Search

Pd catalysts supported on activated carbon (Pd/C–NH3) toward HCOOH dehydrogenation were prepared by a simple adsorption method using ammonia (NH3) and Ar as the working gas. The results show that the TOFinitial of Pd/C–NH3 was 459.8 h−1 at 50 °C. When the reaction was carried out for 4 h, the HCOOH dehydrogenation ratio over Pd/C–NH3 was about 81.2%, which was 1.15 and 1.13 times, respectively, as that of the as-prepared Pd/C catalyst without any treatment (Pd/C–As) and the Pd/C catalyst purchased from Sigma-Aldrich (Pd/C-CM). The total amount of H2 and CO2 produced by using Pd/C–NH3 to decompose HCOOH in the third cycle was 99.4% of the gas produced by the first reaction cycle, and 1.80 and 12.60 times, respectively, as that of Pd/C–As and Pd/C-CM. The characterization results indicated that the Pd active species in Pd/C–NH3 migrated to the outer surface of the carbon support during the reaction, and the pore volume of the carbon support became larger, which were beneficial to the reaction. These factors made Pd/C–NH3 exhibit excellent HCOOH dehydrogenation activity and stability. NH3 adsorption is a simple and effective method for preparing high-performance Pd/C HCOOH dehydrogenation catalysts, and has important guiding significance for the preparation of other carbon supported noble metal catalysts.

A europium salt-Na[Eu(5,5′-DMBP)(phen)3]·Cl3 (Eu(III)-CPLx) was prepared by using various precursors such as 5,5′-Dimethyl-2,2′-bipyridyl (5,5′-DMBP), 1,10-phenanthroline (phen) and europium chloride hexahydrate (EuCl3·6H2O) by a complexation method. The red emission fluorescent Na[Eu(5,5′-DMBP)(phen)3]·Cl3/D-Dextrose (Eu(III)-CPLx/D-Dex) composite was synthesized by using an adsorption method with Eu(III)-CPLx and D-Dextrose (D-Dex). The Eu(III)-CPLx and fluorescent (Eu(III)-CPLx/D-Dex) composites were characterized by numerous techniques. The fluorescent (Eu(III)-CPLx/D-Dex) composite demonstrated a strong red emission and controlled fluorescence quenching in the solid state and was consequently used in latent fingerprint (LFP) detection. The LFPs were developed by using a powder dusting method (PDM) with Eu(III)-CPLx and fluorescent Eu(III)-CPLx/D-Dex composites on different substrates under daylight and UV-light irradiation at 365 nm. The fluorescent Eu(III)-CPLx/D-Dex composite was effectively explored for developing LFP images on various substrates and also acts as a better labeling agent for LFP detection in forensic science crime scene investigations.

The objective of this study was to explore the feasibility of using nanocrystal technology for the design of immediate and sustained release tablets of poorly water soluble drugs. Nanocrystal aggregates comprised of lovastatin, a model drug, 20% PVP K17 and 5% SDS were prepared by spray drying. The nanocrystal aggregates were mixed with lactose, Avicel Ph 101 and Ac-Di-Sol® (blank granules) or 316 Fast Flo® lactose, MCC PH200, and Ac-Di-Sol ® (direct compression), where the composition was optimized by uniform design. The blank granules adsorption method had superior flowability, filling and plastic deformation as well as rapid release rates, and the tableting process did not affect the release rate of nanocrystals. An optimized sustained release tablets formulation was also identified, which decreased the difference of drug release behavior under sink and non-sink conditions. In conclusion, nanocrystal technology is promising for preparing both immediate and sustained release tablets for poorly water soluble drugs with robust drug dissolution and release.

Pesticides have been always restricted by poor efficacy and inacceptable toxicity. In this work, a pH-sensitive controlled-release nano-capsule of fungicide, Boscalid@ZIF-67 (ZIF is a subclass of MOF), was prepared based on metal-organic framework (MOF) for higher antifungal effect and low bio-toxicity. The Boscalid@ZIF-67 was formed by physical adsorption method and it possesses uniform size and dodecahedral shape. The loading ratio is as high as 18%. In addition, the release of fungicide Boscalid showed pH sensitive response due to the weak acidic group in the MOF structure, in which the rate of release was more rapid under acid condition (＜7). Cumulative release rate release was higher about 25% and 38% adjusted from 7 to 3.5 and from 7 to 5.5 on the 6th day than that under neutral condition. At the early stage of infecting the host plant, Botrytis cinerea will produce more acidic substances such as oxalic acid, which are conducive to Boscalid@ZIF-67 disintegration for rapid release of Boscalid. Meanwhile, the antifungal effect of Boscalid@ZIF-67 was 4-6 times more of that commercially available product on Botrytis cinerea, while the bio-toxicity under the same condition is much lower than that of latter. Thus, this work not only proves that Boscalid@ZIF-67 could be used as nanoparticles platform for smart control over Botrytis cinerea, but also has great potential to improve traditional modalities by addressing the crop diseases in economic and ecological manner.

