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The educational environment is an important condition for the development of children. The educational environment contributes to the cultural identity and the philosophy of the educator creating that environment. Currently, in the world there are many different educational perspectives, with their characteristics, creating a rich and diverse early education with its own identity, Reggio Emilia is a typical example. Based on theoretical and practical research methods (quantitative combined with qualitative), the article presents the viewpoint, educational philosophy, characteristics of the Reggio Emilia educational environment, and the actual situation of applying the Reggio perspective. at some preschools in Hanoi today. Research results show that building an educational environment according to Reggio Emilia will help children to be confident, have a balanced and harmonious development between cognition and emotions, and feelings. However, the application of this concept in preschools in Hanoi is still not good, depending on many factors.

Bis(3-indolyl)methanes (BIM) are highly valuable and appear in the core structure of many natural products and pharmacologically active compounds (anticancer, anti-inflammatory, antiobesity, antimetastatic, antimicrobial, etc.). Herein, we have disclosed an air stable and highly efficient CuFe2O4 heterogeneous catalyst for alkylation of indoles with alcohols to give bis(3-indolyl)methanes in very good yields. The CuFe2O4 catalyst has been found to be magnetically recycled at least five times without losing significant catalytic activity.

This paper studied the effects of feed properties in spray drying formulation of prototype industrial cracking catalysts at the laboratory scale. The results showed that the pH of the drying feed mainly affected the active phase HY zeolite. At a high pH value, a strongly alkaline medium (pH 14), the HY zeolite structure was completely destroyed, resulting in the cracking catalyst with a low surface area. Hence, the pH of the drying feed should be adjusted to a low value, preferably a slightly acidic medium (pH 3). The solid content mainly affected the particle size of the cracking catalyst. As increasing the solid content in the drying feed, the particle size of the cracking catalysts increased and reached the maximum average value at about 40 μm which corresponded to the solid content of 15 wt.%. At a higher solid content (20 wt.%), the catalyst particle size and surface area tended to decrease. Thus, the solid content of 15 wt.% was considered to be optimal.

Flight safety and airlines operation have been at the center of research since aircraft were first invented, as even slight errors in aircraft maintenance may cause serious accidents. Thus, aircraft maintenance is critical to the aviation industry all the time. To prevent maintenance errors, it is important to train for aviation maintenance. Therefore, an aircraft maintenance virtual reality (AMVR) system was developed in this study. For a Dornier-228 aircraft, a walk-around visual inspection of its fuel system was designed and tested in a virtual environment. For the system, CATIA V5 and Unity 3D software were used for designing the 3D model of the aircraft and developing the visual environment, respectively. With the software, the visual environment of the aircraft hangar was created for the system. The developed system was tested by students to validate the effectiveness of using the AMVR system in training. The students acknowledged that the system was beneficial to their learning, which proved that the developed system is highly effective for training students to improve aircraft maintenance skills.

The depletion of petroleum reserves along with environmental concerns associated with the use of fossil fuels has driven the search for sustainable sources of fuels and chemicals. In this context, catalytic cracking of triglycerides represents a promising alternative to produce renewable hydrocarbon fuels and chemicals. Zeolite catalysts have played a key role in the catalytic cracking process for years. The shift from fossil to biogenic resources has stimulated immense efforts over the last decades to obtain novel classes of zeolite catalysts with tailored properties for efficient upgrading of triglycerides. The present paper aims to provide a comprehensive review on catalytic cracking of triglycerides over zeolite catalysts with the focus on major achievements in engineering of zeolite crystals for being adapted with triglyceride-based oils. Hence, a brief overview of catalytic cracking of triglycerides was first presented to provide relevant background. Engineering of zeolite crystals by shortening diffusion path lengths and incorporating heteroatoms for catalytic cracking of triglycerides was then discussed along prominent examples from the literature. Several directions for future research to advance zeolite catalysts for efficient upgrading of triglycerides to renewable hydrocarbon fuels and chemicals were finally given.

