Synchronous Type Research Articles

Floral traits and chemical cues associated with rock bee (Apis dorsata Fabricius) for the host selection in West Bengal, India

In the present work, bee foraging plants were determined by palynological analysis of colony stored samples (honey and pollen) of Apis dorsata collected from southern West Bengal, India. Then flowering phenology and pollen morphologies were described to evaluate the forage preference of the bee species. In addition, chemical cues were analysed using gas chromatography-mass spectrometry (GC-MS). Foraging strategy of the bee species was profitable in that almost all the bee-visited plants were utilised for both nectar and pollen sources. The bee species became generalist visitor of several plants having diverse life form, flower characters and pollen morphologies. However, most of the bee-visited plants were of trees with synchronous type of flowering. Most plants had small-sized, yellow, cream and white coloured flowers and pollen was openly presented. We did not find any patterns in the morphological traits of bee collected pollen, though the pollen types were predominantly of medium sized with trizonocolporate apertural pattern and reticulate surface ornamentation. Floral volatile organic compounds (VOCs) of bee visited plants were also diversified. Compounds frequently found in the floral VOC bouquets were amphetamine-3-methyl; butane, 2-cyclopropyl; 2,3-butanediol; cyclohexan, 1-methyl-5-(1-methylethyl); d-limonene; methyl (2E)-2-methoxy-2-butenoate; phenol, 4-[2-(methylamino)ethyl]; phthalic acid, di(2-propylpentyl)ester; propanamide, N-(aminocarbonyl) and pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl). In conclusion, floral traits and chemical cues of plants influence the host selection specificity (to collect floral rewards) of the rock bees.

A novel non-invasive electrical synchrony method to improve cardiac resynchronization therapy responders

Abstract Introduction Cardiac resynchronization therapy (CRT) has emerged as an important treatment for patients with heart failure and reduced ejection fraction (EF) despite optimal pharmacological therapy. Some studies showed non-responders rate near 30%. Nowaday there is no gold standard method for selection, evaluation and follow up on this group of patients. Multiple techniques used and operator dependence made echocardiogram failed. Synchromax 2 is a device designed to evaluate non-invasive electrical synchrony. It is fast, reproducible and non-operator dependent. Synchromax was evaluated and correlated with other techniques in previous studies. Objective Evaluate CRT response rate guided by electrical synchrony during the device implantation and follow up. Material and methods 43 patients were evaluated in an institution in Buenos Aires. A ICD-CRT was implanted in all patients due dilated cardiomyopathy, low EF (less than 35%) and left bundle branch block (LBBB). Non-invasive electrical synchrony evaluation (Synchromax 2) was performed in all patients in baseline condition, during device implantation and the follow up. Synchrony index and curves were analyzed. Curve type 4 and index between 0,4 and 0,7 were considered synchronous. Curve type 6 and 10 and index more than 0.7 were considered disynchronous. Interventricular intervals were modified to achieve the best curve and synchrony index. Super responders were considered when EF increased >50%. Baseline and 6 month after implantation echocardiogram were performed. Results Mean age 64 years. 39% females. Non-coronary dilated cardiomyopathy was main aetiology (63,1%). EF baseline average was 27%. A baseline index more than 0,7 was in 73,3% of the patients. Curve 6 was the most frequent (55,2%). Follow up average EF was 39% (increased 12%), the super responders rate was 18,6% (8 patients). Type 4 curve and index between 0,4 and 0,7 were achieved in 28 cases (65,1%). EF increased from 23% (baseline) to 42% (follow up). Average 19%. Type 4 curve was not achieved in 15 patients (34,9%). In this group, EF increased from 29% (baseline) to 34% (follow up). Average 5%. Conclusion Electrical synchrony evaluation using Synchromax 2 during ICD-CRT device implantation improves responders rate. When synchronous type 4 curve is achieved EF improves significantly. If type 4 curve is not found results will be unsuccessfully. Synchromax is fast, simple and non-operator dependent. Funding Acknowledgement Type of funding source: None

A phylogenetic approach to understand the evolution of reproduction in coleoid cephalopods

