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1
Horst, Axel. "Stable bromine isotopic composition of methyl bromide : Method development and applications." Doctoral thesis, Stockholms universitet, Institutionen för tillämpad miljövetenskap (ITM), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-89454.
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The isotopic composition of ozone depleting methyl halides may provide valuable information on the sources and sinks of these compounds. However, so far mostly stable carbon isotope analysis of methyl chloride and methyl bromide (CH3Br) has been attempted. Especially halogen isotope analysis has been hindered by the challenge to obtain sufficiently large amounts of methyl halides to meet the detection limits of existing isotope analytical methods. The purpose of this doctoral thesis was to develop both a high-volume cryogenic collection system for methyl bromide (Article II) and an analytical technique being able to analyze the sampled amounts of CH3Br for its Br isotopic composition, which was accomplished by using gas chromatography multiple-collector inductively-coupled plasma mass spectrometry (Article I). These methods were applied in the field campaign from which we report the first bromine isotopic values of CH3Br in the atmosphere (Article III), being in the range of -0.47 to + 1.75 ‰ vs. SMOB (Standard Mean Ocean Bromide). A laboratory study on pectin and halophyte plant material (Article IV) gave an insight in Br isotope composition of abiotically formed CH3Br which may be a main source to the atmospheric budget. These plant experiments yielded δ81Br values of 0 to -2 ‰ SMOB. Atmospheric CH3Br and this potential source showed partly distinct δ81Br ranges and demonstrate the potential of Br isotopes for source apportionment.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Accepted. Paper 3: Submited. Paper 4: Manuscript.
2
Baker, Jonathan M. "Natural and anthropogenic sources of methyl bromide." Thesis, University of East Anglia, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266714.
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Knight, Gary Peter. "Kinetic, spectroscopic and theoretical studies involving methyl bromide." Thesis, University of York, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296292.
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Warwick, Nicola Julie. "Global modelling of atmospheric methane and methyl bromide." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619980.
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Rhew, Robert C. "Production and consumption of methyl bromide and methyl chloride by the terrestrial biosphere /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2001. http://wwwlib.umi.com/cr/ucsd/fullcit?p3035891.
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Groszko, Wayne. "An estimate of the global air-sea flux of methyl chloride, methyl bromide, and methyl iodide." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0016/NQ49265.pdf.
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Belcher, Jason Lamar Walker Robert Harold. "Acrolein (2-propenal) a potential alternative to methyl bromide /." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Agronomy_and_Soils/Dissertation/Belcher_Jason_27.pdf.
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Hardacre, Catherine. "Characterisation of CH3X fluxes from Scottish and high latitude wetlands." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4605.
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Methyl bromide (CH3Br) and methyl chloride (CH3Cl) are two halocarbons that are unique in that they play a significant role in stratospheric ozone destruction, and are mainly produced by natural systems. The current average tropospheric mixing ratios are 7.9 pptv CH3Br and 550 pptv CH3Cl (WMO, 2007). Although CH3Br and CH3Cl are present in such low concentrations, their atmospheric life times are sufficiently long that they can be transported to the stratosphere via the tropical tropopause at the equator. This process takes approximately six months.
9
Pepper, Jordan D. "An examination of the environmental Kuznets curve for methyl bromide /." View online, 2010. http://repository.eiu.edu/theses/docs/32211131576463.pdf.
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Preisser, Richard Herman III. "Food Safe Alternatives to Methyl Bromide in Country Ham Production." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/73654.
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Dry cured meat production is a costly and long term investment for producers. Ham mites (Tyrophagus putrescentiae) are a common pest of dry cured products and cause devastating effects, potentially nullifying producers' investments due to loss of salable product, as well as regulatory concerns. Methyl bromide, a chemical fumigant used to control mite populations, is damaging to stratospheric ozone and will no longer be available. Presently, no alternative control measure has been approved to combat the ham mite; therefore, it is essential to identify potential alternatives. Interest in safe alternatives to control arthropod pest populations is gaining momentum, and garlic (Allium sativum) has been used to control other arthropod species including the northern fowl mite, mosquitos, and aphids. We chose to explore the efficacy of garlic juice in controlling T. putrescentiae. Using a choice test design, approximately 65% of the inoculated mites colonized on the control ham cubes, while no mites remained on garlic juice-dipped cubes. Garlic was ineffective when examined for volatile efficacy, but was effective in direct contact assays. However, as garlic juice was aged and diluted, efficacy was reduced even after treatments with antioxidants, metal chelators, and pH neutralization. In total, garlic juice acted as a short term repellent and showed efficacy in contact models, but application is time sensitive due to variable enzymatic degradation.Master of Science
11
Simmons, Lee Julian Rodríguez-Kábana R. "Developing alternatives to methyl bromide a focus on acrolein (2-propenal) /." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Entomology_and_Plant_Pathology/Dissertation/Simmons_Lee_19.pdf.
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Blei, Emanuel. "Study of methyl halide fluxes in temperate and tropical ecosystems." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4717.
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CH3Br and CH3Cl (methyl halides) are the most abundant natural vectors of bromine and chlorine into the stratosphere and play an important role in stratospheric ozone destruction. The current knowledge of their respective natural sources is incomplete leading to large uncertainties in their global budgets. Beside the issue of quantification, characterisation of possible sources is needed to assist modelling of future environmental change impacts on these sources and hence the stratosphere. This study describes measurements conducted at two temperate salt marsh and three temperate forest sites in Scotland, and one tropical rainforest site in Malaysian Borneo to quantify and characterise natural methyl halide producing processes in these respective ecosystems. Measurements were conducted with static enclosure techniques, and methyl halide fluxes were calculated from the concentration difference between blank/background and afterenclosure samples. Methyl halide concentrations were determined via oxygen-doped GCECD with a custom-built pre-concentration unit. External factors such as photosyntheticallyactive radiation (PAR), total solar radiation, air temperature, soil temperature, internal chamber temperature and soil moisture were recorded in parallel to the enclosures to determine possible dependencies. Salt marsh studies were carried out at Heckie’s Hole in East Lothian, and Hollands Farmin East Dumfriesshire for 2 years. The study subjects were salt marsh plants that were enclosed during daylight hours in transparent enclosures for 10min each at 2–4 week intervals throughout the year. Parallel to this monitoring programme, systematic manipulation experiments and diurnal studies were carried out to learn more about the possible influence of potential drivers such as sunlight and temperature. Mean annual net fluxes ( standard deviation (sd)) were 300 44 ngm-2 h-1 for CH3Br and 660 270 ngm-2 h-1 for CH3Cl, with fluxes of both gases following a diurnal as well as an annual cycle, being lowest during winter nights and highest during summer days. A possible link between variations of daytime fluxes over the course of a year and changes in temperature was found. CH3Cl and CH3Br fluxes were positively correlated to each other and average fluxes of CH3Cl were linked to dry mass of certain species such as Puccinellia maritima, Aster tripolium, Juncus gerardi and Plantago maritima as found at the different measurement locations. No link between methyl halide fluxes and total halogen content or halogen concentration of the enclosed vegetation was found. Work in temperate forests was carried out for over one year at Fir Links, a mixed beech/ sycamore forest in East Lothian, and on one occasion each in Griffin Forest, a sitka spruce plantation in Perthshire, and finally the Hermitage of Braid, a mixed woodland park in Edinburgh. The study subject was leaf and needle litter which was enclosed in opaque 12 L containers for 10min–24h. During enclosure, internal chamber temperature was recorded, and leaf/needle litter water content was determined after enclosure. Combined average CH3Br and CH3Cl fluxes from temperate forest litter were 4.3 10-3 ngg-1 h-1 and 0.91 ngg-1 h-1, respectively. Average fluxes measured from leaf and needle litter were comparable in magnitude and CH3Br and CH3Cl were positively correlated. However no correlation of methyl halide fluxes to either temperature or litter water content was observed. Work at Danum Valley inMalaysian Borneo focused on flux measurements from both trees and leaf litter in a tropical dipterocarp forest. Fluxes from tropical trees were measured with transparent branch chambers at 20min enclosure times whilst methyl halide fluxes from leaf litter were measured with opaque 12 L containers at 24h enclosure times. Mean CH3Br and CH3Cl fluxes from branch enclosures were 0.53 ngg-1 h-1 and 27 ngg-1 h-1, respectively, and CH3Br and CH3Cl fluxes from tropical leaf litter were 1.4 10-3 ngg-1 h-1 and 2.3 ngg-1 h-1 respectively. Again fluxes of CH3Br and CH3Cl were positively correlated but no direct environmental driver for flux variations was found. The magnitude of methyl halide fluxes was species specific with individuals of the genus Shorea generally producing large amounts of methyl halide. Tropical rainforests were confirmed to be potentially the largest single natural source of CH3Cl. Global estimates were derived from extrapolating measured fluxes from the respective global land cover areas. These estimates suggest that the ecosystems examined in this study could account for over 1/3 of global CH3Cl production and up to 13%of global CH3Br production in nature. The ratio of CH3Br to CH3Cl emissions for these ecosystems is likely to be dependent on the abundance of bromine in the plant material with higher bromine content boosting CH3Br production and suppressing CH3Cl production. For this reason salt marshes are only a very minor source of CH3Cl.
