Second-order Polynomial Equation Research Articles

Effect of Syringopicroside Extracted from Syringa oblata Lindl on the Biofilm Formation of Streptococcus suis.

Syringopicroside is a natural drug with antibacterial activity, which is the main ingredient of Syringa oblata Lindl (S. oblata). In order to further develop the application of S. oblata and evaluate the ability of syringopicroside against Streptococcus suis (S. suis), this investigation first applied an ultrasonic-assisted method to extract syringopicroside, and then response surface methodology (RSM) was performed to get the optimum condition. Based on RSM analysis, a second-order polynomial equation about the syringopicroside yield and four variables, including ultrasonic power, time, temperature, and liquid-to-solid ratio, was purposed. Through RSM prediction and model verification experiments, the optimum conditions were determined, as follows: ultrasonic time was 63 min, temperature was 60 °C, a liquid-to-solid ratio was set to 63 mL/g, and ultrasonic power was 835 W. Under this condition, a high syringopicroside yield was obtained (3.07 ± 0.13 mg/g), which was not significantly different with a predicated value. After separation and purification by HPD 500 microporous resin, then mass spectrum was applied to identify the main ingredient in aqueous extract. A minimal inhibitory concentration (MIC) assay revealed the value against S. suis of syringopicroside was 2.56 µg/µL and syringopicroside with sub-inhibitory concentrations that could effectively inhibit biofilm formation of S. suis. Besides, scanning electron microscopy analysis indicated syringopicroside could destroy the multi-layered aggregation structure of S. suis. Finally, molecular docking analysis confirmed that syringopicroside was combined with Orfy protein of S. suis through hydrogen bonds, hydrophobic interaction, and π-π stacking.

On solutions of second-order matrix polynomial equation of high degree

In this paper, we focus on discussing diagonal solutions and general solutions of second-order matrix polynomial equation of high degree in complex field. By characterizing some algebraic properties of the mentioned two types of the solutions, we present sufficient conditions that a general second-order matrix polynomial equation has diagonal solutions or general solutions. Analytic expressions of the solutions, as well as the corresponding algorithms for finding the solutions are provided. An example is given so as to verify the theoretical results we have derived.

Nature instigated Grey wolf algorithm for parametric optimization during machining (Milling) of polymer nanocomposites

The new era of engineering society focuses on the utilization of the potential advantage of carbon nanomaterials. The machinability facets of nanocarbon materials are passing through an initial stage. This article emphasizes the machinability evaluation and optimization of Milling performances, namely Surface roughness (Ra), Cutting force (Fc), and Material removal rate (MRR) using a recently developed Grey wolf optimization algorithm (GWOA). The Taguchi theory-based L27 orthogonal array (OA) was employed for the Machining (Milling) of polymer nanocomposites reinforced by Multiwall carbon nanotube (MWCNT). The second-order polynomial equation was intended for the analysis of the model. These mathematical models were used as a fitness function in the GWOA to predict machining performances. The ANOVA outcomes efficiently explore the impact of machine parameters on Milling characteristics. The optimal combination for lower surface roughness value is 1.5 MWCNT wt.%, 1500 rpm of spindle speed, 50 mm/min of feed rate, and 3 mm depth of cut. For lower cutting force, 1.0 wt.%, 1500 rpm, 90 mm/min feed rate and 1 mm depth of cut and the maximize MRR was acquired at 0.5 wt.%, 500 rpm, 150 mm/min feed rate and 3 mm depth of cut. The deviation of the predicted value from the experimental value of Ra, Fc, and MRR are found as 2.5, 6.5 and 5.9%, respectively. The convergence plot of all Milling characteristics suggests the application potential of the GWO algorithm for quality improvement in a manufacturing environment.

Predicting Temporal Gait Kinematics: Anthropometric Characteristics and Global Running Pattern Matter.

