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On the experimental characterization of the fluid volume influence on the friction between rough surfaces

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Friction 2023年第7期11卷 1334-1348页

作者： Lukas STAHL michael MÜLLER Georg-Peter OSTERMEYER Institute of Dynamics and Vibrations Technische Universität BraunschweigBraunschweig 37106Germany

The load-bearing behaviour of lubricated contacts depends primarily on the normal force,the relative velocity,and the ***,with the aid of the Stribeck curve,it is usually well possible to characterize whether hydrodynamics,mixed friction,or boundary friction is more likely to be *** fact that the load regime can also depend on the fluid quantity is obvious,but has hardly been systematically investigated so *** for contacts with microscopic roughness,the defined application of a very small amount of fluid is a very challenging *** this paper,a very fundamental study shows how a pin-on-disc tribometer can be used to achieve the transition from dry friction via mixed friction to predominant hydrodynamics by the amount of supplied *** experiments are carried out on samples filed with different *** addition,the simultaneous influence of partial filling and normal force as well as relative velocity is also *** good reproducibility has been practically reached over the entire range of the *** the quantities for the coefficient of friction(COF),it was concluded that close to full filling,a reduction of the fluid quantity has a similar effect on the COF as the reduction of the *** property goes along with the common theory of starved lubricated *** behaviour was not observed to the same extent for the normal *** the vicinity of smaller fluid quantities,the COF increases very rapidly with further reduction in fluid quantity,far more disproportionately than that with reduction in *** a deeper understanding of this problem,various practical issues such as idling or the run-up process in bearings can also be studied in a more focused manner.

关键词： starved lubrication Stribeck curve pin-on-disc tribometer fluid supply experimental studies

Fast Simulation of Lipid Vesicle Deformation Using Spherical Harmonic Approximation

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Communications in Computational Physics 2017年第1期21卷 40-64页

作者： michael Mikucki Yongcheng Zhou Department of Applied Mathematics&Statistics Colorado School of MinesGoldenColorado80401USA Department of Mathematics Colorado State UniversityFort CollinsColorado80523USA

Lipid vesicles appear ubiquitously in biological *** how the mechanical and intermolecular interactions deform vesicle membranes is a fundamental question in *** this article we develop a fast algorithm to compute the surface configurations of lipid vesicles by introducing surface harmonic functions to approximate themembrane *** parameterization allows an analytical computation of themembrane curvature energy and its gradient for the efficient minimization of the curvature energy using a nonlinear conjugate gradient *** approach drastically reduces the degrees of freedom for approximating the membrane surfaces compared to the previously developed finite element and finite difference *** deformations with a reduced volume larger than 0.65 can be well approximated by using as small as 49 surface harmonic *** method thus has a great potential to reduce the computational expense of tracking multiple vesicles which deform for their interaction with external fields.

关键词： Lipid bilayer curvature energy surface harmonics fast algorithm

Electricity demand forecasting for decentralised energy management

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能源与人工环境(英文) 2020年第2期1卷 178-186页

作者： Sean Williams michael Short School of Computing Engineering&Digital TechnologiesTeesside UniversityTS13BXUK

The world is experiencing a fourth industrial *** development of technologies is advancing smart infrastructure *** observe decarbonisation,digitalisation and decentralisation as the main drivers for *** electrical power systems a downturn of centralised conventional fossil fuel fired power plants and increased proportion of distributed power generation adds to the already troublesome outlook for op-erators of low-inertia energy *** the absence of reliable real-time demand forecasting measures,effective decentralised demand-side energy planning is often *** this work we formulate a simple yet highly effective lumped model for forecasting the rate at which electricity is *** methodology presented focuses on the potential adoption by a regional electricity network operator with inadequate real-time energy data who requires knowledge of the wider aggregated future rate of energy ***,contributing to a reduction in the demand of state-owned generation power *** forecasting session is constructed initially through analysis of a chronological sequence of discrete *** demand data shows behaviour that allows the use of dimensionality reduction *** with piecewise interpolation an electricity demand forecasting methodology is *** of short-term forecasting problems provide credible predictions for energy *** for medium-term forecasts that extend beyond 6-months are also very *** forecasting method provides a way to advance a novel decentralised informatics,optimisa-tion and control framework for small island power systems or distributed grid-edge systems as part of an evolving demand response service.

