| 1. |
- Andersson, M., et al.
(author)
-
A New Class of Labile Surfactants that Break Down to Non-surface Active Products upon Heating or after a Pre-set Time, without the Need for a pH Change
- 2007
-
In: Tenside Surfactants Detergents. - : Walter de Gruyter GmbH. - 0932-3414 .- 2195-8564. ; 44:6, s. 366-372
-
Journal article (peer-reviewed)abstract
- A new class of labile surfactants that break down at a controllable rate without the need for a change in pH will be presented. The invention has been patented by YKI Institute for Surface Chemistry, and is based on use of β-keto acids or their salts as surface-active compounds. These surfactants spontaneously break down through decarboxylation, to form an oil-like ketone and CO 2/HCO 3 -/CO 32 - depending on pH. The rate of breakdown can be controlled within a wide range by temperature or by certain additives, but, unlike most cleavable surfactants, a change in pH is not needed. Furthermore the surfactants can be conveniently activated from a stabile precursor just before use, and one (of many possible) precursors of this kind is already available on the industrial scale in the form of a wellknown chemical that is FDA-approved in other, non-surfactant, applications. The compound in question, alkyl ketene dimer (AKD), is produced in large scale by a number of large chemical producers today, and used for hydrophobization of paper. The present article gives an overview of the surfactant chemistry, with focus on recent studies of the kinetics of activation of the surfactant precursor and breakdown kinetics of the labile surfactant at different conditions. Furthermore, possible industrial applications of the surfactant will be discussed, with one example taken from a recent feasibility study performed within the car washing area. © Carl Hanser Publisher.
|
|
| 2. |
- Hull, A, et al.
(author)
-
Vapour-liquid equilibrium of binary mixtures. 1. Ethanol-1-butanol, ethanol + octane, 1-butanol + octane
- 2006
-
In: Journal of Chemical and Engineering Data. - 0021-9568 .- 1520-5134. ; 51, s. 1996-2001
-
Journal article (peer-reviewed)abstract
- The activity coefficients of the binary mixtures ethanol + 1-butanol, ethanol + octane, and 1-butanol + octane were determined at temperatures of (308.15, 313.15, and 318.15) K. The determination of the vapor phase composition at equilibrium was carried out using headspace gas chromatography analysis. Multiple headspace extraction was used to calibrate the headspace gas chromatograph. Comparison of the phase diagrams produced using standard Legendre orthogonal polynomial techniques with phase diagrams from the literature showed good agreement. The composition of the azeotropes were reported, where applicable.
|
|
| 3. |
- Hull, A, et al.
(author)
-
Vapour-liquid equilibrium of binary mixtures. 2. Ethanol + 2,2,4-trimethylpentane, 1-butanol + 2,2,4-trimethylpentane, and ethanol + o-xylene
- 2006
-
In: Journal of Chemical and Engineering Data. - 0021-9568 .- 1520-5134. ; 51, s. 2002-2008
-
Journal article (peer-reviewed)abstract
- The activity coefficients of the binary mixtures ethanol + 2,2,4-trimethylpentane, 1-butanol + 2,2,4-trimethylpentane, and ethanol + o-xylene were determined at temperatures of (308.15, 313.15, and 318.15) K. The determination of the vapor phase composition at equilibrium was carried out using headspace gas chromatography analysis. Multiple headspace extraction was used to calibrate the headspace gas chromatograph. Comparison of the experimental phase diagrams with phase diagrams from the literature shows good agreement. The composition of the azeotropes are reported, where they exist. The molar Gibbs energy of mixing is reported for all mixtures studied. The infinite dilution activity coefficients are reported for all components of all mixtures. Some thermodynamic models (those of Wilson, NRTL, UNIQUAC, and Flory-Scatchard) have been compared with regard to their suitability for modeling the experimental data.
|
|
| 4. |
- Hull, Angelica, et al.
(author)
-
Alternative fuel for a standard diesel engine
- 2006
-
In: International Journal of Engine Research. - 1468-0874 .- 2041-3149. ; 7:1, s. 51-63
-
Journal article (peer-reviewed)abstract
- Alternative fuels have been developed for the commercial diesel products Mkl and EN590. Appropriate additives were selected from a broad range of oxygenates including alcohols, acetals, ethers, esters, and nitrates by a process of systematic elimination. The resulting fuels called Biodiesel 15 meet all existing standards in force for diesel fuel, are stable, and have similar performance characteristics to standard diesel. Significantly Biodiesel 15 is much cleaner than standard diesel with around 30 per cent or more reductions in particulate matter in the exhaust emissions. Carbon dioxide (CO2) emissions are much lower with Biodiesel 15 than with standard diesel products. Other regulated emissions are on a par with Mkl. The fuel consumption of Biodiesel 15 is 2 per cent lower than that of conventional Mkl.
|
|
| 5. |
- Hull, A, et al.
(author)
-
An alternative fuel for spark ignition engines
- 2006
-
In: International Journal of Engine Research. - 1468-0874 .- 2041-3149. ; 7, s. 203-214
-
Journal article (peer-reviewed)abstract
- Alternative fuels have been developed for standard spark ignition engines. The fuels, which contain generic bio components, maintain all the advantages of ethanol, that is the ability to increase considerably the octane number of gasoline and reduce the amount of harmful pollutants in the exhaust emissions of engines operating on such blends. In contrast to ethanol the new fuel components do not increase the vapour pressure of gasoline-ethanol blends, have a better tolerance to water and do not increase the fuel consumption. The bio component based fuels also compare favourably with mineral sourced octane boosters such as MTBE. Additionally reformulation of the base gasoline becomes unnecessary.
|
|
| 6. |
|
|
| 7. |
- Hull, Angelica, et al.
