Quick Analysis of Organic Amendments via Portable X-ray Fluorescence Spectrometry

The determination of heavy metals in soils and organic amendments, such as compost, manure, biofertilizer, and sludge, generally involves the digestion of samples with aqua regia, and the determination of those in the solution using various techniques. Portable X-ray fluorescence (PXRF) has many advantages in relation to traditional analytical techniques. However, PXRF determines the total elemental content and, until now, its use for the analysis of organic amendments has been limited. The objective of this work is the calibration of a PXRF instrument to determine the aqua regia-soluble elemental contents directly in solid samples of organic amendments. Our proposal will avoid the digestion step and the use of other laboratory techniques. Using a training set of samples, calibration functions were obtained that allow the determination of the aqua regia-soluble contents from the PXRF readings of total contents. The calibration functions (obtained by multiple linear regression) allowed the quantitative determination of the aqua regia-soluble contents of Fe, K, P, S, Zn, Cu, Pb, Sr, Cr, and Mn, as well as the organic matter content and a semi-quantitative assessment of Al, Ca, V, Ba, Ni, and As contents. The readings of Si, Fe, Al, Ca, K, or S were used as correction factors, indicating that the calibrations functions found are truly based on the chemical composition of the sample matrix. This study will allow a fast, cheap, and reliable field analysis of organic amendments and of other biomass-based materials.Spanish Ministry of Science, Innovation and Universities, and the European Regional Development Fund, European Union, (AEI/FEDER, UE), grant number CGL2016-78937-R

A design method for improving assembly and environmental sustainability in packaging solutions: a case study in household appliances

By using a functional requirement analysis, through Design for Manufacture and Assembly and Design for Environment principles, this paper aims at showing a new design method to improve the overall assembly features and environmental sustainability of a packaging solution. This method provides to rank functional requirements according to three different design specifications and also to the number of relationships they have with each other. At the same time, a ranked order of importance for the packaging parts has been realised, considering the number of performed functions. The purpose of this method is to support the designers in focusing their attention on the most important packaging parts and, at the same time, giving them a clear idea of which are the most important functional requirements to be satisfied. This study has been focused on domestic household packaging, but the provided method can be extended to any particular packaging solution and its findings are still valid. According to the Design for Environmental perspective, the actual and the new resulting packaging solutions have been then compared through Life Cycle Assessment method. The results have shown the new packaging solution being able to cut down the environmental impacts, on average, of approximately 30%

Improving Surrogate Monitoring Techniques for Suspended Sediment

The quality of water of our nation’s rivers and streams is important to many vital uses including drinking water treatment, recreation, and the natural environment. Water quality can be severely impacted by the quantity and type of suspended sediment found therein. Because suspended sediment can be associated with many other contaminants that degrade water quality, it is noted as the most common impairment to water quality in the United States. Suspended sediment can cause significant ecological impacts to the chemical and biological characteristics of surface waters. The ability to accurately quantify suspended sediment concentrations at the appropriate time(s) and location(s) is critical in assessing whether streams are meeting their designated beneficial uses and in implementing and evaluating watershed management and mitigation plans and restoration efforts. Currently, new methods for quantifying suspended sediment concentrations use mathematical and statistical techniques to relate turbidity and suspended sediment and have been shown to be affected by several factors, including the size and characteristics of suspended sediment particles. In this research we used turbidity as a surrogate (substitute) for suspended sediment at six locations in the Little Bear River, Utah, U.S.A. We also examined the differences between single-point and width and depth integrated suspended sediment sampling at two sites. This was used to develop a method to account for the differences and improve the resulting estimates of suspended sediment concentrations. Statistical techniques were used to assess—in probabilistic terms—the duration and magnitude of potential water quality criteria exceedance. Findings highlight that among some monitoring locations with wide geographic distances, turbiditysuspended sediment relationships are not site-specific for the more frequent (90th percentile) but lower (\u3c50 \u3eNTU) turbidity values. Comparisons of point measures of turbidity and width and depth integrated suspended sediment samples revealed that suspended sediment is homogenous at their respective stream cross sections for 90% and 99% of the time at sites 2 and 6, respectively. The results are applicable to water managers who are charged with the determination of attainment or exceedance of water quality standards

Manufacturing Energy Consumption and Assessment for Us Small and Medium Sized Manufacturers

