Leader Branches Research Articles

Characteristics and mechanism of a triggered lightning with two polarity reversals of charges transferred to ground

Characteristics of a triggered bipolar lightning flash obtained in the Shandong triggering lightning experiment (SHATLE) are analyzed based on simultaneous observation results of lightning very high frequency (VHF) interferometer map, channel-base current, fast electric field change and high-speed optical images. The flash lasts about 315 ms with only the initial continuous current (ICC). As the polarity of charges transferred to the ground varies from negative to positive and then to negative, the ICC can be mainly divided into three stages including the first negative ICC stage, positive ICC stage, and second negative ICC stage, respectively, for 152.755 ms, 87.225 ms and 75.02 ms. Charges transferred to the ground during the three stages are about –40.0 C, +13.3 C and –1.0 C, respectively, with the peak current of about –3.8 kA, 1.6 kA and –2.25 kA. According to the VHF interferometer map, during the first negative ICC stage, the upward positive leader (UPL) initiated from the top of the wire as negative charges starts to be transferred to the ground. The UPL develops at a two-dimensional (2D) speed of 3.7 × 10<sup>4</sup> m/s into the cloud and multiple positive branches develop in the form of small-scale and dense recoil leaders, keeping the increase of negative charge transferred to the ground. Then a negative leader (NL) initiates on a previously ionized positive branch channel and develops into the virgin air horizontally as a floating channel at a 2D propagation speed of 1.59 × 10<sup>5</sup> m/s. About 28.816 ms later after the NL develops, a negative pulse is detected in the fast electric field change, caused by a negative polarity breakdown discharge from the grounding trunk channel to the floating channel which is observed for the first time. Then about 39 μs later, the first polarity of the channel-base current changes from negative to positive, and rapidly reaches a positive peak in 1.75 ms. Subsequently, with the positive ICC decreasing, the negative leader gradually terminates about 65.85 ms after the first polarity reversal, and then 21.38 ms later the channel-base current slowly changes to the recognizable negative polarity as the second polarity reversal. A recoil leader generating in a previously ionized positive branch channel connects to the trunk channel, resulting in the initial continuous current pulse (ICCP) during the second negative ICC stage. Then several negative recoil leaders occur, tracing back to the previous positive channels without obvious current changes until the flash ends. Based on the analysis, the positive branch channel persistently transfers negative charge to the ground in the whole discharge process by the positive breakdown on the tip or the negative recoil leaders retrograding along the previous positive channels. The trunk channel is connected to the floating channel through negative breakdown discharges, linking at the positive charge accumulation area at the tail end of the negative leader or the positive polar end of a bidirectional leader towards the trunk channel, if the negative leader develops as a bidirectional leader later. Then, the net charge transferred to the ground is dominantly positive and the reversal of first channel current polarity occurs. With the negative leader disappearing, the supply of positive charge ceases, so the current polarity reverses again (the second reversal). Connection of the negative leader to the grounding trunk channel and continuous development of the positive leader are inferred to play an important role in reversing the two current polarities. In this case, the negative leader developing in virgin air might be initiated transversely in an ionized positive channel or from the end of a decayed positive leader branch of the ionized positive channel which is small and undistinguishable from the VHF interferometer map.

“Down Where the South Begins”: Black Richmond Activism before the Modern Civil Rights Movement, 1899–1930

“Down Where the South Begins”: Black Richmond Activism before the Modern Civil Rights Movement, 1899–1930

Analisis Sistem Pengendalian Internal Pada Lembaga Amil Zakat Al Azhar

This study aims to analyze the implementation of the internal control system in the collection process until the distribution of zakat funds in this study was conducted at the Al Azhar Amil Zakat Institution, this research is a qualitative research using a phenomenological approach. Based on the results of this study revealed that the Amil Al Azhar Institution in 1) The control environment in the aspect of integrity and ethical values always emphasizes the standards determined by the center. 2) Risk withdrawal is carried out with each transaction known to the Branch Leader and inputted using the system then for internal changes such as the presence of new employees and the risk assessment. 3) Control activities are carried out by ensuring that the quality of transaction authorization is guaranteed by donors coming to the office for transactions to always fill in the proof of deposit. Good safeguards for assets and independent checks are carried out every few months. 4) Information and communication is carried out by always using the custumer service and internal information systems. There is good communication between divisions. 5) Monitoring mechanism is carried out by monitoring internal and external partiesKeywords: Internal Control, Zakat Collection, Zakat Distribution