Introduction Hydrazines are highly toxic inorganic liquids that are used as propellants in military and aviation industries, such as the U.S. Air Force F-16 Emergency Power Unit and SpaceX SuperDraco Rockets. The most commonly used derivatives include hydrazine, monomethylhydrazine, and 1,1-dimethylhydrazine (unsymmetrical dimethylhydrazine). Industrial workers in close contact with hydrazines during routine maintenance tasks can be exposed to levels well above the National Institute for Occupational Safety and Health relative exposure limits. Materials and Methods A systematic review was performed using PubMed, Web of Science, Google Scholar, National Aeronautics and Space Administration Technical Server, and Defense Technical Information Center, and data related to hydrazine exposures were searched from inception to April 2020. Publications or reports addressing hydrazine toxicity, pathophysiology, and treatment of hydrazine fuel exposure were selected. Results Acute toxic exposures to hydrazine and its derivatives are rare. There are few case reports of acute toxic exposure in humans, and data are largely based on animal studies. The initial search identified 741 articles, manuscripts, and government reports. After screening for eligibility, 51 were included in this review. Eight articles reported acute exposures to hydrazine propellant in humans, and an additional 14 articles reported relevant animal data. Conclusions Exposure to small amounts of hydrazine and its derivatives can cause significant soft tissue injury, pulmonary injury, seizures, coma, and death. Neurologic presentations can vary based on exposure compound and dose. Decontamination is critical as treatment is mainly supportive. High-dose intravenous pyridoxine has been suggested as treatment for hydrazine-related neurologic toxicity, but this recommendation is based on limited human data. Despite recent research efforts to generate less toxic alternatives to hydrazine fuel, it will likely continue to have a role in military and aviation industries. Aerospace and military physicians should be aware of the toxicity associated with hydrazine exposure and be prepared to treat hydrazine toxicity in at-risk populations.

Catalytic cracking of triglycerides over nanosized ZSM-5 (Nano-ZSM-5) and hierarchical ZSM-5 materials namely mesoporous ZSM-5 (Meso-ZSM-5) and nanosized ZSM-5/SBA-15 analog composite (Com-ZSM-5) was evaluated under fluid catalytic cracking conditions aiming to reduce the concentration of aromatics, especially benzene in the gasoline stream. The catalytic experiments were performed in a Single-Receiver Short-Contact-Time Microactivity Test unit (SR-SCT-MAT, Grace Davison) at 500 °C, catalyst-to-oil ratios of 0.3–1.0 (w/w) and contact time of 12 s. It was shown that the reduction of the ZSM-5 crystal size to nanometer (Nano-ZSM-5) or introduction of hierarchical porosity in ZSM-5 crystals (Meso-ZSM-5 and Com-ZSM-5) indeed improved the quality of gasoline by lowering the content of aromatics, particularly benzene. Compared to commercial ZSM-5, Meso-ZSM-5 and Nano-ZSM-5 produced more gasoline hydrocarbons while lowering the benzene content to ca. 2.0%, a relative decrease by ca. 50%. The advantage of Com-ZSM-5 over Meso-ZSM-5 and Nano-ZSM-5 was the lowest benzene level, i.e. ca. 0.8% which was below the permitted limit of less than 1% specified by the European regulation. The improved molecular transport along with the reduced density of strong Bronsted acid sites provided by the nanocrystalline and hierarchical ZSM-5 catalysts might be responsible for their superior catalytic performance.

Activity, selectivity, and deactivation behavior of catalyst materials determine their efficiency in hydrocarbon conversion processes. For hydrocarbon cracking, the industrial catalyst is an important parameter in reaction technology to produce valuable compounds

