Low Current Values Research Articles

3-Phenylquinazolin-4(3H)-one via a renewable approach as an efficient corrosion inhibitor for mild steel in acid media

3-phenylquinazolin-4(3H)-one (3pq) an organic aza-heterocyclic compound synthesised using a renewable biomass source, and the structure is subsequently confirmed using 1H NMR, 13C NMR and FT-IR spectroscopic techniques. The inhibition activity of 3pq was examined with a set of experiments like Weight loss measurements which provided a high inhibition efficiency (IE) of 90.0% and a low corrosion rate (CR) of 1.54 mm/y at 300 ppm. Electrochemical studies such as potentiodynamic polarization study confirmed the mixed inhibition activity of the inhibitor molecule with low corrosion current (icorr) value of 17.4 μA/cm2 in the presence of higher concentration of 3pq, and electrochemical impedance spectroscopy showed higher charge transfer resistance (Rct) value of 524.81 Ω cm2 and all these experiments have been used to examine 3pq′s inhibiting capability for MS in 1 N HCl solution. The examined compound's ability to prevent corrosion is less effective in higher temperature. 3pq followed the Langmuir adsorption isotherm, which showed higher linearity than the Freundlich and Temkin adsorption isotherm models. The surface morphology was examined using scanning electron microscopy (SEM), which showed a smoother surface corresponding to the formation of a protective film signifying effective adsorption of inhibitor on MS surface, atomic force microscopy (AFM) signifies lower surface roughness (19.62 nm) in inhibited MS when compared to the uninhibited MS (81.63 nm) and Contact angle measurement explains the formation of the hydrophobic layer of 3pq on the surface of the MS in which the contact angle rises from 48.5° (uninhibited MS) to 99.7° (inhibited MS). UV–Visible spectroscopy (UV–Vis.) was employed to explain the complex formation of the inhibitor at the MS surface. X-ray photoelectron spectroscopy (XPS) and Fourier transform infra-red Spectroscopy (FTIR) was employed to confirm the effective adsorption of inhibitors on the MS surface. Additionally, computational studies based on Density functional theory (DFT) was employed to study the ability of 3pq to get adsorbed on the MS surface and found that 3pq has a perfect affinity to get adsorbed on the MS.

Evaluation of Galvanic and Crevice Corrosion of Watch Case Middle (1.4435 Steel) and Bottom (Panacea® Steel) Assembly Supposed to Be in Prolonged Contact with the Skin

Today, laws protecting the population at the global level aim to minimize the induction risk of allergies to type IV contact dermatitis. In the European population, the prevalence of nickel allergy is at 10%–15% of adult females and 1%–3% of adult males. A total of 30% of nickel-sensitive people in the general population develop hand eczema. This study concerns the possibility of assembling a bottom of nickel-free austenitic steel (Panacea®) in a watch case middle made of a grade of austenitic steels, steel 316L (DIN 1.44359), to avoid the risks of Ni release and to develop a galvanic pile between these two dissimilar materials. Two types of methods were used: direct measurements and prediction techniques (mixed potentials theory). For the degradation of thbottom-middle watch assembly, Nielsen–Tuccillo tests were performed, and Ni release measurements according to EN 1811 completed the study. All direct electrochemical investigations and galvanic current prediction measurements show low current values of 40–400 nA. Measurements of nickel release of Panacea® and 316L reveal small quantities of nickel, much lower than the 0.5 µg/cm2 per week that the European legislation enforces. The nickel-free steel Panacea® in the work hardening conditions 280, 427, and 510 HV0.1s were also studied. The cation extractions reveal the large quantities released from Cr, Mo, Mn, and Fe, so there is a risk of toxicity in contact with the skin.

A study on the EDM drilling of reaction-bonded silicon carbide using different electrode materials

