Primary Forms Of Energy Research Articles

From petroleum to power sources: Big Oil and the technopolitics of energy conversion

ABSTRACT This paper explores spillover into advanced energy conversion technologies as an oil industry response to US energy and environmental policies from the last third of the twentieth century. These policies initiated the ‘quasi-planned’ renovation of energy infrastructure through an uncoordinated mixture of regulation and innovation/industrial stimulus intended to develop all forms of primary energy and the technologies that could efficiently and cleanly convert that energy. Influenced by this sweeping public policy objective as well as the global consumer electronic industry’s increasing demand for petroleum-derived inputs from the late 1970s, Western oil interests doing business in the US engaged the technoscience of advanced energy conversion. Big Oil researched, developed, and in some cases manufactured materials and components associated with power sources including fuel cells, galvanic batteries, and photovoltaic arrays in projects that illustrate the affinities and antagonisms between enterprises of naturally stored primary energy, energy conversion, and flows and carriers of energy. Case studies of Big Oil’s involvement with these technologies illustrate how public policies supporting all-of-the-above energy and energy conversion limited the extent of oil spillover into advanced energy conversion systems and complicated the transition to a fossil fuel-free future.

Experimental Study of a Homogeneous Charge Compression Ignition Engine Using Hydrogen at High-Altitude Conditions

One of the key factors of the current energy transition is the use of hydrogen (H2) as fuel in energy transformation technologies. This fuel has the advantage of being produced from the most primary forms of energy and has the potential to reduce carbon dioxide (CO2) emissions. In recent years, hydrogen or hydrogen-rich mixtures in internal combustion engines (ICEs) have gained popularity, with numerous reports documenting their use in spark ignition (SI) and compression ignition (CI) engines. Homogeneous charge compression ignition (HCCI) engines have the potential for substantial reductions in nitrogen oxides (NOx) and particulate matter (PM) emissions, and the use of hydrogen along with this kind of combustion could substantially reduce CO2 emissions. However, there have been few reports using hydrogen in HCCI engines, with most studies limited to evaluating technical feasibility, combustion characteristics, engine performance, and emissions in laboratory settings at sea level. This paper presents a study of HCCI combustion using hydrogen in a stationary air-cooled Lombardini 25 LD 425-2 modified diesel engine located at 1495 m above sea level. An experimental phase was conducted to determine the intake temperature requirements and equivalence ratios for stable HCCI combustion. These results were compared with previous research carried out at sea level. To the best knowledge of the authors, this is the first report on the combustion and operational limits for an HCCI engine fueled with hydrogen under the mentioned specific conditions. Equivalence ratios between 0.21 and 0.28 and intake temperatures between 188 °C and 235 °C effectively achieved the HCCI combustion. These temperature values were, on average, 100 °C higher than those reported in previous studies. The maximum value for the indicated mean effective pressure (IMEPn) was 1.75 bar, and the maximum thermal efficiency (ITEn) was 34.5%. The achieved results are important for the design and implementation of HCCI engines running solely on hydrogen in developing countries located at high altitudes above sea level.

Piezoelectricity, Pyroelectricity, and Ferroelectricity in Biomaterials and Biomedical Applications.

Piezoelectric, pyroelectric, and ferroelectric materials are considered unique biomedical materials due to their dielectric crystals and asymmetric centers that allow them to directly convert various primary forms of energy in the environment, such as sunlight, mechanical energy, and thermal energy, into secondary energy, such as electricity and chemical energy. These materials possess exceptional energy conversion ability and excellent catalytic properties, which have led to their widespread usage within biomedical fields. Numerous biomedical applications have demonstrated great potential with these materials, including disease treatment, biosensors, and tissue engineering. For example, piezoelectric materials are used to stimulate cell growth in bone regeneration, while pyroelectric materials are applied in skin cancer detection and imaging. Ferroelectric materials have even found use in neural implants that record and stimulate electrical activity in the brain. This paper reviews the relationship between ferroelectric, piezoelectric, and pyroelectric effects and the fundamental principles of different catalytic reactions. It also highlights the preparation methods of these three materials and the significant progress made in their biomedical applications. The review concludes by presenting key challenges and future prospects for efficient catalysts based on piezoelectric, pyroelectric, and ferroelectric nanomaterials for biomedical applications.

The fundamentals and applications of piezoelectric materials for tumor therapy: recent advances and outlook.

