Solving Some Kinds of Third Order Partial Differential Equations of Degree Four with Three Independent Variables

In this paper, we find a solution for some kinds of nonlinear third order partial differential equations of homogeneous degree with three independent variables

Synthesis, characterization and alteration of phenoxyherbicides-based nanocomposites resulted from mixing two herbicides with Zinc Oxide-layered hydroxide

The present study is a part of an investigation of the effect of ZnO supported for two mixed agent (4-chlorophenoxy acetate (4CPA) as plant growth regulator  and 2,4-dichlorophenoxyacetates (2,4D) as herbicide ) synthesis via the ionic exchange with zinc Oxide layered hydroxide(LH). The product of this process led to the formation of nanocomposites assigned as (Zinc-NCPA). This byproduct represented a mixture of two newly phases was confirmed by X-Ray Diffraction (XRD) which were visualized at 25.6 and 19.14 Å, respectively. These findings were approved by images produced by Scanning Electron Microscopy (SEM). The maximum accumulated release of 4CPA and 2,4D was found to depend on the concentrations of the incoming ions. The accumulated rate of 4CPA was found to be less than 24D. The release behavior of the phenoxy acetate into the aqueous solution was controlled mainly by pseudo-second-order which was followed by pseudo-first order rate expression. This study concluded that Zinc Oxide layered hydroxide (ZLH) have the capability to act as a carrier for mixed active agents of two compounds with two different roles. aCorresponding author E.mail:[email protected] Keywords: Controlled release, chlorophenoxy acetates, Zinc Oxide layered hydroxide, organic-inorganic hybrid nanocomposite

ANTI-PROLIFERATIVE ACTIVITY OF ZIZYPHUS SPINA CHRISTI LEAVES METHANOL EXTRACT AGAINST RHABDOMYOSARCOMA (RD) CELL LINE

Objective: The aim of this study was to investigate the capability of Zizyphus spina christi methanol extract to inhibit cancer cell line proliferation.Methods: The leaves of Zizyphus spina christi were extracted by cold maceration method. The anti-proliferative activity of the methanol extract against rhabdomyosarcoma (RD) cell line was tested by 3-(4, 5 Dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The phytochemical constituents were identified by gas chromatography-mass spectrometry (GC-MS) analysis. The antioxidant activity was assessed by measuring free radical scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Results: The percentage extraction yield for leaves with methanol was 20.64%. The methanol extract showed dose dependent inhibition of RD cell line, the IC50 was 154.44 µg/ml. GC-MS showed the presence of flavonoid fraction and other compounds with antioxidant activity. The methanol extract demonstrated DPPH scavenging activity with IC50 of 33.91 mg/ml.Conclusion: Methanol extract showed potential anti-proliferative activity against RD cell line, which could be due to its antioxidant activity

EXPERIMENTAL STUDY ON SOFT CLAY SOILS TO IMPROVE SETTLEMENT AND ULTIMATE STRESS USING THERMOS MECHANICAL LOADS

The electrothermal method was used to treat soft clay soil under load in this study. The experiment model was adopted to study settlement behavior. The effect of heat on settlement and maximum stress, of soft clay soils, were studied. The variables studied are the distance between the heaters, the heating time, and the temperature of the source. A model was used with dimensions (60 * 40 * 60) cm, and heaters were used in each model, and the power of each heater was 925 watts, and the number of models used was 37 models. The first examination was without heat treatment, and settlement was measured in it directly. As for the rest of the tests, heat treatment was used in it, and the tests were divided into two phases. The first stage is the heat treatment stage, and the second stage is the stage of placing the mechanical load on the soil. The mechanical load is weights placed on the soil through the footing. The tests were divided according to the research structure into three cases and according to the distance between the two heaters (20,30,40) cm. In each case, the tests are conducted according to the heating time, where the heating time was used (4,8,12) consecutive hours, and each time 4 tests were used at different temperatures (200,300,400,500) degrees Celsius. An improvement value of 99.8% in the settlement was obtained when the source temperature was 500°C, with a heating time of 12 hours, and the distance between the heaters was 20 cm. An improvement in maximum stress of 425% was obtained when the source temperature was 500 °C, the heating time was 12 h, and the distance between the heaters was 20 cm. The conclusions of the study are that the settlement decreases with increasing temperature and the ultimate stress increases with increasing temperature

