Miracle-dz/UniFAR-FTUs huggingface dataset:
Fabrication of hybrid PVA-PVC/SnZnOx/SWCNTs nanocomposites as Sn2+ ionic probe for environmental safety

ABSTRACT New hybrid nanocomposites (NCs) based poly(vinyl alcohol) (PVA), poly(vinyl chloride) (PVC), mixed SnZnOx nanocube and single walled carbon nanotube (SWCNTs) have been fabricated by solution dispersion method with the help of ultrasonic irradiation. A fixed amount of SnZnOx and different loading of SWCNTs nanoparticles (NP)s are added successfully during the fabrication process. The SnZnOx nanocubes are synthesized using the wet-chemical procedure. Here, results from XRD, FTIR, TEM, and FE-SEM techniques are examined to provide the fundamental information necessary to fabricate PVA-PVC and their NCs. Morphology findings of SnZnOx and SWCNTs incorporated in the PVA-PCV matrix prove the appearance of nanoparticle in the films. Additionally, thermal and electrochemical behavior of the fabricated NCs have been studied by thermogravimetric technique and electrochemical measurements, respectively. An effectual electrochemical sensor using PVA-PVC/SnZnOx/SWCNTs(3)/binder/GCE assembly selective to Sn2+ ion is fabricated with conductive nafion (5%). The PVA-PVC/SnZnOx/SWCNTs(3) NCs give a good detection of Sn2+ ion and it shows a linear response over the large linear dynamic range (LDR) concentration of 0.1 nM ~ 0.01 mM . The linear relationship slope of (current vs. concentration) is examined to calculate the sensitivity (42.11 µAµM−1cm−2) and detection limit (44.36 ± 2.22 pM) of proposed Sn2+ ionic sensor probe. It has been significantly detected the selective Sn2+ ion from environmental real samples. The insights stated in this manuscript provide a clear understanding of the variable keys involved in the improvement of heavy metal ionic sensor for the application of safety environment in broad scale. GRAPHICAL ABSTRACT
Development of printable, flexible nickel‐iron batteries based on composite electrodes

We present flexible nickel‐iron batteries with printable multiwalled carbon nanotube (MWCNTs) based electrodes. All the metal composites are prepared via a single‐step precipitation reaction to synthesize metal hydroxides on the MWCNTs. High loading of the conductive materials enhances reactivity. Compared with Ni(OH)2‐CNT, β‐NiOOH increases output energy due to higher discharge voltage in flexible cells. Cyclic voltammogram shows that the iron electrode underwent a two‐step redox reaction among Fe, Fe(II), and Fe(III). The flexible Ni‐Fe battery has higher charge‐discharge efficiency when using 6 M KOH electrolyte saturated with LiOH, and with 5% Co(NO3)2 added to anode. The anode exhibits a specific capacity of more than 300 mAh g−1. All the components and the flexible cells themselves show good performance under bending conditions and the fabrication methods are also suitable for scale‐up via printing techniques.
Study of the relaxation and resonance behaviors of ternary composites: Epoxy–strontium titanate–carbon black

The principal subject of the present article is the study of the phenomenon of dispersion as well as the effect of the concentration of strontium titanate (SrTiO3) and carbon black on the complex permittivity of ternary composites: epoxy resin–SrTiO3 –black carbon. The relative permittivity of the mixtures as a function of volume fraction of SrTiO3 was modeled by the modified Lichtenecker mixing law (MLL). A new dispersion model, based on the Lorentzian resonance model, has been proposed to describe the frequency behavior of complex permittivity. For these ternary composites, the frequency dispersion behavior of the complex permittivity that exhibits both relaxation and resonance spectra with increasing SrTiO3 concentration has been showed. The new empirical equation proposed in our work has been well describing the complex permittivity of resonance type for the SrTiO3 and carbon black composites. The effects of SrTiO3 content on the electromagnetic properties and absorption characteristics of electromagnetic waves of epoxy resin composites were studied. As the volume fraction of SrTiO3 increases, it was confirmed that the complex permittivity of the composites follows the MLL and the resonant frequency shifted toward the high frequency range. The resonance frequency of the composites was estimated in good agreement with the theoretical values calculated by the second new equation proposed in this article. Complex permittivity is measured using time domain spectroscopy in the frequency range direct current (DC) to 30 GHz.
Oil Production Optimization in Petroleum Reservoirs by Ant Algorithm