Malignant tumors are one of the main diseases leading to death, and the vigorous development of nanotechnology has opened up new frontiers for antitumor therapy. Currently, researchers are focused on solving the biomedical challenges associated with traditional anti-tumor medical methods, promoting the research and development of nano-drug carriers and new nano-drugs, which brings great hope for improving the curative effect and reducing toxic and side effects. Among the new systems being investigated, piezoelectric nano biomaterials, including ferroelectrics, piezoelectric and pyroelectric materials, have recently received extensive attention for antitumor applications. By coupling force, light, magnetism or heat and electricity, polarized charges are generated in these materials microscopically, forming a piezo-potential and establishing a built-in electric field. Polarized charges can directly act on the materials in the tumor micro-environment and also assist in the separation of carriers and inhibit recombination based on piezoelectric theory and piezoelectric optoelectronic theory. Based on this, piezoelectric materials convert various forms of primary energy (such as light energy, mechanical energy, thermal energy and magnetic energy) from the surrounding environment into secondary energy (such as electrical energy and chemical energy). Herein, we review the basic theory and principles of piezoelectric materials, pyroelectric materials and ferroelectric materials as nanomedicine. Then, we summarize the types of piezoelectric materials reported to date and their wide applications in treatment, imaging, device construction and probe detection in various tumor treatment fields. Based on this, we discuss the relevant characteristics and post-processing strategies of nano piezoelectric biomaterials to obtain the maximum piezoelectric response. Finally, we present the key challenges and future prospects for the development of ferroelectric, piezoelectric and pyroelectric nanomaterial-based nanoagents for efficient energy harvesting and conversion for desirable therapeutic outcomes.

AOP Report: Uncoupling of Oxidative Phosphorylation Leading to Growth Inhibition via Decreased Cell Proliferation.

This report describes a novel adverse outcome pathway (AOP) on uncoupling of oxidative phosphorylation (OXPHOS) leading to growth inhibition via decreased adenosine triphosphate (ATP) pool and cell proliferation (AOPWiki, AOP263). Oxidative phosphorylation is a major metabolic process that produces the primary form of energy (ATP) supporting various biological functions. Uncoupling of OXPHOS is a widely recognized mode of action of many chemicals and is known to affect growth via different biological processes. Capturing these events in an AOP can greatly facilitate mechanistic understanding and hazard assessment of OXPHOS uncouplers and growth regulators in eukaryotes. The four proposed key events in this AOP are intentionally generalized to cover a wide range of organisms and stressors. Three out of four events can be measured using in vitro high-throughput bioassays, whereas for most organisms, growth inhibition can also be measured in a high-throughput format using standard in vivo toxicity test protocols. The key events and key event relationships in this AOP are further assessed for weight of evidence using evolved Bradford-Hill considerations. The overall confidence levels range from moderate to high with only a few uncertainties and inconsistencies. The chemical applicability domain of the AOP mainly contains protonophores uncouplers, which can be predicated using the quantitative structure-activity relationship (QSAR) approach and validated using in vitro high-throughput bioassays. The biological domain of the AOP basically covers all eukaryotes. The AOP described in this report is part of a larger AOP network linking uncoupling of OXPHOS to growth inhibition, and is considered highly relevant and applicable to both human health and ecological risk assessments.

Impact of short-term light variability on the photobiology of turbid water corals

Benthic light availability is readily affected by natural drivers of an ecosystem and by anthropogenic-induced stressors. Rapid urbanization in coastal regions can induce light variability for reef-building corals that use photosynthesis as a primary form of energy. However, very little data exists on the photosynthesis of light-limited coral species and their acclimation responses to an additional light variability. This experimental study explored the effects of two contrasting light intensities: high light (HL) (95% increase to in situ light) and low light (LL) (8–10% of in situ light) on three locally dominant coral species. Turbinaria mesenterina, Porites lutea, and Goniopora cellulosa were collected from a 4-m depth from the turbid regions of Pulau Kendi in Northern Peninsular Malaysia. This study documented current photobiological responses of all species and rapid photoacclimation responses only for T. mesenterina in HL treatment. All three species incurred photoinactivation under LL stress; however, T. mesenterina was photosynthetically healthier for an extended period of the experiment. P.lutea recorded partial photoacclimation and non-recovering photoprotectants to both light stresses. While G. cellulosa incurred rapid declines in photosynthetic yields along with no photoacclimation responses. The data obtained for this geographic range of turbid water corals is important as additional light stress from point-source pollutants and global urbanization activities are expected to increase. Improving our understanding of their responses to environmental change will be central to global coral reef conservation efforts andcan be used for effective management practices in targeted coral conservation and rehabilitation approaches for turbid habitats.