Today, there is a growing demand for efficient hole manufacturing technology in many industries such as aeronautics, automotive and nuclear, among others. Thus, the present study deals with the machining of through holes on SiSiC advanced ceramic by using Electrical Discharge Machining (EDM) drilling technology. Since recommendations related to the electrode characteristics and settings parameters are found to be scant for the industrial use of EDM drilling of SiSiC ceramics, this research work comes to cover this gap as it presents a complete study focused on the influence on different electrodes under rough and finish machining conditions. In particular, the influence of four electrodes materials (copper, copper-tungsten, graphite and copper infiltrated graphite) and three different electrode diameters ranging from 2 to 4 mm are investigated. In addition, the rotational speed of the electrode is also analysed. From the experimental results, both electrode material and machining regime, seem to be the most relevant factors of all. In the case of 2 mm diameter electrode, material removal rate (MRR) with Cu electrode was, approximately, 4.5 times higher than that obtained with a C electrode. In fact, it was found that copper electrode rotating at 20 rpm combined with high values of discharge energy (I = 2 A; ti = 70 µs) is the most economical option in terms of production cost and production time, as it gives a high MRR of 0.4754 mm3/min and a minimum electrode wear (EW) value of 7.52%. Moreover, slightly higher values of MRR were achieved for CuC electrode compared to those obtained with C electrode, indicating that the addition of Cu in the electrode contributes to a greater removal of material. However, a value of Ra of 0.37 µm could be obtained by setting low current intensity values (I = 0.5 A; ti = 45 µs) combined with C electrodes and with no rotation.

Impact of high constant charging current rates on the charge/discharge efficiency in lead acid batteries, for residential photovoltaic system applications

The charging and discharging of lead acid batteries using Traditional Charge Controllers (TCC) take place at constantly changing current rates. These techniques do not permit the accurate estimation of energy input and energy output during charge and discharge processes. In this work, the main objective is to investigate the effect of high constant charging current rates on energy efficiency in lead acid batteries, extending the current range to 8A from 5A already reported in literature. We also present the experimental proof of the variation of electrolyte temperature with magnitude of the constant electric charging current. Firstly, a Constant Current Circuit (CCC), capable of charging the battery at current rates ranging from 0.5A to 8A was built and used to run experiments on two sample lead acid batteries, battery sample 01, the Vanbo battery and battery sample 02, a Winbright battery. Charge and discharge processes were conducted on these batteries through the CCC and efficiencies computed per current rate tested. Secondly, to compare the results of the CCC built with those of a TCC, the very batteries (battery sample 01 and battery sample 02) were charged and discharged through a TCC and their corresponding efficiencies computed. Thirdly, three constant charging current regimes (0.5A, 5A and 8A) were chosen within the tested current rates for which further electrolyte temperature monitoring tests were carried out, using two other lead acid battery samples of different health states. This was carried out on battery sample 03 which was a SIGA lead acid battery type with a compromised state of health and on battery sample 04, another brand new Winbright battery with relatively good state of health. It was noticed that, for the CCC, efficiencies between 62 % and 82 %, were recorded for the Vanbo Battery (Sample 01) while efficiencies of 53 % to 91 % were recorded for the Win Bright Battery (Sample 02). On the other hand, the efficiency of the Vanbo Battery (Sample 01) through the TCC was found to be 66 % while that for the Winbright battery (Sample 02) was found to be 79 %. As for electrolyte temperature monitoring, battery sample 03 with compromised health state registered higher temperatures for higher charging rates while battery sample 04 of good state of health registered no noticeable increase in temperatures even for constant charging current rates up to 8A. Since existing literature had tackled lower current values from 0.5A to 5A, this work therefore comes in with an extension of the current rates, testing higher current magnitudes and obtaining the same results with conclusion that, if the same energy is stored in a lead acid battery at precise rates, the charge/discharge efficiency of the battery increases as the charging current rate increases. As regards electrolyte temperature monitoring, the work provides further proof that even at charging current rates as high as 8A, battery electrolyte temperatures still remain within acceptable limits(below 50 °C).

1,2,3-Triazole mediated, non-halogenated phosphorus containing protective coatings from castor oil: Flame retardant and anti-corrosion applications

