Finger Width Research Articles

Constructal design of top metallic contacts on a disc-shaped solar cell

Trends in crystalline silicon photovoltaic improvements demonstrate that some of the key factors that have contributed to reaching efficiency values up to 23 % are the introduction of the passivated emitter and rear cell structure with local rear contacts in low-cost large-volume fabrication; the reduction of the width of the front metallization fingers, from about 100 microm to less than 30 micro m in large volume production, and the re-emergence of mono-crystalline silicon wafers as a consequence of cost reduction in the Czochralski silicon ingot fabrication process. In the present work, we have developed a theoretical model that defines the geometric arrangement of a branched top metallic contacts network over a solar cell with a disc-shaped body. The solar cell considers two main regions: the solar cell material and an insert of metallic material for the collection of the photogenerated electrical current. The geometric characteristics of the network are defined from the minimization of the resistive power losses applying the constructal design method. As a fundamental result, the optimal lengths, branching angles, and geometrical relationships of the n-branched network are determined. The numerical results show that the dimensionless power losses of the branched arrangement of contacts present minimum values for the allocation of the metallic material and the disc size of the solar cell.

Fabrication and characterization of a porous ZnO flexible UV photodetector on fiberglass and the electrode dimensions effect

In this study, three flexible metal-semiconductor-metal ultraviolet photodetectors are fabricated on the FR4 fiberglass substrate based on the porous zinc oxide by radiofrequency sputtering. Their copper electrodes were created by printed circuit board, a simple and cheap method. Here, the effect of porosity on the photodetector parameters is discussed. The results show that the difference in the finger size in the photodetectors leads to differences in the parameters. In these photodetectors, as the fingers increase in length, dark current increases from 0.25 to 67.3 µA, photocurrent from 1.98 to 208 µA, and response time from 430 to 570 ms. Also, with expanding finger width, these parameters changed 18.48 µA, 26.8 µA, and 440 ms, respectively.

Finger Gate Vacuum Channel Field Emission Transistors: Performance and Sensitivity Analysis

In the current research, for the first time, Nano-scale finger gate vacuum channel field emission transistor (FGVFET) scaling down and its limitations considering electrical characteristics are studied. The FGVFET with different cathode electrode materials, channel dimensions, and finger widths is considered and the impacts of these structural and physical changes on the key indicators of the device are assessed to achieve a comprehensive design guideline. The sensitivity analysis reveals that the channel height modification by changing gate-anode oxide and cathode–gate oxide thicknesses can be assumed as the most significant design factor in the determination of ON–OFF-state currents. The results indicate that the gate leakage current as a salient parameter in device performance is dependent on the cathode material, channel depth, and height. Furthermore, investigating cutoff frequency as the prominent factor in high-speed applications indicates that cathode–gate oxide thickness may fundamentally modify this factor.

Effects of Dissolution Fingering on Mass Transfer Rate in Three‐Dimensional Porous Media

AbstractDissolution mass transfer from the trapped phase to the flowing phase in porous media occurs in various hydrogeology processes. One of the important phenomena is dissolution fingering and its effect on dissolution mass transfer. In this work, dissolution mass transfer in porous media with various particle sizes and distribution was investigated in pore scale and meso‐scale by using X‐ray microcomputed tomography. The specific interfacial area and mass transfer coefficient were measured by following the representative elementary volume concept, and the effect of dissolution fingering was evaluated. Linear instability theory was used for the prediction of dissolution finger width () at the onset of dissolution fingering. Although dissolution fingering tends to develop when the porous media container diameter () is smaller than half of , its effect on mass transfer coefficient starts to occur when is larger than the whole . Starting this point, dissolution fingering decreases the mass transfer coefficient by three times. For validation, an additional experiment with a larger porous media container size was performed, and three dissolution fingers were successfully observed. Their size was found to be comparable with the theoretical prediction based on linear instability theory.

Contact control of Al/Si interface of Si solar cells by local contact opening method

Low-cost aluminum (Al) metallization process on p + side of n-type silicon (Si) substrate with low recombination current density ( J 0met ) is presented. Narrow-line Al screen-printed fingers on symmetrically passivated p + -n-p + Si precursors with local contact opening (LCO) are investigated. The Si content of the Al pastes, LCO patterns and Al finger widths are varied to evaluate the formation quality of the Al-doped p + region. By increasing the pitch distance of the dot-shaped LCOs, the inverted pyramid cavities are found after removing the Al-Si eutectic part by HCl. The tendency of the reaction during the sintering process is controlled by fritting the Al paste with Si, which allows a faster Si saturation in the paste matrix and facilitates faster return of Si to the LCO region. With a combination of narrow-line fingers of 90 μm and a dot-shaped LCO pitch of 140 μm, J 0met value of 420 fA/cm 2 is realized. • Screen-printed narrow-line Al paste application for Si solar cells front side. • Local-contact-opening (LCO) pitches and Al finger affect quality of Al- p + region. • Recombination current density under the Al contact ( J 0met ) be reduced by Al-Si paste. • Optimized the combination of Si ratio in Al paste and LCO pitches for lower J 0met . • Combination of narrow Al-Si fingers and dots LCO, the J 0met shows around 500 fA/cm 2 .

