Studies on lipolytic bacteria in stored fish Etroplus suratensis (Bloch)

The distribution of total hectrotrophic bacteria (THB) and lipolytic bacteria in various regions (body surface, gill, intestine and flesh) of fish Etroplus suratensis (Bloch) during storage at 28 ± 2°C and 4°C was studied. Pseudomonas dominated at reduced temperature whereas at 28 ± 2°C and in fresh condition Vibrio, Aeromonas, and Acinetobacter dominated. Lipolytic activity was elaborated by the members of various genera and their activity varied in different lipid compounds (tributyrin, tween 80, tween 60, tween 40 and tween 20). Tributyrin was utilized by majority of the isolates. All the selected isolates preferred a temperature of 35°C and pH 6.0 for their maximum growth. Aeromonas and Vibrio showed maximum growth at 0.5% NaCl concentration while 3% NaCl was found to be optimum for Pseudomonas.

Study on the sustainability of FPC produced from Kilka (Clupeonella engrauliformis, C. grimmi and C. cultriventris) in two vacuum packaging and modified atmosphere packaging at different environmental factors

Fish protein concentrate (FPC) is a healthy, sustainable and high nutritive product which sanitized produced from fishes in which, protein and other nutrients are more concentrated than in fresh fishes. The aim of this research is to study on the sustainability of FPC produced from Kilka (Clupeonella engrauliformis , C. grimmi and C. cultriventris) in two Vaccum Packaging and Modified Atmosphere Packaging at different environmental factors during six months. In our study the analysis of FPC protein showed 91.2%, lipid: 0.5%, ash: 3.6%, moisture: 2.3%, Total Volatile Nitrogen: 10 ml/100gr and peroxide: 5meq/kg. Amino acids and fatty acids were also determined. Bacteria and Fungi were lower than 1000 colony. Samples are kept in different condition of temperature (5, 20 and 35 degree centigrade), humidity (25, 40 and 90 percent) and light and dark environment in six month. Lipid rate in FPC after 6 months in VP and MAP (60% C02, 30 % N2 and 10% O2), packages was decreased but was not significant (P>0.05). It was also detected that increase temperature lead to more decrease in lipid content. Protein rate of FPC was decreased from 91.2% to 73.6% during six months at 35°C in VP Package and from 91.2% to 69.4% in MAP package. These changes were significant (P<0.05). TVN and PV rate in FPC after 6 months in VP and MAP packages was increased but was significant (P<0.05). Amino acids and fatty acids were also determined. But more changes in MAP packages was detected.

己酸乙酯酯化真菌筛选及发酵条件研究

本文主要研究了具有己酸乙酯酯化活性的真菌菌株的筛选和发酵条件优化。从大曲和糟醅样品中分离纯化获得79株产生透明圈的丝状真菌，菌落形态初步识别结果显示分离菌株包括红曲霉属、根霉属及曲霉属等菌株。其中菌株EM-56酯化酶活力最强，发酵获得的粗酶制剂酶活为172.36 u。根据显微形态、菌落形态及生理生化特征，初步鉴定该菌株为曲霉科红曲霉属紫色红曲霉（Monascus purpureus）。 在此基础上重点研究了菌株EM-56在不同培养基成分及不同培养条件下的产酶情况，确定了最佳培养基和培养条件。通过单因素实验确定在基础培养基中添加最佳碳源为葡萄糖，最佳氮源为蛋白胨。正交优化实验结果确定了最佳培养基组成：以麸皮为基础培养基，添加葡萄糖 2%，蛋白胨 0.3 %，KH2PO4.3H2O 0.05 %，MgSO4.7H2O 0.06 %。菌株EM-56在上述培养基中的最佳发酵条件为：初始pH 5.5，发酵温度为35°C，发酵时间7d，种龄48h，接种量8%，装瓶量50g / 瓶（500mL）。在最佳培养基和发酵条件下，菌株EM-56发酵获得的粗酶制剂酶活达到241.56 u，比优化前提高了40.15%。 In this paper, the research focuses on the selection of fungus with esterifying activity and optimization of fermentation conditions. We isolated 79 strains which had transparent zones from Daqu and fermented grains. The isolated strains contained Monascus、Rhizopus and Aspergillus through primary morphology analysis. The strain of EM-56 which produces strongest esterase was selected. The enzyme activity reached 172.36u. According to related literature, EM-56 was identified as Monascus purpureus through morphology analysis and biochemical determination. We also studied the effects of different medium and fermentation conditions on the esterase production of strain EM-56. The optimal medium and fermentation conditions were determined. Single factor experiment result shows that the optimal carbon source added is glucose and the optimal nitrogen source added is peptone. The optimal fermentation medium determined by orthogonal optimization test is as follows: wheat bran as substrate, glucose 2%, peptone 0.3%, KH2PO4.3H2O 0.05%，MgSO4.7H2O 0.06%. The optimal fermentation conditions are: initial pH 5.5, cultural temperature 35°C, cultural time 7d, seed age 48h, inoculation 8%, medium mass 50g / flask（500mL）. The esterse activity of EM-56 cultivated in the optimal medium and fermentation conditions reached 241.56u and increased by 40.15% compared with the original activity.

