Статті в журналах з теми "Modules de type de Jordan constant"

Integration of seismic refraction tomography and multi-channel analyses shear wave methods were used at Al al-Bayt university campus in Mafraq, NE Jordan to delineate the shallow subsurface layering and determine their geotechnical properties, in addition, to estimate the geotechnical engineering parameters of the superficial deposits for detailed purposes. The P-wave refraction velocities were found to range from 180 to 2300 m/s for the three identified layers which indicating superficial soil deposits with an increasing degree of compaction with depth. The S-wave velocities were found to lie in a narrow velocity range (250 to 600 m/s), which badly resolved the subsurface layering. Moreover, four soil samples were taken from the sites of seismic survey points for density calculations. The average calculated density was found to be 1.85 g/cm3. Two soil samples from nearby seismic profile-1 and seismic profile-4 were tested for geotechnical properties. The results showed that the seismic method is an effective tool to estimate the different elastic moduli; Poisson's ratio, Young's modulus, Bulk modulus, Shear modulus, Lame's constants, and geotechnical engineering parameters; N-value, bearing capacity, material index, concentration index, and stress ratio of the superficial soil deposits. The study recommends conducting a detailed geophysical study before starting any type of geoengineering construction in the area.

Through the development of photovoltaic technologies, the market related to this type of renewable energy grows constantly. In Brazil, the generated power through photovoltaic (PV) power stations approximates to 2.3 GW representing 1.3% of the total Brazilian energy mix. To supply the public it is necessary to offer tools that facilitate consumer decision making or even the work of a solar farm designer. By analyzing the user’s necessity, it is possible to determine that a great parcel needs a quick and simple response to help them with their questions, and programs that are already well established in the marketplace are complex for inexperienced users. For this reason, a software that calculates the best inclination for PV modules using the method proposed by Liu and Jordan in 1962 is developed. It also determines the number of modules that can be installed without any shading between arrays within a user-defined area. This calculation is possible through the standard dimensions provided by the module manufacturers and the solar height and declination study. Through a simple interface, the user quickly receives the optimum tilt angle of installation, the number of PV modules and the maximum generated power.

Abstract We study the variation of the gravitational constant on cosmological scales in scalar-tensor theories of gravity. We focus on the simplest models of scalar-tensor theories with a coupling to the Ricci scalar of the form F(σ) = N 2 pl + ξσ 2, such as extended Jordan-Brans-Dicke (N pl = 0), or a non-minimally coupled scalar field with N pl = M pl, which permits the gravitational constant to vary self-consistently in time and space. In addition, we allow the effective gravitational constant on cosmological scales to differ from the Newton's measured constant G, i.e. G eff(z = 0) = G(1+Δ)2. We study the impact of this imbalance Δ jointly with the coupling ξ into anisotropies of the cosmic microwave background and matter power spectrum at low-redshift. Combining the information from Planck 2018 CMB temperature, polarization and lensing, together with a compilation of BAO measurements from the release DR12 of the Baryon Oscillation Spectroscopic Survey (BOSS), we constrain the imbalance to Δ = -0.022 ± 0.023 (68% CL) and the coupling parameter to 103 ξ < 0.82 (95% CL) for Jordan-Brans-Dicke and for a non-minimally coupled scalar field with F(σ) = M 2 pl + ξσ 2 we constrain the imbalance to Δ > -0.018 (< 0.021) and the coupling parameter to ξ < 0.089 (ξ > - 0.041) both at 95% CL. With current data, we observe that the degeneracy between Δ, the coupling ξ to the Ricci scalar, and H 0 allows for a larger value of the Hubble constant increasing the consistency between the distance-ladder measurement of the Hubble constant from supernovae type Ia by the SH0ES team and its value inferred by CMB data. We also study how future cosmological observations can constrain the gravitational Newton's constant. Future data such as the combination of CMB anisotropies from LiteBIRD and CMB-S4, and large-scale structures galaxy clustering from DESI and galaxy shear from LSST reduce the uncertainty in Δ to σ(Δ) ≃ 0.004.

The study examines the false promise of cooperation in the Jordan River basin through the prism of state policies and determinants. The study is underpinned by the significance of pivotal riparian states. Based on their preeminence in determining the course of cooperation, the study considers Israel, Jordan and Palestine as pivotal riparian states. In terms of research methodology, qualitative approach was used. The study identified that domestic politics, regional dynamics and international water regimes are major determinant factors making cooperation to be a fantasy. Israel’s doctrine of exceptionalism both in the sense of statehood and government type and the reciprocated denial of co-basin states in this regard are domestic political factors that impede the course cooperative events. Israel’s geopolitical calculations via territorial expansion alongside of the Jordan River affect the cooperative milieu. The mere existence of water regimes either in the form of legal agreements or institutional attempts, does not bring effective cooperation. The finding of study shows that, domestic politics, regional dynamics and international water regimes are indeed determinant factors for the cooperative and conflictive nature of water sharing in the basin. The level of their impact however is neither equal nor constant. Importantly, these three factors affect and condition one another.

The present study aims to use systematic conservation planning to analyse and review the national protected areas (PAs) network in Jordan. The analysis included the application of three modules: the environmental risk surface (ERS), the relative biodiversity index (RBI), and the application of Marxan. The methodology was based on using Marxan to achieve solutions for three scenarios for the PAs network. Marxan was applied to the input data, which included vegetation types, distribution of threatened mammals and plants, locations of currently established PAs and other types of designations. The first two scenarios aimed to conserve 4% and 17%, respectively, of each vegetation type, and 10% and 20%, respectively, of the extent of occurrence of threatened mammals and plants. The third scenario aimed to conserve 17% of each vegetation type and 10% of the extent of occurrence of threatened plants and mammals, except for forest and the Hammada vegetation which had the target of 30% and 4%, respectively. The results of the three scenarios indicated that the boundaries of existing reserves should be extended to achieve the conservation targets. Some currently proposed (PAs), such as the Aqaba Mountains, did not appear in any of the solutions for the three scenarios indicating that the inclusion of these sites in the proposed (PAs) network should be reconsidered. All three scenarios highlighted the importance of having conservation areas between the western and eastern parts of the country. Systematic conservation planning is a structured, replicable, transparent, and defensible method for designing PA networks. It allows for finding efficient solutions building on what is currently conserved and minimizing the fragmentation and cost of the proposed solution for conservation areas.

The fundamental difference of the voltage converter of the secondary power supply source for the transmitter-receiver modules of active electronically scanned arrays with impulse load and variable duty cycle from traditional voltage converters that constantly consume power from the primary network is shown. Methods for improving the quality of transient processes in voltage converter with constant power consumption during start-up by soft start are not applicable to improve the quality of transients in periodic current pulses caused by a pulsed load. Since any ripples, noises, instabilities in the power supply of the transmitter-receiver modules of active electronically scanned arrays operating in a linear mode lead to parasitic amplitude modulation of the emitted signal and to a deterioration in the quality of selection and target tracking, very strict requirements are imposed on the quality of the transmitter-receiver modules supply voltage (voltage ripple kп 0,5 %, the amount of overshoot of the output voltage sU 2 %, etc.). The article shows that such a quality of the output voltage with a pulsed load of the transmitter-receiver modules of active electronically scanned arrays can be obtained using a lower-type voltage converter, with a double-circuit negative feedback for the output voltage and current of the inductor, with a storage capacitor and with a power smoothing filter with the characteristics of Chebyshev and Butterworth. The work investigated the influence of the negative feedback depth on the output voltage and current of the smoothing filter choke, the value of the storage capacitor capacity, the type and parameters of the smoothing filter, and recommendations were given to select their optimal values, at which the required quality of the supply voltage for the transmitter-receiver modules of active electronically scanned arrays was ensured, taking into account the minimization of their dimensions.

To optimize thermal dissipation efficiency for cooling high power LED modules is studied and analyzed using ANSYS CFX software and Taguchi method. In liquid-cooling system, four control factors are tested and compared in order to find the best cooling arrangement that are pump flow rate, fan power, cooling liquid type and k- value of thermal compound. The experimental results show that the importance of these cooling parameters applied to high power LED module are k-value of thermal compound, fan power, liquid type and pump flow rate in sequence. For a constant heating power of 90W from an LED lighting module, an optimal thermal resistance of 0.563K/W is obtained that shows a significant improved result then the conventional LED module’s. It has high potential in future high power LED applications.

This paper discusses the conversion of solar irradiance energy into electricity. Double-sided (bifacial) panels are gaining increasing popularity in commercial applications due to the increased energy yield with a constant occupied mounting surface. However, the value of the additional energy yield produced by the back of the panel depends on several important factors. This paper presents the influence of working conditions on electricity generation in bifacial modules. This paper also investigates the influence of weather conditions, the module inclination angle, and the substrate beneath the panel surface on electricity generation. Fill factor and efficiency were calculated for each case included in the study scope. Based on the current voltage, power characteristics, and calculations, the module operation for different conditions was compared. It was observed that the optimal inclination angle to the surface is higher for the bifacial modules compared to the unilateral modules. The type of surface under the module has also been indicated to impact the amount of electricity generated. The additional energy yield associated with the panels’ rear side accounts for 2% to more than 35% of the total power generated by a photovoltaic (PV) module. The unit cost of electricity generation in the analyzed cases was also determined.

We aim to derive the most general f(R) gravity theory, including thematter, so that it be Weyl invariant. Making use of the mathematicalequivalence of these theories with an type of scalar-tensor theory, and byimposing the Weyl invariance for the pure gravity as well as for the mattersector, we obtain the fundamental equation that restricts the form of V (phi) (and, accordingly, of f(R)) so that the resulting action to be Weylinvariant in the Jordan frame. We show that this action is not otherthan the so-called dilaton gravity action with one scalar eld,, whicheective mass is R and Phi dependent. In the Einstein frame, the actionbecomes the Einstein-Hilbert action with the Ricci scalar being constantdue to that the eective mass of scalar eld in this frame vanish. So,we can assume that the Ricci scalar, in the Einstein frame, is the trueCosmological Constant. Therefore, is not preposterous to guess that, atleast mathematically, all Weyl invariant metric f(R) theory in the Jordanframe is equivalent, at classical level, to the Einstein gravity, in theEinstein frame, with a constant Ricci scalar. At quantum level, as it isknown, both theories are not equivalent due to the presence of anomaliesin one of the frames.

Power utilization from renewable sources with efficient modules is very vital. Maitaining harmonics below specific standard during grid interconnection is also a major objective. A novel five-level voltage source inverter which is controlled by synchronous reference frame (SRF) controller for grid interconnection and synchronized power injection. The input of the converter is integrated with renewable energy source photovoltaic arrays (PVA) for the injection of renewable power into the grid. For constant voltage input, the PVAs are connected to a booster converter controlled by the maximum power point tracking (MPPT) algorithm. The design is analyzed with different operating conditions by changing the load type (static and dynamic) using MATLAB/Simulink software. Graphical comparisons are taken for the analysis with the help of ‘powergui’ toolbox available in the software.

