468 resultados para NO stripping
Resumo:
在0.05 mol/L Tris,0.15 mol/L NaCl溶液中,用吸附伏安法研究长春新碱(VCR),其峰电位在-1.68 V(vs. Ag/AgCl),峰电流与1.0*10^{-8}~2.0*10^{-7}mol/L VCR浓度成正比,检测限为7.0*l0^{-9} mol/L,用常规脉冲极谱法、线性扫描和循环伏安法等研究该体系的电化学行为,实验表明,电极还原过程为具有吸附特征的不可逆过程。VCR的吸附符合Frumkin吸附等温式。也研究了VCR与微管蛋白的相互作用。实验表明,VCR与微管蛋白形成一电活性的结合物,这一结合物具有吸附性,且还原过程也为不可逆过程。
Resumo:
11 specimens of Coryphaenoides armatus were collected at former dumping sites for radioactive material in the Iberian deep sea at a depth of 4700 m and their muscle tissue was analysed for four trace elements (copper, zinc, cadmium and lead) by differential pulse anodic stripping voltammetry (DPSAV). Concentrations of zinc were typical for fish muscle in general; copper content was somewhat higher than generally found in fish. The cadmium and lead contents were at a level found in fish from the open sea but the lead content of 2 specimens taken in area East-B was found to be higher.
Resumo:
The (He3, n) reactions on B11, N15, O16, and O18 targets have been studied using a pulsed-beam time-of-flight spectrometer. Special emphasis was placed upon the determination of the excitation energies and properties of states with T = 1 (in Ne18), T = 3/2 (in N13 and F17) and T = 2 (in Ne20). The identification of the T = 3/2 and T = 2 levels is based on the structure of these states as revealed by intensities and shapes of angular distributions. The reactions are interpreted in terms of double stripping theory. Angular distributions have been compared with plane and distorted wave stripping theories. Results for the four reactions are summarized below:
1) O16 (He3, n). The reaction has been studied at incident energies up to 13.5 MeV and two previously unreported levels in Ne18 were observed at Ex = 4.55 ± .015 MeV (Γ = 70 ± 30 keV) and Ex = 5.14 ± .018 MeV (Γ = 100 ± 40 keV).
2) B11 (He3, n). The reaction has been studied at incident energies up to 13.5 MeV. Three T = 3/2 levels in N13 have been identified at Ex = 15.068 ± .008 MeV (Γ ˂ 15 keV), Ex = 18.44 ± .04, and Ex 18.98 ± .02 MeV (Γ = 40 ± 20 keV).
3) N15 (He3, n). The reaction has been studied at incident energies up to 11.88 MeV. T = 3/2 levels in F17 have been identified at Ex = 11.195 ± .007 MeV (Γ ˂ 20 keV), Ex = 12.540 ± .010 MeV (Γ ˂ 25 keV), and Ex = 13.095 ± .009 MeV (Γ ˂ 25 keV).
4) O18 (He3, n). The reaction has been studied at incident energies up to 9.0 MeV. The excitation energy of the lowest T = 2 level in Ne20 has been found to be 16.730 ± .006 MeV (Γ ˂ 20 keV).
Angular distributions of the transitions leading to the above higher isospin states are well described by double stripping theory. Analog correspondences are established by comparing the present results with recent studies (t, p) and (He3, p) reactions on the same targets.
Resumo:
The contribution to the magnetic uniaxial perpendicular anisotropy which arises from substrate constraint through magnetostrictive effects has been measured in Ni-Fe and Ni-Co thin films evaporated on substrates at room temperature. This was accomplished by measuring the perpendicular anisotropy before and after removal of the film from the substrate. Data are given for the fcc crystal structure regions of both alloy systems, but data for Ni-Co include compositions with less than 60% Ni which have a small percentage of the hcp phase mixed with the fcc phase. The constraint contribution to the perpendicular anisotropy correlates well with the value of the bulk magnetostriction constant using the equation ∆K˔=3/2λsσ. Measured values of isotropic stress for films thicker than 600 Å were 1.6 x 1010 dyn/cm2. In films less than 600 Å thick the isotropic stress decreased with decreasing thickness. After removal of the films from the substrates, the measured perpendicular anisotropy deviated from the expected geometrical shape anisotropy near pure Ni in both alloys. This indicates that additional significant sources of anisotropy exist at these compositions.
