Block Shape Research Articles

Analytic representative element rate decline models for naturally fractured reservoir depletion

Representative single anisotropic matrix block 2D Green’s function models for depletion through fully-penetrating, vertical fractures through different numbers of fracture faces are constructed that analytically capture both fracture and block depletion with fracture-matrix mass transfer. The 1D Green’s function for a fracture system is likewise solved in terms of the time evolution of average fracture pressure. While transient average pressure values are not inherently measurable, they are transformed into cumulative production or instantaneous flowrate values, thus producing new rate decline model functional forms. Primary variables in assembling the interacting systems model are the volume ratio, Vf /Vm, permeability ratio, kf /kx, and geometry, (a/b)(ky/kx), with the last term accounting for both block shape and permeability anisotropy. We construct interacting systems models in terms of various ratios of Vf /Vm, and kf /kx for three fracture architecture prototypes: representative matrix blocks depleted by 4, 2, or 1 contacting fractures. The single matrix block models can be migrated to ones for heterogeneous systems using superposition and matrix block distributions, as demonstrated with a binary distribution of block sizes with variable fractions. Analytic solutions for rate decline problems can be used to understand the production signatures of naturally fractured reservoirs and interpretation of fracture volume fraction, permeability ratio, average matrix block size, and measures of heterogeneity.

Formula Optimization and Product Design Analysis of Nougat with Purple Sweet Potato (Ipomoea batatas L), Cowpea (Vigna unguiculata L.) and Stevia Leaves (Stevia rebaudiana)

This study aims to determine the priority attributes of nougat with purple sweet potato, cowpea, and stevia leaves, optimize the nougat formulation from the organoleptic aspect, and determine the physicochemical characteristics of nougat. The research method used the Kano model and the central composite design (CCD) response surface methodology (RSM). The results of this study indicate that the attributes that influence consumer satisfaction are purple color, block shape, and low-calorie natural sweeteners. The optimum formulations obtained from purple sweet potato, cowpea, and stevia leaves were 20%, 1.5%, and 0.15% (Formula A14). Nougat products produce a moisture content of 6.09%-7.35%, ash content of 0.73%-1.95%, reducing sugar content of 11.50-17.11%, sucrose content of 35.14-49.38%, total color difference of 38.15-85.40; and hardness 0.357835-10.455 N. All formulations comply with SNI 3547.2-2008 (soft candy not jelly).

Development Of Paving Block Pave Structure Based On Type Of Pattern In Light Traffic For Traffic Safety And Comfort

Factors that cause accidents include traffic characteristics and road infrastructure, environmental conditions, vehicle design and specifications, and human factors. The object of this study is road infrastructure, namely the road structure at traffic light stops points because the accident hazard at crossroads is a determinant of traffic safety and driving comfort. In Coastal Area/Upstream Area, To overcome road infrastructure problems at traffic light points which are the cause of traffic safety and driving comfort, the design of Concrete block pavement is one of the solutions to overcome these problems. Concrete block pavement is often used for the construction of sidewalks, bicycle paths, residential driveways, parking lots, industrial areas as well as harbors and airports and other permeable areas. Concrete block pavement is used in Europe in extreme weather. Specially designed concrete block pavement innovations can withstand heavy static traffic loads such as rigid pavements, and these can be readjusted easily if a change in pavement layout is required. The method used in this study uses pure experimentation with the parameters of the variation of the pattern, the variation of the type, and the variation of the dimensions. This research uses the Autocad, PLAXIS and SAP2000 programs. This program finds moments and deformations that occur in the modeled paving blocks as well as soil deflections that occur due to deformation loads in various shapes (brick). The results obtained from the analysis of previous research show that there is the most optimum shape among the brick paving block shapes with a thickness of 6, 8 and 10 cm. The way to determine it is to make a paving block preparation simulation with the SketchUp, PLAXIS and SAP2000 programs. From the program calculations, the interlocking aspects, land subsidence and deformation aspects are produced.

