Carbon capture and storage (CCS) technologies aiming at tackling CO2 emission have attracted much attention from scientists of various backgrounds. Most CCS systems require an efficient adsorbent to ...remove CO2 from sources such as fossil fuels (pre‐combustion) or flue gas from power generation (post‐combustion). Research on developing efficient adsorbents with a substantial capacity, good stability and recyclability has grown rapidly in the past decade. Because of their high surface area, highly porous structure, and high stability, various nanoporous materials have been viewed as good candidates for this challenging task. Here, recent developments in several classes of nanoporous materials, such as zeolites, metal organic frameworks (MOFs), mesoporous silicas, carbon nanotubes, and organic cage frameworks, for CCS are examined and potential future directions for CCS technology are discussed. The main criteria for a sustainable CO2 adsorbent for industrial use are also rationalized. Moreover, catalytic transformations of CO2 to other chemical species using nanoporous catalysts and their potential for large scale carbon capture and utilization (CCU) processes are also discussed. Application of CCU technologies avoids any potential hazard associated with CO2 reservoirs and allows possible recovery of some running cost for CO2 capture by manufacturing valuable chemicals.
Nanoporous materials have shown great potential as efficient adsorbents for carbon capture and storage (CCS) technologies. An overview of the properties of these classes of nanomaterials with their advantages and limitations regarding use as CO2 adsorbents is presented. New research directions in CO2 utilization are also discussed.
The Work Design Questionnaire (WDQ) Morgeson, Frederick P; Humphrey, Stephen E
Journal of applied psychology,
11/2006, Letnik:
91, Številka:
6
Journal Article
Recenzirano
Although there are thousands of studies investigating work and job design, existing measures are incomplete. In an effort to address this gap, the authors reviewed the work design literature, ...identified and integrated previously described work characteristics, and developed a measure to tap those work characteristics. The resultant Work Design Questionnaire (WDQ) was validated with 540 incumbents holding 243 distinct jobs and demonstrated excellent reliability and convergent and discriminant validity. In addition, the authors found that, although both task and knowledge work characteristics predicted satisfaction, only knowledge characteristics were related to training and compensation requirements. Finally, the results showed that social support incrementally predicted satisfaction beyond motivational work characteristics but was not related to increased training and compensation requirements. These results provide new insight into how to avoid the trade-offs commonly observed in work design research. Taken together, the WDQ appears to hold promise as a general measure of work characteristics that can be used by scholars and practitioners to conduct basic research on the nature of work or to design and redesign jobs in organizations.
Child stunting is a global problem and is only modestly responsive to dietary interventions. Numerous observational studies have shown that water quality, sanitation, and handwashing (WASH) in a ...household are strongly associated with linear growth of children living in the same household. We have completed three randomised efficacy trials testing improved household-level WASH with and without improved infant and young child feeding (IYCF) on stunting and diarrhoea in Bangladesh, Kenya, and Zimbabwe. In all trials, improved IYCF had a statistically significant benefit, but WASH had no effect on linear growth. In observational analyses of data from the control groups of the three trials, baseline sanitation was a strong risk factor for stunting in the study populations, suggesting this frequently reported association might be confounded by unmeasured factors of household wellbeing. WASH interventions reduced diarrhoea in Bangladesh, but not in Kenya or Zimbabwe. Intervention promoters visited participants six times per month in Bangladesh compared with monthly in Kenya and Zimbabwe; a review of the literature shows that virtually all published studies that have reported an effect on diarrhoea through home-based water treatment and handwashing promotion achieved high adherence by visiting participants at daily to fortnightly intervals. Despite achieving substantial behavioural change and significant reduction in infection prevalence for some enteric pathogens, detection of enteropathogens among children in the WASH groups of the trials was typically at ten times higher prevalence compared with high-income countries. Considering these results, we recommend that future research in the WASH sector focus on developing and evaluating interventions that are radically more effective in reducing faecal contamination in the domestic environment than the interventions implemented in these trials.
