Kc Values Research Articles

Extending the range of liquids available for NMR cryoporometry studies of porous materials

Abstract Nuclear magnetic resonance (NMR) cryoporometry, although well established, can be limited by the inability of any one liquid to probe a broad range of pore sizes, a relatively small number of commonly-used probe liquids and the requirement to match the probe liquid to the chemistry of the material being studied. Here we demonstrate, for the first time, the use of menthol and t-butanol as probe liquids in NMR cryoporometry measurements. Using appropriate estimates for the values of the melting point depression constant, kc, and the non-freezing surface layer, 2sl, NMR melting data was converted into pore size distributions. The melting point depression constant for t-butanol is similar to that of cyclohexane; however due to its functionality, t-butanol may be the preferred liquid used to study the porosity of hydrophilic materials. Menthol, having a larger value of kc, can accurately analyze larger pore sizes up to 100 nm. This represents the first use of menthol and t-butanol to accurately probe pore dimensions in NMR cryoporometry.

Numerical investigations on a framework for fracture prediction in metal forming with a material model based on stress-rate dependence and non-associated flow rule

In this paper, the proposed framework for fracture prediction during sheet metal forming is explained and some numerical investigations are presented to demonstrate the effectiveness of this method. In particular, the role of parameters that affects the forming limit curves, which are represented by the initiation of local bifurcation in each stress rate, are examined; namely, anisotropic parameters and the KC value, which means a stress-rate dependence, and other material properties. The newly proposed concept of forming limit diagram is used to evaluate the formability of the concerned material and working process.

Evapotranspiration, water use efficiency and crop coefficient of three lettuce varieties grown in a tropical region

Three field experiments were carried out in a tropical environment in Brazil in order to evaluate the effect of planting date on crop evapotranspiration (ETc), crop coefficient (Kc) and water use efficiency (WUE) of three lettuce (Lactuca sativa L.) cultivars grown in different seasons (autumn, winter and summer) under tropical climate. ETcvalues were obtained through the soil water balance method and reference evapotranspiration (ETo) through the Penman-Monteith method, using data collected in an automatic weather station located close to the experimental area. The results of the research showed that the mean values of ETc and Kc for lettuce were 3.5 mm day-1 and 0.82, respectively. The curly cultivar showed the highest yield (40.8 kg ha-1) during the autumn transplanting date. Results also showed that the three lettuce varieties have different responses to the climatic conditions. The greatest WUE was observed for the three lettuce varieties when they were grown during the autumn growing season, and the lowest values occurred during the winter growing season.

Response of Lentil (Lens culinaries) to Post-rice Residual Soil Moisture Under Contrasting Tillage Practices

