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The test results obtained for reinforced concrete columns by several studies have revealed that the peak displacement and cumulative hysteresis energy are important parameters for evaluating the damage of columns under horizontal bidirectional and unidirectional loading. Therefore, the seismic parameters related to the nonlinear peak displacement and cumulative hysteresis energy with regard to horizontal bidirectional seismic input should be investigated. In this study, the bidirectional seismic input to an isotropic nonlinear one-mass two-degree-of-freedom system was evaluated. First, a dimensionless parameter γ, which controls the low-cycle fatigue effect, was formulated as a function of two energy input parameters (the maximum momentary input energy and total input energy) and a nonlinear system (ductility and normalized hysteresis energy absorption during a half cycle). Then, the maximum momentary input energy and total input energy were evaluated according to the ground motion characteristics (Fourier coefficient of horizontal ground motion components) and system properties. Finally, the nonlinear peak displacement and parameter γ of the nonlinear system were evaluated on the basis of the maximum momentary input energy and total input energy. The results revealed that the nonlinear peak displacement and parameter γ can be properly evaluated using two energy parameters.

Both spatial and seasonal variation of turbulent diapycnal mixing in the subtropical northwestern Pacific are evaluated by employing a fine‐scale parameterization method based on profiles of potential density, which are obtained from CTD measurements during our recent hydrographic surveys implemented by the China National Key Basic Research Project from 2008 to 2010 and the World Ocean Circulation Experiment. Over smooth seafloor, the value of diffusivity away from the boundary is comparable with the values observed in the stratified midlatitude ocean interior, i.e., O (10−5 m2 s−1). On the other hand, enhanced diapycnal mixing, i.e., O (10−4 m2 s−1) or larger has been found over rough topography such as the Central Basin Trough, Okidaito Ridge, the origin of the Kuroshio Current, and especially Luzon Strait, which might result from dissipation of baroclinic energy generated when barotropic tides rub over rough topography. Over flat bathymetry, mixing is probably stirred by the wind work on near inertial motions in the upper 600 m and enhanced downward propagating energy has been found in the presence of anticyclonic eddies, which points to the important role of anticyclonic eddies in enhancing the diapycnal mixing at greater depth. The diffusivity also displays a distinct seasonal variation with strong (weak) mixing corresponding to strong (weak) wind‐input energy in winter (summer), which, however, is only confined to upper 600 m. This is different from the midlatitude northwestern Pacific, where seasonality of diffusivity can be found at 1500‐m depth. Key Points Seasonality of diapycnal mixing stirred by wind‐input near inertial energy Enhanced downward‐propagating energy in the presence of anticyclonic eddies Enhanced diapycnal mixing over rough bathymetry

Dispersing particles in a liquid phase is significant for producing various functional nano/bio applications. The wet-jet milling method has been gaining attention as an attractive dispersing method in the preparation of soft material suspensions. This is because the main driving force of dispersion by the wet-jet milling method is the shear force, which is weaker than that it is in the ultrasonication dispersing method. In the wet-jet milling method, the pressure of the narrow channel which the liquid is passes through and the number of passes are used as the control parameters for dispersing the particles. However, the values of the pressure depend on the size (diameter and length) of the narrow channel, thus, it is not a commonly used dispersing parameter in dispersing by wet-jet milling to set the dispersing condition by various wet-jet milling instruments. In addition, wet-jet milling users must optimize the dispersing conditions such as the pressure and number of passes in the narrow channel, therefore, a simple prediction/optimization method of the dispersing size by the wet-jet milling method is desired. In this study, we established a novel colloidal dispersing concept, the dispersing energy input based on a calorimetric idea, for particle suspension preparation using the wet-jet milling method. The dispersing energy input by wet-jet milling was quantitatively calculated under various conditions during the dispersing by wet-jet milling, and then, the dispersing size of the particles was easily predicted/optimized. We demonstrated the usability of the concept by preparing aqueous suspensions of calcium carbonate (CaCO3) particles with various surfactants using the wet-jet milling method. Based on the established concept, in a case study on dispersing CaCO3, we found that changes in the micelle sizes of the surfactants played a role in wet-jet milling. The novel idea of the representation of energy input makes it possible to estimate the appropriate condition of the dispersing process by wet-jet milling to control the size of particles.

