Materials selection for superheater tubes in municipal solid waste incineration plants

Corrosion reduces the lifetime of municipal solid waste incineration (MSWI) superheater tubes more than any other cause. It can be minimized by the careful selection of those materials that are most resistant to corrosion under operating conditions. Since thousands of different materials are already known and many more are developed every year, here the selection methodology developed by Prof. Ashby of the University of Cambridge was used to evaluate the performance of different materials to be used as MSWI superheater tubes. The proposed materials can operate at steam pressures and temperatures over 40 bars and 400ºC, respectively. Two case studies are presented: one makes a balanced selection between mechanical properties and cost per thermal unit; and the other focuses on increasing tube lifetime. The balanced selection showed that AISI 410 martensitic stainless steel (wrought, hard tempered) is the best candidate with a good combination of corrosion resistance, a relatively low price (0.83-0.92 e/kg) and a good thermal conductivity (23-27 W/m K). Meanwhile, Nitronic 50/XM-19 stainless steel is the most promising candidate for longterm selection, as it presents high corrosion resistance with a relatively low price (4.86-5.14 e/kg) compared to Ni-alloys.

Histopathology and prognosis of de novo bladder tumors following solid organ transplantation.

BACKGROUND: Patients following solid organ transplantation have an increased risk of developing de novo bladder tumors, but their biology is poorly characterized. METHODS: We studied 1743 patients who underwent a transurethral resection of a newly diagnosed bladder tumor at a single institution. The histopathology, treatment, recurrence-free survival and overall survival were evaluated and compared between transplant and non-transplant patients. RESULTS: We identified 74 transplant patients who developed a de novo bladder tumor after a median post-transplantation interval of 62 months. The tumor was malignant in 29 patients (39 %). The most common benign lesion was nephrogenic adenoma (84 %), which neither coexisted with nor developed into malignant tumors during follow-up. Compared with non-transplant patients (n = 1669), transplant patients were significantly younger (median 55 vs 69 years, P < 0.001) and had a 9.0-fold higher odds of benign tumors (P < 0.001), while there were no differences in pathology among patients with urothelial carcinoma of the bladder (UCB). In a multivariable analysis for non-muscle-invasive UCB that was adjusted for the risk group, patients with a transplant had a 1.8-fold increased risk of recurrence (P = 0.048). Four of five transplant patients did not respond to Bacillus Calmette-Guérin instillations. There were no differences in overall survival after radical cystectomy (P = 0.87). CONCLUSIONS: The majority of bladder tumors in transplant patients are benign, and they neither coexist with nor develop into malignant tumors. Transplant patients with non-muscle-invasive UCB show an increased risk of disease recurrence, while those treated with radical cystectomy have similar outcomes to patients without a transplant.

The Impact of Infection on Chronic Allograft Dysfunction and Allograft Survival After Solid Organ Transplantation.

Infectious diseases after solid organ transplantation (SOT) are a significant cause of morbidity and reduced allograft and patient survival; however, the influence of infection on the development of chronic allograft dysfunction has not been completely delineated. Some viral infections appear to affect allograft function by both inducing direct tissue damage and immunologically related injury, including acute rejection. In particular, this has been observed for cytomegalovirus (CMV) infection in all SOT recipients and for BK virus infection in kidney transplant recipients, for community-acquired respiratory viruses in lung transplant recipients, and for hepatitis C virus in liver transplant recipients. The impact of bacterial and fungal infections is less clear, but bacterial urinary tract infections and respiratory tract colonization by Pseudomonas aeruginosa and Aspergillus spp appear to be correlated with higher rates of chronic allograft dysfunction in kidney and lung transplant recipients, respectively. Evidence supports the beneficial effects of the use of antiviral prophylaxis for CMV in improving allograft function and survival in SOT recipients. Nevertheless, there is still a need for prospective interventional trials assessing the potential effects of preventive and therapeutic strategies against bacterial and fungal infection for reducing or delaying the development of chronic allograft dysfunction.