Soil moisture stress and excessive soil wetness are the main abiotic factors limiting lentil (Lens culinaries Medik) growth and productivity in the humid tropics. Field experiments were conducted during the post-monsoon to winter seasons (November–March) of 2012–2013 to 2013–2014 on a clay loam soil (Aeric Haplaquept) of Eastern India to cultivate rainfed lentil, utilizing the carry-over soil moisture and residual soil fertility, in rice fallow during post-rainy season. Our objective was to determine the effects of three tillage treatments, viz. No tillage with standing rice stubbles (NT), minimum tillage with standing rice stubbles (MT) and conventional tillage (CT), imposed on post-rice soil conditions, on the root-zone soil moisture storage, actual evapotranspiration (ETa) of lentil, actual time and intensity of crop stress exposed, as well as growth, seed yield, and water use efficiency of lentil. The soil moisture storage within the root-zone was 17.1–18.6 cm for NT and MT and 13.8–14.3 cm for CT during the time of sowing and the values declined to 7.5–10.0 cm during harvesting of lentil. Treatment CT declined > 40% of its readily available water at pod-formation stage. Soil moisture storage depletion from sowing to maturity at 0–40 cm depth was found 4.8, 3.4 and 6.9 cm under NT, MT, and CT, respectively. The leaf relative water content (RWC), chlorophyll concentration, crop growth rate (CGR) and biomass were significantly (P < 0.05) higher in NT and MT than CT. Leaf area, chlorophyll concentration and RWC varied significantly (P < 0.05) at critical crop growth periods under different tillage as compared to soil moisture stress. The ratio of CGR to LAI was 1.5 times more under NT and MT than under CT. The ETa was 11.41, 11.16 and 10.28 cm, respectively, for CT, NT and MT with a mean seed yield of 938, 1292 and 1225 kg ha−1 across both the years. Treatments NT and MT had significantly (P < 0.05) higher water use efficiency producing 35.3 kg ha−1 more seed yield per cm of water as compared with CT. The increase in yield was primarily ascribed to the favourable soil moisture content, which increased the plant growth rate (96% as compared with CT), thereby helping the crop to overcome the terminal drought during the later stages of the growth of lentil. Contrasting tillage practices modified the crop coefficient (Kc) values by altering evaporation and transpiration coefficients with mean Kc values for initial, development, mid-season and maturity stages were 0.32, 0.43, 1.12 and 0.39, respectively, under post-rice residual soil moisture. Our study concluded that when long-duration puddled-transplanted monsoon rice (~ 150 days) was the preceding crop in rice fallow situations, NT and MT are better alternatives to CT for the production of lentil.

Sweet Sorghum Canopy Development in Relation to Radiation and Water Use

The present work deals with sweet sorghum canopy development in relation to the radiation capture and water demand. Two experimental sites and four cultivation periods with sweet sorghum (var. Keller and var. MN1500) were used in a plain of Central Greece. The water consumption by the crops, the aerial biomass production, the Leaf Area Index (LAI), as well as the radiation interception under various irrigation rates were monitored and analyzed. Key findings of the work include: (a) canopy penetration of Photosynthetic Active Radiation (PAR) is 10 times less than the global solar radiation, indicating that practically all PAR is intercepted by the leafage; (b) LAI values higher than 6.0 lead to no extra PAR capture and non-significantly higher biomass production; (c) rapid canopy development by rational use of water and fertilizer would attain capture and use of radiation at its maximum availability; (d) for the well watered plots, the Radiation Use Efficiency ranged from 2.8 to 3.63 g dry matter/MJ intercepted and the Water Use Efficiency (WUE) from 43 to 56.5 kg ha−1 mm−1, whereas the corresponding actual cumulative evapotranspiration ranged from 601 to 662 mm. In addition, the crop coefficient Kc values for the various cultivation stages of sorghum were evaluated.

Binding of Cu, Co, and Cs to fluorescent components of natural organic matter (NOM) from three contrasting sites.

Aqueous natural organic matter (NOM) contains different types of functional groups (carboxylic, phenolic, sulfidic, etc.), and hence could change the speciation of metals in environmental systems. This work is a proof-of-concept study on the interaction of three metals (Cu, Co, and Cs) with NOM using fluorescence spectroscopy. The specific aim was to determine the conditional stability constants for these three metals with NOM optical components, obtained from the quenching of fluorescence signals. Three contrasting water types were sampled in Northern Ontario: a pristine source (Cross Rd.), an urban-impacted source (Junction Creek), and an industrially impacted creek (Copper Cliff creek). In this investigation, Cu2+ was used as a benchmark, whereas Co2+ and Cs+ analyses were novel applications of this technique. Humic-like (H-like; terrestrial and microbial), fulvic-like (F-like), and protein-like (P-like) fluorescence components were found in various proportions at the three sampling sites. For these samples, the fluorescence signals of the H-, F-, and P-like components were quenched upon additions of Cu2+. The computed conditional stability constants (as log Kc) ranged from 4.46 to 6.06. In contrast, Kc values with Co2+ were measurable only for the two H-like components of the pristine sample (log Kc 3.02-4.05). Cesium (Cs+) induced quenching only for the P-like component at the industrial-impacted site (log Kc 4.82-5.03). While this study corroborates earlier reports that Cu2+-NOM interactions can be measured by fluorescence, we are showing for the first time a direct chemical interaction of Co2+ and Cs+ with specific NOM components, as reported by fluorescence quenching.

