Acute Toxicity of Clethodim, Cypermethrin and 2,4-D-butylate to the Larva of Chironomus sinicus

[Objective] The aim of this study was to detect the acute toxicity of clethodim, cypermethrin and 2,4-D-butylate. [Method] Chironomus sinicus larvae were exposed to different concentrations of clethodim, cypermethrin and 2,4-D-butylate. Survival rate, lethal concentration 50 （LC50） and superoxide dismutase （SOD） activity in the homogenate of the larvae were monitored to detect the toxicity of the pesti- cides. [Result] The survival rates of C. sinicus larvae exposed to cypermethrin and 2,4-D-butylate for 12 h were almost unchanged at different concentrations, but de- creased with concentration increasing 48 h later. For each pesticide, the differences in survival rates of C. sinicus larvae at 48 h were significant. The 48 h LC50 of clethodim, cypermethrin and 2,4-D-butylate to C. sinicus larvae were 1.842, 0.150 and 1.999 mg/L, respectively. The acute toxicity of cypermethrin was the highest a- mong the three pesticides and that of 2,4-D-butylate was the lowest. Clethodim sig- nificantly reduced the SOD content in a dose-dependent manner. 2,4-D-butylate also reduced SOD content in C. sinicus larvae, but the reduction was not significantly re- lated to its dosage. However, cypermethrin showed no significant effect on SOD ac- tivity in C. sinicus larvae.

Effect of butylated hydroxytoluene on quality of pre-frozen and frozen buffalo semen

Objective: To clarify the antioxidant effect of butylated hydroxytoulene (BHT) at different concentrations on cooled and post frozen semen diluted in tris-citrate-fructose egg yolk glycerol and lecithin -based extenders. Methods: Forty ejaculates were harvested from four buffalo bulls by means of the artificial vagina. Ejaculated semen samples were diluted with each of the tris citrate-fructose egg yolk glycerol and lecithin-based extender diluents. The semen samples diluted with each of the two extenders were added to pre-warmed dried test tubes containing BHT (prepared in ethanol) to get concentrations at 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mM/mL BHT. These ingredients were put at 37 ℃ for 5 min to allow the proper BHT spermatozoal permeation. The diluted semen samples were cooled to 5 ℃ and then frozen to -196 ℃ in 0.25 mL ministraws before dipping in liquid nitrogen pending its evaluation. Sperm motility, viability, morphology, intact acrosome and membrane integrity were tested. Visual motility was tested using a high power ordinary microscope (at 400 × ) with closed circuit television, and sperm concentration was tested using Neubauer haemocytometer and abnormality % using eosin-nigrosin stain. Spermatozoal membrane integrity was tested using the hypo-osmotic swelling test. The sperm with swollen twisting tail was normally intact. Sperm acrosomal integrity % was tested as mentioned by Watson. Results: Addition of BHT improved (P<0.01) progressive motility, viability, morphology and acrosome as well as plasma membrane integrities at 0.5-2.0 mM/mL depending upon types of used extenders and stages of pre-and post-freezing process. Higher levels of 2.5 and 3.0 mM/mL BHT had a deteriorating (P<0.01) result if compared to the control and all extenders assayed. Conclusions: BHT addition at lower concentration can improve pre-frozen and post-thawed buffalo sperm quality.

Influence of butylated hydroxytoluene addition to cryodiluents on freezability and DNA integrity of Boer and Zaraibi buck spermatozoa