Equations predicting stride frequency (SF) and duty factor (DF) solely based on running speed have been proposed. However, for a given speed, kinematics vary depending on the global running pattern (GRP), i.e., the overall individual movement while running, which depends on the vertical oscillation of the head, antero-posterior motion of the elbows, vertical pelvis position at ground contact, antero-posterior foot position at ground contact, and strike pattern. Hence, we first verified the validity of the aforementioned equations while accounting for GRP. Kinematics during three 50-m runs on a track (n = 20) were used with curve fitting and linear mixed effects models. The percentage of explained variance was increased by ≥133% for DF when taking into account GRP. GRP was negatively related to DF (p = 0.004) but not to SF (p = 0.08), invalidating DF equation. Second, we assessed which parameters among anthropometric characteristics, sex, training volume, and GRP could relate to SF and DF in addition to speed, using kinematic data during five 30-s runs on a treadmill (n = 54). SF and DF linearly increased and quadratically decreased with speed (p < 0.001), respectively. However, on an individual level, SF was best described using a second-order polynomial equation. SF and DF showed a non-negligible percentage of variance explained by random effects (≥28%). Age and height were positively and negatively related to SF (p ≤ 0.05), respectively, while GRP was negatively related to DF (p < 0.001), making them key parameters to estimate SF and DF, respectively, in addition to speed.

Optimization of ultrasonic-assisted freezing of Penaeus chinensis by response surface methodology

Abstract Objectives Optimization of ultrasonic-assisted freezing of Penaeus chinensis by response surface methodology was studied in order to (1) obtain frozen Penaeus chinensis of high quality and (2) provide practical guidance for the application of ultrasonic-assisted freezing in Penaeus chinensis. Materials and Methods Three independent and major variables were selected, including initial ultrasonic temperature (°C), ultrasonic power (W) and ultrasonic time (s on/2 s off). On the basis of one-factor experiments, 17 groups of experiments were established by response surface methodology according to Box–Behnken design. Using multiple regression analysis the experimental data were fitted into a second-order polynomial equation, which was tested by proper statistical methods. Results The optimal ultrasonic conditions were as follows: initial ultrasonic temperature 0 °C, ultrasonic power 180 W, ultrasonic time 5 s on/2 s off. Under the optimization conditions, the time of passing through maximum ice crystal generation zone was 105.500 s, which was very close to the predictive passage time of 101.541 s. Conclusions Initial ultrasonic temperature, ultrasonic time and ultrasonic power played an important role in the process of ultrasonic-assisted freezing of Penaeus chinensis. Response surface methodology was used to optimize the three factors in ultrasonic-assisted freezing, which could greatly shorten the time of passing through the maximum ice crystal generation zone and maintain the tissue structure of Penaeus chinensis well.

Development of a Guiding-Groove Precision Metering Device for High-Speed Planting of Soybean

<b>Highlights</b> <list list-type=bullet><list-item> To improve the planting of soybean at high speeds, a guiding-groove precision metering device was developed. </list-item><list-item> The seed feeding and clearing processes were analyzed to determine the critical design and operating factors. </list-item><list-item> The effects of the critical parameters on metering performance were simulated using a discrete element model. </list-item><list-item> The metering performance was evaluated using bench tests with a fabricated metering device. </list-item></list> <b>Abstract</b>. Precision planting is the inevitable trend of agricultural development, and the promotion of precision planting technology is the key to increasing crop yields. To improve the performance of precision planting at high speeds, a mechanical-type precision metering device was developed for soybean. The innovative feature of the device is the guiding-groove (GG) that provides “waiting areas” for seeds to form a line and subsequently enter the seed cells in an orderly and rapid manner. Using force analysis, a mechanical model of the seed feeding stage was developed. Relationships between the design parameters of the GG metering device and its metering performance (multiple index, miss index, quality index, and feeding efficiency index) were obtained through simulations using a discrete element model (DEM). The simulations conducted in this study were based on central composite design (CCD). The relationships were then used to determine the design parameters to achieve the best metering performance. With these design parameters, the GG metering device was fabricated and evaluated using bench tests. Results showed that the critical design parameters were the width of the guiding-groove (L1), angle of the groove bottom surface to the horizontal plane (η), width of the groove wheel (L), and cone angle of the shell (δ). The relationship between these parameters and the metering performance could be described by a second-order polynomial equation, and the best metering performance occurred with L = 25.3 mm, η = 8.3°, L1 = 8.1 mm, and δ = 23.6°. The bench test results showed that the GG metering device designed with these optimal parameters had metering performance values (quality index) of 93% and higher at planter travel speeds of 8 to 15 km h-1. In addition, the coefficients of variation of metering performance over the range of planter travel speeds were lower than 30%.

