Synthesis of a magnetic-separated chitosan-palladium complex and its catalytic activity in the reaction of acrylic acid with iodobenzene

A magnetic-separated catalyst of chitosan-palladium complex （Fe3O-CS-Pd） based on chitosan coated Fe3O4 microspheres was prepared by the ＂bottom-up＂ approach. The catalytic behavior of the catalyst in the cross coupling reaction of acrylic acid （AA） with iodobenzene （ArI） was investigated. Compared with the traditional homogeneous palladium catalysts, the catalyst was easily separated and reused.

Synthesis and catalytic activity of SBA-15 supported catalysts for styrene oxidation

Cu(II) and Mn(II) metals embedded on mesoporous SBA-15 were synthesized by co-precipitation technique.The support and catalysts were characterized by SEM–EDX,TEM,BET,XRD and ICP-AES methods.The catalytic activity of these catalysts was evaluated for styrene oxidation at various reaction conditions such as styrene to TBHP mole ratio,temperature,catalyst amount by using TBHP as an oxidizing agent.Major reaction products were styrene oxide and benzaldehyde and highest styrene conversion(97.3%) was observed at styrene to TBHP mole ratio of 1:4,temperature at 80 °C and 20 mg of catalyst.Further,the recyclability of the catalysts was observed and found that they can be recycled three times without major loss in their activity and selectivity.

Advances in the Structural Composition of Biomass:Fundamental and Bioenergy Applications

Increased environmental pollution due to the organic wastes over the world is one of the most burning issues.These organic wastes lie under the category of biodegradable waste and can be effectively degraded from their complex compound into simple one by the action of microbes or other living organisms.Moreover,lignocellulosic biomass is a major part of the biodegradable waste and belongs to the group of renewable energy source,which can be very effective for bioenergy production.Biomasses are made up of different compounds such as cellulose,hemicelluloses,lignin and protein.Apart from these components,based on the structural analysis biomass also consist of bioactive substances such as carotenoids,flavonoids,lignin and antioxidants.This review explores a complete overview of the classification,component and the structure of the biomass.Moreover,it discusses how biomasses can play the key role of substrate in many sectors such as industrial bioenergy production including gaseous and liquid biofuels.

Preparation and characterization of N-isopropylacrylamide/carboxymethylated chitosan hydrogel

Poly （N-isopropylacrylamide） （PNIPAAm）/carboxymethylated chitosan （CMCH） hydrogels were prepared by irradiating the aqueous solution mixture of NIPAAm and CMCH by 60 Co γ-ray.The effects of feed ratio of NIPAAm and CMCH,temperature,pH and ionic strength on the swelling ratio of PNIPAAm/CMCH hydrogels were studied.The results show that the addition of CMCH shifts the lower critical solution temperature （LCST） of the PNIPAAm hydrogel to higher temperature.The PNIPAAm/CMCH hydrogel displays not only pH-and thermo-sensitivity,but also ion-sensitivity.Differential scanning calorimetry （DSC） was applied for the determination of the LCST of the hydrogel.

Synthesis and characteristics of pH-and temperature-sensitive hydrogels of poly （DMAEMA/NIPAAm）

A kind of novel copolymer hydrogel of poly（N, N-dimethylaminoethyl methacrylate-co-N-isopropylacrylamide） （poly[DMAEMA/NIPAAm]） was synthesized by the initiation of K2S2O8, N, N＇-methylene-bis（acrylamide） （Bis） was used as the crosslinker. The effects of monomer content, pH and temperature on swelling ratio of the hydrogel were investigated; the thermo-sensitivity in deionized water and in physiological saline was determined. It showed that the swelling ratio of the hydrogel could be changed by changing the temperature or pH alternately. Both swelling ratio and LCST （Lower Critical Solution Temperature） of the hydrogel decreased with the increase of NIPAAm in the co-polymer content.