关键词： Demand response Decentralised Grid edge Time series forecasting

Uniform Asymptotic Expansion of the Voltage Potential in the Presence of Thin Inhomogeneities with Arbitrary Conductivity

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Chinese Annals of Mathematics,Series B 2017年第1期38卷 293-344页

作者： Charles DAPOGNY michael S.VOGELIUS Laboratoire Jean Kuntzmann CNRSUniversité Grenoble-Alpes Department of Mathematics Rutgers University

Asymptotic expansions of the voltage potential in terms of the "radius" of a diametrically small(or several diametrically small) material inhomogeneity(ies) are by now quite well-known. Such asymptotic expansions for diametrically small inhomogeneities are uniform with respect to the conductivity of the *** contrast, thin inhomogeneities, whose limit set is a smooth, codimension 1 manifold,σ, are examples of inhomogeneities for which the convergence to the background potential,or the standard expansion cannot be valid uniformly with respect to the conductivity, a, of the inhomogeneity. Indeed, by taking a close to 0 or to infinity, one obtains either a nearly homogeneous Neumann condition or nearly constant Dirichlet condition at the boundary of the inhomogeneity, and this difference in boundary condition is retained in the *** purpose of this paper is to find a "simple" replacement for the background potential, with the following properties:(1) This replacement may be(simply) calculated from the limiting domain Ω\σ, the boundary data on the boundary of Ω, and the right-hand side.(2) This replacement depends on the thickness of the inhomogeneity and the conductivity,a, through its boundary conditions on σ.(3) The difference between this replacement and the true voltage potential converges to 0 uniformly in a, as the inhomogeneity thickness tends to 0.

关键词： Uniform asymptotic expansions Conductivity problem Thin inhomogeneities

Review:Partial discharge diagnostics in wind turbine insulation

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第6期12卷 515-522页

作者： michael G.DANIKAS Athanasios KARLIS Power Systems Lab Department of Electrical and Computer Engineering Democritus University of Thrace Electrical Machines Lab Department of Electrical and Computer Engineering Democritus University of Thrace

The purpose of this paper is to review work undertaken on partial discharges and their influence on the insulation of wind turbines. No matter whether partial discharges can be considered as the main cause of deterioration of the insulation material, the initial cause of failure or not but an indication of the material degradation, there is no doubt that they are intimately linked to the aging of machine insulation. Material degradation can be detected by non-destructive techniques (e.g., partial discharge measurements, change of tan δ) or by destructive techniques, such as by cutting small pieces of the insulating material and by putting them under the scrutiny of the scanning electron microscope (SEM). Wind generators are a modern subject of research, especially in view of the growing demands of electric energy worldwide and the problems facing the environment all over the globe. Wind turbines are a novel field of research regarding partial discharge diagnostics since they are subjected to a variety of aging factors, which are different from conventional turbines. In this respect, particular attention should be paid to the multi-factor stressing of insulation and their consequences on the partial discharges.

关键词： Partial discharges Rotating machine insulation Wind turbines

Prognostic model of survival outcomes in non-small cell lung cancer patients initiated on afatinib: pooled analysis of clinical trial data

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Cancer Biology & Medicine 2019年第2期16卷 341-349页

作者： Ashley M. Hopkins Adel Shahnam Sasha Zhang Chris S. Karapetis Andrew Rowland michael J. Sorich Flinders Centre for Innovation in Cancer Department of Clinical Pharmacology College of Medicine and Public Health Flinders University Adelaide 5042 Australia The Canberra Hospital Garran 2605 Australia

Objective: Several predictors of survival have been identified in EGFR-positive non-small cell lung cancer(NSCLC) patients treated with first generation EGFR inhibitors. Prognostic models of survival outcomes with afatinib have not been ***: A prognostic tool for overall survival(OS)/progression free survival(PFS) based on pre-treatment clinicopathological factors was developed for EGFR-positive advanced NSCLC patients treated with first-line afatinib using penalised regression of individual-participant data from LUX-Lung 3 and 6(n = 468). Favourable, intermediate and poor risk groups were identified and externally validated using LUX-Lung 1(n = 390) and LUX-Lung 2(n = 129) trials that initiated afatinib following previous chemotherapy or EGFR inhibitor ***: Discriminative performance was good in the development and validation cohorts. For patients treated with first-line afatinib, the median OS for the favourable, intermediate and poor risk groups were > 47.7, 29.3 and 16.4 months, respectively, and the median PFS were 17.3, 13.2 and 8.3 months, respectively. The improvement in median OS with afatinib use compared to chemotherapy was > 12.4 months for the favourable risk group, whereas no OS benefit was apparent for the poor risk group. The improvement in median PFS with afatinib use compared to chemotherapy was 10.2 months for the favourable risk group and 3.2 months for the poor risk ***: A prognostic tool was developed and validated to identify favourable, intermediate and poor risk groups for OS/PFS in EGFR-positive advanced NSCLC patients treated with afatinib. The prognostic groups can inform the likely absolute OS/PFS benefit expected from afatinib compared to chemotherapy in first-line treatment.

