bluuebunny/crossref_metadata_2025 huggingface dataset:
АНАЛІЗ КОНСТРУКЦІЇ ТА ТЕХНОЛОГІЇ ВИГОТОВЛЕННЯ ПЕРСПЕКТИВНИХ РОТОРНО-ПОРШНЕВИХ ДВИГУНІВ
Authors: Тимошевський Борис Георгійович , Митрофанов Олександр Сергійович , Познанський Андрій Станіславович , Проскурін Аркадій Юрійович
Published: August 2020

The article discusses the main directions of development of creating new modern and improving existing rotary piston engines. The need for a systematic analysis of existing similar engine designs is established to separate and systematize their advantages and disadvantages at the design stage. As an analysis of the design and manufacturing technology of the existing most promising rotary piston engines, turbocompressor-type circuits with a movable cylinder block is considered, the engines in which the combustion takes place outside the working cylinder, the drum-piston type with movable combustion chambers, rotary expanders, etc. It is established that the structure of the housing of rotary piston engines with an internal cylindrical surface, in which the rotor with working cylinders is located, allows the creation of economical and compact engines. This structure of the engines allows you to reduce vibration and make them safer to use. A comparison of the mechanisms of motion of existing rotary piston engines. Based on the analysis of existing schemes and the design of modern rotary piston engines, a sample of a new design 12 RPE-4.4/1.75 rotary piston engine is designed. The design and basic parameters of a new model of the 12 RPE-4.4/1.75 rotary piston engine with adjustable spool air distribution are presented. The engine has twelve evenly spaced cylinders, provides a balanced engine, and the ability to start at any position of the rotor. The design of the engine designed provides for a central control cam shaft, the rotation of which allows you to adjust the valve timing and engine operation due to the degree of filling of the cylinder in a fairly wide range. A feature of the design of the engine is also that the control cam allows you to change the direction of rotation of the central rotor. It was found that the design of the crank mechanism of the 12 RPE-4.4/1.75 engine is simple in structure and production technology, as well as more reliable compared to similar existing rotary piston engines.
СИНТЕЗ ОПТИМАЛЬНОГО АЛГОРИТМУ ПОЛЯРИЗАЦІЙНОЇ СЕЛЕКЦІЇ КОРИСНИХ СИГНАЛІВ НА ФОНІ ПАСИВНИХ ЗАВАД В РАДАРІ З СИНТЕЗУВАННЯМ АПЕРТУРИ
Authors: Волосюк Валерій Костянтинович , Павліков Володимир Володимирович , Жила Семен Сергійович , Руженцев Микола Вікторович , Кошарський Володимир Віталійович , Одокієнко Олексій Володимирович
Published: August 2020

Using the method of maximum likelihood, the optimal algorithm of polarization selection of objects on the background of the underlying surface, hydrometeors, urban buildings from aerospace carriers of radio electronic equipment has been synthesized. To solve the problem polarimetric properties of the scattered electromagnetic radiation of different natural environments and anthropogenic objects were analyzed. Has been determined the functional-determined mathematical model of the useful signal, the structure and correlation characteristics of scattered background radiation and white noise inside the multichannel receiver. It is assumed that the wanted signals are measured with phase accuracy in a coherent receiver. When solving the optimization problem, the method of the maximum likelihood functional and the likelihood functional for correlated processes were used, contains the inverse matrix of inverse correlation functions of the observation equation. The obtained signal processing algorithm, in addition to the classical operations of accumulating the trajectory signal with the preservation of the phase structure and its matched filtering, provides for polarization and frequency selection in the line of decorrelation filters. In the case when the internal noise is very small in comparison with external interference and the correlation between the channels of vertical and horizontal polarization approaches unity, almost complete compensation of passive interference occurs. Further spectral rejection of the reflected signals is practically unnecessary and it is possible to restrict ourselves only to matched filtering of the useful signal. In the absence of background radiation correlation, the channels for receiving oscillations of different polarizations become independent and the main operation for the selection of useful signals is spectral rejection of passive interference and matched filtering of the useful signal. The developed algorithm can be implement in cognitive radars due to its adaptability to the parameters of background radiation in accordance with the change in the scattering covariance matrix of the underlying surface. Based on the results obtained, a block diagram of a multichannel polarization radar with synthesized antenna aperture has been developed.
ВИКОРИСТАННЯ НАДЛИШКУ ХОЛОДОПРОДУКТИВНОСТІ ХОЛОДИЛЬНИХ МАШИН ПРИ ОХОЛОДЖЕННІ ПОВІТРЯ НА ВХОДІ ГТУ
Authors: Радченко Андрій Миколайович , Радченко Микола Іванович , Портной Богдан Сергійович , Кантор Сергій Анатолійович , Прядко Олександр Ігорович
Published: August 2020

