Influence of Hydrogen and Low Temperature on Pipeline Steels Mechanical Behaviour

Abstract In the presence of H2S, metallic materials, such as carbon and low alloy steels, may suffer hydrogen damage and hydrogen embrittlement. Gas transporting pipes in low temperature environment, during the shutdown and the subsequent re-starting operations, are exposed to very low temperatures (T=-40 °C). In the presence of high H2S content in the gas, the risk of brittle failure can be increased due to the effect of hydrogen on steel toughness. In this paper the influence of hydrogen and low temperature on mechanical properties of two pipeline materials, F22 low alloy and X65 micro-alloyed steels, is studied. Steels have been hydrogen charged by means of an electrochemical method: diffusible hydrogen content of steels is in the range 0.6 to 2 ppm. Charpy and J-R curves tests were carried out in the range from room temperature to T=-120 °C. Hydrogen affects mechanical properties of the tested materials, mainly reducing fracture toughness in J integral tests, while little influence has been observed in CV tests. Fracture surface examination confirms the results of mechanical testing

Fatigue Behavior Of Pipeline Steel Under Hydrogen Environment And Low Temperature

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Regulation of inflammatory responses to Bordetella pertussis by N(G)-monomethyl-L-arginine in mice intranasally infected.

To investigate effect of MMLA, an inhibitor of nitric oxide (NO) production, on regulation of inflammatory responses to Bordetella pertussis infection, mice were infected intranasally, and treated with various concentrations of MMLA. Ten days after infection, mice treated with MMLA at dosage of 100 mg/kg, given intraperitoneally in a single dose or for 5 consecutive days, showed at histopathologic examination, a significant decrease of intensity of inflammation (scores, 0.6 +/- 0.2 and 0.9 +/- 0.5 respectively). A decrease of cellular accumulation of neutrophils and lymphocytes in the bronchoalveolar lavage (BAL) fluid was observed in infected mice treated with MMLA, especially at dosage of 10 mg/kg, given in a single dose intraperitoneally. In addition, BP-infected mice treated with MMLA (100 mg/kg, intraperitoneally) for 5 consecutive days showed higher mortality rate than untreated mice infected with B. pertussis, and the number of B. pertussis in lungs of mice treated with MMLA was significantly increased. However, MMLA treatment of infected mice had some effect on levels of IFN-gamma and nitrite/nitrate (end-stable products of NO) in the BAL fluid. This study indicates that NO may play a role either as microbiocidal agent or as a modulator of immune regulation, inasmuch as it may upregulate tissue inflammatory response to B. pertussis

An in vivo Comparison Study Between Strontium Nanoparticles and rhBMP2

The osteoinductive property of strontium was repeatedly proven in the last decades. Compelling in vitro data demonstrated that strontium hydroxyapatite nanoparticles exert a dual action, by promoting osteoblasts-driven matrix secretion and inhibiting osteoclasts-driven matrix resorption. Recombinant human bone morphogenetic protein 2 (rhBMP2) is a powerful osteoinductive biologic, used for the treatment of vertebral fractures and critically-sized bone defects. Although effective, the use of rhBMP2 has limitations due its recombinant morphogen nature. In this study, we examined the comparison between two osteoinductive agents: rhBMP2 and the innovative strontium-substituted hydroxyapatite nanoparticles. To test their effectiveness, we independently loaded Gelfoam sponges with the two osteoinductive agents and used the sponges as agent-carriers. Gelfoam are FDA-approved biodegradable medical devices used as delivery system for musculoskeletal defects. Their porous structure and spongy morphology make them attractive in orthopedic field. The abiotic characterization of the loaded sponges, involving ion release pattern and structure investigation, was followed by in vivo implantation onto the periosteum of healthy mice and comparison of the effects induced by each implant was performed. Abiotic analysis demonstrated that strontium was continuously released from the sponges over 28 days with a pattern similar to rhBMP2. Histological observations and gene expression analysis showed stronger endochondral ossification elicited by strontium compared to rhBMP2. Osteoclast activity was more inhibited by strontium than by rhBMP2. These results demonstrated the use of sponges loaded with strontium nanoparticles as potential bone grafts might provide better outcomes for complex fractures. Strontium nanoparticles are a novel and effective non-biologic treatment for bone injuries and can be used as novel powerful therapeutics for bone regeneration

Ultrasound stimulus to enhance the bone regeneration capability of gelatin cryogels