High-spin states of odd-odd nuclei in the A similar to 170 mass region

Efforts have been made in our group to study the band structure of odd-odd nuclei in the A similar to 170 mass region. We aimed at providing new data of high-spin states and searching for the low-spin signature inversion in the 2-qp bands built on the pi h(9/2) circle times nu i(13/2) and pi i(13/2)circle times nu i(13/2) configurations. In this talk, main results of our work will be summarized, and some systematic features of signature inversion discussed. The spin and parity assignments for the pi i(13/2) circle times nu i(13/2) band in (184)An could be regarded as firm providing a good example for systematic and theoretical investigations.

An investigation into the subambient behavior of aqueous mannitol solutions using differential scanning calorimetry, cold stage microscopy, and X-ray diffractometry

The subambient behavior of aqueous mannitol solutions is of considerable relevance to the preparation of freeze dried formulations. In this investigation the properties of 3% w/v mannitol solutions were investigated using differential scanning calorimetry (DSC), cold stage microscopy (CSM), and X-ray diffraction (XRD) to identify the thermal transitions and structural transformations undergone by this system. It was found that on cooling from ambient the system formed ice at circa -20°C while a further exotherm was seen at approximately -30°C. Upon reheating an endotherm was seen at circa -30°C followed immediately by an exotherm at circa -25°C. Temperature cycling indicated that the thermal transitions observed upon reheating were not reversible. Modulated temperature DSC (MTDSC) indicated that the transitions observed upon reheating corresponded to a glass transition immediately followed by recrystallization, XRD data showed that recrystallization was into the ß form. Annealing at -35°C for 40 min prior to cooling and reheating resulted in a maximum enthalpy being observed for the reheating exotherm. It is concluded that on cooling 3% w/v aqueous mannitol solutions an amorphous phase is formed that subsequently recrystallises into the ß form. The study has also shown that DSC, CSM, and XRD are useful complementary techniques for the study of frozen systems

PURIFICATION AND PARTIAL CHARACTERIZATION OF AN ENDO-POLYGALACTURONASE FROM ASPERGILLUS NIGER

A pectinase was identified and isolated from a commercial Aspergillus niger pectinase preparation. The crude enzyme preparation, which was prepared by precipitation of the water extract of the culture of A. niger with ammonium sulfate, was further fractionated by three steps of chromatography, i. e., cation exchange, hydrophobic interaction and onion exchange, to obtain an electrophoretically homogeneous pectinase. The molecular weight of the purified enzyme was estimated by SDS-PAGE to be about 40.4 kDa under both nonreducing and reducing conditions, with the optimum pH at 5.0 and the optimum temperature at 36C. The enzyme was stable at temperatures below 35C. The partial N-terminal ammo acid sequence data analysis of the first 19 amina acids of the obtained pectinase revealed 94.7% and 89.5% homology with two reported pectinases from A. niger.

Culture Age, temperature, and pH affect the polyol and trehalose contents of fungal propagules

The growth and conidial physiology of the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Paecilomyces farinosus were studied under different conditions. The effects of culture age (up to 120 days), temperature (5 to 35°C), and pH (2.9 to 11.1) were determined. Growth was optimal at pH 5 to 8 for each isolate and between 20 and 35°C, depending on the isolate. The predominant polyol in conidia was mannitol, with up to 39, 134, and 61 mg g of conidia-1 for B. bassiana, M. anisopliae, and P. farinosus, respectively. Conidia of M. anisopliae contained relatively small amounts of lower-molecular-weight polyols and trehalose (less than 25 mg g-1 in total) in all treatments. Conidia of B. bassiana and P. farinosus contained up to 30, 32, and 25 mg of glycerol, erythritol, and trehalose, respectively, g-1, depending on the treatment. Conidia of P. farinosus contained unusually high amounts of glycerol and erythritol at pH 2.9. The apparent effect of pH on gene expression is discussed in relation to the induction of a water stress response. To our knowledge, this is the first report of polyols and trehalose in fungal propagules produced over a range of temperature or pH. Some conditions and harvesting times were associated with an apparent inhibition of synthesis or accumulation of polyols and trehalose. This shows that culture age and environmental conditions affect the physiological quality of inoculum and can thereby determine its potential for biocontrol.

