Magnetic nanoparticle (Fe3O4) impregnated onto tea waste for the removal of nickel(II) from aqueous solution

The removal of Ni(II) from aqueous solution by magnetic nanoparticles prepared and impregnated onto tea waste (Fe(3)O(4)-TW) from agriculture biomass was investigated. Magnetic nanoparticles (Fe(3)O(4)) were prepared by chemical precipitation of a Fe(2+) and Fe(3+) salts from aqueous solution by ammonia solution. These magnetic nanoparticles of the adsorbent Fe(3)O(4) were characterized by surface area (BET), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Fourier Transform-Infrared Spectroscopy (FT-IR). The effects of various parameters, such as contact time, pH, concentration, adsorbent dosage and temperature were studied. The kinetics followed is first order in nature, and the value of rate constant was found to be 1.90×10(-2) min(-1) at 100 mg L(-1) and 303 K. Removal efficiency decreases from 99 to 87% by increasing the concentration of Ni(II) in solution from 50 to 100 mg L(-1). It was found that the adsorption of Ni(II) increases by increasing temperature from 303 to 323 K and the process is endothermic in nature. The adsorption isotherm data were fitted to Langmuir and Freundlich equation, and the Langmuir adsorption capacity, Q°, was found to be (38.3)mgg(-1). The results also revealed that nanoparticle impregnated onto tea waste from agriculture biomass, can be an attractive option for metal removal from industrial effluent.     

The clinical use of quantitative ultrasound (QUS) in the detection and management of osteoporosis

For the detection and management of osteoporosis and osteoporosis-related fractures, quantitative ultrasound (QUS) is emerging as a relatively low-cost and readily accessible alternative to dual-energy X-ray absorptiometry (DXA) measurement of bone mineral density (BMD) in certain circumstances. The following is a brief, but thorough review of the existing literature with respect to the use of QUS in 6 settings: 1) assessing fragility fracture risk; 2) diagnosing osteoporosis; 3) initiating osteoporosis treatment; 4) monitoring osteoporosis treatment; 5) osteoporosis case finding; and 6) quality assurance and control. Many QUS devices exist that are quite different with respect to the parameters they measure and the strength of empirical evidence supporting their use. In general, heel QUS appears to be most tested and most effective. Overall, some, but not all, heel QUS devices are effective assessing fracture risk in some, but not all, populations, the evidence being strongest for Caucasian females over 55 years old. Otherwise, the evidence is fair with respect to certain devices allowing for the accurate diagnosis of likelihood of osteoporosis, and generally fair to poor in terms of QUS use when initiating or monitoring osteoporosis treatment. A reasonable protocol is proposed herein for case-finding purposes, which relies on a combined assessment of clinical risk factors (CR.F) and heel QUS. Finally, several recommendations are made for quality assurance and control.     

Photoelectrochemical studies on colloidal copper (I) oxide/modified with some organic semiconductors: Incentive for use of nanoparticle systems

Colloidal Cu₂O solutions were used to explore photonic activities at the semiconductor/electrolyte interface. Fluorescence spectroscopic studies were performed on Cu₂O colloidal particles modified with some conjugated organic monomers such as 2-amino-phenyl pyrrole (2-APPy), tri-phenyl amine (TPA), or 2-thionyl pyrrole (2-Th-Py) to investigate the quantum absorbance efficiency at this inorganic/organic interface (IOI). Our study shows that colloidal p-type Cu₂O possesses a bandgap with direct transition of ≈ 2·2 eV and indirect transition of 1·85 eV. The recorded rates of charge injection into colloidal Cu₂O, k _ct, were 2·31 × 10⁹ s⁻¹, 5·05 × 10⁸ s⁻¹, and 7·22 × 10⁸ s⁻¹ for 2-APPy, TPA and 2-Th-Py, respectively. The studied systems show more stability in colloidal form than in thin solid form. Results were interpreted using the optical and electrical parameters of the organic monomer such as ionization potential (IP), electron affinity (EA) and energy bandgap (Eg), and the barrier height at the IOI interface. Stability of the colloidal system is attributed to the physical dimensions of the photoactive system. The nano-colloidal particle offers a condition where its size is less than √Dt.     

