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The present paper describes first an efficient methodology for an easy O -functionalization (alkylation) of tetracyclic hydroxyisoxazolines 1 applied to the synthesis of eight examples of new 3-(alkoxy)-3-(trifluoromethyl)-3,3a-dihydrospiro[chromeno [4,3- c ]isoxazole-4,1′-cycloalkanes] ( 6-9 ) at 61–84% yields, in which the alkoxy substituents were methoxy, benzyloxy, allyloxy, or prop-2-yn-1-yloxy; while the cycloalkanes were 5-, 6-, and 7-membered carbocycles, as well as 4′-methyl- and 4′- t -butyl-cyclohexane. The reaction medium used 1 , four alkyl halides ( 2 - 5 ), K 2 CO 3 , and KI in DMF at room temperature. The selected 3-(prop-2-yn-1-yloxy)-substituted isoxazolines 6 were successfully used as a CC -fragment in the construction of another series of five examples of 3-((1-benzyl-1 H -1,2,3-triazol-4-yl)methoxy)-3-(trifluoromethyl)-3,3a-dihydrospiro[chromeno[4,3- c ]isoxazole-4,1′-cycloalkanes] ( 10 ), at 36–84% yields, through a regioselective 1,3 dipolar cycloaddition reaction catalyzed by copper iodide (CuAAC), using benzyl azide as an NNN -building block (Click Chemistry). [ABSTRACT FROM AUTHOR]

Multiwalled carbon nanotubes (MWCNTs) were fabricated via the detonation of a mixed gas consisting of ferrocene vapor, methane, and oxygen. The samples were characterized using transmission electron microscopy, X-ray diffraction, Raman spectroscopy, vibrating sample magnetometry, and a vector network analyzer. The results indicate that the samples were MWCNTs that were about 30 nm in external diameter, about 15 nm in inner diameter. The ferrocene dosage had an obvious effect on the morphology, degree of graphitization, and magnetic property of the MWCNTs. The growth mechanism of the MWCNTs in the gaseous detonation process was discussed using the detonation Zeldovich-von Neumann-Döring model and a vapor-liquid-solid growth model. The minimum reflection loss of the MWCNTs was −6.1 dB at 11.2 GHz with a thickness of 2 mm, which is lower than that of the MWCNTs prepared via other methods, and the reasons for this result are analyzed in the paper. [ABSTRACT FROM AUTHOR]

Magnesium hydride (MgH 2 ) is a very promising hydrogen storage material and it has been paid more and more attention on the application of supplying hydrogen on-board because the theoretical hydrogen yield is up to 1703 mL/g when it reacts with water. However, the hydrolysis reaction is inhibited rapidly by the passivation layer of Mg(OH) 2 formed on the surface of MgH 2 . This paper reports that high purity MgH 2 (∼98.7 wt%) can be readily obtained by the process of hydriding combustion synthesis (HCS) and the hydrogen generation via hydrolysis of the as-prepared HCSed MgH 2 can be dramatically enhanced by the addition of AlCl 3 in hydrolysis solutions. An excellent kinetics of hydrogen generation of 1487 mL/g in 10 min and 1683 mL/g in 17 min at 303 K was achieved for the MgH 2 -0.5 M AlCl 3 system, in which the theoretical hydrogen yield (1685 mL/g) of the HCSed product was nearly reached. The mechanism of the hydrolysis kinetics enhancement was demonstrated by the generation of a large amounts of H + from the Al 3+ hydrolysis and the pitting corrosion (Cl − ) of the Mg(OH) 2 layer wrapped on the surface of MgH 2 even at a low temperature. In addition, the apparent activation energies for the MgH 2 hydrolysis in the 0.1 M AlCl 3 and 0.5 M AlCl 3 solutions are decreased to 34.68 kJ/mol and 21.64 kJ/mol, respectively, being far superior to that of reported in deionized water (58.06 kJ/mol). The results suggest that MgH 2 + AlCl 3 system may be used as a promising hydrogen generation system in practical application of supplying hydrogen on-board. [ABSTRACT FROM AUTHOR]

In this Digest paper, various approaches toward chemical synthesis of negamycin, a natural dipeptide-like antibiotic, were summarized. The strategy and tactics in each individual synthesis were highlighted. Although the chemical structure of negamycin is relatively simple, the promising bioactivity against Gram-negative bacteria with a novel mechanism of action renders it as an intriguing lead compound for medicinal development. [ABSTRACT FROM AUTHOR]

In this paper, Bi 2 MoO 6 /ZnFe 2 O 4 heterojunctions were successfully obtained by combining electrospinning and a solvothermal technique. The morphology and loading of Bi 2 MoO 6 nanosheets of Bi 2 MoO 6 /ZnFe 2 O 4 heterojunctions could be controlled by adjusting the concentration of molybdenum precursor during the solvothermal process. Comparative experiments revealed that the resulting Bi 2 MoO 6 /ZnFe 2 O 4 heterojunctions exhibit a higher visible light photocatalytic activity for the degradation of Rhodamine B (RB) than pure Bi 2 MoO 6 or ZnFe 2 O 4 . The photocurrent and PL measurements of the Bi 2 MoO 6 /ZnFe 2 O 4 heterojunctions also indicated an enhanced separation of photo-induced electron-hole pairs. Moreover, the heterojunctions could be easily recycled without a decrease in their photocatalytic activity due to their good magnetic separation performance and excellent chemical stability. Based on these findings, Bi 2 MoO 6 /ZnFe 2 O 4 heterojunctions are a promising visible-light-driven photocatalyst for converting solar energy to chemical energy for environmental remediation. [ABSTRACT FROM AUTHOR]

This paper deals with the performance evaluation of dielectric resonator on patch (DRoP) antenna using high dielectric CaCu 3 Ti 4 O 12 nanoparticles (CCTO Nps) synthesized by low-temperature solution combustion method. X-ray diffraction pattern reveals that the optimum calcination temperature required for the formation of single phase CCTO Nps is 900 °C. Near-spherical morphology of CCTO Nps with nano size (∼100 nm) has been visualized using field emission scanning electron microscopic images. High-resolution transmission electron microscopic and selected area electron diffraction data reveal the cubic crystal system of CCTO Nps with preferential orientation of (220) plane. The low-frequency dielectric behaviors of CCTO Nps exhibit excellent properties like high dielectric constant ( ε r = 447) and low dielectric loss (tan δ  = 0.42) at 30 °C. DRoP antenna fabricated using high dielectric CCTO Nps exhibits promising results such as wide bandwidth (540 MHz), good return loss (−21.23 dB) at 2.45 GHz and smaller in sizes (10.17 mm 2 ), which is required for modern-day wireless communication systems. [ABSTRACT FROM AUTHOR]