Inhibition Evaluation of 5-(4-(1H-pyrrol-1-yl)phenyl)-2-mercapto-1,3,4-oxadiazole for the Corrosion of Mild Steel in an Acidic Environment: Thermodynamic and DFT Aspects

In this investigation, an oxadiazole namely 5-(4-(1H-pyrrol-1-yl)phenyl)-2-mercapto-1,3,4-oxadiazole (PMO), was synthesized and explored as an inhibitor against the corrosion  of mild steel in 1.0 M hydrochloric acid environment at various solution temperature 303-333 K. gravimetric, and microscopic techniques, namely, weight loss (WL), and scanning electron microscopy (SEM), have been used to evaluate the inhibitive performance of the tested PMO. The results of the WL method displayed that the inhibition efficiency (%IE) was found to increase with the inhibitor concentration, while it reduced with increasing temperature. Furthermore, the WL results reveal that PMO inhibits corrosion display an IE of 95% at the highest concentration of 0.005 M. The SEM images of the mild steel surface coupon after adding PMO revealed a wide coverage of PMO molecules on the mild steel surface. Hence, the high inhibiting efficiency acquired by the tested inhibitor was explained by the strong adsorption of PMO molecules on the surface of mild steel. A protective layer has been constructed and it separating the mild steel surface from the hydrochloric acid solution, and such adsorption was found to obey Langmuir adsorption isotherm. Moreover, the thermodynamic parameters suggested that the adsorption nature of PMO molecules on the coupon surface was chemo-physisorption. Quantum chemical calculations were conducted by density functional theory (DFT) which help correlate the methodological findings with the theoretical investigations. The mechanisms of PMO molecules as corrosion inhibitor for mild steel surface in the corrosive environment was also discussed

Using scenario modelling for adapting to urbanization and water scarcity: towards a sustainable city in semi-arid areas

Sustainable development on a global scale has been hindered by urbanization and water scarcity, but the greatest threat is from decision-makers ignoring these challenges, particularly in developing countries. In addition, urbanization is spreading at an alarming rate across the globe, affecting the environment and society in profound ways. This study reviews previous studies that examined future scenarios of urban areas under the challenges of rapid population growth, urban sprawl and water scarcity, in order to improve supported decision-making (SDM). Scholars expected that the rapid development of the urbanization scenario would cause resource sustainability to continually be threatened as a result of excessive use of natural resources. In contrast, a sustainable development scenario is an ambitious plan that relies on optimal land use, which views land as a limited and non-renewable resource. In consequence, estimating these threats together could be crucial for planning sustainable strategies for the long term. In light of this review, the SDM tool could be improved by combining the cellular automata model, water evolution and planning model coupled with geographic information systems, remote sensing and criteria analytic hierarchical process modelling. Urban planners could optimize, simulate and visualize the dynamic processes of land-use change and urban water, using them to overcome critical conditions

The Influence of Microstructure on the Corrosion Rate of Carbon Steels

This paper presents the influence of carbon steel microstructure on the corrosion rates. Four types of microstructures have obtained by quenching and tempering and iso-thermal annealing. These microstructures are: banded ferrite/pearlite microstructure, fine ferrite/pearlite microstructure, coarse ferrite/pearlite microstructure and tempered martensite microstructure. General corrosion and localized corrosion (penetration rates) were determined via mass loss and optical microscopy. The different microstructures of steels investigated in this paper revealed corrosion rate variations of 0.8– 3.2 mm y-1 and 3.3–6.4 - mm y-1 for the general and localized forms, respectively. The corrosion stability of the various microstructures may arise from variations of phases within the steel. A banded ferrite/pearlite microstructures have worse general corrosion properties, while tempered martensite worse microstructures have localized pitting corrosion properties. Coarse ferrite/pearlite microstructures have better localized pitting corrosion resistances compared to others investigated microstructures This paper has demonstrated that, microstructure is an important consideration when selecting carbon steel for an industrial corrosion resistance application