The processes of the gas turbine inlet air cooling by exhaust heat conversion chillers, which utilizing the gas turbine exhaust gas heat, converting it into cold were analyzed. The use of two-stage air cooling has been investigated: to a temperature of 15°C – in an absorption lithium-bromide chiller and below to a temperature of 10°C – in an ejector chiller as stages of a two-stage absorption-ejector chiller. To simulate air cooling processes, the program "Guentner Product Calculator", one of the leading manufacturers of heat exchangers "Guentner", was used. The possibility of using the accumulated excess refrigeration capacity of a combined absorption-ejector chiller, which is formed at reduced current heat loads on air coolers at the gas turbine inlet, to cover the refrigeration capacity deficit arising at increased heat loads due to high ambient air temperatures has been investigated. The refrigeration capacity required to the gas turbine inlet air cooling was compared to an excess refrigeration capacity which excess of the current heat load. The considered air cooling system provides pre-cooling of air at the gas turbine inlet by using the excess refrigeration capacity of the absorption-ejector chiller, accumulated in the cold accumulator, to provide the required refrigeration capacity of the air pre-cooling booster stage. The simulation results proved the expediency of the gas turbine inlet air cooling using the accumulated excess refrigeration capacity of the combined absorption-ejector chiller. The proposed solution reduces by about 50% the design refrigeration capacity and, accordingly, the cost of the installed absorption lithium-bromide chiller, which acts as a high-temperature stage for cooling the ambient air at the gas turbine inlet.
ВЛИЯНИЕ ПОЛЗУЧЕСТИ МАТЕРИАЛА НА РАБОТОСПОСОБНОСТЬ ЛОПАТОК СОПЛОВОГО АППАРАТА ТУРБИНЫ ВЫСОКОГО ДАВЛЕНИЯ
Authors: Придорожный Роман Петрович , Шереметьев Александр Викторович , Зиньковский Анатолий Павлович
Published: August 2020

The creation of aircraft gas turbine engines that meet modern requirements for the resource, especially its hot part, requires not only more advanced design methods but also an analysis of operability and damageability during the resource to find reserves aimed at improving reliability. One of the most complex and heat-stressed components of a modern gas turbine engine is the nozzle vanes of a high-pressure turbine, directly perceiving the high temperature of the gas at the exit of the combustion chamber and having an advanced convection-film cooling system. The service life nozzle vanes of modern aviation gas turbine engines can be tens of thousands of hours. At the same time, the maximum operating mode can reach only a few hundred hours. It is believed that damage to nozzle vanes on an engine occurs mainly in hot climatic zones. Nevertheless, as the analysis of computational studies for modern aviation gas turbine engines shows, such statements are erroneous. The direct consequence of the action of elevated temperatures and high thermal stresses is the creep of the material. A computational study of the effect of creep of the material of the nozzle vanes of a high-pressure turbine under various operating conditions of the engine on their operability was carried. It is shown that with increasing flight altitude the working temperature of the nozzle vane begins to increase, and creep processes are accelerated for all climatic zones of operation. Since with increasing flight altitude, the temperature difference for different climatic zones gradually decreases, at high altitudes, where the temperature in different climatic zones differs slightly, stress relaxation processes proceed identically. In this case, with an increase in temperature, creep processes proceed faster, and the stress level to which stress relaxation occurs becomes lower. Thus, with increasing flight altitude, damage in cold conditions approaches that under normal and hot conditions, and at high altitudes, it can even be higher. The regularities of the influence of climatic conditions and flight altitude on the strength of the nozzle vanes of high-pressure turbines and their operability are established, based on which the need to take into account the operating time of the engine in various climatic conditions when determining the service life of nozzle vanes is shown.
NEURAL NETWORK INTERPOLATION PARAMETERS OF A MULTI-MODE DYNAMIC MODEL OF THE AIRCRAFT ENGINE
Authors: Tamargazin Aleksandr , Pryimak Liudmyla
Published: August 2020

The foundations of the concept of creation of intelligent aircraft engine control systems based on the decomposition of control processes within the architecture of open information systems are considered. Unlike well-known approaches, the suggested approach allows achieving the management goal based on the principle of minimum entropy by redistributing system resources in conditions of their shortage, as well as adapting system characteristics when changing the management situation based on self-learning and self-organization of intelligent control systems. Based on an analysis of the development trends of aircraft engines, as well as development trends of production and technological systems, including the creation of new composite materials and new technologies for the manufacture and control of parts and components of aircraft engines, the intellectualization of their automatic control systems is discussed. Moreover, the development trends of aircraft engine control systems are considered from the development of their structures, functions, properties, and abilities for new qualitative changes. The article gives the general characteristics and the main directions of the design of intelligent control systems for aircraft engines as complex technical objects. The problem of designing nonlinear dynamic models of aircraft engines using artificial neural networks is discussed. The statement of this problem and possible approaches to its solution are being formed. The results of the neural network identification of an aircraft engine are compared using the least-squares method. Such a technique for designing a model of aircraft engines makes it possible to indirectly calculate engine coordinates inaccessible to measurement - traction, fuel consumption, etc. The suggested approach allows calculation of the design of neural networks simulating aircraft engines at each step using standard procedures, which makes it possible to automate the creation of neural networks. To reduce the computation time, it is suggested using the optimization algorithms taking into account changes in the state entropy. This simplifies the implementation of the neural network model of an aircraft engine in real time as part of an onboard computer complex.
ОСОБЕННОСТИ ПОСТРОЕНИЯ И ПРИМЕНЕНИЯ ЛОГИЧЕСКИХ МЕТОДОВ ПОИСКА ПРИЧИН ОТКАЗОВ ПОРШНЕВЫХ ДВИГАТЕЛЕЙ ВНУТРЕННЕГО СГОРАНИЯ В ЭКСПЛУАТАЦИИ
Authors: Хрулєв Олександр Едуардович , Клименко Валентин Григорович
Published: August 2020

