• Journal of Food Hygiene and Safety
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• v.13 no.3
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• pp.189-195
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• 1998

Comparative insecticidal efficiency between compounded pyrethroids and its preparations cooperated with several synergists was studied. As main components, Group A contained Permethrine.Phthalthrine, Group B contained Permethrine.Furameth rine and Group C contained Phthalthrine.Dichlorvos. As synergists Piperonyl Butoxide (P.B.O.), N-Octylbicycloheptene dicarboximide (MGK-264), Octachlorodipropylether (8-421) was cooperated in each group. These preparations was treated to either Blattella G. or Musca D. for comparing about insecticidal efficiency[Knock-down rate ($KT_{50},\;KT_{90}$) and cumulative mortaility(percent/hrs)]. When the synergists was added to each Group, the insecticidal efficiency was improved. The most potent synergists was P.B.O. and the potency was decreased in the rank order of S-421>MGK-264. The more the concentration of synergists was increased, the more the insecticidal efficiency was improved. The rank order was $1:5{\geq}1:4>1.3$ in all three groups. The mortality (percent) according to time was similar to either $KT_{50}\;or\;KT_{90}$. Knock-down rate was appropriate parameter for the indicator about potency.

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.1
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• pp.51-56
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• 2001

Field experiments were conducted to find out the effec- tive control measures with some bases alone and in combination with Dichlorvos and Dimethoate for the whitefly Aleuroclava sp. Singh in the mulberry garden. Four common bases marketed in India Soda, Sunlight, Nirma and Surf at 1% concentration and their synergists with 0.02% Dichlorvos and 0.03% Dimethoate applied to mulberry plants reduced the whitefly by 46-95% (adults) 50-90% (nymphs) upto 15 days of application. Amongst the bases 1% Soda is more effective but, the mixing of 0.02% Dichlorvos with 1% Surf found more effective than 0.02% Dichlorvos With 1% Soda solution. As Surf and Dichlorvos mixture is costly for the control of whitely, Soda was found better (in combination with Dichlorvos) as it is cheaper and easily available to the farmers.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.759-763
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• 1993

The antioxidant effects of aqueous green tea extract(AGTE) obtained from green tea and its combinations with several synergists on lard were investigated to equalize with that of crude catechin in green tea. The antioxidant effect of crude catechin was about 3-fold higher than that of AGTE. The suitable synergists for AGTE were ${\delta}-tocopherol$ and lecithin, while the tendency of their synergistic effects was different from each other. Addition of ${\delta}-tocopherol$ within 0.05% dosage to lard showed significant synergistic effect, and its synergistic effect decreased with the concentration of AGTE over 0.1% dosage. In combination of AGTE and lecithin, they gradually enhanced synergistic effect on lard with increasing the concentration. The combinations of AGTE, ${\delta}-tocopherol$ and lecithin showed intense synergistic effects and the optimum level of the each component was 0.1% AGTE, 0.05% ${\delta}-tocopherol$ and 1% lecithin. By adding the optimum level of three components to lard, the induction period was lenghtened approximately 8-fold than that of the control owing to their synergism. Comparing the antioxidant effect between the AGTE with synergists and crude catechin, the former was 60% and 20% higher than the latter at 0.1% and 1% dosage respectively.

• Korean journal of applied entomology
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• v.31 no.3
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• pp.314-327
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• 1992

Insecticide resistance is a serious is a serious threat to IPM, resulting in various adverse effects not to mention the loss of yield in agriculture. One approach to counter the problem is the disruption of resistance mechanisms. This can be achieved by (1) compounds which show a negative correlation with resistance at the site of action, (2) specific metabolic inhibitors which serve as synergists, or (3) a certain combination of two insecticides producing a joint action. This approach, however, requires certain precautions for the side effects may cause an increase in toxicity to mammals. Owing to the recent advances in theoretical studies on resistance management employing computer simulation and mathematical models, a few principles to reduce the risk of development of resistance have been clarified. They are helpful in designing operational strategies with regard to, for instance, insecticide doses to be applied, mode of application, and choice and nature of the insecticide(s) to be used. For restoration of insecticide susceptibility of a resistant population, reintroduction of susceptible individuals to the resistant population is feasible when certain conditions are met. Natural enemies which developed resistance to insecticides can be an important component of IPM as has been shown in the pest management in apple orchards. After all, the implementation of a successful resistance management program depends upon cooperation between different sigments of the agricutural community. Although resistance is a preadaptive phenomenon, in some cases spontaneous loss of resistance does occur without contamination by susceptible individuals. The instability of resistance in these insects implies the possible existence of a switch machanism controlling the expression of resistance gene(s). Elucidation of such a mechanism may eventually provide us with a new technical approach with which we can combat the problem of insecticide resistance.

• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.547-551
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• 1992

The antioxidative effects of Rhus javanica $Linn{\acute{e}}$ ethanol extract (RE) with or without some synergists were determined by measurement of POV and TBA of oil in ramyun and potato flake fried in palm oil or lard. RE with ascorbic acid and with tocopherol significantly increased the oxidative stability of ramyun. The results obtained from sensory evaluation were similar to those of POV and TBA values. RE with phosphoric acid and with ascorbic acid retarded the oxidation of potato flakes fried in palm oil or lard during storage.

