High Voltage Electrical Discharges Treatment Research Articles

Extraction of Mycosporine-like Amino Acids and Proteins from the Agarophyte Gelidium corneum Using Pulsed Power Techniques

Gelidium corneum (syn. sesquipedale) is an industrially and ecologically important species of red alga used for the production of high-quality agar. However, the species is also of growing interest for the production of other valuable compounds, such as mycosporine-like amino acids (MAAs), with potential cosmeceutical and biomedical applications. Novel methods using two pulsed power techniques, high-voltage electrical discharges (HVED) and pulsed electrical fields (PEF), were evaluated for efficacy of MAA extraction. Algal suspensions were prepared at two ratios (1:20 and 1:40 w:v). Four different extraction protocols were compared: (i) high-voltage electrical discharges, (ii) pulsed electric fields, (iii) maceration at room temperature, and (iv) maceration at 50 °C. The algae were treated in three states: freshly harvested, dried, and powdered. HVED and PEF treatments were effective when performed on fresh algae, and in particular the HVED treatment resulted in yields of MAAs twenty times higher than the control: 0.81 ± 0.05 mg/gDry Weight (DW) vs. 0.037 ± 0.002 mg/gDW. This effect was not observed to the same extent when the algae were dried or powdered, although HVED remained the most selective method overall.

Effect of combined pulsed electric energy and high pressure homogenization on selective and energy efficient extraction of bio-molecules from microalga Parachlorella kessleri

This work investigates the potential of pulsed electric energy (pulsed electric fields (PEF) and high-voltage electrical discharges (HVED)) and high pressure homogenization (HPH) for extraction of bio-molecules from Parachlorealla kessleri. The applied procedures included individual pulsed electric energy (PEF, HVED), HPH treatments, and their combination. The cell concentrations of suspension applied in PEF or HVED treatment were 5–25 g/L, while 5 g/L suspension was always applied for HPH treatment. The effects of applied procedures on the extraction of ionic components, carbohydrates, proteins, and pigments were evaluated. The data evidenced that HVED treatment allowed selective extraction of ionic components and carbohydrates, while HPH treatment was most efficient for simultaneous release all the bio-molecules. HPH treatment (120 MPa, 10 passes) gave 4-fold higher content for pigments, 1.2-fold higher content for carbohydrates and 6.5-fold higher content for proteins than HVED treatment (40 kV/cm, 8 ms). For combined procedure, application of preliminary PEF or HVED treatment with 5 g/L suspension allowed increasing the extraction of carbohydrates at high energy consumption. By contrast, application of preliminary HVED treatment with 15 g/L or 25 g/L suspensions allowed enhancing extraction efficiencies of carbohydrates and proteins, and reducing total energy consumption.

Pulsed electric energy and ultrasonication assisted green solvent extraction of bio-molecules from different microalgal species

The effects of physical treatments (pulsed electrical fields (PEF), high voltage electrical discharges (HVED) and ultrasonication (US)) on aqueous extraction of carbohydrates and proteins, and ethanolic extraction of chlorophyll a from three microalgal species (Nannochloropsis sp., P. tricornutum and P. kessleri) have been studied. The total energy consumption of 530 kJ/kg suspension was applied for each treatment. For studied species, HVED was the most effective for extraction of carbohydrates, while US was the most effective for extraction of proteins and chlorophyll a. The observed differences for studied species can reflect the more fragile cell wall structure for P. tricornutum as compared with Nannochloropsis sp. or P. kessleri. The applied PEF, HVED and US treatments along with combinations of aqueous extraction of carbohydrates and proteins, and ethanolic extraction of pigments can be used in future implementations of selective extraction of valuable bio-molecules from microalgae.

