Release Reaction Research Articles

Electrodeposition of Silicon from the Low-Melting LiCl-KCl-CsCl-K2SiF6 Electrolytes

The possibility of silicon electrodeposition from the low-melting LiCl-KCl-CsCl-K2SiF6 electrolytes has been studied. The stability of a silicon-containing additive was studied by cyclic voltammetry, and the rate constant of the chemical reaction of SiF4 release at a temperature of 827 K was calculated. It is determined that the constants of velocity values in the melt based on eutectic composition are 2 orders of magnitude higher, which indicates a higher rate of formation of volatile compounds. Cyclic voltammetry was also used to study the electrochemical behavior of K2SiF6 in the melts under study. It was found that the silicon electroreduction at the cathode is not reversible and proceeds in one 4-electron reaction. The diffusion coefficient calculated by the Matsuda-Ayabe equation was 0.72·10−5 cm2·s−1 at temperature of 823 K. According to the obtained voltammograms, the parameters for the silicon electrodeposition were selected. At a potential of −0.4 V vs QRE, dendritic silicon deposits were obtained.

Insight into the Loading Properties of Na+ Green-Functionalized Clinoptilolite as a Potential Carrier for the 5-Fluorouracil Drug, its Release Kinetics, and Cytotoxicity

Herein, natural zeolite (clinoptilolite) was functionalized by Na+ ions (G.Na+/Clino) utilizing a green tea extract prepared by a green production method as a potential carrier for the 5-fluorouracil (5-Fu) drug with enhanced physicochemical behaviors. The G.Na+/Clino-modified product showed enhanced surface area (312 m2/g) and ion-exchange capacity (387 mequiv/100 g). The loading studies reflect high and controlled loading properties of G.Na+/Clino with an actual loading capacity of 291 and 462 mg/g, respectively. The loading reactions of 5-Fu into G.Na+/Clino were of pseudo-second-order kinetics and exhibited Langmuir isotherm properties. This suggested a monolayer and homogeneous loading process by chemical complexation and ion-exchange mechanisms with a Gaussian energy value of 10.47 kJ/mol. Additionally, these reactions were of endothermic and spontaneous nature based on the determined thermodynamic parameters. The release studies demonstrated the 5-Fu release profile for about 150 h at pH 1.2 and for 80 h at pH 7.4. The release reactions had non-Fickian transport properties and were controlled by both erosion and diffusion mechanisms, considering the release kinetic findings and the values of the diffusion exponent (0.42 at pH 1.2 and 0.37 at pH 7.4). The composite showed remarkable biocompatibility based on the measured cell viability and a cytotoxic effect on normal colorectal cells (CCD-18Co). Additionally, the application of G.Na+/Clino as an inorganic carrier for the 5-Fu drug prompted the cytotoxic effect of the drug on colon cancer cell treatment (HCT-116).

Unveiling thermal decomposition kinetics of Single-Crystalline Ni-Rich LiNi0.88Co0.07Mn0.05O2 cathode for safe Lithium-Ion batteries

Insufficient thermal stabilities of LiNixCoyMn1-x-yO2 (NCM) families have aroused wide concerns and safety threats against large-scale application due to oxygen releasing and exothermic side reactions. Towards energy-dense batteries, single-crystalline NCM has been recently highlighted as a promising substitution in providing improved capacity retention beyond polycrystalline counterparts. However, their thermal-driven degradation mechanism remains under investigation and yet critically essential. In this contribution, we have rationally explored the thermal-driven fading behavior of delithiated single-crystalline and polycrystalline LiNi0.88Co0.07Mn0.05O2. Followed by the Avrami-Erofeev mechanism, a three-step decomposition procedure has been deconvoluted from time-resolved X-ray diffraction and physicochemical analysis, in terms of solid electrolyte interface (SEI) decomposition, layered-to-spinel transition and spinel-to-rock-salt transition. According to thermal kinetic analysis, polycrystalline LiNi0.88Co0.07Mn0.05O2 exhibits higher decomposition temperature and lower decomposition rate than that in single-crystalline counterparts, contributing to better thermal stability. This study has provided a fundamental understanding of the thermal decomposition of Ni-rich LiNi0.88Co0.07Mn0.05O2 cathodes and insights of NCM families protection.