• Korean journal of applied entomology
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• v.35 no.3
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• pp.238-242
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• 1996

The second instar milkweed bugs, Oncopeltus fasciatus were exposed to the residue of 6-methoxy-7-ethoxy-2, 2- dimethylchromene(or 7-ethoxy precocene 11, 7-EP-11) with one, two, or four different kinds of synergist(s) deposited as a residue on 9 cm diameter petri dishes. The anti juvenile hormone analog, 7-EP-I1 yielded a 50% effectiveness concentration at 1.18 wg/cmZ. The concentration of 7-EP-I1 and R020-9747 combined gave 0.084 ~*g/cm', as much 14 times more potent than with 7-EP-I1 alone. Most of the other synergists, including geraniol, 4-chalcone oxide, isosafrole, and piperonyl butoxide however, showed comparatively low level synergism with 1.0-4.3 times, depending upon the combinations of the synergist(s). The obtained results were considered that R020-9747, an analog of benzopyran with similar structure to that of 7-EP-I1 inhibited selectively the insect monooxygenase oxidative defense mechanism, in the body except for corpora allata because general antioxidants of piperonyl butoxide, isosafrole, and 4-phenyl chalcone oxide showed relatively mild synergism.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.56-63
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• 2003

Flame retardancy and mechanical properties of recycled polyolefinic plastics/inorganic filler composite systems were investigated by using several inorganic flame retardants such as magnesium hydroxide and slag powder generated electro arc furnace Compatibilizer user each maleic anhydride functionalized polyethylene (PE-g-MAH) and polypropylene(PP-g-MAH) or used mixture of these. The effect of polymeric compatibilizers on the properties of composites was studied by tensile and impact test, differential scanning calorimetry, in the changed fracture mechanism. The improved adhesion was particularly reflected in the mechanical properties. The flame retardancy of composites was examined by measuring limiting oxygen index(LOI, ASTM D2863), smoke density(ASTM D2843) and vertical burning test(UL94). Regarding the flame retardant effect, the EAF slag powder is behaving as synergists as they are only active in the presence of magnesium hydroxide.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.683-688
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• 1993

The antioxidative effect of the 75% ethanol extracts of preliminary selected Fritillaria ussuriensis Max(Fs), Houttuynia cordata Thunb(Hc), Portulaca oleracea L.(Po) and Perilla frutescene Var javanica Hara cake(Pf) were tested on palm oil and lard by rancimat test. Each solvent fraction of chloroform, ethyl acetate(EtOAc), butanol and water, was also evaluated its antioxidative effect with some synergists, like as ascorbic acid, citric acid and ${\delta}-tocopherol$. Po extract showed higher antioxidative effect on lard and the fraction of all test plants were the most effective on palm oil and lard with ascorbic acid and ${\delta}-tocopherol$. When 200 ppm of EtOAc fraction of Fs, He and Po extract each with 200 ppm of ascorbic acid were added to palm oil, the antioxidative index(AI, induction time of oil containing each extract/induction time of test oil) were 1.60, 1.53 and 1.47 respectively and 200 ppm of EtOAc fraction of Po and Pf extract each with 200 ppm of tocopherol to lard, the AI were 3.19 and 3.63 respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.5
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• pp.589-594
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• 2007

The effect of synergists having chelating ability on inhibiting browning were studied with a giucose-glutamic acid model for doenjang containing citric acid as the anti-browning agent and iron ion. The model solutions were prepared by dissolving 0.1 M glucose, 0.1 M glutamic acid, 50 mM citric acid, 0.2 mM $FeCl_2$ and synergist in 1 M phosphate buffer (pH 7.0), heating at $50^{\circ}C$ for 24 hr and storing at $30^{\circ}C\;or\;40^{\circ}C$ for four weeks. Synergists were chitosan, gallic acid, methyl benzoate, pyrophosphate and tannic acid; they were used at the following concentrations: gallic acid, pyrophosphate and tannic acid at 0.015% and 0.15%; chitosan and methyl benzoate at 0.0075% and 0.015%. Anti-browning capacities had a tendency to decrease greatly after three weeks in the case of storage at $30^{\circ}C$, whereas they decreased with storage time during storage at $40^{\circ}C$. However, anti-browning capacities of samples containing 0.015% tannic acid and 0.15% pyrophosphate were higher than that of sample without synergist by 32% after storage at $30^{\circ}C$ for four weeks. Gallic acid, tannic acid and pyrophsphate also inhibited the formation of Maillard reaction intermediates such as fluorescent compound and 3-deoxyglucosone due to the high chelating ability with iron ion after four weeks of storage at $30^{\circ}C$. The effect of these compounds on the inhibition of formation of Maillard reaction intermediates was higher at 0.15% than at 0.015%. Moreover, gallic acid increased the browning by forming colored complexes, and tannic acid generated black precipitates. Therefore, pyrophosphate of food additives was found to be the most useful synergist of citric acid, the anti-browning agent for doenjang.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.563-568
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• 1988

Relative effectiveness of antioxidants with their synergists was investigated by measuring AOM stability of palm oil and beef tallow during heating. TBHQ added at a concentration of 0.02% gave the highest AOM stability to palm oil among the antioxidants tested at the equivalent concentration. Beef tallow with added TBHQ showed a higher AOM stability than those with α-tocopherol$({\alpha}-toc)$ and a mixture of BHA and BHT, but showed a lower AOM stability than those with {$\delta}-rich$ tocopherol$({\delta}-toc)$ and mixed tocopherol(m-toc). Addition of ${\alpha}-toc$ to palm oil and beef tallow increased the AOM stability less than a mixture of BHA and BHT. Palm oil and beef tallow with added ${\delta}-toc$ and m-toc showed higher AOM stabilities than that with ${\alpha}-toc$, and there was no significant difference in AOM stability noted between ${\delta}-toc$ and m-toc. The synergistic effects of citric acid to ${\alpha}-toc\;and\;{\delta}-toc$ and of ascorbyl palmitate to ${\delta}-toc$ was noted higher in beef tallow than in palm oil, while that of ascorbyl palmitate to ${\alpha}-toc$ was higher in palm oil than in beef tallow.