The objective of the research presented in this paper is to investigate the effectiveness of a new stochastic algorithm to obtain maximum hydrocarbon production rate in petroleum reservoirs. The hydrocarbon production rate is a function of several variables. Some of these variables are production well location, production well flow pressure, injection well location and fluid injection rate. Changing any of the variables will change the hydrocarbon production rate value. By using stochastic optimization techniques, there is no limit to the number of decision variables that can be optimized simultaneously. The presented method in this paper is a new metaheuristic algorithm which enables us to analyze a system of mathematical equations containing a large number of decision variables and determine the optimum values of them that should give the most economic result. This is referred to as the Ant Colony Optimization Algorithm. Ant Colony Optimization technique leads us to lower computational cost to optimize complicated problems too. Although applied to discrete domains, this algorithm with some modifications has been applied to continuous optimization. Here, a numerical simulation is initially applied for modeling the hydrocarbon reservoir and then the results are analyzed and furthermore optimized to enhance profitability using Ant Colony Optimization algorithm. The developed code in MATLAB environment, based on Ant Colony Optimization, is able to estimate production and injection wells location, fluid injection rate and well flow pressure which would result in improved hydrocarbon production. This algorithm is simple to implement and the results of case studies show its ability to provide fast and accurate solutions. Results prove the reliability of algorithm for solving a large class of optimization problems in petroleum engineering.
Partial discharge detection device using ultrasonic sensor on medium voltage XLPE cable

There are many methods that have been studied by earlier researchers in order to detect the acoustic properties of Partial Discharge (PD) emitted by PD sources. One of the methods known as ultrasonic sensing on medium voltage Cross-Linked Polyethylene (XLPE) cable was adopted to detect partial discharges on commercial applications, usually by using Acoustic Emission (AE) sensors. This paper presents the processes of designing a PD sensor to detect the acoustic properties of the partial discharges on medium voltage XLPE cable. This PD sensor method works by detecting the partial discharges occurred at the joint of the cable which can act as an early warning device to help minimize the repair and maintenance costs of degrading cable. Result of the experiment shows the complete design of the prototype device, the device after fabrication and the functionality of the device. This design of the prototype can be beneficial for future uses in designing cost efficient and smaller sized PD detection devices. By positioning the sensor in horizontal position directly to the source of PD on the cable, the sensor will be able to detect acoustic properties of PD, by picking up the frequencies beyond 40 kHz. By varying the voltage applied values, a design of experiment (DOE) is carried out accordingly. Result of the experiment shows that the prototype device is functioning as expected, and hence this finding will be very useful to the consumers of power industries as the sensor device can serve as an alternative device to the commercialized PD sensing devices which are bulky and expensive.
Annulus CO2-corrosion of high strength steel wires from unbounded flexible pipes

Recent premature failures of unbounded flexible pipes brought life to the discussion of the detrimental effects of the CO2 on the structural layers of unbounded flexible pipes. Flexibles are structures composed of several concentric layers of polymers and steel wires. The steel wires support the mechanical loads and reside inside a highly confined annulus space bounded by two polymer layers. The environment in this occluded annulus region evolves as water and other chemicals permeate from the produced fluid in the bore through the inner sheath, or from breaches in the outer sheath. As a result, the armour wires can be subjected to corrosion that needs to be considered against the service environment. The complexity of the annulus environment makes the study of corrosion in it challenging. Thus, understanding the interactions between the steel and the electrolyte is essential for reproducing the corrosion of the structural layers. Despite that, many occluded CO2-corrosion tests are conducted in environments, which neither reproduce the state of the electrolyte, nor the mechanisms found in the field. Although some studies on corrosion in annulus environments have been published, there remains further work to be done to fully understand the extent of variables that may potentially affect the annulus corrosion rate and mechanisms within it, particularly concerning the effect of CO2 permeation. The present study describes the corrosion rates of high strength carbon steel wires in brines with carefully controlled supply rates. A simulation of the gas flow rate was carried to study the permeation behaviour on severe CO2 service conditions. Weight loss and electrochemical measurements were conducted to evaluate the corrosion rates. Pressure, temperature and composition of the brine, covering liquid, gaseous and supercritical states of CO2 have been explored by simulation in search for critical patterns. The data in low pressure are compared to simulation and those of previous studies in the literature. The experiments show low corrosion rates and a clear dependence between the concentration of iron, pH, open circuit potential and corrosion rate. Changes in these properties were found to describe three stages of corrosion. No substantial influence on the maximum corrosion rate was seen after a two-fold increase in the CO2 supply rate.
Effects of extreme environmental conditions on the mesoscale and nanoscale properties of calcite-cemented sandstone