Converter Phenotype: A New Profile That Is Not Exclusive to Taxanes.

Introduction: Phenotype I hypersensitivity reactions are the most commonly reported drug reactions; however, precision medicine has made it possible to characterize new phenotypes. A recent communication proposed the existence of a “converter phenotype,” which would affect patients who present non-immediate hypersensitivity reactions and in subsequent exposures develop immediate hypersensitivity reactions. This study aimed to describe the clinical characteristics of converter phenotype reactions and their evolution during desensitization to chemotherapeutic drugs and monoclonal antibodies.Methods: We retrospectively reviewed our database of patients undergoing desensitization to chemotherapy or biological agents and selected those with a converter phenotype. Demographic and clinical characteristics of the patients, the results of skin tests, tryptase and IL-6 levels, and desensitization outcomes were assessed.Results: Of 116 patients evaluated, 12 (10.3%) were identified as having a converter phenotype. The median interval between drug exposure and reaction was 90.6 h (range 8-288 h). After the conversion, phenotype I was the most frequent (58.3%), followed by cytokine release reactions (33.3%). Fifty-one desensitizations were undertaken and all treatments completed, with 10 (19.6%) breakthrough reactions. No new changes in the phenotype were detected.Conclusions: The symptoms of non-immediate drug hypersensitivity reactions may indicate the need for an early allergological evaluation to assess the risk of future immediate drug reactions. Clinical characteristics, skin test results, and biomarkers can help predict responses to rapid drug desensitization, guiding clinicians on how to optimize therapy delivery while maintaining patient safety.

First-principles-based multiscale modelling of heterogeneous CoO oxidation kinetics in high-temperature thermochemical energy storage

Metal oxides experiencing reversible oxygen release and uptake reactions involve the scale-span (surface→grain→particle→reactor) problem in a thermochemical energy storage reactor. This study developed a first-principles-based multiscale modelling to calculate the heterogeneous CoO oxidation kinetics. At the surface scale, density function theory (DFT) is used to compute the reaction mechanism, and the data from DFT calculation are integrated into the transition state theory (TST) to calculate the reaction rate constants. At the grain scale, a rate equation theory is proposed to couple the surface reaction with the lattice oxygen in bulk phase. At the particle scale, intraparticle diffusion and external diffusion of gas molecules are calculated by the effective factor and mass transfer coefficient. At the reactor scale, a two-phase fluidization model is adopted to describe the mass transfer of oxygen from bubble phase to emulsion phase. The model was used to simulate the oxidation kinetic characteristics of a newly prepared kaolin-supported Co-based oxide. The reaction mechanism and kinetic rates constants obtained from DFT and TST are directly used to predict the CoO oxidation kinetics instead of by fitting the experimental data. The oxidation kinetics were validated by comparing with the experimental data obtained using a micro-fluidized bed thermogravimetric analysis technology. Results show the oxidation will be fully finished within ~10 s in the temperature of 700–750 °C, and the reaction is first-order when the O2 partial pressure is within 21 vol%. The effect of particle size shows three-zone characteristics of chemical reaction and gas diffusion combined controlling mechanism. It is demonstrated the first-principle-based multiscale modelling can provide an accurate prediction of the CoO oxidation kinetics in thermochemical energy storage.

Building Homogenous Li2 TiO3 Coating Layer on Primary Particles to Stabilize Li-Rich Mn-Based Cathode Materials.

