Half Height Research Articles

21 LEVEL HYBRID SINGLE T TYPE DOUBLE HBRIDGE MULTILEVEL INVERTER TOPOLOGY

Inverters are the power electronic circuits which transfers power from direct current source to alternating current load. It manages voltage, current and frequency of the signal. Inverter comprises of various applications like adaptable velocity AC motor drives, uninterruptible power supply, running appliances of AC used in automobile battery, etc. The simulation of 21 level multilevel inverter is taken out using MATLAB/Simulink and the simulated circuit model is discussed. The input DC voltage sources for inverter are assigned with the magnitudes 96V, 96V and 96V satisfying the ratio 3:3:3 for the frequency of 50 Hz and the results analyzed for resistive load and inductive load with fundamental switching pattern. The circuit is simulated with half height method and fundamental equal phase angle method and the THD is calculated and compared.

Experimental evidence for the boundary zonal flow in rotating Rayleigh–Bénard convection

We report on the presence of the boundary zonal flow in rotating Rayleigh–Bénard convection evidenced by two-dimensional particle image velocimetry. Experiments were conducted in a cylindrical cell of aspect ratio $\varGamma =D/H=1$ between its diameter ( $D$ ) and height ( $H$ ). As the working fluid, we used various mixtures of water and glycerol, leading to Prandtl numbers in the range $6.6 \lesssim \textit {Pr} \lesssim 76$ . The horizontal velocity components were measured at a horizontal cross-section at half height. The Rayleigh numbers were in the range $10^8 \leq \textit {Ra} \leq 3\times 10^9$ . The effect of rotation is quantified by the Ekman number, which was in the range $1.5\times 10^{-5}\leq \textit {Ek} \leq 1.2\times 10^{-3}$ in our experiment. With our results we show the first direct measurements of the boundary zonal flow (BZF) that develops near the sidewall and was discovered recently in numerical simulations as well as in sparse and localized temperature measurements. We analyse the thickness $\delta _0$ of the BZF as well as its maximal velocity as a function of Pr, Ra and Ek, and compare these results with previous results from direct numerical simulations.

Study On Productivity Improvement Of Low Permeability Gas Reservoir By Hydraulic Fracturing

The C5 well completed in the LZ tight gas limestone reservoir of C field is considered very good candidate for stimulation by hydraulic fracturing for the following reasons. The reservoir gross thickness of 127 ft is thick enough. Long fractures can be created. Penetrated zone is far from lowest known gas. The permeability of 0.2973 mD and the absolute open flow potential of 2.3 MMscf are low. Estimated proven gas accumulation of 24.5 Bscf is significant. Crosslinked Gel + Hi Temp Stabilizer is used as fracturing fluid due to high temperature reservoir of 334oF. High-strength of Sintered Bauxite proppant with 20/40 mesh sand is selected for this high stress formation of reservoir rock. The desired propped fracture width is 0.1004 inch. The fracture height is approximately 62.5 ft based on the half height from the centre depth of reservoir upward and downward. The propped fracture halflengths are predicted by Perkins-Kern-Nordgren model. Prediction shows that to have the propped fracture half-gths of 1335, 1587, 1850, 2114, 2356, 2576 and 2640 ft for the propped fracture width of 0.1004 inch and the fracture height of 62.5 ft, the required proppant weight in one fracture wing are 139,167,195,221, 246, 271 and 278 Mlbs respectively. With the obtained propped fracture halflengths, the productivities improvement (J/Jo) are 13.8, 16.4, 19.2, 21.9, 24.4, 26.7 and 27.3

Propanol Clustering in Argon Matrix: 2D FTIR Correlation Spectroscopy

The dynamic FTIR spectra of propanol in the argon matrix have been measured using a thermal perturbation by heating the sample from T = 11 K to 30 K stepping by 1 K. The 2D Fourier-transform infrared (FTIR) absorption correlation analysis has been carried out, the main attention being concentrated to the region of propanol O–H stretching vibrations at 3000–3700 cm–1. The peaks of monomers, two conformers of open dimer, and the cyclic structures from a dimer to a pentamer have been resolved and studied in more details. Analyzing the dependences of the integral band intensities of various aggregates on the temperature, it has been deduced that monomers and dimers act in the initial clustering stage as the main "building units" whose diffusion sustains the formation of the higher H-bond structures in the matrix. The full width at half height (FWHH) for each band has been processed as afunction of the aggregation number (n). It is found that the FHWW is a perfectly linear function of n for all cyclic aggregates n ≥ 2. The resonance broadening has been proposed to be the most reliable mechanism for the formation of diffuse O–H stretching bands in the matrix isolated clusters.

