Tolerance Margin Research Articles

COMPARING THE RESISTANCE TO MOTION OF PISTONS COATED WITH A LAYER OF NANOTUBES WITH STANDARD PISTONS

The paper presents preliminary results of testing the resistance to motion of pistons coated with a layer of carbon nanotubes (CNTs). A significant part of this paper was devoted to the problems of putting a layer of nanotubes on the surface of an aluminum alloy. Obtaining a layer of nanotubes of a very narrow margin of tolerance was a difficult technological problem to overcome. A standard process of growing a layer of nanotubes leads to a corrosion damage of the side surface of pistons; therefore, new technologies were developed allowing for obtaining a permanent layer of nanotubes less than 5 microns thick. Pistons whose side surfaces were coated with a layer of nanotubes were mounted to an engine with an external drive, and then measurements of the moment of momentary resistance to motion were performed, which enables capturing these phases of the engine work cycles in which the layer of nanotubes gives the best results. At present, long-term research is being carried out in order to determine the degree of the risk of exfoliation of the layer of nanotubes under the conditions of large mechanical and thermal loads. The special nanotechnology method cold nanosphere lithography has been invested to control the structural properties sand growth of multiwalled carbon nanotubes. The preliminary analysis of dismantled pistons revealed that nanotubes layers were partially worn off at the peaks of micro roughness but in the valleys, the nanotubes accurately adhered to the piston lateral surface.

Deterministic prediction of surface wind speed variations

Abstract. Accurate prediction of wind speed is an important aspect of various tasks related to wind energy management such as wind turbine predictive control and wind power scheduling. The most typical characteristic of wind speed data is its persistent temporal variations. Most of the techniques reported in the literature for prediction of wind speed and power are based on statistical methods or probabilistic distribution of wind speed data. In this paper we demonstrate that deterministic forecasting methods can make accurate short-term predictions of wind speed using past data, at locations where the wind dynamics exhibit chaotic behaviour. The predictions are remarkably accurate up to 1 h with a normalised RMSE (root mean square error) of less than 0.02 and reasonably accurate up to 3 h with an error of less than 0.06. Repeated application of these methods at 234 different geographical locations for predicting wind speeds at 30-day intervals for 3 years reveals that the accuracy of prediction is more or less the same across all locations and time periods. Comparison of the results with f-ARIMA model predictions shows that the deterministic models with suitable parameters are capable of returning improved prediction accuracy and capturing the dynamical variations of the actual time series more faithfully. These methods are simple and computationally efficient and require only records of past data for making short-term wind speed forecasts within practically tolerable margin of errors.

The influence of applying a layer of carbon nanotubes on the piston bearing surface on friction losses

The paper presents results of testing the resistance to motion of pistons whose bearing surface was coated with a layer of carbon nanotubes (CNTs). A part of this paper was devoted to the problems of applying a layer of nanotubes on the surface of an aluminum alloy, which is the most common material used for pistons. Obtaining a layer of nanotubes of a very narrow margin of tolerance was a difficult technological problem to overcome. A standard process of growing a layer of nanotubes leads to corrosion damage of the side surface of pistons; therefore, new technologies were developed which allow for obtaining a permanent layer of nanotubes less than 5 microns thick. Pistons with the bearing surface coated with a layer of nanotubes were mounted to the engine, and then measurements of the moment of momentary resistance to motion were performed. Also capturing phases of the engine work cycles in which the layer of nanotubes gives the best results seems to be possible. At present, long-term research is being carried out in order to determine the degree of the risk of exfoliation of the layer of CNT under the conditions of high mechanical and thermal loads.