Lipocalin 2 Deficiency Diminishes the Metabolic Effect of Ketogenic Diet in Female Mice

Obesity is a worldwide public health concern, and prevalence in the United States is continuously increasing. Treatment of obesity ranges from dietary approaches to gastric surgery; there is no one-size-fits-all approach. In recent years, the ketogenic diet (KD) has become a popular approach for weight loss and metabolic health promotion. The main mechanism of weight loss caused by this diet is to promote the body to use fat as its primary form of energy by drastically reducing carbohydrate intake. Understanding the molecular mechanisms that contribute to the metabolic effect of the KD is critical for determining the appropriateness of this dietary approach. At the cellular and molecular level, the KD has been known to activate mitochondrial function and thermogenesis in thermogenic adipose tissue to stimulate fat utilization. However, specific molecules and genes that are involved in this metabolic regulation remain largely unknown. Lipocalin-2 (LCN2) has been characterized as an adipokine by our group and others. In our previous studies, LCN2 has been suggested as a critical regulator of mitochondrial function and thermogenesis in energy metabolism. LCN2 knockout (KO) mice exhibit impaired thermogenesis as well as exacerbated diet-induced obesity and adipose tissue inflammation. It is of interest to know if LCN2 plays a role in KD-induced energy metabolism. In this study, wild type (WT) and LCN2 KO female mice at 10 months of age were fed either a ketogenic diet or regular chow diet (RCD) for 10 weeks, followed by metabolic assessments including food intake, body weight, fat mass, and histology of tissues. Our results showed that there was no significant difference in daily food intake between WT and LCN2 KO mice under either the RCD or KD. However, we did find thatafter 10 weeks of KD, WT mice had significant loss of body weight by ~15% as well as significantly decreased inguinal and gonadal fat mass when compared with control mice fed a RCD. Interestingly, this effect on body weight and fat mass was not observed in LCN2 KO mice; the body weight and inguinal and gonadal fat depots were not significantly different between RCD- and KD-fed LCN2 KO mice. From the histology of the liver and adipose tissue, the KD led to significantly increased small adipocytes in the inguinal adipose tissue of WT mice, suggesting a healthy remodeling of this tissue. Intriguingly, this remodeling effect was completely absent in LCN2 KO mice. Moreover, we found that in WT mice the KD caused increased lipid accumulation in the liver compared to RCD. This reflects increased utilization of fatty acids and production of ketones. More strikingly, the KD resulted in liver lipid accumulation more profoundly in LCN2 KO mice, which may be due to mitochondrial dysfunction and defective fatty acid oxidation in the absence of LCN2. Together, we demonstrate that LCN2 deficiency diminishes the metabolic effect of the KD. This suggests that the role of LCN2 in regulating mitochondrial metabolism, thermogenesis, and other unknown physiological activities may be an important mechanism by which the KD leads to weight loss and improved metabolic health.

Prediction of remaining useful life for lithium-ion battery with multiple health indicators

Lithium-ion (Li-ion) battery has become a primary energy form for a variety of engineering equipments. To ensure the equipments’ reliability, it is crucial to accurately predict Liion battery’s remaining capacity as well as its remaining useful life (RUL). In this study, we propose a novel method for Li-ion battery’s online RUL prediction, which is based on multiple health indicators (HIs) and can be derived from the battery’s historical operation data. Firstly, four types of indirect HIs are built according to the battery’s operation current, voltage and temperature data respectively. On this basis, a generalized regression neural network (GRNN) is presented to estimate the battery’s remaining capacity, and the nonlinear autoregressive approach (NAR) is applied to predict the battery’s RUL based on the estimated capacity value. Furthermore, to reduce the interference, twice wavelet denoising are performed with different thresholds. A case study is conducted with a NASA battery dataset to demonstrate the effectiveness of the method. The result shows that the proposed method can obtain Li-ion batteries’ RUL effectively.