Halogenated flame retardants are under regulatory scrutiny despite their outstanding flame retardancy. The present study focuses on the development of non-halogenated flame retardant and corrosion-resistant polyurethane coatings from castor oil. Towards this attempt, a non-halogenated, hydroxy functionalized, triazole and phosphorus-containing reactive flame retardant (HTP-FR) with anti-corrosive properties was designed and synthesized by azide-alkyne cycloaddition of 2-azidoethanol, and Diphenyl prop-2-yn-1-yl phosphate. By adding HTP-FR to castor oil in 50 and 100 weight percentages, CO-HTP-PUs (CO-HTP-50, CO-HTP-100, where HTP-FR was loaded as 50 and 100 wt%, respectively) were made and their flame-retardant and corrosion resistance properties were tested. The parent castor oil and MDI-based polyurethane (CO-PU) was concurrently synthesized and investigated as control for comparative appraisal. The FR behaviour of the PUs was examined using bomb-calorimetric testing and lab-scale flame tests. From the lab-scale flame test, it was found that the intumescent char length of the CO-HTP-100 after burning is longer than that of the CO-HTP-50 due to its high HTP-FR content. A substantial decrease in gross heat of 8.23, and 13.17 % was observed for the CO-HTP-50, and CO-HTP-100, respectively compared to the control CO-PU. The intumescent FR mechanism of CO-HTP-PUs was studied using Thermogravimetric Analysis coupled with Mass Spectroscopy (TGA-MS) analysis and Energy-dispersive X-ray spectroscopy (EDX) elemental analysis with mapping. The increase in P content of the post-burn sample in comparison to their unburn counterparts, and the expulsion of nitrogen gas from the triazole moiety from CO-HTP-PUs corroborated the intumescent FR mechanism. High char yields at 700 °C of CO-HTP-100 (20.3 wt%) and CO-HTP-50 (15.5 wt%) when compared to control CO-PU (3.6 wt%) also substantiated the FR behaviour of CO-HTP-PUs. The performance of these protective coatings against corrosion was investigated by the electrochemical methods. The significantly low corrosion current (Icorr) values (2.60 × 10−9 A/cm2), high polarization resistance (42.7 × 104 Ω cm2), bulk resistance values (10.4 × 106 Ω cm2) and low corrosion rate (3.0 × 10−5 mm/year) of CO-HTP-100 demonstrate the excellent corrosion resistance property of HTP-FR.

Effect of ‘Mo’ doping into BiMnO3 on structural, dielectric, and leakage current properties

The simultaneous existence of more than one ferroicorder (ferroelectric, magnetic and ferroelastic) i.e., multiferroism in materials is the center of attention of the current materials researchers. Multiferroism is rare in the materials due to the different chemistry of the ferroic orders and highly useful in various device applications such as in spintronics. In this connection, BiMnO3 is one of the multiferroic materials among the number of available multiferroic materials. It shows ferroelectricity as well as antiferromagnetic nature simultaneously . In the present work, efforts have been made to synthesize the BiMnO3 in pure phase as well as with the doping of ‘Mo’ in the ratio of 2 %, 4 %, and 8 % via solid-state reaction route and denoted by BMM0, BMM2, BMM4, and BMM8, respectively. The structural analysis confirms the monoclinic structure along with some impurities and also confirms the polycrystalline nature of all the samples. Impurities reduce with the ‘Mo’ doping into BiMnO3. The dielectric and leakage current density measurements confirm the high dielectric constant, low dielectric loss, and low leakage current density values in the samples as increment in the ‘Mo’ content into the pure BiMnO3 phase. The BMM8 has the dielectric constant (∼2265 at 1 kHz and ∼ 385 at 10 kHz), dielectric loss (∼2.32 at 1 kHz and ∼ 2.66 at 10 kHz), and leakage current density (∼3.73 × 10-4 A/cm2 at 2 V and ∼ 1.00 × 10-3 A/cm2 at 3 V).

Effect of temperature on anti-corrosion properties of aluminum alloy anodized by sulphuric acid

Temperature is one of the most important parameters in anodizing treatments of aluminum alloys as it directly affects the quality of the anodic coatings. This research study has examined and investigated the effect of this important parameter on the anti-corrosion properties of the anodizing layers of aluminum alloy 5083.The morphology and crystalline structure of anodic oxide layers were characterized respectively by X-ray diffraction, scanning lectron microscopy and EDX analysis. The corrosion behaviour of the alloy, before and after anodization at different temperatures, was analyzed in chlorinated medium using different electrochemical techniques, namely open circuit potential measurement, potentiodynamic polarization and electrochemical impedance spectroscopy. The results showed that temperature has a significant influence on the quality of the anodic oxide layers. Therefore, for a relatively low treatment temperature, the developed anodic films show high surface roughness values and contain fewer pores and defects compared to the films obtained at 20°C. Electrochemical analysis indicates that these films also show good corrosion resistance in the chloride environment. This is reflected by relatively low corrosion current density values as well as relatively high polarization resistance values.