HOTB: High precision parallel code for calculation of four-particle harmonic oscillator transformation brackets

HOTB: High precision parallel code for calculation of four-particle harmonic oscillator transformation brackets

El objetivo de una sociedad inclusiva: bases para una propuesta alternativa

The discourse of the unviable nature of the welfare state is argued as an inevitable consequence of economic logic, but in reality it involves changing the margins of tolerance adopted by society when faced with exclusion or, put another way, abandoning the hitherto accepted concept of an inclusive society. The crisis of an inclusive society is not the result of the failure of certain social policies. When the capacity for inclusion fails, it is the model itself that is failing. This is what, in the current circumstances, makes it obligatory to think again about what is to be included or excluded. The demand for what should be goals of inclusion forms a central plank of the social and economic model and is the best reflection of its view of justice. This paper discusses three reflections. The first of these concerns the need to be familiar with the current features of trends in inequality, which represent the underlying factor weakening inclusiveness. The second takes up the current debate on the concept of welfare and its implications for greater demands for fairness. The third outlines the frame of reference of alternative thought, especially regarding human development, as theoretical categories allowing demands for inclusion to be reframed.

Automatic classification of products in the industry via invariant boundary moments

La técnica de los Momentos Invariantes de Borde (MIB) es aplicada a la clasificación automática de dos diferentes objetos seleccionados al azar, independientemente de sus dimensiones, posición y orientación. Se muestra que si los objetos difieren solo en posición y orientación (sus dimensiones se mantienen), el poder de los MIB es optimo; sin embargo, cuando se incluyen variaciones en las dimensiones, los valores de los MIBs se superponen, lo cual limita su uso como una herramienta de clasificación, en casos como estos, debe introducirse un margen de tolerancia predefinido.

Obtaining a spiral path for machining STL surfaces using non-deterministic techniques and spherical tool

For milling an arbitrary surface, several models exist in which the tool must be moved close and away from the workpiece with its consequential problems caused by the contact between the tool and the mechanized material. One of these problems is the undesirable mechanizing marks on the surface, which can be avoided with the use of tangential tool-paths, causing another disadvantage: the additional time-consumption. Spiral tool-paths eliminate these problems and allow for continuous machining of the part without approach or withdrawal.Deterministic models for obtaining the tool positions referred to the part need to apply complex mathematical operations. For this reason, the idea of using non-deterministic techniques, with a controlled tolerance margin, allows to avoid those mathematical and geometrical operations. It also makes possible to reduce the processing times with no loss of dimensional quality and a good superficial finishing, which was confirmed with a coordinate measuring machine and with confocal microscopy, respectively.Finally, the effectiveness of the described method was assessed comparing its results with the performance of three of the most relevant CAM software commercially available. The obtained results are shown at the end of this paper.

Tolerable delay-margin improvement for systems with input–output delays using dynamic delayed feedback controllers

This paper presents investigations on a dynamic state feedback controller with state delays that improves tolerable delay margin for systems with input–output delays. Using an iterative pole placement technique for time-delay systems, the effect of introducing state delay in the controller dynamics is studied. It is observed that such a controller improves the tolerable delay margins compared to its static or even simple dynamic counterpart.

Transcriptomic analysis of candidate osmoregulatory genes in the eastern oyster Crassostrea virginica.

BackgroundThe eastern oyster, Crassostrea virginica, is a euryhaline species that can thrive across a wide range of salinities (5-35). As with all estuarine species, individual oysters must be able to regulate their osmotic balance in response to constant temporal variation in salinity. At the population level, recurrent viability selection may be an additional mechanism shaping adaptive osmoregulatory phenotypes at the margins of oyster salinity tolerance. To identify candidate genes for osmoregulation, we sequenced, assembled, and annotated the transcriptome of wild juvenile eastern oysters from ‘high’ and ‘low’ salinity regimes. Annotations and candidates were mostly based on the Pacific oyster (Crassostrea gigas) genome sequence so osmoregulatory relevance in C. virginica was explored by testing functional enrichment of genes showing spatially discrete patterns of expression and by quantifying coding sequence divergence.ResultsThe assembly of sequence reads and permissive clustering of potentially oversplit alleles resulted in 98,729 reftigs (contigs and singletons). Of these, 50,736 were annotated with 9,307 belonging to a set of candidate osmoregulatory genes identified from the C. gigas genome. A total of 218,777 SNPs (0.0185 SNPs/bp) were identified in annotated reftigs of C. virginica. Amino acid divergence between translations of C. virginica annotated reftigs and C. gigas coding sequence averaged 23.2 % with an average dN/dS ratio of 0.074, suggesting purifying selection on protein sequences. The high and low salinity source oysters each expressed a subset of genes unique to that group, and the functions for these annotated genes were consistent with known molecular mechanisms for osmotic regulation in molluscs.ConclusionsMost of the osmoregulatory gene candidates experimentally identified in C. gigas are present in this C. virginica transcriptome. In general these congeners show coding sequence divergence too high to make the C. gigas genome a useful reference for C. virginica bioinformatics. However, strong purifying selection is characteristic of the osmoregulatory candidates so functional annotations are likely to correspond. An initial examination of C. virginica presence/absence expression patterns across the salinity gradient in a single estuary suggests that many of these candidates have expression patterns that co-vary with salinity, consistent with osmoregulatory function in C. virginica.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-503) contains supplementary material, which is available to authorized users.

