Diagonal Pattern Research Articles

Analysis Behavior of Openings on Full-Size Cross-Laminated Timber (CLT) Frame Shear Walls Tested Monotonically

Walls, as components of the lateral-force-resisting system of a building, are defined as shear walls. This study aims to determine the behavior of shear wall panel cross-laminated-timber-based mangium wood (Acacia mangium Willd) (CLT-mangium) in earthquake-resistant prefabricated houses. The earthquake performance of CLT mangium frame shear walls panels has been studied using monotonic tests. The shear walls were constructed using CLT-mangium measuring 2400 mm × 1200 mm × 68 mm with various design patterns (straight sheathing, diagonal sheathing/45°, windowed shear wall with diagonal pattern and a door shear wall with a diagonal pattern). Shear wall testing was carried out using a racking test, and seismic force calculations were obtained using static equivalent earthquake analysis. CLT-mangium sheathing installed horizontally (straight sheathing) is relatively weak compared to the diagonal sheathing, but it is easier and more flexible to manufacture. The diagonal sheathing type is stronger and stiffer because it has triangulation properties, such as truss properties, but is more complicated to manufacture (less flexible). The type A design is suitable for low-intensity zones (2), and types B, D, E1 and E2 are suitable for moderate-intensity zones (3, 4), and type C is suitable for severe-intensity zones (5).

Cat Swarm with Fuzzy Cognitive Maps for Automated Soil Classification

Accurate soil prediction is a vital parameter involved to decide appropriate crop, which is commonly carried out by the farmers. Designing an automated soil prediction tool helps to considerably improve the efficacy of the farmers. At the same time, fuzzy logic (FL) approaches can be used for the design of predictive models, particularly, Fuzzy Cognitive Maps (FCMs) have involved the concept of uncertainty representation and cognitive mapping. In other words, the FCM is an integration of the recurrent neural network (RNN) and FL involved in the knowledge engineering phase. In this aspect, this paper introduces effective fuzzy cognitive maps with cat swarm optimization for automated soil classification (FCMCSO-ASC) technique. The goal of the FCMCSO-ASC technique is to identify and categorize seven different types of soil. To accomplish this, the FCMCSO-ASC technique incorporates local diagonal extrema pattern (LDEP) as a feature extractor for producing a collection of feature vectors. In addition, the FCMCSO model is applied for soil classification and the weight values of the FCM model are optimally adjusted by the use of CSO algorithm. For examining the enhanced soil classification outcomes of the FCMCSO-ASC technique, a series of simulations were carried out on benchmark dataset and the experimental outcomes reported the enhanced performance of the FCMCSO-ASC technique over the recent techniques with maximum accuracy of 96.84%.

Computer-Aided Diagnosis Model Using Machine Learning for Brain Tumor Detection and Classification

The Brain Tumor (BT) is created by an uncontrollable rise of anomalous cells in brain tissue, and it consists of 2 types of cancers they are malignant and benign tumors. The benevolent BT does not affect the neighbouring healthy and normal tissue; however, the malignant could affect the adjacent brain tissues, which results in death. Initial recognition of BT is highly significant to protecting the patient’s life. Generally, the BT can be identified through the magnetic resonance imaging (MRI) scanning technique. But the radiotherapists are not offering effective tumor segmentation in MRI images because of the position and unequal shape of the tumor in the brain. Recently, ML has prevailed against standard image processing techniques. Several studies denote the superiority of machine learning (ML) techniques over standard techniques. Therefore, this study develops novel brain tumor detection and classification model using met heuristic optimization with machine learning (BTDC-MOML) model. To accomplish the detection of brain tumor effectively, a Computer-Aided Design (CAD) model using Machine Learning (ML) technique is proposed in this research manuscript. Initially, the input image pre-processing is performed using Gaborfiltering (GF) based noise removal, contrast enhancement, and skull stripping. Next, mayfly optimization with the Kapur’s thresholding based segmentation process takes place. For feature extraction proposes, local diagonal extreme patterns (LDEP) are exploited. At last, the Extreme Gradient Boosting (XGBoost) model can be used for the BT classification process. The accuracy analysis is performed in terms of Learning accuracy, and the validation accuracy is performed to determine the efficiency of the proposed research work. The experimental validation of the proposed model demonstrates its promising performance over other existing methods.

