Study on Dynamics of Calorific Value, Biomass and Energy in Calamagrostis epigejos Population in Songnen Grassland

There were two peaks of seasonal changes of the calorific value in shoot and leaves of Calamagrostis epigejos in middle June and in the early August respectively. The calorific value in stem presented a single peak curve which appeared in the early August. The calorific values in inflorescence and dead standing showed a fluctuation and the peak value of inflorescence was in the early September and that of dead standing was in middle June. The seasonal changes of energy standing crop on the above-ground part synchronized with that of the biomass, which presented a single peak curve. The energy allocated to each organ in different seasons was in the order as leaves > stem > inflorescence in middle June, leaves > stem > dead standing > inflorescence in early July, leaves > stem > inflorescence > dead standing in middle July, and leaves > stem > dead standing > inflorescence from August to September. The vertical allocation of energy in the parts of above-ground was that the energy value gradually increased from the surface to the 20 cm high level and the maximum value at the 10 - 20 cin high level which made up 26.91% of energy on the above-ground partion, and then it was decreased. In the under-ground portion, the energy value progressively decreased with depth and the maximum value was at 0 - 10 cm depth layer which made up 69.01% of energy of the under-ground portion.

Value Addition to Red Sediment Placer Sillimanite Using Microwave Energy and in Depth Structural and Morphological Characterization of Mullite

This paper deals with the effect of microwave energy for mullite formation from placer sillimanite. A mullite formation is seen when 60 % SiC and 5% binder are used with the composite charge material, i.e. sillimanite (60%) and Al2O3 (40%). The maximum temperature of the microwave sintering furnace achieved is 1355°C at 2450 W microwave power. Addition of 10 % binder to the same charge material with 60% SiC, the furnace temperature achieved is 1384°C at microwave power 1900 W. Mullite is formed within 25 minutes from the sillimanite, under the above experimental conditions. Whereas under the similar additive conditions, the mullite formed from sillimanite in conventional furnace heating, it took 3 hours at 1300°C. XRD data show the mullite phase for both the products obtained from microwave sintering furnace and conventional furnace. FESEM image analysis shows the mullite formations, SiC fibrous cluster and alumina needles in microwave treated sample. Thus microwave heat source is much more effective for value addition to red sediment placer sillimanite to form mullite in compare to conventional furnace.

Energy Efficient Packet-Duration-Value Based MAC Protocol for Wireless Sensor Networks

Medium Access Control (MAC) protocol consists of sets of rules that determine which node is allowed to access the transmission medium. It provides mechanism for collision avoidance such that interfering sensor nodes do not transmit at the same time. In the literature, researchers have proposed different MAC protocols with features aimed at improving energy efficiency and thereby prolonging the life of sensor nodes. Sensor MAC, Time-out MAC (T-MAC), Dynamic Sensor MAC (DSMAC), WiseMAC, Quorum-based MAC (Queen-MAC) and Traffic Adaptive Medium Access Protocol (TRAMA) are some examples of proposed MAC protocols. There is a duration field in each transmitted packet. The value of this field indicates how long it will take to complete the remaining packet transmission. In the current paper, a novel energy-efficient MAC protocol is proposed based on the use of duration value in transmitted packets to setup varying sleep/wake-up schedules for neighbouring nodes of the receiver. The effectiveness of this proposed Packet-Duration-Value-based MAC (PDV-MAC) protocol is tested via Simulation which is implemented in Visual C# and MATLAB. It is shown by the results obtained that the proposed MAC protocol can indeed be implemented in sensor nodes to improve energy efficiency in wireless sensor network.