Objective:To evaluate the cryoprotective effect of butylated hydroxytoluene on buck frozen semen.Methods:Semen was collected from Boer(n=6)and Zaraibi(n=6)bucks by electroejaculator for 5 weeks.Semen aliquots were diluted at 38℃in Tris-buffer with egg yolk 15.0%(vol/vol)(Tris-egg yolk extender)or soya lecithin 2.5%(weight/vol)(Tris-soya lecithin extender)supplemented with butylated hydroxytoluene at 0.0(as the control),0.5,1.0,2.0 and 4.0 mM.Post-thawing motility(at 400×magnification),plasma(hypo-osmotic swelling test),acrosome(Trypan blue/Giemsa dual staining)membranes,DNA(comet assay),and lipid peroxidation(by malondialdehyde concentration)were assessed.Results:Spermatozoa motility was enhanced by butylated hydroxytoluene in Tris-soya lecithin extender at 0.5 mM in the two breeds,and in Tris-egg yolk extender at 1.0 mM in Boer and at 2.0 mM in Zaraibi bucks for up to 3 h post-thawing.Plasma and acrosome membranes and DNA integrity of the two breeds were maximally high with butylated hydroxytoluene at 1.0-2.0 mM in Tris-egg yolk extender and at 0.5-1.0 mM in Tris-soya lecithin extender.Lipid peroxidation was minimal with butylated hydroxytoluene at 1.0-2.0 mM in Tris-egg yolk and soya lecithin extenders in the two breeds.Butylated hydroxytoluene at 4.0 mM deteriorated spermatozoa motility,and plasma and acrosome membranes.Conclusions:The consequence of butylated hydroxytoluene on buck frozen-thawed spermatozoa varies with the levels of supplementation,buck breed,and phospholipid source in the extender.Semen parameters of Boer buck are better in their response to butylated hydroxytoluene than Zaraibi buck.Butylated hydroxytoluene at 1.0 and 2.0 mM in Tris-egg yolk extender,and at 0.5 mM in Tris-soya lecithin extender represents the best concentrations and profitably improves the semen quality of buck semen.

Effect of Butylated Hydroxytoluene on Survival of Frozen-TIhawed Fighting Bull Spermatozoa

The aim of the present study was to evaluate effect of 3 levels of butylated hydroxytoluene （BHT） supplemented in extender for fighting bull semen. Ejaculates were obtained from 10 healthy fighting bulls by artificial vagina. Semen with motility of more than 70% was included in the experiment. Tris-fructose-glycerol-egg yolk extender containing 0, 1, 3 and 7 mM BHT was used to dilute semen to final concentration of 200 × 10^6 cells/ml. Diluted semen was frozen in 0.25 mL straws and frozen semen was thawed in a 37 ℃ water bath for 15 sec before being evaluated at 0 and 1 hour. Sperm motility at 0 and 1 hour after thawing did not differ among groups tested （ranged 47.86-53.57 and 21.79-24.29 respectively）. At 0 hour after thawing, percentage of live sperm of 3 mM BHT （37.39% ± 2.91%） was lower than those of 0 and 1 mM BHT （43.71%± 2.76% and 41.46% ±2.59% respectively, P 〈 0.05） but not different from 7 mM BHT （40.89%± 2.50%）. The effect was more significant at 1 hour after thawing and 3 mM BHT （32.07% ± 2.45%） suppressed live cells more than other concentrations （ranged 35.07%-37.46%, P 〈 0.05）. At 0 hour after thawing, percentage of membrane integrity （hypo-osmotic swelling test） was not affected by BHT concentration （ranged 23.89%-28.54%）. However, at 1 hour after thawing, percentage of membrane integrity of 3 mM BHT （19.75% ± 1.41%） was lower that of 7 mM BHT （23.29% ± 1.88%, P 〈 0.05） but not different from those of 0 and 1 mM BHT （20.32% ±1.81% and 22.07% ± 2.27% respectively）. No significant effect was found on percentage of abnormal sperm. There was no effect of BHT supplementation in extender on most of the Hamilton-thorn motility analyser parameters. It may be concluded that 3 mM BHT can be harmful to fighting bull spermatozoa and lower concentrmion can be used without detrimental effect. Further study may be needed to verify use of BHT in lower range of concentrations.

Butyl ether as Co-diluent in medium-concentrated electrolyte for Li-S battery

1. Introduction The Lithium-sulfur battery(LSB) shows promise as a highdensity energy source, with a theoretical energy density of approximately 2600 W h kg^(-1)[1]. However, practical application of the LSB has been hindered by the “shuttle effect” and Li anode corrosion [2,3]. Highly concentrated electrolytes(HCEs) have been proposed as a solution, as they can inhibit the dissolution of lithium polysulfide and promote homogeneous lithium deposition [4].

