scholarly journals Do paleontologists dream of electric dinosaurs? Investigating the presumed inefficiency of dinosaurs contact incubating partially buried eggs

Paleobiology ◽  
2020 ◽  
pp. 1-14
Author(s):  
Jason D. Hogan ◽  
David J. Varricchio
Keyword(s):  
Late Cretaceous ◽  
Energy Input ◽  
High Energy ◽  
Thermodynamic Efficiency ◽  
Efficient System ◽  
Evolutionary Path ◽  
Ambient Temperatures ◽  
Nest Sites ◽  
Guarding Behavior ◽  
Indoor And Outdoor

Abstract Troodon formosus, a theropod from the Late Cretaceous, is one of the few species of dinosaurs with multiple nest sites uncovered. It has been consistently demonstrated that eggs within these nests would have been partially buried in life—an exceedingly rare state in modern vertebrates. There has been debate over Troodon's capacity to engage in thermoregulatory contact incubation, especially regarding an adult's ability to efficiently supply partially buried eggs with energy. An actualistic investigation was undertaken to determine the thermodynamic efficiency of contact incubating partially buried eggs. An efficient system would keep eggs at temperatures closer to the surrogate parent than the ambient, without prohibitively high energy input. For the experiment, a surrogate dinosaur was created and used in both indoor controlled ambient temperature trials and in an outdoor variant. Even with ambient temperatures that were likely cooler than Cretaceous averages, the results showed that contact incubating partially buried eggs did seem to confer an energetic advantage; egg temperatures remained closer to the surrogate than ambient in both indoor and outdoor tests. Still, critics of contact incubating partially buried eggs are correct in that there is a depth at which adult energy would fail to make much of an impact—perhaps more relevant to buried eggs, as partially buried eggs would be in contact with an adult and likely above the thermal input threshold. Additionally, results from this experiment provide evidence for a possible evolutionary path from guarding behavior to thermoregulatory contact incubation.

scholarly journals 4E Analysis of a Fuel Cell and Gas Turbine Hybrid Energy System

2020 ◽  
Vol 11 (1) ◽  
pp. 7568-7579
Keyword(s):  
Fuel Cell ◽  
Cell Voltage ◽  
Energy System ◽  
High Energy ◽  
Exergy Efficiency ◽  
Combined Cycle ◽  
Net Energy ◽  
Exergy Destruction ◽  
Molten Carbonate ◽  
Ambient Temperatures

Exergy analysis of the expansion turbine hybrid cycle of integrated molten carbonate fuel cells is presented in this study. The proposed cycle was used as a sustainable energy curriculum to provide a small hybrid power plant with high energy efficiency. To generate electricity with the system mentioned above, and externally repaired fusion carbon fuel cell was used located at the top of the combined cycle. Moreover, the turbine and steam turbine systems are considered as complementary and bottom layers for co-generation, respectively. The results showed that the proposed system could reach net energy of up to 1125 kilowatts, while the total exergy efficiency (including electricity and heat) for this system is more than 68%. Moreover, the energy supplied and exergy efficiency derived from the proposed cycle are stable versus changes in ambient temperatures. Besides, the effect of increasing the current density on the cell voltage and the total exergy destruction was considered. Also, the new approaches of the exergoeconomics and exergoenvironmental analysis are implemented in this system. The results show that the hybrid system can decrease the exergy destruction costs more than 16%, and the environmental footprint of the system more than 23.4%.

Based on Comparable Price Energy Input-Output Table of Xinjiang to Research Low Carbon Economic Development Strategy

2013 ◽  
Vol 291-294 ◽  
pp. 1573-1576
Author(s):  
Yuan Sheng Huang ◽  
Lu Tong Li
Keyword(s):  
Development Strategy ◽  
Carbon Emissions ◽  
Energy Input ◽  
High Energy ◽  
Low Carbon ◽  
Input Output ◽  
Output Table ◽  
The Mean ◽  
The Cost ◽  
Advanced Production

Based on the input-output theory, the paper using the comparable price energy input-output table,quantitatively estimates the implicit carbon emissions of each industrial department,and analyzes the growth of the implicit carbon emissions of the resident consumption through the structure decomposition.Conclusion indicates:From 1992 to 1997, the mean of the implicit carbon emissions of each industrial department in Xinjiang had been rising; From 1997 to 2007, the mean of the implicit carbon emissions of each industrial department had been declining;The implicit carbon emissions of Hydropower industry, the fire power and other seven similar industrial department were higher than that of each industrial department so that Xinjiang should strengthen monitoring on the high energy consumption.The implicit carbon emissions of the resident consumption was still in the trend of ceaseless growth and all of that states clearly that the economic grows at the cost of the increase of the greenhouse gas emissions.Xinjiang should introduce foreign advanced production technology,further optimizing the structure of the resident consumption.