A study on the effect of thickness and spherical diagonal for LYP Infill Plate of shear walls

One of the most significant parameters which should be considered by all engineers is improving structures’ strength subjected to lateral load. Steel shear wall whose duty is to affect lateral load (wind and earthquake) is a wall which consists of shear part. Application of low yield point (LYP) steel in shear walls allows the employment of moderate and/or stocky infill plates with low yielding and high buckling capacities, which can result in enhanced buckling stability, serviceability, and energy dissipation capacity of such systems. Infill LYP plate is used to improve shear wall behavior which leads to enhancement of stiffness. In the present research, infill plate with spherical appendages is applied, and its impact on plate stiffness, cyclic behavior and energy absorption are investigated. The spherical diameter has been chosen respectively 10 and 20 cm distributed with two patterns (diagonal and plus form). The best performance is for a LYP plate with a 10 cm spherical diagonal pattern.

Effectiveness of Pelvic Proprioceptive Neuromuscular Facilitation Techniques on Balance and Gait Parameters in Chronic Stroke Patients: A Randomized Clinical Trial.

Background Stroke is the second leading reason for death and the third most common reason for disability. Stroke is a source ofpossible substantial harm and is often moredisabling than lethal. Common stroke defects include stiffness, tiredness, loss of balance on the afflicted side, as well as gait impairment, resulting in an inability to sustainpostural alignment. Pelvic proprioceptive neuromuscular facilitation (PNF) is a physical rehabilitation that combines functionally dependent diagonal activity patterns with neuromuscular facilitator strategies to improve motor behaviour, endurance, and muscle activity and control. This protocol was created to describe the experimental study design for evaluating the combined impact of pelvic PNF and task-oriented exercises in chronic stroke patients to improve balance and gait parameters. Aim and objective The purpose of our study is to investigate the effectiveness of pelvic PNF as well as task-oriented exerciseson balance, gait parameters, and in pelvic asymmetry. Methods The participants (n=30) were stroke survivors who fulfilled the inclusion criteria for research and were divided into two groups. The regimen lasted four weeks and took 30 minutes each day. Patients were evaluated at the beginning and end of their treatment. In both groups, pre- andpost-intervention outcome measures were recorded and the data was analyzed. Result Following four weeks of rehabilitation, subjectsshowedremarkableimprovementin balance, gait parameters, and pelvic inclination in both groups, i.e., pelvic PNF and task-oriented exercises in group A and task-oriented exercises in group B, but Group A showed a major improvement in outcome measures.A p-value of less than 0.05 was considered significant. Despite the fact that both treatment regimens were successful for the patient, pelvic PNF combined with task-oriented exercises exhibits a statistically significant difference from task-oriented exercises. Conclusion Pelvic PNF along with task-oriented exercises proved to be beneficial and can help in the restoration of balance and gait parameters as a result of normalisation in the geometry and symmetry of the pelvis in stroke patients. The pelvis, which is a connecting link between the trunk and lower limbs, plays a crucial role in balance and also in lower limb performance exclusively in gait.

A novel scan pattern for reconfiguration of partially shaded photovoltaic arrays for maximum power extraction