Analisys of The Quality of Customer Service Satisfactory of Baitul Maal Wattamwil (BMT) Tamzis at Daerah Istimewa Yogyakarta and Jawa Tengah

The research aim was to analyse the quality of customer service satisfactory of BMT Tamzis at Daerah Istimewa Yogyakarta and Jawa Tengah, as the syariah finance, who has 33 (thirty three) branchs, and its headquarter at Wonosobo, Jawa Tengah. It has at least 2.000 customers in 2018. BMT Tamzis needs some feedback in order to increase their quality of customer service satisfactory as high as possible to reach optimum level, and fulfill qualification of succeed finance business. This research wanted to measure the up dated customer service satisfactory and gave feedback to BMT Tamzis. The research method used quantitative approach to primary data of customer questioneer and scondary data of BMT Tamzis’s headquarter. The questioneers had distributed to customers by proporsional random sampling about 330 examplars, returned back about 320 examplars, and than have been calculated by SPSS method version 10.0. The result research was customer satisfactory perception toward BMT Tamzis reached good and significance level at all branchs, at point 4.031 root mean at 1 until 5 Likert scale. They favored assurance dimension at point 4.215, and than tangibles (3.990), responsiveness (3.989), reliability (3.976), and emphaty (3.986). To be adviced that all branch leaders must increase giving their services until reach the highest level of all dimensions, that are : tangibles, responsiveness, reliability, emphaty, dan assurance.Keyword: satisfactory, service, customer.

Development of Side Bidirectional Leader and Its Effect on Channel Branching of the Progressing Positive Leader of Lightning

AbstractFine time‐resolved images of the development of lightning bidirectional leaders below the cloud base were captured by a high‐speed camera in association with multiband electromagnetic field measurements. The bileaders tended to originate at a radial distance of about 200 m from a progressing positive leader channel, propagating more or less radially toward and away from the main channel. Significant asymmetrical channel extensions at opposite ends were clearly recognized. The positive ends of the bileaders propagated in single paths with average speed of 6.1 × 104 m/s, while the opposite negative end involved obvious branching and stepping propagation with average speed of 1.6 × 105 m/s. The bidirectional leaders eventually connected to the existing main positive leader, producing new branches of the flash. Another cause of positive leader branching was that the positive leader split at its head and developed into different branches synchronously, which were sometimes invisible but were revealed by recoil leaders.

Accessing the IEEE Network [The Way Ahead

Reports on the global reach of the IEEE as an organization and explains its regional areas and operations. The IEEE is geographically broken into 10 Regions. Do you know in which Region you are located? Each Region has a Regional Student Activities Committee (RSAC) chair. RSACs provide policy guidance and coordination about student membership and branch issues within the Region. They also deliver training and resources to Student Branch leaders to help Student Branches achieve their maximum potential in offerings and administration. The SAC makes specific recommendations to the Regional Committee on awards and recognition bestowed upon Student Members, Student Branches, and other volunteers related to the student activity. RSACs support the professional development of future engineer leaders. They promote the academic and professional development and the leadership of the IEEE student community in the Region, through the IEEE and for the volunteers.

Formation Features of Steps and Branches of an Upward Negative Leader

AbstractWe have analyzed the high‐speed video of an upward negative leader that exhibited multiple branches. From the video, which was recorded at a frame rate of 300 kiloframes per second (3.3 μs per frame), we have identified 75 leader steps, 21 being from the leader main channel and 54 from 4 branches of the leader. Through analyzing each individual leader step and branch in detail, we found a similar formation pattern for both the leader step and the branch. This pattern can be described in the following sequence: (1) the streamer area forms ahead of the leader tip, (2) the streamer area and the backward leader channel increase in luminosity, (3) the streamer area and the leader channel decrease in luminosity, (4) the streamer area reilluminates ahead of the leader tip, and (5) the reilluminated streamer area develops to a new leader tip and a new streamer area is emitted forward ahead of the new leader tip.

