Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “ambient temperature”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Enabling thermal energy storage in structural cementitious composites with a novel phase change material microcapsule featuring an inorganic shell and a bio-inspired silica coating

Phase change material (PCM) microcapsules offer a promising approach for integrating PCM into building materials for efficient thermal energy storage. Here, this study presents the development of a novel PCM microcapsule specifically designed for incorporation into cementitious materials. The microcapsule consists of a low-cost PCM core derived from vegetable oil by-products and a durable inorganic shell made from cenosphere, a hollow fly ash generated from coal burning power plants. A novel process is developed to apply a silica coating to these cenosphere-based PCM microcapsules (CPCM), resulting in bioinspired-silica-coated CPCM microcapsules (BCPCM). This coating process draws inspiration from marine microorganism-based silica production and utilizes low-cost sodium silicate as a precursor, enabling eco-friendly and cost-effective manufacturing at ambient temperature and mild pH conditions. The morphology, chemical stability, and thermal properties of the BCPCM along with its thermo-mechanical performance in cementitious composites were comprehensively analyzed. Experimental results demonstrate successful silica deposition on BCPCM, leading to enhanced latent heat properties of the produced BCPCM. With the silica coating, BCPCM exhibits a 50 °C delay in thermal decomposition compared to CPCM, enhancing fire resistance and preventing premature PCM leakage of the microcapsule. The bioinspired silica coating effectively restores over 10% of the strength loss for each percent increase in CPCM incorporated into the mortar. The thermal performance experiments reveal that increasing the BCPCM content reduces temperature peaks and rates of temperature increase, indicating an improved capacity for thermal energy storage. This new PCM microcapsule provides a cost-effective solution to integrate thermal energy storage to cementitious material, as evidenced that over 30% of aggregates (in volume) can be replaced by the microcapsule without a drastic loss of strength.

25 ENERGY STORAGE↗
DOE OSTI2021

Investigation of poly(phenylacetylene) derivatives for carbon precursor with high carbon yield and good solubility

This paper investigates a family of poly(phenylacetylene) derivatives with a p-electrons conjugated polymer backbone and side groups containing only sp 2 and sp carbons. The objective is to identify the suitable carbon precursor that is processible and can be transformed to carbonaceous material with high carbon yield by a simple (one-step) thermal transformation process (without any external reagent). Poly(phenylacetylene) with para-substituted acetylene group poly(PA-A) shows an exceptionally high C-yield (~90%) in one-step heating from ambient temperature to 1000 °C under N 2 atmosphere. Unfortunately, this poly(PA-A) polymer is quite sensitive to heat and light with very limited solubility. On the other hand, poly(phenylacetylene) with para-substituted phenylacetylene group, i.e. poly(PA-PA), offers a relatively high C-yield (~80%) and also good solubility in common organic solvents, such as toluene and tetrahydrofuran (THF). Several uniform dark-red poly(PA-PA) fibers with smooth surface and fiber diameter in the range of 3–6 μm were prepared from 30 wt% poly(PA-PA)/THF solution using electrospinning technique. Furthermore, the resulting precursor fibers were converted to the corresponding carbon structure in a one-step thermal heating process under N 2 atmosphere. Both X-ray and Raman spectra show the polymorphous carbon morphology with the graphene crystalline domains.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Pulsed laminar falling films in vertical tubes: Maintaining a continuous liquid film with reduced film thickness

Falling-liquid-film heat transfer is important to a wide variety of industrial applications, including two-phase thermosyphons, falling-film evaporators in the food industry, heat exchangers in fuel-ethanol processing, and the chemical service industry. Particularly for laminar falling films, the heat transfer increases as the film thickness decreases, hence it is desirable to keep the films as thin as possible. This article presents a periodically-pulsed flow concept to reduce the average mass flow inside a vertical tube. The technique provides thinner films than can be achieved with continuous flow. A drainage model is adopted to predict the film thickness as a function of flow rate and location along the tube. The concept is confirmed experimentally by measuring the film thickness in real time in a circular tube using a laser-based absorption technique. A new heat-transfer-based film continuity measurement is also integrated into the optical film measurement setup. Water at ambient temperature and pressure is used for this work. Film thickness reductions of up to 60%, and liquid-film volume-flow reductions of up to 80% compared to the minimum continuous-flow film have been obtained. The time-varying film thickness profile can also be controlled to a limited extent, which may be of interest for process industries.

