228 research outputs found
Travel
No full text[Extract] In recent years as a the world embraces a global economy, travelling abroad, has now become a common feature of many types of employment. Advances in air travel and accessibility have led to the acceptance of this scenario as a typical job task, and many companies of ten assume that their employees are now 'transnationally competent'
Leveraging wireless network virtualizaton for flexible sharing of WLANs
No full textProviding air-time guarantees across a group of clients forms a fundamental building block in sharing an access point (AP) across different virtual network service providers. Though this problem has a relatively simple solution for downlink group scheduling through traffic engineering at the AP, solving this problem for uplink (UL) traffic presents a challenge for fair sharing of wireless hotspots. Among other issues, the mechanism for uplink traffic control has to scale across a large user base, and provide flexible operation irrespective of the client channel conditions and network traffic loads. In this thesis the SplitAP architecture is proposed that addresses the problem of sharing uplink airtime across groups of users by extending the idea of network virtualization. The architecture discussed in this thesis allows different algorithms to be deployed on it for enforcing UL airtime fairness across different client groups. In this thesis, the design features of the SplitAP architecture are highlighted followed by results from evaluation on a prototype deployed with the two algorithms for controlling UL group fairness like: (1) Linear Proportional Feedback Control (LPFC) and (2) Linear Proportional Feedback Control plus (LPFC+). Performance comparisons on the ORBIT testbed show that the proposed algorithms are capable of providing group air-time fairness across wireless clients irrespective of the network volume, and traffic type. The algorithms show up to 40% improvement with a modified Jain fairness index.M.S.Includes bibliographical referencesby Dipti Vet
Formulation of thermoresponsive and buccal adhesive in situ gel for treatment of oral thrush containing poorly water soluble drug bifonazole
No full textThe aim of the present work is to formulate and evaluate in situ oral topical gels of poorly water soluble drug Bifonazole based on temperature induced systems for the treatment of oral candidiasis. Bifonazole is poorly water soluble and low permeable drug means it′s belongs to BCS Class IV. Due to its poor water solubility, it necessary to enhance solubility in water by make complex with Beta- Cyclodextrin (Drug to βCyclo Dextrine ratio is 1:1). After in situ gel preparation done by using Poloxamer (10% and 15%w/w) along with carbopol 934 (0.2 to 1.0% w/w) and Bifonazole - β CD complex (1%w/w). The formulations were evaluated for physiochemical parameter, gelation Temperature, viscosity, gel strength, content uniformity mucoadhesive force, Diffusion Study
Validated RP-HPLC and TLC methods for simultaneous estimation of tamsulosin hydrochloride and finasteride in combined dosage forms
No full textU radu su opisani razvoj i validacija inverzno fazne kromatografije visoke učinkovitosti (RP-HPLC) i tankoslojne kromatografije (TLC) za simultano određivanje tamsulozin hidroklorida i finasterida kao čistih supstancija i u kombiniranim tabletama. Za RP-HPLC odjeljivanje korištena je Phenomenex C18 kolona (250 mm, 4,6 mm, 5 µm) i metanol/0,02 mol L–1 pufer s amonijevim acetatom/trietilamin (79,9+20+0,1, V/V/V) (pH 9,2) kao pokretna faza, pri protoku 1 mL min-1. TLC odjeljivanje rađeno je na silikagelu 60F254 na aluminijskoj podlozi, koristeći toluen/metanol/trietilamin (9+1,5+1, V/V/V) kao eluens. Za detekciju u RP-HPLC metodi korištena je fotodioda (PDA) pri 235 nm te je provedena kvantitacija u koncentracijskom području 0,5–16 µg mL–1 i 1–50 µg mL–1, uz srednji analitički povrat od 99,8 ± 0,9 % za tamsulozin hidroklorid i 100,0 ± 0,8 % za finasterid. Za kvantitaciju u TLC metodi korištena je UV detekcija pri 270 nm u koncentracijskom području 100–2000 ng po točki za tamsulozin hidroklorid i 250–5000 ng po točki za