305 research outputs found
SOME OBSERVATION ON THE SEDIMENTATION IN DAIDO RIVER
No full textThis paper describes the some results of observation in Daido River which is nowcarring out in order to investigate the behavior of the natural stream channels, especiallythe flow structure, sediment transport and riverbed variation.The Daido River is a typical alluvial stream carring a large amount of sedimentload, since the main part of the geological structure in its mountainous catchmentconsists of much weathered granite. The area of its drainage basin is 189.7 km2 andthe mean gradient of the total plain course is about 4 x l0~. The maximum flow rate inflood seasons, according to recent records, is about 105m5/s and the amount of sedimenttransport is estimated at 105m3/year.The authors intended to measure the dimensions of bed scour by two types of simpledevices. The one was a 2.7 in-long iron rail with a movable ring of 15cm in diameterand the other a lm-deep pole of 10cm square tiles 5mm in thickness. Both devices wereset in six sections of the straight reach at intervals of 20 m and alternatively at eightpoints in a section to compare their efficiency of measurement. For the curved reach, the former type devices were set in five sections at intervals of 100m. Unfortunately, the results were not successful, and the defects of these devices were pointed out.The measurement of the bed load transportation is very diffcult in natural streams.In the Daido River, the most of the bed load carring into the main river Seta depositedat the confluence, and therefore the rate of bed load transportation could be obtained bymeasuring of the total volume of the deposited sediment. The observed values werecompared with the calculated ones by various formulas for bed load transportation.Furthermore, the water-stage hydrograph and the celerity of flood peak in some floodseasons were examined.This paper describes the some results of observation in Daido River which is nowcarring out in order to investigate the behavior of the natural stream channels, especiallythe flow structure, sediment transport and riverbed variation.The Daido River is a typical alluvial stream carring a large amount of sedimentload, since the main part of the geological structure in its mountainous catchmentconsists of much weathered granite. The area of its drainage basin is 189.7 km2 andthe mean gradient of the total plain course is about 4 x l0~. The maximum flow rate inflood seasons, according to recent records, is about 105m5/s and the amount of sedimenttransport is estimated at 105m3/year.The authors intended to measure the dimensions of bed scour by two types of simpledevices. The one was a 2.7 in-long iron rail with a movable ring of 15cm in diameterand the other a lm-deep pole of 10cm square tiles 5mm in thickness. Both devices wereset in six sections of the straight reach at intervals of 20 m and alternatively at eightpoints in a section to compare their efficiency of measurement. For the curved reach,the former type devices were set in five sections at intervals of 100m. Unfortunately,the results were not successful, and the defects of these devices were pointed out.The measurement of the bed load transportation is very diffcult in natural streams.In the Daido River, the most of the bed load carring into the main river Seta depositedat the confluence, and therefore the rate of bed load transportation could be obtained bymeasuring of the total volume of the deposited sediment. The observed values werecompared with the calculated ones by various formulas for bed load transportation.Furthermore, the water-stage hydrograph and the celerity of flood peak in some floodseasons were examined
AMČR - projekt M-202301308
No full textStav: 6Podnět: DMC, DAIDO METAL CZECH fáze 3Označení projektu: 512/202
Organizational Modes within Firms and Productivity Growth
No full textThis paper develops a simple growth model with moral hazard contracting to examine the interactions between the organizational mode of firms and economic productivity growth. The organizational mode of firms differs in terms of the degree to which decisions of R&D investment are delegated to a manager. We show that the market size restricts the extent of delegation with respect to R&D, which in turn determines the productivity growth rate of the economy. We then show that there exist multiple equilibria: gpartial decentralization equilibriumh with a low growth rate and gfull decentralization equilibriumh with a high growth rate. Finally, we study the effects of social capital and competition on equilibrium organizational modes and show that, under some parametric conditions, these factors induce more decentralized organization and higher productivity growth while lowering the risk of the economy converging to a poverty trap.Centralization and Decentralization, Moral Hazard, Social Capital, Multiple Equilibria, Economic Growth, Competitive Policy
FUNDAMENTAL STUDY ON MUD-FLOW (V)
No full textIn this paper, the author discussed a turbulent flow of a non-Newtonian liquid. Fro, ii th~experimental results of the resistance law to a smooth pipes, the author thought that the w ixinglength theory make clear the Reynolds stress and drived a velocity distribution and a resistancelaw to a turbulent flow of a non-Newtonian liquid from the mixingth length theory. Theauthor showed that the universal constant K is function of x~/x~ that the coeffient of eq. (1.10)of the redistance law is constant. The value of K was showed in Fig. 3. In the next, , , heauthor discussed the kinetic similitude in a Bingham flow. The kinetic similitude of a Binghamflow established when the Reynolds number of eq. (3.11) is equal for the plototype and themodel.In this paper, the author discussed a turbulent flow of a non-Newtonian liquid. Fro,ii th~experimental results of the resistance law to a smooth pipes, the author thought that the w ixinglength theory make clear the Reynolds stress and drived a velocity distribution and a resistancelaw to a turbulent flow of a non-Newtonian liquid from the mixingth length theory. Theauthor showed that the universal constant K is function of x~/x~ that the coeffient of eq. (1.10)of the redistance law is constant. The value of K was showed in Fig. 3. In the next, ,,heauthor discussed the kinetic similitude in a Bingham flow. The kinetic similitude of a Binghamflow established when the Reynolds number of eq. (3.11) is equal for the plototype and themodel
AN EXPERIMENTAL STUDY ON THE CRITICAL TRACTIVE FORCE FOR GRAVELS IN MUD STREAM
