Actual Physical Size Research Articles

Influence of avalanche transistor switching mode on waveform characteristics of solid-state pulse source.

The design of the Marx circuit based on avalanche transistors (ATs) is one of the effective techniques for developing solid-state pulse sources to generate nanosecond pulses. However, the influence of the avalanche transistor as a switching device on the output pulse characteristics is still unclear. In this study, investigating the switching mechanism of the AT with a mixed-mode simulation of the semiconductor device has been accomplished. An experiment has checked the simulation model's transient switching characteristics. The switching mechanisms of ATs in the Marx circuit were divided into base triggering mode (BTM) and voltage ramp mode (VRM). This paper proposes a modified circuit for adjusting the output pulse parameters of solid-state pulse sources. The results show that to satisfy the simulation accuracy, the width parameter of the AT model in the BTM must be 100μm, much less than the actual physical size. Because of the higher electric field when the initial impact ionization occurs, the AT operates at a higher switching speed in the VRM than in the BTM. In addition, since the carriers of initial impact ionization locate at the p-n0 interface or the n0-n+ interface, the AT switching process will oscillate in the VRM. All ATs in the modified Marx circuit switch to operate in the BTM. The leading edge of the output pulse increases from 275 to 1125ps, and the pulse trailing oscillation has disappeared. The research results provide an important technical means for optimizing the output waveform of solid-state pulse sources.

Deep grey matter quantitative susceptibility mapping from small spatial coverages using deep learning

IntroductionQuantitative Susceptibility Mapping (QSM) is generally acquired with full brain coverage, even though many QSM brain-iron studies focus on the deep grey matter (DGM) region only. Reducing the spatial coverage to the DGM vicinity can substantially shorten the scan time or enhance the spatial resolution without increasing scan time; however, this may lead to significant DGM susceptibility underestimation. MethodA recently proposed deep learning-based QSM method, namely xQSM, is investigated to assess the accuracy of dipole inversion on reduced brain coverages. The xQSM method is compared with two conventional dipole inversion methods using simulated and in vivo experiments from 4 healthy subjects at 3T. Pre-processed magnetic field maps are extended symmetrically from the centre of globus pallidus in the coronal plane to simulate QSM acquisitions of difference spatial coverages, ranging from 100% (∼32mm) to 400% (∼128mm) of the actual DGM physical size. ResultsThe proposed xQSM network led to the lowest DGM contrast loss in both simulated and in vivo subjects, with the smallest susceptibility variation range across all spatial coverages. For the digital brain phantom simulation, xQSM improved the DGM susceptibility underestimation more than 20% in small spatial coverages, as compared to conventional methods. For the in vivo acquisition, less than 5% DGM susceptibility error was achieved in 48mm axial slabs using the xQSM network, while a minimum of 112mm coverage was required for conventional methods. It is also shown that the background field removal process performed worse in reduced brain coverages, which further deteriorated the subsequent dipole inversion. ConclusionThe recently proposed deep learning-based xQSM method significantly improves the accuracy of DGM QSM from small spatial coverages as compared with conventional QSM algorithms, which can shorten DGM QSM acquisition time substantially.

Addressing Rage: The Fast Fashion Revolt

Addressing Rage: The Fast Fashion Revolt

Modeling of a passive scalar transport from thermal power plants to atmospheric boundary layer

At the moment, there is a tendency to increasing the number of thermal power plants (TPPs); this trend can be associated with industrial development and energy consumption growth. This paper discusses the numerical simulation of the pollution movement from activities of the TPP and the study of the pollution concentration level at various distances from the emission source in actual atmospheric conditions. The approbation of the numerical algorithm and the mathematical model was performed using 2D and 3D test problems. The obtained computational values were compared with measured values and computational values of other authors. In addition, the distribution of pollution in the 3D case was investigated on an actual physical size. The Ekibastuz TPP-1 coal-fired power plant was taken as a real example. A distinctive feature of this TPP is that pollution is emitted from two chimneys of different heights ( $$H_{H} = 330$$ and $$H_{L} = 300$$ m). The obtained values illustrated that, due to the difference between the height of the chimney ( $$H_{H} - H_{L} = 30$$ m), the pollution concentration from the higher chimney ( $$H_{H} = 330$$ m) was fell down far away from the emission source than from the lower chimney ( $$H_{L} = 300$$ m) (2160 and 1970 m, respectively). From the obtained data from computation, it can be argued that the construction of higher chimneys reduces the harmful effects of emissions on the environment. Also, the obtained results will help to predict the optimal and safe distance from cities or settlements during the construction of new thermal power plants.