Adaptive Treatment Planning and Online Setup Measurements to Guide Decision of Margin Size for Hypofractionated Intracranial Radiosurgery

Adaptive Treatment Planning and Online Setup Measurements to Guide Decision of Margin Size for Hypofractionated Intracranial Radiosurgery

Reconfiguring Ottoman Gender Boundaries and Sexual Categories by the mid-19th century

This research extends the theory of the civilizing process of Norbert Elias to the gender issue in the Ottoman Empire and thereby in some respects provides a test of his original theory. This study is based on the assumption that the conscious policy of the Ottoman modernization by the ruling elite exhibited many symptoms resembling those of the European civilizing process. The socio-historical process of bureaucratization of the Ottoman state fostered the changes in manners and forms of cultural expression which brought with it the advance of the threshold of shame and embarrassment in gender relations during this process. Drawing on this assumption, the article looks at the changes in the way people control themselves and others in the expression of their impulses and emotions. In turn, - the question of how the margins of tolerance in sexual matters and in the expression of emotions and desires changed during this civilizing process - formulates the major concern of this paper. Since manuals on etiquette, manners books, diaries and archives are the richest sources for this purpose, this project employs the analysis of these cultural texts, in order to make inferences from the cultural transformations within the Ottoman Empire. The research hopes to offer new perspectives in reorienting the way we look at the development of the Ottoman culture within the context of figurational sociology.

Front-End Narrowband Interference Mitigation for DS-UWB Receiver

Narrow band interference (NBI) suppression is one of major issues for ultra wideband (UWB) wireless communication system operating over huge spectrum occupied by narrow band wireless systems. In this paper, we propose an interference mitigation scheme based on complex-valued adaptive notch filter, which smartly exploits the substantial correlation difference of signals and removes the NBIs in UWB signal with noise by estimating the corresponding central frequencies. To obtain high speed convergence and maintain small signal distortion, a low complexity gradient algorithm for one-order basic adaptive notch filter cell is deduced. Considering that the data rate prior to despreading is extremely high, a novel time-division multiplexing (TDM) parallel approach for eliminating a single NBI is presented, which effectively simplify the hardware design especially in high speed digital signal processing. Based on the one-order basic adaptive notch filter cell, three different implementations including direct forms, linear cascade forms and TDM parallel cascade forms to eliminate multiple NBIs are developed and discussed. Theoretical analysis and simulation results indicate that the proposed scheme possesses the advantages of high convergence speed, small distortion and high stability. Furthermore, the propose scheme utilized as a preprocessing unit prior to despreading can considerably improve the interference tolerance margin of UWB systems, leading to it's suitable for the low complexity direct sequence (DS)-UWB receiver.