Biological X-ray Microanalysis: The Past, Present Practices, and Future Prospects

2001 ◽  
Vol 7 (2) ◽  
pp. 211-219 ◽  
Author(s):  
Patrick Echlin
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Transmission Electron Microscope ◽  
Low Voltage ◽  
High Energy ◽  
Scanning Transmission Electron Microscope ◽  
X Ray ◽  
Ambient Temperatures ◽  
Advantages And Disadvantages ◽  
Transmission Electron

Abstract A brief description is given of the events surrounding the development of biological X-ray microanalysis during the last 30 years, with particular emphasis on the contribution made by research workers in Cambridge, UK. There then follows a broad review of some applications of biological X-ray microanalysis. A more detailed consideration is given to the main thrust of current procedures and applications that are, for convenience, considered as four different kinds of samples. Thin frozen dried sections which are analyzed at ambient temperatures in a transmission electron microscope (TEM); semithin frozen dried sections which are analyzed at low temperature in a scanning transmission electron microscope (STEM); thick frozen hydrated sections which are analyzed at low temperature in a scanning electron microscope (SEM), and bulk samples which are analyzed at low temperature in the same type of instrument. A brief outline is given of the advantages and disadvantages of performing low-voltage, low-temperature X-ray microanalysis on frozen hydrated bulk biological material. The article concludes with a consideration of alternative approaches to in situ analysis using either high-energy beams or visible and near-visible photons.

Energy expenditure for thermoregulation and locomotion in emperor penguins

1976 ◽  
Vol 231 (3) ◽  
pp. 903-912 ◽  
Author(s):  
B Pinshow ◽  
MA Fedak ◽  
DR Battles ◽  
K Schmidt-Nielsen
Keyword(s):  
Metabolic Rate ◽  
Energy Requirement ◽  
Thermal Conductance ◽  
Standard Metabolic Rate ◽  
High Energy ◽  
Breeding Cycle ◽  
Emperor Penguin ◽  
Energy Reserves ◽  
Ambient Temperatures ◽  
Emperor Penguins

During the antarctic winter emperor penguins (Aptenodytes forsteri) spend up to four mo fasting while they breed at rookeries 80 km or more from the sea, huddling close together in the cold. This breeding cycle makes exceptional demands on their energy reserves, and we therefore studied their thermoregulation and locomotion. Rates of metabolism were measured in five birds (mean body mass, 23.37 kg) at ambient temperatures ranging from 25 to -47 degrees C. Between 20 and -10 degrees C the metabolic rate (standard metabolic rate (SMR)) remained neraly constant, about 42.9 W. Below -10 degrees C metabolic rate increased lineraly with decreasing ambient temperature and at -47 degrees C it was 70% above the SMR. Mean thermal conductance below -10 degrees C was 1.57 W m-2 degrees C-1. Metabolic rate during treadmill walking increased linearly with increasing speed. Our data suggest that walking 200 km (from the sea to the rookery and back) requires less than 15% of the energy reserves of a breeding male emperor penguin initially weighing 35 kg. The high energy requirement for thermoregulation (about 85%) would, in the absence of huddling, probably exceed the total energy reserves.

scholarly journals Thermodynamic Effects of Nanotechnological Augmentation of Hydrogen Fuel Cells

2017 ◽  
Vol 4 ◽  
pp. 76-86 ◽  
Author(s):  
Reece Cohen Woodley ◽  
Kane Yang ◽  
Geoffrey Bruce Tanner ◽  
Dennis Tran
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Cell System ◽  
Thermodynamic Efficiency ◽  
Hydrogen Fuel Cells ◽  
Hydrogen Fuel ◽  
Fuel Cell System ◽  
Efficient System ◽  
Structured Catalysts ◽  
Thermodynamic Effects

This meta-study focuses on the research regarding the use of nanotechnology in traditional fuel cells in order to increase thermodynamic efficiency through the exploitation of various thermodynamic systems and theories. The use of nanofilters and nano-structured catalysts improve the fuel cell system through the means of filtering molecules from protons and electrons significantly increases the possible output of the fuel cell and the use of nano-platinum catalysts to lower the activation energy of the fuel cell chemical reaction a notable amount resulting in a more efficient system and smaller entropy in comparison to the use of macro sized catalysts.

