36 research outputs found

    Biomass gasification for syngas and biochar co-production: Energy application and economic evaluation

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    Syngas and biochar are two main products from biomass gasification. To facilitate the optimization of the energy efficiency and economic viability of gasification systems, a comprehensive fixed-bed gasification model has been developed to predict the product rate and quality of both biochar and syngas. A coupled transient representative particle and fix-bed model was developed to describe the entire fixed-bed in the flow direction of primary air. A three-region approach has been incorporated into the model, which divided the reactor into three regions in terms of different fluid velocity profiles, i.e. natural convection region, mixed convection region, and forced convection region, respectively. The model could provide accurate predictions against experimental data with a deviation generally smaller than 10%. The model is applicable for efficient analysis of fixed-bed biomass gasification under variable operating conditions, such as equivalence ratio, moisture content of feedstock, and air inlet location. The optimal equivalence ratio was found to be 0.25 for maximizing the economic benefits of the gasification process

    The Criteria of Passive and Low Energy in Building Design for Tropical Climate in Thailand

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    Due to high level of energy consumption and increasing environmental concerns, energy efficiency has become a critical issue today. Buildings alone account for around 30 percent of the world’s total energy consumption. The way buildings are designed and constructed today will not only have an impact on their operating costs, but it will also affect the world’s energy consumption patterns and environmental conditions for many years to come. For much of the building industry in Thailand, the designed-in approach to energy-efficient design does not reflect current market practice. In reality, without passive design, numerous opportunitiesfor designing better performance buildings can be wasted. The integration of passive design is thus a key to energy conscious buildings. The integration of passive design approach optimizes the interactions between the natural environment, building envelope and systems as an integrated system. This research examines which components work best altogether to save energy and reduce environmental impactson buildings in the tropical region. The outcomes of this research aim to set up the criteria of passive and low energy in building design for the tropical climate in Thailand. These fundamental differences will lead to a very different architectural and constructional design. It is imperative that the decision be made at an early stage in the design and there are tremendous opportunitiesto use smart, energy efficient designs to reduce the energy footprint of the built environment for decades to come

    QCCA-Secure Generic Transformations in the Quantum Random Oracle Model

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    The post-quantum security of cryptographic schemes assumes that the quantum adversary only receives the classical result of computations with the secret key. Further, it is unknown whether the post-quantum secure schemes still remain secure if the adversary can obtain a superposition state of the results. In this paper, we formalize one class of public-key encryption schemes named oracle-masked schemes. Then we define the plaintext extraction procedure for those schemes and this procedure simulates the quantum-accessible decryption oracle with a certain loss. The construction of the plaintext extraction procedure does not need to take the secret key as input. Based on this property, we prove the IND-qCCA security of the Fujisaki-Okamoto (FO) transformation in the quantum random oracle model (QROM) and our security proof is tighter than the proof given by Zhandry (Crypto 2019). We also give the first IND-qCCA security proof of the REACT transformation in the QROM. Furthermore, our formalization can be applied to prove the IND-qCCA security of key encapsulation mechanisms with explicit rejection. As an example, we present the IND-qCCA security proof of TCH\textsf{T}_{\textsf{CH}} transformation, proposed by Huguenin-Dumittan and Vaudenay (Eurocrypt 2022), in the QROM

    Tighter QCCA-Secure Key Encapsulation Mechanism with Explicit Rejection in the Quantum Random Oracle Model

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    Hofheinz et al. (TCC 2017) proposed several key encapsulation mechanism (KEM) variants of Fujisaki-Okamoto (\textsf{FO}) transformation, including \textsf{FO}^{\slashed{\bot}}, \textsf{FO}_m^{\slashed{\bot}}, \textsf{QFO}_m^{\slashed{\bot}}, FO⊥\textsf{FO}^{\bot}, FOm⊥\textsf{FO}_m^\bot and QFOm⊥\textsf{QFO}_m^\bot, and they are widely used in the post-quantum cryptography standardization launched by NIST. These transformations are divided into two types, the implicit and explicit rejection type, including \{\textsf{FO}^{\slashed{\bot}}, \textsf{FO}_m^{\slashed{\bot}}, \textsf{QFO}_m^{\slashed{\bot}}\} and FO⊥,FOm⊥,QFOm⊥\textsf{FO}^{\bot}, \textsf{FO}_m^\bot, \textsf{QFO}_m^\bot, respectively. The decapsulation algorithm of the implicit (resp. explicit) rejection type returns a pseudorandom value (resp. an abort symbol ⊥\bot) for an invalid ciphertext. For the implicit rejection type, the \textsf{IND-CCA} security reduction of \textsf{FO}^{\slashed{\bot}} in the quantum random oracle model (QROM) can avoid the quadratic security loss, as shown by Kuchta et al. (EUROCRYPT 2020). However, for the explicit rejection type, the best known \textsf{IND-CCA} security reduction in the QROM presented by Hövelmanns et al. (ASIACRYPT 2022) for FOm⊥\textsf{FO}_m^\bot still suffers from a quadratic security loss. Moreover, it is not clear until now whether the implicit rejection type is more secure than the explicit rejection type. In this paper, a QROM security reduction of FOm⊥\textsf{FO}_m^\bot without incurring a quadratic security loss is provided. Furthermore, our reduction achieves \textsf{IND-qCCA} security, which is stronger than the \textsf{IND-CCA} security. To achieve our result, two steps are taken: The first step is to prove that the \textsf{IND-qCCA} security of FOm⊥\textsf{FO}_m^\bot can be tightly reduced to the \textsf{IND-CPA} security of FOm⊥\textsf{FO}_m^\bot by using the online extraction technique proposed by Don et al. (EUROCRYPT 2022). The second step is to prove that the \textsf{IND-CPA} security of FOm⊥\textsf{FO}_m^\bot can be reduced to the \textsf{IND-CPA} security of the underlying public key encryption (PKE) scheme without incurring quadratic security loss by using the Measure-Rewind-Measure One-Way to Hiding Lemma (EUROCRYPT 2020). In addition, we prove that (at least from a theoretic point of view), security is independent of whether the rejection type is explicit (FOm⊥\textsf{FO}_m^\bot) or implicit (\textsf{FO}_m^{\slashed{\bot}}) if the underlying PKE scheme is weakly γ\gamma-spread