13
Heyd, Darrick Vaughn. "Photodissociation of methyl bromide adsorbed on LiF(001), NaCl(001), and MgO(001)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0001/NQ27950.pdf.
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Drewer, Julia. "Investigation of natural methyl bromide (CH3Br) fluxes from temperate salt marsh and woodland ecosystems." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/13722.
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In this project, field measurements and controlled experiments were used to investigate the magnitude of, and controls on, some terrestrial sources of CH3Br to help in assessing global fluxes. The influence of factors such as temperature, soil properties, sunshine level, plant species and water table, and correlation to methane (CH4) fluxes, were investigated. Field measurements were carried out using eight static flux chapters installed in pairs in the lower and upper areas of a salt marsh in East Lothian (Scotland) and four at a woodland site in Edinburgh. Mean annual measured net CH3Br emissions from the salt marsh were 350 ng m-2 h-1, with a large variability in fluxes from zero to ~4000 ng m-2 h-1, which increased seasonally. Summer emissions were on average about three times higher than winter emissions. Variation in CH3Br fluxes was larger between individual chambers indifferent pairs at the same salt marsh area (upper or lower) than between the two areas. There was also a strong association between sunny conditions and the timings of the frequent peaks in CH3Br emissions from the high emitting chambers above the general annual trend. There was a distinct diurnal variation in CH3Br fluxes from the salt marsh chambers throughout the year, also strongly correlated to the solar flux, showing highest emissions at mid-day and lowest at night. Salt marsh CH3Br fluxes were highly spatially variable, with a small proportion of “hot spots” accounting for the bulk of the spatially-integrated net emissions. There was no obvious explanation for the spatial heterogeneity of CH3Br emissions. Net CH3Br fluxes at the woodland site were an order of magnitude lower than at the salt marsh site, fluctuating between net uptake and net emission and with a mean in annual measured emissions (minimum and maximum in parentheses) of 27 (-73-279) ng m2 h-1. Net fluxes from the woodland site showed no seasonal trend and only fairly small diurnal variation. There were no or only modest correlations of net CH3Br fluxes with air and soil temperature, CH4 flux and water table depth. Scaling-up the salt marsh CH3Br fluxes from this work globally gave estimated annual emissions of 1 (0.5-3) Gg y-1, which was only ~10% of the global salt marsh emission estimate regularly quoted in the methyl bromide literature. In contrast, the emissions from the temperate woodland gave a global average of 2.7 (1.3-5) Gy y-1 which contradicted the common assumption that woodland soils are only sinks for CH3Br. Global annual net CH3Br fluxes from leaf litter were calculated to be 0.9 (-1.3-4) Gg y-1 which was within the range quoted in the literature, and from conifer needles to 5.3 (1.5-11.6) Gy y-1, slightly higher than previously reported.
15
McAvoy, Theodore Porter. "Managing Weeds and Soilborne Pests with Fumigant and Non-Fumigant Alternatives to Methyl Bromide." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/37813.
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Methyl bromide (MBr) was widely used as a soil fumigant to manage soilborne pests in plasticulture vegetable production; however, it has been banned by the United Nations Environment Programme. Alternatives to MBr must be implemented to sustain fresh market tomato productivity. Possible MBr alternatives include new fumigant compounds, improved plastic mulch, and grafting. Methyl iodide (MeI) and dimethyl disulfide (DMDS) were tested as fumigant alternatives to MBr for the control of yellow nutsedge and soilborne pathogens of tomato. Virtually impermeable film (VIF) and totally impermeable film (TIF) were tested for fumigant retention and yellow nutsedge control in tomato. Grafting onto resistant rootstocks was tested for bacterial wilt and nematode management in tomato. In the absence of a soil fumigant, TIF suppressed yellow nutsedge better than VIF. TIF increased fumigant retention compared to VIF at similar application rates. Reduced fumigant application rates could be used in combination with TIF while maintaining fumigant concentrations, weed control, and crop yields comparable to greater use rates with VIF. Shank applied DMDS rates could be lowered to 281 L/ha under TIF from 468 L/ha under VIF; shank applied MeI application rates could be reduced to 56 L/ha under TIF compared to 93 L/ha under VIF and drip applied DMDS could be reduced from 561 L/ha under VIF film to 374 L/ha under TIF. Grafting susceptible commercial tomato cultivars onto resistant tomato hybrid rootstocks increased yields and plant survival in bacterial wilt infested fields. â Cheong Gangâ , â BHN 998â , and â BHN 1054â were the best performing rootstocks for bacterial wilt resistance and tomato fruit yield in severely infested fields. Grafting increased tomato yield and decreased root galling from root-knot nematodes in an infested field. Hybrid rootstock â RST 106â resulted in the lowest root-knot nematode galling. In conclusion, TIF with reduced rates of DMDS or MeI is a viable MBr alternative for fresh market tomato production to retain effective doses of fumigant, manage yellow nutsedge and maintain yields. Grafting is an effective MBr alternative to manage bacterial wilt and root-knot nematode and maintain tomato yields.Ph. D.
16
Underwood, Jonathan. "Vector properties in molecular photodissociation." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311835.
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Seccombe, Dominic Paul. "The nature of the excited states of some non metal halides and their cations." Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368455.
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Zulhendri, Felix. "Investigation of metabolic-stress disinfection and disinfestation (MSDD) as an alternative to methyl bromide for disinfestation." Thesis, University of Auckland, 2012. http://hdl.handle.net/2292/19410.
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Metabolic-stress disinfection and disinfestation (MSDD) is a Methyl Bromide (MeBr) alternative disinfestation technology that utilises the combination of pressure change, hypercarbia, hypoxia and ethanol treatments. The thesis describes the investigation of the insecticidal efficacy of MSDD against various insect pests; longtailed mealybug (Pseudococcus longispinus), 5th instar light brown apple moth (LBAM, Epiphyas postvittana) larvae and 5th instar codling moth larvae (Cydia pomonella). MSDD consists of 2 phases, namely a physical phase and followed by a chemical phase. The physical phase is characterised by cycles of pressure changes (90-110 kPa) carried out by drawing air from the treatment chamber and replacing it with ballast gases (CO2 or N2). The physical phase usually lasts for 30 min. At the end of the physical phase, the chemical phase is initiated by drawing the pressure down to 10 kPa and ethanol is introduced into the chamber (held for 60 min). This 90 min MSDD treatment protocol was shown to be effective in controlling surface pests. Further investigation showed parameters associated to both the physical phase (the length of the physical phase) and the chemical phase (the concentration of ethanol, the length of chemical phase and the pressure of chemical phase) were required to ensure high mortality of pests. The efficacy of MSDD was limited to surface pests. Inoculation of 5th instar codling moth larvae into the apples severely limited the capacity of MSDD to disinfest. Low mortality was shown to be correlated with the inability of ethanol to penetrate into apple flesh. Ethanol only penetrated 1 cm (from the skin) into the apple flesh. Investigation into the protein changes in the haemolymph of LBAM larvae revealed that the insecticidal efficacy of MSDD is strongly linked to the chemical phase and its ability to disrupt melanisation regulation. MSDD prevented the up-regulation of alaserpin and induced the over-expression of serine protease. Serpin family has been shown to negatively regulate melanisation, whereas serine protease has been shown to promote melanisation. By disrupting this regulation, MSDD induced excessive melanisation in the larvae which was evident in the physical appearance of the treated larvae. Melanisation is an innate immune response against pathogens in most arthropods. However, excessive melanisation has been shown to be cytotoxic to insects. Research into the effect of MSDD on fruit physiology and quality showed that MSDD had adverse effect on 'Hayward' and 'Hort 16A' kiwifruit. The most significant result was the increase in rot incidence in both cultivars. MSDD also resulted in disorders such as flesh breakdown and uneven ripening in the 'Hort 16A' fruit. Ripening (and softening) was also accelerated in the non-cool stored 'Hayward' kiwifruit. Conversely, MSDD treatments did not have noticeable effect on the physiology and quality of 'Cripps Pink' apple and 'Hass' avocado. Ripening physiology and quality parameters, such as rot incidence, internal browning (apple) and flesh greying (avocado) were not affected by MSDD treatments. Packaging materials restricted the efficacy of MSDD. Materials with high ethanol sorption such as cardboard (kiwifruit boxes) reduced the mortality of insects treated with MSDD significantly. Exposure to ethanol was also demonstrated to be a critical factor to ensure high mortality. 'Bulk' treatment using a harvest crate showed that MSDD only managed to disinfest the first layer of fruit. Mortality steeply decreased in the subsequent layers of fruit. Therefore, a single layer fruit tray was needed to ensure high mortality. In conclusion, MSDD treatments were shown to be effective in controlling insect pests. Both the physical and chemical phases were important in achieving high insect mortality. The MSDD mode of action is proposed to be involving the disruption of the melanisation regulation in the form of up-regulation and down-regulation of serine protease and its inhibitor (serpin), respectively. The efficacy of MSDD was limited to surface pests, non-absorbing and single layered packaging materials. 'Cripps Pink' apple and 'Hass' avocado were MSDD tolerant. Conversely, 'Hayward' and 'Hort 16A' were susceptible to over- production of ethanol and flesh breakdown disorder in response to MSDD treatments, respectively.