SISTEM PENDUKUNG KEPUTUSAN PEMILIHAN KEPALA CABANG TERBAIK BANK SUMUT DENGAN MENERAPKAN METODE VIKOR

SUMUT Bank is one of the Banks in Indonesia with the name of the company PT. Regional Development Bank of North Sumatra. The North Sumatra Bank has branches in each region in North Sumatra both in the district and in the sub-district, and each of these branches is led by a branch leader or branch head. The head of this branch is responsible for the reversal of the Bank being led. The best and most accomplished branch heads deserve more and more awards. The selection of the best branch heads is selected transparently and structured in the hope that it can be a motivation for all branch heads to be able to further improve the quality and service of the Bank they lead. Making the best branch head selection done manually will take a long time and tends to be less transparent and structured. One solution so that the implementation of the selection can be carried out easily and quickly, it requires a Decision Support System that can provide consistency of assessment. In this study the method used is the VIKOR method (Visekriterijumsko Kompromisno Rangiranje). This method makes cracking on alternatives based on criteria that have been determined with an ideal compromise solution or the best solution, so that this system can later be beneficial for the SUMUT Bank to get the title in determining the best branch head.Keywords: Decision Support System, North Sumatra Bank, Branch Head, Vikor

Pruning management in a high-density olive orchard

The effect of different pruning strategies and times on olive vegetative-reproductive behavior was studied in a 5-year-old high-density orchard (1250 trees ha-1, cultivar 'Ascolana tenera'). Compared treatments were a) winter hedging and topping, b) summer hedging and winter topping, c) winter hedging and summer topping, and d) summer hedging and topping. Selective spring pruning to a conical shape of the canopy was used as a control. Results showed no significant differences between the tested treatments regarding the maximum canopy diameter (along and perpendicularly to the row). Topping significantly constricted the tree height recorded at the end of the season when compared with the control (3.5±0.46 m); in particular, summer application maintained the final tree height at 2.5±0.21 m. Summer topping and hedging significantly reduced the canopy volume compared with winter and selective spring (control) pruning. No significant differences between the treatments were recorded regarding the number of newly emitted sprouts on the central leader and primary branches, whereas the length of these sprouts was significantly shorter for the trees with summer topping. Vegetative re-sprouting was mainly recorded in the upper portion of the canopy (above 2.0 m), and the total length of the new sprouts in this portion was significantly different for summer and winter pruning (1.2±0.08 and 18.7±0.92 m, respectively). No significant differences between the treatments were registered for the seasonal vegetative growth of 1-year-old mixed shoots. Fruit yield per tree was significantly higher following the winter hedging and summer topping treatment compared with summer hedging and topping (47% increase) and selective spring pruning (control, 64% increase). Results suggest that correct pruning management (winter hedging and summer topping) contributes to maintaining a good vegetative-reproductive balance of young trees (reduced vegetative re-sprouting and high fruit production) in high-density olive orchards.

Interaksi Keberagamaan Dakwah Muhammadiyah di Kota Makassar

Abstract. This research is funded by the Muhammadiyah grant scheme. The purpose of this research in general is to examine the resources of Muhammadiyah da'wah. The type of this research is qualitative, the determination of informant research done by purposive sampling technique and snowball sampling. Data collection techniques through participant observation, in-depth interviews, documentation and participatory, research data will be analyzed through data reduction, display data, conclusion drawing and conclusion drawing. Data validity technique uses internal validity test, external validity, Dependency. Certainty / objectivity, and Triangulation (source, technique and time). The result of the research shows that to become dai Muhammadiyah that is (1) is a cadre, (2) active in organization, (3) recommendation from Branch or branch leader, (4) pass administration selection, (5) pass the reading ability test of Qur'an and the ability to perform lectures or khutbah. Competence must be owned by dai Muhammadiyah that is (1) understand Al Qur'an and hadith, (2) have science and education, (3) follow training. The form of the dai Muhammadiyah model is divided into three forms namely the serious da'wah model, the model of da'wah homoris and the model of serious and humorous combined da'wah. Propagation material muhammadiyah includes 7 material that is aqidah, morals, dates, general studies, special studies and Masail fiqhiyyah. The role of dai includes the mastery of social media, regeneration of dai, understanding of da'wah maps, efficiency of time, conduct study and reading.Keywords: Interaction, Dakwah, Muhammadiyah

