Economic value of improved quantification in global sources and sinks of carbon dioxide

On average, about 45 per cent of global annual anthropogenic carbon dioxide (CO(2)) emissions remain in the atmosphere, while the remainder are taken up by carbon reservoirs on land and in the oceans-the CO(2) 'sinks'. As sink size and dynamics are highly variable in space and time, cross-verification of reported anthropogenic CO(2) emissions with atmospheric CO(2) measurements is challenging. Highly variable CO(2) sinks also limit the capability to detect anomolous changes in natural carbon reservoirs. This paper argues that significant uncertainty reduction in annual estimates of the global carbon balance could be achieved rapidly through coordinated up-scaling of existing methods, and that this uncertainty reduction would provide incentive for accurate reporting of CO(2) emissions at the country level. We estimate that if 5 per cent of global CO(2) emissions go unreported and undetected, the associated marginal economic impacts could reach approximately US$20 billion each year by 2050. The net present day value of these impacts aggregated until 2200, and discounted back to the present would have a mean value exceeding US$10 trillion. The costs of potential impacts of unreported emissions far outweigh the costs of enhancement of measurement infrastructure to reduce uncertainty in the global carbon balance.     

An artificial neural network based adaptive power system stabilizer

An artificial neural network (ANN)-based power system stabilizer (PSS) and its application to power systems are presented. The ANN-based PSS combines the advantages of self-optimizing pole shifting adaptive control strategy and the quick response of ANN to introduce a new generation PSS. A popular type of ANN, the multilayer perceptron with error backpropagation training method, is used in this PSS. The ANN was trained by the training data group generated by the adaptive power system stabilizer (APSS). During the training, the ANN was required to memorize and simulate the control strategy of APSS until the differences were within the specified criteria. Results show that the proposed ANN-based PSS can provide good damping of the power system over a wide operating range and significantly improve the dynamic performance of the system     

Nutrient and trace-metal removal by Bauxsol pellets in wastewater treatment

In this study, Bauxsol pellets packed in PVC columns were used to remove nutrients and trace-metals from municipal wastewater during a 6 months field trial. Bauxsol pellet columns showed a high phosphate removal rate via precipitation of PO(4)(3-) with Ca(2+) and Mg(2+) ions: at 90% in the 1st month; at 80% from the second to fifth months; and at 60% in the sixth month. Pellet bound total phosphorus and Colwell phosphorus were 7.3 g/kg and 2 g/kg and are about 20 times the concentrations found in most fertile soils. Trace-metals in effluents were bound, probably irreversibly under the columns' environmental conditions, to the Bauxsol minerals that have high surface area to volume ratios and high charge to mass ratios. Experimental results showed a complex nitrogen cycle operating within the Bauxsol pellet columns including anoxic nitrification, denitrification, and anammox processes. Although a transient pH spike, associated with the release of unreacted CaO from the cement binder used in the pellets, was observed, this may be readily corrected through post-treatment pH adjustment. Hence, the geochemistry of Bauxsol pellets can effectively remove and bind nutrients and trace-metals during wastewater treatment, and further research may show that saturated spent pellets can be used as fertilizer.     

Nanotribology Application in the Coining Industry (I)—Turn off Stamping Oil Sprayer during Coining

The most common tribological cases involve two solid surfaces repeatedly contacting each other. During coining, however, a pair of dies strikes each blank that has been stamped only once. The requirements of the surface physical and chemical properties for coining are different compared to the common tribological conditions. For example, a low-viscosity stamping oil is used during coining in the United States Mint, as well as other industries. Under coining tonnage this small amount of liquid on die surfaces may promote microcrack propagation. In this case, lubrication does not prolong die life but shortens it.

In this work, the lubrication mechanism during coining was studied. A lubricant layer was applied on blank surfaces before coining. Based on the special stamping condition, blank surfaces must meet several tribological requirements. According to these requirements, a new technology was employed and the use of a new lubricant was implemented. As a result, fatigue die life was increased almost three times on high-volume production lines and coin surface quality was improved.     

Detection and diagnosis of bearing and cutting tool faults using hidden Markov models

Over the last few decades, the research for new fault detection and diagnosis techniques in machining processes and rotating machinery has attracted increasing interest worldwide. This development was mainly stimulated by the rapid advance in industrial technologies and the increase in complexity of machining and machinery systems. In this study, the discrete hidden Markov model (HMM) is applied to detect and diagnose mechanical faults. The technique is tested and validated successfully using two scenarios: tool wear/fracture and bearing faults. In the first case the model correctly detected the state of the tool (i.e., sharp, worn, or broken) whereas in the second application, the model classified the severity of the fault seeded in two different engine bearings. The success rate obtained in our tests for fault severity classification was above 95%. In addition to the fault severity, a location index was developed to determine the fault location. This index has been applied to determine the location (inner race, ball, or outer race) of a bearing fault with an average success rate of 96%. The training time required to develop the HMMs was less than 5 s in both the monitoring cases.     