Evapotranspiration and water balance in a hot pepper (Capsicum frutescens L.) field during a dry season in the tropics

Evapotranspiration and water balance in a hot pepper (Capsicum frutescens L.) field during the 2nd dry season were analyzed in this study. Actual evapotranspiration (ET) was estimated by Bowen Ratio Energy Budget (BREB) method, potential evaporation (EP) was calculated by Penman method, and irrigation volume of water was measured manually. Meteorological instruments were installed in the experimental field during hot pepper cultivation. Leaf area index increased during the growing stages where the highest LAI of 1.65 in the generative stage. The daily average of ET was 1.94 and EP was 6.71 mm resulting in low Kc. The Kc values were significantly different between stage to stage under T-test analysis (α = 0.05). Moreover, Kc in every stage could be related to soil water content (SWC) in logarithmic function. Totally, ET during hot pepper cultivation was 179.19 mm, while rainfall was 180.0 mm and irrigation water was 27.42 mm. However, there was a water shortages during vegetative and generative stages. This study suggested that consumptive water of hot pepper was complimented by soil and groundwater under the condition of water shortages in the vegetative and generative stages during the 2nd dry season.

A theoretical investigation of the influence of the second critical micelle concentration on the solubilization capacity of surfactant micelles

The solubilization of hydrophobic components by surfactants that form microemulsion droplets has been investigated from a theoretical point of view. By means of combining thermodynamics of self-assembly to form small systems with bending elasticity theory, we have been able to demonstrate a strong correlation between the second critical micelle concentration (CMC2) of surfactant micelles and their solubilization capacity (σ). The correlation may be rationalized as a consequence of all three bending elasticity constants spontaneous curvature (H0), bending rigidity (kc) and saddle-splay constant (k¯c) showing similar trends with respect to the two quantities, i.e. σ increases and CMC2 decreases with decreasing values of kcH0 and increasing values of kc and k¯c, respectively. As a result, we demonstrate that the solubilization capacity is predicted to always be higher for a gemini surfactant with CMC2 = 11 mM as compared with a gemini surfactant with CMC2 = 18 mM. The predicted correlation between solubilization capacity and CMC2 agrees with experimental observations showing that surfactants forming larger micelles in general have better solubilization capacity than surfactants forming smaller micelles. The theory also demonstrates, in agreement with experiments, that σ is raised in the entire range of surfactant concentrations, below as well as above CMC2, regardless of micelle size. Consequently, our theory predicts that small micelles formed below CMC2 increase in size, whereas large rodlike or wormlike micelles formed above CMC2 decrease in size, as a hydrophobic solubilizate is added to a micellar solution.

STORM "GREEDY WATER" PALM OIL BASED ON ACADEMIC PERSPECTIVE

The tendentious issue of deforestation, biodiversity, "water greedy" attack ganoderma and carbon emissions continue to heat up in this decade has cornered palm plantations in Indonesia for allegedly either from outside or from inside the country becomes the base of why. To clarify these issues then this article aims to analyze the impact of oil palm plantations in terms of the water balance of plant oil palm. Water use in the oil palm plantations on average 92.05 mm/month or equivalent to 1104.5 mm/year over lamtoro stands is 3,000 mm/year, acacia 2,400 mm/year, sengon of 2,300 mm/year, amounting tea 900 mm/year, rubber amounted to 1,300 mm/year, bamboo amounted to 3,000 mm/year and teak amounted to 1,300 mm/year. The coefficient of oil palm crop of 0.93. The percentage amount of rainfall used palm oil amounted to only 39.60% of the annual rainfall. Percentage of evapotranspiration value is smaller than the value of evapotranspiration pine percentage of 64.5%, A. mangium 68.8%, amounting to 55.1% of ferns and eucalyptus (E.alba) amounted to 52.4%. Meanwhile, rubber plant has a value of 1 kc, other crops such as rice, during the period of growth has kc values between 1.05 to 1.2. Soil water content (KAT) which indicates the storage capacity of the root zone of oil lower than the root zone rubber (Rusmayadi, 2011). This is due to the oil more roots growing in the topsoil to a depth of ± 1 meter and as you go down the less. Rooting most densely contained at a depth of 25 cm. Therefore the ability of smaller savings in oil palm plantations compared to rubber, then the excess water will be removed or overflowed (Ro) is not taken ("greedy water") by palm trees. Palm oil as a commodity to be seen objectively with regard to the nature of biological (plant roots), physiological (crop coefficient), and environmental (water storage capacity). This is to straighten out the problems that it is not water but greedy oil plantation management who do not pay attention to aspects of water conservation.

Evapotranspiration Partition and Crop Coefficients of Tifton 85 Bermudagrass as Affected by the Frequency of Cuttings. Application of the FAO56 Dual Kc Model

This study aims to model the impacts of the frequency of cuttings of Tifton 85 bermudagrass on the dynamics of evapotranspiration (ETc) and to derive crop coefficients appropriate for grass water management. Two seasons of experimentation were used with four different cutting treatments which provided field data for calibration and validation of the soil water balance model SIMDualKc for all treatments. Cuttings were performed after the cumulative growth degree days (CGDD) attained 124 °C, 248 °C and 372 °C, thus from short to very long intervals between cuttings. SIMDualKc adopts the Food and Agriculture Organization (FAO) dual Kc approach for partitioning ET into crop transpiration and soil evaporation, thus providing for an assessment of their dynamics. All treatments were irrigated to avoid water stress. Grass ETc was modelled adopting a Kcb curve to describe the ET variation for each cutting cycle, that is, using the FAO Kc curve that consists of a series of Kcb curves relative to each cutting cycle. Each individual Kcb curve consisted of three segments constructed when knowing the Kcb values at the initial, at the end of rapid growth, and at cutting, respectively Kcb ini, Kcb gro and Kcb cut. These Kcb values were first estimated using the equation relating Kcb to the density coefficient (Kd), which is computed from the fraction of ground cover (fc) and canopy height (h) at the same dates. The goodness of fit indicators relative to the calibration and validation of the SIMDualKc model were rather good, with the normalized root mean square error (RMSE) ranging from 4.0% to 6.7% of the mean available soil water. As an example, the standard Kcb values obtained after model calibration relative to the cuttings treatment with CGDD of 248 °C are: Kcb ini = 0.86, Kcb gro = 0.91 and Kcb cut = 0.96. Kcb values were smaller when the frequency of cuts was larger because h and fc were smaller, and were larger for reduced cuttings frequency since h and fc were then larger. Because the soil was wet most of the time, the soil evaporation Ke varied little but its value was small due to the combined effects of the fraction of crop cover and plant litter covering the soil. The values of Kc = Kcb+Ke also varied little due to the influence of Ke and the Kc curve obtained a form different from the Kcb curves, and a single Kc value was adopted for each cutting frequency, e.g., Kc = 0.99 for the treatment with CGDD of 248 °C. Results of the soil water balance have shown that, during the experimental periods, likely due to the effects of the El Niño Southern Oscillation (ENSO), runoff and deep percolation exceeded ETc. Moreover, the soil evaporation ratio was small: 14% in case of frequent cuttings and less for more spaced cuttings, thus with a transpiration ratio close to 90%, which indicates a very high beneficial consumptive water use, mainly when cuttings are not very frequent.

Crop Evapotranspiration, Irrigation Water Requirement and Water Productivity of Maize from Meteorological Data under Semiarid Climate

Under the semiarid climate of the Southwest United States, accurate estimation of crop water use is important for water management and planning under conservation agriculture. The objectives of this study were to estimate maize water use and water productivity in the Four Corners region of New Mexico. Maize was grown under full irrigation during the 2011, 2012, 2013, 2014 and 2017 seasons at the Agricultural Science Center at Farmington (NM). Seasonal amounts of applied irrigation varied from 576.6 to 1051.6 mm and averaged 837.7 mm and the total water supply varied from 693.4 to 1140.5 mm. Maize actual evapotranspiration was estimated using locally developed crop coefficient curve and the tabulated United Nations Food and Agriculture Organization (FAO) crop coefficients, and from this maize water productivity was determined. Maize actual daily evapotranspiration (ETa) varied from 0.23 to 10.2 mm and the seasonal ETa varied with year and ranged from 634.2 to 697.7 mm averaging 665.3 mm by the local Kc curve, from 687.3 to 739.3 mm averaging 717.8 mm by the non-adjusted FAO Kc values, and from 715.8 to 779.6 mm averaging 754.9 mm with the FAO adjusted Kc values. Maize irrigation requirements varied from 758.4 to 848.3 mm and averaged 800.2 mm using the local developed Kc and varied from 835.5 to 935.6 mm and averaged 912.2 mm using FAO Kc. The net irrigation requirement varied from 606.8 to 678.6 using local Kc curve, and from 682.78 to 748.5 mm when adopting the FAO Kc values. Average irrigation requirement was 641 mm under the local Kc option and 730 mm under FAO Kc values option. Maize crop water use efficiency (CWUE) ranged from 1.3 to 1.9 kg/m3 and averaged 1.53 kg/m3, evapotranspiration water use efficiency (ETWUE) values were higher than CWUE and varied from 2.0 to 2.3 kg/m3, averaging 2.1 kg/m3. Maize irrigation water use efficiency (IWUE) was varied with years and averaged 1.74 kg/m3. There were strong relationships between maize CWUE and maize seasonal irrigation amounts of IWUE and the seasonal irrigation amounts with R2 of 0.97 and 0.92, respectively. Maize CWUE increased linearly with maize IWUE with a coefficient of determination R2 of 0.99, while IWUE showed a strong quadratic relationship with ETWUE (R2 = 0.94). The results of this study can be used as a guideline for maize water management under the semiarid conditions in northwestern New Mexico and other locations with similar climate and management conditions. Irrigation requirements for maize should be adjusted to the local meteorological conditions for optimizing maize irrigation requirement and improving maize water productivity.

Solid State Analysis and In-Vitro Dissolution Behavior of MeloxicamHydroxy Propyl Beta Cyclodextrin-Ethanolamines Ternary Complexes

The present study was aimed to improve the aqueous solubility and dissolution rate of an NSAID meloxicam by hydroxy propyl β-cyclodextrin ternary complexes employing ethanolamines. Initially, meloxicam (MLX) binary complexes with Hydroxy propyl β-Cyclodextrin (HPβCD) were formulated by kneading and solvent evaporation techniques which was followed by ternary complex preparation of selected MLX-HPβCD binary complex employing different ethanolamines by solvent evaporation method. The solvent evaporationwas used in preparing ternary complexes of MLX, because it was proved to be the best method comparatively in yielding promising binary complexes of meloxicam in the initial stage of this study. MLX formed 1:1 M stoichiometric binary and ternary inclusion complexes as demonstrated by the AL-type of phase solubility curve. An increment in the stability constant value (Kc) of MLX- HPβCD complex in the presence of ethanolamines conceded higher complexation efficiency. Solid state analysis (FTIR, TGA, and SEM studies) of ternary compounds evidenced the perfect inclusion complex formation. Ternary complexes showed significant improvement in drug dissolution compared topure MLX and MLX-HPβCD binary complex. The ternary complex containing 1:1:1 molar ratio of MLX-HPβCD-DEA exhibited 86.91% drug dissolution in 1 hour, which was significantly high in relation to ternary complexes containing mono and tri ethanolamines, and it was found to follow imperatively matrix order release mechanism. On aging studied complexes showed no significant change in physical appearance, drug content and drug dissolution attributes, which clearly shows high in-vitro stability of the complexes.

