The increased levels of carbon dioxide in the environment have incited the search for breakthrough technologies to lessen its impact on climate. The CO2 capture from a mixture of CO2/N2 was studied using a molecular sieve (MS) and silica gel type-III. The breakthrough behavior was predicted as a function of temperature, superficial velocity, and CO2 partial pressure. The breakpoint time reduced significantly with increased temperature and increased superficial velocity. The CO2 adsorption capacity increased appreciably with decreased temperature and increased CO2 pressure. The saturation CO2 adsorption capacity from the CO2/N2 mixture reduced appreciably with increased temperature. The molecular sieve contributed to higher adsorption capacity, and the highest CO2 uptake of 0.665 mmol/g was realized for MS. The smaller width of the mass transfer zone and higher column efficiency of 87.5% for MS signify the efficient use of the adsorbent; this lowers the regeneration cost. The findings s... [more]

Being at the heart of modern pulp mills, continuous pulp digesters have attracted much attention from the research community. In this article, a comprehensive review in the area of modeling, control and diagnostics of continuous pulp digesters is conducted. The evolution of research focus within these areas is followed and discussed. Particular effort has been devoted to identifying the state-of-the-art and the research gap in a summarized way. Finally, the current and future research directions in the areas have been analyzed and discussed. To date, digester modeling following the Purdue approach, Kappa number control using model predictive controllers and health index-based diagnostic approaches by utilizing different statistical methods have dominated the field. While the rising research interest within the field is evident, we anticipate further developments in advanced sensors and integration of these sensors for improving model prediction and controller performance; and the explo... [more]

In this study, we investigate how drugs systemically affect genes via pathways by integrating information from interactions between chemical compounds and molecular expression datasets, and from pathway information such as gene sets using mathematical models. First, we adopt drug-induced gene expression datasets; then, employ gene set enrichment analysis tools for selecting candidate enrichment pathways; and lastly, implement the inverse algorithm package for identifying gene−gene regulatory networks in a pathway. We tested LY294002-induced datasets of the MCF7 breast cancer cell lines, and found a CELL CYCLE pathway with 101 genes, ERBB signaling pathway consisting of 82 genes, and MTOR pathway consisting of 45 genes. We consider two interactions: quantity strength depending on number of interactions, and quality strength depending on weight of interaction as positive (+) and negative (−) interactions. Our methods revealed ANAPC1-CDK6 (−0.412) and ORC2L- CHEK1(0.951) for the CELL CYCL... [more]

This study investigated the effect of ionic strength and background electrolytes on the biosorption of Ni2+ from aqueous solutions by the acorn shell of Quercus crassipes Humb. & Bonpl. (QCS). A NaCl ionic strength of 0.2 mM was established to have no effect on the Ni2+ biosorption and the biosorption capacity of the heavy metal decreased as the ionic strength increased from 2 to 2000 mM. The background electrolytes (KCl, NaNO3, Na2SO4, CaCl2, MgSO4, and MgCl2) had no adverse effects on the biosorption of Ni2+ at a concentration of 0.2 mM. However, at background electrolyte concentrations of 2 and 20 mM, divalent cations (Ca2+ and Mg2+) had greater negative effects on the biosorption of Ni2+ compared to the monovalent cations (Na+ and K+). Additionally, the SO42− and Cl− anions affected the biosorption of Ni2+. The fractional power, Elovich, and pseudo-second order models represented the kinetic processes of the biosorption of Ni2+ adequately. The results show that QCS can be a promisi... [more]

The aqueous extraction process (AEP) allows the concurrent extraction of oil and protein from almond flour without the use of harsh solvents. However, the majority of the oil extracted in the AEP is present in an emulsion that needs to be demulsified for subsequent industrial utilization. The effects of scaling-up the AEP of almond flour from 0.7 to 7 L and the efficiency of enzymatic and chemical approaches to demulsify the cream were evaluated. The AEP was carried out at pH 9.0, solids-to-liquid ratio of 1:10, and constant stirring of 120 rpm at 50 °C. Oil extraction yields of 61.9% and protein extraction yields of 66.6% were achieved. At optimum conditions, enzymatic and chemical demulsification strategies led to a sevenfold increase (from 8 to 66%) in the oil recovery compared with the control. However, enzymatic demulsification resulted in significant changes in the physicochemical properties of the cream protein and faster demulsification (29% reduction in the incubation time and... [more]

