Search results for: cracks trees

Authors: Hamisu Jibril

Abstract:

The study explores changes in plant species composition along disturbance gradient in urban areas in Nigeria at Bayero University Kano campuses. The aim is to assess changes in plant species composition and distribution within a degraded dryland environment in Kano Metropolis, Nigeria. Vegetation sampling was conducted using plots quadrat and transect methods, and different plant species were identified in the three study sites. Data were analyzed using ANOVA, t-tests and conventional indices to compare species richness, evenness and diversity. The study found no significant differences in species frequency among sites or sampling methods but observed higher species richness, evenness and diversity values in grasses species compared to trees. The study addressed changes in plant species composition along a disturbance gradient in an urban environment, focusing on species richness, evenness, and diversity. The study contributes to understanding the vegetation dynamics in degraded urban environments and highlights the need for conservation efforts. The research also adds to the existing literature by confirming previous findings and suggesting re-planting efforts. The study suggests similarities in plant species composition between old and new campus areas and emphasizes the importance of further investigating factors leading to vegetation loss for conservation purposes.

Keywords: species diversity, urban kano, dryland environment, vegetation sampling

Procedia PDF Downloads 33

Authors: M. Kumral, A. Abdelnasser, M. Budakoglu, M. Karaman, D. K. Yildirim, Z. Doner, A. Bostanci

Abstract:

The Paraga area is located at the extreme eastern part of Nakhchivan district at the boundary with Armenia. The field study is situated at Ordubad region placed in 9 km from Paraga village and stays at 2300-2800 m height over sea level. It lies within a region of low-grade metamorphic porphyritic volcanic and plutonic rocks. The detailed field studies revealed that this area composed mainly of metagabbro-diorite intrusive rocks with porphyritic character emplaced into meta-andesitic rocks. This complex is later intruded by unmapped olivine gabbroic rocks. The Cu-Mo-(Au) mineralization at Paraga deposit is vein-type mineralization that is essentially related to quartz veins stockwork which cut the dioritic rocks and concentrated at the eastern and northeastern parts of the area with different directions N80W, N25W, N70E and N45E. Also, this mineralization is associated with two shearing zones directed N75W and N15E. The host porphyritic rocks were affected by intense sulfidation, carbonatization, sericitization and silicification with pervasive hematitic alterations accompanied with mineralized quartz veins and quartz-carbonate veins. Sulfide minerals which are chalcopyrite, pyrite, arsenopyrite and sphalerite occurred in two cases either inside these mineralized quartz veins or disseminated in the highly altered rocks as well as molybdenite and also at the peripheries between the altered host rock and veins. Gold found as inclusion disseminated in arsenopyrite and pyrite as well as in their cracks.

Keywords: porphyry Cu-Mo-(Au), Paraga area, Nakhchivan, Azerbaijan, paragenesis, hyrothermal alteration

Procedia PDF Downloads 385

Authors: Mara Getachew Zenebe, Luuk Fleskens, Abdu Obieda Ahmed

Abstract:

