Intensified energetically enhanced steam methane reforming through the use of membrane reactors

This work focuses on the implementation of membrane reactors (MRs) in the production of hydrogen through steam–methane reforming (SMR). A novel equilibrium MR model featuring Gibbs Free Energy Minimization is introduced and applied to the SMR-MR process. In addition, the concept of “energetically enhanced steam methane reforming (EER),” which allows for the use of a hybrid (methane combustion/renewable energy) energy supply in the production of hydrogen, is intensified. The UNISIM software (Honeywell™) is used to create a range of intensified flowsheets depicting the proposed IEER-MR process as well as two baseline flowsheets depicting “a standard SMR-MR process” and “a fully exothermic EER process.” Heat integration studies are carried out on the developed flowsheets, and the baseline designs are compared to the IEER-MR designs to identify energetic intensification.     

Velocity variation effect in fixed bed columns: A case study of CO2 capture using porous solid adsorbents

This study shows that for a reliable evaluation of porous adsorbents for carbon capture based on the fixed bed adsorption analysis, one must consider the effect of velocity variation due to adsorption to make a fair judgment on predicting the performance of materials under flow conditions. A combined experimental and numerical study of CO₂/N₂ adsorption in fixed beds using three forms of adsorbents of amorphous powder (bulk activated carbon, AC), crystalline powder (bulk CuBTC metal‐organic framework, MOF) and crystalline pellets (pelleted CuBTC) was carried out to show the effect of velocity variation on CO₂ breakthrough curves. Significant deviations are observed in the estimated amount adsorbed calculated from fixed bed experiments when models used for interpretation the measured data consider constant gas velocity because the stoichiometric time is underestimated. We show that the difference in breakthrough times estimated in models that consider constant and variable gas velocity grows exponentially with the feed gas concentration. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2189–2197, 2018     

Polystyrene recycling processes by dissolution in ethyl acetate

This study evaluated the thermal, morphological, chemical, and mechanical properties of virgin and recycled polystyrene. The recycling process was carried out by dissolution of polystyrene (extruded and crystal) in ethyl acetate, followed by two processes for solvent removal: vaporization by direct contact with water at 85 °C in a tubular evaporator and vaporization during the extrusion process. For the samples produced by solvent evaporation in the tubular evaporator, there was practically no degradation on polymer chain, neither reduction in glass transition temperature. For the samples produced by solvent evaporation during the extrusion, a polymer chain degradation was noted by reduction in molar weight and in glass transition temperature. The FTIR evaluation suggests that polymer oxidative degradation, in both samples, was more pronounced in the extruded sample. The removal of plasticizing additives could be evidenced by the glass transition temperature increase in the recycled samples produced in the tubular evaporator. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46208.     

Mechanical and Fracture Behaviour Evaluation of Commercial Acrylic Bone Cements

The deformation and fracture behaviour of some commercial acrylic bone cements have been investigated. Cements were characterized by gel permeation chromatography, dynamic mechanical analysis and scanning electron microscopy. The influence of liquid to powder ratio, curing temperature, strain rate and non-reacted monomer was analysed for one radiolucent cement. Results showed that the β transition activation process influences both deformation and fracture behaviour. Fracture surface stress whiteness revealed the presence of crazes as the main plastic deformation mechanism. Non-reacted monomer acted as a plasticizer leading to materials with lower yield strength, σ_y, that induces crack tip blunting and improves toughness. It appears that the presence of radiopacifier fillers also improves fracture toughness by promoting interactions between the crack and the second phase dispersion. © 1997 SCI.     

Impact of Protein Removal by an Upstream Ultrafiltration on the Reverse Osmosis of Skim Milk and Sweet Whey

Concentration of milk and whey by ultrafiltration and reverse osmosis (RO) in cascade mode is an amendment of evaporation for high volume reduction ratios (VRR) prior to drying. This study investigated the impact of a prior protein removal and the transmembrane pressure (TMP) on the RO stage, compared to skim milk and sweet whey. It could be found that removal of the protein fraction of both skim milk and sweet whey improved the efficiency of the RO. An upstream ultrafiltration resulted in higher VRR as well as an increased permeate flux.     

