Border Of Zone Research Articles

Establishing a low-risk zone for a temporary extra-articular calcaneo-tibial pin fixation in an unstable ankle or subtalar joint

This study aimed to establish a low-risk zone to avoid neurovascular injury during a temporary extra-articular calcaneo-tibial pin fixation in an unstable ankle or subtalar joint. A line from the calcaneal tuberosity center to the lateral end of the posterior malleolus at the ankle joint level defines the lateral border of this zone. Another line from the calcaneal tuberosity center to the midpoint of the anterior distal tibial articular surface at the joint level defines its medial border. This region was assumed to have a low neurovascular injury risk upon pin insertion. Fifty ankles from 50 patients who had undergone magnetic resonance imaging (MRI) for ankle disorders were assessed. T1-weighted oblique axial MRI slices were oriented to the pin trajectory. The mean distances between the sural nerve and the lateral border of the low-risk zone and between the posterior tibial neurovascular structures and the medial border of the low-risk zone were 15.0 ± 2.5 (range 9.1 to 21.1) and 12.8 ± 2.6 (6.3 to 20.8) mm, respectively. No neurovascular structures were identified within the low-risk zone. These findings demonstrated that an unstable ankle or subtalar joint can be temporarily fixated with an extra-articular calcaneo-tibial pin at a defined zone with a low neurovascular injury risk.

Application of the Magnetic Geophysical Method to Exploration of the Potassic Zone in Some Porphyry Copper Deposits (Iran)

Haftcheshmeh, Masjeddaghi and Nowchun are three giant porphyry systems located in Iran. Because of the presence of potassic alteration outcrops in the Haftcheshmeh ore deposit (NW Iran), we decided to detect borders of this alteration zone by a ground magnetic method. Goal of exploration is to understand the distribution of concentration in porphyry systems, as the level of magnetization commonly differs across alteration boundaries. Further, 3D interpretation of magnetic data is important to improve our understanding of geology and alteration in the system. In this paper, qualitative and quantitative results of geophysical surveys are presented in the form of total field intensity, second derivative, upward continuation and pole reduction maps. Comparison of magnetic results with borehole logging provides a good pattern to a field geologist to assign and guide an exploration project. According to this pattern, all drill holes in Haftcheshmeh, Masjeddaghi and nowchun porphyry system were designed. According to the results for the mentioned copper systems, anomalous magnetic features are related to the sub-volcanic intrusions and high anomaly zones over the potassic alteration probably show the existence of magnetite. The potassic zone pattern can be used as a key in all further exploration of porphyry systems.

Laser-Powder Bed Fusion of Inconel 718 Alloy: Effect of the Contour Strategy on Surface Quality and Sub-Surface Density

The in-situ contour strategy during Laser-Powder Bed Fusion (L-PBF) process remains one of the most promising solutions to improve the poor surface quality of the parts. On the other hand, it is well established that contour step affects the formation of sub-surface defects. The aim of this work is to assess the entity of sub-surface defects during the Laser-Powder Bed Fusion of Inconel 718 samples for which different contour processing conditions are considered. Cubic samples with 10 mm side were produced through L-PBF using a Concept Laser Cusing M2 L-PBF machine. The samples were printed with fixed bulk laser parameters, adopting a layer thickness of 30 μm and a chessboard laser scanning strategy. The in-situ contour conditions were changed in terms of laser scanning speed and hatch zone border. Afterwards, the samples were analyzed in terms of surface roughness (Sa) and sub-surface density through confocal microscopy. The results revealed that the surface roughness was the most affected output as a function of the varied process parameters, including the sample position on the building platform, with values ranging from 13 to 32 μm. On the other hand, the sub-surface density was always higher than 99%.