Li-rich Mn-based oxides (LRMOs) are promising cathode materials for next-generation lithium-ion batteries (LIBs) with high specific energy (≈900 Wh kg-1 ) because of anionic redox contribution. However, LRMOs suffer from issues such as irreversible release of lattice oxygen, transition metal (TM) dissolution, and parasitic cathode-electrolyte reactions. Herein, a facile, scalable route to build homogenous and ultrathin Li2 TiO3 (LTO) coating layer on the primary particles of LRMO through molten salt (LiCl) assisted solid-liquid reaction between TiO2 and Li1.08 Mn0.54 Co0.13 Ni0.13 O2 is reported. The prepared LTO-coated Li1.08 Mn0.54 Co0.13 Ni0.13 O2 (LTO@LRMO) exhibits 99.7% capacity retention and 95.3% voltage retention over 125 cycles at 0.2C, significantly outperforming uncoated LRMO. Combined characterizations of differential electrochemical mass spectrometry, in situ X-ray diffraction, and ex situ X-ray photoelectron spectroscopy evidence significantly suppressed oxygen release, phase transition, and interfacial reactions. Further analysis of cycled electrodes reveals that the LTO coating layer inhibits TM dissolution and prevents the lithium anode from TM crossover effect. This study expands the primary particle coating strategy to upgrade LRMO cathode materials for advanced LIBs.

Mechanistic studies of visible light-induced CO release from a 3-hydroxybenzo[g]quinolone.

Organic compounds that can be triggered using light to release CO in biological environments are of significant current interest to probe the role of CO in biology and as potential therapeutics. We recently reported that a 3-hydroxybenzo[g]quinolone (5) can be used as a CO delivery molecule to produce anticancer and potent anti-inflammatory effects. Herein we report mechanistic studies of the visible light-induced CO release reaction of this compound. In wet CH3CN under aerobic conditions, 5 releases 0.90(2) equivalents of CO upon illumination with visible light (419 nm) to give a single depside product. Performing the same reaction under an 18O2 atmosphere results in quantitative incorporation of two labeled oxygen atoms in the depside product. Monitoring via1H NMR and UV-vis during the illumination of 5 in CH3CN using 419 nm light revealed the substoichiometric formation of a diketone (6) in the reaction mixture. H2O2 formation was detected in the same reaction mixtures. DFT studies indicate that upon light absorption an efficient pathway exists for the formation of a triplet excited state species (5b) that can undergo reaction with 3O2 resulting in CO release. DFT investigations also provide insight into diketone (6) and H2O2 formation and subsequent reactivity. The presence of water and exposure to visible light play an important role in lowering activation barriers in the reaction between 6 and H2O2 to give CO. Overall, two reaction pathways have been identified for CO release from a 3-hydroxybenzo[g]quinolone.

Ticlopidine induces cardiotoxicity in zebrafish embryos through AHR-mediated oxidative stress signaling pathway

Ticlopidine has inhibitory effects on platelet aggregation via ADP (adenosine diphosphate), platelet release reaction and depolymerization. In clinical practice, it is commonly used to prevent heart, cerebrovascular and other thromboembolic diseases. However, ticlopidine has also been reported to have teratogenic effects on the heart, though its specific molecular mechanism remains unclear. In this study, zebrafish embryos were used as model organisms to examine the toxicity effect of ticlopidine. Zebrafish embryos exposed to 6, 7.5, and 9 mg/L ticlopidine solutions manifested several abnormalities, including body curvature, smaller eyes, slower absorption of the vitella sac, pericardial edema, slower heart rate, increased mortality, longer venous sinus - arterial ball (SV-BA) distance, and increased oxidative stress, which indicated developmental and cardiac toxicity. Abnormal expression of key genes related to heart development was observed, and the level of apoptotic gene expression was up-regulated. Further experiments revealed up-regulation of embryonic oxidative stress following ticlopidine exposure, leading to a decrease in cardiomyocyte proliferation. Conversely, the aromatic hydrocarbon receptor (AHR) inhibitor CH223191 protected embryos from the cardiotoxicity effect of ticlopidine, confirming further the role of up-regulated oxidative stress as the molecular mechanism of ticlopidine-induced cardiotoxicity in zebrafish. In conclusion, ticlopidine exposure leads to developmental and cardiotoxicity in zebrafish embryos. Therefore, further studies are warranted to ascertain such potential harms of ticlopidine in humans, which are vital in providing guidance in the safe use of drugs in clinical practice.