Numerical analysis of direct-current (DC) plasma processing for high-efficient steel surface modification

Nowadays, direct-current (dc) non-transferred arc plasma torch has drawn significant interest from both academia and industry due to the capability to process products in an efficient and convenient way. The core of this technology is to clarify and manipulate the arc behavior at the interior of the dc plasma torch to produce ideal plasma jets for processing. To solve this problem, a quasi-steady axisymmetric model is built to simulate and compare the arc characteristics in different operating conditions and different nozzle structures of the plasma torch. The results uncover distinct aspects of the study on arc characteristics, including the detection of the primary arc attachment region and its spatial features caused by the choking effect of torch structure. The thermal efficiency focused on processing substrate is also calculated in this paper for estimating the performance of plasma processing. The calculated results show that increasing the mass flow rate brings better thermal efficiency and the greatest promotion is at least 6% in the same current value, whereas improving the arc current value causes the opposite result. Meanwhile, two types of nozzle are compared to the original design in thermal efficiency, where the wide nozzle is chosen for torch optimization due to its best power efficiency. The secondary arc attachment on the metal substrate is discovered though its impact scope is only within a radius of 10 mm from the torch axis, its effect on the processing could be ignored for the extremely low electric current value.

Особенности переноса заряда при холодной полевой эмиссии с катодов из углеродных нанотрубок

The conductivity of the emitter section of a nanodiode circuit with an emitter made of an individual closed carbon nanotube (CNT) and arrays of closed CNTs was studied. High values of cold field emission were observed, as well as nonlinearity and anomalies of the current-voltage characteristic (CVC), which manifested themselves in the form of peaks at low and high current values. Peaks in the CVC have distinct areas of negative differential conductivity. The anomalously high currents in the I–V characteristics of cold field emission of electrons from a nanoemitter made of closed CNTs can be associated with a sharp increase in the density of electron states at energies near the van Hove singularity.

Studies and comparison of natural dye-sensitized solar cells and thin-film solar cells

A significant effort is presently underway to improve the efficiency of limited sustainable energy devices. Dye-sensitized solar cells (DSSCs) are one of the most efficient and promising photovoltaic technologies. Tomato and strawberry syrups were used as natural sensitizers of anatase-based nanostructured TiO2 and coated ITO conducting glass to create a generic method for the fabrication of natural dye-sensitized solar cells. The remarkable value of voltage and current was noticed by using a sample preparation method. In addition, CuO thin-film solar cell has been fabricated using DC sputtering to compare with the DSSC solar cells. The low voltage and current values are observed for CuO solar cells, whereas, DSSC solar cells show a good value of efficiency as 1.25 × 10−6 % and 0.14 × 10–6 % for tomato and strawberry syrups respectively, under 775 W/m2 (Sunlight intensity).

The Inhibitive Effect of Sebacate-Modified LDH on Concrete Steel Reinforcement Corrosion

In recent decades, layered double hydroxides (LDH) have been proposed as innovative corrosion inhibitors for reinforced concrete. Their protective action is based on the ability to intercalate specific anions in the interlayer and on their ability to exchange the intercalated anion. In the present study, an organically charged LDH, with sebacate anions in the interlayer (LDH-S), is proposed as a water-repellent additive for mortar. The waterproofing efficiency of LDH-S and the associated corrosion inhibition ability has been evaluated in reinforced mortar samples. A 42% decrease in the water capillary absorption coefficient has been estimated when 3% LHD-S is added to a mortar. Both the passivation processes of the steel rebars during the curing period and the initiation of corrosion due to chloride exposure have been studied by electrochemical measurements. Three different mortars have been evaluated: reference mortar (REF), mortar with Mg-Al LDH (LDH), and mortar with LDH-sebacate (LDH-S). The latter has shown an important protective capacity for preventing the initiation of corrosion by chloride penetration, with an inhibitory efficiency of 74%. The presence of LDHs without sebacate in the interlayer also improved the performance of the mortar against rebar corrosion, but with lower efficiency (23% inhibitory efficiency). However, this protection is lost after continued chloride exposure over time, and corrosion initiates similarly to the reference mortar. The low corrosion current density values registered when LDH-S is added to the mortar may be related to the increased electrical resistance recorded in this mortar.

Synthesis and characterization of ZnO based varistor ceramics: effect of sintering temperatures

PurposeThe purpose of this paper is to investigate the effects of the sintering temperature on the microstructural, morphological and electrical characteristics of Zinc oxide (ZnO)-based varistors.Design/methodology/approachThis study used a conventional method to design and produce ZnO varistors by sintering ZnO powder with small amounts of various metal oxides. Furthermore, the effect of sintering temperature on varistor properties of (Bi, Co, Cr, Sb, Mn)-doped ZnO ceramics was investigated in the range of 1280–1350 °C.FindingsThe obtained results showed an EB value of 2109.79 V/cm, a Vgb value of 0.831 V and a nonlinear coefficient (α) value of 19.91 for sample sintered at temperature of 1300 °C. In addition, the low value of tan δ at low frequency range confirmed that the grain boundaries created in 1300 °C sintering temperature were obviously good.Originality/valueBased on the previous research on the ZnO-based varistors, a thorough study was carried out on these components to improve their electrical characteristics. Thus, it is necessary that those varistors have low leakage current and low value of dissipation factor to ensure their good quality. High breakdown fields and nonlinearity coefficients are also required in such kind of components. The effect of sintering temperature on the varistor properties of the new compositions (zinc, bismuth, manganese, chrome, cobalt, antimony and silicon oxides)-doped ZnO ceramics was studied in the range of 1280–1350 °C. Also, the microstructure and the phase evolution of the samples sintered at various temperatures (1280 °C, 1300 °C, 1320 °C and 1350 °C) were investigated according to X-ray diffraction and scanning electron microscope measurements.

Electrochemical synthesis of 2D copper coordination-polymers: Layer-stacking deviation induced by the solvent and its effect on the adsorptive properties

A 2D Cu-based Metal-Organic Framework (MOF), namely copper-terephthalate (Cu(1,4-BDC)), was successfully synthesized by electrochemical method for effective methylene blue (MB) sorption from aqueous solutions. The composition, morphology, and the presence of functional groups in the obtained material were verified by Fourier Transform Infrared spectroscopy (FTIR), Powder X-Ray Diffraction (PXRD), Thermal (TGA), and Elemental (EA) analysis, as well as Scanning Electron Microscopy (SEM). The effect of electrochemical parameters applied in the synthesis protocol (i.e., a potentiometric or amperometric mode) on the resulting product composition was evaluated. The electric current value was determined as a variable controlling the type of crystal structure present in the obtained MOF. A structure with open channels - CuBDC1 was favored under the current higher than 0.35 A conditions. In contrast, for the lower current values and upon the amperometric mode in the material, a CuBDC2 phase with DMF molecules occupying the grids of the layers was also present. The MB sorption studies were analyzed both with kinetic and equilibrium models. The obtained results showed the time evolution could be fitted with a pseudo-second-order model with the rate constant k2 equal to 0.047 g μmol−1 h−1. According to the Langmuir isotherm model, the maximum sorption capacity was determined as 76.63 μmol g−1. After MB sorption, the MOF material could be easily regenerated under mild conditions with good recyclability up to the four cycles (76.77%).

Плазмохимическое травление в постростовой технологии фотоэлектрических преобразователей

Investigation of the heterostructure plasmachemical etching technology for fabricating multi-junction photovoltaic converters has been carried out. The dividing mesa-structure forming stage at different etching regimes and subsequent disturbed layer removing by liquid chemical treatment has been reviewed. The influence of mesa etching methods on cells photovoltaic characteristics has been investigated. Developed was the technology of photovoltaic converters fabrication with low current leakage values less than 10-9 A at voltage less then 1 V with high resistance to degradation.

Plasmachemical etching in postgrowth technology of photovoltaic converters

Investigation of the heterostructure plasmachemical etching technology for fabricating multi-junction photovoltaic converters has been carried out. The dividing mesa-structure forming stage at different etching regimes and subsequent disturbed layer removing by liquid chemical treatment has been reviewed. The influence of mesa etching methods on cells photovoltaic characteristics has been investigated. Developed was the technology of photovoltaic converters fabrication with low current leakage values less than 10-9 A at voltage less then 1 V with high resistance to degradation. Keywords: photovoltaic converter, heterostructure, plasmachemical etching, mesa-structure.

