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Records with Subject: Biosystems
Showing records 1 to 25 of 82. [First] Page: 1 2 3 4 Last
Comparison of Three Deoxidation Agents for Ozonated Broths Used in Anaerobic Biotechnological Processes
Ewelina Pawlikowska, Jaroslaw Domanski, Piotr Dziugan, Joanna Berlowska, Weronika Cieciura-Wloch, Krzysztof Smigielski, Dorota Kregiel
May 16, 2019 (v1)
Subject: Biosystems
Keywords: deoxidation, iron sulfate, Metschnikowia sp., ozonation, ultrasound
Anaerobic fermentation of organic compounds is used in many biotechnological processes and has been the subject of much research. A variety of process conditions and different growth media can be used to obtain microbial metabolites. The media must be free from contamination before fermentation. Sterilization is most often achieved by applying heat or other treatments, such as ozonation. Sterilization of liquid media using ozone can be very beneficial, but this method introduces high concentrations of residual oxygen, which inhibit anaerobic processes. Deoxidation is therefore necessary to remove the oxygen from ozonated broths. This study evaluates the effectiveness of three deoxidation agents for two kinds of fermentation media based on malt or molasses: ultrasound, iron(II) sulfate, and Metschnikowia sp. yeast. The time needed for deoxidation varied, depending on the kind of broth and the deoxidation agent. In general, the dynamics of oxygen removal were faster in malt broth. A comp... [more]
Integrated Hydrolysis of Mixed Agro-Waste for a Second Generation Biorefinery Using Nepenthes mirabilis Pod Digestive Fluids
Nkosikho Dlangamandla, Seteno Karabo Obed Ntwampe, Justine Oma Angadam, Elie Fereche Itoba-Tombo, Boredi Silas Chidi, Lukhanyo Mekuto
May 16, 2019 (v1)
Subject: Biosystems
Keywords: agro-waste, biorefinery, carboxylesterases, cellulases, Nepenthes mirabilis, total reducing sugars, xylanase, β-glucosidase
To sustainably operate a biorefinery with a low cost input in a commercial setting, the hydrolysis of lignocellulosic biomass must be undertaken in a manner which will impart environmental tolerance while reducing fermenter inhibitors from the delignification process. The challenge lies with the highly recalcitrant lignin structure, which limits the conversion of the holocelluloses to fermentable total reducing sugars (TRS). Due to these challenges, sustainable and innovative methods to pre-treat biomass must be developed for delignocellulolytic operations. Herein, Nepenthes mirabilis digestive fluids shown to have ligninolytic, cellulolytic and xylanolytic activities were used as an enzyme cocktail to hydrolyse mixed agro-waste constituted by Citrus sinensis (orange), Malus domestica (apple) peels, cobs from Zea mays (maize) and Quercus robur (oak) yard waste. The digestive fluids contained carboxylesterases (529.41 ± 30.50 U/L), β-glucosidases (251.94 ± 11.48 U/L) and xylanases (36.0... [more]
Effect of Supercritical Fluid Extraction Process on Chemical Composition of Polianthes tuberosa Flower Extracts
Javier C. Fragoso-Jiménez, Ernesto Tapia-Campos, Mirna Estarron-Espinosa, Rodrigo Barba-Gonzalez, Ma. Claudia Castañeda-Saucedo, Gustavo A. Castillo-Herrera
May 16, 2019 (v1)
Subject: Biosystems
Keywords: chemical composition, Polianthes tuberosa, supercritical fluid extraction
Supercritical fluid extracts from flowers of Polianthes tuberosa var. double were ob tained using carbon dioxide as a solvent. Yield extract obtained was 2.5%. The effects of the pressure process (18 MPa, 28 MPa, and 38 MPa) and temperature process (313 K, 323 K, and 333 K) on the volatile composition of tuberose flowers extracts were evaluated, and a significant variation in chemical composition was found. Characteristic compounds of tuberose as methyl isoeugenol, benzyl benzoate, methyl anthranilate, pentacosene, and heptacosene were obtained mainly at 18 MPa and 333 K process conditions, and could be used in the perfume or fragrance industry. Components such as geraniol, farnesol, and methyl eugenol were also obtained, these extracts could be used in the development of cosmeceutical products. This work allowed to identification of the chemical composition profile and evaluation of the changes in tuberose extracts due to the extraction process.
