Full Height Research Articles

A novel wavelength modulation spectroscopy gas sensing technique with an ultra-compressed wavelength scanning bandwidth

In a wavelength modulation spectroscopy (WMS) gas sensing system, a scanning ramp combined with a high frequency sinusoidal signal is applied to drive the laser source. Generally, a wide wavelength scanning bandwidth realized by voltage scanning ramp is required to fully cover the target gas absorption profile. In this paper, a novel WMS-based strategy is proposed and verified in a CH4 detection system. The wavelength scanning bandwidth is compressed from ∼659 pm to ∼166 pm, even narrower than the half width at full height (HWFM) of the CH4 absorption profile. In addition, the second harmonic signal that induced by the absorption is increased threefold by virtue of making full use of the dynamic range of the preamplifier circuit, and the waveform distortion that comes from the residual amplitude modulation (RAM) effect is eliminated as well. Benefiting from the compressed driving current range, the thermal stability of the laser diode is improved from the original level of 0.5 °C to 0.1 °C. As a result, a linear sensitivity of 75.2 ppb is achieved within 0–3000 ppm CH4 concentration range at 12.7 s time constant.

The relationship between height and fruit/vegetable intakes in adults: A nationwide cross-sectional study.

Background: Worldwide, fruit and vegetable intake is below recommendations. There is increasing evidence to suggest an association between height and diet. Aim: to analyse the associations of fruit and vegetable intake with attained height in Portuguese adults. Methods: A representative sample of 17 480 Portuguese adults (56.7% women) participated in this cross-sectional study. The survey comprised sociodemographic characteristics and self-reported height and weight. We performed regression models to assess the associations between height and fruit and vegetable consumption. Results: Compared with no intakes, those men with higher fruit and vegetables intake had 0.54 cm (95% CI 0.04; 1.04) greater height. Also, women with higher intakes of vegetables, fruit and vegetables combined were directly associated with a greater height of 0.29 cm (95% CI 0.03; 0.56 in vegetables) and 0.51 cm (95% CI 0.09; 0.93 in fruit and vegetables combined). Conclusion: Greater consumption of fruit and vegetables was directly associated with higher height in adults. From a health promotion perspective, intervention programmes aiming at improving fruit and vegetable intake should be highlighted so that full height potential is achieved.

Residential tower of the Koło castle in the light of the latest archaeological research

The Koło castle (Wielkopolskie voivodeship) is the best-preserved royal stronghold in the broadly defined historical province of Wielkopolska (Greater Poland). The castle owes this status not so much to the scale of the structures preserved to this day (i.e., ruins of the bergfried; the west curtain walls, still visible today in full length and considerable height; the greater part of the north curtain wall; and a section of the south one), but rather to the dilapidated condition of other castles founded by Polish monarchs. For a number of years (1977–1983), the Koło castle was subjected to archaeological research led by Łucja Pawlicka-Nowak (Regional Museum in Konin). Among other things, the excavations uncovered the residential tower discussed in thispaper. The excavations at the time covered the western half of the building’s interior, both of its outer southern corners, and the north-western area. The research was resumed in 2019, and the authors of this paper faced the challenge of verifying the earlier fieldwork, the extent of which was very wide and not fully documented. The investigations presented here shed completely new light both on the construction history of the Koło castle, and the issues concerning its chronology, which, in the light of current research, would have been as follows: Casimir the Great acquires the village and founds the town of Koło in 1362; the construction of the castle commences and the work on the site of the residential tower quickly progresses following 1365 (or 1367); the monarch dies in autumn 1370, before or shortly after the unfinished castle is consumed by fire. The article concludes with a chapter showing the Koło tower against the background of similar structures in Europe.