Monitoring of saliva pH using miniaturized sensing tools as an indicator of oral health

The monitoring of oral disease is important, not alone for oral health, but for the detection and prevention of
systemic disease. The link between oral health and systemic disease is the focus of many studies, with
indications emerging of a causal link [1]. For disease diagnostics, blood has typically been the fluid of choice
for analysis, the retrieval of which is invasive and therefore unsuitable for wearable technology. Analysis of
saliva, however, is less invasive than that of blood, requires little or no pre-treatment and is abundantly
available. A strong correlation has been found between the analytes of blood and saliva [2] with saliva
containing biomarkers for diseases such as diabetes, oral cancer and cardiovascular disease. The development of
an implantable multi-parametric wireless sensor, to monitor both salivary analytes and changes in gingival
temperature, is the aim of this research project.
The aim of our current study is to detect changes in salivary pH, using a gold electrode with a pHsensitive
iridium oxide layer, and an Ion Sensitive Field Effect Transistor probe. Characterisation studies were
carried out in artificial saliva (AS). A salivary pH of between 4.5pH-7.5pH [3], and gingival temperature
between 35°C-38°C [4], were identified as the target range of interest for the human oral environment. Sensor
measurements were recorded in solutions of varying pH and temperature. An ISFET probe was then implanted
into a prototype denture and characterised in AS. This study demonstrates the suitability of ISFET and gold
electrode pH sensors for incorporation into implantable oral sensors.
[1] G. Taylor and W. Borgnakke, “Periodontal disease: associations with diabetes, glycemic control and
complications,” Oral Dis., vol. 14, no. 3, pp. 191–203, Apr. 2008.
[2] E. Tékus, M. Kaj, E. Szabó, N. L. Szénási, I. Kerepesi, M. Figler, R. Gábriel, and M. Wilhelm,
“Comparison of blood and saliva lactate level after maximum intensity exercise,” Acta Biol. Hung., vol. 63
Suppl 1, pp. 89–98, 2012.
[3] S. Naveen, M. L. Asha, G. Shubha, A. Bajoria, and A. Jose, “Salivary Flow Rate, pH and Buffering
Capacity in Pregnant and Non Pregnant Women - A Comparative Study,” JMED Res., pp. 1–8, Feb. 2014.
[4] A. F. Holthuis and F. S. Chebib, “Observations on temperature and temperature patterns of the gingiva. I.
The effect of arch, region and health,” J. Periodontol., vol. 54, no. 10, pp. 624–628, Oct. 1983

In situ preparation of 3D graphene aerogels@hierarchical Fe3O4 nanoclusters as high rate and long cycle anode materials for lithium ion batteries

We describe a novel strategy for in situ fabrication of hierarchical Fe₃O₄ nanoclusters-GAs. Fe₃O₄ NCs-GAs deliver excellent rate capability (the reversible capacities obtained were 1442, 392 and 118 mA h g^-1 at 0.1C, 12C and 35C rates), and a high reversible capacity of 577 mA h g^-1 over 300 cycles at the current density of 5.2 A g^-1 (6C).

Bacterial peroxide forming enzymes

Dissertação de mestrado, Engenharia Biológica, Faculdade de Ciências e Tecnologia, Universidade do Algarve; Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2015

Estudo de uma bomba de calor de expansão direta assistida por energia solar para a preparação de AQS