The Study on Extraction Process and Analysis of Components in Essential Oils of Black Pepper (Piper nigrum L.) Seeds Harvested in Gia Lai Province, Vietnam
Thien Hien Tran, Le Ke Ha, Duy Chinh Nguyen, Tan Phat Dao, Le Thi Hong Nhan, Dai Hai Nguyen, Trinh Duy Nguyen, Dai-Viet N. Vo, Quoc Toan Tran, Long Giang Bach
May 16, 2019 (v1)
Subject: Biosystems
Keywords: black pepper (Piper nigrum L.), essential oils, chemical composition analysis, GC-MS, hydrodistillation
Black pepper (Piper nigrum L.) is a tropical crop with extensive medicinal potential in ethnomedicine and nutraceutical applications. The essential oil of black pepper finds wide applications in inhabitation of respiratory infections and soothing of muscular pains due to its warming and energizing property. The pungent bioactive piperine is responsible for this function, and therefore, efficient technology is required for an optimal extraction process of this compound. In the present article, we have developed a procedure for extracting black pepper essential oil from Vietnam, optimizing conditions that affect the extraction process. The effect of process parameters, namely material size, preservation method, the concentration of sodium chloride, the concentration of soak time, the ratio of material to water, temperature extraction, time extraction on the extraction yield, and relative efficiency were investigated. Results demonstrated that 20 g of black pepper milled with a mesh size... [more]
Pilot Plant Data Assessment in Anaerobic Digestion of Organic Fraction of Municipal Waste Solids
Massimo Migliori, Enrico Catizzone, Girolamo Giordano, Adolfo Le Pera, Miriam Sellaro, Alessandro Lista, Giuseppe Zanardi, Luciano Zoia
April 15, 2019 (v1)
Subject: Biosystems
Keywords: biogas, dry anaerobic digestion, municipal waste, wet anaerobic digestion
In this paper, a preliminary study of anaerobic digestion of organic fraction of municipal solid wastes (OFMSW) in presented with the aim to compare the performances of both wet- and dry-type reactors. The treatment of OFMSW via anaerobic digestion (AD) producing biogas is a process that is receiving a growing interest because two different needs can be coupled: the request of sustainable municipal waste treatments and increasing demand renewable energy. This paper aims to offer experimental results comparing batch test and continuous experimental reactors under different conditions of humidity and solid content. Results show that both the investigated configurations may be used for converting OFMSW into a high quality biogas and that the increase of dry matter in the continuous process still allows to achieve significant biogas production rates. A slight reduction of the methane content was observed (less than 5% relative) that can be also related to the change in the level of volatil... [more]
Characterization, Expression Profiling, and Functional Analyses of a 4CL-Like Gene of Populus trichocarpa
Hui Wei, Chen Xu, Ali Movahedi, Weibo Sun, Qiang Zhuge
April 15, 2019 (v1)
Subject: Biosystems
Keywords: 4CL-like, ACS, box I domain, box II domain, CL, Populus trichocarpa, PTS
Adenosine 5′-monophosphate (AMP) (adenylate)-forming acetyl-CoA synthetase (ACS) catalyzes the formation of acetyl-coenzyme A (CoA), and the ACS family is closely related to the 4-coumarate CoA ligase (4CL) family. In this study, a 4CL-like gene was cloned from Populus trichocarpa and named Pt4CL-like. Characterization of Pt4CL-like, using bioinformatics, showed that it contained box I and box II domains at the end of the C-terminal sequence, and there is a characteristic sequence of ACS, namely, peroxisome-targeting sequence (PTS). Real-time PCR results showed that the 4CL-like gene was expressed in all tissues tested, and was highly expressed in the stems. A denaturation and renaturation process was conducted, and the recombinant Pt4CL-like protein was purified through HisTrapTM high performance affinity chromatography. It showed Pt4CL-like protein did not catalyze substrates of 4CL, but could significantly catalyzed sodium acetate. These results indicate that Pt4CL-like protein belo... [more]