Accomplishing provider status: Getting pharmacists paid for their patient care services

Accomplishing provider status: Getting pharmacists paid for their patient care services

Fragility functions for highway RC bridge under various flood scenarios

Bridges are a country's lifeline infrastructure. As a result of climate change and global warming, floods are becoming more frequent and unpredictable. Even well-designed bridges are vulnerable to extreme flooding, as recent flood events have demonstrated. Flood fragility curves are developed for an existing RC rail over bridge considering various loading scenarios such as flood level up to the top of the pier, flood level up to the top of the girder, the impact due to log and debris, the effect of providing shear key and the effect due to scouring. The threshold mean flood velocities for the initiation of serviceability limit state for the above flood scenarios are found out. When there is no shear key, the exceedance probability for the deck displacement is found to increase with the flood water level. This increase is found to be about 92% at a particular mean flood velocity of 8.6 m/s, when the floodwater level increases from 3/4th the height of the girder to the full height of the girder. Typical log impact and debris impact increase the vulnerability of the bridge by about 45% and 80%, respectively, for a particular flood velocity of 6.8 m/s and when the flood level is up to the full height of the girder. The fragility of the bridge increases by about 80% for a scour depth of about 1.5 m at a mean flood velocity of 8.6 m/s.

Assessment of the Possibilities of Forensic Identification Population of Kazakhstan by Craniometric Indicators

BACKGROUND: Craniometric indicators are one of the most reliable sources of information about the population. Despite the development of genetic methods, skull measurements are extremely important in anthropology and forensic medicine. In addition to the history of population development, environmental factors such as climate and lifestyle contribute to variations in human skull shape. Due to the high variability of human individuals, the anthropological study of the population is carried out selectively, with a comparison of different population groups (ethnic, professional, age, gender). The lack of clear ideas about the typical parameters and proportions of the skull among the people of Kazakhstan creates a certain gap in forensic-medical identification.
 AIM: The aim of the work is to check the hypothesis about the relationship between variations in skull morphology and changes in craniometric indicators with climatic conditions and the specifics of lifestyle in populations living in different territories of Kazakhstan.
 METHODS: 187 male and 114 female adult skulls found on the territory of the two largest regions of Kazakhstan were examined. The variable variability of 25 craniometric indicators of skulls found on the territory of Central and South Kazakhstan was studied. All osteometric changes were performed using standard anthropometric instruments, followed by the calculation of craniometric indices. Multidimensional statistics were applied.
 RESULTS: The two populations demonstrate differences in craniometric indicators formed in different geographical and ecological conditions, regardless of gender. It was found that the sizes of the skulls found in the two studied regions of Kazakhstan statistically significantly differ in 5 craniometric indicators for men and 8 craniometric indicators for women. Significant changes were noted in the size of the full and upper height of the face, the average width of the face, the height of the body of the lower jaw and the height of the nose in men. The most dimorphic variables for forensic medical evaluation in the studied populations of female skulls were transverse, altitudinal and zygomatic diameters, mastoid width, width of the base of the skull, width of the occipital foramen, upper face height and nose height. The shape of the skulls found in the studied territories is predominantly brachycephalic. The cranial index was >81.1% - at men, 83% - at women. The study showed that race affects the size of the skull, regardless of gender. Craniometric parameters in male and female skulls vary according to different criteria. In women between races, there are statistically significant differences in the size of the width of the occipital foramen and the average width of the face. Statistically significant differences in the width of the base of the skull, the zygomatic diameter and the average width of the face between the Caucasoid and Mongoloid races were revealed in the studied regions in men. The established differences made it possible to form additional differential diagnostic criteria.
 CONCLUSION: Identification of the features inherent in the population living in certain territories provides auxiliary information for medical and forensic identification of a person. In this study, population-specific craniometric indicators have been developed for inhabitants of two regions of Kazakhstan, which expand and complement identification capabilities when categorizing skeletal remains found in these territories.

