Транспортные системы крупных городов: вопросы эффективности

Yu. V. Trofimenko, M. R. Yakimov. Monograph «Transport planning: formation of efficient transport systems of large cities». 2nd ed., rev. and enl. Perm, RADAR agency, 2022, 536 p. ISBN 978-5-6048401-0-8.The article is a review of the monograph «Transport planning: formation of efficient transport systems in large cities», prepared by well-known Russian transport scientists Yu. V. Trofimenko and M. R. Yakimov. The monograph summarises and systematizes extensive material on topical problems of functioning of the transport systems of large cities. The book also reflects modern approaches to transport planning and organisation of traffic in cities, methods for assessing quality of functioning of urban transport systems, issues of modelling and optimising design solutions for organising transport services for the population, as well as modern approaches to building transport management systems in territorial entities.Монография «Транспортное планирование: формирование эффективных транспортных систем крупных городов». – 2-е изд., перераб. и доп. // Ю. В. Трофименко, М. Р. Якимов. – Пермь: Агентство РАДАР, 2022. – 536 с. ISBN 978-5-6048401-0-8.Статья представляет собой рецензию на монографию «Транспортное планирование: формирование эффективных транспортных систем крупных городов», подготовленную известными российскими учёными-транспортниками Ю. В. Трофименко и М. Р. Якимовым. В работе обобщён и систематизирован обширный материал по актуальным проблемам функционирования транспортных систем крупных городов. В работе нашли отражение современные подходы к транспортному планированию и организации дорожного движения в городах, методики оценки качества функционирования городских транспортных систем, вопросы моделирования и оптимизации проектных решений по организации транспортного обслуживания населения, а также современные подходы к построению систем управления транспортной сферой в территориальных образованиях

Stiffness properties characterization of pneumatic tire by methods of computer-aided 3D modeling

В роботі побудовано тривимірну геометричну та скінчено-елементну моделі пневматичної шини легкового автомобіля, що враховують особливості її геометрії, багатошарову структуру, ортотропію механічних властивостей у гумово-кордних шарах. Запропоновано систему фінітно-тороїдальних систем координат для завдання криволінійної ортотропії відповідним шарам. Наведено результати розрахунків пружної контактної взаємодії шини з дорожнім покриттям при різних типах навантажень: вертикальному, боковому та поздовжньому та за різних значень внутрішнього тиску. Отримано закономірності зміни переміщень (прогину чи зсуву) ободу колеса в залежності від прикладеного навантаження тобто визначені навантажувальні характеристики шини. Із отриманих результатів розраховані коефіцієнти жорсткості пневматичної шини по різним напрямам та закономірності їх зміни за різних значень внутрішнього тиску. Наведено порівняльну оцінку зміни характеру деформацій у внутрішніх шарах шини за різних типів навантажень.The purpose. The paper deals with the computer finite-elements 3D modelling of the pneumatic tires in a contact interaction with the almost rigid road surface that allowed to find the different types of tires operational stiffnesses (vertical, lateral and longitudinal). Design/methodology/approach. In the paper, it is developed a three-dimensional geometry and finite element model of the pneumatic tire, which takes into account the peculiarities of its geometry, multilayer structure and orthotropy of a mechanical properties in the rubber-cord layers. The system of piecewise-toroidal coordinates is proposed to specify the curvilinear orthotropy of the corresponding layers in the model. The calculations of the elastic contact of the tire with the road have been carried out at the different types of load: vertical, lateral and longitudinal with the different values of the internal pressure. Findings. The dependencies of the displacement (vertical compression or lateral shear) of the wheel rim on the applied loads are defined. From the obtained results, the stiffness factors in different directions were calculated and their dependence on the internal pressure value have been analyzed. Originality/value. The results can be used in the development of new tires design parameters, as well as in a computerized systems of the car movement control and stability (ABS, ESP, StabiliTrak).В работе построены трехмерные геометрическая и конечно-элементная модели пневматической шины легкового автомобиля, которые учитывает особенности ее геометрии, многослойную структуру, ортотропию механических свойств в резиново-кордных слоях. Предложена система финитно-тороидальных систем координат для задания криволинейной ортотропии соответствующим слоям. Приведены результаты расчетов упругого контактного взаимодействия шины с дорожным покрытием при различных типах нагрузок: вертикальной, боковой и продольной и при различных значениях внутреннего давления. Получены закономерности изменения перемещений (прогиба или смещения) обода колеса в зависимости от приложенной нагрузки, то есть, определены нагрузочные характеристики шины. Из полученных результатов рассчитаны коэффициенты жесткости пневматической шины по разным направлениям и закономерности их изменения при различных значениях внутреннего давления