Catastrophic Health Expenditures and Its Inequality in Households with Cancer Patients: A Panel Study
Munjae Lee, Kichan Yoon
April 15, 2019 (v1)
Subject: Biosystems
Keywords: cancer patient households, catastrophic health expenditure, healthcare spending, Korea Health Panel, panel logit analysis
This study aims to examine the determinants of catastrophic health expenditure in households with cancer patients by conducting a panel analysis of three-year data. Data are adopted from surveys administered by Korea Health Panel for 2012⁻2014. We conducted correspondence and conditional transition probability analyses to examine households that incurred catastrophic health expenditure, followed by a panel logit analysis. The analyses reveal three notable results. First, the occurrence of catastrophic health expenditure differs by age group, that is, the probability of incurring catastrophic health expenditure increases with age. Second, this probability is higher in households with National Health Insurance than those receiving medical care benefits. Finally, households without private health insurance report a higher occurrence rate. The findings suggest that elderly people with cancer have greater medical coverage and healthcare needs. Private health insurance contributes toward pro... [more]
Multiscale Agent-Based and Hybrid Modeling of the Tumor Immune Microenvironment
Kerri-Ann Norton, Chang Gong, Samira Jamalian, Aleksander S. Popel
April 15, 2019 (v1)
Subject: Biosystems
Keywords: computational biology, immune checkpoint inhibitor, immuno-oncology, immunotherapy, mathematical modeling, multiscale systems biology, quantitative systems pharmacology (QSP)
Multiscale systems biology and systems pharmacology are powerful methodologies that are playing increasingly important roles in understanding the fundamental mechanisms of biological phenomena and in clinical applications. In this review, we summarize the state of the art in the applications of agent-based models (ABM) and hybrid modeling to the tumor immune microenvironment and cancer immune response, including immunotherapy. Heterogeneity is a hallmark of cancer; tumor heterogeneity at the molecular, cellular, and tissue scales is a major determinant of metastasis, drug resistance, and low response rate to molecular targeted therapies and immunotherapies. Agent-based modeling is an effective methodology to obtain and understand quantitative characteristics of these processes and to propose clinical solutions aimed at overcoming the current obstacles in cancer treatment. We review models focusing on intra-tumor heterogeneity, particularly on interactions between cancer cells and strom... [more]
Combining Microwave Pretreatment with Iron Oxide Nanoparticles Enhanced Biogas and Hydrogen Yield from Green Algae
Asad A. Zaidi, Ruizhe Feng, Adil Malik, Sohaib Z. Khan, Yue Shi, Asad J. Bhutta, Ahmer H. Shah
April 15, 2019 (v1)
Subject: Biosystems
Keywords: algae, anaerobic digestion, biogas, biohydrogen, energy assessment, kinetic models, microwave, nanoparticles, pretreatment
The available energy can be effectively upgraded by adopting smart energy conversion measures. The biodegradability of biomass can be improved by employing pretreatment techniques; however, such methods result in reduced energy efficiency. In this study, microwave (MW) irradiation is used for green algae (Enteromorpha) pretreatment in combination with iron oxide nanoparticles (NPs) which act as a heterogeneous catalyst during anaerobic digestion process for biogas enhancement. Batch-wise anaerobic digestion was carried out. The results showed that MW pretreatment and its combination with Fe₃O₄ NPs produced highest yields of biogas and hydrogen as compared to the individual ones and control. The biogas amount and hydrogen % v/v achieved by MW pretreatment + Fe₃O₄ NPs group were 328 mL and 51.5%, respectively. The energy analysis indicated that synergistic application of MW pretreatment with Fe₃O₄ NPs produced added energy while consuming less input energy than MW pretreatment alone. The... [more]
