Debris Area Research Articles

Study on prediction method of controlled re-entry landing area of large spacecraft

Abstract The present paper proposes a calculation method for predicting the dispersion area of debris during the controlled re-entry of a large spacecraft, aiming to determine the controlled re-entry area accurately. This method involves analyzing the overall re-entry trajectory of the spacecraft as a priority, followed by ablation and disintegration analysis, and subsequently simulating the equipment-level trajectories of potential ground-falling components to obtain the final landing area envelope. Simulation results demonstrate that this approach effectively determines the controlled re-entry area, providing essential technical support for formulating implementation plans while ensuring safe and reliable reentries of large spacecraft into predetermined areas. Notably, this method has been successfully applied in previous missions such as Tianzhou-1 to Tianzhou 6 and can be further extended to subsequent controlled reentries involving Tianzhou-series cargo spacecraft and other low-orbit satellites.

Crack failure behaviors of Ti–6Al–4V dovetail joints subjected to fretting fatigue and effect of laser shock dimple-textured surface coated with diamond-like carbon film

Fretting damage can lead to a reduction in fatigue strength by more than half, due to the increased stress on the fretting surface, which accelerates crack initiation and propagation. Laser shock peening (LSP) technology is an advanced method for protecting against fretting fatigue, which reduces the effective stress on the fretting surface of components by introducing a deeper compressive residual stress field. In this work, LSP was utilized to create regularly arranged dimples on the surface of titanium alloy dovetail joints, and followed by diamond-like carbon (DLC) coating to alter fretting friction. Five surface treatment samples including as-machined, conv-LSP, LSP dimple-textured, DLC, LSP dimple-textured + DLC, were prepared for fretting fatigue tests on dovetail joints. The experimental results showed that the fatigue performance of specimens treated with LSP dimple-textured + DLC is better. Furthermore, it is found that wear debris from fretting surface was discharged into crack source area during fretting fatigue, leading to the formation of a fracture debris area forms in the crack initiation zone. The crack initiation zone displays the protrusion morphology characteristics due to the friction effect induced by contact loads. There is an internal correlation between the size of fracture debris area and surface wear resistance. Fracture debris area and the protrusion morphology vary with surface treatments and applied load. This research further reveals that the variation characteristics of the crack initiation area including the fracture debris area, have a positive influence on observing and analyzing failure behavior of fretting fatigue damage.

Agroecological Transformation: Implementation of an Agroforestry System in a Construction Debris Area Focusing on Vegetables Development through Microbial Treatments

Soil microorganisms play an important role on plant development and the homogenization of soil microbiomes is harmful to agri-environments. It is essential that agricultural practices are carried out by taking soil microbiome preservation in consideration. Agroforestry systems are one of the most environmentally friendly agrosystems and its plant diversity directly influences the soil microbiome diversity. In this study, we tested the efficacy of the microbial consortium (MC) obtained from compost and the cyanobacteria Arthrospira platensis (Ap) compared with the application of the vermicompost tea (VT) and bokashi (Bk) in arugula, lettuce, beetroot, and carrot in two seasons in a recently implemented agroforestry system. We aimed to verify if MC and Ap could be new promising sustainable alternatives in vegetables production. The strategy can be broken down into three stages: (1) Green manure management: planting, cutting, griding, and incorporation in the soil, (2) agroforestry system implementation, and (3) treatment application in a completely randomized blocks design. The vegetables yield was measured. Nutritional traits and the plant root system were evaluated for arugula and lettuce. Greater plant yield, nutritional values, and plant root development were observed in the MC-treated plants; Ap and Bk had, in general, similar results. Our data show that both MC and Ap have potential to become a sustainable product for agricultural production.

Nanonetwork-based search and rescue operations in debris areas

Earthquake is one of the most destructive natural disasters. It is vital to carry out search and rescue (SAR) operations in the debris area after such a major disaster. Although there are various technologies to rescue living things in the debris area, reaching narrow gaps in the rubble is a very difficult process. Nanonetworks operating on terahertz (THz) communication channels are composed of thousands of nanodevices that can pass through even ultrasmall gaps. In this paper, we propose an application that utilizes nanodevices for SAR operations in debris areas. To the best of our knowledge, our paper is the first study to provide a detailed and specialized analysis of this application. We work on channel models by extensively analyzing transmittance, propagation loss, absorption loss, path loss, signal-to-noise ratio (SNR), and capacity. Besides, we investigate a physical layer (PHY) model by considering the effects of using directional or omnidirectional antennas to ensure optimal throughput and energy consumption. Moreover, we present an exhaustive performance analysis of the modulation technique with respect to various nanodevice counts and densities.