Nanocovax is a recombinant severe acute respiratory syndrome coronavirus 2 subunit vaccine composed of full-length prefusion stabilized recombinant SARS-CoV-2 spike glycoproteins (S-2P) and aluminium hydroxide adjuvant.We conducted a dose-escalation, open label trial (phase 1) and a randomized, double-blind, placebo-controlled trial (phase 2) to evaluate the safety and immunogenicity of the Nanocovax vaccine (in 25 mcg, 50 mcg, and 75 mcg doses, aluminium hydroxide adjuvanted (0·5 mg/dose) in 2-dose regime, 28 days apart (ClinicalTrials.gov number, NCT04683484). In phase 1, 60 participants received two intramuscular injection of the vaccine following dose-escalation procedure. The primary outcomes were reactogenicity and laboratory tests to evaluate the vaccine safety. In phase 2, 560 healthy adults received either vaccine doses similar in phase 1 (25 or 50 or 75 mcg S antigen in 0·5 mg aluminium per dose) or adjuvant (0·5 mg aluminium) in a ratio of 2:2:2:1. One primary outcome was the vaccine safety, including solicited adverse events for 7 day and unsolicited adverse events for 28 days after each injection as well as serious adverse event or adverse events of special interest throughout the study period. Another primary outcome was anti-S IgG antibody response (Index unit/ml). Secondary outcomes were surrogate virus neutralisation (inhibition percentage), wild-type SARS-CoV-2 neutralisation (dilution fold), and T-cell responses by intracellular staining for interferon gamma (IFNg). Anti-S IgG and neutralising antibody levels were compared with convalescent serum samples from symptomatic Covid-19 patients.For phase 1 study, no serious adverse events were observed for all 60 participants. Most adverse events were grade 1 and disappeared shortly after injection. For phase 2 study, after randomisation, 480 participants were assigned to receive the vaccine with adjuvant, and 80 participants were assigned to receive the placebo (adjuvant only). Reactogenicity was absent or mild in the majority of participants and of short duration (mean ≤3 days). Unsolicited adverse events were mild in most participants. There were no serious adverse events related to Nanocovax. Regarding the immunogenicity, Nanocovax induced robust anti-S antibody responses. In general, there humoral responses were similar among vaccine groups which reached their peaks at day 42 and declined afterward. At day 42, IgG levels of vaccine groups were 60·48 [CI95%: 51·12-71·55], 49·11 [41·26-58·46], 57·18 [48·4-67·5] compared to 7·10 [6·32-13·92] of convalescent samples. IgG levels reported here can be converted to WHO international standard binding antibody unit (BAU/ml) by multiplying them to a conversion factor of 21·8. Neutralising antibody titre of vaccine groups at day 42 were 89·2 [52·2-152·3], 80·0 [50·8-125.9] and 95·1 [63·1-143·6], compared to 55·1 [33·4-91·0] of the convalescent group.Up to day 90, Nanocovax was found to be safe, well tolerated, and induced robust immune responses.This work was funded by the Coalition for Epidemic Preparedness Innovations (CEPI), the Ministry of Science and Technology of Vietnam, and Nanogen Pharmaceutical Biotechnology JSC.

This work aims to fight against the current outbreak pandemic by developing a method to classify suspected infected COVID-19 cases. Driven by the urgency, due to the vastly increased number of patients and deaths worldwide, we rely on situationally pragmatic chest X-ray scans and state-of-the-art deep learning techniques to build a robust diagnosis for massive screening, early detection, and in-time isolation decision making. The proposed solution, X-ray Projected Generative Adversarial Network (XPGAN), addresses the most fundamental issue in training such a deep neural network on limited human-annotated datasets. By leveraging the generative adversarial network, we can synthesize a large amount of chest X-ray images with prior categories from more accurate 3D Computed Tomography data, including COVID-19, and jointly train a model with a few hundreds of positive samples. As a result, XPGAN outperforms the vanilla DenseNet121 models and other competing baselines trained on the same frontal chest X-ray images.

Bis(3-indolyl)methanes (BIM) are highly valuable and appear in the core structure of many natural products and pharmacologically active compounds (anticancer, anti-inflammatory, antiobesity, antimetastatic, antimicrobial, etc.). Herein, we have disclosed an air stable and highly efficient CuFe2O4 heterogeneous catalyst for alkylation of indoles with alcohols to give bis(3-indolyl)methanes in very good yields. The CuFe2O4 catalyst has been found to be magnetically recycled at least five times without losing significant catalytic activity.