This paper seeks to advance our scientific understanding of optimizing flood utilization in regions impacted by climate change, with a focus on enhancing agricultural productivity through effective irrigation management. The study was conducted as part of a three-year (2021 to 2023) USAID-supported initiative aimed at promoting Economic Growth and Peace in the Gash Agricultural Scheme (GAS), situated in Sudan's water-stressed Eastern region. GAS is the country's largest flood-irrigated scheme, covering 100,800 hectares of cultivable land, with a potential to provide the food security needs of over a quarter of a million agro-pastoral community members. GAS relies on the Gash River, which sources its water from high-intensity rainfall events in the highlands of Ethiopia and Eritrea. However, climate change and variations in these highlands have led to increased variability in the Gash River's flow. The study conducted water balance analyses based on a ten-year dataset of the annual Gash River flow, irrigated area; as well as the evapotranspiration demand of the major sorghum crop. Data collection methods included field measurements, surveys, remote sensing, and CropWat modelling. The water balance assessment revealed that the existing three-year rotation-based irrigation system management, capping cultivated land at 33,000 hectares annually, is excessively risk-averse. While this system reduced conflicts among the agro-pastoral communities by consistently delivering on the land promised to be annually cultivated, it also increased GAS's vulnerability to flood damage due to several reasons. The irrigation efficiency over the past decade was approximately 30%, leaving significant unharnessed floodwater that caused damage to infrastructure and agricultural land. The three-year rotation resulted in inadequate infrastructural maintenance, given the destructive nature of floods. Additionally, it led to infrequent land tillage, allowing the encroachment of mesquite trees hindering major sorghum crop growth. Remote sensing data confirmed that mesquite trees have overtaken 70,000 hectares in the past two decades, rendering them unavailable for agriculture. The water balance analyses suggest shifting to a two-year rotation, covering approximately 50,000 hectares annually while maintaining risk aversion. This shift could boost GAS's annual sorghum production by two-thirds, exceeding 850,000 tons. The scheme's efficiency can be further enhanced through low-cost on-farm interventions. Currently, large irrigation plots that range from 420 to 756 hectares are irrigated with limited water distribution guidance, leading to uneven irrigation. As demonstrated through field trials, implementing internal longitudinal bunds and horizontal deflector bunds can increase adequately irrigated parts of the irrigation plots from 50% to 80% and thus nearly double the sorghum yield to 2 tons per hectare while reducing the irrigation duration from 30 days to a maximum of 17 days. Flow measurements in 2021 and 2022 confirmed that these changes sufficiently meet the sorghum crop's water requirements, even with a conservative 60% field application efficiency assumption. These insights and lessons from the GAS on enhancing agricultural resilience and sustainability in the face of climate change are relevant to flood-based livelihood systems globally.

Keywords: climate change, irrigation management and productivity, variable flood flows, water balance analysis

Procedia PDF Downloads 52

Authors: Mirco Tarozzi, Giacomo Pignagnoli, Andrea Benedetti

Abstract:

Structural systems are often subjected to degradation processes due to different kind of phenomena like unexpected loadings, ageing of the materials and fatigue cycles. This is true especially for bridges, in which their safety evaluation is crucial for the purpose of a design of planning maintenance. This paper discusses the experimental evaluation of the stiffness reduction from frequency changes due to uniform damage scenario. For this purpose, a 1:4 scaled bridge has been built in the laboratory of the University of Bologna. It is made of concrete and its cross section is composed by a slab linked to four beams. This concrete deck is 6 m long and 3 m wide, and its natural frequencies have been identified dynamically by exciting it with an impact hammer, a dropping weight, or by walking on it randomly. After that, a set of loading cycles has been applied to this bridge in order to produce a uniformly distributed crack pattern. During the loading phase, either cracking moment and yielding moment has been reached. In order to define the relationship between frequency variation and loss in stiffness, the identification of the natural frequencies of the bridge has been performed, before and after the occurrence of the damage, corresponding to each load step. The behavior of breathing cracks and its effect on the natural frequencies has been taken into account in the analytical calculations. By using a sort of exponential function given from the study of lot of experimental tests in the literature, it has been possible to predict the stiffness reduction through the frequency variation measurements. During the load test also crack opening and middle span vertical displacement has been monitored.

Keywords: concrete bridge, damage detection, dynamic test, frequency shifts, operational modal analysis

Procedia PDF Downloads 167

Authors: A. B. Chehreh, M. Grätzel, M. Klein, J. P. Bergmann, F. Walther

Abstract:

Friction stir welding (FSW) is an advantageous method in the thermal joining processes, featuring the welding of various dissimilar and similar material combinations, joining temperatures below the melting point which prevents irregularities such as pores and hot cracks as well as high strengths mechanical joints near the base material. The FSW process consists of a rotating tool which is made of a shoulder and a probe. The welding process is based on a rotating tool which plunges in the workpiece under axial pressure. As a result, the material is plasticized by frictional heat which leads to a decrease in the flow stress. During the welding procedure, the material is continuously displaced by the tool, creating a firmly bonded weld seam behind the tool. However, the mechanical properties of the weld seam are affected by the design and geometry of the tool. These include in particular microstructural and surface properties which can favor crack initiation. Following investigation compares the dynamic properties of FSW weld seams with conventional and stationary shoulder geometry based on load increase test (LIT). Compared to classical Woehler tests, it is possible to determine the fatigue strength of the specimens after a short amount of time. The investigations were carried out on a robotized welding setup on 2 mm thick EN AW 5754 aluminum alloy sheets. It was shown that an increased tensile and fatigue strength can be achieved by using the stationary shoulder concept. Furthermore, it could be demonstrated that the LIT is a valid method to describe the fatigue behavior of FSW weld seams.