Enabling alcohol as a hydrogen carrier using metal-organic framework-stabilized Ir-Sc bifunctional catalytic sites.

Alcohols are attractive portable chemical carriers of hydrogen thanks to their reversible dehydrogenation, but the hydrogen release reaction is thermodynamically unfavorable. Coupling the alcohol dehydrogenation to acetal formation can shift the reaction thermodynamics for hydrogen production. Here, we stabilized Ir3+ and Sc3+ in a metal-organic framework (MOF) for tandem catalysis. The Ir3+ center bearing an α-hydroxybipyridine ligand catalyzes alcohol dehydrogenation, and the Sc3+ Lewis acid site catalyzes acetal formation that allows further dehydrogenation to form esters. The bifunctional UiO-bpyOH-IrCp-Sc catalyst effectively converts ethylene glycol to ester and H2 without producing CO.

Enhanced Hydrogen Storage Properties of LiAlH4 by Excellent Catalytic Activity of XTiO3@h‐BN (X = Co, Ni)

AbstractThe high desorption temperature and slow kinetics still restrict the applications of LiAlH4 in hydrogen storage. To solve the above problems, NiTiO3@h‐BN and CoTiO3@h‐BN prepared for the first time are introduced into LiAlH4 by ball milling. LiAlH4 doped with 7 wt% NiTiO3@h‐BN, selected as an optimal doping sample, starts to release hydrogen at 68.1 °C, and the total amount of hydrogen released is 7.11 wt% below 300 °C. The activation energies (Ea) of the two‐step hydrogen release reactions are 55.93 and 59.25 kJ∙mol−1, which are 45.8% and 69.0% lower than those of as‐received LiAlH4, respectively. Under 30 bar hydrogen pressure and 300 °C constant temperature, LiAlH4 doped with 7 wt% NiTiO3@h‐BN after dehydrogenation can absorb ≈1.05 wt% hydrogen. Based on density functional theory calculations, AlNi3 and NiTi, in situ formed nanoparticles during ball milling, can decrease the desorption energy barrier of AlH bonding in LiAlH4 and accelerate the breakdown of AlH bonding due to the interfacial charge transfer and the dehybridization. Furthermore, NiTi can enhance the adsorption and splitting of H2, promoting the activation of H2 molecules during the rehydrogenation process.

Boron Hydrogen Compounds: Hydrogen Storage and Battery Applications.

About 25 years ago, Bogdanovic and Schwickardi (B. Bogdanovic, M. Schwickardi: J. Alloys Compd. 1–9, 253 (1997) discovered the catalyzed release of hydrogen from NaAlH4. This discovery stimulated a vast research effort on light hydrides as hydrogen storage materials, in particular boron hydrogen compounds. Mg(BH4)2, with a hydrogen content of 14.9 wt %, has been extensively studied, and recent results shed new light on intermediate species formed during dehydrogenation. The chemistry of B3H8−, which is an important intermediate between BH4− and B12H122−, is presented in detail. The discovery of high ionic conductivity in the high-temperature phases of LiBH4 and Na2B12H12 opened a new research direction. The high chemical and electrochemical stability of closo-hydroborates has stimulated new research for their applications in batteries. Very recently, an all-solid-state 4 V Na battery prototype using a Na4(CB11H12)2(B12H12) solid electrolyte has been demonstrated. In this review, we present the current knowledge of possible reaction pathways involved in the successive hydrogen release reactions from BH4− to B12H122−, and a discussion of relevant necessary properties for high-ionic-conduction materials.

Insight into the Technical Qualification of the Sonocogreen CaO/Clinoptilolite Nanocomposite (CaO(NP)/Clino) as an Advanced Delivery System for 5-Fluorouracil: Equilibrium and Cytotoxicity.

