probe technique

Top PDF probe technique:

Electrical Characterization of CIGS Thin Film Solar Cells by Two and Four-Wires Probe Technique

Electrical Characterization of CIGS Thin Film Solar Cells by Two and Four-Wires Probe Technique

current transport outside the depletion region. This is the case for the case n>2 where the quasi-neutral region is dominated by the trap-assisted tunneling and field-assisted recombination. Nevertheless, we believe that in our case, this high ideality factor is due to nonlinear contact resistances which has reduced for 4-wire probe configuration. Tan et al, suggested different current conduction mechanisms for different voltage regions of device characteristics [17]. For example, lower voltage regions within 0 < V < 0.3 V do not fit the linear straight lines but fit with ¼ powder law given by I ≡ V 1.4 ,

16 Read more

Measurement of pH in a Thin Electrolyte Droplet Using the Kelvin Probe Technique

Measurement of pH in a Thin Electrolyte Droplet Using the Kelvin Probe Technique

The color distribution at the cathode and the color of the solution changed over time. The pH in the vicinity of localized corrosion during the free corrosion period (on the cathode side) was estimated to be 5.5, and the pH distant from the localized corrosion region was 10. Additionally, the pH near the Sb electrode on the cathode increased to over 10 and maintained a constant value based on the solution color results. The pH distribution observed around the pits on the cathode during the free corrosion (Fig. 8(a)) disappeared with increasing the cathodic polarization since the ORR was enhanced on the whole surface of the cathode. In contrast, the pH measurement using the KP system showed that the pH near the steel of the cathode side increased gradually from 7, finally reaching a stable value of 12. Therefore, the pH change induced during the simulated steel corrosion, as measured by the KP system, agreed with that measured with the pH indicator. Thus, it can be concluded that the pH measurement system using the KP technique / Sb electrode combination can be applied to pH measurements of thin electrolyte droplets on a corroding steel.

7 Read more

Synthesisation of 2223 Superconductors Rohitash Kumar, H. S. Singh

Synthesisation of 2223 Superconductors Rohitash Kumar, H. S. Singh

All the measurement were carried out between 298K to157K. All the experimental work wsa carried out at IIT Roorki Uttrakhand. The Tc of the superconducting sample has been measured by using the resistivity measurement carried out by four-probe technique, which is considered as a good method for studying the electrical behavior of superconducting materials and a good tool for determining the Tc [11]. In this method, a small current is passed through a sample and the voltage drop across it. The terminals distinct from those used for passing the main part of the current through the specimen and the electrical contacts of the sample were made of fine copper wires and adhered with silver paste. The system was used for the measurement of critical resistance of the sample, with the presence of liquid nitrogen. The experimental results obtained for the different compounds are show in figure below 4.1 to 4.10. It can be seen from the variation of the resistance the sample exhibit superconducting behavior [12].

9 Read more

Microwave Impedance Microscopy Of Nanostructured Carbon

Microwave Impedance Microscopy Of Nanostructured Carbon

In any scanning probe technique, the tip-sample interaction may be mediated by a host of different electrical, magnetic, chemical, mechanical, and atomic forces, comparing a land- scape rich in physical information that is accessible to measurement. The presence of this multitude of forces also makes the tip-sample interaction inherently complex [39], generally requiring detailed models to be understood. The tip-sample system of MIM is no exception to this need for modeling. While the sole quantities sampled are the magnitude and phase of the electric field reflected by the sample from a source coupled to the probe, numerous questions may arise regarding the resolution of the measurement, how the shape and size of the tip and tip-sample contact affect the applied field, and how that effect changes as the tip wears, for example. As the band structure in ordered materials arises from atomic ar- rangement, one may ask whether local sample stresses induced by the tip alter electrical conductivity or sample structure, as has been demonstrated in imaging of halfnium oxide films [40]. Still other questions may emerge, possibly regarding what methods of electrical transport and polarization are dominant and whether any resonances occur, the frequency dependence of the observed phenomena, whether the power transferred to the sample by the applied field is sufficient to induce a deviation from linearity in polarization response or even a local phase change, whether any resonant modes in the measurement system itself arise, etc.