Different Dictyostelium discoideum strains contain between 2 and 200 copies of a retrotransposable element termed DRE (Dictyostelium repetitive element). From the analysis of more than 50 elements, it can be concluded that DRE elements always occur 50 +/- 3 nucleotides upstream of tRNA genes. All analyzed clones contain DRE in a constant orientation relative to the tRNA gene, implying orientation specificity as well as position specificity. DRE contains two open reading frames which are flanked by nonidentical terminal repeats. Long terminal repeats (LTRs) are composed of three distinct modules, called A, B, and C. The tRNA gene-proximal LTR is characterized by one or multiple A modules followed by a single B module (AnB). With respect to the distal LTR, two different subforms of DRE have been isolated. The majority of isolated clones contains a distal LTR composed of a B module followed by a C module (BC), whereas the distal LTR of the other subform contains a consecutive array of a B module, a C module, a slightly altered A module, another B module, and another C module (BC.ABC). Full-length as well as smaller transcripts from DRE elements have been detected, but in comparison with the high copy number in D. discoideum strains derived from the wild-type strain NC4, transcription is rather poor.

The energy yield from bifacial solar photovoltaic (PV) systems can be enhanced by optimizing the tilt angle. Bifacial modules boost the energy yield by 4% to 15% depending on the module type and ground reflectivity with an average of 9%. The selection of tilt angle depends on several factors, including the geographical location, weather variation, etc. Compared to the variable tilt angle, a constant angle is preferred from the point of view of the cost of installation and the cost of maintenance. This paper proposes a new method for analysing bifacial modules. A simpler rear-side irradiance model is presented to estimate the energy yield of a bifacial solar photovoltaic module. The detailed analysis also explores the optimum tilt angle for the inclined south–north orientation to obtain the maximum possible yield from the module. Taking four regions into account, i.e., Kharagpur, Ahmedabad, Delhi, and Thiruvananthapuram, in the Indian climate, we studied several cases. The Kharagpur system showed a monthly rear irradiance gain of 13%, and the Delhi climate showed an average performance ratio of 19.5%. We studied the impact of albedo and GCR on the tilt angle. Finally, the estimated model was validated with the PVSyst version 6.7.6 as well as real field test measurements taken from the National Renewable Energy Laboratory (NREL) located in the USA.

The study addresses the tensions between the aims and objectives of global, national and local curricula and suggests solutions for mitigating these conflicts using the experience of Estonia as an example. In spite of the success of recent reforms and the good results of students in international comparisons, there are serious deficiencies: an Estonian teacher’s readiness to use professional freedom is modest, personal efficiency, job satisfaction, and students’ motivation to learn is low: there are few outstanding performers. The aim of the study is to propose and analyse a teacher education curriculum innovation model for overcoming the problem. Adaptive model for curriculum design is presented where the predominant outcome-oriented approach was replaced and focus on teaching and learning processes was highlighted, the logic of design in curriculum development was implemented. A model for the practice component of teacher education, based on Wenger`s situated learning model and Engeström’s expansive learning model, is in the focus. It is found that implementing this approach could encourage a development of standards and transform the attitudes of both students and teachers towards increased creativity and professional development. The implementation of the described curriculum innovation model enhances new type of learning and can generate new modules in teacher education curricula. Key words: adaptive competence, curriculum design, Estonian education, practice in teacher education.

The aim of this research is to explore the contributions of FabLabs in applied tertiary education (Bachelor University of Applied Sciences – UAS), and particularly in the form of hybrid teaching modules, combining academic subjects and maker experience. FabLabs can offer services to the professors of various academic fields to reinvent their teaching methodologies, incorporating making as a way to transmit knowledge and enhance student engagement. We have also established with higher education professors and lecturers in mind, the conditions for the implementation of such modules in order to guarantee their success. A pilot project has been conducted with occupational therapy students consisting of a one-semester module of 30 periods, dedicated to developing and prototyping in order to adapt toys and games to be used by children with cerebral palsy of the spastic hemiplegia type. The FabLab was the place where prototypes were made, but also where exchange, collaboration and creativity were catalysed. Our observations showed that the students developed three types of skills: technical (use of digital 3D CAD software and machines), occupational, in the field of occupational therapy (observation and analysis of the accessibility of the environment, solution-oriented approach aimed at increasing occupational performance and participation) and relational (creativity, agility, collaboration). Commitment and pleasure of learning were present throughout the module. The conditions for the success were the co-construction of the learning experience by both the professors and the labmanagers in charge of the FabLab, the establishment of a pedagogical scenario, and constant, open communication between them.

AbstractThe multifactorial etiology of stress-related disorders necessitates a constant interrogation of the molecular convergences in preclinical models of stress that use disparate paradigms as stressors spanning from environmental challenges to genetic predisposition to hormonal signaling. Using RNA-sequencing, we investigated the genomic signatures in the ventral hippocampus common to mouse models of stress. Chronic oral corticosterone (CORT) induced increased anxiety- and depression-like behavior in wild-type male mice and male mice heterozygous for the gene coding for brain-derived neurotrophic factor Val66Met, a variant associated with genetic susceptibility to stress. In a separate set of male mice, chronic social defeat stress (CSDS) led to a susceptible or a resilient population, whose proportion was dependent on housing conditions, namely standard housing or enriched environment. Rank-rank-hypergeometric overlap (RRHO), a threshold-free approach that ranks genes by their p value and effect size direction, was used to identify genes from a continuous gradient of significancy that were concordant across groups. In mice treated with CORT and in standard-housed susceptible mice, differentially expressed genes (DEGs) were concordant for gene networks involved in neurotransmission, cytoskeleton function, and vascularization. Weighted gene co-expression analysis generated 54 gene hub modules and revealed two modules in which both CORT and CSDS-induced enrichment in DEGs, whose function was concordant with the RRHO predictions, and correlated with behavioral resilience or susceptibility. These data showed transcriptional concordance across models in which the stress coping depends upon hormonal, environmental, or genetic factors revealing common genomic drivers that embody the multifaceted nature of stress-related disorders.

The use of solar energy has limitations due to its periodic availability: solar plants do not operate at night and are ineffective in dull weather. The solution of this problem involves the introduction of energy storage and duplication systems into the conversion loop. Among the energy storage systems, solid–liquid phase transition modules have significant energy, ecologic, and cost advantages. Physical processes in modules of this type are described by a system of non-stationary nonlinear partial differential equations with specific boundary conditions at the phase interface. The verification of a method for solving the Stefan problem for a heat-storage material is presented in this paper. The use of the mushy layer method made it possible to simplify the classical mathematical model of the Stefan problem by reducing it to a nonstationary heat conduction problem with an implicit heat source that takes into account the latent heat of transition. The phase transition is considered to occur in an intermediate zone determined by the solidus and liquidus temperatures rather than in in infinite region. To develop a Python code, use was made of an implicit computational scheme in which the solidus and liquidus temperatures remain constant and are determined in the course of numerical experiments. The physical model chosen for computer simulation and algorithm verification is the process of ice layer formation on a water surface at a constant ambient temperature. The numerical results obtained allow one to determine the temperature fields in the solid and the liquid phase and the position of the phase interface and calculate its advance speed. The algorithm developed was verified by analyzing the classical analytical solution of the Stefan problem for the one-dimensional case at a constant advance speed of the phase interface. The value of the verification coefficient was determined from a numerical solution of a nonlinear equation with the use of special built-in Python functions. Substituting the data for the physical model under consideration into the analytical solution and comparing them with the numerical simulation data obtained with the use of the mushy layer method shows that the results are in close agreement, thus demonstrating the correctness of the computer algorithm developed. These studies will allow one to adapt the Python code developed on the basis of the mushy layer method to the calculation of heat storage systems with a solid-liquid phase transition with account for the features of their geometry, the temperature level, and actual boundary conditions.

In this paper, we describe the design and fabrication of a wideband frequency down converter module that has a local circuit with high gain, low spurious, high IP3 (3rd intercept point) characteristics, and reliability; this is accomplished by applying a chip-and-wire process using a bare type monolithic microwave integrated circuit (MMIC) device. To compensate for the mismatch among many sub-modules, an input module, filter bank module, output module, and local oscillator (LO) module suitable for sub-band frequency characteristics were designed and applied to the down converter. Th e frequency down converter module had three paths: 0.5−2 GHz (direct), 2−6 GHz (direct), and 6−18 GHz (converter). Amplitude-matched radio frequency (RF) semi-rigid cables of different lengths were used to connect to the internal sub-modules of the frequency down converter. The main RF line was a dielectric substrate, RT/duroid 5880, with a relative dielectric constant of 2.2 and a dielectric thickness of 0.127 mm. In the wideband frequency down converter module, the gain was 22.7 dB at low band (input frequency, 0.5−2 GHz) with a flatness of about 3.4 dB. Th e gain was 22.6 dB at mid band (input frequency, 2−6 GHz) having flatness about 2.0 dB. The gain was from 30 dB at edge frequency of high band (input frequency, 14−18 GHz) with a flatness of about 4.2 dB. The measured value of IP3 at LB was +23.52 dBm, +25.66 dBm and +23.44 dBm as the maximum value. The measured value of spurious (LO-2IF) at the converter path was 34.97 dBc as the maximum value.

Soft pneumatic actuators are extensively used in soft robots, and their bending angles and kinematic rules at different pressures play a crucial role in practical applications. This investigation aims to model the bending angle and motion of a new type of soft pneumatic actuator that adopts a composite structure consisting of two kinds of pneumatic networks. Based on the structural and deformation characteristics of the proposed soft actuator, the constitutive model is established, and then the moment equilibrium and virtual work principle are combined to model the bending angle of two pneumatic modules. The kinematic model of the proposed soft actuator is co-opted from the kinematic modeling of rigid robots. By employing the piecewise constant curvature method and coordinate transformation, the location of any chamber of the soft actuator can be calculated. The effectiveness of the developed analytical models is then tested, and the calculated results show good agreement with the experimental results. Finally, three soft actuators are used to constitute a soft gripper, and the pinching and enveloping grasping performance are examined. All experimental test results demonstrate that the developed bending angle and kinematic models can explain the bending principle of the proposed soft actuators well.

ABSTRACT Introduction Forces delivered by elastomeric chains are not constant and degrade overtime. The degree of degradation could result in forces that fall below the threshold value, precluding any therapeutic effect. Correct evaluation of degradation of force of these materials under various environmental conditions is the need of hour. Objective To analyze and compare the effects of commonly consumed liquids, such as Cola, tea and mouthwash, on the force degradation of orthodontic elastomeric chains was conducted. Materials and methods An in vitro study was done to assess factors which affect the decay properties of the three elastomeric modules (Ormco Power Chain, 3M Unitek Alastik Chain and American Orthodontics) in the following food stimulants: black tea, milk, aerated drink, mouthwash and artificial saliva. Two different module lengths (long and short) of each product were used for the initial load-comparison study and force decay was evaluated over 21 days at constant extension and at decreasing extension. Means of percentage change in tensile strength were calculated and analyzed using one way analysis of variance (ANOVA) with Tukey's correction for multiple group comparisons. p < 0.05 was considered to be statistically significant. Results The evaluated force degradation in percentage in tensile strength on 21 days post-treatment in tea was significantly higher in product A compared to products B and C with product type short. The evaluated force degradation in percentage in tensile strength on 21 days post-treatment in Cola was significantly higher in products A and C as compared to product B with product type short. The force degradation of product B was significantly less compared to the products A and C initially. However, it degrades at the end of the 21 days and is equivalent with other products. Conclusion Irrespective of the solvents used, the force degradation varies for different products. How to cite this article Nachan RA, Kalia A, Al-Shahrani I. Force Degradation of Orthodontic Elastomeric Chain due to Commonly Consumed Liquids: An in vitro Study. World J Dent 2015;6(1):31-38.