Application of the Concept of Terminal Value in the Analysis of Projects Based on Renewable Energy

Projects for energy supply based on the exploitation of renewable energy have a very predictable cash flow. The initial costs are usually high, with the acquisition of technologically evolving equipment. However, maintenance costs are relatively low and easily predictable. Likewise, operating costs are often very low as there is no need to buy inputs. Power storage devices are often short-lived and contribute to a relative cost increase. At the same time, these projects are often not approved because they are directly compared to projects based on non-renewable resources, with cash flows that may not be so easily predictable and with much lower start-up costs. Fossil fuels have hardly predictable costs, established by non-technical criteria and related to geopolitical issues. In addition, their operating costs are usually very high, precisely because of the need to purchase fossil fuels. This paper proposes the calculation of terminal value in cash flows of power generation projects and its application for feasibility analysis of projects based on renewable resources. The proposed method suggests the calculation of terminal value as the moving average calculated for five-year intervals with constant growth rate of 5%. This method also encourages the inclusion in the cash flow of annual values that add up to the end of the analysis period the sufficient value to renew the system components at the end of the usual analysis period of 20 - 25 years. The application of the proposed method to a diesel wind system simulated with the well-known Homer software indicates the modification of the results of the Homer with the preference for systems with greater wind penetration instead of the systems with greater consumption of fossil fuels.

Production of bio-energy from low-value biomass by bioconversion

Since 1993, China has become a net importer of energy from a net exporter. The total energy con- sumption has been greater than the total supply, and the external dependence of the energy demand increases rapidly. China＇ s crude oil import volume and imports amount reached 253.78 million tons and 196.664 billion US dollars in 2011, with a growth rate of 6 % and 45.3 %, respectively, year-on-year. The significant increase in demand for oil and the caused structural contradictions are increasingly becoming the greatest challenge for China＇ s energy security. The energy crisis has not only touched everyone＇ s nerves, but also sparked a strong desire to find alternative energy.

Operational mechanism of comprehensive benefit evaluation of existing building energy efficient renovation project based on value-added life

The comprehensive benefit evaluation of the existing building energy efficient renovation project cannot be separated from the scientific and effective evaluation mechanism.Based on the value-added life perspective,this paper analyzes the implementation subject,standard,system and principle of the comprehensive benefit evaluation of the existing building energy efficient renovation project.It plans the process of comprehensive benefit evaluation,and builds a scientific and reasonable operation platform of evaluation system,with a view to promoting the effective implementation of the comprehensive benefit evaluation of existing building energy-saving retrofits.

Alternative prediction methods of protein and energy evaluation of pig feeds

Precise knowledge of the actual nutritional value of individual feedstuffs and complete diets for pigs is important for efficient livestock production. Methods of assessment of protein and energy values in pig feeds have been briefly described. In vivo determination of protein and energy values of feeds in pigs are time-consuming,expensive and very often require the use of surgically-modified animals. There is a need for more simple, rapid,inexpensive and reproducible methods for routine feed evaluation. Protein and energy values of pig feeds can be estimated using the following alternative methods: 1) prediction equations based on chemical composition; 2)animal models as rats, cockerels and growing pigs for adult animals; 3) rapid methods, such as the mobile nylon bag technique and in vitro methods. Alternative methods developed for predicting the total tract and ileal digestibility of nutrients including amino acids in feedstuffs and diets for pigs have been reviewed. This article focuses on two in vitro methods that can be used for the routine evaluation of amino acid ileal digestibility and energy value of pig feeds and on factors affecting digestibility determined in vivo in pigs and by alternative methods. Validation of alternative methods has been carried out by comparing the results obtained using these methods with those acquired in vivo in pigs. In conclusion, energy and protein values of pig feeds may be estimated with satisfactory precision in rats and by the two-or three-step in vitro methods providing equations for the calculation of standardized ileal digestibility of amino acids and metabolizable energy content. The use of alternative methods of feed evaluation is an important way for reduction of stressful animal experiments.

Exploring relationships of gross calorific value and valuable elements with conventional coal properties for North Korean coals

Coal in North Korean(NKC)is one of the most important products;however,based on various strategic policies its detail properties remain opaque even for general researchers.Since there are some signs for opening of the North Korea economy,this investigation as a modest effort is going to explore principle relationships among some essential parameters of NKCs such as gross calorific value(GCV),valuable elements and conventional properties by different statistical methods.Correlations indicated that ultimate parameters(carbon,nitrogen,and hydrogen)are the best GCV predictors for NKCs in comparison with proximate parameters(ash,moisture and volatile matter).Multivariable regression demonstrated that predicted GCV based on ultimate properties has a quite accuracy when correlation of determination was 0.99.Descriptive statistics processes showed that on average,the contents of valuable elements such as Ga and V for NKCs are higher than the world coal ranges and they can be considered as byproducts of combustion of NKCs.Pearson correlations indicated that Y may have a mixed organic-inorganic affinity while Ga and V mainly occur in the inorganic part(mineral matter)of NKCs.High inter-correlations between Ga-V and Al showed that aluminosilicates can be considered as their main bring minerals.