Model for Thin Layer Drying of Lemongrass (Cymbopogon citratus) by Hot Air
Thi Van Linh Nguyen, My Duyen Nguyen, Duy Chinh Nguyen, Long Giang Bach, Tri Duc Lam
April 15, 2019 (v1)
Subject: Biosystems
Keywords: activation energy, convection drying, Cymbopogon citratus, lemongrass, mathematical modeling, moisture diffusivity
Lemongrass is a plant that contains aromatic compounds (myrcene and limonene), powerful deodorants, and antimicrobial compounds (citral and geraniol). Identifying a suitable drying model for the material is crucial for establishing an initial step for the development of dried products. Convection drying is a commonly used drying method that could extend the shelf life of the product. In this study, a suitable kinetic model for the drying process was determined by fitting moisture data corresponding to four different temperature levels: 50, 55, 60 and 65 °C. In addition, the effect of drying temperature on the moisture removal rate, the effective diffusion coefficient and activation energy were also estimated. The results showed that time for moisture removal increases proportionally with the air-drying temperature, and that the Weibull model is the most suitable model for describing the drying process. The effective diffusion coefficient ranges from 7.64 × 10−11 m²/s to 1.48 × 10−10 m²... [more]
Early Afterdepolarisations Induced by an Enhancement in the Calcium Current
André H. Erhardt
April 15, 2019 (v1)
Subject: Biosystems
Keywords: bifurcation analysis, calcium current, canard-induced EADs, geometric singular perturbation theory, multiple time scales, nonlinear dynamics
Excitable biological cells, such as cardiac muscle cells, can exhibit complex patterns of oscillations such as spiking and bursting. Moreover, it is well known that an enhancement in calcium currents may yield certain kind of cardiac arrhythmia, so-called early afterdepolarisations (EADs). The presence of EADs strongly correlates with the onset of dangerous cardiac arrhythmia. In this paper we study mathematically and numerically the dynamics of a cardiac muscle cell with respect to the calcium current by investigating a simplistic system of differential equations. For the study of this phenomena, we use bifurcation theory, numerical bifurcation analysis, geometric singular perturbation theory and computational methods to investigate a nonlinear multiple time scales system. It will turn out that EADs related to an enhanced calcium current are canard⁻induced and that we have to combine these theories to derive a better understanding of the dynamics behind EADs. Moreover, a suitable time... [more]
Supercritical CO₂ Transesterification of Triolein to Methyl-Oleate in a Batch Reactor: Experimental and Simulation Results
Geetanjali Yadav, Leonard A. Fabiano, Lindsay Soh, Julie Zimmerman, Ramkrishna Sen, Warren D. Seider
April 9, 2019 (v1)
Subject: Biosystems
Keywords: biodiesel, methyl-oleate, multiphase equilibrium, RK-ASPEN, supercritical CO2
In earlier work (Silva et al., 2016; Soh et al., 2014a; Soh et al., 2015), the supercritical CO₂ transesterification of triolein to methyl-oleate using Nafion solid-acid catalyst and large methanol/triolein molar feed ratios was carried out. Herein, these ratios are adjusted (from 50⁻550) to evaluate the yield of fatty acid methyl esters in batch laboratory reactors as temperature is varied from 80⁻95 °C and pressure is varied from 8.0⁻9.65 MPa. Also, to better understand the effect of varying these operating parameters, batch reactor simulations using the Soave-Redlich-Kwong Equation of State (RK-ASPEN EOS) in ASPEN PLUS are carried-out. A single-reaction kinetic model is used and phase equilibrium is computed as the reactions proceed. Experimental data are compared with these results.
