37 research outputs found
Mg-Based Nano-layered Thin Films for Hydrogen Storage
Magnesium (Mg) based materials are now some of the most promising materials for hydrogen storage due to their light weight and high hydrogen capacity. Their most significant limitation, however, is the high de-hydrogenation temperature and low kinetics. Niobium (Nb) has been proposed for improving the hydrogen sorption kinetics in Mg thin films. In this work, Mg/Nb multi-layered thin films were investigated by theoretical methods and compared to experimental results. Some selected properties such as structural, elastic, energetic and electronic charge properties of the bulk and thin films have been investigated.
Firstly, classical thermodynamic models and first-principles calculations based on Density Functional Theory (DFT) were used for describing the pseudomorphic growth in Mg/Nb multi-layered films observed in experiments. Calculations of the thermodynamic, electronic and structural stability of a body-centered cubic (bcc) Mg show that this structure is in fact metastable under thin film conditions, when Mg grows epitaxially on the bcc Nb, in agreement with experiments. The predicted bi-phase diagram of Mg/Nb multilayers indicated that not only the metastable bcc Mg can be stabilized, but also a hexagonal close packed (hcp) Nb can be stabilized under the specific range of the bilayer thickness and the volume fractions of the constituents.
Next, the hydrogen desorption properties of the free standing Mg films and Mg/Nb multilayers were elucidated by DFT calculations. The computational tools were used for assisting the experimental characterization. As a result, two metastable orthorhombic magnesium hydrides (Os-MgH_(2) and Om –MgH_(2)) were observed in those films. Due to the influence of stress and corresponding formation of these metastable phases, significant destabilization of MgH2 provides ultra-low hydrogen desorption temperature in both free-standing Mg and multilayer Mg/Nb films. Formation of enthalpies (∆Hf) and estimating desorption temperatures (Td) were determined by DFT calculations and indicated that either tension or compression will lead to destabilization of MgH_(2). Moreover the hydrogen diffusion mechanisms were studied in both bulk and thin film structures. The site preference and diffusion activation energy calculations successfully describe hydrogen sorption behavior in Mg/Nb multilayers in experiments.
It is expected that the results of this research will foster further work on the development of the solid-state hydrogen storage systems necessary to bring the hydrogen economy closer to reality
Integrated of Geographic Information System for Supporting Tourism 12 Cities Hidden Gems Plus: Case Study Eastern Region
The aim of this research is to provide a geographic information system on the tourism 12 Cities Hidden Gems plus provincial groups on patrol routes, educational routes, tourist attractions and facilities, and tourist attractions in a sequence of steps in the form of online media on Google Maps. This research used network analysis, considering the distance and time for traveling. There is invent the database of geographic information and maps to show the position of tourist attractions 55 places, 325 places of hotels, 248 places of restaurants, 59 places of police stations, and 40 places of hospitals. The result of the routes analysis is divided into routes from the main road that entrance to the eastern region to Chanthaburi, Sakae, Trat, and Rayong The route takes the most time and distance is highway no.304 to Trat city hall takes 5 hours 13 minutes, distance 295.9 kilometers. The route takes the shortest time and distance is Highway no.304 to Sakaew city hall takes 1 hour 49 minutes, a distance of 92.1 kilometers. And routes from tourist attractions of couple provinces to the other that same type of tourist attractions. There are 8 routes that are divided into 3 routes for Chanthabiri to Sakaew and 5 routes for Trat to Rayong. The result of service area analysis for tourist attractions that can arrive in 15, 30, and 45 minutes. There are 23 places of tourist attractions divided into 6 places of Chanthabiri, 5 places of Sakaew, 6 places of Trat, and 5 places of Rayong. The result