Energy Input and Mass Redistribution by Supernovae in the Interstellar Medium

Supernovae as thermal and kinetic energy input to their environment

We evaluate the large‐scale energy budget of magnetic reconnection utilizing an analytical time‐dependent impulsive reconnection model and a numerical 2‐D MHD simulation. With the generalization to compressible plasma, we can investigate changes in the thermal, kinetic, and magnetic energies. We study these changes in three different regions: (a) the region defined by the outflowing plasma (outflow region, OR), (b) the region of compressed magnetic fields above/below the OR (traveling compression region, TCR), and (c) the region trailing the OR and TCR (wake). For incompressible plasma, we find that the decrease inside the OR is compensated by the increase in kinetic energy. However, for the general compressible case, the decrease in magnetic energy inside the OR is not sufficient to explain the increase in thermal and kinetic energy. Hence, energy from other regions needs to be considered. We find that the decrease in thermal and magnetic energy in the wake, together with the decrease in magnetic energy inside the OR, is sufficient to feed the increase in kinetic and thermal energies in the OR and the increase in magnetic and thermal energies inside the TCR. That way, the energy budget is balanced, but consequently, not all magnetic energy is converted into kinetic and thermal energies of the OR. Instead, a certain fraction gets transfered into the TCR. As an upper limit of the efficiency of reconnection (magnetic energy → kinetic energy) we find η eff=1/2. A numerical simulation is used to include a finite thickness of the current sheet, which shows the importance of the pressure gradient inside the OR for the conversion of kinetic energy into thermal energy.

Thermal energy evolution and mechanical deformation of monocrystalline yttria-stabilized zirconia nanoparticles in aerosol deposition processes

Conservation of total, kinetic, and thermal energy in the atmosphere is revisited, and the derived thermal energy balance is examined with observations. Total energy conservation (TEC) provides a constraint for the sum of kinetic, thermal, and potential energy changes. In response to air thermal expansion/compression, air density variation leads to vertical density fluxes and potential energy changes, which in turn impact the thermal energy balance as well as the kinetic energy balance due to the constraint of TEC. As vertical density fluxes can propagate through a large vertical domain to where local thermal expansion/compression becomes negligibly small, interactions between kinetic and thermal energy changes in determining atmospheric motions and thermodynamic structures can occur when local diabatic heating/cooling becomes small. The contribution of vertical density fluxes to the kinetic energy balance is sometimes considered but that to the thermal energy balance is traditionally missed. Misinterpretation between air thermal expansion/compression and incompressibility for air volume changes with pressure under a constant temperature would lead to overlooking important impacts of thermal expansion/compression on air motions and atmospheric thermodynamics. Atmospheric boundary layer observations qualitatively confirm the contribution of potential energy changes associated with vertical density fluxes in the thermal energy balance for explaining temporal variations of air temperature.

Context. Solar jets play a role in coronal heating and the supply of solar wind. Aims. In this study, we calculate the energies of 23 small-scale jets emerging from a quiet-Sun region in order to investigate their contributions to coronal heating. Methods. We used data from the High-Resolution Imager (HRI) of the Extreme Ultraviolet Imager (EUI) on board the Solar Orbiter. Small-scale jets were observed by the HRIEUV 174 Å passband in the high cadence of 6 s. These events were identified by the time–distance stacks along the trajectories of jets. Using the simultaneous observation from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO), we also performed a differential emission measure (DEM) analysis on these small-scale jets to obtain the physical parameters of plasma, which enabled us to estimate the kinetic and thermal energies of the jets. Results. We find that most of the jets exhibit common unidirectional or bidirectional motions, while some show more complex behaviors; namely, a mixture of unidirection and bidirection. A majority of jets also present repeated eruption blobs (plasmoids), which may be signatures of the quasi-periodic magnetic reconnection that has been observed in solar flares. The inverted Y-shaped structure can be recognized in several jets. These small-scale jets typically have a width of ∼0.3 Mm, a temperature of ∼1.7 MK, an electron number density of ≳109 cm−3, with speeds in a wide range from ∼20–170 km s−1. Most of these jets have an energy of 1023–1024 erg, which is marginally smaller than the energy of typical nanoflares. The thermal energy fluxes of 23 jets are estimated to be (0.74–2.96)×105 erg cm−2 s−1, which is almost on the same order of magnitude as the energy flow required to heat the quiet-Sun corona, although the kinetic energy fluxes vary over a wide range because of their strong dependence on velocity. Furthermore, the frequency distribution of thermal energy and kinetic energy both follow the power-law distribution N(E)∝E−α. Conclusions. Our observations suggest that although these jets cannot provide sufficient energy to heat the whole quiet-Sun coronal region, they are likely to account for a significant portion of the energy demand in the local regions where the jets occur.

