-naftoksi-4-sulfonik asit sodyum)] kobalt(II)ftalosiyanin, NhtCoPc (Nht burada 1-naftoksi-4-sulfonik asit sodyum tuzu), sentezlendi, elementel analiz yöntemi, spektroskopik yöntemlerle (IR ve UV–vis) karakterize edilerek ve elektro-kimyasal, spektroelektrokimyasal ve moleküler oksijenin indirgenmesine yönelik elektro-katalitik davranışları detaylı bir şekilde incelendi. Kompleksleşme reaksiyonu metanol ortamında 2(3),9(10),16(17),23(24)- tetrakis [4-(1-naftoksi-4-sulfonik asit sodyum)] ftalosiyanin, NhtH2Pc’nin UV-vis spektrum değişikliklerine göre takip edildi. Q bandının maksimum şiddette olduğu anda reaksiyon tamamlandı. Elektrokimyasal çalışmalardan şu sonuçlar çıkarılmıştır: DMSO çözeltisinde kobalt(II) kompleksi anodik dalgaya karşılık gelen bir elektronlu iki tersinir indirgenme reaksiyonu ve bir tersinir olmayan yükseltgenme re...

Pc'nin UV-vis spektrum değişikliklerine göre takip edildi. Q bandının maksimum şiddette olduğu anda reaksiyon tamamlandı. Elektrokimyasal çalışmalardan şu sonuçlar çıkarılmıştır: DMSO çözeltisinde kobalt(II) kompleksi anodik dalgaya karşılık gelen bir elektronlu iki tersinir indirgenme reaksiyonu ve bir tersinir olmayan yükseltgenme reaksiyonu sergilemiştir. Gerçekleşen indirgenme reaksiyonları ve yükseltgenme reaksiyonu, Co(1+)Pc( Pt/PAni-NhtCoPc elektrot hazırlandı. Modifiye edilmiş elektrot SEM (elektron mikroskopu ile) karakterize edildi. NhtCoPc'ninpolimerizas-yon ortamına ilavesi ile elde edilen filmin morfolojisi önemli ölçüde değiştiği ve oluşan PAni-NhtCoPc filmin oksijen indirgenmesine yönelik redoks aktivitesinin yalnız platin ya da Pt/PAni elektrodlara kıyasla aynı deney koşullarında arttığı görüldü.

Turkey meat can be salted and dried in one step by soaking in a concentrated salt-glucose syrup solution at low temperature. Sugar impregnation is minimal; only low molecular weight sugars generally penetrate the product. Glucose uptake is very quick, suggesting the possible involvement of passive glucose transporters. The operational scope of this process, depending on the targeted end-product features, was determined for

Isothermal vapour-liquid equilibrium (VLE) data were measured for alcohol-carboxylic acid systems using a dynamic recirculating apparatus operated isothermally. For super-atmospheric pressures, a stainless steel version of the apparatus was used with sight glasses in the Cottrell pump and liquid and condensate sampling chambers to observe flow patterns. Data are presented for 2-propanol + butyric acid, 2-butanol + butyric acid, and 2-methyl-1-propanol + butyric acid at 333.15 K, 353.15 K, and 373.15 K. To account for vapour phase non-ideality the iterative procedure of Prausnitz et al.

Crosslinked hydrogels of poly(acrylic acid) neutralized with calcium hydroxide were synthesized using free radical co-polymerization. The effects of the amount added calcium on the elastic modulus and swelling properties of the gels and the correlation to phase behaviour and structural changes within the gels were studied using texture analysis, gravimetric analysis, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis and atomic force microscopy (AFM). It was found that the elastic modulus decreased nonlinearly with increasing amount of added calcium and that the swelling’s dependence on the amount of added calcium was complicated. The maximum swelling increased with increasing amount of added calcium until a critical calcium content was reached, upon which the gels phase separated, with a strong decrease in swelling as a result. The changes in properties are explained by the fact that calcium affects the structure of the polymer network during synthesis and b...

The effect of three different types of polymer chain structures on the polymer release from hydrophilic matrix tablets was investigated by comparing a synthetic semicrystalline linear polymer (PEO), a branched amorphous polysaccharide (dextran) and an amorphous substituted cellulose derivative (HPMC). The polymer release rates for tablets containing mixtures of high and low molecular weight grades in different ratios were determined by using a modified USP II method and a SEC-RI chromatography system. The results showed that independent of polymer type: (i) plots of the release versus time had similar shapes, (ii) the release of long and short polymer chains was equal and no fractionation occurred during the release and (iii) the release rate could be related to the average intrinsic viscosity of the polymer mixtures. This confirms the hypothesis that the release rate can be related to a constant viscosity on the surface of the hydrophilic matrix tablet and that it is valid for all the investigated polymers.

Photoinduced electron transfer (ET) processes in a donor–acceptor system based on triphenylamine and perylene imide have been studied at the single‐molecule (SM) and ensemble levels. The system exists as two isomers, one of which undergoes forward and reverse ET in toluene with decay constants of 3.0 and 2.2×109 s−1, respectively, resulting in the dual emission of quenched and delayed fluorescence while the other isomer remains ET‐inactive. The fluorescence of both isomers is heavily quenched in the more polar solvent, diethyl ether, by ET. A broad range of ET dynamics is seen at the SM level in polystryene with the two isomers nonresolvable indicating that the local nanoenvironment of the SMs varies considerably throughout the polymer matrix. Both the electronic coupling and the driving force for ET are shown to influence the ET dynamics. Many fluorescence trajectories of SMs show long periods (tens of milliseconds to seconds) where the count rate is attenuated either partly (a “di...