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Jensen, Christopher D. (Christopher David) 1974. "Terrestrial sources and sinks of atmospheric methyl bromide : three-dimensional modeling of tropospheric abundance and sensitivities." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/54436.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1999.Includes bibliographical references (p. 87-92).
Current estimates of methyl bromide surface fluxes are inconsistent with the observed tropospheric mole fractions (9 to 10 ppt, globally averaged) and the calculated atmospheric lifetime (1.7 ± 0.2 years), with mid-range estimates of sinks exceeding sources by at least 50 Gg y-I. Given the uncertainties in process-specific surface flux estimates, we consider several distributions of terrestrial sources and sinks that satisfy the constraints on atmospheric abundance, Mole fractions corresponding to each distribution are simulated with a three-dimensional chemical transport model based on analyzed observed winds, coupled to a simple model of the ocean mixed layer. All of the resulting scenarios overestimate the observed zonal gradient, with interhemispheric ratios ranging from 1.39 to 1.60. In the absence of unknown sources, model results imply a biomass burning source near the upper limit of the range of present estimates (50 Gg y-1). Sensitivities to surface fluxes are also calculated to determine the extent to which uncertain terms in the methyl bromide budget can be better quantified using long-term measurements. Results show that a global network capable of accurately monitoring the monthly, zonal mean distribution of CH3Br would be able to distinguish between biomass burning fluxes and other known terrestrial sources and sinks. Modeled sensitivities to biomass burning emissions also highlight the importance of including tropical locations in any long-term monitoring network. However, technological sources and soil sinks have similar zonal patterns, and long-term, "background" mole fractions are relatively insensitive to zonal flux distributions. It is only when we examine the high frequency variability of the concentration that the effect of longitudinal gradients in the flux field becomes apparent.
by Christopher D. Jensen.
S.M.
20
Ren, YongLin, and n/a. "Carbonyl sulphide as a fumigant for grain and timber : efficacy towards organisms and formation of residues." University of Canberra. Human & Biomedical Sciences, 1997. http://erl.canberra.edu.au./public/adt-AUC20061107.120137.
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This thesis presents an investigation of carbonyl sulphide as a new fumigant
and related methodology studies. The first part involved the investigation of a new
fumigant - carbonyl sulphide, which has the potential to replace methyl bromide.
Its biological response or activity was investigated, e.g. toxicity to target organisms
and phytotoxicity, environmental and worker safety considerations. In the second
investigation, analytical methods were developed for the determination of fumigant
movement through timber and fumigant residues in grains as well as a method of
chemical fractionation to determine the fate of carbonyl sulphide. A comprehensive
literature review of 161 references in these two areas is reported.
Carbonyl sulphide was highly toxic to adults of three coleopteran species
tested, namely Rhyzopertha dominica (F.), Tribolium confusum du Val, and
Sitophilus oryzae (L.), the most sensitive species was R. dominica. For 6 hr
exposure at 25�C, the L(CxT)95 value for R. dominica, S. oryzae and T. confusum
were, respectively, 36.48, 99.82 and 113.0mg h L-1. Carbonyl sulphide inhibited
100% of mould in wet wheat and more than 90% of mould on dry wheat at lOOmg
L-1. Both carbonyl sulphide and hydrogen cyanide were low in phytotoxicity
without affecting germination of wheat, at levels needed to control insects. Unlike
hydrogen cyanide, carbonyl sulphide can be used at minimum levels without
decreasing plumule length of wheat.
Chemical data on the sorption of carbonyl sulphide are compared with data
from methyl bromide. The levels of carbonyl sulphide in the headspace of five
commodities (wheat, barley, paddy, sorghum and peanut) and timbers (hardwood
and softwood) decay more slowly than do levels of methyl bromide. Carbonyl
sulphide was blown through a column of wheat as easily as was phosphine and
more easily than was methyl bromide, and its front was blown out faster than
phosphine and methyl bromide. Movement of two fumigants (methyl bromide and
carbonyl sulphide) through, and sorption on, softwood and hardwood were studied.
Each fumigant was sorbed less on softwood than on hardwood and penetrated
softwood better than hardwood. Carbonyl sulphide penetrated timber better than
did methyl bromide, and was less sorbed on timber. A rapid method of solvent
extraction was developed to enable rapid estimation of the amount on intact
fumigant sorbed in wood. This procedure enabled near quantitative recovery of
methyl bromide as either intact fumigant or as bromide ion.
Carbonyl sulphide residue in unfumigated wheat was found to be around 25-
SOppb. Carbonyl sulphide left little residue on fumigated grains. Desorption of
carbonyl sulphide from the wheat was extremely fast, 85% of it was released after
one day aeration which was very much greater than that of methyl bromide and
carbon disulphide. After 6 days aeration the incorporation of 14COS on mungbean,
wheat, paddy, rice and safflower was lower than 7Oppb (calculated as COS
equivalent). Food value or nutritional quality of foodstuffs is not harmed by
carbonyl sulphide fumigation. This result was assessed by identifying any nonreversible
change or combined residues in biochemical fractions of commodities
including lipids, protein, amino acids, carbohydrate, etc., and no irreversible
reaction between carbonyl sulphide and any constituent such as B vitamin, atocopherol,
lysine, maltose and starch. Fumigants did not affect lipids, although
each fumigant was applied to wheat at exaggerated concentrations, nor wheat germ
oil and canola oil treated with extremely high concentration of fumigants.
Factors which affect analysis of fumigants including stability of chemicals
in extraction solvent and partitioning of fumigant between solvent and air, were
examined. The partition ratio, defined as the fumigant concentration in extraction
solvent to that in the headspace, varied with fumigant. Methods for multi-fumigant
analysis were developed or modified and gave high recoveries and efficiency. The
procedure of Daft of solvent extraction followed by partitioning was modified by
being performed in sealed flasks. This raised the recovery of carbonyl sulphide,
methyl bromide, phosphine and carbon disulphide. Recoveries were near
quantitative at levels down to 6-16ppb (w/w) for tested fumigants. Thus the
modified Daft method can be adapted to enable determination of the main fumigants
used on staple foodstuffs. Microwave irradiation method give higher efficiency of
removal of fumigants from grains. Limits of quantification were < 0.2ng g-1 (ppb
w/w) for each tested fumigant. The detection limit of COS was calculated, as
natural levels of the fumigant were detected in commodities. These are feasible,
simple and rapid (< 2 min.) to be use to analyse fumigant residue in grains.
Carbonyl sulphide has potential as a fumigant for grain and timber and may
replace methyl bromide in some uses, subject to further investigation in commercial
situations.
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Kharel, Kabita. "Evaluation of pyrethrin aerosol insecticide as an alternative to methyl bromide for pest control in flour mills." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/16006.