CRTC2 polymorphism as a risk factor for the incidence of metabolic syndrome in patients with solid organ transplantation.

NlmCategory="UNASSIGNED">Metabolic syndrome after transplantation is a major concern following solid organ transplantation (SOT). The CREB-regulated transcription co-activator 2 (CRTC2) regulates glucose metabolism. The effect of CRTC2 polymorphisms on new-onset diabetes after transplantation (NODAT) was investigated in a discovery sample of SOT recipients (n1=197). Positive results were tested for replication in two samples from the Swiss Transplant Cohort Study (STCS, n2=1294 and n3=759). Obesity and other metabolic traits were also tested. Associations with metabolic traits in population-based samples (n4=46'186, n5=123'865, n6>100,000) were finally analyzed. In the discovery sample, CRTC2 rs8450-AA genotype was associated with NODAT, fasting blood glucose and body mass index (Pcorrected<0.05). CRTC2 rs8450-AA genotype was associated with NODAT in the second STCS replication sample (odd ratio (OR)=2.01, P=0.04). In the combined STCS replication samples, the effect of rs8450-AA genotype on NODAT was observed in patients having received SOT from a deceased donor and treated with tacrolimus (n=395, OR=2.08, P=0.02) and in non-kidney transplant recipients (OR=2.09, P=0.02). Moreover, rs8450-AA genotype was associated with overweight or obesity (n=1215, OR=1.56, P=0.02), new-onset hyperlipidemia (n=1007, OR=1.76, P=0.007), and lower high-density lipoprotein-cholesterol (n=1214, β=-0.08, P=0.001). In the population-based samples, a proxy of rs8450G>A was significantly associated with several metabolic abnormalities. CRTC2 rs8450G>A appears to have an important role in the high prevalence of metabolic traits observed in patients with SOT. A weak association with metabolic traits was also observed in the population-based samples.The Pharmacogenomics Journal advance online publication, 8 December 2015; doi:10.1038/tpj.2015.82.

Empirical analysis of solid management waste costs: Some evidence from Galicia, Spain

This paper analyses the factors that determine solid waste service costs. The empirical analysis is based on information derived from a survey conducted in a sample of Galician municipalities. The results reveal economies of scale in municipalities of fewer than 50,000 inhabitants, such that cooperation between these municipalities could lead to cost savings. It also appears that private delivery is not cheaper than public delivery. Finally, designating a larger proportion of the total waste volume to recycling does not imply greater costs.

Aplicação de SPME (Solid Phase Micro-Extraction) na análise de águas potáveis de três localidades do estado de São Paulo

The technique of solid phase microextraction (SPME) was used for the extraction of halogenated contaminants of water samples from three cities of the State of São Paulo and the extracts were submitted to gas chromatographic analysis with electron capture detection (GC-ECD). In the samples of water collected at the city of São Paulo the detected level of trihalomethanes (THM) expressed as the sum of chloroform, dibromochloromethane and dichlorobromomethane, were higher than the permissible limit established by the Brazilian regulation. In the samples collected at the two other cities the level of any of the three THM remained below the sensitivity of the ECD.

Inclusion complex of the antiviral drug acyclovir with cyclodextrin in aqueous solution and in solid phase

Complexation between acyclovir (ACV), an antiviral drug used for the treatment of herpes simplex virus infection, and beta-cyclodextrin (beta-CD) was studied in solution and in solid states. Complexation in solution was evaluated using solubility studies and nuclear magnetic resonance spectroscopy (¹H-NMR). In the solid state, X-ray diffraction, differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and dissolution studies were used. Solubility studies suggested the existence of a 1:1 complex between ACV and beta-CD. ¹H-NMR spectroscopy studies showed that the complex formed occurs with a stoichiometry ratio of 1:1. Powder X-ray diffraction indicated that ACV exists in a semicrystalline state in the complexed form with beta-CD. DSC studies showed the existence of a complex of ACV with beta-CD. The TGA studies confirmed the DSC results of the complex. Solubility of ACV in solid complexes was studied by the dissolution method and it was found to be much more soluble than the uncomplexed drug.