of closest facility analysis shows the best routes from 23 places of tourist attractions to closest facility, namely 325 places of hotels, 248 places of restaurants, 59 places of police stations, and 40 places of hospitals. There is a public database of geographic information about tourist attractions of 12 Hidden Gems Plus campaign and facilities, namely hotels, restaurants, police stations, hospitals, orchards, and souvenir shops covering provinces in the eastern region on Gmail account [email protected] in form of online media Google Maps to interested persons or related organizations. Those who are interested can use the GIS database prepared to be used for further research. And was inspired to continue to bring the application of GIS It has been used to support tourism in Tourism 12 Cities Hidden Gems Plus in other regions and related agencies can use the research results to support tourism " Tourism 12 Cities Hidden Gems Plus" in the eastern region. And this research has been extended to be prepared in various languages such as English, Chinese, etc. to benefit and convenience for foreign tourists
A Study of Areas Affected by the Burning of Waste Landfills in Samut Prakan Province with the ALOHA Model
The objective of this research was to study the areas affected by the burning of waste landfills in Samut Prakan Province using the ALOHA model. (1) the analysis from the atmospheric dispersion ALOHA model, exposed that Carbon Monoxide has spread covering the area of 6,151.23 rai. The outcome was later confirmed by photos taken from the THEOS satellite over the burning Praeksa landfill and areas covered with smoke on March 18, 2014 with the overall accuracy of 81.98 %. (2) The areas affected from the smoke were divided into 3 categories: buildings and structures, significant places, and areas of land use. Buildings and structures were most affected with the concentration over 3 ppm damaging 3,612 households. For the significant places, the places that has been most affected was found with the concentration over 1-2 ppm. 6 considerable places composed of 4 schools and 2 gas stations were damaged. The last thing was areas of land use, the areas of land use that have been most affected were found with the concentration over 1-2 ppm with a total area of 93,130 rai
Nucleoside/nucleotide reverse transcriptase inhibitor sparing regimen with once daily integrase inhibitor plus boosted darunavir is non-inferior to standard of care in virologically-suppressed children and adolescents living with HIV – Week 48 results of the randomised SMILE Penta-17-ANRS 152 clinical trial
Dolutegravir twice-daily dosing in children with HIV-associated tuberculosis: a pharmacokinetic and safety study within the open-label, multicentre, randomised, non-inferiority ODYSSEY trial
Background:
Children with HIV-associated tuberculosis (TB) have few antiretroviral therapy (ART) options. We aimed to evaluate the safety and pharmacokinetics of dolutegravir twice-daily dosing in children receiving rifampicin for HIV-associated TB.
Methods:
We nested a two-period, fixed-order pharmacokinetic substudy within the open-label, multicentre, randomised, controlled, non-inferiority ODYSSEY trial at research centres in South Africa, Uganda, and Zimbabwe. Children (aged 4 weeks to <18 years) with HIV-associated TB who were receiving rifampicin and twice-daily dolutegravir were eligible for inclusion. We did a 12-h pharmacokinetic profile on rifampicin and twice-daily dolutegravir and a 24-h profile on once-daily dolutegravir. Geometric mean ratios for trough plasma concentration (Ctrough), area under the plasma concentration time curve from 0 h to 24 h after dosing (AUC0–24 h), and maximum plasma concentration (Cmax) were used to compare dolutegravir concentrations between substudy days. We assessed rifampicin Cmax on the first substudy day. All children within ODYSSEY with HIV-associated TB who received rifampicin and twice-daily dolutegravir were included in the safety analysis. We described adverse events reported from starting twice-daily dolutegravir to 30 days after returning to once-daily dolutegravir. This trial is registered with ClinicalTrials.gov (NCT02259127), EudraCT (2014–002632-14), and the ISRCTN registry (ISRCTN91737921).