A new anti-hypoxia functional agent ——Schizophyllum commune fermented broth and its biochemical mechanisms

In order to overcome hypoxia induced sickness, a stable source of anti-hypoxia functional agents, Sehizophyllum commune fermented broth has been developed in this study. Animal experiments were conducted to examine its anti-hypoxia activities and possible mechanisms involved. The acute hypoxic experiment showed that Sehizophyllum commune fermented broth could significantly prolong the survival time of mice. The underlying mechanisms were associated with improved energy metabolism based on a study carried out in rats exposed to a low pressure chamber simulating the low pressure environment of 8 000 m altitude. It was concluded that the Schizophyllum commune fermented broth was an effective anti-hypoxia functional agent and could be greatly bene- ficial to those living and working at high altitudes, such as people who reside in the reconstruction regions of Yushu.

Purification and characterization of schizophyllan from Schizophyllum commune

The schizophyllan from Schizophyllum commune was purified and characterized. The crude schizo-phyllan was obtained from Schizophyllum commune fermentation broth by decoloration with activated carbon,followed by deproteinization with Sevag method and ethanol precipitation. The pure schizophyllan was obtained by gel filtration chromatography with Sephacryl S-500,and its molecular characteristics were examined. The result showed that the molecular weight was 3.8×104 ,and the schizophyllan consisted of glucose with β-(1→6)-glucosidic linkages.

Domestic Wastewater Treatment through the Application of Corchuros olitorius L. as Bio-Coagulant in Cagayan de Oro City, Philippines

This research paper presented the potential of Corchuros olitorius L.as a natural coagulant in the removal of turbidity,total suspended solids,and biochemical oxygen demand from the domestic wastewater of the University of Science and Technology of Southern Philippines.Optimization of the natural coagulant and synthetic coagulant was employed prior to the treatment design.The jar test method was used in the optimization and lab analysis including the gravimetric method,dilution technique,and digital measurements.The optimization results of Corchuros olitorius L.using the jar test method revealed better removal at a lower dosage of 50 mg/L and a higher settling time of 90 minutes.The characterization using FTIR analysis also suggests a functional group that influences coagulation activity.Using the optimum dose and optimum settling time,results with the different treatment designs showed the highest removal at pH 7 showed%BOD removal of 89.78%(A75C25);85.98%(A25C75);88.76%(A50C50).TSS removal measured values of 88.50%(A75C25),85.56%(A25C75),and 87.16%(A50C50),while turbidity removal of 83.47%(A75C25),80.27%(A25C75),and 80.27%(A50C50).Statistically,measured values differ between treatment designs.It is suggested to investigate removal efficiency in more varied pH conditions,different settling times,stirring speed,and other variables for future studies.

Simulation of Low-Temperature Coal Tar Hydrocracking in Supercritical Gasoline

The aim of this paper was preliminary design of the process for low-temperature coal tar hydrocrackmg m supercritical gasoline based on Aspen Plus with the concept of energy self-sustainability. In order to ensure the correct- ness and accuracy of the simulation, we did the following tasks： selecting reasonable model compounds for low-tem- perature coal tar; describing the nature of products gasoline and diesel accurately; and confirming the proper property study method for each block by means of experience and trial. The purpose of energy self-sustainability could be pos- sibly achieved, on one hand, by using hot stream to preheat cold stream and achieving temperature control of streams, and on the other hand, by utilizing gas （byproduct of the coal tar hydrocracking） combustion reaction to provide energy. Results showed that the whole process could provide a positive net power of about 609 kW-h for processing the low- temperature coal tar with a flowrate of 2 268 kg/h. The total heat recovery amounted to 2 229 kW-h, among which 845 kW＇h was obtained from the gas combustion reaction, and 1 116 kW＇h was provided by the reactor＇s outlet stream, with the rest furnished by hot streams of the products gasoline, diesel and residue. In addition, the process flow sheet could achieve products separation well, and specifically the purity of product gasoline and diesel reached 97.2% and 100%, respectively.