Vintage Effect on the Strain Dependent Dynamics of Ethanol Production in Vineries of Tokaj

The dynamics of ethanol production of local strains of three yeast species and their ternary mixtures was examined in two Tokaj vineries. Although, the performance of them diverged significantly in first etaps of vinification—up to the utilization of half of the sugar content of grape juice—the variations vintages per vintages surpassed the strain-dependent alterations. The divergence in the latter aspect diminished during the last etap, and the ethanol concentration in young wines fermented by Saccharomyces cerevisiae, S. uvarum and Starmerella bacillaris (2 local strains of each) and their mixtures did not vary considerably (c.v. 4.2%). The vinification of grape juice performed more rapidly in fermentors inoculated with strains of S. cerevisiae, S. uvarum and St. bacillaris as well as with their mixtures than in spontaneously initiated ones by wild mycoflora in each vintage. The strains responded in different manners to conditions vintage per vintage, however, their ternary mixtures always fermented more intensively the grape juice than the strains alone. The strains affected the dynamics of alcohol production to different extents, but the alterations between them exceeded the variation between the average effects of the species. The circumstances of vinification significantly influenced the subsequent events of fermentation, but the maximum intensity of ethanol production was inversely proportional to the time required to start alcohol production (p > 0.05), similar to that observed in the laboratory under strictly controlled micro-vinification experiments. The maximum intensity of ethanol production (MIE) varied between 0.64 - 2.59 mM ethanol per hour. The coefficients of second-order polynomial equations describing the dynamics of alcohol production in both laboratory micro-scale and medium-scale experiments in cellars revealed similar correlations regarding the interaction of factor groups regulating the process: the constant (time-independent) and secondary (time-dependent) coefficients of these polynomes counteracted to the primary (time dependent) ones strictly in the strain-dependent manner, and the role of these three factors groups varied also in a strain dependent manner during the vinification process independently of the varying circumstances in three vintages.

Optimization and screening of solid lipid nanoparticle production for gene delivery by factorial design and response surface methodology

Aim: A successful gene therapy requires a delivery system for overcoming various biological barriers. For this, we adapted the factorial design and response surface methodology to the cationic solid lipid nanoparticle production process. Methods: Screening and optimization of formulations were carried out with factorial design with 3 factors and 3 levels using Box-Behnken Design. Then, solid lipid nanoparticles were physicochemically characterized. Furthermore, optimal SLN formulation is examined in terms of complex formation with plasmid DNA, its protection potential against nucleases, cytotoxicity profile, and storage stability. Results: Response-surface analyses demonstrated that the selected quadratic model holds significance for particle size and zeta potential. The interaction of independent variables was statistically determined. Optimization and prediction were performed using obtained second-order polynomial equations. Optimal formulation and complexes were found to be nanosized, positively charged and their polydispersity-index values below 0.3 as an indicator of being monodispersed. Cytotoxicity of the optimal formulation is compatible for further studies and no significant increase was observed in particle size until day 21 and until day 60 for polydispersity-index. Conclusion: Optimal formulation provides a good basis as a gene delivery system was produced with developed systematic. Briefly, this methodology could be used to obtain SLNs with desired conditions.

Nonlinear regression analysis and response surface modeling of Cr (VI) removal from synthetic wastewater by an agro-waste Cocos Nucifera: Box-Behnken Design (BBD)