Nutritional management of the infant with chronic kidney disease stages 2–5 and on dialysis

The nutritional management of children with chronic kidney disease (CKD) is of prime importance in meeting the challenge of maintaining normal growth and development in this population. The objective of this review is to integrate the Pediatric Renal Nutrition Taskforce clinical practice recommendations for children with CKD stages 2–5 and on dialysis, as they relate to the infant from full term birth up to 1 year of age, for healthcare professionals, including dietitians, physicians, and nurses. It addresses nutritional assessment, energy and protein requirements, delivery of the nutritional prescription, and necessary dietary modifications in the case of abnormal serum levels of calcium, phosphate, and potassium. We focus on the particular nutritional needs of infants with CKD for whom dietary recommendations for energy and protein, based on body weight, are higher compared with children over 1 year of age in order to support both linear and brain growth, which are normally maximal in the first 6 months of life. Attention to nutrition during infancy is important given that growth is predominantly nutrition dependent in the infantile phase and the growth of infants is acutely impaired by disruption to their nutritional intake, particularly during the first 6 months. Inadequate nutritional intake can result in the failure to achieve full adult height potential and an increased risk for abnormal neurodevelopment. We strongly suggest that physicians work closely with pediatric renal dietitians to ensure that the infant with CKD receives the best possible nutritional management to optimize their growth and development.

Generic Predictive Model of Earthquake-Induced Slope Displacements Derived from Finite-Element Analysis

A generic predictive model of earthquake-induced slope displacement subjected to shallow crustal earthquake events is developed using displacements computed from finite-element (FE) analysis. The maximum displacement on the slope surface at the end of shaking was computed by nonlinear FE simulations for 49 slope models each subjected to 1051 earthquake motions. A unified predictive model of seismic displacement is developed that characterizes the slope in terms of its yield acceleration (ky), the depth of the slip surface relative to the height of the slope (Hratio), and the natural period of the full slope height (Tslope). Across five intensity measures and 10 combinations of intensity measures, peak ground velocity (PGV) is found to be the most efficient parameter for the displacement prediction, leading to significantly smaller aleatory variability. The displacement variability is partitioned into two components: between-slope variability, which represents the variability associated with different slope models, and within-slope variability, which represents the variability due to different input ground motions. The developed generic predictive model can be applied to the probabilistic seismic hazard analysis of slope movements and used for deterministic earthquake scenarios in the design/analysis process.

LIGHT IN THE SACRED SPACE OF THE MODERN GREEK CATHOLIC CHURCHS

Based on domestic and foreign experience, an analysis of the natural light filling of the sacred space of Modern Greek Catholic churches in Ukraine and abroad. Similarities and differences in the formation of the light environment of the modern church, compared with the traditional one, have been establish. The architecture of Modern Greek Catholic churches in Ukraine significantly influenced by the traditions of architectural formation of other branches of Christianity. This influence manifested primarily in the organization of their lighting environment. In Modern Greek Catholic churches, there is a top light from the domes in the cover, but its share in the total flow of daylight significantly reduced. Due to the large stained glass windows in the walls significantly increases the overall illumination of the interior of the temple. Uniform arrangement of windows in the outer walls equalizes the light on the inner surfaces. Contribute to the creation of uniform illumination of surfaces used in the decoration of walls of light colors with the same brightness in the field of view. These factors indicate the convergence of the light composition of the interior of Greek Catholic churches with the interiors of Protestant churches. At the same time, partial (horizontal or vertical) or complete glazing of the walls in the altar, installation of large stained glass windows at full height in the side walls, installation of light lanterns, mostly in the roof over the altar space, bring together modern Greek Catholic churches their space with modern Catholic churches. Modern Greek Catholic churches contain many techniques of light-spatial composition that not related to the tradition already developed by the system of Ukrainian national attributes, and rather reflect the authorial style of an architect.

Simulation of scour and deposition in the flow field and adaptability of fishes around eco-friendly notched groins

Over the past few decades, eco-friendly channel construction has gained wide attention around the world including China, as it considers both navigational and ecological functions. The Groin system is a hydraulic structure that can effectively increase the area of fish habitats. Groin shape has an influence on the local flow field and the scour and deposition pattern near the structure, thereby affecting the adaptability of fishes to the groin fields. In this study, a new groin structure with a notch in its middle part was proposed. A lab experiment was conducted on a physical model to investigate the characteristics of the flow field including patterns of water level distribution, flow velocity distribution, and scour and deposition on different submergence levels and incoming flows. This experiment used four notch depths: 0 (unnotched), 1/3 of groin height, 2/3 of groin height, and full groin height. Then the distribution of habitat suitability index (HSI) was calculated based on the assessment index system of the indicator fish species (Cyprinidae). The results showed that the notches created in the middle of localized overflow groins had a significant effect on the surrounding flow pattern. Due to localized overflow, both the flow velocity and the velocity gradient behind each groin increased. The flow velocity behind each groin was positively correlated with notch depth, while the flow velocity in the main channel was negatively correlated with notch depth. Under the complex flow conditions, depositional features did not occur along the edges of the groin fields, ensuring connectivity between groin fields and the main channel. An analysis of water depth and flow velocity suitability indexes of Cyprinidae suggests when notch depth is 2/3 of groin height, the notched groins have good ecological effects, especially in the groin fields.