Polydopamine polystyrene nanofibers mat (PDA-PS NFsM) was prepared as an adsorbent for the simultaneous removal of multiple antibiotic residues in environmental water for the first time. PDA-PS NFsM can directly be used to adsorb 18 antibiotic residues belonging to 8 classes without any pretreatment of water samples. The adsorption process was completed within 5 min. All antibiotics could be removed at the same time, and the removal rate of each target was above 85%. Moreover, the used PDA-PS NFsM can be easily separated from the environmental water by taking out directly, and can be reused for 10 times after simple regeneration. The thermodynamic and kinetic properties of PDA-PS NFsM adsorption of antibiotic residues were further investigated consequently. It was found that the adsorptions of PDA-PS NFsM to the targets were spontaneous and endothermic process (ΔG 0, ΔS>0). The results of adsorption kinetic experiments illustrated that the adsorption process was rapid, the adsorption equilibrium of which can be reached in 5 min. Adsorption isotherm experiments proved that the adsorption process of PDA-PS NFsM was consistent with Langmuir adsorption (R2 > 0.994), and the maximum adsorption capacity of PDA-PS NFsM towards all targets were 123.76 mg g−1. The developed method is rapid and simple, and can efficiently adsorb and remove a variety of antibiotics in environmental water, which has good practical application prospect.

This article proposes a novel sodium dodecylbenzenesulfonate (SDBS)-assisted equilibrium adsorption method for preparing highly dispersed Ni/Al2O3 and Fe-promoted NiFe/Al2O3 thioetherification catalysts. The proposed strategy anchors nickel cations onto the electronegative surface of an Al2O3 support modified by negatively charged DBS− bilayers. As a result, this method achieves highly dispersed Ni nanoparticles without strengthening the metal-support interaction, promoting the reducibility and sulfurization of the supported Ni species. The as-prepared Ni-based catalysts have a smaller size, a higher dispersion of metal nanoparticles, and a greater amount of active metal sulfides than their counterparts prepared by the conventional impregnation method, endowing them with excellent catalytic performance for the highly selective removal of mercaptans. This method provides a new opportunity to prepare highly dispersed metal nanoparticles without a strong metal-support interaction.

This article describes the preparation of calix[4]arene-bonded silica gels (C[4]BS and DMC[4]BS), and their application to the removal of some selected phenolic compounds such as phenol (PHE), p-chlorophenol (PCP), m-nitrophenol (MNP) and p-nitrophenol (PNP) from aqueous solutions by adsorption method. In initial adsorption experiments appeared that C[4]BS was much more effective in adsorption of PNP rather than PHE, PCP and MNP, whereas DMC[4]BS exhibited too little adsorption ability towards all phenols. Herein, it was concluded that the hydrogen bonding capacities of both phenols and calix[4]arene based adsorbents played a predominant role in the interactions between adsorbate and adsorbent within the adsorption mechanism. Thus, in subsequent studies, the C[4]BS was employed as an adsorbent in the adsorption of PNP, and adsorption conditions were optimized. Furthermore, isotherm and kinetic studies were performed to clarify the phenomena of PNP adsorption onto C[4]BS.

During recent years, the pharmaceutical compounds have been considered as an emerging water micro-pollutant, due to their potential eco-toxicity. Among the various treatment approaches, the adsorption method has been found an attractive, simple and powerful tool for the removal of these compounds. Recently, the chitosan-based materials (composite), as an eco-friendly biopolymers class, show remarkable promise for effective adsorption of these compounds. This paper aims to establish criteria for choosing the finest chitosan-derivatives through a critical review and assess the published researches dealing with the effectiveness of them in the adsorptive removal of pharmaceutical compounds. This is followed by a preliminary summary for pharmaceutical contaminants adsorption performance of studied chitosan-based materials in tables. In this review article, the pharmaceutical materials also introduced into three categories as antibiotics (tetracycline, amoxicillin, etc.), non-steroidal anti-inflammatory (diclofenac, ibuprofen, etc.) and other pharmaceutical compounds (hydroquinone, fluoxetine, etc.), and the employed adsorbents for their removal were studied. This review provides information for the development of composite adsorbents, enhancement of adsorption ability by modification with different functional groups, real wastewater treatment, multicomponent adsorption, regeneration enhancement and fixed-bed studies which is helpful for readers to water and wastewater treatment process at both laboratory and field scales. Along this line, the impact of the various parameters (pH, sorbent amount, initial concentration, temperature, etc.) and the adsorption mechanism are also briefly discussed.