iv LIST OF FIGURES . x LIST OF TABLES . xv ACKNOWLEDGEMENTS . xvi CHAPTER 1 GENERAL INTRODUCTION . 1 1.1 Motivation . 1 1.2 Research objectives . 3 1.3 Thesis organization . 3 1.4 References . 4 CHAPTER 2 BACKGROUND AND LITERATURE REVIEW . 6 2.1 Cracks in rock . 6 2.2 Rock fracture mechanics . 7 2.3 Fracture toughness testing methods . 10 2.4 Factors influencing rock fracture toughness . 12 2.4. 1 Effect of high temperature on rock properties . 12 2.4. 2 Effect of water saturation on rock properties. 13 2.4. 3 Effect of freezing on rock properties . 16 2.5 History of indentation testing . 17 2.5. 1 Nanoindentation tests . 18 2.6 Digital image correlation technique . 21 2.7 Automated mineralogy and scanning electron microscopy . 23 2.8 Conclusions . 24 2.9 References . 24 CHAPTER 3 EFFECTS OF HEAT ON ROCK FRACTURE PROPERTIES: STUDIES OF MODE I FRACTURE TOUGHNESS, CRACK PROPAGATION VELOCITY AND CONSUMED ENERGY IN CALCITE-CEMENTED SANDSTONE . 39 3.1 Abstract. 39 3.2 Introduction . 40 3.3 Materıals and methods . 41 3.3.1 Sample preparation . 41 3.3.2 Porosity and density measurements . 42 3.3.3 Pand S-wave velocity measurements . 43
Plasmon-induced light absorption in mid-infrared based on hexagonal-shape graphene

In this manuscript, we numerically propose the plasmon-induced light absorption based on periodical hexagonal-shape graphene. Under the both TM- and TE-polarization light, the patterned graphene can support surface plasmon resonances (SPRs) and introduce the light absorption in mid-infrared, and the mode properties of SPRs are also studied. Besides, the impacts of geometric parameters, Fermi levels as well as number of layers of graphene on absorption spectrum are thoroughly investigated. Finally, a metal layer is introduced at the bottom of the structure to enhance the absorption. Since such pattern graphene can be naturally grown and shaped due to the atom arrangement of graphene, it has low requirement of optical fabrication, and the supported double SPRs can also provide double-peak absorption. This work can find potential applications such as absorbers, photodetectors and biosensors.
Evaluation and calculations of modes resonant cantilever for laser optical fiber assembly

Biosensors depend on cantilevers have developed a promising tool for detecting biomedical, optical laser communication and many fields of interactions with high accuracy. We modeled the operation of cantilevers with two magnetic and coil using Ansys program. This simulation technique can capably be used to select the appropriate design and dimensions of cantilever with the geometry of system. The primary main of the magnetic design is to improve the geometry of the coil and shape to yield a highly uniform for 3D of optical fiber includes Silica Glass and Nickel cantilever, two magnets and one coil that apply to force on the cantilever cylinder is using as a cantilever in the designing of this case.In conclusion,resonant frequency( tuning applying cantilivier presented in the resracher have larger variable range by using 2-magnets with the coil.However,the adjusting of the system and changing the deminsions.Resolutions to this problematic contain tuning the modes of resonant frequency to produce by cantilivier with 2-magnets and coil when the signal pass from laser source. Based on these simulations and characterization results, the proposed assembly can be a good applicant for evolving a low price, high material platform for many biological, laser optical fiber, communication, machine learning, biosensors and biomedical applications.
Evaluation of immunotherapeutic potential of Ocimum sanctumin bovine subclinical mastitis

Mastitis, the inflammation of mammary glands, is caused by a wide range of contagious and environmental microbes, whose clearance from the udder is generally dependent on the use of antibiotics. However, antibiotic therapy may result in development of drug-resistant microbes and depress the activity of polymorphonuclear cells. The present study was therefore undertaken to explore the immunotherapeutic potential of an herb, Ocimum sanctum, in mastitis in dairy cows. The study involved twenty HF × Sahiwal lactating dairy cows, each identified with at least one specific subclinical mastitis quarter as per International Dairy Federation criteria. The cows were divided into two equal groups: a control group and a group administered O. sanctum leaf powder at 600 mg/kg body weight daily divided into two doses orally for 7 days. The treatment could eliminate 69.23% of intramammary infections (χ 2 = 5.07; P ≤ 0.5) and resulted in a significant reduction in somatic cell count and ceruloplasmin concentration, thus subsiding udder inflammation and improving milk quality. The herb was also found to possess immunomodulation potential, as evidenced by the significant increase in phagocytic activity of milk neutrophils and enhanced lactoperoxidase and myeloperoxidase activities. Thus, the results indicated the immunotherapeutic potential of O. sanctum in treating bovine-specific subclinical mastitis.
Louver Function in Hybrid Aligned Reverse Mode Using Dual Frequency Liquid Crystal

We have proposed reverse mode liquid crystal (LC) cells with a hybrid alignment nematic (HAN). A dual frequency LC which has positive and negative dielectric anisotropies and a reactive mesogen were used to prepare the cell. The reverse mode HAN cell has a transparent state at any incident angle in the voltage off state. The cell scattered a normal incident light by the voltage application and the transmittance, however, becomes high at a certain oblique incident angle like a louver of a window shutter. Such an incident angle can be switched by the frequency of applied voltage since the reoriented LC director changes from perpendicular to parallel to the substrate. Moreover, the incident angle switching was theoretically analyzed using conditions of refractive index matching and mismatching between the LC and the reactive mesogen.
ACUTE RESPONSES OF RATE PRESSURE PRODUCT IN SETS OF RESISTANCE EXERCISE

Objective: To compare the acute responses of rate pressure product (RPP) between dynamic and isometric sets of resistance exercise (RE); compare the acute responses of RPP between upper and lower limbs in RE. Methods: Nineteen active men (22.7 ± 2.2 years) attended this study in a random crossover model. In the first day they performed hemodynamic measurements and one maximum repetition tests (1RM) in leg press (LGP) and bench press (BCP) exercises. In the second, third, fourth and fifth days they performed the following tests: LGP isometric, BCP isometric, LGP dynamic and BCP dynamic, respectively. Isometric protocols were conducted in 3 sets of 40 s (1 st set: 25% 1RM, 2 nd set: 50% 1RM, 3 rd set: 75% 1RM) and dynamic protocols in 3 sets of 10 repetitions (1 st set: 25% 1RM, 2 nd set: 50% 1RM, 3 th set: 75% 1RM). The RPP was obtained immediately after each set. Results: A comparison between protocols showed that RPP was higher (P < 0.05) in dynamic than in isometric protocol. A comparison between exercises showed that RPP was higher (P < 0.05) in LGP than BCP exercise. Conclusions: In similar relative intensities, the acute cardiac responses are influenced by the exercise protocol, since the RPP was higher in the dynamic condition. Furthermore, RPP seems to be related with recruited muscle mass, since that were observed higher values of RPP in exercises for lower limbs .
Study of grain distribution during friction stir welding of Al-Zn-Mg alloys using numerical simulation

During friction stir welding (FSW) of Al-Zn-Mg alloys, the grain size of the welded material significantly affects its mechanical properties. In this study, the FSW process was simulated using the finite element method (FEM). Subsequently, the Zener-Hollomon parameters and grain size were calculated using the results of the stimulation of the temperature and strain rate fields. Also, the accuracy of numerical simulation was proved by experiments. It was found that the Zener-Hollomon relationship correctly predicted the grain size for the weld stirring zone (SZ) and thermal-mechanical affected zone (TMAZ), and we concluded that low rotating and high welding speeds resulted in smaller grain sizes for the SZ. Moreover, the high welding speed could effectively improve the grain condition at the edge of the TMAZ and the specific relationship between Zener-Hollomon parameters and the average grain diameter of SZ can be expressed as: Z = 9.09 × 1013d−4.74.
Laser cladding Ni-Ti-Cr alloy coatings with different process parameters