Economic and financial appraisal of novel large-scale energy storage technologies

Energy storage can store surplus electricity generation and provide power system flexibility. A Generation Integrated Energy Storage system (GIES) is a class of energy storage that stores energy at some point along with the transformation between the primary energy form and electricity. The investigation of the economic and financial merits of novel energy storage systems and GIES is relevant as these technologies are in their infancy, and there are multiple technological, economic, and financial uncertainties and opportunities. This paper presents and applies a state-of-the-art model to compare the economics and financial merits for GIES (with pumped-heat energy storage) and non-GIES (with a Lithium-ion battery) systems coupled with wind generation in the United Kingdom. The deterministic, risk, and sensitivity analyses show that, for GIES’s economics, the key driver is the generator capital cost; for non-GIES, the energy storage capital cost is the most important factor. A Monte Carlo analysis shows that the levelized cost of electricity values for GIES and non-GIES are 0.05 £/kWh - 0.12 £/kWh and 0.07 £/kWh - 0.11 £/kWh, respectively, for a 100 MW wind power generator and 100 MWh energy storage. The internal rate of return values for GIES and non-GIES are uncertain and range between 2%-22% and 5%–14%, respectively.

Recent Advances of Ferro-, Piezo-, and Pyroelectric Nanomaterials for Catalytic Applications

Ferro-, piezo-, and pyroelectric materials are emerging as potential candidates for converting various forms of primary energy from the ambient environment (e.g., sunlight, mechanical, and thermal energy) into secondary energy (e.g., chemical energy). Despite the relatively short investigation time, much progress has been made related to this field. This review covers the fundamental principles of coupling ferro-, piezo-, and pyroelectric effects with different catalytic reactions; the crucial role of a polarization-induced internal electric field in charge separation and transport in these materials is discussed. We particularly focus on recent notable examples of using these three types of nanostructured materials for a variety of catalytic applications in the fields of renewable energy production (e.g., water splitting and CO2 reduction), environmental remediation (e.g., organic pollutant decontamination), and materials synthesis (e.g., selective growth/deposition and organic synthesis). Finally, we conclude this review by proposing critical challenges and future perspectives for developing ferro-, piezo-, and pyroelectric nanomaterial-based catalysts for efficient energy harvesting.

LNG at a Crossroads

For an industry that is just over 50 years old, liquefied natural gas (LNG) has matured rapidly and is playing an ever-growing role in the global energy system. From the start of international trade in the 1960s, demand reached 50 MTPA in 1990, then 100 MTPA in 2000, and 240 MTPA in 2012, according to the Center for Liquefied Natural Gas (CLNG). LNG has become the world’s fastest-growing gas supply source and is now part of an upheaval in the global energy market. Trade has quadrupled over the past two decades and is set to double over the next two. Consumption and share growth have set new records for three consecutive years. New markets for both demand and supply are developing rapidly. Liquefaction facilities and vessel fleets are expanding. Innovative and collaborative trade models are emerging. And, new technologies are being pursued to enhance LNG’s flexibility and competitiveness with other primary energy forms (Fig. 1). LNG is not without risks. These range from project economics, fuel competition, and politics on a local, national, and global scale to partner priorities, marketing, and contractual arrangements. Given the growing world population, the rising demand for more energy, and the need to mitigate climate change, the consensus is that the long-term outlook is bullish. But, says industry technical advisor DNV GL, the sector stands at a crossroads, and the industry must adopt new thinking to address current and future needs of buyers, sellers, and consumers both globally and regionally. What’s Behind the Growth? Three primary factors are behind the current wave of growth in LNG, according to the Shell 2019 LNG Outlook: the energy challenge, new countries choosing LNG for various reasons, and supply and demand. The world’s current population of 7.6 billion people is expected to reach 8.6 billion in 2030, 9.7 billion in 2050, and 11.2 billion in 2100, according to United Nations estimates. Of today’s population, nearly one person in three either has no electricity or struggles with unreliable supplies. As the population grows and more people seek to improve their quality of life, Shell projects that, by 2070, the world is likely to use at least 50% more energy than it does today. Natural gas has an advantage over other energy sources to meet current and future energy challenges because it is abundant, relatively clean, and cost-effective to produce. For these reasons and the role it can play in lowering carbon dioxide emissions, it is being touted as a bridge fuel to renewables as well as a foundational source of energy.