Study of the Relationship between Body Mass Index, Body Image, and Lifestyle Behaviors: A Community Survey in Fiji.

Introduction: Public health promotion efforts aimed at overweight and obesity prevention often proceed from the premise that the first step should be losing weight. Appropriate perceptions of body image may be important for improving weight loss awareness. Therefore, we aimed to examine the relationship between body mass index and body image perception in Fiji, where increasing obesity is currently the most important health-related issue. Methods: Using the resident register based on the governmental census, one household member, aged between 18 and 69 years, was randomly selected from each household in two areas. There were 1,014 participants in the study. The questionnaire items were related to body image, dietary behaviors, physical activity, smoking habits, and alcohol consumption habits. Moreover, information regarding height, weight, blood pressure, and hemoglobin A1c were measured, and questions about social status (age, ethnicity, education, marital status, and employment), and subjective living status were asked. A multivariate logistic regression analysis was performed to analyze the relationship between body mass index (BMI) and body image perception. Results: Data from 391 men and 537 women were analyzed. Men within higher BMI quartiles smoked less (p = 0.0004) and drank less alcohol (p = 0.042). Women in higher BMI quartiles engaged in less physical activity (p = 0.022). Among the assessed data, both men and women in the higher BMI quartiles underestimated their body image compared with their actual physique (p < 0.0001). The higher BMI was associated with underestimated body image (men: odds ratio [OR] = 3.22, 95% confidence interval [CI], 1.94–5.35; p < 0.0001; women: OR = 18.11, 95% CI, 10.10–32.47; p < 0.0001). Conclusions: Higher BMI is strongly associated with underestimated body image among Fiji residents. Health-related counseling should be included within programs that aim to increase recognition of one’s actual physical size.

Design of magneto-acoustic-electrical detection system and verification of its linear sweep theory

Clinical studies had demonstrated that early diagnosis of lesion could significantly reduce the risk of cancer. Magneto-acoustic-electrical tomography (MAET) is expected to become a new detection method due to its advantages of high resolution and high contrast. Based on thinking of modular design, a low-cost, digital magneto-acoustic conductivity detection system was designed and implemented in this study. The theory of MAET using chirp continuous wave excitation was introduced. The results of homogeneous phantom experiment with 0.5% NaCl clearly showed that the conductivity curve of homogeneous phantom was highly consistent with the actual physical size, which indicated that the chirp excitation theory in our proposed system was correct and feasible. Besides, the resolution obtained by 1 000 μs sweep time was better than that obtained by 500 μs and 1 500 μs, which means that sweep time is an important factor affecting the detection resolution of the conductivity. The same result was obtained in the experiments carried out on homogeneous phantoms with different concentrations of NaCl, which demonstrated the repeatability of our proposed MAET system.

Apparent beam size definition of focused ion beams based on scanning electron microscopy images of nanodots

In this paper, the new term apparent beam size of focused ion beam (FIB) is introduced and an original method of its evaluation is demonstrated. Traditional methods of measuring the beam size, like the knife edge method, provide information about the quality of the beam itself, but practically, they do not give information on the FIB sputtering resolution. To do this, it is necessary to take into account the material dependent interaction of the beam with the specimen and the gas precursor in the vacuum chamber. The apparent beam size can be regarded as the smallest possible dot that FIB can sputter in a given specimen. The method of evaluating it, developed in this paper, is based on the analysis of a series of scanning electron images of FIB produced nanodots. Results show that the apparent beam size can be up to five times larger than the actual physical size of the beam and it is significantly influenced by the presence of gas precursor. It is also demonstrated that the apparent beam size can be used as a reference value for optimization of the beam step during raster scanning.