Generation of H(2), O(2), and H(2)O(2) from water by the use of intense femtosecond laser pulses and the possibility of laser sterilization

An intense femtosecond Ti-sapphire laser pulse was focused into water, leading to self-focusing. Apart from generating a white light (supercontinuum), the intense laser field in the self-focusing regions of the laser pulse dissociated the water molecules, giving rise to hydrogen and oxygen gas as well as hydrogen peroxide. Our analysis shows that the formation of free radicals O, H, and OH preceded the formation of the stable products of H(2), O(2), and H(2)O(2). Because O radicals and H(2)O(2) are strong oxydizing agents, one can take advantage of this phenomenon to design a laser scheme for sterilization in medical and biological applications.     

The use of poly(ethylene terephthalate)–poly(aniline) composite for trypsin immobilisation

This paper presents trypsin immobilisation on strips of poly(ethylene terephthalate)–poly(aniline), activated with glutaraldehyde (PET–PANIG) composite. The photomicrography of the material showed changes corresponding to the chemical modifications produced in the steps of synthesis. The immobilisation process was very efficient under optimal conditions (18.6%). The immobilised and free enzyme presented the same pH and temperature optimum. PET–PANIG-trypsin was able to hydrolyse casein, albumin, gelatine, and skimmed milk. Km_app value for PET–PANIG-trypsin was very close to Km of the free enzyme for casein. Immobilised trypsin showed higher stability than the free enzyme, with 100% activity after 14 days of storage at 4 °C and 100% operational stability after 4 cycles of use.     

Monolithic wavelength converter for ultraviolet light by use of a Gd(x)Y(1-x)Ca4O(BO3)3 crystal

Gd(x)Y(1-x)Ca4O(BO3)3 (GdYCOB) is a promising nonlinear optical crystal that shows high effective nonlinearity d(eff), noncritical phase matching, and high chemical stability. We report on the fabrication and characteristics of a monolithic wavelength converter, which generates ultraviolet light by the incidence of a 1.064 microm near-infrared laser. The converter consists of GdYCOB for third-harmonic generation, KTiOPO4 (KTP) for second-harmonic generation, and a wave plate. GdYCOB has the advantage of an extremely wide angular acceptance bandwidth, whereas KTP exhibits a high effective nonlinear coefficient and a broad temperature bandwidth. Consequently the combination of these crystals results in highly efficient and stable ultraviolet conversion for constructing a compact and robust ultraviolet laser.     

Development of photoreactor design equation for the treatment of dye wastewater by UV/H(2)O(2) process.

The treatment of Direct Yellow 86 dye wastewater by the UV/H(2)O(2) process in continuous annular photoreactors was studied under various UV light intensities, influx concentrations of dye, dosages of H(2)O(2) and dimensions of photoreactor. A photoreactor design equation combined the UV light distribution profile in the reactor and the empirical rate expressions for the decomposition of dye and H(2)O(2) was used to predict the destruction of dye within photoreactors of different geometries at various operating conditions. Experimentally observed removal of the dye pollutant in the plug flow annular reactor agreed well with the theoretical solutions modeled by the developed photoreactor design equation.     

Preparation and characterization of Ti/SnO(2)-Sb(2)O(3)-Nb(2)O(5)/PbO(2) thin film as electrode material for the degradation of phenol

In this work, a novel electrode of titanium substrate coated with mixed metal oxides of SnO(2), Sb(2)O(3), Nb(2)O(5) and PbO(2) was successfully prepared using thermal decomposition and electrodeposition. The surface morphology and the structure of the prepared thin film were characterized by scanning electronic microscopy (SEM) and X-ray diffraction (XRD), respectively. Experimental results showed that the structure of the prepared electrode might be described as a Ti/SnO(2)-Sb(2)O(3)-Nb(2)O(5)/PbO(2) thin film and its surface was mainly comprised pyramidal-shape beta-PbO(2) crystals. The modified electrode had higher oxygen evolution potential than that of other PbO(2) modified electrodes. Electrocatalytic oxidation of phenol in aqueous solution was studied to evaluate the potential applications of this electrode in environmental science. The phenol removal efficiency in an artificial wastewater containing 0.50g/L phenol could reach 78.6% at 20 degrees C and pH 7.0 with an applied electricity density of 20mA/cm(2) and treatment time of 120min. When 21.3g/L chloride was added to this wastewater, the removal efficiency could reach to 97.2%.     

The dielectric properties of Ba(0.6)Sr(0.4)Cr(x)Ti(1-x)O(3) thin films prepared by pulsed laser deposition.