Post-harvest characteristics of common beans influences its classification, which significantly affects processing time and energy requirements. In this work, ten bean cultivars were classified as either easy-to-cook (ETC) or hard-to-cook (HTC) based on a traditional subjective finger pressing test and a scientific objective hardness test. The hardness study used seed coat rigidity to explain the structural deformation observed during cooking. The result shows that the average hardness of raw dry ETC and HTC beans was 102.4 and 170.8 N, respectively. The maximum seed coat resistance is observed within the first 30 min of cooking regardless of the classification. The results show that a modified three-parameter non-linear regression model could accurately predict the rate of bean softening (R2 = 0.994−0.999 and RMSE = 3.3−14.7%). The influence of bean softeners such as potassium carbonate (K2CO3) and sodium chloride (NaCl) to reduce cooking time was also investigated. The results showed... [more]

Anaerobic digestion is an important technology to receive energy from various types of biomass. In this work, the impact of granular activated carbon (GAC) on the mesophilic anaerobic co-digestion of sugar beet pulp and distillers grains was investigated. After a short period, anaerobic reactors began to produce biomethane and were ready for completion within 19−24 days. The addition of GAC to reactors (5−10 g L−1) significantly enhanced the methane production rate and consumption of produced volatile fatty acids. Thus, the maximum methane production rate increased by 13.7% in the presence of GAC (5 g L−1). Bacterial and archaeal community structure and dynamics were investigated, based on 16S rRNA genes analysis. The abundant classes of bacteria in GAC-free and GAC-containing reactors were Clostridia, Bacteroidia, Actinobacteria, and Synergistia. Methanogenic communities were mainly represented by the genera Methanosarcina, Methanoculleus, Methanothrix, and Methanomassiliicoccus in GA... [more]

The photovoltaic (PV) industry is an important part of the renewable energy industry. With the growing use of PV systems, interest in their operation and maintenance (O&M) is increasing. In this regard, analyses of power generation efficiency and inverter efficiency are very important. The first step in efficiency analysis is solar power estimation based on environment sensor data. In this study, solar power was estimated using a univariate linear regression model. The estimated solar power data were cross-validated with the actual solar power data obtained from the inverter. The results provide information on the power generation efficiency of the inverter. The linear estimation model developed in this study was validated using a single PV system. It is possible to apply the coefficients presented in this study to other PV systems, even though the nature and error rates of the collected data may vary depending on the inverter manufacturer. To apply the proposed model to PV systems wit... [more]

Anaerobic digestion is an efficient technology for a sustainable conversion of various organic wastes such as animal manure, municipal solid waste, agricultural residues and industrial waste into biogas. This technology offers a unique set of benefits, some of which include a good waste management technique, enhancement in the ecology of rural areas, improvement in health through a decrease of pathogens and optimization of the energy consumption of communities. The biogas produced through anaerobic digestion varies in composition, but it consists mainly of carbon dioxide methane together with a low quantity of trace gases. The variation in biogas composition are dependent on some factors namely the substrate type being digested, pH, operating temperature, organic loading rate, hydraulic retention time and digester design. However, the type of substrate used is of greater interest due to the direct dependency of microorganism activities on the nutritional composition of the substrate. T... [more]

Under-race lubrication can increase the amount of lubricating oil entering a bearing and greatly improve lubrication and cooling effects. The oil-air two-phase flow characteristics inside a ball bearing with under-race lubrication play a key role in lubrication and cooling performance. The motions of ball bearing subassemblies are complicated. Ball spin affects the oil volume fraction. In this paper, the coupled level set volume of fluid (CLSVOF) method is used to track the oil-air two-phase flow inside the ball bearing with under-race lubrication. The influence of various factors on the oil volume fraction inside the ball bearing with under-race lubrication is investigated, particularly rotating speeds, inlet velocity and the size of oil supply apertures under the inner ring. The influence of the ball spinning is analyzed separately. The result demonstrates that, on account of the centrifugal force, lubricating oil is located more on the outer ring raceway at rotational speeds of 5000... [more]