Growth-stage-specific crop coefficient and consumptive use of Capsicum chinense using hydraulic weighing lysimeter

This research was conducted to determine growth stage-specific crop coefficient (Kc) and Consumptive Use (CU), for Capsicum chinense (Ata rodo) grown under irrigation in Omu-Aran, North central Nigeria. Daily CU and growth stage-specific crop coefficient Kc for Capsicum chinense was measured using a developed and calibrated hydraulic weighing lysimeter over 2 consecutive dry seasons (2015/16 and 2016/17). The values of CU and growth stage-specific Kc obtained were compared to that estimated using CROPWAT 8.0 and with existing Food and Agricultural Organization (FAO) Kc values for bell pepper. The Kc values determined over the growing seasons varied from 0.32 to 0.7, 1.02 to 1.45 and 0.76 to 0.9 representing Kc initial, Kc mid-season and Kc late season (Kcini, Kcmid and Kcend), respectively. These Kc varied significantly (P < 0.05) from FAO established Kc values. The observed Kc was validated using relevant statistical methods. The seasonal CU of Capsicum chinense was 580.01 ± 54 mm, while the reference evapotranspiration increased from 3.26 mm day−1 in October to 4.19 mm day−1 in February. The crop factor increased from 0.7 in October to attain its peak of 1.45 in January, but decreased to 0.9 during crop senescence in February. Likewise, the daily crop water need was 2.28 mm day−1 in October but reached its peak of 5.82 mm day−1 in January and thereafter decreased to 3.77 mm day−1 in February. Mean monthly water need of Capsicum chinense pepper was 68.36 mm month−1 in October. The water need of crop rose to its peak of 166.32 mm month−1 in December, and thereafter declined to 113.13 mm month−1 in February It is inferred that the application of growth stage-specific Kc will assist in irrigation management and would serve as useful guide for precise water applications for areas around Omu-Aran as it differs from region to region.

Measuring Crop Water Requirement and Crop Coefficient for Blue Panic Crop Under Arid Conditions Using Draining Lysimeters

AbstractPrevious research results of Blue Panic (Panicum antidotale Retz) in arid conditions under different irrigation methods proved an increase in forage yield and water productivity (WP) under full and water stress conditions. However, a thorough search in the literature revealed that its water requirement has not yet been determined. Therefore the objective of this research was to measure evapotranspiration (ETc) and crop coefficient (Kc) for a Blue Panic crop under arid conditions. Four draining lysimeters constructed in Jeddah (21° 48′ 3′′ N, 39° 43′ 25′′ E) were used to measure its ETc and Kc under a plentiful water supply. Results revealed that ETc varied from 141 mm in the first harvest to 292 mm in the sixth, with an average of 225 mm per harvest. The Kc value was different from one harvest to another. The average Kc over all harvests was 0.7, 1.2, 1.3 and 1.0 for the initial, development, midseason and late stages, respectively. Average fresh and dry forage yields per harvest were 30.5 and 12.6 t ha−1, respectively. Average WP was 55 kg ha−1 mm−1. The predicted ETc based on the measured crop coefficient value and ET0 show a good fit between measured and calculated ETc. Copyright © 2018 John Wiley &amp; Sons, Ltd.