关键词： Afatinib non-small cell lung cancer prognostic model

Benign multicystic peritoneal mesothelioma: A case report and review of the literature

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World Journal of Gastroenterology 2006年第35期12卷 5739-5742页

作者： michael C Safioleas Kontzoglou Constantinos Stamatakos michael Giaslakiotis Konstantinos Safioleas Constantinos Kostakis Alkiviadis 2nd Department of Propedeutic Surgery School of Medicine AthensUniversity Laiko Hospital Athens Greece Depatment of Pathology School ofMedicine Athens University Greece

Benign multicystic peritoneal mesothelioma （BMPM） is a rare tumor that occurs mainly in women in their reproductive age. The pathogenesis of BMPM is unclear and a controversy regarding its neoplastic and reactive nature exists. The biological behavior of BMPM is characterized by its slowly progressive process and high rate of recurrence after surgical resection. In addition this lesion does not present a strong tendency to transform into malignancy. Today approximately 130 cases have been reported. We here report a 62-year-old woman who had diffuse abdominal pain, nausea and vomiting. Physical examination revealed a painful mass in her upper abdomen. She reported a mild dehydration, but the vital signs were normal. Peristaltic rushes, gurgles and highpitched tinkles were audible. Upright plain abdominal film revealed small bowel loops with air-fluid levels. She was diagnosed having an incarcerated incisional hernia that resulted in intestinal obstruction. The patient underwent surgery during which a cystic mass of the right ovary measuring 6 cm × 5 cm × 4 cm, four small cysts of the small bowel （1 cm in diameter） and a cyst at the retroperitoneum measuring 11 cm× 10 cm × 3 cm were found. Complete resection of the lesion was performed. The patient had an uneventful recovery and had no recurrence two years after surgery.

关键词： Acute abdomen Ovary Peritoneum Benign multicystic mesothelioma Adenomatoid tumor

An Evaluation of Edible Plant Extracts for the Phytoremediation of Lead Contaminated Water

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Journal of Environmental Protection 2012年第8期3卷 722-730页

作者： Lovell Agwaramgbo Charne Thomas Chardai GrayS Jessica small Tajeve Young Chemistry Department Dillard University New Orleans USA

There is a growing global concern for the environmental and health hazards posed by heavy metal contaminants, especially lead in the soil and ground water. The potential for plant and animal uptake, metabolism, and propagation into food-chain poses great health risks. World communities face a common need to a cheap, efficient, and effective technology to mitigate the growing problem of heavy metal contaminations. The present investigation was undertaken to evaluate the potential of using aqueous extracts of edible vegetables and fruits for the in-situ remediation of lead contaminated water (1300 PPM). The plants used in this study include Mustard Green (Brassica juncea), Spinach (Spinacea oleracea), Collard Green (Brassica Oleracea), Bitter leaf (Vernonia Amygdalina), Carrot (Daucus Carota Sativus), Red, Green, and Yellow Bell Pepper (Capsicum Annuum ), tomatoes (Lycopersicon esculentum), red and white grape (Vitis vinifera), and lime (Citrus aurantifolia). After shaking triplicate reaction mixtures lead contaminated water with each substrate for 22 hours at room temperature, lead removal by the substrates were analyzed by EPA Method 6010, using Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). Results suggest that the order of lead removal is Collard Green (99.8%) >, Spinach (98.7%) > Mustard Green (98.2%) > Green Bell Pepper (97.8%) > Yellow Bell Pepper (97.75%) > White Grape (96.7%)> Carrot (95.5%) > Red Bell Pepper (94.28%) > Red Grape > 93.5% > Tomatoes (84%) > Bitter Leaf (61%). The study concludes that liquid substrates such as the supernatants from pureed edible tuberous, leafy, and fruity vegetables can effectively remove lead from contaminated water.

关键词： Heavy Metals Bioremediation Lead Remediation Water Contamination Phytoremediation

The Lived Experience of Smoking in Pregnancy

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Open Journal of Nursing 2014年第11期4卷 762-773页

作者： Cynthia L. Murray Sandra P. small Lorraine Burrage School of Nursing Memorial University of Newfoundland St. John’s Canada Newfoundland and Labrador Provincial Perinatal Program St. John’s Canada

Smoking in pregnancy is associated with adverse pregnancy outcomes, such as low birth weight, preterm birth, and perinatal death. Despite widespread public awareness of the deleterious health effects of cigarette smoking, up to a quarter of women in developed countries smoke during their pregnancies. In this hermeneutic phenomenological study, the meaning and experience of smoking in pregnancy were explored. Data were collected through interviews with eight pregnant women from the Canadian province of Newfoundland and Labrador. Four main themes were identified in the participants’ stories, namely living in a smoking world, suddenly finding myself on a moral low road, navigating my own way to a high road, and not preparing for postpartum smoking pitfalls. Smoking was perceived to be salubrious and the participants painted a picture of dealing with smoking in pregnancy as a daunting, lonely endeavor that required life-altering solutions. With a better understanding of what smoking means to pregnant women who smoke, nurses can help these women forge a new and lifelong way to health and wellness.

关键词： Addiction Substance Use Hermeneutic Phenomenology Lived Experience Pregnancy Tobacco Smoking Cessation