Presence Of Different Processes Research Articles

Flow stability for dynamic community detection

Many systems exhibit complex temporal dynamics due to the presence of different processes taking place simultaneously. An important task in these systems is to extract a simplified view of their time-dependent network of interactions. Community detection in temporal networks usually relies on aggregation over time windows or consider sequences of different stationary epochs. For dynamics-based methods, attempts to generalize static-network methodologies also face the fundamental difficulty that a stationary state of the dynamics does not always exist. Here, we derive a method based on a dynamical process evolving on the temporal network. Our method allows dynamics that do not reach a steady state and uncovers two sets of communities for a given time interval that accounts for the ordering of edges in forward and backward time. We show that our method provides a natural way to disentangle the different dynamical scales present in a system with synthetic and real-world examples.

FORMAS DEL SURCO DEL BORDE DE GRANO EN LA SUPERFICIE DE HIELO PURO

In this work we studied the evolution of the groove that forms the grain boundary (BG) when it emerges to a free surface, in the presence of different processes of matter transport. By using a confocal microscope, the shape of the grain edge groove was obtained in an ice sample with orientation <1010>/50◦at −5◦C ; after keeping it 3 h in an environment with dry air. The shapes and depths of the grain boundary groove obtained experimentally, at regular time periods, were satisfactorily fitted considering a process of transport of matter developed by Srinivasan and Trivedi. In this model the transport of matter is mainly ruled by gaseous diffusion and not by surface diffusion.

FORMAS DEL SURCO DEL BORDE DE GRANO EN LA SUPERFICIE DE HIELO PURO

In this work we studied the evolution of the groove that forms the grain boundary (BG) when it emerges to a free surface, in the presence of different processes of matter transport. By using a confocal microscope, the shape of the grain edge groove was obtained in an ice sample with orientation< 1010 >/50◦ at −5◦C ; after keeping it 3 h in an environment with dry air. The shapes and depths of the grain boundary groove obtained experimentally, at regular time periods, were satisfactorily fitted considering a process of transport of matter developed by Srinivasan and Trivedi. In this model the transport of matter is mainly ruled by gaseous diffusion and not by surface diffusion.

МОДЕЛЮВАННЯ ПРОЦЕСУ АКУМУЛЮВАННЯ ЕЛЕКТРОЕНЕРГІЇ В КОМБІНОВАНІЙ ЕНЕРГОСИСТЕМІ

Метою даної роботи є розроблення моделі балансування процесів генерації та споживання електроенергії для енергосистем на основі відновлюваних джерел енергії з використанням системи акумулювання. Режими генерації вітрових і особливо сонячних електростанцій мають значні градієнти поточної потужності, коли істотні зміни можливі за кілька хвилин. При виборі систем акумулювання необхідно враховувати такі фактори, як нерівномірність генерації та споживання, обсяг можливої надлишкової енергії чи її дефіцит, швидкість зміни балансу потужностей та відповідна швидкодія акумуляторів. Об’єкт дослідження - гібридні електроенергетичні системи, які мають властивості локальної мережі. Такі системи чутливі до змінних режимів генерації, а наявність швидких змін потужності вимагає врахування коротких часових проміжків. Методом дослідження є математичне моделювання випадкових процесів споживання та генерації енергії, яке дозволяє аналізувати поточне балансування потужностей та отримувати інтегральні характеристики стану акумулювання і повторного використання енергії. Моделювання режимів роботи сонячних та вітрових електростанцій основане на статистичних даних про погодні фактори. Тоді балансування потужності можна розглядати як суперпозицію випадкових процесів генерації та споживання. Особливістю дослідження є врахування часових градієнтів потужності вітрових та сонячних електростанцій, стану зарядки та швидкодії акумуляторів. Аналітичне дослідження ускладнене фактором наявності різних процесів з особливим характеристиками розподілу, тому запропоновано імітаційну модель з відповідним алгоритмом розрахунку. Запропонована модель енергобалансу дозволяє імітувати процеси накопичення та використання енергії при різних властивостях системи акумулювання. Результати дослідження дозволяють порівнювати різні конфігурації енергосистеми за збалансованістю, потребами в акумулюванні та рівнем втрат енергії. При цьому враховуються місцеві та сезонні кліматичні особливості. Бібл. 21, табл. 1, рис. 2.