Sinuous bar fingers of digitate shallow‐water deltas: Insights into their formative processes and deposits from integrating morphological and sedimentological studies with mathematical modelling

AbstractThis paper helps to address the growing need to resolve the severe loss of deltaic lands by providing a new understanding for shallow‐water digitate delta growth. The integration of satellite image analysis of modern deltas, field studies of the Ganjiang Delta in the Poyang Lake and ‘Delft3D’ simulations further results in improved facies models for shallow‐water digitate deltas. These analyses show that shallow‐water digitate delta bar fingers are sinuous in contrast to the straight deep‐water digitate delta bar fingers. These differences are assigned to the effect of water depth on outflow hydraulics, where friction‐dominated shallow‐water delta effluents promote mouth bar deposition that then divert flow around the mouth bar, resulting in the formation of sinuous bar fingers. These effects are further strengthened by the meandering of the shallow‐water jet that increases lateral sediment transport, and by the higher flow resistance and lower gradient of the shallow‐water outflows. Our data and analyses further show differences in the morphology and deposits of the shallow‐water sinuous bar fingers, where some bar fingers develop sinuous and others meandering (with point bars) distributary channels. Lateral channel migration and point bar formation (meandering) occur as a secondary process that does not change the shape or width of the bar fingers themselves, and is suggested to be a function of slight initial differences in channel sinuosity. These differences in distributary channel morphology have a strong effect on bar finger facies distribution. Sediment cohesion is another important control on bar finger bending processes, because high cohesion promotes formation of enclosed bays, where their bank strength exceeds the centrifugal force of water flow. Lower sediment cohesion results in sinuous bar fingers without formation of enclosed bays. This work provides insights into natural and artificial shallow‐water digitate delta growth and provides new quantitative facies models for shallow‐water digitate deltas.

Characterization of capacitive-type epidermal moisture measurements using disposable printed electrode films

This paper addresses the characteristics of capacitive-type epidermal moisture measurements using disposable electrode films fabricated by a screen-printing method. The disposable electrode films were composed of substrates, comb-shaped electrode layers, and insulating layers. The epidermal moisture measurement obtained higher gain by optimization of the finger width of the comb-shaped electrode layer. The gain and accuracy of measurements were also improved by changing the insulating layer that covered the comb-shaped electrode layer to the striped-pattern type instead of the conventional solid-filling type. This epidermal moisture measuring instrument reduces the cleaning process of the electrode film that directly contacts the skin, simplifies the handling of the devices, and ensures hygienic operation.

Effect of Abdominal Physiotherapy in Reduction of Inter Recti Distance in Postpartum Females

Aim: To see the effect of abdominal exercises in the recovery of diastasis recti in post natal females. Methodology: A Quasi Experimental study design was used to enroll 40 participants from OPD of Gynecology and Obstetrics from a Tertiary Care Hospital Lahore between ages ranged from 18 to 30 years. Using purposive sampling all postpartum females having diastasis of rectus abdominis muscles with inter recti distance more than 2 fingers width were enrolled. All the study participants received abdominal muscle exercises program for 30 min a day in 8 week program. inter recti distance was measured by using two finger palpation method. All the pre intervention and post intervention data were recorded into a short structured proforma.Results were considered significant for p value ≤ 0.05. Results: 40 participants were selected in this study with an age from 18- 30 years. The inter recti distance was significantly reduced as p value was ≤ 0.05 for both (above umbilicus and below umbilicus) groups. Conclusion: It was observed that abdominal exercises helped in the recovery of diastasis and reduced the separation between the muscles in postpartum women. It also enlightens the importance of the prescription of physiotherapy in reduction of post partum complications. Keywords: Abdominal Exercises, Diastasis Recti, Pregnancy, Postnatal period,

Cell constant analytical study of electrochemical flow cell with interdigitated microelectrodes

This paper presents the results of investigating the influence of design parameters of an electrochemical flow cell based on film interdigitated microelectrodes on its cell constant. This investigation is performed by the analytical method. To determine the cell constant the linear resistance between the adjacent fingers of the interdigitated microelectrodes is used. In its turn this resistance is found from the potential distribution in the unit subdomain of the interdigitated microelectrode system of the cell with the limited height. The dependencies of the cell constant on the cell height and the design parameters of the interdigitated microelectrode system (the spacing between fingers and the finger width) are determined. The cell height at which the change of the design parameters of the interdigitated microelectrode system has the least effect on the cell constant is found.