GPI-Anchored Proteins do not Reside in Ordered Domains in the Live Cell Plasma Membrane

The organization and dynamics of proteins and lipids in the plasma membrane, and their role in membrane functionality, have been subject of a long-lasting debate. Specifically, it is unclear to what extent membrane proteins are affected by their immediate lipid and protein environment and vice versa. Studies on model membranes and plasma membrane spheres indicated characteristic preferences of proteins for ordered or disordered lipid phases, however, whether such phases do indeed exist in live cells is still not known. Here, we used a micropatterning approach combined with super-resolution microscopy to quantify the influence of a glycosylphosphatidylinositol-anchored protein (GPI-AP) - a typical marker of ordered lipid phases - on its molecular environment directly in the live cell plasma membrane. Intriguingly, local enrichment and immobilization of a GPI-anchored mGFP - even at highest densities - did not nucleate the formation of ordered membrane regions. At a molecular scale, immobilized mGFP-GPIs essentially behaved as inert obstacles that reduced the mobility of other membrane constituents according to their molecular size and shape. Overall we conclude that GPI-APs do not significantly influence their membrane environment over distances beyond their actual physical size. Further, our results imply that the outer leaflet of the plasma membrane is in a homogenously mixed single phase state under physiological conditions.

Functional and Structural mapping of the somatosensory homunculus in the newborn brain

The human body’s representation within the primary somatosensory cortex of the brain is highly organized, and can be topographically mapped as a “homunculus”. Specific areas of the body are represented in particular regions (the upper body infero-laterally, and the lower body supero-medially) and others are seemingly over-represented due to their rich neural innervation in comparison to their actual physical size (such as the lips and tongue). How and when this representation emerges in early human brain development has not been explored, although animal models suggest both activity-dependent and genetic factors are involved during a critical period equivalent to the second and third trimester [1].

A Size–Distance Scaling Demonstration Based on the Holway–Boring Experiment

We explored size–distance scaling with a demonstration based on the classic Holway–Boring experiment. Undergraduate psychology majors estimated the sizes of two glowing paper circles under two conditions. In the first condition, the environment was dark and, with no depth cues available, participants ranked the circles according to their angular sizes. In the second condition, the environment was illuminated and, with depth cues available, the students ranked the circles according to actual physical size. The demonstration replicated the key elements of the original experiment, and objective and subjective measures indicated that it improved understanding of size–distance scaling. We also describe variants of the experiment suitable for different instructional environments.

Broad-Band Near-Infrared Plasmonic Nanoantennas for Higher Harmonic Generation

We propose a broad-band near-infrared trapezoidal plasmonic nanoantenna, analyze it numerically using finite integration and difference time domain techniques, and explain qualitatively its performance via a multidipolar scenario as well as a conformal transformation. The plasmonic nanoantenna reported here intercepts the incoming light as if it were of cross-sectional area larger than double its actual physical size for a 1500 nm bandwidth expanding from the near-infrared to the visible spectrum. Within this bandwidth, it also confines the incoming light to its center with more than 1 order of magnitude field enhancement. This wide-band operation is achieved due to the overlapping of the different dipole resonances excited across the nanoantenna. We further demonstrate that the broad-band field enhancement leads to efficient third harmonic generation in a simplified wire trapezoidal geometry when a Kerr medium is introduced, due to the lightning rod effect at the fundamental and the Purcell effect at the induced third harmonic.

Localization of 5S and 25S rRNA genes on somatic and meiotic chromosomes in Capsicum species of chili pepper.

The loci of the 5S and 45S rRNA genes were localized on chromosomes in five species of Capsicum, namely, annuum, chacoense, frutescens, baccatum, and chinense by FISH. The 5S rDNA was localized to the distal region of one chromosome in all species observed. The number of 45S rDNA loci varied among species; one in annuum, two in chacoense, frutescens, and chinense, and four in baccatum, with the exceptions that 'CM334' of annuum had three loci and 'tabasco' of frutescens had one locus. 'CM334'-derived BAC clones, 384B09 and 365P05, were screened with 5S rDNA as a probe, and BACs 278M03 and 262A23 were screened with 25S rDNA as a probe. Both ends of these BAC clones were sequenced. FISH with these BAC probes on pachytenes from 'CM334' plant showed one 5S rDNA locus and three 45S rDNA loci, consistent with the patterns on the somatic chromosomes. The 5S rDNA probe was also applied on extended DNA fibers to reveal that its coverage measured as long as 0.439 Mb in the pepper genome. FISH techniques applied on somatic and meiotic chromosomes and fibers have been established for chili to provide valuable information about the copy number variation of 45S rDNA and the actual physical size of the 5S rDNA in chili.