AutoBar: Automatic Barrier Coverage Formation for Danger Keep Out Applications in Smart City.

Barrier coverage is a fundamental application in wireless sensor networks, which are widely used for smart cities. In applications, the sensors form a barrier for the intruders and protect an area through intrusion detection. In this paper, we study a new branch of barrier coverage, namely warning barrier coverage (WBC). Different from the classic barrier coverage, WBC has the inverse protect direction, which moves the sensors surrounding a dangerous region and protects any unexpected visitors by warning them away from the dangers. WBC holds a promising prospect in many danger keep out applications for smart cities. For example, a WBC can enclose the debris area in the sea and alarm any approaching ships in order to avoid their damaging propellers. One special feature of WBC is that the target region is usually dangerous and its boundary is previously unknown. Hence, the scattered mobile nodes need to detect the boundary and form the barrier coverage themselves. It is challenging to form these distributed sensor nodes into a barrier because a node can sense only the local information and there is no global information of the unknown region or other nodes. To this end, in response to the newly proposed issue of the formation of barrier cover, we propose a novel solution AutoBar for mobile sensor nodes to automatically form a WBC for smart cities. Notably, this is the first work to trigger the coverage problem of the alarm barrier, wherein the regional information is not pre-known. To pursue the high coverage quality, we theoretically derive the optimal distribution pattern of sensor nodes using convex theory. Based on the analysis, we design a fully distributed algorithm that enables nodes to collaboratively move toward the optimal distribution pattern. In addition, AutoBar is able to reorganize the barrier even if any node is broken. To validate the feasibility of AutoBar, we develop the prototype of the specialized mobile node, which consists of two kinds of sensors: one for boundary detection and another for visitor detection. Based on the prototype, we conduct extensive real trace-driven simulations in various smart city scenarios. Performance results demonstrate that AutoBar outperforms the existing barrier coverage strategies in terms of coverage quality, formation duration, and communication overhead.

Study on the Legal Regime for Space Debris Mitigation — Taking the Inter-Agency Space Debris Coordination Committee Space Debris Mitigation Guidelines as an Example

As human space activities continue, the problem of space debris which is regarded as the “killer of satellites, spacecraft, and space shuttles”, remains unresolved. 2021 saw the release of the latest version of the IADC Space Debris Mitigation Guidelines (hereinafter referred to as the IADC Guidelines), the only remediation program to date that has had a significant positive impact on addressing the accumulation of space debris. The IADC Guidelines complement the body of outer space law in the area of space debris and provide a good model for addressing the issue of space debris mitigation. The present paper proposes a path for the future development of the IADC Guidelines to contribute to the improvement of the legal regime for space debris mitigation.

Spatial differences of ice volume across High Mountain Asia

Advanced knowledge of glacier ice volume is vital for water resource assessment. Previous studies have focused on the estimation of ice volume, but the quantitative understanding of the spatial variability of ice volume across High Mountain regions is currently lacking. Here, we used global-scale ice thickness, debris cover and equilibrium line data to analyse ice-volume differences at various scales across High Mountain Asia (HMA). The results showed that 6.3% of the HMA glaciers are covered by debris, with debris area and volume accounting for 9% and 13.8% of the total glacier area and volume, respectively. An average debris-cover volume ratio of 13% was observed. The spatial distribution of ice volume across the HMA varies considerably from region to region. The ice volume is predominately distributed on north-facing slopes and accounts for approximately 38% of the total. It is very common in Altay and Sayan, East Tian Shan, West Kunlun, East Kunlun and Qilian Shan. Meanwhile, ice volumes in the Himalayas and Hengduan Shan are mainly distributed on the southeast aspect. Relative weight functions showed that glacier area, maximum length and average thickness are closely related to ice volume, with average relative weights of 63.7%, 22.5% and 9.8%, respectively. This study is important for the evolution of glacier volume and water resource assessment.

Floating Debris in the Northern Gulf of Mexico after Hurricane Katrina.