In this paper, gold nanoparticles-doped Cu 2 O cubes (Cu 2 O Au nanocomposites) with peroxide-like character were readily prepared through a simple two-step method and were used for sensitive readout of H 2 O 2 with color variation for the first time. By changing reaction temperature and feed rate, Cu 2 O nanocrystals with very small size were obtained and were then used to prepare Cu 2 O Au nanocomposites. HR-TEM, SEM, and XRD were used to characterize their morphology and size. The results revealed that the as-prepared Cu 2 O Au nanocomposites displayed rough cube morphology, with Cu 2 O cube, ca. 85 nm in size, filled with 8 nm spheres. In the presence of H 2 O 2 , 3,3,5′,5′-tetramethyl benzidine (TMB) was catalyzed by Cu 2 O Au nanocomposites and generated color changes, which was employed to detect H 2 O 2 . By comparison with Cu 2 O nanocrystals with different sizes, Cu 2 O Au nanocomposites exhibited highest peroxide-like activity, which relies heavily on the pH and temperature in the reaction systems and satisfies with the Michaelis-Menten kinetics. Based on these findings, a colorimetric method was developed to detect H 2 O 2 over a range between 0.4 μM and 1000 μM. This platform extends a great prospect in the field of clinical diagnosis, food safety, and environmental monitoring. [ABSTRACT FROM AUTHOR]

Efficient energy storage of lithium-ion batteries plays a significant role across lots of sectors including consumer electronics, electric and hybrid electric vehicles and a smart grid accommodating intermittent renewable energy sources. Nanostructured cathode materials present fascinating opportunities for high-performance lithium-ion batteries, but intrinsic problems linked with the high surface area to volume ratios in the nanometer-range have restricted their adoption for practical applications. We demonstrate processing platform that realize high-performance nanostructured-LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM) layer cathode with carbon coating as a conductive additive. In this paper, we first presented a green, novel, economic and controllable chemical vapor deposition (CVD) method with sucrose as carbon source to coating NCM. Sol-gel synthesized NCM of carbon coated with optimized thickness by this formula are shown to have outstanding rate performance and robust cycle lifetime. The thickness - optimized sample of discharge capacity is as high as 104.5 mAh g −1 for 10 C (6s). High capacity retentions of 94.29% and 94.78% after 100 cycles for 0.1 C, respectively. Compared with the heat evaporation method, with the CVD method has better uniformity and higher quality. This approach further improves evidently the NCM of electrochemical performance and thus promotes lithium-ion battery development technology into unprecedented regimes of operation. [ABSTRACT FROM AUTHOR]

A carbazole-based fluorescent probe, 2-(9-ethyl-9H-carbazol-3-yl) isoindoline-1,3-dione, with a low detection limit (2.673 × 10 −6 M) for the detection of hydrazine is designed and synthesized based on Gabriel reaction. The probe responds selectively to hydrazine over other amino compounds with marked fluorescence enhancement. Moreover, test paper experiments indicated its great potential in the environment monitoring of hydrazine in aqueous solution. [ABSTRACT FROM AUTHOR]

More and more serious energy crisis and greenhouse effect force people to find the appropriate solutions. Photocatalytic reduction of CO 2 into hydrocarbon fuels is one of the most potential strategies. In this paper, novel one-dimensional (1D) carbon nanofibers@TiO 2 core-shell nanocomposites have been prepared via electrospun synthesis of carbon nanofibers core followed by in situ growth of TiO 2 shell, which exhibit a 2.3-fold higher photocatalytic activity than the pure TiO 2 . The increase of catalytic performance attributed to higher specific surface areas of carbon nanofibers@TiO 2 core-shell nanocomposites for providing more surface-active sites. Moreover, the black carbon nanofibers promote light absorption, and the light energy can be converted into heat energy that can speed up the diffusion of reactants and products. Most importantly, the carbon nanofibers with good electrical conductivity can speed up the separation of the photo-induced electron and hole pairs in photocatalyst. This work provides a good synthesis of 1D core-shell heterostructure, and proves that the carbon nanofibers can be an ideal cocatalyst for enhancing photocatalytic CO 2 reduction performance of TiO 2 . [ABSTRACT FROM AUTHOR]

Preventing or reducing negative effects on the environment from the waste landfilling is the main goal defined by the European Landfill Directive. Generally geopolymers can be considered as sustainable binders for immobilization of hazardous wastes containing different toxic elements. In this paper the influence of addition of high amount of lead on structure, strength, and leaching behavior (the effectiveness of Pb immobilization) of fly ash-based geopolymers depending on the geopolymer curing conditions was investigated. Lead was added during the synthesis of geopolymers in the form of highly soluble salt – lead-nitrate. Structural changes of geopolymers as a result of lead addition/immobilization were assessed by means of XRD, SEM/EDS, and 29 Si MAS NMR analysis. Investigated curing conditions significantly influenced structure, strength and leaching behavior of geopolymers. High addition of lead caused a sizeable decrease in compressive strength of geopolymers and promoted formation of aluminum-deficient aluminosilicate gel (depolymerization of aluminosilicate gel), regardless of the curing conditions investigated. According to the EUWAC limitations, 4% of lead was successfully immobilized by fly ash-based geopolymers cured for 28 days in a humid chamber at room temperature. [ABSTRACT FROM AUTHOR]

Cellulose-silica aerogels (CSAs) are organic-inorganic hybrid composites possessing both the porous characteristics and high mechanical properties. In this paper, two kinds of CSAs were in-situ synthesized by facile one-step impregnating cellulose layers directly into silica hydrosols and alcosols, respectively. The porous microstructures and the bonding linkage were investigated by means of Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption-desorption porosimetry. The results show that the silica particles successfully in-situ crosslink on/into the cellulose matrix and maintain the porous characteristics. The regeneration of the CAs directly in the alcosols is more beneficial to realize the crosslinking between silica particles and cellulose fibrils. The silica modification tends to increase the mechanical properties over those of the CAs due to the additional effects of silica particles impregnating into cellulose matrix. [ABSTRACT FROM AUTHOR]

The present investigation is based on the production of reduced graphene oxide (r-GO) from the graphene oxide using Hummer's (GO) and improved Hummer's methods (IGO) at elaborated conditions, named as GO and IGO, respectively hereafter. In contrast to previously known techniques, the presented process does not generate toxic gas. Meanwhile, the reduction temperature can be easily controlled. This approach provides a more significant amount of hydrophilic oxidized graphene as compared to GO and IGO with the use of additional KMnO 4 . Thus synthesized IGO was used to produce r-GO by thermal treatment. The morphological characteristics show that the obtained samples have a wrinkled paper-like morphology with severely folded lines. However, r-GO has double layers and multilayer at the edges. All the products (GO, IGO, and r-GO) have been decorated with ZnO nanoparticles (NPs). The XRD patterns of ZnO@GO composites have confirmed the characteristic peaks of wurtzite ZnO indicating the formation of ZnO nanoparticles onto the surface of graphene. The microscopic studies confirm the random growth/decoration of ZnO NPs on the surface of GO/IGO/r-GO sheets. However, in IGO and r-GO, loading/growth of ZnO NPs are less as compared to ZnO@GO. Overall structural studies indicate the oxidation of graphite and reduction of graphene oxide into r-GO sheets and ZnO decoration. Upon UV excitations, a bright blue emission has been exhibited by the GO that originates from geminate recombination of localized e-h pairs in sp 2 clusters those primarily act as the luminescent centers. The noteworthy enhancement in the emission intensities after the incorporation of ZnO nanoparticles on the surface of GO is observed. The improved synthesis method and low-temperature reduction technique of GO may be essential for the large-scale production of r-GO as well as the construction of devices composed of ZnO@GO/IGO/r-GO. [ABSTRACT FROM AUTHOR]

