Changes In Total Intensity Research Articles

MagMaR III—Resisting the Pressure, Is the Magnetic Field Overwhelmed in NGC6334I?

We report on Atacama Large Millimeter/submillimeter Array observations of polarized dust emission at 1.2 mm from NGC6334I, a source known for its significant flux outbursts. Between five months, our data show no substantial change in total intensity and a modest 8% variation in linear polarization, suggesting a phase of stability or the conclusion of the outburst. The magnetic field, inferred from this polarized emission, displays a predominantly radial pattern from northwest to southeast with intricate disturbances across major cores, hinting at spiral structures. Energy analysis of CS (J = 5 → 4) emission yields an outflow energy of approximately 3.5 × 1045 erg, aligning with previous interferometric studies. Utilizing the Davis–Chandrasekhar–Fermi method, we determined magnetic field strengths ranging from 1 to 11 mG, averaging at 1.9 mG. This average increases to 4 ± 1 mG when incorporating Zeeman measurements. Comparative analyses using gravitational, thermal, and kinetic energy maps reveal that magnetic energy is significantly weaker, possibly explaining the observed field morphology. We also find that the energy in the outflows and the expanding cometary HII region is also larger than the magnetic energy, suggesting that protostellar feedback may be the dominant driver behind the injection of turbulence in NGC6334I at the scales sampled by our data. The gas in NGC6334I predominantly exhibits supersonic and trans-Alfvenic conditions, transitioning towards a super-Alfvenic regime, underscoring a diminished influence of the magnetic field with increasing gas density. These observations are in agreement with prior polarization studies at 220 GHz, enriching our understanding of the dynamic processes in high-mass star-forming regions.

Effects of HiPIMS Duty Cycle on Plasma Discharge and the Properties of Cu Film.

In this paper, Cu thin films were deposited on Si (100) substrates by the high-power impulse magnetron sputtering (HiIPMS) technique, and the effects of different duty cycles (from 2.25% to 5.25%) on the plasma discharge characteristics, microstructure, and electrical properties of Cu thin films were investigated. The results of the target current test show that the peak target current remains stable under 2.25% and 3% duty cycle conditions. Under the conditions of a 4.5% and 5.25% duty cycle, the target peak current shows a decreasing trend. The average power of the target shows a rising trend with the increase in the duty cycle, while the peak power of the target shows a decreasing trend with the increase in the duty cycle. The results of OES show that with the increase in the duty cycle, the total peak intensity of copper and argon emissions shows an overall increasing trend. The duty cycle from 3% to 4.5% change in copper and argon emission peak total intensity change is not obvious. The deposition rate and surface morphology of the copper film were investigated by scanning electron microscopy, and the deposition rate of the copper film increased with the increase in the duty cycle, which was mainly due to the increase in the average power. The surface roughness of the copper film was evaluated by atomic force microscopy. X-ray diffraction (XRD) was used to analyze the grain size and texture of the Cu film, and the results showed that the average grain size of the Cu film increased from 38 nm to 59 nm on the (111) and (200) crystal planes. Four-probe square resistance test copper film resistivity in 2.25%, 3% low duty cycle conditions of the copper film resistivity is generally higher than 4.5%, 5.25% high duty cycle conditions, the copper film resistivity shows the trend of change is mainly affected by the copper film grain size and the (111) face of the double effect of the optimal orientation. The lowest resistivity of the copper film measured under the 4.5% duty cycle condition is 1.7005 μΩ·cm, which is close to the intrinsic resistivity of the copper film of 1.67 μΩ·cm.

Decomposition and macroeconomic drivers of energy intensity: The case of Ethiopia

This study aims to provide a decomposition analysis on aggregate energy intensity in Ethiopia over 1990–2017 using Logarithmic Mean Divisia Index (LMDI) I decomposition method. It also investigates the main driving forces influencing the observed energy intensity trend in the presence of a structural break. The LMDI I decomposition results indicate that the efficiency component has played a prominent role in reducing the overall energy intensity while the contribution of structural component for the change in total intensity has been very negligible. On the other hand, the model estimation results with structural break invariably confirm that economic growth, modern renewable energy, and institutional quality appear to have a significant negative effect on total energy intensity in the long run (contribute positively for energy efficiency improvement) while industrialization and FDI stock tend to induce higher energy intensity. Further, modern renewable energy negatively moderates the effect of growth and industrialization on energy intensity. After all, the results suggest the need for giving a strong emphasis for sector-specific energy efficiency which may have an important implication not only on economic growth but also on environmental sustainability. Policy measures promoting clean energy transformation and better institutional setup also need to be highly encouraged.