Caffeine metastable zone width and induction time in anti-solvent crystallization

In this study, the anti-solvent approach was used to investigate caffeine's induction time and metastable zone width (MSZW). Chloroform is used as a solvent, and carbon tetrachloride is used as an anti-solvent. Initially, caffeine solubility data is gathered in the chloroform/carbon tetrachloride mixture at various chloroform mass fractions. Caffeine solutions with various concentrations were then created to determine the MSZW. The anti-solvent (carbon tetrachloride) was injected into the solution to achieve supersaturation. The metastable zone limit was obtained by adding the anti-solvent at a constant rate and using turbidity changes in the system. The time of induction in various supersaturations was also investigated. In this section, various concentrations of solutions were created. Then, the system was instantly supersaturated with an anti-solvent. The period between the addition of the anti-solvent and the change in the turbidity of the solution was known as the induction time. The visual technique is compared to the use of an online turbidimeter before starting induction time measurements, and it is shown that the induction times obtained with the online turbidimeter are shorter and more accurate. Additionally, the induction time was investigated by various supersaturations, and it was discovered that as the supersaturation approaches the metastable zone border, the induction time decreases. Furthermore, in the same supersaturations, the influence of mixing on induction time was explored, and it was revealed that the higher the stirring speed, the shorter the induction time. Finally, the interfacial energy of solid–liquid phase was calculated for two systems with different initial chloroform mass fractions. It was shown that a reduction in polarity of medium increases the interfacial energy.

Major Cereal Crops Damage by Wildlife: A Case Study from Chitwan National Park, Nepal

Human-wildlife conflict is a major issue for policymakers and conservationists due to economic damage by wild animals, resulting in increasing poverty. This study assesses the wildlife-induced damage to the major food crops viz. rice, wheat, and maize. A total of 434 households from the 10 forest user groups near the Chitwan national parks and buffer zone were randomly selected and interviewed by the use of questionnaires in 2021. A total of 87.86% of rice-growing households reported damage to rice, whereas 90.32% and 87.68% of households reported damage to wheat and maize, respectively. The annual loss of 78 kg of rice per household (NRs. 1776 at prevailing market rates) was reported in the study area. The loss of wheat and maize per household was 86 and 96 kg with the worth of NRs. 2523 and 2019, respectively. The severity of wildlife-induced damage to crops was more near the borders of national parks and buffer zone. Apart from the construction and maintaining permanent fences on the border of the national parks, there should be the provision of conservation education to communities residing along the buffer zone and near the protected areas to practice sustainable agriculture and income-generating programs that are conservation-friendly.

Accounting dust emission in the system of management of ambient air quality

Introduction. The fulfillment of effective measures to manage the level of dust pollution in the atmospheric air of settlements requires correct hygienic assessments of the situation and reliable data on the sources of particulate emissions. The purpose of the study was to substantiate what is need to take into account the entire set of solid emitted components when conducting hygienic assessments of the situation, including the consideration and approval of draft standards for permissible emissions and projects of sanitary protection zones. Materials and methods. On the example of a large industrial enterprise, calculations of the dust emissions dispersion were made with and without taking into account the total mass of solid components. Source parameters are taken according to the enterprise inventory list. Dispersion calculations were carried out using the standardized program “Ecolog-City”. Results. For each individual solid substance at the border of the sanitary protection zone and at the points of the nearest housing no violations of hygienic standards were established to be recorded. The situation was characterized as normative, not requiring measures to improve the safety of the population. The total release of the solid component of emissions (TSP) created an excess of the hygienic standard for the group “suspended substances” (0.5 mg/m3) at the border of the sanitary protection zone. The zone of excess pollution (more than 1 MPC) extended to the residential area. The level of pollution calculated from the totality of solid substances was satisfactorily corresponded with the data of instrumental measurements. Limitations. The limitation of the study is related to the fact that the obtained results characterize a particular enterprise, however, the principal approaches used can be applied to any similar studies. Conclusion. It seems appropriate to harmonize the concept of “suspended matter” with the definition adopted by the World Health Organization, establishing that suspended matter is the total amount of solid particles of organic and inorganic substances. Fixing such a concept in sanitary rules and regulations ensures the correctness of the hygienic assessment of the situation, the comparability of calculated and natural data, the absence of contradictions between the established emission standards for each type of dust and the results of a health risk assessment (performed taking into account the sum of all particulate matter). The use of MPCs for various types of dust remains an important tool for identifying emission sources and preventing the negative impact of dusts with carcinogenic or highly toxic properties.