Comparison of aqueous extraction efficiency and biological activities of polyphenols from pomegranate peels assisted by infrared, ultrasound, pulsed electric fields and high-voltage electrical discharges

Abstract The effects of aqueous extraction of bioactive compounds from pomegranate peels using conventional extraction (CE) and extraction assisted by infrared irradiation (IR), ultrasound (US), pulsed electric fields (PEF), and high-voltage electrical discharges (HVED) have been compared. For the extractions assisted by US, PEF and HVED, the saturation in extraction was observed approximately at the same specific energy input in the order of W ≈ 90–100 kJ/kg. HVED assisted extraction enhanced the recovery of polyphenols by ≈3 and ≈1.3 times as compared to US and PEF assisted extractions, respectively. Scanning electron microscopy (SEM) data evidenced that the highest yield of total polyphenols after the HVED treatment can reflect the presence of a strong damage of the microstructure of pomegranate skins. The obtained data on inhibition of growth of A. flavus and biosynthesis of aflatoxin B1 were explained accounting for the presence of different synergetic effects of phenolic compounds on inhibition of different bioactivities. All the studied extracts (0.2 mg/mL) demonstrated the higher inhibition efficiency for S. aureus (up to ≈80%) as compared to E. coli (up to ≈33%). PEF selectively extracted and enhanced the recovery of ellagic acid (≈740 μg/g DM), whereas HVED (≈345 μg/g DM) intensified gallic acid extraction compared to US, IR, HVED and WB.

Phenolic and Antioxidant Analysis of Olive Leaves Extracts (Olea europaea L.) Obtained by High Voltage Electrical Discharges (HVED).

Background: The aim of this study was to evaluate high voltage electrical discharges (HVED) as a green technology, in order to establish the effectiveness of phenolic extraction from olive leaves against conventional extraction (CE). HVED parameters included different green solvents (water, ethanol), treatment times (3 and 9 min), gases (nitrogen, argon), and voltages (15, 20, 25 kV). Methods: Phenolic compounds were characterized by ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS), while antioxidant potency (total phenolic content and antioxidant capacity) were monitored spectrophotometrically. Data for Near infrared spectroscopy (NIR) spectroscopy, colorimetry, zeta potential, particle size, and conductivity were also reported. Results: The highest yield of phenolic compounds was obtained for the sample treated with argon/9 min/20 kV/50% (3.2 times higher as compared to CE). Obtained results suggested the usage of HVED technology in simultaneous extraction and nanoformulation, and production of stable emulsion systems. Antioxidant capacity (AOC) of obtained extracts showed no significant difference upon the HVED treatment. Conclusions: Ethanol with HVED destroys the linkage between phenolic compounds and components of the plant material to which they are bound. All extracts were compliant with legal requirements regarding content of contaminants, pesticide residues and toxic metals. In conclusion, HVED presents an excellent potential for phenolic compounds extraction for further use in functional food manufacturing.

High voltage electric discharges treatment for high molecular weight hemicelluloses extraction from spruce

The aim of this work is to extract hemicelluloses polymers from spruce sawdust using High Voltage Electrical Discharges (HVED) pretreatment. HVED pretreatment was carried out in order to improve deconstruction of the wood matrix and to allow easier release of high molecular mass hemicelluloses. The results revealed the advantage of HVED activation step in the process of extraction. The yield of hemicellulose extraction increased with HVED treatment time. In fact, after 4 ms of HVED treatment time in 1 M NaOH solution, the yield obtained was higher as compared to the untreated sample (19 mg/g of dry matter and 15.8 mg/g of dry matter respectively). The molecular weights of extracted hemicelluloses are very high (55 kDa and 47 kDa for 4 ms of HVED-treatment in 1 M NaOH solution and water respectively). The use of different mediums of extraction with HVED pretreatment have revealed a selective solubilization of spruce hemicelluloses.

High voltage electric discharges assisted extraction of phenolic compounds from grape stems: Effect of processing parameters on flavan-3-ols, flavonols and stilbenes recovery

Abstract This work aimed at providing some novel aspects pertaining to flavan-3-ols, flavonols and stilbenes extraction from grape stems using high voltage electrical discharges (HVED). Treatment time, pH and ethanol concentration affecting the extractability of these compounds were optimized through response surface methodology. The results from the optimized extraction technique (pH = 2.5; Time = 4.0 ms: Ethanol = 50%) were compared to a conventional hydro-alcoholic extraction. HVED improved significantly the extraction of flavan-3-ols and flavonols but was less efficient on stilbenes. The efficiency of HVED is directly correlated with the other processing conditions (pH, ethanol concentration). Prolonged HVED treatment at low pH value was a positive combination for flavan-3-ols. The proposed procedure (pH = 2.5; Time = 4.0 ms; Ethanol = 50%) allowed the release of almost 35% of additional phenolic compounds, which can be attributed to a better extractability of flavan-3-ols (+ 21%) and of flavonols (+ 12%), compared to conventional hydro-alcoholic extraction.