Stochastic Dynamics of the Specialized Vehicle with Nonlinear Suspension

This work deals with the theoretical modelling of the vertical dynamics of the vehicle which has an additional level of suspension for a cargo platform with the nonlinear stiffness. The paper presents the design scheme of the additional level of cushioning having a quasi-zero stiffness in the equilibrium position. The mathematical model of the dynamic behavior of specialized vehicles is developed as a nonlinear discrete system. The results of numeric calculations of the vehicle dynamic response on the stochastic load is represented based on the developed model. Vertical vibrations of the cargo platform caused by the kinematics random influence applied to the axels of the vehicle are analyzed. The load is applied to the axels of the vehicle with a time delay. The results of the comparative analysis are displayed for the frequencies and amplitudes of the vehicle vertical vibrations within two different suspensions: in the linear and nonlinear statements

Регулирование международных перевозок: современные аспекты

Platonov, O. I. Multimodal transportation of goods: the state of affairs today and the prospects for implementation. Kiev, 2018, 160 pThe reviewed monograph by O. I. Platonov «Multimodal transportation of goods: the state of affairs today and the prospects for implementation» explores the current state and prospects for further development of international transportation of goods using several modes of transport. The book presents the results of a comparative analysis of the provisions of many interstate, intergovernmental and industry agreements, international standards, regulations, strategies and other governing documents related to organization of multimodal transportation. The author paid special attention to ensuring economic security in multimodal supply chains for foreign trade goods. The appendix contains a brief glossary of key terms and definitions developed by the authorIn the context of the monograph review, a discussion was initiated on the approaches to classification of international transport according to various criteria.Рец. на книгу: Платонов О. И. Мультимодальные перевозки грузов: положение дел на сегодняшний день и перспективы внедрения. – Киев, 2018. – 160 с.В рассматриваемой монографии О. И. Платонова «Мультимодальные перевозки грузов: положение дел на сегодняшний день и перспективы внедрения» исследованы современное состояние и перспективы дальнейшего развития международных перевозок грузов с использованием нескольких видов транспорта. В работе приведены результаты сравнительного анализа положений многих межгосударственных, межправительственных и отраслевых соглашений, международных стандартов, регламентов, стратегий и прочих руководящих документов, имеющих отношение к организации смешанных перевозок. Автор уделил особое внимание вопросам обеспечения экономической безопасности в мультимодальных цепочках поставок внешнеторговых грузов. В приложении представлен краткий глоссарий основных терминов по рассматриваемой тематике в авторском изложении. В контексте рецензирования монографии инициировано обсуждение подходов к классификации смешанных сообщений по различным критериям

Nonperturbative ghost dynamics in the maximal Abelian gauge

We construct the effective potential for the ghost condensate in the maximal Abelian gauge. This condensate is an order parameter for a global continuous symmetry, which is spontaneously broken since a nonvanishing value of lowers the vacuum energy. The associated Goldstone mode turns out to be unphysical.Comment: 16 pages. v2: version accepted for publication in JHE

Pheochromocytoma diagnosed during pregnancy: lessons learned from a series of ten patients

