Test Conditions for Pipeline Materials Selection with High Pressure Sour Gas

Acid gases, such as CO2, H2S, and/or sulfur in oil industry's production fluids, can be responsible for both general and localized corrosion, acting with different mechanisms, which depend on chemical and physical properties of the produced fluids. Materials selection for handling such fluids is performed by combining experience with suggestions from standards and regulations. A good deal of knowledge is available to predict corrosion rates for CO2-containing hydrocarbons, but the effect of high H2S pressure is less understood, mainly due to the difficulty of performing laboratory tests in such challenging conditions. For instance, the so-called NACE solution to assess SSC (Sulfide Stress Cracking) susceptibility of steels is a water-based solution simulating production fluids in equilibrium with one bar bubbling H2S gas. This solution does not represent environments where high gas pressure is present. Moreover, it does not take into account the corrosive properties of sulfur and its compounds that may deposit in such conditions. Besides, properties of high pressure gases are intermediate between those of a gas and those of a liquid: high pressure gases have superior wetting properties and better penetration in small pores, with respect to liquids. These features could enhance and accelerate damage, and nowadays such conditions are likely to be present in many production fields. This paper is aimed to point out a few challenges in dealing with high pressure gases and to suggest that, for materials selection in sour service, a better correspondence of test conditions with the actual field conditions shall be pursued

Using WiMAX technology to improve volcano monitoring: the WEIRD System

IEEE 802.16 standards (IEEE, 2004; IEEE, 2005), commonly known as WiMAX (Worldwide Interoperability for Microwave Access Forum), is one of the most promising broadband wireless access technology for next generation all-IP networks. This access technology allows reaching high bit rate and covering large areas with a single Base Station (BS). Thanks to these features, IEEE 802.16 opens the way for the use and the introduction of wireless technologies in particular emergency scenarios, like volcano monitoring. Active volcano surveillance is based prevalently on the analysis of geophysical and geochemical parameters gathered by monitoring networks. Of all, seismology is one of the most useful methods for volcano monitoring. In fact, several types of seismic signals, e.g. volcano-tectonic earthquakes (VT), long-period events (LP), volcanic tremor, can occur before and during an eruption. The analysis and interpretation of these seismic signals are a very important task for the volcanic eruption forecasting (Scarpa and Tilling, 1996). WiMAX technology can be applied to provide broadband wireless access in volcano monitoring scenarios, in order to solve all the problems that today limit the possibility to realize a real-time and accurate monitoring of volcanoes activities in emergency situations. In particular, this paper focus on a novel solution, designed within the IST FP6 EU WEIRD (WiMAX Extension to Isolated Research Data networks) Integrated Project, to perform volcano monitoring using the features offered by IEEE 802.16 networks in order to improve transmission of data acquired by temporary seismic stations deployed during emergencies. Tests performed on field demonstrate the advantages offered by the use of WiMAX compared with other commonly used technologies

Using wireless point-to-point connections to improve volcano monitoring: a feasibility study of the WiMAX technology applied to the Campi Flegrei volcanic area (Southern Italy)

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Innovative photoelectrocatalytic water remediation system for ammonia abatement

Ammonia, produced by human and animal activities, contributes to water and soil pollution because it is toxic for aquatic flora and fauna, and responsible for eutrophication. In this work, the photoelectrocatalytic (PEC) oxidation of ammonia is investigated employing a stainless-steel PEC reactor, consisting of a central UV Hg-vapor lamp surrounded by a metallic Ti mesh coated with a photoactive TiO2 film, directly grown by Plasma Electrolytic Oxidation (PEO). The so prepared TiO2 film is characterized by XRD, SEM, UV–vis DRS and IPCE. The PEC reactor operates at 4 V potential drop between the TiO2 coated mesh (photoanode) and the body of the reactor (cathode). The effect of the operating parameters (recirculation flowrate and air bubbling) and type of electrolyte solution (KCl or K2SO4) on the PEC performance are investigated in terms of ammonia conversion and selectivity to nitrite, nitrate and molecular nitrogen. Full ammonia conversion (XNH3) with a selectivity to molecular nitrogen up to 67 % are attained after 12 h in 5 mM KCl electrolyte solution. Nitrite is produced within the first 6 h irradiation and then fully converted into nitrate. By contrast, only a slight XNH3 (ca. 10 %) is observed in K2SO4 electrolyte solution. These results suggest that chlorine has a crucial role in the ammonia PEC oxidation process: photo-generated holes on the photoanode surface can oxidize Cl− to Cl• (electro-induced process), which is a reactive radical able to oxidase ammonia

Potent trophic activity of spermidine supramolecular complexes in in vitro models