Can temperate insects take the heat? A case study of the physiological and behavioural responses in a common ant, Iridomyrmex purpureus (Formicidae), with potential climate change

Insects in temperate regions are predicted to be at low risk of climate change relative to tropical species. However, these assumptions have generally been poorly examined in all regions, and such forecasting fails to account for microclimatic variation and behavioural optimisation. Here, we test how a population of the dominant ant species, Iridomyrmex purpureus, from temperate Australia responds to thermal stress. We show that ants regularly forage for short periods (minutes) at soil temperatures well above their upper thermal limits (upper lethal temperature=45.8±1.3°C; CTmax=46.1°C) determined over slightly longer periods (hours) and do not show any signs of a classic thermal performance curve in voluntary locomotion across soil surface temperatures of 18.6–57°C (equating to a body temperature of 24.5–43.1°C). Although ants were present all year round, and dynamically altered several aspects of their thermal biology to cope with low temperatures and seasonal variation, temperature-dependence of running speed remained invariant and ants were unable to elevate high temperature tolerance using plastic responses. Measurements of microclimate temperature were higher than ant body temperatures during the hottest part of the day, but exhibited a stronger relationship with each other than air temperatures from the closest weather station. Generally close associations of ant activity and performance with microclimatic conditions, possibly to maximise foraging times, suggest I. purpureus displays highly opportunistic thermal responses and readily adjusts behaviour to cope with high trail temperatures. Increasing frequency or duration of high temperatures is therefore likely to result in an immediate reduction in foraging efficiency. In summary, these results suggest that (1) soil-dwelling temperate insect populations may be at higher risks of thermal stress with increased frequency or duration of high temperatures resulting from climate change than previously thought, however, behavioural cues may be able to compensate to some extent; and (2) indices of climate change-related thermal stress, warming tolerance and thermal safety margin, are strongly influenced by the scale of climate metrics employed.

Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC): Occupational Health and Safety Aspects

BackgroundPressurized intraperitoneal aerosol chemotherapy (PIPAC) is a novel approach for treating peritoneal carcinomatosis. First encouraging results have been obtained in human patients. However, delivering chemotherapy as an aerosol might result in an increased risk of exposure to health care workers, as compared with other administration routes.MethodsPIPAC was applied in two human patients using chemotherapeutic drugs (doxorubicin and cisplatin), and air contamination levels were measured under real clinical conditions. Air was collected on a cellulose nitrate filter with a flow of 22.5 m3/h. To exclude any risk for health care workers, both procedures were remote controlled. Toxicological research of cisplatin was performed according to NIOSH 7300 protocol. Sampling and analysis were performed by an independent certification organization.ResultsThe following safety measures were implemented: closed abdomen, laminar airflow, controlled aerosol waste, and protection curtain. No cisplatin was detected in the air (detection limit < 0.000009 mg/m3) at the working positions of the surgeon and the anesthesiologist under real PIPAC conditions.ConclusionsFor the drugs tested, PIPAC is in compliance with European Community working safety law and regulations. Workplace contamination remains below the tolerance margin. The safety measures and conditions as defined above are sufficient. Further protecting devices, such as particulate (air purifying) masks, are not necessary. PIPAC can be used safely in the clinical setting if the conditions specified above are met. However, a toxicological workplace analysis must be performed to confirm that the procedure as implemented complies with local regulations.

Review of radiation hard electronics activities at European Space Agency

Several Research and Development activities are ongoing at European Space Agency [1] to secure the supply of key electronic parts for current and future space avionics systems. Analogously to astro-particle and high-energy physics, the space missions radiation environment drives the radiation hardness requirements, which limits availability of suitable electronic components. In particular for the future ESA flagship Jupiter science mission, thenecessary processing, reliability, mass, power performancerequirements are difficult to meet with current components and systemswith sufficient radiation tolerance margins. Improved radiationcharacterisation and modelling of the Jupiter radiation environment aswell as operational radiation monitoring during the mission will bekey in ensuring adequate margins for the operation of electroniccomponents.

Thermal reaction norms and the scale of temperature variation: latitudinal vulnerability of intertidal nacellid limpets to climate change.