Keywords: aluminum alloy, fatigue performance, fracture, friction stir welding

Procedia PDF Downloads 137

Authors: Peter Križan, Juraj Beniak, Ľubomír Šooš, Miloš Matúš

Abstract:

Biomass treatment through densification is very suitable and important technology before its effective energy recovery. Densification process of biomass is significantly influenced by various technological and also material parameters which are ultimately reflected on the final solid Biofuels quality. The paper deals with the experimental research of the relationship between technological and material parameters during densification of fast-growing trees, roundly fast-rowing willow. The main goal of presented experimental research is to determine the relationship between pressing pressure raw material fraction size from a final briquettes density point of view. Experimental research was realized by single-axis densification. The impact of fraction size with interaction of pressing pressure and stabilization time on the quality properties of briquettes was determined. These parameters interaction affects the final solid biofuels (briquettes) quality. From briquettes production point of view and also from densification machines constructions point of view is very important to know about mutual interaction of these parameters on final briquettes quality. The experimental findings presented here are showing the importance of mentioned parameters during the densification process.

Keywords: briquettes density, densification, fraction size, pressing pressure, stabilization time

Procedia PDF Downloads 346

Authors: Mourad Morsli, Mohamed Tahiri, Azzedine Samdi

Abstract:

The Cities are the urbanized territories most favorable to the consumption of resources (materials, energy). In Morocco, the economic capital Casablanca is one of them, with its 4M inhabitants and its 60% share in the economic and industrial activity of the kingdom. In the absence of legal status in force, urban development has favored the generation of millions of tons of demolition and construction waste scattered in open spaces causing a significant nuisance to the environment and citizens. Hence the main objective of our work is to valorize concrete waste. The representative wastes are mainly concrete, concrete, and fired clay bricks, ceramic tiles, marble panels, gypsum, and scrap metal. The work carried out includes: geolocation with a combination of artificial intelligence, GIS, and Google Earth, which allowed the estimation of the quantity of these wastes per site; then the sorting, crushing, grinding, and physicochemical characterization of the collected samples allowed the definition of the exploitation ways for each extracted fraction for integrated management of the said wastes. In the present work, we proceeded to the exploitation of the fractions obtained after sieving the representative samples to incorporate them in the manufacture of new ecological materials for construction. These formulations prepared studies have been tested and characterized: physical criteria (specific surface, resistance to flexion and compression) and appearance (cracks, deformation). We will present in detail the main results of our research work and also describe the specific properties of each material developed.

Keywords: demolition and construction waste, GIS combination software, inert waste recovery, ecological materials, Casablanca, Morocco

Procedia PDF Downloads 115

Authors: Carlos H. Cuadra, Nobuhiro Shimoi

Abstract:

Application of piezoelectric sensors to detect structural damage due to seismic action on building structures is investigated. Plate-type piezoelectric sensor was developed and proposed for this task. A film-type piezoelectric sheet was attached on a steel plate and covered by a layer of glass. A special glue is used to fix the glass. This glue is a silicone that requires the application of ultraviolet rays for its hardening. Then, the steel plate was set up at a steel column-beam joint of a test specimen that was subjected to bending moment when test specimen is subjected to monotonic load and cyclic load. The structural behavior of test specimen during cyclic loading was verified using a finite element model, and it was found good agreement between both results on load-displacement characteristics. The cross section of steel elements (beam and column) is a box section of 100 mm×100 mm with a thin of 6 mm. This steel section is specified by the Japanese Industrial Standards as carbon steel square tube for general structure (STKR400). The column and beam elements are jointed perpendicularly using a fillet welding. The resulting test specimen has a T shape. When large deformation occurs the glass plate of the sensor device cracks and at that instant, the piezoelectric material emits a voltage signal which would be the indicator of a certain level of deformation or damage. Applicability of this piezoelectric sensor to detect structural damages was verified; however, additional analysis and experimental tests are required to establish standard parameters of the sensor system.

