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A review of biohydrogen productions from lignocellulosic precursor via dark fermentation: perspective on hydrolysate composition and electron-equivalent balance
Get PDFThis paper reviews the current technological development of bio-hydrogen (BioH2) generation, focusing on using lignocellulosic feedstock via dark fermentation (DF). Using the collected reference reports as the training data set, supervised machine learning via the constructed artificial neuron networks (ANNs) imbedded with feed backward propagation and one cross-out validation approach was deployed to establish correlations between the carbon sources (glucose and xylose) together with the inhibitors (acetate and other inhibitors, such as furfural and aromatic compounds), hydrogen yield (HY), and hydrogen evolution rate (HER) from reported works. Through the statistical analysis, the concentrations variations of glucose (F-value = 0.0027) and acetate (F-value = 0.0028) were found to be statistically significant among the investigated parameters to HY and HER. Manipulating the ratio of glucose to acetate at an optimal range (approximate in 14:1) will effectively improve the BioH2 generation (HY and HER) regardless of microbial strains inoculated. Comparative studies were also carried out on the evolutions of electron equivalent balances using lignocellulosic biomass as substrates for BioH2 production across different reported works. The larger electron sinks in the acetate is found to be appreciably related to the higher HY and HER. To maintain a relative higher level of the BioH2 production, the biosynthesis needs to be kept over 30% in batch cultivation, while the biosynthesis can be kept at a low level (2%) in the continuous operation among the investigated reports. Among available solutions for the enhancement of BioH2 production, the selection of microbial strains with higher capacity in hydrogen productions is still one of the most phenomenal approaches in enhancing BioH2 production. Other process intensifications using continuous operation compounded with synergistic chemical additions could deliver additional enhancement for BioH2 productions during dark fermentation
Multi - mechanism coalescence design and matrix expression of logic action sequences of the over-turn nursing robot Part I: Functions and coalescence design
Get PDFIn order to effectively solve the problem in over-turn of a bedridden person with the assistance of external force, a double bed face- three embedded leave over-turn nursing robot with the flexible compensation was put forward, with the abstraction of the bedridden person as an organism. This robot, on the basis of concept gesture of the person in bed and the state of the robot supporting and proving the gesture with the actions and combination of the two bed faces, held the complete function of over-turn nursing with 7 states corresponding to 5 gestures of the bedridden person obeying the fundamental requirements of safety, rapidity, and comport. The design method of "PS-MM-KD" was proposed for multi-mechanism coalescent system with related specific tasks induced from the original problems with Systems Engineering. Mechanics and Mechanisms, then applied in the concrete sub-system design followed by analysis and verification of both the scheme and the sub-systems in the design, using the Kinematics and Dynamics, implementing the gears, chain wheel, slewing mechanism, screw nut and mortise and tenon joint type clutch mechanism design successfully. Based on those above, a "two-bed face/three-leaf embedded flexible compensation nursing robot" was designed adopting to all ages, people of various kinds of body geometry. PLC, sensor and logic algorithm were used to carry out the control and operation of 7 state-5 posture sequences for realization of the automation and intelligent over-turning in safety, comfort, and convenience
Study of bandgap property of a bilayer membrane-type metamaterial applied on a thin plate
Get PDFThis work is aimed to study the bandgap property of a thin plate structure with periodically attached bilayer membrane-type resonators. An analytical method based on the Plane Wave Expansion (PWE) method combined with the Rayleigh method, is proposed to predict the bandgap property of bilayer membrane-type metamaterials. The accuracy of the proposed method is verified by the finite element analysis, and a parametric analysis is conducted to reveal the effect of parameters on the bandgap performance. It is found that such a metamaterial can generate two separated bandgaps through the contribution of its two layers of membranes. It is observed that the increase of membrane tensile stress or the magnitude of attached mass can lead to the broadening of bandgaps, whilst the change of unit cell’s periodicity has the opposite effect. In addition, if compared with the corresponding single layer membrane-type metamaterials, it is shown that the bilayer membrane-type’s first bandgap is suppressed while the second one is extended. However, by applying proper membrane tensile stress and mass magnitude, the suppression of the first bandgap can be weakened whilst allowing the tuning of the bandgap location. These characteristics reveal the benefits of using bilayer membrane-type metamaterial as it possesses higher agility in bandgap tuning. The proposed method can provide an effective tool for the bilayer membrane-type metamaterial design and optimisation
Optimal rearrangement problem and normalized obstacle problem in the fractional setting
Get PDFWe consider an optimal rearrangement minimization problem involving the fractional Laplace operator (−∆) s , 0 0} , which happens to be the fractional analogue of the normalized obstacle problem ∆u = χ{u>0}
Electrospinning and emerging healthcare and medicine possibilities