Abstract Small Modular Pressurized Water Reactor (PWR) can be used to overcome the problem of electricity shortages in remote areas with fewer populations. These reactors usually use uranium-based fuel. Currently, the use of thorium-based fuels for this type of reactor has received constant attention, leading to several investigations of fuel performance. This study aims to determine the performance of thorium-based fuel in the PWR core at a power level of 300 MWt. The analysis was carried out by varying the percentage of U-233 as fissile material in Thorium (Th-233U)O2 fuel by 3%-8% and Pa-231 variation as burnable poison 0.2%-5%. In addition, analysis of changes in the volume fraction of fuel ranging from 40%-60%, with the type of cladding used in the form of Zirlo. The calculation system uses the SRAC computer code with PIJ and CITATION modules for cell and core calculations, using JENDL-4.0 nuclide data. Parameters analyzed from the fuel cell calculation results are reactor criticality, excess reactivity, and power density profile. The analysis results show that the best fuel performance is found in fuel volume fraction of 60%, U-233 configuration on the fuel of 4-5-6%, and the addition of 2.5% Pa-231. This fuel configuration can achieve cycles of up to 19 years with excess reactivity at BOL of 2.57% dk/k and excess reactivity at EOL of 0.87% dk/k.

The constant growth of pathologies affecting human mobility has led to developing of different assistive devices to provide physical and cognitive assistance. Smart walkers are a particular type of these devices since they integrate navigation systems, path-following algorithms, and user interaction modules to ensure natural and intuitive interaction. Although these functionalities are often implemented in rehabilitation scenarios, there is a need to actively involve the healthcare professionals in the interaction loop while guaranteeing safety for them and patients. This work presents the validation of two visual feedback strategies for the teleoperation of a simulated robotic walker during an assisted navigation task. For this purpose, a group of 14 clinicians from the rehabilitation area formed the validation group. A simple path-following task was proposed, and the feedback strategies were assessed through the kinematic estimation error (KTE) and a usability survey. A KTE of 0.28 m was obtained for the feedback strategy on the joystick. Additionally, significant differences were found through a Mann–Whitney–Wilcoxon test for the perception of behavior and confidence towards the joystick according to the modes of interaction (p-values of 0.04 and 0.01, respectively). The use of visual feedback with this tool contributes to research areas such as remote management of therapies and monitoring rehabilitation of people’s mobility.

Introduction. Modern vehicles are equipped with radars, which serve as the main sensors of driver assistance systems detecting objects in all weather conditions. Antenna arrays (AA) are the most common type of radar antennas. The coefficient of mutual coupling between adjacent antenna channels has a significant effect on the formed radiation pattern (RP) of an AA. This aspect is important for achieving the required values of gain and side-lobe level (SLL). This article analyses the effect of the proposed design solutions on the main parameters of an automotive radar AA, in particular, on the mutual coupling coefficient between the channels and the SLL of the DP.Aim. To develop an optimal approach to constructing an AA topology in terms of reducing the level of mutual influence of adjacent array channels and obtaining a DP with specified characteristics.Materials and methods. To achieve the required parameters of the designed AA topology, the coplanar and microstrip lines were calculated using the finite element method and shield models.Results. An electrodynamic modeling of a millimetre-wave AA was carried out. The effect of coplanar transmission lines on the RP was shown. The features of applying shielding elements in the AA structure were investigated. Antenna patterns were obtained for both an AA designed based on coplanar transmission lines and that based on the use of shields. The conducted comparative analysis determined the parameters of the substrate optimal for achieving a better level of decoupling between adjacent antenna channels. The values of AA RP obtained during modeling were presented.Conclusion. The use of coplanar transmission lines can significantly reduce the SLL of the DP in the elevation plane. When implementing the module structure of an array (using of sub-arrays), the power dividers are realized. In this case, instead of coplanar lines, it is advisable to use specific microstrip constructions covered with shielding surfaces. In this case, the formation of a given amplitude-phase distribution over aperture is possible. A comparative analysis of the AA topologies with different substrates was carried out with the purpose of achieving improved decoupling. The obtained values of the coefficient of mutual influence of adjacent array channels correspond to those of modern AA of automotive radars. The methods of reducing the parasitic radiation of transmission lines were considered. The AA RP obtained via electrodynamic modeling were presented. The use of a thin substrate with a higher dielectric constant makes it possible to improve the AA characteristics.

When measuring low-power optical signals, it is necessary to ensure the highest reliability of the received data, which is especially important for single-photon communication channels. This determines the expediency of using photon counters as receiving modules for such channels. They are highly sensitive, but are characterized by data recording errors. Therefore, the purpose of this work was to investigate the influence of the intensity of the registered optical radiation J0 during the transmission of binary symbols “0” on the probability of registering symbols “1” at the output of the communication channel in the presence of symbols “0” at its input P(1/0).The statistical distributions of the mixture of the number of dark and signal pulses at the output of the photon counter during the registration of binary symbols “0” Pst0 (N ) were determined. To do this, a technique was used to reduce information loss. As a result, the minimum probability P(1/0) was reached.The probabilities P(1/0) were calculated for a communication channel containing a photon counter as a receiving module. This calculation was carried out at different values of the supply voltage of the avalanche photodetector U and the intensity of the optical signal used to transmit the binary symbols “0” J0 .The experimental results showed that with increasing optical signal intensity J0 , the dependences P(1/0) on J0 initially remain almost unchanged and retain a constant value. However, with a further increase in J0 , there is a linearly increasing character of the dependences P(1/0) on J0 . Moreover, with other equal reception parameters, such a character of the dependences P(1/0) on J0 begins to manifest itself at higher intensities of the optical signal J0 with an increase in the supply voltage of the avalanche photodetector.

For too long, many refined transportation models have focused solely on private and public transportation, assuming that bicycles only require simple models, such as bird flight distance or trips on horizontal tracks at a constant speed. This paper aims to study the impact of the road characteristics, such as road gradient, type of road and pavement surface of the road, on cyclists’ behavior using dedicated modules of MATSim. For that, we compare two approaches: a standard approach which does not consider the road characteristics, and a second approach that uses MATSim bicycle extension of Ziemke et al. The two approaches are analyzed over a sub-regional area around a district, focusing on a suburban city with an undulating relief made of average-to-steep hills. The focus is on the bicycle transportation model because the catchment area has a particularly challenging altitude profile and a large variety of roads, whether in type—from residential to national highway—or in pavement surface due to the number of green areas, such as parks and forests. This area is defined as a rather large 7 × 12 km, including five suburban cities in the South of Paris, France. A synthetic population of 126,000 agents was generated at a regional scale, with chains of activity made of work, education, shopping, leisure, restaurant and kindergarten, with activity-time choice, location choice and modal choice. We wanted to know how accurately a standard model of bicycle travels can be made with a 2D flat Earth assumption by comparing it to an algorithm extension that explicitly considers road characteristics in cyclists’ route choices. Our finding is that the MATSim bicycle extension model impacts mainly the long trips. Otherwise, the differences are minimal between the two models in terms of travel time and travel distance.

A photovoltaic system is a set of devices that take advantage of the energy produced by the sun and convert it into electrical energy. The impact produced by the possibility of using solar energy in a controlled manner for different uses and purposes has allowed the development of complete systems of transformation, storage and distribution of the energy produced with photovoltaic systems as appropriate. The production of electricity from solar radiation using solar cells and photovoltaic panels is an application that has yet fully disseminated in Third World countries, such as Ecuador. The generation of electric power will depend on the hours that the sun shines and affects the solar panel, the type and quantity of modules installed, orientation, inclination, solar radiation that reaches them, quality of the installation and the power that can be delivered to the user. Ecuador is in a privileged location in terms of solar radiation, because the equatorial line that divides the planet into two hemispheres passes through it, being almost perpendicular to the radiation it receives. In addition, this does not change during the year and there a constant angle of incidence, characteristics that give photovoltaic solar energy a great potential for use. In the investigation, an analysis of how the prices of photovoltaic systems affect the Province of Manabí, the methodology used has been the bibliographic review to know as much as possible about what replenishes the costs of photovoltaic systems.

The article presents description, advantages, and use of the Achievement Testing Software (ATS) developed by the authors – the teaching staff of the Military Diplomatic Academy named after Yevheniy Bereznyak – for cadets’ achievement testing in the educational process of higher military educational institutions. The authors prove the necessity of the ATS introduction into the educational process of such institutions due to the inability of existing computer testing software to fully satisfy their needs (high costs of technical maintenance, closed exit codes, and constant reliance on the Internet connection making it impossible to provide sensitive information security). Unlike other systems, the ATS is a reliable instrument of military educational control, capable of operating off-line. It was developed based on fundamental works in test theory, measurement and evaluation by Ukrainian and foreign scholars. It can be widely used for different types of achievement testing in higher military educational institutions: classroom; entrance or summative; and in any type of military course. The ATS rational use allows saving learning time and teachers’ effort, simultaneous engagement of many cadets in the training process, as well as objective measurement and evaluation through its automation. The ATS also provides capabilities of control over the educational process which allow curricula correction due to the constant feedback from cadets. Basically, the ATS performs two interrelated functions: test development and editing (by teachers); and academic achievement measuring (by cadets through the developed test items). The system can be easily installed on personal computers with Windows XP Professional SP2 operational system. The article describes in greater detail the procedure of operating in two modules: the Teacher’s Module and the Testing Module. Here, the ATS provides a user-friendly menu that can be easily navigated by pressing on buttons and selecting necessary options according to the instructions. The test entrance is password-protected, the test is encrypted, and the test score can be quickly viewed by cadets and teachers immediately after its completion. The ATS efficiency was proved through an experiment involving cadets of the Military Diplomatic Academy named after Yevheniy Bereznyak by demonstrating improvement in their performance.

For several decades development of methods for generating ultrashort pulses has been an independent urgent scientific and technical problem. There is a constant improvement both in the methods of such pulses receiving and in methods of their use. The aim of this work was to investigate the possibility of realizing the coordinated operation of two fundamentally different types of pump lasers for the femtosecond oscillator and amplifier based on one single-lamp laser head and to create on this basis a compact high-power femtosecond system with pulsed pumping and one power unit.The practical implementation of two types of pulsed lasers (nano- and picosecond ones operating, respectively, in Q-switch and modelock regime) on a single laser head with two active elements and one pump lamp is carried out. The required synchronization in time the pump pulse femtosecond amplifier formation and quasi-stationary region of generated pulses in the output radiation of a femtosecond Ti:sapphire is obtained.On this basis a compact, pulse pumped monoblock laser system has been developed that can generate femtosecond pulses with a duration of 50–150 fs with an energy up to 1 mJ and a high enough pulse repetition rate (up to 1 kHz which is determined by the type of laser head and pump unit used). In the developed laser system a compact scheme of a stretcher-compressor with a single common diffraction grating is used.Laser systems of this type characterized by a relatively low cost due to the use of a single power supply unit for simultaneous pumping of the amplifier and oscillator, as well as lower requirements for the quality of optical elements and usage conditions due to the pulse mode of operation, are quite practical and can be used both in scientific research in the field of ultra-high-speed kinetic spectroscopy and nonlinear optics, as well as in numerous technical applications, particular in the precision processing of materials, as optical simulators of the action of heavy charged particles in testing the radiation resistance of integrated circuits and electronic modules.