An investigation of simultaneous osmosis and diffusion was conducted in a setup consisting of a cylindrical ceramic element initially filled with 0.9 % sodium chloride (NaCl) aqueous solution and immersed a beaker initially filled with deionized water. The cylindrical element was made of kaolin with chemical composition Al 2 O 3 (52 %) SiO 2 (47 %) Na 2 O (0.3 %) K 2 O (0.7 %) and pore size of 0.1 -0.2 µm The levels of both liquids were the same at the start of the experiment and their ionic concentrations were monitored by measuring electrical conductivity with two identical meters with fixed probes in the corresponding sections. At a temperature of 20.4 o C, the final equilibrium occurred in 339 hours. Subsequently, the hydrogen bonds energy distributions of the two sulutions already with equal sodium chloride (NaCl) concentrations were measured with the methods of Non-equilibrium Energy Spectrum (NES) and Differential Non-equilibrium Energy Spectrum (NES). Distinct differences between the spectra were found in the whole range of (-E) from 0.0937 to 0.1387 eV, particularly at (0.1112 eV) (λ = 11.15 μm) (ṽ = 897 cm -1 ) eV and (0.1362 eV) (λ = 11.15 μm) (ṽ = 897 cm -1 ). In addition, the average strength of hydrogen bonds in the ceramic element was calculated as greater than that in the beaker.

Three varieties of pineapple were brought from Jimma Agricultural Research Center plant tissue culture and evaluated during 2015/2016 main cropping season at Teppi. The experiment was carried out to test the adaptability of improved pineapple varieties and to identify the best high yielding and pest and disease resistant/ tolerant variety/ies for the target area. The mean yield of tested varieties was ranged from 19.8tonne/ha for Queen to 70.4 tonne/ha for Smooth cayenne. The mean days to flowering was 406 days for smooth cayenne and 455 days for sugar loaf and Queen. The mean plant height was 82.33 cm for Queen to 113.93 cm for sugar loaf. The mean leaf length was 58.13 cm for Queen and 91.93 cm for Sugar loaf. The mean fruit length was 10.7 cm for Queen and 14.57 cm for Smooth Cayenne. The mean fruit diameter was 10.05 cm for Queen and 11.68 cm for Smooth cayenne. The mean average fruit weight was 1.01 kg for Queen and 1.65 kg for sugar loaf. Sugar loaf (69.7tonnes/ha) and Smooth ...

Heats of formation, entropy changes, free energy changes and equilibrium constant values at 25 °C were calculated by the use of AM1 semiempirical quantum chemical method. The calculations were performed on unsubstituted formamide-formamidic acid tautomeric system, as well as on substituted systems. The equilibrium constant value for the unsubstituted system was found to be 2.21 × 10 –9 . It is found that the tautomerization equilibria for the substituted systems, for all of the substituents employed in this work, have lower equilibrium constant values compared to that obtained for the unsubstituted system. These values were found to be several orders of 10 less, depending upon the substituent. Geometrical parameters (bond lengths and bond angles) were, also, reported for all of the compounds studied in this work. The results were compared to the available experimental values, and to those obtained from ab initio and DFT obtained at different levels of theory.

Defect engineering is a strategy that has been widely used to design active semiconductor photocatalysts. However, understanding the role of defects, such as oxygen vacancies, in controlling photocatalytic activity remains a challenge. Here we report the use of chemically-triggered fluorogenic probes to study the spatial distribution of active regions in individual tungsten oxide nanowires using super-resolution fluorescence microscopy. The nanowires show significant heterogeneity along their lengths for the photocatalytic generation of hydroxyl radicals. Through quantitative, coordinate-based colocalization of multiple probe molecules activated by the same nanowires, we demonstrate that the nanoscale regions most active fo the photocatalytic generation of hydroxyl radicals also possess a greater concentration of oxygen vacancies. Chemical modifications to remove or block access to surface oxygen vacancies, supported by calculations of binding energies of adsorbates to different surface sites on tungsten oxide, show how these defects control catalytic activity at both the ensemble and single-particle level. These findings reveal that clusters of oxygen vacancies activate surface-adsorbed water molecules towards photooxidation to produce hydroxyl radicals, a critical intermediate in several photocatalytic reactions.

Giant magnetostriction in Fe-- x Ga alloys ( 15 -- x - 27 ) offers potential for future generations of sensors and actuators. A maximum in the magnetostrictive strain is found at Ga content of about 19 percent, which is ten times higher than that of pure alpha-Fe. To investigate the behavior of FeGa alloys under pressure, we chose a slow cooled alloy of FeGa-19 as our sample and performed x-ray diffraction experiments in a diamond anvil cell up to 45 GPa. Diffraction pattern shows powder rings associated with (110), (200), and (211) Bragg reflections from expected bcc structure of iron below 24 GPa. We also observed the intensity increases along the powder rings associated with the crystal structure of Galfenol. Considering the (110) Bragg peak splits into three peaks above 24 GPa, our results indicate that FeGa alloy undergoes a bcc cubic to a hexagonal transition around 24 GPa. When the pressure is decreased, the hcp phase transforms back to the bcc phase. The transition mechanism...