42 ENGINEERING↗
DOE OSTI2024

Experimental evaluation of thermal-fluids performance of Helium-Cooled Flat Plate (HCFP) divertor

Various helium (He)-cooled solid-tungsten (W) divertor concepts have been proposed for long-pulse magnetic fusion energy reactors. Among these concepts, the He-cooled flat plate divertor (HCFP) modules have the largest plasma-facing surface area of ~0.2 m 2 . Simulations have shown that the most recent version of the design can withstand heat fluxes as great as 8 MW/m 2 . Earlier experimental studies of a single shortened HCFP cooling unit with a slot length of 7.6 cm used air at ambient temperature and pressures below 0.6 MPa. Here, we present initial experimental studies of a copper alloy and steel test section modeling a shortened HCFP cooling unit using He at prototypical pressure of 10 MPa, inlet temperatures T i ≤ 200 °C and steady-state incident heat fluxes q" ≤ 1.2 MW/m 2 . Results for Nusselt number Nu as a function of Reynolds number Re were obtained for Re = 1.2×10 4 –3.4×10 4 , and used to develop a Nu(Re) correlation and validate numerical models of the test section using commercial computational fluid dynamics (CFD) software. Simulations with this model are performed to evaluate the effect of the shortened slot. Furthermore, these analyses are used to estimate the thermal-fluids performance of the HCFP under prototypical conditions.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2024

Efficient data-driven models for prediction and optimization of geothermal power plant operations

Increasing the capacity of geothermal energy as a renewable resource calls for development and deployment of efficient control and optimization technologies for geothermal power plants. A data-driven prediction and optimization model is presented as a cost-effective and efficient alternative to physics-based approach. The model predicts power output and operational cost by propagating the influence of control and disturbance variables within an artificial neural network (ANN). Numerical experiments with simulated and field data from a real geothermal power plant are first used to demonstrate the prediction performance of the ANN model. The model is then adopted to maximize the net predicted power production by automatically adjusting the working fluid circulation rate. The optimization performance of the model in evaluated using a thermodynamic flowsheet simulation model. The workflow is applied to model and control the effect of ambient temperature on an air-cooled binary cycle power plant, which is complex and costly to perform using a physics-based predictive model. As a result, the performance of the method is demonstrated by applying it to both simulated and field datasets from a binary cycle geothermal power plant.

15 GEOTHERMAL ENERGY↗
DOE OSTI2024

The EGS Collab project: Outcomes and lessons learned from hydraulic fracture stimulations in crystalline rock at 1.25 and 1.5 km depth

With the goal of better understanding stimulation in crystalline rock for improving enhanced geothermal systems (EGS), the EGS Collab Project performed a series of stimulations and flow tests at 1.25 and 1.5 km depths. The tests were performed in two well-instrumented testbeds in the Sanford Underground Research Facility in Lead, South Dakota, United States. The testbed for Experiment 1 at 1.5 km depth contained two open wells for injection and production and six instrumented monitoring wells surrounding the targeted stimulation zone. Four multi-step stimulation tests targeting hydraulic fracturing and nearly year-long ambient temperature and chilled water flow tests were performed in Experiment 1. The testbed for Experiments 2 and 3 was at 1.25 km depth and contained five open wells in an outwardly fanning five-spot pattern and two fans of well-instrumented monitoring wells surrounding the targeted stimulation zone. Experiment 2 targeted shear stimulation, and Experiment 3 targeted low-flow, high-flow, and oscillating pressure stimulation strategies. Hydraulic fracturing was successful in Experiments 1 and 3 in generating a connected system wherein injected water could be collected. However, the resulting flow was distributed dynamically, and not entirely collected at the anticipated production well. Thermal breakthrough was not observed in the production well, but that could have been masked by the Joule-Thomson effect. Shear stimulation in Experiment 2 did not occur - despite attempting to pressurize the fractures most likely to shear - because of the inability to inject water into a mostly-healed fracture, and the low shear-to-normal stress ratio. The EGS Collab experiments are described to provide a background for lessons learned on topics including induced seismicity, the correlation between seismicity and permeability, distributed and dynamic flow systems, thermoelastic and pressure effects, shear stimulation, local geology, thermal breakthrough, monitoring stimulation, grouting boreholes, modeling, and system management.