Este estudo consiste na caracterização da eficiência energética de uma bomba de calor de expansão direta que utiliza a energia solar como fonte térmica. De uma forma geral, teve-se a obrigação de procurar cada vez mais recursos renováveis e neste sentido a bomba de calor de expansão direta tem um papel importante no aquecimento de águas quentes sanitárias (AQS). Como ponto de partida, foi realizada uma descrição detalhada sobre todos os equipamentos da bomba de calor e elaborado um desenho técnico que identifica todos os componentes. No laboratório (casa inteligente) realizaram-se vários ensaios a fim de interpretar com rigor os resultados obtidos do desempenho da bomba de calor (COP) e do fator médio de desempenho sazonal (SPF). No início, realizaram-se ensaios para determinar as perdas estáticas do sistema termodinâmico, de seguida foram elaborados ensaios segundo a norma EN 16147 e por fim, ensaios de acordo com o perfil de utilização de AQS definido. No estudo experimental do COP, obteve-se uma elevada eficiência energética com um valor médio de 4,12. O COP aumenta para valores médios de 5 quando a temperatura de água no termoacumulador desce para 35ºC. Verificou-se que durante o período diurno o COP aumenta aproximadamente de 10% relativamente ao período noturno. A potência elétrica é mais elevada (450W) quando a água no termoacumulador está perto da temperatura desejável (55ºC), originando um esforço maior da bomba de calor. No estudo experimental do SPF, verificou-se que nos ensaios segundo a norma EN16147 os valores obtidos variaram entre 1,39 e 1,50 (Classe “B”). No estudo realizado de acordo com o perfil de utilização de AQS definido pelo utilizador, o SPF é superior em 12% relativamente ao obtido segundo os ensaios realizados de acordo a norma EN16147. Verificou-se que o aumento da temperatura do ar exterior implica um aumento do SPF (cerca de 2% a 5%), enquanto a energia solar não influência nos resultados.

Kinetic and mechanistic studies for the molybdenum- catalyzed oxidation of organic sulfides and olefins by t- DuO2H

This research was focussed on the effects of light, solvent and substituents in the molybdenum-catalyzed oxidation of phenylmethyl sulfides with t-Bu02H and on the effect of light in the molybdenum-catalyzed epoxidation of l-octene with t-Bu02H. It was shown that the Mo(CO)6-catalyzed oxidation of phenylmethyl sulfide with t-Bu02H~ at 35°C, proceeds 278 times faster underUV light than under laboratory lighting, whereas the Mo02(acac)2-catalyzed oxidation proceeds only 1.7 times faster under UV light than under normal laboratory lighting. The difference between the activities of both catalysts was explained by the formation of the catalytically active species, Mo(VI). The formation of the Mo(VI) species, from Mo(CO)6 was observed from the IR spectrum of Mo(CO)6 in the carbonyl region. The Mo(CO)6-catalyzed epoxidation of l-octene with t-Bu02H showed that the reaction proceeded 4.6 times faster under UV light than in the dark or under normal laboratory lighting; the rates of epoxidations were found to be the same in the dark and under normal laboratory lighting. The kinetics of the epoxidations of l-octene with t-Bu02H, catalyzed by Mo02(acac)2 were found to be complicated; after fast initial rates, the epoxidation rates decreased with time. The effect of phenylmethyl sulfide on the Mo(CO)6-catalyzed epoxidation of l-octene waS studied. It was shown that instead of phenylmethyl sulfide, phenylmethyl sulfone, which formed rapidly at 85°C, lowered the reaction rate. The epoxidation of l-octene was found to be 2.5 times faster in benzene than in ethanol. The substituent effect on the Mo02(acac)2-catalyzed oxidations of p-OH, p-CHgO, P-CH3' p-H, p-Cl, p-Br, p-CHgCO, p-HCO and P-N02 substituted phenylmethyl sulfides were studied. The oxidations followed second order kinetics for each case; first order dependency on catalyst concentration was also observed in the oxidation of p-CHgOPhSMeand PhSMe. It was found that electron-donating groups on the para position of phenylmethyl sulfide increased the rate of reaction, while electronwithdrawing groups caused the reaction rate to decrease. The reaction constants 0 were determined by using 0, 0- and 0* constants. The rate effects were paralleled by the activation energies for oxidation. The decomposition of t-Bu02H in the presence of M.o (CO)6, Mo02 (acac)2 and VO(acac)2 was studied. The rates of decomposition were found to be very small compared to the oxidation rates at high concentration of catalysis. The relative rates of the Mo02(acac)2-catalyzed oxidation of p-N02PhSMe by t-Bu02H in the presence of either p-CH30PhSMe or PhSMe clearly show that PhSMe and p-CHgOPhSMe act as co-catalysts in the oxidation of p-N02PhSMe. Benzene, mesity1ene and cyclohexane were used to determine the effect of solvent in the Mo02 (acac)2 and Mo(CO)6-catalyzed oxidation of phenylmethyl sulfide. The results showed that in the absence of hydroxylic solvent, a second molecule of t-Bu02H was involved in the transition state. The complexation of the solvent with the catalyst could not be explained.The oxidations of diphenyl sulfoxide catalyzed by VO(acac)2, Mo(CO)6 and Mo02(acac)2 showed that VO(acac)2 catalyzed the oxidation faster than Mo(CO)6 and Mo02 (acac)2_ Moreover, the Mo(CO)6-catalyzed oxidation of diphenyl sulfoxide proceeded under UV light at 35°C.