The thermal reaction norms of 4 closely related intertidal Nacellid limpets, Antarctic (Nacella concinna), New Zealand (Cellana ornata), Australia (C. tramoserica) and Singapore (C. radiata), were compared across environments with different temperature magnitude, variability and predictability, to test their relative vulnerability to different scales of climate warming. Lethal limits were measured alongside a newly developed metric of “duration tenacity”, which was tested at different temperatures to calculate the thermal reaction norm of limpet adductor muscle fatigue. Except in C. tramoserica which had a wide optimum range with two break points, duration tenacity did not follow a typical aerobic capacity curve but was best described by a single break point at an optimum temperature. Thermal reaction norms were shifted to warmer temperatures in warmer environments; the optimum temperature for tenacity (Topt) increased from 1.0°C (N. concinna) to 14.3°C (C. ornata) to 18.0°C (an average for the optimum range of C. tramoserica) to 27.6°C (C. radiata). The temperature limits for duration tenacity of the 4 species were most consistently correlated with both maximum sea surface temperature and summer maximum in situ habitat logger temperature. Tropical C. radiata, which lives in the least variable and most predictable environment, generally had the lowest warming tolerance and thermal safety margin (WT and TSM; respectively the thermal buffer of CTmax and Topt over habitat temperature). However, the two temperate species, C. ornata and C. tramoserica, which live in a variable and seasonally unpredictable microhabitat, had the lowest TSM relative to in situ logger temperature. N. concinna which lives in the most variable, but seasonally predictable microhabitat, generally had the highest TSMs. Intertidal animals live at the highly variable interface between terrestrial and marine biomes and even small changes in the magnitude and predictability of their environment could markedly influence their future distributions.

Portfolio Management under Constraints on Ex-Ante and Ex-Post Tracking-Errors

Investment fund managers are judged by ex post or realized tracking error rather than the ex ante tracking error, which is unobservable. The main objective of this paper is to examine the relation between the theoretical tracking error that the manager defines ex ante and the realised tracking error that is actually measured ex post. We determine the ex ante tracking error that must be set in order for the ex post tracking error to remain within a given tolerance margin.

Majority Gate for Nanomagnetic Logic With Perpendicular Magnetic Anisotropy

A majority gate for nanomagnetic logic with perpendicular magnetic anisotropy is presented. A novel technique of local focused ion beam irradiation generating artificial domain wall nucleation centers is used to enable directed signal flow and logic computation in an array of field-coupled nanomagnets. The switching behavior of the majority gate is characterized and logic operation is experimentally proven using magneto-optical and magnetic force microscopy. The findings are supported by numerical and micromagnetic simulations. Tolerance margins for fabrication and computing frequencies for correct operation are explored. The presented majority gate allows for complex, non-volatile logic with synchronous global clocking at room-temperature.

Performance criteria to evaluate air quality modeling applications

A set of statistical indicators fit for air quality model evaluation is selected based on experience and literature: The Root Mean Square Error (RMSE), the bias, the Standard Deviation (SD) and the correlation coefficient (R). Among these the RMSE is proposed as the key one for the description of the model skill. Model Performance Criteria (MPC) to investigate whether model results are ‘good enough’ for a given application are calculated based on the observation uncertainty (U). The basic concept is to allow for model results a similar margin of tolerance (in terms of uncertainty) as for observations. U is pollutant, concentration level and station dependent, therefore the proposed MPC are normalized by U. Some composite diagrams are adapted or introduced to visualize model performance in terms of the proposed MPC and are illustrated in a real modeling application. The Target diagram, used to visualize the RMSE, is adapted with a new normalization on its axis, while complementary diagrams are proposed. In this first application the dependence of U on concentrations level is ignored, and an assumption on the pollutant dependent relative error is made. The advantages of this new approach are finally described.

The efficacy and safety of Tolvaptan on treating congestive heart failure patients with hyponatremia

ObjectiveTo evaluate the efficacy and safety of Tolvaptan on treating congestive heart failure patients with hyponatremia.MethodsThis randomised double-blind placebo–controlled trial enrolled 65 patients with congestive heart failure and hyponatremia (serum...