hydrogen embrittlement in pipelines transporting sour hydrocarbons

Abstract Lamination-like defects in pipeline steels can be of both metallurgical and operational origin. In pipelines transporting hydrocarbon usually such defects are not a big challenge since they do not propagate under operating conditions. Nonetheless, in presence of a corrosion phenomenon and sour gas (H2S), it is possible to observe blisters and cracks which may propagate in the steel. The observed damage mechanisms is Hydrogen Embrittlement and in spite of a huge amount of study and publications available, it is quite difficult for a pipeline owner to get practical data (crack propagation rate for instance) allowing a reliable estimate of the fitness for service of a pipeline. Taking advantage of a pipeline spool containing internal defects that was in service for more than 10 years and recently removed, a comprehensive study is underway to obtain a complete assessment of the pipeline future integrity. The program is comprehensive of study and comparison of ILI reports of the pipeline, to determine the optimum interval between inspections, assessment of inspection results via an accurate nondestructive (UT) and destructive examination of the removed section, to verify ILI results, lab tests program on specimens from the removed spool at operating conditions (75-80 bar and 30°-36° C) in presence of a small quantity of water, H2S (5%) and CO2 (7%), in order to assess defect propagation and to obtain an estimate of crack growth rate, and test in field of available methods to monitor the presence of Hydrogen and/or the growth of defects in in-service pipelines. This quite ambitious program is also expected to be able of offering a small contribution toward a better understanding of HE mechanisms and the engineering application of such complex, often mainly academic, studies

Temporal Trends Of Energy Consumption And CO2 Emissions In Riyadh, Saudi Arabia

The consumption of material, energy, and water resources is inextricably linked to population growth with a unique impact on urban areas, especially in light of significant investments in infrastructure to support urban development. Urban metabolism is becoming popular as it provides a framework accounting the mass and energy flows through a city. An urban metabolism study was conducted to estimate the inputs and outputs of energy and pollutants from Riyadh, Saudi Arabia. The objective of this study was to determine the energy consumption of Riyadh using locally generated data from 1986, 1996, 2006, and 2012 and analysing the temporal trends of energy consumption and associated environmental impact. The socioeconomic and biophysical characteristics of Riyadh are well represented in its metabolism indicators. The high growth rate in population along with urban expansion has resulted in an increase in energy consumption. Riyadh has seen an increase in energy consumption at a rate of about 6% per annum. On a per capita basis, preliminary results show that the energy consumption increased by 31% from 1996 to 2012. Also, per capita CO2 emissions have increased by the same percentage. Results also show increasing mobile energy consumption from 20k TJ in 1986 to 157k TJ in 2012, which points to Riyadh’s inefficient urban form. The study findings highlight the importance for developing effective policies for improving the use of resources

Experimental Study of Concrete Class Influence on Cracks Openings

The aim of this experimental work is to study reinforced concrete continuous beams cracking by considering different classes of concretes. As it is well known, the design of reinforced concrete structures considers three limit states (limit state of collapse, limit state of strain and limit state of cracking). The cracks in reinforced concrete structures are admitted in the phase II (cracked sections). Thus, the phenomenon of cracks can be treated as a normal state only when the cracks opening is limited to avoid a permanent risk of collapse and ensure durability for the civil engineering constructions. Tests on real scale reinforced concrete continuous beams were carried out under concentrated loads increasing from zero up to collapse. The influence of the concrete classes on crack opening has been investigated

Propuesta guía para una planeación y ejecución en proyectos de vivienda unifamiliar con enfoque Lean Construction

Trabajo de investigaciónEste trabajo contempla el desarrollo de una matriz enfocada en la metodología Lean Construction para la planeación y ejecución en proyectos de vivienda unifamiliar. Así mismo se evidencia un análisis de manera cuantitativa y cualitativamente en la adopción de la filosofía Lean Construction en procesos de la gestión de la planeación y ejecución de proyectos, que permite establecer un orden de actividades y sub actividades que componen las fases de un proyecto de vivienda unifamiliar en la relación del alcance exitoso en productividad y rendimiento.INTRODUCCIÓN 1. GENERALIDADES 2. METODOLOGÍAS EN EL MARCO DE LA PLANEACIÓN Y EJECUCIÓN DE PROYECTOS 3. LEAN CONSTRUCTION EN ACTIVIDADES DE CONSTRUCCIÓN 4. IMPLEMENTACIÓN DE LA MATRIZ EN CASO DE ESTUDIO 5. CONCLUSIONES 6. RECOMENDACIONES BIBLIOGRAFÍA ANEXOSPregradoIngeniero Civi

Structure and function of the human Gly1619Arg polymorphism of M6P/IGF2R domain 11 implicated in IGF2 dependent growth