139 Read more

Lanthanum Probe Studies of Cellular Pathophysiology Induced by Hypoxia in Isolated Cardiac Muscle

Lanthanum Probe Studies of Cellular Pathophysiology Induced by Hypoxia in Isolated Cardiac Muscle

This study was undertaken to evaluate directly the relationship between evolution of irreversible myocardial injury induced by hypoxia in an isolated papillary muscle preparation and the development of pathophysiological alterations related to severely impaired membrane function. An ionic lanthanum probe technique was employed as a cytochemical marker to monitor the progression of cellular injury, and data from this cytologic technique were correlated with ultrastructure and measurements of contractile parameters in a total of 67 muscles subjected to control conditions or to graded intervals of hypoxia with or without reoxygenation. Marked depression of developed tension and rate of tension development occurred after 30 min of hypoxia. Contractile function showed

15 Read more

All-optical switching using nonlinear subwavelength Mach-Zehnder on silicon

All-optical switching using nonlinear subwavelength Mach-Zehnder on silicon

respectively. This indicates that the optical power density in the wire waveguide is ~15 times greater than that of the SWG waveguide. Now if the proper conditions are met [1], and sufficient level of the optical clock peak power is delivered to the MZIS input, the nonlinear index change triggered inside the wire waveguide will be larger than in the SWG waveguide. This will induce a relative phase change between both arms of the MZIS which will be experienced by the optical probe signal (cw or low power data pulses) immediately following such high peak power optical clock. If the phase difference equals π, complete switching is achieved at the MZIS output. If not, incomplete switching will be observed. However, in order to satisfy interferometric conditions at the device output the use of optical pulses as the probe signal would also require both of the MZIS arms to be of equal optical length. Since in our experimentation with the MZIS device this was not fulfilled, we used cw laser light as the optical probe and the pump probe technique as a method for the demonstration of ultrafast picosecond all-optical switching capabilities of this novel interferometric structure. Our approach is conceptually illustrated in Fig. 4.

9 Read more

A colloidal probe microscopy study of cellulose/gypsum interactions

A colloidal probe microscopy study of cellulose/gypsum interactions

Drywall, which is made primarily of a calcium sulfate dihydrate (gypsum) core with paper on both sides, is one of the most widely used construction materials. Because board failure often occurs at the gypsum core/paper interface, it has become important to know the exact nature of the gypsum/cellulose bond. This study provides data about the nature of this interaction by means of AFM and Colloidal Probe Microscopy. These methods made it possible to distinguish among the different crystal faces and their respective interactions with cellulose. Measured in air, the adhesive forces between the AFM tip and the different faces varied according to f(010) < f(120) < f(111) at 50 % relative humidity. The differences in adhesive force with the different gypsum crystals can be attributed to the differences in surface chemistry. The information obtained will help guide improvements in the crystal production process to obtain better bonding between the crystal and the paper.

8 Read more

Subsequently 90 Repositioned Triple E Shaped Microstrip Patch Antenna Design for Multiband Application

Subsequently 90 Repositioned Triple E Shaped Microstrip Patch Antenna Design for Multiband Application

using is an integrated full wave EM simulator. It was found that the feeding position and the unique technique have provided the antenna to operate in X and Ku (12GHz) band. It was also concluded that the slots help to agitate the surface current path on the patch that generates local inductive effect which is responsible for multiband operation. We find this design very helpful for inter-galaxy and inter-satellite communication.

5 Read more

Rectangular Microstrip Patch Antenna Using Coaxial Probe Feeding Technique to Operate in S - Band

Rectangular Microstrip Patch Antenna Using Coaxial Probe Feeding Technique to Operate in S - Band

Microstrip antennas are characterized by a larger number of physical parameters than conventional microwave antennas. They can be designed to have many geometrical shapes and dimensions but rectangular and circular Microstrip resonant patches have been used extensively in many applications (Ramesh et al, 2001). In this paper, the design of probe feed rectangular microstrip antenna is for satellite applications is presented and is expected to operate within 2GHz - 2.25GHz frequency span. This antenna is designed on a double sided Fiber Reinforced (FR-4) epoxy and its performance characteristics which include Return Loss, VSWR, and input impedance are obtained from the simulation.

5 Read more

New approaches and applications in electrochemical scanning probe microscopy

New approaches and applications in electrochemical scanning probe microscopy

acid by FcTMA 2+ . This highlighted the challenges of using nanoscale probes for quantitative analysis, and in particular the difficulty in using FEM models to calcu- late the nanoscale probe geometry based on in-situ current measurements. Probes, both nanoscale and micronscale, were then employed in a scanning electrochemical microscopy (SECM) configuration, and approaches curves to insulating and con- ducting surfaces conducted. The interaction of FcTMA 2+ with the photosynthetic light dependent electron transport pathway that is embedded within the thylakoid membranes of higher plants was then investigated. A micron scale probe was placed precisely over a sparse monolayer of isolated thylakoid membranes and changes in FcTMA + and FcTMA 2+ concentration were measured as the sample was illumi- nated. To our knowledge this is the first report of the use of FcTMA 2+ as an artificial electron acceptor within photosynthesis. Finally, in generation/collection mode, using the FcTMA +/2+ couple, a 2 dimensional image of a single thylakoid membrane was constructed by scanning a DCE, at a constant height, over the sur- face.