ABSTRACT In this work, the alloy coatings were fabricated from Ni-Ti-Cr powder by laser cladding with different process parameters on Q235 mild steel. The effects of laser cladding process parameters on the microstructure and properties of the coating were studied. The crack resistance of coating is improved by adjusting process parameters and in situ synthesized NiTi. A good metallurgical bonding is formed between the substrate and the coating and no obvious cracks are found. Under the lowest specific energy, the edge of the coating has no bonding with the substrate. The coatings are mainly composed of NiTi, Cr2Ti, and Cr. With the increase of specific energy, the grain size of the coatings becomes coarser, and the content of Cr2Ti increases. The microhardness and wear resistance of the coatings increase at first and then decrease. In comparison to the substrate, the microhardness of coatings is enhanced dramatically, and the highest microhardness was achieved under Es = 50.0 J mm−2. The wear resistance of the coatings is also improved significantly compared to that of the substrate.
Assessment of ICESat‐2 Ice Sheet Surface Heights, Based on Comparisons Over the Interior of the Antarctic Ice Sheet

We collected kinematic Global Navigation Satellite Systems (GNSS) surface height data, on a 750‐km ground‐based traverse of the flat interior of the Antarctic ice sheet, for comparison with Ice, Cloud, and Land Elevation Satellite‐2 (ICESat‐2) surface heights. Vertical errors in the GNSS data are estimated to be 5.6 cm, comparable to results from a previous traverse and with year‐to‐year comparisons. Comparisons of the GNSS heights and 6 months of ICESat‐2 ATL03 photon‐based heights and ATL06 segment‐based heights indicate that the accuracy and precision of ICESat‐2 data are comparable to that of results from the ICESat mission: ATL03 is currently accurate to better than 5 cm with better than 13 cm of surface measurement precision, while ATL06 is currently accurate to better than 3 cm with better than 9 cm of surface measurement precision.
Wideband infrared metal wire grating polarizer using holographic lithography and lift-off process

In this work we design a wire grid polarizer(WGP) with silver nanowire grids on a germanium(Ge) substrate with 550nm period and 200nm thickness double-layer and single-layer wire grids based on FDTD method, which can achieve an average TM transmittance(TMT) over 70% and 48% and an extinction ratio(ER) over 76dB and 32dB respectively in the range of 3~15μm waveband. The photoresist grating was made by the Lloyd’s mirror interferometer interference lithography (IL) systems and the metal silver was deposited by thermal evaporation, which avoid the high cost of electron beam lithography and the difficult process of wet etching or dry etching. The fabrication shows that method is proved to be easy implement in the fabrication of sub-wavelength metal gratings. The experiment results show the polarizer has uniform polarization characteristics in the wide infrared band that the average TMT and ER of the doublelayer polarizer are 72.6% and 27.5dB in 3~15μm with single side antireflection coating. The average TMT and ER of the single-layer polarizer are 59.1% and 25.1dB in 3~15μm.
Micro-Mechanical Analysis of Corrosion Products Formed During Long-Term Carbonation Induced Corrosion of Steel

During corrosion distinct types of corrosion products form, composed of different ratios of ferrous ions and oxide, hydroxides. Corrosion products have different physical and mechanical properties, mainly density, resistivity, volume and modulus of elasticity compared to iron. Knowing properties of corrosion products is indispensable for service life modelling of structures and can give valuable insight into the long-term corrosion propagation process. In this study micro-indentation method was used to evaluate mechanical properties of different layers formed during long-term carbonation induced corrosion of steel in concrete. Investigation was performed on three sets of reinforced concrete samples, that underwent corrosion during 50, 60 and 70 years. Raman microspectroscopy was performed locally to determine and locate the constitutive phases of the corrosion system and to correlate them to the results of micro-indentation. Using grid technique, spatial distribution of phases with different mechanical properties was obtained for samples of different age. Comparison of values of mechanical properties for the same phases obtained on different samples, allowed hypothesis on their long-term behaviour.