Diverse and abundant applications of the eutectic solvents have appeared in the last years. Their promising tunable properties, eco-friendly character and the possibility of being prepared from numerous compounds have led to the publication of numerous papers addressing their use in different areas. Terpenes and terpenoids have been employed in the formulation of eutectic solvents, though they also have been applied as solvents in extraction processes. For their hydrophobic nature, renewable character, low environmental impact, cost and being non-hazardous, they have also been proposed as possible substitutes of conventional solvents in the separation of organic compounds from aqueous streams, similarly to hydrophobic eutectic solvents. The present work reviews the application of eutectic solvents in liquid−liquid extraction and terpenes and terpenoids in extraction processes. It has been made a research in the current state-of-the-art in these fields, describing the proposed applicati... [more]

This study investigates the effects of convective hydrothermal pretreatment (CHTP) compared to microwave pretreatment (MWP) on the anaerobic digestion of hybrid Napier grass for biomethane production. For rapid estimation of methane yield (YCH4), enzymatic hydrolyzability (EH), whose test lasts only 2 days was used as a surrogate parameter instead of the biochemical methane potential (BMP) assay that normally takes 45−60 days. The relationship between EH and BMP was successfully modeled with satisfactory accuracy (R2 = 0.9810). From CHTP results, quadratic regression characterised by p < 0.0001 and R2 = 0.8364 shows that YCH4 increase was clearly sensitive to detention time at all CHTP temperatures. The maximal YCH4 achieved of 301.5 ± 3.0 mL CH4/gVSadd was 53.2% higher than the control. Then, MWP was employed at various power levels and microwave exposure times. Changes in lignocellulosic structure by Fourier-transform infrared spectroscopy (FTIR) and energy balance demonstrate tha... [more]

The study aimed to describe the utilization of waste frying oils, originated mainly from households, in home-made soap production and to emphasize the advantages of soap biodegradation in comparison to biological treatment of oils. The physicochemical analyses of soaps were used to check the differences between the samples made of fresh and fried oils. Significant (p < 0.05) difference between the soaps made of fresh/fried olive oil pair was obtained, while the rapeseed sample pair did not differ significantly (p < 0.05). Malondialdehyde (MDA) exhibited notable differences with an increase from 1.94 μg/g to 2.33 μg/g for olive oil fresh/fried pair and from 3.43 μg/g to 4.10 μg/g for rapeseed−palm oil fresh/fried pair. The studies addressing the soap biodegradation process revealed that soaps are degrading up to four times faster than oils in waste processing plants. Literature data showed the syntrophic ways of soap degradation and degradation solely done by sulfate-reducing bact... [more]

Flavonoids have a broad spectrum of established positive effects on human and animal health. They find an application in medicine for disease therapy and chemoprevention, whence the interest in flavonoids increases. In addition, they are used in food and cosmetic industries as pigments and biopreservatives. Plants are an inexhaustible source of flavonoids. The most important step of plant raw material processing is extraction and isolation of target compounds. The quality of an extract and efficiency of a procedure are influenced by several factors: Plant material and pre-extracting sample preparation, type of solvent, extraction technique, physicochemical conditions, etc. The present overview discusses the common problems and key challenges of the extraction procedures and the different mechanisms for selective extraction of flavonoids from different plant sources. In summary, there is no universal extraction method and each optimized procedure is individual for the respective plants.... [more]

Elaeocarpus serratus L. leaves contain significant polyphenols, flavonoids, and myricitrin with medicinal property, which are byproducts after harvest and can be recovered for potential food applications. In this study, the effective extraction method for bioactive compounds and myricitrin from Elaeocarpus serratus L. leaves was investigated by comparing ultrasound-assisted extraction (UAE) and shaking-assisted extraction (SAE) for total phenolic content (TPC), total flavonoid content (TFC), myricitrin, and antioxidant capacity (as ferric reducing antioxidant power, FRAP). A first-order kinetic model of extraction was also proposed to correlate the observed extraction rate coefficient and limiting concentration of myricitrin in various solvents. Using defatted leaves (DL) as the substrate at the UAE condition of 95% ethanol with 1/10 (g/mL) of DL to solvent ratio under 40 kHz/300 W of ultrasound, 26.63% of yield of extract, and 199.75 mg-ferrous-sulfate-heptahydrate-equivalent/g-DL of... [more]