ESTUDIO DE LA EVOLUCIÓN SUPERFICIAL DE UN BORDE DE GRANO EN HIELO PURO POR PROCESOS EVAPO-DIFUSIVOS

In this work, we studied the evolution of the groove that forms the grain boundary (BG)when it emerges to a free surface, in the presence of different processes of matter transport. The depth of a groove of the BG was obtained in an ice sample with orientation <1010>/50º at -5 ºC for 3h in dry air, by using a confocal microscope. The experimental results are fitted correctly with a process of transport of matter governed mainly by gaseous diffusion.

Analysis of landscape evolution in a vulnerable coastal area under natural and human pressure

To preserve integrity and functioning of coastal ecosystems services, monitoring and protection actions have to be realized on an ecosystem perspective and consider an integrated observing approach. We implemented a multidisciplinary study, based on remote sensing and geophysical techniques, landscape ecology tools, and geospatial data analysis for monitoring a coastal area (Basilicata Ionian coast) with a high concentration of forest ecosystems services: five Natura 2000 protected sites, intensive agriculture, and touristic infrastructures. The analysis of landscape evolution performed within five protected sites over about 30 years (1985–2013) shows the presence of different processes acting along the investigated coast. Where coniferous forests were involved in marked fragmentation processes geophysical measurements highlighted saltwater infiltrations in superficial layers. Since severe shoreline changes interested the investigated littoral, erosional processes could have increased the saltwater intrusion phenomena favoring the forest degradation and limiting its recovery after fires. Touristic activities do not seem to alter the forest evolution except for very localized segments. The implemented study suggests that the integration of remote sensing and in situ information coupled with landscape ecology perception can be a suitable support tool for planning and management activities in coastal areas (e.g. ecological interventions, and earthen block or barrage construction).

Comparison of angular dependence of magnetic Barkhausen noise of hysteresis and initial magnetization curve in API5L steel

This work analyzes the differences between the magnetic Barkhausen noise corresponding to the initial magnetization curve and Barkhausen noise corresponding to one branch of the hysteresis loop in API-5L steel. The outcomes show that the Barkhausen noise signal corresponding to the initial magnetization curve and that corresponding to the hysteresis are significantly different. This difference is due to the presence of different processes of the domain wall dynamics in both phenomena. To study the processes present in magnetization dynamics for an applied field of H>0, research into the angular dependence of a Barkhausen signal using applied field bands has revealed that a Barkhausen signal corresponding to the initial magnetization curve is more suitable than a Barkhausen signal corresponding to the hysteresis loop.

Basic concepts about brain pathophysiology and intracranial pressure monitoring

IntroductionMany brain processes that cause death are mediated by intracranial hypertension (ICH). The natural course of this condition inevitably leads to brain death. The objective of this study is to carry out a systematic review of cerebral pathophysiology and intracranial pressure (ICP) monitoring. DevelopmentStudying, monitoring, and recording ICP waves provide data about the presence of different processes that develop with ICH. ConclusionsCorrect monitoring of ICP is fundamental for diagnosing ICH, and even more importantly, providing appropriate treatment in a timely manner.

Conceptos básicos sobre la fisiopatología cerebral y la monitorización de la presión intracraneal

IntroductionMany brain processes that cause death are mediated by intracranial hypertension (ICH). The natural course of this condition inevitably leads to brain death. The objective of this study is to carry out a systematic review of cerebral pathophysiology and intracranial pressure (ICP) monitoring. DevelopmentStudying, monitoring, and recording ICP waves provide data about the presence of different processes that develop with ICH. ConclusionsCorrect monitoring of ICP is fundamental for diagnosing ICH, and even more importantly, providing appropriate treatment in a timely manner.

Differential expression of the regulated catecholamine secretory pathway in different hereditary forms of pheochromocytoma.