A Model-Based Investigation of Cytokine Dynamics in Immunotherapies
Brooks Hopkins, Yiming Pan, Matthew Tucker, Zuyi (Jacky) Huang
April 9, 2019 (v1)
Subject: Biosystems
Keywords: cytokine release syndrome, hierarchical clustering, immunotherapy, Monte Carlo sampling, principal component analysis, sensitivity analysis
With the advent of effective immunotherapies to battle cancers and diseases, an obstacle in recovery has become the potential side effects, specifically cytokine release syndrome (CRS). As there is little quantitative understanding of risks for developing CRS and the degree of its severity, this work explored a model-based approach to produce a library of in silico patients through sensitivity analysis of cytokine interaction parameters and a Monte Carlo sampling. The objective of producing the in silico patients was to correlate a known grading system of cytokine release syndrome severity and thus design a new formula for grading CRS. Using our CRS grading system as the foundation, this work produced not only a formula which related the in silico patient data to the different grades, but we effectively demonstrated a selective approach to reduce the grade of CRS with sequential cytokine inhibition targets. We achieved the reduction of grades by applying the insight from the sensitivit... [more]
High-Throughput Microfiltration Membranes with Natural Biofouling Reducer Agent for Food Processing
Panggulu Ahmad R. Utoro, Agung Sukoyo, Sandra Sandra, Nimatul Izza, Shinta Rosalia Dewi, Yusuf Wibisono
April 9, 2019 (v1)
Subject: Biosystems
Keywords: biofouling, cellulose acetate, microfiltration, mixed matrix membrane, Moringa oleifera
The effect of natural antibiotics Moringa oleifera seeds powder in cellulose acetate membranes as biofouling reducer agent was investigated. Mixed matrix membranes (MMM) were synthesized by adding 100 mesh M. oleifera seeds powder with variation of three concentrations (1 wt%, 2 wt%, and 3 wt%), into a mix polymer solution of CA (cellulose acetate) and two different solvents, i.e., DMF (dimethylformamide) and DMAc (dimethylacetamide). The synthesized membranes morphology was observed under scanning electron microscopy and from the images can be seen that the membranes made of DMAc formed rather large macrovoid as compared to DMF-based membranes. The microstructure affected the water flux through the membranes, in which the DMAc membranes provided a higher flux value and served as high-throughput microfiltration membranes. Antibacterial properties of MMM were tested using Escherichia coli adhesion onto membrane surfaces. The results showed that M. oleifera has been proven to eradicate E... [more]
Towards an Aspect-Oriented Design and Modelling Framework for Synthetic Biology
Philipp Boeing, Miriam Leon, Darren N. Nesbeth, Anthony Finkelstein, Chris P. Barnes
April 8, 2019 (v1)
Subject: Biosystems
Keywords: aspect-oriented software engineering, CAD, host context, mathematical modelling, modularity, SynBioWeaver, synthetic biology
Work on synthetic biology has largely used a component-based metaphor for system construction. While this paradigm has been successful for the construction of numerous systems, the incorporation of contextual design issues—either compositional, host or environmental—will be key to realising more complex applications. Here, we present a design framework that radically steps away from a purely parts-based paradigm by using aspect-oriented software engineering concepts. We believe that the notion of concerns is a powerful and biologically credible way of thinking about system synthesis. By adopting this approach, we can separate core concerns, which represent modular aims of the design, from cross-cutting concerns, which represent system-wide attributes. The explicit handling of cross-cutting concerns allows for contextual information to enter the design process in a modular way. As a proof-of-principle, we implemented the aspect-oriented approach in the Python tool, SynBioWeaver, which e... [more]
Mathematical Modeling of RBC Count Dynamics after Blood Loss
Manuel Tetschke, Patrick Lilienthal, Torben Pottgiesser, Thomas Fischer, Enrico Schalk, Sebastian Sager
April 8, 2019 (v1)
Subject: Biosystems
Keywords: erythropoiesis, Modelling, numerical simulation, parameter estimation, phlebotomy