On Hypsometric Curve and Morphological Analysis of the Collapsed Irrigation Reservoirs

The impact of irrigation reservoirs requires investigation through hydrological analysis to identify the flood control functions of these reservoirs. However, there is insufficient information concerning important geographical, morphological, and topographic characteristics, such as the reservoir cross-section. Therefore, this study aimed to identify the morphological and topographic characteristics of reservoirs using geographical information instead of measurement data. Ten reservoirs, including the Ga-Gog reservoir located in Miryang City, South Korea, were selected. The topographic information of the reservoirs was obtained using topographic maps and GIS techniques. Based on this information, the volume (V)-area (A)-depth (H) relationship and the hypsometric curve (HC) according to the relative area (a/A) and relative height (h/H) were created. A comparison of the reservoir volume, estimated using topographic information, with the measured volume revealed an error rate between 0.23% and 14.27%. In addition, two collapsed reservoirs located near Miryang City were investigated by creating V-A-H relationships and HCs using topographic information. The morphological characteristics of the reservoirs were identified by analyzing the (1) morphology index, (2) full water storage area-levee height relationship, and (3) full water storage area relationship. The analysis results showed that the collapsed reservoirs had high water depth and a large area relative to other reservoirs. Similar types of reservoirs were grouped by conducting a cluster analysis using basic properties such as the basin area, storage, and levee height. The cluster analysis results, based on HC analysis, grouped the reservoirs into three shapes: convex upward (youthful stage), relatively flat (mature stage), and convex downward (old stage). The HCs of the collapsed reservoirs exhibited a convex downward shape, indicating that they were subjected to considerable erosion due to aging. Moreover, this considerable erosion caused a large quantity of sediment to accumulate in the reservoirs, resulting in an insufficient allowable storage capacity of the reservoir because the flood control capacity was reduced, which may have led to their collapse during heavy rainfalls. Therefore, the identification of potential causes of reservoir collapse through the morphological characteristics and HCs of reservoirs are expected to support the operation and management of reservoirs to reduce flood damage.

Optimisation of drainage performance of the thin-walled core barrel sealing technology for pressure preservation sampling

Pressure preservation sampling technology is a crucial method to assess natural gas hydrates. There are limitations to directly applying conventional pressure preservation technology for seafloor drills, such as large and complex structures. The working and design principle of the thin-walled core barrel sealing technique is introduced. To solve the problem of low core recovery percent during sediment drilling, the flow field characteristics of the valve spool in different working conditions are discussed. The area of the cross-section and the calculation method under the typical position are obtained. The valve spool structural parameters are determined and verified by a laboratory drilling test. The results show that: the larger the cone angle of the spool or the smaller the percentage of valve spool cone height to valve spool full cone height (the following is called P), the smaller the opening value when the cross-section area reaches a stable level. When the cone angle is 30, and the P is 20%, the cross-sectional area reaches stable after the opening is 4.5 mm. When the opening exceeds 3.0 mm, the flow rate changes little. When drilling in the sediment, the average coring recovery percent exceeds 70%.