Dynamically tunable ultralong photonic nanojets by a curved surface truncated dielectric microcylinder

As for microparticles (microspheres or microcylinders) that form photonic nanojets (PNJs) in the near field, a curved truncated dielectric microcylinder structure (CSTDM) is investigated by the finite element method which can form ultralong PNJs with the longest effective length: 209.49 Changing parameter h of the structure can realize long dynamic range tuning of the effective length of the PNJ. The effective length varies quasi-periodically with h; the law of the variation of main indicators of the microcylinder is further discussed, such as the effective length, the working distance, peak electric field intensity, and full width at half height.

Temperature analyses of porous asphalt mixture using steel slag aggregates heated by microwave through laboratory tests and numerical simulations

The temperature distribution of porous asphalt mixtures with steel slag aggregates (SSA) heated by microwave was analyzed through laboratory tests and numerical simulations in this study. Nine groups of porous asphalt mixture specimens with different SSA replacement ratios and particle sizes were designed to investigate their influences on the microwave heating efficiency. The semi-cylindrical specimen (Φ150 × 50) was placed in the center of microwave oven and heated 120 s. The surface temperature was measured by the thermal imaging camera every 20 s. The photos were imported into Flir tools to obtain the temperature of every pixel. Both the maximum heating temperature and the average heating temperature indicated that when 50% of 4.75–9.5 mm aggregates and 50% of 9.5–13.2 mm aggregates were replaced by SSA, the microwave heating efficiency improvement was optimal. When all the coarse aggregates were replaced by SSA, the average microwave heating efficiency was not as good as other groups. Both the laboratory tests and numerical simulations indicated that the inner heating rate was greater than the surface heating rate. The final inner temperature was higher than the surface temperature. After 120 s heating, there were one or two temperature peaks in the diametric direction of the specimen, and the first peak was at the position of 45–60 mm and the second peak was at the position of 120 mm. The temperature along the height direction firstly increased and then decreased, and the maximum temperature was at the half height of the specimen. The numerical simulation results were well consistent with the results of laboratory tests.

EVALUASI KUAT TEKAN BETON MUTU TINGGI YANG MENGANDUNG TULANGAN SATU ARAH

The concrete compressive strength in existing buildings can be determined by the destructive method (DM) and the non-destructive method (NDM). The non-destructive method can be carried out to determine the distribution of the compressive strength of concrete in structural elements, but the value given is not absolutely representative of the actual compressive strength of the concrete. To find out the actual compressive strength of concrete is to carry out destructive tests such as core drilling oncrete. In general, core concrete is not allowed to have reinforcement, but this is sometimes unavoidable. The purpose of this study was to evaluate the compressive strength of high-strength concrete due to the content of reinforcement in the concrete. This study used a concrete cylindrical specimen with a diameter of 10 cm with a variation of the ratio L/D = 1 and L/D = 2. One reinforcement was placed on 1/4 L and 1/2 L of each specimen horizontally with the number of specimens per variation being 5 specimens. The total number of cylindrical specimens was 30 specimens. In this study, specimens without reinforcement were also made as control specimens. Based on the results, it was found that the value of the reinforcement content factor (C 2 ) was still relevant to be used for the L/D = 2 specimens because it still had a deviation below 5%. Meanwhile, for L/D = 1 multiplication with the value of C 2 shows a deviation above 5%. The position of the reinforcement that was getting closer to the half height of the specimens decreases the compressive strength of high-strength concrete.

Beç Tavuklarında (Numida meleagris) Sayısal Görüntü Analizi ve Matematiksel Formüller Kullanılarak Yumurta Kalite Özelliklerinin Belirlenmesi

A total of 200 Guinea fowl (Numidae meleagris) eggs were obtained from guinea fowl flock at the age of 42 weeks of age, which are breeding at an altitude of 1240 m in the Wild Animals Breeding Station affiliated to Ministry of Forest and Water Affairs in Yozgat/Turkey. Eggs were taken at a resolution of 72 pixels per inch and 5184 × 3456 pixels in size, with the individual egg weights. Average Projection area (16,07 cm2), Perimeter (15,82 cm), Circularity (0,81), Height (5,17 cm), Width (4,04 cm), Mean grey value (82,82), Semi axis (2,02 cm), First long half height (2,96 cm), Second short half height (2,20 cm) values were determined by numerical image analysis. Mean Elongation (1,28), Shape Index (78,27) were calculated over the obtained data. Surface area (55,43 cm2), Height (5,16 cm), Width (3,77 cm), Elongation (1,37), Shape Index (73,01), Volume (40,14 cm3), Surface / Volume ratio (1,38), Shell weight (3,17 g), Shell thickness (0,28 mm), pore numbers (6666,25; 5132,39; 5011,12), pore density (120,32; 92,56; 90,31), Yellow ratio (14,85), Yellow Weight (5,95 g), Albumen Weight (30,75), Albumen ratio (77,21) parameters have been calculated using individual egg weights. Eggs were divided into 3 groups as 90 in terms of gray value, eggs 79 in terms of shape index, and 43 in terms of weight. The effects on the properties were investigated. As a result, it is thought that the data obtained can be used in scientific studies.

Detection of highly overlapping peaks via adaptive apodization

Accurate peak detection is an essential component of many NMR tasks such as peak alignment, compound identification, and global spectral deconvolution. However, current peak detection approaches are generally limited by their ability to deal with spectral overlap, which has a deleterious effect on downstream data processing. In this work, we present the use of an adaptive apodization strategy that improves the detection of highly overlapping peaks. Sensitivity enhancement is used to identify general regions of interest and resolution enhancement is used to separate overlapping peaks, with parameters for both calculated directly from the data. Further limits on peak width help to reduce false positives. The method proposed in this work has been implemented in an open-source R package called rnmrfind that is available for download on GitHub (https://github.com/ssokolen/rnmrfind). A set of default parameters have been chosen to provide effective peak detection while keeping false positives to a minimum; however, application-specific tuning is possible through the modification of minimum peak width at half height (in Hz) and noise cutoff threshold (as a factor of estimated standard deviation). Comparison to existing packages rNMR and speaq on a series of 1H NMR spectra demonstrates improved peak resolution with little to no apparent drawbacks.

Preparation, Characterization and Analytical Studies of novel Azo dyes and Diazo dyes

The amino {4-hydroxy-3-[(E)-{4-[(5-methylisoxazol-3-yl) sulfamoyl] phenyl} diazenyl] phenyl} acetic acid (1) and the amino {4-hydroxy-3,5-bis[(E)-{4-[(5-methylisoxazol-3-yl) sulfamoyl] phenyl} diazenyl] phenyl} acetic acid (2) were Prepared. The resulting azo and diazo dyes were then characterized using m.p., IR, UV-visible, mass spectrum and 1H-NMR spectrum. Analytical studies were carried on the azo dye (1) and the diazo dye (2). The best solubility of (1) and (2) was in methanol and ethyl acetate respectively, with no deviation from the linear relationship in each dye, which is due to the fact that the effect of the dielectric constant is the main factor that can control the shift of the absorption beaks. Though, the pH effects of (1) and (2) in a range of buffer solution were showed one and two isopiestic points respectively. Calculation of the ionization (pKa) and the protonation (pKp) constants by using the half height method was associated to the nitrogen atom and the OH-groups respectively. The pKp1, pKa1 and pKa2 were also intended. But, the value of the pKp2 was absent in the azo dye (1) and seems to be equal to 2.5 in the diazo dye (2). These results were indicated the suggested ionization scheme in acidic and basic medium of each dye. Furthermore, the dyes with different concentrations have harmless, nontoxic and no haemolysis effects.

A Novel Hexagonal-Shaped Multilevel Inverter with Reduced Switches for Grid-Integrated Photovoltaic System

To date, the grid-connected solar photovoltaic (PV) system has drawn consideration from researchers and academicians due to the speedy improvement and the declining price of solar panels. The proficiency and dependability of a grid integrated PV system rest mainly on the power conversion unit and the proper controlling mechanism. This paper introduces a novel asymmetric hexagonal-shaped fifteen-level inverter designed to feed a grid-integrated solar PV system. First, it aims to reduce the number of components and thereby decrease the installation space and cost of the multilevel inverter. Moreover, it has a low total blocking voltage (TBV) and total device rating (TDR) and uses few switching devices for generating per level of output voltage. The proposed topology utilizes only eight switching devices for generating fifteen levels at the output, which is lower than conventional multilevel inverter topologies. Here, a low-frequency modulation scheme using the half-height (HH) method generates switching pulses to minimize the complexity. The proposed multilevel inverter topology is also validated through the simulations in the MATLAB SIMULINK environment. The proposed inverter need for filters is illustrated according to different grid codes for integrating PV systems to the grid.

Analysis of short-chain bioactive peptides by unified chromatography-electrospray ionization mass spectrometry. Part I. Method development

A method to analyse short-chain bioactive peptides (MW < 800 Da) and their impurities was developed with a unified chromatography (UC) analysis, including a wide mobile phase gradient ranging from supercritical fluid to near-liquid conditions, with UV and electrospray ionization mass spectrometry detection (ESI-MS). Four stationary phases and three mobile phase compositions were examined. Ten model peptides were first selected to identify the best operating conditions, including five linear tripeptides and five cyclic pentapeptides, with log P values ranging from -5.9 to 3.6, and including isomeric species. Derringer desirability functions were designed to identify optimal operating conditions based on 7 criteria, namely the number of peaks detected (including all impurities resolved), the proportion of the chromatogram occupied by target peaks, the least favourable resolution observed between the main peptide and impurities, peak shape features (asymmetry and peak width at half height), and finally the signal-to-noise ratio observed both with UV (210 nm) and ESI-MS in positive ionization mode.The optimum conditions were obtained on Ascentis Express OH5 stationary phase, with a mobile phase composed of carbon dioxide and methanol, comprising 2% water and 20 mM ammonium hydroxide. The final gradient program ranged from 5 to 80% co-solvent in CO2, with a reversed flow rate gradient ranging from 3.0 to 1.5 mL/min. Back-pressure was set at 120 bar and the column oven temperature at 60°C. Optimal conditions were applied to a large set of 76 peptides (34 linear tripeptides and 42 cyclic pentapeptides) and provided adequate scattering of the peaks in the retention space, together with some separation of isomeric species, particularly for the cyclic peptides.

Digitally Driven Aerosol Jet Printing to Enable Customisable Neuronal Guidance.

Digitally driven manufacturing technologies such as aerosol jet printing (AJP) can make a significant contribution to enabling new capabilities in the field of tissue engineering disease modeling and drug screening. AJP is an emerging non-contact and mask-less printing process which has distinct advantages over other patterning technologies as it offers versatile, high-resolution, direct-write deposition of a variety of materials on planar and non-planar surfaces. This research demonstrates the ability of AJP to print digitally controlled patterns that influence neuronal guidance. These consist of patterned poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) tracks on both glass and poly(potassium 3-sulfopropyl methacrylate) (PKSPMA) coated glass surfaces, promoting selective adhesion of SH-SY5Y neuroblastoma cells. The cell attractive patterns had a maximum height ≥0.2 μm, width and half height ≥15 μm, Ra = 3.5 nm, and RMS = 4.1. The developed biocompatible PEDOT:PSS ink was shown to promote adhesion, growth and differentiation of SH-SY5Y neuronal cells. SH-SY5Y cells cultured directly onto these features exhibited increased nuclei and neuronal alignment on both substrates. In addition, the cell adhesion to the substrate was selective when cultured onto the PKSPMA surfaces resulting in a highly organized neural pattern. This demonstrated the ability to rapidly and flexibly realize intricate and accurate cell patterns by a computer controlled process.