The regeneration of red blood cells (RBCs) after blood loss is an individual complex process. We present a novel simple compartment model which is able to capture the most important features and can be personalized using parameter estimation. We compare predictions of the proposed and personalized model to a more sophisticated state-of-the-art model for erythropoiesis, and to clinical data from healthy subjects. We discuss the choice of model parameters with respect to identifiability. We give an outlook on how extensions of this novel mathematical model could have an important impact for personalized clinical decision support in the case of polycythemia vera (PV). PV is a slow-growing type of blood cancer, where especially the production of RBCs is increased. The principal treatment targeting the symptoms of PV is bloodletting (phlebotomy), at regular intervals that are based on personal experiences of the physicians. Model-based decision support might help to identify optimal and ind... [more]
Agent-Based Modeling of Immune Response to Study the Effects of Regulatory T Cells in Type 1 Diabetes
Qian Xu, Mustafa Cagdas Ozturk, Ali Cinar
April 8, 2019 (v1)
Subject: Biosystems
Keywords: agent-based modeling, CD4+ T cells, CD8+ T cells, dendritic cells, regulatory T cells, Type 1 Diabetes, α cells
Regulatory T cells (Tregs) have an important role in self-tolerance. Understanding the functions of Tregs is important for preventing or slowing the progress of Type 1 Diabetes. We use a two-dimensional (2D) agent-based model to simulate immune response in mice and test the effects of Tregs in tissue protection. We compared the immune response with and without Tregs, and also tested the effects of Tregs from different sources or with different functions. The results show that Tregs can inhibit the proliferation of effector T cells by inhibiting antigens presenting via dendritic cells (DCs). Although the number and function of Tregs affect the inhibition, a small number of Tregs compared to CD4⁺ T cells can effectively protect islets in pancreatic tissue. Finally, we added Tregs to the system in the middle phase of the immune response. The simulation results show that Tregs can inhibit the production of effector CD8⁺ T cells and maintain a good environment for β cell regeneration.
A Systems and Treatment Perspective of Models of Influenza Virus-Induced Host Responses
Ericka Mochan, Emily E. Ackerman, Jason E. Shoemaker
April 8, 2019 (v1)
Subject: Biosystems
Keywords: influenza A virus, interferon pre-stimulation, mathematical modeling, sensitivity analysis, systems biology
Severe influenza infections are often characterized as having unique host responses (e.g., early, severe hypercytokinemia). Neuraminidase inhibitors can be effective in controlling the severe symptoms of influenza but are often not administered until late in the infection. Several studies suggest that immune modulation may offer protection to high risk groups. Here, we review the current state of mathematical models of influenza-induced host responses. Selecting three models with conserved immune response components, we determine if the immune system components which most affect virus replication when perturbed are conserved across the models. We also test each model’s response to a pre-induction of interferon before the virus is administered. We find that each model emphasizes the importance of controlling the infected cell population to control viral replication. Moreover, our work shows that the structure of current models does not allow for significant responses to increased interf... [more]
Photocatalytic Inactivation of Enterobacter cloacae and Escherichia coli Using Titanium Dioxide Supported on Two Substrates
Yelitza Aguas, Margarita Hincapié, Camilo Sánchez, Liliana Botero, Pilar Fernández-Ibañez
April 8, 2019 (v1)
Subject: Biosystems
Keywords: Enterobacter cloacae, Escherichia coli, heterogeneous photocatalysis, solar disinfection, supported TiO2
The antibacterial photocatalytic activity of TiO₂ supported over two types of substrates, borosilicate glass tubes (TiO₂/SiO₂-borosilicate glass tubes (BGT)) and low-density polyethylene pellets (TiO₂-LDPE pellets), which were placed in a compound parabolic collectors (CPC) reactor, was evaluated against Enterobacter cloacae and Escherichia coli under sunlight. Three solar photocatalytic systems were assessed, suspended TiO₂, TiO₂/SiO₂-BGT and TiO₂-LDPE pellets, at three initial bacterial concentrations, 1 × 10⁵; 1 × 10³; 1 × 10¹ CFU/mL of E. coli and total bacteria (E. cloacae and E. coli). The solar photo-inactivation of E. coli was achieved after two hours with 7.2 kJ/L of UV-A, while total bacteria required four hours and 16.5 kJ/L of UV-A. Inactivation order of E. coli was determined, as follows, suspended TiO₂/sunlight (50 mg/L) > TiO₂-LDPE pellets/sunlight (52 mg/L) > TiO₂/SiO₂-BGT/sunlight (59 mg/L), the best E. coli. inactivation rate was obtained with TiO₂-LDPE pellets/sunlig... [more]