(author)
-
Vapour-Liquid Equilibrium of Binary Mixtures. Part II; ethanol+2,2,4-trimethyl pentane, 1-butanol+2,2,4-trimethyl pentane, ethanol+o-xylene
- 2006
-
In: J. Chem. Eng. Data, 2006, 51, 2002-2008.
-
Journal article (peer-reviewed)
|
|
| 8. |
- Kizling, J, et al.
(author)
-
On the formation and stability of high internal phase O/W emulsions
- 2006
-
In: Advances in Colloid and Interface Science. - 0001-8686 .- 1873-3727. ; 123-126, s. 295–302-
-
Journal article (peer-reviewed)abstract
- High internal phase o/w emulsions have been investigated with respect to stability. A series of aliphatic hydrocarbons were used as the oil component. By matching the refractive index of both phases, transparent, concentrated emulsions were produced and these emulsions were found to have the highest long-term stability. The long-term stability of transparent emulsions is attributed to a minimum in free energy at the equilibrium thickness, which, in turn, is related to a reduced attraction over the thin aqueous lamellae. Another factor that contributes to the stability is the absence of the destabilizing mechanisms commonly encountered for ordinary emulsions and foams.
|
|
| 9. |
- Retino, A., et al.
(author)
-
Cluster observations of energetic electrons and electromagnetic fields within a reconnecting thin current sheet in the Earth's magnetotail
- 2008
-
In: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 113:A12
-
Journal article (peer-reviewed)abstract
- We study the acceleration of energetic electrons during magnetotail reconnection by using Cluster simultaneous measurements of three-dimensional electron distribution functions, electric and magnetic fields, and waves in a thin current sheet. We present observations of two consecutive current sheet crossings where the flux of electrons 35 127 keV peaks within an interval of tailward flows. The first crossing shows the signatures of a tailward moving flux rope. The observed magnetic field and density indicate that the flux rope was very dynamic, and a comparison with numerical simulation suggests a crossing right after coalescence of smaller flux ropes. The second crossing occurs within the ion diffusion region. The flux of electrons is largest within the flux rope where they are mainly directed perpendicular to the magnetic field. At the magnetic separatrices, the fluxes are smaller, but the energy spectra are harder and electrons are mainly field aligned. Reconnection electric fields E-Y similar to 7 mV/m are observed within the diffusion region, whereas in the flux rope, EY are much smaller. Waves around lower hybrid frequency do not show a clear correlation with energetic electrons. We interpret the field-aligned electrons at the separatrices as directly accelerated by the reconnection electric field in the diffusion region, whereas we interpret the perpendicular electrons as trapped within the flux rope and accelerated by a combination of betatron acceleration with nonadiabatic pitch-angle scattering. Our observations indicate that thin current sheets during dynamic reconnection are important for in situ production of energetic electrons and that simultaneous measurements of electrons and electromagnetic fields within thin sheets are crucial to understand the acceleration mechanisms.
|
|
| 10. |
|
|
| 11. |
- Virtanen, S. M., et al.
(author)
-
Age at introduction of new foods and advanced beta cell autoimmunity in young children with HLA-conferred susceptibility to type 1 diabetes
- 2006
-
In: Diabetologia. - Natl Publ Hlth Inst, Dept Hlth Promot & Chron Dis Prevent, Helsinki 00300, Finland. Tampere Univ, Tampere Sch Publ Hlth, FIN-33101 Tampere, Finland. Tampere Univ Hosp, Res Unit, Tampere, Finland. London Sch Hyg & Trop Med, Dept Epidemiol & Populat Hlth, Med Stat Unit, London WC1, England. Finnish Canc Registry, Helsinki, Finland. Univ Helsinki, Dept Publ Hlth, Helsinki, Finland. : SPRINGER. - 0012-186X .- 1432-0428. ; 49:7, s. 1512-1521
-
Journal article (peer-reviewed)abstract
- Aims/hypothesis: Evidence for the role of infant feeding in the development of beta cell autoimmunity is inconsistent. We set out to study the effects of breastfeeding and of age at introduction of supplementary foods on the development of beta cell autoimmunity. Subjects and methods: A prospective birth cohort of 3,565 infants with HLA-DQB1-conferred susceptibility to type 1 diabetes was recruited between 1996 and 2001 from two university hospital areas in Finland. Blood samples were collected at 3- to 12-month intervals to measure antibodies against islet cells, insulin, glutamate dehydroxylase and islet antigen 2. The families kept a record on the age at introduction of new foods, and for each visit completed a structured dietary questionnaire. The endpoint was repeated positivity for islet cell antibodies together with at least one of the other three antibodies. Results: The overall or exclusive duration of breastfeeding was not associated with the risk of developing the endpoint. An early age at introduction of fruits and berries (<= 4 months) was related to increased risk of developing positivity for the endpoint (hazard ratio [95% CI] for earliest tertile 2.02 [1.03-3.95] and for midtertile 1.97 [1.06-3.64] compared with latest tertile > 4 months). Also, introducing roots between 3 and 3.9 months (midtertile) was related to increased risk of the endpoint (hazard ratio [95% CI] for the earliest tertile 1.04 [0.57-1.90] and for midtertile 1.82 [1.19-2.79] compared with latest tertile). These associations were independent of several putative socio-demographic and perinatal confounding factors. Conclusions/interpretation: Our findings suggest that an early age at introduction of fruits and berries and roots associates independently with beta cell autoimmunity, contradicting earlier findings from smaller birth cohort studies.
|
|