In this study, conventional tillage (CT), reduced tillage (RT) and zero tillage (ZT) methods energy input-output analysis during second crop corn production have been carried out. The trials were performed between 2015-2016 in Ceylanpinar Directorate of Agricultural Enterprises Karatas region, Turkey. The findings showed that among tillage methods, the least energy input was ZT (23724.15 MJ ha-1), and the most energy output was CT (138510 MJ ha-1). In energy productivity, the highest value was on ZT (5.54). The highest value in corn yield was found in CT method with 9500 kg ha-1. This is followed by ZT (9100 kg ha-1) and RT (8750 kg ha-1), respectively. As a result, although CT can be preferred due to its high yield, it has been observed that ZT and RT tillage methods should be supported especially due to its ecological and high energy productivity.

To investigate the energy evolution characteristics of rock materials under uniaxial compression, the single-cyclic loading–unloading uniaxial compression tests of four rock materials (Qingshan granite, Yellow sandstone, Longdong limestone and Black sandstone) were conducted under five unloading stress levels. The stress–strain curves and failure characteristics of rock specimens under the single-cyclic loading–unloading uniaxial compression tests basically corresponded with those of under uniaxial compression, which indicates that single-cyclic loading–unloading has minimal effects on the variations in the loading–deformation response of rocks. The input energy density, elastic energy density and dissipated energy density of four rocks under five unloading stress levels were calculated using the graphical integration method, and variation characteristics of those three energy density parameters with different unloading stress levels were explored. The results show that all three energy density parameters above increased nonlinearly with increasing unloading stress level as quadratic polynomial functions. Meanwhile, both the elastic and dissipated energy density increased linearly when the input energy density increased, and the linear energy storage and dissipation laws for rock materials were observed. Furthermore, a linear relationship between the dissipated and elastic energy density was also proposed. Using the linear energy storage or dissipation law, the elastic and dissipated energy density at any stress levels can be calculated, and the internal elastic (or dissipated) energy density at peak compressive strength (the peak elastic and dissipated energy density for short) can be obtained. The ratio of the elastic energy density to dissipated energy density with increasing input energy density was investigated using a new method, and the results show that this ratio tends to be constant at the peak compressive strength of rock specimens.

Agriculture is the largest sector of Pakistan’s economy, contributing almost 22% to the GDP and employing almost 45% of the total labor force. The two largest food crops, wheat and rice, contribute 3.1% and 1.4% to the GDP, respectively. The objective of this research was to calculate the energy return on investment (EROI) of these crops on a national scale from 1999 to 2009 to understand the size of various energy inputs and to discuss their contributions to the energy output. Energy inputs accounted for within the cropping systems included seed, fertilizer, pesticide, human labor, tractor diesel, irrigation pump electricity and diesel, the transport of fertilizer and pesticide, and the embodied energy of tractors and irrigation pumps. The largest per-hectare energy inputs to wheat were nitrogen fertilizer (52.6%), seed (17.9%), and tractor diesel (9.1%). For rice, the largest per-hectare energy inputs were nitrogen fertilizer (32%), tube well diesel (19.8%), and pesticide (17.6%). The EROI of wheat showed a gradual downward trend between 2000 and 2006 of 21.3%. The trend was erratic thereafter. Overall, it ranged from 2.7 to 3.4 with an average of 2.9 over the 11-year study period. The overall trend was fairly consistent compared to that of rice which ranged between 3.1 and 4.9, and averaged 3.9. Rice’s EROI dipped sharply in 2002, was erratic, and remained below four until 2007. It rose sharply after that. As energy inputs increased, wheat outputs increased, but rice outputs decreased slightly. Rice responded to inputs with greater output and an increase in EROI. The same was not true for wheat, which showed little change in EROI in the face of increasing inputs. This suggests that additional investments of energy in rice production are not improving yields but for wheat, these investments are still generating benefits. The analysis shows quantitatively how fossil energy is a key driver of the Pakistani agricultural system as it traces direct and indirect energy inputs to two major food crops.

In many cases tree felling and processing operations are carried out motor-manually and knowledge about fossil fuel consumption and direct energy inputs when using such equipment is required for different purposes starting with operational costing and ending with environmental assessment of forest operations. In this study, fuel mixture, chain oil and direct fossil energy inputs were evaluated for two chainsaws which were used to fell and process trees in two silvicultural systems. The results of this study suggest that there is a strong dependence relation between selected tree size variables such as the diameter at breast height and tree volume on one hand and the fuel mixture, chain oil and direct fossil energy inputs when felling and processing broadleaved hardwood and resinous softwood trees on the other hand. For the broadleaved trees (mean tree volume of 1.50 m3 × tree-1, DBH of 45.5 cm and tree height of 21.84 m) the mean direct fossil energy input was of 3.86 MJ m-3 while for resinous trees (mean tree volume of 1.77 m3 tree-1, DBH of 39.28 cm and tree height of 32.49 m) it was of 3.93 MJ m-3. Other variables, including but not limited to the technology used, work experience and procedural pattern, may influence the mentioned figures and extensive studies are required to clarify their effects.