THE UPWIND FINITE DIFFERENCE METHOD FOR MOVING BOUNDARY VALUE PROBLEM OF COUPLED SYSTEM

Coupled system of multilayer dynamics of fluids in porous media is to describe the history of oil-gas transport and accumulation in basin evolution.It is of great value in rational evaluation of prospecting and exploiting oil-gas resources.The mathematical model can be described as a coupled system of nonlinear partial differential equations with moving boundary values.The upwind finite difference schemes applicable to parallel arithmetic are put forward and two-dimensional and three-dimensional schemes are used to form a complete set.Some techniques,such as change of variables,calculus of variations, multiplicative commutation rule of difference operators,decomposition of high order difference operators and prior estimates,are adopted.The estimates in l~2 norm are derived to determine the error in the approximate solution.This method was already applied to the numerical simulation of migration-accumulation of oil resources.

The Q value variations in the preparing pro－cess of rock rupture

In this paper, the 'spectral amplitude ratio method'(SAR) , 'energy method'(EN) and 'coda wave method'(CW) are used to calculate the Q value variations of gneiss in the preparing rupture process. The obtained results show that the variation state of Q values by SAR features the shape of relative stability gradual increment to the maximum then decrement and final rupture.The variation state of Q values by EN is just contrary to that by SAR,i.e.with the shape of stability decrement increment and final rupture . The varation state of Q values by CW is similar to that by EN, its main frequency features the shape of relatively high value decrement to the minimum increment and final rupture.But to the high frequency (higher than the main frequency),the variation state of Q values features the shape of the stable value increment to the maximum decrement and final rupture.At the same time, the results by coda wave amplitude spectrum show that, when stress reaches 70% of rupture stress, the high frequency component of S wave rapidly reduces( Q c increasing); at the time of impending the main rupture, the main frequency component reduces with a large scale( Q c increasing again), this may be the reason which causes the different variation states of two coda Q values.The result of amplitude spectra of P, S(initial wave) waves also show that with the appearance of microcracks the frequency band of S wave turn to be narrow, the high frequency component is reduced quickly, i.e. the S wave spectra have different variation states with different frequeny components. That is why the Q s obtained by different methods have different variation characteristics.

Modified characteristic finite difference fractional step method for moving boundary value problem of nonlinear percolation system

A fractional step scheme with modified characteristic finite differences run- ning in a parallel arithmetic is presented to simulate a nonlinear percolation system of multilayer dynamics of fluids in a porous medium with moving boundary values. With the help of theoretical techniques including the change of regions, piecewise threefold quadratic interpolation, calculus of variations, multiplicative commutation rule of differ- ence operators, multiplicative commutation rule of difference operators, decomposition of high order difference operators, induction hypothesis, and prior estimates, an optimal order in 12 norm is displayed to complete the convergence analysis of the numerical algo- rithm. Some numerical results arising in the actual simulation of migration-accumulation of oil resources by this method are listed in the last section.

A Compact Difference Scheme for Multi-point Boundary Value Problems of Heat Equations

In this paper,a compact difference scheme is established for the heat equations with multi-point boundary value conditions.The truncation error of the difference scheme is O(τ2+h^4),where t and h are the temporal step size and the spatial step size.A prior estimate of the difference solution in a weighted norm is obtained.The unique solvability,stability and convergence of the difference scheme are proved by the energy method.The theoretical statements for the solution of the difference scheme are supported by numerical examples.

