- The brush of a motor tooth
-
A cleaning section (10; 110) of an electrical toothbrush having a motor and a drive shaft, the cleaning section (10; 110) comprising a movable bristle holder (26; 126) structured to receive a drive motion from the motor via the drive shaft having a longitudinal axis, wherein the drive shaft is structured to oscillate around its longitudinal axis a head (22; 122) including a first plurality of cleaning bristles (24; 124) arranged in a static bristle field and a second plurality of cleaning bristles (28; 128) supported within the movable bristle holder to have at least one freedom of motion relative to the first plurality of cleaning bristles, wherein the movable bristle holder (26; 126) is movable with respect to the head and the static bristle field such that a cleaning motion of the second plurality of bristles includes an oscillating movement relative to the first plurality of cleaning bristles, and wherein the oscillating movement of the second plurality of bristles is caused by the oscillating movement of the drive shaft, and wherein the head further includes an opening (42; 142) sized to receive the movable bristle holder (26; 126) therein.
- -
-
-
- New sources of "active" halogen bis(dialkylamide)hydrogen dibromobromates, efficient reagents for destruction of ecotoxicants
-
Bis(dialkylamide)hydrogen dibromobromates were synthesized and their reactivity was investigated in decomposition of diethylphosphonic, diethylphosphoric, and 4-toluenesulfonic acids 4-nitrophenyl esters. The nucleophilic reactivity of a typical α-nucleop
- Prokop'eva,Mikhailov,Turovskaya,Karpichev,Burakov,Savelova,Kapitanov,Popov
-
experimental part
p. 637 - 646
(2009/04/10)
-
- Inorganic anionic oxygen-containing α-nucleophiles - Effective acyl group acceptors: Hydroxylamine ranks first among the α-nucleophile series
-
Comparative analysis of the nucleophilicity of inorganic oxygen-containing α-nucleophiles (hydroxylamine and ClO-, BrO--, HOO--, NH2O-, and F- ions) covering the pKa range from -2 to 13.81 toward 4-nitrophenyl esters (4-nitrophenyl acetate, 4-nitrophenyl p-toluenesulfonate, diethyl 4-nitrophenyl phosphate, ethyl 4-nitrophenyl ethylphosphonate, and 4-nitrophenyl dimethylcarbamate) in water at 25°C (ionic strength μ 1.0, KCl) was performed in terms of the extrathermodynamic Brosted relation. It was found for the first time that hydroxylamine anion ranks first among the series of α-nucleophiles. It is more reactive than HOO- ion with respect to 4-nitrophenyl acetate (by a factor of ~8), 4-nitrophenyl p-toluenesulfonate (by a factor of ~4) and 4-nitrophenyl dimethylcarbamate (by a factor of ~10). The nucleophilicities of HOO- and NH 2O- ions toward diethyl 4-nitrophenyl phosphate and ethyl 4-nitrophenyl ethylphosphonate are comparable. Taking into account that neutral hydroxylamine exhibits an anomalously high reactivity, as compared to not only common organic but also inorganic α-nucleophiles, it may be regarded as a unique α-nucleophile. Both neutral hydroxylamine and its anion as O-nucleophiles ensure high rates of acyl group transfer throughout a wide range of pH.
- Simanenko,Popov,Prokop'eva,Karpichev,Savelova,Suprun,Bunton
-
p. 1286 - 1298
(2007/10/03)
-
- Reactivity of methoxide ion in concentrated methanolic solutions of Et4NOCH3 and Et4NCl
-
Bimolecular rate constants k were determined for reactions of 4-nitrophenyl 4-toluenesulfonate, diethyl 4-nitrophenyl phosphate, and ethyl 4-nitrophenyl ethylphosphonate with tetraethylammonium methoxide Et4NOCH3 in methanol at 25°C over a wide range of Et4NOCH3 concentrations, where the reagent acts simultaneously as electrolyte, and at [Et4NOCH3] ≤ 0.1 M (reagent) with variation of Et4NCl (electrolyte) concentration. The relation logk = logk0 + b[Et4NX] is fulfilled up to [Et4NX] = 3.5 M, indicating that the electrolyte affects the reaction rate through restructurization of methanol as reaction medium.
- Savelova,Belousova,Simanenko,Popov
-
p. 1790 - 1796
(2007/10/03)
-