    Identification of PTPN22 as a potential genetic biomarker for abdominal aortic aneurysm

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    Abdominal aortic aneurysm (AAA) is a severe life-threatening disease that is generally asymptomatic and is diagnosed at a very late stage. The genetic component underpinning AAA is considerable, with an estimated heritability of up to 70%. Therefore, identifying genetic biomarkers for AAA is valuable for predicting high-risk populations. We used integrative bioinformatics and cellular AAA model-based validation to reveal that the gene encoding protein tyrosine phosphatase non-receptor type 22 (PTPN22) may be a potentially useful diagnostic biomarker for AAA. Integrative bioinformatics analyses of clinical specimens showed that PTPN22 expression was consistently upregulated in aortic tissues and peripheral blood mononuclear cells (PBMCs) derived from patients with AAA. Moreover, transcriptomics data revealed that PTPN22 is a potential biomarker for AAA with limited diagnostic value in patients with thoracic aortic aneurysm/dissection. Single-cell RNA sequencing-based findings further highlight PTPN22 expression in aortic immune cells and vascular smooth muscle cells (VSMCs) is consistently upregulated in patients with AAA. A cellular AAA model was eventually employed to verify the increase in PTPN22 expression. Collectively, the results indicate that PTPN22 could be a potentially useful diagnostic biomarker for AAA

    Optimal translational termination requires C4 lysyl hydroxylation of eRF1

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    Efficient stop codon recognition and peptidyl-tRNA hydrolysis are essential in order to terminate translational elongation and maintain protein sequence fidelity. Eukaryotic translational termination is mediated by a release factor complex that includes eukaryotic release factor 1 (eRF1) and eRF3. The N terminus of eRF1 contains highly conserved sequence motifs that couple stop codon recognition at the ribosomal A site to peptidyl-tRNA hydrolysis. We reveal that Jumonji domain-containing 4 (Jmjd4), a 2-oxoglutarate- and Fe(II)-dependent oxygenase, catalyzes carbon 4 (C4) lysyl hydroxylation of eRF1. This posttranslational modification takes place at an invariant lysine within the eRF1 NIKS motif and is required for optimal translational termination efficiency. These findings further highlight the role of 2-oxoglutarate/Fe(II) oxygenases in fundamental cellular processes and provide additional evidence that ensuring fidelity of protein translation is a major role of hydroxylation

    The Criteria of Passive and Low Energy in Building Design for Tropical Climate in Thailand

    Get PDF
    Due to high level of energy consumption and increasing environmental concerns, energy efficiency has become a critical issue today. Buildings alone account for around 30 percent of the world’s total energy consumption. The way buildings are designed and constructed today will not only have an impact on their operating costs, but it will also affect the world’s energy consumption patterns and environmental conditions for many years to come. For much of the building industry in Thailand, the designed-in approach to energy-efficient design does not reflect current market practice. In reality, without passive design, numerous opportunitiesfor designing better performance buildings can be wasted. The integration of passive design is thus a key to energy conscious buildings. The integration of passive design approach optimizes the interactions between the natural environment, building envelope and systems as an integrated system. This research examines which components work best altogether to save energy and reduce environmental impactson buildings in the tropical region. The outcomes of this research aim to set up the criteria of passive and low energy in building design for the tropical climate in Thailand. These fundamental differences will lead to a very different architectural and constructional design. It is imperative that the decision be made at an early stage in the design and there are tremendous opportunitiesto use smart, energy efficient designs to reduce the energy footprint of the built environment for decades to come

    Advances in solar heating and cooling

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    Pathways to Energy‐efficient Water Production from the Atmosphere

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    Abstract Atmospheric water harvesting (AWH) provides a fascinating chance to facilitate a sustainable water supply, which obtains considerable attention recently. However, ignoring the energy efficiency of AWH leads to high energy consumption in current prototypes (ca. 101 to 102 MJ kg−1), misfitting with the high‐strung and complicated water‐energy nexus. In this perspective, a robust evaluation of existing AWHs is conducted and a detailed way to high‐efficiency AWH is paved. The results suggest that using cooling‐assisted adsorption will weaken the bounds of climate to sorbent selections and have the potential to improve efficiency by more than 50%. For device design, the authors deeply elucidate how to perfect heat/mass transfer to narrow the gap between lab and practices. Reducing heat loss, recovering heat and structured sorbent are the main paths to improve efficiency on the device scale, which is more significant for a large‐scale AWH. Besides efficiency, the techno‐economic evaluation reveals that developing a cost‐effective AWH is also crucial for sustainability, which can be contributed by green synthesis routes and biomass‐based sorbents. These analyses provide a uniform platform to guide the next‐generation AWH to mitigate the global water crisis
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