Structural, electrical and magnetic properties of Dy 1-x Ba x MnO 3 compounds synthesized by the standard solid state reaction route are reported in this paper. For x = 0.0 to 0.5, the compounds have orthorhombic structure and for x = 0.8 and 1.0, the structure changed to hexagonal structure corresponding to 2H. Raman spectra of the materials compliment structural phase transition. Phonon lifetimes estimated from the Raman line width were found to be in the order of pico seconds. X-ray photoelectron spectra of Dy 1-x Ba x MnO 3, revealed the presence of Dy, Ba, Mn and O elements with respective binding energies. Mn ions were found to be in the mixed valent states of Mn (III) and Mn (IV) and their ratio decreased with increasing Ba concentration. Temperature behavior of electrical resistivity of all the compounds showed semiconducting behavior that persisted in the entire temperature range with small polaron hopping conduction mechanism. As Ba content increased, activation energies for hopping of polarons decreased in the orthorhombic phase and increased in the hexagonal phase. Magnetic studies as a function of temperature indicated that ordering temperatures of rare earth (Dy) moments are suppressed with Ba substitution. Random occupation of magnetic Dy 3+ , Mn 3+ and Mn 4+ ions in Dy 1-x Ba x MnO 3 system resulted in complex magnetic structures. The reduction in the experimental effective magnetic moments determined from the Curie-Weiss fit parameters followed the magnetic dilution. Isothermal magnetization curves confirmed the presence of multiple interactions between the magnetic ions. [ABSTRACT FROM AUTHOR]

The 1,3-dithian-2-yl-methyl (Dim) and its analogous groups including dimethyl-Dim (dM-Dim) can provide a new dimension of orthogonality for carboxylic acid protection. They can be deprotected under nearly neutral oxidative conditions. In this paper, the protection of carboxylic acid with dM-Dim, deprotection of dM-Dim ester with sodium periodate, stability of dM-Dim protected carboxylic acid under acidic and basic conditions, and selective deprotection of dM-Dim protected carboxylic acids in the presence of tertiary butyl and methyl esters are presented. [ABSTRACT FROM AUTHOR]

Designing high-efficiency electrocatalysts for glucose concentration detection plays a pivotal role in developing various non-enzymatic glucose detection devices. Herein, we have successfully designed and synthesized various cobalt nitrides (Co 4 N) by using different weak bases ( i.e. hexamethylenetetramine (HMT), urea, and ammonium hydroxide (AH)) through nitridation treatment in ammonia (NH 3 ) atmosphere. Physical characterization results demonstrate that Co 4 N-NSs (nanosheets) with vast meso/macropores and large BET surface are successfully constructed once adding carbon paper and HMT into precursors. As the synergistic effect of metallic character of Co 4 N phase , excellent electroconductibility of pyrolytic carbon, and large surface area, Co 4 N-NSs surfaces can form more Co 4+ active sites in electrochemical reaction processes. Meanwhile, the abundant meso/macroporous structures constructed in Co 4 N-NSs further promoted its mass transfer ability. Benefitting from the above mentioned advantages, Co 4 N-NSs therefore exhibit more excellent glucose oxidation ability than another three control samples ( i.e. Co 4 N-HMT, Co 4 N-Urea and Co 4 N-AH). When used for glucose detection, the optimal Co 4 N-NSs display excellent detection parameters as well, such as: a wide linear range of 0.6–10.0 mM, a large sensitivity of 1137.2 uA cm −2 mM −1 glucose, a low detection limit of 0.1 µM, a small response time of 1.7 s, good reproducibility and stability, and the excellent anti-interference to other electroactive molecules and Cl − . Upon utilized for measuring glucose concentrations in human blood serum samples, the detection results on Co 4 N-NSs are accurate and satisfying as well. This work opens a new possibility for boosting electrochemical catalysis abilities of Co 4 N samples by the structure design. [ABSTRACT FROM AUTHOR]

Graphical abstract Simultaneous synthesis of a multiple-effect evaporation system and its background process. Highlights • A superstructure model for a MEE system with its background system is proposed. • The energy consumption and the cost of the coupled system are targeted. • The optimal structure and operational parameters are determined simultaneously. Abstract Multiple-effect evaporation (MEE) is one of the energy-intensive processes. To reduce the energy consumption of this process, it is effective to integrate the MEE with its background process as a whole system. In this paper, a stage-wise superstructure model is proposed, which takes all possibilities in integration of the MEE coupled with its background process into consideration. The corresponding mathematical programming model, featuring a mixed-integer nonlinear programming formulation is then presented to minimize the total energy consumption (TEC) and the total annual cost (TAC) of the system. The optimal topology and operating parameters of the whole system are determined simultaneously by solving the proposed model. The application and effectiveness of the proposed model are illustrated through a case study of a concentrating sugar juice production process. The results obtained by the proposed method agree well with those obtained by the analytical methodology in literature when the energy demand is targeted. To further clarify the advantages of the proposed method, the coupled system with the lowest TAC is also analyzed and discussed, in which the stream matches and operating parameters are determined accordingly. [ABSTRACT FROM AUTHOR]

In this paper, aliphatic diamine sulphonate (AAS-Na) and liquefiable dimethylol propionic acid (LDMPA) were used together to synthesize waterborne polyurethane (WPU) with excellent property. The influence of -COOH/-SO 3 Na molar ratio on the structure and properties of the waterborne polyurethanes were characterized by IR, particle size analysis, DSC, DMA, apparent viscosity, water absorption, contact angle, tensile and peel strength tests. It was found that with decreasing -COOH/-SO 3 Na molar ratio from 10:0 to 3:7, (1) the particle size of the waterborne polyurethane emulsion decreased, while the apparent viscosity of the samples increased. (2) the water absorption of the WPU films decreased, while the contact angle of the films increased. (3) The tensile strength, elongation at break and peel strength of the samples increased. Furthermore, the results of DMA showed that incorporation of AAS-Na increased the storage modulus of the sample. And the results of DSC showed that with decreasing -COOH/-SO 3 Na molar ratio from 10:0 to 3:7, T g of soft segment shifted to lower temperature, which indicated that the micro-phase separation degree of the samples increased. [ABSTRACT FROM AUTHOR]