Impact of pulsed-electric field and high-voltage electrical discharges on red wine microbial stabilization and quality characteristics.

In this study, pulsed-electric fields (PEF) and high-voltage electrical discharges (HVED) are proposed as new techniques for the microbial stabilization of red wines before bottling. The efficiency of the treatment was then evaluated. PEF and HVED-treatments have been applied to wine for the inactivation of Oenococcus oeni CRBO 9304, O.oeni CRBO 0608, Pediococcus parvulus CRBO 2.6 and Brettanomyces bruxellensis CB28. Different treatment times (1, 2, 4, 6, 8 and 10ms) were used at 20kVcm(-1) for the PEF treatments and at 40kV for the HVED treatments, which correspond to applied energies from 80 to 800 kJl(-1) . The effects of the treatments on the microbial inactivation rate and on various characteristics of red wines (phenolic composition, chromatic characteristics and physico-chemical parameters) were measured. The application of PEF or HVED treatments on red wine allowed the inactivation of alteration yeasts (B.bruxellensis CB28) and bacteria (O.oeni CRBO 9304, O.oeni CRBO 0608 and P.parvulus CRBO 2.6). The electric discharges at 40 kV were less effective than the PEF even after 10ms of treatments. Indeed, 4ms of PEF treatment at 20kVcm(-1) were sufficient to inactivate all micro-organisms present in the wines. Also, the use of PEF had no negative impact on the composition of wines compared to the HVED treatments. Contrary to PEF, the phenolics compounds were degraded after the HVED treatment and the physico-chemical composition of wine were modified with HVED. PEF technology seems to be an interesting alternative to stabilize microbiologically wines before bottling and without modifying their composition. This process offers many advantages for winemakers: no chemical inputs, low energy consumption (320kJl(-1) ), fast (treatment time of 4ms) and athermal (ΔT≈10°C).

Bioaccessibility of Bioactive Compounds and Antioxidant Capacityfrom Orange Peel after Pulsed Electric Fields and High Voltage Electrical Discharges

In the present study changes of bioactive compounds and antioxidant capacity in orange peel treated by pulsed electric fields (PEF), high voltage electrical discharges (HVED) at two equivalent energy inputs (55-364 kJ/kg) as well as relative bioaccessibility was evaluated. PEF treatment led to decrease in ascorbic acid when energy input increased. Moreover TPC after PEF and HVED treatments increased significantly with higher energy input applied. By contrast, HVED at 364 kJ/kg diminished carotenoids content. The relative bioaccessibility of carotenoids after HVED (55 kJ/kg)was 75.3%. When increasing the energy input from 55 to 364 kJ/kg in HVED the bioaccessibility percentage of carotenoids increased in a 82.5%. On the other hand TPC bioaccessibility for PEF at lower energy input was 40.7%. However increasing the energy input to 364 kJ/kg led to decrease of the TPC independently of treatment applied. Consequently, results indicated that non thermal treatments such as (PEF, HVED) can enhance the release of bioactive compounds and total antioxidant capacity after in vitrogastrointestinal digestion in orange peel. However, further research is required tooptimize processing conditions. In the present study changes of bioactive compounds and antioxidant capacity in orange peel treated by pulsed electric fields (PEF), high voltage electrical discharges (HVED) at two equivalent energy inputs (55-364 kJ/kg) as well as relative bioaccessibility was evaluated. PEF treatment led to decrease in ascorbic acid when energy input increased. Moreover TPC after PEF and HVED treatments increased significantly with higher energy input applied. By contrast, HVED at 364 kJ/kg diminished carotenoids content. The relative bioaccessibility of carotenoids after HVED (55 kJ/kg)was 75.3%. When increasing the energy input from 55 to 364 kJ/kg in HVED the bioaccessibility percentage of carotenoids increased in a 82.5%. On the other hand TPC bioaccessibility for PEF at lower energy input was 40.7%. However increasing the energy input to 364 kJ/kg led to decrease of the TPC independently of treatment applied. Consequently, results indicated that non thermal treatments such as (PEF, HVED) can enhance the release of bioactive compounds and total antioxidant capacity after in vitro gastrointestinal digestion in orange peel. However, further research is required tooptimize processing conditions.