Regional PM2.5 pollution confined by atmospheric internal boundaries in the North China Plain: Analysis based on surface observations

There are plenty of mesoscale meteorological discontinuities in the atmosphere, acting as atmospheric internal boundaries (AIBs). In conjunction with the atmospheric boundary layer in the vertical direction, they form confined three-dimensional structures that significantly affect air pollution. However, the role of AIBs in regional pollution has not been systematically elucidated. Based on surface observations, this study investigates PM2.5 pollution distributions under the forcing of various AIBs in the North China Plain. A total of 98 regional pollution episodes are identified during the autumn and winter of 2014–2020, and are further classified according to the impact of AIBs. In the pollution formation-maintenance stage, there are three categories. The frontal category (with a frequency of 41%), including the frontal trough type and frontal inverted trough type, displays the most polluted air masses along the mountains. The frontal AIB defines the lateral border of the pollution zone and forms a frontal inversion above, creating a closed and stable structure wherein the highest concentration of PM2.5 accumulates. The wind shear category (29%) is decided by the dynamic convergence AIB, which causes lighter PM2.5 pollution with diverse spatial patterns corresponding to west-southwest shear, southeast-east shear, and south-north shear. The topographic obstruction category (14%) presents as a narrow arc-shaped pollution belt at the foot of the windward mountains, resulting from the cold air damming AIB with dynamical obstruction and thermal stratification. Pollution diffuses in three ways: northwest, west, and northeast, respectively. The first one is the strongest and most frequent (42%), with both strong horizontal wind and vertical mixing. The second category is relatively rare (17%), characterized by foehn-induced active vertical ventilation. The last one is frequent (41%), but relatively weak, mainly relying on horizontal diffusion. Some evolution details of the AIB affecting PM2.5 pollution are also illustrated by a typical case.

The assessment of the level of environmental pollution at the solid waste landfill of KazEcoProm LLP (Pavlodar, Republic of Kazakhstan)

This paper presents a study of the impact of the KazEcoProm LLP landfill located in the north-east of Kazakhstan (Pavlodar) on groundwater, soil and atmospheric air. Sampling for each environmental component was carried out once per quarter at the landfill site. The amount of pollutants in the components of the environment was determined in a specialized accredited laboratory of KazPII KazakhstanProject LLP. The level of pollution of environmental components by harmful substances of wastes was assessed by the ratio of the total indicator of pollutants for each component to the maximum permissible concentration on the border of the sanitary-protection zone of the landfill. No exceedances of the maximum permissible concentrations were detected. Thus, the conducted investigations have showed that the level of environmental pollution on the territory of the landfill is assessed as permissible. However, further monitoring of the negative impact of the landfill on the environment is required. The received data can be used to estimate a level of environmental pollution and determine an observance of norms and rules of storage and gathering of wastes on a landfill.

Monitoring the waste management system in preschool educational institutions

The article presents the results of assessing the degree of negative impact of the enterprise LLC Collective fishery "Tihiy okean" on the atmospheric air. The enterprise releases 33 pollutants into the atmosphere. Substances of the first hazard class include: dimethylamine, benzo/a/pyrene. Substances of the second hazard class include: manganese and its compounds, sulfuric acid, hydrogen sulfide, gaseous fluorides, poorly soluble fluorides, phenol, formaldehyde. All other substances belong to 3–4 hazard classes, or are not assigned to any. The work takes into account 23 sources of air pollution at the enterprise, operating at the time of the inventory of them: including 9 — organized, fourteen — unorganized. In order to analyze the compliance of indicators with hygienic standards for the quality of the surface layer of air, according to the content of 23 pollutants in it, was carried out using a unified program — UPRZA Ecolog ver. 3.0. assessment of the magnitude of surface concentrations of these impurities at the border of the sanitary protection zone of the enterprise. The results of the calculations indicate the observance of hygienic standards of atmospheric air quality, taking into account background atmospheric pollution for 23 substances emitted by the sources of the enterprise LLC "Cf" Tihiy okean. Consequently, emission limits are proposed at the level of existing emissions. The development of air protection measures is not required, but it is recommended to use the most environmentally friendly equipment currently available. The purpose of the work is to assess the degree of negative impact of the enterprise LLC Collective fishery "Tihiy okean" on the atmospheric air, determination of the level of air pollution by the enterprise.