Despite the successes in research and development of designs of modern internal combustion engines for various purpose vehicles, including aircraft, to date, no reliable methods have been created to determine the causes of their failures. The application of well-known methods in practice, including the diagnosis of engine technical condition, not only requires a lot of labor and highly qualified personnel but in many cases, it is practically ineffective. This is especially true for severe operational damage arising from the destruction of the parts and accompanied by disturbing the synchronization of their reciprocating and rotational motion. On the other hand, the performed research shows that the causes of ICE failures can also be determined by logical-probabilistic methods, including based on the fault tree analysis, drawing on the available experience of studying various engine faults. However, it is not possible to use the well-known models and methods built based on the failure tree analysis in problems of finding the causes of engine failure. The reason is since such methods have been developed for the tasks of calculating the reliability characteristics of developed engines, rather than finding the causes of their failure in operation. The solution to this problem was found in several stages. Initially, by structuring the symptoms, a fault tree was compiled that logically describes the cause-effect relationships between the failure event and the initial damage that caused it. This is done separately for each of the types of failures selected for analysis and associated with severe damage to the studying engine type. Further, for a finite number of selected types of failures, a modified (inverted) fault tree was developed. It allows you to perform a simple logical analysis in the opposite direction to the generally accepted direction - from the system failure event to the basic events initiating the failure. After that, a modified engine fault tree common to the considered types of failures was compiled. As a result of using the proposed methodology in practice, it became possible to determine the causes of engine failure with sufficient reliability with minimal time.
СВОБОДНЫЕ КОЛЕБАНИЯ ЛОПАТОК ОСЕВОГО КОМПРЕССОРА ГАЗОТУРБИННОГО ДВИГАТЕЛЯ
Authors: Ткач Михаил Романович , Моргун Сергей Александрович , Золотой Юрий Григорьевич , Проскурин Аркадий Юрьевич , Галынкин Юрий Николаевич
Published: August 2020

The required level of reliability of modern gas turbine engines cannot be achieved without ensuring the vibrational strength of the compressor blades. One of the tasks of ensuring vibrational strength is to determine the frequency spectrum of free vibrations, as well as the arising forms of vibrations. Moreover, the most reliable results are achieved by combining experimental and theoretical research methods. Experimental studies of the free vibrations of the blades were carried out by the time-dependent holographic interferometry method. A description of the experimental stand is given, the features of using optical equipment and processing units are indicated. The implemented algorithm for conducting experimental studies is described, the features of the digitization of optical signals implemented in the developed software are indicated, the mathematical equations used in the implementation of this software are presented, and some emerging experimental forms are illustrated. To verify the experimental data based on the finite element method, an updated mathematical model of the free vibrations of compressor blades has been developed. The characteristics of the finite element from which the mathematical model is formed, the basic equations used in the simulation of free vibrations are given. As an object of study, we considered a compressor blade 54 mm high and 37 mm long chord with a peripheral section twist angle of 17°, the considered blade is made of a titanium alloy. For this blade, some waveforms were obtained, the location of the nodal lines was shown, and data obtained experimentally and analytically were compared. An analysis was made of the frequency spectrum of the natural oscillations of the compressor blades, which showed that the difference between the vibration frequencies obtained by experimental and numerical methods for the same modes does not exceed 5 %.
УРАВНЕНИЯ ПРОСТРАНСТВЕННОГО ДВИЖЕНИЯ ТВЕРДОГО ТЕЛА С ПОДАТЛИВЫМ КРЕПЛЕНИЕМ К ФУНДАМЕНТУ (ЗАДАЧА АМОРТИЗАЦИИ В ПРОСТРАНСТВЕ)
Authors: Тарасенко Андрей Александрович , Тарасенко Александр Иванович
Published: August 2020

The task of fastening equipment, especially ship equipment, is considered important in conditions of vibration and shock. Equipment can be mounted on shock absorbers. These shock absorbers solve the problems of vibration isolation and shock protection. The classic case is the use of rubber-metal shock absorbers. The equipment can be attached to the foundation with bolts and dowels. In this case, the bolts mustn't collapse and the joints do not open during shock. An interesting case is an attachment, the fastening of which should not be destroyed. Attachments are usually attached by bolts, the destruction of which is not permissible. In the case of plastic deformation of the bolts they can be tightened, and then replacing the collapsed shock absorber is not easy. The condition of the fastening devices can be investigated by modeling, using computer technology, the movement of the unit. The use of computer technology is justified by the cumbersomeness of the task, the nonlinear characteristics of rubber-metal shock absorbers, and bolts in the case of plastic deformations. Typically, when modeling the movement of shock-absorbing equipment, they are limited to a flat task or a case of hard keys. To solve the spatial problem, we introduce three coordinate systems. One system is non-mobile and connected to the foundation. Two other coordinate systems have a beginning at the center of gravity of the unit. The axes of one of these systems are parallel to the axes of the system associated with the foundation. And the other of these systems are rigidly connected to the unit. At the initial moment, in case of rest, all three systems coincide. For the general case of motion, Euler angles can be used, but due to the small movements of the equipment, accuracy is lost. Indeed, the intersection line of the planes determining the Euler angles is determined with an error (the case of almost parallel planes). To solve this problem, the authors used the angles between the axes associated with the equipment and the foundation plane. Then, through these angles, Euler angles were expressed and expressions were obtained that allow the use of numerical methods to solve the equations of motion.
ЧИСЕЛЬНЕ ВИЗНАЧЕННЯ ЕФЕКТИВНИХ ПРУЖНИХ ХАРАКТЕРИСТИК ТРИВИМІРНОАРМОВАНОГО ВОЛОКНИСТОГО КОМПОЗИЦІЙНОГО МАТЕРІАЛУ
Authors: Морозов Андрій Володимирович
Published: August 2020