There is a growing awareness of the need to mitigate greenhouse gas emissions and the inevitable depletion of fossil fuel. With the market pull for the growth in sustainable and renewable alternative energy, the challenge is to develop cost-effective, large-scale renewable energy alternatives for all energy sectors, of which transport fuels are one significant area. This work presents a summary of novel methods for integrating kraft mills with a hydrothermal liquefaction process. The application of these methods has resulted in a proposed kraft mill-integrated design that produces a liquid fuel and could provide net mitigation of 64.6 kg CO2-e/GJ, compared to conventional petrol and diesel fuels, at a minimum fuel selling price of 1.12−1.38 NZD/LGE of fuel, based on the case study. This paper concludes that a hydrothermal liquefaction process with product upgrading has promising economic potential and environmental benefits that are significantly amplified by integrating with an existi... [more]

In the light of the significance of the rotating machinery and the possible severe losses resulted from its unexpected defects, it is vital and meaningful to exploit the effective and feasible diagnostic methods of its faults. Among them, the emphasis of the analysis approaches for fault type and severity is on the extraction of useful components in the fault features. On account of the common cyclostationarity of vibration signal under faulty states, fault diagnosis methods based on cyclostationary analysis play an essential role in the rotatory machine. Based on it, the fundamental definition and classification of cyclostationarity are introduced briefly. The mathematical principles of the essential cyclic spectral analysis are outlined. The significant applications of cyclostationary theory are highlighted in the fault diagnosis of the main rotating machinery, involving bearing, gear, and pump. Finally, the widely-used methods on the basis of cyclostationary theory are concluded, an... [more]

[Context] Freelancers could catalyze the software development process by providing their niche skills to generate high quality outputs. They could help companies (including startups) to foster innovations by suggesting creative ideas and providing their expertise in implementing them (for instance, designing solutions, coding solutions etc.). Freelancers could effectively and efficiently work as a virtual member of the software development team. The company must make informed decisions about which task to allot to the freelancer, which freelancer to select, pricing the task, and evaluating the submitted work. On the other hand, the freelancer should make an informed decision about evaluating the monetary value of the task to be charged, trusting the requester, analyzing the skills requirement of the task (finding matches between skill requirement and skills processed), selecting the best task, and maintaining the highest level of reputation. However, the literature does not provide fre... [more]

A two-dimensional (2D) Computational Fluid Dynamics (CFD) scale-up model of the Fischer Tropsch reactor was developed to thermally compare the Microfibrous-Entrapped-Cobalt-Catalyst (MFECC) and the conventional Packed Bed Reactor (PBR). The model implements an advanced predictive detailed kinetic model to study the effect of a thermal runaway on C5+ hydrocarbon product selectivity. Results demonstrate the superior capability of the MFECC bed in mitigating hotspot formation due to its ultra-high thermal conductivity. Furthermore, a process intensification study for radial scale-up of the reactor bed from 15 mm internal diameter (ID) to 102 mm ID demonstrated that large tube diameters in PBR lead to temperature runaway >200 K corresponding to >90% CO conversion at 100% methane selectivity, which is highly undesirable. While the MFECC bed hotspot temperature corresponded to 30% CO conversion, attributing to significantly high thermal conductivity of the MFECC bed. Moreover, a noticeable i... [more]

It has been proven that vehicle emissions such as oxides of nitrogen (NOx) are negatively affecting the health of human beings as well as the environment. In addition, it was recently highlighted that air pollution may result in people being more vulnerable to the deadly COVID-19 virus. The use of biofuels such as E5 and E10 as alternatives of gasoline fuel have been recommended by different researchers. In this paper, the impacts of port injection of water to a spark ignition engine fueled by gasoline, E5 and E10 on its performance and NOx production have been investigated. The experimental work was undertaken using a KIA Cerato engine and the results were used to validate an AVL BOOST model. To develop the numerical analysis, design of experiment (DOE) method was employed. The results showed that by increasing the ethanol fraction in gasoline/ethanol blend, the brake specific fuel consumption (BSFC) improved between 2.3% and 4.5%. However, the level of NOx increased between 22% to 48... [more]