Device-Circuit Interaction and Performance Benchmarking of Tunnel Transistor-Based Ex-OR Gates for Energy Efficient Computing

2020 ◽  
Vol 29 (14) ◽  
pp. 2050235
Author(s):  
Sadulla Shaik
Keyword(s):  
Energy Efficient ◽  
Design Procedure ◽  
High Energy ◽  
Steep Slope ◽  
Efficient System ◽  
Minimum Power ◽  
Transmission Gate ◽  
Transition Speed ◽  
Half Adder ◽  
Tunnel Transistor

This paper explores the design and analysis of 20[Formula: see text]nm tunnel transistor-based Exclusive-OR (Ex-OR) gates and half-adder cells with circuit interaction (co-design) approach for energy efficient and reliable computing architectures at scaled supply voltages (50–300[Formula: see text]mV). TFETs have attracted much attention recently for energy efficient system designs. The circuit interaction is made possible for designing more consistent functional architectures at the minimum power supply of 50–300[Formula: see text]mV. Using this technique, the core computational blocks of basic adder blocks and Ex-OR gates are designed with TFET as a fundamental device and the whole design procedure is elaborated in this paper. The primary classifications of Tunnel FETs, viz. Homo-junction TFET (HoJn TFET) and Hetero-junction TFETs (HeJn TFET) are investigated thoroughly under different constraints specifically at the device configurations. By considering the above-mentioned subtypes of TFETs, three variants of Ex-OR primitive gates are modeled and are named with respect to the use of transistors as static complementary TFET-12T (SC12T), Transmission Gate logic-8T (TG8T) and Improved Transmission Gate logic-6T (ITG6T) Ex-OR gate designs. The benchmarking of the proposed gates is done using double-gate Si FinFET at 20[Formula: see text]nm technology. Amongst all the three proposed Ex-OR designs of SC12T, TG8T and ITG6T in addition to that of LVT and HVT FinFET/CMOS, only ITG6T is the designer’s choice by offering the minimum power consumption as well as high energy, improved choice compared to the other two styles of designs and also when robustness and reliability are taken into account, SC12T and TG8T designs are not providing the full swing of outputs. The minute glitch with that of ITG6T designs is a lesser reliability feature and for this the best alternative is TFET TG8T by providing suppressed over shoots and enhanced transition speed. From the performed multi simulations under different critical conditions and at supply voltage of 100[Formula: see text]mV, it is being demonstrated that the energy efficient circuit option is the SC12T and ITG6T Ex-OR designs which are validated with the steep slope characteristics of TFET’s and also these two designs offer reliability advantage. The major restrictions from the energy efficiency issues are eliminated and disclosed in the HoJn TFETs and HeJn TFET by using circuit co-design methodology and TFETs steep slope characteristics.

Chathamirhynchia kahuitara, a new genus and species of Late Cretaceous rhynchonellide brachiopod from the Chatham Islands, New Zealand: shell structure, palaeoecology and biogeography

2007 ◽  
Vol 98 (3-4) ◽  
pp. 357-367 ◽  
Author(s):  
Daphne E. Lee ◽  
Neda Motchurova-Dekova
Keyword(s):  
New Zealand ◽  
Shallow Water ◽  
Volcanic Rock ◽  
Late Cretaceous ◽  
Shell Structure ◽  
New Genus ◽  
High Energy ◽  
New Genus And Species ◽  
Cardinal Process ◽  
Energy Environment

ABSTRACTA new rhynchonellide brachiopod has been collected from the Kahuitara Tuff (Campanian–Maastrichtian) of Pitt Island, Chatham Islands, New Zealand. Brachiopods are extremely rare in Cretaceous rocks from New Zealand, and this new genus and species is unlike any other rhynchonellide known from Australasia or elsewhere. Chathamirhynchia kahuitara is distinguished by its small size, strong ribbing, and well-developed sulciplicate folding, and internally by a large, robust cardinal process and raduliform crura. The shell structure of C. kahuitara is shown to be of typical fine fibrous ‘rhynchonellidine’ type. This brachiopod was probably strongly attached to volcanic rock or shells in a shallow-water, high-energy environment. Implications for the biogeography of brachiopods during the Late Cretaceous are briefly discussed.