U.S. Manufacturing sector consumes remarkable amount of energy while the energy efficiency is quite low. Energy consumption of CNC machines is significant and various empirical models have been developed to model the Specific Energy Consumption (SEC) of CNC machines. However, most of the models are developed for specific machines, hence have limited applications in manufacturing industry. In this research, a general empirical SEC model for milling machine at certain power level is developed based on actual cutting experimental data. In this model, stand-by power and spindle power are used in the SEC model for the first time. The Material Removal Rate (MRR) is used to represent cutting parameter. The proposed model is fitted by regression analysis and validated using experimental data. Results show that the proposed model can be applied on various milling machines with an average absolute residual ratio of 6%. The model is also validated through a series of cutting experiments on a machine center, with an accuracy of 91.5%, for the SEC calculation. Compressed Air Systems (CAS) are the 3rd energy source in industrial facilities and has a significant impact on the energy efficiency of manufacturing systems. This thesis provides an overview of all typical energy conservation measures (ECM) for CAS as well as all the energy savings calculations methods. To provide a simple guideline for decision maker, an economic benchmark analysis is presented for typical ECMs using the baseline conditions from Technical Reference Manuals (TRM) of multiple States in the US. Due to the ECMs correlate with each other, the comprehensive savings from multiple ECMs is not the simple summation of each individual measure. An integrated model is proposed to investigate the interrelationships of all measures and obtain combined savings. Meanwhile, the dryer’s impact to the other ECMs is included for the first time in the proposed model. CAS is a dynamic system with changing load, operations, and specifications etc. Therefore, the savings is a variable depending on system situations. The reliabilities of the ECMs are analyzed to obtain their dynamic characteristics. The optimization of the ECMs is discussed to demonstrate the interrelationships and dynamic of the savings mechanisms. While the above studies focus on the energy modeling and savings of important system of manufacturing activities, it is important to have an overall understanding of the energy efficiency and saving potentials. Energy intensity is commonly used as an indicator for the energy efficiency. Encourage the implementation of proposed ECMs is the main strategy for energy efficiency improvement programs to influence the plant’s energy intensity. Study the trends of energy intensity of SMEs and the acceptance of proposed ECMs could draw outlines of the changes of energy usage, understand the flavor of plant managers towards energy savings projects and reflect the shift of technologies in the past decades. This thesis found that the industry structure of SMEs had limited effects on the energy usage while the fluctuation of producing activities and improvement of energy efficiency were the main contributors over the past three decades. Compared with the manufacturing plants with best energy efficient practices, an average of 15.71% of electricity and 14.51% of natural gas could be saved. However, the saving potentials of each subsectors varies dramatically due to the differences of production processes and energy use strategies. This discrepancy also reflected on the implementation of ECMs. Special planning and stimulations should be developed to accommodate the unique saving demands for different industries, ECM types and regions

Multivariate adaptive regression splines for estimating riverine constituent concentrations

Regression-based methods are commonly used for riverine constituent concentration/flux estimation, which is essential for guiding water quality protection practices and environmental decision making. This paper developed a multivariate adaptive regression splines model for estimating riverine constituent concentrations (MARS-EC). The process, interpretability and flexibility of the MARS-EC modelling approach, was demonstrated for total nitrogen in the Patuxent River, a major river input to Chesapeake Bay. Model accuracy and uncertainty of the MARS-EC approach was further analysed using nitrate plus nitrite datasets from eight tributary rivers to Chesapeake Bay. Results showed that the MARS-EC approach integrated the advantages of both parametric and nonparametric regression methods, and model accuracy was demonstrated to be superior to the traditionally used ESTIMATOR model. MARS-EC is flexible and allows consideration of auxiliary variables; the variables and interactions can be selected automatically. MARS-EC does not constrain concentration-predictor curves to be constant but rather is able to identify shifts in these curves from mathematical expressions and visual graphics. The MARS-EC approach provides an effective and complementary tool along with existing approaches for estimating riverine constituent concentrations

Identification of candidate genes involved in wax deposition in Poa pratensis by RNA-seq

A, Randomness test of cDNA fragments; B, Sequencing saturation analysis. T1 and T2 represent NEZm; T3 and T4 represent EBZ. (PDF 290 kb

Modeling the Effect of a Road Construction Project on Transportation System Performance

Road construction projects create physical changes on roads that result in capacity reduction and travel time escalation during the construction project period. The reduction in the posted speed limit, the number of lanes, lane width and shoulder width at the construction zone makes it difficult for the road to accommodate high traffic volume. Therefore, the goal of this research is to model the effect of a road construction project on travel time at road link-level and help improve the mobility of people and goods through dissemination or implementation of proactive solutions. Data for a resurfacing construction project on I-485 in the city of Charlotte, North Carolina (NC) was used evaluation, analysis, and modeling. A statistical t-test was conducted to examine the relationship between the change in travel time before and during the construction project period. Further, travel time models were developed for the freeway links and the connecting arterial street links, both before and during the construction project period. The road network characteristics of each link, such as the volume/ capacity (V/C), the number of lanes, the speed limit, the shoulder width, the lane width, whether the link is divided or undivided, characteristics of neighboring links, the time-of-the-day, the day-of-the-week, and the distance of the link from the road construction project were considered as predictor variables for modeling. The results obtained indicate that a decrease in travel time was observed during the construction project period on the freeway links when compared to the before construction project period. Contrarily, an increase in travel time was observed during the construction project period on the connecting arterial street links when compared to the before construction project period. Also, the average travel time, the planning time, and the travel time index can better explain the effect of a road construction project on transportation system performance when compared to the planning time index and the buffer time index. The influence of predictor variables seem to vary before and during the construction project period on the freeway links and connecting arterial street links. Practitioners should take the research findings into consideration, in addition to the construction zone characteristics, when planning a road construction project and developing temporary traffic control and detour plans