This paper presents the synthesis and detailed characterization of two polyphosphazene based polymers, including different cyclic ether side groups. The final polymers were obtained by a well-known method employing a living cationic polymerization and subsequent nucleophilic substitution. The synthesized polymers Poly [(1,3-dioxane-5-oxy) (1,3-dioxolane-4-methoxy)phosphazene] (DOPP) and Poly[bis(2-Tetrahydro-3-furanoxy)phosphazene] (THFPP) were mixed with varied amounts of lithium bis(trifluoromethane)sulfonamide (LiTFSI) and the interactions between the salt and the polymer chains were studied by Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) measurements. Electrochemical characterization was performed by electrochemical impedance spectroscopy (EIS) and direct current polarization in the temperature range of 20–60 °C. These measurements were utilized to calculate the lithium transference number ( t + ), the lithium conductivity ( σ ) and its activation energy in order to elucidate the lithium transport behavior. Relatively high lithium transference numbers of 0.6 (DOPP) and 0.7 (THFPP) at 60 °C are found and reveal maximum lithium conductivities of 2.8·10 −6  S⋅cm −1 and 9.0·10 −7  S⋅cm −1 for DOPP and THFPP at 60 °C, respectively. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of zinc oxide (ZnO) nanofibers, changing the molar concentration (M) of zinc acetate dihydrate (ZnAc) using 2-methoxyethanol and monoethanolamine. X-ray diffraction pattern reveal that ZnO thin films indicate good crystallinity at high precursor concentration. Atomic force microscopy (AFM) images show the formation of ZnO nanofibers. The optical properties changing with increasing concentration are understood from the recorded transmittance, absorbance and reflectance measurements. The band-gap narrowing (from 3.28 eV to 3.22 eV) of n-type ZnO thin films is observed through the absorption edge by an increase in molar concentration. n-ZnO/p-Si heterojunction structure exhibits low rectifying ratio ( RR ). The current-voltage ( I - V ) characteristics show that the conductivity increases as the molar concentration of precursor decreases from 0.5 to 0.2 M. An optimum value of molar percentage for precursor concentration of ZnAc is promising for photovoltaic and display applications. [ABSTRACT FROM AUTHOR]

In this paper, Ca 6 BaP 4 O 17 :Sm 3+ and Li + co-doped Ca 6 BaP 4 O 17 :Sm 3+ phosphors were synthesized in air and argon atmospheres using a solid-state reaction method. The phosphor morphologies and crystal structure were studied using scanning electron microscopy and X-ray diffraction, respectively. The emission and absorption characteristics were investigated using photoluminescence emission spectroscopy and diffuse reflectance spectroscopy. The surface states and composition of phosphor were investigated using X-ray photoelectron spectroscopy. The emission integrated intensities of the phosphors sintered in an argon atmosphere increased 3.5 fold than the ones sintered in air atmosphere, with Li + ions becoming embedded in the lattice of the Ca 6 BaP 4 O 17 :Sm 3+ phosphor. This occurs because there are fewer defect/oxygen vacancies and less of the secondary phase forms, leading to better Sm 3+ emission. The results suggest that sintering a mixture of the raw materials of a phosphor in an argon atmosphere is a good approach for synthesizing Ca 6 BaP 4 O 17 :Sm 3+ phosphor powders. The color purity and CIE values of an optimized phosphor sample sintered in an argon atmosphere with an Li + ion compensator were calculated to be ~ 99.6% and (0.612,0.386) in the orange–red region under 405-nm excitation, respectively. Moreover, the solid solubility of Sm 3+ ions in the Ca 6 BaP 4 O 17 host can be enhanced by using an argon atmosphere in the synthesis process. [ABSTRACT FROM AUTHOR]

In this paper, we fabricate the nickel thin film on copper and acrylonitrile-butadiene-styrene (ABS) polymer substrate by means of electroless deposition method and compare their hydrogen evolution reactions (HER). Ni deposited on both specimens reveals the preferred crystalline orientation of (111) plane and petal like topography. The HER activity and durability of the Ni electrode is investigated through linear sweep voltammetry and Tafel polarization studies. We measure the current density value of the first cycle at 350 mV vs. RHE and found that nickel deposited on the ABS polymer and a copper substrate exhibits the cathode current density of 29 and 4 mA cm −2 respectively. After 1000 cycles, 61% of HER activity has been retained in nickel deposited on the ABS polymer whereas nickel plated on the copper strip retains only 20% of HER activity. A small Tafel slope of 82 and 144 mV dec −1 is observed for nickel deposited on the ABS polymer and copper samples respectively. [ABSTRACT FROM AUTHOR]

This paper reports a simple fabrication strategy towards 3-dimensionally ordered macroporous (3DOM) poly(3,4-ethylenedioxythiophene) (PEDOT) thin films via vapor phase polymerization (VPP) coupled with colloidal crystal templating. PEDOT was synthesized by VPP over a colloidal crystal thin film composed of monodisperse polystyrene colloids functionalized with a Fe(III) tosylate catalyst, after which the polystyrene template was selectively removed. The resulting 3DOM PEDOT films comprised a face-centered cubic array of 280–290 nm spherical macropores in a PEDOT matrix, around 5–6 μm thick. Cyclic voltammetry (CV) was used to probe electrochemistry and highlighted the merits of the fabrication strategy introduced here; the 3DOM PEDOT films exhibit a 2.9-fold increase in electrochemically available surface area compared to the non-templated PEDOT films. As a demonstration of functionality, ion-exchange of the dopant tosylate for the anionic drug dexamethasone phosphate (dexP ˉ ) was explored. Loading by passive ion exchange was three-fold higher for 3DOM PEDOT compared with non-templated PEDOT. Notably, CV-driven ion exchange was more efficient to load drug into the polymer than passive ion exchange, and occurred to similar extents for both non-templated PEDOT and 3DOM PEDOT structures. Following loading, minimal dexPˉ release was observed in the absence of an electrical stimulus, while dexPˉ release was triggered upon application of a suitable electrical stimulus. 3DOM PEDOT prepared by VPP thus represents a promising material for use as an ion exchange resin with drug loading achieved subsequent to polymerization and electrically triggered drug release demonstrated. [ABSTRACT FROM AUTHOR]

Understanding the influence of synthesis parameters on morphology and electrochemical properties of carbon nanostructure is necessary for the development of application-tailored materials. We report on the synthesis by plasma enhanced chemical vapor deposition, morphology and catalytic activity towards oxygen reduction reaction (ORR) of hierarchical carbon nanowalls (hCNW) at different deposition times. hCNW are an advancement of common CNW possessing an increased surface area while retaining the ideal mass transport characteristics of common CNW. The hCNW structure results from a synthesis using p -xylene as an aromatic precursor. hCNW are non-doped and metal-free with easily accessible graphitic edge sites at the top of the walls and numerous defects sites located within the porous side walls, which are ideal sites for adsorption and electron transfer. hCNW reveal a high amount of different electrochemically active sites that dominate the material character depending on the deposition time. The hCNW exhibit excellent catalytic activity towards ORR with very high ORR onset potential of 830 mV vs RHE in 0.1 mol L −1 KOH solution and selectivity towards a two electron transfer mechanism. Thereby, the onset is higher than that of several nitrogen doped carbons and one of the highest for pure carbon electrodes. In contrast to other pure carbon materials with similar onsets, oxygen doping of hCNW before the experiments could be ruled out. As such, the results of this paper indicate the existence of inner sphere ORR on sp 2 -carbon. Additionally, the results emphasize the relevance of often overlooked material properties such as surface accessibility as well as electrical conductivity for ORR. [ABSTRACT FROM AUTHOR]