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Master of ScienceDepartment of Entomology
Frank H. Arthur
Kun Yan Zhu
Experiments were conducted to assess the effects of direct and indirect exposure scenarios, different degrees of residual flour, open and obstructed positions, and seasonal temperature variations on the efficacy of synergized pyrethrin against the red flour beetle, Tribolium castaneum (Herbst) and the confused flour beetle, Tribolium confusum Jacquelin du Val. To evaluate effects of direct and indirect exposures of T. castaneum and T. confusum eggs, larvae, pupae, or eggs to the insecticide aerosol within a flour mill, the following treatments were made to each life stage: insects treated with aerosol and transferred to treated or untreated flour, untreated insects transferred to treated flour, and insects and flour combined and treated together. Different degrees of harborage or sanitation levels were created by exposing T. confusum larvae, pupae, and adults to pyrethrin aerosol in Petri dishes containing 0, 0.1, 1, 5, and 10 g of wheat flour. Effects of pyrethrin dispersal in open and obstructed positions and seasonal temperature variations were assessed by exposing T. confusum pupae and adults in open positions and inside wooden boxes (1 m long, 20 cm wide, and 5, 10, or 20 cm high) inside experimental sheds maintained at target temperatures of 22, 27, and 32 °C. Results showed that when T. castaneum and T. confusum were directly exposed to aerosol without the flour source, or with a low amount of flour at open exposed areas, the aerosol provided good control against all life stages of T. castaneum and T. confusum. However, when insects were indirectly exposed (treated together with flour or untreated insects were transferred to treated flour), or treated together with deeper flour amounts, and exposed inside the boxes, the efficacy was greatly reduced. Eggs and pupae of both the species were more susceptible compared to larvae and adults. Additionally, the moribund adults initially observed in indirect exposure treatments, or at the deeper flour depth and exposure positions insides the boxes, were better able to recover. Generally, temperatures in the range of 22-32 °C had no significant effects on overall efficacy of pyrethrin aerosol.
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Steel, Colin James. "Automated radiosynthesis of 2-['1'1C]thymidine and ['1'1C]methyl halides for use in Positron Emission Tomography." Thesis, University of Hertfordshire, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323444.
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Muhareb, Jeannette S. "A comparsion to methyl bromide with two alternatives treatments; sulfuryl fluoride and heat to control stored products insects." Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/4201.
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Muhareb, Jeannette S. "A comparison to methyl bromide with two alternatives treatments; sulfuryl fluoride and heat to control stored products insects." Thesis, Kansas State University, 2010. http://hdl.handle.net/2097/4201.
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Master of AgribusinessDepartment of Agricultural Economics
Subramanyam Bhadriraju
Environmental concerns are growing as new information is being discovered as to what is harmful to the environment. The desire to help the environment along with improving fumigations is a big concern and effects many people. Ongoing research to improve fumigations without harming the environment has shown great promise in advancing technology and lowering the cost in protecting commodities consumed by the consumer. Methyl Bromide (MB) has been the major fumigant used to control stored-product insects for many commodities for many years. There has been a lot of concern surrounding MB because of health and environmental drawbacks. These concerns have caused MB to be reduced by 2005. With the total phase out of MB becoming critical, there is much anticipation as what will be the alternative(s). The research presented in this thesis describes two different and very effective methods of controlling stored product insects. Although there are many other methods of fumigating this thesis analyzes two forms; Sulfuryl Fluoride and Heat. The first presented alternative in this paper will be heat treatments. It has the attraction that chemical forms of treatments do not have by having pesticide-free products. The total cost of heat fumigation depends on the complexity of the lay-out/structure and the cost heaters and electricity. This cost can range anywhere from $15,000-25,000. The second alternative that will be discussed is sulfuryl fluoride. This fumigant has many positive aspects that counter act the negative aspects that have been a concern with methyl bromide treatments. These positive aspects include environmentally safe and fast off-gassing. Sulfuryl fluoride is also very efficacious with stored product insects. The labor costs per job, ProFume shows a cost of about $216.00 less than that of a methyl bromide treatment.
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Struss, John Anthony. "New Methods for the Formation of Methyl Bearing Stereogenic Centers via Methylketene Dimerization and Free Radical Additions to Allyl Bromides." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/28734.
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Two organic synthetic methods for the generation of methyl bearing chiral centers have been developed using: 1) dimerization of methylketene and 2) a free radical-based addition/elimination reaction involving allyl bromides. The first method, the asymmetric dimerization of methyl ketene, followed by an asymmetric aldol reaction and the appropriate functional group manipulations enabled us to construct the (2S, 4S, 6S) trimethylnonyl subunit found in the siphonariene class of natural products. The latter method explored the stereoselective potential of a free radical-based condensation reaction by examining compounds which are known to be able to support chiral auxiliaries and chiral Lewis acids. Additionally, substituent effect on the rates of this reaction were examined closely and found to be comparable to similar, previously examined systems. The synthetic utility, magnitude and scope of this reaction are discussed.Ph. D.
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Clark, L. J., and E. W. Carpenter. "The Effects of Methyl Bromide Fumigants on Verticillium Wilt on Two Varieties of Short Staple Cotton, Safford Agricultural Center, 1988." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/204842.
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Methyl bromid/chloropicrin formulations were applied to strips in the verticillium nursery at the Safford Agricultural Center where two varieties of short staple cotton were subsequently planted. More robust plant growth and reduced incidence of disease were noted with some of the treatments. Yield increases over the check plots were also seen. A study of the residual effects of the treatments will be performed in 1989.
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Abbar, Salehe. "Methods for management of Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae) in dry-cured ham facilities." Diss., Kansas State University, 2016. http://hdl.handle.net/2097/34466.
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Doctor of PhilosophyDepartment of Entomology
Thomas W. Phillips
Robert "Jeff" J. Whitworth
Dry-cured ham is protected from infestations of Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae) with the fumigant methyl bromide. Developing feasible alternatives to methyl bromide is necessary due to the phase out of methyl bromide. The effectiveness of food-safe compounds for preventing infestations of T. putrescentiae on dry-cured hams was evaluated by dipping ham pieces in solutions of various food additives. Propylene glycol (1, 2-propanediol), lard, ethoxyquin and butylated hydroxytoluene prevented or significantly reduced mite population growth. A combination of carrageenan + propylene glycol alginate + 40% propylene glycol was effective in reducing mite numbers on treated whole-aged hams compared with untreated hams. Dose/response tests with twelve registered residual insecticides were conducted to assess contact toxicity to T. putrescentiae. Three of these insecticides were evaluated for persistence over a 2-month period on different surfaces. Commercial formulations of deltamethrin plus chlorpyrifos-methyl, chlorfenapyr, and malathion showed promising results for contact toxicity against T. putriscentiae. Chlorfenapyr applied to metal, concrete, and wood resulted in 100% mortality of treated ham mites for up to 8 weeks. The effect of high and low temperatures on mortality of T. putrescentiae was studied in the laboratory. Groups of 10 eggs and groups of a mixture of 40 adults and nymphs were separately exposed to several high and low temperatures, ranging from +35 to 45°C and from −20 to +5°C, for several time periods. Eggs were found to be more tolerant to both high and low temperatures compared with adults and nymphs. Results showed that high temperatures from 40-45°C killed all T. putrescentiae eggs, adults, and nymphs within 4-1 d, while −10°C or lower killed all the same stages in less than 1 d. Combinations of the fumigant sulfuryl fluoride (SF) applied under high temperatures ranging from 25-40ºC, were studied to determine the highest temperature, shortest exposure time, and the lowest value of a concentration-by-time product (CTP) of SF against T. putrescentiae. Results showed that complete control of all life stages of T. putrescentiae was achieved at 40ºC with SF. More than one day of exposure was required to kill adults and nymphs and eggs at 40ºC at a CTP close to the EPA labeled rate of 1500 gh.m⁻³. Results indicated that adults and nymphs were more susceptible to SF compared to eggs. This study focused on investigating different control methods for T. putrescentiae in dry-cured ham facilities and most of examined techniques are preventive, although some of them can be applied as remedial methods after mite infestations are noticed.
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Brijwani, Monika. "Effect of sanitation on responses of Tribolium castaneum (herbst) (Coleoptera: tenebrionidae) life stages to structural heat treatments." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/8439.