Ba(0.6)Sr(0.4)Cr(x)Ti(1-x)O(3) (BSCT) films were prepared by pulsed laser deposition with the value of x varying from 0 mol% to 2.0 mol%. X-ray diffraction analysis detected an increase in the lattice parameters, which could be due to the characteristics of the growth process. Dielectric properties and tunability of the BSCT films were measured. The dissipation factors of the films decreased with increasing Cr-concentration. The highest figure of merit (FOM) value of 33.3 was obtained in 1.0 mol%-doped BSCT film. As a result, the effect of Cr doping is positive.     

Utilization of strontium added NiAl(2)O(4) composites for the detection of methanol vapors

Strontium added NiAl(2)O(4) composites prepared by sol-gel technique was utilized for the detection of methanol vapors. X-ray diffraction, scanning electron microscopy (SEM), FT-IR spectroscopy and nitrogen adsorption/desorption isotherm at 77K was employed respectively to identify the structural phases, surface morphology, vibrational stretching frequencies and BET surface area of the composites. The composites were prepared with the molar ratios of Ni:Sr as (1.0:0.0, 0.8:0.2, 0.6:0.4, 0.4:0.6, 0.2:0.8, 0.0:1.0) keeping the aluminum molar ratio as constant for all the compositions and were labeled as NiSA1, NiSA2, NiSA3, NiSA4, NiSA5 and NiSA6, respectively. The samples sintered at 900 degrees C for 5 h were subjected to dc resistance measurements in the temperature range of 30-250 degrees C to study the methanol vapor detection characteristics. The results revealed that the sensitivity in detecting methanol vapor increased with increase in temperature up to 175 degrees C for the composites NiSA1 and NiSA6 while for the other composites up to 150 degrees C and thereafter decreased. The sensitivity increased with increase in methanol concentration from 100 to 5000 ppm at 150 degrees C. Among the different composites NiSA5 showed the best sensitivity to methanol detection at an operating temperature of 150 degrees C.     

The use of yttrium-rare earth aluminium garnet solid solutions for bulk-acoustic-wave (BAW) devices

The isomorphic solid solution of yttrium-rare earth aluminium garnets is suggested as a dielectric material for acoustic waveguides with extremely low acoustic-wave absorption (AWA) at room temperature and for frequencies higher than 10 GHz. The two main mechanisms by which substitutional atoms decrease the bulk AWA are determined. The first one is the decrease in effective lifetime of the thermal phonons resulting in the corresponding reduction of the viscoelastic absorption-this mechanism is important for the shear acoustic waves. The second is more important for longitudinal waves. It is the reduction of Gruneisen constants for solid solution as compared to the crystal matrices.     

Research progress in the use of ferrate(VI) for the environmental remediation

The aim of this paper is to review the research progress of using ferrate(VI) in following fields of environmental remediation: (1) water disinfection; (2) degradation of synthetic organic pollutants; (3) treatment of emerging organic pollutants; (4) oxidation of inorganic pollutants; (5) removing humic substance; (6) wastewater treatment and disinfection; and (7) sewage sludge treatment. Whilst the superior performance of potassium ferrate(VI) as an oxidant/disinfectant for the environmental remediation has been demonstrated in various recent researches, challenges have existed to the implementation of ferrate(VI) technology in full-scale water, wastewater and sewage sludge treatment owing to either the instability property of a ferrate(VI) solution or a high preparation cost of a solid ferrate(VI). In addition to this, there are some fundamental issues which have not yet been studied thoroughly which are crucial for the implementation of ferrate(VI)-these lead to the future research work recommended by this paper.     

CISPR22(2008)第六版的解释单

2007年10月27日,CISPR/I分会在其年会上讨论决定,CISPR22(第6版)的维护日期延至2012年,因此,文件CISPR/I/279/MCR暂时不予考虑。但是,在随后的CIS PR/I分会WG3会议上,委员们认为,文件维护文件中的部分内容     

The use of boundary strip method (BSM) for evaluation of the transverse mechanical properties of fibrous composites

The boundary strip method (BSM) is applied for evaluation of the transverse mechanical properties of fibrous composites with random and periodical fiber distributions. This special semi numerical method helps find the link between the microscopic behavior of the composite material and its macroscopic response in a rather detailed manner, enabling definition of stress and strain magnitudes at each point of the cross section. Here, specifically statistical model based on the boundary strip method, is used for assessment of the transverse effective moduli of fibrous composites. Random fiber distributions are compared with periodic fiber distributions having square or hexagonal array arrangements. Those are the common models used nowadays and modeled by the finite element or the boundary element. A comparison with the bounds of the polarization extremum principles is conducted too. The influence of the randomly distributed fibers on the transverse effective moduli is investigated and a good correlation is found between the results of the present model and the lower bound of the polarization extremum principles.     