Geophysical research for organization and service of the regional permafrost monitoring network in the Yamalo-Nenets Autonomous District

The results of the application of geophysical methods for the organization and maintenance of the regional permafrost monitoring network in the Yamalo-Nenets Autonomous District are described in the paper. Arctic Research Center in 2021 used the method of electrical resistivity tomography to determine the locations of the thermometric well. The consistency and necessity of using geophysical methods to search permafrost with deep top near the border of continuous and discontinuous permafrost zone is confirmed. Ground-penetrating radar was used at the CALM R53 site as an additional tool for determining the thickness of active layer. It is shown that the complex of geophysical methods and traditional measurements with a permafrost probe when studying the active layer in hard lithological conditions is necessary to refine and supplement the data.

Species Richness, Abundance, and Productivity of Birds Along a Powerline Right-of-way within a Forested Landscape, Northeastern United States

Utility rights-of-way (ROW) serve as nesting areas and maintain a high diversity of early successional birds. ROW incorporating wire zone–border zone and integrated vegetation management can be used as examples of early successional habitat management for bird conservation more generally in the Northeastern United States, given artificial disturbances not created solely for natural resource conservation comprise approximately 80% of early successional habitats. The objective of our study was to determine the effect of herbicide and mechanical vegetation management approaches on the abundance, species richness, and reproductive success of breeding bird species occupying an electric transmission line ROW in central Pennsylvania. The overall abundance of birds was significantly lower within the wire and border management zones, following initiation of a new vegetation management cycle at State Game Lands (SGL 33) than in the years prior to management. Sections of ROW with no border zones contained the lowest abundance and species richness of breeding birds compared to sections with borders prior to the initiation of a new management cycle. Sections of ROW with no border zones and mowing sections had the lowest bird abundance and species richness of all ROW sections at the onset of a new management cycle, and contained the lowest number of bird species displaying evidence of breeding, both prior to and at the beginning of management cycles. Sections of ROW managed using herbicides were comparable or more beneficial to bird communities in terms of abundance, species richness, indices of productivity, and nesting success than sections maintained via mechanical treatments (mowing and hand cutting), both at the end and beginning of management cycles within a forested landscape in the central Appalachian Mountains and surrounding forested regions in the northeastern United States.

SEVERSKY PIPE PLANT – THE LEADER IN THE ENVIRONMENTAL ACTIVITIES IN RUSSIA – 2021

Seversky Pipe Plant (STZ) is one of the oldest metallurgical enterprises in Russia and one of the most hightech pipe plants in the world. A Strategic program for the technical revamping of the plant has been developed and implemented, within the framework of the Strategic Program for the development of the TMK enterprises (STZ became its part in 2002). The environmental measures in this program are considered as the biggest priority. The total investments included 35 billion rub., and 5.5 billion rub. of this amount were assigned for the implementation of measures directed to the environmental safety. As a result of its implementation, 19 significant sources of hazardous emissions into the atmosphere were decommissioned, including four open-hearth furnaces. Eight newly commissioned facilities are equipped with modern gas treatment equipment. These measures contributed to 4 times reduction in the specific emissions of steelmaking production. Ten new recirculation cycles of water supply were introduced during the revamping. The water intake for technical water supply was reduced by 4 times, the volume of effluents decreased in more than half. The introduction of the best available technologies made it possible to bring the border of the sanitary protection zone very close to the border of the enterprise territory. The effluents discharged by the plant have several times lower hazardous substance concentration than the background ones on a number of components. In 2021, STZ became the winner of the XVII All-Russian competition “The leader in the environmental activities in Russia-2021” in the nomination of “The best environmentally responsible town-forming enterprise”.

Drawing the borders of the mesophotic zone of the Mediterranean Sea using satellite data

The 30–150 m bathymetric range is commonly adopted in the literature to constrain the mesophotic zone. However, such depth interval varies depending on sunlight penetration, which is primarily a function of solar radiation incidence and water clarity. This is especially obvious in the Mediterranean Sea with its peculiar biophysical properties. Integrating information on light regime in the estimation of the bathymetric range of the mesophotic zone would provide a more robust definition, orienting conservation actions targeting its ecosystems. We present a first assessment of the spatial and vertical extension of the mesophotic zone in the Mediterranean Sea based upon light penetration, comparing our prediction with literature data. Our study also represents a baseline to monitor future variations in the bathymetric interval associated with the mesophotic zone in the Mediterranean Sea in relation to global changes.