China’s roadmap to low-carbon electricity and water: Disentangling greenhouse gas (GHG) emissions from electricity-water nexus via renewable wind and solar power generation, and carbon capture and storage

Electricity and water form an intricate nexus, in that water is crucial for power generation, and electricity (or other primary forms of energy) is the key enabler for water purification and waste-water treatment. Nonetheless, both energy conversion and water purification result in substantial amounts of greenhouse gas (GHG) emissions. These negative interactions with potential “snowball” effect, can be decoupled via the deployment of renewable power generation, and carbon capture from fossil-fuelled technologies. However, such retrofits pose new challenges as wind and solar energy exhibit intermittent generation patterns. In addition, integrating thermal power plants with carbon capture and storage (CCS) imposes energy penalties and increases water requirements. In the present research, an optimization framework is developed which enables systematic decision-making for the retrofit of existing power and water infrastructure as well as investment in renewable and green technologies. A key aspect of the applied framework is the simultaneous optimization of design and operational decisions in the presence of uncertainties in the water demand, electricity demand, as well as wind and solar power availability. The proposed methodology is demonstrated for the case of the water-electricity nexus in China, and provides in-depth insights into regional characteristics of low carbon electricity generation, and their implications for water purification and wastewater treatment, demonstrating a roadmap towards sustainable energy and electricity.

On generation-integrated energy storage

Generation-integrated energy storage (GIES) systems store energy at some point along the transformation between the primary energy form and electricity. Instances exist already in natural hydro power, biomass generation, wave power, and concentrated solar power. GIES systems have been proposed for wind, nuclear power and they arise naturally in photocatalysis systems that are in development. GIES systems can compare very favourably in both performance and total cost against equivalent non-integrated systems comprising both generation and storage. Despite this, they have not hitherto been recognised as a discrete class of systems. Consequently policy decisions affecting development or demonstration projects and policy approaches concerning low-carbon generation are not fully informed. This paper highlights that policy structures exist militating against the development and introduction of GIES systems-probably to the detriment of overall system good.

Assessing the Impact of Embodied Water in Manufacturing Systems

In recent years the issue of improving energy and water efficiency in manufacturing systems has received increased attention. Rising energy prices, scarcity of quality water and imposed environmental regulations have been the main contributors to this issue. Water is consumed not only for raw material and products, but also for primary forms of energy, such as electricity. Therefore, it is important to measure energy and water consumption and to obtain insight into their usage patterns in manufacturing systems. In particular, such measurements can help to identify hotspots and inefficient processes. So far, a number of approaches have been developed to assess the environmental footprint of water and energy consumption, but few studies have been carried out to establish approaches to quantify their consumption, especially for water.This paper introduces a simulation-based approach that can be implemented to model energy and water flows in manufacturing systems. The approach contains a generic state-based model for a single machine and follows a bottom-up approach to construct the model of the whole system. This approach provides a reliable base for simulating operating conditions and evaluating different what-if scenarios in order to improve system performance. Then, one of the most appropriate methods for water footprint assessment in manufacturing industry is chosen, and a manufacturing site of a pharmaceutical company, as a case is studied to show how the proposed model can be applied.

More caution is needed when using life cycle assessment to determine energy return on investment (EROI)

Cumulative energy demand (CED) estimates from life cycle assessments (LCAs) are increasingly used to determine energy return on investment (EROI), but the difference in indicators can lead to a misclassification of energy flows in the assessment. The core idea of EROI is to measure the relation of energy diverted from society to make energy available to society. CED, on the other hand, includes forms of energy that are not appropriated by society, such as fugitive methane emissions from oil wells as well as losses of heating value of coal during transport and storage. Such energy forms should be excluded from EROI; failure to do so leads to results that are inconsistent with the intention of EROI and potentially misleading. We demonstrate how this problem is at least partially rectifiable by adopting consistent energy accounting, but also note that among the energy flows not appropriated by society occurring in CED, not all flows can easily be removed. Further, we point to inconsistencies in heating value assumptions in a widely used database that have misled analysts. Finally, we argue that the differential weighting of primary energy forms in published CED-based EROI work is unsubstantiated and should be reconsidered.