In recent years, society has faced the problem of constantly increasing energy consumption. This increases the rate of consumption of minerals. Another problem is the increase in harmful emissions into the Earth's atmosphere. Both problems pose tasks that need to be addressed first. The most promising sources of "clean" energy today are wind and solar energy. The rapid development of the industry leads to the constant generation of new ideas and new technical solutions both in the industry itself and in related areas of economic activity. The idea of distributed energy generation, which is still implemented by classical technologies, requires a similar application of renewable energy sources in the modern distribution of energy balance. Given the advantages and disadvantages of different types of wind turbines, it was determined that in the conditions of settlements it is advisable to use wind turbines with a vertical axis. This design allows for small size and dense mutual location to create compact and energy-independent power supply systems for construction equipment. Given the trends of global manufacturers to expand the range of construction equipment through models type zero emission - without harmful emissions into the atmosphere, will increase the number of batteries that will need to be serviced in enterprises. Such operations can be provided at the expense of distributed generation facilities, which are aggregated by "clean" energy sources. The introduction of the concept of modular equipment and modular systems of construction equipment allows to develop compact technical solutions in the form of mobile energy modules that can ensure energy independence of individual construction sites. Given the current geopolitical situation in the world, this concept of energy infrastructure can be applied not only in the field of construction.

A synchronous homopolar motor (SHM) has a salient pole passive rotor, an excitation winding located on the stator, and no permanent magnets, which ensures high reliability and makes this type of motor a good alternative to motors traditionally used in traction drives. However, there is no comparison between SHMs and conventional brushed synchronous machines for traction applications in the literature. In this paper, the performances of a wound rotor synchronous machine (WRSM) and SHM are theoretically compared at the operating points of a 370 kW dump mining truck drive traction curve that has a 10:1 constant power range in the field weakening region. The nine-phase motors under comparison have the same outer diameter of the stator lamination. Before comparison, both motor designs are optimized using the Nelder–Mead method to minimize the semiconductor inverter rated current and the operating cycle power loss. The main advantages of the WRSM, which was designed, are reduction in stator length, smaller losses, and smaller inverter. The reduction in the total stator length was by 1.23 times taking into account the winding end parts as well. Losses were reduced by 1.21 times for the same radius of the stator lamination. Finally, the cost of power modules of the inverter was decreased by 1.4 times. SHM is more reliable since its rotor does not have an excitation winding and a diode rectifier, as in a WRSM with a brushless exciter. In addition, SHM provides lower consumption of copper, which reduces the total mass and cost of active materials. This article also introduces a new term, “inverter utilization factor”, which can be useful, more informative than motor power factor, when comparing traction drives with different types of motors.

The problems of steady-state vibrations of functionally graded electroelastic rods for two types of polarization were investigated. The functional gradient is characterized by a change along the longitudinal coordinate of the isothermal elastic compliance and the piezoelectric modulus. The linear, quadratic and exponential laws of inhomogeneity are used in the work. To simulate damping, a model of a standard viscoelastic body was used, which is used within the framework of the concept of complex modules. For the numerical solution of the tasks set, the shooting method was applied. In order to verify the computational scheme, an exact solution of the problem is constructed for the case of constant properties. An analysis of the influence of the laws of inhomogeneity was carried out for laws that have the same mean integral values. The amplitude-frequency characteristics of current and conductivity are constructed. Antiresonances are investigated, the presence of two types is established, depending on the laws of inhomogeneity. An asymptotic analysis of the problem is performed for the case of low frequencies. It is shown that in the low-frequency range, the mechanical longitudinal stress depends only on the law of change in the piezoelectric modulus, while the displacement also depends on the law of change in elastic compliance. As a result of computational experiments, the features of the current's amplitude-frequency characteristic (AFC) structure in the vicinity of the second resonance were revealed. The AFC has a different quality factor depending on whether the compliance functions and the piezoelectric modulus have the same or different types of monotonicity. It is revealed that the first resonance from the frequency range under consideration has low sensitivity to the laws of inhomogeneity, and the third resonance is affected sufficiently by the inhomogeneity laws and can be used to determine the type of monotonicity when solving inverse problems on reconstructing properties.

Glucose sensors have been seen as a greater research interest because they are related to type I diabetes disease and because individuals diagnosed with this disease are more susceptible to complications, such as high blood pressure, high cholesterol levels, eye problems, and even death. Self-powered glucose biosensor (SPGB) based on biofuel cells (BFCs) combine the operational systems of a BFC and a biosensor in where the energy could be used for glucose quantification as an SPGB and operate the sensor without the need for any external energy source. This strategy could have certain advantages as the sensor is limited to two electrodes without applying an external voltage, it can be fed with the same biological fluid with the prospect of being implanted, the interferers can be decreased by not applying a potential, and a single concentration of the substrate is sufficient to calibrate the system. In this context, the microfluidics has proven to be an important technology in the area of biosensors and has been used to transport or mix the sample, this device using different and independent electrolytes depends on the enzyme to improve performance, reported in the work group before. The glucose oxidase (GOx) bioanode was prepared using dimethylferrocene-modified linear polyethyleneimine (FcMe2-LPEI). On other hand, the laccase (Lc) biocathode was prepared using anthracene-modified MWCNTs (AnMWCNTs). The microfluidic device consisted of two parts fabricated from PMMA using a micromilling system CNC (Computer Numerical Control). For the calibration curve, it was used as anolyte PBS pH 7.4 (0.1 M) using 0, 1, 3, 5, 7, 10, and 20 mM glucose and PBS pH 5.6 (0.1 M). In the case of the real samples, the anolyte was blood or serum, and the catholyte was PBS pH 5.6. The electrolytes were fed using a syringe pump (Kd Scientific) at a flow rate of 3 mL h-1. Polarization curves for microfluidic self-powered glucose biosensing (m-SPGB) were obtained by linear polarization from OCP to 0 V at 2 mV s-1. All experiments were performed in triplicate, and the average ± standard deviation was reported. The interferers evaluated in the m-SPGB were 0.025 mM ascorbic acid (AA), 0.1 mM uric acid (UA) and 0.5 mM dopamine (DA) and arranged in the anolyte prepared with PBS pH 7.4 (0.1 M). The architecture of the m-SPGB device is defined mainly by two modules: the sensor unit and the Wi-Fi transmission/reception unit. The electrochemical characterization of the FcMe2-LPEI/GOx bioanode and AnMWCNT/Lc biocathode immobilized on TCP was performed by cyclic voltammetry (CV), showing activity towards glucose oxidation and oxygen reduction respectively. Confirming the electrocatalytic activity of the bioelectrodes, both were used in the m-SPGB using PBS pH 7.4 and different concentrations of glucose in the anolyte and PBS pH 5.6 as the catholyte. Under these operating conditions, the average OCP was 0.81 ± 0.021 V constant voltage at the different glucose concentrations evaluated. The result is important because the system is sensitive to low glucose concentrations of 1 mM and 3 mM, and an increase in the current is observed, differentiating very well in each concentration from 0 to 20 mM. Plots of the comparative responses to the increase in current and power in the m-SPGB versus glucose concentration. The linear ranges of both parameters were 0–10 mM with correlation coefficients (R2) of 0.9907 and 0.9913, respectively; in both cases, they were within the range to measure blood or serum glucose. On the other hand, the sensitivity was higher, at a current of 1.24 μA mM-1, while the power was 0.19 μW mM-1, with a better limit of detection (LOD) of 0.48 mM vs. 0.76 mM of the power. The electronic device connected to the m-SPGB was used for the quantification of the different glucose concentrations, sending the wireless-type information to a laptop for processing and more efficient interpretation without the need for a potentiostat/galvanostat and the connection between the electronic device for sending and processing the information and the microfluidic device where the enzymatic reactions are carried out. In summary, the results, in general, are comparable and superior to other SPGBs published by other authors and show their importance in using a microfluidic system.

Введение. Самообразование является для взрослого умением, необходимым для полноценной жизнедеятельности в условиях постоянной неопределенности. Данный вид деятельности неразрывно связан с субъектной позицией, авторским отношением к своему образованию и жизни в целом. Этапность формирования субъектности включает школьный и вузовский период, построение индивидуального образовательного пути зависит от сформированной готовности к самообразованию, наличия соответствующего опыта. Поддержку в развитии умения самообразования возможно получить в формальном образовании, в сообществах неформального образования, а также с помощью просветительских информальных ресурсов. Практики этих видов непрерывного образования составляют пространство образования взрослых, реализующее вариативность поддержки.Цель – проанализировать имеющиеся в пространстве образования взрослых ресурсы поддержки развития умения самообразования, а также дефициты в данной области.Материал и методы. Материалом послужили теоретические источники и практики обучения самообразовательной деятельности и развития умения самообразования, интервью адъюнктов заочной формы обучения Санкт-Петербургского университета МВД России.Результаты и обсуждение. Тема подготовки к самообразовательной деятельности достаточно исследована. В советский период были описаны способы и приемы соответствующего обучения в школьный период. В настоящее время среднее образование решает задачу, включая ребят в исследовательскую деятельность, развивается движение персонализированного образования. Однако степень продвижения в данном вопросе остается неудовлетворительной. Проблематизируется подготовка педагогов к самообразовательной деятельности, так как без наличия подобного умения невозможно организовать развитие обучающихся. В организациях высшего образования выявленная неразвитость самообразовательной деятельности может быть компенсирована соответствующими программами психолого-педагогической поддержки. Необходимы специальные педагогические умения у преподавателей высшего образования. В области неформального образования взрослый имеет возможность развить умение самообразования, включившись в самоорганизующиеся сообщества при возникающей потребности возобновить познание. Однако напряженность его жизнедеятельности нередко препятствует этому. Ресурс информального образования (просветительский контент) не вполне актуален. Востребованы офлайн-взаимодействие с ментором, консультантом, стратегия быстрого сопровождения возобновления образовательной деятельности. Важен аспект психологической поддержки. Заключение. Проблема развития умения самообразования взрослых решается при реализации триединства формального, неформального и информального видов непрерывного образования как структуры, раскрывающей варианты устранения дефицита знаний и умений: от практико-ориентированных модулей в образовательных программах формального образования, взаимообучения в самоорганизующихся сообществах неформального образования до навигации информальных источников. Introduction. Self-education is for an adult a skill necessary for a full-fledged life in conditions of constant uncertainty. This type of activity is inextricably linked with the subject position, the author’s attitude to his education and life in general. The stage-by-stage formation of subjectness includes the school and university period, the further construction of an individual educational path depends on the formed readiness for self-education, the availability of relevant experience. Support in the development of self-education skills can be obtained in formal education, in non-formal education communities, as well as in educational informational resources. These practices of these types of continuing education constitute the space of adult education that implements the variability of support.The aim of the research is to analyze the resources available in the space of adult education to support the development of self-education skills, as well as deficits in this area.Material and methods. The material was the theoretical sources and practices of teaching self-education and the development of the ability of self-education, interviews with part-time adjuncts of St. Petersburg University of the Ministry of Internal Affairs of Russia.Results and discussion. The topic of teaching self-educational activity has been sufficiently studied. In the Soviet period, the methods and techniques of appropriate teaching during the school period were described. Currently, secondary education solves the problem by engaging children in research activities, so it leads to the progress of personalized education development. However, progress on this issue remains unsatisfactory. The preparation of teachers for self-educational activity is problematized, because without such skills, it is impossible to organize the development of students. In organizations of higher education, the revealed underdevelopment of self-educational activity can be compensated by appropriate programs of psychological and pedagogical support. Teachers need special pedagogical skills. In the field of non-formal education, an adult has the opportunity to develop the ability of self-education by joining self-organizing communities when the need arises to renew knowledge. However, the intensity of his life activity often prevents this. The resource of informal education (educational content) is not quite relevant. Live offline interaction with a mentor, consultant, a strategy for quick support of the resumption of educational activities are in demand. The aspect of psychological support is important.Conclusion. The problem of developing the ability to self-educate adults is seen as being solved by implementing the trinity of formal, non-formal and informal types of lifelong education as a structure that reveals options for eliminating the deficit of knowledge and skills: from practice-oriented modules in educational programs of formal education, mutual learning in self-organizing communities of non-formal education before navigating informal sources.