15 - GEOTHERMAL ENERGY↗
DOE OSTI2022

Process design of the piperazine advanced stripper for a 460 MW NGCC

The Texas Carbon Management Program is conducting a Front-End Engineering Design (FEED) for Piperazine with the Advanced Stripper™ (PZAS™) at a natural gas combined cycle power plant in west Texas. Here, this paper presents the design of the advanced stripper system with an emphasis on the selection of packing type, packing height, column diameter, and heat exchanger size, demonstrates the effect of ambient temperature swing on the regeneration energy requirement, and investigates two alternate process configurations that provide better energy performance than PZAS™. The design uses 2 stripper trains, and each train uses two cold cross exchangers, one hot cross exchanger, a stripper column, a CO 2 exchanger, and a condenser. Each column consists of two sections of random packing with RSR 2 packing at the top and RSR 3 packing at the bottom, with a total packed height of 7.5 m. The cold exchanger was designed with an NTU of 6, the hot exchanger with an NTU of 2, and the CO 2 exchanger with an NTU of 5. At 0.4 rich loading and 0.2 lean loading, this design resulted in a heat duty of 2.85 GJ/tonne CO 2 . The heat duty can vary up to 3.1 GJ/tonne CO 2 due to lower rich loading at higher summer temperature, but the absolute steam requirement is 8–15% lower in the summer. An alternate design, PZAS with hot rich bypass, is proposed, which can reduce the equivalent work of stripping by 1.5–3.5% compared to PZAS at low heat exchanger size, due to a reduction in stripper driving force. Using a hot rich bypass increases the vapor fraction of the total rich bypass stream from 0.3 to 1 mol% compared to using the warm rich bypass, which also contributes to a reduction in lost work in the column. PZAS with hot rich bypass outperforms PZAS in energy requirement below a packing height of 15 m, but fails to do so above 15 m of packing due to a column pinch that results in little change in LMTD of the column. PZAS with hot rich bypass has the potential to minimize capital cost in addition to reducing energy requirement as it requires less packing to strip CO 2 than PZAS and requires only one cross exchanger with 8 heat transfer units.

03 NATURAL GAS↗
DOE OSTI2025

Beta-Amino Carboxylate (BAC) non-aqueous physical solvents for enhanced CO2 separations in pre-combustion carbon capture, industrial CO 2 capture, and biogas upgrading processes

Novel beta-amino carboxylate (BAC) solvents have been synthesized and tested to efficiently capture carbon dioxide (CO 2 ) from process gas streams with CO 2 partial pressure intermediate between pre-combustion and post-combustion capture. The BAC solvents have molecular structures characterized by alkyl-substituted amides or esters containing a secondary amine functional group on the second carbon from the carbonyl carbon (referred to as the beta “β” carbon). The ester or amide functional group combined with optimal steric crowding around the amine nitrogen by proximate alkyl groups are tailored to modify the strength of CO 2 binding in the solvent. The solvents possess high CO 2 solubilities and high gas selectivity including good CO 2 /H 2 O selectivity and can be utilized for CO 2 absorption over a range of partial pressures. Due to low volatility, many of the solvents can be operated at or above ambient temperature which eliminates solvent chilling and allows regeneration using low grade waste heat. These novel solvents offer an opportunity for efficient carbon capture for a range of applications including biogas upgrading, hydrogen production, and pre-combustion carbon capture.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Isotope exchange of ND 3 on Pt catalyst-loaded 13X molecular sieve