Highly functional binding surface for miniaturised solid-phase immunoassays. - A spot story -

Several bioaffinity assays are based on the detection of an analyte which is bound on a solid substrate via biochemical interaction. These so called solid phase assays are based on the adhesion of the primary binding partner on a solid surface, which then binds the analyte to be detected. In this thesis work a novel solid phase based assay technology, known as spot technology, was developed. The spot technology is based on combination of high-capacity solid phases, concentrated in a spot format, utilising modified streptavidin molecules and recombinant antibody fragments. The reduction of the solid phase binding surface to a size of a spot enabled denser binding of the target molecules, providing improved signal intensities and signal-to-background ratio when applied in different solid phase immunoassays. Streptavidin-biotin interactions are commonly utilised in numerous different bioaffinity assays and the ultimate nature of streptavidin to bind biotin is among the strongest non-covalent interaction reported between two biomolecules. In this study native core streptavidin was chemically modified to provide polymerised streptavidin molecules with altered adsorption properties. These streptavidin conjugates, when coated onto polystyrene surface, provided enhanced biotin binding capacity and surface stability when compared to a reference coating constructed with native streptavidin. Furthermore, the combination of chemically modified streptavidin, sitespecifically biotinylated antibody fragments and the spot coating technology provided highly dense solid phase coating with improved binding properties. The performance of the spot assay technology was further demonstrated in different immunoassay configurations. Human thyroid stimulating hormone (TSH) and human cardiac troponin I (cTnI) were used as model analytes to show the applicability of the highly sensitive spot-based solid-phase immunoassay for detection of very low levels of analytes. It was demonstrated that the spot technology provided an assay concept with enhanced sensitivity and short turn-around times, characteristics that are highly suitable for point-of-care applications.

Production of fungal protein by solid substrate fermentation of cactus Cereus peruvianus and Opuntia ficus indica

Agricultural wastes from cactus Cereus peruvianus and Opuntia ficus indica were investigated for protein production by solid substrate fermentation. Firstly, the polyelectrolytes were extracted and used in water cleaning as auxiliary of flocculation and coagulation. The remaining fibrous material and peels were used as substrate for fermentation with Aspergillus niger. Glucoamylase and cellulase were the main enzymes produced. Amino acids were determined by HPLC and protein by Lowry's method. After 120 hours of fermentation the protein increased by 12.8%. Aspartic acid (1.27%), threonine (0.97%), glutamic acid (0.88%), valine (0.70%), serine (0.68%), arginine (0.82%), and phenylalanine (0.51%) were the principal amino acids produced.

Enantioselective synthesis of aziridines using asymmetric transfer hydrogenation as a precursor for chiral derivatives used as bonding agent for rocket solid propellants

A rapid, expedient and enantioselective method for the synthesis of beta-hydroxy amines and monosubstituted aziridines in up to 99% e.e., via asymmetric transfer hydrogenation of a-amino ketones and cyclisation through treatment with tosyl chloride and base, is described. (1R,2R)-N-(para-toluenesulfonyl)-1,2-ethylenediamine with formic acid has been utilised as a ligand for the Ruthenium (II) catalysed enantioselective transfer hydrogenation of the ketones.The chiral 2-methyl aziridine, which is a potentially more efficient bonding agent for Rocket Solid Propellant has been successfully achieved.

Intermunicipal cooperation and privatization of solid waste services among small municipalities in Spain

The aim of this paper is to analyze the effects of intermunicipal cooperation and privatization on the delivery costs of urban solid waste services. The results of our empirical analysis, which we conducted among a sample of very small municipalities, indicate that small towns that cooperate incur lower costs for their waste collection service. Cooperation also raises collection frequency and improves the quality of the service in small towns. By contrast, the form of production, whether it is public or private, does not result in systematic differences in costs. Interestingly, the degree of population dispersion has a significant positive relation with service costs. No evidence of scale economies is found because, it would seem, small municipalities exploit them by means of intermunicipal cooperation.