Effects of galvanic interaction between galena and pyrite on their flotation in the presence of butyl xanthate

The effects of galvanic interaction between galena and pyrite on their flotation and electrochemical characters were studied by electrochemical,adsorption,flotation and FTIR techniques,respectively.Electrochemical tests indicate that galena is electrochemically more active than pyrite and serves as an anode in galvanic combination with pyrite.The galvanic current density from a mixture of galena and pyrite is 4 times as high as the self corrosion current density of galena,which indicates that the corrosion rate of galena is accelerated.Adsorption tests show that the adsorption of butyl xanthate on galena surface is enhanced,and affected by a combination of pyrite-galena mixtures and conditioning time.Compared with individual mineral particles,galvanic interaction reduces the floatability difference between galena and pyrite.The flotation recovery of galena decreases while that of pyrite increases when two minerals are mixed together due to the influence of galvanic interaction on the formation of hydrophilic/hydrophobic product.The FTIR results show that the formation of dixanthogen on pyrite surface is depressed due to the galvanic interaction.

Investigation on the Factors Influencing the Synthesis of Butyl Polyglycosides and Its Synthesis Kinetics

[ Objective ] The paper was to study the factors influencing the synthesis of butyl polyglycosides and its synthesis kineties. [ Method ] In the synthesis process of alkyl polyglycosides by transglyeosidation method, p-toluenesulfonie acid and stearie acid were used as composite catalyst, intermediate product butyl polyglycosides was prepared via reactive distillation technology. [ Result ] The suitable preparation conditian of butyl polyglyeasides was as follows： catalyst usage, 1.2 g（ p-toluenesulfoni ：stearie acid = 6：1 ） ; reaction temperature, 110 ℃ ; the ratio of butanol and glucose, 8： 1. The results showed that the larger the molar ratio of butanol and glucose was,the more the butyl monoside content was, and the less the polymerizatian degree of butyl glyeasides was. The catalyst usage and reaction temperature had little influence on the component of butyl polyglyeesides. With the increase of catalyst usage or reaction temperature,the reaction time was shortened dramatically. The kinetic equation for the synthesis of butyl glueeside was finally obtained as follows： -dCA/dt =0.163 7exp（ -1. 968×10^3/RT）CA -0.003 49 exp （ -2.727×10^3/RT） Ce. [ Conclusionl The suitable condition for the preparation of butyl polyglyeasides and its synthesis kinetic equation obtained in the study could provide theoretical basis for the synthesis of long-chain alkyl polyglyeasides.

Floc flotation of marmatite fines in aqueous suspensions induced by butyl xanthate and ammonium dibutyl dithiophosphate

The hydrophobic flocculation of marmatite fines in aqueous suspensions induced by butyl xanthate （KBX） and ammonium dibutyl dithiophosphate （ADD） was investigated using laser particle size analysis, microscopy analysis, electrophoretic light scattering, contact angle measurement and infrared spectroscopy. The studies were performed on single minerals with size 〈20 μm by varying several parameters, including pH, collector concentration and kerosene addition. The results show that the floc fotation closely correlated with the size of flocs and the particle hydrophobicity, but was not lowered with increasing the particle surface charges due to collector adsorption. Under good operating conditions, the floc flotation of marmatite fines as a function of KBX and ADD can all reach floatability over 90%, in comparison with conventional flotation obtaining floatability of about 60%. It also has been found that a small addition of kerosene greatly improved the floc flotation because of the formation of oil films on marmatite particles. The results of FTIR spectra indicate that adsorption of the two collectors onto marmatite were chemical adsorption.

Assessment of phytochemicals and antioxidant activities of raw and germinating Ceiba pentandra (kapok) seeds

To determine the significance of germination on phytochemical constituents and non-enzymatic antioxidant activ- ities of Ceiba pentandra seed extracts. Phytochemicals and antioxidant activities of raw and germinating seeds of Ceiba pentandra were estimated by different methods. The levels of phytochemical constituents were influenced by germination and increased except alkaloids and tannins, which were decreased significantly during germination. Among non-enzymatic antioxidants like DPPH, FRAP, reducing assay and hydroxyl radical scavenging activity all showed improved activity compared with non-germinating seeds. This may be due to various reactive oxygen species （ROS） that were generated as by-products of metabolism during germination. This group of ROS included superoxide radicals （O2）, hydrogen peroxide radicals （HzOz） and hydroxyl radicals （OH）. The formation of these oxygen radicals resulted in the accumulation of lipid hydroperoxides by radical chain oxidation via phospholipids peroxy radicals within membranes. Therefore, it was hypothesized that this could be related to the increase of anti- oxidant activity in large unilamellar vesicles observed in germinated seeds. The implication of this study is that the Ceiba pentandra seeds as natural antioxidant agents and put forward the possibility of employing for therapeutic potential.