A Single‐Material Multi‐Source Energy Harvester, Multifunctional Sensor, and Integrated Harvester–Sensor System—Demonstration of Concept

Kinetic and potential energy are included in the first law of thermodynamics in quite a contradictory way. Whereas in thermodynamics the total energy is understood as the sum of internal, kinetic and potential energy, the total energy in continuum mechanics incorporates only internal and kinetic energy, the potential energy being part of the work. The Gibbs ' fundamental equation is also occasionally extendend to contain a term for the potential energy. Some serious contradictions may result from this. As is first shown, kinetic and potential energy do not have any influence on the internal energy as long as relativistic effects are excluded. The Gibbs' fundamental equation therefore describes exchange processes between the “internal variables„ of a system and its surroundings. Proceeding from this result one obtains a general definition of heat in open systems, including electromagnetic reactions, surfaceeffects and variable mole numbers. Exchange processes between the “external variables„ of a system and its surroundings and hence also the influence of kinetic and potential energy are described by another independent equation, i.e. the energy equation of mechanics. Addition of both equations leads to the heat definition which is usually but under some further neglects given in textbooks. This definition has considerable disadvantages compared to the one derived before. In particular it is no longer possible to realize how mechanical and thermal energy are transformed into each other, which may give rise to errors.

Summary This paper evaluates the technical potential, the energy balance, and the economics of reinjecting produced brines into geopressured/geothermal aquifers. This analysis of reinjecting brines shows that, depending on the hydraulic turbine technology, 50 to 90% of the power requirements of reinjection into the producing aquifer can be met by extracting the thermal and kinetic energy from the produced geopressured/geothermal brines. Moreover, the technically recoverable methane resource could be increased 20 times by reinjecting the brines into the producing formation, compared to using more conventional disposal options. In addition, the reinjection of brines would reduce the potential for environmental damage. Reinjecting the produced brines could enable geopressured aquifers to become economical in the future, particularly when the gas content of the produced bane is relatively large. In addition, the resource will become produced bane is relatively large. In addition, the resource will become more economical as real energy prices increase, since a reinjection-based system, to a large degree, will be independent of outside purchased power. However, because of high costs and risk, geopressured aquifers are not yet an economically competitive energy source. Introduction Geopressured aquifers have been estimated to contain an in-place resource of 1,800 Tcf [51 × 10 12 m3] of methane in Texas and 1,300 Tcf [37 × 10 12 m3] in Louisiana in the onshore sandstones. Another 2,600 Tcf [74 × 10 12 m3] is estimated in the offshore sandstones. Because of the large size of this unconventional gas resource, efforts have been directed toward establishing the amount of gas that is economically and technically recoverable and the alternative technologies for producing these high-pressure, high-temperature formations. This work has included efforts by the U.S. DOE to drill wells specifically for testing and producing geopressured formations (design wells) and to collect information on dry wells drilled in the search for oil or gas that have penetrated geopressured formations (wells of opportunity). Earlier studies on the economics of producing methane from geopressured brines have concluded that the resource is marginally economical because of high capital costs, unproved technology, and the small net energy gain associated with only capturing the dissolved methane. Further, since the reservoir energy is sufficient to produce only 1 to 4% of the water in place, a viable project requires giant reservoirs of 3 cu miles [12.5 km3] or more, containing more than 1 billion bbl [0.16 × 10 9 m3] of water in place. One way to increase the attractiveness of the geopressured aquifers is to use the associated thermal and kinetic energy to reinject the brines back into the producing aquifers. This total energy system would have the following benefits. 1. It would lead to a greater recovery of the resource. 2. Environmental effects, such as subsidence, would be minimized. 3. Reservoirs that are an order of magnitude smaller than the "giants"could become feasible resource targets. 4. The productive life of the geopressured reservoirs would be extended greatly. 5. The use of the thermal and kinetic energy would reduce the need to purchase outside power for reinjection. Fig. 1 is a line diagram of a total energy system. The produced geopressured brines initially are flowed through a hydraulic turbine. As the pressure is reduced, kinetic energy is converted into electric power, and the released methane is captured in a gas/water separator. The brines then flow through a heat exchange where the thermal energy is extracted before they are reinjected. This paper examines the use of such a total energy system and the technical and economic potential of reinjection into producing geopressured/geothermal aquifers. producing geopressured/geothermal aquifers. Sample Reservoirs The analysis is based on five actual geopressured aquifers (in Texas and Louisiana) on which data have been gathered. The reservoir parameters of these five sample reservoirs are shown in Table 1. These parameters are based on published values and personal communication. The geopressured waters were assumed fully saturated with methane, and the gas content was derived from published correlations, allowing for temperature, pressure, and salinity differences (Fig. 2). The geopressured reservoirs are all hydrocarbon-bearing reservoirs larger than normal, and have high temperatures, pressures, and salinities. The first three represent shallow geopressured, deep geopressured, and ultradeep geopressured reservoirs in Texas; the last two represent shallow geopressured and deep geopressured reservoirs in Louisiana. JPT p. 1164

توسعه پایدار تولید یک محصول در هر منطقه مستلزم توجه به سیر انرژی سامانه تولیدی آن است، در عین حال توجه به نهاده‌های ورودی سامانه تولیدی با نگرش مدیریت محیط زیست نیز از اهمیت ویژه ای برخوردار است. در این تحقیق انرژی مصرفی و انتشار گازهای گلخانه‌ای تولید چای در استان گیلان مورد بررسی قرار گرفت. اطلاعات از طریق مصاحبه حضوری با 75 چای‌کار گیلانی و تطبیق اطلاعات با دفترچه چای هر کشاورز جمع‌آوری شد. مجموع انرژی‌های ورودی 60/39060 مگاژول بر هکتار بود. کارایی انرژی 22/0 محاسبه شد. کودهای شیمیایی بیش‌ترین سهم را در انرژی‌های مصرفی و انتشار گازهای گلخانه‌ای به ترتیب با 55/58 و 22/74 درصد در تولید چای به خود اختصاص دادند. مجموع انتشار گازهای گلخانه‌ای تولید چای در منطقه kgCO2eq. ha-1 82/1281 بود. نتایج استفاده از تابع کاب داگلاس و تحلیل حساسیت انرژی تولید چای در استان گیلان نشان داد که تأثیر تمامی نهاده‌های انرژی ورودی به غیر از سموم شیمیایی بر عملکرد مثبت بود و تأثیر نهاده انرژی نیروی کارگری بر عملکرد در سطح یک درصد معنی‌دار شد. نهاده انرژی نیروی کارگری، حساس‌ترین و همچنین بیش‌ترین تأثیر را بر عملکرد داشت و پس از آن نهاده‌های انرژی ماشین‌ها و سموم شیمیایی بیش‌ترین تأثیر را بر عملکرد چای در استان گیلان داشتند. توسعه پایدار تولید یک محصول در هر منطقه مستلزم توجه به سیر انرژی سامانه تولیدی آن است، در عین حال توجه به نهاده‌های ورودی سامانه تولیدی با نگرش مدیریت محیط زیست نیز از اهمیت ویژه ای برخوردار است. در این تحقیق انرژی مصرفی و انتشار گازهای گلخانه‌ای تولید چای در استان گیلان مورد بررسی قرار گرفت. اطلاعات از طریق مصاحبه حضوری با 75 چای‌کار گیلانی و تطبیق اطلاعات با دفترچه چای هر کشاورز جمع‌آوری شد. مجموع انرژی‌های ورودی 60/39060 مگاژول بر هکتار بود. کارایی انرژی 22/0 محاسبه شد. کودهای شیمیایی بیش‌ترین سهم را در انرژی‌های مصرفی و انتشار گازهای گلخانه‌ای به ترتیب با 55/58 و 22/74 درصد در تولید چای به خود اختصاص دادند. مجموع انتشار گازهای گلخانه‌ای تولید چای در منطقه kgCO2eq. ha-1 82/1281 بود. نتایج استفاده از تابع کاب داگلاس و تحلیل حساسیت انرژی تولید چای در استان گیلان نشان داد که تأثیر تمامی نهاده‌های انرژی ورودی به غیر از سموم شیمیایی بر عملکرد مثبت بود و تأثیر نهاده انرژی نیروی کارگری بر عملکرد در سطح یک درصد معنی‌دار شد. نهاده انرژی نیروی کارگری، حساس‌ترین و همچنین بیش‌ترین تأثیر را بر عملکرد داشت و پس از آن نهاده‌های انرژی ماشین‌ها و سموم شیمیایی بیش‌ترین تأثیر را بر عملکرد چای در استان گیلان داشتند.