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Master of ScienceDepartment of Grain Science and Industry
Subramanyam Bhadriraju
Heat treatment involves raising the ambient temperature of food-processing facilities such as flour mills to 50-60oC for killing stored-product insects. However, very little is known about the influence of sanitation on responses of stored-product insects to structural heat treatments. The impact of sanitation on responses of life stages of the red flour beetle, Tribolium castaneum, an economically important pest in flour mills, were investigated during three 24 h structural heat treatments of the Kansas State University pilot flour mill. Two sanitation levels, dusting of wheat flour (~0.5 g) and 2-cm deep flour (~43 g), were created in 25 plastic bioassay boxes each holding 50 eggs, 50 young larvae, 50 old larvae, 50 pupae, and 50 adults of T. castaneum in separate compartments. Five boxes were placed on each of five floors of the pilot mill during 13-14 May 2009, 25-26 August 2009, and 7-8 May 2010 heat treatments using forced air gas heaters. During the August 2009 and May 2010 heat treatments, 100 eggs or 100 adults of T. castaneum were exposed inside each 20 cm diameter by 15 cm high PVC ring placed only on first and third floors and holding 0.1 (15 g), 0.2 (38 g), 1 (109 g), 3 (388 g), 6 (937 g), or 10 (1645 g) cm deep wheat flour. Among the mill floors, first floor had lower maximum temperature. The first floor rests on a thick concrete foundation, did not get heated from both sides unlike other floors, and had poor air movement resulting in cold pockets (temperatures <50oC). Mortality of life stages was lower on first floor than other floors and adults were less susceptible than other life stages especially on first floor. In general, both these tests have shown that the mortality of T. castaneum life stages were influenced by how quickly temperatures reached 50oC, how long temperatures were held above 50oC, and the maximum temperature. Protective effects of sanitation were evident only if temperatures did not reach 50oC. However, removal of flour accumulations is essential to improve heat treatment effectiveness against all T. castaneum life stages during a 24 h treatment.
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van, Haandel Andre. "Irradiation as an alternative phytosanitary treatment for Arhopalus ferus and Hylurgus ligniperda." Thesis, University of Canterbury. School of Forestry, 2014. http://hdl.handle.net/10092/10506.
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Wood products all require treatment to mitigate phytosanitary risk prior to exportation. The most common phytosanitary treatment applied to Pinus radiata logs is Methyl Bromide (MeBr). The Environmental Protection Agency (EPA) in 2010 stated that MeBr must not be release into the atmosphere past 2020. This poses a problem for New Zealand log exports. Radiation has been identified as a possible alternative phytosanitary treatment for export wood products.
This study aimed to quantify the effective dose of radiation necessary to sterilise two forest pest species; Arhopalus ferus and Hylurgus ligniperda. These species are representative of two different types of forestry pests; bark beetles (H. ligniperda) and wood borers (A. ferus). All applicable life stages for both species were tested.
Arhopalus ferus adults were the most susceptible life stage identified with an LD99 of 30.2Gy ± 13.5 Gy (95% confidence interval). Arhopalus ferus eggs were less susceptible with a LD99 of 750Gy ± 776Gy observed; however there is low confidence in this result due to a methodological issue in one treatment replicate. Hylurgus ligniperda eggs were observed to be less susceptible than A. ferus eggs with a LD99 of 289Gy ± 92Gy. Results for the other life stages were inconclusive due to poor control survival, however the information gained was used to develop improved methods for further experimentation, which is on-going and showing positive results so far.
The results of this experiment have indicated that radiation can be an effective method of sterilising forestry pests. To date radiation has not been used as phytosanitary risk mitigation for wood exports; however it is widely used for risk mitigation in agricultural products. Currently there remains a large amount of unknown information regarding, the effectiveness for irradiation of logs, the effective dose require for sterilisation of the most tolerant forestry pest and public acceptability of irradiation as a phytosanitary treatment. These knowledge gaps and an economic assessment must be completed before irradiation can be used as a phytosanitary risk mitigation technique for forestry products.
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Carter, Mel. "Investigating novel approaches for the integrated control of the soilborne strawberry pathogens Macrophomina phaseolina and Fusarium oxysporum f. sp. fragariae." DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1628.
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Macrophomina phaseolina (Mp) and Fusarium oxysporum f. sp. fragariae (Fof) are emerging soilborne pathogens causing crown rot and Fusarium wilt, respectively, in commercial strawberry production in California. Fungicides representing eight active ingredients from four different mode of action groups (FRAC groups 1, 3, 7 and 12) were evaluated for their efficacy against each pathogen in vitro and each disease in planta. Fungicide active ingredients were evaluated for their ability to inhibit mycelial growth of both pathogens in vitro. Half-strength potato dextrose agar was amended with six different concentrations (0.01, 0.1, 1.0, 5.0, 10, 50 µg a.i./ml) of seven fungicides in FRAC groups 3, 7 and 12. Concentrations that inhibited fungal growth by 75% (EC75) compared to unamended media were determined for two different isolates each of Mp and Fof and were used to determine fungicide rates for subsequent in planta studies. Tebuconazole strongly inhibited the mycelial growth of both pathogens (average EC75 for Mp was 2.4 ppm; average EC75 for Fof was 7.48 ppm), as did metconazole (average EC75 for Mp was2.53 ppm; average EC75 for Fof was 1.28 ppm). Fludioxonil strongly inhibited mycelial growth of Mp, but had no impact on the growth of Fof. Penthiopyrad, fluopyram, flutriafol, and flutolanil were less effective at inhibiting fungal growth of either fungus. Greenhouse in planta studies evaluated twenty-four fungicide treatments (eight fungicides at low, med and high rates) that were drench applied to infested potting media two days prior to planting of pathogen susceptible strawberry cultivars (San Andreas for Mp and Monterey for Fof) and again at day 21. Controls were a non-inoculated and an inoculated water-drench treatment. Buried inoculum was recovered at days 2 and 23 and plated on selective media for colony forming unit (CFU) quantification. Plant disease assessments were made each week for 11 weeks. An analysis of variance (ANOVA) of CFUs revealed no significant differences (p > 0.05) among treatments and when compared to the non-treated control for both Mp and Fof, but showed significant decreases (p < 0.05) in CFUs between weeks 1 and 3 for both Mp and Fof. An ANOVA for disease assessments in the form of area under the disease progress curve (AUDPC) showed significant decreases of disease severity in treatments with penthiopyrad only (low, medium and high rates) (p < 0.05). There were no significant differences (p > 0.05) in AUDPC among treatments and when compared to the non-inoculated and no-fungicide controls for Fof. The data indicates that these fungicides used alone are not effective against these pathogens in planta.
A strawberry plant extract (germination stimulant) was assessed for its ability to stimulate germination of Mp microsclerotia in vitro and in planta. The germination stimulant was applied as a drench at six different concentrations (0, 10, 100, 1,000, 10,000 and 30,000 ppm) to soil containing filter disk packets of microsclerotia of Mp at day 0 and 14. Filter disk packets were retrieved three days after the drench and microsclerotia were observed microscopically for germination. Results showed that the number of germinating microsclerotia was significantly higher after the application of the germination stimulant compared to non-drench and 0 ppm controls (p < 0.001).
An integrated container trial was also conducted using the germination stimulant at 10,000 ppm applied three days prior to a fungicide drench with tebuconazole or thiophanate-methyl to determine the effect of fungicides on the germinated microscleotia. The use of the germination stimulant with label rates of the fungicides lowered the number of germinated intact microsclerotia significantly (p < 0.001) especially after two drench applications. The use of the germination stimulant with fungicides could be investigated further as one method for controlling soilborne diseases of strawberry.
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Adamovic, Ivana. "Solvation!" Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2004. http://www.osti.gov/servlets/purl/835373-NLtQXD/webviewable/.
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19 Dec 2004.Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 2009" Ivana Adamovic. 12/19/2004. Report is also available in paper and microfiche from NTIS.
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Ridley, Paul. "Underpotential deposition of lead on gold and platinum (111) electrode surfaces investigated by scanning tunnelling microscopy." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343615.
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Lagrange, Thierry. "Intoxication accidentelle collective familiale au bromure de méthyle : à propos de 4 cas." Montpellier 1, 1990. http://www.theses.fr/1990MON11266.
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Chang, Xue Feng. "Development and application of a rapid micro-scale method of lignin content determination in Arabidopsis thaliana accessions." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2448.
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Lignin is a major chemical component of plants and the second most abundant natural polymer after cellulose. The concerns and interests of agriculture and industry have stimulated the study of genes governing lignin content in plants in an effort to adapt plants to human purposes. Arabidopsis thaliana provides a convenient model for the study of the genes governing lignin content because of its short growth cycle, small plant size, and small completely sequenced genome. In order to identify the genes controlling lignin content in Arabidopsis accessions using Quantitative Trait Locus (QTL) analysis, a rapid micro-scale method of lignin determination is required.