Constant demand for new naval and commercial vessels has created special conditions for the Government-owned Soviet shipbuilding industry, which practically has not been affected by the world shipbuilding crisis. On the other hand, such chronic diseases of the centralized economy as lack of incentive, material shortage and poor workmanship cause specific problems for ship construction. Being technically and financially unable to rapidly improve the overall technology level and performance of the entire industry, the Soviets concentrate their efforts on certain important areas and have achieved significant results, especially in welding and cutting titanium and aluminum alloys, modular production methods, standardization, etc. All productivity improvement efforts are supported by an army of highly educated engineers and scientists at shipyards, in multiple scientific, research and design institutions. Discussion Edwin J. Petersen, Todd Pacific Shipyards Three years ago I addressed the Ship Production Symposium as chairman of the Ship Production Committee and outlined some major factors which had contributed to the U.S. shipbuilding industry's remarkable achievements in building and maintaining the world's largest naval and merchant fleets during the five-year period starting just before World War II. The factors were as follows:There was a national commitment to get the job done. The shipbuilding industry was recognized as a needed national resource. There was a dependable workload. Standardization was extensively and effectively utilized. Shipbuilding work was effectively organized. Although these lessons appear to have been lost by our Government since World War II, the paper indicates that the Soviet Union has picked up these principles and has applied them very well to its current shipbuilding program. The paper also gives testimony to the observation that the Soviet Government recognizes the strategic and economic importance of a strong merchant fleet as well as a powerful naval fleet. In reviewing the paper, I found great similarity between the Soviet shipbuilding productivity improvement efforts and our own efforts or goals under the National Shipbuilding Research Program in the following areas:welding technology, flexible automation (robotics), application of group technology, standardization, facilities development, and education and training. In some areas, the Soviet Union appears to be well ahead of the United States in improving the shipbuilding process. Most noteworthy among these is the stable long-and medium-range planning that is possible by virtue of the use and adherence to the "Table of Vessel Classes." It will be obvious to most who hear and read these comments what a vast and significant improvement in shipbuilding costs and schedules could be achieved with a relatively dependable 15year master ship procurement plan for the U.S. naval and merchant fleets. Another area where the Soviet Union appears to lead the United States is in the integration of ship component suppliers into the shipbuilding process. This has been recognized as a vital step by the National Shipbuilding Research Program, but so far we have not made significant progress. A necessary prerequisite for this "supplier integration" is extensive standardization of ship components, yet another area in which the Soviets have achieved significantly greater progress than we have. Additional areas of Soviet advantage are the presence of a multilevel research and development infrastructure well supported by highly educated scientists, engineering and technical personnel; and better integration of formally educated engineering and technical personnel into the ship production process. In his conclusion, the author lists a number of problems facing the Soviet economy that adversely affect shipbuilding productivity. Perhaps behind this listing we can delve out some potential U.S. shipbuilding advantages. First, production systems in U.S. shipyards (with the possible exception of naval shipyards) are probably more flexible and adjustable to meet new circumstances as a consequence of not being constrained by a burdensome centralized bureaucracy, as is the case with Soviet shipyards. Next, such initiatives as the Ship Production Committee's "Human Resources Innovation" projects stand a better chance of achieving product-oriented "production team" relationship among labor, management, and technical personnel than the more rigid Soviet system, especially in view of the ability of U.S. shipyard management to offer meaningful financial incentives without the kind of bureaucratic constraints imposed in the Soviet system. Finally, the current U.S. Navy/shipbuilding industry cooperative effort to develop a common engineering database should lead to a highly integrated and disciplined ship design, construction, operation, and maintenance system for naval ships (and subsequently for commercial ships) that will ultimately restore the U.S. shipbuilding process to a leadership position in the world marketplace (additional references [16] and [17]).On that tentatively positive note, it seems fitting to close this discussion with a question: Is the author aware of any similar Soviet effort to develop an integrated computer-aided design, production and logistics support system? The author is to be congratulated on an excellent, comprehensive insight into the Soviet shipbuilding process and productivity improvement efforts that should give us all adequate cause not to be complacent in our own efforts. Peter M. Palermo, Naval Sea Systems Command The author presents an interesting paper that unfortunately leaves this reader with a number of unanswered questions. The paper is a paradox. It depicts a system consisting of a highly educated work force, advanced fabrication processes including the use of standardized hull modules, sophisticated materials and welding processes, and yet in the author's words they suffer from "low productivity, poor product quality, . . . and the rigid production systems which resists the introduction of new ideas." Is it possible that incentive, motivation, and morale play an equally significant role in achieving quality and producibility advances? Can the author discuss underlying reasons for quality problems in particular—or can we assume that the learning curves of Figs. 5 and Fig. 6 are representative of quality improvement curves? It has been my general impression that quality will improve with application of high-tech fabrication procedures, enclosed fabrication ways, availability of highly educated welding engineers on the building ways, and that productivity would improve with the implementation of modular or zone outfitting techniques coupled with the quality improvements. Can the author give his impressions of the impact of these innovations in the U.S. shipbuilding industry vis-a-vis the Soviet industry? Many of the welding processes cited in the paper are also familiar to the free world, with certain notable exceptions concerning application in Navy shipbuilding. For example, (1) electroslag welding is generally confined to single-pass welding of heavy plates; application to thinner plates—l1/4 in. and less when certified—would permit its use in more applications than heretofore. (2) Electron beam welding is generally restricted to high-technology machinery parts; vacuum chamber size restricts its use for larger components (thus it must be assumed that the Soviets have solved the vacuum chamber problem or have much larger chambers). (3) Likewise, laser welding has had limited use in U.S. shipbuilding. An interesting theme that runs throughout the paper, but is not explicitly addressed, is the quality of Soviet ship fitting. The use of high-tech welding processes and the mention of "remote controlled tooling for welding and X-ray testing the butt, and for following painting" imply significant ship fitting capabilities for fitting and positioning. This is particularly true if modules are built in one facility, outfitted and assembled elsewhere depending on the type of ship required. Any comments concerning Soviet ship fitting capabilities would be appreciated. The discussion on modular construction seems to indicate that the Soviets have a "standard hull module" that is used for different types of vessels, and if the use of these hull modules permit increasing hull length without changes to the fore and aft ends, it can be assumed that they are based on a standard structural design. That being the case, the midship structure will be overdesigned for many applications and optimally designed for very few. Recognizing that the initial additional cost for such a piece of hull structure is relatively minimal, it cannot be forgotten that the lifecycle costs for transporting unnecessary hull weight around can have significant fuel cost impacts. If I perceived the modular construction approach correctly, then I am truly intrigued concerning the methods for handling the distributive systems. In particular, during conversion when the ship is lengthened, how are the electrical, fluid, communications, and other distributive systems broken down, reassembled and tested? "Quick connect couplings" for these type systems at the module breaks is one particular area where economies can be achieved when zone construction methods become the order of the day in U.S. Navy ships. The author's comments in this regard would be most welcome. The design process as presented is somewhat different than U.S. Navy practice. In U.S. practice, Preliminary and Contract design are developed by the Navy. Detail design, the development of the working drawings, is conducted by the lead shipbuilder. While the detail design drawings can be used by follow shipbuilders, flexibility is permitted to facilitate unique shipbuilding or outfitting procedures. Even the contract drawings supplied by the Navy can be modified— upon Navy approval—to permit application of unique shipbuilder capabilities. The large number of college-trained personnel entering the Soviet shipbuilding and allied fields annually is mind-boggling. According to the author's estimation, a minimum of about 6500 college graduates—5000 of which have M.S. degrees—enter these fields each year. It would be most interesting to see a breakdown of these figures—in particular, how many naval architects and welding engineers are included in these figures? These are disciplines with relatively few personnel entering the Navy design and shipbuilding field today. For example, in 1985 in all U.S. colleges and universities, there were only 928 graduates (B.S., M.S. and Ph.D.) in marine, naval architecture and ocean engineering and only 1872 graduates in materials and metallurgy. The number of these graduates that entered the U.S. shipbuilding field is unknown. Again, the author is to be congratulated for providing a very thought-provoking paper. Frank J. Long, Win/Win Strategies This paper serves not only as a chronicle of some of the productivity improvement efforts in Soviet shipbuilding but also as an important reminder of the fruits of those efforts. While most Americans have an appreciation of the strengths of the Russian Navy, this paper serves to bring into clearer focus the Russians' entire maritime might in its naval, commercial, and fishing fleets. Indeed, no other nation on earth has a greater maritime capability. It is generally acknowledged that the Soviet Navy is the largest in the world. When considering the fact that the commercial and fishing fleets are, in many military respects, arms of the naval fleet, we can more fully appreciate how awesome Soviet maritime power truly is. The expansion of its maritime capabilities is simply another but highly significant aspect of Soviet worldwide ambitions. The development and updating of "Setka Typov Su dov" (Table of Vessel Classes), which the author describes is a classic example of the Soviet planning process. As the author states, "A mighty fishing and commercial fleet was built in accordance with a 'Setka' which was originally developed in the 1960's. And an even more impressive example is the rapid expansion of the Soviet Navy." In my opinion it is not mere coincidence that the Russians embarked on this course in the 1960's. That was the beginning of the coldest of cold war periods—Francis Gary Power's U-2 plane was downed by the Russians on May 1, 1960; the mid-May 1960 Four Power Geneva Summit was a bust; the Berlin Wall was erected in 1961 and, in 1962, we had the Cuban Missile Crisis. The United States maritime embargo capability in that crisis undoubtedly influenced the Soviet's planning process. It is a natural and normal function of a state-controlled economy with its state-controlled industries to act to bring about the controlled productivity improvement developments in exactly the key areas discussed in the author's paper. As the author states, "All innovations at Soviet shipyards have originated at two main sources:domestic development andadaptation of new ideas introduced by leading foreign yards, or most likely a combination of both. Soviet shipbuilders are very fast learners; moreover, their own experience is quite substantial." The Ship Production Committee of SNAME has organized its panels to conduct research in many of these same areas for productivity improvement purposes. For example, addressing the areas of technology and equipment are Panels SP-1 and 3, Shipbuilding Facilities and Environmental Effects, and Panel SP-7, Shipbuilding Welding. Shipbuilding methods are the province of SP-2; outfitting and production aids and engineering and scientific support are the province of SP-4, Design Production Integration. As I read through the descriptions of the processes that led to the productivity improvements, I was hoping to learn more about the organizational structure of Soviet shipyards, the managerial hierarchy and how work is organized by function or by craft in the shipyard. (I would assume that for all intents and purposes, all Russian yards are organized in the same way.) American shipyard management is wedded to the notion that American shipbuilding suffers immeasurably from a productivity standpoint because of limitations on management's ability to assign workers across craft lines. It is unlikely that this limitation exists in Soviet shipyards. If it does not, how is the unfettered right of assignment optimized? What are the tangible, measurable results? I believe it would have been helpful, also, for the author to have dedicated some of the paper to one of the most important factors in improvement in the labor-intensive shipbuilding industry—the shipyard worker. There are several references to worker problems—absenteeism, labor shortage, poor workmanship, and labor discipline. The reader is left with the impression that the Russians believe that either those are unsolvable problems or have a priority ranking significantly inferior to the organizational, technical, and design efforts discussed. As a case in point, the author devotes a complete section to engineering education and professional training but makes no mention of education or training programs for blue-collar workers. It would seem that a paper on productivity improvement efforts in Soviet shipbuilding would address this most important element. My guess is that the Russians have considerable such efforts underway and it would be beneficial for us to learn of them.