Insight into synergistic antioxidation mechanisms of butyl hydroxyanisole with common synthetic antioxidants

Butyl hydroxyanisole(BHA) is usually blended with other synthetic antioxidants to improve the antioxidative property due to synergistic antioxidation. However, the synergistic antioxidation mechanisms of BHA with synergists have not been revealed yet. Thus, the antioxidation of BHA with butylated hydroxytoluene(BHT), tert-butylhydroquinone(TBHQ), or propyl gallate(PG) was investigated in the 2,2-azobis(2-amidino-propane) dihydrochloride oxidizing system. The contents of BHA, BHT, TBHQ,PG, and transformation products were measured by high-performance liquid chromatography. Transformation products were identified with liquid chromatography-mass spectrometry and gas chromatography–mass spectrometry. Results showed that synergistic antioxidation occurred between BHA and BHT, TBHQ, or PG. The synergistic antioxidation effect of BHA and BHT was attributed to the regeneration of BHA by BHT. Transformation products of BHA and BHT(compounds 6 and 7, dimers of BHA and BHT) had little contribution due to the relatively low content(<0.6%). The synergistic antioxidation effect of BHA and TBHQ or BHA and PG was attributed to the protective mechanism of TBHQ or PG on BHA. No transformation products were detected of BHA and TBHQ. Transformation products of BHA and PG(compounds 9 and 10, dimers of BHA and PG) had limited contribution due to the relatively low percentage(<7%). Therefore, BHA and BHT performed competitive antioxidation,while BHA and TBHQ or PG performed protective antioxidation.

Flotation behaviors and mechanisms of chalcopyrite and galena after cyanide treatment

Adsorbing tests between CN? and chalcopyrite or galena were conducted firstly, and then flotation tests of the twocyaniding minerals were investigated in butyl xanthate (BX) system. Results showed that the interaction between CN? and the twomineral surfaces were both chemical adsorption and can be described by the Langmuir adsorption isotherm model. In the optimumcondition of pH 6.5 and 4.0 mg/L BX, the recovery of cyaniding chalcopyrite and galena reached 82.1% and 63.9%, respectively. BXimproved the hydrophobicity of the surfaces of the two minerals, although CN? reduced the contact angle on the surface of minerals.The inhibitory effect of CN? on chalcopyrite far outweighed galena. Electrostatic adsorption exists in the interaction between BX andthe surface of galena after cyanide treatment in the pH range of 4.2?8.4, while the interactions between BX and the surface ofchalcopyrite after cyanide treatment is chemical adsorption.

Developmental Toxicity in Mice Following Paternal Exposure to Di-N-Butyl-Phthalate (DBP)

Objective The aim of the present study was to investigate the effects of paternal Di‐N‐butyl‐phthalate （DBP） exposure pre‐ and postnatally on F1 generation offspring,and prenatally on F2 generation offspring.Methods Male mice were exposed to either 500 mg/kg or 2 000 mg/kg of DBP for 8 weeks,and mated with non‐exposed females.Three‐quarters of the females were sacrificed a day prior to parturition,and examined for the number of living and dead implantations,and incidence of gross malformations.Pups from the remaining females were assessed for developmental markers,growth parameters,as well as sperm quantity and quality.Results There were no changes in the fertility of parents and in intrauterine development of the offspring.Pups of DBP‐exposed males demonstrated growth‐retardation.Following paternal exposure to 500 mg/kg bw of DBP,there were almost twice the number of males than females born in the F1 generation.F1 generation females had a 2.5‐day delay in vaginal opening.Paternal exposure to 2 000 mg/kg bw of DBP increased the incidence of sperm head malformations in F1 generation males;however,there were no changes in the fertility and viability of foetuses in the F2 generation.Conclusion Paternal DBP exposure may disturb the sex ratio of the offspring,delay female sexual maturation,and deteriorate the sperm quality of F1 generation males.