Electrical, mechanical, and chemical effects of high-voltage electrical discharges on the polyphenol extraction from vine shoots

Abstract The aim of this work was to study the mechanical, electrical and chemical effects of high-voltage electrical discharges (HVED) and their role in polyphenol extraction from vine shoots. Cutting and grinding pretreatments were conducted prior to HVED treatment. Thus, different initial specific surface areas ( a 0 = 6, 8.5, 11, 84 and 1885.19 cm − 1 ) of vine shoots were tested. When the initial specific surface areas were low ( a 0 = 6, 8.5, 11 cm − 1 ), the HVED induced damage degrees ( D ) were the highest, leading to a better enhancement of polyphenol extraction. However, no product fragmentation was found for the lowest particle size ( a 0 = 1885.19 cm − 1 ) before and after the HVED treatment, and despite it, an amelioration of polyphenol content in extract of 20 mg/L was observed. The electrical arc generated H 2 O 2 but did not lead to polyphenol degradation. Industrial relevance This study gives significant information about the action mechanisms of high voltage electrical discharge treatment presenting relevant data for the design of the process. It shows the effectiveness of electrical discharges for the intensification of the extraction of bioactive molecules (polyphenols) from a specific byproduct (vine shoots). The paper also presents an energy-saving extraction process, relevant for industrial application, since no organic solvents were used. Process duration and temperature were also reduced.

Emerging technologies for the recovery of isothiocyanates, protein and phenolic compounds from rapeseed and rapeseed press-cake: Effect of high voltage electrical discharges

Abstract The aim of the present research study was to gain insight into the applicability of high voltage electrical discharges (HVED) technology for obtaining high-added value compounds (protein, polyphenols and isothiocyanates) from rapeseeds and rapeseed press-cake. For this purpose, HVED treatment was applied at different energy inputs (0–400 kJ/kg) to raw rapeseed and rapeseed press-cake water suspensions at different liquid-to-solid ratios (1:5–1:20, w/w). The obtained results clearly show the high potential of HVED to recover isothiocyanates, phenolic compounds and proteins which can be used as food additives and/or nutraceuticals. In almost all cases, an optimal treatment energy input (80 kJ/kg or 240 kJ/kg) was observed beyond which the content of the biocompounds decreases. This optimal energy input was changing depending on the considered compounds and on the raw materials. For example, for polyphenols, the optimal energy was 80 kJ/kg with rapeseed press-cake, but it was 240 kJ/kg with rapeseeds.

Comparison of the effect of pulsed electric field or high voltage electrical discharge for the control of sweet white must fermentation process with the conventional addition of sulfur dioxide

The present work discusses the efficiency of pulsed electrical treatments for the inactivation of yeasts. The application of pulsed electric fields (PEFs) and high voltage electrical discharges (HVEDs) as alternatives to sulfites, which are used as anti-microbial to stop the fermentation of sweet white wine, was investigated. The influence of sulfite concentration (from 0mg·L−1 to 500mg·L−1), PEF (from 4kV·cm−1 to 20kV·cm−1; from 0.25ms to 6ms) and HVED (40kV/cm; 1ms or 4ms) treatments on the inactivation of total yeasts and non-Saccharomyces yeasts was determined. The addition of SO2 (250mg·L−1) resulted in 8 log total yeast reduction. The maximum yeast inactivation obtained with PEF and HVED was respectively 3 and 4 logs. The use of SO2, HVED and PEF allows decreasing the non-Saccharomyces yeast level by 7, 5 and 4 logs respectively. However, the wine browning was less pronounced for the samples treated by PEF in comparison with HVED and SO2 treatments. PEF seems to be the most suitable alternative technique to sulfite addition.

