bluuebunny/crossref_metadata_2025 huggingface dataset:
Single‐phase common‐grounded transformer‐less grid‐tied inverter for PV application
Authors: Vosoughi Naser , Hosseini Seyed Hossein , Sabahi Mehran
Published: October 2019

In this study, a novel topology for the single‐phase transformerless grid‐connected inverters family is proposed. By using the series–parallel switching conversion of the integrated switched‐capacitor module in a packed unit, several merits can be added to the proposed inverter, such as higher efficiency, boosting ability within a single‐stage operation, and removing the leakage current problem by using the common grounding technique. In this study, a peak current controller strategy is implemented in order to generate the gate pulses of semiconductor switches. Moreover, this strategy is used to control both the active and reactive powers. Therefore, a thoroughly controlled current with a proper quality can be supplied to the grid from a single source renewable energy resource. The operating procedure, design consideration, comparison study, and the experimental results for a 510 W prototype are presented in order to validate the correctness and feasibility of the proposed topology.
Stochastic unit commitment with air conditioning loads participating in reserve service
Authors: Zhang Menglin , Le Lingling , Fang Jiakun , Ai Xiaomeng , Yao Wei , Wen Jinyu
Published: October 2019

The demand response, providing the reserve service, becomes more and more important in the wind‐power‐integrated power systems. This study proposes a two‐stage stochastic unit commitment model with the air conditioning (AC) aggregators providing the reserve service. A classification compensation scheme is proposed to promote AC users to provide more reserve capacity, which quantifies the users' comfort and their contribution to the system. Besides, a new AC scheduling method with adaptive response capacity (ARC) is proposed to help system operators to determine reasonable reserve capacity with smaller total cost. In addition, the inactive constraints identification is utilised to improve computational performance. Finally, the effectiveness of the proposed method is tested on the modified IEEE 118‐bus system with 50 AC aggregators. The simulation results show that the proposed classification compensation scheme and the ARC method can promote more AC response capacity and save the total and reserve costs. The price game between the AC aggregators and the thermal units have a great impact on the decision results. The inactive constraints identification can save the total time by about 70%.
Isochrone-cloud fitting of the extended main-sequence turn-off of young clusters
Authors: Johnston C. , Aerts C. , Pedersen M. G. , Bastian N.
Published: October 2019

Context. Extended main-sequence turn-offs (eMSTOs) are a commonly observed property of young clusters. A global theoretical interpretation for eMSTOs is still lacking, but stellar rotation is considered a necessary ingredient to explain eMSTOs.

Aims. We aim to assess the importance of core-boundary and envelope mixing in stellar interiors for the interpretation of eMSTOs in terms of one coeval population.

Methods. We constructed isochrone-clouds based on interior mixing profiles of stars with a convective core calibrated from asteroseismology of isolated galactic field stars. We fitted these isochrone-clouds to the measured eMSTO to estimate the age and core mass of the stars in the two young clusters NGC 1850 and NGC 884, assuming one coeval population and by fixing the metallicity to the one measured from spectroscopy. We assessed the correlations between the interior mixing properties of the cluster members and their rotational and pulsational properties.

Results. We find that stellar models based on asteroseismically-calibrated interior mixing profiles lead to enhanced core masses of eMSTO stars. Additionally, these models can explain a significant fraction of the observed eMSTOs of the two considered clusters in terms of one coeval population of stars, which have similar ages to those in the literature, given the large uncertainties. The rotational and pulsational properties of the stars in NGC 884 are not sufficiently well known to perform asteroseismic modelling as it is achieved for field stars from space photometry. The stars in NGC 884 for which we have v sin i and a few pulsation frequencies show no correlation between these properties and the core masses of the stars that set the cluster age.

Conclusions. Future cluster space asteroseismology may allow for the interpretation of the core masses in terms of the physical processes that cause them, based on the modelling of the interior mixing profiles for the individual member stars with suitable identified modes.
The XIII International Research and Practice Conference “Ukrainian School of Mining Engineering” as a step to the new direction of innovative technologies and intelligent systems in the mining industry
Authors: Bondarenko Volodymyr , Kovalevska Iryna , Lysenko Roman , Malova Olha
Published: October 2019

For the thirteenth time International Research and Practice Conference “Ukrainian School of Mining Engineering” has made an important contribution to the mining industry, science and education, expanding the boundaries of interaction between representatives of science and practicing industry experts, opening up new opportunities for the exchange of experience, solving the most acute problems, presenting a new vision of the future of mining sector and industrial development not only in Ukraine, but also all over the world. This year the conference is mostly dedicated to the new 4.0 level of the industry and had the main topic of “Innovative technologies and intelligent systems in mining”. Also, the following problems were not disregarded such as major mining trends, mining mechanical engineering, alternative energy sources, stoping and tunneling equipment, mine workings maintaining and supporting, mineral enrichment, crisis management, safety of mining, sanitation, labor protection, and etc. The results of the conference once again proved that only the community created over the years, where a collision of sciences and various practicing schools takes place, is able to bring the most advanced and innovative ideas to life, laying the foundation for future achievements of the mining industry.
Designing the half-masks of filter respirators for workers of mining enterprises
Authors: Holinko Vasyl , Cheberiachko Ivan , Symanovych Hennadii , Kicki Jerzy
Published: October 2019