Clinoptilolite as a natural zeolite was integrated with green CaO nanoparticles forming the green nanocomposite CaO(NP)/Clino. The CaO(NP)/Clino composite was assessed as a potential carrier for 5-fluorouracil (5-FL) drug. The CaO(NP)/Clino carrier achieved an enhanced 5-FL loading capacity of 305.3 mg/g as compared to 163 mg/g for pure clinoptilolite. The kinetics of the 5-FL loading follow the properties of the pseudo-first-order model, while the equilibrium results are related to the Langmuir isotherm. Therefore, the 5-FL loading processes occurred in the monolayer formed by homogeneous active loading receptors on the surface of the CaO(NP)/Clino carrier. The Gaussian energy of the 5-FL loading reaction (9.2 KJ/mol) reflected the dominant effect for the chemical mechanisms, especially the zeolitic ion-exchange mechanisms. Additionally, the thermodynamic parameters suggested endothermic, feasible, and spontaneous properties for the occurred 5-FL loading reactions. The release profile of 5-FL from CaO(NP)/Clino has continuous and long properties (150 h) at pH 1.2 (gastric fluid) and pH 7.4 (intestinal fluid). The kinetic studies of the release reactions show considerable agreement with Higuchi, Hixson–Crowell, and Korsmeyer–Peppas models. Such high fitting results and the diffusion exponent values (0.49 at pH 1.2 and 0.48 at pH 7.4) reflected the release properties of the Fickian transport behavior involving complex erosion and diffusion mechanisms. The cytotoxicity study of CaO(NP)/Clino on colorectal normal cells (CCD-18Co) declare the safe and biocompatible effect as a carrier for the 5-FL drug. Additionally, CaO(NP)/Clino as a carrier causes considerable enhancement for the cytotoxic effect of the loaded 5-FL drug on colon cancer cells (HCT-116).

Assessment of local and non–local turbulent flow components on turbulence–flame interaction

In the framework of turbulence-flame interaction, the flame is characterized by the gradient of a reactive scalar such as the progress variable, whereas the turbulence is represented by the vorticity and the strain rate. Quantitative assessment of this interaction is performed trough the study of the coupled transport between these quantities that are subject to the effects of heat release and chemical reactions. The present analysis aims at improving the understanding of the small scale turbulence – flame interaction properties, through the introduction of an additive decomposition of the strain rate and vorticity fields into their local and non-local components. The respective role of the local and non-local effects is studied for a broad range of Karlovitz numbers, by virtue of direct numerical simulations (DNS) of turbulent, premixed, lean, and statistically planar flames of methane-air. In the conditions of the present study, the alignment between flame front normals and the strain rate is found to be dominated by the local contribution from the strain rate tensor.

Phosphorus solubility and dynamics in a tropical soil under sources derived from wastewater and sewage sludge

Conventional phosphate fertilizers are usually highly water-soluble and rapidly solubilize when moistened by the soil solution. However, if this solubilization is not in alignment with plants demand, P can react with the soil colloidal phase, becoming less available over time. This is more pronounced in acidic, oxidic tropical soils, with high P adsorption capacity, reducing the efficiency of P fertilization. Furthermore, these fertilizers are derived from phosphate rock, a non-renewable resource, generating an environmental impact. To assess these concerns, waste-recycled P sources (struvite, hazenite and AshDec®) were studied for their potential of reducing P fixation by the soil and improving the agronomic efficiency of the P fertilization. In our work, we compared the solubilization dynamics of struvite, hazenite, AshDec® to triple superphosphate (TSP) in a sandy clay loam Ferralsol, as well as their effect on solution pH and on soil P pools (labile, moderately-labile and non-labile) via an incubation experiment. Leaching columns containing 50 g of soil with surface application of 100 mg per column (mg col−1) of P from each selected fertilizer and one control (nil-P) were evaluated for 60 days. Daily leachate samples from the column were analyzed for P content and pH. Soil was stratified in the end and submitted to P fractionation. All results were analyzed considering p < 0.05. Our findings showed that TSP and struvite promoted an acid P release reaction (reaching pHs of 4.3 and 5.5 respectively), while AshDec® and hazenite reaction was alkaline (reaching pHs of 8.4 and 8.5 respectively). Furthermore, TSP promoted the highest P release among all sources in 60 days (52.8 mg col−1) and showed rapid release dynamic in the beginning, while struvite and hazenite showed late release dynamics and lower total leached P (29.7 and 15.5 mg col−1 P respectively). In contrast, no P-release was detected in the leachate of the AshDec® over the whole trial period. Struvite promoted the highest soil labile P concentration (7938 mg kg−1), followed by hazenite (5877 mg kg−1) and AshDec® (4468 mg kg−1), all higher than TSP (3821 mg kg−1), while AshDec® showed high moderately-labile P (9214 mg kg−1), reaffirming its delayed release potential.

