Molecular beam growth of graphene nanocrystals on dielectric substrates

We demonstrate the growth of graphene nanocrystals by molecular beam methods that employ a solid carbon source, and that can be used on a diverse class of large area dielectric substrates. Characterization by Raman and Near Edge X-ray Absorption Fine Structure spectroscopies reveal a sp2 hybridized hexagonal carbon lattice in the nanocrystals. Lower growth rates favor the formation of higher quality, larger size multi-layer graphene crystallites on all investigated substrates. The surface morphology is determined by the roughness of the underlying substrate and graphitic monolayer steps are observed by ambient scanning tunneling microscopy.Comment: Accepted in Carbon; Discussion section added; 20 pages, 6 figures (1 updated

Sustainability practices at higher education institutions in Asia

https://v2.sherpa.ac.uk/id/publication/2806Purpose - It is still unclear how Asian universities incorporate the theory or practice of sustainable development (SD) in their research and education programmes. To address this gap, the purpose of this paper is to report on a study that has examined how universities in Asian countries handle and address matters related to SD. Design/methodology/approach - The study used a bibliometric analysis and an online survey-method. The online survey data were analysed through descriptive analysis and one-sample student’s t-test. Findings – The study indicates that there is considerable variation among the Asian countries regarding sustainability practices in higher education institutions (HEIs). The HEIs in far eastern countries, such as Indonesia, Malaysia and Thailand are perceived to demonstrate more sustainability practices. Research limitations/implications - Even though a substantial number of participants participated in the survey, it did not cover all Asian countries. The online survey was carried out over a limited period of time, and not all HEIs in the field may have received information about the study. Practical implications – Asia is the largest continent facing a number of sustainability challenges. In this context, the contribution of HEIs is very important. The findings of the current study may serve as a baseline for Asian HEIs to take more initiatives towards SD goals, as HEIs are responsible for the education and training of hundreds of thousands of students who will be occupying key positions in industry, government or education in the coming years. Originality/value – The study contributes to the existing literature in two distinct ways. First, it was possible to develop a comprehensive instrument to measure sustainability practices in HEIs. Second, this study has filled the gap of the scarcity of studies regarding sustainability practices in HEIs in Asia.info:eu-repo/semantics/publishedVersio

Recovery of carbon fibres and production of high quality fuel gas from the chemical recycling of carbon fibre reinforced plastic wastes

A solvolysis process to depolymerize the resin fraction of carbon fibre reinforced plastic waste to recover carbon fibre, followed by hydrothermal gasification of the liquid residual product to produce fuel gas was investigated using batch reactors. The depolymerisation reactions were carried out in ethylene glycol and ethylene glycol/water mixtures at near-critical conditions of the two solvents. With ethylene glycol alone the highest resin removal of 92.1% was achieved at 400 °C. The addition of water to ethylene glycol led to higher resin removals compared to ethylene glycol alone. With an ethylene glycol/water ratio of 5, at 400 °C, resin removal was 97.6%, whereas it was 95.2% when this ratio was 3, at the same temperature. The mechanical properties of the recovered carbon fibre were tested and showed minimal difference in strength compared to the virgin carbon fibre. The product liquid, containing organic resin degradation products was then subjected to catalytic supercritical water gasification at 500 °C and 24 MPa in the presence of NaOH and Ru/AlO as catalysts, respectively. Up to 60 mol.% of H gas was produced with NaOH as catalyst, and 53.7 mol.% CH gas was produced in the presence of Ru/AlO

MARTA: a high-energy cosmic-ray detector concept for high-accuracy muon measurement

A new concept for the direct measurement of muons in air showers is presented. The concept is based on resistive plate chambers (RPCs), which can directly measure muons with very good space and time resolution. The muon detector is shielded by placing it under another detector able to absorb and measure the electromagnetic component of the showers such as a water-Cherenkov detector, commonly used in air shower arrays. The combination of the two detectors in a single, compact detector unit provides a unique measurement that opens rich possibilities in the study of air showers.Peer Reviewe

Muon Array with RPCs for Tagging Air showers (MARTA)

We discuss the concept of an array with Resistive Plate Chambers (RPC) for muon detection in ultra-high energy cosmic ray (UHECR) experiments. RPC have been used in particle physics experiments due to their fast timing properties and spatial resolution. The operation of a ground array detector poses challenging demands, as the RPC must operate remotely under extreme en- vironments, with limited power and minimal maintenance. In its baseline configuration, each MARTA unit includes one 1.5x1.2 m 2 RPC, with 64 pickup electrodes (pads). The DAQ sys- tem is based on an ASIC, allowing one to read out the high number of channels with low power consumption. Data are recorded using a dual technique: single particle counting with a simple threshold on the signal from each pad and charge integration for high occupancy. The RPC, DAQ, High Voltage and monitoring systems are enclosed in an aluminum-sealed case, providing a com- pact and robust unit suited for outdoor environments, which can be easily deployed and connected. The RPCs developed at LIP-Coimbra are able to operate using very low gas flux, which allows running them for few years with a small gas reservoir. Several full-scale units are already installed and taking data in several locations and with different configurations, proving the viability of the MARTA concept. By shielding the detector units with enough slant mass to absorb the electro- magnetic component in the air showers, a clean measurement of the muon content is allowed, a concept to be implemented in a next generation of UHECR experiments. The specificities of a MARTA unit are presented, which include particle counting with high efficiency, time resolu- tion and spatial segmentation. The potential of the MARTA concept for muon measurements in air showers is assessed, as well as tentative methods for calibration and cross-calibrations with existing detectors.Peer Reviewe

Identification of Streptococcus pneumoniae by a real-time PCR assay targeting SP2020.

Real-time PCR targeting lytA (the major autolysin gene) and piaB (permease gene of the pia ABC transporter) are currently used as the gold-standard culture-independent assays for Streptococcus pneumoniae identification. We evaluated the performance of a new real-time PCR assay - targeting SP2020 (putative transcriptional regulator gene) - and compared its performance with the assays previously described. A collection of 150 pneumococci, 433 non-pneumococci and 240 polymicrobial samples (obtained from nasopharynx, oropharynx, and saliva; 80 from each site) was tested. SP2020 and lytA-CDC assays had the best performance (sensitivity of 100% for each compared to 95.3% for piaB). The specificity for lytA and piaB was 99.5% and for SP2020 was 99.8%. Misidentifications occurred for the three genes: lytA, piaB and SP2020 were found in non-pneumococcal strains; piaB was absent in some pneumococci including a serotype 6B strain. Combining lytA and SP2020 assays resulted in no misidentifications. Most polymicrobial samples (88.8%) yielded concordant results for the three molecular targets. The remaining samples seemed to contain non-typeable pneumococci (0.8%), and non-pneumococci positive for lytA (1.7%) or SP2020 (8.7%). We propose that combined detection of both lytA-CDC and SP2020 is a powerful strategy for the identification of pneumococcus either in pure cultures or in polymicrobial samples

Homemade oral supplement: a proposal for the nutritional recovery of children and adolescents with cancer

Objective The aim of this study was to evaluate the impact of homemade oral supplements on the nutritional recovery of patients with mild or severe malnutrition or at nutritional risk. Methods Eight recipes of homemade oral supplements containing 30% to 35% of the total energy expenditure were proposed. The patients with severe malnutrition (group B) received the oral supplement for 2 weeks and the others for 4 weeks (group A). Oral supplementation with homemade supplements was compared with oral supplementation with store-bought supplements, investigated earlier with a protocol with the same design. Results Homemade oral supplements contain much lower amounts of certain micronutrients but are five times cheaper than store-bought supplements. In group A, 88% of the patients taking homemade oral supplements and 84% of the patients taking store-bought supplements responded positively to supplementation. In group B, 22% of the patients taking homemade oral supplements and 25% of the patients taking store-bought supplements recovered. The difference was not significant. The impact of store-bought supplementation on the triceps skinfold thicknesses and arm circumferences of the patients in group A was greater than that obtained with homemade supplements. In group B, the effect on triceps skinfold thickness was not significant (p=0.16). Patients taking homemade or store-bought oral supplements presented similar protein and energy intakes and improvements in nutritional status. Only the body composition of patients in group A taking store-bought oral supplements was better. Conclusion The results obtained by this study suggest that the therapeutic use of homemade oral supplements is an alternative capable of promoting the nutritional recovery of cancer patients, especially those who cannot afford store-bought supplements.Objetivo Avaliar o impacto do suplemento oral artesanal na recuperação do estado nutricional de pacientes com desnutrição leve, grave e com risco nutricional. Métodos Propuseram-se oito receitas de suplementos visando ofertar entre 30,0% e 35,0% do gasto energético total. Os pacientes com desnutrição grave (grupo B) receberam o suplemento oral por duas semanas, e os demais pacientes (grupo A), por quatro semanas. Para a comparação dos resultados obtidos com o emprego do suplemento oral artesanal, foram utilizados dados referentes a um protocolo anterior, com o mesmo desenho, entretanto, com a utilização de suplemento oral industrializado. Resultados O suplemento oral artesanal fica muito aquém no que diz respeito a alguns micronutrientes, entretanto é cinco vezes mais barato do que a preparação com o suplemento oral industrializado. Os pacientes do grupo A com suplemento oral artesanal apresentaram 88,0% de resposta positiva na semana de avaliação, enquanto os com suplemento oral industrializado tiveram 84,0%. No grupo B, foram recuperados 22,0% dos pacientes com suplemento oral artesanal e 25,0% do grupo com suplemento oral industrializado, não apresentando, portanto, diferença significante. Comparando o impacto do industrializado com o do artesanal na prega cutânea tricipital e circunferência do braço, verificou-se que o suplemento oral industrializado no grupo A apresentou melhores resultados que o suplemento oral artesanal, e no grupo B, esse efeito observado na prega cutânea não foi significante (p=0,16). Os consumos de energia e de proteína, assim como a evolução nutricional, foram semelhantes entre suplemento oral industrializado e suplemento oral artesanal. Apenas a composição corpórea no grupo A com suplemento oral industrializado apresentou melhores resultados. Conclusão Os resultados apresentados neste estudo sugerem que o emprego da terapia com suplemento artesanal seja uma opção capaz de auxiliar na recuperação nutricional de pacientes oncológicos e uma opção para populações financeiramente desfavorecidas.Hospital Samaritano de São PauloInstituto Adriana GarófoloUniversidade Federal de São Paulo (UNIFESP) Departamento de Pediatria Instituto de Oncologia PediátricaUniversidade Federal de São Paulo (UNIFESP) Departamento de PediatriaUNIFESP, Depto. de Pediatria Instituto de Oncologia PediátricaUNIFESP, Depto. de PediatriaSciEL