Performance evaluation of ProJet multi-material jetting 3D printer

The purpose of this paper is to quantitatively evaluate the performance of a multi-material jetting 3D printer, ProJet 5500X, especially the capability for micro manufacturing. Unlike other single material 3D printer, ProJet 5500X uses photopolymers as the build material and wax as the support material. The building performance was evaluated by building a modified version of the standard benchmark model with a high-resolution printing mode. The dimensional error, forming quality and surface roughness of the printed parts have been measured and analysed using a microscope, a 3D coordinate measuring machine and a surface profilometer. Using wax as the support material, fine features as small as 0.25?mm, lateral features and sharper edges could all be properly built, despite the rough side surfaces observed in the printed part. Identical features (3?mm pins) were precisely built with an accuracy of 15?µm. The research provides first-hand detailed performance knowledge in the ProJet system for understanding the working principle and comparison with other 3D printing systems.     

Red-green-blue laser emissions from dye-doped poly(vinyl alcohol) films

A microscope slide acting as a passive waveguide was coated by three separate poly(vinyl alcohol) films that were doped with Coumarin 460, Disodium Fluorescein, and Rhodamine 640 perchlorate. On collinear pumping by a nitrogen laser, these dyes furnished primary red-green-blue laser emissions that were collected and waveguided by the microscope slide but exited from both ends. Frosting the waveguide exit introduced light scattering at the glass-air interface and spatially overlaid the red-green-blue laser emissions that emerged as a uniform white-light beam.     

On minimizing the heat leak of current leads in cryogenic vacuum systems

Electronic devices such as infrared detectors in remote sensing instruments are frequently placed in cryogenic vacuum systems, such that the ratio of signal to noise can be enhanced. The heat leak of leads supplying usually small electric current to these electronic devices is a critical issue in system designs. Cu is a typical material for current leads. In this work, however, we suggest employing the Peltier current lead to lower the heat leak. It comprises a thermoelectric element and a Cu lead at the hot and cold ends, respectively. In considering the heat radiation between Cu leads and the vacuum vessel, both all-Cu and Peltier current leads are optimised so as to minimise their resulting heat leaking into cryogenic vacuum systems. Moreover, temperature–entropy (T–s) diagrams are constructed to track the actual thermodynamic processes in the two types of current leads. The heat leak of a current lead in the presence of heat radiation can be easily identified from the simple 2-D T–s plane. It is also proved that the effect of heat radiation on the heat leak of current leads is usually negligible.     

Survival of Blastocystis hominis clones after exposure to a cytotoxic monoclonal antibody

Our previous studies have shown that monoclonal antibodies (MAbs) to Blastocystis hominis react mainly with carbohydrate epitopes, while 1 MAb (1D5) reacts specifically with a protein of 30.5 kDa. In the present study, 3 monoclonal antibodies (1D5, 1E7 and 4F7) were used in immunogold localization. 1E7 and 4F7 were found to react primarily with the surface coat, while 1D5 was plasma membrane-specific. In the presence of complement, only 1D5 exhibited a cytotoxic effect on B. hominis whereas 1E7 and 4F7 did not, suggesting that the surface coat of B. hominis could serve as an immunological barrier against host antibodies. Using a recently described agar plating method, only 1D5 exhibited significant (P < 0.01) complement-independent cytotoxicity to B. hominis, inhibiting colony growth at low concentrations. Parasites that had been exposed to 1D5 were morphologically smaller than those that were not exposed to this MAb. Colonies that grew in the presence of 1D5 were isolated and grown in liquid medium containing increasing amounts of the cytotoxic MAb. Two clones that grew well in liquid medium containing 1D5 were also able to develop into colonies in soft agar. This study has shown that the 30.5 kDa protein found on the plasma membrane of B. hominis is a functionally important protein and that not all cells within a certain population would be susceptible to the cytotoxic effects of 1D5. These findings suggest that a heterogenous population exists in continuously maintained cultures of B. hominis.     

Effects of Weathering on Treatment of Lead Contaminated Soils

Treatment of lead-contaminated material focuses on the reduction of leached lead concentrations in laboratory leaching tests. There has been little study on the chemical stability of treated materials after waste disposal. To investigate the effects of weathering on several solidification/stabilization chemistries, lead-contaminated soil was treated with various agents (cement, phosphates, dithiocarbamate, calcium hydroxide, calcium carbonate, and metallic iron) and subjected to natural weathering for one year. Lead concentrations and pH values in field percolates and leachates from toxicity characteristic leaching procedure (TCLP) and water leaching tests were used to evaluate changes in the treatment effectiveness. Weathering altered the treatment chemistry of several additives—alkaline additives were neutralized, while reduced additives were oxidized. Lead concentrations in field percolates from the untreated soil were around 1.0?mg/L, and did not vary over one year of weathering time. After one year of weathering, lead concentrations in field percolates from most samples were reduced to low levels (<0.15 mg/L). Weathering also affected lead concentrations in the TCLP and water leach test leachates from the treated wastes. Treated wastes in which the alkaline additives were neutralized or reduced additives oxidized gave higher TCLP lead concentrations after weathering than before, in contrast to the decreasing lead concentrations in the field percolates. Water leaching tests on the alkaline treated wastes had lower lead concentrations after weathering than before.     

