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This paper presents a time domain technique used to solve the fault location problem for power distribution systems considering the dynamic load model. The proposed technique uses the voltage and current signals during the transient and steady states, measured at the main distribution substation, through time and phasor domain iterative analysis. The load dynamics is considered by its estimation at each sampling step. The accuracy of the proposed technique is determined by using a fault database obtained from the IEEE 34 bus distribution system. The fault locator is tested considering uncertainties associated with the fault type, fault resistance, voltage magnitude and angle unbalance at the source, load magnitude, power factor and the power system frequency. The obtained results show that the fault locator accuracy depends on the time of data acquisition, and the obtained performance is adequate for utility applications. [ABSTRACT FROM AUTHOR]

Axial modulation of liquid jets leads to the well-known jet 'bunching'effect. The associated accumulation of liquid in certain parts of the jet is advantageous, as it can increase the mechanical effect of the jet when it hits a surface. This advantage is known from empirical studies on cleaning with pulsating jets as well as from biological studies on the hunting method of archerfish. So far, however, there have been no systematic studies on modulating jets to enhance their impact on a solid surface. In this paper the VOF methodology is used to simulate jets with an axial velocity modulation. The modulation aims to accumulate the ejected liquid in a single droplet at the tip of the jet. This accumulation process has a decisive influence on the jet impact, as it changes the distribution of pressure and wall shear stresses in the impact area, which are difficult to determine experimentally. The validity of the numerical model is ensured by benchmark experiments in which both the drop shape and the impact force are used as comparison criteria. For this purpose, the velocity at the nozzle outlet was measured with high temporal resolution in the experiments, as it defines the inflow boundary conditions for the simulations. The results lead to a better understanding of the basic accumulation process. Furthermore, the improvement of the impact behaviour by jet modulation can be estimated. • Accumulation of ejected liquid in the tip of the jet due to velocity modulation. • Velocity modulation can increase the impact of a jet on a solid surface. • Significant increase in local pressures and wall shear stresses. [ABSTRACT FROM AUTHOR]

Abstract: An innovative pulsed reflection microscope (PRM) is used for optical in situ investigations of overload effects during fatigue crack growth in nodular cast iron. The optical system is based on the principle of a reflected-light microscope and can be integrated in any standard testing machines. Using the PRM the microstructural processes near the crack tip are visualized when an overload is applied. With the help of the presented optical system, the microstructural phenomena responsible for the acceleration effects in nodular cast iron are elucidated for the first time. Furthermore, scanning electron microscopy is used a posteriori to investigate the crack profiles and the fracture surfaces of the fatigue crack for the different stages of the overload event. [Copyright &y& Elsevier]

DMD-carriers were traditionally considered asymptomatic given the X-linked recessive inheritance pattern of these diseases. Yet, it has recently been discovered that they exhibit different levels of muscle involvement. This study aimed to characterize and compare the muscle structure on MRI of DMD-carriers and a control group. Secondly, we pursue a correlation between levels of muscle involvement and clinical manifestations, creatine kinase (CK) levels, DMD molecular alteration and X-chromosome inactivation (XCI) patterns. We enrolled 30 genetically confirmed DMD female carriers and 30 healthy non-carrier controls, BMI and age matched. All individuals underwent whole-body MRI, where semi-quantitative scales were used to assess muscle edema, trophism and fatty infiltration. Neurological examination, Serum CK measurement, DMD genetic screening, and XCI studies were only performed on the DMD-carriers. Statistically significant differences in muscle involvement were observed between DMD-carriers and the control group. Female carriers exhibited muscle affection in 33% of the 48 muscle groups analyzed, while the control group presented only the 10% affected. Most of the DMD-carriers' implicated muscles showed mild atrophy and mild to moderate fatty infiltration. The muscles more frequently affected were gastrocnemius, gluteus maximus and soleus. No statistical correlation was found between the levels or pattern of muscle involvement on MRI and the neurological examination, CK values, type of genetic variant and XCI patterns. DMD-carriers exhibit frequent and distinctive muscle involvement patterns on MRI, questioning the conception of "asymptomatic" DMD-Carriers. These results, together with findings in other X-linked disorders, lead to a revision of the concept of asymptomatic carriers of X-linked recessive diseases and raise awareness of the need to develop best practice guidelines for the evaluation and management of these females. [ABSTRACT FROM AUTHOR]

Objective: To determine whether brain white matter hyperintensities (WMH) influence l-dopa response in Parkinson's disease (PD) patients. Methods: We prospectively evaluated 60 PD patients with an acute l-dopa challenge test, and assessed motor performance with the Movement Disorders Society revised Unified Parkinson's Disease Rating Scale (MDS-UPDRS) during "ON" and "OFF" medication states. Magnetic resonance images were examined using a visual semi-quantitative rating scale for quantification and distribution analysis of WMH. l-dopa challenge test response was correlated to extent and location of WMH, to determine a potential association between them. Results: Subjects with greater deep WMH burden, showed less response to l-dopa on axial motor symptoms (R = -0.35; p < 0.027), when tested with Part III of the MDS-UPDRS before and after acute levodopa challenge. Conclusions: Results suggest WMH may affect response to l-dopa on axial function of PD patients, which could be due to either non-dopaminergic (cortico-basal ganglia) motor pathway disruption, or postsynaptic nigrostriatal pathway involvement. [ABSTRACT FROM AUTHOR]

: BackgroundDespite improvements in small bowel transplantation (SBTx), early referral of patients with irreversible intestinal failure (IF) remains a major obstacle. In this study we evaluated the demand for SBTx among seven surgical pediatric centers located at least 200 km from our center.: MethodsFrom 1997 to 2001, 640 patients have been treated for neonatal diseases, including 248 who underwent a minor or major intestinal resection. Twenty-four patients with major resections presented with short gut syndrome, requiring total parenteral nutrition (TPN). The greatest demand was in postsurgical neonates with necrotizing enterocolitis, gastroschiesis, onphalocoeles, or midgut volvulus, and in three adults with postradiotherapy arteritis (n = 2) and mesenteric vein thromboses (n = 1). The median length of residual bowel after resection was 20 to 30 cm, without an ileocecal valve. Four patients were referred for SBTx evaluation; three died while awaiting a donor; 20 were not referred, among whom 14 died of TPN complications.: ResultsApproximately 62 children per year require nutritional support for IF, most of whom develop complications related to TPN. Because many patients who are TPN-dependent develop complications, we believe that early referral would reduce mortality.: ConclusionsGreater medical awareness about the feasibility of SBTx procedures and earlier referral may improve results and quality of life after transplant. [Copyright &y& Elsevier]