Forty Years of the BLS Export and Import Price Indexes: Trends and Competition

[Excerpt] U.S. competitiveness is measured in many different ways. However, two sets of measures that historically have been of interest in helping to assess the strength of the economy are the price trends of U.S. exports and of U.S. imports. The Bureau of Labor Statistics (BLS, the Bureau) first began publication of a limited set of export price indexes in 1971, followed 2 years later by a set of import price indexes. The Bureau developed these series in response to two key concerns, one statistical and the other economic. The statistical issue was over the validity of the import and export unit value indexes published by the Census Bureau. The economic question had to do with the nation’s ability to compete in the increasingly global economy. The publication of detailed export and import price indexes helped address these concerns because those indexes were true price indexes and because they provided a greater level of detail than the analogous indexes previously published by the Census Bureau. The number of published series increased until the Bureau was able to publish the first all-import price index in 1983, followed a year later by the first all-export price index. Although the publication of these series alleviated the need to rely upon the unit value data—indeed, the Census Bureau discontinued publication of its unit value indexes in 1989—concerns over U.S. competitiveness have only grown over time

Lifecycle Assessment of Microalgae to Biofuel: Thermochemical Processing through Hydrothermal Liquefaction or Pyrolysis

Microalgae have many desirable attributes as a renewable energy recourse. These include use of poor quality land, high yields, and it is not a food recourse. This research focusses on the energetic and environmental impact of processing microalgae into a renewable diesel. Two thermochemical bio-oil recovery processes are analyzed, pyrolysis and hydrothermal liquefaction (HTL). System boundaries include microalgae growth, dewatering, thermochemical bio-oil recovery, bio-oil stabilization, conversion to renewable diesel, and transportation to the pump. Two system models were developed, a small-scale experimental and an industrial-scale. The small-scale system model is based on experimental data and literature. The industrial-scale system model leverages the small scale system model with scaling and optimization to represent an industrial-scaled process. The HTL and pyrolysis pathways were evaluated based on net energy ratio (NER), defined here as energy consumed over energy produced, and global warming potential (GWP). NER results for biofuel production through the industrial-scaled HTL pathway were determined to be 1.23 with corresponding greenhouse gas (GHG) emissions of -11.4 g CO2 eq (MJ renewable diesel)-1. Biofuel production through the industrial-scaled pyrolysis pathway gives a NER of 2.27 and GHG emissions of 210 g CO2 eq (MJ renewable diesel)-1. For reference, conventional diesel has an NER of 0.2 and GHG emissions of 18.9 g CO2 eq MJ-1 with a similar system boundary. The large NER and GHG emissions associated with the pyrolysis pathway are attributed to feedstock drying requirements and combustion of co-products to improve system energetics. Process energetics with HTL and pyrolysis are not currently favorable for an industrial scaled system. However, processing of microalgae to biofuel with bio-oil recovery through HTL does produce a favorable environmental impact and a NER which is close to the breakeven point of one

Fibre laser using a microchannel based loss tuning element for refractive index sensing

We have proposed and demonstrated a fibre laser system using a microchannel as a cavity loss tuning element for surrounding medium refractive index (SRI) sensing. A ~6µm width microchannel was created by femtosecond (fs) laser inscription assisted chemical etching in the cavity fibre, which offers a direct access to the external liquids. When the SRI changes, the microchannel behaves as a loss tuning element, hence modulating the laser cavity loss and output power. The results indicate that the presented laser sensing system has a linear response to the SRI with a sensitivity in the order of 10-5. Using higher pump power and more sensitive photodetector, the SRI sensitivity could be further enhanced

Fiber laser incorporating an intracavity micro-channel for refractive index and temperature sensing

In this letter, we present a standard linear cavity fiber laser incorporating a microchannel for refractive index (RI) and temperature sensing. The microchannel of ~6µm width created by femtosecond laser aided chemical etching provides an access to the external liquid; therefore, the laser cavity loss changes with the liquids of different RIs. Thus, at a fixed pump power, the output laser power will vary with the change of RI in the microchannel. The results show that the proposed sensing system has a linear response to both the surrounding medium RI and temperature. The RI sensitivity of the laser system is on the order of 10-3, while the temperature sensitivity is about 0.02 C. Both sensitivities could be further enhanced by employing a more sensitive photodetector and using higher pump power

Real-time detection of DNA interactions with long-period fiber-grating-based biosensor

Using an optical biosensor based on a dual-peak long-period fiber grating, we have demonstrated the detection of interactions between biomolecules in real time. Silanization of the grating surface was successfully realized for the covalent immobilization of probe DNA, which was subsequently hybridized with the complementary target DNA sequence. It is interesting to note that the DNA biosensor was reusable after being stripped off the hybridized target DNA from the grating surface, demonstrating a function of multiple usability. © 2007 Optical Society of America

A scientific basis for restoring fish spawning habitat in the St. Clair and Detroit Rivers of the Laurentian Great Lakes

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110848/1/rec12159.pd

Environmental Impact Assessment of Microalgae to Biofuel Utilizing Thermochemical Processing

Microalgae are currently being investigated as a renewable transportation fuel feedstock based on various advantages that include high annual yields, utilization of poor quality land, does not compete with food and can be integrated with waste streams. This study focuses on directly assessing the impact of two different thermochemical conversion technologies on the microalgae to biofuel process through life cycle assessment. A system boundary of a cradle to pump is leveraged and sub \u27process models are developed to be representative of a large-scale microalgae to biofuel process including growth, dewatering, drying, bio-oil recovery, bio-oil stabilization, and conversion to renewable diesel. Two different thermochemical bio-oil conversion systems are modeled and compared, pyrolysis and hydrothermal liquefaction (HTL). Both technologies having the capability of improving yields through the conversion of non-lipid constituents to bio-oil. Systems engineering models were experimentally validated and integrated with life cycle modeling to determine the environmental impact of the various pathways. Metrics of net energy ratio (NER) defined here as energy consumed over energy produced and global warming potential (GWP) are used to directly quantify and compare the modeled process to conventional fuels. Biofuel production through HTL was determined to be the more favorable process with a NER of 1.42 and GHG emissions of -1.1 g CO2 eq (MJ renewable diesel)-1 compared to pyrolysis with a NER of 2.40 and GHG emissions of 272.6 g CO2 eq (MJ renewable diesel)-1. Results include a detailed breakdown of the overall process energetics and GWP for the HTL and pyrolysis processing pathways, impact of modeling at laboratory- scale compared to large-scale, and environmental impact sensitivity to systems engineering input parameters

Refractive index sensing properties of long-period fibre grating with sol-gel derived coatings

Long-period fibre gratings (LPGs) have previously been used to detect quantities such as temperature, strain and refractive index (RI). The responsivity to surrounding refractive index means that, potentially, LPGs could be realised as optical biosensors for applications in biochemical and biomedical application areas. We report here to our best knowledge the first investigation on refractive index sensing properties of LPGs with sol-gel derived titanium and silicon oxide coatings. It is revealed that the RI sensitivity of an LPG is affected by both the thickness and the index value of the coating; the coating with higher index and thickness will enhance the LPG RI sensitivity significantly. The surrounding refractive index induced LPG resonance shift has been evaluated over the LPGs’ most sensitive RI region from 1.42 to 1.44. We have identified that, in this region, the uncoated LPG has an RI sensitivity of (-673.0±0.4)nm/uri (unit of refractive index) while the LPG coated with titanium oxide exhibits a sensitivity as high as (-1067.15±0.04)nm/uri