A central question in the evolution of life-histories is whether organisms reproduce once or repeatedly. For cephalopods, the main differences between semelparous and iteroparous are based on ovulation pattern and spawning type. The different reproductive strategies in coleoid cephalopods could be related to the habitat in which the species dwell (coastal vs. oceanic) and/or to environmental forces, thus, both aspects should be quantitatively evaluated under an evolutionary perspective to reconstruct: (a) the ancestral ovulation type of coleoid cephalopods, and (b) the potential of correlated evolution between ovulation type versus habitat and environment. Ancestral states of ovulation type were estimated using stochastic mapping based on literature data (i.e. synchronous or asynchronous), and this information was combined with a new molecular phylogeny including 165 species. The evolutionary correlation between ovulation type, habitat, and environment was estimated by means of the Markov model comparing the rates of gain and loss. The estimates of ancestral states of ovulation type for coleoid cephalopods resulted in a high probability that Octopodiformes evolved from synchronous ovulation type, and Decapodiformes from asynchronous ovulation type. The three traits evaluated presented phylogenetic signal, although no correlation was found between habitat and ovulation type. Overall, species in stable environments showed a tendency towards synchronous ovulation type, while the asynchronous ovulation pattern was found more frequently in species that live in unstable environments, being this last trait also responsible for triggering the change of ovulation type in some species throughout evolution.

Synchronous Primary Endometrial and Ovarian Cancers: Trends and Outcomes of the Rare Disease at a South Asian Tertiary Care Cancer Center.

Background and objectiveThe incidence of synchronous primary endometrial and ovarian cancer is uncommon and poses a diagnostic challenge to the treating physician about their origin as either primary or metastasis. The purpose of this study was to evaluate the clinicopathological behavior, treatment modality-related outcomes, and prognosis related to primary endometrial and ovarian cancers at a tertiary care referral center in South Asia.MethodsWe retrospectively analyzed 30 patients with synchronous ovarian and endometrial cancers treated at Shaukat Khanum Memorial Cancer Hospital and Research Centre in Lahore, Pakistan from January 2005 to August 2017.ResultsThe median age of the patients at the time of diagnosis was 51 years (range: 25-72 years). The common presenting symptoms were irregular uterine bleeding (30%), post-menopausal bleeding (26.7%), abdominal mass (16.7%), and abdominal pain (26.7%). Endometrial adenocarcinoma type was the most common histological variant found among the participants: 90% (n=27) of uterine and 56.7% (n=17) of ovarian cancers. All patients underwent surgical intervention. Among them, 25 patients received platinum-based adjuvant chemotherapy, four received neoadjuvant chemotherapy, and 18 received adjuvant radiotherapy. The early-stage group [International Federation of Gynecology and Obstetrics (FIGO) stage I and II] had a more favorable prognosis than the advanced stage group (FIGO stages III and IV).ConclusionBased on our findings, patients with synchronous primary endometrial and ovarian cancers have better overall survival rates than patients with single primary ovarian or endometrial cancers. Also, synchronous primary endometrial and ovarian cancer endometroid types have better overall survival than patients with non-endometrioid or mixed histologic types.

Sizing Up Transport Poverty Alleviation: A Structural Equation Modeling Empirical Analysis

The aim of this paper was to systematically obtain the poverty reduction effects and diversified poverty alleviation paths of road infrastructure, to assist in the planning of transport poverty alleviation and rural revitalization in the concentrated contiguous poverty-stricken areas. The measurement methods for impact effects and paths of transport poverty alleviation have been scientifically proposed based on methods of transportation economics and transportation geography. Firstly, an overview of the interactive mechanism and processes by which road infrastructure investment influences poverty reduction has been offered, and the characteristics of poverty space and spatial coupling result of road infrastructure have been systematically obtained. The results show that about 70% of the district counties’ road infrastructure and poverty rate are in a state of spatial coupling imbalance; the coordinated synchronous type is mainly distributed along the road network. Secondly, the structural equation model system has been formulated with variables that reflect transportation input in adjacent geographical units to consider spatial spillover effects. The results show that the direct poverty reduction effect of road infrastructure (0.105) is much lower than the indirect poverty reduction effect (0.830). Thirdly, empirical analysis at regional level of the concentrated contiguous poverty-stricken areas in China has been conducted. As a result, while addressing the limitations of previous studies, the poverty alleviation path that has been proposed also aims to catalyze actions to reduce the transport-related exclusion in poverty-stricken areas caused by the lack of access to basic facilities.

