2,307 research outputs found
Morphology and Luminescence Properties of Poly(phenylenevinylene) and Poly(N-vinyl-pyrrolidone) Polyblends
No full textForced convective heat transfer of 45° rib-roughened fin flows
No full textThe detailed heat transfer measurements in three side-open & bottom-sealed rectangular channels with two opposite walls roughened by 45° full staggered ribs were performed using the infrared radiometer. The present flow configuration simulated an enhanced coolant channel of the fin-type heat-sinks for cooling of electronic chipsets. The hydraulic diameter of three test channels was 14.8 mm with different length-to-gap (L/B) ratios of 21.33, 17.11 & 13.56. The influences of L/B ratio on the local & spatially averaged heat transfers over the rib-roughened surface at Reynolds numbers (Re) of 500, 1000, 2000, 3000 & 3300 were examined. A selection of heat transfer results illustrated the interactive effects between the side-profile leakage-flow & the rib-induced flow phenomena, which were L/B ratio dependent. Heat transfer levels over the rib-roughened surface consistently increased with the increase of Reynolds number or the decrease of L/B ratio. The skewed streamwise ‘‘saw-tooth’’ heat transfer variations gradually emerged over the rib-roughened surface when the Reynolds number systematically increased. Comparing with the heat transfers in the likewise channels but roughened by 90° staggered ribs, the 45° staggered ribs could further enhance heat transfers over 10% for L/B = 21.33 & 50% for L/B = 13.56. Heat transfer correlation for the spatially averaged Nusselt number over a rib-roughened fin surface was generated using Re & L/B ratio as the controlling parameters. A criterion for determining the optimal L/B ratio that could provide the maximum cooling power over a rib-roughened fin surface was subsequently derived to aid the design tools for the heat-sink selection
(26(3):216-223)STUDIES ON FUSARIAL WILT AND ROOT DISEASE COMPLEXES OF ASPARAGUS IN TAIWAN
No full text調查本省苗栗、彰化、嘉義及屏東等四縣主要蘆筍栽培鄉鎮共11,201處（每處01公頃）蘆筍田，發現根部病害周年發生率達1.8～5.2％。全部罹病株中Fusarium oxysporum f. sp. asparagi引起之立枯病約佔46％，F. moniliforme引起之根腐病約17％，餘為其他病原菌如F. solani, Rhizoctonia solani及Pythium sp.等所引起。土壤種類對根部病害之發生有很大的影響，周年平均發病率壤土為.％，砂壤土為.％，壤砂土及砂土為5.2％。
以F. oxysporum f . sp. asparagi與F . moniliforme 兩種病原菌探討土壤溫度及濕度與發病之關係，發現兩者均以土壤溫度25℃發病最嚴重，但土壤濕度則前者以21% MHC ，後者以26% MHC 最易發病。F. oxysporum f. sp. asparagi在中性（PH7）土壤，F. moniliforme 以略偏酸性（PH6）土壤較適於發病。
A survey on fusarial wilt and other root diseases of asparagus was carried out from 11,201 fields located at 4 different asparagus growing prefectures in Taiwan in 1975. It was found that annual average of wilt and root diseases reached as high as 1.8-5.2%. Among diseased plants fourty six percent were proved to be incited by Fusarium oxysporum f. sp. asparagi, 17% by F. moniliforme, and the rest of them by F. solani, Rhizoctonia solani and Pythiurn sp. The soil type of asparagus field was proved to be closely related to the severity of root diseases; those of loam soil showed 2.4% of disease, sandy loam 3.6%, but loamy sand and sand 5.2%.
Although the optimum soil temperatures for disease incidence of both F. oxysporum sp. asparagi and F. moniliforme were at 25°C, the former was more prevalent if soil water holding capacity was at 21% with soil pH at 7, and the latter was more favorable at 26 % of water holding capacity with a soil pH around 6
(25(1):13-22)CULTURE CHARACTERISTICS, CHEMICAL TOLERANCE AND SYMPTOM TYPES OF SINGLE-BASIDIOSPORE ISOLATES OF THANATEPHORUS CUCUMERIS
No full text本研究以自然環境下發生於黃麻田間成熟黃麻株接近地面莖部之Thanatephorus cucumeris子實層所分離之17個單擔胞子菌株和母菌株（分離自次子實層菌絲單綑胞）為材料。各單擔胞子菌株之培養性狀，包括菌絲生長速度、培養基酸鹼度之變化、菌落色澤和菌核產生情形等，不但和母菌株不盡相同，而且菌株間亦互不一致。少數菌株對五氯硝苯(PCNB)之抗性和母菌株相似，但大部份菌株之抗藥性均有增強之趨勢。
供試各菌株對黃麻幼苗均有病原性，罹病幼苗於近地面莖部初呈水浸狀斑點，繼之呈黑褐色不規則形斑塊，略凹陷，俟病斑擴大環繞全莖後表皮裂開，纖維裸露，並自病患處腰折枯死。各菌株對水稻亦有不同程度之病原性，但病徵型却可分成三種：7個菌株和母菌株之病徵型相同，產生典型紋枯病雲狀病斑；另4個菌株產生較小型類似紋枯病之斑駁，惟病斑中央為灰褐色；其餘6個菌株產生褐色條狀斑，並具淡黃色暈圈。
Seventeen single-basidiospore isolates were isolated from the hymenial layer of Thanatephorus cucumeris produced on the mature jute stem in the field. These isolates showed great variations on hyphal growth rate, PH value changes of culture medium, colony color, and sclerotial formation. The parent clone showed a moderate tolerance to penta-chloronitrobenzen (PCNB) with 42-66% of growth inhibition at the concentrations of 100-4,000 ppm. However, 2 single-basidiospore isolates showed the same degree of PCNB tolerance as the parent clone, 4 isolates lower, and the rest 11 isolates higher than the parent.