The determination of sinigrin in Brassica, and investigations into the use of allyl-isothiocyanate as a nematicide

The goal of this thesis was to study factors related to the development of Brassica juncea as a sustainable nematicide. Brassica juncea is characterized by the glycoside (glucosinolate) sinigrin. Various methods were developed for the determination of sinigrin in Brassica juncea tissue extracts. Sinigrin concentrations in plant tissues at various stages of growth were monitored. Sinigrin enzymatically breaks down into allylisothiocyanate (AITC). AITC is unstable in aqueous solution and degradation was studied in water and in soil. Finally, the toxicity of AITC against the root-lesion nematode (Pratylenchus penetrans) was determined. A method was developed to extract sinigrin from whole Brassica j uncea tissues. The optimal time of extraction wi th boiling phosphate buffer (0.7mM, pH=6.38) and methanol/water (70:30 v/v) solutions were both 25 minutes. Methanol/water extracted 13% greater amount of sinigrin than phosphate buffer solution. Degradation of sinigrin in boiling phosphate buffer solution (0.13%/minute) was similar to the loss of sinigrin during the extraction procedure. The loss of sinigrin from boiling methanol/water was estimated to be O.Ol%/minute. Brassica juncea extract clean up was accomplished by an ion-pair solid phase extraction (SPE) method. The recovery of sinigrin was 92.6% and coextractive impurities were not detected in the cleaned up extract. Several high performance liquid chromatography (HPLC) methods were developed for the determination of sinigrin. All the developed methods employed an isocratic mobile phase system wi th a low concentration of phosphate buffer solution, ammonium acetate solution or an ion-pair reagent solution. A step gradient system was also developed. The method involved preconditioning the analytical column with phosphate buffer solution and then switching the mobile phase to 100% water after sample injection.Sinigrin and benzyl-glucosinolate were both studied by HPLC particle beam negative chemical ionization mass spectrometry (HPLCPB- NCI-MS). Comparison of the mass spectra revealed the presence of fragments arising from the ~hioglucose moiety and glucosinolate side-chain. Variation in the slnlgrin concentration within Brassica juncea plants was studied (Domo and Cutlass cuItivars). The sinigrin concentration in the top three leaves was studied during growth of each cultivar. For Cutlass, the minimum (200~100~g/g) and maximum (1300~200~g/g) concentrations were observed at the third and seventh week after planting, respectively. For Domo, the minimum (190~70~g/g) and maximum (1100~400~g/g) concentrations were observed at the fourth and eighth week after planting, respectively. The highest sinigrin concentration was observed in flower tissues 2050±90~g/g and 2300±100~g/g for Cutlass and Domo cultivars, respectively. Physical properties of AITC were studied. The solubility of AITC in water was determined to be approximately 1290~g/ml at 24°C. An HPLC method was developed for the separation of degradation compounds from aqueous AITC sample solutions. Some of the degradation compounds identified have not been reported in the literature: allyl-thiourea, allyl-thiocyanate and diallyl-sulfide. In water, AITC degradation to' diallyl-thiourea was favored at basic pH (9.07) and degradation to diallyl-sulfide was favored at acidic pH (4 . 97). It wap necessary to amend the aqueous AITC sample solution with acetonitrile ?efore injection into the HPLC system. The acetonitrile amendment considerably improved AITC recovery and the reproducibility of the results. The half-life of aqueous AITC degradation at room temperature did not follow first-order kinetics. Beginning with a 1084~g/ml solution, the half-life was 633 hours. Wi th an ini tial AITC concentration of 335~g/ml the half-life was 865 hours. At 35°C the half-life AITC was 76+4 hours essentially independent of the iiisolution pH over the range of pH=4.97 to 9.07 (1000~g/ml). AITC degradation was also studied in soil at 35°C; after 24 hours approximately 75% of the initial AITC addition was unrecoverable by water extraction. The ECso of aqueous AITC against the root-lesion nematode (Pratylenchus penetrans) was determined to be approximately 20~g/ml at one hour exposure of the nematode to the test solution. The toxicological study was also performed with a myrosinase treated Brassica juncea extract. Myrosinase treatment of the Brassica juncea extract gave nearly quantitative conversion of sinigrin into AITC. The myrosinase treated extract was of the same efficacy as an aqueous AITC solution of equivalent concentration. The work of this thesis was focused upon understanding parameters relevant to the development of Brassica juncea as a sustainable nematicide. The broad range of experiments were undertaken in support of a research priority at Agriculture and Agri-Food Canada.