Histological analysis of ovarium development of Hampala macrolepidota Kuhl & Van Haselt, 1823 from Jatigede Reservoir, West Java

This research was conducted from May to September 2018 at the Biotechnology Laboratory, Faculty of Fisheries and Marine Sciences, University of Padjadjaran. Fish samples were taken from Jatigede Reservoir, Sumedang, West Java. The hampala fish consisted of female hampala barb with gonadal maturity level (GML) IV, GML V, and GML VI. Ovarian histological preparations were made at the Animal Microtechnical Laboratory, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran. This research aimed to determine the stages of ovarian development of hampala barb, and determine the types of spawning. The hampala barb in the Jatigede Reservoir had five stages of oocyte development, namely chromatin nucleolus stage, perinucleolus stage, cortical alveolus stage, vitellogenesis, and oocyte maturation with multi-spawner group synchronous type of ovarian development.

ESS 전원동기방식을 이용한 인버터 구동 공간 벡터 유도전동기 속도제어기 설계

ESS 전원동기방식을 이용한 인버터 구동 공간 벡터 유도전동기 속도제어기 설계

Incidence of Multiple Metachronous Gastric Cancers After Pyloric-Preserving Gastrectomy.

Pylorus-preserving gastrectomy (PPG) is widely used for early gastric cancer located in the middle third of the stomach. The minimization of the extent of gastrectomy may increase the risk of metachronous multiple gastric cancer (MGC). We report the findings of a study that was conducted to evaluate the prevalence of MGC after PPG. The clinical data of 533 patients who underwent PPG for gastric cancer between 1993 and 2018 were reviewed. The clinicopathological characteristics at the time of the primary treatment that were predictive of the development of MGC were explored. The median (range) observation period was 112.4 (8.1-290.7) months. Metachronous MGC was diagnosed in 33 of the 533 patients. The cumulative 5-year and 10-year event rates were 3.3% and 6.2%, respectively. The patient gender, presence/absence of synchronous MGC and the macroscopic type of the primary gastric cancer were significantly associated with the risk of development of metachronous MGC. Multivariate analysis identified the presence of synchronous MGC (hazard ratio [HR]: 4.828, 95% confidence interval [CI]; 1.611-12.30, p = 0.004) and Type 0-IIa primary gastric cancer (HR 2.810, 95% CI; 1.113-7.090, p = 0.029) as independent factors associated with the risk of development of MGC. All the patients could be treated by surgical or endoscopic resection for the metachronous MGC. Recurrence was observed in one patient. There was quite a few incidence of development of metachronous MGC after PPG. Nevertheless, PPG remains reasonable treatment option, if adequate postoperative surveillance can be ensured.

PECULIARITIES OF INTERACTION OF PARTICIPANTS OF THE EDUCATION PROCESS IN HIGHER EDUCATION INSTITUTIONS IN THE IMPLEMENTATION OF DISTANCE LEARNING TECHNOLOGIES

У даній роботі розглянуті теоретичні підходи до вивчення проблеми міжособистісного спілкування викладача зі студентами при впровадженні дистанційних технологій у навчальний процес закладів вищої освіти. Результати теоретичного дослідження доводять, що в умовах традиційного навчання студенти активно спілкуються, обмінюються інформацією, встановлюють емоційні зв’язки. Асинхронний тип комунікації у навчальних мережах і середовищах часто призводить до фрустрації, викликаної почуттям самотності і незадоволеною потребою у спілкуванні. Проблема міжособистісного спілкування викладача зі студентами при впровадженні дистанційних технологій у навчальний процес закладів вищої освіти може бути у певній мірі розв’язана завдяки поєднанню традиційного із елементами дистанційного навчання. Застосування синхронного типу комунікації у навчальних мережах і середовищах буде сприяти вирішенню даної проблеми. Цей тип комунікації дозволяє умови спілкування максимально (наскільки це можливо) приблизити до природних, що дає можливість для командної роботи, надання допомоги один одному тощо. Даний тип комунікації необхідно поєднувати із асинхронним, який має переваги, що дають час і можливість отримати і опрацювати інформацію. Результати емпіричного дослідження дають можливість стверджувати, що більшість студентів денної форми навчання надають перевагу такій моделі, яка по суті поєднує дистанційне і традиційне навчання. Ключові слова: дистанційне навчання, міжособистісне спілкування, традиційне навчання, комунікація, комфортність у дистанційному навчальному середовищі. Отримано: 17.03.2020 Відрецензовано: 28.03.2020 Опубліковано: 03.04.2020 DOI: http://doi.org/10.31108/3.2020.4.1.1

