A reliability-based rock engineering system for clean blasting: risk analysis and dust emissions forecasting

Clean Technologies and Environmental Policy - Experts are increasingly interested in incorporating environmental and climate action into all projects. Mining projects face a broader range of...     

Detector for liquid chromatography based on acoustic emissions from an oscillating flame

The acoustic flame detector (AFD) is examined as a novel detector for liquid chromatography (LC). It is based upon the acoustic emission frequency of an oscillating hydrogen/oxygen premixed flame and produces a universal response toward organic molecules. A stable frequency near 1000 Hz, which further depends on mobile-phase composition, is achieved for flow rates in the microliter per minute range. The mass flow sensitivity of the AFD demonstrates a linear response over 3 orders of magnitude and a detection limit (S/sigma = 3) of approximately 15 ng of C/s for a series of alcohols. For cyclopentanol, this amounts to an injected mass of approximately 77 ng based on a 0.5-microL injection of a 196 ppm solution in methanol (flow rate 20 microL/min methanol; peak width 30 s). Similar sensitivity is observed using a water mobile phase. Low-frequency (1/f ) noise contributions are dominant with or without mobile phase present. The AFD demonstrates a uniform molar sensitivity toward carbon compounds independent of their optical properties or volatility. Results suggest the device might serve as a simple, inexpensive universal LC detector.     

Industry evolution and key technologies in China based on patent analysis

Patents are the manifestation of the industry’s research and development (R&D) endeavor; therefore, this paper studies the industry evolution of and key technologies in China from the perspective of patent analysis. Patents in six types of industries, including Chemical (excluding Drugs), Computers and Communications, Drugs and Medical, Electrical and Electronics (E&E), Mechanical, and Others are analyzed in this study. Findings from the analysis show a steady increase of US granted utility patents in China as well as percentage of these patents in the world over the period between 2003 and 2008. All the above industries in China have been growing rapidly during this period, which is very different from the global industry development. Despite the rapid development, the citation rates of these patents have been low, reflecting a need for improvement in the quality of patents and R&D performance for these six industries in China in order to exert more influence in the industry world. The analysis on patents also reveals China’s industry distribution to be similar to the global industry distribution, with the exception of E&E industry which weights over one third of the total patents in technologies. The E&E industry is also the field with largest economic growth which rises more rapidly after 2006 with a sudden increase of patents in USPC 361. Detailed tracking of the key technology evolution reveals that 90% of the newly issued patents in USPC 361 after 2006 are owned by Foxconn Technology Co., Ltd, pointing to an unbalanced R&D environment in China’s E&E industry sector. By providing the insight into the evolution of China’s industrial and technological development through the perspective of patent analysis, this paper hopes to provide an objective statistic reference for future policy directions and academic researches.     

Economic and cross-media effect analyses of best available techniques for caustic recovery from mercerization textile wastewater

Clean Technologies and Environmental Policy - Caustic can be recovered from textile mercerization wastewaters by evaporation or membrane filtration. The main objective of this study was to evaluate...     

Suppression mechanism of micron/nano PMMA dust flame based on thermal analysis

The suppression mechanism of NaHCO₃ on micron/nano PMMA dust cloud flame based on thermal analysis was investigated. The results showed that the pyrolysis oxidation processes of 30 μm and 100 nm PMMA dusts were suppressed by NaHCO₃, and the apparent activation energy E and pre-exponential factor A were increased. The flame combustion intensity and propagation velocity of both micro and nano PMMA dusts were decreased obviously. Compared with 30 μm PMMA, NaHCO₃ maintained an efficient suppression on 100 nm PMMA with the mass ratio of NaHCO₃ increased with no suppression saturation phenomenon appeared. And 100 nm PMMA were more sensitive to particle size of NaHCO₃. In the flame preheat zone, the suppression effect of NaHCO₃ was mainly dominated by physical suppression, including the cooling effect of both pyrolysis reaction and products and the dilution effect on the concentration of combustible reactant. In the combustion reaction zone, the suppression effect of NaHCO₃ was mainly dominated by chemical suppression. The free radicals were absorbed by the active groups NaOH, forming the Na?NaOH suppression cycle. The E of nano PMMA dust flame was sustainably increased in both preheat and combustion reaction zones, contributing to the continuous high efficiency suppression and the sensitiveness to the particle size of explosion suppressant.     

Revisiting the environmental impact of financial development on economic growth and carbon emissions: evidence from South Asian economies

Clean Technologies and Environmental Policy - It is a global challenge to achieve sustainable economic growth by improving the environment. The present study discussed the role of the financial...     