AIM: To test the growth-promoting activity of the polyamine spermidine bound to various polymeric compounds in supramolecular complexes. METHODS: A thiazolyl blue cell viability assay was used to determine the growth-promoting potency of spermidine-supramolecular complexes in a human skin fibroblast cell line exposed to spermidine and different spermidine-supramolecular complexes that were obtained by combining spermidine and polyanionic polymers or cyclodextrin. Reconstituted human vaginal epithelium was exposed to a specific spermidine-supramolecular complex, i.e., spermidine-hyaluronan (HA) 50, and cell proliferation was determined by Ki-67 immunohistochemical detection. Transepithelial electrical resistance and histological analysis were also performed on reconstituted human vaginal epithelium to assess tissue integrity. RESULTS: The effect of spermidine and spermidine-supramolecular complexes was first tested in skin fibroblasts. Spermidine displayed a reverse dose-related mode of activity with mmol/L growth inhibition, whereas 30% stimulation over basal levels was detected at μmol/L and nmol/L levels. Novel spermidine-supramolecular complexes that formed between spermidine and polyanionic polymers, such as HA, alginate, and polymaleate, were then tested at variable spermidine concentrations and a fixed polymer level (0.1% w/v). Spermidine-supramolecular complexes stimulated the cell growth rate throughout the entire concentration range with maximal potency (up to 80%) at sub-μmol/L levels. Similar results were obtained with spermidine-(α-cyclodextrin), another type of spermidine-supramolecular complex. Moreover, the increased expression of Ki-67 in the reconstituted human vaginal epithelium exposed to spermidine-HA 50 showed that the mode of action behind the spermidine-supramolecular complexes was increased cell proliferation. Functional and morphological assessments of reconstituted human vaginal epithelium integrity did not show significant alterations after exposure to spermidine-HA, thus supporting its safety. CONCLUSION: Spermidine found in spermidine-supramolecular complexes displayed potentiated regenerative effects. Safety data on reconstituted human vaginal epithelium suggested that assessing spermidine-supramolecular complex efficacy in atrophic disorders is justified

The influence of acute exercise on bone biomarkers: protocol for a systematic review with meta-analysis. [Protocol]

Background: Bone is a plastic tissue that is responsive to its physical environment. As a result, exercise interventions represent a potential means to influence bone. However, little is currently known about how various exercise and participant characteristics interact to influence bone metabolism. Acute, controlled, interventions provide an in-vivo model through which the acute bone response to exercise can be investigated, typically by monitoring circulating bone biomarkers. Currently, substantial heterogeneity in factors such as study design, quality, exercise and participant characteristics render it difficult to synthesize and evaluate the available evidence. Using a systematic review and meta-analytic approach, the aim of this investigation is to quantify the effect of an acute exercise bout on circulating bone biomarkers as well as examine potential factors that may moderate this response e.g., variation in participant, exercise and sampling characteristics. Methods: This protocol was designed in accordance with PRISMA-P guidelines. Seven databases (Medline, Embase, Sport Discus, Cochrane CENTRAL, PEDro, LILACS and Ibec) will be systematically searched and supplemented by secondary screening of the reference lists of all included articles. The PICOS (Population, Intervention, Comparator, Outcomes and Study Design) approach was used to guide the determination of eligibility criteria. Participants of any age, sex, training or health status will be considered for inclusion. We will select studies that have measured the bone biomarker response before and after an acute exercise session. All biomarkers considered to represent bone metabolism will be considered for inclusion and sensitivity analyses will be conducted using reference biomarkers for the measurement of bone resorption and formation (namely β-CTX-1 and P1NP). Multi-level, meta-regression models within a Bayesian framework will be used to explore the main effect of acute exercise on bone biomarkers as well as potential moderating factors. Risk of bias for each individual study will be evaluated using a modified version of the Downs and Black checklist while certainty in resultant outcomes will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Discussion: A better understanding of the bone metabolic response to an acute bout of exercise has the potential to advance our understanding of the mechanisms through which this stimulus impacts bone metabolism, including factors that may moderate this response. Additionally, we will identify current gaps in the evidence base and provide recommendations to inform future research. Registration: This protocol was prospectively registered in the Open Science Framework Registry (https://osf.io/6f8dz

Exploring the Emotional Breastfeeding Experience of First-Time Mothers : Implications for Healthcare Support

