Top PDF Cluster observations and theoretical identification of broadband waves in the auroral region

Cluster observations and theoretical identification of broadband waves in the auroral region

Cluster observations and theoretical identification of broadband waves in the auroral region

density ratio between the hot and the cold component is 3/2. Reasonable parallel drift velocities can be read from the sec- ond and third panels. The second panel shows parallel and perpendicular bulk velocities for the cold component, that is, velocities are calculated integrating over energies in the range 0–1000 eV. The third panel presents corresponding pa- rameters for the hot component. Seconds prior to our event at 14:31:18–14:31:19 UT there are dips in the parallel ve- locities (i.e. larger parallel drifts anti-parallel to the ambient magnetic field). We regard these large drifts neither as nec- essary for the intense wave burst nor as representative of the whole time period and therefore use more moderate drifts. Hence, the parallel drift of the cold component is approxi- mated to −70 km/s. The minus sign indicates that the ions drift anti-parallel to the background magnetic field, that is, upward from the ionosphere. The drift velocity of the hot component is set to zero, as the observed drift is just a small fraction of the thermal velocity and is not likely to affect the wave mode structure.
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Cluster observations of surface waves on the dawn flank magnetopause

Cluster observations of surface waves on the dawn flank magnetopause

A significant volume of work exists on the role of the KHI at the magnetopause, from a theoretical (Dungey, 1955; Southwood, 1968; Southwood and Hughes, 1983; Pu and Kivelson, 1983a, b), observational (Ogilvie and Fitzenre- iter, 1989; Fitzenreiter and Ogilvie, 1995; Kivelson and Chen, 1995; Fairfield et al., 2000) and simulation point of view (Muira, 1995 and references therein, Otto and Fair- field, 2000; Nykyri and Otto, 2001). A comprehensive case study of magnetopause waves was carried out by Chen et al. (1993) (see also Chen and Kivelson, 1993; Kivelson and Chen, 1995), where they compared boundary observations made by ISEE-1 and -2 to MHD simulations reported by Miura (1990). These authors determined the normals of the inbound and outbound magnetopause crossings by calculat- ing the cross product of vectors measured simultaneously on opposite sides of the boundary. They suggested that the re- sults were consistent with a symmetric tilting of the normals, such that the boundary wave would be of a non-sinusoidal na- ture. Interestingly, the results were consistent with the lead- ing, downtail edges of the boundary waves being much shal- lower (i.e. less inclined from a nominal magnetopause orien- tation) than the trailing, sunward-facing edge. The waveform is thus somewhat akin to a wedge shape moving tailwards, with the thinnest edge leading. These observational results are at odds with theory, which suggests that the steepened- face of the boundary wave should be at the leading (more tail- ward) edge (Miura, 1990). However, more recently, Fairfield et al. (2000) compared GEOTAIL observations to the MHD simulation results from a companion paper by Otto and Fair- field (2000). In this case, the observations were consistent with the simulations, with the steepening of the leading edge of the waves (downtail side), as predicted by KHI theory. The reason for this discrepancy is not clear. Kivelson and Chen (1995) suggest that the magnetic curvature forces at the low shear boundary induce these steepened trailing edges. Fair- field et al. (2000) raise a question about the applied meth- ods of determining the boundary normal directions in Chen et al. (1993); small-scale variations along the boundary and the incorrect determination of the boundary dimensions itself (compared to the separation scale of the spacecraft) could produce the erroneous results in the two-spacecraft method applied by Chen et al. (1993).
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Observations of nightside auroral plasma upflows in the F-region and topside ionosphere

Observations of nightside auroral plasma upflows in the F-region and topside ionosphere