The purpose of paper is to develop an algorithm for designing the half-masks of air-purifying respirators and assessment of their safety factor of insulation. To create a 3D model of a head, two-parameter NIOSH tables (National Institute for Occupational Safety and Health) were used. The model drawings were made with the use of Solid works software package. Differential geometrical method based on applying the moving Frénet trihedral was used to design half-masks. Two designs of the respirator half-mask were developed based on the averaged length and width of face (Modification 1), and length of face and lips (Modification 2). As a result of modeling test, the area and perimeter of the mask contact line have been defined. The safety factor of half-mask insulation was calculated theoretically. It has been established that the safety factor of Modification 1 half-mask is 2.5 times higher.
An innovative method for creating and using nanoparticles for gas extraction from gas hydrates
Authors: Bondarenko Volodymyr , Svietkina Olena , Prokopenko Kostiantyn , Liu Baochang
Published: October 2019

The growth of prices for traditional energy sources prompts Ukraine to seek new approaches to solving energy problems. Today, the country has intensified its work in this direction, in particular, legislative support is being developed and improved, and the investment climate for alternative energy projects is improving. In many countries of the world, it has long been understood how serious and necessary is the development of alternative energy. At present, in the face of various gas contradictions and unstable oil prices, the need for energy carriers is constantly increasing, which makes it necessary to seek the latest solutions to the energy problem. Many leading countries in the world are engaged in the search for alternative sources of energy, one of which is natural gas hydrates. This relatively new resource offers great opportunities both for economic growth and stability of states, and for the development of scientific institutions in this field. Flagships in the study and development of gas-hydrated deposits are the United States, China, Japan and Canada. Along with them should be noted the achievements of scientists in India, EU countries, Ukraine, Russia and Bulgaria.
Assessing safety conditions in underground excavations after a methane-air mixture explosion
Authors: Nalisko Mykola , Sobolev Valerii , Rudakov Dmytro , Bilan Nataliia
Published: October 2019

A technique for evaluation of shock wave impulse after a methane-air mixture explosion is elaborated. The numerical model developed in previous studies has been verified in the laboratory by using laser initiation of explosives and measuring the pressure impulses of explosion products on a ballistic pendulum. To evaluate the mechanical impulse the functional correlations between its magnitude, the swing angle, and the pendulum characteristics have been derived analytically. The reliability of experimental results is ensured by calibrating the sensor that measures the pendulum swing angle and estimating the impulse measurement errors caused by specifics of angle measurements by a digital voltmeter, pendulum axis friction, and the pauses between measurements. Testing the developed technique to evaluate the shock wave impact showed satisfactory consistency of experimental and theoretical results with the momentum deviation below 9%, which confirms model applicability and correct reproducibility of the shock wave propagation process.
Features of initiating the light-sensitive explosive composites for safe blasting of borehole charges in coal mines
Authors: Kulivar Viacheslav , Usyk Ihor , Shepel Nina , Kravchenko Kostiantyn
Published: October 2019

The purpose of paper is to study physical and chemical patterns for starting detonation in the explosive charges by means of laser pulse radiation. Studies of the physical and chemical properties of the mechanism for stimulating the detonation of explosives by pulse radiation of an optical quantum generator have been carried out. Methodology of experimental and theoretical studies as well as mathematical modeling, involving gas-dynamics equations, has been applied. Basic research results as for studying sensitivity of the explosives being initiated by pulse light radiation have been analyzed. Numerical modeling was performed taking into consideration the real process of igniting the explosive by infrared laser radiation. The proposed mathematical model makes it possible to study the peculiarities of initiating the explosive transformation of bursting explosives by means of short light pulses. Tetranitropentaerytrite (PETN) was used to show that the process is determined completely by the parameters which characterize radiation intensity and absorption properties of the explosive. Depending on these parameters values, initiation processes may be implemented qualitatively – either on the surface or inside the explosive. In the latter case, the release of chemical energy results in the formation of so-called “chemical” pressure peak. With the use of lead azide, it has been shown experimentally that the initial temperature does not affect the increase in explosive sensitivity even in case when laser radiation takes place in the nanosecond pulse mode. Experimental results are applied while developing light-sensitive composites with the preset explosive and physical-chemical properties. The determined patterns were used in the development of the light-sensitive explosive composites for blasting agents of explosive charges.
On improving the efficiency of blasting operations in underground and open-pit mining
Authors: Kyrychenko Oleksii , Kurliak Anton , Balakin Oleh , Baskevych Oleksandr
Published: October 2019