Green Synthesis of Cu<sub>2</sub>O Nanoparticles and Their Application for the Photodegradation of Methyl Orange in Aqueous Media

The existence of colorants in water has caused many disadvantages to aquatic systems and the environment. Scientists have made efforts to decompose and remove them using many different methods. In this study, Cu2O nanoparticles were synthesized with a mixture of reducing agents, including glucose and ascorbic acid, as a photocatalyst for decomposing azo dyes. The prepared nano Cu2O was fully characterized using scanning electron microscope (SEM) imaging, X-ray diffraction (XRD) diffraction measurements, and band gap energy determination. The obtained nano Cu2O was of a uniform truncated block shape with particle size ranging from 50 to 150 nm. The prepared nano Cu2O showed remarkable photocatalytic behavior toward methyl orange under visible light radiation with the removal percentage of 95.46% after 4 hours of reaction. In addition, the catalyst can be reused many times without much impact on catalytic efficiency. Photocatalytic degradation using Cu2O nanoparticles is a promising method for the removal of methyl orange, contributing to creating a safe and sustainable environment.

Variation of the shapes of catalytic blocks in the autothermal reforming of hexadecane, propane and methane using mathematical modeling

In this work, mathematical modeling of the autothermal reforming of hexadecane, propane and methane on catalytic blocks of different geometric shapes was carried out. It was shown that the convex shape of the block towards the oncoming reaction flow can increase the maximum temperature in the frontal zone, while the concave shape contributes to a more uniform temperature distribution along the entire length of the catalytic layer. The work also investigated the effect of the reaction flow rate on the change in the temperature gradient, which can subsequently be used to prevent the formation of hot spots and catalyst deactivation. The results obtained can serve as the basis for future research in the field of autothermal reforming and optimization of the geometric parameters of catalysts for the conversion of hydrocarbon fuels into synthesis gas.

Dog identification based on textural features and spatial relation of noseprint

This study proposes dog identification technology based on dog noseprints, which are equivalent to human fingerprints and possess unique characteristics. The aim is to utilize this technology for identifying and managing stray animals. The study presents three processing stages. In the first stage, YOLOv3 detects the dog's nose and nostril regions. The second stage involves enhancing the image's contrast and the contour of the scaly block using the multi-scale line detector. Finally, in the third stage, the shape and spatial features of the scaly block are extracted and utilized for dog identification. The study included a dataset of 276 dogs from multiple animal families and public shelters in Taiwan. The dataset was randomly divided into three groups to determine the optimal parameters for matching the dog noseprint via experimentation. Each dog identification group achieved an accuracy (ACC) exceeding 97.83 %, demonstrating that the proposed parameter-matching method offers high stability. Furthermore, in an additional experimental dataset consisting of dog noseprint images used for dog identification, the proposed method achieved an ACC exceeding 90.22 % in the Top 1 and 94.57 % in the Top 3. The ACC results across different groups consistently demonstrate the proposed method's ability to achieve high accuracy in dog identification. The source code and trained models are publicly available at: https://github.com/Chuen-HorngLin/Dog-Identification-Noseprint.

Experimental and numerical evaluation of geometrical imperfection effects on the load bearing capacity of small-scaled voussoir arches

The study of the behaviour of masonry arches represents a complex problem, which involves different aspects that can significantly affect the load bearing capacity of such structures. In this regard, geometrical imperfections, such as the irregular shape of the arch blocks, the initial position of the first and last voussoirs (boundary conditions), the alignment between the adjoining blocks and the rounded corners of each block, play an important role. An experimental campaign was conducted on a toy arch made by eleven irregular blocks, with the aim of evaluating the effect of such irregularities. A numerical model was developed basing on lower bound (LB) and upper bound (UB) limit analysis approaches (referred to as the static and the kinematic theorem, respectively). A linear programming (LP) solving algorithm was implemented in the software MATLAB and used to solve the minimization/maximization problems. The probability distribution of each considered nonlinearity was estimated, the results of the numerical analysis were correlated with the experimental outcomes and a Montecarlo simulation was carried out to validate the hypothesised probability distributions.

Microstructure and Wear Resistance of Si-TC4 Composite Coatings by High-Speed Wire-Powder Laser Cladding.