A semi-automated procedure for the emitter–receiver geometry characterization of motor-controlled lidars

Abstract. To correctly understand and interpret lidar-acquired signals and to provide high-quality data, the characterization of the lidar transmitter–receiver geometry is required. For example, being fundamental to correctly align lidar systems, this characterization is useful to improve the efficiency of the alignment procedure. In addition, some applications (e.g. air quality monitoring) need to quantitatively interpret the observations even in the range where the overlap between the telescope field of view and the laser beam is incomplete. This is generally accomplished by correcting for the overlap function. Within the frame of lidar-based networks (e.g. ACTRIS/EARLINET, the Aerosol, Clouds and Trace Gases Research Infrastructure/European Aerosol Research Lidar Network), there is a need to define standardized approaches to deal with lidar geometry issues. The multi-wavelength multi-telescope Rayleigh–Mie–Raman “9-eyes” system in Rome Tor Vergata, part of ACTRIS/EARLINET, has the capability, through computer-controlled servomotors, to change the orientation of the laser beams and the 3D position of the diaphragm of the receiving optical system around the focal point of the telescopes. Taking advantage of these instrumental design characteristics an original approach to characterize the dependency of the acquired signal from the system relative transmitter–receiver geometry (the mapping procedure) was developed. The procedure consists in a set of programs controlling both the signal acquisition as well as the motor movements. The approach includes solutions to account for atmospheric and laser power variability likely to occur during the mapping sessions. The paper describes in detail the developed procedure and applications such as the optimization of the telescope/beam alignment and the estimation of the overlap function. The results of the mapping applied to a single combination of telescope-laser beam are shown and discussed. The effectiveness of the mapping-based alignment was successfully verified by comparing the whole signal profile and the outcome of the telecover test, adopted in EARLINET, for a manual and a mapping-based alignment. A significant signal increase and lowering of the full overlap height (from 1500 m to less than 1000 m) was found. The overlap function was estimated down to 200 m and compared against the one obtained from a geometric model. The developed procedure also allowed estimating the absolute and relative tilt of the laser beam. The mapping approach, even in simplified versions, can be adapted to other lidars to characterize and align systems with non-motorized receiving geometry.

Understanding the Impact of Scale Height on the Kinetics and Kinematics of Dogs in Working Trials.

Working trials is a canine discipline that originated from police and military dog work. One aspect of working trials competition is for a dog to “scale” a 6ft high wooden wall. Concern has been raised in other canine disciplines that landing forces after traversing jumps may lead to soft tissue injuries. There is a paucity of research into the impact of scale height on peak vertical landing force (PVF) in dogs participating in working trials. The aim of this work was to determine whether an alteration in scale height impacts PVF and apparent joint angulation on landing. Twenty-one dogs who regularly competed in working trials traversed the scale at three different heights; 6ft (full height), 5.5ft and 5ft. Changes in PVF, apparent carpal and shoulder joint angulation and duration of landing were analyzed using general linear mixed models. Dogs weighing >25 kg had greater PVF at 6ft than at 5ft (p < 0.05). There was no effect of scale height on PVF in dogs <25kg. Duration of landing was longer at 5ft than 5.5ft (p < 0.001) and 6ft (p < 0.001). Apparent carpus angle on landing was smaller at 6ft than 5ft (p < 0.05) and 5.5ft (p < 0.05) for dogs <25 kg. Apparent carpus angle on landing did not differ at any height for dogs >25 kg (p > 0.05). Apparent shoulder angle was not affected by scale height for any dogs (p > 0.05). There was considerable variation in the study population, but this research indicates that when the scale height was lowered to 5.5ft dogs had reduced PVF and less compressed joint angles on landing. When the scale height was lowered to 5ft they altered their traversing style and greater compression and increased PVF was seen. Evidence-based approaches to canine working trials are important to ensure minimum impacts on physical health and welfare of participating dogs, in terms of risk of injury in both competition and training. Based on these findings it is recommended that the maximum height of the scale is reviewed for training and competitive purposes, to ensure minimal impacts on the health of competing dogs, while maintaining the level of competitive challenge.