The purpose is to study the effect of microstructure defects of initiating explosives on the process of initiating detonation by a laser monopulse. The results of experimental studies and physico-mathematical modeling of the effect of microstructural defects in crystals of photosensitive initiating explosives under the action of a single laser pulse are given. The paper covers a brief analysis of the history of the issue being studied and physico-mathematical modeling using the theory of elastic scattering, i.e. Gustav Mie theory. The technique for determining the absorption cross section of laser radiation by micro-sized inclusions of explosive has been developed and tested. In experiments on explosives ignition using a laser monopulse, the laser monopulse shape was recorded, the energy distribution over the laser beam radius and the explosive ignition delay time were controlled. The basis is the proposed method of calculating the absorption cross section and intensity in terms of the laser radiation wavelength by the inclusion of an explosive with using the theory of elastic scattering of optical radiation on particles in micrometer size range. It is shown that the absorption properties of the particle essentially depend on the properties of the particle medium and the wavelength of radiation. For smoke particle within PETN the absorption for wavelength of laser radiation of 1.06 μm is stronger than for that of 0.69 μm. A different absorption occurs if a lead particle is within a lead azide: absorption for wavelength of 0.69 μm is twice as strong as for wavelength of 1.06 μm. During the manufacture of explosives the additional defects in the explosives microstructure are desired to be created to increase the efficiency of laser initiation. Findings are used in the development of technical specifications for the design of optical detonators for laser initiation systems.
Parameters for simulation of the thermal state and fire-resistant quality of hollow-core floors used in the mining industry
Authors: Kovalov Andrіі , Konoval Volodymyr , Khmyrova Anastasiia , Dudko Kateryna
Published: October 2019

The statistical data of the fire and technogenic safety in Ukrainian mines have been studied. A literary analysis has been made of advanced expertise in determining the fire resistance of building structures. It has been studied the thermal state and fire resistance of hollow-core floors using the fire tests and the calculated determination of the fire resistance degree of a structure based on a two-dimensional model of thermal conductivity and convective heat transfer implemented in the ANSYS R17.1 software complex. The fire test of hollow-core floor has been analysed and the use of a computational-experimental method is proposed to determine the parameters when simulating the thermal state and the fire resistance of both protected and unprotected hollow-core floors. A technique has been developed for simulating the thermal state and the fire resistance of hollow-core floors, which can be used in assessment of the fire resistance degree of reinforced concrete building structures both in industrial construction and in the mining industry.
Improving the geometric topology of geothermal heat exchangers in oil bore-holes
Authors: Fyk Mykhailo , Biletskyi Volodymyr , Ryshchenko Ihor , Abbood Mohammed
Published: October 2019

A review has been conducted of key trends in the development of geometric topology of geothermal heat exchangers. Authors proposed approaches to improving the designs and network structures for heat-transfer media circulation in the bottom-hole space of oil-and-gas reservoirs. Four geometric topologies of geothermal heat exchangers have been analysed: І – ІІ – rectilinear vertical smooth and finned pipelines; ІІІ – IV – a cluster in the form of a set of smooth and finned single-pipe elements, representing a figure of “squirrel wheel” or “meridian sphere” type. It is shown that the most effective technical solution, which ensures the increase in the coefficient of performance (COP) of bore-hole geothermal systems is finning the heat exchanging pipes. For the heat exchangers of І – ІІ type, the calculated increase in COP in comparison with smooth pipes is 40%, and for ІІІ – IV type – 95%. The key parameters influencing the COP of a geothermal heat exchanger are: the radius of fluids draining out during the heat exchange process, the radius of pipelines with circulating heat-transfer medium, the diameter of a cluster heat exchanger, the heat exchange area, the parameters of rocks thermal resistance in the bottom-hole zone of heat-receiving.
Influence of chosen technical constraints on stability of 3D geological model-based schedule in a complex longwall operation
Authors: Malinowski Leszek
Published: October 2019

In Polish underground mining digital 3D geological models and mine structure models are becoming popular as an aid in creating design and schedules of mine workings. Article highlights development made in generating and optimizing mining operations. Having created a model it is possible to test schedule scenarios using a number of constraints. One of the constraint limiting coalmines is ventilation, which may be magnified by high content of methane in coal deposits. In this article two methods of introducing ventilation constraints have been presented. One limits number of longwall shearers working simultaneously in excavations ventilated by the shaft. The other limits tonnage of coal which can be extracted in each ventilation zone. Scenarios governed by the second method turned out to result in more stable exploitation than a base scenario. More precise calculations are possible if a model contains an accurate prognosis of methane emissions that would be caused by extraction of the coal deposit. The aim of the paper is to present possibilities of analysing and upgrading mining operations with the help of digital solutions.
Innovative technology for insulating the borehole absorbing horizons with thermoplastic materials
Authors: Sudakov Andrii , Chudyk Ihor , Sudakova Diana , Dziubyk Liudmyla
Published: October 2019

The purpose of the work is to increase the insulation work efficiency by using thermoplastic mixes based on polyethylene terephthalate. The tasks set were solved by a complex method of research, including the analysis and synthesis of the literary and patent sources, as well as conducting the analytical and experimental studies. The experimental data were processed on a PC using the methods of mathematical statistics. A method for insulating the absorbing horizons with thermoplastic materials has been developed and substantiated. To implement it, the following technological operations should be performed: supply of the thermoplastic materials to the borehole bottom, melting and squeezing of thermoplastic materials into absorption channels. For various geological and technical conditions of drilling, technological schemes of insulating the absorbing horizons with thermoplastic materials are proposed. The use of the household waste based on polyethylene terephthalate has been proposed as the plugging material to insulate the absorbing horizons of boreholes. For the first time, the possibility of using the household waste based on polyethylene terephthalate as the plugging thermoplastic material has been substantiated and proved. For the first time, a method for determining the efficient range of technology application for absorbing and unstable horizons insulation with thermoplastic materials through the use of bottom hole thermal sources has been substantiated analytically.
Increasing mine train mass by means of improved efficiency of service braking
Authors: Novytskyi Oleksii , Taran Ihor , Zhanbirov Zhemazhan
Published: October 2019