The use of Functional Resonance Analysis Method (FRAM) in a mid-air collision to understand some characteristics of the air traffic management system resilience

The Functional Resonance Analysis Model (FRAM) defines a systemic framework to model complex systems for accident analysis purposes. We use FRAM in the mid-air collision between flight GLO1907, a commercial aircraft Boeing 737-800, and flight N600XL, an executive jet EMBRAER E-145, to investigate key resilience characteristics of the Air Traffic Management System (ATM). This ATM system related accident occurred at 16:56 Brazilian time on September 29, 2006 in the Amazonian sky. FRAM analysis of flight monitoring functions showed system constraints (equipment, training, time, and supervision) that produce variability in system behavior, creating demand resources mismatches in an attempt to perceive and control the developing situation. This variability also included control and coordination breakdowns and automation surprises (TCAS functioning). The analysis showed that under normal variability conditions (without catastrophic failures) the ATM system (pilots, controllers, supervisors, and equipment) was not able to close the control loops of the flight monitoring functions using feedback or feedforward strategies to achieve an adequate control of an aircraft flying in the controlled air space. Our findings shed some light on the resilience of Brazilian ATM system operation and indicated that there is a need of a deeper understanding on how the system is actually functioning.     

The annealing of misfit dislocations in the (111) Cu/(111) Cu2O system

Recent work on the early stages of the epitaxial oxidation of (111) Cu at 350 °C and in oxygen pressures between 10^-7 and 10^-4 Torr has resulted in the determination of the growth modes that occur and the accompanying elastic strains. Initially a hexagonal 3 × 3 oxide superlattice is formed which continues to grow by a layer growth mechanism up to a theoretically estimated thickness of approximately five monomolecular layers. Subsequent oxidation occurs by the formation of lamellar islands containing misfit dislocations which reduce the coincidence lattice misfit strain. In the present work these (111) Cu/(111) Cu₂O bilayers were annealed and examined in situ in the transmission electron microscope in the temperature range 25–350 °C. The misfit dislocation density decreased as the temperature was increased. The annealing effects are complex and interdiffusion phenomena can be observed even at 60 °C.     

溶胶-凝胶技术制备(Bi4-x,Lax)Ti3O12陶瓷的工艺技术研究

采用3种溶胶－凝胶（sol-gel）工艺，以硝酸铋、硝酸镧和钛酸丁酯为原料，制备掺镧钛酸铋（Bi4-x,Lax)Ti3O12（简记为BLT）陶瓷。通过控制溶胶－凝胶工艺，分析比较不同溶胶－凝胶过程对陶瓷结构的影响，为后续BLT铁电薄膜的溶胶－凝胶制备选择最佳工艺技术条件。研究发现采用滴定方式的sol-gel工艺制备的陶瓷具有较好的取向和结构。     

A lean environmental benchmarking (LEB) method for the management of cutting tools

Manufacturing companies are striving hard to remain competitive hence, they rely on a number of resources to meet customers’ expectations, among which cutting tools are included. This paper addresses the problems faced in the management of cutting tools activities. Production managers have highlighted the lack of procedures containing metrics and targets that would show them whether their company is able to perform an efficient management, and if it is capable of supporting the deployment process. In this context, this paper presents a novel lean environmental benchmarking (LEB) method for performing a diagnosis of practices and performances to support the implementation of a cutting tool management strategy and/or the effective management of these assets. Strategic, technical and logistical aspects are addressed, particularly, with regard to management focused on lean manufacturing and environmental aspects. Field studies were performed in nine Brazilian companies in the metal-mechanical sector to validate the LEB method proposed. The LEB method helped the participant organisations to clarify the various activities that involved the management of their cutting tools, while the field studies indicated that all nine organisations had a great concern regarding the preservations of the environment, and also an effective utilisation of resources spent for machining components.