The processes occurring in composite materials are determined by differential equations in partial derivatives with variable coefficients. Most composite materials have a periodic structure, so the coefficients in the equations are rapidly oscillatory periodic functions. The most effective method for studying the stress and deformation field in structures made of composite materials is the method of finite elements, where a nonhomogeneous composite material is replaced by an equivalent homogeneous anisotropic material. To determine averaged characteristics of a composite material with a periodic structure requires a verified methodology allowing to do this. Therefore, the fundamental goal of the mechanics of composite materials is to calculate the effective elastic characteristics of the material. The paper considers the urgent issue of determining effective elastic characteristics of three-dimensional reinforced composite materials based on known elastic properties of fibers and matrix and distribution of reinforcing fibers by volume of composite material.The paper presents the mathematical modeling of the minimum three-dimensional representative volume element based on the specified reinforcement scheme and geometrical dimensions of components. Numerical experiments are performed with the ANSYS software package. A series of numerical experiments simulate six deformation cases: uniaxial tension in the X, Y, Z directions, and shear in the XY, YZ, and XZ planes. Numerical studies of the stress and strain state of the representative volume element of composite material determine the effective elastic constants of equivalent homogeneous material. Two series of calculations are performed with specifying appropriate symmetry and periodicity conditions.The results of the experimental study allow for the verification of the proposed methodology for determining the effective elastic characteristics of three-dimensional reinforced fiber composite materials. The developed numerical methodology enables us to solve the issues of the mechanics of composite materials with the help of modern software packages in the mathematical framework of which the finite element method is used.
ФОРМОУТВОРЕННЯ ПРОСТОРОВИХ ОБОЛОНОК ЗА ДОПОМОГОЮ ВИБУХОВОГО ШТАМПУВАННЯ
Authors: Третяк Володимир Васильович
Published: August 2020

A target of work is verification of the adequacy of the theoretical model of correction by the dynamic fold and verification of capacity of principle technological charts of the explosive stamping of flat purveyances.  Of researches, exposure is a task of technological dependences, the receipt of which is possible only by the experimental path. The article presented results of experimental verification of the technological process of formation of form for the spatial shells on the typical models. Of the conducted work verification was a target of the rightness of theoretical positions, results of mathematical design and conclusions, and also approbation of methods of computations of technical parameters and charts of punching. The experiments are conducted on the flat models of edging, spherical and parabolic edging of large flexibility, and also curvilinear baskets models, models, and model standards. In the article, a process is explored of slanting collision, remaining tensions, deformations, and form of edging after deformation. Influencing of size, forms, and distances of charge on deviation from the matrix. The approbation was conducted on the party of the spherical model edging.  Purveyances are approved on the model fragment.Formulated conclusions and prospects of development and introduction of technology in thermonuclear researches, building, mining industry, rocket, and air production. Experimentally it is set, that the reduction of distance below recommended results in exceeding of deformation of punching of the middle part (curvature more than matrix) and reduction of deformation of punching of the periphery (curvature is a less than matrix). Most rejections are details noticeable in the angular areas. This it is possible to explain by the regional effect from the waves of unloading, and by some asymmetry of installation of charge. The greater part of the surface has a rejection of about 1 mm, which is exceeded by exactness on 8 degrees on the base of 1200 mm. Application of technological admittances by the size of about 50 mm with subsequent their deleting, allows to decrease the mean deviation twice (0,5 mm), and promote exactness of the prepared edging. The experimental working off of technology of correction of declivous petals of double curvature showed a rightness of outputs of the theoretical part.
БАЗОВОЕ ИСПОЛНЕНИЕ РЕГУЛЯТОРА АВИАДВИГАТЕЛЯ И ЕГО МОДИФИКАЦИИ
Authors: Ранченко Геннадий Степанович , Буряченко Анна Григорьевна , Грудинкин Вячеслав Михайлович , Данилов Всеволод Владимирович
Published: August 2020