This study presents the combined findings of laboratory experiments conducted to assess the efficacy of various ameliorants on saline-sodic soils in the foothill plain of Ile Alatau in the Northern Tianshan region. The investigation focused on the influence of phosphogypsum, elemental sulfur, nano sulfur, and sulfuric acid on the ionic composition of the soil solution and their impact on the soil-absorbing complex. Different doses of these ameliorants were applied to saline-sodic soil samples, and their incubation period was observed. The analysis of the aqueous extract of the soil emphasized the presence of bicarbonate, carbonate, sulfate, calcium, and sodium ions. The results revealed that sulfuric acid was the most effective ameliorant, rapidly neutralizing extreme alkalinity, reducing bicarbonate and carbonate ion content, and increasing sulfate and sodium ion concentrations. Elemental sulfur ranked second in effectiveness, significantly decreasing bicarbonate and carbonate ions...

The application of scanning electrochemical techniques to evaluate and spatially resolve corrosion activity has progressively increased over the last 20 years. Electrochemical scanning techniques are based principally upon the assumption that localised corrosion, where the anodic and cathodic processes take place at separate sites, can be represented as point sources. The electric field generated by sites of localised corrosion consists of equipotential lines which can be measured and graphically represented as a contour map. Many modern day systems use either a static or vibrating reference or quasi-reference electrode, to measure the electric field, more specifically the field normal (perpendicular) to the surface. The latter of these systems, namely the vibrating electrode, allows for improved resolution and a lower minimum detectable signal. The following paper presented here discusses a study conducted to evaluate the influence of the operating parameters on the resolution and minimum detectable signal measurable using a scanning vibrating electrode system. Measurement of the electric field generated at a point source, namely, a gold point in space (PIS) electrode, is used to evaluate the effect of parameters such as probe scan speed, vibration amplitude and probe-sample distance on the peak output potential and the resolution, defined here as the ratio of the peak potential to the full width at half-maximum peak potential (FWHM).

In order to provide boundary conditions for the numerical modeling of cathodic protection, a phenomenologicalmodel of the electrochemistry of steel in solutions or varying pH and pCI has been developed. Polarization curves have been measured for a range of solutions, and the results have been used to train neural networks to provide a predictor of the current density as a function of pH, pCI and applied potential. The resultant modelsproduce predicted polarization curves that are reasonably similar to the measured curves, although interpolated curves tend to have rather unrealistic fluctuations in current density as a function of applied potential.

Objective: Basis of this experiment was progressive preparation and evaluation of generated metronidazole loaded microsphere by desired ratio of polymers which can improve its therapeutic efficacy and reduce the need for frequent dosing. The use of microspheres can improve the bioavailability of the medication by protecting it from degradation and improving its absorption in the body. Drug release pattern can be altered by swelling Index and diffusion. Methods: Metronidazole loaded microsphere was prepared by ionotropic gelation technique using different combination of polymers, such as of Sodium alginate, Hydroxy propyl methylcellulose and Carbopol. Evaluation process for microspheres was performed by size analysis, percentage yield, swelling index, drug entrapment efficiency, drug release study (In-Vitro), kinetics models (Zero order, First order, Higuchi, Hixon-Crowell and Korsmeyers-Peppas) and stability testing. Findings: The average sizes of F1, F2 and F3 were observed and F2 had the lowest particle size. Swelling index was observed for all formulations, and F3 had the highest swelling property about 90%. During in-vitro drug release study it was noticed that F2 gives the highest percentage of drug release about 88.44% in comparison to other batches. Drug release kinetic study shows that F2 follows zero order and Higuchi model mostly with R 2 value 0.9987 and 0.9861 respectively. Stability study report for F2 batch was also acceptable for this study. Novelty: Previous researches was concentrated on controlled drug release study, bioavailability improvements and for dosage frequency reduction. But novelty of this project is to improve swelling potentiality of formulations by Ionotropic gelation techniques and finding out the association in between swelling property, drug diffusion and release kinetics of drugs that was not detected in prior studies. Also, this study determines better combination of hydrophilic polymer with respect to drug release property and improved release kinetics.

We present a general method to realize resonant coupling between spins even though their energies are of different scales. Applying the method to the electron and nuclear spin systems such as a nitrogen-vacancy (NV) center with its nearby nuclei, we show that a specific dynamical switching of the electron spin Rabi frequency achieves efficient electron-nuclear coupling, providing a much stronger quantum sensing signal and dynamic nuclear polarization than previous methods. This protocol has applications in high-field nanoscale nuclear magnetic resonances as well as low-power quantum control of nuclear spins.

Present paper deals with the synthesis, spectral characterization and X-ray diffraction study of Zn(II) complex with Pioglitazone a new oral antidiabetic drug. The conductometric titration using monovariation method indicate that complex is ionic and L 2 M type which was further confirmed by Job's method of continuous variation as modified by Turner and Anderson. Analytical data agree with the molecular formula of complex viz. [(C 19 H 19 N 2 O 3 S) + 2 Zn]2Cl -. Structure of complex was assigned as tetrahedral, in which ligand molecules lies horizontally joining the central Zn(II) atom, supported by IR, 1 H NMR and Mass studies. X-ray diffraction data also supports the complex formation and symmetry of complex.