Infrared signature of NEPE, HTPB rocket plume under varying flight conditions and motor size

In this study, radiation signatures of rocket plumes based on HTPB and NEPE propellants are simulated under varying altitudes, flight Mach numbers, and motor size. The flow field of plume is calculated by computational fluid dynamics, and the infrared signature is predicted using a Ludwig model. To verify the numerical method, experiments were conducted using small rocket motors and radiometric FTIR. The acceptable agreement between numerical calculation and the experiment was obtained in 2–5 μm wavelength region. The total radiance decreases with increasing altitude whether afterburning exists or not. A decreasing rate in the radiance of the plume with strong afterburning is larger than that of the plume with weak afterburning. The change in total intensity according to altitude depends on the afterburning and is directly affected by the radiating area. As the flight Mach number increases, total radiance, total intensity, and radiating area decrease. The motor size makes radiation intensity increase exponentially; exponent value is from 2.6 to 2.7. As the motor size increases, the effect of altitude increases, while the effect of flight Mach number decreases.

Peculiar spin frequency and radio profile evolution of PSR J1119−6127 following magnetar-like X-ray bursts

We present the spin frequency and profile evolution of the radio pulsar J1119$-$6127 following magnetar-like X-ray bursts from the system in 2016 July. Using data from the Parkes radio telescope, we observe a smooth and fast spin-down process subsequent to the X-ray bursts resulting in a net change in the pulsar rotational frequency of $\Delta\nu\approx-4\times10^{-4}$\,Hz. During the transition, a net spin-down rate increase of $\Delta\dot\nu\approx-1\times10^{-10}$\,Hz\,s$^{-1}$ is observed, followed by a return of $\dot{\nu}$ to its original value. In addition, the radio pulsations disappeared after the X-ray bursts and reappeared about two weeks later with the flux density at 1.4\,GHz increased by a factor of five. The flux density then decreased and undershot the normal flux density followed by a slow recovery back to normal. The pulsar's integrated profile underwent dramatic and short-term changes in total intensity, polarization and position angle. Despite the complex evolution, we observe correlations between the spin-down rate, pulse profile shape and radio flux density. Strong single pulses have been detected after the X-ray bursts with their energy distributions evolving with time. The peculiar but smooth spin frequency evolution of PSR~J1119$-$6127 accompanied by systematic pulse profile and flux density changes are most likely to be a result of either reconfiguration of the surface magnetic fields or particle winds triggered by the X-ray bursts. The recovery of spin-down rate and pulse profile to normal provides us the best case to study the connection between high magnetic-field pulsars and magnetars.

Insight into Resolution Enhancement in Generalized Two-Dimensional Correlation Spectroscopy

Generalized two-dimensional correlation spectroscopy (2D-COS) can be used to enhance spectral resolution in order to help differentiate highly overlapped spectral bands. Despite the numerous extensive 2D-COS investigations, the origin of the 2D spectral resolution enhancement mechanism(s) is not completely understood. In the work here, we studied the 2D-COS of simulated spectra in order to develop new insights into the dependence of 2D-COS spectral features on the overlapping band separations, their intensities and bandwidths, and their band intensity change rates. We found that the features in the 2D-COS maps that are derived from overlapping bands were determined by the spectral normalized half-intensities and the total intensity changes of the correlated bands. We identified the conditions required to resolve overlapping bands. In particular, 2D-COS peak resolution requires that the normalized half-intensities of a correlating band have amplitudes between the maxima and minima of the normalized half-intensities of the overlapping bands.