Modeling of the as-cast structure and macrosegregation in the continuous casting of a steel billet: Effect of M-EMS

Mold electromagnetic stirring (M-EMS) has been introduced into the continuous casting of steel billets to promote the formation of a central equiaxed zone; however, the formation mechanism of the equiaxed crystals and the effect of M-EMS on crystal transport are not fully understood. Currently, a three-phase volume average model was used to study the solidification in a billet continuous casting (195 mm × 195 mm). The modeling results showed that the main function of M-EMS in this type of billet casting is to promote superheat dissipation in the mold region, leaving the liquid core out of the mold region undercooled. Although both, heterogeneous nucleation and crystal fragmentation, are considered to be the origins of equiaxed crystals, M-EMS appeared to impact crystal fragmentation more effectively. A small portion of equiaxed crystals could be brought by the M-EMS induced swirling flow into the superheated zone (upper mold region) and remelted; most equiaxed crystals settled in the lower undercooled zone, where they continued to grow and form a central equiaxed zone. These simultaneous phenomena represent an important species/energy transport mechanism, influencing the as-cast structure and macrosegregation. Negative segregation occurred in the central equiaxed zone, positive segregation occurred at the border of the columnar zone, and a trail of negative segregation occurred in the subsurface region of the billet. Finally, parameter studies were performed, and it was found that the shielding effect of the copper mold, electrical isolation at the strand-mold interface, and relatively high electrical conductivity of the strand shell affect the M-EMS efficiency.

Repressive Interactions Between Transcription Factors Separate Different Embryonic Ectodermal Domains.

The embryonic ectoderm is composed of four domains: neural plate, neural crest, pre-placodal region (PPR) and epidermis. Their formation is initiated during early gastrulation by dorsal-ventral and anterior-posterior gradients of signaling factors that first divide the embryonic ectoderm into neural and non-neural domains. Next, the neural crest and PPR domains arise, either via differential competence of the neural and non-neural ectoderm (binary competence model) or via interactions between the neural and non-neural ectoderm tissues to produce an intermediate neural border zone (NB) (border state model) that subsequently separates into neural crest and PPR. Many previous gain- and loss-of-function experiments demonstrate that numerous TFs are expressed in initially overlapping zones that gradually resolve into patterns that by late neurula stages are characteristic of each of the four domains. Several of these studies suggested that this is accomplished by a combination of repressive TF interactions and competence to respond to local signals. In this study, we ectopically expressed TFs that at neural plate stages are characteristic of one domain in a different domain to test whether they act cell autonomously as repressors. We found that almost all tested TFs caused reduced expression of the other TFs. At gastrulation these effects were strictly within the lineage-labeled cells, indicating that the effects were cell autonomous, i.e., due to TF interactions within individual cells. Analysis of previously published single cell RNAseq datasets showed that at the end of gastrulation, and continuing to neural tube closure stages, many ectodermal cells express TFs characteristic of more than one neural plate stage domain, indicating that different TFs have the opportunity to interact within the same cell. At neurula stages repression was observed both in the lineage-labeled cells and in adjacent cells not bearing detectable lineage label, suggesting that cell-to-cell signaling has begun to contribute to the separation of the domains. Together, these observations directly demonstrate previous suggestions in the literature that the segregation of embryonic ectodermal domains initially involves cell autonomous, repressive TF interactions within an individual cell followed by the subsequent advent of non-cell autonomous signaling to neighbors.

Physician-modified endograft in ruptured aortic arch.

We present the case of a 27-year-old motorcyclist after a multi-organ trauma. He suffered a rupture of the aortic arch located in zone 2 and was disqualified from surgical replacement of the aortic arch due to active bleeding from parenchymal organs. Instead, he was provided with a physician-modified endograft (PMEG) to complete fenestrated thoracic endovascular aortic repair as a damage control procedure. No reports in the world literature are found regarding the use of PMEG technology in truly ruptured post-traumatic pseudo-aneurysm on the border of zone 1 and 2 of the aortic arch in emergency settings. The surgery provided temporary supply of the aorta and allowed all of the other surgical and orthopedic procedures to be completed. Endovascular treatment of aortic arch damage with PMEG is possible and can be effectively used for urgent indications when an open operation is not possible.

