15 research outputs found
The Relationship Between Population Distribution, Relief and Level of Socio-Economic Development in the S.A.P. Kosovo
No full textS ipomoću koeficijenta znakova (vrste koeficijenta
korelacije) autor dokazuje znatnu podudarnost
(0,571) distribucije površina i stanovništva između
izohipsa. U manje razvijenim općinama, s manjim
općinskim centrom i jednostavnom hipsometrijskom
strukturom (strukturom reljefa) postoji visoka podudarnost
distribucije površina i stanovništva. Što je
veći stupanj razvijenosti općine i veća koncentracija
stanovništva (veći udio urbanog stanovništva)
a reljef složeniji, vrijednost je koeficijenta to manja,
tj. podudarnost je slabija. Autor također dokazuje
da se s povećanjem stupnja razvijenosti povećava
ii indeks koncentracije stanovništva (Ginijev
indeks i indeks koncentracije). Da bi dokazao proces
spuštanja stanovništva, autor se koristio visinom
vertikalnog razmještaja, koji je u SAP Kosovu
godine 1948. bio 613 m, a 1981. — 574 m.Using sign coefficients (a type of
coefficient correlation) the author
proves a high coincidence (0.571)
in the distribution of area and
population between oontour-lines.
In less developed communes, with
smaller commune centres and a
simple hypsometrical structure
(relief structure), there is a high
coincidence between the distribution
of area and population. The
higher the level of development in
a commune, the more concentrated
its population (a greater participation
of the urban population)
and the more complex its relief,
the smaller the value of the coefficient,
i.e. the lower the coincidence.
The author also proves
that the index of papulation concentration
grows with the level
of development (Gini’s index and
the index of concentration). To
prove that the population is descending,
the author uses the height
of the vertical distribution,
which was 613 m. in the S.A.P.
Kosovo in 1948, and 574 m. in
1981
Catalytic control in out-of-equilibrium assembly systems
No full textNature is capable of constantly adapting some of its assembled structures in response to external and internal signals. For instance, microtubuli grow and shrink upon cell division and cellular transport. Furthermore, actin fibers play a major role in muscle contraction and cell signaling. To achieve these transient functions, such assembled structures operate in an out-of-equilibrium state. Energy input and dissipation enables structure growth and subsequent collapse. Regulating the energy input with fuel concentration and the activity of associated enzymatically catalyzed processes leads to a high level of kinetic control in biological out-of-equilibrium processes....ChemE/Advanced Soft Matte
The evolution of pacemakers
No full textMicroelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc
Mitigation of the Urban Heat Island effect by using water and vegetation
No full textUrban areas are confronted with higher temperatures compared to rural areas during summer. Buildings, roads and paved surfaces store the heat during the day and then release it slowly during the evening keeping urban lands hotter than surrounding areas. This phenomenon is called Urban Heat Island effect and the differences can be up to 8°C. A rise in mortality and decrease of work productivity are only some of the consequences. To see if and how vegetation, and water can mitigate this urban heat island effect, measurements are done in the city of Rotterdam, using temperature sensors, sap flow measurements and DTS by fiber optic cables. Measurement results of the temperature sensors show that temperature differences between an urban area and a small park within this urban area can be 3°C, when air temperatures are 25°C. Under these circumstances, temperature in the park is equal to the temperature measured outside the city, meaning that the urban heat island effect is abolished in the park. The results also shows that the urban heat island intensity for the city of Rotterdam is the largest during the night and can be up to 7°C. Trees can help mitigate the UHI by evaporating sap which is transported through the trunk to the leaves. The measurements show an increase of sap flow going further in the growing season, starting from about 10 liter per day towards over 500 liters a day. When this amount of water is divided by the surface area of the tree crown, the considered trees can evaporate 4.5 mm/day. The cooling effect of surface water is hard to measure, mainly because it is not possible to compare the temperature just above the water surface with temperatures above paved surface at the same time. It can be seen that water is a good mitigation measure, because DTS measurements show that a minimum of 14% of daily incoming solar energy is absorbed by surface water. DTS show also that the cooling effect of trees can be up to 5°C, partly by providing shade and partly by evaporation of water through the leaves. The same measurements show that the cooling effect by shade of trees is larger compared to the cooling effect by shade of buildings. When water evaporates form a paved surface this results in a decrease of air temperature. The measurements show that this decrease can be 2°C close to the ground when 1 mm of water evaporates and up to 6°C close to the ground when an infinite amount of water is available. Towards a height of 2 meter, the cooling effect decreases to 1°C and 2°C respectively. The directly measureable cooling effect of vegetation is larger than the cooling effect of water. This is mainly caused by the fact that a large part of the cooling effect of trees is provided by shade, which is of course absent with water. Nevertheless, water is a good mitigating factor of the UHI. Surface water is very use full to absorb incoming solar energy.Water ResourcesWater ManagementCivil Engineering and Geoscience
An ultra low power CMOS pA/V transconductor and its application to wavelet filters
