Hollow core photonic bandgap fibers provide a new geometry for the realization and enhancement of many nonlinear optical effects. Such fibers offer novel guidance and dispersion properties that provide an advantage over conventional fibers for various applications. Dispersion, which expresses the variation with wavelength of the guided-mode group velocity, is one of the most important properties of optical fibers. Photonic crystal fibers (PCFs) offer much larger flexibility than conventional fibers with respect to tailoring of the dispersion curve. This is partly due to the large refractive-index contrast available in the silica/air microstructures, and partly due to the possibility of making complex refractive-index structure over the fiber cross section. In this paper the fundamental physical mechanism has been discussed determining the dispersion properties of PCFs, and the dispersion in a gas filled hollow core photonic crystal fiber has been calculated. We calculate the dispersion of air filled hollow core photonic crystal fiber, also calculate the dispersion of N2 gas filled hollow core photonic crystal fiber and finally we calculate the dispersion of He gas filled hollow core photonic crystal fiber.
The problem of frequency estimation of a single sinusoid observed in colored noise is addressed. Our estimator is based on the operation of the sinusoidal digital phase-locked loop (SDPLL) which carries the frequency information in its phase error after the noisy sinusoid has been acquired by the SDPLL. We show by computer simulations that this frequency estimator beats the Cramer-Rao bound (CRB) on the frequency error variance for moderate and high SNRs when the colored noise has a general low-pass filtered (LPF) characteristic, thereby outperforming, in terms of frequency error variance, several existing techniques some of which are, in addition, computationally demanding. Moreover, the present approach generalizes on existing work tha
... Show MoreGiving advice refers to an attempt by the speaker to express what the addressee should do in a particular situation or what is good for him/her. It is also a feature of making social relations and communications move smoothly and become stronger. The current study aims to investigate the strategies of the speech act of advice by old females and males for the younger generation in written signs. Comparison is made between old females and males regarding their pragmatic use of advice and the way they are manifested in expressing gender identity differences. The sample of the study consists of (30) written signs of advice divided equally between the two gender groups. Hinkel’s (1997) classification of the strategies for perceiving th
... Show MoreCosmetic products contain variable amounts of nutrients that support microbial growth. Most contaminants in cosmetic products include bacteria such as Staphylococcus, Pseudomonas, Klebsiella, Achromobacter and Alcaligenes. Contaminated water is a likely source of organisms found in cosmetic products. Products such as shampoo, hand and body lotion, facial cleanser, and liquid soaps were analyzed. In this study, out of 60 cosmetic products analyzed, 26.4% were found to be contaminated. Most of the contamination was from bacteria and no fungal contamination was detected. The highest level o
... Show MoreConflict is a common but complicated phenomenon. It has been extensively researched in many domains, including philosophy, sociology, psychology, and linguistics. Using the Critical Discourse Approach, this study examines the issue of self-society conflict in The Handmaid’s Tale. The significance of this work lies in the identification and explanation of the discursive strategies that force the ideological polarization of the positively portrayed self versus the negatively portrayed other. The purpose of this study is to answer two questions: what are the discursive strategies used in The Handmaid’s Tale to create a positive or negative representation, and how are these strategies implemented? Five extracts from The Handmaid’s
... Show MoreThe study evaluated the recovery performance of any home herbs group as first aid in some emergency cases. The study involved 10 items of herbs (chamomile, black pepper, cloves, cinnamon, and anise) which used in acute cases such as cold, colic, inflammation of the intestine and tonsillitis, and (hibiscus, catnip, dried lime, cress seed, and ginger) were used for chronic cases such as hypertension, cardiovascular disease, and arthritis. The results showed the herbs had healing power and efficiency in the primary remedy for the above-mentioned diseases. The side effects, the contradictions, and the overdoses of these substances were discussed. It was concluded that home herbs could be used for treatment in emergency cases until moder
... Show MoreThe purpose of this paper is to study the properties of the
partial level density ( ) l g and the total level density g ( ),
numerically obtained as a l sum of ( ) l g up to 34 max l , for
a Harmonic – Oscillator potential well. This method applied the
quantum – mechanical phase shift technique and concentrated
on the continuum region. Also a discussion of peculiarities of
quantal calculation for single particle level density of energy –
dependent potential
Teresa Fitzpatrick presents a connection between oppressed women and the plant of Wisteria in gothic fiction in her article “Wisteria: A Female Eco-Gothic Metaphor in American Fiction Through the Ages.” The connection between women and nature is common in literature as women are usually compared to the beauty or ferocity of flowers, rivers, or natural phenomena in general. The connection extends to the architecture and sort of plants that appear in gothic literature. Gothic novels have routinely been connected to the secrets and life stories of women who cannot have the liberty to live or share them outside their homes. A fearful house with a prisoned person, ghost, or a secret is mostly normally found in gothic writing. Women have exce
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