During D-T fusion operations the capture, purification, and recycling of unburned tritium will be crucial, as the formation of tritium containing molecules require additional processing. Here, removing the tritium can require costly processing to be unbound from the tritium-containing molecules and improvements to these processes will be necessary moving forward. Existing techniques using sorbent material beds to remove tritium-containing molecules from process gas streams undergo repeated high-heat cycling which leads to diminished bed lifespans, necessitating replacement and associated downtime. This work demonstrates the capture and isotopic exchange technique of deuterated ammonia (ND3), used as a surrogate for tritium, at ambient temperature using a Pt catalyst-loaded 13X molecular sieve. Unmodified 13X molecular sieve is capable of adsorbing and retaining the ND3 however, incorporation of a catalyst facilitates the isotopic exchange of the hydrogen isotopes. The effluent gas streams were analyzed in conjunction with desorbed ammonia isotopologues post-exchange to verify these results. Isotopically exchanging and removing heavier hydrogen isotopes using this technique provides an alternative to traditional removal methods.

08 HYDROGEN↗
DOE OSTI2020

Synthesis of bulk reactive Ni–Al composites using high pressure torsion

Self-propagating exothermic reactions, for instance in the nickel-aluminum (Ni-Al) system, have been widely studied to create high performance intermetallic compounds or for in-situ welding. Their easy ignition once the phase spacing is reduced below the micron scale, makes top-down methods like high-energy ball milling, ideal to fabricate such reactive nanostructures. A major drawback of ball milling is the need of a sintering step to form bulk pieces of the reactive material. However, this is not possible, as the targeted reactions would already proceed. Therefore, we investigate the ability of high pressure torsion as an alternative process, capable to produce bulk nanocomposites from powder mixtures. Severe straining of powder mixtures with a composition of 50 wt% Ni and 50 wt% Al enables fabrication of self-reactive bulk samples with microstructures similar to those obtained from ball milling or magnetron sputtering. Additionally, samples deformed at ambient temperature are highly reactive and can be ignited significantly below the Al melting point, finally predominantly consisting of Al 3 Ni 2 and Al 3 Ni, independent of the applied strain. Although the reaction proceeds first at the edge of the disk, the strain gradient present in the disks does not prevent reaction of the whole sample.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Designing sequence-defined peptoids for fibrillar self-assembly and silicification

In the biological environment, mineral crystals exquisitely controlled by biomacromolecules often show intricate hierarchical structures and superior mechanical properties. Among these biominerals, spicules, hybrid silica/protein superstructures serving as skeletal elements in demosponges, represent an excellent example for motivating the synthesis of silica materials. Herein, by designing sequence-defined peptoids containing side chains with a strong binding to silica, we demonstrated that self-assembly of these peptoids into fiber structures enables the mimicking of both biocatalytic and templating functions of silicatein filaments for the formation of silica fibers at near-neutral pH and ambient temperature. We further showed that the presence of amino groups is significant for the nucleation of silica on self-assembled peptoid nanofibers. Molecular dynamics simulation further confirmed that having silica-binding of amino side chains is critical for self-assembled peptoid fibers in triggering silica formation. Here, we demonstrated that tuning inter-peptoid interactions by varying carboxyl and amino side chains significantly influences the assembly kinetics and final morphologies of peptoid assemblies as scaffolds for directing silica mineralization to form silica spheres, fibers, and sheets. The formation of silica shell on peptoid fibers increased the mechanical property of peptoid hydrogel materials by nearly 1000-fold, highlighting the great potential of using silicification to enhance the mechanical property of hydrogel materials for applications including tissue engineering. Since peptoids are highly robust and programmable, we expect that self-assembly of peptoids containing solid-binding side chains into hierarchical materials opens new opportunities in the design and synthesis of highly tunable scaffolds that direct the formation of composite nanomaterials.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Efficient SF 6 /N 2 separation at high pressures using a zirconium-based mesoporous metal–organic framework