In many products proteins have become an important component, and the long-term properties of these products are directly dependent on the stability of their proteins. To enhance this stability it has become common to add disaccharides in general, and trehalose in particular. However, the mechanisms by which disaccharides stabilize proteins and other biological materials are still not fully understood, and therefore we have here used broadband dielectric spectroscopy to investigate the stabilizing effect of the disaccharides trehalose and sucrose on myoglobin, with the aim to enhance this understanding in general and to obtain specific insights into why trehalose exhibits extraordinary stabilizing properties. The results show the existence of three or four clearly observed relaxation processes, where the three common relaxations are the local (b) water relaxation below the glass transition temperature (T g ), the structural a-relaxation of the solvent, observed above T g , and an even slower protein relaxation due to large-scale conformational protein motions. For the trehalose containing samples with less than 50 wt% myoglobin a fourth relaxation process was observed due to a b-relaxation of trehalose below T g . This latter process, which was assigned to intramolecular rotations of the monosaccharide rings in trehalose, could not be detected for high protein concentrations or for the sucrose containing samples. Since sucrose has previously been found to form more intramolecular hydrogen bonds at the present hydration levels, it is likely that this rotation becomes too slow to be observed in the case of sucrose. However, this sugar relaxation has probably less influence on the protein stability below T g , where the better stabilizing effect of trehalose on proteins can be explained by our observation that trehalose slows down the water relaxation more than sucrose does. Finally, we show that the a-relaxation of the solvent and the large-scale protein motions exhibit similar temperature dependences, which suggests that these protein motions are slaved by the a-relaxation. Furthermore, the a-relaxation of the trehalose solution is slower than for the corresponding sucrose solution, and thereby also the protein motions become slower in the trehalose solution, which explains the more efficient stabilizing effect of trehalose on proteins above T g .

The surface properties of several modified stainless steel samples were characterized according to their chemical composition, roughness, topography and wettability. The modifications tested were SiF þ 3 and MoS 2þ 2 ion implantation; diamond-like carbon (DLC) sputtering; DLC, DLC-Si-O and SiO x plasma enhanced chemical vapor deposition (PECVD); autocatalytic Ni-P-PTFE and silica coating. X-ray photoelectron spectroscopy (XPS) and X-ray microanalysis were applied to determine the surface chemical composition. Atomic force microscopy (AFM) and stylus-type instruments were used for roughness determination, and the surface topography was imaged with AFM and scanning electron microscopy (SEM). The contact angle and surface tension were measured with the Wilhelmy plate method and the sessile drop method. For thick modified layers, only the elements of the coating were detected at the surface, whereas for thin layers the surface composition determined was that of the stainless steel substrate. The roughness of the 2R (cold rolled and annealed in a protective atmosphere) surfaces was not altered by the modification techniques (except for the Ni-P-PTFE coating), while for the 2B (cold rolled, heat treated, pickled and skinpassed) surfaces an increase in roughness was observed. The silica coating produced surfaces with consistent roughness, independent of which steel substrate was used. DLC sputtering and Ni-P-PTFE coating produced surfaces with the highest roughness. All modified surfaces revealed a similar surface topography with the exception of the Ni-P-PTFE coating, for which the coating masked the underlying steel topography. In terms of wettability, the SiO x -plasmaCVD and Ni-P-PTFE coating techniques produced the most hydrophilic and hydrophobic surfaces, respectively.

Johne's disease (JD; paratuberculosis) control programs have been regionally implemented across the globe, but few have successfully eradicated the pathogen (Mycobacterium avium ssp. paratuberculosis; MAP) causing this disease. The limited success may partly be attributed to excluding young stock (calves and replacement heifers or bulls) from testing strategies aimed at identifying MAP-infected cattle. Young stock can shed MAP in feces and can have detectable MAP-specific antibodies in blood, as confirmed in experimentally and naturally infected cattle. Furthermore, MAP transmission causes new infections in young stock. Calves and heifers are often included in JD management strategies on dairy farms but excluded from conventional diagnostic tests due to a presumed lag between infection and detection of MAP shedding and MAP-specific serum antibodies. We summarize evidence of MAP shedding early in the course of infection and discuss promising diagnostics, testing and management strategies to support inclusion of young stock in JD control programs. Improvements in fecal PCR, interferon-gamma release assay (IGRA), and ELISA enable earlier detection of MAP and specific early immune responses. Studies on IGRA and ELISA have focused on evaluation of new antigens and optimal age of testing. New diagnostics have been developed, including phage-based tests to detect viable MAP, as well as gene expression patterns and metabolomics to detect MAP-infected young stock. In addition, refinements in testing and management of calves and heifers may enable reductions in MAP prevalence. We provide recommendations for dairy farmers, researchers, veterinarians, and other stakeholders that may improve JD control programs with an objective to control and potentially eradicate JD. Additionally, we have identified the most pressing gaps in knowledge that currently hamper inclusion of young stock in JD prevention and control programs. In summary, transmission among young stock may cause new MAP infections, and appropriate use of new diagnostic tests, testing and management strategies for young stock may improve the efficacy of JD control programs.