Pheochromocytomas in patients with von Hippel-Lindau (VHL) syndrome and multiple endocrine neoplasia type 2 (MEN 2) differ in the types and amounts of catecholamines produced and the resulting signs and symptoms. We hypothesized the presence of different processes of catecholamine release reflecting differential expression of components of the regulated secretory pathway among the two types of hereditary tumors. Differences in catecholamine secretion from tumors in patients with VHL syndrome (n = 47) and MEN 2 (n = 32) were examined using measurements of catecholamines in tumor tissue, urine, and plasma, the last of which was under baseline conditions in all subjects and in a subgroup of patients who received intravenous glucagon to provoke catecholamine release. Microarray and proteomics analyses, quantitative PCR, and Western blotting were used to assess expression of tumor tissue secretory pathway components. The rate constant for baseline catecholamine secretion was 20-fold higher in VHL than in MEN 2 tumors (0.359 +/- 0.094 vs. 0.018 +/- 0.009 day(-1)), but catecholamine release was responsive only to glucagon in MEN 2 tumors. Compared with tumors from MEN 2 patients, those from VHL patients were characterized by reduced expression of numerous components of the regulated secretory pathway (e.g., SNAP25, syntaxin, rabphilin 3A, annexin A7, calcium-dependent secretion activator). The mutation-dependent differences in expression of secretory pathway components indicate a more mature regulated secretory pathway in MEN 2 than VHL tumors. These data provide a unique mechanistic link to explain how variations in the molecular machinery governing exocytosis may contribute to clinical differences in the secretion of neurotransmitters or hormones and the subsequent presentation of a disease.

Using photoelectron spectroscopy to unravel the excited-state dynamics of benzene

Experimental and calculated spectra are presented for the two-photon ionisation of benzene via the S 1(B 2u) excited-state. The experimental spectra are produced using a femtosecond pump–probe set-up with the signal captured by photoelectron imaging. The calculations use wavepacket dynamics simulations using a simple model Hamiltonian to represent the benzene molecule interacting with the laser pulses, which are included explicitly. Comparison of the two sets of spectra help to untangle the presence of different processes.

Magnetic and structural properties of the Supermalloy powders produced by mechanical alloying and annealing

Nanocrystalline Supermalloy powders were obtained by mechanical alloying under argon atmosphere and subsequent annealing. Several milling times have been used and a heat treatment has been performed in order to improve the solid-state reaction and remove the internal stresses. The evolution of the Supermalloy formation by mechanical alloying and annealing was confirmed by X-ray diffraction and magnetic measurements. A minimum in the spontaneous magnetisation vs. milling time shows the presence of different processes in the Supermalloy formation by milling.

Morfogênese quaternária e intemperismo: colúvios do Planalto do Itatiaia

No setor inferior das vertentes do planalto do ltatiaia (2.300 -2.500m) ocorrem duas gerações de colúvios que testemunham fases de intensificação das ações erosivas nas vertentes. Estudo mineralógico e micromorfológico permitiu reconhecer tendência geral laterítica nos materiais de alteração in situ e colúvios. A análise micromorfológica dos colúvios evidencia mistura de materiais com diferentes graus de alteração, mais especialmente em CII, caracterizado por contrastes maiores que o comum num mesmo nível de perfis de alteração. Intensamente argilificados mas pouco pedogeneizados, ricos em fragmentos das rochas subjacentes e com menores contrastes de alteração, os colúvios CI poderiam ter sido originados por movimentos de massa que atingiram o regolito em maior profundidade. Em CII, altero e litorrelíquias bem menos comuns e grãos de esqueleto sempre menores indicariam materiais de origem inicialmente mais evoluídos; mistura de graus extremos de alteração sugere retrabalhamento por processos superficiais de coluviação, com inclusão de fragmentos de rocha menos alterada durante o transporte vertente abaixo. A atuação de diferentes processos nas vertentes permite inferir variações nas condições ambientais do planalto. De climas úmidos mais estáveis, e talvez mais quentes, favoráveis à alteração do regolito, ter-se-ia passado a uma fase de intensificação ou concentração das chuvas, capaz de explicar o desencadeamento das corridas de lama que depositaram CI. Nos últimos 8.000 anos, condições úmidas mas com maiores oscilações da temperatura, incluindo fases de maior intensidade dos processos de gelifração, teriam sido responsáveis pela deposição dos materiais, ora finos ora cascalhentos, das seqüências CII. Estas variações não foram entretanto suficientes para mudar a tendência laterítica da alteração, que teria persistido após o último máximo glacial.