The determination of free drug concentration is a very important issue in the field of pharmacology because only the unbound drug fraction can achieve a pharmacological effect. Due to the ability to solubilize many different compounds in micellar aggregates, micellar liquid chromatography (MLC) can be used for direct determination of free drug concentration. Proteins are not retained on the stationary phase probably due to the formation of protein - surfactant complexes which are excluded from the pores of stationary phase. The micellar method is simple and fast. It does not require any pre-preparation of the tested samples for analysis. The main aim of this paper is to demonstrate a completely new applicability of the analytical use of MLC concerning the determination of free drug concentration in the standard solution of human serum albumin. The well-known adsorption method using RP-HPLC and the spectrophotometric technique was applied as the reference method. The results show that the free drug concentration value obtained in the MLC system (based on the RP-8 stationary phase and CTAB) is similar to that obtained by the adsorption method: both RP-HPLC (95.83μgmL(-1), 79.86% of free form) and spectrophotometry (95.71μgmL(-1), 79.76%). In the MLC the free drug concentration was 93.98μgmL(-1) (78.3%). This indicates that the obtained results are within the analytical range of % of free ampicillin fraction and the MLC with direct sample injection can be treated like a promising method for the determination of free drug concentration.

Adsorption is considered to be the most effective method for removing environmental pollutants. Covalent organic frameworks (COFs, state-of-art 2D or 3D crystalline porous polymers linked by covalent bonds) have been widely used in environmental remediation due to the superior physicochemical properties such as huge specific surface area, high porosity, admirable physicochemical stability, fast charge-carrier mobility, tunable functionality. However, few investigation on the progress of COFs in environmental remediation are available. In this review, recent signs of progresses of COFs as superior materials for the efficient capture of gases, organics, heavy metals and radionuclides are critically reviewed. Finally, the current challenges and further research (e.g., large-scale synthesis, detoxification, sustainability and cost evaluation) were discussed. Hopefully, this review could contribute to exploit the extensive application of COFs on the removal of various environmental contaminants in environmental cleanup.

In the present study, an efficient preparative procedure was developed for the preparation of three main acylated pentasaccharides from Polygalae Radix using integrated extraction–adsorption method followed by semi-preparative high performance liquid chromatography. Firstly, the acylated pentasaccharides were simultaneously extracted and purified by column chromatographic extraction integrated with macroporous resin purification. Comparing this integrated process to conventional one, some obvious advantages were observed, namely more than 38.9% enhancement of the recovery of acylated pentasaccharides, about 49.4% and 50.4% reduction in water and ethanol consumption, respectively. And then, the obtained extracts were further purified by semi-preparative high performance liquid chromatography. Finally, three known acylated pentasaccharides were purified from 100 g of Polygalae Radix, including tenuifoliose I (13 mg), tenuifoliose H (15 mg), and tenuifoliose A (21 mg). The purities of the compounds were determined by high performance liquid chromatography and the chemical structures were confirmed by mass spectrometric and NMR analysis.

The Mg–Al-CO 3 -LDH with Mg 2+ /Al 3+ molar ratio of 2 was prepared via coprecipitation method at constant pH of 9–10 and used to remove three red dyes by batch adsorption method. The results showed the Mg–Al-LDH were well crystallized and can adsorb the red dyes effectively. The optimal adsorbent dosage and contact time were 1.0 g and 60 min, respectively. Adsorbed amount hardly changed when pH

In this paper, we present a novel method for determining the maximal amount of ethane, a minor gas species, adsorbed in a shale sample. The method is based on the time-dependent release of ethane from shale samples measured by headspace gas chromatography (HS-GC). The study includes a mathematical model for fitting the experimental data, calculating the maximal amount gas adsorbed, and predicting results at other temperatures. The method is a more efficient alternative to the isothermal adsorption method that is in widespread use today.