Methods to increase mine train mass allowable for braking have been studied. Possibility to use rail magnetic brakes to improve efficiency of dynamic braking has been analyzed. Mathematical model of the train braking involving a magnetic rail device to increase locomotive axial load has been proposed. Results of the braking calculations with the use of the modeling results have made it possible to conclude on the fact that a magnetic rail device used to increase locomotive axial load allows improving considerably braking characteristics of a locomotive and increasing mine train mass allowable for braking.
Drive systems of the drilling rigs for open pits in Ukraine: state and ways for improvement
Authors: Khilov Viktor , Hlukhova Nataliia , Somin Andrii , Kiiko Volodymyr
Published: October 2019

A comparative analysis is presented of the characteristics of drilling rigs used in open-pit mining in Ukraine. The experimental studies have been conducted of the drive systems and drilling rigs influence on the dynamics of the drilling process under the mining and geological conditions of the Central Mining and Processing Plant (Kryvyi Rih city, Ukraine). The frequency characteristics have been obtained and the dynamic properties of the automated drive systems, as well as frequency characteristics of the rotation mechanism transmissions have been analyzed. The behavior of natural oscillation frequencies in closed control loops of rotational drives was studied, and it has been determined that they exceed the cutoff frequency and fall into the pass band from the attenuation band in frequency-controlled induction motors of most advanced drilling rigs with the maximum number of rods connected in the drill string. It has been established that low oscillation frequencies due to the side frequencies, generated by the drill rod oscillations, fall into the fastest internal current loop. The tasks have been formulated for further research. The purpose of research is to solve the actual scientific and applied problem of dynamic compatibility of frequency characteristics in the modern high speed drive systems with the dynamic characteristics of drilling rigs, which are multi-mass mechanisms with distributed and concentrated parameters with a change in added masses.
Analysis of Black Spot of Traffic Accident in Wuhan Port
Authors: Xia Feng , Yang Ya-dong
Published: October 2019

The proposal to build the “Yangtze River Golden Waterway” strategy has enabled the shipbuilding volume of the Yangtze River trunk to grow rapidly. With the increase of ship traffic flow, the Yangtze River water traffic safety is facing severe challenges. This paper draws on the road traffic black spots and existing research methods of water traffic accidents and the definition of water traffic black spots. The DBSCAN algorithm and the accident-level weighted average method are used to establish the blackpoint identification model for waterborne traffic. The model is applied to the Yangtze River mid-stream Wuhan Port 2013-2017 water traffic safety accident as an example. Ten black spots and corresponding boundaries are identified. The black point analysis method used in this paper can effectively quantitatively analyze the spatial distribution and characteristics of water traffic black spots, which can provide a new theoretical basis for ensuring the safety of water traffic.
Analysis of Key Issues on Man-Control to System-Control Leap in Autonomous Driving
Authors: Liu Zongwei , Tan Hong , Hao Han , Zhao Fuquan
Published: October 2019

Autonomous driving is recognized as a global development direction and a major opportunity. The function and use of the vehicle has changed profoundly. The vehicle is gradually transformed from a simple transportation tool to a smart mobile space. The ultimate goal of autonomous driving is to achieve driverless driving. In the course of its development, man-control will gradually turn into to system-control. In other words, the transition from level 3 (L3) to level 4 (L4) is a fundamental leap. At present, the specific path to achieve this leap is not yet clear. Different companies have different and even opposite thinking and choices. In this study, the grading standard for autonomous driving was clearly explained, and the technical route selection of the company was analysed. Based on the analysis, the requirements of sensing, decision making, execution between the L3 and L4 were compared. Moreover, the key technical difficulties of L3 to L4 were clarified. In the end, suggestions on the commercialization of autonomous driving were given.
Prediction of Ship Traffic Volume in Jiujiang Port Based on Genetic Wavelet Neural Network
Authors: XIE Shouwei , YANG Yadong
Published: October 2019

In recent years, the traffic volume of the Yangtze River has increased dramatically. In order to provide more favorable assistance to port planning and traffic management, the accuracy of port ship traffic volume prediction is very important. In this paper, genetic algorithm and wavelet analysis and neural network are used to construct the genetic wavelet neural network model prediction model, and BP neural network prediction model is established. The ship volume of Jiujiang Port is used as experimental data to simulate and analyze. The results show that the prediction accuracy of the genetic wavelet neural network prediction model is significantly higher than that of the BP neural network prediction model. It is proved that the genetic wavelet neural network has broad application prospects for ship traffic flow prediction in the Yangtze River port. This method has practical application significance.
The Development of Safety Performance Functions for Roundabouts in Amman, Jordan
Authors: AL- Nabulsi Diana , Jadaan Khair
Published: October 2019

It is now well established that crash occurrences at roadway segments or intersections are associated with a large variety of factors. Safety Performance Functions (SPF) are statistical models developed to predict crash frequencies for various design variables.