There is indeed evidence of auroral precipitation be- tween 2200 and 2205 UT (Fig. 2), both in the enhanced- topside and F-region electron temperature, and in the increased electron density at 120- and 200-km altitude. The interval of F-region frictional heating is associated with an elevated perpendicular electric field, which is ob- served approximately 3 min prior to the density enhance- ment and, therefore, apparently situated on the leading edge of the arc. There is no indication of any latitudinal drift of the feature at 2200 UT; the enhancement in ion temperature is observed at all heights simultaneously, which is consistent with the small meridional velocity measured at the time. The F-region ion temperature re- turns to more moderate values between 2200 and 2202 UT, concomitant with a reversal in the zonal vel- ocity from 1200 m s~1 westwards to around 200 m s~1 eastwards, corresponding to a change from a region of large northward electric field to a moderate (\10 mV m~1) southward field. The timing is such that this southward turning of the electric field is coincident with the enhancement in F-region electron temperature. These observations are consistent with ion heating in- duced by a convection velocity shear, as discussed by Ganguli et al. (1994). These authors described how strong- ly sheared flows in the topside ionosphere could generate low-frequency plasma waves, potentially leading to ion heating and thermal ion upflows. The electron heating is seen first at the higher altitudes, indicating an equator- ward drift of perhaps 600 m s~1; this is greater than the meridional velocity measured at 2200 UT at 315 km, but is similar to velocities measured between 2205 and 2210 UT. The increased ionization is also observed first at 200 km, with higher energy precipitation evident later at 120-km altitude. This again is consistent with an equator- ward-drifting field-aligned arc.
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Spatial and temporal characteristics of poloidal waves in the terrestrial plasmasphere: a CLUSTER case study

Spatial and temporal characteristics of poloidal waves in the terrestrial plasmasphere: a CLUSTER case study

Abstract. Oscillating magnetic field lines are frequently ob- served by spacecraft in the terrestrial and other planetary magnetospheres. The CLUSTER mission is a very suitable tool to further study these Alfv´en waves as the four CLUS- TER spacecraft provide for an opportunity to separate spa- tial and temporal structures in the terrestrial magnetosphere. Using a large scaled configuration formed by the four space- craft we are able to detect a poloidal Ultra-Low-Frequency (ULF) pulsation of the magnetic and electric field in order to analyze its temporal and spatial structures. For this purpose the measurements are transformed into a specific field line related coordinate system to investigate their specific ampli- tude pattern depending on the path of the CLUSTER space- craft across oscillating field lines. These measurements are then compared with modeled spacecraft observations across a localized poloidal wave resonator in the dayside plasma- sphere. A detailed investigation of theoretically expected poloidal eigenfrequencies allows us to specify the observed 16 mHz pulsation as a third harmonic oscillation. Based on this we perform a case study providing a clear identification of wave properties such as an spatial scale structure of about 0.67 R E , the azimuthal wave number m≈30, temporal evo-
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Auroral current systems in Saturn's magnetosphere: comparison of theoretical models with Cassini and HST observations

Auroral current systems in Saturn's magnetosphere: comparison of theoretical models with Cassini and HST observations

Within this general scenario, two basic processes have been discussed that may lead to a fall in plasma angular velocity with latitude, and the consequent formation of a ring of upward-directed field-aligned current. The first is plasma production, pick-up, and radial transport from inter- nal gas sources such as planetary moons and rings, leading to sub-corotation of the magnetospheric plasma on closed magnetic field lines (e.g. Hill, 1979; Vasyliunas, 1983; Saur et al., 2004). This is the process believed to produce the “main oval” at Jupiter (Cowley and Bunce, 2001; Hill, 2001; Southwood and Kivelson, 2001), mapping magnetically into the middle magnetosphere (Clarke et al., 1998; Prang´e et al., 1998). However, modelling of the same current system at Saturn based on Voyager plasma angular velocity measure- ments led Cowley and Bunce (2003) to conclude that the field-aligned currents are too weak in this case to result in significant electron acceleration and auroral emission, and also occur at too low latitude to account for the observed auroral oval. The second possibility is the flow shear ex- pected to occur at the boundary between closed field lines that moderately sub-corotate, and open field lines in the po- lar region that strongly sub-corotate according to both the- ory and observation (Isbell et al., 1984; Stallard et al., 2003, 2004). Cowley et al. (2004a) thus suggested that Saturn’s main oval maps to this upward current layer at the boundary between open and closed field lines, a suggestion shown in subsequent modelling to be plausible in terms of accelerated electron and auroral parameters (Cowley et al., 2004b; Jack- man and Cowley, 2006). Similar processes may also occur at Jupiter, forming a component of the auroras lying poleward of the main oval (Cowley et al., 2005).
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Observations of HF-induced instability in the auroral E region