Hurricane Katrina (category 5 with maximum wind of 280 km/h when the eye is in the central Gulf of Mexico) made landfall near New Orleans on August 29, 2005, causing millions of cubic meters of disaster debris, severe flooding, and US$125 billion in damage. Yet, despite numerous reports on its environmental and economic impacts, little is known about how much debris has entered the marine environment. Here, using satellite images (MODIS, MERIS, and Landsat), airborne photographs, and imaging spectroscopy, we show the distribution, possible types, and amount of Katrina-induced debris in the northern Gulf of Mexico. Satellite images collected between August 30 and September 19 show elongated image features around the Mississippi River Delta in a region bounded by 92.5°W-87.5°W and 27.8°N-30.25°N. Image spectroscopy and color appearance of these image features indicate that they are likely dominated by driftwood (including construction lumber) and dead plants (e.g., uprooted marsh) and possibly mixed with plastics and other materials. The image sequence shows that if aggregated together to completely cover the water surface, the maximal debris area reached 21.7 km2 on August 31 to the east of the delta, which drifted to the west following the ocean currents. When measured by area in satellite images, this perhaps represents a historical record of all previously reported floating debris due to natural disasters such as hurricanes, floodings, and tsunamis.

Interdecadal glacier inventories in the Karakoram since the 1990s

Abstract. Multi-temporal glacier inventories provide key information about the glaciers, their characteristics, and changes and are inevitable for glacier modelling and investigating geodetic mass changes. However, to date, no consistent multi-temporal glacier inventory for the whole of the Karakoram exists, negatively affecting the monitoring of spatio-temporal variations in glaciers' geometric parameters and their related applications. We used a semi-automatic method combining automatic segmentation and manual correction and produced a multi-temporal Karakoram glacier inventory (KGI) compiled from Landsat TM/ETM+/OLI (Thematic Mapper, Enhanced Thematic Mapper Plus, and Operational Land Imager) images for the 1990s, 2000s, 2010s, and 2020s. Our assessments using independent multiple digitisation of 37 glaciers show that the KGI is sufficiently accurate, with an overall uncertainty of ±3.68 %. We also performed uncertainty evaluation for the contiguous glacier polygons using a buffer of half a pixel, which resulted in an average mapping uncertainty of ±5.21 %. We calculated more than 20 attributes for each glacier, including coordinates, area, supraglacial debris area, date information, and topographic parameters derived from the ASTER GDEM (Advanced Spaceborne Thermal Emission and Reflection Radiometer global digital elevation model). According to KGI-2020s, approximately 10 500 alpine glaciers (>0.01 km2 each) cover an area of 22 510±828 km2 of which 10.18±0.38 % (2290±84 km2) is covered by supraglacial debris. Over the past 3 decades, the glaciers experienced a loss of clean ice and/or snow area but a gain in supraglacial debris. Supraglacial debris cover has increased by 17.63±1.44 % (343.30±27.95 km2), while non-debris-covered glaciers decreased by 1.56±0.24 % (319.85±49.92 km2). The total glacier area was relatively stable and showed only a slight insignificant increase of 23.45±28.85 km2 (0.10±0.13 %). The glacier area has declined by 3.27±0.24 % in the eastern Karakoram, while the glacier area slightly increased in central (0.65±0.10 %) and western Karakoram (1.26±0.11 %). Supraglacial debris has increased over the whole of Karakoram, especially in areas above 4200 m a.s.l. (above sea level), showing an upward shift. The glacier area changes were characterised by strong spatial heterogeneity, influenced by surging and advancing glaciers. However, due to global warming, the glaciers are on average retreating. This is in particular true for small and debris-free glaciers. The multi-temporal KGI data are available at the National Cryosphere Desert Data Center of China: https://doi.org/10.12072/ncdc.glacier.db2386.2022 (F. Xie et al., 2022).

Fatigue failure mechanism of aluminium alloy riveted single-shear lap joints

The fatigue life of the joint, the evolution process of the contact interface damage and the fatigue fracture behaviour of the joint were studied through a fatigue test of an aluminium alloy single-shear lap joint riveted by a swage-locking pin. Combined with optical microscope (OM), scanning electron microscope (SEM), electron probe microanalyzer (EPMA) and three-dimensional white light interferometry (WLI) and other equipment, and using computer image recognition algorithm, the characteristics and area of debris at the interface of the lap-plate under different cycles were studied, and the damage evolution process of the contact area was revealed. Results show two fatigue failure modes of the joint under different fatigue loads. The contact at the interface is non-uniform, and two morphologies are observed in the contact area: wear and non-wear areas. As the cycles increased from 130,000 to 230,000, the debris area in the contact area increased by 22%, while that in the non-contact area increased by 152%. Micro-cracks are generated in the contact area under the action of fretting wear, and the highest maximum principal stress exists at the crack source.