Clinical pharmacology of bruceantin by radioimmunoassay

During the phase I clinical trial of a new antitumor agent, bruceantin, the pharmacology was studied in 18 cancer patients. The drug was infused intravenously (IV) for 3 h at doses ranging from 1 to 3.6 mg/m2 per day for 5 days. The plasma drug disappearance curves were biphasic, with a fast initial half-life of less than 15 min. The second half-life (t1/2 beta) varied from 0.7 to 38 h among different patients and was not dose-related. The difference between the t1/2 beta on day 1 and that on day 5 was not significant. In patients with normal liver function, the mean plasma concentration at the end of infusion was 22 ng/ml, and the value of the area under the concentration X time curve (AUC) was 111 (ng/ml)h. In contrast, in patients with abnormal liver function the corresponding values were 115 ng/ml and 830 (ng/ml)h, respectively. In addition, these patients had a slower elimination half-life of 10.9 h and a decreased total clearance of 157 ml/min/m2, as compared with 2.6 h and 671 ml/min/m2, respectively, for the normal group. All these differences were statistically significant. Patients with abnormal liver function developed more severe toxicity, including fever, severe nausea, vomiting, and hypotension. Two patients with severe hepatic dysfunction received a reduced dose and developed no toxicity. These results demonstrated the importance of the effects of liver dysfunction on drug disposition and showed that the dosage should be reduced in patients with hepatic dysfunction.     

Time-dependent Neutronic Analysis for High Level Waste Transmutation in a Fusion-driven Transmuter

This study presents time-dependent transmutations of high-level waste (HLW) including minor actinides (MAs) and long-lived fission products (LLFPs) in the fusion-driven transmuter (FDT) that is optimized in terms of the neutronic performance per fusion neutron in our previous study. Its blanket has two different transmutation zones (MA transmutation zone, TZ_MA, and LLFP transmutation zone, TZ_FP), located separately from each other. High burn-up pressured water reactor (PWR)-mixed oxide (MOX) spent fuel is used as HLW. The time-dependent transmutation analyses have been performed for an operation period (OP) of up to 10 years by 75% plant factor (η) under a first-wall neutron load (P) of 5 MW/m². The effective half-lives of the MA and LLFP nuclides can be shortened significantly in the considered FDT while substantial electricity is produced in situ along the OP.     

A systematic approach in appliance disaggregation using k-nearest neighbours and naive Bayes classifiers for energy efficiency

One of the ways to achieve energy efficiency in various residential electrical appliances is with energy usage feedback. Research work done showed that with energy usage feedback, behavioural changes by consumers to reduce electricity consumption contribute significantly to energy efficiency in residential energy usage. In order to improve on the appliance-level energy usage feedback, appliance disaggregation or non-intrusive appliance load monitoring (NIALM) methodology is utilized. NIALM is a methodology used to disaggregate total power consumption into individual electrical appliance power usage. In this paper, the electrical signature features from the publicly available REDD data set are extracted by the combination of identifying the ON or OFF events of appliances and goodness-of-fit (GOF) event detection algorithm. The k-nearest neighbours (k-NN) and naive Bayes classifiers are deployed for appliances’ classification. It is observed that the size of the training sets effects classification accuracy of the classifiers. The novelty of this paper is a systematic approach of NIALM using few training examples with two generic classifiers (k-NN and naive Bayes) and one feature (power) with the combination of ON-OFF based approach and GOF technique for event detection. In this work, we demonstrated that the two trained classifiers are able to classify the individual electrical appliances with satisfactory accuracy level in order to improve on the feedback for energy efficiency.     

A study on the hydrogen storage properties and reaction mechanism of Na3AlH6LiBH4 composite system

In this work, the hydrogen storage properties of different molar ratio (in mole of 1:3 and 1:4) Na₃AlH₆LiBH₄ system is investigated for the first time. X-ray diffraction and Fourier transform infrared results show that the Na₃AlH₆LiBH₄ with molar ratio of 1:3 and 1:4 composite was transformed to Li₃AlH₆ and NaBH₄ phases via a metathesis reaction during a ball-milling process for 6 h. Temperature-programmed-desorption (TPD) results show three stages of decomposition for the Na₃AlH₆LiBH₄ (in mole ratio of 1:3 and 1:4) composite resulting from Li₃AlH₆ and NaBH₄ phases. From the TPD graph, the Na₃AlH₆LiBH₄ composite with molar ratio of 1:4 had showed better performance of hydrogenation properties compared to with molar ratio of 1:3. The composite began to release hydrogen at 180 °C in relation to decomposition of the Li₃AlH₆ stage into LiH and Al. The NaBH₄ stage then began to decompose at approximately 380 °C, after reacting with Al to form an intermetallic phase, AlB₂, which occurred at 100 °C lower than as-milled NaBH₄. At 430 °C, the un-reacted NaBH₄ was decomposed after catalysing with AlB₂. Kissinger analysis shows the apparent activation energy of NaBH₄ decomposition in the hydrides composite was reduced by about 75 kJ/mol compared to the as-milled NaBH₄. The rehydrogenation process evidenced the reversibility of NaBH₄. Based on these results, the intermetallic phase, AlB₂, is considered to have played an important role by lowering the operating temperature and providing access to the full hydrogen content in the Na₃AlH₆LiBH₄ composite system.