The influence of executives’ characteristics on bank performance: The case of emerging market

This research is expected to provide information for the benefits of Bank SulutGo and also the Government of North Sulawesi in forming the composition of the board of directors and board of commissioner and all bank officials in SulutGo Bank. The population and samples are SulutGo Bank officials consisting of boards of commissioners, boards of directors, division leaders and branch leaders of all the Banks of SulutGo. They consist of 4 Commissioners, 5 Directors, 2 Heads of Department, 19 Heads and Divisional Representatives, plus 94 head offices (head office, branch offices and sub-branch offices) scattered throughout the provinces of North Sulawesi, Gorontalo, DKI Jakarta and East Java. In measuring the performance of BPD, Capital Adequacy Ratio (CAR), Return on Assets (ROA) and Return on Equity (ROE) are employed. The results show age, education level, work period and gender has a positive relationship with CAR, but there is no relationship with ROA, ROE and Total Assets. The same with the F-test, simultaneously age, education level, work period and gender has a positive relationship with CAR but there is no relationship with ROA, ROE and Total Assets.

Dynamics of branching of negative downward lightning leaders

The branching of negative downward lightning leaders is of both theoretical insterest and practical importance. In the lightning protection of ground structures, a clearer understanding of the mechanism and dynamics of leader branching is needed to identify possible lightning strike locations as well as vulnerable parts of the protection systems. In this work, we start with the image analysis of a lightning leader process recorded with a high-speed camera and to show that the anode-directed streamer zone developed from space stems in front of a leader tip needs be smaller in size (<10 m) to make branching more likely to occur. Then, we propose a kinetic model to describe the growth of the meter-scale streamer zone, which essentially states that the growth speed decreases as the streamer zone expands. The exponent in the kinetic model can be estimated by comparing the numerical and observational results. Based on the model, the streamer zone dynamics on the meter-scale differs from that of a single streamer in that the slowing down of the growth is accompanied by the recovery of the electric field at the discharge front, which may result in new bursts of streamers. This model, if further verified, could be the foundation of inferring the structure and dynamics of the streamer zone from the morphology of the leader channel, which would significantly advance the knowledge of the streamer zone in negative lightning leaders.

Upward negative leaders in positive triggered lightning: Stepping and branching in the initial stage

AbstractBy conducting comprehensive observation on the rarely triggered positive lightning flashes, two cases of upward negative leaders were quantitatively investigated with simultaneous data of current, optical, and electromagnetic field changes at fine time resolution. The impulsive channel current associated with the initial leader stepping involved pulse interval, peak, charge of 19.1 μs, 122.3 Å, 465.9 μC, and 20.3 μs, 58.4 Å, 267.2 μC, for the two cases, respectively. The negative charge of an individual step was nearly an order of magnitude larger than that of the positive leader step in triggered lightning. The upward negative stepped leader branches shortly after initiation, and consequently, the stepping‐caused current pulses became multipeaked, wider, and more frequent in waveforms. The main leader tip propagated at an average speed of 2.10 × 105 m/s, while its partial speed fluctuated a lot as was significantly influenced by the behaviors of subbranches development.