AbstractReconfiguration plays an indispensable role in augmenting the output of the photovoltaic (PV) array under partial shading conditions. Various reconfiguration schemes have been proposed in the literature to disperse the shade in partially shaded PV arrays. Nevertheless, most of these schemes can be employed only for less‐rated arrays, are not compatible with all array sizes, fails in effective shade dispersion over the entire array, and so forth. To overcome these shortcomings, a calligraphy‐based diagonal scan pattern is proposed to reconfigure the PV array to improve the row currents of the PV array thereby reducing the mismatch between them. The superiority of the proposed scheme is examined by comparing it with conventional Series‐Parallel, Total‐Cross‐Tied, and the existing image processing based‐Chaotic Baker Map, Odd‐Even, and Odd‐Even‐Prime configurations. Besides, the system is extensively studied for various symmetrical 9 × 9, 8 × 8, 4 × 4, and unsymmetrical 8 × 6 PV arrays under 34 distinct shading cases with various performance indices. An experimental laboratory prototype model of a 4 × 4 PV array reconfiguration system is developed and studied under distinct shading conditions. Subsequently, an inclusive economic analysis is also conducted, and it is noted that there is a notable enhancement in electricity units and revenue generation by executing the proposed reconfiguration scheme.

Mechanism of improvement in the shear performance of RC beams due to multiple small transverse openings

This paper evaluated the improvement effect of multiple small circular transverse openings (diameter is 1/10 of member height) on the shear performance of RC beams without shear reinforcement and explained the shear resistance mechanism, using three dimensional Rigid-Body-Spring-Method (3D RBSM). First, 3D RBSM was employed to reproduce the shear loading test on the RC beams with multiple small circular transverse openings, and the contributions of beam and arch actions to the shear resistance at each loading stage was evaluated. The analytical load-deflection relationship and cracking behavior were in good consistent with the experiment, and it was noted that the connecting line of the opening centers (line of openings) could control the path of critical diagonal crack, and transfer the failure mode of one of the beams from the diagonal tension pattern to the shear compression pattern. Moreover, the shear strength and ultimate deflection of this beam with openings were significantly improved due to the increase in the shear resistance contribution of arch action. Furthermore, the analysis of additional cases with three transverse openings at each shear span were conducted aiming to explore the possibility that a proper setting of openings can reliably improve the shear performance of RC beams. The line of openings was on a straight line and passed through the loading point at the same side, and the main parameter was set as the angle of the line of openings to beam axis (25°-50°). As a result, the role of the transverse openings in improving the shear performance was confirmed and the corresponding mechanism was explained based on the investigation on the beam and arch actions and crack behaviors.

An appraisal of the Vierendeel mechanism capacity of cellular beams with sinusoidal openings

The aim of this research is to investigate the performance of castellated beams with sinusoidal openings against Vierendeel mechanism (VM). Material nonlinear finite element (FE) analyses were conducted in two beams subjected to four-point bending with geometries selected to exhibit the desired plastification mode. Results of simulations revealed failure mode associated with the formation of four predominant plastic hinges along with shear yielding of the web-post necked region. Differently from the usual castellated beams with hexagonal or cellular openings, the critical hinges did not form at the ‘corners’ around a single opening, but at the innermost and outermost ‘corners’ at shear span. A significant stress redistribution could also be observed during the plastification process. The observation of a unique diagonal stress pattern along the web of the analyzed beams inspired the development of a simple two-dimensional model to predict the performance. A simplified nonlinear procedure was successfully developed to assess the evolution of plastification process with loading, with good agreement with the FE model and with an experimental result reported elsewhere in literature. Finally, it is shown that the current design guidelines for castellated beams (hexagonal and cellular) are not readily applicable to beams with sinusoidal openings for assessment of VM capacity.

Evaluasi Kesesuaian Lahan untuk Tanaman Mulato (Brachiaria hybrid cv. Mulato) pada Tiga Lokasi yang Berbeda

The objective of this research is to evaluate actual and potential land suitability of mulato grass (Brachiaria hybrid cv. Mulato) as forage crop at Dago Dairy Lembang, UPBS Pangalengan and UPBS’s field at Cipunagara. The research is qualitative descriptive research with survey that the data taken from the field and supported by laboratory analysis. Soil sampling carried out by composite sampling method with diagonal systhematic pattern. Land quality obtained from land observation and laboratory analysis compared with mulato’s land suitability criteria to obtain the land suitability level. The actual land suitability level of mulato grass were about S2 (moderately suitable) to S3 (marginally suitable) at Dago Dairy’s field, S2 and S3 at UPBS Pangalengan’s field, S2, S3 and N (non-suitable) at UPBS’s field at Cipunagara. Limiting factors found were oxygen availability (oa), nutrient retention ability (nr), nutrient availability (na) and erosion hazard (eh). Each limiting factor fixed by soil drainage, calcium carbonate or sulfur application, fertilization and cover crop cultivation. Potential suitability of mulato grass after improvement were S1 to S2 at Dago Dairy, S1 to S2 at UPBS Pangalengan and S1, S2 to S3 at UPBS’s land at Cipunagara.

Real-time 3D measurement of freeform surfaces by dynamic deflectometry based on diagonal spatial carrier-frequency pattern projection

Deflectometry is a three-dimensional optical technique based on structured light projection for measuring and inspecting specular freeform surfaces. Conventional deflectometry method needs complicated calibration and time-consuming phase-extraction algorithm, which are not suitable for industrial metrology requiring dynamic and high-speed measurement. In this paper, a novel dynamic deflectometry method with a simple system setup and calibration is proposed for the three-dimensional measurement of specular freeform surfaces with high speed and high accuracy. We developed a very simple calibration method using a reference flat mirror which helps to save calibration time and computer resources. We also proposed a one-shot method by using a spatial carrier-frequency diagonal fringe pattern for screen projection along with an algorithm to separate a diagonal phase into vertical and horizontal phases. We extensively evaluated the feasibility of proposed calibration and one-shot method by different simulations and measuring several specular surfaces experimentally. Our novel deflectometry gives similar measurement accuracy compared to traditional contact measurement technique while offering much higher measurement speed. Dynamic surface shape measurement of silicon wafer due to temperature’s variation proved the real-time measurement ability of our proposed method.

Gonolobus cthulhui (Apocynaceae), una nueva especie de Oaxaca, México

Antecedentes y Objetivos: En México, el género Gonolobus actualmente está representado por 43 especies. Gonolobus ha sido estudiado en algunas floras regionales y continuamente se describen novedades taxonómicas. En este contexto, durante la revisión del material de herbario y colectas realizadas en el estado de Oaxaca, se encontró un ejemplar que no pudo ser asignado a ningún Gonolobus descrito en México y Mesoamérica. Por ello, el objetivo de este trabajo fue describir una nueva especie de Gonolobus de Oaxaca. Métodos: Se revisaron 11 herbarios y cinco colecciones virtuales, y en 2018 se realizaron varios viajes de campo a Oaxaca para recolectar especímenes. El material estudiado se comparó con otros de morfología similar, se elaboró una tabla comparativa y se incluyó un mapa de distribución. Se presenta el estado de conservación de la especie, según los criterios de la Lista Roja de la UICN y observaciones de campo. Resultados clave: Se describe una nueva especie de Gonolobus del sureste de Oaxaca, México, con grandes corolas verdes. Se proporciona una descripción e imágenes de la nueva especie. Gonolobus cthulhui es morfológicamente similar a G. leianthus y G. pancololote, pero se diferencia por sus sépalos de punta negra y ampliamente ovados a suborbiculares, el patrón diagonal pubescente en los lóbulos de la corola y el anillo faucal más delgado y discontinuo. Se sugiere una categoría de conservación en peligro (EN) para esta especie. Conclusiones: Este descubrimiento destaca a Oaxaca como el segundo estado, después de Chiapas, con más especies de Gonolobus (19 spp.), y a México como un centro de diversidad para el género, con 44 especies registradas y 52.2% de las especies endémicas del país.