In this study mixture of coconut shell and coir was used for Cr (VI) removal from synthetic wastewater and statistical tool Response Surface Modeling (RSM) was applied to optimize process parameters. The solution pH (2–6), reaction time (20–100 minutes) and adsorbent quantity (0.03–0.2 g) was optimized to find the maximum response of Cr (VI) removal using statistical Box-Behnken design (BBD) software. The equilibrium data obtained by the batch experiment were analyzed by ANOVA and found fitted in a second-order polynomial equation through multiple regression analysis. The optimum value of pH, adsorbent quantity and reaction time for 99% of Cr(VI) was found as 2, 0.1 g and 100 minutes, respectively. By using non-linear regression method it was found that Freundlich isotherm and Pseudo-second-order kinetic with high correlation coefficient (R 2), low Chi-square (χ 2) and root mean squares errors (RMSE), best describe the adsorption of Cr (VI) on mixture of coconut shell and coir (MCSC) surface. Positive enthalpy (ΔH°) and negative Gibbs free energy (ΔGo) values confirm the endothermic and spontaneous nature of adsorption process. Pre and post adsorption phenomenon was confirmed by characterization of adsorbent using AFM, FTIR, SEM, and EDX analysis. The adsorbent MCSC has regenerative property and can be reused 3–4 times after treating with alkaline medium (0.2 N NaOH) and offered more than 60% removal of Cr (VI) at the fourth cycle. It can be inferred based on this study that MCSC is an effective adsorbent for Cr (VI) removal and can be used on an industrial scale for social and environmental benefit. Novelty statement An agriculture waste mixture of coconut shell and coir (MCSC) without the addition of any chemical reagent, was used for Cr(VI) removal. As per literature survey and best of our knowledge, the adsorbent MCSC has not been reported for Cr (VI) removal. In the previous study, authors reported either coconut coir pith or coconut shell or coconut charcoal as adsorbent for Cr (VI) removal. The adsorbent MCSC is efficient even at very low doses (0.1 g) as compared to the reported adsorbent.

Application of Response Surface Method to Copper Cementation by Metallic Aluminum Particles

In the present study, the interactive effects of the process variables containing copper concentration, temperature, and time on the efficiency of copper cementation by metallic aluminum particles were examined by using response surface methodology (RSM). It was observed that the efficiency of cementation increased with an increase in the initial concentration of copper, temperature and time. The multiple regression analysis to the experimental data was applied to see the interactive effects of process variables. The second-order polynomial equation was obtained. The optimal values were found to be 0.075 mol/l, 303 K, and 90 min to maximize the amount of the deposited copper.

Decolorization kinetics and mass transfer mechanisms of Remazol Brilliant Blue R dye mediated by different fungi

The release of synthetic dye into the environment causing abnormal growth of phytoplankton may lead to a decline in the photosynthetic performance of aquatic ecosystem. Scientific knowledge of Remazol Brilliant Blue R (RBBR) decolorization is essential for designing the engineered bioremediation systems of employing fungal mycelium. The biodegradation of RBBR dye mediated by an appropriate fungus was analyzed using the modified mass transfer factor models to get better understanding on the decolorization kinetics and mechanisms of external and internal mass transfer. The results showed that the limited capacities of the kinetic and isotherm models are still not able to comprehensively explain many important phenomena of RBBR decolorization mediated by the T. citrinoviride, T. koningiopsis and Pestalotiopsis sp. strains. The rate-limiting step of RBBR decolorization depends on the EMT resistance and the vegetative growth rates of T. citrinoviride, T. koningiopsis and Pestalotiopsis sp. strains can be described by second-order polynomial equation. The analysis of decolorization performance may provide a new insight on the role of fungus in the degradation of RBBR dye.

Investigating the performance of an organically cross-linked grafted copolymer gel under reservoir conditions for profile modifications in injection wells

The injection of cross-linked polymer gels to block high permeability zones and divert subsequent water/surfactant flooding to low permeability streaks to improve hydrocarbon production efficiency is commonly known as profile modification. Moreover, in a reservoir condition with high temperature, pH, and salinity, these cross-linked polymeric gels are unstable, leading to early syneresis. In this research work, poly(Acrylamide)-grafted-xanthan gum copolymer was synthesized by free radical polymerization using potassium persulfate as an initiator. Field-Emission Scanning Electron Microscopy and Fourier Transform Infrared spectroscopy characterize the grafted copolymer in this study. This grafted copolymer, which is soluble in water, was cross-linked with a low toxic organic cross-linker. The organic cross-linker is composed of hexamethylenetetramine (HMTA) and hydroquinone (HQ). The rheological examination and gelation conduct of this polymeric gel was analyzed using a bottle test. The experimental design in response surface method generated a second-order polynomial equation for the gelation time responses to the change in the reservoir parameters (salinity, pH, and temperature) and their interactions. The results exhibited that the response surface model can be applied successfully to analyze gelation time with the various reservoir parameters. Laboratory prepared sand pack flow experiment demonstrated a decent diverting capability of the grafted copolymer gel than commercially used polyacrylamide gels. Subsequently, this grafted copolymer gel can be suitable for profile modification jobs required for improving oil recovery from mature oil fields with high reservoir heterogeneities.