Introduction. A revision of syntaxa was carried out within the framework of the classification of the Brown-Blanquet school identified in the Russian Arctic. A geodatabase (GDB) and GIS, which include several interconnected main modules (see: Matveyeva et al., 2019a, b), with information on species composition, structure, ecology, and geography of syntaxa of all levels, integrated in these databases, became the basis of the presented checklist. This is the first result of compiling information on the vegetation classification, performed with the prospect to produce Prodromus of syntaxa, identified in this territory, with detailed information (character/differential/diagnostic species, ecology, zonal position, geography, bibliography), available in the GDB. It will be in time included in the Prodromus and later will become the basis for a volume in multivolume series on the vegetation of the Russian Federation (see: Plugatar et al., 2020). Territory. The checklist contains information on syntaxa established in the Russian Arctic within the boundaries of the Circumpolar Arctic Vegetation Map (hereafter CAVM) (CAVM Team, et al., 2003; Walker et al., 2005; Raynolds et al., 2019), as well as on the Barents Sea coast of the Kola Peninsula, which is referred to the tundra zone in accordance with the zonation of the Russian Arctic flat territory (see: Matveyeva, 1998). The list includes syntaxa found north of the treeline — in the tundra zone (subzones of the southern, typical, and arctic tundra) and polar deserts.1 Hence, it follows that there are no syntaxa from the forest-tundra as well as those above the treeline in the mountains adjacent to the tundra zone (Putorana and Anabarskoe plateaus). The syntaxa from the territory of the «Russian Arctic» (Barentsburg, Pyramida) on the West Spitsbergen Island (Spitsbergen archipelago) are also not taken into account (their positioning is logical in Spitzbergern syntaxonomy). History. The study of the Russian Arctic plant cover began in the second third of the XIXth century in the north-east of the European Russia (Schrenk, 1855) and in Siberia on the Taymyr Peninsula (Middendorf, 1860–1867). After a significant break, it continued in the USSR in the pre-war time and intensified after the end of the Great Patriotic War. The most intense (both in the size of the studied areas and the numbers and duration of the field works) was the period from the mid-1960s to the early 1990s. Researchers working both in other zones and in the Arctic processed the obtained data in accordance with the approaches of the dominant classification, and the relevés were either not published or presented in a small (4–5) number for association. Despite the obvious limitations of this approach, there were published (both in the form of text with listing of few dominants and with relevé tables) both general (Gorodkov, 1935) and regional (Andreev, 1932; Bogdanovskaya-Giyenef, 1938; Smirnova, 1938; Dedov, 2006 [1940]; Aleksandrova, 1956, 1983; Gorodkov, 1956, 1958 a, b; Katenin, 1972) classifications, and checklists — a draft classification of vegetation of the whole Arctic (Aleksandrova, 1979) and classification of Taymyr vegetation (Matveyeva, 1985). In the late 1980s, Russian phytosociologists turned to the Brown-Blanquet floristic (= floristic-sociological (Theurillat et al., 2021), or ecological-floristic (Mirkin, Naumova, 2014)), classification system as the most conceptually substantiated, with generally accepted rules for describing communities in the field and the technique of relevé tabular processing, and also with clear rules for the formation of syntaxon names. In this system, the obligatory publication of the original data and the requirements for its validity when describing the basic syntaxon are strictly postulated, which provides an objective comparison and classification of any plant community types, in whatever system these data are not submitted. Just as it is impossible to imagine the development of taxonomy without the existence of herbarium collections, so it should be an axiom for phytosociologists that since the relevé is the only documentary reflection of a natural phenomenon named «plant community» (Matveyeva, 2008), it should be available for analysis to all syntaxonomists. Since the second decade of the XXth century, the followers of the Braun-Blanquet system have published thousands of relevés from different regions of the globe, which made it possible to produce a unified classification of vegetation from the Arctic to the tropics and its constant replenishment. Currently, the process of creating electronic databases (archives) of relevés, including the Arctic Vegetation Archive, which accumulates information on circumpolar vegetation is accumulated, is actively underway (Walker et al., 2018). The starting point when Russian tundra experts began to work consistently, following the principles of this classification, is the first International Meeting on the Classification and Mapping of Arctic Vegetation, which took place in 1992 in Boulder, CO (USA). For the publication of its data, a special issue of the Journal of Vegetation Science (1994, Vol. 5, N 6) named «Circumpolar arctic vegetation» (where 4 papers by Russian syntaxonomists were published) was provided. After 1992, when the intensity of field works decreased sharply, the number of publications with complete characteristics of the communities of the Russian Arctic increased rapidly.The proposed checklist of syntaxa is the result of this almost 30-year acti­vity. The checklist structure. The arrangement of syntaxa of class rank is mainly the same as in the EuroVegChecklist — hereafter EVC (Mucina et al., 2016): zonal and intrazonal communities of the polar desert zone (one class); zonal (one class) and landscape-forming intrazonal (five classes) communities of the tundra zone; intrazonal communities (13 classes), united into groups according to the gradients of moisture, snow depth and soil mechanical composition. A syntaxon is represented as follows: — higher units of the rank Class/Order/Allian­ce (Suballiance): number (for Class), abbreviated rank in English (Cl., Ord., All. (Suball.)), in square brackets — code (if any) from EVC (Mucina et al., 2016); full name, author(s) and year; below is a brief description in two languages: English — in general as in the cited paper with some corrections due to the specificity in syntaxon geography and ecology in the Asian part; Russian — partly in accordance with the English version and/or to Prodromus of higher vegetation units of Russia (Ermakov, 2012), sometimes with minor corrections or clarifications. For new orders and alliances within the zonal tundra class differential taxon combinations are listed; — syntaxa of the rank Association, Community Type, Community, established on the territory of the Russian Arctic: abbreviated rank in English (Ass., Com. Type, Com.), name, author(s) and year (besides association, the cited papers are included in the Refe­rences). If syntaxon was previously described by European/American authors outside the Russian Fede­ration, the link to the publication, where it was found in the Russian Arctic, is placed in brackets. The ­arrangement of associations is alphabetical; — syntaxa of units of a lower (within association) rank (subassociation and vicariant, variant, subvariant, facies): abbreviated rank in English (subass. and vicar., var., subvar., fac.), name, in brackets author, year (besides subassociation, the cited papers are included in the References). The arrangement of the syntaxa is as follows: typicum(-cal, -ca), inops, then alphabetically. For subass. typicum authors are not listed (Theurillat et al., 2021), but if it was described by another author and/or in another paper, then the link to it is given in brackets and the paper is included in the References. All names of syntaxa are given in the author’s edition (as it was published), including the endings of a typical syntaxon within an association (subassociation, vicariant, variant, facia) — typicum, typical, typica. In different papers, there are two English spellings of Russian surnames: Aleksandrova/Alexandrova, Andreev/Andreyev, Bogdanovskaya-Giyenef/Bogdanovskaya-Gienef, Pristyazhnyuk/Prystyazhnyuk, Savich/Savič. A uniform (the first one) spelling of the surname is used here. If there was something that caused a disagreement with the author’s decision (including the assignment of an association to a syntaxon of a higher rank), there is a superscript number before the syntaxon name, or before the author’s surname (when it is in brackets), referring to critical comments. Critical comments. 1 – The name is invalid or needs change because: 1a – no reference to the nomenclature type; 1b – published ineffectively (names published as ‘manuscript’ or ‘unpublished’); 1c – not accompanied by a sufficient diagnosis, no tables with original relevés; 1d – suggested by the author as preliminary; 1e – not obvious from what species syntaxon epithet is formed and it cannot be extracted from the diagnosis and/or tables); 1f – syntaxon with the same name was described earlier (including the case of inversion); 1g – the form of the syntaxon name does not correspond to Art. 10 of «International Code of Phytosociological Nomenclature» — hereafter ICPN (Theurillat et al., 2021); 1h – the given nomenclature type belongs to a different syntaxon, validation does not correspond to ICPN; 1i – the relevé chosen as an association or subassociation nomenclature type does not contain the name-giving taxon of this syntaxon; 1j – there is a subspecies in the original diagnosis and in the tables, while in the syntaxon name the species name is used; 1k – the nomenclature type is given for 2 variants of the vicariant, among which there is no tyicum one; 1l – published or validated in 2002 or later with no indication of novelty (like, Ass. nov.). 2 – the author(s) did not place the syntaxon among the higher units. 3 – the author(s) placed the syntaxon in other higher units than suggested in this list. 4 – the syntaxon was renamed due to a change in its rank; in this checklist it is also given under a new name. 5 – the syntaxon is described by the author(s) in the Community rank but is assigned within the known association as a unit of it internal division. 6 – the author(s) assigned the syntaxon to this class with a question. 7 – the author(s) unreasonably (noted in literature) placed the communities in given syntaxon that needs revision. 8 – in the EVC there is only one author, while in the original source there are two. 9 – it is written that the title proposed by the first author was valid, but according to Principle II of the ICPN it is not. 10 – the author(s) of the syntaxon is(are) incorrect: the syntaxonomic units originally described in the framework of the ecological-physiognomic classification are invalid in accordance with Principle II (Art. 3d ICPN), and have been validated by subsequent authors. 11 – the author(s) assigned the syntaxon to this class/order, but did not refer to an alliance or placed in the alliance other than that proposed in this checklist. 12 – the author(s) attributed the syntaxon to this alliance, but as part of a different class/order, or not attributed to the class/order. 13 – the author(s) changed the rank of the syntaxon in comparison with the original description. 14 – the spelling of the syntaxon name does not correspond to the rules of the ICPN; the correct name [recte[ is given in square brackets. 15 – in the EVC the alliance is placed in another order. 16 – the author(s) of the syntaxon are incorrect, the first author (in brackets) did not give such a name, or incorrect year. 17 – the author(s) of the syntaxon incorrectly cited, priority belongs to other author(s) who published the name earlier and/or effectively. 18 – in the EVC the alliance is placed in synonyms for another alliance, which name was changed but not yet approved (nom. mut. propos). THE CHECKLIST — see the main text. Brief analysis of the composition. The checklist is based upon analysis of more than 70 papers, professionally reviewed and published, which contain more than 6,000 geobotanical relevés, that make available information on the composition and structure of 734 syntaxa ranging from association/community type/community to facies. At the mid-2021, the checklist includes 241 associations (152 subassociations and 25 vicariants, 190 variants and 61 subvariants, 13 facies), 35 types of communities and 17 communities from 62 alliances (6 suballiances), 33 orders and 20 classes. Most of the higher rank units — Class/Order/Alliance — are taken from the classification of vegetation in Europe (Mucina et al., 2016) Class. Of the 20 classes, 19 are in EVC (Mucina et al., 2016), to which we have assigned 207 associations, although we do not consider this decision final. A new class for zonal tundra vegetation Carici arctisibiricae–Hylocomietea alaskani class. prov.2 so far is left in the provisional status. Conventionally is used the class Betulo carpaticae–Alnetea viridis which contains willow scrubs in the valleys and on the interfluves. Order. Of the 33 orders 29 are in EVC. Among the known ones there is formally described Salicetalia glauco-lanatae so far located in Betulo carpaticae–Alnetea viridis. Three orders (Arctophiletalia fulvae; Chamerio–Betuletalia nanae; Schulzio crini­tae–Aquilegietalia glandulosae) were described by Russian authors. Three new orders (Salici polaris–Hylocomietalia alaskani ord. nov. prov., Caricetalia arctisibiricae-lugentis ord. nov. prov., Eriophoretalia vaginati ord. nov. prov.) are suggested here in the provisional status, for establishing within the tund­ra zonal class Carici arctisibiricae–Hylocomietea alaskani class. prov. Nameless order is proposed for communities dominated by mesophytic arctic and/or arcto­alpine herbs often with dwarf shrubs (Salix arctica/polaris/reticulata, Dryas octopetala/punctata) and few mosses on the southern slopes of hills and high river banks in the tundra zone of Eurasia; conventionally it is placed in the Mulgedio–Aconitetea. According to both species composition and habitat the order Arabidetalia caeruleae is moved from Thlaspietea rotundifolii (as in EVC) into Salicetea herbaceae. Alliance. Of the 62 alliances 36 are in EVC, 5 of which (Arctophilion fulvae; Caricion stantis, Chamerio angustifolii–Matricarion hookeri; Dryado octopetalae–Caricion arctisibiricae, Polemonio acutiflorum–Veratrion lobeliani) are described by Russian authors. Alliance Oxytropidion nigrescentis, validated in 1998 (Matveyeva 1998, p. 81), is given as valid. The following 8 alliances are valid: Aulacomnio palustris–Caricion rariflorae, Polemonio acutiflorum–Salicion glaucae and Rubo chamaemori–Dicranion elongati on the European North, Carici concoloris–Aulacomnion turgidi, Oxytropido sordidae–Tanacetion bipinnati in Siberia, Androsaco arctisibiricae–Aconogonion laxmannii, Aulacomnio turgidi–Salicion glaucae, Salici pulchrae–Caricion lugentis on Chukotka. Another 7 alliances have invalid names (suggested as preliminary, no nomenclature type was chosen, etc.). For 6 of these validation is necessary and quite simple. An exeption is the alliance Luzulo–Festucion rubrae (Ektova, Ermokhina, 2012), with all invalid associations (no both relevés and diagnoses); after the later are validated they logically could be placed in Loiseleurio-Arctostaphylion. Within the tundra zonal class the alliance Salici polaris–Hylocomion alaskani all. nov. is formally described and the alliances Cassiopo tetragonae–Eriophorion vaginati all. nov. prov. and Poo arcticae–Calamagrostion holmii all. nov. prov. are proposed provisionally. It is recommended to establish 6 alliances (in the checklist with no name) in classes Drabo corymbosae–Papaveretea dahliani (3), Betulo carpaticae–Alnetea viridis (1), Thlaspietea rotundifolii (1) and Mulgedio-Aconitetea (1). Syntaxonomic decisions, other than those derived from the EVC, are made on the positions of 4 alliances within the higher-rank units: Caricion stantis was moved from Sphagno warnstorfii–Tomentypnetalia to Caricetalia fuscae; Dryado octopetalae–Caricion arctisibiricae — from Carici rupestris–Kobresietea bellardii to Carici arctisibiricae–Hylocomietea alaskani class. prov. (see: Lavrinenko, Lavrinenko, 2018a); Potentillo–Polygonion vivipari is recognized (Koroleva et al., 2019) as different from Kobresio-Dryadion, synonym with which it is given in the EVC; the Honckenyo–Leymion arenarii is used compare to the EVC where it is the synonym of Agropyro–Honckenyion peploidis nom. mut. propos. Compared to the author’s decision, the alliance Carici concoloris–Aulacomnion turgidi from Loiseleurio procumbentis–Vaccinietea is moved to Carici arctisibiricae–Hylocomietea alaskani class. prov. Suballiance. Of the 6 suballiances 4 (Androsaco arctisibiricae–Aconogonenion laxmannii; Astragalo pseudadsurgentis–Calamagrostienion purpurascentis; Caricenion rariflorae; Oxytropido vassilczenkoi–Dryadenion punctatae) are valid, and two (Anemono parviflorae–Salicenion and Pediculari lapponicae–Salicenion) require validation. The suballiance Caricenion rariflorae placed in the checklist in Scheuchzerion palustris was originally established within the Sphagnion baltici, which in the EVC is synonymous with the first name. Association. Of 241 associations only 34 are known outside the Russian Arctic, and the remaining 207 are new. The known ones are mainly on coastal bio­topes — marshes (15) and dunes (3) — and extremely wet habitats (9). There are 4 associations described earlier in Europe within the large landscape-forming classes (Dryadetum octopetalae, Empetro–Betuletum nanae, Loiseleurio-Diapensietum, Phyllodoco–Vaccinietum myrtilli) which distribution ranges are extended to the European North of Russia, and 3 within small intrazonal classes (Geranietum sylvatici, Potentillo crantzii–Polygonetum vivipari, and Rumici–Salicetum lapponi) found on Kola Peninsula. Only 2 associations, described by European (Dryado–Cassiopetum tetragonae) and American syntaxonomists (Sphagno–Eriophoretum vaginati), occur in the Asian part of the Russian Arctic (with new subunits within both). The most association-rich are 8 main classes. The two zonal classes include Drabo corymbosae–Papaveretea dahliani (20 associations) in the polar desert zone and Carici arctisibiricae–Hylocomietea alaskani class. prov. (34 associations) in the tundra zone — 54 in total. 129 associations are identified in the 6 main classes of intrazonal vegetation: Be­tulo carpaticae–Alnetea viridis (29 associations) Loiseleurio procumbentis–Vaccinietea 1960 (22 associations), Carici rupestris–Kobresietea (21 associations), Salicetea herbaceae (16), Scheuchzerio palustris–Caricetea fuscae (25 associations); Juncetea maritimi (16 associations) — 187 in total. The vegetation of other 12 classes is described locally geographically and selectively syntaxonomically. 37 associations were not assigned to any of the known classes. This, in particular, was the case with the vegetation of the polar desert zone (Matveyeva, 2006) before Drabo corymbosae–Papaveretea dahliani class was described in 2016. But it also happened when deciding to assign an association to some well-known class, authors stressed that they did this forcibly in the absence of an adequate unit. For example, before the proposal, albeit provisionally, of the class Carici arctisibiricae–Hylocomietea alaskanii class. prov., even zonal communities from the Arctic tundra subzone were placed in the Loiseleurio procumbentis–Vaccinietea class accentuating that they do not contain a single characteristic species of this class (Kholod, 2007). Community type is distinguished when author does not establish new association due to the small number (less than 10) relevés in one location, leaving this for the future There are 35 such units, most of which (9) are in the Drabo corymbosae–Papaveretea dahliani in the polar desert zone. It is worth noting two points: 1) almost never Community types reach the association status; 2) not all authors are stopped by a small number of relevés, when naming syntaxa, and many associations are based upon on less than not 10, but even 5 relevés. As a result, units of different status often contain equally little information about their composition. Community. This rank exists when there is only one relevé, due to both the type rarity and the lack of time. There are 17 such units, with 7 in the polar desert zone. Two main subordinate levels are used within the association: the first — subassociation and vicariant (not protected by the ICPN), the second — variant. Both reflect small but obvious differences in composition, abundance, constancy of species from the type of association (typicum), conditioned edaphically, locally-climatically, chorologically (Ellenberg, 1956; Braun-Blanquet, 1964) or indicate different stages of succession (Westhoff, van der Maarel, 1978). Differences in the listed characteristics from the type group (typicum) due to ecology are an undoubted reason for identifying several subassociations even in a landscape. To reflect similar differences due to the object location in several areas on latitudinal (in different tundra subzones) or longitudinal (in different sectors of the same zone/subzone) gradients in similar habitats (on the same landscape elements, with the same soil type), subassociation (a unit protected by the ICPN) is used as well. However, the desire to distinguish the reasons that caused such differences is also understandable. Hence, understandable is the interest to the concept of geographic vicariant, perceived by some Russian syntaxonomists working in the Arctic, which is reflected in the checklist (since the unit is not protected by ICPN, after the name in brackets there is a link to References). Leading European phytosociologists E. van der Maarel and W. Westhoff, who in 1993 reviewed an article by N. Matveyeva on the vegetation of Taymyr (Matveyeva, 1994), recalling the concept of geographical races (Becking, 1957), or vicariants (Barkman, 1958), recommended to use the status of a geographic vicariant to reflect changes in the composition of communities of one association related with a geographic location, leaving ecologically determined differences for subassociations.The need for such a division is reflected in the famous paper of F. Daniëls (1982) on Greenland, where the author distinguishes ecologically (habitat-differential) and geographically (area-differential) determined syntaxa, although uses only the name of subassociations. It is a great pity that the concept of a geographical vicariant, which was formed in the minds of the classics of phytosociology almost 60 years ago, did not find formal support: this unit was not included nor in the 3rd edition of the ICPN (Weber et al., 2000), neither in the 4th (Theurillat et al., 2021). The question of whether such a unit should be covered by the ICPN regulations «... can be resolved with the accumulation of experience in its application» (Weber et al., 2000, p. 6); the results of such experience are reflected in this checklist. Subassociation. There are 152 subassociations within 71 associations: most of all in the Carici arctisibiricae–Hylocomietea alaskani (24), slightly less in Loiseleurio procumbentis–Vaccinietea (21) and Betulo carpaticae–Alnetea viridis (23), more than 11 in Carici rupestris–Kobresietea bellardii (16), Scheuchzerio palustris–Caricetea fuscae (17), Juncetea maritimi (12) and Thlaspietea rotundifolii (12). Usually there are 2–3 subassociations in one association. Vicariant. There are 25 vicarians in the 14 associations. 19 of these are latitudinal in associations of zonal, mire, snowbed (Matveyeva, 1994, 1998, 2006) and herb meadow (Zanokha, 1993, 1995a, b) communities within 3 tundra subzones and syntaxa, replacing them in the polar deserts on Severnaya Zemlya (Zanokha, 2001; Matveyeva, 2006. The appeal to the concept of vicariant on Taymyr, where in the only place on the Earth on the mainland at about 900 km a full latitudinal gradient from the tree line to the polar deserts is expressed (Matveyeva, 1998), is quite understandable and logical. The other 6 vicariants are longitudinal: 1 in the European North of Russia (Matveyeva, Lavrinenko, 2011) and 5 on Wrangel Isl. (Kholod, 2007). Variant. There are 190 variants within 66 associations. There are no clearly formulated rules regarding their fundamental difference from subassociations. It is also not obvious whether the level of variant is the next after subassociation in association subdivision, or these are units of the same rank: in 31 associations, variants are allocated within subassociations or vicariants, in 34 — directly in the association. There is no clear logic behind why even one and the same author follows the first way in some cases, and the second in others. Subvariant. This unit was used for the division of variants of technogenically disturbed vegetation (Sumina, 2012, 2018), where 54 subvariants (2–5 in each) were identified in 20 variants of 6 associations, as well as of the baydzharakh vegetation in the arctic tundra subzone in Siberia (7 subvariants). Facies. The unit without differentiaal taxa, recognized by the predominance (with a high abundance) of a species of the «normal» floristic complex of the association, due to particular or sometimes ­extreme abiotic factors, or under anthropogenic impact (Westhoff, van der Maarel, 1978). There are 14 facies in 2 associations of 2 classes on Wrangel Isl. (Kholod, 2007) and in 3 syntaxa of 3 classes in the Bolshezemelskaya tundra (Neshataev, Lavrinenko, 2020). Conclusion. One of the purposes of publishing this checklist is to draw the attention of northern phytosociologists to assessing the validity of syntaxa and the legality of their position in the Braun-Blanquet system. Our task was to bring together all available information, which is done in this article. Even a simple list of syntaxa makes it possible to assess the completeness of the geographical and syntaxonomic knowledge of vegetation. Geographically, sytaxonomic information is available for 12 of the 13 Russian floristic provinces (according to CAVM), in which about 130 districts have been investigated. The most studied provinces (from west to east) are Kanino-Pechora, Yamalo-Gydan, Taymyr, East Chukotka, Wrangel Island (the number of published relevés in each more than 600. There are no published data for the Kharaulakh province. It is not possible to say for sure to what extent the number of associations reflects the presence and distribution communities of 20 classes in different regions of the Russian Arctic. The completeness of the vegetation study depended on the tasks and on the possibility of their implementation. High attention to zonal vegetation is natural, since it is used for subdivision of the territory, for zonal division, and for maps of various scales. Both snowless (Carici rupestris–Kobresietea bellardii) and snowbed (Salicetea herbaceae) communities, as specific for the Arctic, are also always in the sphere of interests. Polygonal mires and bog-hollow vegetation (Scheuchzerio palustris–Caricetea) certainly require much more research, due to their vast areas in the eastern regions of the Siberian Arctic, where these types are not described. For the relatively well-studied shrub communities in the Asian part (conditionally assigned to the Betulo carpaticae–Alnetea viridis), validation of many syntaxa are required; the gap in the description of this object in the northern European regions has just begun to be filled. For 12 associations of grass-forbs communities on the well heated slopes conditionally positioned in the Mulgedio-Aconitetea, new orders and allian­ces, and, potentially, the class are necessary to be established. Unreasonably little data are available for raised bogs (Oxycocco-Sphagnetea), if even these are ­rather common of the southern regions of the tundra zone. Very scattered geographically and sparse syntaxonomic data are on the vegetation of naturally eroded mobile substrates (sand screes, gravel debris, landslides). In the Arctic, as in other regions of the globe, communities are placed in this class not by their species composition, but by habitat (unstable substrate), and the fact of the sparse cover. Only recently the zonal vegetation of polar deserts on horizontal surfaces with quite stable loamy substrates has been classified as a distinct class (Daniëls et al., 2016). In the list of habitat types with associated described Brown-Blanquet syntaxa from Arctic regions of Europe, Greenland, western North America, and Alaska, there are 5 classes (Walker et al., 2018) which are absent in our checklist: Juncetea trifidi Hadač in Klika et Hadač 1994, Saxifrago cernuae–Cochlearietea groenlandica Micuna et Daniëls in Mucina et al. 2016, Vaccinio-Piceetea Br.-Bl. in Br.-Bl. et al. 1939, Asplenietea trichomanis (Br.-Bl. in Meier et Br.-Bl. 1934) Oberd. 1977, Salicetea purpureae Moor 1958. Communities of these classes either exist in the Russian Arctic, but were not described (e. g. forest «islets» in tundra landscapes — Vaccinio-Piceetea, and the vegetation of rocks and rubble talus — Asplenietea trichomanis), or they exist, but are positioned in the other classes. An open question remains with Junce­tea trifidi on acidic substrates. Final conclusions on these classes will become possible after the thorough analysis of syntaxa throughout the entire circumpolar space. Even a very brief analysis of the available data revealed numerous cases of invalid names of syntaxa (no indication of the nomenclature type) or inconsistency names with ICPN rules (correct [recte] names are given for 43 ones); leaving the association outside of higher-level units or assigning one basic unit to ­several higher ones, etc. There are more such cases than we have noted now, especially taking into ­account the new edition of the ICPN (for example, the obligatory Latin or English terminology for denoting ranks and new units (ICPN 4th, Art. 3d, 3i, 3o, 5), mutation ­cases (Lat. mutatum, ICPN. 4th, Art. 45), inversions (Lat. inversum, ICPN. 4th, Art. 42) of names and autonym (Lat. autonym, ICPN 4th, Art. 13b, 4d). Now it becomes possible for each author to take measures to eliminate errors of various kinds to validate their syntaxa. Consolidated participation in joint publication is also possible. This is a necessary step for the next action — preparing the Prodromus of the vegetation syntaxa of the Russian Arctic with the expanded characteristics for all levels.