Design, Frame Analysis and Manufacture of Handcycle Prototype

Handcycle is a transportation tool for individuals with lower limb disabilities. This study designed a handcycle as a mode of transportation to facilitate the accessibility of persons with disabilities. The design of the handcycle was designed on a prototype scale. It referred to recumbent and synchronous frame geometry types for arm crank set up to do finite element analysis studies using Autodesk Fusion 360 software to find the value of the strength of the handcycle frame design. A decent frame at 160 kg loading with a critical value of 330 MPa was designed and became a reference for the handcycle production process.

A Comprehensive Review of Power Flow Controllers in Interconnected Power System Networks

Energy security is one of the most crucial factor in the development of any nation. Interconnections among different power system networks are made to lower the overall price of power generation as well as enhance the reliability and the security of electric power supply. Different types of interconnection technologies are employed, such as AC interconnections, DC interconnections, synchronous interconnections, and asynchronous interconnections. It is necessary to control the power flow between the interconnected electric power networks. The power flow controllers are used to (i) enhance the operational flexibility and controllability of the electric power system networks, (ii) improve the system stability and (iii) accomplish better utilization of existing power transmission systems. These controllers can be built using power electronic devices, electromechanical devices or the hybrid of these devices. In this paper, control techniques for power system networks are discussed. It includes both centralized and decentralized control techniques for power system networks. This paper also presents a comprehensive review of HVDC interconnections, asynchronous AC interconnections, synchronous AC interconnections and different types of power flow controllers used in these interconnections. Moreover, some important and multivariable flexible AC transmission system (FACTS) devices such as UPFC and IPFC are also discussed with their merits and limitations. Finally, a new asynchronous AC link called flexible asynchronous AC link (FASAL) system is also described in detail. At last, a summary of the comparative analysis of power system link and power flow controllers is given based on recent publications. More than 400 research articles and papers on the topic of power transfer control are covered in this review and appended for a quick reference.

Testing of electrical parameters at direct start-up of a synchronous motor of 4650 kW/6 kV

The paper presents parameter testing in the transitory process of direct start-up of a synchronous motor of 4650kW/6kV used in actuating of natural gas compressors from storing stations. The electric drive motor is of synchronous type with rotational excitation and the actual operating conditions of it determine additional mechanical and electrical stresses, which can influence its performance. The asynchronous start-up mode assumed experimental determination of asynchronous start-up current values, asynchronous start-up time, excitation voltage and excitation current of exciter, voltage drop in stator winding. These experimental determinations were made using a dedicated data acquisition system. Graphical plotting was made and considered parameters were evaluated in continuous mode, then obtained values were compared with catalogue values, with conclusions being drawn for each case study.

Didáctica Para Enseñar A Jugar En La Educación Física Escolar

El presente artículo tiene como propósito la construcción de una didáctica específica que enseñe a jugar lúdicamente a partir de la matriz pedagógica de docentes de Educación Física progresistas.La pesquisa da cuenta de un tipo de estudio temporalmente sincrónico, de esquema descriptivo y enfoque cualitativo de acuerdo al tratamiento de la información. Para la producción de los datos se utilizó la entrevista semiestructurada y en profundidad, para una muestra intencional de setenta y cinco (75) profesores/as argentinos/as, de los/as cuales doce (12) fueron seleccionados en base al estado de arte, por ser identificados/as como progresistas de acuerdo a su posición ideológica y la práctica pedagógica que ejercen. Los resultados permiten identificar que los/as docentes progresistas, que ubican al juego como objeto de transmisión cultural, un derecho de las personas y, por ende contenido de la educación física, manifiestan generar condiciones de apertura a partir de enunciados (invitaciones) transparentes y posteriores intervenciones que permiten a los/as niños/as y adolescentes conectarse con la cultura diversa de juegos tradicionales, modificar juegos conocidos, inventar nuevos, combinar variados sentidos por los cuales jugar ampliando la exclusividad competitiva, y aprendiendo diferencias entre los modos de involucrarse a jugar en el marco de la educación física.

