Bake hardening effect of the low strength interstitial free steel

This paper investigates the influence of pre-strain and temperature on the bake hardening (BH) effect of the low strength interstitial free (IF) steel with the yield strength of 137 MPa. The tensile specimens were pre-strained to 2-4-6 % at room temperature followed by baking at temperatures of 150-200-250 oC for 20 minutes. The BH strength was determined by a standard procedure based on the difference between the lower yield strength of the baked specimen and the flow stress of the initial one. The microstructure of the IF steels was characterized by optical microscopy and scanning electron microscopy for the purpose of explaining the BH effect. All the initial and baked steels show a microstructure that includes the ferrite phase, of an average grains size of 45 µm. This observation was consistent with the mechanical properties of the initial steel. The BH strengths have been achieved from 12 to 35 MPa, in which the maximum value was found for the specimen that pre-strained to 6 % and baked at 200 oC. The BH strengths increased with increasing the pre-strain, but slightly decreased when the baking temperature was 250 oC. This mechanism is attributed to pinning of dislocation by carbon solute atoms during the baking process, and the BH strength was correlated with grain boundary segregation

Thin films of Co1.7Fe1.3O4 prepared by radio frequency sputtering - the first step towards their spinodal decomposition

Pure thin films of Co1.7Fe1.3O4 spinel iron cobaltites were prepared for the first time by radio frequency sputtering. Such films are made of small crystallites of about 20 to 30 nm in diameter. Because Co1.7Fe1.3O4 films have a composition located in the miscibility gap of Fe3O4–Co3O4, they can be submitted to spinodal transformation below about 900 °C. This transformation was also confirmed at 600 °C by X-ray diffraction and transmission electron microscopy studies. It was demonstrated however that this spinodal transformation occurs after only a few hours at low temperature. Indeed, after annealing in air at 300 to 450 °C for a few hours, the spinodal transformation leading to two-phase spinels, one rich in iron and the other rich in cobalt, was clearly revealed by Raman spectroscopy and electrical measurements

Preparation of iron cobaltite thin films by RF magnetron sputtering

Iron cobaltite thin films with spinel structure have been elaborated by radio-frequency (RF) magnetron sputtering from a Co1.75Fe1.25O4 target. Influence of argon pressure on structure, microstructure and physical properties of films has been examined. Iron–cobalt oxide thin films essentially consist of one spinel phase when deposited at low pressure (0.5 and 1.0 Pa). At high pressure (2.0 Pa), the global stoichiometry of the film is changed which results in the precipitation of a mixed monoxide of cobalt and iron beside the spinel phase. This in-situ reduction due to an oxygen loss occurring mainly at high deposition pressure has been revealed by X-ray diffraction and Raman spectroscopy. Microstructural evolution of thin film with argon pressure has been shown by microscopic observations (AFM and SEM). The evolution of magnetic and electrical properties, versus argon pressure, has been also studied by SQUID and 4 point probe measurements

Multiobjective Logistics Optimization for Automated ATM Cash Replenishment Process

In the digital transformation era, integrating digital technology into every aspect of banking operations improves process automation, cost efficiency, and service level improvement. Although logistics for ATM cash is a crucial task that impacts operating costs and consumer satisfaction, there has been little effort to enhance it. Specifically, in Vietnam, with a market of more than 20,000 ATMs nationally, research and technological solutions that can resolve this issue remain scarce. In this paper, we generalized the vehicle routing problem for ATM cash replenishment, suggested a mathematical model and then offered a tool to evaluate various situations. When being evaluated on the simulated dataset, our proposed model and method produced encouraging results with the benefits of cutting ATM cash operating costs