It is shown that the creation of a unified electronic control and control equipment for aircraft gas turbine engines is one of the determining trends in the experimental design work of enterprises developing components of aircraft equipment. The results of the creation of some helicopter and aircraft engine controllers (turboshaft and turboprops) in JSC Element are presented. The basic model for them was the regulator RDC-450М (category A component product according to AP-21 classification), which was developed for the AI-450M family of turboshaft engines of Мi-2M and Mi-2MSB and in 2014 received the APPLIANCE DESIGN APPROVAL. There is given information concerning the mass-produced regulator RDTs-450M rework to meet the new requirements specified by the engine designer as the results of certification tests of the AI-450M engine and state tests of the Mi-2M and Mi-2MSB helicopters. It is shown that the rework was carried out taking into account the maximum possible “modifiability” of the regulator, which is the maximum ease of its adaptation in the future to new requirements, including requirements for working with other types of engines, including turboprops. The modular principle of constructing the functional structure and design of the regulator is described; its structural scheme is given. Data are given on the results of equivalent cyclic tests of the regulator RDTs-450M, which was modified to meet the new requirements, and on subsequent work on its adaptation to monitor and regulate the modes of turboprop aircraft engines AI-450C (including its modifications) and MS-500V-02S. Information is given on the newly developed regulators RDTs-450M-S, RDTs-450M-S-1, RDTs-450M-S-T-P, RDTs-450S-500, among which there is an engine regulator designed for an unmanned aerial vehicle. It is noted that the modular design assumes the presence of a significant number of board-to-board connections, and the prospects of increasing the reliability of regulator having a modular design by using the technology of flexible-rigid boards are described.
Nudge and Improvement of Quality in Public Service: Process and Enlightenment
Authors: Lin Hongbin
Published: August 2020

The improvement of quality in public service is an inevitable requirement during the development of public service practices. Public satisfaction is an important criterion to measure the quality of public service. The value rationality of public behavior is a significant factor that affects public satisfaction and governments’ credibility. In recent years, "nudge" theory in behavioral economics has received wide attention and application.
Evaluasi Implementasi Hasil Diklat Teknis Guru IPA Madrasah Tsanawiyah
Authors: Hidayati Umul
Published: August 2020

AbstractThe research entitled Implementation Evaluation of the Results of the 2019 Tsanawiyah Madrasah Teacher Training was conducted in 10 BDK regions. The results showed that after the training, teachers experienced a very high increase in competence, obtaining scores above 80. Generally, science teachers, alumni of education, and training felt that after attending the training, there is an increase in incompetence in terms of knowledge, skills, and attitudes. Among the three competency supporting variables, the attitude variable has the highest contribution, followed by the knowledge and skills variables. The increase in the high competence of science teachers after attending this training was observed by their ability to implement them in learning. However, the results of this training have not had a significant impact on improving the quality of madrasas, because, in most madrasas, the results of training are still challenging to implement due to many factors, including unavailability of laboratory facilities, the uneven ability of science teachers both in learning and in utilization. science equipment, the number of science teachers who have received training is still very few, and madrasah policies that do not support science learning. AbstrakPenelitian berjudul Evaluasi Implementasi Hasil Diklat Teknis Guru Madrasah TsanawiyahTahun 2019 yang dilakukan di 10 wilayah BDK, hasilnya menunjukkan bahwa pasca diklat guru mengalami peningkatan kompetensi sangat tinggi, dengan memperoleh skor di atas 80. Umumnya para guru IPA alumni diklat merasakan bahwa setelah mengikuti diklat, ada peningkatan kompetensi baik dari sisi pengetahuan, keterampilan dan sikap. Diantara ketiga variabel pendukung kompetensi tersebut, variabel sikap mempunyai kontribusi tertinggi, disusul variabel pengetahuan dan keterampilan. Peningkatan kompetensi guru IPA yang tinggi setelah mengikuti diklat ini sebenarnya juga diikuti oleh kemampuannya mengimplementasikan dalam pembelajaran. Namun demikian, hasil diklat ini belum berdampak signifikan dalam meningkatkan mutu madrasah, karena pada sebagian besar madrasah, hasil diklat masih sulit diimplementasikan karena terkendala banyak faktor antara lain: sarana laboratorium yang belum tersedia, kemampuan guru IPA yang belum merata baik dalam pembelajaran maupun dalam pemanfaatan peralatan IPA, jumlah guru IPA yang pernah memperoleh diklat masih sangat
The Effect of The Addition of Promoting Microbes (PROMI) In Making Media of Pleurotus ostreatus
Authors: Karmila  , Ira Taskirawati  , Baharuddin
Published: August 2020

In making oyster mushroom growing media, one of the stages that must pass is composting of growing media (baglog). At this stage, it takes a week or more to compile the media, so the media is ready to be inoculated by the fungus. This long composting time, economically slow down production in the cultivation of oyster mushrooms. Thus, using an activator to speed up the composting process is often done. During this time, the most widely used activators to shorten composting time is Effective Microorganism (EM4). In this study, another type of activator with the same function as EM4 was tried, namely Promoting Microbes (PROMI). The purpose of this study to determine the effect (dose) compromise on the making of oyster mushroom growing media to mycelium growth time, pinhead growth time; harvest time; the number of the fruiting body, and the weight of fresh mushrooms.  The raw material used candlenut wood sawdust (Aleurites moluccana Willd) in the making of media. The method used in this study is the making of growing media, composting, sterilization, inoculation of the fungus, and maintenance. Growing media consisted of sawn wood sawdust, PROMI, bran, CaSO4, CaCO3, and water. The treatment used is the addition of compromise to the growing media before composting. The doses of PROMI given are as follows: 0 g (P1); 0.25 g (P2); 0.5 g (P3), and 0.75 g (P4), each of which dissolved in 200 ml of water. This study's results indicate that different PROMI when mixing raw materials influences the time of mycelium closure in growing media and the time of harvesting mushroom fruit bodies. For the time of mycelial closing, giving as much as 0.5 g, PROMI has different control effects.  The provision of PROMI as much as 0.5 g and 0.75 g also influences the control in terms of harvest time.
Chemical Compounds and Decomposition Process from Four Species Leaf Litter As a Source of Organic Matter Soil in Anggori Education Forest, Manokwari
Authors: Aditya Rahmadaniarti  , Wolfram Y. Mofu
Published: August 2020