194 Read more

Detecting Target Identity—Location/Response Binding in Visuo spatial Tasks Using a Cueing Procedure: An Exploratory Study

Detecting Target Identity—Location/Response Binding in Visuo spatial Tasks Using a Cueing Procedure: An Exploratory Study

Actually, there is another aspect to the possibility that validly cueing an im- pending binding violation could reduce or eliminate the latency impact of un- expected violations that is worthwhile highlighting. It has to do with the recog- nition that the consequences of prime trial binding to future processing in which they participate are mixed; being “beneficial” in reducing RT size when prime and probe processing demands fully match, but “detrimental” when earlier binding is violated (i.e., partial prime repetition). This maladaptive feature of cognition, which runs counter to the notion that we are evolving into a state of intelligent processing design, has been seen before. For example, consider the phenomenon of negative priming in general (e.g., D’Angelo, Thomson, Tipper, & Milliken, 2016; Frings, Schneider, & Fox; 2015) and spatial negative priming (SNP) in particular (e.g., Fitzgeorge, Buckolz, & Khan, 2011). An SNP effect is observed when the RT for a current (probe) target is significantly greater when it arises at a location formerly occupied by a to-be-ignored distractor, relative to when it occurs at a spatial position that was previously (prime) empty. So, when an irre- levant location (i.e., distractor-occupied) becomes relevant (i.e., target-occupied), target RT is interfered with. Interestingly, the negative influence reflected in the SNP phenomenon can be prevented in a number of ways, including cueing the use of the prime distractor response on the probe trial (e.g., Buckolz, Boulou- gouris, & Khan, 2002; Buckolz, Edgar, Kajaste, Lok, & Khan, 2012; Fitzgeorge & Buckolz, 2008). It will be interesting to determine whether this same interference prevention is possible with prime trial binding.

14 Read more

Designing of a Coaxial fed antenna for S band Applications

Designing of a Coaxial fed antenna for S band Applications

In this type of feed technique, the radiating patch and the microstrip feed line are separated by the ground plane. Coupling between the patch and the feed line is made through a slot or an aperture in the ground plane and variations in the coupling will depend upon the size i.e. length and width of the aperture to optimize the result for wider bandwidths and better return losses. The coupling aperture is usually centered under the patch, leading to lower cross-polarization due to symmetry of the configuration. Since the ground plane separates the patch and the feed line, spurious radiation is minimized.

7 Read more

FORENSIC SKETCH-PHOTO MATCHING USING SIFT- MLBP- LFDA

FORENSIC SKETCH-PHOTO MATCHING USING SIFT- MLBP- LFDA

686 images (VIS).Only one paper is published in forensic sketch matching till date. Klare and Jain [11] published a Local Feature based Discriminant Analysis (LFDA) approach for matching forensic sketches to mug shot photos. It is claimed as the first large scale experiment conducted on forensic sketch matching in which 159 forensic sketches are matched against 10159 mug shot photographs. We propose a technique based on pre-processing algorithm that could solve the problem of forensic sketch matching in a much better manner. Our results are compared to LFDA; since it is reported to be the one with highest accuracy till date in forensic sketch matching. We also compare our results to face VACS, a commercially off the shelf system for traditional face recognition.

13 Read more

Designed and Analyzing Different Conical Probes for Detecting Tumor in Skin

Designed and Analyzing Different Conical Probes for Detecting Tumor in Skin

Skin cancer is a common type of cancer.[1] It is extended due to the development of abnormal growth of cells that emerges from the skin. [2] These cells can damage other parts of the body. The frequencies of 35 GHz and 95 GHz is known to be very sensitive to water content. By using these frequencies band we can detect the skin cancer. Since skin tumors contain more moisture than healthy skin, it leads to stronger reflections on this frequency band. Hence the dielectric probe can detects abnormalities.

7 Read more

Quantitative NDE of Surface Cracks in Ceramic Materials by means of a High Frequency Electromagnetic Wave

Quantitative NDE of Surface Cracks in Ceramic Materials by means of a High Frequency Electromagnetic Wave

The HFT technique can detect surface cracks by variation of the high-frequency current that flows in the probe placed above the specimen. The high-frequency current that flows in the probe, which is a transmission line, is affected by the shape and properties of the transmission line and the specimen. In the previous section, the relationship between the amplitude ratio and the crack depth was determined to be linear, and it was also determined that there were differences between the signal transmission characteristics of specimens with and without artificial cracks. The issues need to solve are to determine the factors, which affect the variation in the amplitude ratio and the sensitivity of this variation to these factors.