Effectiveness of ventilation regulation in a simple diagonal system of underground mines

Purpose. Each ventilation system has its own important elements, such as the various branches of the system, which can be connected in a normal and diagonal pattern, ventilation regulators and fans. Based on a professional approach to the analysis of this aeration system, a comparison of reliability results has been conducted, which indicates the real state of the microclimate in underground mines, affecting the increase in the prospects for the development of mining activity. Methods. This paper deals with the problem of ventilation in underground mines, especially in diagonal systems, and the importance of regulating ventilation to provide the required amount of air (Q, m3/min) through the entire system, taking into account the determination of the main fan depression. Findings. To ensure the required (designed) amount of air through the system branches, various methods of effective regulation are used in mining engineering. Therefore, based on research and measurements in different mine workings, our findings provide complete safety and comfort of microclimate during mining activity. Originality. The measurements performed and the database created according to the values and results obtained from the analytical calculations present the best possible estimate, which is substantiated in the paper. Practical implications. The problem of calculating and regulating aeration for a simple diagonal system has been solved, taking into account the determination of the main mine fan depression before and after the use of aeration regulators.

Impact of Intestinal Microbiota on Cognitive Flexibility by a Novel Touch Screen Operant System Task in Mice.

Cognitive flexibility is the ability to rapidly adapt to a constantly changing environment. It is impaired by aging as well as in various neurological diseases, including dementia and mild cognitive impairment. In rodents, although many behavioral test protocols have been reported to assess learning and memory dysfunction, few protocols address cognitive flexibility. In this study, we developed a novel cognitive flexibility test protocol using touch screen operant system. This test comprises a behavioral sequencing task, in which mice are required to discriminate between the “rewarded” and “never-rewarded” spots and shuttle between the two distantly positioned rewarded spots, and serial reversals, in which the diagonal spatial patterns of rewarded and never-rewarded spots were reversely changed repetitively. Using this test protocol, we demonstrated that dysbiosis treated using streptomycin induces a decline in cognitive flexibility, including perseveration and persistence. The relative abundances of Firmicutes and Bacteroides were lower and higher, respectively, in the streptomycin-treated mice with less cognitive flexibility than in the control mice. This is the first report to directly show that intestinal microbiota affects cognitive flexibility.

Flexural and impact behavior of textile reinforced concrete panel

Steel is susceptible to corrosion and requires a significant concrete cover, which increases self-weight and cost. Therefore, an alternative to traditional reinforcements is needed. Textile reinforced concrete (TRC) is a favorable composite using textile material as reinforcement with a fine-grained concrete matrix. This study represents a comparison between different TRCs having different textile reinforcements subjected to flexural bending and impact loading. Four types of textiles—glass (GT), a square oriented galvanized iron (SGIT), diagonal pattern galvanized iron (DGIT), and carbon (CT) are used. All four types of textiles are used to prepare 400 x 50 x12 mm textile reinforced mortar (TRM) and tested for tensile strength properties. This study tests TRC panel and plate samples by three-point bending and drop-weight impact methods. The uniaxial tensile strength test of the textiles shows that CTs can take around 2.3 times higher tensile load than SGITs. However, their tensile load capacity is almost similar in the case of TRM, where SGIT textile shows about 30% higher extension. The flexural bending test of the TRC panels shows that the load-carrying ability increases nearly two times with the increase of 25 mm in thickness even when the number of reinforcement layers remains the same. With the increase in thickness, SGIT textile shows better performance. Drop-weight impact test of the TRC plates shows that the impact energy absorption in CT textile plates is up to two times higher than SGIT plates for various thicknesses. This study summarizes that CT shows overall better performance than SGIT.

Selection of the optimal diagrid patterns in tall buildings within a multi-response framework: Application of the desirability function