Observations of HF-induced instability in the auroral E region

Below the reflection altitude of the pump wave, the pump wave is in resonance with upper-hybrid oscillations. The res- onance instability (Vaskov and Gurevich, 1984; Mjølhus, 1993) acting at this altitude, a few kilometres below the pump reflection altitude, causes the generation of small-scale (1–10 m) field-aligned density irregularities (striations). Pre- existing irregularities trap the induced upper-hybrid waves, leading to heating of the electrons. Due to plasma transport along the magnetic field lines, the density irregularities are enhanced. The growth of the striations gives rise to anoma- lous absorption of HF waves at the upper-hybrid resonance altitude. Therefore, pump-induced enhanced radar backscat- ter from the pump reflection altitude is usually only observed during the first hundreds of milliseconds of pumping. How- ever, when pumping on a electron gyroharmonic frequency, the growth of striations is suppressed (Honary et al., 1995; Robinson et al., 1996) and enhanced radar backscatter per- sists (Honary et al., 1999).
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WIND observations of coherent electrostatic waves in the solar wind

WIND observations of coherent electrostatic waves in the solar wind

We shall consider the question of how the electrostatic activity observed by the WIND/WAVES experiment depends on the local parameters of the solar wind. The 38-day period considered here is well suited for such an investigation since it exhibits a large range of variations of the physical properties of the solar wind. WIND was more then 85% of the time in the free solar wind i.e. not magnetically connected to the Earth's bow shock. It crossed three high speed ¯ows, two in the Northern magnetic ®eld Hemisphere, one in the Southern Hemi- sphere (Sanderson et al., 1998) and spent a long interval of time in a relatively low speed wind, in both hemispheres (Fig. 8). Six main crossings of the magnetic sector boundary were observed (days 142±143, 150, 158± 159, 165, 168±170 and 176) as well as four reverse interplanetary shocks (days 144, 150, 170 and 177). Unfortunately, however, natural electrostatic activity is observed by the TDS experiment only in regions of the solar wind where the particle density is below N  12 cm ÿ3 , because of the artefacts discussed in Sect. 2. As a consequence, we were not able to make a complete statistical study of the occurrence of the IAC wave activity. Nevertheless, some interesting results have been obtained, which we shall now describe.
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CONTINUOUS CREATION IN THE PROBABILISTIC WORLD OF THE THEOLOGY OF CHANCE

CONTINUOUS CREATION IN THE PROBABILISTIC WORLD OF THE THEOLOGY OF CHANCE

I think we can answer this question in the positive: Yes, He can, because He is the most perfect being and His omnipotence is absolutely unlimited. A very important premise underlying the answer to the last question is that the risk is not so great, or even that it is very small. It is so because the nature and mechanism of the created world ensure with a very high proba- bility that all purposes intended by God will be attained without his causal action in the processes occurring in the world. The emergence of life in the universe is almost inevitable, because the universe is large and old enough, and biochemical mechanisms are very effective. The emergence of sentient beings was also almost inevitable because of longstanding and countless mutations and adaptations of living organisms to their environment. All this was very probable and hence in a sense necessary (inevitable). The great advantage of the non-deterministic world is its own creativity, which is possible because of the chance events happening in a way restricted only by the laws of nature. Thus, if one evolutionary path fails another one is opened. Perhaps a mutation suitable for the growth and development of a given species happened by chance and enabled it to survive in hard con- ditions and further develop. Elasticity and redundancy are very typical for the world of chance, but because of these properties, this world has a large number of possibilities and abilities to develop and regenerate after various natural catastrophes (Łukasiewicz 2006).
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Joint Analysis of the Discount Factor and Payoff Parameters in Dynamic Discrete Choice Games