The effect of substrate constraint on the crystalline anisotropy K1 of Ni-Fe epitaxial films has been studied by use of a film removal technique, which involves the evaporation of an epitaxial layer of LiF on MgO, the epitaxial growth of the metallic film on the LiF, and the stripping of the film with water soluble tape. Films ranging in composition from 50% to 100% Ni have been studied. For compositions below 90% Ni the experimental values agree reasonably well with the first order theoretical prediction, ∆K1=[-9/4(C11-C12)λ2 100+9/2C44λ2111].
In order to compare the magnetic properties of epitaxial thin films more completely with the properties of bulk single crystals, Ni-Fe films ranging in composition from 60% to 90% Ni, which were evaporated epitaxially on (100) MgO substrates, have been subsequently annealed at 400°C in a vacuum of less than 10-7 Torr to form the ordered Ni3Fe structure near the 75% composition. This ordered structure has been confirmed by electron diffraction.
The saturation magnetization at Ni3Fe increased about 6% with ordering which is in good agreement with previous bulk data. Measurements of the magnetocrystalline anisotropy energy K1 for the epitaxial films show the same large changes with ordering as observed in bulk single crystal samples. In the (001) plane the magnetostriction constants λ100, λ111 are directly related to the induced anisotropy due to a uniform uniaxial strain in the [100] and [110] directions respectively. Assuming that the elastic constants of a film are the same as in bulk material and are unchanged by ordering, the changes in strain sensitivity with ordering for the epitaxial films are found to be in good agreement with values predicted from bulk data. The exchange constant A as measured by ferromagnetic resonance has been measured at the Ni3Fe composition and found to increase 25% with ordering. This seems to indicate a significant increase in the Curie temperature which has only been inferred indirectly for bulk material.
Resumo:
23 p.
Resumo:
In 1948, the U.S.S.R. began a global campaign of illegal whaling that lasted for three decades and, together with the poorly managed “legal” whaling of other nations, seriously depleted whale populations. Although the general story of this whaling has been told and the catch record largely corrected for the Southern Hemisphere, major gaps remain in the North Pacific. Furthermore, little attention has been paid to the details of this system or its economic context. Using interviews with former Soviet whalers and biologists as well as previously unavailable reports and other material in Russian, our objective is to describe how the Soviet whaling industry was structured and how it worked, from the largest scale of state industrial planning down to the daily details of the ways in which whales were caught and processed, and how data sent to the Bureau of International Whaling Statistics were falsified. Soviet whaling began with the factory ship Aleut in 1933, but by 1963 the industry had a truly global reach, with seven factory fleets (some very large). Catches were driven by a state planning system that set annual production targets. The system gave bonuses and honors only when these were met or exceeded, and it frequently increased the following year’s targets to match the previous year’s production; scientific estimates of the sustainability of the resource were largely ignored. Inevitably, this system led to whale populations being rapidly reduced. Furthermore, productivity was measured in gross output (weights of whales caught), regardless of whether carcasses were sound or rotten, or whether much of the animal was unutilized. Whaling fleets employed numerous people, including women (in one case as the captain of a catcher boat). Because of relatively high salaries and the potential for bonuses, positions in the whaling industry were much sought-after. Catching and processing of whales was highly mechanized and became increasingly efficient as the industry gained more experience. In a single day, the largest factory ships could process up to 200 small sperm whales, Physeter macrocephalus; 100 humpback whales, Megaptera novaeangliae; or 30–35 pygmy blue whales, Balaenoptera musculus brevicauda. However, processing of many animals involved nothing more than stripping the carcass of blubber and then discarding the rest. Until 1952, the main product was whale oil; only later was baleen whale meat regularly utilized. Falsified data on catches were routinely submitted to the Bureau of International Whaling Statistics, but the true catch and biological data were preserved for research and administrative purposes. National inspectors were present at most times, but, with occasional exceptions, they worked primarily to assist fulfillment of plan targets and routinely ignored the illegal nature of many catches. In all, during 40 years of whaling in the Antarctic, the U.S.S.R. reported 185,778 whales taken but at least 338,336 were actually killed. Data for the North Pacific are currently incomplete, but from provisional data we estimate that at least 30,000 whales were killed illegally in this ocean. Overall, we judge that, worldwide, the U.S.S.R. killed approximately 180,000 whales illegally and caused a number of population crashes. Finally, we note that Soviet illegal catches continued after 1972 despite the presence of international observers on factory fleets.
Resumo:
This is the report from the Lune, Wyre and Furness Fisheries Advisory Committee meeting, which was held on the 19th January 1976. The report contains information on land drainage representation on local committees, fisheries activities report, Heysham and Lancaster sewage disposal, planning study for the post 1981 period and progress made in implementing the recommendations contained in the 'Taking Stock' publication. The section on fisheries activities reported by area fisheries officers looks at fish taken for stripping at River Lune Broadraine and Northern area, the presence of feral mink, fish mortalities at Killington Beck and number of fish counted through the fish monitoring stations at River Leven and River Lune. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.