In Jordan, almost half of all road crashes occur at intersections, mostly in urban areas. There is a significant number of roundabouts throughout Amman which is increasing without evaluating their safety performance. To assess safety benefits of this kind of intersections, transportation professionals need the powerful statistical tool; the SPF.

This study aims to develop SPFs for roundabouts in Amman. The models consider the crash frequency, traffic volume and geometric features of all the studied 20 roundabouts. The developed SPFs were statistically significant (R^2 = 0.91) .The findings of the study revealed that crash frequency has a strong relation with the AADT, roundabout entry angle-degrees, entry path radius, splitter radius, pedestrian crossing structure, inscribed diameter, central diameter, circulating width, entry width, number of circle legs. The developed SPFs are evaluated through a comparison with others from developed countries.
Research on Maintenance Support System Based on Complex Network
Authors: Ke Yang , Shi-dong Fan , Yu-nan Yao
Published: October 2019

The design and collaboration analysis of maintenance support system network is a critical challenge. So the network model of ship maintenance support system was proposed, it involved all levels of distributed maintenance support participating nodes and formed a net chain structure. The network characteristic was analysed using complex network theory. The impact of topology characteristic and dynamic evolution on the cooperation effectiveness of maintenance support system was discussed. And an optimal evolution algorithm of support network was put up to so that the optimal support network would be designed．
Research on Two-stage Order Picking Sequencing for Intensive Shelf
Authors: Tian Xue , Zhou Li , Yang Jianglong
Published: October 2019

The increasingly usage of Intensive shelves, greatly increase the utilization of storage space, but also is more demanding on order picking time . Based on the storage layout of intensive mobile shelves, this paper combines the time cost of shelf movement with the moving distance under the guidance of seeking global optimum. Transform the single order picking process into TSP problem, while considering the picking process. The waiting cost of the order, and the minimum of the picking cost and the waiting cost of the whole batch of orders requiring shelf movement, to establish a two-stage mathematical model of the order picking order. Then, the algorithm for solving the model is designed, and the simulation is carried out by numerical examples to illustrate the law and characteristics of the problem more vividly, in order to provide reference and reference for the order picking activities of intensive mobile shelves.
Assessment and Characterizing Mechanical Damage in Packaged Bananas in the Post-harvest Supply Chain
Authors: Fernando I. , Fei J. , Stanley R. , Enshaei H
Published: October 2019

Quality deterioration in packaged bananas caused by mechanical damage along the post-harvest supply chains (SC) remains obscure until the packages are unpacked for sale at the retail stores and therefore, the mechanism of damage occurrence remains unclear. This study assessed the mechanical damage levels of bananas in 300 cartons from pack houses to retail stores in Australia. The damage across the SC were shown to be progressive across the SC. Bruising and neck damage levels in bananas increased from the distribution centre (DC) to the retail stores. Mechanical damage in unripe bananas was influenced by the package location in the stacked-pallet, and the transport and handling of packages within the last-mile of the SC (DC to retail) further exacerbated the damage. This study further characterized the damage development by subjecting packaged bananas to simulated vibration, top-load compression and drop impact. It was revealed that the exposure to vibration resulted in rubbing; top-load package compression contributed to bruising and, the drop impact caused severe neck injuries in bananas. The knowledge of the damage incidences across the SC and causes of damage may contribute to the development of interventions targeted at improving the quality of bananas in the post-harvest SC in Australia.
An Approach to Develop the Sustainable Warehousing Assessment Model
Authors: Malinowska Magdalena
Published: October 2019

The aim of the art icle is to present an approach to define the set of criteria applied to create the sustainable warehousing assessment model. The criteria were ident ified on the basis of expert analysis and the literature review includin g the scient ific approach as well as standards applied for the purpose of assessing the level of sustainable bui ldin gs. It allowed to include in the proposed model the broad spect rum of factors, which affect the warehousing sustainabi lity in economic, social and environmental aspect . As a solut ion ut ilized for the purpose of sustainable warehousing assessment model creat ion the COMET method (characterist ic object method) was applied. This const itutes the basis for applying the fuzzy set theory to propose the characterist ic of each criteria used for the assessment.
Optimization of DND Multi-Depot Split-Load Pickup-Delivery Problem
Authors: Boukhtouta Abdeslem , Ray Sujoy , Soeanu Andrei , Pall Raman , Berger Jean
Published: October 2019