The hardness and wear resistance of the surface of TC4 titanium alloy, which is widely used in aerospace and other fields, need to be improved urgently. Considering the economy, environmental friendliness, and high efficiency, Si-reinforced Ti-based composite coatings were deposited on the TC4 surface by the high-speed wire-powder laser cladding method, which combines the paraxial feeding of TC4 wires with the coaxial feeding of Si powders. The microstructures and wear resistance of the coatings were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), Vickers hardness tester, and friction and wear tester. The results indicate that the primary composition of the coating consisted of α-Ti and Ti5Si3. The microstructure of the coating underwent a notable transformation process from dendritic to petal, bar, and block shapes as the powder feeding speed increased. The hardness of the composite coatings increased with the increasing Si powder feeding rate, and the average hardness of the composite coating was 909HV0.2 when the feeding rate reached 13.53 g/min. The enhancement of the microhardness of the coatings can be attributed primarily to the reinforcing effect of the second phase generated by Ti5Si3 in various forms within the coatings. As the powder feeding speed increased, the wear resistance initially improved before deteriorating. The optimal wear resistance of the coating was achieved at a powder feeding rate of 6.88 g/min (wear loss of 2.55 mg and friction coefficient of 0.12). The main wear mechanism for coatings was abrasive wear.

Enhancing shipyard transportation efficiency through dynamic scheduling using digital twin technology.

Uncertainties, such as road restrictions at shipyards and the irregular shape of blocks, pose challenges for transporter scheduling. Efficient scheduling of multiple transporters is critical to improving transportation efficiency. The digital twin (DT) technology offers numerous benefits, enabling interactions between the virtual and real worlds, real-time mapping, and dynamic performance evaluation. Based on DT technology, this study proposes a dynamic scheduling approach for cooperative transportation utilizing multiple transporters. The scheduling problem for multiple transporters is addressed and modeled in this study, considering factors such as block size and transporter loading. To solve this problem, a framework of DT-based multiple transporters system is established in a virtual environment. By inputting block information into this system, a solution is generated using transporter scheduling rules and interference detection methods. Experimental comparisons are conducted in this paper, exploring various scenarios with different number of tasks and the application of DT. The results demonstrate that the proposed approach effectively enhances transportation efficiency and improves ship construction efficiency. Hence, this study expands the application of DT technology in dynamic scheduling of transportation in shipyards and provides new ideas for shipbuilding company managers.

Coevolving edge rounding and shape of glacial erratics: the case of Shap granite, UK

Abstract. The size distributions and the shapes of detrital rock clasts can shed light on the environmental history of the clast assemblages and the processes responsible for clast comminution. For example, mechanical fracture due to the stresses imposed on a basal rock surface by a body of flowing glacial ice releases initial “parent” shapes of large blocks of rock from an outcrop, which then are modified by the mechanics of abrasion and fracture during subglacial transport. The latter processes produce subsequent generations of shapes, possibly distinct in form from the parent blocks. A complete understanding of both the processes responsible for block shape changes and the trends in shape adjustment with time and distance away from the source outcrop is lacking. Field data on edge rounding and shape changes of Shap granite blocks (dispersed by Devensian ice eastwards from the outcrop) are used herein to explore the systematic changes in block form with distance from the outcrop. The degree of edge rounding for individual blocks increases in a punctuated fashion with the distance from the outcrop as blocks fracture repeatedly to introduce new fresh unrounded edges. In contrast, block shape is conservative, with parent blocks fracturing to produce self-similar “child” shapes with distance. Measured block shapes evolve in accord with two well-known models for block fracture mechanics – (1) stochastic and (2) silver ratio models – towards one or the other of these two attractor states. Progressive reduction in block size, in accord with fracture mechanics, reflects the fact that most blocks were transported at the sole of the ice mass and were subject to the compressive and tensile forces of the ice acting on the stoss surfaces of blocks lying against a bedrock or till surface. The interpretations might apply to a range of homogeneous hard rock lithologies.