Effect of substrate bias voltage on defect generation and their influence on corrosion and tribological properties of HIPIMS deposited CrN/NbN coatings

Substrate bias voltage is one of the most influential deposition parameter for physical vapour deposition processes as it can directly control the adatom mobility during coating growth. It influences the hardness, roughness as well as the microstructure of the coatings. Thus, bias voltage could also affect the defect formation during the coating deposition. High Power Impulse Magnetron Sputtering (HIPIMS) has been proven useful in producing void free and arc droplet free dense coatings. However, such coatings can still suffer from some defects associated with external factors (independent of deposition technique), such as substrate irregularities and the flakes coming from the chamber components. In order to study the effects of bias voltage (Ub) on the defect formation during HIPIMS process, four sets of CrN/NbN coatings were deposited at Ub = −40 V, −65 V, −100 V and −150 V. Microscopic studies revealed that with the increase in bias voltage the coatings morphology was altered and the percentage of surface area covered by optically visible defects was increased from 3.13% to 4.30%. The defects on the coatings deposited at Ub = −100 V and −150 V led to preferential corrosive attack resulting in a sharp increase in corrosion current density during Potentiodynamic polarisation experiments. Room temperature pin-on-disc tribological tests exhibited the influence of defects on the wear behaviour; however, the coefficient of friction (μ) values were mainly influenced by the nature of the oxides formed during the tests. Coating microstructure and bilayer thickness, along with the coating defects determined the coefficient of wear (Kc) values. This study revealed that the coating deposited at Ub = −65 V had the highest wear resistance (Kc = 2.68 × 10−15 m3 N−1 m−1) and the lowest friction (μ = 0.48).

Evapotranspiration and crop coefficient for Typha latifolia in constructed wetlands

Abstract The purpose of this work was to estimate the crop evapotranspiration (ETc) and to determine the crop coefficient (Kc) of Typha latifolia in constructed wetlands. The experiment used two horizontal subsurface flow constructed wetlands (HFCWs) cultivated with T. latifolia. Each HFCW received 50 L of secondary effluent daily, resulting in 3.2 days of nominal hydraulic retention time (disregarding effects of evapotranspiration and precipitation). In order to determine the ETc, water mass balance of the HFCWs was performed. In this analysis, ETc was considered equal to the difference between the inflow (secondary effluent + precipitation) and the outflow. The Kc was calculated using ETc and reference evapotranspiration (ETo) data (Kc = ETc/ETo). The results showed that 7-day average ETc varied dramatically within the range of 4.9–20.0 mm day−1, with a monthly average of 9.85 mm day−1. The mean monthly values of Kc varied from 2.03 to 3.68 (mean: 2.74). ETc is very important with respect to the HFCW water balance because it decreases effluent outflow considerably. Therefore, the findings of this work indicate that water losses caused by evapotranspiration should be considered when designing constructed wetlands.

Performance of methods for estimation of table beet water requirement in Alagoas

ABSTRACT Optimization of water use in agriculture is fundamental, particularly in regions where water scarcity is intense, requiring the adoption of technologies that promote increased irrigation efficiency. The objective of this study was to evaluate evapotranspiration models and to estimate the crop coefficients of beet grown in a drainage lysimeter in the Agreste region of Alagoas. The experiment was conducted at the Campus of the Federal University of Alagoas - UFAL, in the municipality of Arapiraca, AL, between March and April 2014. Crop evapotranspiration (ETc) was estimated in drainage lysimeters and reference evapotranspiration (ETo) by Penman-Monteith-FAO 56 and Hargreaves-Samani methods. The Hargreaves-Samani method presented a good performance index for ETo estimation compared with the Penman-Monteith-FAO method, indicating that it is adequate for the study area. Beet ETc showed a cumulative demand of 202.11 mm for a cumulative reference evapotranspiration of 152.00 mm. Kc values determined using the Penman-Monteith-FAO 56 and Hargreaves-Samani methods were overestimated, in comparison to the Kc values of the FAO-56 standard method. With the obtained results, it is possible to correct the equations of the methods for the region, allowing for adequate irrigation management.