Predicción de las propiedades mecánicas de un hormigón utilizando técnicas inteligentes para reducir las emisiones de CO2

The contribution to global CO2 emissions from concrete production is increasing. In this paper, the effect of concrete mix constituents on the properties of concrete and CO2 emissions was investigated. The tested materials used 47 mixtures, consisting of ordinary Portland cement (OPC) type I, coarse aggregate, river sand and chemical admixtures. Response surface methodology (RSM) and particle swarm optimisation (PSO) algorithms were employed to evaluate the mix constituents at different levels simultaneously. Quadratic and line models were produced to fit the experimental results. Based on these models, the concrete mixture necessary to achieve optimum engineering properties was found using RSM and PSO. The resulting mixture required to obtain the desired mechanical properties for concrete was 1.10-2.00 fine aggregate/cement, 1.90-2.90 coarse aggregate/cement, 0.30-0.4 water/cement, and 0.01-0.013 chemical admixtures/cement. Both methods had over 94% accuracy, compared to the experimental results. Finally, by employing RSM and PSO methods, the number of experimental mixtures tested could be reduced, saving time and money, as well as decreasing CO2 emissions.La contribución a las emisiones globales de CO2 debidas a la producción de hormigón está aumentando. En este trabajo, se investigó el efecto de los componentes de la mezcla de hormigón en las propiedades del mismo y las emisiones de CO2. Los materiales estudiados fueron 47 mezclas, que consistieron en cemento Portland ordinario (OPC) tipo I, árido grueso, arena de río y aditivos químicos. Se utilizaron algoritmos de metodología de respuesta de superficie (RSM) y optimización de nube de partículas (PSO) para evaluar los componentes de la mezcla a diferentes niveles simultáneamente. Se elaboraron modelos cuadráticos y lineales para ajustar los resultados experimentales. Basándose en estos modelos, utilizando RSM y PSO, la mezcla de hormigón logró propiedades óptimas de ingeniería. La mezcla resultante requerida para obtener las propiedades mecánicas deseadas para el hormigón fue de 1.10-2.00 árido fino / cemento, 1.90-2.90 árido grueso / cemento, 0.30-0.4 agua / cemento y 0.01-0.013 aditivos químicos / cemento. Ambos métodos tuvieron más del 94% de precisión, en comparación con los resultados experimentales. Finalmente, al emplear los métodos RSM y PSO, el número de mezclas experimentales probadas podría reducirse, ahorrando tiempo y dinero, así como disminuyendo las emisiones de CO2

Strut-and-tie model for externally bonded CFRP-strengthened reinforced concrete deep beams based on particle swarm optimization algorithm: CFRP debonding and rupture

A substantial number of studies have been done on the shear strengthening of reinforced concrete (RC) beams with externally bonded carbon fibre reinforced polymers (CFRP). However, in reference to shear, there are still many questions concerning the complexity and nature of the failure mechanism of RC structures strengthened in shear using CFRP. This is particularly true for concrete deep beams because of the nonlinearity of the stress distribution. This study had the goal of developing a simple procedure or model for estimating the shear capacity of RC deep beams strengthened with CFRP sheets. The proposed model was designed based on an extension of the strut-and-tie model (STM) used for un-strengthened RC deep beams to the case of those shear strengthened with CFRP sheets. The technique avoided the traditional trial-and-error procedure for obtaining the unknown coefficients of the proposed model. It utilized a particle swarm optimization algorithm (PSO), in which the optimal STM of an CFRP-strengthened RC beam was determined by searching for the optimum unknown coefficients (stress distribution and concrete tensile stress reduction factors). This model considered the effects of two CFRP failure modes, namely the CFRP debonding and CFRP tensile rupture failure modes. The proposed model was validated using experimental data collected from the current study and existing literature. The hybrid PSO-STM predicted a mean value = 1.1, SD = 0.098, and coefficient of variation (CoV) = 8.9%. These results showed that the proposed model has high accuracy and consistency and it can accurately estimate the ultimate shear strength of CFRP-strengthened RC deep beams