Findings:
Between Sept 20, 2016, and June 28, 2021, 37 children with HIV-associated TB (median age 11·9 years [range 0·4–17·6], 19 [51%] were female and 18 [49%] were male, 36 [97%] in Africa and one [3%] in Thailand) received rifampicin with twice-daily dolutegravir and were included in the safety analysis. 20 (54%) of 37 children enrolled in the pharmacokinetic substudy, 14 of whom contributed at least one evaluable pharmacokinetic curve for dolutegravir, including 12 who had within-participant comparisons. Geometric mean ratios for rifampicin and twice-daily dolutegravir versus once-daily dolutegravir were 1·51 (90% CI 1·08–2·11) for Ctrough, 1·23 (0·99–1·53) for AUC0–24 h, and 0·94 (0·76–1·16) for Cmax. Individual dolutegravir Ctrough concentrations were higher than the 90% effective concentration (ie, 0·32 mg/L) in all children receiving rifampicin and twice-daily dolutegravir. Of 18 children with evaluable rifampicin concentrations, 15 (83%) had a Cmax of less than the optimal target concentration of 8 mg/L. Rifampicin geometric mean Cmax was 5·1 mg/L (coefficient of variation 71%). During a median follow-up of 31 weeks (IQR 30–40), 15 grade 3 or higher adverse events occurred among 11 (30%) of 37 children, ten serious adverse events occurred among eight (22%) children, including two deaths (one tuberculosis-related death, one death due to traumatic injury); no adverse events, including deaths, were considered related to dolutegravir.
Interpretation:
Twice-daily dolutegravir was shown to be safe and sufficient to overcome the rifampicin enzyme-inducing effect in children, and could provide a practical ART option for children with HIV-associated TB
Neuropsychiatric manifestations and sleep disturbances with dolutegravir-based antiretroviral therapy versus standard of care in children and adolescents: a secondary analysis of the ODYSSEY trial
BACKGROUND: Cohort studies in adults with HIV showed that dolutegravir was associated with neuropsychiatric adverse events and sleep problems, yet data are scarce in children and adolescents. We aimed to evaluate neuropsychiatric manifestations in children and adolescents treated with dolutegravir-based treatment versus alternative antiretroviral therapy. METHODS: This is a secondary analysis of ODYSSEY, an open-label, multicentre, randomised, non-inferiority trial, in which adolescents and children initiating first-line or second-line antiretroviral therapy were randomly assigned 1:1 to dolutegravir-based treatment or standard-of-care treatment. We assessed neuropsychiatric adverse events (reported by clinicians) and responses to the mood and sleep questionnaires (reported by the participant or their carer) in both groups. We compared the proportions of patients with neuropsychiatric adverse events (neurological, psychiatric, and total), time to first neuropsychiatric adverse event, and participant-reported responses to questionnaires capturing issues with mood, suicidal thoughts, and sleep problems. FINDINGS: Between Sept 20, 2016, and June 22, 2018, 707 participants were enrolled, of whom 345 (49%) were female and 362 (51%) were male, and 623 (88%) were Black-African. Of 707 participants, 350 (50%) were randomly assigned to dolutegravir-based antiretroviral therapy and 357 (50%) to non-dolutegravir-based standard-of-care. 311 (44%) of 707 participants started first-line antiretroviral therapy (ODYSSEY-A; 145 [92%] of 157 participants had efavirenz-based therapy in the standard-of-care group), and 396 (56%) of 707 started second-line therapy (ODYSSEY-B; 195 [98%] of 200 had protease inhibitor-based therapy in the standard-of-care group). During follow-up (median 142 weeks, IQR 124–159), 23 participants had 31 neuropsychiatric adverse events (15 in the dolutegravir group and eight in the standard-of-care group; difference in proportion of participants with ≥1 event p=0·13). 11 participants had one or more neurological events (six and five; p=0·74) and 14 participants had one or more psychiatric events (ten and four; p=0·097). Among 14 participants with psychiatric events, eight participants in the dolutegravir group and four in standard-of-care group had suicidal ideation or behaviour. More participants in the dolutegravir group than the standard-of-care group reported symptoms of self-harm (eight vs one; p=0·025), life not worth living (17 vs five; p=0·0091), or suicidal thoughts (13 vs none; p=0·0006) at one or more follow-up visits. Most reports were transient. There were no differences by treatment group in low mood or feeling sad, problems concentrating, feeling worried or feeling angry or aggressive, sleep problems, or sleep quality. INTERPRETATION: The numbers of neuropsychiatric adverse events and reported neuropsychiatric symptoms were low. However, numerically more participants had psychiatric events and reported suicidality ideation in the dolutegravir group than the standard-of-care group. These differences should be interpreted with caution in an open-label trial. Clinicians and policy makers should consider including suicidality screening of children or adolescents receiving dolutegravir
Theoretical Insight into Catalytic Propane Dehydrogenation on Ni(111)
Here, propane dehydrogenation (PDH)
to propylene and side reactions,
namely, cracking and deep dehydrogenation on Ni(111) surface, have
been theoretically investigated by density functional theory calculation.