Electron Donors Rather Than Reactive Oxygen Species Needed for Therapeutic Photochemical Reaction of Near-Infrared Photoimmunotherapy.

Near-infrared photoimmunotherapy (NIR-PIT) employs molecularly targeted antibodies conjugated with a photoabsorbing silicon-phthalocyanine dye derivative which binds to cancer cells. Application of NIR light following binding of the antibody-photoabsorber conjugates (APCs) results in ligand release on the dye, dramatic changes in solubility of the APC-antigen complex, and rapid, irreversible cell membrane damage of cancer cells in a highly selective manner, resulting in a highly immunogenic cell death. Clinically, this process results in edema after treatment mediated by reactive oxygen species (ROS). Based on the chemical and biological mechanism of NIR-PIT cytotoxicity and edema formation, in order to minimize acute inflammatory edema without compromising therapeutic effects, l-sodium ascorbate (l-NaAA) was administered to quench harmful ROS and accelerate the ligand release reaction. l-NaAA suppressed acute edema by reducing ROS after NIR-PIT yet did not alter the therapeutic effects. NIR-PIT could be performed safely under existence of l-NaAA without side effects caused by unnecessary ROS production.

New insights of the interaction of H2S with mackinawite FeS in a wet environment: An ab initio molecular dynamics study

Mackinawite FeS is the most common corrosion product in the early stage of steel in H2S environment and also has an effective catalysis for hydrodesulfurization, hydrogen release reactions and heavy metal ion removal since its high specific surface area and reactive surface like other van der Waals materials. In this paper, ab initio molecular dynamics (AIMD) is used to study the interactions between small molecules (H2S, H2O and H) and FeS at 300 K. The calculation results show that the primary dissociation of H2S only occurs on the FeS(111) surface and H2S is chemically adsorbed on the (011) and (100) surfaces but physically adsorbed on the (001) surface. It will dissociate and generate H atoms when different amounts H2S or H2O molecules appear in the interlayer of FeS, in which H2S is more prone to dissociation. The dissociated H atoms will be “captured” by Fe/S atoms in mackinawite FeS, leading to the shrink of layer. Moreover, H atoms could combine into H2, which suggests that layered FeS has great potential for hydrogen generation. The diffusion coefficient of H atoms in mackinawite FeS layer is estimated about 1.67 × 10−8 m2/s. These findings have significant meaning for application of mackinawite FeS in corrosion science, hydrogen generation, hydrogen storage and other fields.

Constructing stable surface structures enabling fast charging for Li-rich layered oxide cathodes

Li-rich Mn-based layered oxides (LLOs) exhibiting ultrahigh specific capacity larger than 250 mAh g−1 have become the most promising cathode candidate for high energy density lithium-ions batteries (LIBs). Fast charging capability and cycling stability are highly desirable for LIBs so as to satisfy specific application scenarios such as electric vehicles. However, stable cycling and fast charging properties are severely hindered by obstacles including irreversible oxygen release, structural degradation and poor reaction kinetics. In this work, an integrative and facile surface structures constructing strategy to achieve stable cycling and fast charging in LLOs was provided. Oxygen vacancies and double coating layers including lithium phosphate layer and spinel layer were constructed on the surface through ammonium dihydrogen phosphate (NH4H2PO4) pretreatment. The designed material with induced stable bi-phase coating layers delivers a high discharge specific capacity of 284.6 mAh g−1 at 0.1 C with an ultrahigh initial coulombic efficiency of 95.3% and excellent rate performance of 132.2 mAh g−1 at 10 C. Even after 100 cycles, it can display a remarkable capacity of 215.8 mAh g−1 under 1 C/1 C and 205.1 mAh g−1 under 3 C/1 C. The excellent fast charging performance and cycling stability can be attributed to accelerated Li+ transportation rate due to its surface ion conductive layer and surface spinel phase layer, as well as suppressed oxygen release, transition metals dissolution and electrolyte attack resulting from surface oxygen vacancies and dual protective layers.