Characteristics of Sunsik, a Cereal-Based Ready-to-Drink Korean Beverage, with Added Germinated Wheat and Herbal Plant Extract.

The purpose of this study was to develop a formulation of Sunsik with improved health benefits by adding germinated wheat (GW) and herbal plant extract (HPE) using a response surface methodology (RSM). The central composite experimental design (CCD) was used to evaluate the effects of Sunsik with added HPE (2–4%) and GW (10–20%) on total phenolic content (TPC), total flavonoid content (TFC), Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, gamma butyric acid (GABA) content, total color changes (△E), browning index (BI), water absorption index (WAI), and water solubility index (WSI). As a result of the CCD, the independent and dependent variables were fitted by the second-order polynomial equation, and the lack of fit for response surface models was not significant except in relation to WSI. The GABA content, TPC, and TEAC were more adequate for a linear model than for a quadratic model, and they might be affected by GW rather than HPE. Alternatively, the TFC, DPPH radical scavenging capacity, WAI, WSI, △E, and BI were fitted with quadratic models. The optimum formulation that could improve antioxidant and physicochemical properties was Sunsik with 3.5% and 20% added HPE and GW, respectively.

Application of reflux classifier with closely spaced inclined channels in pre-concentrate process of fine antimony oxide particles

In this work, the reflux classifier with closely spaced inclined channels is used as the pre-concentration facility to improve the separation efficiency before the shaking table separation. Three operating parameters of reflux classifier (RC) to pre-concentrate fine(0.023–0.15 mm) tailings of antimony oxide were optimized by response surface methodology (RSM) using a three-level Box-Behnken design (BBD). The parameters studied for the optimization were feeding speed, underflow, and ascending water speed. Second-order response functions were produced for the Sb grade and recovery rate of the concentrate. Taking advantage of the quadratic programming, when the factors of feeding, underflow and ascending water are respectively 225, 30 and 133 cm3/min, a better result can be achieved for the concentrate grade of 2.31% and recovery rate of 83.17%. At the same time, 70.48% of the tailings with the grade of 0.20% were discarded out of the feeding. The results indicated that the reflux classifier has a good performance in dealing with fine tailings of antimony oxide. Moreover, second-order polynomial equations, ANOVA, and three-dimensional surface plots were developed to evaluate the effects of each parameter on Sb grade and recovery rate of the concentrate.

Enhancing production of fucoxanthin by the optimization of culture media of the microalga Tisochrysis lutea

Fucoxanthin is a bioactive carotenoid, found in algal species. The marine microalga Tisochrysis lutea is an interesting source of nutrients and valuable compounds like fucoxanthin. In the present work, the response surface methodology was applied to optimize the culture media in order to achieve high level of fucoxanthin from the T. lutea cultivated in 1-L batch photo-bioreactors. The relationship between fucoxanthin production and the culture medium parameters was fitted with a second-order polynomial equation using a multiple regression technique from the experimental results of the response surface methodology. The optimum composition required to obtain the highest amount of fucoxanthin was determined as follows: salinity, 36.27 g L−1; carbon source (starch), 3.90 g L−1; nitrogen source (nitrate), 0.162 g L−1. Optimum conditions significantly enhance the production of fucoxanthin (79.40 ± 0.95 mg g−1 dry weight) and decrease the period of cultivation from 14 days (in non-optimized conditions) to 4 days.