Joint Analysis of the Discount Factor and Payoff Parameters in Dynamic Discrete Choice Games

contains aggregate prices and quantities for all the US regional markets from the US Geological Survey’s Mineral Yearbook. The other contains the capacities of plants and plant-level information that Ryan has collected for the Portland cement industry in the United States from 1980 to 1998. Data on plants includes the name of the …rm that owns the plant, the location of the plant, the number of kilns in the plant and kiln characteristics. Following Ryan we assume that the plant capacity equals the sum of the capacity of all kilns in the plant and that di¤erent plants are owned by di¤erent …rms. We observe that plants’ names and ownerships change frequently. This can be due to either mergers and acquisitions or to simple changes in the company name. We do not treat these changes as entry/exit movements. We check each observation in the sample using the kiln information (fuel type, process type, year of installation and plant location) installed in the plant. If a plant changes its name but keeps the same kiln characteristics, we assume that the name change is not associated to any entry/exit movement. This way of preparing the data enables us to match most of the summary statistics of plant-level data in Table 2 of Ryan. Any discrepancies most likely can be attributed to the way we treat the change in plants’ names, which may di¤er to Ryan in a
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Determinants and Consequences of   the Website Perceived Value

Determinants and Consequences of the Website Perceived Value

Customer value begins to emerge in the 1990s as an issue of growing interest to business, in particular to marketing at both academic and practitioner levels. This concept is considered to be one of the most significant factors in the success of an organisation and an important element of online shopping (Burke 1999; Pulliam 1999; Klein 1998; Hoffman and Novak 1996). It has been envisioned as a critical strategic weapon in attracting and retaining customers (Lee and Overby, 2004). In this sense, the study in hand focuses on three consequences of the perceived value of the site which are site preference, future patronage intent and e-loyalty. Besides, previous researches (Parasuraman, 1997; Holbrook, 1999) have demonstrated the multi-dimensional and highly context-dependent nature of the perceived value. In the online retailing setting, not only the product itself, but also the web site contributes value to customer. Two fundamental variables are taken in consideration to describe the site quality namely telepresence and flow state.
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Evaluation And Characterization Of Trace Metals Contamination In The Surface Sediment Using Pollution Load Index PLI And Geo-Accumulation Index Igeo Of Ona River Western Nigeria

Evaluation And Characterization Of Trace Metals Contamination In The Surface Sediment Using Pollution Load Index PLI And Geo-Accumulation Index Igeo Of Ona River Western Nigeria

The existence of trace metals in aquatic environments has led to serious concerns about their influence on plant and animal life [2]. Geo-accumulation index is the quantitative measure of the degree of pollution in aquatic sediment. It consists of seven grades ranging from unpolluted to very extremely polluted and the Pollution load index is a quick tool in order to compare the pollution status of different places, the pollution load index is use to determine the pollution severity and its variation along the different sample stations [3]. Heavy metals are chemical elements having atomic weights between 63.546 and 200.590 and a specific gravity that is 5 times greater than that of water. They exist in water in colloidal, particulate and dissolved phases with their occurrence in water bodies being either of natural origin (e.g. eroded minerals within sediments, leaching of ore deposits and volcanism extruded products) or of anthropogenic origin(that is; solid waste disposal, industrial or domestic effluents, harbour channel dredging) [4]. Furthermore, trace toxic metals are not easily removed from the environment nor are readily detoxified or degraded by metabolic activities in the body of the organism, thereby resulting in accumulation [5, 6]. Research has been that, they are no studies on sedimentology and geochemistry of the sediment in Ona River. To provide baseline information and also enlightened the people of the area about the immediate effect of the water body studied, they is need to determine trace metals pollution in sediment using pollution load index and Geo-accumulation Index. This study reports the levels of __________________________
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Identification of boundary heat flux on the continuous casting surface