On the basis of adsorption energies, propane is physisorbed on Ni(111)
surface, whereas propylene exhibits chemisorption supported by electronic
charge results. In the PDH reaction, possible pathways can occur via
two possible intermediates, i.e., 1-propyl and 2-propyl. Our results
suggest that PDH reaction through 1-propyl intermediate is both kinetically
and thermodynamically more favorable than another pathway. The C–C
bond cracking during PDH process is more difficult to occur than the
C–H activation reaction because of higher energy barrier of
the C–C bond cracking. However, deep dehydrogenation is the
preferable process after PDH, owing to the strong adsorption of propylene
on Ni(111) surface, resulting in low selectivity of propylene production.
This work suggests that Ni(111) has superior activity toward PDH;
however, the enhancement of propylene desorption is required to improve
its selectivity. The understanding in molecular level from this work
is useful for designing and developing better Ni-based catalysts in
terms of activity and selectivity for propane conversion to propylene
Environmental, Economic, Social and Health Impacts from the Flood Situation in Kham Riang Sub-district, Kantharawichai District, Maha Sarakham Province, Thailand in 2022
The purpose of this research was to study the environmental, economic, social and health impacts of the flood situation in Kham Riang sub-district, Kantharawichai district, Maha Sarakham province. The sample used in the study were 140 villagers, 10 villagers per village, 14 villages of affected by environmental, economic, social and health impacts of the flood situation in Kham Riang sub-district, Kantharawichai district, Maha Sarakham province, from purposive sampling. The tools used in the study were: 1) interview form for the impact of the flood situation, 2) questionnaire on the impact of the flood situation. Qualitative data were analyed as descriptive. The results of the study showed that :1) Environmental impact from the flood situation, it was found that most of them were damaged in agriculture, for example, the flooding of rice fields and vegetable gardens, resulting in the lack of agricultural products for villagers and lack of income from agriculture. 2) The economic impact from the flood situation was found to affect agricultural crops and made the villagers lose income from their work due to inability to travel to work. And after the flood disaster disappeared must borrow debt borrowing money to repair the house which such villagers has been doing agriculture for the most part by damage to the plantation will fall at 1,750 baht per rai. There were some families relying on agriculture as their main occupation, the next occupation is trading. There are no products to be sold and do not have money to go buy things to resell. 3) Social impact from the flood situation, it was found that most of them were damaged in housing such as doors, windows, home appliances that were broken. The road has been damaged by water erosion, making traffic difficult for a long time, having to use a boat instead of a car to travel. Agricultural crops are damaged, especially the rice fields that were mostly damaged.4) Health impact from the flood situation, it was found that most of them had water allergies, such as biting feet. The cause of water bites is caused by irritation of the skin. Due to wetness and exposure to dirt, various chemicals in flooded areas can cause eczema. The skin looks peeling, especially at the niche of the toes which has a red rash, burning, itching, including causing stress and anxiety in the lives of the villagers in everyday life
Phase speciation and surface analysis of copper phosphate on high surface area silica support by in situ XAS/XRD and DFT: Assessment for guaiacol hydrodeoxygenation
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