Can an intermittent cathodic protection system prevent corrosion of buried pipeline?

Carbon steel pipelines are provided with corrosion prevention systems, namely an insulating coating and a cathodic protection (CP) system that reduces corrosion rate below 10 μm/a. CP is applied by a stationary cathodic current, which effectiveness on the metal surface is twofold: oxygen consumption and alkalinization (pH > 10) at the metal-to-electrolyte interface. The increase of pH is beneficial, promoting passive condition. In this paper, a preliminary study of the effect of intermittent CP has been carried out in order to investigate the effect of a temporary current interruption on the potential monitoring and on the residual corrosion of the metal. During the on period, oxygen is consumed and alkaline pH is established, during off period, the alkalinity and the slow oxygen replacement assure corrosion rates lower than in free corrosion condition. Test has been performed both in normal and overprotection condition, varying the off period duration, monitoring weekly the protection potential

Being physically active minimizes the effects of leg muscle fatigue on obstacle negotiation in people with Parkinson's disease

It is challenging for people with Parkinson's disease (PwPD) to adjust their gait to perturbations, including fatigue. Obstacle negotiation increases the risk of tripping and falling in PD. Being physically active can improve gait control and the ability to negotiate obstacles while walking under fatigue state. We thus determined the effects of Parkinson's disease, fatigue, and level of physical activity on gait during the approach to and crossing an obstacle during gait. Forty participants were stratified to people with Parkinson's disease active and inactive, and control individuals active and inactive. Participants walked on an 8 m walkway and stepped over an obstacle placed at the middle (4 m). They performed three trials before and after repeated sit-to-stand (rSTS)-induced fatigue state. Maximum voluntary force was assessed before and after rSTS. We measured the length, width, duration, and velocity of the approach (stride before obstacle) and crossing (step over the obstacle) phases and the leading and trailing placements and clearance during crossing phase. Fatigue trait was determined by multidimensional fatigue inventory. Before rSTS, people with Parkinson's disease inactive vs. other subgroups approached the obstacle using 18-28% shorter, wider and slower steps and crossed the obstacle slower (all p < 0.04). After rSTS, people with Parkinson's disease inactive increased (23-34%) stride length and velocity and decreased (-21%) the step width (p < 0.01). People with Parkinson's disease approached the obstacle similarly to control individuals. Physical activity minimizes Parkinson's disease-typical gait impairments during obstacle negotiation and affords a protective effect against fatigue-effects on obstacle negotiation

Does the impaired postural control in Parkinson's disease affect the habituation to non-sequential external perturbation trials?

Background: How people with Parkinson's disease habituate their postural response to unpredictable translation perturbation is not totally understood. We compared the capacity to change the postural responses after unexpected external perturbation and investigated the habituation plateaus of postural responses to non-sequential perturbation trials in people with Parkinson's disease and healthy older adults. Methods: In people with Parkinson's disease (n = 37) and older adults (n = 20), sudden posterior support-surface translational were applied in 7 out of 17 randomized trials to ensure perturbation unpredictability. Electromyography and center of pressure parameters of postural response were analyzed by ANOVAs (Group vs. Trials). Two simple planned contrasts were performed to determine at which trial the responses first significantly habituate, and by which trials the habituation plateaus. Findings: Older adults demonstrated a first response change in trial 5 and habituation plateaus after trial 4, while for people with Parkinson's disease, the first change occurred in trial 2 and habituation plateau after trial 5 observed by center of pressure range. People with Parkinson's disease demonstrated a greater center of pressure range in trial 1 compared to older adults. Independent of trial, people with Parkinson's disease vs. older adults demonstrated a greater ankle muscle co-activation and recovery time. Interpretation: Despite the greater center of pressure range in the first trial, people with Parkinson's disease can habituate to unpredictable perturbations. This is reflected by little, to no difference in the time-course of adaptation for all but 2 parameters that showed only marginal differences between people with Parkinson's disease and older adults

Guidelines of the Italian Society of Videosurgery in Infancy for the minimally invasive treatment of the ureteropelvic-junction obstruction

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Guidelines of the Italian Society of Videosurgery in Infancy for the minimally invasive treatment of the esophageal atresia

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Guidelines of the Italian Society of Videosurgery (SIVI) in Infancy for the minimally invasive treatment of Hypertrophic Pyloric Stenosis in neonates and infants

The most appropriate treatment for the infantile Hypertrophic Pyloric Stenosis (HPS) is still debated. The non-surgical conservative treatment with oral or intravenous administration of atropine does not enjoy a widespread appreciation for several factors (...

Guidelines of the Italian Society of Videosurgery in Infancy (SIVI) for the minimally invasive treatment of fetal and neonatal ovarian cysts

In the last three decades, fetal ovarian cysts were diagnosed more frequently, due to technological improvement and the increasing use of prenatal screening ultrasound. Nonetheless, treatment uncertainties are still present, either prenatally or postnatally. Recently, significant innovations on diagnosis and treatment have been proposed and a more conservative, minimally invasive approach may be offered to the Pediatrician or the Surgeon who face with this condition during prenatal or neonatal age. (...

Double obstacles increase gait asymmetry during obstacle crossing in people with Parkinson’s disease and healthy older adults: A pilot study

Gait asymmetry during unobstructed walking in people with Parkinson's disease (PD) has been well documented. However, under complex situations, such as environments with double obstacles, gait asymmetry remains poorly understood in PD. Therefore, the aim of this study was to analyze inter-limb asymmetry while crossing a single obstacle and double obstacles (with different distances between them) in people with PD and healthy older adults. Nineteen people with PD and 19 healthy older people performed three conditions: (i) walking with one obstacle (Single); (ii) walking with two obstacles with a 50 cm distance between them (Double-50); (iii) walking with two obstacles with a 108 cm distance between them (Double-108). The participants performed the obstacle crossing with both lower limbs. Asymmetry Index was calculated. We found that people with PD presented higher leading and trailing toe clearance asymmetry than healthy older people. In addition, participants increased asymmetry in the Double-50 compared to Single condition. It can be concluded that people with PD show higher asymmetry during obstacle crossing compared to healthy older people, independently of the number of obstacles. In addition, a challenging environment induces asymmetry during obstacle crossing in both people with PD and healthy older people

The content and form evolution in modern Persian poetry

Práce se zabývá fonnálními a obsahovými proměnami moderní perské poezie na pozadí společenského a literárního vývoje Íránu. Rozebírané období zahrnuje konec 19. století a pokračuje až do počátku islámské revoluce roku 1979. Studie obsahuje ukázky přeložené a přebásněné poezIe.Institute of Near Eastern and African StudiesÚstav Blízkého východu a AfrikyFilozofická fakultaFaculty of Art

Guidelines of the Italian Society of Videosurgery in Infancy for the minimally invasive treatment of pediatric nephrectomy and partial nephrectomy

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