Lightness and brightness

Lightness and brightness

An Astrometric Calibration of theMV-PorbRelationship for Cataclysmic Variables based onHubble Space TelescopeFine Guidance Sensor Parallaxes

We present new, high-precision astrometric parallaxes for three cataclysmic variables: WZ Saggitae, YZ Cancri, and RU Pegasi, obtained using the Fine Guidance Sensors on the Hubble Space Telescope. The addition of these three parallaxes to the existing data set allows us to examine the outburst luminosities for dwarf novae spanning the orbital period range 1.36 hrPorb � 8.99 hr. We find that, after correcting for the orbital inclination, there is a simple linear relationship between the absolute visual magnitude at outburst and the orbital period. Such a relationship suggests that the only difference in the outbursts between long- and short-period systems is the actual physical size of their accretion disks. When we compare the rare outbursts of three intermediate polar systems (EX Hydrae, TV Columbae, and V1223 Sagittarii), and the visual high states of the nova-like variable RW Tri, four other cataclysmic variables with published HST parallaxes, with the new MV-Porb relationship derived for the dwarf novae, we find that the absolute visual magnitudes during the ''outbursts'' of these four systems attain the luminosity predicted for their orbital period. This suggests that these short-lived outbursts may also be steady state accretion events like the eruptions of dwarf novae.

Temporal precision of interceptive action: differential effects of target size and speed

The duration of movements made to intercept moving targets decreases and movement speed increases when interception requires greater temporal precision. Changes in target size and target speed can have the same effect on required temporal precision, but the response to these changes differs: changes in target speed elicit larger changes in response speed. A possible explanation is that people attempt to strike the target in a central zone that does not vary much with variation in physical target size: the "effective size" of the target is relatively constant over changes in physical size. Three experiments are reported that test this idea. Participants performed two tasks: (1). strike a moving target with a bat moved perpendicular to the path of the target; (2). press on a force transducer when the target was in a location where it could be struck by the bat. Target speed was varied and target size held constant in experiment 1. Target speed and size were co-varied in experiment 2, keeping the required temporal precision constant. Target size was varied and target speed held constant in experiment 3 to give the same temporal precision as experiment 1. Duration of hitting movements decreased and maximum movement speed increased with increases in target speed and/or temporal precision requirements in all experiments. The effects were largest in experiment 1 and smallest in experiment 3. Analysis of a measure of effective target size (standard deviation of strike locations on the target) failed to support the hypothesis that performance differences could be explained in terms of effective size rather than actual physical size. In the pressing task, participants produced greater peak forces and shorter force pulses when the temporal precision required was greater, showing that the response to increasing temporal precision generalizes to different responses. It is concluded that target size and target speed have independent effects on performance.

Aerothermal Model for Real-Time Digital Simulation of a Mixed-Flow Turbofan Engine

Thispaperpresents awayto simplifyanexplicitly time-integrated,aerothermodynamictransientmodelofa twinspool,mixed- ow turbofan engine based on state variables and control volumesapproach such that computational performance becomes suitable for real-time digital simulation. The key simpliŽ cation lies in the modeling of main mixer, in which the mixing of core and bypass streams takes place. The number of state variables in an existing thermodynamicmodel has been reduced to six from nine by assuming that, instead of a uniform rate of static pressure rise, the static pressure is uniform across the main mixer. Computational time decreases primarily because the model is now less sensitive to pressure dynamics, thus allowing a larger integration time step. The accuracy of transient simulationsis also less affected by artiŽ cial increases in actual physical size of controlvolumes, permitting further increase in integration time step. Numerical experiments show that simpliŽ ed mixer modeling together with an increase in control volumes size by a factor of three resulted in an integration time step of 1.2 ms. It enables the model to run in real time on a stateof-the-art personal computer type of digital platform, without loosing the accuracy and numerical stability of the analysis. The formulation,validation,and real-time capabilities of the proposed methodology are discussed.

Sequential priming in hierarchically organized figures: effects of target level and target resolution.

Three experiments are reported in which participants identified target letters that appeared at either the global or local level of hierarchically organized stimuli. It has been previously reported that response time is facilitated when targets on successive trials appear at the same level (L. M. Ward, 1982; L. C. Robertson, 1996). Experiments 1 and 2 showed that this sequential priming effect can be mediated by target-level information alone, independent of the resolution, or actual physical size, of targets. Target level and resolution were unconfounded by manipulating total stimulus size, such that global elements of the smaller stimuli subtended the same amount of visual angle as local elements of the larger stimuli. Experiment 3, however, showed that when level information is less useful than resolution in parsing targets from distractors, resolution does become critical in intertrial priming. These data are discussed as they relate to the role of attention in local vs. global (part vs. whole) processing.