Decomposition is a simple change of physical and chemical processes by soil microorganisms—the rate of decomposition process influenced by climate and litter quality factors. Litter content of chemical compounds is essential to determine the litter's quality so that it can be estimated the decomposition process. Leaves litter of Magnolia tsiampacca, Intsia bijuga, Cinnamomum cullilawan, and Aglaia sp., were collected and analyzed for their chemical compounds. Based on lignin and nitrogen content (L/N) value, Cinnamomum cullilawan have the fastest decomposition process. On the contrary, Intsia bijuga has low litter quality, so that has the slowest decomposition process. However, it has the lowest lignin content and high polyphenol content. Our research found that four observed species were able to be used as sources of soil organic matter, although the litter quality is relatively low.
Instrutor Militar: A prática docente na formação de soldados da Força Aérea
Authors: Lima Willis Correia de
Published: August 2020

Neste artigo propõe-se identificar a relevância do Instrutor Militar na formação dos soldados da Força Aérea Brasileira. Mesmo que se tenha a informação empírica dessa importância, mas cabe a sua identificação e mensuração. Tal relevância se deu ao constatar que a maioria dos instruendos tem esse pensamento do quanto se faz ímpar o instrutor em suas formações. Para tanto, foi utilizado uma pesquisa, onde se utilizou de um formulário para coletar e ratificar o pensamento inicial da relevância do Instrutor Militar e a necessidade de uma capacitação continuada aos mesmos. Sendo assim, a formação dos soldados está intimamente associada ao padrão de excelência de seus Instrutores Militares.
Teknik modifikasi ekstraoral radiografi Newman dan Friedman sebagai alternatif radiografi intraoral periapikal pada masa pandemi COVID-19
Authors: Dewi Indri Kusuma , Sitam Suhardjo
Published: August 2020

Objectives: This review is aimed to propose a method that could be an alternative in taking intra-oral radiographs during the COVID-19 pandemic.
Literature Review: The COVID-19 pandemic is the most concerning health problem in the world today. The transmission of COVID-19 is through direct or close contact with infected secretions or aerosol droplets. Individuals with COVID-19 may be asymptomatic or presymptomatic (20%-86% of all infections). Thus, patients with undiagnosed COVID-19 can come to dental clinics and Oral and Maxillofacial Radiology centers anytime. The Oral and Maxillofacial Radiology centers from dental clinics can be a source of transmission of COVID-19 to operator and dental patients. In extraoral radiography modification technique of Newman and Friedman, the sensor is placed on the cheek outside of the oral mucosa, so that the sensor does not contact the mucosal fluid from the patient.
Conclusion: Newman and Friedman's extraoral radiography modification techniques can be use as an alternatives to periapical intraoral radiographs to minimize the transmission of COVID-19.
Paradigma baru konsep proteksi radiasi dalam pemeriksaan radiologi kedokteran gigi: dari ALARA menjadi ALADAIP
Authors: Rahman Fadhlil Ulum Abdul , Nurrachman Aga Satria , Astuti Eha Renwi , Epsilawati Lusi , Azhari Azhari
Published: August 2020

Objectives: This article is aimed to widely share information and discuss further about the emerging transformation theories of the traditional radiation protection concept of ALARA into some more modern proposed concepts, particularly in dentomaxillofacial radiology.
Literature Review: The concept of radiation protection in the use of X-ray modalities in the medical field has developed along with the development of science over past decades. The concept of ALARA which has been widely known for a long time and is used as a basic of theory or main reference in radiation protection policies in several countries or at the international level now becomes a traditional, conservative and invalid principle to apply. There are several emerging theories which are considered to be more valid and representative to replace the ALARA principle.
Conclusion: Newer concepts of radiation protection that have developed, ALADAIP, are considered to be more precise and specific to be the main principle of radiation protection at this time, especially in the field of dentomaxillofacial radiology.
A POLÍTICA DE COTAS COMO FORMA DE ACESSO DEMOCRÁTICO AO ENSINO SUPERIOR PÚBLICO
Authors: Meirielle Marques Tamirys , Rodrigues Rogério
Published: August 2020

Este estudo tem como principal objetivo trazer considerações acerca da política de cotas como mecanismo de acesso democrático ao ensino superior público e ainda, inquirir sobre a igualdade de oportunidades no acesso à educação superior. Para alcançar o objetivo, utilizou-se como recurso metodológico a pesquisa bibliográfica, realizada a partir da leitura de livros e artigos científicos divulgados em meio eletrônico e, também, a leitura pormenorizada dos documentos que regulamentam as cotas: Lei nº 12.711 de 29 de agosto de 2012, Decreto nº 7.824, de 11 de outubro de 2012 e Portaria Normativa nº 18, de 11 de outubro de 2012. Ao término desse estudo, conclui-se que a política de cotas e as ações afirmativas surgiram como meio de contribuir para a igualdade de oportunidades e vêm cumprindo o proposto, na medida em que proporcionam o acesso de uma parcela de estudantes antes excluídos desse espaço de conhecimento, que é a universidade.
Determinants of Labor Productivity in Malian Firms
Authors: Anna Traore , Lansine Sountoura , Fadogoni Diallo , Breïma Traore
Published: August 2020