Carotenoid producing Bacillus aquimaris found in chicken gastrointestinal tracts

Pigmented spore-forming bacterial strains were isolated from the gastrointestinal tracts of chickens for screening for heat-stable carotenoid-producing strains that could be applied as feed supplements. Of the seven heat-stable pigmented isolates screened, only two, yellow Sporosarcina saromensis CH1 and red-orange Bacillus aquimaris CH9, produced pigments with typical carotenoid absorbance peaks (400–500 nm). The CH9 carotenoids exhibited higher scavenging activity (73.2%) of DPPH free radicals than the CH1 carotenoids (35.9%) and carotenoids of the reference B. indicus HU36 strain (78.4%), in comparison to 100% activity of acid ascorbic at 18.75 M as the standard. The CH9 strain produced high levels of carotenoids (439 g [g DW]-1) and formed nearly 100% spores, whereas the CH1 strain produced low levels of carotenoids (92 g [g DW]-1) and only achieved 30% sporulation. Chromatographic and spectral profiles of the carotenoids found in CH9 indicated the presence of as many as 11 different carotenoid types closely related to 1-HO-demethylspheroidene and keto/hydroxyl derivatives of carotene. We successfully produced concentrated orange CH9 spore powder at a high concentration of 6.1 × 1011 CFU g-1; these spores were much more heat-stable (66% survival at 80°C for 20 min) than the reference B. indicus HU36 spores (9% survival at 50°C for 20 min). In conclusion, B. aquimaris CH9 is a promising probiotic carotenoid-producing strain, with heat-stable spores that should withstand the heat-treatment processing required for feed and food supplement production

Outcome and impact assessment of the Climate-Smart Village Program in Northern Vietnam

Yen Bai province inherits representative biophysical, socio-economic, smaller-holder farming characteristics to economic marginalization and climatic risks and impacts to agricultural production and local livelihoods of Vietnam’s northern mountain region (NMR). The CCAFS project deployed to Ma Climate-Smart Village (CSV) in Yen Bai in 2015 with bilateral funding support from two other research projects aimed at setting up a demonstration-for-scaling example of a rural community equipped with capacities for enhanced climate adaptation and resilience. This study applied a three tier interview data collection methodology (key informant interviews – focus group discussions – indepth farmer interviews) to thoroughly investigate 120 households about six main outcomes accomplished by the project up until 2021. The project has achieved great outcomes from the village to the provincial levels. However, the project work still has a potential to be scaled to the National Target Program on New Rural Development (NTM) given its interest in developing resilient communities in climate-vulnerable regions across the country applying the CSV approach in its 2021-2025 strategy. Despite the closing of the CCAFS program by December 2021, this most important scaling pathway will be continued by the VIBE 2018.05 (funded by the Irish Aid) and COALESCE/2020/34 (funded by the Irish Research Council) under the management of Vietnam National University of Agriculture – a long-term strategic partner of the CCAFS program in the NRM

CSA: Thực hành nông nghiệp thông minh với khí hậu ở Việt Nam

During the last five years, Vietnam has been one of the countries most affected by climate change. Severe typhoons, flooding, cold spells, salinity intrusion, and drought have affected agriculture production across the country, from upland to lowland regions. Fortunately for Vietnam, continuous work in developing climate-smart agriculture has been occurring in research organizations and among innovative farmers and entrepreneurs. Application of various CSA practices and technologies to adapt to the impact of climate change in agriculture production have been expanding. However, there is a need to accelerate the scaling process of these practices and technologies in order to ensure growth of agriculture production and food security, increase income of farmers, make farming climate resilient, and contribute to global climate change mitigation. This book aims to provide basic information to researchers, managers, and technicians and extentionists at different levels on what CSA practices and technologies can be up scaled in different locations in Vietnam

Echinacea purpurea: An overview of mechanism, efficacy, and safety in pediatric upper respiratory infections and otitis media

Pediatric upper respiratory infections (URIs) and otitis media (OM) significantly impact the health of children globally. Echinacea purpurea, known for its immunomodulatory, anti-inflammatory, and antimicrobial properties, has been historically used to treat various ailments, suggesting its potential as an adjunctive treatment in pediatric respiratory conditions. This narrative review synthesizes literature from January 2000 to December 2023 on the efficacy and safety of E. purpurea in treating pediatric URIs, including OM. It focuses on clinical trials and empirical studies that explore the mechanisms of action, such as the modulation of cytokine production, inhibition of NF-κB signaling, and antimicrobial effects. The analysis reveals mixed outcomes regarding the efficacy of E. purpurea in pediatric populations, attributed partly to variability in study designs and lack of standardized treatment protocols. While some studies report reduced severity and duration of respiratory symptoms, others indicate minimal or no significant difference compared to placebo. The review also highlights the need for specifically designed products that cater to the unique physiological and metabolic needs of children. Rigorous, well-designed clinical trials are crucial for establishing clear guidelines on the use of E. purpurea in pediatric respiratory care, ensuring its safe and effective application in improving health outcomes for children

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke