Sc Value Research Articles

Research on Detection Technology of Abnormal Data in College Physical Education Network Teaching Test Results

In recent years, with the rapid development of big data technology, more and more data are continuously generated with the summary of university systems. Therefore, how to use these educational data to provide more scientific decision-making information for university information builders is very important. This research collected various educational data through the network teaching system and campus information system. After that, the collected data was used to analyze the students' online behavior and to excavate valuable behavioral characteristics. In addition, the experiment also proposed indicators to describe students' behavior, such as network course behavior, network viscosity and life regularity, to provide the basis for the subsequent abnormal performance prediction model. Finally, the experiment used DBSCAN algorithm based on distance optimization for clustering analysis, and constructed a NA model based on multiple classifiers. The research results showed that when, the SC value was 0.711, which was the optimal solution of D-DBSCAN algorithm. At this time, the corresponding number of clusters was 4. When N=2, that was, the base classifier of NA model is composed of C4.5 model and SVM model, the prediction accuracy and time consumption are the most appropriate. The accuracy, recall and F1 values of NA model were 98.16\%, 97.26\% and 0.958 respectively, which was better than that of single model. To sum up, the NA model based on classifiers proposed in the study had higher accuracy and better model performance, can effectively reflect students' academic level, and could provide accurate abnormal performance data for college sports online teaching tests.

Photovoltaic properties of halide perovskites for solar cell application with efficiency greater than 18.

The opto-electronic properties and solar cell efficiency of halide perovskites A2LiInBr6 (A = Rb, Cs) are investigated using density functional theory (DFT) through WEIN2k and SCAPS-1D. The electronic characteristic of A2LiInBr6 (A = Rb, Cs) compounds reveal their direct bandgap semiconductor nature and are active in visible rang. The results indicate that substituting Cs with Rb causes a slight narrowing of the bandgap. According to the optical analysis, these compounds possess dynamic visible-range optical properties that make them ideal for application in opto-electronic devices and solar cells. The A2LiInBr6 (A = Rb, Cs) absorber layer is employed to simulate the solar cell efficiency of these lead free perovskite-based device. The optimized FTO/WS2/A2LiInBr6 (A = Rb, Cs)/Spiro-MeOTAD/Cu solar cells exhibit the best performance with WS2 as the ETL and Spiro-MeOTAD as the HTL having V oc value of 2.27 V and 1.85 V, J sc value is 11.35 and 11.44 mA cm-2, FF is 73.24% and 83.84%, PCE is 18.88% and 17.97%, R s is 9.94 and 4.88 Ω cm2 and R sh is 1.35 and 1.14 Ω cm2 respectively. As a result, this research paves the way for future experiments to create entirely inorganic perovskite photovoltaics, free of lead toxicity and exhibit improved photovoltaic ability.

Prediksi Sifat Mekanik Aluminium Berdasarkan Unsur Kimia Paduan Menggunakan Model Machine Learning

This study designs and compares optimal machine learning models for predicting the mechanical properties of alloyed aluminum with code 1050 (A91050) based on the percentage composition of chemical elements using the software RapidMiner with decision tree and Random Forest algorithms. The aim is to develop a data-driven predictive model with high accuracy to minimize the need for physical testing on aluminum with various compositional variations. The machine learning modeling in this study involves nine input variables, comprising chemical elements such as Al, Mg, Zn, Ti, Cu, Mn, Cr, Fe, Si, and two output or target variables, YS and TS (yield strength and tensile strength). Additionally, a Heatmap correlation is employed to observe the correlations between the chemical elements and the mechanical properties of the alloyed aluminum. The comparison of these algorithms reveals that Random Forest (RF) outperforms other algorithms in predicting YS with a Mean Absolute Error (MAE) of 7.157, Root Mean Square Error (RMSE) of 11.248, and a coefficient of determination (SC) of 0.977. On the other hand, Random Forest (RF) also exhibits better performance in predicting TS with an MAE of 29.296, RMSE of 42.382, and SC value of 0.443.

Groundwater monitoring and specific yield estimation using time-lapse electrical resistivity imaging and machine learning

This paper presents an alternative method for monitoring groundwater levels and estimating specific yields of an unconfined aquifer under different seasonal conditions. The approach employs the Time-Lapse Electrical Resistivity Imaging (TL-ERI) method and machine learning-based time series clustering. A TL-ERI survey was conducted at ten sites (WS01-WS10 sites) throughout the dry and wet seasons, with five-time measurements collected for each site, in the Taichung-Nantou Basin along the Wu River, Central Taiwan. The obtained resistivity raw data was inverted and converted into normalized water content values using Archie’s law, followed by applying the Van Genuchten (VG) model for the Soil Water Characteristic Curve to estimate the Groundwater Level (GWL), and estimated the theoretical specific yield (Sy) by computing the difference between the saturated and residual water contents of the fitted VG model. In addition, the specific yield capacity (Sc), representing the nature of the storage capacity in the aquifer, was also calculated. The results showed that this approach was able to estimate those hydrogeological parameters. The spatial distribution of the GWL reveals that during the dry-wet seasons from February to July, there was a high GWL that extended from southeast to northwest. Conversely, during the wet-dry seasons from July to October, the high GWL shrank, which can be attributed to recharge variations from rainfall events. The determined spatial distribution of Sy and Sc fall within the range of 0.03–0.24 and 0.14–0.25, respectively. To quantitatively establish areas of similar groundwater level changes along with the VG model parameter variations during the study period, a Time series Clustering analysis (TSC) was performed by utilizing Hierarchical Agglomerative Clustering (HAC). The findings suggest that the WS03 site is a promising area for further investigation due to its highest Sc value with a slight change in groundwater levels during the dry and wet seasons. This study brings an advanced development of the geoelectrical method to estimate regional hydrogeological parameters in an area with limited available groundwater observation wells, in different seasonal conditions for groundwater management purposes.

Chemical Composition and Biological Activities of Essential Oils of Four Asarum Species Growing in Vietnam

The essential oils (EOs) of the aerial parts of four Asarum species (A. geophilum, A. yentunensis, A. splendens and A. cordifolium) were isolated by steam distillation and analyzed by the GC/MS method. The A. cordifolium EO contains 33 constituents with the main component being elemicine (77.20%). The A. geophilum EO was contains 49 constituents with the main components being determined as 9-epi-(E)-caryophyllene (18.43%), eudesm-7(11)-en-4-ol (13.41%), β-caryophyllene (8.05%) and phytol (7.23%). The A. yentunensis EO contains 26 constituents with the main components being safrole (64.74%) and sesquicineole (15.34%). The EO of A. splendens contains 41 constituents with the main components being 9-epi-(E)-caryophyllene (15.76%), eudesm-7(11)-en-4-ol (14.21%), β-caryophyllene (9.52%) and trans-bicyclogermacrene (7.50%). For antimicrobial activity, the A. yentunensis EO exhibited the highest inhibition activity against Staphylococcus aureus and the A. cordifolium EO against Bacillus subtillis (MIC values of 100 μg/mL). For antioxidant activity, the A. geophilum EO showed the highest potential with an SC (%) value of 63.34 ± 1.0%, corresponding to an SC50 value of 28.57 µg/mL. For anti-inflammatory activity, the A. splendens EO exhibited the highest potential with an IC50 value of 21.68 µg/mL, corresponding to an inhibition rate of NO production of 69.58 ± 1.3% and the percentage of cell life was 81.85 ± 0.9%.

Experimental study about the effect of SiO2 nanoparticle in surfactant performance on IFT reduction and wettability alteration

Recently, serious attention to the high potential of nanotechnology in the enhanced oil recovery (EOR) processes have been attracted. In this study, the effects of addition of SiO2 nanoparticle into the aqueous solutions containing octyl phenol ethoxylate (Triton-x100), sodium lauryl sulfate (SLS), and octyl pyridinium chloride ([C8Pyr][Cl]) on the interfacial tension (IFT) reduction, wettability alteration of carbonate rock, and the spreading coefficient were investigated. EDX and FeSEM analysis were taken on the rock that indicate the dolomite nature of the rock sample. The equilibrium IFT and contact angle values of different cases were measured in two series (i.e. with and without SiO2 nanoparticles). It is found that the performance of SiO2 nanoparticle remarkably affected by surfactants type and their combination. SiO2 could not have a positive effect on the IFT reduction and wettability alteration and had an adverse effect on the performance of some surfactants. In more details, SiO2 nanoparticles was able to slightly improve the TiO2 surfactant performance by falling the IFT value from 2.8 to 1.5 mN/m, while it did not have a significant effect on the performance of Pyr surfactant by changing the IFT value from 14 to 13.3 mN/m. The performance order of IFT reduction and wettability alteration was completely different as the lowest IFT and contact angle values were observed for the SLS in the presence of SiO2 (IFT reduction from 0.36 to 0.1 mN/.m) and Tr in the absence of SiO2 (wettability change from 49º to 32.5º), respectively. However, SiO2 nanoparticles have a favorable effect on the spreading coefficient of SLS, Pyr, SLS+Pyr, and SW; among them, the best performance was observed for SLS with spreading coefficient (Sc) value of − 0.06 mN/m.

Redox Shuttle-Based Electrolytes for Dye-Sensitized Solar Cells: Comprehensive Guidance, Recent Progress, and Future Perspective.

A redox electrolyte is a crucial part of dye-sensitized solar cells (DSSCs), which plays a significant role in the photovoltage and photocurrent of the DSSCs through efficient dye regeneration and minimization of charge recombination. An I-/I3 - redox shuttle has been mostly utilized, but it limits the open-circuit voltage (V oc) to 0.7-0.8 V. To improve the V oc value, an alternative redox shuttle with more positive redox potential is required. Thus, by utilizing cobalt complexes with polypyridyl ligands, a significant power conversion efficiency (PCE) of above 14% with a high V oc of up to 1 V under 1-sun illumination was achieved. Recently, the V oc of a DSSC has exceeded 1 V with a PCE of around 15% by using Cu-complex-based redox shuttles. The PCE of over 34% in DSSCs under ambient light by using these Cu-complex-based redox shuttles also proves the potential for the commercialization of DSSCs in indoor applications. However, most of the developed highly efficient porphyrin and organic dyes cannot be used for the Cu-complex-based redox shuttles due to their higher positive redox potentials. Therefore, the replacement of suitable ligands in Cu complexes or an alternative redox shuttle with a redox potential of 0.45-0.65 V has been required to utilize the highly efficient porphyrin and organic dyes. As a consequence, for the first time, the proposed strategy for a PCE enhancement of over 16% in DSSCs with a suitable redox shuttle is made by finding a superior counter electrode to enhance the fill factor and a suitable near-infrared (NIR)-absorbing dye for cosensitization with the existing dyes to further broaden the light absorption and enhance the short-circuit current density (J sc) value. This review comprehensively analyzes the redox shuttles and redox-shuttle-based liquid electrolytes for DSSCs and gives recent progress and perspectives.

Pengelompokkan Penyakit Pasien Menggunakan Algoritma K-Means

Health is one of the most important factors besides education and income. Everyone has the same human rights to get good health services. A government agency that functions to serve all people who need medical services in Indonesia, namely the puskesmas. Ujung Batu Health Center which is located in Ujung Batu sub-district, Rokan Hulu Regency as one of the government agencies. The Ujung Batu health center stores patient medical record data, only sorting out the disease. Therefore, the medical record data needs to be processed using clustering or grouping using the K-Means method. This algorithm partitions the data into clusters so that data with the same characteristics are grouped into the same cluster and data with different characteristics are grouped. into another cluster. The data used consisted of 3875 records and 5 attributes, namely Gender, Participant Type, Diagnosis, Return Status, Address. From the test using the K-means algorithm, the clustering results show that cluster 1 has 710 data while cluster 2 has 3165 data. The results of the study show that the use of 2 clusters is the best cluster with a Silhouette Coefficient value showing results with a SC value of 0.646.

A detailed surface characterization study of SBA-15 and B-SBA-15-x mesoporous materials using the IGC technique

Pure and boron-containing B-SBA-15-x (molar ratio, Si/B = 50, 30, 10) mesoporous materials were synthesized by a direct hydrothermal procedure. Samples were characterized by XRD, ICP-OES, FT-IR, BET and SEM. Inverse gas chromatography (IGC) technique was used to determine the dispersive surface energies (γSd), adsorption thermodynamic parameters (ΔH, ΔG, ΔS) and the acid-base constants (KA and KD) of the samples. IGC experiments were performed at infinite dilution region at 200, 210, 220 and 230 °C. The surface characterization results confirmed that the SBA-15 structure was formed, boron was added to the structure and all samples have meso pores. The surface area of the pure SBA-15 was determined as 745.288 m2/g and it was found that the surface area decreases with increasing boron content. Physical adsorption occurred between the IGC probe molecules and all SBA-15 materials according to the adsorption thermodynamic parameters. (γSd) values of pure SBA-15, B-SBA-15-50, B-SBA-15-30 and B-SBA-15-10 were found at 40.873, 37.039, 36.636 and 37.444 mJ/m2 at 200 °C, respectively. It has been observed that the dispersive surface energy of all samples decreases with increasing temperature. According to the SC value calculated from the KA and KD parameters, the surface of B-SBA-15-10 with the highest boron content was found to be acidic. On the other hand the surfaces of all other samples were determined as basic.

A Novel Method for Estimating Acoustic Emission b Value Using Improved Magnitudes

The acoustic emission (AE) b value plays an important role in studying structural damage evolution and disaster precursors. The b value can be obtained from the least square fit between AE event number and magnitude (the Gutenberg-Richter relationship), where the magnitude is generally calculated through the maximum amplitude of an AE signal. However, the magnitudes obtained from amplitudes of different AE signals may be quite different, due to the influence of coupling state between the sensor and specimen (expressed as the sensor sensitivity coefficient, Sc). Thus, the b values obtained from a single sensor and without magnitude correction may not be reliable. To address this, this study used pencil-lead breaks and far-field theory to obtain Sc values. One Sc value may be as much as double another, demonstrating that signal maximum magnitudes should be corrected before b value estimation. The Sc -corrected median magnitude is then treated as the AE event magnitude and used to estimate the b value. Application to uniaxial compression AE data from a red sandstone indicates that the improved magnitude reduces the instability compared to magnitude based on a single sensor. The b value time series among sensors exhibit large differences, while the improved b values agree well with AE event locations and rock specimen failure mode. This research demonstrates for the first time the necessity of amplitude correction in AE magnitude and b value computation.

Synthesis, characterization and photovoltaic studies of 2,2′;6′,2ʺ-terpyridine-based ruthenium complexes with phenylamino, anthranyl and furfuryl substitutions at the 4′-position

A series of two heteroleptic ruthenium complexes of the type [Ru(X-tpy)(bpy-COOH)(NCS)](PF6) (where X-tpy = 4′-(4-N,N-dimethylaminophenyl)-2,2′:6′,2ʺ-terpyridine for complex 1 and 4′-(9-anthryl)-2,2′:6′,2ʺ-terpyridine for complex 2, bpy-COOH = 4,4′-dicarboxy-2,2′-bipyridine) and another heteroleptic ruthenium complex of the type [Ru(X-tpy)(bpy-COOH)(NCS)]Cl (where X-tpy = 4′-(furan-2-yl)-2,2′:6′,2ʺ-terpyridine for complex 3, bpy-COOH = 4,4′-dicarboxy-2,2′-bipyridine) have been synthesized and fully characterized. The effects of these substitutions with varying electronic properties on the resulting ruthenium dyes were studied in relation to their electronic structure and consequent redox chemistry and photovoltaic performance in a DSSC setup. Complex 1 registers a better photovoltaic performance with photon to conversion efficiency (PCE) of (η = 1.41%) with a J sc value of 2.1 mA cm−2 and V oc 0.58 V followed by 2 (η = 0.44%) and 3 (η = 0.13%). The pattern for the photovoltaic performance has been justified with a theoretical analysis of the directionality of the most intense charge transfers taking place in the dyes upon light irradiation.

Salivary markers of stress system activation and social withdrawal in humans

IntroductionSocial withdrawal is an early and common feature of psychiatric disorders. Hypothalamic-pituitary-adrenal (HPA)-axis activation through increased salivary cortisol (sC) and sympathetic activation through increased salivary alpha-amylase (sAA) may play a role.ObjectivesWe aimed to study whether the link between increased sC and sAA on the one hand and depression on the other hand is mediated by social withdrawal.MethodsIn this cross-sectional, observational study, sC and sAA measures were measured in seven saliva samples in 843 participants (231 psychiatric patients and 612 healthy controls). Social withdrawal was assessed through the Brief Symptom Inventory (BSI)-, the Short Form 36-, and the Dutch Dimensional Assessment of Personality Pathology social withdrawal subscales, and analyzed using linear regression and mediation analyses. On average, participants were 44.0 years old (SD=12.8; 64.1% female).ResultsBasal and diurnal sAA were unrelated to any social withdrawal scale and depression. Certain sC measures were positively associated with the BSI social withdrawal subscale (i.e., area under the curve with respect to the increase, beta=0.082, p=0.02; evening sC value: beta=0.110, p=0.003; and mean sC value: beta=0.097; p=0.01). We found limited support for statistical mediation by social withdrawal (measured using a composite social withdrawal score) on the relationship between evening sC and depression.ConclusionsThus, although we found no support for a role of basal and diurnal sAA in social withdrawal, HPA-axis activation may partly aggravate social withdrawal in depressive disorders.

Controllable Synthesis, Core-Shell Nanostructures, and Supercapacitor Performance of Highly Uniform Polypyrrole/Polyaniline Nanospheres

The sea urchin-like polyaniline (i.e., PANI) had been successfully grown on the surface of polypyrrole (i.e., PPy) nanospheres to form PPy@PANI composites with a core-shell structure by dilute solution polymerization. The shell thickness of the PANI could be adjusted from 20 to 120 nm via modulating the moles of aniline. The core-shell structure and molecular structure of PPy@PANI composites had been confirmed by TEM images and Raman and XPS spectra. Interestingly, the core-shell PPy@PANI nanospheres exhibited outstanding electrochemical properties and could be acted as a good electrode material for supercapacitors. The maximum specific capacitance (i.e., SC) of the PPy@PANI electrode was 510 F/g at 10 mV/s. The good rate capability (about 27.6% loss of the initial SC from 10 to 200 mV/s) and long cycle stability (the SC loss was about 12.4% after 1000 charge/discharge cycles) had been also verified by the further electrochemical measurement. It was ascribed to the synergistic effect between cored PPy and shelled PANI layer. In addition, the SC value of core-shell PPy@PANI nanospheres was closely related to the thickness of the PANI shell and the shape effect of sea urchin-like PANI. Moreover, the high utilization rates of PPy and PANI were crucial for the excellent supercapacitive energy storage of core-shell PPy@PANI nanospheres.

Salivary markers of stress system activation and social withdrawal in humans

Social withdrawal is an early and common feature of psychiatric disorders. Hypothalamic-pituitary-adrenal (HPA)-axis activation through increased salivary cortisol (sC) and sympathetic activation through increased salivary alpha-amylase (sAA) may play a role. We aimed to study whether the link between increased sC and sAA on the one hand and depression on the other hand is mediated by social withdrawal. In this cross-sectional, observational study, sC and sAA measures were measured in seven saliva samples in 843 participants (231 psychiatric patients and 612 healthy controls). Social withdrawal was assessed through the Brief Symptom Inventory (BSI)-, the Short Form 36-, and the Dutch Dimensional Assessment of Personality Pathology social withdrawal subscales, and analyzed using linear regression and mediation analyses. On average, participants were 44.0 years old (SD = 12.8; 64.1% female). Basal and diurnal sAA were unrelated to any social withdrawal scale and depression. Certain sC measures were positively associated with the BSI social withdrawal subscale (i.e., area under the curve with respect to the increase, beta = 0.082, p = 0.02; evening sC value: beta = 0.110, p = 0.003; and mean sC value: beta = 0.097; p = 0.01). We found limited support for statistical mediation by social withdrawal (measured using a composite social withdrawal score) on the relationship between evening sC and depression. Thus, although we found no support for a role of basal and diurnal sAA in social withdrawal, HPA-axis activation may partly aggravate social withdrawal in depressive disorders.

Analysis of one-dimensional models for exchange flows under strong stratification

One-dimensional models of exchange flows driven by horizontal density gradients are well known for performing poorly in situations with weak turbulent mixing. The main issue with these models is that the horizontal density gradient is usually imposed as a constant, leading to non-physically high stratification known as runaway stratification. Here, we propose two new parametrizations of the horizontal density gradient leading to one-dimensional models able to tackle strongly stratified exchange flows at high and low Schmidt number values. The models are extensively tested against results from laminar two-dimensional simulations and are shown to outperform the models using the classical constant parametrization for the horizontal density gradients. Four different flow regimes are found by exploring the parameter space defined by the gravitational Reynolds number Reg, the Schmidt number Sc, and the aspect ratio of the channel Γ. For small values of RegΓ, when diffusion dominates, all models perform well. However, as RegΓ increases, two clearly distinct regimes emerge depending on the Sc value, with an equally clear distinction of the performance of the one-dimensional models.

Diagnosis of Cervical cancer using CLAHE and SGLDM on RGB Pap smear Images through ANN

Cervical cancer is one of the most preventable Cancers in the present day. PAP and HPV tests are followed for early diagnosis for screening procedure. In medical field, it is difficult to detect Pap smear images through microscope. Image processing is a vital role to take right decision by using various technique and algorithms. In this paper, the proposed technique is used to enhance the Pap smear images by comparing Histogram Equalization in Contrast Stretching algorithm, Power Law Transformation for Gamma Correction, Shading Correction, Contrast Limited Adaptive Histogram Equalization (CLAHE). The Quality measurement MSE, PSNR, SC and NAC value has been calculated to find performance analysis of enhanced Pap smear images. Then proposed four different feature extraction algorithms SGLDM- Spatial Gray Level Difference Method, RDM- Run Difference Method, LBP- Local Binary Pattern and HOG-Histogram of Oriented Gradients are used to extract features of Pap images. Experimental results are obtained for a data set of 215 Pap images taken from the Management and Decision Engineering Laboratory (MDE-LAB) database. MATLAB R2016a used as a programming tool. ANN Classification is used for each feature extraction algorithm to evaluate the accuracy level. Thus, CLAHE achieved the good result for enhancement and SGLDM feature extraction algorithm reached 93% accuracy using ANN.

Electrochemical synthesis of PPy composites with nanostructured MnOx, CoOx, NiOx, and FeOx in acetonitrile for supercapacitor applications

In the present study, the polypyrrole (PPy) composites with nano-structured CoOx, NiOx, MnOx, and FeOx were synthesized using the galvanostatic method on their own metal-intercalated graphite surfaces. The deposition and intercalation are performed in TBABF4/acetonitrile solution with related metal (II) tetrafluoroborate salts, pyrrole, HBF4, H2O, Triton-X 100 (TX100) and carboxymethyl cellulose (Na-CMC). For the PPy/MnOx/Na-CMC composite, the effects of intercalation and additives on the specific capacitance were examined in an H2SO4/water medium by using cyclic voltammetry (CV) and the Electrochemical Impedance Spectroscopy (EIS). Using the optimum deposition conditions determined for Mn composite (additive concentrations and galvanostatic parameters), PPy/CoOx/Na-CMC, PPy/NiOx/Na-CMC, and PPy/FeOx/Na-CMC coatings with a mass loading of 4.0 mg cm−2 were deposited on their own metal-intercalated graphite electrodes in the deposition solutions containing Co(BF4)2, Ni(BF4)2 and Fe(BF4)2, respectively. XRD, TEM, XPS, SEM-EDX, BET, and EIS techniques were used in characterizing the coatings. Subsequently, the capacitive properties of the composite coatings were examined by means of the galvanostatic charge-discharge test. The highest SC value is recorded for the Mn-based composite (463 F g−1), whereas the lowest is for Fe-based (311 F g−1) one. Finally, symmetric and asymmetric supercapacitor configurations incorporating two electrodes with 10 mg cm−2 active material were used in making measurements to determine the capacitive behaviors of PPy/Metal oxide composites. The symmetric supercapacitor with PPy/MnOx/Na-CMC composite providing 0.29 kW kg−1 and 15.0 Wh.kg−1 at 0.5 A g−1 maintains 62% of its power and energy densities at 2.5 A g−1 at the end of 5000 cycles at a potential range of 0.8 V.