All single-basidiospore isolates as well as the parent clone were pathogenic to jute seedlings showing typical symptoms of seedling damping-off. These isolates were also pathogenic to rice plants but with variable symptoms. The symptoms on rice plants could be grouped into 3 types: seven isolates and the parent clone showed the typical sheath blight spot, 4 isolates produced sheah blight-like spot with grayish-brown color in the central part, and the rest 6 isolates produced rod-like brown spot with yellowish-brown margin. Since the variations are too great among single-basidiospore isolates, it is, therefore, concluded that neither culture characteristic nor symptom type can be served to distinguish strains of T. cucumeris
Niet zonder conflicten
No full textDuurzame ontwikkeling in het ingenieursonderwijs blijkt geen snelle conflictloze strategie voor verduurzaming. Met als gevolg dat het breder leren denken van de ingenieur in opleiding nog in de kinderschoenen staat.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Organisation & Governanc
Heat transfer in a twin-blow narrow channel with two opposite walls roughened by skewed ribs arranged in staggered manner
No full textCharacterization of production in different branches of production in different branches spanish industrial activity, by means of time series analysis.
No full textThis work presents a quantitative study of the evolution of spanish industrial activity, measured by the indices of industrial production, by means of Time Series analysis. Univariate ARIMA models with intervention analysis for all the series of these indices have been constructed. The use of Univariate Time Series models to characterise economic phenomena is justified and the type of characterisation made for each industrial branch is described. The procedures for automatic modelling of series are presented. Then the characteristics of the Spanish industrial branches are shown. These results are collected in a diskette for use of researchers.ARIMA model; Intervention analysis; Univariate model; Industrial production; automatic modelling;
Grammatical classes in the brain: MVPA reveals the cortical signature of verbs, adjectives and nouns
No full textThis study identified selective functional brain correlates of the distinct grammatical categories of verb, adjective and noun within a left lateralized language network. These results provide a robust indication of the neural underpinning of nouns and the first evidence on the representation of adjectives as grammatical category, thus making specific contributions also to the study of conceptual combination processes involving noun+adjective combinations, associated with the left anterolateral temporal lobe. Moreover, these data confirm the most consistent neuroanatomical findings from previous studies on verb-selectivity and provide new evidence on how grammatical category-specific information is represented in the brain when stimuli are controlled for crucial semantic features of verbs, as opposed to other word classes, and the effect of familiarity, imageability and concreteness is ruled out. In summary, this study specifically expands the current knowledge on how grammatical categories are captured in the brain, by assessing the role of language-sensitive regions in representing word classes and by identifying the kind of distinctions that drives neural selectivity
A decade of ERS satellite orbits and altimetry
No full textThe First European Remote Sensing Satellite, ERS-1, was launched in July 1991, fol- lowed by ERS-2 in April 1995. Both satellites carry a radar altimeter to serve oper- ational applications and scientific research in the fields of geodesy, oceanography, glaciology and meteorology. Together, the satellites have now been operating for over twelve years. This thesis embarks on the a voyage along several milestones in the lifetime of these satellites, and particularly of its altimeters. Both altimeter missions were hampered by a number of misfortunes, ranging from hardware failures, via design mishaps, to a sub-optimally designed ground segment. Yet, the altimeter data, when properly processed and supplied with a precise orbit, can compete favourably with data supplied by specialised altimeter satellites like TOPEX/Poseidon and Jason-1. The upgrading of all altimeter cor- rections and the tweaking of the basic altimeter measurements of range, significant wave height and backscatter coefficient, are essential steps in this process, outlined in this thesis. Having accomplished that, the ERS altimeters allow the monitor- ing of annual, semi-annual and secular changes in sea level, which are important factors in study of climate change. A key role in the processing of altimeter data plays the position of the satellite, and its progress in time, the satellite orbit. The quality of the recovered sea surface height is limited by the precision at which the orbit can be determined. A long journey along several stepwise improvements of the orbit determination process, both in the technique as well as in the modelling, have resulted in the reduction of the orbit error by a factor of 30! A major player in this process was the estab- lishment of a gravity field model tailored to the ERS satellites that, when applied to ERS orbit determination, outperformed any of the previous and contemporary general-purpose models. Yet, it is shown that this model, DGM-E04, is not just a fabrication for the benefit of ERS only, but is equally suitable for the orbit determ- ination of TOPEX/Poseidon and as a long-wavelength geoid model. The calibration of the ERS-1 altimeter in 1991 required, at a time when the orbit errors were still counted in decimetres, if not metres, a short-arc orbit determin- ation technique centred over the calibration site off the coast of Venice. Again, through elaborate surveying, gathering of altimeter corrections and tide gauge measurements, problem solving and elimination of errors, a final absolute range bias of 41.5 cm was established, a value that is still within the error margins of more recent estimates. A timing error in the ERS altimeter data was discovered in 1995 and its cause remained a mystery ever since, especially when the timing error appeared to ex- hibit daily, annual and inter-annual variations as well. Although the exact cause may never be found, the issue is examined in fine detail and a model is constructed to eliminate the timing error for the benefit of the quality of the altimeter data.Aerospace Engineerin
- …