The present study investigated capillary electrophoretic detection of vanillin in vanilla perfume and air. An UV-absorbance detector was used in a home-made capillary electrophoretic instrument. A fused silica capillary (outer diameter: 364 μm, inner diameter: 50 μm) was used as a separation capillary, and a high electric voltage (20 kV) was applied across the two ends of the capillary. Total length of the capillary was 70 cm, and the effective length was 55 cm. Experimental results showed that the vanillin peak was detected at about 600, 450, and 500 seconds when pH of running buffers in CE were 7.2, 9.3, and 11.5, respectively. The peak area of vanillin was proportional to its concentration in the range of 0-10(-2) mol/L. The detection limit was about 10(-5) mol/L. Vanillin concentration in a 1% vanilla perfume sample was determined to be about 3×10(-4) mol/L, agreed well with that obtained by a HPLC method. Furthermore, determination of vanillin in air by combination of CE and active carbon adsorption method was investigated.

A novel method for Cu 2+ sequestration in Cu 2+ aqueous solution has been demonstrated using amine-functionalized double-walled silica nanotubes (DWSNTs). Herein, the precipitation method and the adsorption method are combined to remove Cu 2+ in the Cu 2+ aqueous solution. Primary (1°), secondary (2°), tertiary (3°), di-, tri-amines are immobilized on the surface of DWSNT as the adsorption site. The results show that the Cu 2+ adsorption amount on the amine-functionalized DWSNTs is in the following order: tri-amine > di-amine > 1° amine > 2° amine > 3° amine. The complexed Cu 2+ s with the amine-functionalized DWSNTs become Cu(OH) 2 crystals due to the reaction with OH − s dissociated from water. Thus, the amine-functionalized DWSNTs show the superior sequestration capacity of Cu 2+ in the Cu 2+ aqueous solution owing to the Cu(OH) 2 crystals growth on them. FT-IR, FEG-SEM, HR-TEM, and XRD studies demonstrate the mechanism of the Cu 2+ adsorption and the Cu(OH) 2 crystals growth. The crystallization-technique of the heavy metal ion on the amine-functionalized DWSNTs is also expected to have potential applications such as the facile synthesis of nano- and microparticles, and the metal catalyst supporter.

The effective production of xylooligosaccharides (XOS) from wheat bran was investigated. Wheat bran contains rich hemicellulose which can be hydrolyzed by enzyme; the XOS were obtained by microwave assisted enzymatic hydrolysis. To improve the productivity of XOS, repeated microwave assisted enzymatic hydrolysis and activated carbon adsorption method was chosen to eliminate macromolecules in the XOS. On the basis of experimental data, an industrial XOS production process consisting of pretreatment, repeated microwave assisted enzymatic treatment and purification was designed. Using the designed process, 3.2g dry of purified XOS was produced from 50 g dry wheat bran powder.

This work is devoted to researching the kinetics of the formation of particle surfaces and interfaces during the milling of nanostructured tungsten carbide/cobalt (WC–Co) powders in a planetary ball mill. The power consumption of the mill and the energy transferred to the powder are measured. The contents of Co and WC at the surface of the particle, the specific surface areas (SSAs) of the particles, and the SSAs of the WC phase and the WC grains were determined using various methods. The features of the SSA analysis using the laser diffraction method and the Brunauer–Emmett–Teller (BET) gas adsorption method are discussed. The specific interface areas (SIAs) of the WC/WC and WC/Co boundaries were calculated based on the obtained data. The SSA of the powder and the SIA of the WC/WC linearly increased during the beginning of the milling process, the rates of growth subsequently decreased, and the SSA and the SIA approached their limits. The SIA of WC/Co increases linearly without limit. The employed model made it possible to determine the milling rates and the limits of the SSA and the SIA. Based on the obtained results and literature data, the energy that was stored in different surfaces and interfaces was calculated.

Poly(p-phenylene benzobisoxazole) (PBO) fibre has excellent mechanical properties and good thermal stability. However, the use of PBO fibre is limited because of its low photostability. Thus, this work aimed to study the improvement of PBO fibre photostability. Two methods of adhering UV absorbers to PBO fibre surface, namely, coordination bond method and physical adsorption method, were compared. The photo aging results show that the PBO fibres covered by UV absorbers via the coordination bond method were smooth and had no evident particle agglomeration. These fibres showed more improved photostability compared with those covered by UV absorbers via physical adsorption. After 125 h of photo aging, the tensile strength retention rate of PBO fibres covered with UV absorbers via the coordination bond method was still over 90%, which is far higher than that of untreated PBO fibres (approximately 75%).