No full textTwo compact ultra low-power CMOS triode transconductor topologies denoted VLPT-g(m) and Delta-g(m) are proposed. In both circuits, input transistors are kept in the triode region to benefit from the lowest g(m)/I-D ratio. This allows achieving a small-signal transconductance g(m) down to hundreds of pA/V, making such transconductors attractive for the synthesis of g(m)-C filters with cut-off frequencies in the range of Hz and sub-Hz. The g(m) value is adjusted by a well defined aspect-ratio (W/L) and drain-source voltage V-DS, the latter a replica of the tuning voltage V-TUNE imposed as drain-source voltage of input devices. VLPT-g(m) reaches a minimum g(m) of 1 nA/V, whereas Delta-g(m) exhibits a g(m) as low as 400 pA/V. Input-referred noise spectral density is typically 12.33 mu V/Hz(1/2) @ 1 Hz and 93.75 mu V/Hz(1/2) @ 1 Hz for VLPT-g(m) and Delta-g(m), respectively. In addition, setting their g(m) equal to 1 nA/V and arranging them as first-order lossy integrators, Delta-g(m) presents higher bandwidth with respect to VLPT-g(m). Cut-off frequencies are 1.33 kHz and 24 kHz for VLPT-g(m) and Delta-g(m) integrators, respectively. Finally, as an application example, both transconductors were used as building blocks to realize a 6th-order wavelet g(m)-C filter. For both approaches, THD was kept below 1% for signal swings up to 200 mV(pp). The design complies with a 1.5 V supply and a 0.35 mu m CMOS process and features an overall power consumption of 51 and 114 nW, respectively for VLPT-g(m) and Delta-g(m) filtersElectronics Research LaboratoryElectrical Engineering, Mathematics and Computer Scienc
Integration of a Pulse Generator on Chip Into a Compact Ultrawideband Antenna
No full textFor impulse radio ultrawideband communications an “antenna plus generator” system is co-designed and an on chip generator is integrated into the antenna. This approach does away with the need for intermediate transmission lines conventionally placed between an RF device/generator and an antenna and therefore eliminates the need for a balun, prevents excitation of the common-mode currents and allows the device to be mounted directly on the antenna. The antenna and generator are designed taking into account both impedance matching and the generator’s influence on the antenna’s radiation properties. The suggested approach is verified experimentally at a scaled up version of the antenna.Microelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc
A fuel-driven chemical reaction network based on conjugate addition and elimination chemistry
No full textFuel-driven chemical reaction networks provide an opportunity to develop chemical systems that operate out-ofequilibrium. There remains a need to design and develop new fueldriven chemical reaction networks capable of repeated operation using simple and benign chemistry. Here, we propose a new chemical reaction network for fuel-driven transient formation of covalent bonds,based on redox-controlled conjugate addition and elimination chemistry. By investigating the separate reactions making up the cycle, we find that the bond formation, breaking and regeneration processes can be realized. At present, substantial side reactivity prevents achieving repeated operation of a full cycle in a single system. If such obstacles would be overcome, this chemical reactionnetwork could be a valuable addition to the toolbox for out-ofequilibriumsystems chemistryChemE/Advanced Soft Matte
Aniline Catalysed Hydrazone Formation Reactions Show a Large Variation in Reaction Rates and Catalytic Effects
No full textHydrazone formation reactions from aldehydes and hydrazides have the remarkable qualities that they proceed in water and the kinetics can be controlled by organocatalysis. For these reasons, this class of reactions finds widespread use in biological as well as material settings. We recently reported a protected aniline catalyst for hydrazone formation that can be activated using a chemical signal. In our search to find a suitable hydrazone formation reaction to investigate the activation of this pro-catalyst, we found a wide variety in reaction rates and response to catalysis. Here we report an overview of hydrazone formation reactions, their reaction rates and response to aniline catalysis, their compatibility for kinetic analysis by UV/Vis spectroscopy, and their compatibility with the reaction environment and with the pro-catalyst pro-aniline.ChemE/Advanced Soft Matte
STUDI IMPLEMENTASI KEBIJAKAN PENGADAAN DAN PENYALURAN PUPUK BERSUBSIDI DI KABUPATEN TUBAN
No full textFertilizer subsidy is one of policy that a historically is the backbone of the
agricultural subsidy policy in Indonesia. Since 2006, the budget allocation of
fertilizer subsidy by the government nevermore through a gas price subsidy
mechanism, but in the form of fertilizer prices subsidy. Starting of mid-2008,
distribution system of subsidized fertilizer does an enclosed manner. It�s the
trading system of procurement and canalization based on area of responsibility
every producer. This study aims to analyze the implementation process and an
actor role in the implementing procurement and canalization policy of subsidized
fertilizer in Tuban.
The author use descriptive research method with qualitative approaches.
While the technique of its data collecting through observation, in-depth interview,
and documentation. Source of date in this study came from informant in the work
environment Office of Agriculture and Office of Economic Affair and Tourism
Tuban Regency, a member of the Supervisory Commission of Subsidized Fertilizer
and Pesticide (KP3) Tuban Regency, distributors and authorized retail of
subsidized fertilizer, and peasant from villages of Sumurjalak and Sukoharjo.
Base on research result, it was concluded that the issue of fertilizer
scarcity other than caused by natural factor like availability of raw material,
natural disaster, and climate conditions also be caused by the implementation of
fertilizer trading system policy. During 2010, does not occurred scarcity of
subsidized fertilizer in Tuban, but not solely upon the success of implementing
procurement and canalization policy but also due to decreased of fertilizer
requirement by peasant compared with previous years. At the level of policy
implementation, the procurement and canalization process of subsidized fertilizer
has been running well according to the provisions, but the problem arising in the
field precisely in technical matters it policy implementation. It is caused the
cooperation between actors (peasants, retailers, distributors, producers, and
government) has not been running well.
Policy recommendations that can be writer suggested, among others, in
determining allocation of subsidized fertilizer the central government should
consider the proposal of fertilizer requirement by the peasant, necessary of
certainty the type and amount of subsidized fertilizer within one sales package,
worth considering an actor that involved in distribution network of subsidized
fertilizer, and need improving on the determination who�ll be responsible every
area of procurement and canalization the subsidized fertilizer