International audience; In everyday life, we often use graphical interfaces where the visual space is mapped to the motor space with a visuomotor gain called the Control Display gain. One of the key objectives in the field of Human Computer Interaction is to design this Control Display gain so as to enhance users' performance. Although the Control Display gain involved in Operating Systems has been found to improve users' pointing performance, the reasons for this improvement have not yet been fully elucidated, especially because the Control Display gains on Operating Systems are both non-constant and non-linear. Here we tested non-constant but linear velocity-based Control Display gains in order to determine which parameters were responsible for pointing performance changes based on analyses of the movement kinematics. Using a Fitt's paradigm, Constantains of 1 and 3 were compared with a linearly Increasing Gain (i.e., the Control Display gain increase with the motor velocity) and a Decreasing Gain (i.e., the Control Display gain decrease with the motor velocity). Three movements with various Indexes of Difficulty (ID) were tested (ID3, ID5 and ID7). The Increasing Gain was expected to increase the velocity of the initial impulse phase and decrease that of the correction phase, thus decreasing the Movement Time (MT); and the contrary in the case of the Decreasing Gain,. Although the Decreasing Gain increased MT at ID3, the Increasing Gain was found to be less efficient than the Constant Gain of 3, probably because a non-constant gain between the motion and its visual consequences disrupted the sensorimotor control. In addition, the kinematic analyses of the movements suggested that the motion profile was planned by the central nervous system based on the visuomotor gain at maximum motor velocity, as common features were observed between the Constant Gain of 1 and the Decreasing Gain, and between the Constant Gain of 3 and the Increasing Gain. By contrast, the amplitude of the velocity profile seemed to be specific to each particular visuomotor mapping process.

Recently, more and more hybrid robots have been designed to meet the increasing demand for a wide spectrum of applications. However, development of a general and systematic method for kinematic design and dynamic analysis for hybrid robots is rare. Most publications deal with the kinematic and dynamic issues for individual hybrid robots rather than any generalization. Hence, in this paper, we present a novel method for kinematic and dynamic modelling for a class of hybrid robots. First, a generic scheme for the kinematic design of a general hybrid robot mechanism is proposed. In this manner, the kinematic equation and the constraint equations for the robot class are derived in a generalized case. Second, in order to simplify the dynamic modelling and analysis of the complex hybrid robots, a Lemma about the analytical relationship among the generalized velocities of a hybrid robot system is proven in a generalized case as well. Last, examples of the kinematic and dynamic modelling of a newly designed hybrid robot are presented to demonstrate and validate the proposed method.

A comparative study of hierarchical ZSM-5 materials including nanosized ZSM-5 (Nano-ZSM-5), nanosized ZSM-5/SBA-15 composite (Com-ZSM-5) and mesoporous ZSM-5 (Meso-ZSM-5) for the enhanced cracking of bulky hydrocarbons is reported. The studied materials were thoroughly characterized by XRD, SEM, TEM, N2-sorption, AAS, ICP-AES, NH3-TPD, FTIR of adsorbed pyridine before being tested in the cracking of 1,3,5 tri-isopropyl-benzene (TIPB) as a representative of bulky hydrocarbons. It was found that all synthesized hierarchical ZSM-5 materials exhibit the preservation of intrinsic, strong Bronsted acidity of ZSM-5 along with the enlarged external/mesoporous surface. The catalytic test results show that these hierarchical ZSM-5 materials indeed promote successive cracking reactions, leading to the enhanced TIPB conversion and selectivity to the deep cracking products, i.e. cumene and benzene compared to those of bulk, commercial ZSM-5. However, the development of mesoporosity by reducing the crystal size of ZSM-5 appears limited (Smeso = 134 m2 g−1). As a result, Nano-ZSM-5 affords only the moderate TIPB conversion and selectivity to deep cracking products (ca. 70% and ca. 20% respectively). Remarkably, the introduction of either intercrystalline mesopores by dispersion of Nano-ZSM-5 in the mesoporous SBA-15 analog matrix (Com-ZSM-5) or intracrystalline mesopores by the alkaline-acid treatments (Meso-ZSM-5) significantly improves the external/mesoporous surface (Smeso = 233–297 m2 g−1), giving rise to both the high TIPB conversion and selectivity to the deep cracking products (ca. 90% and ca. 25% respectively).