SNARE-Mediated Fusion Pore Dynamics from Quantitative TIRF Microscopy

Neurotransmitter and hormone release occurs when vesicles filled with these cargoes fuse with the plasma membrane. Electrophysiological recordings from neuroendocrine cells and neurons indicate the initial connection between the vesicular and the plasma membrane is a small, highly dynamic pore that can rapidly flicker between open and closed (unfused) states before either fully expanding or permanently closing (“kiss and run” fusion). The dynamics of the fusion pore regulate the release process and have been proposed to play important physiological roles for different cell types. However, the molecular mechanisms governing the pore dynamics are not known. To examine this problem we have used a recently developed in vitro fusion assay in which fluorescent liposomes reconstituted with the neuronal v-SNAREs (v-SUVs) dock and fuse with planar bilayers containing cognate t-SNAREs (t-SBLs). Upon fusion, fluorescently labeled lipids transfer from the SUV to the SBL. Under appropriate conditions, this transfer results in a change in the total fluorescence due to the properties of TIRF excitation. Here, using a mathematical model for lipid release through a flickering pore we show that the quantitative analysis of the total intensity changes upon fusion allows extraction of the pore connectivity, C_pore, the mean fraction of time the pore is connected. The single-molecule sensitivity of the measurements allowed us to determine the sizes of individual fusing vesicles of sub-optical dimensions. We have studied how the fusion pore dynamics depend on the lipid composition and vesicle size. Cholesterol, when included at physiological quantities, increases the pore connectivity, whereas vesicle size has little influence on the pore dynamics and the fusion probability.

Environmental Effects on the Performance of Nanocrystalline Silicon Solar Cells

In this paper the global, direct and diffuse solar radiation incident on solar cells is simulated using the spectral model SMARTS2, for varying environmental conditions on the site of Setif. The effect of changes in total intensity and spectral distribution on the short circuit current and efficiency of nanocrystalline silicon (nc-Si: H) is examined. The results show a reduction in the short circuit current due to increasing turbidity. It is 27.06% and 67.97% under global and direct radiation respectively. However it increases under diffuse radiation. This increase is about 53.97%. Increasing albedo leads to an increase in the short circuit current of 5.70% and 27.05% for global and diffuse solar radiation, respectively and it is not influenced under direct solar radiation. The performance of the cells is notably reduced, both in terms of efficiency and open circuit voltage, with increasing air mass. It is about 81.86%, 37.47% and 94.18% for global, diffuse and direct solar radiation respectively.

Magnetoreception

Few subjects in animal behavior have more exotic mystery than magnetic-field sensitivity. A force we cannot sense, generated by events no one completely understands, creates field lines that pass through our bodies without any evident effect on us or on them. It is an energy felt as much by migrating lobsters on the sea floor as by ocean-crossing birds thousands of meters overhead, transduced in generally poorly understood ways. Despite the blindness of humans, modern life depends on this invisible, ghostlike field. Aside from lights and heaters, nearly every electrical device we own makes use of electromagnetism, and that same magnetism is essential in generating the power these new-found necessities consume. But for many animals, the reliance is far older and more basic: their life-or-death ability to find their way around in the world depends on correctly interpreting the earth's magnetic field.

P29 1986年伊豆大島火山噴火フェイズIIに伴う全磁力変化の再検討(ポスターセッション,日本火山学会2006年秋季大会)

P29 1986年伊豆大島火山噴火フェイズIIに伴う全磁力変化の再検討(ポスターセッション,日本火山学会2006年秋季大会)

X-ray Interference Studies of Crossbridge Action in Muscle Contraction: Evidence from Muscles During Steady Shortening

During normal muscle shortening, the myosin heads must undergo many cycles of interaction with the actin filaments sliding past them. It is important to determine what range of configurations is found under these circumstances, and, in terms of the tilting lever arm model, what range of orientations the lever arms undergo. We have studied this using the X-ray interference technique described in the previous article, focusing mainly on the changes in the first order meridional reflection (M3) as compared to isometric. The change in ratio of the heights of the interference peaks indicates how far the mean lever arm angle has moved towards the end of the working stroke; the total intensity change depends on the angle change, on the number of heads now attached at any one time, and on the dispersion of lever arm angles. The latter provides a measure of the distance over which myosin heads remain attached to actin as they go through their working strokes. Surprisingly, the mean position of the attached heads moves only about 1 nm inwards (towards the center of the A-band) at low velocity shortening (around 0.9 T 0): their dispersion changes very little. This shows that they must be detaching very early in the working stroke. However, at loads around 0.5 T 0, the mean lever arm angle is about half way towards the end of the working stroke, and the dispersion of lever arm angles (with a uniform dispersion) is such as to distribute the heads throughout the whole of the working stroke. At higher velocities of shortening (at 0.3 T 0), the mean position shifts further towards the end of the stroke, and the dispersion increases further. The details of the measurements, together with other data on muscle indicate that the force-generating mechanism within the myosin heads must have some unexpected properties.

