ACID GAS ABSORPTION STUDIES IN PACKED COLUMN

Carbon dioxide is a major greenhouse gas that results in climatic changes. Reducing CO2 emission for addressing the climatic change concerns is becoming increasingly important as the CO2 concentration in the atmosphere has increased rapidly since the industrial revolution. Many mitigation methods, including CO2 sequestration and novel CO2 utilization, are currently under investigation. Most of these processes require CO2 in a concentrated form. However the CO2 from large sources such as fossil fueled power plants is mixed with nitrogen, water vapor, oxygen and other impurities. The current commercial operations for capturing CO2 from flue gas use a chemical absorption method with Monoethanol Amine (MEA) as the sorbent. The method is expensive and energy intensive. The cost of capturing a ton of CO2 including removing impurities and compressing CO2 to supercritical pressure using existing MEA technology would be very high, and the power output would be significantly reduced by the energy consumption in capturing and compressing CO2. In this work alternative solvent ammonia, is used which can overcome the disadvantages of current technology using amines such as MEA and DEA

Laser performance of perylenebis (dicarboximide) dyes with long secondary alkyl chains

The laser performance and related photophysical properties of two very soluble perylene dyes with long chain secondary alkyl groups were investigated in cyclohexane solution. With a dye laser as pump source a tuning range of 555–580 nm was obtained at an optimum concentration of 3×10–4 M. The quantum efficiencies (=0.29 and 0.21) were better than 1/2 that of rhodamine 6G. No photodegradation was observed over an excitation period of several hours

Gravitational Lensing at Millimeter Wavelengths

With today's millimeter and submillimeter instruments observers use gravitational lensing mostly as a tool to boost the sensitivity when observing distant objects. This is evident through the dominance of gravitationally lensed objects among those detected in CO rotational lines at z>1. It is also evident in the use of lensing magnification by galaxy clusters in order to reach faint submm/mm continuum sources. There are, however, a few cases where millimeter lines have been directly involved in understanding lensing configurations. Future mm/submm instruments, such as the ALMA interferometer, will have both the sensitivity and the angular resolution to allow detailed observations of gravitational lenses. The almost constant sensitivity to dust emission over the redshift range z=1-10 means that the likelihood for strong lensing of dust continuum sources is much higher than for optically selected sources. A large number of new strong lenses are therefore likely to be discovered with ALMA, allowing a direct assessment of cosmological parameters through lens statistics. Combined with an angular resolution <0.1", ALMA will also be efficient for probing the gravitational potential of galaxy clusters, where we will be able to study both the sources and the lenses themselves, free of obscuration and extinction corrections, derive rotation curves for the lenses, their orientation and, thus, greatly constrain lens models.Comment: 69 pages, Review on quasar lensing. Part of a LNP Topical Volume on "Dark matter and gravitational lensing", eds. F. Courbin, D. Minniti. To be published by Springer-Verlag 2002. Paper with full resolution figures can be found at ftp://oden.oso.chalmers.se/pub/tommy/mmviews.ps.g

Basic considerations in the dermatokinetics of topical formulations

Assessing the bioavailability of drug molecules at the site of action provides better insight into the efficiency of a dosage form. However, determining drug concentration in the skin layers following topical application of dermatological formulations is a great challenge. The protocols followed in oral formulations could not be applied for topical dosage forms. The regulatory agencies are considering several possible approaches such as tape stripping, microdialysis etc. On the other hand, the skin bioavailability assessment of xenobiotics is equally important for topical formulations in order to evaluate the toxicity. It is always possible that drug molecules applied on the skin surface may transport thorough the skin and reaches systemic circulation. Thus the real time measurement of molecules in the skin layer has become obligatory. In the last two decades, quite a few investigations have been carried out to assess the skin bioavailability and toxicity of topical/dermatological products. This review provides current understanding on the basics of dermatokinetics, drug depot formation, skin metabolism and clearance of drug molecules from the skin layers following application of topical formulations

A model for drug dispensing service based on the care process in the Brazilian health system