Puberty and growth in patients with pediatric intestinal failure

BackgroundPediatric intestinal failure (PIF) affects nutrition, metabolism, and endocrine development, but its downstream impact on puberty is unknown. MethodsA retrospective review was performed of patients age >8 years with PIF managed at an intestinal rehabilitation program. Outcomes of interest were peak height velocity (PHV), age at PHV, and age at pubertal onset (Tanner stage 2). Outcomes were stratified by sex and compared to established norms. ResultsOf 110 patients with PIF, 54.5% were male. Compared to the CDC 50th percentile, PHV in PIF patients was similar for females (8.09±2.36 vs. 7.37 cm/yr;p = 0.23) but significantly higher for males (9.27±2.56 vs. 7.91 cm/yr;p = 0.038). Age at PHV in PIF patients was significantly younger for both males (12.31±2.14 vs. 13.38 years;p = 0.049) and females (10.70±1.06 vs. 11.71 years;p = 0.001). PIF patients reached pubertal onset earlier than published norms; this was significant for males (12.41±1.80 vs. 13.44 years;p = 0.014), but not for females (10.45±1.81 vs. -11.15 years;p = 0.13). The mean height-for-age Z-score was -1.2, with 20% of patients having a Z-score less than -2. ConclusionsPubertal onset and growth are neither delayed nor diminished in patients with PIF. The high incidence of short stature, however, highlights the importance of optimizing prepubertal linear growth to attain full height potential.Type of Study: Prognosis study (Retrospective cohort study)

Performance Research of Materials and Engineering Application of Overburden Strata Separation-Zone Grouting Technology

To solve the ground subsidence problem associated with thick coal seam mining under the railway in the Tangshan Mine, the technology of overburden strata separation-zone grouting (OSSG) was proposed. Based on the analysis of the full height overlying strata structure in the range of the six working face areas of the second mining district, the spatial distribution characteristics of the separation zone within the overlying strata are obtained after fully mining the six working faces. Then, emphasis was placed on the selection ratio of grouting materials and the hydrodynamic properties of different grout types, and grouting grout with a high concentration, slow precipitation rate, and good stability was obtained by taking fly ash and local clay as aggregates. The designed grout concentration was approximately 40%; the bulk density was approximately 1.20; and the clay content in the aggregates was approximately 40–50%. The separation-zone grouting plan was designed for the six working faces, and continuous grouting technology with the characteristics of multiple separation zones within the full-height section with a large flow and a high concentration was proposed to form a complete grouting system and reasonable grouting process. After engineering verification, the technology has an ash injection ratio of 24.2%, a grouting ratio of 100.3%, and a reduction in the ground subsidence ratio of 51.5%, effectively reducing mining damage to the ground surface and ensuring the safe operation of ground surface railways. Simultaneously, this advancement improves the resource recovery rate of coal mines and provides greater benefits for mining enterprises.

HYPSOMETRY AND VOLUMETRY OF Eucalyptus urograndis IN A CROP-FOREST INTEGRATION SYSTEM

Due to the positive impact that the eucalyptus species has on the Brazilian economy, it is currently the most used forest essence. The objective of this work was to evaluate different hypsometric and volumetric models for Eucalyptus urograndis clones (Eucalyptus urophylla S.T. Blak and Eucalyptus grandis W. Hill ex Maiden) in a Crop-Forest Integration (CFI) system. The trees were evaluated at 7 years of age and arranged in double rows, occupying 20.76% of the total system area. The individuals were subjected to rigorous volumetric cubing according to the Smalian method at intervals of one meter up to full height. The following models were evaluated for the collected height data: Linear, Trorey, Stofels, Curtis, Henriksen, Prodan, Chapman &amp; Richards, Petterson and Bailey &amp; Clutter. Furthermore, the Spurr, Hohenald-Krenn, Stoate, Schumacher Hall, Meyer, Husch, Ogaya and Takata models were used for volume data. The results were determined through the coefficient of determination (R2), standard error of the estimate in percentage (Syx%), significance of the regression coefficients (𝛽) and graphical distribution. The hypsometric model which best fit the database among tested models was the Prodan equation, with a coefficient of determination (R²) of 0.89, while the best result for volumetric models was found using the Meyer model, with a coefficient of determination (R²) of 0.99. All evaluated models were efficient in estimating the height and volume of the Crop-Forest Integration (CFI) system, thus demonstrating that GG100 eucalyptus is a good option in integrated systems.