In this paper, we prove that for x ∈ (0, π ∕ 2) (cos p0 x)1 ∕ p0 < (sin x ∕ x) < (cos (x ∕ 3 ))3 with the best constants p0 ≈ 0.34731 and 1 ∕ 3. Moreover, for x ∈ (0, c) ⊆ (0, π ∕ 2) the double inequality βp (c)(cos px)1 ∕ p < (sin x ∕ x) < (cos px)1 ∕ p holds if p ∈ (0, 1 ∕ 3], where βp (c) = c-1 (cos pc)-1 ∕ p and 1 are the best possible. Its reverse one holds if p ∈ [1∕ 2, 1). As applications, some precise estimates for sine integral and Catalan constant are given.

In the present paper, we give some geometric conditions in terms of the von Neumann-Jordan type constant and the Dominguez-Benavides' coefficient which in turn are sufficient for the existence of fixed points of multivalued nonexpansive and 1-χ-contractive nonself mappings satisfying the inwardness condition and normal structure in a reflexive Banach space. Our main results improve some well known results in the recent literature.

Background: Type 1 diabetes is the most common endocrine condition among adolescents. Diabetes self-management can be challenging during adolescence. Objective: The objective of this study is to understand how adolescents and their parents manage type 1 diabetes in Jordan. Methods: Constructivist grounded theory methodology principles were used to achieve the study aim. A total of 48 participants were recruited using purposive and theoretical sampling techniques, including adolescents and their parents. Data were collected (October 2016 - April 2017) using 38 semi-structured, audio-recorded interviews (one-to-one or joint interviews based on participants’ preferences). Data were collected and analyzed concurrently using different levels of coding, constant comparative analysis, and memo writing. This study was approved by relevant ethics committees from the University of Manchester and Jordan University Hospital. Results: The theme of living with diabetes is presented and discussed in this article. Culture emerged as the central theme; two aspects of culture are presented in this article: collectivism and cultural beliefs. Conclusion: This study identified that diabetes self-management could be influenced by the culture in which Jordanian adolescents live in as well as being shaped by their religious beliefs. These findings are potentially transferable to other Arab and non-Arab countries that share similar cultural aspects and religious beliefs.

In this paper we prove that the cohomology groups with compact support of stacks of shtukas are modules of finite type over a Hecke algebra. As an application, we extend the construction of excursion operators, defined by V. Lafforgue on the space of cuspidal automorphic forms, to the space of automorphic forms with compact support. This gives the Langlands parametrization for some quotient spaces of the latter, which is compatible with the constant term morphism. Comment: published version

In this work we explore an instance of the \tauτ-function of vertex type operators, specified in terms of a constant phase shift in a free-fermionic basis. From the physical point of view this \tauτ-function has multiple interpretations: as a correlator of Jordan-Wigner strings, a Loschmidt Echo in the Aharonov-Bohm effect, or the generating function of the local densities in the Tonks-Girardeau gas. We present the \tauτ-function as a form-factors series and tackle it from four vantage points: (i) we perform an exact summation and express it in terms of a Fredholm determinant in the thermodynamic limit, (ii) we use bosonization techniques to perform partial summations of soft modes around the Fermi surface to acquire the scaling at zero temperature, (iii) we derive large space and time asymptotic behavior for the thermal Fredholm determinant by relating it to effective form-factors with an asymptotically similar kernel, and (iv) we identify and sum the important basis elements directly through a tailor-made numerical algorithm for finite-entropy states in a free-fermionic Hilbert space. All methods confirm each other. We find that, in addition to the exponential decay in the finite-temperature case the dynamic correlation functions exhibit an extra power law in time, universal over any distribution and time scale.

Abstract In the present study, a novel solar still incorporated with fins and phase change material (PCM)-based energy storage was designed. To investigate the influence of fins and energy storage unit, four cases of stills were considered. In case I, a conventional type was considered, whereas square hollow fins were fitted over the basin liner of the still in case II. In addition to fins as in case II, case III employs an energy storage unit wherein PCM was packed beneath the basin liner. Case IV was similar to case III except for the extension of fins into the storage unit. The addition of fins above the basin liner improved the absorber surface area and the extension of the same beneath the basin liner enhanced the storage efficiency. Experiments were carried out on all the four modules with a constant basin water depth of 2 cm. The maximum productivity of the conventional solar still was found to be 3.25 L/m2/day. On the other hand, the results reveal improvement in productivity of 17.54%, 48.61%, and 55.69% with cases II, III, and IV, respectively. Although stills with energy storage units exhibited higher exergy efficiency, the presence of fins in the PCM increases the internal irreversibilities. The cost of water yielded by modified solar still (MSS) used in case IV is proved to be less as compared to conventional solar still (CSS). Further, the payback period of MSS is found to be lesser than that of CSS.

Abstract In the last few decades, the varieties of semiconductors have been explored for electronic and thermoelectric applications. As per such motivations, in present research work, the investigation of two quaternary Heuslers (QHs) i.e. LiHfCoGe and LiHfCoSn (having semiconducting nature) have been carried out for structural, electronic, vibrational, elastic, mechanical, thermodynamical and thermoelectric properties within the computational approach of Density Functional Theory (DFT) and Boltzmann transport equations. Both the alloys are enriched with p-type semiconducting nature along with the dynamical stability that crystallizes in FCC cubic structure of F-43m space group. The high Seebeck coefficient values are like of excellent fundamental thermoelectric character. The high melting points expose their scope in the high-temperature regions. Even the figure of merit (ZT) is of average range but better than many of the compounds of the same kind for the constant relaxation time approximations however all the thermoelectric properties are also measured and presented at the calculated relaxation time by deformation potential theory. The effect of spin orbit coupling is also studied on the thermoelectric properties. The practical utilization of the materials can be evaluated from the elastic and mechanical properties that are favorable to manufacturing efficient and reliable Thermoelectric Modules in high-temperature range. A sufficient discussion of thermodynamic properties is carried out to give an image of the internal lattice thermal vibrations. It is worth mentioning that the present research work has the standards to be discussed in experimental research areas of energy conversion techniques.