Get PDFElectrospinning forms fibers from either an electrically charged polymer solution or polymer melt. Over the past decades, it has become a simple and versatile method for nanofiber production. Hence, it has been explored in many different applications. Commonly used electrospinning assembles fibers from polymer solutions in various solvents, known as solution electrospinning, while melt and near-field electrospinning techniques enhance the versatility of electrospinning. Adaption of additive manufacturing strategy to electrospinning permits precise fiber deposition and predefining pattern construction. This manuscript critically presents the potential of electrospun nanofibers in healthcare applications. Research community drew impetus from the similarity of electrospun nanofibers to the morphology and mechanical properties of fibrous extracellular matrices (ECM) of natural human tissues. Electrospun nanofibrous scaffolds act as ECM analogs for specific tissue cells, stem cells, and tumor cells to realize tissue regeneration, stem cell differentiation, and in vitro tumor model construction. The large surface-to-volume ratio of electrospun nanofibers offers a considerable number of bioactive agents binding sites, which makes it a promising candidate for a number of biomedical applications. The applications of electrospinning in regenerative medicine, tissue engineering, controlled drug delivery, biosensors, and cancer diagnosis are elaborated. Electrospun nanofiber incorporations in medical device coating, in vitro 3D cancer model, and filtration membrane are also discussed
The Motion Picture Editors Guild treatment of the film sound membership: enforcing status quo for Hollywood’s post-production sound craft
Get PDFThe Motion Picture Editors Guild (MPEG) is the labor union representing post-production workers in the Hollywood motion picture industry, including seven sound craft classifications. The sound craft has low status within the hierarchical structure of the Hollywood film industry in comparison to other filmmaking crafts. This article evaluates the workings of the MPEG in concerns with the sound craft and status within the industry through a thirty-plus year review of their professional journal, website, sound practitioner discourse, and other industrial documents. The article argues that the union does not sufficiently protect sound practitioners from employer exploitation, contributes to the alienation of sound practitioners from their work, and constraints the level of and recognition for creative contributions. These actions are seen as perpetuating the low status of sound practitioners and the sound craft, which weakens the power of the union
Structure and dynamics of iron pentacarbonyl
Get PDFThe dynamics of CO ligand scrambling in Fe(CO)5 has been investigated by linear infrared spectroscopy in supercritical xenon solution. The activation barrier for the Berry pseudorotation in Fe(CO)5 was determined experimentally to be Ea = 2.5 ± 0.4 kcal mol–1 by quantitative analysis of the temperature-dependent spectral line shape. This compares well with the range of Ea/(kcal mol–1) = 2.0 to 2.3 calculated by various DFT methods and the value of 1.6 ± 0.3 previously obtained from 2D IR measurements by Harris et al. ( Science 2008, 319, 1820). The involvement of Fe(CO)5···Xe interactions in the ligand scrambling process was tested computationally at the BP86-D3/AE2 level and found to be negligible
Information technology issues in China
Get PDFIn this chapter, we provide important information technology (IT) issues in China, such as organizational IT issues, technology issues, and individual issues. In the World IT Project survey, we recruited 310 IT workers in China. Most of the respondents were in their early career and worked full time in China's IT organizations. The findings show that the most important IT-related organizational issues are: IT reliability and efficiency, security and privacy, and IT strategic planning. Among technology issues, IT professionals identified the following issues as the top concerns: networks/telecommunications, big data systems, data mining, software as a service, and business intelligence/analytics. Most IT employees seem to be satisfied with their current jobs and felt a sense of accomplishment at work. Results further show that more than half of the IT workers would not change their jobs in the short term and felt secure in their current jobs. In addition, there were no significant work-life conflicts among the surveyed IT employees. © 2020 The Author(s)
Sustainable flood risk and stormwater management in blue‐green cities; an interdisciplinary case study in Portland, Oregon
Get PDFBlue-Green Infrastructure (BGI) is recognized as a viable strategy to manage stormwater and flood risk, and its multifunctionality may further enrich society through the provision of multiple cobenefits that extend far beyond the hydrosphere. Portland, Oregon, is an internationally renowned leader in the implementation of BGI and showcases many best practice examples. Nonetheless, a range of interdisciplinary barriers and uncertainties continue to cloud decision making and impede wider implementation of BGI. In this paper, we synthesize research conducted by the “Clean Water for All” (CWfA) research project and demonstrate that interdisciplinary evaluation of the benefits of Portland’s BGI, focusing on green street bioswales and the East Lents Floodplain Restoration Project, is essential to address biophysical and sociopolitical barriers. Effective interdisciplinary approaches require sustained interaction and collaboration to integrate disciplinary expertise toward a common problem-solving purpose, and strong leadership from researchers adapt at spanning disciplinary boundaries. While the disciplinary differences in methodologies were embraced in the CWfA project, and pivotal to providing evidence of the disparate benefits of multifunctional BGI, cross-disciplinary engagement, knowledge coproduction, and data exchanges during the research process were of paramount importance to reduce the potential for fragmentation and ensure research remained integrated. © 2020 The Authors. Journal of the American Water Resources Association published by Wiley Periodicals LLC on behalf of American Water Resources Associatio
Are nontariff measures and tariffs substitutes? Some panel data evidence
Get PDFUsing new estimates of ad valorem equivalent of nontariff measures (NTMs) over time, this paper examines NTMs and tariffs’ relationship for a sample of 70 economies for 4,949 products at the 6‐digit harmonized system level over the period 2003–2015. A panel data methodology models the lagged adjustment of NTMs to tariffs, consistent with a causal relationship. Trade policy substitution is found when the models are estimated in both levels and changes; with this holding for both OECD and non‐OECD countries, but not for the agriculture sector in OECD countries. Overall, there is a fairly complete substitution between policy instruments in absolute terms
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