Prediction of emerging technologies based on analysis of the US patent citation network

The network of patents connected by citations is an evolving graph, which provides a representation of the innovation process. A patent citing another implies that the cited patent reflects a piece of previously existing knowledge that the citing patent builds upon. A methodology presented here (1) identifies actual clusters of patents: i.e., technological branches, and (2) gives predictions about the temporal changes of the structure of the clusters. A predictor, called the citation vector, is defined for characterizing technological development to show how a patent cited by other patents belongs to various industrial fields. The clustering technique adopted is able to detect the new emerging recombinations, and predicts emerging new technology clusters. The predictive ability of our new method is illustrated on the example of USPTO subcategory 11, Agriculture, Food, Textiles. A cluster of patents is determined based on citation data up to 1991, which shows significant overlap of the class 442 formed at the beginning of 1997. These new tools of predictive analytics could support policy decision making processes in science and technology, and help formulate recommendations for action.     

Experimental investigation on the wettability of respirable coal dust based on infrared spectroscopy and contact angle analysis

Respirable dust does great harm to human health. In this paper, we focused on the wetting characteristics of respirable coal dust, and the effect of functional groups of respirable coal dust on its wettability was investigated. We selected five different types of coal samples (Lignite, Gas fat coal, Coking coal, 1/3 Coking coal, and Anthracite) from some typical mining areas in China. We used a Fourier Transform Infrared Spectrometer (FT-IR) to obtain the IR spectrum of the respirable coal dust, and the percentage of functional groups for each respirable coal dust was obtained by the peak area normalization method and then analyzed. And the wettability of respirable coal dust was evaluated by contact angle measurement. It is found that the benzene rings, aromatic hydrocarbons with benzene rings, aliphatic hydrocarbons with methyl, methylene, and so on, which have carbon-containing macromolecular structures, are hydrophobic. While the oxygen-containing functional groups represented by hydroxyl and carboxyl groups, and silicates and carbonate minerals are hydrophilic. Besides, the results show that respirable coal dust of different metamorphic grade coals has different wettability. This study has important theoretical significance for understanding the wettability of respirable coal dust.     

Carbon emissions pinch analysis (CEPA) for emissions reduction and energy planning in Canada

Clean Technologies and Environmental Policy - Canada has made a commitment in the Paris Agreement to reduce its total greenhouse gas emissions by 40–45% from 2005 levels by year 2030...     

Polymeric composites based on polystyrene and cement dust wastes

Due to the economical and environmental concern, polymer mortar and polymeric composites were prepared by mixing recycled polystyrene waste and cement dust waste as a filler. Virgin polystyrene and portland cement were used for comparison. Cement dust was treated by the reaction with stearic acid to increase the adhesion between the filler and the polymer matrix. The composites were prepared by mixing different concentration of treated and untreated cement dust (30, 50, 70 and 90 wt.%) with either virgin or recycled polystyrene. The suitability of the prepared polymeric composites as building materials in terms of mechanical properties, water absorption and chemical resistance was studied. After 1 week immersion in water, 10% sodium chloride (NaCl) and 10% sodium sulfate (Na₂SO₄) solutions, it was found that the chemical resistance and the mechanical properties were enhanced and the water absorption was retarded. The recycled polystyrene composites filled with treated cement dust gave the highest abrasion resistance and the lowest weight loss, also the best compressive and bending strength.     

Modelling and analysis of MEMS sensor based on piezoresistive effects

In this paper, we present a detailed study and analysis of piezoresistive effects on a membrane suspended in air based sensor. The variation of its capacitance under flow of stress or gas is investigated. The developed approach allows us to extract the material parameters in accurate way.     

Failure mode and effects analysis based on D numbers and TOPSIS

Failure mode and effects analysis (FMEA) is a widely used technique for assessing the risk of potential failure modes in designs, products, processes, system, and services. One of the main problems with FMEA is the need to address a variety of assessments given by FMEA team members and the sequence of the failure modes according to the degree of risk factors. Many different methods have been proposed to improve the traditional FMEA, which is impractical when the risk assessments given by multiple experts to one failure mode are imprecise, incomplete, or inconsistent. However, the existing methods cannot adequately handle these types of uncertainties. In this paper, a new risk priority model based on D numbers and technique for the order of preference by similarity to ideal solution (TOPSIS) is proposed to evaluate the risk in FMEA. In the proposed model, the assessments given by the FMEA team members are represented by D numbers, where a new feasible and effective method can effectively represent the uncertain information. The TOPSIS method, a multicriteria decision‐making method is presented to rank the preference of failure modes with respect to risk factors. Finally, an application of the failure modes of the rotor blades of an aircraft turbine is provided to illustrate the efficiency of the proposed method.     