Integral measures of the zero pressure gradient boundary layer over the Reynolds number range ≤Rτ&amp;lt;∞

A recently developed mixing length model of the turbulent shearing stress has been shown to generate a universal velocity profile that provides an accurate approximation to incompressible pipe flow velocity profiles over a wide Reynolds number range [B. J. Cantwell, “A universal velocity profile for smooth wall pipe flow,” J. Fluid Mech. 878, 834–874 (2019)]. More recently, the same profile was shown to accurately approximate velocity profiles in channel flow, the zero pressure gradient boundary layer, and the boundary layer in an adverse pressure gradient [M. A. Subrahmanyam, B. J. Cantwell, and J. J. Alonso, “A universal velocity profile for turbulent wall flows,” AIAA Paper No. 2021-0061, 2021 and M. A. Subrahmanyam, B. J. Cantwell, and J. J. Alonso, “A universal velocity profile for turbulent wall flows including adverse pressure gradient boundary layers,” J. Fluid Mech. (unpublished) (2021)] The universal velocity profile is uniformly valid from the wall to the free stream at all Reynolds numbers from zero to infinity. At a low Reynolds number, the profile approaches the laminar channel/pipe flow limit. The primary measure of the Reynolds number used in this work is the friction Reynolds number Rτ=uτδ/ν. It is a little unusual to use Rτ for the boundary layer since it requires that the velocity profile be cutoff using an arbitrarily defined overall boundary layer thickness, δ. Because of the slow approach of the velocity to the free stream, different conventions used to define the thickness lead to different values of Rτ assigned to a given flow. It will be shown in this paper that, through its connection to channel/pipe flow, the universal velocity profile can be used to define a practically useful, unambiguous, measure of overall boundary layer thickness, called here the equivalent channel half height, δh. For Rτ&amp;gt;≈5000, the universal velocity profile defines a Reynolds number independent shape function that can be used to generate explicit expressions for the infinite Reynolds number behavior of all the usual integral boundary layer measures; displacement thickness, momentum thickness, energy thickness, overall boundary layer thickness, and skin friction. The friction coefficient Cf(Rδ2) generated by the universal velocity profile accurately approximates data over a wide range of momentum thickness Reynolds numbers collected by Nagib et al. [“Can we ever rely on results from wall-bounded turbulent flows without direct measurements of wall shear stress?,” AIAA Paper No. 2004-2392, 2004]. The universal velocity profile is used to integrate the von Kaŕmań boundary layer integral equation [T. von Kármán, “Uber laminaire und turbulente reibung,” Z. Angew. Math. Mech. 1, 233–252 (1921)] in order to generate the various thicknesses and friction velocity as functions of the spatial Reynolds number, Rx=uex/ν.

Expanding the Use of Dynamic Electrostatic Repulsion Reversed-Phase Chromatography: An Effective Elution Mode for Peptides Control and Analysis.

Bioactive peptides are increasingly used in clinical practice. Reversed-phase chromatography using formic or trifluoroacetic acid in the mobile phase is the most widely used technique for their analytical control. However, sometimes it does not prove sufficient to solve challenging chromatographic problems. In the search for alternative elution modes, the dynamic electrostatic repulsion reversed-phase was evaluated to separate eight probe peptides characterised by different molecular weights and isoelectric points. This technique, which involves TBAHSO4 in the mobile phase, provided the lowest asymmetry and peak width at half height values and the highest in peak capacity (about 200 for a gradient of 30 min) and resolution concerning the classic reversed-phase. All analyses were performed using cutting-edge columns developed for peptide separation, and the comparison of the chromatograms obtained shows how the dynamic electrostatic repulsion reversed-phase is an attractive alternative to the classic reversed-phase.

Synthesis of narrow-band red-emitting SrLiAl3N4:Eu2+ phosphor and the study of its influencing factors on luminescence performance

In this paper, safer raw materials were used to synthesize SrLiA13N4:Eu[Formula: see text] phosphors under high purity nitrogen gas by high-temperature solid-state method, and the effects of activator doping concentration, calcination temperature, calcination time and matrix lattice cation substitution on their luminescence performance were studied. All the samples can emit red light effectively excited by ultraviolet or blue light, and the narrow-band red emission peak is at [Formula: see text]651 nm. Energy Dispersive Spectroscopy (EDS) results show that the Eu[Formula: see text] element has been successfully doped and uniformly distributed. The X-ray powder diffraction (XRD) pattern showed that impurities of AlN and SrO were present in the synthesized samples, and the impurity phase was significantly reduced or eliminated with the increase of calcination temperature. The relationship between luminescence intensity of phosphor and Eu[Formula: see text] doping concentration indicates that with the increase of Eu[Formula: see text] doping concentration, the luminescence intensity of powder first increases and then decreases, and the optimal doping concentration is 0.02. Concentration quenching will occur if the doping amount of Eu[Formula: see text] continues to increase. The addition of Ca makes it replace Sr in the crystal lattice, resulting in the reduction of field force in the lattice expansion crystal, resulting in the reduction of luminescence intensity, the red shift of emission peak, and the increase of half height and width. The results exhibit that SrLiAl3N4:Eu[Formula: see text] may be a more suitable phosphor than CaLiAl3N4:Eu[Formula: see text] as a narrow-band red component in white LEDs.

Integration of vibration and optical techniques for watermelon firmness assessment

Fruit firmness is one of the key quality indices of fruit at different stages of the food supply chain. In this study, a new detection system based on the acoustic vibration method and visible/near-infrared (Vis/NIR) spectroscopy was developed to evaluate watermelon firmness. To diminish the influences of the shape index and white peel thickness on the second resonance frequency (f2), a multiple linear regression model was established by the finite element analysis (FEA) method to optimize the measured f2 to the modified second resonance frequency (f0) of a single-tissue watermelon. Besides, the machine vision system was designed to obtain the real white peel thickness and shape index. And the peel thickness was non-destructively predicted by Vis/NIR spectroscopy. In addition, a new puncture probe with ten cylinders was developed to determine the destructive firmness of the whole watermelon. The flesh firmness (FF) of watermelon was selected as an output variable in the prediction models due to its high correlation coefficients with vibration parameters. Regarding the acoustic vibration method, better prediction performance of FF was obtained in a back propagation neural network (BPNN) model by using the modified elasticity index (EI0), the peak width at half height (w), the peak value at f2 (A) and the peak area (S) as input variables. The correlation coefficient of prediction (rp) and root mean square error of prediction (RMSEP) were 0.655 and 0.971 N. Considering the merits and limitations of acoustic vibration method, a low-level data fusion method was applied to combine the vibration and Vis/NIR spectrum data to acquire more comprehensive firmness information. The successive projections algorithm (SPA)-BPNN model using 13 spectrum features achieved better prediction results than other prediction models (rp = 0.841, RMSEP = 0.932 N). It was found that the integration of vibration and optical techniques could be an effective approach to provide more detailed information about watermelon firmness.

Design of Angle based 27-level Trinary Ladder Inverter Using Cross Compiler

This paper presents the design of the Multi-Level Inverter circuit based on the switched ladder topology using the angle events for the level changes. The change of events for the inverter is formulated using the Half Height Algorithm. The VHDL code is utilized for the generation of the angles as digital equivalence with the resolution of 27 bits. In ladder topology, there are several types of inverter namely Binary Ladder Inverter, Ye Progression, Luo Progression. Among all these topologies, the Trinary Ladder topology is advantageous for the number of levels attainment with the less number of switches. Also, the carrier-based modulation is erroneous with the High THD% and low Voltage Parameter values. The use of the non-carrier half-height method manipulates the accurate angle to measure acceptable THD %. The proposed Trinary Switched Ladder Inverter is cross-compiled with Xilinx Vivado and Matlab Simulink Took to evaluate the parameters such as THD%, VRMS, VPEAK, for the 27-level. The parametric analysis exhibits improvement in the proposed Ladder topology with cost, size, and performance when synthesized using the Xilinx Vivado tool.