The acetyl bromide method has been modified to enable the rapid micro-scale determination of lignin content in Arabidopsis. Modifications included the use of a micro-ball mill, adoption of a modified rapid method of extraction, use of an ice-bath to stabilize solutions and reduction in solution volumes. The modified method was shown to be accurate and precise with values in agreement with those determined by the conventional method. The extinction coefficient for Arabidopsis lignin, dissolved using acetyl bromide, was determined to be 23.35 g-iLcm-1. This value is independent of the Arabidopsis accession, environmental growth conditions and is insensitive to syringyl/guaiacyl ratio. The modified acetyl bromide method was shown to be well correlated with the 72% sulfuric acid method once the latter had been corrected for protein contamination and acid-soluble lignin content (R² = 0.988, P < 0.0001).
As determined by the newly developed acetyl bromide method and confirmed by the sulfuric acid method, lignin content in Arabidopsis was found to be a divergent property. Lignin content in Arabidopsis was found to be weekly correlated with growth rate among Arabidopsis accessions (R² = 0.48, P = 0.011). Lignin content was also found to be correlated with plant height among Arabidopsis accessions (R² = 0.491, P < 0.0001).
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Haroutunian, Garabed. "La fumigation biologique comme alternative au bromure de méthyle pour le contrôle du nématode Méloïdogyne incognita dans la production de concombre dans les serres." Thesis, Paris, AgroParisTech, 2013. http://www.theses.fr/2013AGPT0025/document.
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Les nématodes à galles demeurent l'un des problèmes les plus graves des agriculteurs de serres du Liban et du Moyen-Orient. Dans le passé, la fumigation du sol au bromure de méthyle a été considérée comme la meilleure mesure de contrôle contre ces nématodes. Toutefois, à la lumière de l'élimination globale du bromure de méthyle, l'accès aux alternatives efficaces et durables est devenu une nécessité essentielle.L'objectif de cette étude est d'évaluer l'efficacité des deux engrais verts, le radis huileux (Raphanus sativus oleifera) et à la roquette (Eruca vesicaria sativa) appliquées avec ou sans bâche en plastique, séparément et en combinaison avec Oxamyl, dans la gestion des nématodes à galles en cultures de concombres de serre. En outre, cette étude vise à évaluer la faisabilité financière de la technique de biofumigation avec les deux cultures utilisées et de la rentabilité finale de ces engrais verts en termes de taux coût-profit par rapport au bromure de méthyle.A cette fin, trois expériences sur le terrain ont été menées dans des serres commerciales, situées sur la zone côtière du Liban.Dans les deux expériences A et B, des résultats cohérents ont été enregistrés en termes de production de rendements significativement plus élevés et de la réduction des populations de nématodes avec les engrais verts utilisés avec ou sans bâche en plastique, par rapport au témoin non traité.Quant aux résultats obtenus par les engrais verts par rapport au bromure de méthyle, dans l'expérience A, le rendement produit par le bromure de méthyle était significativement plus élevé que celui du radis huileux avec bâche en plastique. Cependant, la différence n'était pas significative entre la réduction de la population de nématodes résultant du bromure de méthyle et celle du radis huileux avec bâche en plastique. Les différences du rendement ainsi que la réduction des nématodes étaient significatives entre le bromure de méthyle et le radis huileux sans bâche en plastique.Dans l'expérience B, aucune différence significative n'a été observée dans le rendement ni la réduction de la population de nématodes entre aucun des deux engrais verts utilisés avec bâche en plastique et le bromure de méthyle. Ces différences étaient significativement en faveur du bromure de méthyle uniquement lorsque le radis huileux a été utilisé sans bâche en plastique.Dans l'expérience C, où Vydate (Oxamyl) a été appliqué à la dose de 1 litre par 1,000 m2 à tous les traitements, il n'y avait pas de différence significative dans le rendement ni la réduction de la population de nématodes entre chacun des deux engrais verts utilisés avec ou sans bâche en plastique et le bromure de méthyle.L'analyse coût-profit menée sur tous les traitements appliqués dans les 3 expériences a montré que dans tous les cas, tous les traitements appliqués, qu'ils soient chimiques, non-chimique (avec ou sans bâche en plastique) ou en association ont produit des bénéfices nets supérieurs au bromure de méthyle, même lorsque le rendement produit par le bromure de méthyle était significativement plus élevée.L'utilisation du plastique pour couvrir les radis huileux a généralement produit de meilleurs résultats en termes de production de rendements plus élevés, une meilleure réduction des populations de nématodes à galles dans le sol, ainsi conduisant à des augmentations raisonnables des profits nets.A la base de ces résultats et à la lumière de l'élimination globale du bromure de méthyle, on peut conclure que l'utilisation du radis huileux et la roquette comme engrais verts avec bâche en plastique peut être considéré comme un outil alternatif pour la gestion des nématodes à galles dans la production de concombres de serre dans les conditions libanaises.Root-knot nematodes remain one of the most serious problems faced by greenhouse farmers of Lebanon and the Middle East region. In the past, soil fumigation with methyl bromide has been considered as the best control measure against root-knot nematodes. However, in the light of the global phase out of methyl bromide, finding efficient and viable alternatives is an essential necessity.The objective of this study is to evaluate the efficacy of the two biofumigation crops Oil Radish (Raphanus sativus oleifera) and Arugula (Eruca vesicaria sativa) applied with and without plastic tarp, separately and in combination with Oxamyl in the management of the root-knot nematodes in greenhouse cucumber crops. Additionally, this study aimed at assessing the financial feasibility of the biofumigation technique with the two cops used and the final profitability of these green manure crops in terms of cost to benefit ratio as compared to methyl bromide.For this purpose, three field experiments were carried out in commercial greenhouses situated on the coastal zone of Lebanon.In both experiments A & B consistent results were recorded in terms of production of significantly higher yields and reduction of nematode population with the biofumigation crops used whether with or without plastic cover, as compared to untreated fallow.As to the results achieved by the biofumigation crops with respect to methyl bromide, in experiment A yield produced by methyl bromide was significantly higher than oil radish with plastic cover. However, no significant difference was found between reduction of nematode population resulting from methyl bromide and oil radish with plastic cover. Difference was significant between methyl bromide and oil radish without plastic cover in both yield and reduction of nematodes.In experiment B no significant difference was observed in neither yield nor reduction of nematode population between any of the two biofumigation crops used with plastic cover and methyl bromide. These differences were significantly in favor of methyl bromide only when oil radish was used without plastic cover.In experiment C where Vydate (Oxamyl) was incorporated at the rate of 1 liter per 1,000 m2 to all treatments, there was no significant difference in neither yield nor reduction of nematode population between any of the two biofumigation crops used with or without plastic cover.Cost-benefit analysis made on all treatments applied in the 3 experiments showed that in all cases, all treatments applied, whether chemical, non-chemical (with or without plastic cover) or in combination have produced higher net profits than methyl bromide, even when yield produced by methyl bromide was significantly higher.Use of plastic for covering oil radish has generally produced better results in terms of production of higher yields, better reduction of soil populations of root-knot nematodes and leading to reasonable increases of net profits.Based on these findings and in the light of global phase out of methyl bromide, it can be concluded that the use of oil radish and arugula as biofumigation crops with plastic cover can be considered as an alternative management tool for the root-knot nematode in greenhouse cucumber production under Lebanese conditions.
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SANTOS, ROBINSON A. dos. "Otimização da metodologia de preparação do cristal de brometo de tálio para sua aplicação como detector de radiação." reponame:Repositório Institucional do IPEN, 2012. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10085.
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Made available in DSpace on 2014-10-09T12:34:35Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:00:07Z (GMT). No. of bitstreams: 0
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IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Lacerda, Roseli Sengling. "Teores de lignina determinados através do método espectrofotométrico lignina solúvel em brometo de acetila de alguns cultivares de aveia." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/74/74131/tde-04072002-153418/.