Effect of alternative physical pretreatments (pulsed electric field, high voltage electrical discharges and ultrasound) on the dead-end ultrafiltration of vine-shoot extracts

This work is devoted to the dead-end ultrafiltration of vine shoot extracts; these extracts were obtained after a previous step of solid–liquid extraction assisted by different physical pretreatments. Grinding, high-voltage electrical discharges (HVED), pulsed electric fields (PEF) and ultrasounds (US) were studied. The highest cellular damage (Z) was provoked by grinding (360kJ/kg; Z=1) then HVED (242kJ/kg; Z=0.71). The resulting protein and polyphenol concentrations were 0.097 and 0.4mg/mL for grinding and 0.082 and 0.3mg/mL after HVED pretreatment. A relationship between the extraction process and the unstirred dead-end ultrafiltration parameters was found. The highest cellular damage obtained with grinding (Z=1) gave the greatest specific cake resistances (αc≈4.8×1013m/kg). A correlation was therefore observed between cellular damage resulting in a higher polyphenol concentration and the membrane fouling phenomenon. HVED treatment (242kJ/kg) gave a lower specific cake resistance (αc≈4×1013m/kg) than grinding. Dynamic ultrafiltration was also conducted to decrease membrane fouling and study polyphenol purification and concentration in retentates. The experimental conditions leading to the highest filterability (highest flux J) and polyphenol retention conducted on HVED (242kJ/kg) extracts were a stirring velocity of 150rpm, a pressure value of 4.5×105Pa and a nominal molecular weight cut-off equal to 50kDa for the polyethersulfone membrane. Under these conditions, the filterability of HVED extracts (2.7×10−6m3/m2s) was higher than that of grinding (2×10−6m3/m2s). Up to 8% of polyphenols from the grinding extract were shown to deposit on the membrane. A lower percentage was found for HVED (7%). Polyphenols were therefore shown to be implicated in membrane fouling and pore blocking for unstirred and dynamic ultrafiltration processes.

Effect of pulsed electric fields and high voltage electrical discharges on polyphenol and protein extraction from sesame cake

Abstract The study evaluates the effect of pulsed electric fields (PEF) and high voltage electrical discharges (HVED) on the extraction of sesame cake compounds. Different energy inputs were applied and, afterwards, PEF and HVED were used as pre-treatments to diffusion. Diffusion kinetics were evaluated in diverse ethanol concentrations and temperatures. The extracts were analyzed for polyphenols, lignans and proteins. According to the results, the disintegration index and the polyphenol and protein contents increased with the energy inputs, until 83 kJ/kg was reached. During diffusion, both pre-treatments improved extraction yields of polyphenols and lignans through different solvents. For diffusion in different temperatures, PEF and HVED had a significant positive effect on the extraction of proteins and polyphenols when compared to the control sample. Results show that the use of PEF or HVED can reduce the use of organic solvents and the need for high temperatures to improve diffusion. Industrial relevance There is an increasing demand by the industry for the development of extraction procedures that reduce or eliminate the need for organic solvents and high temperatures. Also, food producers are aiming to find new application for by-products from the industry. PEF and HVED assisted extraction damages the product cells, increasing diffusion from the product to the solvent. The concentration of polyphenols and protein in the solvent after PEF and HVED treatments shows that the use of these techniques is relevant for an industrial use, since solvent amount and extraction time and temperature can be reduced.

High Voltage Electrical Discharges, Pulsed Electric Field, and Ultrasound Assisted Extraction of Protein and Phenolic Compounds from Olive Kernel

The study was aimed at improvement of recovery of intracellular valuable compounds from olive kernels (Olea europaea). High voltage electrical discharges (HVED), pulsed electric field (PEF), and ultrasound (US) were applied as pretreatments before extraction. The influence of HVED energy input (0–109 kJ/kg), pH (2.5–12), and ethanol (0–50 %) on the efficiency of the extraction was studied. The extracts obtained immediately after pretreatments were analyzed for total phenolic compounds, antioxidant activity, proteins, and pigments. HVED treatment was demonstrated to be more effective than ultrasound and pulsed electric field in terms of energy input and effective treatment time to extract phenolic compounds and proteins. Moreover, the application of HVED increased significantly the aqueous and hydro-ethanolic extractions of total phenolic content (TPC), and proteins of the recovered extracts when energy input was augmented. pH and ethanol percentage had also a significant influence in TPC, protein, and antioxidant recovery. The interesting observation is that pH 2.5 resulted in the optimum conditions to recover TPC and antioxidant capacity. However, the higher protein content was found when pH 12 was used. Multiple response optimization showed that TPC, content of proteins, and antioxidant capacity (Trolox equivalent antioxidant capacity (TEAC) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) values) of the sample were further maximized after HVED pretreatment at energy input 66 kJ/kg at pH 2.5 followed by extraction in 49 % ethanol. TPC, content of proteins, TEAC, and DPPH values under such conditions of extraction were 626.6 mg GAE/L, 0.225 mg/mL, 9.80 mM TE, and 7.61 mM TE, respectively.