Recycling treatment of cable insulation resin generated from electric wires and cables was investigated. Conventional insulation PVC contains a lead component, tribase, as a thermal stabilizer and lead removal is necessary to recycle this PVC as insulation resin. This paper describes a solid surface adsorption method using ion exchange resin to remove the fine lead containing particles from PVC dissolved solution. Low lead concentration in the recovered PVC, complying with the requirements of RoHS, was achieved.

Scores of abrasive wear problems particularly those in the harsh environments involve remarkable breakage of the abrasive. One notable case is the ore breakage and the media wear in the comminution devices such as tumbling mills, where the abrasive breakage is indeed the objective of the process. While there are standard test methods for wear or breakage characterization of the materials individually, there is a need for standard test methods enabling us to conduct a combined study of the wear and breakage to create an environment similar to the actual applications. Steel Wheel Abrasion Test is one of the candidates providing us with such an environment to study wear, abrasive fragmentation and their inter-relation in one single apparatus because of its high-stress nature of abrasion. Moreover, there is a need for more precise tools of describing the quantity and quality of the abrasive breakage, and surface wear. In this research, breakage has been characterized through size distribution of the abrasive before and after the test, and estimation of the created surface area in abrasive based on the size distribution. Wear particles are collected from the used abrasive after the test using an electromagnet, precisely analyzed with laser scattering machine and their surface area density is calculated using the gas adsorption method. Characterization of the wear debris along with precise quantifying of the abrasive fragmentation provided powerful tools in studying the abrasive wear. Experimental results extracted from the Steel Wheel Abrasion Test indicate a strong correlation between the abrasive breakage and the wear which newly introduced tools were successfully capable of predicting. Additionally, the combined study of the wear and breakage enabled us to give explanation for some anomalous wear trends which were not justifiable in the past.

The direct electrochemistry of hemoglobin (Hb) immobilized on the siliceous mesostructured cellular foam (MCF) modified glassy carbon electrode (GC) was presented. Using a simple physical adsorption method, Hb was immobilized on MCF and the influences of concentration of Hb and the pH value of solution were investigated. UV–vis and FTIR spectra displayed that Hb maintained its natural structure inside the pores of MCF. The electrochemical property of Hb/MCF/GC modified electrode was studied by cyclic voltammetry. A couple of quasi-reversible redox peaks of Hb were observed on the Hb/MCF/GC electrode at about −0.396 V and −0.321 V in PBS (pH 7.0). The results indicated that MCF provided a favorable microenvironment for immobilization of Hb and facilitated the electron transfer between Hb and electrode surface.

In this paper, a uniform calf thymus deoxyribonucleic acid (DNA) network has been constructed on a bare mica surface using a simple adsorption method. The effect of the immersion time in water on the characteristics of the morphological transitions of DNA molecules adsorbed on the mica surface was investigated by atomic force microscopy. It was found that the DNA molecules underwent conformational transitions from stretched wormlike coil to rod and to network by changing the immersion time in water and the formation mechanism was explained briefly.

The factors affecting the preparation of Au/TiO2 catalysts and their activity in the total oxidation of n-hexane were investigated. The mechanism of gold deposition-precipitation is discussed through comparison of the samples prepared by this method and others prepared by anion adsorption method. The influence of the pH and of the origin of TiO2 support used are additionally addressed. The difference of gold dispersion observed between the two methods is attributed to a difference of mobility of the gold precursors during the thermal treatment rather than to a difference of dispersion over the uncalcined samples. The mechanism of gold deposition-precipitation actually involves the reactions of gold hydroxy-chloride species with the surface. Another pan of the work, thus, concerned the use of the deposition-precipitation method to prepare a Au/MnO2 catalyst. It is shown that the activity of gamma-MnO2 is directly proportional to its surface area and that the deposition-precipitation procedure decreases the surface and activity of MnO2. However, the deposition of gold allows to avoid a too deep sintering of gamma-MnO2 and, thus, helps to somehow preserve its activity. (c) 2006 Elsevier B.V. All rights reserved.

It is indicated that modified carbon is a practical sorbent for removal of NO and SO2 from waste gases by the adsorption method. The ideal compositions for the prepared sorbent were 4.0 wt.% and 2.5 wt.% Na2CO3 and KOH at the experimental conditions, respectively, shortened as ACNaK2.5. Experimental investigation showed that the sorbent had a comparatively high breakthrough adsorption capacity of NO and SO2, about 5.8 g (NO + SO2)/100 g sorbent. It is indicated that a relatively high adsorption temperature would benefit the sorbent adsorption capacities on NO and SO2 at a certain space velocity and pressure. Further study revealed that the ACNaK2.5 sorbent had good regenerability at the experimental conditions, which implied that the ACNaK2.5 sorbent would be a useful sorbent for simultaneous removal of NO and SO2 from waste gases by adsorption.

