Controlling Metamaterial Resonances with Light

We investigate the use of coherent optical fields as a means of dynamically controlling the resonant behaviour of a variety of composite metamaterials, wherein the metamaterial structures are embedded in a dispersive dielectric medium. Control and switching is implemented by coherently driving the resonant permittivity of the embedding medium by applied optical radiation. The effect of embedding Split ring resonators (SRR) in a frequency- dispersive medium with Lorentz-like dispersion or with dispersion engineered by electromagnetic induced transparency (EIT), is manifested in the splitting of the negative permeability band, the modified (frequency-dependent) filling fractions and dissipation factors. The modified material parameters are strongly linked to the resonant frequencies of the medium, while for an embedding medium exhibiting EIT, also to the strength and detuning of the control field. The robustness of control against the deleterious influence of dissipation associated with the metallic structures as well as the inhomogeneous broadening due to structural imperfections is demonstrated. Studies on plasmonic metamaterials that consist of metallic nanorods arranged in loops and exhibit a collective magnetic response at optical frequencies are presented. Control and switching in this class of plasmonic nanorod metamaterials is shown to be possible, for example, by embedding these arrays in a Raman active liquid like CS$_2$ and utilizing the Inverse Raman Effect.Comment: 9 pages, 9 figure

Distribution of Capillary Transit Times in Isolated Lungs of Oxygen-Tolerant Rats

Rats pre-exposed to 85% O2 for 5–7 days tolerate the otherwise lethal effects of 100% O2. The objective was to evaluate the effect of rat exposure to 85% O2 for 7 days on lung capillary mean transit time (t¯c) and distribution of capillary transit times (h c(t)). This information is important for subsequent evaluation of the effect of this hyperoxia model on the redox metabolic functions of the pulmonary capillary endothelium. The venous concentration vs. time outflow curves of fluorescein isothiocyanate labeled dextran (FITC-dex), an intravascular indicator, and coenzyme Q1 hydroquinone (CoQ1H2), a compound which rapidly equilibrates between blood and tissue on passage through the pulmonary circulation, were measured following their bolus injection into the pulmonary artery of isolated perfused lungs from rats exposed to room air (normoxic) or 85% O2 for 7 days (hyperoxic). The moments (mean transit time and variance) of the measured FITC-dex and CoQ1H2 outflow curves were determined for each lung, and were then used in a mathematical model [Audi et al. J. Appl. Physiol. 77: 332–351, 1994] to estimate t¯c and the relative dispersion (RDc) of h c(t). Data analysis reveals that exposure to hyperoxia decreases lung t¯c by 42% and increases RDc, a measure h c(t) heterogeneity, by 40%

Plasmon polaritons in photonic superlattices containing a left-handed material

We analyze one-dimensional photonic superlattices which alternate layers of air and a left-handed material. We assume Drude-type dispersive responses for the dielectric permittivity and magnetic permeability of the left-handed material. Maxwell's equations and the transfer-matrix technique are used to derive the dispersion relation for the propagation of obliquely incident optical fields. The photonic dispersion indicates that the growth-direction component of the electric (or magnetic) field leads to the propagation of electric (or magnetic) plasmon polaritons, for either TE or TM configurations. Furthermore, we show that if the plasma frequency is chosen within the photonic $=0$ zeroth-order bandgap, the coupling of light with plasmons weakens considerably. As light propagation is forbidden in that particular frequency region, the plasmon-polariton mode reduces to a pure plasmon mode.Comment: 4 pages, 4 figure

Strategies for improving the sustainability of data centers via energy mix, energy conservation, and circular energy

Information and communication technologies (ICT) are increasingly permeating our daily life and we ever more commit our data to the cloud. Events like the COVID-19 pandemic put an exceptional burden upon ICT. This involves increasing implementation and use of data centers, which increased energy use and environmental impact. The scope of this work is to summarize the present situation on data centers as to environmental impact and opportunities for improvement. First, we introduce the topic, presenting estimated energy use and emissions. Then, we review proposed strategies for energy efficiency and conservation in data centers. Energy uses pertain to power distribution, ICT, and non-ICT equipment (e.g., cooling). Existing and prospected strategies and initiatives in these sectors are identified. Among key elements are innovative cooling techniques, natural resources, automation, low-power electronics, and equipment with extended thermal limits. Research perspectives are identified and estimates of improvement opportunities are mentioned. Finally, we present an overview on existing metrics, regulatory framework, and bodies concerned

ETHNO-VETERINARY HERBAL REMEDIES OF GUJJARS AND OTHER FOLKLORE COMMUNITIES OF ALWAR DISTRICT, RAJASTHAN, INDIA

The present study encompasses the in-depth investigation on Medicinal plants which were used on Ethno-veterinary medicine in the district of Alwar, Rajasthan India. The present ethno-botanical explorations conducted in the Alwar district of Rajasthan revealed that about 37 species of plants belonging to 32 genera under 24 families have been noticed which they use for veterinary health care. A total of 27 healers and herbal practitioners were interviewed during the study. Total of 47 remedies were recorded for 19 veterinary disease conditions of which 21 remedies were recorded under digestive disorders (9 remedies for bloat, 3 stomach pain and 5 for constipation, 3 food poison and 1 diarrhoea) 9 remedies under reproductive problems (3 for anoestrus, 2 for galactagogue, 3 for retained placenta, and 1 for prolapsed uterus). 5 remedies for diseases of sense organs (2 skin infection, 3 for wounds and maggot wounds). 2 remedies were documented under infectious disease (1 for Foot and Mouth Disease, 1 for Foot rot, 2 for Haemorrhagic septicemia). 1 remedy recorded for general fever. Following data includes botanical name of species, family name, vernacular name, plant part used method of medicine and details of the applications. Among the plant parts used in different formulations, leaves are predominantly used and scored number one position followed by fruits, roots/ rhizomes, stem and bark.

A study of antinociceptive effect of venlafaxine in albino mice

Background: Serotonin and norepinephrine are important neurotransmitters involved in pain inhibition in descending pain inhibitory tracts. Venlafaxine being an antidepressant exerts its mechanism mainly by inhibiting reuptake of serotonin and norepinephrine like Tramadol. The objectives were to study the antinociceptive activity of Venlafaxine and its comparison with Pethidine.Methods: A total of 32 Swiss albino mice were divided into 4 groups with 8 animals in each group. Group 1 received normal saline as control in dose of 5ml/kg i.p, Group 2 received Pethidine as standard in dose of 30mg/kg s.c, Group 3 received Venlafaxine as in dose of 10mg/kg i.p and Group 4 received Venlafaxine in dose of 22.5mg/kg. Tail flick test and hot plate test were used for evaluating antinociceptive activity. All animals were subjected to the above mentioned tests before and 30 minutes after the administration of the drugs. Results were subjected to suitable statistical analysis.Results: The results from the above mentioned tests showed that Venlafaxine in dose of 10mg/kg showed significant antinociceptive activity as compared to normal saline (p 0.05). Venlafaxine in dose of 22.5mg/kg showed significant antinociceptive activity as compared to normal saline (p <0.05) and activity was comparable to Pethidine.Conclusions: Venlafaxine in both the doses showed significant antinociceptive activity in acute models of pain in animals

Kinetics of Reaction between Iodine & o-Chloromercuriphenol in Methanol, Ethanol, n-Propanol, Isopropanol, n-Butanol & n-Pentanol

88-9