Rock mass classification in slope engineering with special emphasis on Slope mass rating: Current status and future projections

Rock mass classification (RMC) systems in the realm of rock slope engineering have gathered a lot of attention. The present review article delves into the major RMC systems, elucidating their fundamental principles, key parameters and practical applications. Among the various RMC systems for rock slope designing, Romana's Slope mass rating (SMR) was found to be the most comprehensive; therefore, the focus of the discussion centres around the SMR method. The article provides a crisp overview of the major advancements, evolution and potential challenges of SMR. The radical concept of wedge failure in SMR and the use of continuous functions are discussed in detail. A thorough discussion is provided on the efforts made by different researchers, encompassing the inclusion of novel factors such as slope height, heterogeneity in rock mass or lithology, weighted consideration of existing discontinuities, fuzzy sets and overburden thickness. Various automated calculation techniques and empirical correlations of SMR with other classification systems and rock engineering parameters are also outlined. Moreover, a critical examination of the variations among major extensions of SMR and their geotechnical relevance have also been discussed. Based on a meticulous assessment of the susceptibility to toppling failure in SMR, two sub‐factors to include block shape and interlayer slip between discontinuities have been suggested. These sub‐factors were validated by Goodman's tests for toppling failure. The scope of future projections or possible aspects for revisiting and refinement of the SMR method are suggested to enhance the applicability of the method under a diverse initial set of geotechnical conditions.

Comparative clinical study of phosphorous necrosis and medical-related osteonecrosis of the jaws.

Phosphorous necrosis of the jaw (PNJ) exhibits similar clinical and pathological features as medical-related osteonecrosis of the jaw (MRONJ). This study aims at comparing the similarities and differences between PNJ and MRONJ regarding pathological features and to provide a theoretical basis for the clinical diagnosis and management of PNJ. A retrospective analysis was conducted to assess clinical differences among 38 PNJ patients and 31 MRONJ patients, who were diagnosed and treated between January 2009 and October 2022. Pathological alterations in bone tissue were evaluated using EDS, H&E, Masson, and TRAP staining on five specimens from both MRONJ and PNJ cases; furthermore, immunohistochemistry was used to determine the expression levels of OPG, RANKL, and Runx2. The mandibular coronoid process was removed from individuals with temporomandibular joint ankylosis to serve as a control. CBCT imaging demonstrated necrotic bone formation in block, strip, or plaque shapes. EDS analysis showed that the calcium/phosphorus ratio in the bone tissue of PNJ and MRONJ was significantly lower than that of the control group (P < 0.05). Additionally, staining indicated reduced osteoblast counts, disrupted bone trabecular structure, and decreased collagen fiber content in the bone tissues of PNJ and MRONJ. Immunohistochemistry demonstrated that RANKL expression was significantly lower in MRONJ compared to PNJ and control groups (P < 0.05). Conversely, Runx2 expression was significantly higher in PNJ than in MRONJ and control groups (P < 0.05), and there was no significant difference in OPG expression. PNJ and MRONJ demonstrate comparable clinical manifestations and pathological traits, although disparities may exist in their underlying exhibit comparable clinical manifestations, pathological traits, and molecular mechanisms.

Pemakaian Serbuk Ban Untuk Paving Blok Bentuk Heksagon (Segi Enam)

Paving blocks are one of the elements that are often found in building structures, because paving blocks are easy to print and maintain. Paving blocks mixed with tire powder have a light weight so that they do not overload the structure in building construction.This study aims to test the strength of paving blocks in the laboratory mixed with tire powder with a content of 0%, 5%, 10%, 20%, and 30% of the volume of sand. The paving blocks tested were hexagon-shaped. The results showed the same trend as shown by previous studies. The more tire powder content in the paving block, the shock strength of the paving block increases along with the addition of tire powder from 20 blows at 0% tire powder content to 58 blows at 30% tire powder content. Of the paving block shapes, hexagon-shaped paving blocks have better performance. The hexagon shape paving blocks produced in this study include quality B paving blocks in accordance with SNI 03-0691-1996 which can be used for parking lot and yard equipment.