Effect of Pt-doped on the photocurrent of MSM photodetector

This article report the fabrication and characteristics of MSM photo detector by compare between non-doped and doped platinum (Pt) atom. Fabrication process has same but different in Pt doping process for atom doping and diffusion process. The metal finger width 2um with 50 um spacing between metal contact. At bias voltage 10 voltage show higher capacitance-voltage and photocurrent increase after doped with Pt atom. By experiment shows photocurrent increase around 4 times from 45.98 to 197.22 uA at bias 10 voltage by photoluminescence 25,000 lux.

Modelling finger propagation in elasto-rigid channels

Abstract

An Observational Study to Assess the Validity of Anguli Pramana in the Present Era

Introduction: The concept of Anguli pramana is one of the hypothetical concepts in Ayurved put forth by acharyas. It mainly deals with the measurements of various parts of the human body. After reviewing the previous research done, it was noticed that, not a single study was being carried out by anyone of the researchers for assessing the validity of Anguli pramana in the present era. Therefore, the present study was planned. Method: After ethical clearance, the study was conducted. In total 770 participants of age group 18-50 years from Ahmednagar and Nashik region were selected. Measurements were taken for selected parameters, recorded and converted into Swa-anguli pramana. Swa-anguli pramana was measured by taking width of the middle finger at the proximal interphalangeal joint of right hand. All the measurements were taken following Standard Operating Procedure. The data was analyzed with the test of Normality, Z score using Systat 13.0 version software. Result: In the present study, obtained value and standard value stated by Acharya Charaka for the selected parameters were compared and found statistically different. Similarly, obtained value and standard value stated by Acharya Sushruta for the selected parameters were compared and found statistically different. Discussion: The results were negative i.e., non comparable with the standard values stated by acharas for the selected parameters. It was observed that the Anguli pramana mentioned in ancient literature may not be considered valid in the present era. It may be because of evolutionary changes and lifestyle changes of the human being.

X-RAY OSTEOMETRY OF SOME LINE PARAMETERS OF THE MIDDLE PHALANGES OF THE HAND IN CHILDREN AND ADOLESCENTS IN TERM OF DIFFERENT AGE AND ETHNICITY

The aim of the study is a comparative analysis of the linear parameters of the length and width of the diaphysis of the middle phalanges in children and adolescents of Tajikistan and Western India, and also the possibility of using these linear parameters to establish the age of children of the compared ethnic groups. On 325 radiographs of the right hand in male children and adolescents of the Kanibadam region of the Republic of Tajikistan and the city of Mumbai (Western India) at the age of 6-17 years, the length of the middle phalanges and the width of their diaphysis were determined. To determine the relationship between the age of children of the compared ethnic groups and the linear parameters of the length and width of the shaft of the phalanges, Spearman's nonparametric correlation coefficient was used. Comparative assessment of the values ​​of indicators by age was carried out by the method of parametric and non-parametric analysis. In boys of Tajikistan, the closest correlation was established between the age of children and the length of the middle phalanx of the third finger, while in their Indian peers this ratio was determined evenly for the II-IV fingers of the hand. The width of the diaphysis of the phalanges of the fourth finger increased most significantly with age in boys of Tajikistan, and in the Indians, the width of the third finger, the smallest increase in the width of the diaphysis in the compared groups was determined for the phalanges of the second finger. The linear parameters of the middle phalanges of the hand can be used to identify the age of children and adolescents in Tajikistan and Western India at the age of 6-17 years. For Tajik children, the best predictor of age is the linear parameter of the length of the middle phalanx of the index, and for their Indian peers, the length of the middle phalanx of the II-IV fingers is equally.