This article identifies the determinants of labor productivity of Malian firms using 2007-2015 panel data. These data were collected by the World Bank in 2016 from industrial companies and services. The Hausman test made it possible to choose the composite error panel model for the estimation. The results indicate that there is a positive correlation between capital intensity, commodity imports and labor productivity. Labor productivity decreases with the number of years the manager has spent at the head of the company, the use of new information and communication technologies, and the purchase of fixed assets. We also find that formal firms seem to have higher productivity when confronted with stronger local informal competition. Overall, 79.5 percent of companies reported power outages. Power outages have a negative impact on labor productivity.
Klasifikasi Topik Tugas Akhir Mahasiswa menggunakan Algoritma Particle Swarm Optimization dan K-Nearest Neighbor
Authors: Sumarni Sumarni , Rustam Suhardi
Published: August 2020

Problems the Topic of the final project is a form of scientific writing that contains the results of observations from a study of the problems that occur with the use of methods related to the particular field of science. Every student in every program of study must draw up a final project. However, before embarking on writing the final project, each student must have the topic area as a destination, the step of selection the topic of final project is an initial step before working on the final task. One way to get the final task is to see the value of general courses as well as courses, concentration majors, the value of which dominate the is is decent to scope the research topic. this research is conducted on the application of the method of K-Nearest Neighbor (KNN) for categorization of the value of the courses of concentration for the coverage of the research topic, topic the entire value in the dataset will be classified by KNN and in the optimization with the Particle swarm Optimization algorithm (PSO). The experimental categorization of the final project is built with the training data Mahasiswa Universitas Ichsan Gorontalo that has been classified previously and test data derived from the entire value of the courses is not yet known categories. The results of the experiments, the value of the resulting accuracy of algorithms KNN, namely the value of the best accuracy with K=3, K Folds = 10 has an accuracy that is 72.46% and the Algorithm of KNN-PSO best accuracy with K=3, K Folds = 10 has an accuracy that is 89.86%, shows the accuracy is better by using the optimization algorithm
On the Use of High-resolution Time-frequency Distribution Based on a Polynomial Compact Support Kernel for Fault Detection in a Two-level Inverter
Authors: Seninete Sara , Abed Mansour , Bendiabdellah Azeddine , Mimi Malika , Belouchrani Adel , Ould Ali Abdelaziz , Cherif Bilal Djamal Eddine
Published: August 2020

Quadratic Time-Frequency Distributions (TFDs) become a standard tool in many fields producing nonstationary signatures. However, these representations suffer from two drawbacks: First, bad time-frequency localization of the signal's autoterms due to the unavoidable crossterms generated by the bilinear form of these distributions. This results on bad estimation of the Instantaneous Frequency (IF) laws and decreases, in our case, the ability to precisely decide the existence of a motor fault. Secondly, the TFD's parameterization is not always straightforward. This paper deals with faults' detection in two-level inverter feeding induction motors, in particular open-circuit Insulated Gate Bipolar Transistor (IGBT) faults. For this purpose, we propose the use of a recent high-resolution TFD, referred as PCBD for Polynomial Cheriet-Belouchrani Distribution. The latter is adjusted using only a single integer that is automatically optimized using the Stankovic concentration measure, otherwise, no external windows are needed to perform the highest time-frequency resolution. The performance of the PCBD is compared to the best-known quadratic representations using a test bench. Experimental results show that the frequency components characterizing open-circuit faults are best detected using the PCBD thanks to its ability to suppress interferences while maintaining the signal's proper terms.
Old Norse and Old English Language Contact: Scandinavian Legal Terminology in Anglo-Saxon Laws
Authors: Miglio Viola
Published: August 2020

The Scandinavian occupation of wide territories in the British Islands from about 900 CE onwards has left a number of vestiges both in place-names, in the pronunciation and lexicon of northern dialects, especially Scottish, as well as loanwords in standard English, some of which are remarkably common, ugly, to take and window to name but three.
Arne Jönsson, Valborg Lindgärde, Elisabet Göransson (eds.), Wår Lärda Skalde-Fru Sophia Elisabeth Brenner och hennes tid (Ängelholm: Skåneförlaget, 2011)
Authors: Storskog Camilla
Published: August 2020

The poetess Sophia Elisabeth Brenner (Stockholm, 1659-1730) is likely to be a household name with a readership familiar with the fictive universe of the contemporary Swedish literary scholar and novelist Carina Burman. At the centre of Burman’s second novel Den tionde Sånggudinnan (1996) stands in fact the fictionalised life of Brenner.
Francesco Giacomantonio, Introduzione al pensiero politico di Habermas. Il dialogo della ragione dilagante (Milano-Udine: Mimesis, 2010)
Authors: Baruchello Giorgio
Published: August 2020