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Para quantificar o teor de lignina em alguns cultivares de aveia, foi utilizado o método espectrofotométrico "lignina solúvel em brometo de acetila LSBA", onde a lignina é solubilizada em uma solução a 25% de brometo de acetila em ácido acético glacial e em seguida sua absorbância lida a 280 nm; como padrão de referência foi utilizada a lignina extraída da aveia através de uma solução ácida de dioxana. A quantificação da lignina foi realizada em oito cultivares de aveia, nas frações planta inteira, caule e folha, em três estádios de maturidade (45, 55 e 65 dias de idade). Os resultados obtidos foram comparados com três métodos gravimétricos: lignina detergente ácido (LDA), lignina permanganato de potássio (LPer) e lignina Klason (LK). Os quatro métodos estudados mostraram teores de lignina diferentes entre si. Os resultados de LSBA foram superiores para quase todos os cultivares, ocorrendo o inverso para a LDA. Houve uma pequena diferença em relação aos dias de corte, com dados superiores para LSBA, onde o caule apresentou maior variação em relação às demais frações. As curvas de regressão e os espectrogramas indicaram presença de diferenças qualitativas entre as ligninas provenientes da aveia forrageira nos diferentes estádios de maturidade.To quantify lignin content in some varieties of oat, it was employed the spectrophotometric method acetyl bromide soluble lignin ABSL where lignin is dissolved into a 25% acetyl bromide solution in glacial acetic acid and its absorbance read at 280 nm; as a standard it was employed a, lignin extracted by mild acidic dioxane solution from the same sample. Lignin quantification was evaluated in eight oat cultivars, divided in three vegetable parts (whole plant, stem and leaf), and three different maturity stages (cuts at 45, 55 and 65 days). Obtained results were compared with three gravimetric methods: acid detergent lignin (ADL), potassium permanganate lignin (PerL) and Klason lignin (KL). All four methodologies yielded different results. Overall, ABSL yielded highest values whereas ADL yielded the lowest ones. There was a slight difference related to maturity, with higher values for ABSL, where stem fraction showed higher variation when comparing to the two other vegetable parts. Regression equations and espectrograms indicated the presence of qualitative differences between lignins from at distinct maturity stages.
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Kruger, John Scott. "Synthesis and characterization of several novel aluminum and gallium phosphates templated by cobalt complexes." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/30553.
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Kadry, Ahmed Y. "Removal of selected water disinfection byproducts, and MTBE in batch and continuous flow systems using alternative sorbents." Thesis, University of North Texas, 2002. https://digital.library.unt.edu/ark:/67531/metadc3285/.
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A study was conducted to evaluate the sorption characteristics of six disinfection byproducts (DBPs) on four sorbents. To investigate sorption of volatile organic compounds (VOCs), specially designed experimental batch and continuous flow modules were developed. The investigated compounds included: chloroform, 1,2-dichloroethane (DCE), trichloroethylene (TCE), bromodichloromethane (BDCM), methyl tertiary butyl ether (MTBE), bromate and bromide ions. Sorbents used included light weight aggregate (LWA), an inorganic porous material with unique surface characteristics, Amberlite® XAD-16, a weakly basic anion exchange resin, Amberjet®, a strongly basic anion exchange resin, and granular activated carbon (GAC). Batch experiments were conducted on spiked Milli-Q® and lake water matrices. Results indicate considerable sorption of TCE (68.9%), slight sorption of bromate ions (19%) and no appreciable sorption for the other test compounds on LWA. The sorption of TCE increased to 75.3% in experiments utilizing smaller LWA particle size. LWA could be a viable medium for removal of TCE from contaminated surface or groundwater sites. Amberlite® was found unsuitable for use due to its physical characteristics, and its inability to efficiently remove any of the test compounds. Amberjet® showed an excellent ability to remove the inorganic anions (>99%), and BDCM (96.9%) from aqueous solutions but with considerable elevation of pH. Continuous flow experiments evaluated GAC and Amberjet® with spiked Milli-Q® and tap water matrices. The tested organic compounds were sorbed in the order of their hydrophobicity. Slight elevation of pH was observed during continuous flow experiments, making Amberjet® a viable option for removal of BDCM, bromate and bromide ions from water. The continuous flow experiments showed that GAC is an excellent medium for removal of the tested VOCs and bromate ion. Each of the test compounds showed different breakthrough and saturation points. The unique design of the continuous flow apparatus used in the study proved to be highly beneficial to assess removal of volatile organic compounds from aqueous solutions.
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Zheldakov, Igor. "Ultrafast Photophysics and Photochemistry Of Hexacoordinated Bromides of Pt(IV), Os(IV), and, Ir(IV) in the Condensed Phase Studied by Femtosecond Pump-Probe Spectroscopy." Bowling Green State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1279998360.
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Santamaria, Marcos Felipe Zuñiga. "Otimização do método lignina brometo de acetila na determinação do teor de lignina em plantas forrageiras e comparação com os métodos lignina detergente ácido e lignina Klason." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/10/10135/tde-09052016-112358/.
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Técnicas analíticas empregadas para a quantificação do teor de lignina em plantas forrageiras, atualmente em uso, são questionáveis quanto às suas acurácias. O método lignina detergente ácido (LDA), que é um dos métodos mais utilizado em Ciência Animal e Agronomia, apresenta algumas falhas, particularmente devido à parcial solubilização da lignina durante a preparação da fibra em detergente ácido (FDA). A lignina Klason (LK), outro método muito usado, apresenta o inconveniente de mensurar a proteína da parede celular como sendo lignina. Em ambos os procedimentos recomenda-se também mensurar cinzas nos resíduos de lignina. A quantificação da concentração de lignina pelo método espectrofotométrico lignina brometo de acetila (LBA) vem ganhando interesse de pesquisadores no Brasil e no exterior. Nesta metodologia, a lignina da planta contida na preparação parede celular (PC) é solubilizada numa solução a 25% de brometo de acetila em ácido acético e a absorbância mensurada é com luz UV a 280 nm. O valor da absorbância é inserido numa equação de regressão e a concentração de lignina é obtida. Para que esta técnica analítica seja mais aceita pelos pesquisadores, ela deve ser, obviamente, convincente e atrativa. O presente trabalho analisou alguns parâmetros relacionados à LBA em 7 gramíneas e 6 leguminosas, em dois estádios de maturidade. Dentre as diferentes temperaturas de pré-secagem, os resultados indicaram que os procedimentos de 55°C com ventilação e liofilização podem ser utilizados com a mesma eficácia. As temperaturas de 55°C sem ventilação e 80°C sem ventilação não são recomendadas, pois aumentaram os valores de FDA e LDA, possivelmente devido ao surgimento de artefatos de técnica como os compostos de Maillard. No método LBA os valores menores das amostras de leguminosas chamaram a atenção e colocaram em questão se a lignina destas plantas seria menos solúvel no reagente brometo de acetila. Dentre algumas alterações na metodologia da técnica LBA, a utilização do moinho de bolas (para diminuir o tamanho particular) nas amostras de PC não mostrou efeito; a hipótese era melhorar a solubilização da lignina usando partículas menores. O uso de um ultrasonicador, que aumenta a vibração das moléculas e assim, facilitaria a solubilização da lignina no reagente brometo de acetila, melhorou a solubilização da lignina em cerca de 10%, tanto nas gramíneas como nas leguminosas. Foi acoplado um ensaio biológico como referência, a degradabilidade in vitro da matéria seca (DIVMS); e como a lignina está intimamente associada à estrutura fibrosa da parede celular, também foi feito um ensaio de degradabilidade in vitro da fibra em detergente neutro (DIVFDN). Os resultados confirmaram o efeito da maturidade, reduzindo a degradabilidade nas plantas mais maduras, e que o teor de lignina de leguminosas é realmente inferior ao de gramíneas. Os resultados de degradabilidade apresentaram coeficientes de correlação mais elevados com o método LBA, quando foi empregada a técnica do ultrasom; o método LK mostrou os menores coeficientes. Também testou-se, com sucesso, a utilização da FDN, como preparação fibrosa, ao invés de PC. A razão é simples: enquanto que a FDN é amplamente conhecida, a preparação PC não o é. Inquestionável que esta manobra facilitará substancialmente a divulgação desse método, tornando-a mais aceitável pela comunidade científicaAnalytical techniques employed to quantify lignin content in forages, currently in use, are questionable as to their accuracies. The method acid detergent lignin (ADL), which is one of the most used method in Animal Science and Agronomy, has some flaws, due to the partial lignin solubilization during the preparation of acid detergent fiber (ADF). The Klason lignin method (KL), another analytical procedure commonly used, has the drawback of measuring the cell wall protein as lignin. In both procedures also are recommended to measure ash content in the lignin residues. Quantification of lignin concentration by the spectrophotometric acetyl bromide lignin method (ABL) has been gaining interest from researchers in Brazil and abroad. In this methodology, the lignin contained in the plant cell wall preparation (CW) is solubilized in a 25% acetyl bromide in acetic acid solution and the absorbance is measured with UV light at 280 nm. The absorbance value is inserted in a regression equation and the concentration of lignin is obtained. For this analytical technique be better accepted by researchers, it must be, obviously, convincing and attractive. This study analyzed some LBA-related parameters in 7 grasses and 6 legumes in two stages of maturity. Among the different temperatures of pre-drying, the results indicated that the procedures at 55°C with ventilation and lyophilization can be used just as effectively. Temperatures of 55 and 80 both without ventilation are not recommended because they increased ADF and ADL values, possibly due to the emergence of technical artifacts such as the compounds of Maillard. The ABL method yielded lower values for legume samples which called into question if the lignin of these plants is less soluble in the acetyl bromide reagent. Among some changes studied in the ABL technique it was the utilization of ball milling in the PC samples, which showed no effect; the hypothesis was to reduce the particle size and thus improve the solubilization of lignin. The use of an ultrasonicator, which increases the vibration of molecules and possibly allowing better solubilization of lignin in the acetyl bromide reagent improved lignin solubilization by about 10%, both in grasses. As a reference, an in vitro dry matter degradability (IVDMD) was conducted. Because lignin is closely linked to the fibrous structure of the cell wall, an in vitro neutral detergent fiber degradability (IVNDFD) test of. Results confirmed the effect of maturity, reducing degradability as the plants matured, and that concentration of lignin is lower in legumes than in grasses. The degradability results showed higher correlation coefficients with the ABL method when the ultrasonicator was used; the KL method showed the lowest coefficients. We also tested, successfully, the use of NDF as a fiber preparation, instead of crude CW. While NDF is widely known, CW preparation is not. This maneuver will substantially facilitate the dissemination of this method, making it more acceptable to the scientific community
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GALEA, HELENE. "Synthese de radioligands marques au brome-76 et au carbone-11 pour l'etude des recepteurs n-methyl-d-aspartate par tomographie d'emission de positons." Caen, 1998. http://www.theses.fr/1998CAEN2015.