Identification of boundary heat flux on the continuous casting surface

The numerous experiments show that conductional component of heat transfer corresponding to the direction of casting displacement is very small (this component constitutes about 5% of the heat conducted from the axis to the lateral surfaces), this means that the component div ⎡λ ⎣ ( ) T grad T ⎤ ⎦ can be simplified to the form

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Assessment Of Some Acceleration Schemes In The Solution Of Systems Of Linear Equations.

Assessment Of Some Acceleration Schemes In The Solution Of Systems Of Linear Equations.

Many practical problems can be reduced to systems of linear equations Ax = b, where A, b are known matrices and x is a vector of unknowns. Systems of linear equations play a prominent role in economics, engineering, physics, chemistry, computer science and other fields of Pure and Applied Sciences [2]. A solution to a system of linear equations is a set of numerical values ….. that satisfies all the equations in a system [1]. There are two classes of iterative methods [3]: linear stationary and linear nonstationary. The stationary iterative methods are the Jacobi, Gauss-Seidel and SOR and Nonstationary include Krylov subspace methods: Conjugate Gradient, Minimal Residual, Quasi-Minimal Residual, Generalizes Minimal Residual and Biconjugate gradient methods. The choice of a method for solving linear systems will often depend on the structure of the matrix A. According to [8] ideally, iterative methods should have the property that for any starting vector , it converges to a solution Ax = b. [5] is of the view that examination of the Jacobi iterative method shows that in general one must save all the components of the vector while computing the components of the vector for an iterative method. According to Hadjidimos [6], the first step in the construction of solution of stationary iterative methods usually begins with splitting of matrix A. Thus, A = M – N where det M and M is easily invertible so that A = b is equivalent to = T + C , where T = and C = giving the iterative scheme = T + C , (k = 0,1,2……). [2] noted that for systems of linear equation A the splitting matrix may be chosen in a different way; that is, one can split matrix A as A = D L U where D is the diagonal matrix, L and U are strictly lower and strictly upper triangular matrices respectively. In solving the systems of linear equations Ax = b, therefore, we consider any convergent method which produces a sequence of iterates { [7] .Quite often the convergence is too slow and it has to be accelerated. According to [9] to improve the convergence rate of the basic iterative methods, one may transform the original system A = b into the preconditioned form PA = Pb, where � is called the preconditioned or a preconditioning matrix. Convergent numerical sequences occur quite often in natural Science and Engineering. Some of such sequences converge very slowly and their limits are not available without suitable convergent acceleration method. Some known acceleration schemes are: Chebyshev Extrapolation scheme [4] and residual Smoothing.
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Investigating The Use Of Mobile Computing In Zimbabwe Polytechnics Case Of A Polytechnic In Zimbabwe

Investigating The Use Of Mobile Computing In Zimbabwe Polytechnics Case Of A Polytechnic In Zimbabwe