BACKGROUND: Pheochromocytoma (PHEO) in pregnancy is a life-threatening condition. Its management is challenging with regards to the timing and type of surgery. METHODS: A retrospective review of the management of ten patients diagnosed with pheochromocytoma during pregnancy was performed. Data were collected on the initial diagnostic workup, symptoms, treatment, and follow-up. RESULTS: PHEO was diagnosed in ten patients who were between the 10th and the 29th weeks of pregnancy. Six patients had none to mild symptoms, while four had complications of paroxysmal hypertension. Imaging investigations consisted of MRI, CT scan and ultrasounds. All had urinary metanephrines, measured as part of their workup. Three patients had MEN 2A, one VHL syndrome, one suspected SDH mutation. All patients were treated either with α/β blockers or calcium channel blockers to stabilize their clinical conditions. Seven patients underwent a laparoscopic adrenalectomy before delivery. Three out of these seven patients had a bilateral PHEO and underwent a unilateral adrenalectomy of the larger tumor during pregnancy, followed by a planned cesarean section and a subsequent contralateral adrenalectomy within a few months after delivery. Three patients had emergency surgery for maternal or fetal complications, with C-section followed by concomitant or delayed adrenalectomy. All newborns from the group of planned surgery were healthy, while two out three newborns within the emergency surgery group died shortly after delivery secondary to cardiac and pulmonary complications. CONCLUSIONS: PHEO in pregnancy is a rare condition. Maternal and fetal prognosis improved over the last decades, but still lethal consequences may be present if misdiagnosed or mistreated. A thorough multidisciplinary team approach should be tailored on an individual basis to better manage the pathology. Unilateral adrenalectomy in a pregnant patient with bilateral PHEO may be an option to avoid the risk of adrenal insufficiency after bilateral adrenalectomy

Surgical correction of false congenital diaphragmatic hernias in children by means of anatropic osteotomy

Introduction: Congenital diaphragmatic hernias (CDH) belong to the group of vitally dangerous defects of development of respiratory system accompanied by heavy derangements of respiratory, cardiovascular, nervous systems and the organs of gastrointestinal path. According to scientific works in this field the frequency of this anomaly is very high - 1 case on 2000-4000 newborns, including mortinatus. The lethality at the pathology has been quite high, it averages 18-33,4%. Despite significant achievements in the treatment of CDH, surgical treatment still is the most effective method, consisting in clearing pleural cavity of hernial contents with the further liquidation of the diaphragmatic defect. However, even among the children operated in due time the lethality is 40-60 %. Timeliness, the choice of surgical interfere, method and techniques of a plasticity of the diaphragm, the liquidation of visceroabdominal disproportion and of the respiratory distress, the prevention of postoperative complications still are controversial points. All this requires the search of the new surgical approaches, the development of which is impossible without an adequate experimental model of the diaphragmatic hernia. Objective: The purpose of the work is to develop an experimental model of a false diaphragmatic hernia on dogs with the possibility of the further surgical correction with the application of anatropic osteotomy. Materials and methods: Surgical interfere was carried out upon 12 mongrels aged from 1 to 2 months. After the survey X-radiography of the organs of thoracic and abdominal cavities, animals received the combined intravenous narcosis supplemented with endotracheal intubation. Further on the edge of the left costal arch laparotomy was carried out. Having provided access to the left dome of a diaphragm, the superposition of ligature for fixing was carried out, between which a big rag in the form of a triangle was cut. Through the formed defect the loops of the small intestine were introduced into the pleural cavity and fixed at the level of gate of the created diaphragmatic hernia by the sero-muscular sutures. The pleural cavity was draining. The wound of the anterior abdominal wall was layer by layer stitched up in separate nodal tight sutures. In 2 hours after the end of surgery investigation a control survey X-radiography was carried out. Considering the fact that the created model of the diaphragmatic hernia has to resemble the natural one as much as possible, the second stage of surgery investigation was carried out a month later. Under the combined intravenous narcosis in the projection of the 6th rib of the animals thoracotomy was carried out. Having removed fixation sutures, small intestine loops were displaced to the pleural cavity. Having found the 6th rib, the soft fabrics were dissected layer by layer to a rib with dissection periosteum, its mobilization and performance triangular osteotomy, with the further renewal of integrity periosteum. Then the edges of gate diaphragmatic hernia was stitched with U-shaped suture and the defect in the diaphragm was consistently sewn up, its edges pulled together without tension. An operational wound was sewn up layer by layer and tightly. Then the extubation of the animals was conducted and in 2 hours time after the end of the surgery investigation a control survey X-radiography was carried out. Results: Starting with the first days after the surgery, the dogs had general delicacy, disturbia, refusing to take water and nutrition. The objective changes signified the development of the syndrome of intrathoracic strain: frequent shallow breathing, a tachycardia, the sunk down gaste, asymmetry, deformation, blasting and backlog in the certificate of breath of the wounded half of the thorax. Percussion in the low parts of the thorax on the side of a probable hernia helped to determined tympany. At auscultation in this field the sharp indulgence of breath and periodic peristaltic noise was heard. In 2 hours after the operation on the plain film in two projections the regions of a ring-shaped clarification and the level of the lungs collapse were positioned. Within a month, despite the improvement of the state, the animals still had the signs of the intrathoracic strain. After conducting thoracotomy and returning the loops of a small intestine into the abdominal cavity, the defect of the diaphragm of significant dimensions and high position of bottom edge of the left lung were preserved. After osteotomy the rib lost rigidity of an arch and sag in pleural cavity under the traction of the surrounding intercostal muscles, letting to occlude the defect of the diaphragm reliably and without additional tension. Conclusion: Thus a simple and reliable way of modeling of a false diaphragmatic hernia is offered, resembling the congenital one as much as possible, and a new method of surgical correction of the pathology with the application of osteotomy in a projection of the diaphragmatic defect is developed

