Current Technology Assessment Research Articles

Lignin as a Renewable Building Block for Sustainable Polyurethanes.

Currently, the pulp and paper industry generates around 50–70 million tons of lignin annually, which is mainly burned for energy recovery. Lignin, being a natural aromatic polymer rich in functional hydroxyl groups, has been drawing the interest of academia and industry for its valorization, especially for the development of polymeric materials. Among the different types of polymers that can be derived from lignin, polyurethanes (PUs) are amid the most important ones, especially due to their wide range of applications. This review encompasses available technologies to isolate lignin from pulping processes, the main approaches to convert solid lignin into a liquid polyol to produce bio-based polyurethanes, the challenges involving its characterization, and the current technology assessment. Despite the fact that PUs derived from bio-based polyols, such as lignin, are important in contributing to the circular economy, the use of isocyanate is a major environmental hot spot. Therefore, the main strategies that have been used to replace isocyanates to produce non-isocyanate polyurethanes (NIPUs) derived from lignin are also discussed.

TECHNOLOGY ASSESSMENT IN DEVELOPING COUNTRIES: SUSTAINABLE ENERGY SYSTEMS IN THE AFRICAN CONTEXT

Technology assessment is an important component for effective technology management (TM) and occurs in initial technology life-cycle phases. However, technology assessment practices have largely evolved in developed countries. Current technology assessment methods also do not consider social-ecological complexity, which is important if the sustainability of technologies is to be assessed; this is especially true of energy systems in developing countries. This paper subsequently investigates how the understanding of the principles of sustainability science may lead to better assessment practices that can be used upfront, in the TM cycle, by policy- and decision-makers of renewable energy technologies in the African context.

Offline Chinese handwriting recognition: an assessment of current technology

Offline Chinese handwriting recognition (OCHR) is a typically difficult pattern recognition problem. Many authors have presented various approaches to recognizing its different aspects. We present a survey and an assessment of relevant papers appearing in recent publications of relevant conferences and journals, including those appearing in ICDAR, SDIUT, IWFHR, ICPR, PAMI, PR, PRL, SPIEDRR, and IJDAR. The methods are assessed in the sense that we document their technical approaches, strengths, and weaknesses, as well as the data sets on which they were reportedly tested and on which results were generated. We also identify a list of technology gaps with respect to Chinese handwriting recognition and identify technical approaches that show promise in these areas as well as identify the leading researchers for the applicable topics, discussing difficulties associated with any given approach.

Bias assessment of current technologies used for the determination of low levels of moisture in mineral oil samples.

The problem in the current debate on the accuracy of Karl Fischer (KF) titrations lies in the fact that coulometry is being compared to volumetry on mineral oil samples for which the true moisture content is unknown. To clarify this point, dehydrated oil samples equilibrated under known temperature and relative humidity conditions and equilibrated oil samples containing known amounts of added moisture were used to assess the accuracy of the determinations. In addition, the measurements were extended to other techniques given that it is unlikely that they would be affected by the same phenomenon causing the KF systematic errors. The samples sent to different laboratories were analyzed by headspace/capillary gas chromatography, gas-phase H2 sensor, oil-phase or gas-phase RH sensors, KF coulometric titration with direct or indirect injection, and KF volumetric titration using a standard or NIST modified procedure. The laboratory comparison showed that with the exception of 4 techniques out of 10 that were tested, the measurements gave results in the expected concentration range. Considering the exceptions, two techniques based on volumetric titration yielded results tainted with an important positive bias for both sample types. This bias, tentatively associated with the high iodine end point concentration used by these systems, was estimated at approximately 22 ppm under the conditions applied by NIST. On the other hand, the two RH sensors showed a marked tendency to underestimate the value of the samples containing high moisture content. In this case, a loss of analyte through wall adsorption during the time required to achieve steady-state conditions in the measuring chamber seems to be at the origin of the negative biases.

Human Factors Engineering of a Virtual Laboratory for Students with Physical Disabilities

Medical advances, new legislation, and changing social attitudes have encouraged more students with disabilities to enter college. Educational systems consequently must continue to respond to the unique needs of these Individuals by developing adaptive educational tools. Laboratory courses requiring hands-on experience, such as physics and biology, are challenging to students with physical limitations. One promising and innovative way to provide access is through virtual environment technology, which can provide a unique tool for students with physical disabilities by offering opportunities for mobility and manipulative exploration without requiring physical access, dexterity, and strength. We are developing a virtual physics laboratory that should benefit students with physical disabilities by providing them greater control over their environment and more educational opportunities. These benefits also will be realized by nondisabled students. We discuss some of the issues and technologies employed to design the laboratory, including user needs analyses, task analyses, and assessment of current technologies.

Assessment of the quality of life before and following liver transplantation. First results.

Analysis of quality-of-life effects is part of the current technology assessment of the Dutch orthotopic liver transplant-program. Data are collected by means of computer-assisted interviewing, including one interview before transplantation and annual follow-up interviews. Data on psychiatric morbidity are obtained from medical records. This article shows preliminary results of a cross-sectional analysis of data collected from 1987 to 1989. Eighty-eight measurements were obtained from 46 adult patients (response rate 82%). Pretransplant scores suggest major restrictions on all domains of life, especially a low amount of energy. After transplantation all indicators show improvement, although the level of the general population is not always attained. Improvement of subjective quality of life is more marked, possibly due to euphoria at surviving the hazardous procedure. Psychiatric events occurred only infrequently. We conclude that orthotopic liver transplantation contributes positively to the quality of life of surviving patients. In addition, computer-assisted interviewing proved to be a feasible survey technique, even when very ill patients were involved.

Fail-safe devices for the prevention of hazardous materials spills

Many hazardous material spills can be prevented by the use of automatic container-filling procedures to determine when maximum capacity is reached. This project assessed current fail-safe technology, conducted laboratory tests of automatic devices and monitored performance of on-site automatic level controllers. In the assessment of current technology, available data on devices used to prevent tank overflow were identified and reviewed. Fourteen types of devices were investigated to determine their potential for automatic container-filling control. Although most of the fourteen level detectors could measure for either wet or dry products, some could measure both wet and dry products. The detectors were activated by electrical, electric/pneumatic, pneumatic, or mechanical action. The fourteen types of level detector devices are pressure devices, float level controls, capacitance level detectors, conductive level measurements, thermal probes, sonic-echo level monitors, inductive-level detectors, rotating-paddle level detectors, vibration-level detectors, automatic sounding, light and sight glass measurement, radiation-level measurement, microwave-level measurement, and pressure tape. Three different types of industrial plants, each having an overfilling problem with a different material, cooperated in the field testing phase. The three level control devices tested were ultrasonic, vibrating tines, and magnetic-coupled- float types, respectively. Two of the units were activated by electricity and the third was activated pneumatically. One unit controlled dry powder, the second, a viscous liquid, and the third, an aqueous liquid. Each location required an explosion-proof system. All three units were installed without significant revisions to existing containers, and all operated well for an extended period under severe weather conditions. The proper controller configuration must be compatible with the environment and must also incorporate requisite safety features and demonstrate corrosion fouling and weather resistance.