Hasil untuk "physics.app-ph"

ENI PURWANI, ALIYA M. PUTRI, AAN SOFYAN

Objective: There is no further research related to the development of Pegagan leaves; this innovation is expected to be able to process a product that is useful for health, one of which can be used as a functional drink. Therefore from that, he purpose is to research the effects of the combination of black tea with Pegagan leaves (Centella asiatica) on pH, total acids, and flavonoids. Methods: The type of this study was experimental. This study was conducted by combining black tea with different Pegagan leaves. The research design used a Completely Randomized Design with 3 combinations of Pegagan leaves in black tea, which were P1 (0%:100, P2(25%:75), and P3(50%:50). Results: The results showed the highest flavonoid levels in the combination of black tea with P3 Pegagan leaf tea (50%:50%) of 0.020%. There was no significant effect on the pH value and total acid content. However, on the flavonoid content, there was a significant effect on the combination of black tea and Pegagan leaf tea. Conclusion: Based on the results of the study, it can be concluded that the combination of black tea and Pegagan leaf tea had no effect on pH value (p=0.911) and total acids (p=0.749). In the flavonoid level, the results of the study showed that there was an effect on the combination of black tea and Pegagan leaf tea (p=0.007).

Roger Marrannes

Sanjib Kumar Agarwalla

The discovery of neutrino mixing and oscillations over the past decade provides firm evidence for new physics beyond the Standard Model. Recently,θ13has been determined to be moderately large, quite close to its previous upper bound. This represents a significant milestone in establishing the three-flavor oscillation picture of neutrinos. It has opened up exciting prospects for current and future long-baseline neutrino oscillation experiments towards addressing the remaining fundamental questions, in particular the type of the neutrino mass hierarchy and the possible presence of a CP-violating phase. Another recent and crucial development is the indication of non-maximal 2-3 mixing angle, causing the octant ambiguity ofθ23. In this paper, I will review the phenomenology of long-baseline neutrino oscillations with a special emphasis on sub-leading three-flavor effects, which will play a crucial role in resolving these unknowns. First, I will give a brief description of neutrino oscillation phenomenon. Then, I will discuss our present global understanding of the neutrino mass-mixing parameters and will identify the major unknowns in this sector. After that, I will present the physics reach of current generation long-baseline experiments. Finally, I will conclude with a discussion on the physics capabilities of accelerator-driven possible future long-baseline precision oscillation facilities.

Mateusz L. Donten, Peter Hamm

Ph. Hägler

Guohua Jiang

AbstractThe intracellular delivery of active biomacromolecules from endosomes into the cytoplasm generally requires a membrane‐disrupting agent. Since endosomes have a slightly acidic pH, anionic carboxylated polymers could be potentially useful for this purpose because they can destabilize membrane bilayers by pH‐triggered conformational change. In this study, different pH‐sensitive 2‐ethylacrylic acid and alkyl methacrylate [butyl methacrylate and hexyl methacrylate] copolymers were synthesized by reversible addition‐fragmentation chain transfer polymerization with high yields. pH‐dependent membrane disruptive activity was investigated with respect to their physicochemical and membrane lytic properties as a function of pH, concentration, and molecular weight. Hemolysis assays demonstrated that the presence of the hydrophobic monomer and sufficient protonation of the carboxylic acid groups were important parameters for efficient membrane destabilization. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Bumsang Kim, Youngchan Shin

AbstractThe pH‐sensitive swelling and release behaviors of the anionic P(MAA‐co‐EGMA) hydrogels were investigated as a biological on–off switch for the design of an intelligent drug delivery system triggered by external pH changes. There was a drastic change of the equilibrium weight swelling ratio of P(MAA‐co‐EGMA) hydrogels at a pH of around 5, which is the pKa of poly (methacrylic acid) (PMAA). At a pH below 5, the hydrogels were in a relatively collapsed state but at a pH higher than 5, the hydrogels swelled to a high degree. When the molecular weight of the pendent poly(ethylene glycol) (PEG) of the P(MAA‐co‐EGMA) increased, the swelling ratio decreased at a pH higher than 5. The pKa values of the P(MAA‐co‐EGMA) hydrogels moved to a higher pH range as the pendent PEG molecular weight increased. When the feed concentration of the crosslinker of the hydrogel increased the swelling ratio of the P(MAA‐co‐EGMA) hydrogels decreased at a pH higher than 5. In release experiments using Rhodamine B (Rh‐B) as a model solute, the P(MAA‐co‐EGMA) hydrogels showed a pH‐sensitive release behavior. At low pH (pH 4.0) a small amount of Rh‐B was released while at high pH (pH 6.0) a relatively large amount of Rh‐B was released from the hydrogels. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

C. Ducoin, Ph. Chomaz, F. Gulminelli

Ph. Hägler

S. T. Eckersley, A. Rudin

AbstractThe effect of several variables relevant to film formation in 49 : 49 : 2 poly(methyl methacrylate‐co‐butyl acrylate‐co‐methacrylic acid) latexes were studied.Plasticization of the terpolymer by both an anionic [sodium dodecyl benzene sulphonate (NaDBS)] and a nonionic [nonyl phenol ethylene oxide adduct (NP40), forty ethylene oxide units on average] surfactant were investigated. Dynamic mechanical measurements indicated that NP40 plasticized the polymer, whereas NaDBS did not. This was attributed to the compatibility of the nonionic emulsifier and the polymer. The influence of the surfactants on the film formation process was studied using minimum film temperature (MFT) measurements and scanning electron microscopy (SEM). As expected, the MFT was independent of NaDBS concentration. However, the MFT was also independent of NP40 concentration. Film formation was further investigated using SEM. The series of micrographs at varying NaDBS concentrations showed no effect on the degree of film fusion. However, surface exudates were observed. The micrographs revealed that increasing NP40 content resulted in an apparently greater degree of film coalescence. That is, there was bridging of the particles in the interstitial regions. This was attributed to localized plasticization of the polymer in these regions by NP40.The effect of water plasticization of the latex polymer was studied using dynamic mechanical measurements. The physical character of the terpolymer was varied using mol wt modifiers (CBr4 chain transfer agent and ethylene glycol dimethacrylate crosslinker). It was found that all of the polymers were plasticized by water.Finally, the film forming behavior was investigated as a function of latex pH. MFT measurements indicated an independence of pH. © 1993 John Wiley & Sons, Inc.

L Alvarez-Gaumé, Ph Zaugg

M. Benayoun, Ph. Leruste, J.L. Narjoux et al.

Ph Brax, J Mourad

Hongmei Kang, Jianjun Xie

AbstractPolyacrylate superabsorbent (PAS) was synthesized by aqueous solution polymerization crosslinked by N,N‐methylene bisacrylamide. The effect of pH and concentration of several solutions on absorbency (Q) of PAS was studied. The results showed that the absorbency increased at first and then decreased with the increase of the solution's pH; the summit of the absorbing curve was attained when pH was about 6.25. The relation between absorbency and pH could be represented by a quadratic equation and the square difference was relatively small. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 494–499, 2003

T.R. Ophel, S.D. Cloud, Ph. Martin et al.

P. Parneix, Ph. Bréchignac, F. Calvo

Ph. Blanchard, A. Jadczyk

Ph. Labbe, B. Raveau

Alexandra Boltasseva