Channel branching and zigzagging in negative cloud-to-ground lightning

A fundamental question in lightning flash concerns why the discharge channel propagates in a zig-zag manner and produces extensive branches. Here we report the optical observation of two negative cloud-to-ground lightning discharges with very high temporal resolution of 180,000 frames per second, which shows in detail the dependence of channel branching and tortuous behavior on the stepping process of the leader development. It is found that the clustered space leaders formed in parallel ahead of the channel tip during an individual step process. The leader branching is due to the multiple connection of the clustered space leaders with the same root channel tip, which occur almost simultaneously, or successively as some space leaders/stems resurrect after interruption. Meanwhile, the irregularity of angles between the clustered space leaders and the advancing direction of leader tip is the origin of channel tortuosity. The statistical analysis on 96 steps shows a geometric-mean value of 4.4 m for the step length, ranging between 1.3 and 8.6 m, while the distance from the center of space leader to the channel is 3.6 m, ranging between 2.1 and 6.9 m. More than 50% steps occurred within an angle range of ±30° from the advancing direction of the leader.

Planting systems of sweet cherries in Belgium

The choice of a planting distance or planting system depends on soil type, cultivar or rootstock. Moreover, the experience of the grower is an important factor. If one has little experience with the training and pruning of sweet cherries, it may be appropriate to plant wider. With intensive plantings it is necessary to prune consistently to avoid problems with growth. In 2003, we started a trial with 4 planting systems with ‘Sweetheart’ on Gisela 5. Until now the classical system and the English system do well. The Spanish bush, on the other hand, had very low productions in the first years. In the V-system the total production ha-1 is obviously lower than in the other 3 systems, due to some disappointing productions during the last years. In a second trial ‘Kordia’ and ‘Sweetheart’ on Gisela 5 were planted in a V-system in spring 2005. A V-system is a very expensive and labour intensive system. For the planting of a V-system, a self-fertile cultivar like ‘Sweetheart’ has to be preferred as it gets in this trial clearly better yields than ‘Kordia’. On ‘Kordia’ the vigour was quite strong, even when the trees were repeatedly root pruned. A cultivar like ‘Kordia’ yields insufficiently on the leader branches. This kept the production too low each year. In spring 2009 ‘Skeena’ on Gisela 6 was planted as a classical system and according to the “UFO”-method. “UFO” stands for upright fruiting offshoot. The whips were planted under an angle of 45°. From the central leader shoots were tied to grow upright. This results in a narrow system. Up to now the “UFO”-method is very labour intensive, especially the tying and removing of the branches take time. After 7 production years the yield of the “UFO”-system is 32% lower compared to the standard training system. The fruit size is also slightly smaller for the UFO-system.

재식거리 확보에 의한 '캠벨얼리' 포도의 생육 및 과실 특성

주지 연장지를 활용한 간벌에 의해 재식거리가 확보된 포도캠벨얼리 품종의 수체와 과실 생육 특성을 조사하였다. 포도나무의 전정 전 가지 굵기는 11.8 mm였고, 간벌구는 가지 굵기가 9.3 mm로 감소되었다. 간벌구의 신초 수는 주당 55.9~64.5개로 증가하였고, 신초당 송이 착과율은 간벌구가 1.5~1.75개로 대조구의 약 0.8개보다 높게 나타나 간벌구가 주당 98.1~106.5송이로 대조구의 24.4~28.0송이 보다 착과량이 많았다. 과실 특성 중 가용성고형물 함량 및 산도는 간벌구과 대조구간에 차이가 없었다. 포도 캠벨얼리 품종의 상품과 기준인 351 g 이상 송이 비율은 간벌구가 81.0로 대조구구의 35.7%보다 현저히 높았다. 따라서 과실 특성과 생산량을 볼때 캠벨얼리 품종에서 수세가 강하면 주지연장지를 활용한 간벌 처리가 효과적인 것으로 판단되었다. Shoot and the fruit growth characteristics of 'Campbell Early' grape cultivar were investigated after vine thinning using the main branch leader. Before vine thinning, branch diameter was 11.8 mm, but it decreased to 9.3 mm after vine thinning. The number of shoots per vine increased to 55.9-64.5 after vine thinning. The number of fruit clusters per shoot was higher (1.5-1.75) in the vine thinning plot than in the control (0.8). Consequently, the number of clusters per vine was 98.1-106.5 in the vine thinning plot, while that in the control was 24.4-28.0. However, soluble sugar content (SSC) and tartaric acidity showed no significant differences between the control and the vine thinning plot. The proportion of >351 g fruit cluster weight after vine thinning (81.0%) was significantly higher than that of the control (32.5%). These results imply that fruit quality based on the variation in cluster weight and fruit yield was enhanced by vine thinning using the main branch leader.