Zeolite-assisted etherification of glycerol with butanol for biodiesel oxygenated additives production

This research was focused on the valorisation of glycerol,exploring the feasibility of an efficient route for oxygenated additives production based on its etherification with bio-butanol.A home-made BEA zeolite sample with a tuneable acidity has been proposed as the catalytic system,being tested in a stirred reactor under different etherification conditions.Although a reaction temperature as high as 200℃resulted to be beneficial in terms of glycerol conversion(-90%),only by operating at milder conditions the product selectivity to glycerol-ethers can be better controlled,in order to obtain a bio-fuel complying with the requirements for mixing with fossil diesel or biodiesel,without any need of purification from large amount of by-products.A comprehensive identification of all the compounds formed during the reaction was performed by a GC-MS analysis,on the basis of the complex network of consecutive and parallel reaction paths leading not only to the desired ethers,but also to many side products not detected in similar acid-catalyzed reactions in liquid phase and not available in the most used mass-spectra libraries.

Chlorinated butyl rubber/two-step modified montmorillonite nanocomposites:Mechanical and damping properties

Montmorillonite(MMT) was modified by ultrasound and castor oil quaternary ammonium salt intercalation method to prepare a new type of organic montmorillonite(OMMT). The surface structure, particle morphology, interlayer distance, and thermal behavior of the samples obtained were characterized. The modified OMMT was then added to chlorinated butyl rubber(CIIR) by mechanical blending, and a composite material with excellent damping properties was obtained. The mechanical experiment results of CIIR nanocomposites showed that the addition of OMMT improved their tensile strength, hardness,and stress relaxation rate. Compared with pure CIIR, when the content of OMMT was 5 phr(part per hundred of rubber), the tensile strength of the nanocomposite was increased by 677% and the elongation at break was also increased by 105.4%. The enhancement of this performance was mainly due to the dispersion of the nanosheets in CIIR rubber and the chemical interaction between the organoclay and the polymer matrix, which was confirmed by morphology and spectral analysis. OMMT also endowed a positive effect on the damping properties of CIIR nanocomposites. After adding 5 phr of OMMT, the nanocomposite owned the best damping performance, and the damping factor, tanδmax, was 37.9% higher than that of pure CIIR. Therefore, the good damping and mechanical properties of these CIIR nanocomposites provided some novel and promising methods for preparing high-damping rubber in a wide temperature range.

Preparation of Butyl Chloride from Butanol and Hydrochloric Acid Using Ionic Liquids as Catalyst

The catalytic performance of some quaternary ammonium salts for the liquid phase reaction of butanol and hydrochloric acid at different conditions was studied experimentally and compared with the traditional catalyst （ZnCl2）. The organic ammonium catalysts investigated include ionic liquids N-butyl-N-methyl imidazolium fluoborate （[BMIM][BF4]） and N-butyl-N-methylimidazolium chloride （[BMIM]Cl） as well as hydrochloric salts of N-methylimidazol （[HMIM]Cl）, pyridine （[HPy]Cl） and triethylamine （[HEt3N]Cl）. It is shown that the intrinsic catalytic performance of all organic ammonium salts except [HEt3N]Cl is slightly superior to ZnCl2, while the selectivity of butyl chloride is nearly at the same level around 96%. The conversion of butanol increases slightly with temperature and the catalyst amount added while the variation of selectivity is not obvious. Based on the recycle experiments, the ionic liquids as catalyst for the reaction of butanol and hydrochloric acid can be used more than 5 times, which suggests great potential of using ionic liquids as novel catalyst for such reactions.

Adsorption kinetics and thermodynamics of sodium butyl xanthate onto bornite in flotation

In this paper,the effect of sodium butyl xanthate(NaBX)adsorption on the surface of bornite at different pH on flotation was studied by adsorption kinetic and thermodynamic.The flotation results demonstrated that the recovery was the highest when pH was 9 in NaBX solution(4×10^?5 mol/L).The adsorption kinetics showed the reaction of NaBX on the bornite conformed to the second order kinetic equation;it belonged to the multimolecular layer adsorption of Freundlich model;the maximum adsorption rate constant was 0.30 g/(10^?6 mol·min),and the equilibrium adsorption capacity was 2.70×10^?6 mol/g.Thermodynamic calculation results indicated that the adsorption process was spontaneous chemisorption,and the adsorption products of NaBX on bornite surface were cupric butyl xanthate,ferric butyl xanthate and dixanthogen,which were confirmed by infrared spectrum measurements.