A model for screen utility to predict the future of printed solar cell metallization

Fine line screen printing for solar cell metallization is one of the most critical steps in the entire production chain of solar cells, facing the challenge of providing a conductive grid with a minimum amount of resource consumption at an ever increasing demand for higher production speeds. The continuous effort of the industrial and scientific community has led to tremendous progress over the last 20 years, demonstrating an average reduction rate for the finger width of approximately 7 µm per year with the latest highlight of achieving widths of 19 µm. However, further reductions will become a major challenge because commonly used metal pastes are not able to penetrate arbitrary small screen opening structures. Therefore, this study introduces the novel dimensionless parameter screen utility index SUI which quantifies the expected printability of any 2-dimensional screen architecture in reference to a given paste. Further, we present a full theoretical derivation of the SUI, a correlation to experimental results and an in-depth simulation over a broad range of screen manufacturing parameters. The analysis of the SUI predicts the point when commonly used wire materials will fail to provide sufficient meshes for future solar cell metallization tasks. Therefore, novel wire materials (e.g. the use of carbon nanotubes) with very high ultimate tensile strengths are discussed and suggested in order to fulfill the SUI requirements for printing contact fingers with widths below 10 µm. We further analyze economic aspects of design choices for screen angles by presenting an analytical solution for the calculation of mesh cutting losses in industrial screen production. Finally, we combine all aspects by presenting a generalized approach for designing a 2-dimensional screen architecture which fulfills the task of printing at a desired finger width.

Assessment of traits for grain yield under drought in finger millet

Climate change models predict that drought stress (DS) would continue as a major abiotic limitation for food production. For DS conditions, finger millet would be a better option as compared to other cereal crops because of its drought resilience. However the yield improvement of finger millet through yield per se selection has reached a plateau. Hence, trait based breeding approach in addition to yield per se would help in further yield enhancement. For which, identification of traits those tolerate DS from among stable released varieties would be more appropriate. Imposing DS for 36 days from earhead emergence to grain filling under field condition in 16 released varieties, reduced the grain yield by 36.6% with decreased physiological and yield contributing traits. Considering the per cent reduction of a given parameter due to DS, path analysis and backward step wise regression analysis, the leaf temperature (LT) was found the most important physiological trait under DS. Among the agronomic traits, productive tillers, mean ear size and threshing percentage equally and positively contributed towards the grain yield under DS. Finger width had an additional contribution towards grain yield under DS condition. Our results also reports, that Cv. PR-202 is relatively drought tolerant and; Cv. ML-365 performed similar to that of popularly cultivated Cv.GPU-28.

The evaluation of maximum condyle-tragus distance can predict difficult airway management without exposing upper respiratory tract; a prospective observational study

BackgroundRoutine preoperative methods to assess airway such as the interincisor distance (IID), Mallampati classification, and upper lip bite test (ULBT) have a certain risk of upper respiratory tract exposure and virus spread. Condyle-tragus maximal distance(C-TMD) can be used to assess the airway, and does not require the patient to expose the upper respiratory tract, but its value in predicting difficult laryngoscopy compared to other indicators (Mallampati classification, IID, and ULBT) remains unknown. The purpose of this study was to observe the value of C-TMD to predict difficult laryngoscopy and the influence on intubation time and intubation attempts, and provide a new idea for preoperative airway assessment during epidemic.MethodsAdult patients undergoing general anesthesia and tracheal intubation were enrolled. IID, Mallampati classification, ULBT, and C-TMD of each patient were evaluated before the initiation of anesthesia. The primary outcome was intubation time. The secondary outcomes were difficult laryngoscopy defined as the Cormack-Lehane Level > grade 2 and the number of intubation attempts.ResultsThree hundred four patients were successfully enrolled and completed the study, 39 patients were identified as difficult laryngoscopy. The intubation time was shorter with the C-TMD>1 finger group 46.8 ± 7.3 s, compared with the C-TMD<1 finger group 50.8 ± 8.6 s (p<0.01). First attempt success rate was higher in the C-TMD>1 finger group 98.9% than in the C-TMD<1 finger group 87.1% (P<0.01). The correlation between the C-TMD and Cormack-Lehane Level was 0.317 (Spearman correlation coefficient, P<0.001), and the area under the ROC curve was 0.699 (P<0.01). The C-TMD < 1 finger width was the most consistent with difficult laryngoscopy (κ = 0.485;95%CI:0.286–0.612) and its OR value was 10.09 (95%CI: 4.19–24.28), sensitivity was 0.469 (95%CI: 0.325–0.617), specificity was 0.929 (95%CI: 0.877–0.964), positive predictive value was 0.676 (95%CI: 0.484–0.745), negative predictive value was 0.847 (95%CI: 0.825–0.865).ConclusionCompared with the IID, Mallampati classification and ULBT, C-TMD has higher value in predicting difficult laryngoscopy and does not require the exposure of upper respiratory tract.Trial registrationThe study was registered on October 21, 2019 in the Chinese Clinical Trial Registry (ChiCTR1900026775).