Porous nature of silica gel samples comprising of micro- and meso-pores were studied with the help of positron annihilation lifetime spectroscopy based on a simple and realistic model which was further compared by nitrogen gas adsorption method namely Brunauer, Emmett and Teller isotherm. The final results illustrate the merits and fineness of the former, the extent of corroboration of the results and also the discrepancies accruing due to the limitations of the latter.

The molecular units of polyoxomolybdates containing transition metal ions [XMo 6 O 24 n − ; XMo6, X = Fe, Co, Ni] were quite homogeneous and thus could be densely dispersed on alumina chemically modified with N -(2-aminoethyl)-3-aminopropyltrimethoxysilane by an equilibrium adsorption method [XMo6/DAPS-Al 2 O 3 ]. The catalytic features of XMo6/DAPS-Al 2 O 3 thus prepared for methanol-oxidation were extensively examined. On XMo6/DAPS-Al 2 O 3 , the methanol-conversion increased up to 100% with an increase in the reaction temperature (200 → 300 °C) while maintaining the formaldehyde-selectivity at a high level such as 80–90% or more; e.g., the high selectivity of 91% was found in the 83%-conversion on the most efficient catalyst, FeMo6/DAPS-Al 2 O 3 , at 300 °C. Such catalytic features were found to be induced from the disk-like XMo6-molecular units that were projected perpendicular and densely over the DAPS-Al 2 O 3 surfaces in the saturated states. The mechanistic aspects were also easy to explain based on the XMo6-dispersed model. Finally, we proposed that the premodification method of the carrier surfaces with silane agents should be widely applied as a very useful technique for the preparation of fixed-polyoxometalate catalysts.

A preconcentration method for silver in environmental waters involving adsorption on a tungsten wire, followed by electrothermal atomic absorption spectrometry with a tungsten tube atomizer is described. The optimal immersing time was 90s. The best pH for the adsorption of silver was 3. Under the optimal conditions, the detection limit for silver by the tungsten wire preconcentration method was 5.0ngl(-1) (3S/N) and the relative standard deviation was 8.2%. The effects of large amounts of concomitants on the preconcentration of silver were evaluated. Even though 10(3)- to 10(4)-fold excess of matrix elements existed in water, the silver response was not significantly affected by the matrix elements. The method with preconcentration on a tungsten wire was applied to the determination of silver in waters and proved to be sensitive, simple, and convenient. This adsorption method can be utilized in in situ sampling of ultra-trace silver in environmental samples (waters). Furthermore, after sampling it is easy to carry and store the tungsten wire without contamination for a long time.

Fractal dimensions of three different samples of lanthanum ferrite were computed using single adsorption method. The fractal Dubinin–Radushkevitch isotherm was used to fit directly the experimental nitrogen adsorption data. Avnir–Jaroniec method for fractal dimension determination was also used. Low and intermediate fractal dimensions were obtained according to BET specific surface areas.

The micropores of USY and ZSM-5 zeolites were modified with the transition-metal oxides, such as Fe 2 O 3 , MoO 3 and V 2 O 5 . The structures of the modified samples were characterized by XRD and the physical features were determined by N 2 adsorption method. The results show that the transition-metal oxides can diffuse well into the micropores of zeolites. The surface area, micropore area, pore volume and typical pore diameter of the modified samples change respectively, and the change might result in a novel process for the design of the shape-selective catalysts and special adsorbents.

Image analysis has been applied to the TEM observation of activated carbon fibers, in order to evaluate the pore structure visually. It is suggested that the present method can show the shape of the pores as well as providing a quantitative estimation of the pore structure. The results are consistent with those obtained by common gas adsorption method and with synthesized molecular graphics TEM images of pores. The pore analysis on activated carbon fibers by TEM combined with image processing can provide a powerful tool to characterize the porous structure of activated carbons from a different new viewpoint.

Interest in the ultralow density X-ray laser target has led to the development of methods for preparing low density materials containing special elements such as Ge and Ta. A new method is used to synthesize ultralow density SiO2GeO2 binary aerogels, the density achieved can be as low as 5 kg/m3 and the weight percent of germanium can be higher than 40. TEM micrographs show that these SiO2GeO2 binary aerogels have a network structure with an average chain diameter of about 8 nm. SEM micrographs show their mesopores to be of the size 102 nm, while their pores of the size 1–102 nm are measured by the N2 adsorption method.