On Launching Environmental Law into Orbit in the Age of Satellite Constellations

In September 2022, the Federal Communications Commission adopted a new rule changing the deorbiting timeframe for satellites ending their missions in low Earth orbit from a twenty-five-year recommendation to a five-year legal requirement. The adoption of this rule, which seeks to cultivate a sustainable orbital environment for satellites, followed the United States’ July 2022 National Orbital Debris Implementation Plan, which tasked federal agencies with reviewing the effectiveness of their orbital debris-related rules. In the wake of the Supreme Court’s June 2022 West Virginia v. EPA decision, however, federal rulemaking in the area of orbital debris may not survive judicial scrutiny in the absence of explicit congressional authorization to do so. The purpose of this Article is to provide arguments for why Earth’s orbital environment should be protected under the National Environmental Policy Act and to provide draft legislation that is responsive to both the Orbital Debris Plan and the Supreme Court’s recent EPA ruling, which will enable FCC rulemaking in the area of orbital debris.

Experimental investigation on strength-weakening effect and fracture behavior of red sandstone under coupled static and dynamic cyclic loadings

Underground rock masses are often exposed to dynamic disturbances due to seismic waves and blasting excavation disturbances, resulting in significant changes in their physical and mechanical properties. To reveal the strength-weakening effect of rock under the coupled stress, the Brazilian disc tests of red sandstone were carried out by coupling pre-static and dynamic disturbing. The impacts of preloading, loading wave amplitude, dynamic disturbance frequency, and cycle number were studied on the weakening of Brazilian disc splitting strength. Furthermore, the fracture behaviors were characterized and discussed from the fracture morphology and fractal dimension. The results show that the loss ratios are positive under dynamic disturbance loading, indicating that the Brazilian splitting strength is weakened. For the same load wave amplitude, the loss of strength and P-wave velocity under 70 % preloading is more than twice that under 55 % preloading. At high preloading, the maximum strength loss and wave velocity losses are 13.7 % and 19.2 %, respectively. Comparing the disturbance degree of the sample with the increase of frequency by 1 Hz, cycle number by one time, and load wave amplitude by 1 % PS, it is concluded that the decline of wave velocity for the rock sample with the increase by 1 % PS in load wave amplitude is the largest, followed by the frequency and cycle. Only micro-cracks appear on the fracture surface under pure static loading. However, when the dynamic load disturbance is applied, the cement wrapped with debris falls off, besides micro-cracks. And with the increase of amplitude, the area of bare debris also progressively intensifies. Meanwhile, the width and number of micro-cracks gradually increased, with the broadest micro-crack reaching 18.2 μm. Preloading, loading wave amplitude, loading frequency, and cycles are positively correlated with fractal dimension D. The higher the D value, the more broken the sample.

Categorization of Debris Flow And Its Prediction along The Highway Roadside of Duhok- Shekhan

Debris flow is caused by various triggers including intensive rainfall, snowmelt, and earthquakes. Quantifying the number, area, and volume of debris is critical to determine debris volume and its risks. Soil physical analysis in conjunction with laboratory geotechnical soil properties of some selected site along the highway roadsides of Duhok-Shekhan assisted in developing empirical models to predict debris flows volume from some input parameters like area, vegetation cover percent, and, the site slope. The debris flow volume was based on measuring (the length, width, and depth) of the individual debris flow sites. The results indicated that debris flows were significantly correlated with debris flow area. In contrast, it was poorly correlated with each of the vegetation cover percentages and site slope; Furthermore, it was shown that the debris flow can be predicted with reasonable accuracy at this stage of study by an exponential model based on debris flow area only. This will enable the responsible agents to take measures to mitigate the risk of a debris flow along the highway roadsides in the study area