Measurement and comparison of head scatter factor for 9MV photon beam using the build-up cap and a columnar mini-phantom

Introduction: The Sc is an important parameter to monitor unit (MU) calculation in radiation therapy procedure. The aim of this study is to measurement and comparison of head scatter factor (Sc) for 9MV photon beam using the build-up cap and a columnar mini-phantom. Materials and Methods: The measurements performed using a calibrated ion chamber (Scanditronix / Wellhofer Farmer Type Chamber FC65-G), and electrometer (Scanditronix / Wellhofer, Dose 1 Reference class electrometer). Sc’s values were measured on Neptun linear accelerator. The Sc measured in the source to surface distance (SSD) of 100cm in different square field sizes (5×5 to 38×38 cm) using two available devices: the PMMA build- up cap and dmax dose water equivalent columnar mini-phantom. Results: Sc’s values for 5×5, 10×10, 15×15, 20×20, 25×25, 30×30, 35×35 and 38×38 cm2 field sized with columnar mini-phantom were 0.97, 1, 1.02, 1.04, 1.06, 1.07, 1.08, and 1.09, respectively. Sc’s values for 5×5, 10×10, 15×15, 20×20, 25×25, 30×30, 35×35 and 38×38 cm2 field sized with build-up cap were 0.96, 1, 1.03, 1.06, 1.08, 1.09, 1.10, and 1.11, respectively. Conclusion: Though measured Sc value using build-up cap in 5×5 cm2 field size was smaller than of those Sc measured using columnar mini-phantom, higher values result in larger field sizes than 10×10 cm2.

Surfactant-assisted Pulse Electrodeposition of Hausmannite Nano-rods/particles with Improved Pseudocapacitive Performance

Pulse cathodic electrodeposition of manganese oxide was performed from 0.005M MnCl2 in the presence of cetyl trimethylammonium bromide (CTAB). The electrosynthesis experiments were done at the simple pulse mode (ton=1ms and toff=1ms) with applying current density of 10 mA cm–2. The structural analyses through XRD and FTIR revealed that the prepared sample have the pure hausmannite crystal structure. Morphological observations by SEM showed that the deposited hausmannite has mixed rod/particle morphology. The charge storage performances of the prepared hausmannite were evaluated by cyclic voltammetry and charge-discharge techniques. The Mn3O4 working electrode exhibited only 13% capacity decay after 1000 cycles at the current load of 2 A g–1, and its SC value reduced from 239 F g–1 to 207 F g–1. The results proved that the prepared Mn3O4 nano-rods/particles are suitable electrode material for supercapacitors.

Comparative study of oil spreading characteristics for water and carbonated water systems using live and dead oils

In order to investigate the potential of water alternating gas (WAG) and carbonated water alternating gas (CWAG) injection methods, a series of interfacial tension (IFT) experiments for the binary systems of brine/carbonated brine (CB), carbon dioxide (CO2) and live and dead crude oils were performed. The experiments done using the axisymmetric drop shape analysis (ADSA) technique at temperatures of 40 °C and 50 °C and different pressures up to 13.79 MPa. The IFT results are used to estimate and determine optimum value of spreading coefficient, which is known as a key enhanced oil recovery (EOR) parameter at the pore scale. The experimental results demonstrate that CB decreases the equilibrium IFT of crude oil compared to the brine at the same conditions (for example, the difference of IFT is 5.2 mN/m and 7.6 mN/m at temperature of 40 °C and pressures of 2.76 and 13.79 Mpa, respectively). The equilibrium IFT of the live oil-brine/CB system is greater than that of dead oil-brine/CB. The estimated SC shows that the presence of CO2 in the aqueous phase significantly affects the SC value. That is, it becomes positive for the dead/live oil-CB-CO2 system, and improve the performance of EOR process while it is negative for the dead/live oil-brine-CO2 system. The presence of CH4 gas in the oil phase reduces the SC values at different pressure conditions. Moreover, using the SC results are determined the optimum conditions during CWAG injection. Based on the observed results in the dead/live oil-CB systems, swelling phenomena of the dead oil drop be slightly lower than that of the live oil drop.