Electricity and the environment

Energy and electricity services are closely related to the quality of life. Energy and electricity are essential for meeting the basic human needs for food, water, health and shelter. They offer higher levels of prosperity through comfort, mobility and provision of goods and services. However, electricity is a derived good and the conversion of primary energy forms into electricity impacts the environment and requires the mobilization of several important resources such as financing. The issues of increasing electricity demands, environmentally friendly technologies, environmental impacts and risks from electricity chains, and the decision–making dimension in electricity planning were discussed intensively at the Senior Expert Symposium on Electricity and the Environment held in Helsinki in May 1991. This article summarizes the findings of the joint activities of eleven international organizations based on the work of a number of experts and the recommendations as they emerged from the symposium.

A Robust Optimization Approach for the Interdependency Analysis of Integrated Energy Systems Considering Wind Power Uncertainty

As power generation plants which use wind energy are increasingly integrated into existing electric power systems, it becomes important to evaluate how the wind power uncertainties affect the power system's operation as well as its interdependency with those infrastructures utilized to transport the various forms of primary energy that is converted into electric energy. This paper proposes a robust optimization model for analyzing the interdependency between natural gas, coal and electricity infrastructures considering their operation constraints and wind power uncertainties. The optimization model obtains an uncertainty-immunized solution in a unified framework based on the balance of nodal energy flows, which remains feasible and nearly optimal for all values of uncertain data. Case studies are presented to verify the effectiveness of the proposed solution for a multi-energy system composed by the IEEE-118 test system coupled to a 15-nodes natural gas network and a 4-nodes coal distribution system as well as for the real life Belgian natural gas and electricity infrastructures.

A Critical Review of the Nigerian Energy Scenario

Abundant and economical energy is the life blood of modern civilization. Energy poverty continues to be a major constraint to the developmental and economic of Nigeria and the crucial challenge of the energy sector in the country includes the issues of inadequate energy supply, energy security and sustainability. This study appraises critically the current energy scenario in Nigeria and examines the roles of all the primary energy forms in the country as well as alternative energy forms in the provision of adequate energy supply and energy security for the future, particularly as it pertains to the attainment of the country’s goals for boosting energy supply as articulated in all its policy and developmental documents. The study identified poor energy mix, slow implementation of policy and inadequate private sector participation as major constraints and challenges of the energy sector and recommends appropriate strategies to improve the energy scenario in the country.

Towards an electricity-powered world

The purpose of this review is examination of the present scenario of electricity production and investigation of whether an electricity powered world is possible, indicating which primary energy forms should be preferably utilized. Currently, most of the primary energy used by mankind, including that employed to generate electricity, comes from fossil fuels, which need to be phased out because they bring about severe damage to climate, environment, and human health and, additionally, their stock will be largely depleted during the present century. All the energy technologies poised to replace those based on fossil fuels, namely nuclear and renewables (wind, hydro, concentrated solar power, photovoltaics, biomass, geothermal, tidal, wave) essentially produce electricity, and this suggests that we will progressively shift to an electricity-based economy over the course of the 21st century. The economic, technical, ethical and social issues entangled with nuclear technologies and the unexpectedly fast expansion of renewable energies (particularly wind and solar) point to an increasingly important role of the latter in electricity generation. The present one way utility-to-customer energy system, designed over one century ago, will need substantial reshaping to enable the build up of a smart grid capable of dealing with variable renewable supply and fluctuating end-user demand by exchange of information between customer and utility. To accomplish this result, effort in research and development of storage devices and facilities on the small (e.g., batteries, capacitors) and large (e.g., pumped hydro, compressed air storage, electrolytic hydrogen) scale is needed. In the medium and long term, the expansion of electricity production will also likely lead to progressive replacement of internal combustion engines with electric motors in the automotive sector, accompanied by a shift from individual to mass transportation systems. We have still a long way out of the fossil fuel era, but this challenge can be won only if carbon-free electricity largely replaces the direct combustion of irreplaceable and climate-altering fossil fuel resources.

THE CASE FOR NON-BARYONIC ENERGY AS THE PRIMARY OUTPUT OF GRBs

The evidence is reviewed that the primary form of energy that escapes to infinity from gamma-ray bursts (GRBs) is gamma-rays, and/or Poynting flux, and that the kinetic energy in ultrarelativistic baryons is a secondary component resulting from acceleration of baryons by radiation pressure near or beyond the photosphere. This could account for several observed characteristics of observed GRB spectra and light curves, such as the typical peak photon energy, the correlation of this peak with apparent GRB energy, and the profiles and spectral lagging of GRB subpulses.