Visual presentation for monitoring layer-wise curing quality in DLP 3D printing

Purpose This paper aims to address the problem of uncertain product quality in digital light processing (DLP) three-dimensional (3D) printing, a scheme is proposed to qualitatively estimate whether a layer is printed with the qualified quality or not cured . Design/methodology/approach A thermochromic pigment whose color fades at 45°C is prepared as the indicator and it is mixed with the resin. A visual surveillance framework is proposed to monitor the visual variation in a period of the entire curing process. The exposure region is divided into 30 × 30 sub-regions; gray-level variation curves (curing curves) in all sub-regions are classified as normal or abnormal and a corresponding printing control strategy is designed to improve the percentage of qualified printed objects. Findings The temperature variation caused by the releasing reaction heat on the exposure surface is consistent in different regions under the homogenized light intensity. The temperature in depth begins to rise at different times. The temperature in the regions near the light source rises earlier, and that far from the light source rises later. Thus, the color of resin mixed with the thermochromic pigment fades gradually over a period of the entire solidification process. The color variation in the regions with defects of bubbles, insufficient material filling, etc., is much different from that in the normal curing regions. Originality/value A temperature-sensitive organic chromatic chemical pigment is prepared to present the visual variation over a period of the entire curing process. A novel 3D printing scheme with visual surveillance is proposed to monitor the layer-wise curing quality and to timely stop the possible unqualified printing resulted from bubbles, insufficient material filling, etc.

Theoretical Study on Storage and Release of Firefly Luciferin.

Among numerous bioluminescent organisms, firefly is the most studied one. Recent experiment proposed that sulfoluciferin (SLH2 ) may serve as a storage form of luciferin (LH2 ). In the present article, we employed density functional theory calculation to uncover the mechanism and detailed process of the storage and release reactions. Due to lack of available crystallographic structure of the related enzyme, the calculation was performed on a model system. For the storage reaction, possible amino acid residues were used for imitating the protein environment. For the release reaction, the dielectric constant of 3.0 was employed to simulate the polarity of the protein cavity. The computational results indicated that the reactions from LH2 to SLH2 and from SLH2 to LH2 are both exergonic, which favor the storage and release processes and coincide with the experimental observation. Basing on experimental and current theoretical study, we supplemented the stages of LH2 storage and release in the entire bioluminescent cycle of firefly. The current theoretical calculation could inspire the study on LH2 storage and release of other bioluminescent organisms.

Dynamic analysis of PEM fuel cells and metal hydrides on a zero-emission ship: A model-based approach

As the interest in hydrogen and PEM fuel cells is growing, it is crucial to define the best technology for fuel storage, especially in the transportation field. Metal hydrides show different benefits, including the possibility of thermally coupling the hydrogen storage and utilization systems: fuel cells require heat subtraction for ensuring proper operation, while metal hydrides require heat to activate the hydrogen release reactions. This work describes the integration of PEMFCs and metal hydrides on board a zero-emissions ship, with a special focus on their thermal coupling; a model-based approach is developed to ensure the system's feasibility at different load demands for the vessel, including transient conditions. The study is based on the real application of an innovative zero-emissions ship (ZEUS) financed by Fincantieri-Isotta Fraschini S.p.A, where the total power installation is set at 144 kW by PEMFC and 50 kg of hydrogen are stored by metal hydrides.