finasterid, uz srednji analitički povrat od 98,9 ± 0,9, odnosno 99,6 ± 0,7 %. Obje metode su jednostavne, precizne, točne i osjetljive i mogu se primijeniti za simultano određivanje tamsulozin hidroklorida i finasterida kao čistih supstancija i u kombiniranim dozirnim oblicima.Reversed phase high-performance liquid chromatography (RP-HPLC) and thin-layer chromatography (TLC) methods have been developed and validated for simultaneous estimation of tamsulosin hydrochloride and finasteride in bulk drug and in combined dosage forms. RP-HPLC separation was achieved on a Phenomenex C18 column using methanol/0.02 mol L-1 ammonium acetate buffer/triethylamine (79.9 + 20 + 0.1, V/V/V) (pH 9.2) as mobile phase. The TLC separation was achieved on an aluminium-backed layer of silica gel 60F254 using toluene/methanol/triethylamine (9 + 1.5 + 1, V/V/V) as eluent. Quantification was achieved with photodiode array (PDA) detection at 235 nm over the concentration range 0.5–16 and 150 µg mL1 with mean recovery of 99.8 ± 0.9 and 100.0 ± 0.8 % for tamsulosin hydrochloride and finasteride, respectively, by the RP-HPLC method. Quantification was achieved with UV detection at 270 nm over the concentration range 100–2000 ng per spot and 250–5000 ng per spot with mean recovery of 98.9 ± 0.9 and 99.6 ± 0.7 % for tamsulosin hydrochloride and finasteride, respectively, by the TLC method. Both methods are simple, precise, accurate and sensitive and are applicable to the simultaneous determination of tamsulosin hydrochloride and finasteride in bulk drug and in combined dosage forms
Reduction and desymmetrisation of the uranyl dication in a macrocyclic framework
No full textThe transamination reaction between a Schiff base polypyrrolic macrocycle, H4Ltet/oct,
where tet = tetramethyl (C38H36N8), oct = octamethyl (C42H44N8), and
[UO2(THF)2{N(SiMe3)2}] results in the sole formation of mono uranyl complexes
[UO2(THF)(H2Ltet)], 7, and [UO2(THF)(H2Loct)], 8. The molecular structure of 8 was
confirmed by an X-ray diffraction study which shows that the macrocycle folds to form
a Pac-man shape. The reaction between 7 and [M{N(SiMe3)2}2], where M = Mn, Fe, Co
or Zn, results in the formation heterobimetallic complexes, [UO2(THF)M(THF)(Ltet)], 9,
10, 11, and 13, respectively. The structures of 9 and 11 have been confirmed by X-ray
crystallography and show that there is a direct donor bond from one oxo ligand of the
uranyl dication to the transition metal, and characterisation by vibrational spectroscopy
suggests that the bonding of the uranyl dication has weakened. The double deprotonation
of 8 with KN(SiMe2R)2, where R = Me, Ph, and subsequent salt elimination reaction
with MX2, where M = Fe, X = I and M = Zn, X = I, Cl, results in the formation of the
first discrete reductively functionalised pentavalent uranyl complexes
[UO(OSiMe3)(THF)(FeI)2(Loct)], 17, [UO(OSiMe2Ph)(THF)(FeI)2(Loct)], 18,
[UO(OSiMe3)(THF)(ZnI)2(Loct)], 19, and [UO(OSiMe3)(THF)(ZnCl)2(Loct)], 20, which
contain a covalent Si–O bond to one oxo-group. Complexes 17 to 20 have been fully
characterised and the solid state molecular structures of 17 and 19 were determined.
Investigation into the mechanism of the functionalisation suggests that the intermediate
complex [UO2(THF)(K2L)] is highly oxidising and reactive and promotes the single electron transfer reaction with trimethylsilyl reagents and results in the homolytic
cleavage of bonds and concurrent reduction of the uranyl ion. The solution redox
properties of 8 have been measured by cyclic voltammetry, and exhibits a single electron
reduction at -1.17 V (vs. Fc/Fc+). The reaction of 8 with one equivalent of cobaltocene
results in the formation of the pentavalent uranyl complex [CoCp2][UO2(THF)(H2Loct)],
26. The reaction of 8 with two or three equivalents of B(C6F5)3 results in the formation
of [UO2(H2Loct)B(C6F5)3], 31, and [UO2(H2Loct)(B{C6F5}3)2], 34, respectively, which are
examples of uranyl macrocyclic borane adducts. Reaction of complex 31 with an excess
of PMe3 results in the formation of the THF-free uranyl macrocyclic complex
[UO2(H2Loct)], 35
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