This paper presents a solution approach to optimize vehicle routes for a multi-depot, multi-vehicle, pickup and delivery problem over a large ground transportation network. More precisely, we address ground transportation of orders for the Canadian Department of National Defence using heterogeneous vehicle fleets. The fleets consist of limited number of organizational vehicles hosted at pre-established depots and commercial order delivery services. The proposed approach involves leveraging an insertion cost gradient-descent heuristic followed by a greedy randomized adaptive search procedure. Experimental results generated using the historical orders of the organization indicate that the developed approach is effective in handling a wide range of scenarios and may generate near-optimal vehicle routes with an annual transportation cost reduction between 7.7% and 16.7%.
Fully covered self-expanding metal stents for refractory pancreatic duct strictures in symptomatic chronic pancreatitis, US experience
Authors: Sharaiha Reem Z. , Novikov Aleksey , Weaver Kristen , Marfatia Pawan , Buscaglia Jonathan M. , DiMaio Christopher J. , Diehl David , Gabr Moamen M. , Gaidhane Monica , Siddiqui Ali , Kahaleh Michel
Published: October 2019

Background and study aims Fully covered self-expanding metal stents (FCSEMS) have been used to treat refractory pancreatic duct strictures. We aimed to evaluate the feasibility, safety, and efficacy of FCSEMS in chronic pancreatitis with refractory pancreatic duct strictures.

Patients and methods This was a retrospective multicenter cases series of patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) with FCSEMS placement in the main pancreatic duct (MPD) at five tertiary care centers between February 2010 and June 2016. Primary endpoints were technical success, clinical success, and procedure-related morbidity. Secondary endpoints were pain relief at the end of follow-up and resolution of the pancreatic stricture on ERCP.

Results Thirty-three patients with previously drained stents, 76 % of whom were male, underwent ERCP with FCSEMS placement. Mean duration of follow-up was 14 months. All of the patients had prior therapy. The technical success rate for FCSEMS placement was 100 % (n = 33) and the clinical success rate was 93 % (was n = 31). Stents were removed after a median duration of 14.4 weeks. After stent removal, the diameter of the narrowest MPD stricture had increased significantly from 1 mm to 4.5 mm (P < 0.001). There was a statistically significant improvement on the Visual Analogue Scale (VAS) from a median of 8.5 to 2.5. At the end of the study, (n = 27) 87.1 % of patients reported significant pain reduction with reduced narcotic use.

Conclusion FCSEMS appeared to be a feasible, safe, and potentially effective Intervention in patients who had not responded to endoscopic therapy with plastic stents.
Carl Wernicke (1848–1905) und die „Wernicke-Kleist-Leonhard Schule“. Beziehungen zur „Erlanger Schule“ der Psychiatrie
Authors: Braun Birgit
Published: October 2019

Hintergrund: Anlässlich seines 170. Geburtstages soll Carl Wernicke als Hauptvertreter einer neurobiologischen Psychiatrie im ausgehenden 19. Jahrhundert gewürdigt werden. Anliegen der vorliegenden Arbeit ist es, mögliche Beziehungen Wernickes und der „Wernicke-Kleist-Leonhard (WKL) Schule“ zur „Erlanger Schule“ der Psychiatrie näher zu beleuchten.

Methoden: Primär- und Sekundärliteratur wurden unter dem Aspekt der Hypothesenprüfung ausgewertet. Quellenarbeit erfolgte.

Ergebnisse: Wernickes Bemühen um die klinische Umsetzung seines nosologischen Systems wurde von seinem jüngsten Hallenser Schüler Karl Kleist (1879–1960) fortgesetzt. Nach Wernickes frühem Unfalltod wurde Kleist zum Schüler Gustav Spechts (1860–1940) in Erlangen. Geprägt von der „Erlanger Schule“ Spechts entwickelte der spätere Kleist-Schüler Karl Leonhard (1904–1988) auf der Grundlage der Forschungen Wernickes und Kleists eine sehr differenzierte Aufteilung endogener Psychosen.

Diskussion: Die von Specht begründete klassische „Erlanger Schule“ der Psychiatrie stellt möglicherweise ein Bindeglied in der Entwicklung der „Wernicke-Kleist-Leonhard Schule“ dar. Wernickes Beschreibung der „Angstpsychose“ veranlasste Specht zu einer Abhandlung über den Angstaffekt im „manisch-depressiven Irresein“. Diese wiederum regte Karl Leonhard zu seiner späteren Konzeption der „Angst-Glücks-Psychose“ an. Generell hatte Leonhard unter Spechts Leitung ein Gespür für Bipolaritäten als entscheidenden Aspekt seines späteren Konzeptes der zykloiden Psychosen entwickelt. Spechts Darstellung zum „pathologischen Affekt“ in der Paranoia beeinflusste das Leonhardsche Konzept der „affektvollen Paraphrenie“.

Schluss: Moderne Verfahren der funktionellen Bildgebung eröffnen dem Lokalisationsgedanken Wernickes neue Perspektiven. Die naturwissenschaftlich-philosophische „Doppelausrichtung“ der WKL-Schule kann zu einer erneut vermehrten Integration von philosophischen Elementen (Ethik, Religiosität, Spiritualität) im psychiatrisch-psychosomatischen und psychotherapeutischen Berufsfeld anregen.
Das Management der Mid-Portions-Achillessehnentendinopathie in der Physiotherapie – eine systematische Literaturrecherche
Authors: Heitkamp Hauke S. J. , Kapitza Camilla
Published: October 2019

Hintergrund Die Mid-Portions-Achillessehnentendinopathie (MPAT) ist ein Beschwerdebild, welches häufig sowohl bei Sportlern als auch bei Nicht-Sportlern auftritt. Während gute Evidenz zur Wirksamkeit von Wadentraining besteht, existiert keine aktuelle Literaturarbeit zur Ermittlung der Wirksamkeit von Physiotherapie, die das Gesamtspektrum physiotherapeutischer Möglichkeiten berücksichtigt.