Resumo:
This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 8th January, 1979. It covers information on Ravenglass Salmon Garth, South West Cumbria and opencast coal workings. The section on the report by the area fisheries officer on fishing activities includes river conditions and fishing, and an update on Holmwrangle Hatchery which includes stock numbers and fish distribution. Fish disease and biological work undertaken on fish in Ennerdale Lake are also added, as well as numbers of salmon and sea trout stripping from the River Marron for Holmwrangle Hatchery. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.
Resumo:
This is the report from the Eden and District Fisheries Advisory Committee meeting, which was held on the 9th January, 1979. It covers the section on the report by the area fisheries officer on fishing activities includes river conditions and fishing for salmon, sea trout, brown trout and coarse fish and an update on Holmwrangle hatchery which includes stock numbers and fish distribution. Fish disease on the Border Esk are included as well as numbers of salmon and sea trout stripping for Holmwrangle hatchery. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.
Resumo:
A proposta deste trabalho é estudar a tecnologia para a remoção de amônia do lixiviado através do processo físico-químico de arraste com ar e a sua caracterização por processos de fracionamento com membranas de MF e UF. Foram analisados no processo de arraste de ar os parâmetros pH, vazão de ar e tempo de operação. Foi verificada a remoção de nitrogênio amoniacal de 93,5% em um tempo de operação de 6 horas, com ajuste de pH igual a 11 e vazão de ar 100 L/h. Após a remoção do nitrogênio amoniacal, os lixiviados foram submetidos a processo de fracionamento com membranas de microfiltração (MF) e ultrafiltração (UF), sendo investigadas a remoção de amônia, a condutividade, DQO, COD, cloreto e pH. Obtiveram-se resultados praticamente constantes à medida que o lixiviado permeou nas membranas de MF e UF. Ademais, empregaram-se testes de toxicidade e ensaios de tratabilidade biológica com amostras de lixiviado bruto, lixiviado tratado (baixa concentração de amônia) e lixiviados fracionados com membranas de MF e UF. Nos ensaios de tratabilidade biológica os resultados mostraram que não houve uma remoção significativa de matéria orgânica e nos testes de toxicidade com organismos Danio rerio, embora tenha ocorrido uma redução na toxicidade na sequência dos experimentos, foi constatado que o lixiviado bruto, lixiviado tratado com remoção de amônia e fracionados com membranas de MF e UF mantiveram elevada toxicidade.
Resumo:
A semi-arid environment is a major constraint for production of carp seed through hypophysation. At a water temperature above 31 degree C fishes often fail to respond to induced breeding or produce partial or full eggs with fairly less fertilization, leading to their mortality during embryonic development. Field trials with Labee rohita and Cyprinus carpio communis prove that hypophysation followed by stripping and hatching in a water medium with reduced temperature (below 31 degree C) through controlled use of ice-water and water showers can result in 50-60% fertilization of eggs and 50-72% hatching for L. rohita, and 40-90% fertilization and 49-77% hatching for C. carpio communis. Simultaneous breeding experiments of the species in normal water temperature (>31 degree C) showed negative results.
Resumo:
In order to study the early developmental stages of Nandus nandus an experiment was conducted, where eggs and milt were obtained from the laboratory reared N nandus by stripping after 15 hours of 150 mg/kg body weight of carp PG extract injection. Then the eggs were fertilized in the laboratory and subsequent developmental stages were studied. First cleavage (two cell), four cell, eight cell, sixteen cell and multi cell stages were found 30, 50, 70, 105 and 160 minutes after fertilization respectively. Morula, early gastrula, middle gastrula, late gastrula and yolk plug stages were found 5, 8, 9, 11 and 13 hours after fertilization respectively. Hatching occurred within 20±2 hours after fertilization, and larvae were measured 1.60 mm in diameter. After one hour of hatching two melanophore bands were found at the caudal region of the body of the larvae. Eyes were first observed in l 0 hours, pectoral and pelvic fin buds appeared in 22 hours and well developed in 38 hours old larvae. Mouth cleft and brain lobes were visible when the larvae were 34 and 38 hours old respectively. Myomeres partially appeared in 16 hours, which were clearly visible in 74 hours old larvae. Larvae started wandering and searching for food after 56 hours of hatching. The yolk sac was completely absorbed when larvae became 62 hours old.