Study of dielectric relaxation and polaron conductivity mechanism in sodium nitroprusside (SNP): Na2[Fe(CN)5(NO)]·2H2O

In this study, the crystal structure of sodium nitroprusside, Na 2 [Fe(CN) 5 (NO)]·2H20, has been determined by an analysis by X-ray diffraction (XRD). The crystal is orthorhombic, space group Pnnm. This compound is characterized by different techniques: X-ray diffraction (XRD), differential scanning calorimetry (DSC) and impedance spectroscopy. For electrical properties, impedance spectroscopy was performed at a frequency range of 20 Hz–2 MHz. The dependence of AC conductivity on frequency was found to satisfy Jonscher's universal power law at different temperatures σ ( ω ) = σ D C ( ω , T ) + A ω S ( T , ω ) . This suggested hoping conduction due to three theoretical models. The latter can be attributed to the correlated barrier hopping (CBH) model in region I, overlapping large polaron tunneling (OLPT) in region II and non-overlapping small polaron tunneling (NSPT) mechanism in region III. The temperature dependence and dielectric relaxation of the DC conductivity satisfied the Arrhenius law. The activation energy ranged from 0.033 to 0.164 eV and was similar in the conduction and relaxation mechanisms, indicating that the transport mechanisms were based on hopping phenomena. Moreover, the modulus plots has been characterized by full width at half height or in terms of a non-experiential decay function ϕ(t) = exp(−t/τ)β. The values of the activation energies obtained from the electrical conductivity and electric modulus are near; which suggests that the transport is probably due to the ion hopping mechanisms. Furthermore, this behavior was confirmed by both Nyquist and Argand's plots of dielectric impedance at different measuring temperatures. Crystal structure, Molecular Hirshfeld surfaces, hydrogen bonding, UV absorption and phase transition of the β-NH 3 (CH 2 ) 2 NH 3 SnCl 6 compound. • This compound is crystallized in the orthorhombic system (Pnnm space group). • Differential scanning calorimetric (DSC) experiments show a phase transition at 130 K and 155 K. • The conduction mechanism is attributed to the (CBH) model, (OLPT) and (NSPT) mechanism. • The activation energies suggest that the transport is probably due to the ion hopping mechanisms. • The near value of activation energies obtained from the analysis of M.

Experimental study of jacket height and reinforcement effects on seismic retrofitting of concrete columns

This study evaluates the jacket height and reinforcement effects on reinforced concrete (RC) square columns retrofitted with normal concrete. Five one-third scale columns with non-ductile reinforcement were tested. Four columns were retrofitted with RC jackets with quarter height (h/4) and half height (h/2) where h is the column height. Subjected to cyclic loading, the failure pattern, lateral load capacity, stiffness, ductility, and energy dissipation of the column were investigated. Results show that increasing the jacket height significantly affected the failure pattern and lateral load capacity. Increasing the jacket height from h/4 to h/2 showed a pronounced shear failure and steeper diagonal cracks. Columns jacketed with h/2 jacket almost doubled the original lateral load capacity. The difference in the lateral load capacity of columns with h/2 jackets and h/4 jackets was above 23%. The jacket reinforcement confinement reduced the level of jacket damage and increased the damage and concrete crush in the column above the jacket. However, the unreinforced jacket increased the jacket damage and reduced the damage above the jacket. The jacket reinforcement increased the lateral load capacity by the shear transfer mechanism while the jacket height enhanced the energy dissipation of the jacketed columns by arch (strut) action. In addition, the jacket height and reinforcement increased the column’s stiffness and consequently, the stiffness irregularity produced short column shear failure above the jacket. From the results, a simplified analytical model was developed to predict the structural capacities of the jacketed column.