A series of micro/mesoporous nano-ZSM-5/SBA-15 analog composites (ZSC) was prepared from ZSM-5 precursors with variable aluminum contents (Si/Al ratio = 10–50) and their catalytic performance was evaluated in the cracking of waste vegetable oil under the fluid catalytic cracking conditions using a Single-Receiver Short-Contact-Time Microactivity Test unit (SR-SCT-MAT, Grace Davison). It was found that the preparation of the ZSC catalyst by properly tuning the initial aluminum content enables to improve its catalytic performance in terms of selectivity toward light olefins and quality of gasoline. Compared to single materials, i.e. microporous H-ZSM-5 and mesoporous Al-SBA-15, the ZSC catalyst shows the enhanced concentration of C3 and C4 olefins in the gaseous hydrocarbon fraction (ca. 85%) while lowering that of aromatic hydrocarbons in the gasoline fraction (ca. 40%). Furthermore, the reduced aromatic hydrocarbons are offset by the more environment-friendly components for boosting the octane rating of gasoline, i.e. iso-paraffins and iso-olefins. The superior catalytic performance of the ZSC catalyst can be attributed to the bimodal pore system coupled to the medium acid amount, which effectively suppresses hydrogen transfer reactions of primary light olefins while facilitating the cracking and isomerization transformations of hydrocarbon intermediates, leading to the improved formation of C3 and C4 olefins and branched gasoline hydrocarbons.

The analysis of short tandem repeat (STR) loci using PCR followed by capillary electrophoresis (CE) remains the gold standard in forensic genetics and human identity testing. However, the quality of the STR allele frequency databases for Vietnamese Kinh population is not assured and the number of investigated STR loci in the researches is limited. To increase the reliability of allele frequency databases and the associated statistical parameters used for personal identification, paternity testing, and forensics, genetic polymorphisms at 23 STR loci were examined in a large sample comprising 1000 unrelated Vietnamese Kinh individuals. Our dataset was submitted to STRidER (STRs for Identity ENFSI Reference Database) for quality control. The data were verified and successfully passed the inspection of STRidER (Reference No. STR000345). No significant deviation from the Hardy Weinberg equilibrium was found for the observed loci after applying the Bonferroni correction. All loci showed a high degree of genetic polymorphism, the most informative locus among the study panel was Penta E. The combined power of discrimination (CPD) and the combined power of exclusion (CPE) for all 23 STR loci were 1 and 0.9999999992, respectively. We aimed to identify allele frequencies which could be used for forensic applications and found several distinct alleles upon comparing our results with those of previous STR loci studies in the Vietnamese population. Taken together, these results indicate that these 23 STR loci are suitable genetic markers for forensics, personal identification, and paternity testing in the Vietnamese Kinh population.

The influence of post-synthetic modifications of Al-rich ZSM-5 (Si/Al ratio ca. 10) involving alkaline and subsequent acid treatments on the textural, acidic and catalytic properties in the cracking of bulky hydrocarbon molecules at low temperature is reported. It was found that the optimized base treatment, i.e. 0.5 M NaOH should be used for the substantial generation of intracrystal mesoporosity while preserving the intrinsic zeolite properties of ZSM-5 zeolite. A subsequent strong acid washing, i.e. 0.5 M HCl is required to completely remove Al-rich debris formed during the base treatment, thereby improving the textural and acidic properties. The catalytic performance of the parent and treated ZSM-5 materials was evaluated in the gas phase cracking of 1,3,5-triisopropylbenzene (TIPB) and cumene as test reactions. The results showed that under the applied cracking conditions, the introduction of mesoporosity by the optimized base–acid treatments on the one hand increased the accessibility of Bronsted acid sites, producing a higher TIPB conversion (82.5% as compared to 61.9% of the parent ZSM-5), on the other hand, it promoted the transformation of pre-cracking products, leading to a higher selectivity to deep cracking products, i.e. the selectivity of cumene and benzene of 22.7% as compared to 17.6% of the parent ZSM-5. A similar conclusion has been reached in the cracking of cumene where the presence of considerable mesoporosity indeed improved cumene reactivity of the alkaline and acid treated ZSM-5 as its density of strong zeolite Bronsted sites was mainly retained.