In order to solve wellbore instability problems in the drilling process, high-performance shale stabilizers in water-based drilling fluids are essential. In this paper, a novel shale stabilizer based on polyethylene glycol grafted nano-silica composite (PEG-NS) was successfully synthesized. Conventional techniques were used to characterize PEG-NS including Flourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscopy (TEM), particle size distribution (PSD) and thermogravimetric analysis (TGA). The results showed that the structure of PEG-NS was in agreement with the design objective. The particle size of PEG-NS ranged from 110 to 434 nm, and PEG-NS had good thermal stability. Pressure transmission test, pore structure characterization of shale, rolling recovery test were applied to evaluate the comprehensive performance of PEG-NS as a novel shale stabilizer. The experimental data indicated that PEG-NS could effectively retard the pore pressure transmission and reduce the permeability of shale sample. PEG-NS could adsorb onto the shale surface and a dense plugging film could finally coat on it. Moreover, PEG-NS also exhibited better inhibition performance compared with that of potassium chloride (KCl) and polymeric alcohol (JHC) at the same concentration. Hence, PEG-NS could be a good shale stabilizer in water-based drilling fluids for drilling reactive shale formations. [ABSTRACT FROM AUTHOR]

In this paper, we present an environment friendly hydrothermal process to synthesize nano/sub micro particles of the rare earth activated complex fluoride NaMgF 3 at 180 °C. The tittle compound synthesis was carried out at elevated pressure and temperature in an aqueous medium. The powder X-ray diffraction pattern was recorded to check the phase purity of the synthesised compound. Synthesized compounds were micro and nanocrystalline with orthorhombic perovskite crystal structure, space group Pcmn. In order to identify the functional groups Fourier Transform Infrared spectral analysis have been performed. The size and shape of the synthesised compounds were studied by using Field Emission - Scanning Electron Microscope images. Chemical composition of the synthesised compounds were checked by the energy - dispersive X-ray spectra. The absorption bands around 220 and 270 nm were observed which is corresponding to the electronic transition between 4f and 5d configuration of Ce 3+ . Photoluminescence emission related to the 5 d → 4 f transitions in Ce 3+ was observed at 324 nm. Thermoluminescence properties were studied for the X-ray irradiated samples. The glow curve kinetic parameters of activation energy (E) and frequency factor (S) were calculated using standard methods. [ABSTRACT FROM AUTHOR]

In this paper, ZnNiAl-layered double hydroxide (LDH) photocatalysts were successfully prepared using a facile and timesaving microwave-assisted method. ZnNiAl-layered double oxides (LDOs) were then achieved from ZnNiAl-LDHs photocatalyst with calcination treatment. As a control, the corresponding photocatalysts were synthesized using a traditional hydrothermal method. A set of characterization technologies including XRD, SEM, FT-IR, and N 2 adsorption was carried out to investigate the physical and chemical properties of the prepared photocatalysts. The photocatalytic activities were evaluated by the degradation of p-nitrophenol (PNP) under visible-light irradiation. Moreover, the influences of calcination temperature, photocatalyst dosage, and initial PNP concentration were also explored in this system. The results indicated that the sample transformed from LDH to LDO after 700 ○ C calcination treatment and the prepared LDO showed an outstanding photocatalytic activity. When the photocatalyst dosage was 1.0 g·L −1 and initial PNP concentration was 10 mg·L −1 , PNP removal efficiency was as high as 93.0% within 180 min under visible-light irradiation. After six cycles, the newly designed photocatalyst showed a good stability and reusability. This study shares a new preparation method for ZnNiAl-LDO as a novel photocatalyst with high efficiency for wastewater treatment. [ABSTRACT FROM AUTHOR]

More than one million tons of secondary aluminum dross as a hazardous waste are produced by aluminum manufacturers per year throughout the world, which imposes high disposal costs and serious environmental problems. As secondary aluminum dross is considered as an alumina-rich inorganic waste, this study aims to propose a promising approach for clean production of activated-alumina as a widely-used adsorbent, catalyst and catalyst support. In this paper, synthesis and characterization of high crystalline activated-alumina nanopowder from secondary aluminum dross using a novel five-step leaching-based process are presented. To optimize the process, various parameters of dross particle size, leaching time, leaching temperature, acid concentration, and liquid-to-solid ratio were studied using One-Factor-At-a Time approach (OFAT). For the following optimum leaching conditions: particle sizes between 38 and 75 μm, leaching time of 120 min, leaching temperature of 85 °C, acid concentration of 5 M, and the liquid-to-solid ratio of 20 ml/g, the extraction efficiency of alumina was around 83%. The leach liquor was purified by adding 2 N NaOH resulting in sodium aluminate-rich solution. The purified liquor was treated by adding HCl to precipitate Al(OH) 3 , and the Al(OH) 3 was then washed and calcined at 700 °C for 2 h to obtain alumina. Chemical composition, mineralogical phases, chemical bonds, morphology, and particle size distribution of the as-synthesized activated-alumina were determined using X-ray fluorescence (XRF), X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), and dynamic light scattering (DLS), respectively. The as-synthesized activated-alumina exhibited 97.61% purity. Its XRD pattern showed mainly characteristic peaks of gamma phase of alumina. Morphological study by FESEM revealed that the as-synthesized alumina particles have rounded-corner shape. The crystal and average particle size values were about 18.47 and 513 nm, respectively. [ABSTRACT FROM AUTHOR]

The paper is focused on the development and techno-economic assessment of a sustainable process for the production of valuable hydrocarbons from CO 2 and H 2 O. With help of process modeling tools an advantageous and highly integrated process design is identified. The application of co-electrolysis for direct syngas production as well as the implementation of advanced heat integration concepts allow for an energetic efficiency of η en  > 0.6. Additionally, the amount of reactors and heat exchangers in the proposed process is reduced in comparison to other Power-to-X concepts. The high efficiency and the focus on valuable products like waxes is also beneficial for the economic feasibility of the process. The implications of product value as well as availability and costs of renewable electricity are discussed in the context of a potential market entry of Power-to-X technologies. [ABSTRACT FROM AUTHOR]

