625 research outputs found
Spin and charge dynamics in [TbPc] and [DyPc] single molecule magnets
Magnetization, AC susceptibility and SR measurements have been performed
in neutral phthalocyaninato lanthanide ([LnPc) single molecule magnets
in order to determine the low-energy levels structure and to compare the
low-frequency spin excitations probed by means of macroscopic techniques, such
as AC susceptibility, with the ones explored by means of techniques of
microscopic character, such as SR. Both techniques show a high temperature
thermally activated regime for the spin dynamics and a low temperature
tunneling one. While in the activated regime the correlation times for the spin
fluctuations estimated by AC susceptibility and SR basically agree, clear
discrepancies are found in the tunneling regime. In particular, SR probes
a faster dynamics with respect to AC susceptibility. It is argued that the
tunneling dynamics probed by SR involves fluctuations which do not yield a
net change in the macroscopic magnetization probed by AC susceptibiliy. Finally
resistivity measurements in [TbPc crystals show a high temperature
nearly metallic behaviour and a low temperature activated behaviour.Comment: 8 pages, 12 figure
Power Purchase Agreements for Risk and Rent Sharing in Himalayan Hydropower Developments
The Himalayan Rivers have an enormous hydropower potential that is still not exploited fully for the benefit of the region. Bhutan and Nepal together have an economically feasible potential of 60,000 MW of hydroelectric power generation capacity but are too weak financially to bear alone the risks associated with the development of their hydro resources. India is the only potential market for the electricity supplied from these sources. The power purchase agreement framework for the 336 MW Chukha Hydel Project in Bhutan could serve as a model with regards to the transfer of risks, management of risks, and sourcing of finance in exchange for the sharing of the economic rents associated with such projects. India undertook the costs and risks of constructing the hydroelectric dam and power plant in exchange for a reduced purchase price of electricity from the completed facility. This paper contains a financial and economic assessment of the Chukha Hydel Project. While India is in a position to exercise monopsonic power in this electricity market, this analysis shows that it is possible to have an agreement for sharing of the risks and returns between India and the Himalayan countries that is highly beneficial to all the stakeholders.power purchase agreement, Himalayas, hydropower, electricity, Bhutan, India, electricity exports, risk sharing, economic rents
Numerical and analytical investigation towards performance enhancement of a newly developed rockfall protective cable-net structure
In a previous companion paper, we presented a three-tier modelling of a particular type of rockfall protective cable-net structure (barrier), developed newly in Japan. Therein, we developed a three-dimensional, Finite Element based, nonlinear numerical model having been calibrated/back-calculated and verified with the element- and structure-level physical tests. Moreover, using a very simple, lumped-mass, single-degree-of-freedom, equivalently linear analytical model, a global-displacement-predictive correlation was devised by modifying the basic equation â obtained by combining the principles of conservation of linear momentum and energy â based on the back-analysis of the tests on the numerical model. In this paper, we use the developed models to explore the performance enhancement potential of the structure in terms of (a) the control of global displacement â possibly the major performance criterion for the proposed structure owing to a narrow space available in the targeted site, and (b) the increase in energy dissipation by the existing U-bolt-type Friction-brake Devices â which are identified to have performed weakly when integrated into the structure. A set of parametric investigations have revealed correlations to achieve the first objective in terms of the structure's mass, particularly by manipulating the wire-net's characteristics, and has additionally disclosed the effects of the impacting-block's parameters. Towards achieving the second objective, another set of parametric investigations have led to a proposal of a few innovative improvements in the constitutive behaviour (model) of the studied brake device (dissipator), in addition to an important recommendation of careful handling of the device based on the identified potential flaw
Productivity and Profitability Assessment of Drought Tolerant Rice Cultivars under Different Crop Management Practices in Central Terai of Nepal
Reduction in productivity has led to lower profitability of rice production in Nepal. Proper selections of resource conservation technologies and drought tolerant cultivars are being potential strategies determining productivity of rice in drought prone areas. Thus, a field experiment was accomplished in central-terai of Nepal during 2014 to assess the productivity and profitability of drought tolerant rice cultivars under different crop management practices. The experiment was carried out in strip-plot design with three replications consisting four drought tolerant rice cultivars and three crop management practices. The analyzed data revealed that SRI (System of Rice Intensification) produced significantly higher grain yield (5.28 t ha-1) than other management practices. The straw yield of SRI (5.12 t ha-1) was also significantly higher than other management practices. The cultivars had no influence on grain yield, but the straw yield was significantly influenced by cultivars, with the highest straw yield in Sukkha-3 (5.21 t ha-1). Similarly, SRI management practice also had significantly higher gross returns (NRs. 144652 ha-1), net return (NRs. 56647 ha-1) and B:C ratio (1.64:1). Thus, SRI management practice can be adopted as adaptation approach for obtaining higher productivity and profitability in central terai and similar agro-climatic regions of Nepal
Spalling of Concrete - Implications for Structural Performance in Fire
This preliminary paper is a progress report on an analytical investigation into the implications
of explosive spalling on the fire performance of reinforced concrete structural elements and whole structures.