Oranges are a rich source of bioactive compounds with recognized benefits for human health. To guarantee high quality and production levels, citrus farms usually employ the combination of selected cultivars with well adapted rootstocks. This study analyzes the impact of four different citrus rootstocks (Forner-Alcaide no.5, ‘Cleopatra mandarin’, Citrus volkameriana and Carrizo citrange) on the bioactive compounds and antioxidant activity of two orange cultivars (‘Salustiana’ and ‘Sanguinelli’) widely used in the orange juice industry. For the hydrophilic fraction, the phenolic compound, anthocyanin, and organic acid profiles were determined by HPLC-DAD-HRMS, and the antioxidant activity by ABTS, DPPH, and ORAC assays. Besides, the total carotenoids and ABTS concentrations were calculated for the hydrophobic fraction. A set of three flavanones, one flavone, and eight anthocyanins were tentatively identified and quantified in the orange cultivars tested. The predominant phenolic compound... [more]

The wire arc additive manufacturing (WAAM) process used to manufacture aluminum parts has a number of variables. This study focuses on the effects of the heat input and the current and voltage ratio on the deposition efficiency. The effects of the heat input and current and voltage ratio (V/A) on the bead geometry were analyzed, depending on the cross-sectional geometry of the deposition layers, for nine different deposition conditions. The deposition efficiency was also analyzed by analyzing the cross-sectional geometry of the thin-wall parts made of aluminum. The heat input range was about 2.7 kJ/cm to 4.5 kJ/cm; the higher the heat input, the higher the deposition efficiency. The maximum deposition efficiency achieved in this study was 76%. The current and voltage ratio was used to quantify the portion of voltage (V) in the total heat input (Q), and the effect on the bead geometry was analyzed. As the portion of voltage in the quasi heat input decreased by about 10%, it was found th... [more]

Uncertainty is a common feature of biological systems, and model-free extremum-seeking control has proved a relevant approach to avoid the typical problems related to model-based optimization, e.g., time- and resource-consuming derivation and identification of dynamic models, and lack of robustness of optimal control. In this article, a review of the past and current trends in model-free extremum seeking is proposed with an emphasis on finding optimal operating conditions of bioprocesses. This review is illustrated with a simple simulation case study which allows a comparative evaluation of a few selected methods. Finally, some experimental case studies are discussed. As usual, practice lags behind theory, but recent developments confirm the applicability of the approach at the laboratory scale and are encouraging a transfer to industrial scale.

Olive oil mills represent an important sector in the Mediterranean Sea Basin but also an environmental hazard due to untreated wastewater. Recovery of nutrients from olive oil mill wastewater (OMWW) as protein-rich microbial biomass can produce novel feed and reduce its chemical oxygen demand; however, low-protein containing products have been reported. New strategies leading to higher protein-containing fungal biomass could renew the research interest on bioconversion for pollution mitigation of OMWW. In this work, through cultivation of edible filamentous fungi (Aspergillus oryzae, Neurospora intermedia, and Rhizopus delemar), a link between the protein content in the originated fungal biomass, and the addition of nitrogen and medium dilution was established. Addition of nitrogen in the form of NaNO3 reduced the cultivation time from 96 h to 48 h while achieving a similar biomass mass concentration of 8.43 g/L and increased biomass protein content, from w = 15.9% to w = 29.5%. Nitrog... [more]

The impact of hot-melt extrusion (HME) on the solid-state properties of four methacrylic (Eudragit® L100-55, Eudragit® EPO, Eudragit® RSPO, Eudragit® RLPO) and four polyvinyl (Kollidon® VA64, Kollicoat® IR, Kollidon® SR, and Soluplus®) polymers was studied. Overall, HME decreased Tg but increased electrostatic charge and surface free energy. Packing density decreased with electrostatic charge, whereas Carr’s and Hausner indices showed a peak curve dependency. Overall, HME reduced work of compaction (Wc), deformability (expressed as Heckel PY and Kawakita 1/b model parameters and as slope S′ of derivative force/displacement curve), and tablet strength (TS) but increased elastic recovery (ER). TS showed a better correlation with S′ than PY and 1/b. Principal component analysis (PCA) organized the data of neat and extruded polymers into three principal components explaining 72.45% of the variance. The first included Wc, S′ and TS with positive loadings expressing compaction, and ER with n... [more]