Diagrids are efficient structural systems for tall building design and construction due to their high lateral stiffness. Their structural response can be optimized by changing the geometrical pattern of external diagonals. This has usually been carried out by looking for the diagonal pattern that employs the minimum amount of structural material, while complying with strength and stiffness requirements. However, other responses can be significant for the selection of the optimal pattern, such as the torsional flexibility and construction complexity of the building. In this work, the desirability function approach has been used for selecting the optimal diagonal pattern for diagrid tall buildings in a multi-response framework. The most desirable diagonal layout has been selected based on its overall desirability to minimize: (i) the wind-induced lateral displacement, (ii) the torsional rotation, (iii) the diagrid structural weight, and (iv) the construction complexity. The application of this methodology straightforwardly provides the optimal diagrid pattern considering the four responses simultaneously. The method has been applied initially to a limited set of uniform-angle patterns, and afterwards to a wider population of varying-angle geometries. Four different floor plan shapes were also taken into account. The outcomes of the analysis revealed that the specific plan shape plays only a minor role in the definition of the optimal structure, whereas the diagonal layout affects greatly the efficiency of the solution. Uniform-angle diagrids are generally the most desirable, even for taller buildings, due to their higher performance in terms of torsional rigidity and construction complexity. Among these, the patterns in which the diagrid triangular module spans over two-three floors, corresponding to diagonal inclinations of about 55°–65°, have the highest desirability. Notably, because of the competition between the different responses, this optimal inclination is not found to increase as the building becomes taller.

A Novel Fixed BIPV Array for Improving Maximum Power with Low Mismatch Losses Under Partial Shading

Partial shading is a significant limitation that decreases the maximum power output of large photovoltaic (PV), and building integrated photovoltaic (BIPV) arrays installed in modern buildings. One of the optimum solutions to mitigate the difficulty related to partial shading is applying different interconnected fixed BIPV array configurations. This research article aims to modelling, simulation, and performance analysis of a novel conventional 7 × 8 Quarter-Tied (QrTd) fixed BIPV array configuration under the centre, left staircase, frame, left corner, diagonal, and left side shading pattern cases in Matlab/Simulink. Moreover, a comprehensive study with existing conventional fixed BIPV array configurations such as Series-Parallel (SePl), Bridge-Linked (BdLk), Honey-Combed (HnCb), Triple-Tied (TrTd), Total-Cross-Tied (TtCrTd) array interconnections is also executed. The variable parameters for performance evaluation include global maximum power point (GlMxPoPt), mismatch losses (MmLs), fill factor (FiFa), efficiency (Effy), relative power loss (RlPwLs) and relative power gained (RlPwGn). Experimental validation under two partial shading cases is also reported for the justification of simulation results. The simulation results infer that the proposed QrTd configuration improves GlMxPoPt by 4.31%, reduces MmLs by 3.54%, and improves FiFa & Effy by 2.44% and 0.34%, respectively, under six different shading cases. The experimental results conclude that the proposed QrTd configuration improves GlMxPoPt by 1.62%, reduces MmLs by 1.15%, and improves FiFa & Effy by 0.65% and 0.14%, respectively, under two shading cases. Moreover, the wiring requirement and the wiring losses are also lower in the proposed QrTd configuration than in the TtCrTd configuration.

KARAKTERISTIK GLULAM BAMBU APUS (Gigantochloa Apus) MENGGUNAKAN PEREKAT STYROFOAM BERDASARKAN JUMLAH DAN POLA PEYUSUNAN LAPISAN

Wood was a construction raw material that has long been developed before the advent of concrete and steel technology. The need of wood raw materials for construction was increasingly increasing while the availability of high quality wood was increasingly scarce. Therefore, in order to meet this an effort was needed to produce raw materials to replace wood, its was the development of laminated products or glulam made of bamboo apus (Gigantochloa apus) as structural and construction materials. Based on this, this study was conducted to determine the quality of glulam from Gigantochloa apus by using styrofoam adhesives based on number and pattern of layer arrangement. Sample was made of Gigantochloa apus with sized 30cm × 10cm arranged with the number and pattern of layer arrangement that have been determined. This study uses a complete randomized design combination with two treatments. Factor A was the number of layers (three layers, four layers and five layers) and factor B was the arrangement pattern (diagonal, horizontal and vertical). The physical and mechanical properties of glued laminated beams of Gigantochloa apus were tested based on JAS 234: 2003 Standard. The results showed that the quality of glulam met the physical properties of moisture content. While the mechanical properties of MOE and MOR did not meet the standards, so they did not be use as structural materials. Combination with horizontal, diagonal and horizontal lamina arrangement patterns gives the best results on the mechanical properties of glulam.