Volcanomagnetic changes accompanying the onset of the 2002–2003 eruption of Mt. Etna (Italy)

Remarkable changes in the local magnetic field were associated with the onset of the 2002–2003 flank eruption at Mt. Etna. After differential magnetic field measurements were filtered from the external noise by using adaptive filters, we recognized two stages in the total intensity changes, which are closely related to different volcanic events: (a) rapid variations of about 4–5 nT associated with October 26 seismic swarm recorded beneath the summit craters; (b) step-like variations of 9–10 nT coincident with October 27 eruptive fissures opening up in the north flank. These observations are generally consistent with those calculated from simple magnetic models of these volcanic processes, in which the magnetic changes are generated by stress redistribution due to magmatic intrusions at different depth. The magnetic data not only allow the timing of the intrusive event to be described in greater detail but also, together with other volcanological and geophysical evidences, permit some constraints to be set on the characteristics of propagation of a shallow dike. Firstly, at around midnight on 26 October magma was rapidly injected to a depth of 3–4 km just below the summit craters. Secondly, after 1:00 on 27 October, continued intrusion magma occurred upward and culminated a few hundred meters below the free surface fractured along a N–E direction. Thirdly, at about 2:28, magma gave rise to an explosive fissural vent at the northern base of the NE crater near 3000 m a.s.l. Finally, at about 5:00, the first eruptive fissure became active along the eastern border of the NE rift at 2500 m a.s.l. The rate of growth of the magnetic anomalies, moreover, leads to the interpretation that the magmatic intrusion travelled northward from base of the NE crater to the NE rift at approximately 14 m/min.

Magnetic field distortions produced by protective cages around sea turtle nests: unintended consequences for orientation and navigation?

The Earth’s magnetic field plays an important role in the orientation and navigation of sea turtles. Galvanized steel wire cages are often placed over turtle nests to protect them from predators, but the material typically used in cages has a high magnetic permeability and might therefore affect the nearby field. Here we report magnetometer measurements indicating that standard nest cages do indeed significantly alter the local magnetic field in the area where eggs develop. The mean change in total intensity was 26% at a level corresponding to the top of the egg chamber and 5% at a level corresponding to the bottom. Similarly, the mean change in field inclination was 20% for the top level and 4% for the bottom. In principle, the altered magnetic environment might affect subsequent magnetic orientation and navigation behavior in several ways, although whether turtles that develop in an unnatural magnetic field actually suffer navigational impairment has not yet been studied. Constructing protective cages out of magnetically inert materials provides a way to deter predators without risking unintended behavioral consequences of distorting the ambient field.

Volcanomagnetic signals associated with the 2001 flank eruption of Mt. Etna (Italy)

Geomagnetic changes were observed during the 2001 flank eruption at Mt. Etna. After differential magnetic fields were filtered from the seasonal thermic noise by using temperature data, we recognized three stages in the total intensity changes related to different volcanic events: (a) rapid variation of 4 nT associated with July 12 seismic swarm recorded beneath the summit craters, (b) step‐like variation of 7 nT occurring during the quick propagation of fractures in the south flank, which was followed by the off‐set of 2 nT before July 17 when the lava outpoured from fissures, and (c) quick variation of 3 nT coincident with July 19 eruptive fissures opening up in the Valle del Leone. These observations are consistent with those calculated from volcanomagnetic models, in which the magnetic changes are generated by stress redistribution due to magmatic intrusions at different depth and by the thermal demagnetization at a rather shallow depth.