Background: Among breastfeeding determinants, the unique emotional breastfeeding experience has been poorly explored. The present study aimed to investigate the emotional breastfeeding experience in a cohort of first-time mothers. Materials and methods: We conducted a prospective observational study that enrolled primiparas having delivered singleton healthy term newborns, and exclusively breastfeeding at hospital discharge. At 3 months post-delivery mothers accessed an online questionnaire investigating their emotional breastfeeding experience. The chi-squared test was used to assess the association between the feelings experienced during breastfeeding and feeding outcomes at 3 months. Results: Out of the 421 enrolled mothers, 273 (65%) completed the questionnaire. At 3 months post-delivery exclusive breastfeeding was reported by a 66% of mothers, a 19% reported complementary feeding, and a 15% of mothers reported exclusive formula feeding. Breastfeeding experience was described as positive by 62% of mothers although breastfeeding difficulties were reported by 80% of the mothers. The mothers that had experienced fear, sadness, anger or concern during breastfeeding showed a significant higher exclusive formula feeding rate at 3 months post-delivery than those who did not (25.5 vs. 12.8%, p = 0.021; 28.6 vs. 13.4%, p = 0.02; 40 vs. 13.4%, p = 0.005; 20.5 vs. 11.8%, p = 0.049, respectively). An 85% of mothers stated that their breastfeeding experience was different from what they would have expected, blaming for this discrepancy the occurrence of difficulties during breastfeeding and the complexity of breastfeeding itself (50%), pain experience (8%), being dependent from the baby (6%), and breastfeeding failure (11%). A total of 25% of mothers, however, reported they found breastfeeding to be a much more positive experience than what they had expected. Conclusion: Breastfeeding care should include a tailored emotional support of first time-mothers in addition to the implementation of their breastfeeding knowledge and skills

Monod kinetics degradation of low concentration residual organics in membraneless microbial fuel cells

Microbial fuel cells (MFCs) are attracting considerable attention as innovative systems for energy production from renewable residual biomass and biomass-derived wastes dissolved in wastewaters. The current produced by a microbial fuel cell can also be used to quantify the rate of specific metabolic processes and the substrate concentration in real time. Aim of this work is the study of the correlation between the decay of current density in a microbial fuel cell and the concentration of the residual organic substrates when it reaches low concentration, in the rage of 0-500 mg/L COD. Tests were performed in continuous flow using an air breathing, membraneless MFC using sodium acetate as organic substrate. A direct concentration-dependent current output was achieved in the range of 0-100 mg/l, with a Monod kinetics as the best-fitting model. A step of current was also achieved at concentration higher than 120 mg/L

Clinical use of polymerase chain reaction performed on peripheral blood and bone marrow samples for the diagnosis and monitoring of visceral leishmaniasis in HIV-infected and HIV-uninfected patients: a single-center, 8-year experience in Italy and review of the literature

Background. To overcome some of the limitations of conventional microbiologic techniques, polymerase chain reaction (PCR)–based assays are proposed as useful tools for the diagnosis of visceral leishmaniasis. Patients and methods. A comparative study using conventional microbiologic techniques (i.e., serologic testing, microscopic examination, and culture) and a Leishmania species–specific PCR assay, using peripheral blood and bone marrow aspirate samples as templates, was conducted during an 8-year period. The study cohort consisted of 594 Italian immunocompetent (adult and pediatric) and immunocompromised (adult) patients experiencing febrile syndromes associated with hematologic alterations and/or hepatosplenomegaly. Identification of the infecting protozoa at the species level was directly obtained by PCR of peripheral blood samples, followed by restriction fragment–length polymorphism analysis of the amplified products, and the results were compared with those of isoenzyme typing of Leishmania species strains from patients, which were isolated in vitro. Results. Sixty-eight patients (11.4%) had a confirmed diagnosis of visceral leishmaniasis. Eleven cases were observed in human immunodeficiency virus (HIV)–uninfected adults, 20 cases were observed in HIV-infected adults, and the remaining 37 cases were diagnosed in HIV-uninfected children. In the diagnosis of primary visceral leishmaniasis, the sensitivities of the Leishmania species–specific PCR were 95.7% for bone marrow aspirate samples and 98.5% for peripheral blood samples versus sensitivities of 76.2%, 85.5%, and 90.2% for bone marrow aspirate isolation, serologic testing, and microscopic examination of bone marrow biopsy specimens, respectively. None of 229 healthy blood donors or 25 patients with imported malaria who were used as negative control subjects had PCR results positive for Leishmania species in peripheral blood samples (i.e., specificity of Leishmania species– specific PCR, 100%). PCR and restriction fragment–length polymorphism analysis for Leishmania species identification revealed 100% concordance with isoenzyme typing in the 19 patients for whom the latter data were available. Conclusions. PCR assay is a highly sensitive and specific tool for the diagnosis of visceral leishmaniasis in both immunocompetent and immunocompromised patients and can be reliably used for rapid parasite identification at the species level