Heterogeneity and the determinants of PM2.5 in the Yangtze River Economic Belt

Haze has reached epidemic levels in many Chinese cities in recent years. Few studies have explored the determinants and heterogeneity of PM2.5. This paper investigates the spatiotemporal characteristics of PM2.5 through spatial analytical methods based on aerosol optical depth data from the Yangtze River Economic Belt (YREB) between 2000 and 2017. Geographically weighted regression and geodetector models were applied to assess the heterogeneity of key factors influencing PM2.5. The results indicate that the annual concentrations of PM2.5 in the YREB were 23.49–37.37 μg/m3, with an initial increase and a later decrease. PM2.5 pollution showed a diagonal high spatial distribution pattern in the northeast and a low spatial distribution in the southwest, as well as a noticeable spatial convergence. The spatial variability of PM2.5 was enlarged, and its main fractal dimension was in the northeast-southwest direction. There were clear spatiotemporal variations in the impacts of natural and anthropogenic factors on PM2.5. Our findings contribute to a better understanding of the impact mechanisms of PM2.5 and the geographic factors that form persistent and highly polluted areas and imply that more specific coping strategies need to be implemented in various areas toward successful particulate pollution prevention and control.

Mitigation of Cross-Coupling Effects in PV String-Integrated-Converters Employing SEPIC Converter with P&O MPPT Technique

Photovoltaic (PV) string-integrated-converter (S-I-C) topology allows each PV string to operate at their respective maximum power point (MPP) corresponding to the variations in solar insolation. The S-I-C topology comprises an individual DC–DC converter integrated into each PV string. The output terminals of the S-I-Cs are connected either in the series or parallel configuration. There are certain limitations in each of the series/parallel configured PV S-I-Cs. By employing DC–DC boost converter as an S-I-C, cross-coupling effect is the main limitation of a series configured S-I-Cs. The cross-coupling effect causes the deviation in operating points (MPPs) of the shaded & unshaded PV strings and this leads to power consumption by the boost type S-I-Cs instead of delivering to the load. This article presents the mitigation of cross-coupling effects by employing a single-ended primary inductor converter (SEPIC) as an S-I-C in a series configuration of S-I-Cs. The conventional perturb & observe (P&O) MPPT technique is used to track the maximum power from PV strings. The results of the series configuration of SEPIC converter-based S-I-Cs are compared with the boost converter-based series configuration along with the mathematical analysis under uneven-row, uneven-column, diagonal, and long & narrow shading patterns.

A Dynamic Image Analysis Method for Fragmentation Measurement in Blasting

Fragment size optimization with selection of best values of blast design variables is an important process in mine-mill fragmentation system to maximize the system performance. This calls for measurement and analysis of mean fragment size with respect to blast design parameters. Digital image analysis technique is the most accepted method for measurement of blasted fragment sizes and their distribution. For quick assessment of the fragment sizes, a new novel method based on the digital images extracted from a blast video is reported in this paper. Correction factor for the size of fragments, considering the face movement is also proposed. The method has been tested with the help of seven blast data sets. The proposed dynamic image analysis technique can not only be used in fragment size estimation but also to assess the time-progressive size reduction in a blast, which can help designing the delay timing. Further, a possibility to estimate the in-situ block size is also explored with this method. The images of blast fragmentation were extracted from their videos at an interval of 0.08 s. These images were analyzed later for measurement of mean fragment size at respective times. The fragment size of the complete muck generated by the blast was also measured and correlated well with the sizes achieved from video analysis. The analysis revealed that from 0.08 s to 0.56 s from the initiation of the blasts, the fragment size reduction progressed from 58% to 80% of the estimated in-situ rock block sizes. Significant effect of blast design variables and two firing patterns on the mean fragment size was also observed. The analysis suggested that V-type firing pattern provides finer fragment size in comparison to the diagonal firing pattern. The suggested method provides an easy yet fast way for the assessment of blast fragment size.