Experimental Behaviour of Hybrid Fiber-Reinforced Low Calcium Ferro Geopolymer Paver Block

The environment friendly and creative material in the construction field is the Geopolymer concrete. The two main constituents of Geopolymer are the source material and the alkaline liquids. In previous studies, alternate for alumino silicate source material as wood ash in geopolymer concrete was found and optimized with fly ash. Moreover, from the previous literatures it could be noted that, GPC had a less brittleness and energy absorbent. To improve the brittleness and energy absorption capacity polypropylene fibre and rubber fibre were added by 0, 0.25, 0.5, 0.75, and 1 % of volume fraction at different ratios. Further, effects on addition of polypropylene and rubber fibres of the optimized wood ash-fly ash based low calcium geopolymer were studied. In the previous study, hybridization of fibres was found out. On other hand, concrete paver block has major disadvantages of less skid resistance, less strength, less energy absorbent, less slip resistance. Hence, the research on finding an alternative to the cement paver block is needed. Ferro-cement was a wonderful technology in the construction industry which have tendency to give more strength to the structure. In this study, the low calcium ferro-geopolymer paver block for an alternate of cement paver block was proposed. Meanwhile, the ferrogeopolymer technology was used by varying the different type of meshes and different layout patterns of meshes. The optimized ferro-geopolymer paver block is going to be produced by varying the shape and size of paver block, surface texture of the paver block. The compressive behaviour, split tensile behaviour, and flexural behaviour is going to be studied for the optimization of low calcium ferro-geopolymer paver block. Micro-structural characterization is also going to be studied for the detailed understanding of inside reaction of low calcium ferro-geopolymer paver block by SEM and EDX.

Reuse of concrete for the construction of a retaining wall: a case study

A promising strategy to reduce the environmental impact of the construction industry is the reuse of structural elements resulting from the deconstruction of existing buildings. However, despite a growing interest from the academic and industrial communities, practical examples of the reuse of structural elements remain very scarce at present, especially in the case of reinforced concrete buildings, which generally consist of a monolithic load-bearing skeleton that has not been designed for dismantling or reuse. This paper presents the results of a study on the reuse of concrete blocks from the deconstruction of an existing building as components for the in-situ construction of a new retaining wall. A real case study is considered. It consists of a building constructed in the 1970s. The developer of the new building wishes to reuse parts of the old building to create a new retaining wall on the boundary of the plot, with a length of 105 metres and a variable height between 60 and 250 cm. The dimensions and shape of the concrete blocks can vary considerably depending on the deconstruction technique used. In order to take into account this aspect, as well as the variable height and the mechanical support of the retaining wall, alternative solutions have been analysed. This paper presents the conceptual design and preliminary dimensioning of these solutions, as well as a discussion of their ability to meet all the technical and normative requirements.

Evolution of CrCx Ceramic Induced by Laser Direct Energy Deposition Multilayered Gradient Ni204-dr60 Coating.

The manufacturing process for many large components of machines leads to a difference in their properties and performances based on changes in location. Functionally graded materials can meet these requirements and address the issue of generation and expansion of interface cracks. Ni204-dr60 gradient coatings were successfully fabricated using laser direct energy deposition (LDED). Microstructure mechanism evolution and microhardness of the gradient coating were comprehensively investigated. The change in the precipitated phase at the grain boundary and the intergranular zones resulted in a change in microstructural characteristics and also affected the microhardness distribution. The reinforced phase of the Ni204 → dr60 gradient zone from Ni204 to dr60 gradually precipitated and was rich in Mo and Nb phase, lath-shaped CrCx phase, network-shaped CrCx phase, block shape (Ni, Si) (C, B) phase, block CrCx phase, and block Cr (B, C) phase. The gradient coating thus acts as a potential candidate to effectively solve the problem of crack generation at the interface of dr60 and the substrate.

A diffuse interface–lattice Boltzmann model for conjugate heat transfer with imperfect interface