On the Thermal Dynamics of Metallic and Superconducting Wires. Bifurcations, Quench, the Destruction of Bistability and Temperature Blowup

In the present study, a numerical bifurcation analysis is carried out in order to investigate the multiplicity and the thermal runaway features of metallic and superconducting wires in a unified framework. The analysis reveals that the electrical resistance, combined with the boiling curve, are the dominant factors shaping the conditions of bistability—which result in a quenching process—and the conditions of multistability—which may lead to a temperature blowup in the wire. An interesting finding of the theoretical analysis is that, for the case of multistability, there are two ways that a thermal runaway may be triggered. One is associated with a high current value (“normal” runaway) whereas the other one is associated with a lower current value (“premature” runaway), as has been experimentally observed with certain types of superconducting magnets. Moreover, the results of the bifurcation analysis suggest that a static criterion of a warm or a cold thermal wave propagation may be established based on the limit points obtained.

Increasing of the corrosion resistance by preparing the trivalent nickel complex

This paper is intended to investigate the preparation of a complex ion Ni chloride (II) and with ligand Schiff base (N, N) dimethyl of the amino Benzaldhyde and characterized ligand prepared and complexion Ni chloride(II). These metallic organic chemical compounds have been checked using Spectroscopic Techniques Spectrums of infrared and spectra of UV. The study included a test of the Corrosion Rate of free matter and nickel complex in tap water solution in a linear polarization method By the linear polarization curves resulting from Tafel device readings. The results showed that the nickel complex has an effective inhibitory effect due to the low current value, which increases its corrosion resistance.

Extraordinarily high ultraviolet photodetection by defect tuned phosphorus doped ZnO thin film on flexible substrate

Phosphorus (P) doped zinc oxide (ZnO) thin film has skillfully been deposited on flexible substrate using radio frequency sputtering technique at room temperature under controlled oxygen ambient to tune its point defects. P doped ZnO film shows a very high ultraviolet (UV) photosensitivity with responsivity and detectivity values of 23.5 mA/W and 1.86×1013 Jones respectively as compared to the values of 0.073 mA/W and 2.56×1010 Jones respectively for pristine ZnO. Incorporation of P dopant under controlled oxygen ambient results in a very low dark current value due to acceptor-donor compensation leading to an unprecedentedly ultra-high photo-to-dark current ratio of 2.15×105 under 350 nm illumination. A photosensitivity under repetitive flat and bending conditions has been attained. Further, photoresponse towards a low intensity UV illumination of power 29 μW/cm2 has been noted with a photo-to-dark current ratio of 3.88×103 indicating an excellent photodetection efficiency of the P doped ZnO film.

Optimizing multi-circuit transmission lines for single-phase auto-reclosing

In this paper, novel multi-circuit transmission line (MCTL) designs with low secondary arc current (SAC) values are proposed. The Non-dominated Sorting Genetic Algorithm II (NSGA-II) was used to generate the optimized tower structures. The aim is to select the MCTL configuration that satisfies multiple objectives such as increased capacity, reduced cost, right-of-way (ROW), and tower height, while satisfying several constraints such as SAC limit, ampacity, electric field, etc. The objective function is formulated as a mathematical function of design variables such as sub-conductor position, phase arrangement, etc., and several constraints. Two-port theory is used to calculate the SAC resulting from different faults along the line, which is significantly faster compared with time-domain Electromagnetic Transient (EMT) simulations. Comparisons of MCTLs with and without SAC constraints are presented, clearly showing the importance of taking into account SAC limits during the optimization process. As a result, MCTL structures with SAC reductions of up-to 64% were obtained, indicating that the MCTL are able to successfully handle Single Phase Auto-Reclosing (SPAR).

Fabrication of Small-Pixel CdZnTe Sensors and Characterization with X-rays

Over the past few years, sensors made from high-Z compound semiconductors have attracted quite some attention for use in applications which require the direct detection of X-rays in the energy range 30–100 keV. One of the candidate materials with promising properties is cadmium zinc telluride (CdZnTe). In the context of this article, we have developed pixelated sensors from CdZnTe crystals grown by Boron oxide encapsulated vertical Bridgman technique. We demonstrate the successful fabrication of CdZnTe pixel sensors with a fine pitch of 55 and thickness of 1 and 2 . The sensors were bonded on Timepix readout chips to evaluate their response to X-rays provided by conventional sources. Despite the issues related to single-chip fabrication procedure, reasonable uniformity was achieved along with low leakage current values at room temperature. In addition, the sensors show stable performance over time at moderate incoming fluxes, below photons .