Progressive Freeze Concentration for Volume Reduction of Produced Water and Biodiesel Wastewater

One way to conserve fresh water resources is by reusing water from wastewater. For instance, water can be removed from wastewater through formation of ice crystal layers by progressive freeze concentration (PFC). The application of PFC to remove water from produced water and biodiesel wastewater was assessed through the final concentration of concentrated wastewater and purity of melted ice crystals. No PFC study has been done on these applications. In order to evaluate the efficiency of PFC, the effective partition constant (K) and separation efficiency (S_E) were calculated for the effect of stirring rate and coolant temperature. The results demonstrate that PFC is a more practical method for produced water, as compared to biodiesel wastewater which is based on the value of low K and high S_E.     

Advances in green synthesis of selenium nanoparticles and their application in food packaging

The past decade has seen nanotechnology progressively being adopted by the food industry. Its wide application in food packaging has redefined conservative food packaging with active and intelligent packaging. Nanomaterials do not only influence food quality and safety but also offer health-related benefits. Selenium nanoparticles (SeNPs) have been preferred in recent years because of their high biological activity. However, they are generally synthesised using physicochemical methods which are associated with toxicity. In the past decade, efforts have been directed towards advancement of green synthesis of SeNPs to minimise hazardous by-products. The antioxidant and biocidal effects of SeNPs are generally investigated by direct contact between the oxidisable matter and/or test organisms. Lately, there is focus on the effect SeNPs incorporated into packaging films. This paper will review developments on SeNPs synthesised via plant extracts from the year 2010 to present and their potential application in active food packaging.     

Circulating endotoxin during initial antibiotic treatment of severe gram-negative bacteremic infections

The second most common cause of congenital adrenal hyperplasia is 11 beta-hydroxylase deficiency, an autosomal recessive disorder. We performed genetic analysis of CYP11B1, the gene encoding steroid 11 beta-hydroxylase, in three patients with classic 11 beta-hydroxylase deficiency. Herein we describe the first splice donor site mutation, a new nonsense mutation, and a new missense mutation in this disorder. An African-American patient was found to be a compound heterozygote for a codon 318 + 1G --> A substitution at the 5'-splice donor site of intron 5, in combination with Q356X, a nonsense mutation previously reported in an African-American patient. A Caucasian patient was found to be a compound heterozygote with a novel missense mutation, T318R, in combination with a previously reported 28-bp deletion in exon 2. A different mutation at codon 318 (T318M) has been described previously. A Caucasian patient was heterozygous for a novel nonsense mutation (Q19X) in exon 2. The second mutation was not identified in this patient. Multiple apparent polymorphisms were also observed. Two of these polymorphisms in CYP11B1 represent sequences from CYP11B2, suggesting that gene conversion may have occurred. In summary, we have identified three novel mutations and two previously reported mutations in CYP11B1 patients with 11 beta-hydroxylase deficiency. Our data suggest the presence of a mutational hot spot at codon 318 of CYP11B1, and the possibility of a founder effect in frequently identified mutations.     

产品剖析:驰骋于沙漠的无人驾驶汽车

Darpa Grand Challenge--自从各种传说中的横贯大陆的竞赛在一个世纪以前开始举办以来,从来没有哪一种令人生畏的工作能吸引如此多的工程师、教授、学生、企业团队以及汽车修理工参与其中.表面上看,它似乎是不可能被完成的.     

All‐Carbon Electrode Molecular Electronic Devices Based on Langmuir–Blodgett Monolayers

Nascent molecular electronic devices, based on monolayer Langmuir–Blodgett films sandwiched between two carbonaceous electrodes, have been prepared. Tightly packed monolayers of 4‐((4‐((4‐ethynylphenyl)ethynyl)phenyl)ethynyl)benzoic acid are deposited onto a highly oriented pyrolytic graphite electrode. An amorphous carbon top contact electrode is formed on top of the monolayer from a naphthalene precursor using the focused electron beam induced deposition technique. This allows the deposition of a carbon top‐contact electrode with well‐defined shape, thickness, and precise positioning on the film with nm resolution. These results represent a substantial step toward the realization of integrated molecular electronic devices based on monolayers and carbon electrodes.     