A diffuse interface-lattice Boltzmann model is proposed for modeling conjugate heat transfer problems with imperfect interfaces. According to the continuity condition of heat flux and jump condition of temperature across the imperfect interface, a unified sharp interface equation of the temperature field with a singular source term in the composite media domain is established. Then a diffuse interface equation is obtained by making a smoothed approximation of the unified sharp interface equation. The novel diffuse interface equation is restructured into a second-order heat diffusion equation with an anisotropic diffusion coefficient tensor. To numerically solve the second-order anisotropic diffusion equation, a multiple-relaxation-time (MRT) lattice Boltzmann (LB) scheme is employed. Several numerical simulations of benchmark test examples with analytical solutions are carried out to demonstrate the accuracy of the present model, including the steady-state heat diffusion in a two-layer medium with a flat interface, steady heat diffusion in a square domain with a curved interface and unsteady-state temperature diffusion with two-layer media. The numerical results show that the phenomenon of temperature jump across the imperfect interface can be successfully and correctly captured. Moreover, as an example of practical application, the new proposed diffuse interface model is utilized to predict the effective thermal conductivity of porous media with thermal contact resistance at pore scale. The variation law of the effective thermal conductivity is obtained for each parameter by studying the effects of thermal conductivity ratios of the dual-component material, the shape and volume fraction of blocks in the material, the interfacial thermal conductance coefficient, and the number of blocks on the effective thermal conductivity. Both uniform and random pore structures are considered. The previous theoretical equations strongly support the validity of the present model.

놀잇감과 영아의 성별에 따른 어머니의 공간 언어 사용 차이

Objectives This study examined whether block plays have an advantage in promoting infants’ exposure to spatial language, and if so, whether the advantage would vary depending on the variability in block shapes. In addition, it was investigated whether infants’ sex influences their exposure to spatial language during mother-infant play.&#x0D; Methods Forty-three 8-month-old infants and their mothers living in Seoul Metropolitan areas participated in this study. Mother-infant pairs were asked to play with a set of stuffed animal toys and then with a set of blocks. During the block play session, half of the participants were provided with colorful blocks that were identical in terms of shape; the other participants were provided with colorful blocks that varied in shapes. Spatial language that mothers used during plays was coded and classified into categories. Frequency and diversity of spatial language were calculated.&#x0D; Results Although mothers produced spatial language in both the animal toy play and the block play, their spatial language use was more frequent and more diverse when they played with blocks than with animal toys. Importantly, this advantage of block play in infants’ exposure to spatial language only appeared when the blocks varied in shapes. In addition, while mothers used the same amount of spatial language to girls and boys, they used more diverse spatial language to girls than boys.&#x0D; Conclusions These results indicate that the spatial language input that mothers provide during mother-infant plays is affected by the characteristics of the play materials and the infants. Specifically, this study suggests that blocks with a variety of shapes can promote mothers’ use of rich spatial language in the context of mother-infant play.

Occurrence conditions of the reverse rotation of rockfall and its influence on the restitution coefficient

When rockfall occurs along dense rock slopes, the rotation direction of rockfall is not always downhill. Specifically, the rockfall may obtain a reverse rotation speed (RRS) after impact under certain conditions, the effect of which on the restitution coefficient (RC) cannot be ignored. According to the statistical results of the reverse rotation (RR) phenomena of blocks obtained from previous experiments, the occurrence of RR is correlated to the block shape, incident angle, and contact attitude. In this study, considering a typically shaped cubic block, the critical condition for the RR is preliminarily deduced. Based on the results, the influence of the RRS on the RC for four typically shaped blocks is examined using a customized device. Results show that the tangential RC (Rt) values of each block are not sensitive to the change in the RRS, the distribution is relatively concentrated and the values are high. Moreover, the normal RC (Rn) values are not sensitive to the RRS, and the distribution is relatively discrete. The RRS influences Rn; however, it is difficult to directly establish the relationship between them. To this end, considering the contact attitude and shape of the block, an integral variable, the impact coefficient (Ic), is proposed to determine the influence of RRS on Rn. Moreover, the impact-bounce behaviours of the block are categorized and analysed. For the block rebound following a single impact, Ic and Rn are positively and negatively correlated when the mass centre of the block (MC) is in front and behind the contact point (CP), respectively. For the block rebound following two successive impacts, with the increase in Ic, the Rn increases. These conclusions help clarify the mechanism of the influence of the RRS on RC and provide vital information and ideas for the development and optimization of a program to accurately predict rockfall trajectories.

Influence of uncertainties: A focus on block volume and shape assessment for rockfall analysis

Influence of uncertainties: A focus on block volume and shape assessment for rockfall analysis