Pengaruh Gaya Kepemimpinan Transaksional Melalui Motivasi Terhadap Kinerja Karyawanan Pada Bank Pembangunan Daerah Kalimantan Selatan (Kantor Cabang Utama Banjarmasin)

The purpose of this research is test the influence of transactional leadership style (X) and the motivation (Z) againts employee performance (Y) in Bank Pembangunan Daerah Kalimantan Selatan (Kantor Cabang Utama Banjarmasin).Samples taken as many as 78 people which is the overall number of employees (excluding the branch leader and section leader). Collecting data using the questionnaire while data analysis using the PLS (Partial Least Square) by using the smartPLS. The test results prove the transactional leadership style have a significant effect on employee motivation with the effect of 38.08%, motivation significantly influence performance of employees with the effect of 2.40%, transactional leadership style significantly influence employee performance with the effect of 59, 96%. Key words: transactional leadership style, motivation and employee performance

Characteristics of leader pulses in positive ground flashes in Sweden

This paper presents the characteristics of the electric field pulses observed during leader propagation in positive ground flashes. We analysed in detail the electric field changes occurring just before the first return stroke in 51 positive ground flashes during 2014 summer thunderstorms in Uppsala, Sweden. Pronounced leader pulses (having the same polarity as the return stroke) were observed in 22% of the cases. They were observed to occur within 1.4ms before the first return stroke. Interpulse duration ranged from 13.3 to 50.3μs with a mean value of 24.7μs. The peak amplitude of the leader pulses relative to the return stroke peak ranged from 2.7 to 17.8%. The presence of these pulses shows that the leaders propagate in a stepped manner. Based on the leader pulses’ time of initiation and average speed of the leader, the distance travelled by the leader was also estimated. One case of positive ground flash preceded by opposite polarity leader pulses just before the return stroke is also reported. To the best of our knowledge, this is the first time that such a case in positive ground flashes is reported. We suggest that these opposite polarity leader pulses are due to the negatively-charged leader branch of a bi-directional leader inside the cloud that propagates towards observation point.

Effect of branching on the channel tortuosity of positive leader

Experiments on leader development were carried out in 10 m and 6 m rod-plane gaps under positive impulse. Leader propagation was recorded by high speed CCD camera. Effect of branching on its channel tortuosity was studied based on these high speed photographs. Over 70% of turning points along the 2-D leader channel are accompanied with leader branching in the experiment. That is branching makes an important contribution to the channel tortuosity of positive leader.

Observations of the connection of positive and negative leaders in meter‐scale electric discharges generated by clouds of negatively charged water droplets

AbstractDetailed observations of the connection between positive and negative leaders in meter‐scale electric discharges generated by clouds of negatively charged water droplets are presented, and their possible implications for the attachment process in lightning are discussed. Optical images obtained with three different high‐speed cameras (visible range with image enhancement, visible‐range regular, and infrared) and corresponding current recordings were used. Two snapshots of the breakthrough phase of the leader connection, showing significant leader branching inside the common streamer zone, are presented for the first time. Positive and negative leader speeds inside the common streamer zone for two events were found to be similar. Higher leader speeds were generally associated with higher leader currents. In the case of head‐to‐head leader connection, the infrared brightness of the junction region (probably representing the gas temperature and, hence, the energy input) was typically a factor of 5 or so higher than for channel sections either below or above that region. In 16% of cases, the downward negative leader connected to the upward positive leader below its tip (attached to the lateral surface of the positive leader), with the connection being accomplished via a channel segment that appeared to be perpendicular to one or both of the leader channels.