Keywords: piezoelectric sensor, static cyclic test, steel structure, seismic damages

Procedia PDF Downloads 109

Authors: Smail Chafaa, Abdelkrim Si Bachir

Abstract:

Our work aims to study the insect diversity based on bioclimatic levels of pests in olive cultures (Olea europea L.) in the area of Batna (arid and semi arid north eastern Algeria) during the period from January 2011 to May 2011. Several sampling techniques were used, those of hunting on sight, visual inspection, hatches traps, colored traps, Japanese umbrella and sweep net. We have identified in total, 2311 individuals with results in inventory 206 species divided to 74 families and 11 orders, including Coleoptera order is quantitatively the most represented with 47.1%. The most dominant diet in our inventory is the phytophagous. Between the herbivorous insects that we have listed and which are the main olive pest of olive cultivation; we quote the olive fly (Bactrocera oleae), cochineal purple olive (Parlatoria oleae) the psyllid olive (Euphyllura olivina) and olive Trips (Liothrips oleae). The distribution of species between stations shows that Boumia resort with the most number of species (113) compared to other resorts and beetles are also better represented in three groves. Total wealth is high in Boumia station compared with the others stations. The values of (H') exceeding 3.9 bits for all the stations studied indicate a specific wealth and diversity of ecological nests in insect species. The values of equitability are near the unit; that suggests a balance between the numbers of insect populations sampled in the various stations.

Keywords: entomology, olive, grove, batna, Algeria

Procedia PDF Downloads 320

Authors: Reza Mohammadzadeh

Abstract:

The major challenges in geotechnical engineering in underground spaces arise from uncertainties and different probabilities. The collection, collation, and collaboration of existing data to incorporate them in analysis and design for given prospect evaluation would be a reliable, practical problem solving method under uncertainty. Machine learning (ML) is a subfield of artificial intelligence in statistical science which applies different techniques (e.g., Regression, neural networks, support vector machines, decision trees, random forests, genetic programming, etc.) on data to automatically learn and improve from them without being explicitly programmed and make decisions and predictions. In this paper, a conceptual database schema of geotechnical risks in underground coal mining based on a cloud system architecture has been designed. A new approach of risk assessment using a three-dimensional risk matrix supported by the level of knowledge (LoK) has been proposed in this model. Subsequently, the model workflow methodology stages have been described. In order to train data and LoK models deployment, an ML platform has been implemented. IBM Watson Studio, as a leading data science tool and data-driven cloud integration ML platform, is employed in this study. As a Use case, a data set of geotechnical hazards and risk assessment in underground coal mining were prepared to demonstrate the performance of the model, and accordingly, the results have been outlined.

Keywords: data model, geotechnical risks, machine learning, underground coal mining

Procedia PDF Downloads 249

Authors: Khater N., Rahmine S., Bougoffa C., Bouguenna T., Ouanes H.

Abstract:

Moringa oleifera L. species is considered one of the most useful trees in the world, possessing many interesting properties that make it of great scientific interest. It has been described as the miracle tree, the tree of a thousand virtues, the tree of life and God's gift to man. The present study aims to introduce, produce, and develop Moringa Oleifera as a species with high ecological potential (resistance to biotic and abiotic stresses and productivity), high added value, and multiple virtues. The aim of this work is to study the germination potential of this species under different temperature conditions. In this study, the germination assay was tested in two different temperature ranges: internal (laboratory ambient temperature between 22°c and 25°c) and external (seasonal temperature between 4°c and 8°c). Morphological and physiological analyses were carried out by Shoot length (SL), root length (RL), diameter at the crown (DC), fresh weight of shoots (FWS), fresh weight of roots (FWR), dry weight of shoots (DWS) and dry weight of roots (DWS). For all these variables, the results of the study reveal a significant difference between the two temperature intervals, with a high germination rate of 81. 81% and plant growth was rapid (7cm during 24h) in the laboratory temperature; in contrast to the external temperatures, a germination rate value of around 27% was recorded, and germination took place after 20 days of sowing, with slower plant growth. The results obtained show that a temperature greater than or equal to 25° is the ideal temperature for the germination and growth of moringa seeds and has a positive influence on the speed and percentage of germination.