Optimization of Reducing Sugar Production from Manihot glaziovii Starch Using Response Surface Methodology
Abdi Hanra Sebayang, Masjuki Haji Hassan, Hwai Chyuan Ong, Surya Dharma, Arridina Susan Silitonga, Fitranto Kusumo, Teuku Meurah Indra Mahlia, Aditiya Harjon Bahar
March 26, 2019 (v1)
Subject: Biosystems
Keywords: alternative fuel, bioethanol, Fermentation, hydrolysis, Manihot glaziovii (M. glaziovii), Optimization
Bioethanol is known as a viable alternative fuel to solve both energy and environmental crises. This study used response surface methodology based on the Box-Behnken experimental design to obtain the optimum conditions for and quality of bioethanol production. Enzymatic hydrolysis optimization was performed with selected hydrolysis parameters, including substrate loading, stroke speed, α-amylase concentration and amyloglucosidase concentration. From the experiment, the resulting optimum conditions are 23.88% (w/v) substrate loading, 109.43 U/g α-amylase concentration, 65.44 U/mL amyloglucosidase concentration and 74.87 rpm stroke speed, which yielded 196.23 g/L reducing sugar. The fermentation process was also carried out, with a production value of 0.45 g ethanol/g reducing sugar, which is equivalent to 88.61% of ethanol yield after fermentation by using Saccharomyces cerevisiae (S. cerevisiae). The physical and chemical properties of the produced ethanol are within the specifications... [more]
Bioenergy from Low-Intensity Agricultural Systems: An Energy Efficiency Analysis
Oludunsin Arodudu, Katharina Helming, Hubert Wiggering, Alexey Voinov
March 26, 2019 (v1)
Subject: Biosystems
Keywords: bioenergy, biofuel, Energy Efficiency, EROEI, high-intensity industrialized agricultural production systems, low-intensity eco-agricultural production systems, NEG
In light of possible future restrictions on the use of fossil fuel, due to climate change obligations and continuous depletion of global fossil fuel reserves, the search for alternative renewable energy sources is expected to be an issue of great concern for policy stakeholders. This study assessed the feasibility of bioenergy production under relatively low-intensity conservative, eco-agricultural settings (as opposed to those produced under high-intensity, fossil fuel based industrialized agriculture). Estimates of the net energy gain (NEG) and the energy return on energy invested (EROEI) obtained from a life cycle inventory of the energy inputs and outputs involved reveal that the energy efficiency of bioenergy produced in low-intensity eco-agricultural systems could be as much as much as 448.5⁻488.3 GJ·ha−1 of NEG and an EROEI of 5.4⁻5.9 for maize ethanol production systems, and as much as 155.0⁻283.9 GJ·ha−1 of NEG and an EROEI of 14.7⁻22.4 for maize biogas production systems. Thi... [more]
Analysis of Micronized Charcoal for Use in a Liquid Fuel Slurry
John M. Long, Michael D. Boyette
March 26, 2019 (v1)
Subject: Biosystems
Keywords: biochar, biofuel, Biomass, charcoal, Diesel, slurry
Yellow poplar (Liriodendron tulipifera) was chosen as the woody biomass for the production of charcoal for use in a liquid fuel slurry. Charcoal produced from this biomass resulted in a highly porous structure similar to the parent material. Micronized particles were produced from this charcoal using a multi-step milling process and verified using a scanning electron microscope and laser diffraction system. Charcoal particles greater than 50 µm exhibited long needle shapes much like the parent biomass while particles less than 50 µm were produced with aspect ratios closer to unity. Laser diffraction measurements indicated D10, D50, and D90 values of 4.446 µm, 15.83 µm, and 39.69 µm, respectively. Moisture content, ash content, absolute density, and energy content values were also measured for the charcoal particles produced. Calculated volumetric energy density values for the charcoal particles exceeded the No. 2 diesel fuel that would be displaced in a liquid fuel slurry.