We have studied the reactivity towards dihydrogen of Ni 2+ -Ni + reduced ions, residing above two framework oxygen atoms, using a 18 SiO 4 tetrahedrals (18T) model cluster representing the intersection of the straight and the sinusoidal channels in ZSM-5 zeolite. Reported are a detailed analysis of the Ni + -H 2 orbital interactions, the thermodynamic stability, and characteristic spectral signatures of the predicted Ni + (H 2 ) n nonclassical hydrides for n = 1 and 2, at the B3LYP level of theory. Comparison is made to existing spectroscopy data for a Ni + (H 2 ) complex formed in Ni-exchanged ZSM-5 zeolite .

Quantum chemical calculations including DFT, MP2, MP4 and QCISD predict the formation of non-classical g 2 -hydride of Ag + coordinated to two oxygen atoms, in the frameworks of various zeolites. These model calculations are compared with existing zeolite structural data, other modelling works, and Inelastic Neutron Scattering (INS) spectroscopy data of dihydrogen adsorbed in a Ag-exchanged zeolite with LTA topology. It is also found that, although a little less stable, the corresponding g 2 -H 2 -Ag + exist as well in the gas phase.

In this work, we have studied the vacancy formation energy of TiN alloy of structure B2 of size 10 × 10 × 10 for nitrogen percentages of 45%, 50% and 55% under the influence of temperature at 1320 K, 1420 K and 1520 K using the Modified Embedded Atom Method MEAM under the calculation code LAMMPS version 2020. This study has enabled us to understand the behavior of the TiN alloy under different nitrogen percentages in terms of total energy, vacancy formation energy, crystalline parameter, occupancy rate and order parameter. For total energy, we have shown that as temperature increases, total energy decreases, making it easier to obtain TiN at higher temperatures; reaching the value of -7344.9169 eV for the 55% nitrogen structure for the temperature of 1420 K. For the energy of formation, we have shown that the compounds obtained at 1320 K and 1520 K have a more considerable energy of formation than that obtained at 1420 K. The study of fractions and the order parameter showed us that the structure of TiN with 55% nitrogen is less likely, as the composition obtained is at most 53.35%.

Wadi Bandawaya, which is 40 km north of Mosul in Iraq, pierces Mount Dahqan and creates a small valley that is ideal for the construction of a dam for harvesting rainwater. Water quality is evaluated for domestic and agricultural uses using chemical analyses of the main cations (Ca 2+ , Mg 2+ , Na + , K + ), anions (HCO 3 -SO4 2-, Cl -, NO 3 -), as well as measurements of the acidity function (pH), electrical conductivity (Ec), concentration of total dissolved salts (TDS), and total hardness (TH). The valley water is considered to be within the limits permitted for drinking by the World Health Organization. If held inside the water harvesting project of the Bandawaya dam, the water of Bandawaya Valley is freshwater, suitable for drinking and domestic applications, according to the water quality index (WQI). It is also suitable for irrigation of agricultural lands adjacent to the valley in accordance with standards of the percentage of sodium (SSP), the rate of sodium adsorption (Sodium Adsorption Ratio, SAR), the quantity of residual sodium carbonate (Residual Sodium Bicarbonate, RSBC), and the percentage of magnesium (MAR). When there is little rain, the harvested water will be used for irrigation, as well as for supplemental irrigation techniques. Particularly in semi-arid and Mediterranean climate regions, the recent climatic ______________________________________________________

pH regulation is essential to allow normal cell function, and their imbalance is associated with different pathologic situations, including cancer. In this study, we present the synthesis of 2-(((2-aminoethyl)imino)methyl)phenol (HL1) and the iron (III) complex (Fe(L1)2Br, (C1)), confirmed by X-ray diffraction analysis. The absorption and emission properties of complex C1 were assessed in the presence and absence of different physiologically relevant analytes, finding a fluorescent turn-on when OH− was added. So, we determined the limit of detection (LOD = 3.97 × 10−9 M), stoichiometry (1:1), and association constant (Kas = 5.86 × 103 M−1). Using DFT calculations, we proposed a spontaneous decomposition mechanism for C1. After characterization, complex C1 was evaluated as an intracellular pH chemosensor on the human primary gastric adenocarcinoma (AGS) and non-tumoral gastric epithelia (GES-1) cell lines, finding fluorescent signal activation in the latter when compared to AGS cells...

