Due to high consumption and non-renewable nature of fossil fuels, rapid development of potential renewable energies such as biofuel derived from microalgae is necessary for achieving the goals of ...sustainable growth and carbon neutrality. However, the high energy consumption required for microalgal biomass harvesting is regarded as a major obstacle for large-scale microalgal biofuel production. In the present study, the marine green microalgae Tetraselmis sp. was used to investigate a rapid and energy-efficient biomass collection method among different methods such as gravity sedimentation, auto-flocculation (at target pH), flocculation by polymers followed by magnetic separation, and centrifugation. The results showed that sufficient high cell densities of microalgae were obtained under the optimized growth conditions after 21 days of cultivation, and the microalgae could be easily flocculated and collected by magnetic separation using synthesized magnetic nanocomposites. The results also showed that among the different methods, magnetic separation was more efficient for biomass harvesting because of its simple and fast processing steps as well as low energy consumption. However, further investigation on different target microalgal species and their cultivation conditions, such as salinity and medium pH, will be required before application for large-scale biofuel production in the future.
The fragmentation rate and particle size distribution of the muckpile after blasting have important influences on the performance of subsequent mining activities such as loading, hauling, crushing, ...grinding, and the overall costs of the mine. Drilling and blasting are important steps in the chain of mining processes, and its results affect the efficiency of downstream processes accordingly. There is an increasing body of blasting research that indicates the significant impacts in mining downstream processes. Within the scope of this study, a series of blasts were conducted in a sandstone quarry, and the throughput of the jaw crusher was recorded after each blasted rocks are fed. These measurements consisted of analysis of the particle size distribution of each muckpile after shots, and the assessment of particle size distributions of each truck—load fragmented rock. Digital image processing method was used for the assessment of the particle size distribution of blasted rock. The fragmentation results then were paired with the crusher throughput values, and series of regression analysis were done in order to understand the effects of blast fragmentation on crusher throughput. The analysis includes the relationship between
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values of size distributions and the crusher throughput results. Depending on the correlation degree of each relationship, effects of each size distribution parameter on crushing performance were discussed. Established empirical equations with reliable correlation coefficients can be used to estimate the crusher performance depending on fragmentation results of a blast and therefore, and blast designs can also be modified.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
High quality nucleic acids (with high integrity, purity, and biological activity) have become indispensable products of modern society, both in molecular diagnosis and to be used as ...biopharmaceuticals. As the current methods available for the extraction and purification of nucleic acids are laborious, time-consuming, and usually rely on the use of hazardous chemicals, there is an unmet need towards the development of more sustainable and cost-effective technologies for nucleic acids purification. Accordingly, this study addresses the preparation and evaluation of silica-based materials chemically modified with chloride-based ionic liquids (supported ionic liquids, SILs) as potential materials to effectively isolate RNAs. The investigated chloride-based SILs comprise the following cations: 1-methyl-3-propylimidazolium, triethylpropylammonium, dimethylbutylpropylammonium, and trioctylpropylammonium. All SILs were synthesized by us and characterized by solid-state 13C Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), elemental analysis, and zeta potential measurements, confirming the successful covalent attachment of each IL cation with no relevant changes in the morphology of materials. Their innovative application as chromatographic supports for the isolation of recombinant RNA was then evaluated. Adsorption kinetics of transfer RNA (tRNA) on the modified silica-based materials were investigated at 25 °C. Irrespective to the immobilized IL, the adsorption experimental data are better described by a pseudo first-order model, and maximum tRNA binding capacities of circa 16 µmol of tRNA/g of material were achieved with silica modified with 1-methyl-3-propylimidazolium chloride and dimethylbutylpropylammonium chloride. Furthermore, the multimodal character displayed by SILs was explored towards the purification of tRNA from Escherichia coli lysates, which in addition to tRNA contain ribosomal RNA and genomic DNA. The best performance on the tRNA isolation was achieved with SILs comprising 1-methyl-3-propylimidazolium chloride and dimethylbutylpropylammonium chloride. Overall, the IL modified silica-based materials represent a more efficient, sustainable, and cost-effective technology for the purification of bacterial RNAs, paving the way for their use in the purification of distinct biomolecules or nucleic acids from other sources.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Part 8 of the series Magnetic field assisted fluidization (MFAF) – A unified approach deals with biochemical upstream (production) and downstream (separation) processes performed in magnetically ...assisted reactors. Basic reactor principles well-implemented in chemical engineering science are used to analyze the existing situation of those special types of mass transfer devices. The hydrodynamics of all systems reviewed in the previous parts of the series (G-S, L-S and G-L-S) serves as a foundation assuring proper understanding of their mass transfer performances. Thorough analysis of magnetically assisted bioprocesses is performed together with suitable devices for their performance. Part 8 refers not only to reactors with magnetic biosupports but also to processes with free-suspended cells imposed to magnetic field action and micro devices for upstream processing.