Ultra-trace monitoring of copper in environmental and biological samples by inductively coupled plasma atomic emission spectrometry after separation and preconcentration by using octadecyl silica membrane disks modified by a new schiff's base

Ultra-trace amounts of Cu(II) were separated and preconcentrated by solid phase extraction on octadecyl-bonded silica membrane disks modified with a new Schiff,s base (Bis- (2-Hydroxyacetophenone) -2,2-dimethyl-1,3-propanediimine) (SBTD) followed by elution and inductively coupled plasma atomic emission spectrometric detection. The method was applied as a separation and detection method for copper(II) in environmental and biological samples. Extraction efficiency and the influence of sample matrix, flow rate, pH, and type and minimum amount of stripping acid were investigated. The concentration factor and detection limit of the proposed method are 500 and 12.5 pg mL-1, respectively.

Reciclagem química de zeólitas comerciais desativadas

Pyro and hydrometallurgical processes were applied to the treatment of spent commercial zeolites (a molecular sieve and a ZSM-5 sample). Both catalysts were employed in pilot plant units. They were kept in their original shape, they were not regenerated and were not subjected neither to mechanical stress nor to overheating zones during their time on-stream. Two recycling processes were tested: (i) direct solubilization of samples in mixtures of HF + H2O2 (60 ºC, 1 h). Although silicon was solubilized, insoluble matter was found in both samples, particularly in the molecular sieve, due to its high amounts of alkaline and alkaline-earth metals; (ii) fusion with KHSO4 (5 h, 600 ºC) with KHSO4/zeolite mass ratio 6:1. After fusion the solid was solubilized in water (100 ºC), leaving silicon as SiO2 residue. In both processes, solubilized metals were isolated by conventional selective precipitation techniques. Analysis of final products by common analytical methods shows that metals present in the original catalysts were recovered with very high yields except when the molecular sieve was treated with HF + H2O2. This reactant mixture proved to be suitable for processing zeolites with a low alkaline and alkaline-earth metal content whereas fusion with KHSO4 appeared to be adequate for all types of zeolites.

Solid phase extraction of iron and lead in environmental matrices on amberlite xad-1180/pv

A solid phase extraction procedure using Amberlite XAD-1180/Pyrocatechol violet (PV) chelating resin for the determination of iron and lead ions in various environmental samples was established. The procedure is based on the sorption of lead(II) and iron(III) ions onto the resin at pH 9, followed by elution with 1 mol/L HNO3 and determination by flame atomic absorption spectrometry. The influence of alkaline, earth alkaline and some transition metals, as interferents, are discussed. The recoveries for the spiked analytes were greater than 95%. The detection limits for lead and iron by FAAS were 0.37 µg/L and 0.20 µg/L, respectively. Validation of the method described here was performed by using three certified reference materials (SRM 1515 Apple Leaves, SRM 2711 Montana Soil and NRCC-SLRS-4 Riverine Water). The procedure was successfully applied to natural waters and human hair.

Recuperação de metais de catalisadores de hidrorrefino usados via fusão com KHSO4

This work describes a process for metal recovery from spent NiMo and CoMo/Al2O3 commercial hydrorefining catalysts. The samples were treated by fusion with potassium hydrogen sulfate (5 h, 600 ºC) with a KHSO4/catalyst mass ratio of 10:1. After fusion the solid was solubilized in water (100 ºC), leaving silicon compounds as residue. Losses of nickel and cobalt may reach 16 wt% of the amount present in the sample, depending on the silicon content. Soluble metals were isolated by selective precipitation techniques (nickel, cobalt, aluminum) or by solvent extraction with methyl-isobutyl ketone (molybdenum) in a hydrochloric acid medium. All metals were recovered in very good yields except for nickel and cobalt in the presence of considerable amounts of silicon. Soluble wastes consist of potassium/sodium sulfates/chlorides. Solid wastes correspond to about 4 wt% of the catalyst and can be discarded in industrial dumps.