Variable Frequency Average Current Mode Control for ZVS Symmetrical Dual-Buck H-Bridge All-GaN Inverter

The quasi-square-wave (QSW) zero-voltage-switching (ZVS) symmetrical dual-buck H-bridge (DBHB) all-GaN inverter has been proven to have high efficiency and high density in Google's Little Box Challenge. This variable frequency QSW ZVS inverter is drawing more and more interest in the industry and academia. However, the ac current control with cycle-by-cycle variable frequency ZVS operation is a basic challenge for this inverter. The conventional control methods for this QSW ZVS inverter, such as the hysteresis current mode control and the variable on-time control, require high-speed current sensing or zero-crossing detection (ZCD) circuits, which are very sensitive to noises. In this article, achieving variable frequency average current mode control with variable frequency pulsewidth modulation (VFPWM) is discussed and implemented for this QSW ZVS inverter to eliminate high-speed current sensing or ZCD circuits. For any synchronous half-bridge type converter, the voltage conversion ratio is dependent only on the duty-cycle in either continuous conduction mode (CCM) or QSW ZVS mode. The frequency of the PWM triangular carrier is another degree of freedom. In this control method, the averaged inductor current is sensed and regulated by the average current mode feedback controller and the duty-cycle is generated by the average current controller. The frequency of the PWM carrier is variable and directly calculated based on the duty-cycle signal and the sensed and filtered voltage and current signals. Since all the sensed signals for this current controller are low speed and filtered signals, this current control is highly immune to noises. The reliability of ZVS for this inverter is improved. The complexity of the controller is also reduced. A detailed analysis of the QSW ZVS conditions for the full range operation of the symmetrical DBHB inverter is done in this article. More negative currents can be introduced to reduce the switching frequency and increase the reliability of ZVS. A frequency limiter helps limit the frequency when the current is close to zero or under light load conditions. A frequency updating method with a constant and low interrupt frequency in a digital controller is also discussed. Finally, to verify this control method, a 1-kW all-GaN DBHB inverter prototype is developed and tested in this article.

Predictive auto‐reclosure approach to enhance transient stability of grid‐connected DGs

This study introduces a predictive auto-reclosure scheme based on faster-than-real-time (FTRT) analysis for synchronous generator type of distributed generation (DG) units to decrease DG oscillations after successful reclosure and also enhance transient stability margin of the unit after unsuccessful reclosure. The FTRT analysis, as a new concept for the protective relaying, represents a powerful predictive auto-reclosure scheme which is based on a state-space model of the DG unit. After a fault scenario and the first operation of the associated breaker, the FTRT analysis predicts energy level of the DG unit and determines an optimum dead-time corresponding to the minimum energy level of the DG unit for reclosure that can provide an appropriate margin for transient stability. The effectiveness and accuracy of the proposed method are verified based on a test system. The results confirm that the proposed approach can effectively enhance transient stability for unsuccessful reclosure and reduce the corresponding oscillations after reclosure.

Comparative analysis of salient pole and flux barrier rotor for synchronous reluctance machines including flux weakening range

Here, synchronous reluctance machine types related to electrical traction applications are investigated including flux weakening range. A flux barrier (FB) machine with a carbon fibre-reinforced plastic bandage and a salient pole machine are designed by finite element analysis and built up as prototype. Both rotors are implemented in a stator of an existing induction machine. A comparative analysis is presented using finite element simulation as well as experimental results. Measurements in the base speed range confirm the machine designs. An analysis of the flux weakening operation at high speeds show the possible limitations by increasing harmonics with the given single-layer winging. The implementation of a short pitched winding is an approach to improve harmonic behaviour of the salient pole (SP) machine at high rotational speeds.