This paper reports a novel synthesis of iron (Fe) powders in which high-purity and controlled primary and secondary assembled particles can be produced at low cost with safe process. Iron hydroxide powder precursors with fine-sized and acicular morphology were prepared and then reduced at an optimum temperature under reducing atmosphere by using single-step and two-step reduction. In the case of two-step reduction, the precursor powders were reduced by using a hydrogen/argon mixed gas for 1.5 h with a subsequent second reduction using higher hydrogen/argon mixed gas for 2 h. The morphology of the Fe powders strongly depends on the reduction conditions and precursor's morphology. The two-step reduced powders had pure iron powders with large elongated shape and porous sponge-like interlocking structure. The synthesized Fe powders were mixed with KClO 4 and the pyrotechnic performance was examined. It is found that metal powder prepared by using two-step reduction is very suitable for producing porous sponge-like microstructure and for pyrotechnic applications. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of different particle size La 0.7 Sr 0.3 MnO 3 (LSMO) nanoparticles using non-aqueous sol gel synthesis route by calcination at temperatures 750 °C, 850 °C and 950 °C. In the present work, the effect of particle size of LSMO nanoparticles on its structural, magnetic and transport properties has been studied in detail. The X-ray diffraction analysis confirms the formation of LSMO nanoparticles having rhombohedral ( R 3 ̅ c ) structure with average particle size of 20 nm, 22.5 nm and 25.6 nm. An increase in magnetization and decrease in coercivity with increase in particle size is attributed to the magnetically disordered surface layer. The bifurcation in ZFC-FC magnetization indicates the possibility of spin glass like behavior of the LSMO nanoparticles. The effect of particle size on the resistivity and magnetoresistance were studied by using different conduction mechanism for different temperature regions. The upturn in the ρ-T curve at lower temperatures was explained by using Kondo-like transport mechanism. The maximum LFMR achieved was 32.3% at a field of 1 T at 10 K for 20 nm LSMO nanoparticle. [ABSTRACT FROM AUTHOR]

In this paper, the urea content was manipulated to synthesize nano-size AlN powders by a wet chemical route. The thermal decomposition pathway of the precursor salts and the corresponding products were discussed thoroughly. The microstructure and the morphology for both of the as-received and resultant powders were characterized by FTIR, XRD, SEM and TEM. The photoluminescence (PL) property of AlN was also used for the investigation of the microstructure defects. The effect of the urea content on the powder purity, grain crystallization, microstructure and the morphology of the AlN was studied seriously. [ABSTRACT FROM AUTHOR]

In this paper, three metal-organic frameworks (Materials of Institut Lavoisier: MILs-100 (Fe)) as porous nanomaterials were synthesized using FeCl 3 , Fe(NO 3 ) 3 and Fe 2 (SO 4 ) 3 and denoted as MIL-100-1, MIL-100-2 and MIL-100-3, respectively. The synthesized MILs-100 (Fe) were characterized by FTIR, SEM, TEM, XRD, UV–vis DRS and zeta potential. Basic Blue 41 (BB41) was used as a model dye to study the photocatalytic dye degradation ability of the synthesized metal organic frameworks. The results showed that the synthesized nanomaterials decolorized BB41. The decolorization kinetics followed first-order kinetic model. The rate constant was 0.0034, 0.0041, 0.0091 and 0.0289 (1/min) for 0.01, 0.02, 0.03 and 0.04 g of photocatalyst. The data indicated that MIL-100-1 had higher photocatalytic activity. The photocatalytic activity of MIL-100 did not decrease significantly for three cycles. It can be concluded that the synthesized MILs-100 (Fe) could be used as alternative catalysts for photocatalytic decolorization of colored wastewater. [ABSTRACT FROM AUTHOR]

In this paper, the synthesis of pure hematite nanoparticles, magnetic properties and its removal capacity of metal cations from acid mine drainage are well described. Initially, mixtures of iron oxide nanoparticles were synthesised using hydrated ferric chloride and ferrous sulphate salt solution by co-precipitation method and converted to hematite via calcination at 500 °C. The synthesised hematite nanoparticles have shown superparamagnetic character with saturation magnetisation of 5.6 emu g −1 . Treatment of partially aerated acid mine drainage in the presence of 0.85 g L −1 of synthesised hematite resulted in complete removal of Al, Mg, Mn and Fe while for Zn and Ni over 80% and Ca and Na in between 47 and 72% removals. The sludge generated from the treated acid mine drainage was also characterised by relevant analytical instruments. Overall, the non-toxicity, stability and high metal removal capacity of hematite nanoparticles is promising for the future application in large-scale acid mine drainage treatment. [ABSTRACT FROM AUTHOR]

Superfine ettringite (S-ettringite) synthesized in this research presents same structure with the ettringite produced by the hydration of cement, which is expected to promote the hydration of sulphoaluminate cement-based materials. There are few literature reports on laboratory synthesis of superfine ettringite. In this paper, preparation of S-ettringite via separate nucleation and aging steps method by introduction of citric acid is presented. The effect of the S-ettringite on hydration, microstructure and properties of CSA cement-based grouting materials (CBGM) was experimentally investigated. Results show that specimens containing S-ettringite displayed a significant improved performance with regard to compressive strength at early and later ages and setting time. Compared to the control specimen, 4-h compressive strength increased by 380% and initial setting time shortened by 55.6% when 4 wt% S-ettringite was added, respectively. Due to the crystallization inducting effect and seed effect, the addition of S-ettringite changed the morphology of ettringite, and meanwhile promoted the hydration exothermic rate and increased the amount of hydration products, which thus generate higher compressive strength and shorter setting time. [ABSTRACT FROM AUTHOR]

This paper addresses a new post-treatment strategy for the formation of carbon-encapsulated nickel-cobalt alloys nanoparticles, which is easily controlled the performance of target products via changing precursor composition, calcination conditions (e.g., temperature and atmosphere) and post-treatment condition. Glassy carbon electrode (GCE) modified by the as-obtained carbon-encapsulated mono- and bi-transition metal nanoparticles exhibit excellent electro-catalytic activity for hydrogen production in alkaline water electrolysis. Especially, Ni 0.4 Co 0.6 @N-Cs 800 -b catalyst prepared at 800 °C under an argon flow exhibited the best electrocatalytic performance towards HER. The high HER activity of the Ni 0.4 Co 0.6 @N-Cs 800 -b modified electrode is related to the appropriate nickel-cobalt metal ratio with high crystallinity, complete and homogeneous carbon layers outside of the nickel-cobalt with high conductivity and the synergistic effect of nickel-cobalt alloys that also accelerate electron transfer process. [ABSTRACT FROM AUTHOR]

The proper choice of the energy system configuration and design parameters, generally named “synthesis/design problem”, is only rarely straightforward because of the many variables involved. The goal of a standard for the generation of new system configurations has recently led to superstructures that potentially include all possible configurations, among which the optimum one, yet the ability of defining in advance such superstructures is a fundamental limit of this technique. To overcome this problem a bottom-up methodology is proposed, which relies on the basic idea that the system configuration is certainly based on one or more thermodynamic cycles that may share some processes or be combined in a cascade form. Accordingly, all the possible ways of combining elementary cycle processes into meaningful system configurations are first identified using a comprehensive and rigorous set of rules. An optimization is then performed in which the search space consists of all the obtainable configurations and associated design parameters. The paper shows all steps of this original synthesis/design optimization methodology and its effectiveness in the search for the best two-pressure level ORC system configuration. The optimum results obtained using different working fluids and temperatures of the heat source allow general design guidelines to be identified. [ABSTRACT FROM AUTHOR]