Development of a metric to assess the complexity of assembly/disassembly tasks in open architecture products

This paper describes two metrics to measure the complexity involved in assembly and disassembly tasks for open architecture products during its use phase. The approach proposed is based on the summary of all tasks required to assemble and disassemble a predefined set of modules to generate several product variants, which comprise different working levels or functionalities. The aim of the method is to provide a useful tool to designers in the analysis of product complexity regarding use and further phases in which the assembly and disassembly of modules are required. The benefits and usefulness of the metrics are oriented to enhance the sustainability performance of products through the measurement of complexity in modular systems for the decision-making during the design stage. The reduction of complexity involves significant benefits in all lifecycle phases of product, especially when the user or customer is responsible for many related tasks (maintenance, upgrading, reconfiguration and final disposal of modules). The metrics and their calculation process are illustrated using two case study products.     

Functional characterisation of mechanical joints to facilitate its selection during the design of open architecture products

New trends in product design require the use of modularity as key feature aimed to improve functional performance and the generation of open architecture products. For mechanical systems, one of the challenges during early design stages of these products involves the proper selection of joining methods among their constructive components. A robust joint selection process must consider product requirements, life cycle analysis and eventual procedures for assembly and disassembly. However, the general approach towards a Design-for-Assembly (DFA)/Design-for-Disassembly (DFD) only considers design, manufacturing and in some cases final disposal stage. Additionally, most of the works found in the literature are merely focused on assembly operations, disregarding economic and environmental benefits from optimising disassembly complexity. Herein, a functional characterisation of mechanical joint methods for the assembly and disassembly activities that take place throughout the product life cycle is proposed, focusing on open architecture products. Additionally, a classification of joining methods, a joint complexity metric valuation and a selection process are proposed for the conceptual design stage. The approach integrates both DFA and DFD principles in a formal methodology. The proposed selection roadmap can be implemented to increase product sustainability positively regarding resources optimisation, operational time and costs in reuse, remanufacturing and recycling tasks.     

Cyclodextrin‐dendrimer functionalized polysulfone membrane for the removal of humic acid in water

Commercial polysulfone (PSf) membranes were crosslinked with a β‐cyclodextrin‐poly (propyleneimine) (β‐CD‐PPI) conjugate which had β‐CD pendant arms using trimesoyl chloride (TMC) by interfacial polymerization. The morphology and physicochemical properties of the nanofiltration membranes were characterized using Fourier transform infrared/attenuated total reflectance (FT‐IR/ATR) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and cross‐flow filtration system. Water‐contact angle, water‐intake capacity, and rejection capacities of the membranes were evaluated. The β‐CD‐G4 (generation 4)‐PPI‐PSf and β‐CD‐G3 (generation 3)‐PPI‐PSf membranes both exhibited high humic acid rejection of 72% as compared to the commercial PSf which exhibited 57%. The modified membranes were also more hydrophilic (36° to 41°) than PSf (76°). These results suggest that β‐CD‐PPI nanostructures are promising materials for the synthesis of membranes for the removal of humic acid from water. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4428–4439, 2013     

Biochemical conversion of fruit rind of Telfairia occidentalis (fluted pumpkin) and poultry manure

Environmental pollution by solid wastes and inadequate energy supply are some of the major challenges facing the developing world. This study evaluated the potentials of Fluted pumpkin fruit rind and poultry manure for biogas generation. Mechanical and thermo-alkaline pre-treatments were applied to two samples labeled ‘O’ and ‘P’ while the third sample (Q) had no thermo-alkaline treatment. The physicochemical characteristics of the substrates revealed richness in nutrients and mineral elements. The results showed that use of a combination of pre-treatment methods enhanced the biogas yield in the pre-treated substrates. Analysis of the gas composition showed 66.5 ± 2.5% Methane, 25 ± 1% Carbon dioxide; 58.5 ± 2.5% Methane, 26 ± 1% Carbon dioxide; 54.5 ± 1.5% Methane, 28 ± 2% Carbon dioxide for the three experiments, respectively. All the obtained values show the models had a high predictive ability. The substrates should be further used for energy generation.