We live in an age of crisis. The Enlightenment faith in reason, method, and comprehensive synthesis had filled modernity with pride, hopefulness, and “grand theories” (16). In recent times, this faith seems to have vanished, analogously to what had already happened in Europe during the 1930s (17-8). One of the clearest indications of this state of crisis is the recurrent use of the prefix “post-” in a variety of characterisations of the present: “post-ideological, post-philosophical, post-modern, post-metaphysical, post-human, post-Fordist, post-democratic, etc.” (11). Indeed, during the last four decades, overarching philosophical and scientific worldviews have themselves been regarded as ill-fated. We live somehow in a post-rational world.
Michelle Facos, Symbolist Art in Context (Berkeley: University of California Press, 2009)
Authors: Bottai Stella
Published: August 2020

Michelle Facos is professor of art history at Indiana University. She is an expert in 19th-century European art, especially Scandinavian. I have been following Facos’ studies since 2005, when I started my Ph.D. research in Finnish art. Her book Nationalism and the Nordic Imagination: Swedish Painting in the 1890s (Berkeley: University of California Press, 1998) led me through Swedish art and National Romanticism in Northern countries. In her new book, Facos explores Symbolist art within several contexts, with a modern approach to the study of this influential movement.
Reflections on the economic crisis one year on: an interview with Huginn Freyr Þorsteinsson
Authors: Þorsteinsson Huginn Freyr
Published: August 2020

The editor-in-chief of Nordicum-Mediterraneum interviewed Huginn Freyr Þorsteinsson, Political Advisor to the current Icelandic Minister of Finance, on the international economic crisis exploded in 2008 and its troublesome implications for Iceland, to which was devoted a special section in the 2010 issue of the journal. Given the left-wing composition of the current parliamentary majority and the affiliation of the members of the governing cabinet, questions were asked whilst keeping in mind the traditional aims, policies and interpretations of the political left.
H. Beale et al., Cases, Materials and Texts on Contract Law, 2nd ed. (Oxford: Hart Publishing, 2010); and T. K. Graziano, Comparative Contract Law: Cases, Materials and Exercises (Basingstoke: Palgrave MacMillan, 2009)
Authors: Johnstone Rachael L.
Published: August 2020

Nordicum-Mediterraneum may seem an odd forum for a review essay on contract law casebooks; but these are no standard classroom texts. In contrast to the traditional research and education in each country of studying only the private law of the provincial legal system, each of these texts approaches contract law from a comparative and European perspective.
Law and Justice in Community: The Significance of the Living Law
Authors: Doyle Oran
Published: August 2020

Law and Justice in Community provides an account of law that privileges the role of custom, which the authors characterise as the living law. In this paper, I argue that the authors’ account of law observes the same features as those observed by Hart in his Concept of Law. However, Hart viewed all law through the lens of state law, with the result that he did not identify the purpose of law. Conversely, Barden and Murphy view all law through the lens of the living law, with the result that they do not identify some of the most acute issues raised by pervasive state law. Ultimately, each account is helpful as a corrective to the other.
Biomass Waste and Low Rank Coal Gasification Technology with Carbon Capture System to Optimize A Clean Energy Production as An Alternative Solution to Achieve Energy Security in Indonesia
Authors: Baskoro Ardian N. , Aptari Odara E.
Published: August 2020

A shift into a more developed country means an increase in various aspects of economy, energy, social, and even environment. For Indonesia, a major change that the country needs to face is the increase of energy demand of 7% every year, reaching a final average expected energy consumption of 497.77 MTOE in 2050. In order to fulfil all upcoming energy demands and achieve energy security, it is crucial to utilize the available abundant resources that the country possesses. Two of these potential resources include coal (22.6 billion tons) and biomass (32.6 GW). Gasification is an alternative clean technology that can utilize low rank coal or biomass to convert it into syngas. The quality of syngas was characterized using the H2/CO ratio parameter. The greater the carbon density in a material, the greater H2/CO ratio will be. However, syngas produced from conventional gasification still emits CO2. Since CO2 is still emitted in coal gasification technology, a carbon capture system called HyPr-RING process is implemented as an alternative to reduce CO2 and increase the quality of syngas up to 91% volume of H2. The process uses CaO as a sorbent to capture CO2 and convert it into CaCO3 in a gasifier. Then, the CaCO3 is calcinated in a calciner to release back CaO that is recycled to capture more of the CO2. Aside from the high availability of coal and biomass, CaO as a major substance used in the CO2 capture process is also abundant in Indonesia (2,156 billion tons). This technology innovation is also economically feasible as it creates a net profit of USD 58,215 and ROI of 11%.
A Highly Approximate Pseudo-Spectral Method for the Solution of Convection-Diffusion Equations
Authors: EL-AZAB Magdi , EL-ASHWAH Rabha , ABBAS Maha , EL-BAGHDADY Galal
Published: August 2020

The main purpose of this paper is to compute a highly accurate numerical solution of two dimensional convection--diffusion equations with variable coefficients by using Legendre pseudo-spectral method based on Legendre-Gauss-Lobatto nodes. The Kronecker product is used here to formulate a linear system of differentiation matrices; this system was reduced to be more accurate with less memory usage. Error analysis with test problems are introduced to show that the suggested scheme of the spectral method has high accuracy.