The kinetics and mechanism of the thermal decomposition of sec-Butyl peroxide in liquid phase /|nby Sandor Szilagyi. -- 260 St. Catharines, Ont. : [s. n.],

Re~tes artd pJ~oducts of tllerma]. d,ecom.position of sec-butyl peroxide at 110 - 150°C i.n four solvents h,ave been determined. The d,ecompos i tion vJas sb.o\'\Tn to be tlnlmolecl.llar wi tho energies of activation in toluene, benzene, and cyclohexane of 36 .7-+ 1.0, 33.2 +- 1..0, 33.t~) +.. 1.0 I'(:cal/mol respectively. The activation energy of thermal decomposition for the d,et.1terated peroxide was found to be 37.2 4:- 1.0 KC8:1/1TIol in toluene. A.bo1J.t 70 - 80/~ ol~ tJJ.e' pl~od.1..1CtS could, be explained by kn01rJ11 reactions of free allcoxy raclicals J and very littJ...e, i.f allY, disPl"Opox~tiol'lation of tll10 sec-butoxy radica.ls in t116 solvent cage could be detected. The oth,er 20 - 30% of the peroxide yielded H2 and metb.:'ll etb..yl 1{etol1e. Tl1.e yield. o:f H2 "'lIas unafJ:'ected by the nature or the viscosity of the solvent, but H2 was not formed when s-t1U202 lrJaS phctolyzed. in tolttene at 35°C nor 'tl!Jrl.en the peroxide 1;'JaS tl1.ermally o..ecoJnposed. in the gas p11ase. ~pC-Dideutero-~-butYlperoxide was prepared and decomposed in toluene at 110 - 150°C. The yield of D2 was about ·•e1ne same 248 the yield. of I{2 from s-Bu202, bU.t th.e rate of decomposition (at 135°C) 1iJas only 1/1.55 as fast. Ivlecl1.anisms fOl') J:1ydrogen produ.ction are discussed, but none satisfactorily explains all the evidence.

Kinetic and product studies for the oxidtion of organic sulfides and sulfoxides in the presence of transition metal complexes

Rates and products of the oxidation of diphenyl sulfide, phenyl methyl sulfide, p-chlorophenyl methyl sulfide and diphenyl sulfoxide have been determined. Oxidants included t-Bu02H alone, t-Bu02H plus molybdenum or vanadium catalysts and the molybdenum peroxo complex Mo0(02)2*HMPT. Reactions were chiefly carried out in ethanol at temperatures ranging from 20° to 65°C. Oxidation of diphenyl sulfide by t-Bu02H in absolute ethanol at 65°C followed second-order kinetics with k2 = 5.61 x 10 G M~1s"1, and yielded only diphenyl sulfoxide. The Mo(C0)g-catalyzed reaction gave both the sulfoxide and the sulfone with consecutive third-order kinetics. Rate = k3[Mo][t-Bu02H][Ph2S] + k^[Mo][t-Bu02H][Ph2S0], where log k3 = 12.62 - 18500/RT, and log k^ = 10.73 - 17400/RT. In the absence of diphenyl sulfide, diphenyl sulfoxide did not react with t-Bu02H plus molybdenum catalysts, but was oxidized by t-Bu02H-V0(acac)2. The uncatalyzed oxidation of phenyl methyl sulfide by t-Bu02H in absolute ethanol at 65°C gave a second-order rate constant, k = 3.48 x 10~"5 M^s""1. With added Mo(C0)g, the product was mainly phenyl methyl sulfoxide; Rate = k3[Mo][t-Bu02H][PhSCH3] where log k3 = 22.0 - 44500/RT. Both diphenyl sulfide and diphenyl sulfoxide react readily with the molybdenum peroxy complex, Mo0(02)2'HMPT in absolute ethanol at 35°C, yielding diphenyl sulfone. The observed features are mainly in agreement with the literature on metal ion-catalyzed oxidations of organic compounds by hydroperoxides. These indicate the formation of an active catalyst and the complexation of t-Bu02H with the catalyst. However, the relatively large difference between the activation energies for diphenyl sulfide and phenyl methyl sulfide, and the non-reactivity of diphenyl sulfoxide suggest the involvement of sulfide in the production of an active species.