Optimizing the Extraction of Phenolic Compounds with High Anti-oxidant Activity from Mango Seed Kernel Wastes Using Response Surface Methodology

Mango seed kernels (MSK), which are waste streams in mango processing industry, are good sources of phenolic compounds with high anti-oxidant, anti-bacterial, and anti-viral properties. These phenolic compounds are reported to have an increasing demand over the years in the quest for healthy ready-to-eat food and nutraceuticals. To recover these compounds from MSK, solid-liquid extraction (SLE) can simply be applied, although there is a knowledge gap in in the systematic exploration of this process for mango-based phenolic compounds. In this work, phenolic compounds were extracted from MSK through SLE using ethanol-water solvent system. A statistical-based approach was used to evaluate and optimize the extraction conditions in relation to yield of phenolic compounds from MSK. The central composite design together with response surface methodology was adopted to assess the effect of extraction temperature (30oC, 45oC, and 60oC) and ethanol concentration (25% – 75%) under fixed extraction time (105 min) and solid-to-solvent ratio (1:10) on the extraction yield. Both temperature and ethanol concentration provided positive effects on the yield and the following optimum conditions of temperature and ethanol concentration were obtained at 63.21oC and 53.21% ethanol, respectively. A second-order polynomial equation was obtained describing the extraction process, and a validation test of this response model showed that it sufficiently described the process. Furthermore, the extracts obtained at optimal conditions possess a potential antioxidant activity at IC50 = 45 ± 0.002 µg GAE mL-1 extract. The results indicated that phenolic compounds in MSK can be recovered through extraction using aqueous ethanol. This study also promotes value-addition of a seemingly useless waste material while reducing its health and environmental impact.

Exploitation of Kiwi Juice Pomace for the Recovery of Natural Antioxidants through Microwave-Assisted Extraction

In a completely green approach to the exploitation of kiwi juice pomace (KP), a microwaved-assisted extraction (MAE) process was performed to extract antioxidant compounds present in KP, evaluating the influence of four independent process variables (temperature (T), extraction time (E), solvent composition (C), and solid-to-solvent ratio (R)) on the response of total phenolic content (TPC). The optimal conditions for the green extraction of total polyphenols from KP were obtained using a three-level fractional factorial design under response surface methodology (RSM) coupled with desirability optimization, and a feed-forward multilayered perceptron artificial neural network (ANN) with a back-propagation algorithm. Data were analyzed by ANOVA and fitted to a second-order polynomial equation using the regression method. Results showed that T was the most influential factor, followed by R and C, whereas the extraction time (E) was not shown to have a significant linear effect on the extraction yield of total polyphenols (TPs). The optimal conditions based on both individual and combinations of all responses were found out (T: 75 °C; E: 15 min; C: 50% ethanol:water; R: 1:15), and under these conditions the obtained extract showed both a high bioactive compound content and a high antioxidant potential, pointing out how this by-product could become an inexpensive source of compounds with high added value. A very good agreement was observed between experimental and calculated extraction yields, thus supporting the use of these models to quantitatively describe the recovery of natural antioxidants from KP. Finally, the ANN model exhibited more accurate prediction and better generalization capabilities than the RSM model (R2: 0.90 and 0.99, for RSM and ANN, respectively).

High leucine levels affecting valine and isoleucine recommendations in low-protein diets for broiler chickens

Four experiments were conducted to estimate the optimal standardized ileal digestible (SID) level of branched-chain amino acids in low-protein diets during the starter, grower, and finisher periods, using the response surface methodology, and to study their effects on performance and mRNA expression of genes involved in the mechanistic target of rapamycin (mTOR) pathway of broiler chickens from 8 to 21 D of age. In experiments 1, 2, and 3, a total of 1,500 Cobb male broiler chickens were assigned to 15 diets of a central composite rotatable design (CCD) of response surface methodology containing 5 levels of SID Leu, Val, and Ile with 5 replicate pens of 20 birds each. A 3-factor, 5-level CCD platform was used to fit the second-order polynomial equation of broiler performance. In experiment 4, a total of 540 8-day-old Cobb male broiler chickens were distributed in a completely randomized 2 x 3 x 3 factorial arrangement with 2 SID Leu levels (1.28 or 1.83%), 3 SID Val levels (0.65, 0.90, or 1.20%), and 3 SID Ile levels (0.54, 0.79, or 1.09%) for a total of 18 treatments with 5 replicate cages of 6 birds each. High Leu levels impaired (P < 0.05) gain:feed when birds were fed marginal Val or Ile diets. However, gain:feed was restored when both Val and Ile were supplemented to reach adequate or high levels. High Leu levels increased (P < 0.05) mRNA expression of S6K1 and eEF2 genes only in birds fed high Ile levels. Dietary SID Leu, Val, and Ile levels required for gain:feed optimization in low-protein diets were estimated at 1.37, 0.94, and 0.87% during the starter period; 1.23, 0.82, and 0.75% during the grower period; and 1.15, 0.77, and 0.70% during the finisher phase, respectively. Higher Val and Ile levels are required to optimize the effect of Leu supplementation on mRNA expression of mTOR pathway genes in the pectoralis major muscle of broilers from day 1 to 21 after hatch.