The impact of terrain model source and resolution on snow avalanche modeling

Abstract. Natural hazard models need accurate digital elevation models (DEMs) to simulate mass movements on real-world terrain. A variety of platforms (terrestrial, drones, aerial, satellite) and sensor technologies (photogrammetry, lidar, interferometric synthetic aperture radar) are used to generate DEMs at a range of spatial resolutions with varying accuracy. As the availability of high-resolution DEMs continues to increase and the cost to produce DEMs continues to fall, hazard modelers must often choose which DEM to use for their modeling. We use satellite photogrammetry and topographic lidar to generate high-resolution DEMs and test the sensitivity of the Rapid Mass Movement Simulation (RAMMS) software to the DEM source and spatial resolution when simulating a large and complex snow avalanche along Milford Road in Aotearoa/New Zealand. Holding the RAMMS parameters constant while adjusting the source and spatial resolution of the DEM reveals how differences in terrain representation between the satellite photogrammetry and topographic lidar DEMs (2 m spatial resolution) affect the reliability of the simulation estimates (e.g., maximum core velocity, powder pressure, runout length, final debris pattern). At the same time, coarser representations of the terrain (5 and 15 m spatial resolution) simulate avalanches that run too far and produce a powder cloud that is too large, though with lower maximum impact pressures, compared to the actual event. The complex nature of the alpine terrain in the avalanche path (steep, rough, rock faces, treeless) makes it a suitable location to specifically test the model sensitivity to digital surface models (DSMs) where both ground and above-ground features on the topography are included in the elevation model. Considering the nature of the snowpack in the path (warm, deep with a steep elevation gradient) lying on a bedrock surface and plunging over a cliff, RAMMS performed well in the challenging conditions when using the high-resolution 2 m lidar DSM, with 99 % of the simulated debris volume located in the documented debris area.

Equine cutaneous habronematidosis

Clinical history: A 4-year-old Quarter Horse stallion was unsuccessfully treated for a circumscribed and ulcerated lesion of unknown duration located lateral to the prepuce. Microscopic description: The superficial and deep preputial dermis contains multifocal to coalescing, well-demarcated eosinophilic granulomas characterized by a central area of abundant eosinophilic necrotic debris mixed with degenerate eosinophils surrounded by numerous epithelioid macrophages and occasional multinucleated giant cells (foreign-body type), rimmed by ill-defined layers of fibrous connective tissue. In the center of the granulomas, there are cross-sections of degenerate nematode larvae. The adjacent dermal collagen is expanded by dense inflammatory infiltrate composed mainly of eosinophils and a few lymphocytes and plasma cells. The dermal microvasculature is prominent, with hypertrophic reactive endothelial lining. There is also vascular proliferation amidst perpendicularly oriented plump fibroblasts embedded in collagen (granulation tissue). In addition, there are numerous shrunken, hypereosinophilic, fragmented or hyalinized collagen bundles, occasionally surrounded by degranulated eosinophils.

Relationship between ocean area and incidence of anthropogenic debris ingested by longnose lancetfish (Alepisaurus ferox)

Marine debris is present between the sea surface and the sea floor, but few studies have investigated plastic in water column. Therefore, we chose longnose lancetfish (Alepisaurus ferox) as a sample, this study samples mesopelagic species that ingest marine debris in the water column. We conducted a survey of the stomach contents of longnose lancetfish caught by longline fishing in three areas (Sagami Bay, Northwestern Pacific Ocean about 190 km southeast of Kyushu, Indian Ocean about 1200 km southwest of Sumatra Island, Indonesia). A total of 164 longnose lancetfish were caught. Our results highlighted four marine debris patterns. First, longnose lancetfish caught near the coast had a higher frequency of ingested anthropogenic items (Sagami Bay: 69%) than longnose lancetfish caught in the open ocean area (Northwestern Pacific Ocean: 13%, Indian Ocean: 18%). Second, the size of the plastic present in the ocean in the sea area close to the coast ingested by longnose lancetfish tended to be smaller than in the open ocean area. Third, 93% of the anthropogenic items obtained from the stomach were plastic, of which ¿90% was either polypropylene (PP) or polyethylene (PE). And last, the sources of marine debris in the middle and deep regions of the open ocean are fishing activities carried out in that sea area and items that drift from the land without losing buoyancy. Our research makes new discoveries about characteristics of the marine debris in the ocean.