Diketopyrrolopyrrole (DPP) is one of the most widely used organic dye moieties in conjugated organic semiconductors for use in organic electronics. To enrich the library of DPP based organic semiconductors and to further understand the structure-property-performance relationship of this type materials, in this paper, the diketopyrrolopyrrole moiety was functionalized with three-dimensional (3D) π-conjugated dendritic oligothiophenes (DOTs), and four diketopyrrolopyrrole compounds decorated with dendritic oligothiophenes (DOT-c-DPPs) were obtained and characterized in detailed. Results show that all these four compounds are monodisperse with defined molecular structure. Spectroscopy and cyclic voltammetry measurement results showed that the introduction of dendritic oligothiophene unit on the DPP unit improves the light absorption ability over 350–500 nm, and decreases the optical band gap slightly, which are in good accordance with theoretical calculation results that the frontier molecular orbitals are mainly located at the central DPP unit. Solution processed organic solar cells using these DOT-c-DPPs as the electron donor were fabricated and tested. Improved device performance was found for the bigger molecule for its less aggregation tendency. [ABSTRACT FROM AUTHOR]

Ampicillin belongs to the class of beta-lactam antibiotics, which corresponds the most prescribed antibiotics in medicine. This justifies the importance of elucidating the effect of several variables for the synthesis process (pH, temperature, co-solvent) on the behavior of the compounds involved in the enzymatic reaction. This paper aims to present new ampicillin solubility data in aqueous medium and the characterization of the solid phase of the antibiotic. In the phase equilibrium experiments it was considered the effect of pH (3 up to 7.5), temperature (283.15 K up to 298.15 K) and the ethanol concentration in the aqueous solution (varying between 0 and 70 wt% ethanol). The solubility curves deviate from U-shape solubility curves with respect to pH in the range of 0–70 wt%. This is due to ampicillin anhydrous becomes trihydrated molecule in the solid phase at alkaline pH region, changing the antibiotic properties significantly. This change in crystalline structure was confirmed by characterization of antibiotic solid phase carried out from thermogravimetric (TGA), Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analyses. Dissociation constants have also been measured at the studied values of temperature and ethanol composition, using potentiometric titration. Finally, a thermodynamic model considering the ideal solution was applied to describe mathematically the solubility curves measured close to experimental uncertainties. [ABSTRACT FROM AUTHOR]

The Fe 2 V 4 O 13 is considered as one of the most promising cathode materials for next generation secondary batteries owing to its high specific capacity and energy density. However, the synthesis of pure Fe 2 V 4 O 13 is difficult because of complicated Fe 2 O 3 –V 2 O 5 phase diagram. Thus, in this paper, a facile solution combustion method which operates relatively at low temperature was proposed to synthesize impurity free Fe 2 V 4 O 13 nanoparticles. The selection of fuel, oxidizer/fuel (O/F) ratio and temperature on the formation of impurity free Fe 2 V 4 O 13 has been investigated. The optimum temperature and time for the preparation of impurity free Fe 2 V 4 O 13 nanoparticles was found to be 350 °C/1 h. The synthesized Fe 2 V 4 O 13 nanoparticles exhibit monoclinic phase with high surface area of 36 m 2 /g. The prepared Fe 2 V 4 O 13 nanoparticles were tested as cathode material for lithium secondary battery and charge discharge results show that the 154 mAh·g −1 is retained after 50 cycle. [ABSTRACT FROM AUTHOR]

In this paper, hybrid-coprecipitation and combustion methods were used to synthesis MgAl 2 O 4 spinel. Of interest was also to evaluate the effect of different synthesis methods on the characteristics and performance of MgO/MgAl 2 O 4 catalyst in biodiesel production. Physicochemical characteristics of synthesized catalysts were evaluated by XRD, FESEM, surface particle size distribution (SPSD), EDX-Dot Mapping, BET-BJH and FTIR analysis. Moreover, the final performance of the samples was investigated in biodiesel production. The results of the XRD analysis showed that the highest crystallinity and crystal size belonged to the sample synthesized by the combustion method. Furthermore, the FESEM analysis showed that the sample synthesized by the combustion method had a unique morphology and the other samples had almost the same morphology. The BET-BJH analysis indicated that the least surface area and pore volume were related to the sample prepared by the combustion method. However, by perusing the samples in biodiesel production, it was found that the combustion prepared sample had the largest conversion value (95.7%) and great reusability (6 cycles). According to the total analysis, it can be said that the size and shape of the pores as well as the catalyst crystallinity are the most important specifications for biodiesel production. [ABSTRACT FROM AUTHOR]

A novel 3D-porous ZnO/Ag SERS-active substrate with ultrasensitive and repeatable detectability is designed and prepared in this paper. Without using any expensive materials and complicated methods, this substrate obtains a lowest detectable concentration of 10 −11 M for rhodamine and shows outstanding sensitivity for many other probe molecule as well, e.g., crystal violet, malachite green and Sudan I, etc. Benefitting from the improved photocatalytic activity of ZnO/Ag heterostructure, the substrate can entirely degrade the target molecules in situ under ultraviolet radiation for 30 min, and then 100 percent recover the detectability, which endows this base excellent repeatability. The enhancement mechanisms of this base are meticulously analyzed, and the finite-different time-domain simulations are introduced as well for further exhibiting the ‘hot spots’ distributions. The simple method and prominent Raman enhancement property make this base a quasi-commercial SERS-active substrate, which will certainly show promising applications in chemical and biological detection. [ABSTRACT FROM AUTHOR]

This paper describes the design, synthesis and hydraulic activity of novel Sr 2+ -doped Ca 7 ZrAl 6 O 18 cement in respect of potential applications as: matrix used in nuclear waste immobilisation, components of X-rays and gamma radiation shielding concretes or utilized in refractories technology. The obtained material was characterized by X-ray diffraction (XRD), scanning electron microscopy combined with energy-dispersive spectrometry (SEM/EDS) and heat flow calorimetry techniques. It was well established that the addition of Sr 2+ cations to form solid solution with Ca 7 ZrAl 6 O 18 can alter the hydraulic behaviour of this phase. A microcalorimetric study (heat flow calorimetry technique) of Sr 2+ -doped Ca 7 ZrAl 6 O 18 cement hardening was combined with the phase characterisation by XRD and SEM/EDS. The thermal stability and mechanism dehydration formed hydrates were assessed by simultaneous thermal analysis i.e. thermogravimetry (TG) and differential thermal analysis (DTA) at different hydration times. The detailed scheme of thermal decomposition of the hydrated Sr 2+ -doped Ca 7 ZrAl 6 O 18 cement has been clarified based on evolved-gas-analysis data with a quadrupole mass spectrometer (QMS). Two hydrated phases C 4 AH 19 and C 2 AH 8 persisted at the early stage of hydration, whilst recrystallisation to Ca-rich C 3 AH 6 was inhibited. Hydration of Sr 2+ -doped Ca 7 ZrAl 6 O 18 resulted in the formation of two hydrogarnet phases, one Sr-rich and the other Ca-rich. [ABSTRACT FROM AUTHOR]