Je souhaite en premier lieu adresser mes sincères remerciements à ma directrice de thèse, Marie-France BARTHE (Directrice de Recherche, CEMHTI, CNRS, Orléans), pour m'avoir confié ce travail de recherches et accueilli au sein de son équipe. Je lui suis également reconnaissant pour son aide, le temps qu'elle m'a accordé, ses qualités pédagogiques et scientifiques, sa loyauté et sa sympathie. J'ai beaucoup appris à ses côtés et je lui exprime toute ma gratitude. Mes remerciements vont également à Marie-

A variety of heterocyclic analogs of Win 54954 have been synthesized and tested in vitro against human rhinovirus type 14 (HRV-14) in a plaque reduction assay. The more active compounds were tested against 14 additional serotypes, and the concentration which inhibited 80% of the serotypes tested (MICN) was measured. One compound, 37, exhibited activity comparable to Win 59454. Physicochemical as well as electrostatic parameters were calculated and the results subjected t o a QSAR analysis in an effort t o explain differences in activity observed between these compounds; however, no meaningful correlation with biological activity was found with any of these parameters. During the past several years, we have been investigating the inhibition of uncoating as a viable approach to the chemotherapy of picornavirus infections. Arildone (1) was first shown to prevent replication of polio virus type 2,' and disoxaril (2) was subsequently found to inhibit the 2 replication of rhinovirus type 2 (HRV-2) by this mechanism.2 The significance of this approach in the chemotherapy of enteroviral infections has been demonstrated with the prevention of paralysis and death when several of these compounds were administered to mice infected with either polio or ECHO virus, as late as 72 h postinfe~tion.3-'~ The determination of the three-dimensional structure of human rhinovirus-14 (HRV-14)" subsequently resulted in the elucidation of the binding site of disoxariland related

Potassium-ion-based batteries have emerged as promising alternatives to traditional lithium-ion batteries for energy storage systems due to their affordability, wide accessibility and comparable chemical characteristics to lithium. This study employs molecular dynamics simulations to explore the physical phenomena of potassium fluoride in aqueous solutions. The interatomic interactions were defined using the OPLS-AA force field, while the SPC/E water model and ions were represented as charged Lennard-Jones particles. The simulations were conducted across concentrations ranging from 0.1 to 1.0 mol kg -1 . The insights derived from this investigation provide valuable understanding into the behaviour of KF electrolytes and their potential utility in energy storage systems. A comprehensive comprehension of the impact of KF electrolyte concentration on structural, dynamic and dielectric properties is pivotal for the design and optimization of potassium-ion batteries, as well as other electrochemical devices leveraging KF-based electrolytes. This research significantly contributes to the ongoing endeavours aimed at developing efficient and economically viable energy storage solutions that transcend the confines of traditional lithium-ion batteries.

The paper presents extensive parametric study on ultrashort pulse laser micromachining of different materials. The experiment was conducted using SpectraPhysics femtosecond laser system. The laser offers 35 fs pulses with tunable wavelength and 1 kHz repetition rate. Therefore, the system itself allows to perform a complex research for a wide range of various parameters and materials. Laser micromachining is a process based on a laser ablation phenomenon, i.e. microscopic removal of the material from the sample surface during laser irradiation. The process is strongly dependent from the applied laser radiation parameters and is considered the most precise method of material removal. The use of femtosecond laser pulses in micromachining allows a high concentration of energy within a single laser pulse and enables the detachment of particles from the irradiated target without any thermal damage to the surrounding material. The removal of the material occurs in the Rayleigh range from ...

On account of its surpassing theoretical specific capacity (1675 mAh/g) and energy density (2600 wh/Kg), lithium-sulfur (Li-S) battery has attracted extensive attention nowadays. However, its practical application is hindered by the electric insulativity of sulfur and Li 2 S as well as the well-known shuttle effect. In this work, a novel method, supercritical CO 2 (SCCO 2 ) assisted precipitation, is reported to load sulfur onto commercial activated carbon (QR1500) as cathode material of Li-S battery, which exhibits improved cycling performance. SCCO 2 provides low viscosity, low surface tension and high diffusivity like gas as well as appreciable density and solvation power like liquid, enabling uniform dispersion of sulfur into porous QR1500 and intimate contact of sulfur with carbon. As cathode materials of Li-S battery, the resultant composite gives rise to an initial discharge capacity of 810 mAh/g at 0.5˚C, which is higher than that of 139 mAh/g for its counterpart prepared by traditional melting infiltration. Furthermore, 55% of capacity was preserved after 150 cycles.

The development of Hybrid Optical Devices, using some flexible optically transparent substrate material and organic semiconductor materials, has been widely utilized by the organic electronic industry, when manufacturing new technological products. The Hybrid Optical Device is constituted by the union of the electrochromic device and the organic solar cell. The flexible organic photovoltaic solar cells, in this hybrid optical device, have been the Poly base (3-hexyl thiophene), P3HT, Phenyl-C61-butyric acid methyl ester, PCBM and Polyaniline, PANI, all being deposited in Indium Tin Oxide, ITO. In addition, the thin film, obtained by the deposition of PANI, and prepared in perchloric acid solution, has been identified through PANI-X1. In the flexible electrochromic device, the Poly base (3,4-ethylenedioxythiophene), PEDOT, has been prepared in Propylene Carbonate, PC, being deposited in Indium Tin Oxide, ITO. Also, both devices have been united by an electrolyte solution prepared wit...

Lithium-ion cells can be considered a laminate of thin plies comprising the anode, separator, and cathode. Lithium-ion cells are vulnerable toward out-of-plane loading. When simulating such structures under out-of-plane mechanical loads, subordinate approaches such as shells or plates are sub-optimal because they are blind toward out-of-plane strains and stresses. On the other hand, the use of solid elements leads to limitations in terms of computational efficiency independent of the time integration method. In this paper, the bottlenecks of both (implicit and explicit) methods are discussed, and an alternative approach is shown. Proper generalized decomposition (PGD) is used for this purpose. This computational method makes it possible to divide the problem into the characteristic in-plane and out-of-plane behaviors. The separation of space achieved with this method is demonstrated on a static linearized problem of a lithium-ion cell structure. The results are compared with conventional solution approaches. Moreover, an inplane/out-of-plane separated representation is also built using proper orthogonal decomposition (POD). This simply serves to compare the in-plane and out-ofplane behaviors estimated by the PGD and does not allow computational advantages relative to conventional techniques. Finally, the time savings and the resulting deviations are discussed.