A Simple Method for the Detection of Long-Chain Fatty Acids in an Anaerobic Digestate Using a Quartz Crystal Sensor
Takuro Kobayashi, Hidetoshi Kuramochi, Kouji Maeda, Kaiqin Xu
March 26, 2019 (v1)
Subject: Biosystems
Keywords: anaerobic digestion (AD), inhibition, long-chain fatty acids (LCFA), quartz crystal microbalance (QCM)
In anaerobic digestion (AD), long-chain fatty acids (LCFAs) produced by hydrolysis of lipids, exhibit toxicity against microorganisms when their concentration exceeds several millimolar. An absorption detection system using a quartz crystal microbalance (QCM) was developed to monitor the LCFA concentration during an anaerobic digester’s operation treating oily organic waste. The dissociation of the LCFAs considerably improved the sensor response and, moreover, enabled it to specifically detect LCFA from the mixture of LCFA and triglyceride. Under alkaline conditions, the frequency-shift rates of the QCM sensor linearly increased in accordance with palmitic acid concentration in the range of 0⁻100 mg/L. Frequency changes caused by anaerobic digestate samples were successfully measured after removing suspended solids and adjusting the pH to 10.7. Finally, the QCM measurements for digestate samples demonstrated that frequency-shift rates are highly correlated with LCFA concentrations, whi... [more]
The Effect of Two Types of Biochars on the Efficacy, Emission, Degradation, and Adsorption of the Fumigant Methyl Isothiocyanate
Wensheng Fang, Aocheng Cao, Dongdong Yan, Dawei Han, Bin Huang, Jun Li, Xiaoman Liu, Meixia Guo, Qiuxia Wang
March 15, 2019 (v1)
Subject: Biosystems
Keywords: Adsorption, biochar, dazomet, degradation, methyl isothiocyanate (MITC)
Biochar (BC) is increasingly applied in agriculture; however, due to its adsorption and degradation properties, biochar may also affect the efficacy of fumigant in amended soil. Our research is intended to study the effects of two types of biochars (BC-1 and BC-2) on the efficacy and emission of methyl isothiocyanate (MITC) in biochar amendment soil. Both types of biochars can significantly reduce MITC emission losses, but, at the same time, decrease the concentration of MITC in the soil. The efficacy of MITC for controlling soil-borne pests (Meloidogyne spp., Fusarium spp. Phytophthora spp., Abutilon theophrasti and Digitaria sanguinalis) was reduced when the biochar (BC-1 and BC-2) was applied at a rate of higher than 1% and 0.5% (on a weight basis) (on a weight basis), respectively. However, increased doses of dazomet (DZ) were able to offset decreases in the efficacy of MITC in soils amended with biochars. Biochars with strong adsorption capacity (such as BC-1) substantially reduce... [more]
Effect of Air Staging Ratios on the Burning Rate and Emissions in an Underfeed Fixed-Bed Biomass Combustor
Araceli Regueiro, David Patiño, Jacobo Porteiro, Enrique Granada, José Luis Míguez
February 5, 2019 (v1)
Subject: Biosystems
Keywords: air staging, bed stoichiometry, biomass combustion, burning rate, fixed-bed
This experimental work studies a small-scale biomass combustor (5⁻12 kW) with an underfed fixed bed using low air staging ratios (15%⁻30%). This document focuses on the influence of the operative parameters on the combustion process, so gaseous emissions and the distribution and concentration of particulate matter have also been recorded. The facility shows good stability and test repeatability. For the studied airflow ranges, the results show that increasing the total airflow rate does not increase the overall air excess ratio because the burning rate is proportionally enhanced (with some slight differences that depend on the air staging ratio). Consequently, the heterogeneous reactions at the bed remain in the so-called oxygen-limited region, and thus the entire bed operates under sub-stoichiometric conditions with regards of the char content of the biomass. In addition, tests using only primary air (no staging) may increase the fuel consumption, but in a highly incomplete way, appro... [more]
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