An efficient calcium-based sorbent for flue gas dry-desulfurization: promotion roles of nitrogen oxide and oxygen.

The development of sorbents for flue gas desulfurization in a dry mode is essential to control emission of sulfur dioxide. Based on the novel concept of "treating waste with waste", a low-cost and highly activated calcium-based sorbent (ACS) was prepared using coal fly ash, CaO and waste gypsum as the raw materials the one-step incipient wetness impregnation method. Based on characterization using scanning electron microscopy and nitrogen adsorption-desorption, the ACS possessed a fibrous and netted structure with high porosity, which improved SO adsorption greatly.

Hydrogenation of CO to olefins over a supported iron catalyst on MgAlO spinel: effects of the spinel synthesis method.

In the process of CO hydrogenation to olefins by the Fischer-Tropsch synthesis (FTO), the support is a key factor in the activity, selectivity, and thermal and chemical stability of the catalysts, and magnesium aluminate spinel (MgAlO) has recently been reported to be very effective. In this work, three methods, namely, citric acid solution combustion (MAC), EDTA sol-gel (MAG) and NH-coprecipitation (MAP) have been employed to prepare the spinel with detailed characterization of the structure, specific surface area, porosity, and alkalinity properties of both the as-synthesized spinel and the supported catalysts. The results showed that MAC and MAG possessed stronger basicity with more homogeneous particle sizes and narrower distribution of the pore size due to the formation of the metal-nitrate-chelate-complex.

Deactivation kinetics of individual C-C aromatics' generation from methanol over Zn and P co-modified HZSM-5.

A deactivation kinetic model has been determined for the methanol to aromatic process over a HZSM-5 zeolite catalyst (SiO/AlO = 30) modified by 1.0 wt% ZnO and 2.0 wt% P, in which the generation rates of C-C aromatics are treated individually while olefins and paraffins are lumped as intermediate and byproduct, respectively.

Repair of critical size bone defects with porous poly(D,L-lactide)/nacre nanocomposite hollow scaffold.

Objective: To generate a novel porous poly(D,L-lactide)/nacre nanocomposite hollow scaffold.

Methods: This study was performed in the Department of Spine Surgery, Southern Medical University, Guangzhou, China from September 2010 to September 2011. Nacre nanoparticles were prepared using a physical process and identified by x-ray diffraction and transmission electron microscopy, to generate a novel scaffold though the salt leaching processing technique.

Amide-linkage formed between ammonia plasma treated poly(D,L-lactide acid) scaffolds and bio-peptides: enhancement of cell adhesion and osteogenic differentiation in vitro.

The surface characteristics of scaffolds for bone tissue engineering must support cell adhesion, migration, proliferation, and osteogenic differentiation. In the study, poly(D,L-lactide acid) (PDLLA) scaffolds were modified by combing ammonia (NH(3) ) plasma pretreatment with Gly-Arg-Gly-Asp-Ser (GRGDS)-peptides coupling technologies. The x-ray photoelectron spectroscopy (XPS) survey spectra showed the peak of N1s at the surface of NH(3) plasma pretreated PDLLA, which was further raised after GRGDS conjugation.

Hypertrophy of ligamentum flavum in lumbar spine stenosis associated with the increased expression of connective tissue growth factor.

Hypertrophy of the ligamentum flavum (LF) contributes to lumbar spinal stenosis (LSS), and results mainly from fibrosis. Connective tissue growth factor (CTGF) is a profibrotic factor involved in the fibrotic process. This study aimed to evaluate CTGF expression in hypertrophied lumbar LF and the involvement of CTGF in LF hypertrophy.

[Histology and proliferative capability of thoracic vertebral body growth plates of rats at different ages].

Objective: To compare the histological features of the thoracic vertebral body growth plates (VBGPs) of rats at different ages and assess their proliferative capability.

Methods: The thoracic VBGPs obtained from rats aged 1 day and 1, 4, 8, 16 and 28 weeks were identified using safranin O-fast green staining, and the height of the hypertrophic zone, proliferative zone, and resting zone were measured. The chondrocytes were isolated from these VBGPs with a modified trypsin-collagenase type II digestion method for primary culture in vitro.

[Effects of bioactive modification of poly-D,L-lactide acid scaffolds on the biological behaviors of the seed cells].

Objective: To study the changes in the biological behavior of bone marrow mesenchymal stem cells (BMSCs) transfected with red fluorescent protein by lentivirus (RFP-BMSCs) seeded on in poly-D, L-lactide acid (PDLLA) scaffolds with bioactive modification by ammonia plasma and Gly-Arg-Gly-Asp-Ser (GRGDS) in vitro.

Methods: Circular sheets of PDLLA scaffolds (8 mm in diameter and 1 mm in thickness) were prepared and aminated with PDLLA (group A) or modified with the peptide conjugate A/PDLLA (group PA), with untreated PDLLA as the control (group P). The RFP-BMSCs were seeded on the scaffold materials and their proliferation and metabolic activity were detected using CyQuant NF and Alamar blue staining.

Experimental determination of equilibrium constant for the complexing reaction of nitric oxide with hexamminecobalt(II) in aqueous solution.

Ammonia solution can be used to scrub NO from the flue gases by adding soluble cobalt(II) salts into the aqueous ammonia solutions. The hexamminecobalt(II), Co(NH3)6(2+), formed by ammonia binding with Co2+ is the active constituent of eliminating NO from the flue gas streams. The hexamminecobalt(II) can combine with NO to form a complex.

Novel homogeneous catalyst system for the oxidation of concentrated ammonium sulfite.

A homogeneous catalyst system made up of [Co(NH3)6]2+/I- has been put forward to catalyze the oxidation of concentrated ammonium sulfite. The experiments were performed in a packed column with sulfite concentrations above 2.5 mol l(-1), temperature range 20-65 degrees C, and oxygen partial pressure 0.

Kinetics of gas-liquid reaction between NO and Co(NH3)6(2+).

Wet ammonia desulphurization process can be retrofitted for combined removal of SO2 and NO from the flue gas by adding soluble cobalt(II) salts into the aqueous ammonia solutions. The Co(NH3)6(2+) formed by ammonia binding with Co2+ is the active constituent of scrubbing NO from the flue gas streams. A stirred vessel with a plane gas-liquid interface was used to measure the chemical absorption rates of nitric oxide into the Co(NH3)6(2+) solution under anaerobic and aerobic conditions separately.

[Removal of nitric oxide from waste gas streams with hexamminecobalt solution].

Aqueous ammonia solution can be used to remove NO from waste gas streams by adding soluble cobalt(II) salt into aqueous ammonia solution. The hexamminecobalt(II) cations can not only bind nitric oxide but also activate oxygen molecules in aqueous solutions. Nitric oxide is absorbed and oxidized simultaneously in the same reactor.

Simultaneous absorption of NO and SO2 into hexamminecobalt(II)/iodide solution.

An innovative catalyst system has been developed to simultaneously remove NO and SO2 from combustion flue gas. Such catalyst system may be introduced to the scrubbing solution using ammonia solution to accomplish sequential absorption and catalytic oxidation of both NO and SO2 in the same reactor. When the catalyst system is utilized for removing NO and SO2 from the flue gas, Co(NH3)(6)2+ ions act as the catalyst and I- as the co-catalyst.