Counter-rotating type tidal stream power unit: Excellent performance verified at offshore test

A counter-rotating type tidal stream power unit, composed of tandem propellers and a peculiar generator with double rotatable armatures, was provided for verification tests at offshore. The front propeller with diameter of 1 m has three blades, and the rear propeller with diameter of 0.95 m has five blades. The blade profiles were optimized with the blade element-momentum theory and CFD, and then covered with CFRP. The front and the rear propellers connect to inner and outer armatures in a synchronous type generator with net output 1.5 kW, whose efficiency was improved by heat pipes and the modification of the armature profiles. The shafts are equipped with mechanical seals to protect electric circuits from seawater. A rotational speed control system was also prepared not only to adjust the output but also to overcome the static friction torque due to bearings, slip rings and mechanical seals while starting-up. The power unit takes the maximum output with excellent efficiency at the relative tip speed ratio specified in the unit design. The unit can start-up after maintenance works and the output can be adjusted smoothly in the stream.

Fractional order control scheme in pitch control loop of synchronous generator wind turbine type 4 at high wind speed operation in a microgrid

This paper deals with the performance improvement of synchronous generator Type 4 driven by the wind turbine at high wind speed operation in a microgrid connected to a weak utility grid. The importance of applying the pitch angle control loop at high wind speeds in wind turbine generators is undeniable to prevent overloading and other destructive effects on the generator parameters caused by the wind speed increase. Thus, a robust control scheme in the pitch angle loop would certainly improve the performance of the wind turbine generator. In this study, the principle of the proposed method is based on the design and applying the different fractional order controllers including the Fractional Order Proportional Integral (FOPI) and FO[PI] types in the pitch compensation loop, instead of the conventional Proportional Integral (PI) controller to extract the proper values for the pitch angle reference profile. An analytical method is extended to the pitch servo control for designing the PI and fraction order PI controllers to ensure the frequency domain specifications. To verify the efficacy of the FOPI and FO[PI] controllers in comparison with the PI one, various simulation results in the high wind speed operation mode of 18 m/s considering 10% turbulence intensity are obtained using MATLAB/SIMULINK software. The performance enhancement is surveyed by monitoring the generator parameters including the mechanical torque, the active/reactive power, and the DC link voltage profiles. The results validated the effectiveness of the proposed controllers.

Comparative Evaluation of AC Electric Motors of Asynchronous and Synchronous Types for Use in Rowing Electric Drives High Power Icebreakers

Comparative Evaluation of AC Electric Motors of Asynchronous and Synchronous Types for Use in Rowing Electric Drives High Power Icebreakers

Intensity‑modulated radiotherapy for synchronous cancer of the anal canal and cervix

Due to recent advancements in diagnostic techniques, the incidence of multiple primary cancer has increased; however, synchronous cancer of the anal canal and cervix (SCACC) is rare, and no previous studies have investigated the treatment of this disease. The present study reports a case in which intensity-modulated radiotherapy (IMRT) was used to treat a 64-year-old female with SCACC, inguinal lymphadenopathy and anal pain. The patient was diagnosed with cT3N3M0 stage IIIb anal canal squamous cell carcinoma and cT1b1N0M0 stage Ib1 cervical squamous cell carcinoma, based on biopsy and imaging study data. According to the definitive treatment for advanced-stage anal canal cancer, outpatient treatment with chemoradiotherapy (CRT) using S-1 for SCACC was recommended, as the patient did not want to undergo resection of the anus. Considering the lymph node regions involved in SCACC and the necessary doses, the treatment plan was as follows: Whole pelvis and inguinal lymph node region radiation (36 Gy/20 fractions); a first booster radiation dose (9 Gy/5 fractions) for the whole pelvis; and a second booster radiation dose (14.4 Gy/8 fractions) for the primary lesions. The patient was prescribed S-1 at a dose of 60 mg/m2/day twice daily on days 1–14 and 29–42. The patient experienced grade 2 diarrhea and anal mucositis, but CRT was completed without discontinuation and hospitalization. The patient exhibited a complete response and remained disease-free without any treatment-associated complications at the 6-month follow-up. In conclusion, SCACC was successfully treated with IMRT in the present case. It is important to determine the treatment strategy for synchronous cancer types, taking into consideration the tumor stage, tumor location and patient situation.