). This shows that there has been upgrading and improvement in mobile computing device characteristics since Zimm erman’s research up to now. Dahlstrom (2012), a senior research analyst at EDUCAUSE, in his article titled ―Executive Summary: Student Mobile Computing Practices—lessons learned from Qatar‖ says that students find Mobile technology convenient and engaging and institutions need to invest more in mobile device use and support. In Qatar the Education City conducted a survey jointly with ECAR (Every Child a Reader) of United Kingdom (UK) on student mobile computing technology and the results were not only relevant to their student’s experiences but also speaks to the global revolution of mobile technology in the academic environment. The findings revealed that, for students, technology plays an important role in productivity and communication, students want technology integrated into their academic experience and students want to better utilise mobile technology in their learning environments doing such things as creating content for course assignments, accessing course related material and pushing the limits of mobile device productivity. Kim et al (2006) identified the benefits of using mobile wireless phones as freedom of location and time, increasing speed in teaching and learning, enabling one-to-one learning based on individual educational histories or test results, better communication opportunities and better collaboration in group discussions. They also identified the specific benefits of using Personal Data Assistants in m-learning as mobility, information management capacity, beaming capability, ability to work in many places and replacement of pen and paper. A UK essays website argued that the major challenge for educators and trainers is how to develop learning materials for delivery on
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T H E PAT H F R O M R E S E A R C H T O H U M A N B E N E F I T

T H E PAT H F R O M R E S E A R C H T O H U M A N B E N E F I T

The H eard Island experiment launched the Acoustic Thermometry of O cean Climate (ATO C) project, led by Walter Munk at Scripps and involving scientists from 13 countries in 1992. A key objective is to establish baseline ocean temperatures in the Pacific against which changes can be measured. Because of concern about the effects that the sounds might have on marine mammals, the ATO C transmis- sions were delayed until 1996. H owever, in April 1994, a team of U .S. and Russian scientists led by Peter Mikhalevsky at Science Applications International Corporation transmitted sound across the Arctic O cean and made a startling discovery. This Transarctic Acoustic Propagation (TAP) experiment not only proved the feasibility of long-range acoustic thermom- etry in the ice-covered Arctic, but the travel-time mea- surements revealed an average warming of approxi- mately 0.4 degree Celsius [0.72 degrees Fahrenheit], when compared to historical temperature measure- ments, at the mid-depths of the Arctic O cean along the propagation path. Extensive measurements by submarines and ice-breakers have subsequently docu- mented this pervasive temperature change in the Arctic O cean, which is now the focus of intensive new research. The TAP experiment launched the joint U .S. and Russian Arctic Climate O bservations using U nderwater Sound (ACO U S from the Greek, akouz, meaning “listen!”) program in 1995.
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Evaluation of susceptibility of the ZRE1 alloy to hot cracking in conditions of forced strain

Evaluation of susceptibility of the ZRE1 alloy to hot cracking in conditions of forced strain

In order to evaluate the susceptibility to hot cracking in the high-temperature brittleness range, we have determined the changes of temperature of individual points when the alloy was cooled down from the solidus temperature. The tests were performed on the cylindrical Ø 10 x 120 mm specimens, using the Gleeble 3800 simulator, at Iron Metallurgy Institute in Gliwice. Four S-type thermocouples were pressure welded to the specimens: in the specimen axis and 2, 5 and 8 mm away from the axis. The specimens were fixed in copper holders, keeping a constant distance of 33 mm, and then were heated in the argon atmosphere at the 20 0 C/s rate to the temperature of liquid phase appearance, and were afterwards freely cooled. Changes in
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	Field Cancerisation of the Upper Aerodigestive Tract: Screening for Second Primary Cancers of the Oesophagus in Cancer Survivors

Field Cancerisation of the Upper Aerodigestive Tract: Screening for Second Primary Cancers of the Oesophagus in Cancer Survivors

41. Wang WL et al. The beneit of pretreatment esophageal screening with image-enhanced endoscopy on the survival of patients with hypopharyngeal cancer. Oral Oncol. 2013;49(8):808-13. 42. de Monès E et al; Socéité Française de l’Otorhinolaryngologie. Initial staging of squamous cell carcinoma of the oral cavity, larynx and pharynx (excluding nasopharynx). Part 2: Remote extension assessment and exploration for secondary synchronous locations outside of the upper aerodigestive tract. 2012 SFORL guidelines. Eur Ann Otorhinolaryngol Head Neck Dis. 2013;130(2):107-12.
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Synthesis of nanoparticeles in ductile iron with small additions of vanadium and niobium and its mechanical properties