Influence of Proportion of Skin Present During Malaxing on Pigment Composition of Cold Pressed Avocado Oil

The effect of the proportion of ‘Hass’ avocado skin tissue present during aqueous cold pressed avocado oil extraction on the pigment concentration and oil quality was determined. Increasing amounts of skin (i.e., from 0 to 100% of available skin) were included with the flesh before grinding and malaxing in a laboratory-scale cold pressed extraction process. The recovered oils were analyzed for oil quality and color. The pigment concentrations in the oil were determined by high performance liquid chromatography (HPLC). With increasing amounts of skin addition, there was an increase in the green color, as indicated by hue angle, of the avocado oils. There were also increased concentrations of carotenoids and chlorophylls in the oil as the proportion of skin during malaxing was increased. The lutein concentration in the oils increased from 1.13 to 3.21 μg g⁻¹ as the amount of skin added to the malaxer increased from 0 to 100% skin, and the total chlorophyll concentration in the same oils increased from 7.3 to 27.5 μg g⁻¹. The green color of cold pressed avocado oil and the pigment concentrations can be increased by adding more skin to the malaxer during oil extraction.     

奥斯陆莫藤斯鲁德教堂

该教堂坐落在一个小山脊的顶部,周围是高大的松树林和一些裸露的岩石。从几何学角度来说,这座教堂是现有基地的附加体,除了小心地移除薄薄的土壤层之外,基地不需要进行爆破和挖掘。这种处理方法更易于保持现有的植被和地形,从而增加了人们对建筑另一层面上的体验。     

Analysis of installation damage tests for LRFD calibration of reinforced soil structures

North American design codes are now committed to the development of load and resistance factor design (LRFD) for reinforced soil structures including internal stability limit states. Reliability-based analysis is required to carry out these calibrations. A framework for LRFD calibration has been proposed by the writers that requires bias statistics for load and resistance terms for each limit state function. In this paper the formulation of the limit state for reinforcement tensile rupture is developed and the component strength-reduction bias statistics identified. The paper describes how to compute bias statistics from project-specific installation damage trials for use in reliability-based design for the reinforcement rupture limit state or using data from multiple sources for LRFD calibration. A database of results from field installation damage trials on 103 different geosynthetic products was collected from 20 different sources. A total of 799 and 2248 in-air tensile test results were reviewed for undamaged and damaged geosynthetic specimens, respectively. This database is used to compute installation damage bias statistics for six different categories of geosynthetic and four categories of backfill soils classified according to the D₅₀ particle size. A practical outcome is that for analysis purposes, bias statistics can be grouped into two ranges for each geosynthetic type based on D₅₀ of the soil greater than or less than 19 mm. The paper shows how bias statistics together with load and resistance factors for the geosynthetic rupture limit state function recommended by AASHTO (2010) can be used to calculate probability of failure using Monte Carlo simulation and demonstrates the sensitivity of probability of failure to magnitude of installation damage bias statistics. The installation damage data is valuable for future LRFD calibration to select resistance factors for use in design codes for the geosynthetic rupture limit state in reinforced soil structures.     

Facile synthesis of reduced graphene oxide/MWNTs nanocomposite supercapacitor materials tested as electrophoretically deposited films on glassy carbon electrodes

This paper reports on a facile synthesis method for reduced graphene oxide (rGO)/multi-walled carbon nanotubes (MWNTs) nanocomposites. The initial step involves the use of graphene oxide to disperse the MWNTs, with subsequent reduction of the resultant graphene oxide/MWNTs composites using l-ascorbic acid (LAA) as a mild reductant. Reduction by LAA preserves the interaction between the rGO sheets and MWNTs. The dispersion-containing rGO/MWNTs composites was characterized and electrophoretically deposited anodically onto glassy carbon electrodes to form high surface area films for capacitance testing. Pseudo capacitance peaks were observed in the rGO/MWNTs composite electrodes, resulting in superior performance with capacitance values up to 134.3 F g^?1 recorded. This capacitance value is higher than those observed for LAA-reduced GO (LAA-rGO) (63.5 F g^?1), electrochemically reduced GO (EC-rGO) (27.6 F g^?1), or electrochemically reduced GO/MWNTs (EC-rGO/MWNTs) (98.4 F g^?1)-based electrodes.     

Mobile phone ownership and usage among pre-adolescents

Research has revealed that the mobile phone is, for adolescents, a medium which permits communication without the surveillance of parents, families and teachers. Indeed, the current study found this to be the case with younger pupils, too. However, communicating with family members appeared just as important, if not more, for these primary aged children. This study focused on the ownership and usage of mobile phones in a sample (N=351) of 10- to 11-year-old children in Gloucestershire primary schools (N=7). Some 45% of the sample possessed mobile phones. Nearly half of their calls (47%) were used for chatting with family or friends; 26% were to let their parents know their whereabouts; and others (20%) were “convenience” calls, i.e. to ask to be picked up etc. Other uses of the mobile in addition to chatting and making arrangements, although not always positive, were also made apparent. Thus, some two fifths of the children reported that they had made an “emergency” call (examples were given), about 17% had received “frightening” calls. A sizeable minority (20%) reported that their mobile had been damaged or stolen. This research also considers the amount of money that the pupils claimed to spend on their mobile calls every month as well as their means of purchasing the mobile and its up-keep.