바이오 디젤 생산량 증가에 따라 공정 중에 부산물로 발생하는 글리세린의 과잉공급 및 가격 하락이 이루어지고 있다. 이에 따라 글리세린에 기반한 다양한 화학제품생산과 관련된 연구가 활발히 진행되고 있으며 글리세린을 탄소원으로 한 1,3-프로판디올의 생물학적 생산은 그 중 하나이다. 1,3-프로판디올은 지금까지 화학적인 방법을 통해 생산되어 왔으나 생물학적인 ...방법을 통해 생산될 경우 공정의 친환경성 및 경제성 확보와 더불어 1,3-프로판디올을 중합원료로 하는 PTT (Poly(trimethylene terephthalate))의 바이오폴리머로서의 활용을 가능하게 한다. 그럼에도 글리세린 유래 1,3-프로판디올의 생물학적 생산의 경제성에 있어 핵심은 경제적인 분리공정의 수립에 있다. 본 총설에서는 1,3-프로판 디올을 분리하기 위한 공정들에 대한 연구 동향을 소개하고 최근 에너지 절감과 더불어 1,3-프로판디올 분리와 부산물 제거를 동시에 달성할 있는 공정으로 주목 받고 있는 수상이성분계 추출에 대한 연구개발 동향 및 전망을 제시하고자 한다.
As the biodiesel production is increasing rapidly, the crude glycerol, which is principal by-product of biodiesel production, has also been generated in a large amount. Many research studies on value-added utilization of glycerol are under investigation. 1,3-Propandiol is a promising chemical which can be produced from fermentation of glycerol because the application of 1,3-propanediol is mainly in the production of bio-PTT (Poly(trimethylene terephthalate). However, the cost of downstream processes in the biological production of 1, 3-propanediol can make a high portion in the total production cost. This review summarizes the present state of separation processes in each step studied for the removal of impurities and the recovery of 1, 3-propanediol from its fermentation broth. Furthermore, ATPE (Aqueous Two Phases Extraction) process is suggested as an attractive alternative for the primary separation process of 1,3-propanediol because ATPE is convenient for the simultaneous removal of microbial cells and impurities such as salts of organic acids and the separation of 1,3-propanediol from fermentation broth.
'What' do we call consciousness? 'When' and 'Where' in the brain do conscious states occur, and 'How' conscious processing and conscious access to a given content work? In the present paper, we ...present a non-exhaustive overview of each of these 4 major issues, we provide the reader with a brief description of the major difficulties related to these issues, we highlight the current theoretical points of debate, and we advocate for the explanatory power of the "global workspace" model of consciousness (Baars 1989; Dehaene and Naccache 2001; Dehaene, Changeux et al. 2006) which can accommodate for a fairly large proportion of current experimental findings, and which can be used to reinterpret apparent contradictory findings within a single theoretical framework. Most notably, we emphasize the crucial importance to distinguish genuine neural signatures of conscious access from neural events correlated with consciousness but occurring either before ('upstream') or after ('downstream').
BACKGROUND: Vinasses, the main liquid wastes from the distillation process of grape marc and wine lees, are acidic effluents with high organic content, including acids, carbohydrates, phenols, and ...unsaturated compounds with high chemical oxygen demand, biological oxygen demand and solid concentrations. These wastes can be revalued to provide additional benefits when they are employed as feedstock of some compounds including tartaric acid, calcium tartrate and economic nutrients for the elaboration of fermentable broths.RESULT: This study attempts to recover tartaric acid and calcium tartrate from vinasses. All the tartaric acid initially solubilised was recovered in both processes. The residual streams can be successfully employed as economic nutrients for the xylose to xylitol bioconversion, achieving higher global volumetric productivities (QP, xylitol = 0.232 g L⁻¹ h⁻¹) and products yields (Yxylitol/S = 0.57 g g⁻¹) than fermentations carried out using commercial nutrients (QP, xylitol = 0.193 g L⁻¹ h⁻¹ and Yxylitol/S = 0.55 g g⁻¹ respectively).CONCLUSION: Tartaric acid can be recovered from vinasses in the form of tartaric acid crystals and calcium tartrate. The residual streams generated in the process can be used as economic nutrients for the production of xylitol by D. hansenii. Copyright
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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