Growth and characterization of InP ringlike quantum-dot molecules grown by solid-source molecular beam epitaxy

In this paper, we have studied the fabrication of InP ringlike quantum-dot molecules on GaAs(001) substrate grown by solid-source molecular beam epitaxy using droplet epitaxy technique and the effect of In deposition rate on the physical and optical properties of InP ringlike quantum-dot molecules. The In deposition rate is varied from 0.2 ML/s to 0.4, 0.8 and 1.6 ML/s. The surface morphology and cross-section were examined by ex-situ atomic force microscope and transmission electron microscope, respectively. The increasing of In deposition rate results in the decreasing of outer and inner diameters of InP ringlike quantum-dot molecules and height of InP quantum dots but increases the InP quantum dot and ringlike quantum-dot molecule densities. The photoluminescence peaks of InP ringlike quantum-dot molecules are blue-shifted and FWHM is narrower when In deposition rate is bigger.     

Development of solar cooling load factors for fenestration in Thailand

Abstract

This article describes the development of solar cooling load factors (SCL) for calculating cooling load from the fenestration part of the building envelopes in Thailand using Bangkok weather data. The Bangkok weather data are selected from 12 years of data collected by the meteorological department. Two sets of weather data are chosen based on dry bulb temperature of 0.4% annual cumulative frequency of occurrence and based on dry bulb temperature of 0.4% hourly cumulative frequency of occurrence and solar radiation obtained from the ASHRAE mathematical model. The building parameters that have effects on the room thermal response are studied. 288 different room types were checked. The values of amplitude and delay based on solar weighting factors are analyzed. Then, rooms with similar thermal response are grouped together and represented by a single point for the group. Each group is defined as a single zone type. Four different zone types are established. For each set of weather data, the values of solar cooling load factors for each zone type are developed.     

Cytotoxic assessment of flying barb fish (Esomus metallicus) from a gold mine area with heavy metal contamination

This study aimed to investigate contamination by heavy metals including arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), and manganese (Mn) and to conduct a cytotoxic assessment of Esomus metallicus from a gold mine area compared with that from the non-affected area. The E. metallicus samples were collected downstream of a gold mine area. The heavy metal concentrations were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The average amounts of As, Cd, Cr, Pb and Mn in water and E. metallicus samples from the gold mine area were 0.368 ± 0.009, 0.008 ± 0.006, 0.009 ± 0.001, 0.006 ± 0.002, 1.438 ± 0.058 mg/L, 0.65 ± 0.25, 0.03 ± 0.03, 2.12 ± 0.05, 0.25 ± 0.07 and 18.28 ± 6.82 mg/kg, respectively. The difference of As, Cr and Mn concentrations in E. metallicus samples between gold mine and non-affected areas was statistically significant (p < 0.05) except for Cd and Pb. The diploid chromosome number of E. metallicus from both areas was 2n = 50. There are six types of chromosomal aberrations including centric fragmentation (CF), centric gap (CG), single chromatid gap (SCG), fragmentation (F), deletion (D) and polyploidy (P). The most common chromosomal aberration type in the samples from the gold mine area was CG, and the difference in chromosomal aberration and the number of cells with chromosomal aberrations in E. metallicus between the study areas was statistically significant (p < 0.05). The percentages of chromosomal aberrations in the E. metallicus samples from gold mine and non-affected areas were 14.66 and 3.00, respectively.     

Dust exposure and lung function of workers in the brick and clay pottery factories in the Northeast of Thailand

This study aimed to determine the particulate matter concentrations (PM10) in workplace air and personal dust, and their effects on the respiratory health of exposed workers. The lung function of 449 exposed workers was examined. The concentration of PM10 in workplace air and personal dust exposure was measured. Spirometry was used to evaluate the lung function capacity included forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), forced expiratory volume ratio (FEV%) and peak expiratory flow rate (PEF). The forced expiratory flow at 25% to 75% of the FVC (FEF 25-75%) was determined. The PM10 concentration in workplace air (6 study sites) and personal dust (4 study sites) exceeded the standard (REL) of 0.12 mg/m3. The results of this study showed a decrease in the mean values and percent predicted value of FVC, FEV1, FEV1%, PEF and FEF 25-75%. The lung capacity of participants revealed that 24.50%, 4.45% and 7.13% had mildly, moderately restrictive and small airway disease. The respiratory symptoms were dyspnoea (22.49%), wheezing (10.69%), chest pain (10.69%) and chronic cough (2.90%). Factors influencing lung capacity included mask usage (Adj.OR: 0.44 CI: 0.25-0.79 p-value: 0.006) and chest pain (Adj.OR: 2.68 CI: 1.14-6.30 p-value: 0.024).     

Physicochemical investigation and molecular modeling of cyclodextrin complexation mechanism with eugenol

The inclusion complexes between a series of cyclodextrins (CDs), which are αCD, βCD, γCD and hydroxypropyl-β-CD (HPβCD), and eugenol was studied by spectroscopy, thermal analysis and in silico molecular modeling. Molecular modeling provided conformation and thermodynamic data, and also confirmed experimental observations that, in aqueous phase, the complex formation was found at 1:1 mole ratio of eugenol and all CDs except those of γCD. Free energy of solvation of CDs and its cavity size are the most crucial factors for complex formation. The aromatic portion of eugenol was partially incorporated in αCD hydrophobic cavity whereas for βCD and HPβCD their aromatic parts could completely translocate inside. Moreover, a presence of free eugenol absorbed on CD hydrophilic surface were found as the following order, βCD < HPβCD < αCD, resulting in varying extents of eugenol release profiles. The intermolecular forces were found primarily due to intermolecular hydrogen bonding, resulting in stable complexes.     

Lead recovery from waste frit glass residue of electronic plant by chemical-electrochemical methods

This work aims at recovering lead from frit glass waste of electronic plants by using the electrochemical method comprising two successive steps of lead leaching and electrodeposition. In the leaching step, it was found that nitric acid and acetic acid are better solutions for the dissolution of lead oxide compared with sodium hydroxide, hydrochloric acid, and sulfuric acid. More than 95% of the lead was leached by 0.1 M nitric acid or 0.5 M acetic acid at 0.5% weight by solid volume. In the electrodeposition step, more than 95% of lead can be removed with high current efficiency from the leaching solution at an optimum current density. The values of the optimum current density of 0.5 and 1 M acetic electrolytes were between 8.8–10 mA/cm², whereas those for 0.1 M and 0.5 M of nitric acid were 15 and 27.5 mA/cm², respectively.     

Checking safety properties on-the-fly with the sweep-line method

The sweep-line state space method allows states to be deleted from memory during state exploration, thus alleviating the state explosion problem. Properties of the system (such as the absence of deadlocks) can then be verified on-the-fly. This paper presents an extension to the sweep-line method that allows on-the-fly checking of safety properties expressed as sequences of actions of the modelled system. This has been implemented in a prototype sweep-line library for Coloured Petri nets. We evaluate the prototype by applying it to the connection management procedures of the Datagram Congestion Control Protocol, a new Internet transport protocol. This paper was supported by Australian Research Council Discovery Grants DP0210524 and DP0559927. L. M. Kristensen was supported by the Carlsberg Foundation and the Danish Research Council for Technology and Production.