Plasminogen activators are the proteases which convert plasminogen into plasmin dissolving, in its turn, the major component of blood clots, fibrin. They are extremely useful in heart attack therapy. Modern and most appropriate way of scaled up production of these valuable proteins is gene engineering. In this case, a separation and a purification of target product become the important steps of the whole process. Recently developed affinity chromatography on short monolithic columns seems to be a very attractive method for these purposes. High speed of a process prevents the protein's denaturation due to temperature or/and solvents influence. The better mass transfer mechanism (convection rather than diffusion) allows considering only biospecific complexing as time limiting step. Specificity of several synthetic peptides to plasminogen activators have been studied by affinity chromatography on short monolithic columns. Peptide ligands were synthesized by conventional solid phase peptide synthesis (SPPS). The immobilization procedure was carried out as a one step process at static conditions. The results of quantitative evaluation of such affinity interactions were compared with those established for plasminogen that is the natural affinity counterpart to both proteases. Additionally, some of investigated peptides were synthesized directly on GMA-EDMA disks and their affinity properties were compared with those established for the case of immobilized ligands. The possibility of using of synthetic peptidyl ligands for plasminogen activators isolation from native cell supernatant and model protein mixtures has been demonstrated.

The purpose of the present study was to investigate the possibility of improving the dissolution properties of glisentide, a poorly water-soluble antidiabetic drug, by grinding in a high energy micromill, alone or in mixture with polyvinylpyrrolidone (PVP). Conventional and modulated differential scanning calorimetry (DSC, MDSC), thermogravimetry (TGA), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), hot-stage FT-IR thermomicroscopy and scanning electron microscopy (SEM) were used to characterize the drug solid state, whereas its dissolution rates were determined according to the dispersed amount method. The techniques utilized enabled exclusion of polymorphism phenomena as a consequence of mechanical treatment, and revealed a progressive drug amorphization during grinding. In particular, MDSC allowed a clear determination of the glass transition temperature of the amorphous drug, enabling separation of glass transition from enthalpic relaxation. The amorphous state of the ground drug was the main responsible factor for the obtained 100% dissolution efficiency increase in comparison with the untreated drug. Further significant increases in dissolution properties, directly related to the polymer content in the mixture, were obtained by co-grinding with PVP, whose presence clearly favored drug amorphization, allowing a strong reduction of time and frequency of grinding necessary for obtaining complete drug amorphization.

In heterogeneous catalysis, carrier systems are most often composed of inorganic materials whereas organic scaffolds are much less represented. Heterogeneous catalysis using metal nanoparticles often suffers from loss of activity over time due to undesired release of metal into the reaction medium (catalyst bleeding). As an alternative to the direct loading of nanoparticles to the matrices, we have developed electroless plating methods for porous bodies that afford metal loading as films rather than particles. These films are distributed more evenly among the inner surface of the porous scaffold and less prone to typical degradation mechanisms such as nanoparticle detachment, nanoparticle agglomeration, or leaching. Here, we show that aerogels can be metalized using the electroless plating approach. More specifically, we demonstrate the homogenous decoration of porous organic scaffolds based on cellulose and resorcinol-formaldehyde with various transition metals including silver, go...

A simplified apparatus is described that measures the damping of a suspended measuring device. The movement of the device (bob) is damped by the properties of the air-water surface adsorbed material. Its value lies in describing the surface chemomechanical properties of ingredients and excipients used in food, nutraceutical, cosmetic (cosmeceutical), and natural drug-food product formulations that traverse the food sciences. Two surfactants, two food and drug-grade polymers, and five naturally occurring food and serum proteins were tested and used to estimate and model interfacial viscoelasticity. Equilibration times of >15 min were found to give sufficiently stable interfaces for routine assessment. The viscoelasticity of the air-water interface was estimated with reference to model solutions. These model solutions and associated self-assembled interfacial nanostructured adsorbed layers were fabricated using a preliminary screening process with the aid of a specialized foaming apparatus (C 300 values), surface tension measurements (23-73 mN/m), and referential surface shear and dilation experiments. The viscoelasticity measured as a percentage of surface damping (D) of a pendulum was found to range from 1.0 to 22.4% across the samples tested, and this represented interfacial viscosities in the range of 0-4630 µNs/m. The technique can distinguish between interfacial compositions and positions itself as an easily accessible valuable addition to tensiometric and analytical biochemistry-based techniques.