Forecasting the stranded area of marine debris in Indonesian coasts using mobidrift model and floating drifter

The problem of marine debris became a concern of world scientists that placed Indonesia as the second contributor of the world. Plastic litter that leaked from the land and came through the river is a major source of Indonesia marine debris. This marine debris is a serious threat for ocean and coastal ecosystems. The Ministry of Marine Affairs and Fisheries of Indonesia supports the Presidential Regulation to reduce the plastic litter to 70% by 2025 by developing numerical modeling of marine plastic litter trajectory. Using a user-friendly web portal interface, we can simulate the trajectory of marine plastic litter from different points of source at different seasons. Wind, current, and tide data were used to force the particle on the simulation. The result of the model was compared with the record of the real time movement of twenty drifters that were released from three rivers mouth. The development of this trajectory model will become a useful tool to provide the information of the movement of marine debris in Indonesian sea waters and beyond. Knowing the path and stranded location in each season will improve our policy of planning and mitigate the impact of marine debris.

Modelling supraglacial debris-cover evolution from the single-glacier to the regional scale: an application to High Mountain Asia

Abstract. Currently, about 12 %–13 % of High Mountain Asia’s glacier area is debris-covered, which alters its surface mass balance. However, in regional-scale modelling approaches, debris-covered glaciers are typically treated as clean-ice glaciers, leading to a bias when modelling their future evolution. Here, we present a new approach for modelling debris area and thickness evolution, applicable from single glaciers to the global scale. We derive a parameterization and implement it as a module into the Global Glacier Evolution Model (GloGEMflow), a combined mass-balance ice-flow model. The module is initialized with both glacier-specific observations of the debris' spatial distribution and estimates of debris thickness. These data sets account for the fact that debris can either enhance or reduce surface melt depending on thickness. Our model approach also enables representing the spatiotemporal evolution of debris extent and thickness. We calibrate and evaluate the module on a selected subset of glaciers and apply GloGEMflow using different climate scenarios to project the future evolution of all glaciers in High Mountain Asia until 2100. Explicitly accounting for debris cover has only a minor effect on the projected mass loss, which is in line with previous projections. Despite this small effect, we argue that the improved process representation is of added value when aiming at capturing intra-glacier scales, i.e. spatial mass-balance distribution. Depending on the climate scenario, the mean debris-cover fraction is expected to increase, while mean debris thickness is projected to show only minor changes, although large local thickening is expected. To isolate the influence of explicitly accounting for supraglacial debris cover, we re-compute glacier evolution without the debris-cover module. We show that glacier geometry, area, volume, and flow velocity evolve differently, especially at the level of individual glaciers. This highlights the importance of accounting for debris cover and its spatiotemporal evolution when projecting future glacier changes.

Прямая лазерная запись и исследование оптофлюидных элементов внутри нанопористой силикатной матрицы

The paper demonstrates direct laser writing by femtosecond laser pulses (λ = 1030 nm, τ = 220 fs, v = 200 kHz) of functional optofluidic elements inside a nanoporous silicate matrix (NPSM). The influence of focused laser pulses led to the compaction of the nanoporous frame, which made it possible to fabricate barriers for the isolation of nanoporous cells and channel optical waveguides. The writing of microchannels in the mode of decompression of a nanoporous matrix with subsequent purification of area of debris in distilled water under the action of ultrasound is also demonstrated. For each type of elements, the dependences of geometric characteristics on the energy parameters of laser radiation are established. The methods of testing the elements were also developed - checking the permeability of the barrier, the entering of laser radiation into channel waveguides.

Direct Laser Writing and Investigation of Optofluidic Elements inside Nanoporous Silicate Matrix

The paper demonstrates direct laser writing by femtosecond laser pulses (λ = 1030 nm, tau = 220 fs, v = 200 kHz) of functional optofluidic elements inside a nanoporous silicate matrix (NPSM). The influence of focused laser pulses led to the compaction of the nanoporous frame, which made it possible to fabricate barriers for the isolation of nanoporous cells and channel optical waveguides. The writing of microchannels in the mode of decompression of a nanoporous matrix with subsequent purification of debris area in distilled water under the action of ultrasound is also demonstrated. For each type of elements, the dependences of geometric characteristics on the energy parameters of laser radiation are established. The methods of testing the elements were also developed --- checking the permeability of the barrier, the entering of laser radiation into channel waveguides. Keywords: Direct laser writing, femtosecond laser pulses, barriers, waveguide, microchannel, porous silicate matrix, nanopores.