Higher moments of nucleon spin structure functions in heavy baryon chiral perturbation theory and in a resonance model

The third moment $d_2$ of the twist-3 part of the nucleon spin structure function $g_2$ is generalized to arbitrary momentum transfer $Q^2$ and is evaluated in heavy baryon chiral perturbation theory (HBChPT) up to order ${\mathcal{O}}(p^4)$ and in a unitary isobar model (MAID). We show how to link $d_2$ as well as higher moments of the nucleon spin structure functions $g_1$ and $g_2$ to nucleon spin polarizabilities. We compare our results with the most recent experimental data, and find a good description of these available data within the unitary isobar model. We proceed to extract the twist-4 matrix element $f_2$ which appears in the $1/Q^2$ suppressed term in the twist expansion of the spin structure function $g_1$ for proton and neutron.Comment: 30 pages, 7 figure

Relating Physical Observables in QCD without Scale-Scheme Ambiguity

We discuss the St\"uckelberg-Peterman extended renormalization group equations in perturbative QCD, which express the invariance of physical observables under renormalization-scale and scheme-parameter transformations. We introduce a universal coupling function that covers all possible choices of scale and scheme. Any perturbative series in QCD is shown to be equivalent to a particular point in this function. This function can be computed from a set of first-order differential equations involving the extended beta functions. We propose the use of these evolution equations instead of perturbative series for numerical evaluation of physical observables. This formalism is free of scale-scheme ambiguity and allows a reliable error analysis of higher-order corrections. It also provides a precise definition for $\Lambda_{\overline{\rm MS}}$ as the pole in the associated 't Hooft scheme. A concrete application to $R(e^+e^- \to {\rm hadrons})$ is presented.Comment: Plain TEX, 4 figures (available upon request), 22 pages, DOE/ER/40322-17

Remarks on a class of renormalizable interpolating gauges

A class of covariant gauges allowing one to interpolate between the Landau, the maximal Abelian, the linear covariant and the Curci-Ferrari gauges is discussed. Multiplicative renormalizability is proven to all orders by means of algebraic renormalization. All one-loop anomalous dimensions of the fields and gauge parameters are explicitly evaluated in the MSbar scheme.Comment: 24 pages. no figure