Nonfoaming Bubble Separation for Recovery of Butyl Acetate from Discharged Wastewater During Penicillin Production

Two nonfoaming bubble separation techniques, air stripping and solvent sublation, are presented and discussed in order to recover butyl acetate (BA) from discharged wastewater after solvent extraction of penicillin. Results show air stripping is not suitable for the recovery of BA from the wastewater. Axial concentration of BA had a noted maximum point along the column. In contrast, solvent sublation is very effective to recover BA from the wastewater. In solvent sublation experiments, axial concentration of BA along the column first increased and then decreased from the bottom to the top because of two primary mass transport processes. One is the transport by adsorption or attachment to ascending bubbles, and the other is by dispersion at water-solvent interface and by water film in organic solvent layer. In order to elucidate the high removal efficiency in solvent sublation, the microstructure of the wastewater was studied with optic microscope, which was showed to be an emulsion of BA in water at large concentration of BA. Solvent sublation can be successfully used in the removal of BA from its emulsion in the wastewater. The surface tension of simulated solution composed of lysozyme and BA was studied to understand mutual effect of biological materials and BA. Results show that lysozyme affects the adsorption of BA at air-water interface and they may form a complex between BA and lysozyme molecules.

Compatibilization of PBT/PP Blends by Adding Side-chain Liquid Crystalline Ionomer with Quaternary Pyridinium Groups

A side-chain liquid crystalline ionomer（SLCI） was synthesized by grafting copolymerization of 4-（4-ethoxybenzoyloxy）-4＇-allyloxybiphenyl and N-allyl-pyridium bromide on polymethylhydrosiloxane. The SLCI was blended with polypropylene（PP） and polybutylene terephthalate（PBT） by melt mixing. The thermal behavior, liquid crystalline properties, morphological structure, and mechanical properties of the blends were investigated by differential scanning calorimetry（DSC）, polarizing optical microscopy（POM）, scanning electron microscopy（SEM）, and tensile measurement. When a proper amount of SLCI was added, fine configurations were formed in the PBT/PP/SLCI blend system, and the mechanical properties were improved due to improved adhesion at the interface. When excess SLCI was added, an inhomogeneous structure resulted, which caused the mechanical properties to deteriorate.

Mechanism of different particle sizes of quartz activated by metallic ion in butyl xanthate solution

To investigate effect of metallic ion activation on different particle sizes of quartz in butyl xanthate solution,six common ions(Pb^(2+),Cu^(2+),Fe^(3+),Fe^(2+),Mg^(2+) and Ca^(2+)) were introduced as activators.The approaches of micro-flotation,adsorption test and zeta potential measurement were adopted to reveal the mechanism of ion activation.The results show that Pb^(2+),Cu^(2+) and Fe^(3+) are effective activators for the flotation of quartz in butyl xanthate solution because of their absorption on activated quartz surface.Average recoveries of fine particles(<37 μm) are greater than those of coarser particles(37-74 μm),suggesting that the former is easier to be activated and more likely to be floated and thus entrained in sulphide concentrate.From another perspective,addition of metallic ions(Pb^(2+),Cu^(2+) and Fe^(3+)) renders zeta potentials move positively,and addition of the same metallic ions and butyl xanthate makes zeta potential drop apparently,which support a mechanism where they adsorb onto quartz surface,resulting in an expected increase in butyl xanthate collector adsorption with a concomitant increase in the flotation recoveries.

Speeds of Sound and Excess Isentropic Compressibilities of Butyl Acetate＋Aromatic Hydrocarbons

Speed of sound data for butyl acetate＋benzene, or toluene, or o-xylene, or m-xylene, or p-xylene binary mixtures have been measured over the entire range of mole fraction at 308.15 K. The excess isentropic compressibilities （ Ks^E ） were computed from speed of sound and density data, derived from molar excess volume data. The Ks^E values were analyzed by using graph theoretical approach. The Ks^E values evaluated by graph theory compared reasonably well with their corresponding experimental values. The Ks^E data were also expressed in terms of Redlich-Kister polynomial equation to derive the coefficients and the standard deviation.