In a trial involving patients with relapsed or refractory chronic lymphocytic leukemia, the BCL2 inhibitor venetoclax in combination with rituximab resulted in a higher 2-year rate of ...progression-free survival than bendamustine in combination with rituximab (85% vs. 36%).
Onsite wastewater treatment systems (OWTSs) and private wells are commonly used in Eastern North Carolina, USA. Water from private wells is not required to be tested after the initial startup, and ...thus persons using these wells may experience negative health outcomes if their water is contaminated with waste-related pollutants including bacteria, nitrate or synthetic chemicals such as hexafluoropropylne oxide dimer acid and its ammonium salt (GenX). Water samples from 18 sites with OWTSs and groundwater wells were collected for nitrate, Escherichia coli (E. coli), total coliform, and GenX concentration analyses. Results showed that none of the 18 water supplies were positive for E. coli, nitrate concentrations were all below the maximum contaminant level of 10 mg L
, and one well had 1 MPN 100 mL
of total coliform. However, GenX was detected in wastewater collected from all 18 septic tanks and 22% of the water supplies tested had concentrations that exceeded the health advisory levels for GenX. Water supplies with low concentrations of traditionally tested for pollutants (nitrate, E. coli) may still pose health risks due to elevated concentrations of emerging contaminants like GenX and thus more comprehensive and routine water testing is suggested for this and similar persistent compounds.
Magnetic nanoparticles for gene and drug delivery McBain, Stuart C; Yiu, Humphrey H P; Dobson, Jon
International Journal of Nanomedicine,
01/2008, Letnik:
3, Številka:
2
Journal Article, Book Review
Recenzirano
Odprti dostop
Investigations of magnetic micro- and nanoparticles for targeted drug delivery began over 30 years ago. Since that time, major progress has been made in particle design and synthesis techniques, ...however, very few clinical trials have taken place. Here we review advances in magnetic nanoparticle design, in vitro and animal experiments with magnetic nanoparticle-based drug and gene delivery, and clinical trials of drug targeting.
Enzymatic reduction using oxidoreductases is important in commercial chemical production. This enzymatic action requires a cofactor (e.g., NADH) as a hydrogen source that is consumed during reaction ...and must be regenerated. We present, for the first time, an in situ NADH regeneration (NAD+ → NADH) using a heterogeneous catalyst (Pt/Al2O3) and H2 coupled with an enzymatic reduction. This regeneration system can be operated at ambient pressure where NADH yield and turnover frequency (TOF) increased with temperature (20–37 °C) and pH (4.0–9.9) delivering full selectivity to enzymatically active NADH. Cofactor regeneration by heterogeneous catalysis represents a cleaner (H+ as sole byproduct) alternative to current enzymatic and homogeneous (electro- and photo-) catalytic methods with the added benefit of facile catalyst separation. The viability of coupling cofactor regeneration with enzymatic (alcohol dehydrogenase, ADH) reaction is established in aldehyde reduction (propanal to propanol) where 100% alcohol yield was achieved. The potential of this hybrid inorganic–enzymatic system is further demonstrated in the continuous (fed-batch) conversion of propanal with catalyst (activity/selectivity) stability for up to 100 h.
The authors developed and meta-analytically examined hypotheses designed to test and extend work design theory by integrating motivational, social, and work context characteristics. Results from a ...summary of 259 studies and 219,625 participants showed that 14 work characteristics explained, on average, 43% of the variance in the 19 worker attitudes and behaviors examined. For example, motivational characteristics explained 25% of the variance in subjective performance, 2% in turnover perceptions, 34% in job satisfaction, 24% in organizational commitment, and 26% in role perception outcomes. Beyond motivational characteristics, social characteristics explained incremental variances of 9% of the variance in subjective performance, 24% in turnover intentions, 17% in job satisfaction, 40% in organizational commitment, and 18% in role perception outcomes. Finally, beyond both motivational and social characteristics, work context characteristics explained incremental variances of 4% in job satisfaction and 16% in stress. The results of this study suggest numerous opportunities for the continued development of work design theory and practice.
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