Limited hydrolysis of soy proteins with endo- and exoproteases

Changes in the native state and functional properties of soy protein achieved by limited proteolysis of soy flour were investigated. Different enzyme-to-substrate ratios (E/S) were used to obtain low (3–5%) and medium (5–10%) degrees of hydrolysis (DH). Six protease preparations (three with predominately exopeptidase activities and three with predominately endopeptidase activities) were evaluated, and their effects on solubility, emulsification capacity, SDS-PAGE profiles, and denaturation enthalpies were characterized. Endoproteases (Multifect^® Neutral, Protex^? 6L, and Multifect^® P-3000) and exoproteases (Fungal Protease Concentrate, Experimental Fungal Protease #1, and Experimental Fungal Protease #2) yielded similar increases in soy protein solubility. The modifications to the soy peptide profile were similar for the three exoprotease mixtures at a 1% E/S ratio, whereas the extent of hydrolysis with Protex^? 6L was more pronounced than with the two other endoproteases (Multifect^® Neutral and Multifect^® P-3000). The emulsification capacity of protease-modified soy flour declined regardless of DH and enzyme type (exo- or endoprotease). After hydrolysis to >4% DH, denaturation enthalpies of glycinin and β-conglycinin decreased significantly, whereas hydrolysis to lower DH did not affect these values.     

Development of electronic textiles to support networks, communications, and medical applications in future U.S. military protective clothing systems.

The focus of this paper is on the development of textile-based wearable electronics that can be integrated into military protective clothing. A materials and manufacturing survey was conducted to determine the best performing and most durable materials to withstand the rigors of textile manufacturing and potential military use. Narrow woven technology was selected as one of the most promising textile manufacturing methods. A working wearable narrow fabric version of the Universal Serial Bus (USB), as well as a radiating conductor, were successfully developed and fabricated. A circular knit T-shirt with an integrated spiral bus was also developed. Military products developed include components of a personal area network providing data and power transport, and a body-borne antenna integrated into a load-bearing vest.     

Poverty and environmental impacts of electricity price reforms in Montenegro

The creation of the Energy Community of South Eastern Europe in 2005 committed countries in South Eastern Europe to liberalize their energy markets in accordance to EU regulations. The Government of Montenegro is thus in the process of reforming its energy sector, which includes an electricity tariff reform. This paper analyzes the environmental and social impacts of an increase in residential electricity tariffs contemplated – which is expected to range anywhere from 40 to over 100% increase. As this analysis shows, such a significant price rise will impose a heavy burden on the poor households and it may adversely affect the environment. In an ex ante investigation of the welfare impact of this price increase on households in Montenegro, we show that the anticipated price increase will result in a very significant increase in households' energy expenditures. A simulation of alternative policy measures analyzes the impact of different tariff levels and structures, focusing on the poor and vulnerable households. Higher electricity prices could also significantly increase the proportion of households using fuelwood for space heating. Thus the level of fuelwood consumption should be carefully monitored under the electricity tariff reforms and the Government of Montenegro should combine the tariff reforms with a carefully evaluated set of policy measures to mitigate the effect of the electricity price increase on the poor.     

A Longitudinal Study of Gendered Vocabulary and Communicative Action in Young Children.

Development of children's vocabularies for gender-typed words and communicative actions was investigated longitudinally from 13 to 36 months and in a group of 9.5-month-olds. Vocabularies of gendered words were assessed using lists of adult-rated gender-typed words from the MacArthur-Bates Communicative Development Inventories (CDI; L. Fenson et al., 1994). At 24 to 36 months, girls' and boys' productive vocabularies contained more same-gender-typed words than other-gender-typed words. Receptive vocabulary gender-differential effects were apparent among boys at 18 months. At 13 and 18 months, gender-typed differences were apparent in communicative actions. The research reveals the utility of unobtrusive, nonexperimental measures for assessing gender-related knowledge and behavior in young children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Participation, Barriers, and Opportunities in PFI: The United Kingdom Experience

Private finance initiative (PFI) projects play an increasingly important role for both the United Kingdom government and the construction sector. It is still a relatively new form of procurement that requires a wide range of specialist advice during the bidding stage and in-depth knowledge of how the facility will perform in the long term. This paper investigates the level of participation in PFI projects in the United Kingdom, the opportunities available for the construction sector, the types of problems experienced, and the challenges for the future. It achieves this by analyzing the results of a questionnaire survey of a large number of client and construction organizations. The study finds that there is a wide gap in the level of PFI experience between client and construction organizations, affordability of PFI projects, and high bidding costs are key issues for client and construction organizations, respectively, and, given the nature of PFI projects, there is considerable scope for knowledge transfer both during the project and between different PFI projects.