Titanium nitride (TiN) as catalyst support has a very good application prospect due to its chemical stability, electrical conductivity and the metal-support interaction. But it is difficult to synthesize nano-TiN with the uniform dispersion by a simple method. This paper proposes a novel and easy strategy to address the problem. The mesoporous g-C 3 N 4 has been synthesized and used as both nano-reactor and nitrogen source for the synthesis of nano-TiN evenly dispersed onto Vulcan XC-72. The uniform dispersion of nano-TiN is conducive to depositing and anchoring the PtRu nanoparticles, further increasing the long-time catalytic durability. Moreover, the electronic effect of TiN obviously improves the catalytic activity and the adsorbed CO tolerance ability of PtRu catalysts for methanol oxidation. Compared with the PtRu/C catalyst, the activity of PtRu/C-TiN for methanol oxidation has been increased by 47.3%. Meanwhile, its durability has been improved by 6.5% after 1000 cycles. In addition, this novel and easy method can be generalized to the synthesis of other nano-size nitrides. The applications of nano-size nitrides modified carbon black in other fields are also expected in the future. [ABSTRACT FROM AUTHOR]

In this paper, we obtained two novel 2D layered cobalt coordination polymers, namely [(Co(o-BDC)] n ( 1 ) and (Co(3-Cl-o-BDC)] n ( 2 ), through solvothermal method with acetone as solvent based on phthalic acid (o-H 2 BDC) and 3-chloro-phthalic acid (3-Cl-o-H 2 BDC) respectively. Due to the steric hindrance effect of chloric substituent, the two ligands revealed different coordination modes. And cobalt centers of 1 and 2 showed CoO 6 octahedral and CoO 4 tetrahedral configurations respectively. As a result, 1 and 2 revealed different layered constructions: a 5-connected topology with 4 8 .6 2 Schläfli symbol for 1 , and a 4-connected topology with 4 4 .6 2 Schläfli symbol for 2 , respectively. Besides, Compound 1 and 2 reveal ferromagnetic and antiferromagnetic behaviors, respectively. [ABSTRACT FROM AUTHOR]

This paper describes the synthesis, spectroscopic characterization and quantum mechanical calculations of three azo-azomethine dyes. The dyes were synthesized via condensation reaction between 4-(dimethylamino)benzaldehyde and three different 4-aminobenzene azo dyes. Quantum chemical calculations on the optimized molecular geometry and electron densities of the trans (E) and cis (Z) isomers and their vibrational frequencies have been computed by using DFT/B3LYP density-functional theory with 6-311 ++G(d,p) basis set in vacuo. The thermodynamic parameters such as total electronic energy E (RB3LYP) , enthalpy H 298 (sum of electronic and thermal enthalpies), free Gibbs energy G 298 (sum of electronic and thermal free Gibbs energies) and dipole moment μ were computed for trans (E) and cis (Z) isomers in order to estimate the ΔE trans → cis , Δ μ trans → cis, ΔH trans → cis , ΔG trans → cis and ΔS trans → cis values. After molecular geometry optimization the electronic spectra have been obtained by TD-DFT calculations at same basis set and correlated with the spectra of vapour deposited nanosized films of the dyes. The NBO analysis was performed in order to understand the intramolecular charge transfer and energy of resonance stabilization. Solvatochromism was investigated by UV-VIS spectroscopy in five different organic solvents with increasing polarity. The dynamic photoisomerization experiments have been performed in DMF by pump lasers λ = 355 nm (mostly E → Z) and λ = 491 nm (mostly Z → E) in spectral region 300 nm – 800 nm at equal concentrations and times of illumination in order to investigate the photodynamical trans-cis-trans properties of the CH N and N N chromophore groups of the dyes. [ABSTRACT FROM AUTHOR]

The paper herein proposes a new simple method for the synthesis of two reactive belite cements at low temperature (1000 °C). Silica fume, as subproduct of metallurgic industry and commercial natural zeolite were utilized as raw materials. The implemented raw materials were utilized with no additional purification process. Belite cements properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and gas sorption by BET (Brunauer, Emmett, and Teller) techniques. Hydration capacity of belite cements was calculated while the mechanical strength was determined in ordinary Portland cement pastes (PC) and gypsum pastes, respectively, using in each case a 10% partial replacement of the belite cements obtained. Results showed belite cements presented relatively high surface areas, at early ages mechanical strengths similar to those of alite cement and comparable to strengths of belite cements obtained by different synthesis methods. Cements obtained in this work showed good hydraulic reactivity properties. [ABSTRACT FROM AUTHOR]

To obtain large sample volume and prolong service life, a novel high pressure die for synthesizing diamond was investigated using the finite element method. This device was the multi-layer stagger-split type die with prism type cavity which the cylinder and two layers supporting rings were divided into several parts. In this paper, we studied the stress features of this type pressure die, at the same time the results were compared with those of traditional belt type die. Numerical simulation results showed that the stress and stress distribution of the multilayer stagger-split type die were reasonable and the materials were utilized effectively. Experiment results indicated that the multi-layer stagger-split type die with prism type cavity was able to bear the greatest pressure, furthermore the split type die has strong pressure bearing capacity and replaceable performance. [ABSTRACT FROM AUTHOR]

In the last two decades, different prosthetic hands have been developed. However, little attention has been given to thumb designing. This paper presents the design and kinematic synthesis of a new 2 DOF 9-bar spatial mechanism that can be used as a prosthetic thumb focused on emulating the 5 movements of human thumb joints. The mechanism replicates the movements of the interphalangeal (IP), metacarpophalangeal (MCP) and carpometacarpal (CMC) joints, with the limitation that only the movements of the CMC joint are independent and the movements of the remaining joints are dependent on CMC movements. All the links of the mechanism are contained within an anthropomorphic shape, and its tip is capable of generating a 3D surface as working envelope. These features are the result of combining the mathematical representation of a deep knowledge of the kinematics and anthropometry of the thumb with techniques of optimal synthesis and spatial mechanisms design. [ABSTRACT FROM AUTHOR]

Over the years, the production of waste ash from many sources (e.g. coal, biomass, industrial, animal, and municipal solid waste) and from conventional and renewable energy technologies has increased, generating environmental problems due to the increasing amount of material disposed of in landfills. Fly ash from coal and biomass represent the foremost waste products produced by fossil fuel combustion and alternative natural energy sources, respectively. These waste materials are most widely utilized in agricultural applications, soil stabilization, and the cement and concrete industries. Among the various methods proposed for the reuse of fly ash, conversion to zeolite offers the greatest benefits; the process diverts ash waste materials from disposal sites and transforms them into useful secondary products for applications ranging from environmental mitigation to catalysis. The vast amount of literature on fly ash application is the fruit of growing waste production and the consequent need to find innovative methods to reduce the amount of waste deposited in landfills. This article summarizes studies concerning both coal and biomass fly ash. The characterization and potential applications of these materials are analysed in detail through reference to the numerous studies published on fly ash worldwide over the last number of decades. A considerable number of experiments have been conducted using ash as a raw material for zeolite synthesis, and many others concern the utilization of the newly-formed mineral. This paper discusses the key factors affecting zeolite synthesis, primarily from coal fly ash; the drawbacks of each approach are also analysed. [ABSTRACT FROM AUTHOR]