BIOMETRIC VERIFICATION SYSTEM BASED ON HAND GEOMETRY

Biometric systems are widely used in medium and low security applications. Verification systems based on the geometry of the hand utilize some geometrical characteristics of the hand including measurements of fingers, shape of the palm, etc. In this work, we have developed an unconstrained and contact-based hand geometry verification system, using a combination of length and width of fingers. New measurements at different points of fingers were introduced in this paper to improve the performance of the recognition of persons. A total of 135 hand images were enrolled in this study. The Euclidean distance was used as a similarity function for different values of threshold. The proposed method was compared to state-of-the-art approaches. The results obtained reveal the high performance of the proposed approach and outperformed the existing methods with an accuracy of Acc = 98.67%.

EFFECTS OF WETTABILITY ON DISPLACEMENT EFFICIENCY OF TWO-PHASE FLOW IN POROUS MEDIA

Displacement efficiency and displacement pattern of multiphase flow in porous media have a profound influence on many geo-energy applications such as geologic CO$_{2}$ sequestration and enhanced oil recovery. Wettability is one of the most important factors affecting the displacement pattern and displacement efficiency of multiphase flow in porous media. Here, we combined the glass microfluidics, inverted microscope and high speed CMOS camera to set up a visualization experimental system and modified the surface wettability of the glass microfluidics using the silanization treatment and piranha solution. Pore-scale visualization displacement experiments were conducted on five flow rates and two wetting conditions (hydrophilic and hydrophobic conditions) in glass microfluidics which are fabricated from the pore structure of natural sandstone. Experimental results show that the displacement pattern shifts from capillary fingering to compact displacement pattern both in the hydrophilic and hydrophobic media as the flow rate increases. Under lower flow rates, the capillary force plays the dominant role in the fluid invasion processes. The invasion finger width and the number of air clusters in hydrophilic media are both smaller than those in the hydrophobic media, but the maximum air cluster radius, the average cluster radius and the standard deviation of cluster radius are all greater under hydrophilic conditions. The results also demonstrate that the displacement efficiency under hydrophilic condition is significantly lower than that of hydrophobic conditions due to single-channel flow and by pass flow phenomena which both only occur in hydrophilic media. Finally, a modified capillary number was introduced in order to consider the role of wettability (contact angle) under favourable displacement. Then, a relationship between the displacement efficiency and the modified capillary number was proposed, which provides a potential and useful method for the prediction of displacement efficiency under different wetting conditions during favourable displacement.

Hand anthropometry and its relation to grip/pinch strength in children aged 5 to 13 years.

ObjectiveTo evaluate the development level of children’s physiological hand shape indicators and their relationship with grip/pinch strength.MethodsHand shape and grip/pinch strength in 1255 Chinese children aged 5 to 13 years were prospectively measured. Development curves of physiological hand shape indicators and grip/pinch strength were constructed.ResultsThe physiological hand shape indicators (full length, middle finger length, width, and wrist thickness) and grip/pinch strength of boys and girls increased with age and showed statistically significant differences at different ages. In most age groups, hand shape indicators and grip/pinch strength were larger in boys than in girls of the same age. After puberty, the physiological hand shape indicators and grip/pinch strength increased more rapidly in girls than in boys of the same age, and the differences gradually decreased thereafter. Moreover, a significant difference in pinch strength between the right and left hands was observed in most age groups. Pearson correlation analysis showed that the physiological hand shape indicators were significantly positively correlated with grip/pinch strength, height, weight, and body mass index.ConclusionsThis study revealed the relationship between physiological hand shape indicators and grip/pinch strength and provided reference ranges of physiological hand shape indicators and grip/pinch strength for children.

Design of GGNMOS ESD protection device for radiation-hardened 0.18 μm CMOS process

In this paper, the ESD discharge capability of GGNMOS (gate grounded NMOS) device in the radiation-hardened 0.18 μm bulk silicon CMOS process (Rad-Hard by Process: RHBP) is optimized by layout and ion implantation design. The effects of gate length, DCGS and ESD ion implantation of GGNMOS on discharge current density and lattice temperature are studied by TCAD and device simulation. The size of DCGS, multi finger number and single finger width of ESD verification structures are designed, and the discharge capacity and efficiency of GGNMOS devices in ESD are characterized by TLP test technology. Finally, the optimized GGNMOS is verified on the DSP circuit, and its ESD performance is over 3500 V in HBM mode.