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Les recepteurs n-methyl-d-aspartate (nmda) sont impliques dans diverses pathologies du systeme nerveux central telles que les accidents vasculaires cerebraux, les traumatismes, l'epilepsie et les maladies de parkinson et d'huntington. Malgre l'interet que represente la possibilite de visualiser in vivo les recepteurs nmda par tomographie d'emission de positons (tep), aucun radioligand exploitable n'existe a ce jour. Nous avons prepare et teste les analogues radiomarques de deux antagonistes des recepteurs nmda : le #7#6brrpr104632 (acide 6,8-dichloro-3,4-dihydro-2-(3-#7#6brbromobenzyl)-2h-1,2,4-benzothiadiazine-1,1-dioxyde-3-carboxylique) et le #1#1cly202157 (acide #1#1c-(3s,4ar,6s,8ar)-6-(1h-tetrazol-5-ylmethyl)-1,2,3,4,4a,5,6,7,8,8a-decahydroisoquinoleine-3-carboxylique). Le #7#6brrpr104632 a ete prepare avec un rendement de 7,7% en moyenne (non corrige de la decroissance) pour un temps de synthese de 150-180 minutes a partir du #7#6brbromure d'ammonium. Le #1#1cly202157 a ete obtenu avec un rendement moyen de 8,1% (corrige de la decroissance) pour un temps de synthese total d'environ 60 minutes a partir du #1#1cmethane. La cinetique cerebrale des deux composes radiomarques a ete etudiee chez le rat. Leur passage de la barriere hemato-encephalique est tres mauvais et par consequent les concentrations dans le cerveau sont tres faibles. En conclusion, aucun de ces deux composes ne peut etre exploite comme radioligand pour la tep.
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BERTOLINI, THARCILA C. R. "Estudo comparativo sobre a adsorção de diferentes classes de corantes em zeólitas de cinzas de carvão: modelagem cinética e de equilíbrio." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10557.
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Tausch, Jeremy Verfasser], Friedemann [Akademischer Betreuer] Schrenk, and Timothy [Akademischer Betreuer] [Bromage. "A new method for examining hominin dietary strategy: occlusal microwear vector analysis of the Sangiran 7 Homo erectus molars / Jeremy Tausch. Gutachter: Friedemann Schrenk ; Timothy Bromage." Frankfurt am Main : Univ.-Bibliothek Frankfurt am Main, 2012. http://d-nb.info/1044275332/34.
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Tausch, Jeremy [Verfasser], Friedemann Akademischer Betreuer] Schrenk, and Timothy [Akademischer Betreuer] [Bromage. "A new method for examining hominin dietary strategy: occlusal microwear vector analysis of the Sangiran 7 Homo erectus molars / Jeremy Tausch. Gutachter: Friedemann Schrenk ; Timothy Bromage." Frankfurt am Main : Univ.-Bibliothek Frankfurt am Main, 2012. http://nbn-resolving.de/urn:nbn:de:hebis:30:3-248492.
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Andraud, Chantal. "Defauts d'empilement dans le materiau unidimensionnel cscdbr::(3) : etude spectroscopique." Paris 6, 1987. http://www.theses.fr/1987PA066140.
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L'etude des proprietes optiques de cscdbr::(3) a montre l'existence de centres br::(2)**(2-). L'excitation des echantillons par des rayonnements ionisants (rx, faisceau d'electrons) et des experiences d'absorption a deux photons ont permis d'associer les differentes bandes d'emission et d'absorption observees a des transitions appartenant a ces centres. L'existence de ces centres br::(2)**(2-) est attribuee a la presence de defauts d'empilement. L'effet d'une pression hydrostatique, le dopage par des ions pb**(2x) et le recuit des cristaux confirment l'hypothese
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OLIVEIRA, ICIMONE B. de. "Desenvolvimento do cristal semicondutor de brometo de tálio para aplicações como detector de radiação e fotodetector." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11385.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
FAPESP:01/09049-5
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PEREIRA, MARIA da C. C. "Desenvolvimento de cristais baseados em iodeto de césio para aplicação como detectores de radiação." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11434.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Yahiaoui, Mohamed. "ETUDE DU DIAGRAMME DE PHASE ET DU COMPORTEMENT VERRE DE SPIN DU SYSTEME ISOLANT DILUE FexMg1-xBr2." Toulouse, INSA, 1988. http://www.theses.fr/1988ISAT0014.
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Etude par mesures de susceptibilite magnetique et d'aimantation du systeme du titre. Ce compose stratifie est un systeme d'ising 3d. On etudie le diagramme de phase et on met un comportement de verre de spin. Pour x=0,72, les mesures montrent l'importance du comportement reentrant. L'analyse du comportement critique pour x=0,35 est analyse par l'etude de l'aimantation non lineaire. Mise en evidence d'une transition de phase. Valeur des exposants critiques. On compare ensuite le comportement avec celui des systemes bidimensionnels d'ising
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SANTOS, ROBINSON A. dos. "Estudo da influência de impurezas e da qualidade das superfícies em cristais de brometo de tálio para aplicação como um detector de radiação." reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26818.
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Neste trabalho, cristais de TlBr foram crescidos e purificados pelo método de Bridgman Repetido, a partir de sais comerciais de TlBr, e caracterizados para serem usados como detectores de radiação à temperatura ambiente. Para avaliar a eficiência de purificação, estudos da diminuição da concentração de impurezas foram feitos após cada crescimento, analisando as impurezas traço por Espectrometria de Massas com Plasma (ICP-MS). Um decréscimo significativo da concentração de impurezas em função do número de purificações foi observado. Os cristais crescidos apresentaram boa qualidade cristalina de acordo com os resultados de análise por Difração de Raios X (DRX), boa qualidade morfológica e estequiometria adequada de acordo com os resultados de análise por MEV(SE) e MEV(EDS). Um modelo matemático definido por equações diferenciais foi desenvolvido para avaliar as concentrações de impurezas no cristal de TlBr e suas segregações em função do número de crescimentos pelo método de Bridgman. Este modelo pode ser usado para calcular o coeficiente de migração das impurezas e mostrou ser útil para prever o número necessário de repetições de crescimento Bridgman para atingir nível de pureza adequado para assegurar a qualidade do cristal como detector de radiação. Os coeficientes se segregação obtidos são parâmetros importantes para análise microestrutural e análise de transporte de cargas nos cristais detectores. Para avaliar os cristais a serem usados como detectores de radiação, medidas de suas resistividades e resposta à incidência de radiação gama das fontes de 241Am (59,5keV) e 133Ba (81 keV) foram realizadas. Essa resposta foi dependente da pureza do cristal. Os detectores apresentaram um avanço significativo na eficiência de coleta de cargas em função da pureza.
Tese (Doutorado em Tecnologia Nuclear)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP