Microwave-assisted synthesis and characterization of zinc oxide/carbon nanotube composites

A composite material of zinc oxide and carbon nanotubes were successfully synthesized via a sol process using zinc acetate dihydrate and treated multi-wall carbon nanotubes under microwave irradiation. The morphology, microstructure and chemical bonding of as-obtained composites were well characterized using X-ray diffraction, scanning electron microscope, transmission electron microscope, and Fourier transform infrared spectroscopy. Zinc oxide nanoparticles were dispersively coated on the surface of carbon nanotube when the precursor was dried under microwave irradiation without post-annealing. X-ray diffraction results obviously showed the mixture of two phases of carbon nanotube and wurzite zinc oxide whose size is approximately 15 nm. The formation of zinc oxide nanoparticles on carbon nanotube surface in the composite prepared by microwave heating is much better than the composite heated by conventional annealing. Fourier transform infrared spectroscopic results suggest that carboxylic groups and uniform heating by microwave heating could play key roles on the nucleation of zinc oxide on carbon nanotube surface.     

Industrial water use estimate in Bangkok metropolitan area and its vicinity

Abstract

Water is essential to industrial development. Due to the groundwater control measures in the Bangkok Municipal Area and its vicinity, the actual amount of industrial water use needs to be assessed. The study proposes an estimation method of industrial water use in the area, using the existing registered data from the Ministry of Industry. With the derived water use unit for both domestic and processing purposes, the distribution of industrial water use by type and location in the study area can be derived. More industrial water demand was confirmed from the questionnaire survey and more groundwater wells tended to be developed to solve water deficit. Integrated water resources development and a more persuasive industrial water saving policy for the area need to be considered in order to cope with increasing industrial water demand and groundwater control policy.     

High Solid‐State Near Infrared Emissive Organic Fluorophores from Thiadiazole[3,4‐c]Pyridine Derivatives for Efficient Simple Solution‐Processed Nondoped Near Infrared OLEDs

Many efforts have been dedicated to developing near infrared (NIR) fluorescent emitters with strong emission especially in the range of 700–1000 nm due to their potential applications in biomedical and optoelectronic fields. However, high solid state NIR emission fluorophores are still rare for applications. Herein, two efficient donor‐π‐acceptor type NIR emitters, C3HTP and C4HTP , are designed and synthesized by end‐capping two isomeric bis(n‐hexylthienyl)thiadiazole[3,4‐c]pyridines as π‐acceptor with structural bulky, electron rich tercarbazole moiety. They exhibit excellent solid state NIR emission with an emission peak at 725 nm, especially C3HTP , reaching a record high photoluminescence quantum yield (Φ_PL) of 34% for NIR organic fluorescent materials. By taking advantage of their Φ_PL values in the film state (Φ_PL = 10–34%), suitable energy levels (highest occupied molecular orbital (HOMO) level ≈ ?5.3 eV), high hole mobility (5.49 × 10^?8 cm² V^?1 s^?1) as well as good amorphous film forming ability by solution casting, they are used to fabricate a nondoped emissive layer (EML) in simple double‐layer solution processed NIR electroluminescent (EL) devices. The device containing C3HTP as the EML shows a NIR emission peaking at 726 nm and excellent EL performance with a high external quantum efficiency of 1.51%, which is the best solution processed nondoped NIR organic light‐emitting diodes reported to date. Importantly, this represents an advance in near infrared organic fluorescent materials and EL devices that meet the requirements of many applications.     

Chemical composition of alkaline-pretreated sugarcane bagasse and its effects on the physicochemical characteristics of fat-replaced sausage

The potential of cellulose from sugarcane bagasse used for pork sausage was investigated. The purity level of cellulose fibre from sugarcane bagasse and the functional characteristics in pork sausage were studied. The differences in the sugarcane fibre and sausage characteristics were strongly related to the cellulose/lignin content of the extracted cellulose under different amounts of bleaching. Bleached sugarcane fibres showed better water (3.55) and oil (2.34) holding capacity in comparison with untreated fibre (2.92 and 2.38, respectively). The sugarcane fibres in each treatment stage showed different effects on sausage properties. Sausages with 1% cellulose fibres added had an improved texture profile, but the addition of 3% cellulose fibres to sausages resulted in a higher cooking yield. Consumers considered the sensory characteristics of all sausages as acceptable. These results indicated that low levels of cellulose extracted from sugarcane bagasse could be added and maintain the inherent characteristics of meat products.     

The Influences of Steeping Duration and Temperature on the α‐ and β‐Amylase Activities of Six Thai Rice Malt Cultivars (Oryza sativa L. Indica)

A preliminary study of malting conditions for six Thai rice cultivars was conducted. Three non‐glutinous rice cultivars (KDML105, PT60, and WR) and three glutinous rice cultivars (SPT, RD6, and KND) were selected. The steeping durations (24, 48, and 72 h) and temperatures (20, 25 and 30°C) were investigated for their effect on α‐ and β‐amylase, the key enzymes for malt quality evaluation. During steeping, the production of both enzymes was lower than at the germination process. The longer the steeping duration, the lower the maximum β‐amylase activity obtained. The contradictory effect was observed for α‐amylase activity, near the end of the germination time. Additionally, temperature influenced the water absorption content as well as the amylolytic enzyme activity. Particularly at 30°C, the maximum β‐amylase activity (6.7 unit/mg protein) was found in KND malt steeped for 24 h, and maximum α‐amylase activity (20 unit/mg protein) was found in PT60 malt steeped for 72 h. The amount of enzyme production depended on the variety rather than the amylose content in the rice. The optimal condition for malting rice regarding β‐amylase activity and α‐amylase activity was analyzed at 30°C, with steeping for 24 h and germination for 4–5 days.     

Reliability-aware performance model for optimal GPU-enabled cluster environment

Given that the reliability of a very large-scaled system is inversely related to the number of computing elements, fault tolerance has become a major concern in high performance computing including the most recent deployments with graphic processing units (GPUs). Many fault tolerance strategies, such as the checkpoint/restart mechanism, have been studied to mitigate failures within such systems. However, fault tolerance mechanisms generate additional costs and these may cause a significant performance drop if it is not used carefully. This paper presents a novel fault tolerance scheduling model that explores the interplay between the GPGPU application performance and the reliability of a large GPU system. This work focuses on the checkpoint scheduling model that aims to minimize fault tolerance costs. Additionally, a GPU performance analysis is conducted. Furthermore, the effect of a checkpoint/restart mechanism on the application performance is thoroughly studied and discussed.     

Investigating the effect of SiO2–TiO2–CaO–Na2O–ZnO bioactive glass doped hydroxyapatite: characterisation and structural evaluation

The effects of increasing bioactive glass additions, SiO₂–TiO₂–CaO–Na₂O–ZnO up to 25 wt% in increments of 5 wt%, on the physical and mechanical properties of hydroxyapatite (HA) sintered at 900, 1000, 1100 and 1200 °C for 2 h was investigated. Increasing both the glass content and the temperature resulted in increased HA decomposition. This resulted in the formation of a number of bioactive phases. However the presence of the liquidus glass phase did not result in increased densification levels. At 1000 and 1100 °C the additions of 5 wt% glass resulted in a decrease in density which never recovered with increasing glass content. At 1200 °C a cyclic pattern resulted from increasing glass content. There was no direct relationship between strength and density with all samples experiencing no change or a decrease in strength with increasing glass content. Weibull statistics displayed no pattern with increasing glass content.