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.

Some aspects of energy methods for the inelastic seismic response of ductile SDOF structures

This study illustrates a factory’s production efficiency by demonstrating its energy efficiency in the dairy milk industry. Determining the thermal energy to save energy enhances the prof-itability of the factory. The aim of this study is to conduct a thermal energy and production analysis of a dairy milk factory based on annual production. This study intends to make the conclusions more realistic by using production and energy data dependability analysis. The overall power consumption for the thermal and electric energy processes was found to be as 180,520 [W]. The target-specific energy consumption value was computed for Case 1 as 6,352.14 [MJ/t], for Case 2 as 5,898.67 [MJ/t], and for Case 3 as 5,445.21 [MJ/t]. The annual thermal (steam boiler) and electrical energy expenditures were obtained, with 315.87 [kW] of thermal (steam) energy and 80.98 [kW] of electrical energy. The total thermal and electri-cal energy reached 396.85 [kW]. Despite the factory’s expenditure on thermal and electrical energy, the energy efficiency was determined to be as 45.5%. The input energy was obtained to be 374.24 [kW] in Case 1, 356.33 [kW] in Case 2, and 342.08 [kW] in Case 3. The energy efficiency was calculated as 48.2 [%] for Case 1, 50.7 [%] for Case 2, and 52.8 [%] for Case 3. This study, which is expected to inspire future research, is also likely to assist livestock and agriculture in the energy field. The novelty of this study is that optimizing product efficiency and energy consumption in the production of milk and dairy products positively increases the energy efficiency of factories.

view Abstract Citations (7) References (13) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Diffusive hydromagnetic flow in the vicinity of a neutral point. Yeh, T. Abstract In the hydromagnetic interactions of magnetic merging, the electrical resistivity determines the time scale for the temporal approach toward a steady state and the length scale for the dynamical balance in a steady state. These intrinsic scales are different from those externally identifiable scales. In a steady state, conversion of magnetic energy into kinetic and thermal energies requires the upstream Alfven number to be less than unity. Solutions in the vicinity of a neutral point show that the use of Ohm's law with a simple resistivity is appropriate in the modeling of field-line reconnection. Publication: The Astrophysical Journal Pub Date: August 1976 DOI: 10.1086/154554 Bibcode: 1976ApJ...207..837Y Keywords: Energy Conversion; Magnetic Fields; Magnetohydrodynamic Flow; Solar Magnetic Field; Sunspots; Electrical Resistivity; Kinetic Energy; Magnetic Storage; Steady State; Thermal Energy; Plasma Physics full text sources ADS |