The 2000 Activity of Miyake-jima Volcano as Inferred from Electric and Magnetic Field Observations

Electric and magnetic field observations have been extensively carried out since 1995. A precursory magnetic anomaly was detected in July 1996, which was ascribed to thermal demagnetization at a depth of several hundreds of meters beneath the southern periphery of the summit Hatcho-taira caldera. Magnetic data revealed that the large depression at the summit associated with the steam explosion on July 8, 2000 had been completed within four minutes. Since the beginning of July, anomalous magnetic changes were observed at several magnetometer sites along the central N-S line of Miyake-jima volcano, which indicated the rise of a demagnetized area from depth to the summit. On July 4, a few days before the steam explosion, an area survey of SP in the summit caldera was conducted, discovering an extremely negative zone around the forthcoming depression, which suggested the intense absorption of ground water. Tilt-step events; i.e., abrupt uplifts around the summit area, were accompanied by electric field variations, which were very similar to the velocity waveform of the ground motion, as well as magnetic variations with step-like changes. An electric field can be interpreted as being due to electric currents generated by the forced injection of steam and/or water from the pressure source (electrokinetic phenomena). Magnetic changes are attributed to the piezomagnetic effect of rocks due to increased stresses. The geomagnetic total intensity showed large variations after the July 8 eruption, the typical feature of which was positive at the east and west sides and negative along the central north-south line of the volcano. They are ascribed to 1) the loss of magnetic mass from the summit and 2) the thermal demagnetization at depth. After the August 18 eruption, which was the largest, the steep changes in total intensity became flat, which suggested that the temperature rise at depth had weakened. At the time of the August 18 eruption, a large increase in self-potential was observed around the southwestern foot of the central cone Oyama : This implies that a definite change occurred in the hydrothermal system of the volcano.

An efficient method for continuous measurement of projectile motion in ballistic impact experiments

This paper provides a description of a simple and cost-effective continuous measurement system for impact. Originally developed at Johns Hopkins university for use in flyer plate impact experiments, the measurement system has been enhanced for the continuous, non-contact measurement of projectile displacement during ballistic impact events. A sheet of laser light is progressively blocked and unblocked by the projectile, and the corresponding change in total intensity is measured and converted to a displacement–time curve. Through the use of simple mathematical operations, the system can be used to determine the time histories of projectile velocity and acceleration, impact force and projectile energy loss during an impact event. While this technique can be applied to a wide range of engineering materials, this paper presents examples of measurement results for impact of composite and textile targets.

Seismomagnetic models for earthquakes in the eastern part of Izu Peninsula, Central Japan

Seismomagnetic changes accompanied by four damaging earthquakes are explained by the piezomagnetic effect observed in the eastern part of Izu Peninsula, Central Japan. Most of the data were obtained by repeat surveys. Although these data suffered electric railway noise, significant magnetic changes were detected at points close to earthquake faults. Coseismic changes can be well interpreted by piezomagnetic models in the case of the 1978 Near Izu-Oshima (M 7.0) and the 1980 East Off Izu Peninsula (M 6.7) earthquakes. A large total intensity change up to 5 nT was observed at a survey point almost above the epicenter of the 1976 Kawazu (M 5.4) earthquake. This change is not explained by a single fault model; a 2-segment fault is suggested. Remarkable precursory and coseismic changes in the total force intensity were observed at KWZ station along with the 1978 Higashi-Izu (M 4.9) earthquake. KWZ station is located very close to a buried subsidiary fault of the M 7.0 Near Izu-Oshima earthquake, which moved aseismically at the time of the M 7.0 quake. The precursory magnetic change to the M 4.9 quake is ascribed to aseismic faulting of this buried fault, while the coseismic rebound to enlargement of the slipping surface at the time of M 4.9 quake. This implies that we observed the formation process of the earthquake nucleation zone via the magnetic field.

Cytochrome c folding kinetics studied by time-resolved electrospray ionization mass spectrometry.