No full textThis paper deals with the critical tractive force for gravels in a mud stream. Whether thestream is a mu& or clear flow, the mechanism of initial movement of gravels is similar. But, it is hard to analyze theoretically the mechanism in a mudstream because the fluid characteristicsare not clarified yet.In this paper the author presents an arrangement of the experimental results on the criticaltractive force in a mud stream using a Reynolds number derived from the kinetic similitude ofmovement of gravels. The Reynolds number is expressed as a function of the Reynolds numberof critical tractive force proposed by Shields and the ratio of yield stresses of fluid to boundaryshear. It was concluded from the treatment that the critical tractive force for gravels in amud stream is expressed by the same relation as that in a clear stream, and that the relationshipis in good agreement with the experimental results.This paper deals with the critical tractive force for gravels in a mud stream. Whether thestream is a mu& or clear flow, the mechanism of initial movement of gravels is similar. But,it is hard to analyze theoretically the mechanism in a mudstream because the fluid characteristicsare not clarified yet.In this paper the author presents an arrangement of the experimental results on the criticaltractive force in a mud stream using a Reynolds number derived from the kinetic similitude ofmovement of gravels. The Reynolds number is expressed as a function of the Reynolds numberof critical tractive force proposed by Shields and the ratio of yield stresses of fluid to boundaryshear. It was concluded from the treatment that the critical tractive force for gravels in amud stream is expressed by the same relation as that in a clear stream, and that the relationshipis in good agreement with the experimental results
A technology assessment of photovoltaic concentrator systems (CPV) and their prospects
No full textThis dissertation attempts to put some clarity and order into our understanding of the dynamic development of Concentrator Photovoltaic Systems (CPVs) in the world today. The photovoltaic industry is showing high growth and this is being driven by the demand for flat plate silicon modules (about 90 % of the market) and thin film modules (almost all of the remaining 10 percent). In the last two years we have seen a ‘perfect storm’ situation of favourable factors driving the development of CPV in line with the growth in the rest of the industry. The reasons behind this storm are multifactorial, including silicon supply shortages, increases in the power output of high efficiency cells, recognition that ‘climate change’ is a problem that needs remedying. Technology development programs have helped to solve problems that high concentration of sunlight cause, such as photovoltaic (PV) cell damage, tracking inaccuracy and lens degradation. My method of adding clarity was to simply find out as much information as possible on CPV technologies and the businesses that are attempting to develop them and to then devise a method of rating their likelihood of success in this new market.
Information was very hard to come by with companies guarding their secrets well. After examining the data collected, trends such as lenses being preferred over mirrors in High Concentrator Photovoltaic (HCPV) systems became evident. HCPV conversion devices were more numerous in type and overall numbers deployed on the ground. This popularity over Low Concentrator Photovoltaic (LCPV) systems was by a factor of three with only two companies, Entech and Whitfield Solar, developing what I term a Medium Concentrator Photovoltaic System. (MCPV). Finally I rated ten firms as market leaders because of their potential to develop near MW and MW levels of power in 2008. Special mention is given to four firms who may be able to ramp up their production quickly. The industry has been changing rapidly during the short time of my research with firm acquisitions, mergers, technology sharing and buyouts common. An added bonus to my research is the collection of company contacts that may help interested parties keep abreast of this dynamic industry
The Pygmalion Effect: An Agency Model with Reference Dependent Preferences
No full textWe attempt to formulate and explain two types of self-fulfilling prophecy, called the Pygmalion effect (if a supervisor thinks her subordinates will succeed, they are more likely to succeed) and the Galatea effect (if a person thinks he will succeed, he is more likely to succeed). To this purpose, we extend a simple agency model with moral hazard and limited liability by introducing a model of reference dependent preferences (RDP) by Kõszegi and Rabin (2004). We show that the agent with high expectations about his performance can be induced to choose high effort with low-powered incentives. We then show that the principal’s expectation has an important role as an equilibrium selection device.self-fulfilling prophecy, Pygmalion effect, Galatea effect, reference dependent preferences, agency model, moral hazard
Practice led research into stream-form composition methods, freeassociation, and synaesthesia in audio/visual compostion.
No full text.haul / S is a portfolio of audio/visual works, all with a common start point, synaesthesia: a
powerful and highly personal phenomenon. In this portfolio I examine my own synaesthetic perceptions of sound and image, and how they direct my compositional decisions and aesthetic tastes. These perceptions, and the resulting compositions, are compared to the experiences of synaesthete composers, and their goals in composing from such an abstract source material, as well as synaesthetes not engaged in musical
endeavours. In doing so, I speculate how the act of making from such personal, abstract, and ultimately indescribable and unsharable experiences affects an audience’s reception
of the pieces produced. As such, I produce works that are as close to being about nothing as I could posit: pieces that feature no defined subject, theme, or narrative, outside of their constituent parts. This nothingness, or lack of concrete reference is speculative, aiming to open discussion on perception and synaesthesia (which I do not consider a special condition only experienced by few), and strives to inform further work actively influenced by this composer/audience feedback loop.
The compositions in this portfolio are also the result of practice-led research into stream
form composition methods, and examinations of free-association in audio/visual composition. The aim of this research is to open discussion on intuitive composition practices, and composers’ aesthetic judgments and decisions when producing a work. It also examines synaesthesia as a compositional tool, as a means of suggesting further research in a field which is still poorly understood
On The Occurrence Of Mud-Debris Flow
No full textThis paper is concerned with the phenomenon of mud-debris flow attributable to the flow of deposits in a valley. The author points out that mud-debris flow is due to the difference of the gradient of sediment deposited by the action of mass force and by the action of the surface stream. For the threshold condition of large rocks, the influence of high concentration of clay particles in a stream and the influence of the differences in water level at both sides of a rock, are also discussed in this paper
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