6 Read more

An Efficient Technique for Design of Electrically Thick Differentially-Driven Probe-Fed Microstrip Antennas

An Efficient Technique for Design of Electrically Thick Differentially-Driven Probe-Fed Microstrip Antennas

Abstract—This paper presents a computationally efficient technique for designing electrically thick differentially-driven rectangular microstrip antennas with coaxial probe feed. It concerns the use of a transmission line model for probe positioning, along with a full-wave field simulator that yields accurate results with reduced number of required full-wave simulations. An electrically thick antenna was designed with the proposed technique to operate at 2442 MHz, having its radiation patterns and input impedance measured and compared against a single-feed rectangular microstrip antenna to demonstrate the advantages of using differential feed to reduce cross-polarization in H -plane.

8 Read more

Growth mechanism and magnon excitation in NiO nanowalls

Growth mechanism and magnon excitation in NiO nanowalls

The chemical vapor deposition technique was success- fully utilized to grow NiO nanowalls on a Ni grid with various mean widths without using any catalyst. The growth temperature for the NiO nanowalls was confined from 400°C to 800°C, which is 0.275 and 0.55 times the Ni melting point, following the parabolic rate law of Wagner ’ s scaling theory. X-ray refinement reveals that the NiO nanowalls with the Miller index [1 1 1] oxi- dized more rapidly than with the other index [2 0 0], and the oxidized faces grow at a rate dependent upon the crystallographic preferred orientation of the NiO [1 1 1] faces. The length of diffusion of nickel along the [1 1 1] plane at various growth temperatures can be obtained from EDS mapping. The results agreed with the short-circuit diffusion mechanism simulation. Con- focal Raman scattering was utilized to study the phonon and magnon configurations for these samples. The appearance of integrated intensity for the one- and two- phonon modes reflects the existence of the finite size effect and nickel vacancies. Two- and four-magnon exci- tations generated in NiO nanowalls may help to identify the Ni 2+ -O 2- -Ni 2+ superexchange mechanism associated with the short-range magnetic interactions and magnon configurations.

14 Read more

52Mn Production for PET/MRI Tracking Of Human Stem Cells Expressing Divalent Metal Transporter 1 (DMT1)

52Mn Production for PET/MRI Tracking Of Human Stem Cells Expressing Divalent Metal Transporter 1 (DMT1)

In vitro assays were used to confirm DMT1 ex- pression by transfected cells and to test the potential toxicity of combined DMT1 expression and manga- nese supplementation. The observation of slowly de- creasing DMT1 over-expression is acceptable for these proof-of-concept studies and has been previously ob- served in our other reporter gene studies [8]. Howev- er, a line of cells stably expressing DMT1 needs to be developed for long-term cell tracking, detecting cell graft rejection, and more thoroughly characterizing the effect of this imaging technique on hNPC dynam- ics. The cell viability study showed that transient DMT1 over-expression and Mn supplementation did not have significant effects on cell viability at relevant concentrations for in vivo MRI, in agreement with previous studies investigating combined DMT1 ex- pression and Mn supplementation on cells [15]. However, investigations of the effects of Mn on hNPC show more significant toxicity and indicate that try- pan blue may not be the most sensitive method for detecting effects on cell viability [31]. The cell viability study further showed that extremely high concentra- tions of Mn have significant detrimental effects on cells. This result indicates the value of minimizing the supplemented Mn concentration, which a 52 Mn PET

13 Read more

AUTOMATION OF X BAND MICROWAVE BENCH

AUTOMATION OF X BAND MICROWAVE BENCH

The stepper motor driver unit is a switching circuit consisting of medium power transistors. These transistors are used in the switching mode as shown in Figure 3. The power transistors provide the necessary current to the field coils of the motor. Four power transistors are used to drive the coils of motor. The 4-bit (D0-D3) output of the printer port is fed to the bases of the power transistors, which in turn are used to control the movement or the rotation of the motors, under the software control. For moving the probe of slotted section of microwave bench, the nut is welded to the probe of slotted section whereas the shaft to the stepper motor to facilitate the displacement of the probe.

8 Read more

Design And Analysis of Co-Planar Wideband Microstrip Slot Antenna Using MATLAB

Design And Analysis of Co-Planar Wideband Microstrip Slot Antenna Using MATLAB

Abstract – A Novel Co-Planar Wide Band Slot Antenna is proposed in this paper. In this paper a new design technique for enhancing bandwidth that improves the performance of a conventional microstrip patch antenna is proposed. This proposed antenna has been excited by probe feed technique. On a thin FR –4 lossy substrate this antenna achieves 1.87 GHz impedance bandwidth in the range of 2.24 - 4.11 GHz at -10 dB return loss (VSWR ≤ 2). Analysis of the antenna in terms of return loss and the E and H-plane radiation pattern and other important parameters using MATLAB.

6 Read more

Show all 10000 documents...