scholarly journals UV-effects on antioxidant activity of selected carotenoids in the presence of lecithin estimated by DPPH test

2008 ◽  
Vol 73 (11) ◽  
pp. 1051-1061 ◽  
Author(s):  
Dragan Cvetkovic ◽  
Dejan Markovic
Keyword(s):  
Antioxidant Activity ◽  
Ultraviolet Radiation ◽  
Energy Input ◽  
High Energy ◽  
Antioxidant Action ◽  
Dpph Radical ◽  
Dpph Test ◽  
Uv Photons

The effects of ultraviolet radiation (UV) on the antioxidant action of three selected carotenoids (?-carotene, lycopene and lutein) in the presence of a lipoidal lecithin mixture were studied by the DPPH (1,1-diphenyl-2-picrylhydrazyl) test. The test is based on the measurement of the decrease of the free DPPH radical absorbance at 517 nm caused by the antioxidant action of carotenoids, which appeared to be strongly affected by UV-action. The high-energy input of the involved UV-photons plays a major governing role.

Metal Atom Routes to Metal-Based Clusters in Polymers

1988 ◽  
Vol 131 ◽  
Author(s):  
Mark P. Andrews ◽  
Mary E. Galvin ◽  
Sharon A. Heffner
Keyword(s):  
Polymer Composites ◽  
Metal Atom ◽  
Chemical Reduction ◽  
Incident Light ◽  
High Energy ◽  
Plasmon Mode ◽  
Ambient Temperatures ◽  
Metal Vapors ◽  
Precursor Molecules

ABSTRACTPast syntheses of polymer composites have largely evolved from chemical reduction or thermal decomposition of organometallic or inorganic precursor molecules in polymers, or plasma and thermal co-deposition of metal vapors and carbonaceous free radicals. Our approach involves the site-specific capture of metal atoms deposited in vacuum to give isolated, high energy mononuclear organometallic centers within a polymer film. These centers can be converted at ambient or sub-ambient temperatures (ie, below the polymer glass transition temperature) to, for example, metal oxide microclusters.We describe the results of our studies of a prototypical system involving chromium atoms and their conversion to corundum-type oxide microclusters in arene-functionalized polymer films. Thus Cr was deposited into 150 K liquid tetrahydrofuran solutions of polystyrene or poly(styrene-isoprene-styrene) triblock, spun in vacuo as thin films on the surface of a rotating glass cryostat. Evidence from epr spectrscopy shows that the resulting polymer-anchored (inter/intra-chain) bis(arene)Cr sandwich complex is locally mobile in the macroscopically rigid film at room temperature. The Cr atom is discharged from the rings by subsequent reaction with oxygen diffused into the film. Although α Cr2 O3 is a classic twosublevel antiferromagnet that is not epr active above 308 K, we observe an intense signal even at 77 K in these films. Cr2O3 microclusters are indicated, and these are confirmed by in situ measurements of the oxidation and aggregation process.The metal atom methodology has also been used to synthesize silver microsphere/polymer composites. With quadratic electrooptic phase modulation, these composites were found to show a third order susceptibility enhanced by coupling the dipolar surface plasmon mode of the particles with incident light.

scholarly journals Thermoforming carbon fibre-reinforced thermoplastic composites

2012 ◽  
Vol 226 (2) ◽  
pp. 91-102 ◽  
Author(s):  
R McCool ◽  
A Murphy ◽  
R Wilson ◽  
Z Jiang ◽  
M Price ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Energy Input ◽  
High Energy ◽  
Thermoplastic Composites ◽  
Control Parameters ◽  
Fuel Burn ◽  
Fibre Composites ◽  
Carbon Fibre Composites ◽  
Optimal Window ◽  
Very High

The use of carbon fibre composites is growing in many sectors but their use remains stronger in very high value industries such as aerospace where the demands of the application more easily justify the high energy input needed and the corresponding costs incurred. This energy and cost input is returned through gains over the whole life of the product, with for example, longer maintenance intervals for an aircraft and lower fuel burn. Thermoplastic composites however have a different energy and cost profile compared to traditional thermosets with notable differences in recyclability, but this profile is not well quantified or documented. This study considers the key process control parameters and identifies an optimal window for processing, along with the effect this has on the final characteristics of the manufactured parts. Interactions between parameters and corresponding sensitivities are extracted from the results.

Sign in / Sign up

Export Citation Format

Share Document