Minerals phase transformation by hydrogen reduction technology: A new approach to recycle iron from refractory limonite for reducing carbon emissions

Limonite is a potentially vital iron ore resource, but it is hard to be effectively utilized by conventional mineral processing methods due to the high aluminum, silicon and water content. This paper proposed the phase transformation by hydrogen reduction technology to treat refractory limonite ore. The optimal conditions were determined as a roasting temperature of 500 °C, the reducing gas concentration of 20 % (H₂:CO = 3:1), roasting time of 25 min, grinding fineness of 85 % passing 0.038 mm, the magnetic field strength of 187.5 kA/m. Under the above conditions, the concentrate with an iron grade of 59.85 % and recovery of 98.47 % was obtained. X-ray diffraction, iron chemical phase analysis and Vibrating Sample Magnetometer showed that the phase transformation of iron oxide was goethite/hematite → magnetite. Thus, the magnetism was significantly enhanced, which was conducive to magnetic separation. Electron Probe Micro Analysis indicated that it was difficult to further improve the quality of iron concentrate due to the existence of aluminum in the form of extremely fine minerals and the isomorphic replacement between aluminum and iron.     

Universal and specific features of Ukrainian economic research: publication analysis based on Crossref data

Scientometrics - Our study is one of the first examples of multidimensional and longitudinal disciplinary analysis at the national level based on Crossref data. We present a large-scale...     

Optical pH detector based on LTCC and sol-gel technologies

This paper presents an investigation on using sol-gel thin film as a material for sensors application in LTCC (Low Temperature Co-fired Ceramics) technology. This material gives the opportunity to make new, low-cost highly integrated optoelectronic devices. Sensors with optical detection are a significant part of these applications. They can be used for quick and safe diagnostics of some parameters. Authors present a pH detector with the optical detection system made of the LTCC material. The main part of the device is a flow channel with the chamber and sol-gel active material. The silica sol-gel with bromocresol green indicator was used. As the absorbance of sol-gel layer changes with the pH value of a measured medium, the transmitted light power was measured. The pH detector was integrated with the electronic components on the LTCC substrate.     

Advancing low-carbon emissions in Asia: mitigation of greenhouse gases and enhancing economic feasibility for major sectors

Clean Technologies and Environmental Policy -     

Reliability analysis for accelerated degradation data based on the Wiener process with random effects

On the basis of the principle of degradation mechanism invariance, a Wiener degradation process with random drift parameter is used to model the data collected from the constant stress accelerated degradation test. Small-sample statistical inference method for this model is proposed. On the basis of Fisher's method, a test statistic is proposed to test if there is unit-to-unit variability in the population. For reliability inference, the quantities of interest are the quantile function, the reliability function, and the mean time to failure at the designed stress level. Because it is challenging to obtain exact confidence intervals (CIs) for these quantities, a regression type of model is used to construct pivotal quantities, and we develop generalized confidence intervals (GCIs) procedure for those quantities of interest. Generalized prediction interval for future degradation value at designed stress level is also discussed. A Monte Carlo simulation study is used to demonstrate the benefits of our procedures. Through simulation comparison, it is found that the coverage proportions of the proposed GCIs are better than that of the Wald CIs and GCIs have good properties even when there are only a small number of test samples available. Finally, a real example is used to illustrate the developed procedures.     

Modern and appropriate technologies for the reduction of gaseous pollutants and their effects on the environment

Harmful effects on environment such as global warming and climate change may result from the gases emanating from fossil fuel combustion. Jordan and most Middle East countries use fossil fuels exclusively. Therefore, new technologies which could accommodate the demand for cleaner effluents, such as: combined cycles, fluidized bed combustion, magneto hydrodynamics, fuel cells, nuclear power, natural gas, renewable energy, and energy conservation have been considered. CO₂ being the most produced gas, many technical methods of reducing and reusing CO₂ have been suggested such as: Injection in oceans, storage in caverns, injection in depleted oil and gas fields, pumping during oil recovery, storage as CO₂ ice, elimination by fixation using water algae, and increasing plantation especially forestation. These methods are being used at different degrees in the Middle East countries. Reduction of formation and harmful effects of other gaseous pollutants is also discussed, with some concentration on the transportation sector, energy efficiency and fuel cells, which have special importance for the developing countries.