Purpose. To show that thermally stimulated depolarization currents (TSDC), which is a dielectric experimental technique relatively unknown in the pharmaceutical scientists community, is a powerful technique to study molecular mobility in pharmaceutical solids, below their glass transition temperature (T g ). Indomethacin (T g ‫ס‬ 42°C) is used as a model compound. Methods. TSDC is used to isolate the individual modes of motion present in indomethacin, in the temperature range between -165°C and +60°C. From the experimental output of the TSDC experiments, the kinetic parameters associated with the different relaxational modes of motion were obtained, which allowed a detailed characterization of the distribution of relaxation times of the complex relaxations observed in indomethacin. Results. Two different relaxational processes were detected and characterized: the glass transition relaxation, or ␣-process, and a sub-T g relaxation, or secondary process. The lower temperature secondary process presents a very low intensity, a very low activation energy, and a very low degree of cooperativity. The fragility index (Angell's scale) of indomethacin obtained from TSDC data is m ‫ס‬ 64, which can be compared with other values reported in the literature and obtained from other experimental techniques. Conclusions. TSDC data indicate that indomethacin is a relatively strong glass former (fragility similar to glycerol but lower than sorbitol, trehalose, and sucrose). The high-resolution power of the TSDC technique is illustrated by the fact that it detected and characterized the secondary relaxation in indomethacin, which was not possible by other techniques.

The economics and environmental impact of a new technology for the production of urea from municipal solid waste, particularly the residue-derived fuel (RdF) fraction, is analyzed. Estimates indicate a cost of production of approximately €135 per ton of urea (internal rate of return more than 10 %) and savings of approximately 0.113 tons of CH4 and approximately 0.78 tons of CO2 per ton of urea produced. Thus, the results show that this waste-to-urea (WtU) technology is both economically valuable and environmentally advantageous (in terms of saving resources and limiting carbon footprint) for the production of chemicals from municipal solid waste in comparison with both the production of urea with conventional technology (starting from natural gas) and the use of RdF to produce electrical energy (waste-to-energy). A further benefit is the lower environmental impact of the solid residue produced from RdF conversion. The further benefit of this technology is the possibility to realize...

Aqueous organic redox-flow batteries have emerged as promising candidates for the low-cost long-duration energy storage solution that is required to integrate renewable energy into the electricity grid. However, their widescale deployment is currently limited by crossover of redoxactive material through the separator membrane, which leads to capacity decay over time. Traditional membrane permeability measurements only account for diffusional crossover, and do not capture all contributions to membrane transport in working batteries, including migration. Here we present a new method for characterising crossover in operating aqueous organic redox-flow batteries, using on-line 1 H NMR analysis. Using the 2,6-dihydroxyantharquinone/ferrocyanide battery as a model, we observed a doubling of 2,6-dihydroxyantharquinone crossover rates during battery charging, which we believe is due to additional transport by migration. This method can distinguish different transport mechanisms during battery charging and will aid the optimisation of charging protocols and membrane design in the future. Tackling the climate crisis requires huge increases in renewable power generation from wind and solar 1 . Established technologies are too expensive to regulate their intermittent energy output on a large scale 2,3 , hence research into aqueous organic redox-flow batteries (AORFBs) has recently intensified . An AORFB consists of two aqueous electrolytes (anolyte and catholyte) that are separated by an ion-selective membrane (Fig. ). The electrolytes are pumped into the electrochemical cell, where they are charged or discharged. Utilising a modular design and organic redox-active materials, these batteries have the potential to meet cost, scalability, safety and sustainability targets . However, the lifetime of these batteries is limited by crossover-driven capacity fade . "Crossover" describes the unwanted transport of redox-active components through the membrane. This is generally assessed using single-electrolyte diffusion-cell experiments 9,11-15 , though the measured permeabilities do not always correlate well with battery performance 9 . To further advance membrane design, there is a need for methods that accurately capture crossover in operating AORFBs 10-12 .

Soft-templating synthesis provides an effective route to prepare ordered mesoporous carbons (MCs) that can be used for supercapacitors. During this process, the cross-linking of carbon precursors is critical to obtain tailored pore structural MCs, thus careful selection of appropriate cross-linking agents is required. Despite the shift from the prevailing cross-linker formaldehyde to its more environmentally friendly alternatives, detailed understanding on the influence of different crosslinking agents on templating synthesis is still lacking. Therefore, it remains challenging to draw a conclusion which crosslinker can effectively enable an ideal cross-linking and a robust templating synthesis of ordered MCs. This work presents a systematic study, by comparing three typical cross-linkers (formaldehyde, glyoxal, and glyoxylic acid), on the pore architecture, surface functionality, and electrochemical performance of resulting MCs. Both the type of cross-linker and its ratio with precursor monomer were found to be crucial for the pore architecture and electrochemical performance of resulting MCs. Glyoxal showed to be a promising cross-linker for easily generating ordered mesopores between 3.3-6.1 nm when the molar ratio between cross-linker and carbon precursor ranged from 1 to 2, whereas glyoxylic acid and formaldehyde induced interrupted or disordered mesopores. When the resulting MCs were used as supercapacitor electrodes, those cross-linked with glyoxal also led to overall higher capacitance in both 6 M KOH aqueous and ionic liquid [N2220][NTf2]/acetonitrile electrolytes thanks to the dominance of ordered mesopore channels, especially MC prepared at glyoxal/precursor molar ratio of 1.5. These findings on the effect of cross-linking on templating synthesis can be used to guide the customisation of MCs for supercapacitors and other applications by smartly choosing a suitable cross-linking agent and its ratio with the precursor.