Evaluating the potential of cell disruption technologies for green selective extraction of antioxidant compounds from Stevia rebaudiana Bertoni leaves

An increased interest has been shown by both food technologists and food industry regarding Stevia rebaudiana Bertoni leaves (Stevia) for their high content of bioactive components (phenolic compounds, vitamin C, carotenoids). The aim of this work was to study the effect of emerging technologies such as high voltage electrical discharges (HVED) and pulsed electric fields (PEF) and ultrasounds (US) on the intensification of the extraction of valuable compounds from Stevia leaves. The proposed processes combined pretreatment (HVED, PEF and US) and extraction of intracellular compounds using water as solvent at ambient temperature. The energy inputs of the treatments varied from 24 to 141kJ/kg and the results were compared to control diffusion experiments. Chlorophyll a, and b, total carotenoid, total phenolic compounds and antioxidant capacity (DPPH) were determined. A significant increase in soluble matter and antioxidant compounds was found after HVED, PEF and US-assisted extraction as compared to control samples. Results showed that HVED, PEF and US treatments improved both kinetics and extraction yield of soluble matter. These results show the ability of HVED to be used as a potential technology to enhance protein recovery using water and avoiding the use of other solvents and grinding. Chlorophyll content was significantly higher (3-fold increase) after HVED assisted extraction at 141kJ/kg in comparison to control sample (0.352 and 0.355mg/L for chlorophyll a and b, respectively). The same energy input for HVED permitted attain highest extraction diffusivities of total soluble matter (D=3.06×10−09m2/s), followed by total phenolic compounds (D=2.60×10−10m2/s) and then proteins (D=6.00×10−11m2/s).

Intensification of polyphenols extraction from grape seeds by high voltage electrical discharges and extract concentration by dead-end ultrafiltration

Grape seed is a rich source of polyphenols. In this study, the high voltage electrical discharges (HVED) were used as alternative method for polyphenols extraction from grape seeds. The extraction efficiency was evaluated by conductivity disintegration index Z and polyphenols concentration in extracts. It was shown that HVED treatment permits effective extraction of polyphenols from grape seeds. The maximal concentration of extracted polyphenols reached 8.3 g GAE/100 w db after 300 discharges. The extraction of polyphenols was satisfactorily described by the Peleg’s model ( R 2 > 0.995). Extracts obtained with HVED were then concentrated using membranes with different molecular weight cut off (0.15 μm, 150 and 50 kDa). The dead-end filtration of obtained extracts followed the cake filtration mechanism with membranes UP150 (150 kDa) and UV050 (50 kDa), and the combined mechanism (standard pore blocking/cake filtration) with FSM0, 15PP membrane (0.15 μm). The polyphenols content and physico-chemical properties of the permeates and retentates were evaluated. The polyphenols rejection of 87% and 91% were achieved with UP150 and UV050 membranes, respectively.

Electrically Assisted Extraction of Soluble Matter from Chardonnay Grape Skins for Polyphenol Recovery

The objective of this study was to investigate the effects of pulsed electric field (PEF) and high-voltage electrical discharges (HVED) application on the efficiency of aqueous extraction of total soluble matter and polyphenols from grape skins ( Vitis vinifera L.) at different temperatures within 20-60 degrees C. The highest level of polyphenol concentration C was reached after about 60 min of extraction for HVED treatment: C(HVED) = 21.4 +/- 0.8 micromol of gallic acid equivalent (GAE)/g of dry matter (DM). Almost the same level of C was reached after 180 min of extraction for the PEF-treated skins. These levels exceeded the value C = 19.1 +/- 0.5 micromol of GAE/g of DM for the untreated samples. The difference between degrees Brix values for HVED-treated and untreated systems decreased with temperature increase (from 40 to 60 degrees C), but a large difference in the total amount of polyphenols was observed for HVED-treated and untreated systems. The activation energies were W(u) = 31.3 +/- 3.7 kJ/mol and W(PEF) = 28.9 +/- 5.5 kJ/mol for untreated and PEF-treated systems, respectively.