Differences between male and female college lean sport athletes, nonlean sport athletes, and nonathletes on behavioral and psychological indices of eating disorders

Abstract This study examined the relative frequency of behavioral and psychological indices of eating disorders in collegiate athletes and nonathletes. Participants were 230 male and 250 female nonathletes. and 187 male and 113 female varsity athletes. The male and female athletes were classified separately as either in a lean sport (i.e., where weight or appearance was central to success) or a nonlean sport and then compared with their nonathlete counterparts. After controlling for the effects of actual physical size, multivariate analyses revealed that (a) female athletes in lean sports were more weight preoccupied than nonlean sport female athletes and female nonathletes, (b) nonathletes, both male and female, expressed more dissatisfaction with their bodies than both of their respective athlete comparison groups, and (c) nonathletes, both male and female, felt less worthwhile and less effective in their lives than their respective gender's nonlean sport athletes. These findings are discussed in terms ...

A new analogue scale for assessing children's pain: an initial validation study

A new instrument was designed to provide a practical clinical measure for assessing children's pain intensity and pain affect. The pocket size measure includes a Coloured Analogue Scale (CAS) to assess intensity and a facial affective scale to assess the aversive component of pain. Both scales have numerical ratings on the back, so that the person administering it can quickly note the numbers that represent a child's pain. This study was conducted to determine: the validity of the new instrument by evaluating the psychophysical properties of the intensity scale and by evaluating the discriminant validity of the intensity and affective scales. Since visual analogue scales (VAS) are valid and reliable measures for assessing children's pain, children's ability to use the new analog scale was compared with their performance on a VAS. Children's ability to rate pain affect using an affective scale, in which the 9 faces on a Facial Affective Scale (FAS) are presented in an ordered sequence from least to most distressed, was compared to their performance on the original FAS, in which the same faces were presented in a random order. Using a parallel groups design, 104 children (5–16 years; 60 female, 44 male; 51 healthy and 53 with recurrent headaches) were randomized into two groups: CAS or VAS. Children used the assigned scale to complete a calibration task, in which they rated the sizes of 7 circles varying in area (491, 804, 1385, 2923, 3848, 5675 and 7854 mm 2). The psychophysical function relating perceived circle size to actual physical size was determined for the CAS and VAS. Children's CAS and VAS responses on the calibration task yielded similar mathematical relationships; Φ cas = 0.035 I 0.87, Φ vas = 0.027 I 0.89, where Φ = perceived magnitude and I = stimulus intensity. The R 2 values were 0.921 and 0.922 for the CAS and VAS groups, respectively. Analyses of covariance revealed no significant differences in the characteristics of these relationships, i.e., R 2, slope, or y intercept, by scale type. Children used the same scale to complete the Children's Pain Inventory (CPI), in which they rated the intensity and affect of 16 painful events (varying in nature and extent of tissue damage). Children's CAS and VAS responses on the CPI were similar. Analyses of covariance indicated that there were no differences in either intensity or affective ratings by scale type. However, the mean number of painful events experienced by children increased significantly with age ( P = 0.0001). Intensity ratings decreased significantly with age ( P = 0.002), but affective ratings did not vary with age. The new instrument has equivalent psychometric properties to a 165 mm VAS. However, the CAS was rated as easier to administer and score than the VAS, so it may be more practical for routine clinical use. Since the CAS has fulfilled the first two criteria for a pain measure (psychophysical properties and discriminant validity), it is ethical to proceed with the formal definitive test for construct validity, in which children from various clinical populations use the CAS scale to assess their own pain.

X-ray photoemission of polynuclear aromatic carbon

The evolution of the C(1s) x-ray photoelectron spectrum is examined as a function of the size of the polynuclear aromatic molecules. The transition from a symmetric line shape to an asymmetric one occurs in the narrow range of the layer size between 10 and 22 Å. It is shown that the asymmetry reflects the area of the layer over which the π electrons can be delocalized and that it is more closely related to the actual physical size of the layer than measurements from x-ray diffraction. The latter is illustrated in coal tars which have undergone heat treatment. The effect of the evolution of the line-shape asymmetry on the determination of the fraction of polynuclear aromatic carbon in heterogeneous carbon materials by x-ray photoelectron spectroscopy is also discussed.