197 research outputs found
On the Variability of Mesospheric OH Emission Profiles
Mesospheric OH radiance limb profiles measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument aboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) spacecraft were inverted to yield altitude profiles of OH volume emission rates. The Abel inversion results of two months of data (from 1 June to 31 July 2004) were analyzed for the layer mean and standard deviation as a function of latitude and local time. Statistical analysis of SABER data shows that the global difference between the mean and standard deviation profiles for the OH(vu = 7, 8, 9; ∆v = 2) emission (at 2.0 µm) is approximately 2.8 km, very similar to the theoretical model prediction by Liu and Swenson (2003). This agreement is an indication that these variations from the mean are likely caused by atmospheric tides and gravity waves
Estimation of Gravity Wave Momentum Flux with Spectroscopic Imaging
Atmospheric gravity waves play a significant role in the dynamics and thermal balance of the upper atmosphere. In this paper, we present a novel technique for automated and robust calculation of momentum flux of high-frequency quasi-monochromatic wave components from spectroscopic imaging and horizontal radar wind measurements. Our approach uses the two-dimensional (2-D) cross periodogram of two consecutive Doppler-shifted time-differenced (TD) images to identify wave components and estimate intrinsic wave parameters. Besides estimating the average perturbation of dominant waves in the whole field of view, this technique applies 2-D short-space Fourier transform to the TD images to identify localized wave events. With the wave parameters acquired, the momentum flux carried by all vertically propagating wave components is calculated using an analytical model relating the measured intensity perturbation to the wave amplitude. This model is tested by comparing wave perturbation amplitudes inferred from spectroscopic images with those from sodium lidar temperature measurements. The proposed technique enables characterization of the variations in the direction and strength of gravity waves with high temporal resolution for each clear data-taking night. The nightly results provide statistical information for investigating seasonal and geographical variations in momentum flux of gravity waves
Evaluation of phenolics, capsaicinoids, antioxidant properties, and major macro-micro minerals of some hot and sweet peppers and ginger land-races of Malaysia
There are compelling evidences that oxidative stress plays important role in age‐related neurodegenerative diseases and natural food‐derived dietary antioxidants appear to be the first line of defence to take care of the oxidative stress. The analysis results of this study showed that Cili Burung of the hot pepper landraces contained the highest amount of TPC (1.00 mg/g DW), TFC (0.17 mg/g DW), capsaicinoids (0.05 mg/g), and the highest FRAP activity (439 mg/g DW). However, DPPH assay revealed the highest DPPH scavenging activity (IC50 = 250 μg/ml) in Halia Bara rhizome. Rhizomes of both landraces of ginger showed a significant amount of capsaicinoids. Hot pepper Cili Ungu (5.50 g/kg) and sweet pepper Cili Kulai had the highest P contents (~5.5 g/kg). Halia Bentong ginger rhizome had the highest content of K (33.84 g/kg); however, Halia Bentong ginger roots had remarkably greater contents of Ca (10.96 g/kg). Ginger rhizomes and roots had greater contents of micro minerals compared to hot and sweet chili peppers. Ginger roots contained good amounts of bioactive compounds and mineral nutrients indicating its commercial value
Cognitive load during planned and unplanned virtual shopping: Evidence from a neurophysiological perspective
Rapid adoption of virtual-reality-assisted retail applications is inadvertently reshaping consumer buying patterns, making it crucial for businesses to enhance their shopping experience. This new scenario challenges marketers with unique hurdles in both the commercialization of products and in managing information cues derived via VR retailing. Therefore, this study examined consumers’ impulsive behavior and unplanned purchases in a virtual retail store, using self-reports and electroencephalography. Borrowing assorted perspectives from retailing, virtual reality, and neuromarketing literature, we extended the stimulus-organism-response framework to evaluate how unplanned behavior evolves through conscious and unconscious measures. We found that consumers’ impulsiveness was significantly associated with their unplanned expenditure and the number of unplanned purchases. Using mediation analysis, we observed that flow experience during shopping partially mediated the relationship between the sense of presence and the desire to stay longer in a virtual shopping store. Desire to stay in the virtual store positively influenced store satisfaction, basket-size deviation, and budget deviation. Additionally, cognitive workload obtained via electroencephalogram revealed significant differences during both planned and unplanned purchases. These findings provide fresh opportunities for retailers to leverage the disruptive potential of immersive and interactive virtual technology to transform consumer shopping experiences
Regulation of fruit colour development, quality and storage life of Hibiscus sabdariffa L. as influenced by plant growth regulators
The physico-chemical properties of abscisic acid (ABA) and IAA treated roselle calyces stored in different storage temperature was determined in this study. Mature roselle was dipped in distilled water (control),10-4 mol/l of ABA and 10-4mol/l of IAA for 5 minutes. All treated calyces were kept at ambient temperature (23°C) for 4 days, or stored at cold storage (10°C) for 8 days. Low temperature (10°C) can
prolong the shelf life of roselle about 4 days longer than ambient storage (23°C). However, plant growth regulator (ABA or IAA) only showed minimal effect on quality and shelf life of roselle. Therefore,the application of higher concentration of ABA or IAA as well as dipping for more than 5 minutes can influence the postharvest quality and shelf life of roselle calyces, respectively
Regulation of fruit colour development, quality and storage life of Hibiscus sabdariffa L. as influenced by plant growth regulators
The physico-chemical properties of abscisic acid (ABA) and IAA treated roselle calyces stored in different storage temperature was determined in this study. Mature roselle was dipped in distilled water (control),10-4 mol/l of ABA and 10-4mol/l of IAA for 5 minutes. All treated calyces were kept at ambient temperature (23°C) for 4 days, or stored at cold storage (10°C) for 8 days. Low temperature (10°C) can
prolong the shelf life of roselle about 4 days longer than ambient storage (23°C). However, plant growth regulator (ABA or IAA) only showed minimal effect on quality and shelf life of roselle. Therefore,the application of higher concentration of ABA or IAA as well as dipping for more than 5 minutes can influence the postharvest quality and shelf life of roselle calyces, respectively
Emergence of semi-localized Anderson modes in a disordered photonic crystal as a result of overlap probability
In this paper we study the effect of positional randomness on transmissional
properties of a two dimensional photonic crystal as a function of a randomness
parameter ( completely ordered, completely
disordered). We use finite-difference time-domain~(FDTD) method to solve the
Maxwell's equations in such a medium numerically. We consider two situations:
first a 90\degr bent photonic crystal wave-guide and second a centrally
pulsed photonic crystal micro-cavity. We plot various figures for each case
which characterize the effect of randomness quantitatively. More specifically,
in the wave-guide situation, we show that the general shape of the normalized
total output energy is a Gaussian function of randomness with
wavelength-dependent width. For centrally pulsed PC, the output energy curves
display extremum behavior both as a function of time as well as randomness. We
explain these effects in terms of two distinct but simultaneous effects which
emerge with increasing randomness, namely the creation of semi-localized modes
and the shrinking (and eventual destruction) of the photonic band-gaps.
Semi-localized (i.e. Anderson localized) modes are seen to arise as a
synchronization of internal modes within a cluster of randomly positioned
dielectric nano-particles. The general trend we observe shows a sharp change of
behavior in the intermediate randomness regime (i.e. )
which we attribute to a similar behavior in the underlying overlap probability
of nano-particlesComment: New published version with a new title. This article is featured on
the cover of the corresponding journal (Nov. issue of EJPB
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