In the present study, gelatin-based cryogels have been seeded with human SAOS-2 osteoblasts. In order to overcome the drawbacks associated with in vitro culture systems, such as limited diffusion and inhomogeneous cell-matrix distribution, this work describes the application of ultrasounds (average power, 149 mW; frequency, 1.5 MHz) to physically enhance the cell culture in vitro. The results indicate that the physical stimulation of cell-seeded gelatin-based cryogels upregulates the bone matrix production

Food-dependent Cushing's syndrome: from molecular characterization to therapeutical results

ObjectiveCortisol secretion in ACTH-independent macronodular adrenal hyperplasia (AIMAH) may be regulated by the aberrant expression of several G-protein-coupled receptors. Bilateral adrenalectomy is the treatment of choice in most cases. We searched for aberrant receptor expression in a patient with AIMAH and evaluated the response to medical and surgical treatment.PatientA 35-year-old woman with amenorrhea, hirsutism, and hypertension presented ACTH-independent cortisol secretion with high androgen levels. Abdominal computed tomography showed bilateral adrenal macronodules (4.5 cm right and 1.0 cm left). Scintigraphy with I131-norcholesterol showed bilateral uptake, prevalent on the right side. Several in vivo stimulation tests were assessed before and after treatment and in vitro studies were performed after unilateral adrenalectomy.ResultsPlasma cortisol increased after a standard meal test (60%) and oral glucose loading (147%), and the response was blunted by pretreatment with 100 μg s.c. octreotide. The therapy with long-acting release octreotide (octreotide-LAR) showed an improvement in urinary free cortisol (UFC) levels. Unilateral adrenalectomy was performed and histopathology revealed macronodular AIMAH. Cortisol and androgens increased after perifusion of tumoral tissue with glucose-dependent insulinotropic polypeptide (GIP), and GIP and LH-receptor overexpression was found in both the adrenal nodules and the adjacent cortex. After surgery, UFC and androgen levels normalized followed by clinical improvement.ConclusionsGIP and LH-receptor expression may coexist in AIMAH, influencing the functional and morphological phenotype. Aberrant hormone receptor expression enables specific pharmacological treatment, but long-term studies are needed to evaluate its real efficacy. Unilateral adrenalectomy may be a safe initial option, particularly for asymmetric bilateral adrenal enlargements

Desenvolvimento inicial de eucalipto submetido à fertilização química e aplicação de dejetos líquidos de suínos.

O presente estudo tem por objetivo identifi car doses mais adequadas do resíduo da biodigestão de dejetos líquidos de suínos (DLS) para aplicação em plantios de eucalipto estabelecidos na região Oeste do Paraná. O experimento está sendo condu- zido na Fazenda Piquiri, Palotina, PR, em tratamentos sob uso de DLS e sob fertiliza- ção mineral. A avaliação do desenvolvimento das árvores ao longo do ciclo da cultura permitirá comparar o desempenho das diferentes doses de DLS na produção de biomas- sa e, desta forma, obter recomendações silviculturais para o estabelecimento de plantios fl orestais energéticos na região

Sistematização de experiências agroflorestais no estado de São Paulo: diagnóstico das temáticas abordadas com base nos congressos brasileiros de sistemas agroflorestais.

Este trabalho teve como objetivo realizar um diagnóstico das publicações referentes ao Estado de São Paulo nos Congressos Brasileiros de Sistemas Agroflorestais (CBSAFs), identificando o número de trabalhos, principais temas abordados e instituições responsáveis por suas autorias. A partir de consultas aos anais dos dez CBSAFs realizados entre 1994 e 2016, foram pesquisados um total de 1686 trabalhos, dos quais 88 fazem referência ao Estado de São Paulo. Observou-se que houve um aumento considerável no número de publicações do Estado de São Paulo a partir do V CBSAF (2004) e que o maior número de publicações ocorreu nos VII (2009) e VIII (2011) CBSAFs. Foram identificados treze temas principais, sendo ?caracterização de Sistemas Agroflorestais?, ?monitoramento de espécies vegetais?, ?monitoramento de solo? e ?restauração? os temas principais que ocorreram com maior frequência nos trabalhos. Um total de 28 instituições ou organizações foram identificadas como responsáveis pelas autorias dos trabalhos, destacando-se a ESALQ/USP, a UNESP, a Embrapa Meio Ambiente e a UFSCar como as instituições que apresentaram o maior número de trabalhos publicados. A categoria instituições de ?ensino? foi a que apresentou o maior número de trabalhos publicados, seguida por instituições de ?pesquisa?, ?Organizações Governamentais? e ?ONGs?