A new method for studying the folding kinetics of proteins is described. The method combines a continuous flow mixing technique with an electrospray mass spectrometer. Different protein conformations in solution are detected by the different charge states they produce during electrospray ionization. Unfolded proteins generally have more accessible protonation sites and give higher charge states than native proteins. The method is applied to study the refolding of acid-denatured cytochrome c. Global data analysis is used to obtain the exponential lifetimes which are associated with the refolding process. The kinetics can be described by two lifetimes of 0.17 +/- 0.02 and 8.1 +/- 0.9 s which are in accordance with the results of stopped flow experiments previously described in the literature. These lifetimes are associated with roughly 90 and 10% of the total intensity changes in the mass spectrum, respectively, and most likely reflect fast and slow refolding subpopulations of cytochrome c in solution.

Resolution of multiphasic reactions by the combination of fluorescence total-intensity and anisotropy stopped-flow kinetic experiments

Multiphasic kinetics are often observed in stopped-flow investigations. To characterize further these kinetic phases, we have developed a methodology whereby fluorescence total intensity and anisotropy stopped-flow data can be combined in a single analysis. Fluorescence total intensity and anisotropy are highly interrelated and contain two very complementary forms of information. Total-intensity changes are useful in determining changes in populations with differing quantum yields, whereas anisotropy changes contain additional contributions caused by the rotational dynamics of the species. For cases in which the fluorescence quantum yield increases, the observed rate of anisotropy change will be more rapid than the total-intensity change, whereas in cases in which the total intensity decreases, the observed change in anisotropy will lag behind. In all cases, with quantum yield changes the stopped-flow anisotropy signals cannot be fit with models consisting of exponentials. Case studies examining these effects are described for the protein folding/refolding transitions of Staphylococcal nuclease and phosphoglycerate kinase. A multiphasic DNA exonuclease reaction using bacteriophage T4 DNA polymerase is also examined. In all of these cases, combined analysis of both data types revealed insights into reaction mechanism, which could not be obtained by either data type in isolation. Quantum yields and steady-state anisotropies associated with transiently populated intermediate species can be resolved. The data analysis methodologies described allow characterization of multiphasic reactions in terms of internally consistent kinetic rates, quantum yields, and steady-state anisotropies.

Stereospecific reaction of muscle fiber proteins with the 5' or 6' isomer of (iodoacetamido)tetramethylrhodamine.

The labeling of muscle fiber proteins with iodoacetamido)tetramethylrhodamine (IATR) was reinvestigated with the purified 5' or 6' isomers of IATR. Both isomers modify the myosin heavy chain within the 20-kDa fragment of myosin subfragment 1 (S1) but with different rates, and only the 5'-IATR alters K(+)-EDTA- and Ca(2+)-activated ATPases. Absorption spectroscopic and ATPase studies of probe stoichiometry indicate that for 5'-IATR there are two probes per myosin sulfhydryl 1 (SH1). Quantitative fluorograms of the SDS-PAGE gels confirm that there are one covalent and one noncovalent probe per SH1 when S1 is labeled with 5'-IATR (5'-IATR-S1) and that there are one covalent and two noncovalent probes per S1 when S1 is labeled with 6'-IATR (6'-IATR-S1). The 5'- and 6'-IATR probes have similar fluorescent lifetimes when bound to S1, but quenching studies with potassium iodide show that 5'-IATR-S1 has a single class of strongly bound chromophores while 6'-IATR-S1 has two or more classes of chromophores. It is possible that 5'-IATR labels SH1 as a dimer. The polarization anisotropies of 5'- and 6'-IATR-S1 indicate that 5'-IATR is immobilized, while 6'-IATR is moving independently, on the surface of S1. The emission spectrum from 5'-IATR-S1 is unaffected by the addition of MgATP, while 6'-IATR-S1 shows a spectral shift and total intensity change. When labeling muscle fibers, 5'-IATR labels myosin SH1 and differentiates between the fiber physiological states by indicating cross-bridge rotation in quantitative agreement with previous results [Burghardt et al. (1983) Proc. Natl. Acad. Sci. U.S.A. 80, 7515]. 6'-IATR reacts preferentially with actin in muscle fibers and does not differentiate between fiber physiological states as expected for an actin probe. The stereospecificity of the rhodamine isomers for SH1 indicates features of the local protein structure. The experimental results are used with theoretical methods for determining molecular structure to suggest a qualitative scheme for the specific interaction of 5'-IATR with its binding pocket on the surface of S1.