Problems of acoustic safety in power engineering

Environmental safety issues are becoming increasingly important in the life of society. Among environmental safety issues in power engineering, acoustic safety occupies a special place. The problem of acoustic safety is associated with the fact that the regular operation of power equipment leads to an increased noise level, and power facilities are located in close proximity to residential areas. In this work, acoustic calculations were performed to determine the sanitary protection zone for gas turbines units (GTU) and combined cycle gas turbine units (CCGT) of various capacities. A formula was obtained for calculating the width of the sanitary protection zone depending on the capacity of gas turbine units and combined cycle plants and their number. It is shown that the sanitary protection zone (SPZ) of a power unit of high capacity is smaller than the sanitary protection zone of several power units of the same capacity. It is found that the noise levels from individual groups of equipment can determine the noise level at the entire border of the sanitary protection zone or in its individual sections. At the same time, noise suppression measures should be taken for all sources that generate noise levels in excess of standards. It is necessary to start noise suppression measures from those sources that generate excess noise in a larger section of the sanitary protection zone.

Arctic: sustainable development of the region and ensuring national security

Competition for access to resources in the modern world is often decisive in shaping the state policy of many countries. The clash of geopolitical and economic interests of various states, including those in the Arctic, leads to an aggravation of conflicts between them. The Arctic region, due to its unique natural resource, geopolitical and human potential, is certainly a zone of strategic interests of our country. To date, the most relevant are the problems of ensuring the state security of the Russian Federation in the Arctic, as well as ensuring sustainable socio-economic development of the Arctic zone of the Russian Federation, while maintaining a favorable state of the environment and its unique nature. An important role in this process is played by the formation of a comprehensive and balanced system of legal regulation both at the national and international and interstate levels. One of the urgent problems in ensuring the national security of Russia in the Arctic region is the completion of the process of establishing, in accordance with the norms of International Law, the limits of the extension of its sovereign rights to the spaces of the Arctic Ocean and its natural resources. The international legal consolidation of the borders of the Arctic zone of the Russian Federation is the basis for the implementation of the sovereign rights of our state on the Arctic shelf as one of the components of ensuring national security in the region. In the sustainable development of the Russian Arctic, one of the key tasks is the organization of sea cargo transportation along the Northern Sea Route under the control of the Russian Federation, as well as ensuring the competitiveness of this national transport artery in the world market. The issues of environmental protection and the unique Arctic nature that need to be addressed on a priority basis also seem to be a priority. Appropriate measures should be developed on the basis of advanced scientific achievements and implemented by all subjects of economic and other activities in the region.

НОВОЕ МЕСТОНАХОЖДЕНИЕ, ОЦЕНКА СОСТОЯНИЯ И РИСКИ ИСЧЕЗНОВЕНИЯ ОХРАНЯЕМОГО ВИДА ЛИШАЙНИКА MENEGAZZIA TEREBRATA (PARMELIACEAE) В ХАБАРОВСКОМ КРАЕ

In the article, the author provides the data on a new locality in the Khabarovsk Territory of the rare species of lichen Menegazzia terebrata , included in the Red Data Books of the Khabarovsk Territory and the Russian Federation. It is made an assessment of its condition at the control point on the border of the Malmyzhskoye deposit development sanitary protection zone. The author shows the risks of this rare species extinction and offers measures for its conservation.

On negative effective mass and negative group velocity in anharmonic seismic metamaterials

In this work, an anharmonic mass-in-mass system that can be employed as a nonlinear seismic metamaterial is represented as an equivalent anharmonic mass-spring system via an effective medium approach. The dispersion relation and the behavior of the effective mass as a function of the angular frequency obtained in the regime of weak anharmonicity deviate from those of the corresponding linear system because of the effect of the fourth-order potential anharmonicity. In the presence of anharmonic soft springs it is found a range of wave vectors close to the Brillouin border zone at which the group velocity of the acoustic and optical modes is negative, namely it is opposite to the phase velocity, and a wider band gap at the border of the first Brillouin zone with respect to that of the linear case. Both effects can be tuned by varying the anharmonicity strength. The huge band gap amplitude together with the strong reduction of the frequency of the acoustic mode could be exploited for the design of nonlinear seismic metamaterials at the basis of composite foundations operating in the stop band frequencies.