Fragestellung Welche Rolle spielen manuelle Techniken und aktive Herangehensweisen beim physiotherapeutischen Management von MPAT bezogen auf Schmerz, Funktion und Lebensqualität?

Methoden Die Recherche erfolgte in den Datenbanken MEDLINE, Cinahl, SPORTDiscuss, PEDro und Cochrane, ergänzend in Journalen, grauer Literatur und über eine Handsuche. Inkludiert werden sollten ausschließlich randomisierte kontrollierte Studien (RCTs). Es folgte eine narrative Synthese. Die Beurteilung der Evidenz unterschiedlicher physiotherapeutischer Herangehensweisen erfolgte nach der „Body-of-Evidence-Matrix“ des NHMRC Australiens.

Ergebnisse 19 RCTs mit insgesamt 792 Patienten wurden inkludiert. In jeder dieser Studien kam ein exzentrisches Training (ET) zur Anwendung, wobei das Alfredson-Protokoll das am häufigsten genutzte war. Zum einen wurden die Wirkungsweisen unterschiedlicher Formen eines ET miteinander verglichen. Des Weiteren fanden Vergleiche zwischen ET und anderen Trainingsformen, zwischen ET und Wadendehnungen, zwischen ET und therapeutischem Ultraschall und zwischen ET und diversen nicht physiotherapeutischen Therapieformen statt. Keine inkludierte Studie befasste sich mit der alleinigen oder ergänzenden Wirksamkeit von manuellen Herangehensweisen.

Diskussion Die größte Evidenz existiert für ein ET insbesondere nach dem Alfredson-Protokoll. Auch wenn für Tendinopathien häufig ein Heavy-Slow-Resistance-Training empfohlen wird, ist die Beweislage für die Behandlung von MPAT noch dürftig. Andere Übersichtsarbeiten, die sich ausschließlich mit der Wirksamkeit von Wadentraining beschäftigten, kamen auf vergleichbare Ergebnisse. Wichtige Kriterien beim Training scheinen Intensität, Progression, Geschwindigkeit bzw. Spannungsdauer und der Umgang mit Schmerz zu sein.

Schlussfolgerung Eine aktive Therapie in Form eines exzentrischen Wadentrainings oder eines Heavy-Slow-Resistance-Trainings sind nach aktueller Beweislage die empfehlenswertesten Therapieformen bei MPAT. Nach dieser Arbeit gehend existiert keine Evidenz zur alleinigen oder ergänzenden Wirksamkeit von manuellen Techniken bei diesem Beschwerdebild.
Sarcoma of the Uterus. Guideline of the DGGG and OEGGG (S2k Level, AWMF Register Number 015/074, February 2019)
Authors: Denschlag Dominik , Ackermann Sven , Battista Marco Johannes , Cremer Wolfgang , Egerer Gerlinde , Follmann Markus , Haas Heidemarie , Harter Philipp , Hettmer Simone , Horn Lars-Christian , Juhasz-Boess Ingolf , Kast Karin , Köhler Günter , Kröncke Thomas , Lindel Katja , Mallmann Peter , Meyer-Steinacker Regine , Mustea Alexander , Petru Edgar , Reichardt Peter , Schmidt Dietmar , Strauss Hans-Georg , Tempfer Clemens , Thiel Falk , Ulrich Uwe , Vogl Thomas , Vordermark Dirk , Gass Paul , Beckmann Matthias W.
Published: October 2019

Aims This is an official guideline published and coordinated by the German Society of Gynecology and Obstetrics (DGGG) and the Austrian Society of Gynecology and Obstetrics (OEGGG). Because of their rarity and heterogeneous histopathology, uterine sarcomas are challenging in terms of how they should be managed clinically, and treatment requires a multidisciplinary approach. To our knowledge, there are currently no binding evidence-based recommendations for the appropriate management of this heterogeneous group of tumors.

Methods This S2k guideline was first published in 2015. The update published here is the result of the consensus of a representative interdisciplinary group of experts who carried out a systematic search of the literature on uterine sarcomas in the context of the guidelines program of the DGGG, OEGGG and SGGG. Members of the participating professional societies achieved a formal consensus after a moderated structured consensus process.

Recommendations The consensus-based recommendations and statements include the epidemiology, classification, staging, symptoms, general diagnostic work-up and general pathology of uterine sarcomas as well as the genetic predisposition to develop uterine sarcomas. Also included are statements on the management of leiomyosarcomas, (low and high-grade) endometrial stromal sarcomas and undifferentiated uterine sarcomas and adenosarcomas. Finally, the guideline considers the follow-up and morcellation of uterine sarcomas and the information provided to patients.
Maintaining the blind in sham controlled interventional trials: lessons from the EPISOD study
Authors: Cotton Peter , Pauls Qi , Wood April , Durkalski-Mauldin Valerie
Published: October 2019

Objective and study aims This study was designed to demonstrate the techniques used and the effectiveness of blinding in the EPISOD study (Evaluating Predictors and Interventions in Sphincter of Oddi Dysfunction). This was a large sham-controlled trial evaluating the efficacy of endoscopic sphincterotomy treatment for patients with suspected sphincter of Oddi dysfunction.