This study does not attempt to predict whether spalling will occur. For accurate prediction of the occurrence
of spalling a complete and fully coupled hygro-thermal-mechanical (HTM) analysis is required, as described
by a comprehensive review of current research into the parameters and mechanisms that influence spalling,
including a review of physical spalling criteria. This paper describes the structural performance of spalled concrete
elements, using finite element analysis where spalling is modelled by removing layers of concrete when
a set of spalling criteria are met. The method is presented using a case study of a simply supported reinforced
concrete beam, where the analytical results indicate that spalling invariably triggers an early failure (well short
of the required FRR rating) of a beam exposed to the standard fire
Low-loss singlemode PECVD silicon nitride photonic wire waveguides for 532-900 nm wavelength window fabricated within a CMOS pilot line
PECVD silicon nitride photonic wire waveguides have been fabricated in a CMOS pilot line. Both clad and unclad single mode wire waveguides were measured at lambda = 532, 780, and 900 nm, respectively. The dependence of loss on wire width, wavelength, and cladding is discussed in detail. Cladded multimode and singlemode waveguides show a loss well below 1 dB/cm in the 532-900 nm wavelength range. For singlemode unclad waveguides, losses < 1 dB/cm were achieved at lambda = 900 nm, whereas losses were measured in the range of 1-3 dB/cm for lambda = 780 and 532 nm, respectively
Assessment of Yield and Yield Attributing Characters of Hybrid Maize using Nutrient ExpertÂź Maize Model in Eastern Terai of Nepal
Indiscriminate use of fertilizer and lack of site specific nutrient management technology is the main cause of low maize productivity in Nepal. Thus, field experiments on farmer\u27s field were conducted on maize to assess the productivity at two sites of Jhapa district viz. Damak and Gauradaha using Nutrient ExpertÂź Maize model from November 2015 to May 2016. The experiment was laid out in Randomized Completely Block Design consisting two treatments viz. NE (Nutrient Expert recommendation) and FFP (Farmer\u27s Fertilizer Practice) with twenty replications. The result revealed significant differences in terms of grain yield, stover yield, biological yield, and yield attributing characters. NE based practices produced higher grain yield (9.22 t ha-1), which was 86.6 percent higher than FFP (4.94 t ha-1). Similarly, higher average cob number m 2 (8.2), average kernel rows cob-1 (14.2), average kernels number row-1 (589.9) and test weight (361.4 g) were recorded in NE based practice. Thus, NE based practice can be adopted for obtaining higher productivity in eastern terai region of Nepal
Characterization of PECVD Silicon Nitride Photonic Components at 532 and 900 nm Wavelength
Low temperature PECVD silicon nitride photonic waveguides have been fabricated by both electron beam lithography and 200 mm DUV lithography. Propagation losses and bend losses were both measured at 532 and 900 nm wavelength, revealing sub 1dB/cm propagation losses for cladded waveguides at both wavelengths for single mode operation. Without cladding, propagation losses were measured to be in the 1-3 dB range for 532 nm and remain below 1 dB/cm for 900 nm for single mode waveguides. Bend losses were measured for 532 nm and were well below 0.1 dB per 90 degree bend for radii larger than 10 mu m
The presentation of academic self in the digital age: the role of electronic databases
A growing number of online electronic resources present academic work. We are not focusing here on specialised electronic databases that store bibliographic research data, such as Medline, PubMed, ASSIA, ERIC, JSTOR, but databases or social networking websites /platforms for academics/researchers that profile research, academic and professional activities, such as SCOPUS, WoS (Web of Science), Academia.edu, KUDOS, ORCiD, ResearchGate, LinkedIn, GoogleScholar and Mendeley. We discuss databases or platforms can promote the profile of an individual academic, highligthing their research interests, grants and publications. These databases are good outlets for Early Career Researchers (ECRs) to build, improve and promote their public profile. However, the level of efforts requires to open an account or to maintain these databases regularly can be a daunting task for some scholars. This paper outlines some of these key databases and their functions and reflects on advantages and disadvantages of engaging with the most popular ones. We remind the reader that many of these databases require academicsâ attention and input, and thus create more work
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