Absolute Reference Values of the Real Gas

With his publication in 1873 [1] J. W. Gibbs formulated the thermodynamic theory. It describes almost all macroscopically observed properties of matter and could also describe all phenomena if only the free energy U - ST were explicitly known numerically. The thermodynamic uniqueness of the free energy obviously depends on that of the internal energy U and the entropy S, which in both cases Gibbs had been unable to specify. This uncertainty, lasting more than 100 years, was not eliminated either by Nernst’s hypothesis S = 0 at T = 0. This was not achieved till the advent of additional proof of the thermodynamic relation U = 0 at T = Tc. It is noteworthy that from purely thermodynamic consideration of intensive and extensive quantities it is possible to derive both Gibbs’s formulations of entropy and internal energy and their now established absolute reference values. Further proofs of the vanishing value of the internal energy at the critical point emanate from the fact that in the case of the saturated fluid both the internal energy and its phase-specific components can be represented as functions of the evaporation energy. Combining the differential expressions in Gibbs’s equation for the internal energy, d(μ/T)/d(1/T) and d(p/T)/d(1/T), to a new variable d(μ/T)/d(p/T) leads to a volume equation with the lower limit vc as boundary condition. By means of a variable transformation one obtains a functional equation for the sum of two dimensionless variables, each of them being related to an identical form of local interaction forces between fluid particles, but the different particle densities in the vapor and liquid spaces produce different interaction effects. The same functional equation also appears in another context relating to the internal energy. The solution of this equation can be given in analytic form and has been published [2] [3]. Using the solutions emerging in different sets of problems, one can calculate absolutely the internal energy as a function of temperature-dependent, phase-specific volumes and vapor pressure.

Dimension of Solar Panels Surface Based to the Net Present Value for the Albanian Conditions

Active exploitation of solar energy is achieved in systems that absorb this energy through flat collectors. Hot water can be used for space heating, when its temperature is high, but it is used largely for DHW （domestic hot water） needs. Now days, this technology has resulted as the most viable for exploitation of solar energy, and various countries such as Israel, Turkey, and Greece provide hot water for residential and service sectors using systems of solar panels. In this proceeding we are writing about the dimension of the solar panels surface based to the net present value in Hotels of Albania.

Theoretical Derivation of Thermal Value Equations for Heating Furnaces

Based on thermal value theory, the aim of this paper is to deduce the theoretical formulas for evaluating the energy effective utilization degree in technological pyrological processes exemplified by metallurgical heating furnaces. Heat transfer models for continuous heating furnaces, batch-type heating furnaces, and regenerative heating furnaces are established, respectively. By analyzing the movement path of injected infinitesimal heat attached on steel or gas, thermal value equations of continuous, batch-type, and regenerative heating furnaces are derived. Then the influences of such factors as hot charging, gas preheating and intake time of heat on energy effective utilization degree are discussed by thermal value equations. The results show that thermal value rises with hot charging and air preheating for continuous heating furnaces, with shorter intake time when heat is attached on steel or longer intake time when heat is attached on gas for batch-type heating furnaces and that with more heat supply at early heating stage or less at late stage for regenerative heating furnaces.

A Value Engineering Analysis of Head Loss in Pumping Mains

With net zero carbon emissions targets approaching over the next 20 to 30 years, the water industry must act now to develop energy efficient techniques and designs to reduce emissions and reduce the carbon footprint of water utility providers. There is also the potential for significant energy and therefore financial savings to be realised from the adoption of more energy efficient designs approaches. Water utility providers account for a significant proportion of national electricity consumption. The purpose of this research is to determine if, over the long term, opting for a larger diameter pipe at design stage can lead to significant financial and emissions savings for water utility providers when considering pumping mains. Pumping mains are widely used throughout the water and wastewater industry where a gravity solution is not possible. 72 hypothetical water main design scenarios were analysed and the long term financial and environmental impact of each hypothetical water main was assessed. It was found across all design scenarios that larger diameter water mains were capable of delivering the same rate of flow of smaller diameter pipes at a much reduced velocity and requiring reduced pumping power. It was concluded that pumped mains of larger diameters can ultimately be more energy efficient and cost effective over the long term when selected in favour of smaller diameter pumped mains in otherwise identical design scenarios.