The mannose 6-phosphate/IGF 2 receptor (IGF2R) is comprised of 15 extra-cellular domains that bind IGF2 and mannose 6-phosphate ligands. IGF2R transports ligands from the Golgi to the pre-lysosomal compartment and thereafter to and from the cell surface. IGF2R regulates growth, placental development, tumour suppression and signalling. The ligand IGF2 is implicated in the growth phenotype, where IGF2R normally limits bioavailability, such that loss and gain of IGF2R results in increased and reduced growth respectively. The IGF2R exon 34 (5002A>G) polymorphism (rs629849) of the IGF2 specific binding domain has been correlated with impaired childhood growth (A/A homozygotes). We evaluated the function of the Gly1619Arg non-synonymous amino acid modification of domain 11. NMR and X-ray crystallography structures located 1619 remote from the ligand binding region of domain 11. Arg1619 was located close to the fibronectin type II (FnII) domain of domain 13, previously implicated as a modifier of IGF2 ligand binding through indirect interaction with the AB loop of the binding cleft. However, comparison of binding kinetics of IGF2R, Gly1619 and Arg1619 to either IGF2 or mannose 6-phosphate revealed no differences in ‘on’ and ‘off’ rates. Quantitative PCR, 35S pulse chase and flow cytometry failed to demonstrate altered gene expression, protein half-life and cell membrane distribution, suggesting the polymorphism had no direct effect on receptor function. Intronic polymorphisms were identified which may be in linkage disequilibrium with rs629849 in certain populations. Other potential IGF2R polymorphisms may account for the correlation with childhood growth, warranting further functional evaluation

Effect of H2O2 pretreatment on the response of two seashore paspalum (Paspalum vaginatum Sw.) cultivars (Salam and Seaspray) to cold stress

Seashore paspalum is a warm season grass that requires few maintenance inputs. Expanded use of seashore paspalum could play a key role in making recreational sites more sustainable and environmentally. However, one key barrier to widespread Seashore paspalum use is a relative lack of winter hardiness. Under severe stress conditions, the antioxidant capacity may not be sufficient to minimize the harmful effect of oxidative injury. The search for signal molecules that mediate the stress tolerance is an important step in better understanding how plants acclimate to the adverse environment. This study aims to screen the responses of two Paspalum vaginatum cultivars (Salam and Seaspray) to local weather conditions and to study how to enhance its cold tolerance by a foliar pretreatment by hydrogen peroxide at low concentrations of 10 mM under controlled conditions. The current study provides evidence that exogenous H2O2 decreases the endogenous content of H2O2 in the first three days of exposure to cold stress in pretreated ‘Seaspray’ plants. in comparison to their control and pretreated ‘Salam’ which was in concomitant with malondialdehyde (MDA) changes. Indicating that pretreatment with 10 mM H2O2 could improve the tolerance of seashore paspalum to cold stress, especially cultivar Seaspray which showed better response to cold stress compared to ‘Salam’. Exogenous H2O2 could constitute a signaling molecule that significantly increases POD relative density, and decreases MDA and H2O2 content

Effect of thermal treatment on the growth, structure and luminescence of nitride-passivated silicon nanoclusters

Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effects that deposition and processing parameters have on their growth, luminescent properties, and electronic structure. Luminescence was observed from Si-ncs formed in silicon-rich silicon nitride films with a broad range of compositions and grown using three different types of chemical vapour deposition systems. Photoluminescence (PL) experiments revealed broad, tunable emissions with peaks ranging from the near-infrared across the full visible spectrum. The emission energy was highly dependent on the film composition and changed only slightly with annealing temperature and time, which primarily affected the emission intensity. The PL spectra from films annealed for duration of times ranging from 2 s to 2 h at 600 and 800°C indicated a fast initial formation and growth of nanoclusters in the first few seconds of annealing followed by a slow, but steady growth as annealing time was further increased. X-ray absorption near edge structure at the Si K- and L3,2-edges exhibited composition-dependent phase separation and structural re-ordering of the Si-ncs and silicon nitride host matrix under different post-deposition annealing conditions and generally supported the trends observed in the PL spectra

Correction to: GSTM1 and GSTT1 double null genotypes determining cell fate and proliferation as potential risk factors of relapse in children with hematological malignancies after hematopoietic stem cell transplantation

Transplantation and immunomodulatio

GSTM1 and GSTT1 double null genotypes determining cell fate and proliferation as potential risk factors of relapse in children with hematological malignancies after hematopoietic stem cell transplantation

Purpose This study aimed to retrospectively evaluate the genetic association of null variants of glutathione S-transferases GSTM1 and GSTT1 with relapse incidence in children with hematological malignancies (HMs) undergoing busulfan (BU)- containing allogeneic hematopoietic stem cell transplantation (HSCT) and to assess the impact of these variants on BU-induced cytotoxicity on the immortalized lymphoblastoid cell lines (LCLs) and tumor THP1 GST gene-edited cell models. Methods GSTM1- and GSTT1-null alleles were genotyped using germline DNA from whole blood prior to a conditioning BU-based regimen. Association of GSTM1- and GSTT1-null variants with relapse incidence was analyzed using multivariable competing risk analysis. BU-induced cell death studies were conducted in GSTs- null and non-null LCLs and CRISPR-Cas9 gene-edited THP1 leukemia cell lines. Results Carrying GSTM1/GSTT1 double null genotype was found to be an independent risk factor for post-HSCT relapse in 86 children (adjusted HR: 6.52 [95% Cl, 2.76-15.42; p = 1.9 x 10(-5)]). BU-induced cell death preferentially in THP1(GSTM1(non-null)) and LCLs(GSTM1(non-null)) as shown by decreased viability, increased necrosis and levels of the oxidized form of glutathione compared to null cells, while GSTT1 non-null cells showed increased baseline proliferation. Conclusion The clinical association suggests that GSTM1/GSTT1 double null genotype could serve as genetic stratification biomarker for the high risk of post-HSCT relapse. Functional studies have indicated that GSTM1 status modulates BU-induced cell death. On the other hand, GSTT1 is proposed to be involved in baseline cell proliferation.Transplantation and immunomodulatio