Optimasi Produksi Asap Cair Dari Kayu Medang (Cinnamomum sp.) Menggunakan Metode Permukaan Respon

In this work medang wood (Cinnamomum spp.) was pyrolyzed to produces wood vinegar. The effect of several parameters including the wood particle size, pyrolysis temperature, and pyrolysis time on the pyrolysis efficiency was tested to identify the optimal wood vinegar production conditions. The efficient response surface methodology (RSM) with the Box-Behnken design (BBD) was used for modeling and optimization of the process parameters. RSM used three variable designs namely particle size of wood of 2.38, 3.36, and 4.76 mm, respectively, pyrolysis temperature of 370, 400 and 430°C, respectively, and pyrolysis times 90, 120 and 150 minutes, respectively, with the total of 15 experimental runs. The responses of the BBD fitted with a second-order polynomial equation, illustrating the wood vinegar yield was Y = 15.20 + 0.31 X1 + 5.00 X2 + 0.48 X3 – 1.84 X12 – 1.18 X22 + 0.63 X1.X2 + 0.35 X1.X3 + 0.31 X2.X3 – 0.27 X3.X3. The optimal conditions found to be at the particle size of wood, pyrolysis temperature, and pyrolysis time were 4.76 mm, 475 °C, 195 minutes, respectively, and yield of wood vinegar was 22.90%.

Evaluation of crop water stress index and leaf water potential for differentially irrigated quinoa with surface and subsurface drip systems

A 2-year field experiment was conducted with the objectives to evaluate the physiological and yield response of quinoa cv Titicaca to various deficit irrigation strategies applied with surface drip (SD) and subsurface drip systems (SSD) under the Mediterranean climatic conditions in 2016 and 2017. The treatments consisted of regulated deficit irrigation (RDI), partial root-zone drying (PRD50), conventional deficit irrigations (DI50, DI75) and full irrigation (FI) under SD and SSD. A rainfed treatment was also included. The experimental design was split plots with four replications. DI75 and DI50 received 75 and 50% of FI, respectively. PRD50 plots received 50% of FI, but from alternative laterals in each application. RDI received 50% of FI during vegetative stage until flowering, then received 100% of water requirement. The results indicated that RDI resulted in water saving of 23 and 21% for surface drip (SD) and SSD systems, respectively, and RDI produced statistically similar yield to FI treatment in both experimental years. DI75 treatment resulted in water savings of 16% for both drip methods in the first year and 10 and 25% for SD and SSD systems, respectively, in the second year. Thus, RDI and DI75 treatments appear to be good alternative to FI for sustainable quinoa production in the Mediterranean environmental conditions. Greater leaf water potential (LWP) and smaller crop water stress index (CWSI) values were measured in FI plots under both drip systems than deficit irrigation treatment plots. Significant second-order polynomial relations were determined between CWSI and LWP for the drip systems. Leaf area index (LAI), LWP decreased and CWSI increased as the drought increased. CWSI correlated significantly (P < 0.01) and negatively with grain yield, dry matter yield, LAI, and mean soil water content indicating that grain yield of quinoa declined with increasing CWSI values. All these relations are best described by significant second-order polynomial equations. The results revealed that quinoa should be irrigated at LWP values between − 1.35 and − 1.60 MPa, and average CWSI value of approximately 0.35 for high yields.