Nano-ZSM-5/SBA-15 analog composites (ZSC) were prepared in a two-step process from ZSM-5 precursors with different Si/Al molar ratios (10–50) via high-temperature synthesis in mildly acidic media (200 °C, pH 3.5) aiming to evaluate the influence of the initial Si/Al ratio on their structural, acidic and catalytic properties. The resulting materials were characterized by SAXS, XRD, FTIR, TEM, N2 sorption, 27Al solid state-NMR, NH3-TPD, FTIR spectroscopy of adsorbed pyridine, AAS and ICP-AES. Under the applied synthesis conditions, a ZSC material with controlled distribution of nano-ZSM-5 and SBA-15 analog phases can be prepared from ZSM-5 precursors by adjusting the initial Si/Al ratio in the range of 20–30. Increasing the initial Si/Al ratio to 50, only ZSM-5 nanocrystals were obtained whereas reducing the initial Si/Al ratio to 10 led to the formation of a disordered mesoporous SBA-15 analog. The total acidity increases with the crystallinity of the ZSM-5 phase as varying the Si/Al ratio from 10 to 30 despite the decreased amount of incorporated aluminum. However, the acidity declines slightly when raising the Si/Al ratio to 50 because of the low incorporated aluminum. The catalytic performance of the ZSC materials compared to the reference materials, i.e. purely mesoporous Al-SBA-15 and purely microporous H-ZSM-5 was assessed in the gas phase cracking of cumene and 1,3,5-tri-isopropylbenzene (TIPB) as test reactions. The results show that a balanced ratio of nano-ZSM-5 and SBA-15 analog phases obtained by tuning the initial Si/Al ratio is crucial to achieve superior catalytic performance of the ZSC materials in the cracking of both cumene and TIPB.

Ion exchange and thermal stability of hierarchical Y zeolites obtained by the acid and subsequent base treatments of commercial NaY zeolite were studied. It was found that the resulting hierarchical Y zeolite exhibited lower lanthanum ion exchange efficiency and thermal stability compared to the parent NaY zeolite. The introduction of lanthanum in the hierarchical Y zeolite significantly enhanced its thermal stability due to the advantageous combination of the stabilized effect of lanthanum and the reduced content of residual sodium ions. The latter was of paramount importance because the presence of sodium ions promoted breakdown of the hierarchical Y zeolite framework by dislodging aluminum enriched on the zeolite surface during the base treatment. Notably, the generated mesopores facilitated removal of residual sodium ions during the ammonium ion exchange treatment. Consequently, the hierarchical Y zeolite displayed superior thermal/hydrothermal stability even with a low La loading of 3 w t.%.

We study the coupling of GaAs quantum wells to waveguide–plasmon polaritons supported by a thin InAlGaAs-based slab waveguide and a Ag grating. The hybrid photon–plasmon modes are excited in a freestanding emitter–waveguide–plasmon structure realized by rolling-up strained InAlGaAs-based layers and nanopatterned Ag structures. By varying the grating’s bar width, we tune the plasmonic resonance of the system. We observe by means of spatially, spectrally, and temporally resolved photoluminescence measurements, a coupling of the quantum-well emission to the waveguide–plasmon system for a specific grating’s bar width. Supported by finite-element simulations, we can assign the coupling to the excitation of a waveguide–plasmon polariton.