Synthesis of nanoparticeles in ductile iron with small additions of vanadium and niobium and its mechanical properties

mechanical grinding and polishing. Back scattered electrons (BSE) were utilized in SEM in order to reveal difference in chemical compositions of microcomponents present in particular samples. The SEM investigations were used to reveal the distribution of graphite and other big particles. Transmission electron microscopy (TEM), on the other hand, was applied for examination of nanosized secondary precipitates, i.e. vanadium or niobium carbides and/or nitrides (or carbonitrides). The thin foil technique was implemented for this purpose. The 3 mm disks were ground down on sand papers and then dimpled to about 0.1 mm thickness. Afterwards the disks were further thinned in an ion mill until a perforation had appeared. The TEM investigation was carried out by means of a JEOL 2010 ARP analytical scanning transmission electron microscope operating at acceleration voltage of 200 kV. Imaging was performed by conventional transmission mode while for chemical analysis (X-ray Energy Dispersive Spectroscopy - EDS) the nanoprobe mode was utilized. The nanoprobe mode enabled to obtain electron probes approaching a few nanometers in diameter (practically about 10 nm because at smaller electron probes the number of X-ray counts is usually too low for analysis). The EDS analysis was performed by Oxford-Link system attached to the microscope. The Oxford- Link system was equipped with Si(Li) detector. This system detects all elements down to boron. In order to examine the crystallography of precipitates the Selected Area Diffraction (SAD) patterns analysis was also performed.
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Current-voltage relationship in the auroral particle acceleration region

Current-voltage relationship in the auroral particle acceleration region

The above features in electron distribution functions in- dicate that the particle acceleration region often varies in time, which is inconsistent with the time-stationary assump- tion of Knight’s model. We emphasize that the low-energy electrons, which contribute to the currents in such a time- variable case, exist in the “forbidden” region of phase space in the time-stationary model. When we consider the time- variability of the acceleration region, the ionospheric cold electron, which successfully moves into the inverted-V re- gion from the edge region, can be a candidate for the low- energy electrons which contribute to the current. However, the pitch angle of such electrons will probably be very small, which is inconsistent with our result that a part of the field- aligned current is carried by the electrons in the “forbidden” region. In addition, they can only explain the low-energy electrons at a narrow edge area of the acceleration region, as mentioned above. Therefore, the ionospheric electrons can- not be a charge carrier of the filed-aligned current.
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Buying Behavior Of Organic Vegetables Product The Effects Of Perceptions Of Quality And Risk

Buying Behavior Of Organic Vegetables Product The Effects Of Perceptions Of Quality And Risk

quality of alternatives with regard to price within a category (Jin & Suh, 2005). Organic vegetable products have advantages and technologies related of environmental friendly. Perceived quality is not the actual quality of the brands or products. Rather, it is the consumers’ judgment about an entity’s or a service’s overall excellence or superiority (Aaker, 1991). Sometimes is directly related to the reputation of the firm that manufactures the product (Davis et al. 2003), and viewed as the degree and direction of discrepancy between consumers’ perceptions and expectations (Chen & Chang, 2005). Perceived quality and perception of quality had closer theoretical, perception defined is the mental process that persons go through in selecting, organizing and interpreting information into meaningful patterns (Truong & Yap, 2010:532). It can be interpreted that perception of quality is overall judgment of superior quality of organic products as result from selecting, organizing and interpreting form the alternative product. Measurement of customer perception of quality on organic products is divide on several things, included guarantee (origin, brand, label, variety), organoleptic characteristic (firmness, color, flavor, aroma), and external factors (damage, size, price) (Carrasco et al., 2012:1422). In other side on organic product it measured with environmental concern, environmental consideration, environmental performance, environmental image, and environmental reputation (Chen & Chang, 2013:71).
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