Laser additive manufacturing of Si/ZrO_(2)tunable crystalline phase 3D nanostructures

The current study is directed to the rapidly developing field of inorganic material 3D object production at nano-/micro scale.The fabrication method includes laser lithography of hybrid organic-inorganic materials with subsequent heat treatment leading to a variety of crystalline phases in 3D structures.In this work,it was examined a series of organometallic polymer precursors with different silicon(Si)and zirconium(Zr)molar ratios,ranging from 9:1 to 5:5,prepared via sol-gel method.All mixtures were examined for perspective to be used in 3D laser manufacturing by fabricating nano-and micro-feature sized structures.Their spatial downscaling and surface morphology were evaluated depending on chemical composition and crystallographic phase.The appearance of a crystalline phase was proven using single-crystal X-ray diffraction analysis,which revealed a lower crystallization temperature for microstructures compared to bulk materials.Fabricated 3D objects retained a complex geometry without any distortion after heat treatment up to 1400℃.Under the proper conditions,a wide variety of crystalline phases as well as zircon(ZrSiO_(4)-a highly stable material)can be observed.In addition,the highest new record of achieved resolution below 60 nm has been reached.The proposed preparation protocol can be used to manufacture micro/nano-devices with high precision and resistance to high temperature and aggressive environment.

Evaluation of hydrodynamic dispersion parameters in fractured rocks

A numerical procedure to determine the equivalent hydrodynamic dispersion coefficients and Péclet number（Pe） of a fractured rock is presented using random walk particle tracking method.The geometrical effects of fracture system on hydrodynamic dispersion are studied.The results obtained from the proposed method agree well with those of empirical models,which are the scale-dependent hydrodynamic dispersion coefficients in an asymptotic or exponential form.A variance case is added to investigate the influence of longitudinal hydrodynamic dispersion in individual fractures on the macro-hydrodynamic dispersion at the fracture network scale,and its influence is demonstrated with a verification example.In addition,we investigate the influences of directional flow and stress conditions on the behavior of hydrodynamic dispersion in fracture networks.The results show that the magnitudes of the hydrodynamic dispersion coefficients are relatively smaller when the flow direction is parallel to the dip directions of fracture sets.Compressive stresses significantly reduce hydrodynamic dispersion.However,the remaining questions are：（1） whether the deformed fracture network under high stress conditions may make the scale-dependent hydrodynamic dispersion coefficients have asymptotic or exponential forms,and（2） what the conditions for existence of a well-defined equivalent hydrodynamic dispersion tensor are.They need to be further investigated.

Intensification of photocatalytic decomposition of water by ultrasound

Photocatalysis of water with and without ultrasound was studied using rGO supported CdS catalyst utilizing visible light. A higher hydrogen production was observed when ultrasound was used. This is attributed to a faster removal of bubbles of hydrogen from the surface of photocatalyst due to the mechanical energy associated with ultrasound overcoming surface tension. It has been further reported that the rate of hydrogen production decreased with time due to reversible deactivation of catalyst. This has been attributed to decrease in rate of hydrogen desorption with time.

低温固体氧化物燃料电池新型CeO2基复合电解质研究

采用一种钐掺杂的氧化铈(SDC)-碳酸盐复合物作为低温固体氧化物燃料电池(LTSOFC)的电解质.利用交流阻抗测试400～700℃不同气氛下的导电性能:电解质的电导率在大约500℃发生突变,表明传导机理发生改变;500℃以上电导率随碳酸盐组分增加而增大;还原性气氛下的电导率高于氧化性气氛下的电导率.以不同碳酸盐含量的电解质材料制备阳极支撑型单电池,运行中发现,在阴极和阳极侧均有水产生,说明同时存在氧离子和质子传导.电流-电压特性和功率特性显示,所有复合物电解质均有优于纯SDC电解质的电池性能,其中碳酸盐含量为20wt%时性能最好,500℃开路电压为1.00V,最大功率密度达415mW·cm^(-2).

β-Cyclodextrin functionalized graphene oxide： an efficient and recyclable adsorbent for the removal of dye pollutants

A novel method for the preparation of β- cyclodextrin grafted graphene oxide （GO-β-CD） has been developed. The GO-β-CD was characterized by Fourier transform infrared spectroscopy, 13C NMR spectroscopy, Raman spectroscopy and thermogravimetric analysis. The ability of GO-β-CD to remove fuchsin acid from solution was also studied. The GO-β-CD had an excellent adsorption capacity for fuchsin acid and could be recycled and reused. The adsorption capacities of GO-β-CD for other dye pollutants such as methyl orange and methylene blue were also investigated. The absorption capacities for the three dyes are in the order： fuchsin acid 〉 methylene blue 〉 methyl orange.