A Comparison of the Inhibiting Effect of CO and CO2 to Hydrogen Permeation and n-Value in Pd and Pd/Ag Membranes Prepared on Alumina Support

The mitigation of the CO inhibition effect in palladium membranes is necessary due to its significance in the efficiency of membrane reactors and hydrogen production systems. In this work, the hydrogen separation performance of a Pd and Pd/Ag membrane both of thickness 2 μm is investigated using a mixed gas with composition (H2 = 50%, CO = 28%, CO2 = 10%, CH4 = 8%, N2 = 4%) at temperature 623 - 873 K and pressure (0.05 - 0.4 bar) was investigated. The component gases CO and CO2 were observed to inhibit hydrogen permeation through the membrane and lead to deviations from Sievert’s law for n values 0.55 and 0.62 for the Pd membrane and unity for the Pd/Ag membrane. For the Pd/Ag membrane, the concentration of CO in the permeate stream was reduced as a result of the addition of Ag. The effect of the component gases to hydrogen permeation was observed to be lower for the Pd/Ag membrane. Annealing the membrane in hydrogen at high temperature decreased the inhibition effect and enhanced hydrogen permeation through the membrane.

Optimal Configuration of Multitype Energy Storage for Integrated Energy Systems Considering System Reserve Value

An integrated energy system(IES)contributes to improving energy efficiency and promoting sustainable energy development.For different dynamic characteristics of the system,such as demand/response schemes and complex coupling characteristics among energy sources,siting and sizing of multitype energy storage(MES)are very important for the economic operation of the IES.Considering the effect of the diversity of the IES on system reserve based on electricity,gas and heat systems in different scenarios,a two-stage MES optimal configuration model,considering the system reserve value,is proposed.In the first stage,to determine the location and charging/discharging strategies,a location choice model that minimizes the operating cost,considering the system reserve value,is proposed.In the second stage,a capacity choice model,to minimize the investment and maintenance cost of the MES,is proposed.Finally,an example is provided to verify the effectiveness of the MES configuration method in this paper in handling operational diversity and ensuring system reserve.Compared with the configuration method that disregards the system reserve value,the results show that the MES configuration method proposed in this paper can reduce the annual investment cost and operating cost and improve the system reserve value.

The Impact of Global Value Chain Embedment on Energy Conservation and Emissions Reduction:Theory and Empirical Evidence

An in-depth investigation into the effect of embedment in global value chain(GVC)on energy conservation and emissions reduction is of great significance for scientifically assessing the environmental impact of GVC participation,and promoting high-quality development in China.This paper incorporates GVC embedment,energy consumption and carbon emissions into the same analysis framework for the first time.Based on the WIOD database,this paper theoretically and empirically examines the impact and mechanism of global value chain embeddedness on carbon emission reduction from two dimensions:energy consumption intensity and energy consumption structure.The study found that GVC embedment significantly reduced the industry’s carbon emission intensity;developing economies’embedment in GVC helped reduce their carbon emission intensity,while the effect was not obvious in developed economies.GVC embedment had a significant inhibitory effect on the carbon emissions in both upstream and downstream industries,but not conducive to carbon reduction of lowtech manufacturing.The mechanism test shows that the GVC embedment not only exhibits the dual effects of energy conservation and emissions reduction,but also has a significant impact on carbon emissions by reducing the energy consumption intensity and improving the energy consumption structure.

Prospects for key technologies of new-type urban integrated energy system

In recent years,primary energy consumption in China’s urban areas has increased rapidly,facing the problems of extensive use of energy,high energy consumption and insufficient intensified use of energy resources.Improving multienergy supply,increasing the proportion of clean energy and integrated energy efficiency are the main goals of urban development.The integrated energy system with multi-functional synergy and open trading will become one of the new directions for the development of new urban energy systems.This paper summarizes the main problems faced by the current towns and the characteristics of the new urban energy system,analyzes the development of new urban energy system from three aspects including energy interconnection hub infrastructure construction,energy management platform construction and energy value sharing,and forecasts the future development direction of new urban energy systems.