Keywords: moringa oleifera, temperature, germination rate, growth, biomass

Procedia PDF Downloads 38

Authors: R. Saravanakumar, A. Siva, R. Banupriya, K. Balasubramanian

Abstract:

Slurry infiltrated fibrous concrete (SIFCON) is one of the recently developed construction material that can be considered as a special type of high performance fibre reinforced concrete (HPFRC) with higher fibre content. Fibre reinforced concrete is essentially a composite material in which fibres out of waste having higher modulus of elasticity. SIFCON is a special type of high fibrous concrete and it is having a high cementious content and sand. The matrix usually consists of cement-sand slurry or fluent mortar. The construction industry is in need of finding cost effective materials for increasing the strength of concrete structures hence an endeavour has been made in the present investigations to study the influence of addition of waste material like Lathe waste from workshop at different dosages to the total weight of concrete. The waste of steel scrap material which is available from the lathe is used as a steel fibre for innovative construction industry. To get sustainable and environmental benefits, lathe scrap as recycled fibres with concrete are likely to be used. An experimental program was carried out to investigate the flexural behavior of Slurry infiltrated fibrous concrete (SIFCON) in which the fibres having an aspect ratio of 100 is used. The investigations were done using M25 mix and tests were carried out as per recommended procedures by appropriate codes. SIFCON specimens with 8%, 10% and 12% volume of fraction fibres are used in this study. Test results were presented in comparison of SIFCON with and without conventional steel reinforcement. The load carrying capacity of SIFCON specimen is higher than conventional concrete and it also reduced crack width. In the SIFCON specimen less number of cracks as compared with conventional concrete.

Keywords: SIFCON, lathe waste, RCC, fibre volume, flexural behaviour

Procedia PDF Downloads 299

Authors: P. Wongmatar, C. Hansapinyo, C. Buachart

Abstract:

Failure of typical seismic frames has been found by plastic hinge occurring on beams section near column faces. Past researches shown that the seismic capacity of the frames can be enhanced if the plastic hinges of the beams are shifted away from the column faces. This paper presents detailing of reinforcements in the interior beam–column connections aiming to relocate the plastic hinge of reinforced concrete and precast concrete frames. Four specimens were tested under quasi-static cyclic load including two monolithic specimens and two precast specimens. For one monolithic specimen, typical seismic reinforcement was provided and considered as a reference specimen named M1. The other reinforced concrete frame M2 contained additional intermediate steel in the connection area compared with the specimen M1. For the precast specimens, embedded T-section steels in joint were provided, with and without diagonal bars in the connection area for specimen P1 and P2, respectively. The test results indicated the ductile failure with beam flexural failure in monolithic specimen M1 and the intermediate steel increased strength and improved joint performance of specimen M2. For the precast specimens, cracks generated at the end of the steel inserts. However, slipping of reinforcing steel lapped in top of the beams was seen before yielding of the main bars leading to the brittle failure. The diagonal bars in precast specimens P2 improved the connection stiffness and the energy dissipation capacity.

Keywords: relocation, plastic hinge, intermediate bar, T-section steel, precast concrete frame

Procedia PDF Downloads 255

Authors: Andrew Gryguć, Seyed Behzad Behravesh, Hamid Jahed, Mary Wells, Wojciech Macek, Bruce Williams

Abstract:

This extended abstract investigates the influence of the multiaxial loading on the fatigue behavior of forged magnesium through quantitative analysis of its fracture surface topography and mesoscopic cracking orientation. Fatigue tests were performed on hollow tubular sample geometries extracted from closed-die forged AZ80 Mg components, with three different multiaxial strain paths (axial/shear), proportional, 45° out of phase, and 90° out of phase. Regardless of the strain path, fatigue cracks are initiated at the outer surface of the specimen where the combined stress state is largest. Depending on the salient mode of deformation, distinctive features in the fracture surface manifested themselves with different topographic amplitudes, surface roughness, and mesoscopic cracking orientation in the vicinity of the initiation site. The dominant crack propagation path was in the circumferential direction of the hollow tubular specimen (i.e., cracking transverse to the sample axis, with little to no branching), which is congruent with previous findings of low to moderate shear strain energy density (SED) multiaxial loading. For proportional loading, the initiation zone surface morphology was largely flat and striated, whereas, at phase angles of 45° and 90°, the initiation surface became more faceted and inclined. Overall, both a qualitative and quantitative link was developed between the fracture surface morphology and the level of non-proportionality in the loading providing useful insight into the fracture mechanics of forged magnesium as a relevant focus for future study.