Soil Carbon Dynamics Under Changing Climate A Research Transition from Absolute to Relative Roles of Inorganic Nitrogen Pools and Associated Microbial Processes:A Review

It is globally accepted that soil carbon （C） dynamics are at the core of interlinked environmental problems, deteriorating soil quality and changing climate. Its management remains a complex enigma for the scientific community due to its intricate relationship with soil nitrogen （N） availability and moisture-temperature interactions. This article reviews the management aspects of soil C dynamics in light of recent advances, particularly in relation to the availability of inorganic N pools and associated microbial processes under changing climate. Globally, drastic alterations in soil C dynamics under changing land use and management practices have been primarily attributed to the variation in soil N availability, resulting in a higher decomposition rate and a considerable decline in soil organic C （SOC） levels due to increased soil CO2 emissions, degraded soil quality, and increased atmospheric CO2 concentrations, leading to climate warming. Predicted climate warming is proposed to enhance SOC decomposition, which may further increase soil N availability, leading to higher soil CO2 effiux. However, a literature survey revealed that soil may also act as a potential C sink, if we could manage soil inorganic N pools and link microbial processes properly. Studies also indicated that the relative, rather than the absolute, availability of inorganic N pools might be of key importance under changing climate, as these N pools are variably affected by moisture-temperature interactions, and they have variable impacts on SOC turnover. Therefore, multi-factorial studies are required to understand how the relative availability of inorganic N pools and associated microbial processes may determine SOC dynamics for improved soil C management.

Synthesis,characterization and application of Lagerstroemia speciosa embedded magnetic nanoparticle for Cr(Ⅵ)adsorption from aqueous solution

Lagerstroemia speciosa bark（LB） embedded magnetic nanoparticles were prepared by co-precipitation of Fe2＋ and Fe3＋ salt solution with ammonia and LB for Cr（Ⅵ） removal from aqueous solution.The native LB,magnetic nanoparticle（MNP）,L.spedosa embedded magnetic nanoparticle（MNPLB） and Cr（Ⅵ） adsorbed MNPLB particles were characterized by SEM-EDX,TEM,BET-surface area,FT-IR,XRD and TGA methods.TEM analysis confirmed nearly spherical shape of MNP with an average diameter of 8.76 nm and the surface modification did not result in the phase change of MNP as established by XRD analysis,while led to the formation of secondary particles of MNPLB with diameter of 18.54 nm.Characterization results revealed covalent binding between the hydroxyl group of MNP and carboxyl group of LB particles and further confirmed its physico-chemical nature favorable for Cr（Ⅵ） adsorption.The Cr（Ⅵ） adsorption on to MNPLB particle as an adsorbent was tested under different contact time,initial Cr（Ⅵ） concentration,adsorbent dose,initial pH,temperature and agitation speed.The results of the equilibrium and kinetics of adsorption were well described by Langmuir isotherm and pseudo-second-order model,respectively.The thermodynamic parameters suggest spontaneous and endothermic nature of Cr（Ⅵ）adsorption onto MNPLB.The maximum adsorption capacity for MNPLB was calculated to be 434.78 mg/g and these particles even after Cr（Ⅵ） adsorption were collected effortlessly from the aqueous solution by a magnet.The desorption of Cr（Ⅵ）-adsorbed MNPLB was found to be more than 93.72%with spent MNPLB depicting eleven successive adsorption-desorption cycles.

A study on Fricke-PVA-xylenol orange hydrogel dosimeter for E-beam radiotherapy

A Fricke-PVA-xylenol orange (FPX) hydrogel dosimeter, in good transparency, was prepared by physical crosslinking for three-dimensional dose measurements. The process of mixing the chemical dosimeter with the PVA solution was carried out at room temperature, which reduced the influence of auto-oxidation rate. Gradation in color was obviously observed with different distance from the radiation source after 6 MeV electron beam irradiation for radiotherapy. The effects of irradiation dose and three components of the FPX gel dosimeter, i.e. ferrous ions, xylenol orange (XO) and sulphuric acid on sensitivity and stability of dose response were investigated by UV-vis spectropho-tometric measurement. The dose response of the FPX gel dosimeter was linear in the range 0~2.0 Gy. The orthogonal test was employed to find the optimal composition of the gel dosimeter with a sensitivity of about 0.095 cm-1·Gy-1. It was found that XO concentration greatly affected the sensitivity of dose response and lower concentrations of the ferrous ion and XO gave higher sensitivity within the range 0~2.0 Gy.