Thermoplastic starch (TPS) materials have great potential to replace some conventional synthetic plastics, and have the advantage of being economical, biodegradable, renewable, and can usually be processed using conventional plastic processing equipment. An important requirement is that TPS materials should have acceptable mechanical and biodegradability properties as a given functional material. The structure of TPS materials, at the molecular, crystalline and granular levels, may be altered during processing, which in turn affect their mechanical properties and biodegradability. This dissertation encompasses a detailed understanding of starch structural changes resulting from an archetypal processing procedure, and also examines its effects on mechanical properties and biodegradability. The effects of the thermal and mechanical energies of extrusion on the starch degradation at multiple structural levels were quantitatively investigated. Waxy (WMS), normal (NMS), and high-amylose maize starch (HAMS) with different amylose contents of 0, 34 and 63%, were extruded with varying temperatures, screw speeds, and plasticizer contents. The size distributions of individual branches did not show any significant change after extrusion. The whole amylopectin molecules were degraded into smaller sizes during extrusion while whole amylose molecules were not significantly affected. The crystalline and granular structures were disrupted during extrusion, without changing the crystalline polymorph displayed, suggesting that the crystalline structure remaining mainly originated from ungelatinized starch, which was confirmed by polarized light microscope images. Starch structural degradation was more severe at lower plasticizer content due to the greater amount of mechanical energy input at the same screw speed. Higher processing temperature (thermal energy) did not have any significant effect on the crystalline structure. The effects of mechanical and thermal energies on starch structural degradation were analyzed separately using Pearson correlation tests to compare the effect of the different parameters, showing that mechanical energy caused more significant degradation on starch structure than thermal energy. The starch extrudates obtained previously were compression-molded and the crystalline structure of NMS films was further altered using a hydrothermal treatment (HTT). The mechanical properties of starch films with various molecular and crystalline structures were investigated. For WMS, which contains only amylopectin, the degradation at the molecular level did not affect the mechanical properties significantly. HAMS films, with a higher amylose content and longer branches, showed higher elongation at break, and tensile strength than WMS and NMS films. The effects of amylose content on the mechanical properties were not significant when the plasticizer content was low, probably because the starch chains were restrained in a more rigid network. As distinct from previous studies reporting that an increase in crystallinity enhanced some mechanical properties, the present study found that the crystallinity of different films prior HTT was not significantly correlated with their mechanical properties, which might be due to these crystalline structure from the remaining ungelatinized starch granules unable to form a continuous network. On the other hand, the alteration of TPS crystalline structure by HTT increased the tensile strength and Young’s modulus, while decreased the elongation at break. The results indicate that the crystallinity from the remaining ungelatinized starch granules has less significant effects on the mechanical properties of TPS than the crystalline structure formed from starch retrogradation, probably due to the leached-out amylose forming a stronger network surrounding the remaining starch granules. The effects of starch structures on the biodegradability of TPS films were investigated by hydrolyzing starch films using fungal α-amylase. The substrates comprised varied starch structures obtained by different degrees of acid hydrolysis, different granular sizes using size fractionation, and different degrees of crystallinity by aging for different times (up to 14 days). Two stages are identified for unretrograded films by fitting degradation data using first-order kinetics. Starch films containing larger molecules were degraded faster, but the rate coefficient was independent of the granule size. Retrograded films were degraded much slower than unretrograded ones, with a similar rate coefficient to that in the second stage of unretrograded films. Although initially the smaller molecules or the easily accessible starch chains on the amorphous film surface were degraded faster, the more ordered structure (resistant starch) formed from retrogradation, either before or during enzymatic degradation, strongly inhibits film biodegradation. Starch structural changes induced by processing at different levels can be inter-related with one another; for example, amylopectin molecules present in the rigid semi-crystalline conformation in native starch granules undergo severe shear scission by mechanical energy during extrusion, decreasing the degree of crystallinity and destroying the granular structure. Crystalline structure from the continuous network in TPS materials is dominant in improving the mechanical properties and decreasing the degradation rate of TPS. Although the molecular size does not influence the mechanical properties, it has a great impact on the biodegradability of starch films.

The sources of thermal energy exchange accompanying microbial catabolism