Resumo:
Sperata aor and S. seenghala are the two important native catfishes of Bangladesh but commercial farming of these species is not possible due to lack of naturally collected or artificially produced seeds for stocking. Attempts were made to develop techniques for seed production by artificial breeding and nursery-rearing of fries of these catfishes. A total of 60 S. seenghala (750-1,500 g) and 10 S. aor (600-1,000 g) broods were collected from the Brahmaputra river-basin and floodplains in Mymensingh region four months prior to their breeding season. The collected brood fishes were reared in separate earthen ponds with supplementary feeds comprising of rice bran (40%), mustard oil cake (29%), fish meal (30%) and vitamin-premix (1 %). Three experiments were conducted to optimize the hormone dose. A total of nine S. seenghala females weighing from 750 to 1,500 g were given an initial and resolving dose of 12-20 and 16-24 mg PG/kg body weight, respectively. The males weighing from 650-950 g were administered a single dose of 18-26 mg PG/kg body weight at the time of the time of administering the resolving dose to the females. The females ovulated partially and the eggs were examined under a compound microscope, but most of them were found to be less ripe or damaged. Collection of milt by stripping the males was not successful. The testes were taken out and sperm were observed to be non-motile and less developed. In view of stimulating natural propagation of S. seenghala, artificial holes (nests) were constructed in the pond bottom. Each hole was 0.7 m in diameter and 0.3 m in depth. A total of 10 holes were made and then 10 pairs of S. seenghala breeders (800-1,200 g) were stocked in the pond. In mid February, 3,000 fry of S. seenghala with a mean length of 4.60 cm and weight of 0.36 g were collected by repeated netting followed by drying of the pond. The fry were then stocked in a nursery pond and fed with commercial feed (SABINCO starter-1). The average length and weight of the fingerlings were 9.01 cm and 3.95 g, respectively and the estimated survival was 60% after two months of rearing. S. aor did not respond to natural spawning. Further study is essential to develop techniques for their successful artificial and natural breeding.
Resumo:
Brood catfish, Heteropneustes fossilis were collected from Tamirabarani river basin of Tamil Nadu, India and kept in cement tanks. Three inducing hormones viz, Ovaprim, Ovatide and WOVA-FH were injected at the rate of 0.5, 1.0, 1.5 and 2.0 ml/kg body weight in order to induce oocyte maturation and ovulation. After 10-13h of injection at a water temperature of 27±-0.5°C, stripping of eggs and in vitro fertilization was done. Ovaprim gave maximum (94.67%) hatching rate followed by Ovatide (90.33%) and WOVA-FH (77.33%).
Resumo:
Effects of post-ovulatory and post-stripping retention time and temperature on egg viability rates were studied in kutum (Rutilus frisii kutum). Eggs were retained inside (in vivo storage) or outside the ovarian cavity with ovarian fluid (in vitro storage) at various temperatures. Two experiments were performed: 1) Partial volumes of eggs were stripped and fertilized at 24- hour intervals for 96 hours post-ovulation (HPO) (at 11 °C) and at 12-hour intervals for 72 HPO (at 14 °C), and 2) stored eggs were fertilized after 0, 2, 4, 6, and 8 hours post-stripping (HPS) at temperatures of 4, 10, 12, and 26 °C. In the first experiment, the highest eyeing and hatching rates (76% and 60% at 11 °C; 81% and 71% at 14 °C) and the lowest eyed-egg mortalities (20% at 11 °C; 12% at 14 °C) occurred in the eggs fertilized immediately (0–24 HPO at 11 °C and 0–12 HPO at 14 °C) after ovulation. Egg viability, as shown by successful eyeing and hatching rates, was completely lost by 72–96 HPO at 11 °C, and 60–72 HPO at 14 °C. In the second experiment, the maximum eyeing (87%) and hatching (75%) rates of eggs took place at 0 HPS followed by 8 HPS (> 80% and > 70%, respectively) at 4 °C. As storage temperature increased, egg viability decreased: 80%, 70%, and 50% viable at 8 HPS at 4, 10, and 12 °C, respectively. The eggs stored at 26 °C lost their viability almost completely after 4 HPS. Eyed-egg mortality increased from 13% at 0 HPS to 48.2% at 4 HPS at 26°C. These results demonstrate that egg stripping should take place within 168 °C-hours after ovulation and that complete loss of viability of the eggs occurs by 672°C-hours after ovulation. The in vivo storage method is more effective compared to in vitro storage. Also successful in vitro storage of eggs can be used atleast within 8 hours at temperatures ranging from 4 to 12ºC.