A long-term sampling method for PCDF/D in emissions from combustion facilities is presented. The sampling of PCDF/D was performed over a four week period. The results are compared to results of four one-week measurements.

The charcoal adsorption method was used to measure radon concentrations in air inside buildings in and around the Charnwood Forest area of Leicestershire, UK. Measured concentrations within the same buildings were shown to be variable and dependent upon air disturbances. However, buildings within the same geographical locations showed definite trends in radon concentrations. Buildings built close to exposed rock showed higher levels of airborne radon than those where the rock is covered by clays and mercia mudstone.

A sampling method for PCDF/D in emissions from combustion and other industrial facilities is presented in which these substances are deposited in one collection unit consisting of a combination of quartz wool and a polymeric adsorbent (pretreated XAD-2 resin). In combination with a cooled probe, this sampling method can be used for flue gas at temperatures up to more than 1,000 °C, with dust contents up to more than 1 g/m 3 and water contents of more than 300 g/m 3 . Performance characteristics referring relative standard deviations from parallel determinations and comparison with other sampling methods are presented for PCDF/D flue gas concentrations between 2 and 0.02 ng (TE)/m 3 (Toxicity equivalent according to NATO/CCMS).

Some commercial gas adsorption instruments still use a rough method for calculation of mesopore size distribution. Therefore, we have reviewed some practical methods of calculation proposed in the literature. We have found that most of these methods and many reports have some incorrectness in the geometric factor Qi used for the calculation of pore volume Δi from core volume ΔVKi. It has been proved that the correct expression for Qi should be [r¯i/(r¯ik+12Δti)]2 for cylindrical pores and r¯i/(r¯ik+12Δti) for slit-shaped pores. On the basis of this correct Qi, these methods were applied to the desorption isotherms. The results were compared and analyzed.

The purpose of this study was to determine if 2 paints of chlorhexidine as a skin preparation was as effective as a 5-minute povidone-iodine scrub followed by 2 paints of Betadine solution (Betadine solution, povidone-iodine 10% equal to 1% available iodine; Purdue Frederick, Norwalk, Connecticut). In the first trial involving 10 volunteers, one side of the back was painted with 2 coats of chlorhexidine and the other side of the back was scrubbed with povidone-iodine for 5 minutes, left to dry, and then painted with Betadine. Cultures were obtained using the membrane filter adsorption method before the skin preparation and at 30, 60, and 120 minutes after the preparation. In the second trial, both the Betadine and chlorhexidine paints were dried. Bacterial counts were then obtained at 48 hours. There was no difference between the number of colonies cultured from the povidone-iodine/Betadine compared with the chlorhexidine skin preparation. This finding suggests that chlorhexidine is as effective as 5 minutes of povidone-iodine scrub with 2 paints of povidone-iodine solution.

The electrophoretic properties of WO 3 /γ-Al 2 O 3 catalysts prepared by the adsorption equilibrium method at pH values between 1 and 10 were studied. This study indicates the formation of a tungsten monolayer structure if pH values lower than six are used, and a multilayer structure if pH values higher than six are employed. Activity for the hydrodesulfurization of gas-oil shows that multilayer structure leads to higher activity than monolayer structure.

Activated carbon (AC) was modified with sodium citrate at a concentration of 5–15% by impregnation to develop a new type of adsorbent, named N x –AC where x is the concentration. Their pore structures and surface chemical properties were characterized by N 2 adsorption, Boehm titration and FT-IR. The adsorption of copper ions by the N x –AC and the regenerated ones were investigated through a static adsorption method. Results showed that the carboxyl content had a great influence in the adsorption properties of N x –AC for copper with the adsorption capacity of N 15 –AC being 1.76 times higher than the parent AC, which was higher than those of the N 5 –AC and the N 10 –AC. The adsorption capacity of the regenerated N 15 –ACs for copper can reach 98.2% and 95.9% of the original N 15 –AC for the first and second regenerations, respectively. [New Carbon Materials 2013, 28(2): 156–160]

The effects of neurotensin on the release of endogenous dopamine (DA) from rat striatal slices were investigated. DA was extracted by the aluminium adsorption method and assayed electrochemically by high-performance liquid chromatography. Neurotensin (2-100 microM) potentiated the potassium-induced release of striatal endogenous DA in a concentration-dependent manner. This neurotensin-induced release of DA was completely abolished in calcium-free medium containing EGTA 1 mM. The presence of tetrodotoxin 2 microM did not alter the effect of neurotensin 10 microM. On the other hand, neurotensin did not affect the uptake of [3H]DA into the striatal slices. In additional experiments, we confirmed that the KCl-induced release of DA in the nucleus accumbens was also potentiated b neurotensin. These results suggest that neurotensin has a direct effect on the central DA nerve terminals and releases DA in a Ca2+-dependent manner.

The adsorption method for determination of the distribution of neptunium among its oxidation states at tracer concentrations by use of silica gel and barium sulfate as adsorbents is described. In the pH range 6–7, Np(VI) was quantitatively adsorbed on silica gel, while Np(V) remained in the supernatant solution. In acid solutions, the precipitate of barium sulfate adsorbed Np(IV) selectively, leaving Np(V) and Np(VI) in solution. By means of these adsorption methods combined with the use of TBP extractions, the oxidation-state distribution of neptunium in acid or neutral solution in the presence of various redox reagents was determined and shown to be consistent with the expectation from the oxidation potential of the solution.

A new kind of molecular interaction between low molecular weight, sulfur-containing ligands immobilized on agarose and some specific types of proteins was recently discovered. The interaction, tentatively called ‘thiophilic,’ is salt-promoted but is in many aspects distinct from hydrophobic-type interactions. The practical application of this adsorption method, particularly in the purification of immunoglobulins from the sera of a variety of animal species on an analytical or a preparative scale will be reviewed. Two alternative and feasible models of the ligand—ligate complex will also be presented to illustrate the type of binding forces that operate at the molecular level when adsorption takes place.

A method for measuring the permeability of tablets was developed. The specific surface areas of the tablets were then deduced using the permeability equation corrected for slip flow. The method was tested on some experimental parameters which had only a minor effect on the tablet surface area. The effect of compaction pressure on tablet surface area, obtained using both a gas adsorption method and a permeametry technique, were then studied for sodium chloride and saccharose (fraction 212–250 μm). The two methods gave similar surface area-pressure curves up to 150 MPa, both substances showing increasing surface area with pressure but a faster increase for saccharose. The permeametry surface area curves continued to increase within the whole pressure range, while the gas adsorption surface area levelled out for saccharose and decreased at the highest pressures for sodium chloride.

The root surface area is important in planning treatment for restorative and preventive dentistry. Most of the methods presented in literature are based on membrane techniques using different materials. These methods become less accurate and cumbersome when root surface areas of multirooted teeth have to be measured. This report presents a method based on adsorption of benzene on plaster models of teeth to determine their surface areas.

In a laboratory study the influence of aquatic humus with time on low concentrations of alkanes, polycyclic aromatic hydrocarbons (PAH) and chlorinated hydrocarbons have been investigated. The feasibility of a liquid/liquid extraction method and a resin (XAD-2) adsorption method for analysing these pollutants in humus water has also been studied. The interaction between the organic pollutants and the humus were found to vary considerably between different classes of compounds as well as between compounds of the same class. None of the two analytical methods investigated were found feasible for determining the total amount of organic pollutants present in humus water.

(Na,H)-Y zeolites, prepared by dealumination of Na-Y by means of SiCl 4 and transformed to an acidic form, have been used for the determination of acidic properties. The acidity was measured by the calorimetric adsorption method. Agreement has been found between the amount of the Bronsted and Lewis acid centres determined by the calorimetric method (adsorption of n-butylamine) and the IR spectroscopic method (adsorption of pyridine).

This paper proposes a new theory for withdrawal from viscous Newtonian liquids by vertical plates. The thickness of the liquid layer on the withdrawn plate was determined experimentally by a light adsorption method. Theory and experiments both indicate that the maximum possible thickness is not realised in cases where the action of the capillary pressure of the meniscus can be neglected. The realised flux is 17 per cent lower than the maximum flux.

Mathematical relations are presented showing the effect of light absorption by the solvent on the absorption measurements. A simple modification in the silica-gel adsorption method of purifying iso octane is described that greatly improves the transmittance in the 2000 A region. A procedure of purifying dioxan is also included.

A new method is described for the estimation of corticosteroid-binding globulin by means of the hydrophobia resin adsorption method. Corticosteroid-binding globulin in the serum is saturated by incubation with cortisol, unbound and albumin-bound cortisol is removed by shaking with the resin, and cortisol remaining in the supernatant fluid is measured by fluorometry, its represents the cortisol-binding capacity of corticosteroid-binding globulin. Normal range of cortisol-binding capacity was 0.154–0.222 μg/ml at 15°.