Patients and methods We describe the methods intended to ensure that the subjects, caregivers and those assessing the outcomes were blinded to the treatment allocation and systematically assess the success of subject blinding procedures using the Bang’s Blinding Index (BI) for each treatment arm as an indicator of potential unblinding.

Results Blinding procedures proved to be acceptable and adhered to by the study team at each site. The BI indicated “wishful thinking” by the subjects regardless of treatment assignment, even when they were confident in their opinions.

Conclusion We conclude that it is possible to design and maintain a system for blinding the treatment allocation in a sham-controlled interventional study. Treatment guess plus confidence in the guess should be collected to examine the success of blinding procedures. The EPISOD study provides a blueprint for future sham-controlled trials in endoscopy.
EUS-guided fiducial marker placement for radiotherapy in rectal cancer: feasibility of two placement strategies and four fiducial types
Authors: Rigter Lisanne S. , Rijkmans Eva C. , Inderson Akin , van den Ende Roy P.J. , Kerkhof Ellen M. , Ketelaars Martijn , van Dieren Jolanda , Veenendaal Roeland A. , van Triest Baukelien , Marijnen Corrie A.M. , van der Heide Uulke A. , van Leerdam Monique E.
Published: October 2019

Background and study aims To facilitate image guidance during radiotherapy of rectal cancer, we investigated the feasibility of fiducial marker placement. This study aimed to evaluate technical success rate and safety of two endoscopic ultrasound (EUS)-guided placement strategies and four fiducial types for rectal cancer patients.

Patients and methods This prospective multicenter study included 20 participants who were scheduled to undergo rectal cancer treatment with neoadjuvant short-course radiotherapy or chemoradiation. EUS-guided endoscopy was used for fiducial placement at the tumor site (n = 10) or in the mesorectal fat and in the tumor (n = 10). Four fiducial types were used (Visicoil 0.75 mm, Visicoil 0.50 mm, Cook, Gold Anchor). The endpoints were technical success rate and retention of fiducials, the latter of which was evaluated on cone-beam computed tomography scans during the first five radiotherapy fractions.

Results A total of 64 fiducials were placed in 20 patients. For each fiducial type, at least three fiducials were successfully placed in all patients. Technical failure consisted of fiducial blockage within the needle (n = 2) and ejection of two preloaded fiducials at once (n = 4). No serious adverse events were reported. In three patients, one of the fiducials was misplaced without clinical consequences; two in the prostate and one in the intraperitoneal cavity. After a median time of 17 days after placement (range 7 – 47 days), a total of 42/64 (66 %) fiducials were still present (24/44 intratumoral vs. 18/20 mesorectal fiducials, P = 0.009).

Conclusions Placement of fiducials in rectal cancer patients is feasible, however, retention rates for intratumoral fiducials were lower (55 %) than for mesorectal fiducials (90 %).
Validity and safety of endoscopic biliary stenting for biliary stricture associated with IgG4-related pancreatobiliary disease during steroid therapy
Authors: Kuraishi Yasuhiro , Muraki Takashi , Ashihara Norihiro , Ozawa Makiko , Nakamura Akira , Watanabe Takayuki , Ito Tetsuya , Hamano Hideaki , Kawa Shigeyuki
Published: October 2019

Background Patients with IgG4-related sclerosing cholangitis and autoimmune pancreatitis frequently develop obstructive jaundice, which requires endoscopic biliary stenting (EBS) during steroid therapy to prevent bile duct infection from cholestasis and adverse steroid effects. However, it is controversial whether EBS during steroid therapy is advisable, because the procedure itself carries a risk of cholangitis and procedure-related adverse events. This study aimed to clarify the validity and safety of EBS for patients with biliary stricture associated with IgG4-related pancreatobiliary disease (IgG4-PBD) during steroid therapy.

Methods We enrolled 59 patients who presented with biliary stricture exhibiting jaundice or liver dysfunction and who were treated with EBS. The incidences of recurrent biliary obstruction and acute cholangitis were compared for EBS cases with and without steroid administration.

Results EBS was present in 55 periods with steroid administration and 110 periods without. The incidence of recurrent biliary obstruction was significantly lower in cases with steroids than in those without (1-month no obstruction rate: 100 % vs. 82 %; log-rank test P = 0.0015). The incidence of acute cholangitis related to stenting was significantly lower in cases with steroids than in those without (1-month no acute cholangitis rate: 100 % vs. 90 %; log-rank test P = 0.0278). Biliary stents could be removed without acute cholangitis, liver dysfunction, or stent replacement in 96 % of patients who underwent endoscopic retrograde cholangiopancreatography 1 month after commencing steroid administration.

Conclusions EBS during steroid administration was both valid and safe in patients with biliary stricture associated with IgG4-PBD. Stents could be safely removed 1 month after steroid initiation.