Adsorptive separation of SF 6 /N 2 mixtures is an important issue since SF 6 is a significant greenhouse gas. Although separation performances should be evaluated under high pressure conditions to find an efficient adsorbent candidate for pressure swing adsorption (PSA) processes, no studies on metal–organic frameworks (MOFs) have focused on SF 6 /N 2 separation at high pressures above 1 bar. In this study, we evaluated the potential of three hydrothermally stable adsorbents, including two MOFs (UiO-66 and UiO-67) and zeolite-13X, for SF 6 /N 2 separation under normal PSA operation pressures (~10 bar). Interestingly, UiO-67 with a high surface area and large pore size exhibited very high SF6/N2 selectivity (30~37) at 10 bar as well as a significantly large SF6 working capacity (5.94 mmol g-1) between 10 bar and 1 bar. Moreover, UiO-67 showed facile regeneration at the ambient temperature as well as good cyclic adsorption and desorption behavior during 20 cycles. These results show that UiO-67 is a potential adsorbent for adsorptive SF 6 /N 2 separation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

High-pressure Cr 3+ luminescence and Raman spectroscopy of a natural MgAl 2 O 4 spinel to ∼60 GPa

Cr 3+ luminescence and Raman spectroscopy of a natural spinel were collected up to ∼60 GPa at ambient temperature using a Ne or a 4:1 methanol-ethanol mixture as the pressure transmitting media. Here, in the Ne experiments above ∼40 GPa, and in the 4:1 methanol–ethanol experiments above ∼20 GPa, all luminescence emission lines shift non-linearly, and by 59 GPa the spectra are broadened and are significantly changed. The Raman modes shift smoothly to higher frequencies with pressure, with a slight change in slope above 40 GPa, with no kinks or discontinuities. By ∼60 GPa, only the most intense Eg mode remains resolvable, appearing broadened and reduced in intensity. The change in slope in the Raman modes and luminescence bands may be due to a change in the compression mechanism of spinel. When spinel was decompressed from 40 GPa all changes were fully reversible; however, when the samples were decompressed from 54 to 60 GPa in Ne and 59 GPa in 4:1 methanol-ethanol the spectra were irreversibly changed. The change in the luminescence spectra and the Raman spectra are likely due to a pressure induced disorder of the anions or partial amorphization between 40 and 60 GPa.

Cr3+↗
DOE OSTI2021

Molecular Iodine Interactions with Metal Substrates: Towards the Understanding of Iodine Interactions in the Environment Following a Nuclear Accident

In order to evaluate the potential impacts to the public from radioiodine in a nuclear event, it is vital to expand our understanding of the interaction of molecular iodine with various surfaces. There are many potential surfaces that iodine could interact with in and around a nuclear facility, including stainless steel. This study, carried out at ambient temperature, pressure and humidity, demonstrates the highly adsorptive nature of molecular iodine on two types of austenitic stainless steel, 304L and 316L. In the authors review of available literature, Fe is the only metal in stainless steel that is assumed to react with gas-phase molecular iodine. By using a novel approach which combines Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) with surface Energy Dispersive X-ray Spectroscopy (EDS) there is evidence of the formation of metal iodides that have not previously been verified or quantified. Samples exposed to gaseous molecular iodine formed an iodine containing corrosion product visible by scanning electron microcopy (SEM). Evaluation of the metals in the corrosion region using EDS was compared to a water leach of the same samples analyzed using ICP-OES. A comparison of the results provide evidence that the water leachate is representative of the corrosion layer and not the base material. Furthermore, it provides confirmation of metal iodide formation with minor stainless-steel constituents including: FeI2, NiI2, MnI2 and CrI2.

Beck, Chelsie L.↗
DOE OSTI2023

Phase transformations and thermal expansion coefficients of unirradiated U-X wt.% Zr (X = 6, 10, 20, 30) measured via neutron diffraction

This work characterizes the crystallographic evolution of unirradiated U-X wt.% Zr (X = 6, 10, 20, 30) while cooling from equilibration, single phase γ-U-Zr, at 900 °C to ambient temperature using time-of-flight neutron diffraction. The β-U phase was unobserved during cooling at 1 °C/min in all alloys. All alloys followed the phase transformation pathway of γ-U-Zr→γ-U-Zr+α-U→α-U +δ-UZr2 with an observed miscibility gap in γ-U-Zr. The α-U and δ-UZr2 transformation took place simultaneously in the U-30 wt.% Zr sample. These findings strengthen the need to re-approach the U-Zr phase diagram in entirety. Bulk volumetric CTEs agree well with published data, strengthening the quantification of lattice-specific CTEs reported in this study. A compositionally dependent discontinuity in thermal expansion, increasing in magnitude with decreasing U content, occurs during the γ-U-Zr→α-U+δ-UZr2 transformation. The γ-U-Zr lattice parameter was measured to have a compositional dependency.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Model predictive control of heating, ventilation, and air conditioning (HVAC) systems: A state-of-the-art review