Crystal Structure, Thermal Analysis and Theoretical Calculation of a One-dimensional Chain Complex [Zn(dafo)_2(H2O)_2](NO_3)_2

A novel one-dimensional chain complex [Zn(dafo)2(H2O)2](NO3)2 was obtained when we tried synthesizing a mixed ligand supramolecular compound of Zinc(II) with dafo and o-phthalic acid. Its structure was determined by single-crystal X-ray diffraction analysis. The crystal belongs to triclinic system, P-1 space group. The crystallo- graphic data: a=0.6989(4) nm, b=0.8281(5) nm, c=1.0231(5) nm, α=94.934(5)°, β=91.366(7)°, γ=99.820(7)°, V=0.5809(5) nm3, Z=1, F(000)=300, Mr=589.78, Dc=1.686 g/cm3, μ(Mo Kα)=1.130 mm-1, R1=0.0521, wR2 =0.1096. The analysis of the crystal structure indicates that the compound has a one-dimensional chain structure which is formed by hydrogen bonds. The constitutes of the title complex were proved by elemental analysis, IR spectra and thermal analysis. On the basis of the experimentation, the complex was calculated by DFT-B3LYP/LANL2DZ in Gaussian-98w also.

Synthesis and Crystal Structure of a New Diamine Complex CuCl_4(H_2tn)

In an attempt to synthesize a new pyrimidine complex of copper(II) in a solution reaction of CuBr2 with 2,2'-bis(hexahydropyrimidine) and hydro-chloric acid, we unexpectedly obtained a bright yellow chip-like crystal of CuCl4(H2tn) [H2tn=(H3NCH2CH2CH2NH3)2+]. Its structure was determined by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic system, space group Pnma, with cell parameters: a=0.7216(2) nm, b=1.8308(6) nm, c=0.7553(3) nm, V=0.9953(6) nm3, Z=4, F(000)=564, Mr=281.49, Dc=1.879 g/cm3. (Mo Ka)=3.204 mm-1, R1=0.0248, wR2=0.0575. The analysis of the crystal structure indicates that the complex has a three-dimensional network structure, which is formed by hydrogen bonds and electrostatic interaction.

Application of hopcalite catalyst for controlling carbon monoxide emission at cold-start emission conditions

Carbon monoxide(CO) is a poisonous gas particularly to all leaving being present in the atmosphere.An estimate has shown that the vehicular exhaust contributes the largest source of CO pollution in developed countries.Due to the exponentially increasing number of automobile vehicles on roads,CO concentrations have reached an alarming level in urban areas.To control this vehicular exhaust pollution,the end-of-pipe-technology using catalytic converters is recommended.The catalysts operating efficiently in a catalytic converter are a challenging class of materials for applications in cold start of engines to maintain indoor air quality.In the cold start period,the catalytic converter was entirely inactive,because the catalytic converter had not been warmed up.The cold start phase is also depending upon the characteristics of vehicles and property of catalysts.The increasing cost of noble metals with the increasing number of vehicles motivates the investigation of material concepts to reduce the precious metal content in automotive catalysts or to find a substitute for noble metals.Hopcalite(CuMnOx) catalyst could work very well at the low temperature;thus,it can overcome the problem of cold-start emissions if used in a catalytic converter.Further,low cost,easy availability and advanced synthesis methods with stabilizer,promoter,etc.,advocates for the use of hopcalite as an auto exhaust purification catalyst.Although there are numerous research articles present on this topic until now,no review has been presented for demanding this issue.So there is a space in this area,and it has been made an attempt to seal this hole and progress the future scope for hopcalite catalyst for purification of exhaust gases by this review.