Flexural Behaviour of Different Stiffener Section Area on Full Height Rectangular Opening Castellated Steel Beam

Vierendeel is one of failure mechanisms in a castellated steel beam. Vierendeel mechanism is the main failure that occurs in a full high rectangular opening castellated beam. Vierendeel decrease castellated flexural capacity compare to the original wide flange section beam. One solution to prevent the vierendeel mechanism is by installing a diagonal stiffener in form of a steel bar on a castellated beam. The research’s purpose is finding the effect of different size of steel bar diameter on the flexural capacity. Four different sizes of steel bar diameter used in this research: 10 mm, 12mm, 16 mm, and 19 mm. Castellated beam flexural capacity is analysed with the method of truss analysis and pushover analysis. This study shows it can be infer that the bigger size of steel bar diameter does not always determine the higher flexural capacity of the castellated beam. Optimum value of the beam’s flexural capacity is affected by the strength of the flange section. The largest increment of flexural capacity between original wide flange compare to the castellated beam is 139.4% by using 16 mm diameter of the diagonal stiffener.

ВПЛИВ ЗАТОПЛЕННЯ ВИРОБЛЕНИХ ПРОСТОРІВ ВУГІЛЬНИХ ШАХТ НА ЗСУВИ ЗЕМНОЇ ПОВЕРХНІ НА ПРИКЛАДІ ШАХТИ «КОТЛЯРЕВСЬКА»

Purpose. The study of the influence of mine water rising level of longwalls gob on the activation of deformation processes on the undermined earth’s surface. Methods. In the study was used the method of engineering and graphic analysis for calculating the parameters of the displacement trough according to the normative method. The finite element method that was implemented in the Ansys code was used to carry out studies of the influence of mine water rising level on the deformation of the earth’s surface. The problem is solved in an elastic-plastic setting, taking into account the heterogeneity of rocks. Findings. In accordance with the conditions of the southern part of the mine field, a landslide trough was drawn, and a plan of subsidence isolines was constructed with surface infrastructure objects. Surface objects, the risk of destruction of which increases when the mine water level rises, have been identified. The position of the cut line, which characterizes the most dangerous position, is determined. After the analysis and generalization of the results of the numerical experiment, it was established that the rise of mine water level in the gobs of 1th and 2th southern longwall of the coal seam l1 of Kotlyarevsky mine leads to the activation of landslides on the earth’s surface. At the same time, the vertical subsidence in the displacement trough in the case of flooding (to the full height of the zone of ordered destruction) increases by 22.4%, and the width of the trough increases disproportionately – by 1.3%. This contributes to a significant increase in hazards for surface infrastructure objects due to the increase in slopes and curvatures. Originality consists in establishing of the features of changes in surface displacement in the area of undermined earth’s surface due to the rise of mine water level. Practical implication. The results of the study can be used in the prediction of subsidence and other elements of landslides in the displacement trough, which are activated due to the rise of mine water level. At the same time, the possibility of timely planning and development of a set of measures to protect surface infrastructure objects from the negative impact of undermining is ensured. Keywords: earth’s surface displacement, surface undermine, landslides, displacement trough, rise of mine water level, surface displacement forecast.

Header Shape Effect on the Inlet Velocity Distribution in Cross-Flow Double-Layered Microchannel Heat Sinks

Counter-flow double-layered microchannel heat sinks are very effective for thermal control of electronic components; however, they require rather complicated headers and flow maldistribution can also play a negative role. The cross-flow configuration allows a much simpler header design and the thermal performance becomes similar to that provided by the counter-flow arrangement if the velocity distribution in the microchannels is not uniform. The aim of this work is to show the possibility of achieving a favorable flow distribution in the microchannels of a cross-flow double-layered heat sink with an adequate header design and the aid of additional elements such as full or partial height baffles made of solid or porous materials. Turbulent RANS numerical simulations of the flow field in headers are carried out with the commercial code ANSYS Fluent. The flow in the microchannel layers is modeled as that in a porous material, whose properties are derived from pressure drop data obtained using an in-house FEM code. It is demonstrated that, with an appropriate baffle selection, inlet headers of cross-flow microchannel heat sinks yield velocity distributions very close to those that would allow optimal hotspot management in electronic devices.