Due to the fast advancement of communication and information technology, intelligent buildings have garnered great interest. These buildings can forecast weather, ambient temperature, and sun irradiation and can modify heating, ventilation, and air conditioning (HVAC) operations appropriately, based on current and previous data. This change is intended to reduce HVAC system energy usage while maintaining an appropriate degree of thermal comfort and indoor air quality. Since its inception, model predictive control (MPC) has been one of the prospective solutions for HVAC management systems to reduce both costs and energy usage. Additionally, MPC is becoming increasingly practical as the processing capacity of building automation systems increases and a large quantity of monitored building data becomes available. MPC also provides the potential to improve the energy efficiency of HVAC systems via its capacity to consider limitations, to predict disruptions, and to factor in multiple competing goals such as interior thermal comfort and building energy consumption. Although substantial research has been conducted on MPC in building HVAC systems, there is a shortage of critical reviews and a lack of a comprehensive framework that formulates and defines the applications. Here, this article provides a comprehensive state-of-the-art overview of MPC in HVAC systems. Detailed discussions of modeling approaches and optimization algorithms are included. Numerous design aspects such as prediction horizon, occupancy behavior, building type, and cost function, that impact MPC performance are discussed in detail. The technical characteristics, advantages, and disadvantages of various types of modeling software are discussed. The primary objective of this work is to highlight critical design characteristics for the MPC control scheme and to give improved suggestions for future research. Moreover, numerous prospective scenarios have been suggested that might provide future research direction.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

Comparative performance assessment of air-source and ground-source heat pumps using CO₂ and R-410A with water well integration: A simulation study

This study investigates the performance and feasibility of heat pump systems for residential space heating in cold climates, with a particular focus on ground source heat pumps (GSHPs) with water wells. Four configurations are modeled and compared, a CO 2 air-source heat pump (ASHP), an R-410A ASHP, a CO 2 GSHP with water well integration, and an R-410A ground-source heat pump with water well integration. System simulations are conducted at both equipment and whole-building levels, followed by a nationwide analysis across ten representative cities using EnergyPlus. Results show that water-well-coupled GSHPs maintain approximately 87 % of their efficiency and 85.5 % of heating capacity as ambient temperature drops from 47 °F/8.3 °C to −15 °F/-26.1 °C, whereas ASHPs retain only 55 % efficiency and 44.5 % capacity. R-410A systems achieve higher efficiency, while CO 2 systems provide significant environmental advantages, including reduced risks of groundwater contamination from refrigerant leakage. On average, the CO 2 GSHPs deliver 35–45 % heating energy savings relative to ASHPs and demonstrate strong potential as a replacement for gas furnaces in cold climates. This work represents a systematic comparative assessment of CO 2 and R-410A air-source and ground-source heat pumps with water well integration. In conclusion, the findings highlight the technical viability, environmental benefits and deployment potential of CO 2 GSHPs, offering a pathway toward efficient and sustainable residential heating solutions in diverse U.S. climates.

CO 2 GSHP↗
DOE OSTI2025

Ethyl transfer reactions of NaBEt 4 with Cp*Rh(PMe 3 )PhBr and elimination reactions

The reaction of NaBEt 4 with Cp*Rh(PMe 3 )PhBr produces Cp*Rh(PMe 3 )PhEt by ethyl transfer. Single crystal X-ray analysis shows a typical piano-stool geometry. This compound reacts photochemically (λ > 320 nm) to give Cp*Rh(PMe 3 )PhH as the major product, plus ethylene. A secondary product was assigned as the square planar complex RhPh(PMe 3 )(η 4 -C 5 Me 5 Et) on the basis of NMR spectroscopy. Finally, the molecule decomposes over several days at ambient temperature, releasing C 5 Me 5 Et.

02 PETROLEUM↗