In selective laser melting (SLM) the variation of process parameters significantly impacts the resulting workpiece characteristics. In this study, AISI 316L was manufactured by SLM with varying laser power, layer thickness, and hatch spacing. Contrary to most studies, the input energy density was kept constant for all variations by adjusting the scanning speed. The varied parameters were evaluated at two different input energy densities. The investigations reveal that a constant energy density with varying laser parameters results into considerable differences of the workpieces’ roughness, density, and microhardness. The density and the microhardness of the manufactured components can be improved by selecting appropriate parameters of the laser power, the layer thickness, and the hatch spacing. For this reason, the input energy density alone is no indicator for the resulting workpiece characteristics, but rather the ratio of scanning speed, layer thickness, or hatch spacing to laser power. Furthermore, it was found that the microhardness of an additively manufactured material correlates with its relative density. In the parameter study presented in this paper, relative densities of the additively manufactured workpieces of up to 99.9% were achieved.

The concept of agricultural and environmental sustainability refers to minimizing the degradation of natural resources while increasing crop productions; assessment of inflow and outflow energy resources is helpful in highlighting the resilience of the system and maintaining its productivity. In this regard, the current study evaluated the amount of energy input–output of cotton productions and their environmental interventions. Data are randomly collected from 400 cotton farmers through face-to-face interview. Results suggested that the major energy is consumed by three culprits, i.e., chemical fertilizer, diesel fuel, and irrigation water (11,532.60, 11,121.54, and 4,531.97 MJ ha −1 , respectively). Total greenhouse gas (GHG) emission is 1,106.12 kg CO 2eq ha −1 with the main share coming from diesel fuel, machinery, and irrigation water. Stimulating data of energies, e.g., energy use efficiency (1.53), specific energy (7.69 MJ kg −1 ), energy productivity (0.13 kg MJ −1 ), and net energy gained (16,409.77 MJ ha −1 ). Further analysis using data envelopment analysis (DEA) showed that low technical efficiency, i.e., 69.02%, is the most probable cause of poor energy use efficiency. The impermanent trend in growth of energy efficiency has been witnessed with plausible potential of energy savings from 4,048.012 to 16,194.77 MJ ha −1 and a reduction of 148.96–595.96 kg CO 2eq ha −1 in GHG emission. Cobb–Douglas production function is further applied to discover the associations of energy input to output, which inferred that chemical fertilizer, diesel fuel, machinery, and biocides have significant effect on cotton yield. The marginal physical productivity (MPP) values obliged that the additional use in energy (1 MJ) from fuel (diesel), biocides, and machinery can enhance cotton yield at the rate of 0.35, 1.52, and 0.45 kg ha −1 , respectively. Energy saving best links with energy sharing data, i.e., 55.66% (direct), 44.34% (indirect), 21.05% (renewable), and 78.95% (nonrenewable), further unveiled the high usage of nonrenewable energy resources (fossil fuels) that ultimately contributes to high emissions of GHGs. We hope that these findings could help in the management of energy budget that we believe will reduce the high emissions of GHGs.

This article presents the results of a field experiment investigating the energy efficiency of grain produced by a semi-dwarf genotype of winter triticale at different levels of agricultural inputs. The energy efficiency of winter triticale grain production was evaluated in two low-input and two high-input cultivation practices that differed in the rate of nitrogen fertilizer (split application) and disease control. The energy inputs associated with the production of winter triticale grain at low levels of agricultural inputs were determined to be 14.5 to 14.7 GJ ha−1. Higher levels of agricultural inputs increased the demand for energy in grain production by 25% on average. The energy output of grain peaked (163.3 GJ ha−1) in response to a fertilizer rate of 120 kg ha−1 applied in a split ratio of 50:50 (BBCH 27/32) and two fungicide treatments (BBCH 31 and 39). The energy output of grain from the remaining cultivation regimes was 3–13% lower. The energy efficiency ratio was highest in the low-input cultivation regime with a nitrogen rate of 90 kg ha−1 split into two applications (60 and 30 kg ha−1 for BBCH 27 and 32, respectively), seed dressing with fungicide (thiram and tebuconazole) and one fungicide treatment (azoxystrobin) (BBCH 39).