Host-guest interaction study of Efavirenz with hydroxypropyl‑β‑cyclodextrin and l‑arginine by computational simulation studies: Preparation and characterization of supramolecular complexes

The present study demonstrates the solubility and dissolution enhancement of Efavirenz (EFV) through preparation of supramolecular inclusion complexes. The supramolecular system comprising of EFV, hydroxypropyl‑β‑cyclodextrin (HP-β-CD) and l‑Arginine was prepared by physical mixing and spray drying methods. The complexes were characterized by powder X-ray diffraction, differential scanning calorimetry, 1H NMR spectroscopy and FT-IR spectroscopy to study alteration in crystallinity of drug. Intrinsic stability constant values (Kc) and complexation efficiency (CE) of HP-β-CD was substantially enhanced due to addition of l‑Arginine. Improved solubility and dissolution was evidenced in the supramolecular system than binary system of EFV and HP-β-CD. Computational modelling and molecular dynamics study revealed that l‑Arginine increased the stability of the complex by bridging between the EFV and the HP-β-CD. It also confirmed that l‑Arginine was positioned on the outer surface of complex and improved polar surface of inclusion complex resulting in increased solubility of the complex. Thus, supramolecular inclusion complexes of EFV with HP-β-CD and l‑Arginine could contribute as an innovative outcome in formulation development of EFV through solubility and dissolution enhancement.

UHPC Reinforced by Hybrid Fibers and its Resistance to High Temperature Loading

As part of the development and research of UHPC materials, the broad professional public deals mainly with the determination of the basic physical and mechanical parameters, in particular the compressive strength, that is considered as a determining parameter for these cement-based composites. The strength of the composite material is determined under normal laboratory conditions. Fine cement-based composite materials are increasingly used not only for academic purposes but also for practical applications. Therefore, it is necessary to focus on other parameters that determine these new Hi-Tech materials. The mechanical properties of materials at elevated temperatures belong to an area that is not properly defined not only in the Czech Republic but also in the world. Research into the behavior of these composite materials and their thermal loading can provide additional information and basics to expand these building materials such as France, USA, Japan and other countries around the world. In the Czech standards applicable to the design of concrete structures subjected to thermal stress, the values of the reduction coefficient Kc, θ are used only for commonly used dense concrete and also for expanded concrete. It is clear that these values cannot be used for fine-grained composite materials with cement binder reinforced hybrid reinforcements. The aim of the paper is to determine and describe the behavior of these materials in the temperature range of 20 ° C to 1000 ° C for two test modes that affect residual strength and high temperature strength.

Short-term daily forecasting of crop evapotranspiration of rice using public weather forecasts

Accurate forecasts of daily crop evapotranspiration (ETc) are essential for real-time irrigation management and water resource allocation. This paper presents a method for the short-term forecasting of ETc using a single-crop coefficient approach and public weather forecasts. Temperature forecasts with a 7-day lead time in 2013–2015 were retrieved and entered into a calibrated Hargreaves–Samani model to compute daily reference evapotranspiration (ET0) forecasts, while crop coefficient (Kc) empirical values were estimated from both observed ETc value and calculated ET0 values using the Penman–Monteith equation for the period of 2010–2012. Daily ETc forecasts of irrigated double-cropping rice were determined for three growing seasons during the period of 2013–2015 and were compared with ETc values measured by the weighing lysimeters at the Jiangxi experimental irrigation station in southeastern China. During the early rice season, the average mean absolute error (MAE) and root-mean-square-error (RMSE) values of ETc forecasts ranged from 0.95 to 1.06 mm day−1 and from 1.18 to 1.31 mm day−1, respectively, and the average correlation coefficient (R) ranged from 0.39 to 0.54; for late rice, the average MAE and RMSE values ranged from 1.01 to 1.09 mm day−1 and from 1.32 to 1.40 mm day−1, respectively, and the average R value ranged from 0.54 to 0.58. There could be three factors responsible for errors in ETc forecasts, including temperature forecast errors, Kc value errors and neglected meteorological variables in the HS model, including wind speed and relative humidity. In addition, ETc was more sensitive to changes in temperature than Kc. The overall results indicated that it is appropriate to forecast ETc with the proposed model for real-time irrigation management and water resource allocation.