Access to medication emphasizes the availability of the product at the expense of providing a service. The goal of this paper is to propose a theoretical model for a drug dispensing service, beginning with a reflection on the current realities of the Unified Health System and drug dispensation in Brazil. A conceptual analytical research made by a methodological course called disciplined imagination was mainly the approach applied to develop the model. The drug dispensing service is part of the care process, which considers access as an attribute; reception, connection and accountability, management, and clinical pharmaceutical aspects as components; and the rational use of drugs as the purpose. The proposed model addresses access to the dispensing service and demands a reorientation of routines, instruments, and practices.O acesso a medicamentos enfatiza a disponibilidade do produto em detrimento da provisão de um serviço. O objetivo deste trabalho é propor um modelo teórico para um serviço de dispensação de medicamentos, iniciando com uma reflexão sobre a realidade atual do Sistema Único de Saúde e a dispensação de medicamentos no Brasil. Uma pesquisa analítica conceitual realizada por meio de um percurso metodológico chamado de imaginação disciplinada constituiu a estratégia principal para o desenvolvimento do modelo. O serviço de dispensação é parte do processo de cuidado, o qual considera o acesso como um atributo; os aspectos acolhimento, vínculo e responsabilização, gestão e clínica farmacêutica como componentes e o uso racional de medicamentos como o propósito. O modelo proposto direciona o acesso para o serviço de dispensação e demanda a reorientação de rotinas, instrumentos e práticas

Self-emulsifying therapeutic system: a potential approach for delivery of lipophilic drugs

Self-emulsifying therapeutic system (SETs) provide an effective and intelligent solution to the various issues related to the formulation of hydrophobic drugs with limited solubility in gastrointestinal fluid. Although the potential utility of SETs is well known, only in recent years has a mechanistic understanding of the impact of these systems on drug disposition emerged. These in situ emulsion-forming systems have a high stability when incorporated in various dosage forms. SETs are being looked upon as systems which can overcome the problems associated with delivery of poorly water soluble drugs. An in-depth knowledge about lipids and surfactants that can contribute to these systems, criterion for their selection and the proportion in which they can be used, represent some crucial factors determining the in vivo performance of these systems. This article presents a comprehensive account of various types of self-emulsifying formulations with emphasis on their composition and examples of currently marketed preparations.O sistema terapêutico auto-emulsionante (SETs) fornece solução eficaz e inteligente para os vários problemas relativos à formulação de fármacos hidrofóbicos com solubilidade limitada no fluido gastrintestinal. Embora a utilidade potencial dos SETs seja bem conhecida, só recentemente se compreendeu, mecanisticamente,o impacto desses sistemas na disposição de fármacos. Estes sistemas de formação de emulsão in situ têm alta estabilidade, quando incorporados em várias formas de dosagem. Os SETs têm sido considerados como sistemas que podem resolver problemas associados à liberação de fármacos pouco solúveis em água. O conhecimento profundo dos lipídios e tensoativos que podem ser utilizados para estes sistemas e o critério para a sua seleção e proporção na qual eles são utilizados são alguns dos fatores cruciais que determinam o desempenho do sistema in vivo. Este artigo apresenta o relato abrangente de vários tipos de formulações auto-emulsificantes, com ênfase em sua composição e exemplos das preparações que são correntemente comercializadas

First measurement of Ωc0 production in pp collisions at s=13 TeV

The inclusive production of the charm–strange baryon 0 c is measured for the first time via its hadronic √ decay into −π+ at midrapidity (|y| &lt;0.5) in proton–proton (pp) collisions at the centre-of-mass energy s =13 TeV with the ALICE detector at the LHC. The transverse momentum (pT) differential cross section multiplied by the branching ratio is presented in the interval 2 &lt; pT &lt; 12 GeV/c. The pT dependence of the 0 c-baryon production relative to the prompt D0-meson and to the prompt 0 c-baryon production is compared to various models that take different hadronisation mechanisms into consideration. In the measured pT interval, the ratio of the pT-integrated cross sections of 0 c and prompt + c baryons multiplied by the −π+ branching ratio is found to be larger by a factor of about 20 with a significance of about 4σ when compared to e+e− collisions