Keywords: fatigue, fracture, magnesium, forging, fractography, anisotropy, strain energy density, asymmetry, multiaxial fatigue

Procedia PDF Downloads 63

Authors: Burcu Inal, Irfan Kandemir

Abstract:

Sequences of mitochondrial cytochrome oxidase I (COI) gene of twenty-five Turkish and one Greek Myzus cerasi (Fabricus) (Hemiptera: Aphididae) in populations were collected from Prunus avium and Prunus cerasus. The partial coding region of COI studied is 605 bp for all the populations, from which 565 nucleotides were conserved, 40 were variable, 37 were singleton, and 3 sites were parsimony-informative. Four haplotypes were identified based on nucleotide substitutions, and the mean of intraspecific divergence was calculated to be 0.3%. Phylogenetic trees were constructed using Maximum Likelihood, Minimum Evolution, Neighbor-joining, and Unweighed Pair Group Method of Arithmetic Averages (UPGMA) and Myzus persicae (Sulzer) and Myzus borealis Ossiannilson were included as outgroups. The population of M. cerasi from Isparta diverged from the rest of the groups and formed a clade (Haplotype B) with Myzus borealis. The rest of the haplotype diversity includes Haplotype A and Haplotype C with individuals characterized as Myzus cerasi pruniavium and Haplotype D with Myzus cerasi cerasi. M. cerasi diverge into two subspecies and it must be reevaluated whether this pest is monophagous or oligophagous in terms of plant type dependence. The obligated endosymbiont Buchnera aphidicola was also found during this research, but no facultative symbionts could be found. It is expected further studies will be required for a complete barcoding and diversity of bacterial endosymbionts present.

Keywords: bacterial endosymbionts, barcoding, black cherry aphid, nucleotide diversity

Procedia PDF Downloads 153

Authors: Reza Soleimanpour, Ching Tai Ng

Abstract:

Fibre-composites are widely used in various structures due to their attractive properties such as higher stiffness to mass ratio and better corrosion resistance compared to metallic materials. However, one serious weakness of this composite material is delamination, which is a subsurface separation of laminae. A low level of this barely visible damage can cause a significant reduction in residual compressive strength. In the last decade, the application of guided waves for damage detection has been a topic of significant interest for many researches. Among all guided wave techniques, nonlinear guided wave has shown outstanding sensitivity and capability for detecting different types of damages, e.g. cracks and delaminations. So far, most of researches on applications of nonlinear guided wave have been dedicated to isotropic material, such as aluminium and steel, while only a few works have been done on applications of nonlinear characteristics of guided waves in anisotropic materials. This study investigates the nonlinear interactions of the fundamental antisymmetric lamb wave (A0) with delamination in composite laminates using three-dimensional (3D) explicit finite element (FE) simulations. The nonlinearity considered in this study arises from interactions of two interfaces of sub-laminates at the delamination region, which generates contact acoustic nonlinearity (CAN). The aim of this research is to investigate the phenomena of CAN in composite laminated beams by a series of numerical case studies. In this study interaction of fundamental antisymmetric lamb wave with delamination of different sizes are studied in detail. The results show that the A0 lamb wave interacts with the delaminations generating CAN in the form of higher harmonics, which is a good indicator for determining the existence of delaminations in composite laminates.

Keywords: contact acoustic nonlinearity, delamination, fibre reinforced composite beam, finite element, nonlinear guided waves

Procedia PDF Downloads 182

Authors: Tamirat Solomon, Tadesse Faltamo, Belete Limani

Abstract:

This study was conducted on the mountain Damota of Wolaita to assess the abundance and spatial distribution of two locally important indigenous medicinal plants on the mountain landscape. A total of 130 plots measuring 20x20m were established along eight systematically laid transect lines. In each plot, the abundance and distribution of Hagenia abyssinica (tree) and Pentas schiperiana Vatke (shrub) were evaluated. The abundance and distribution of H. abyssinica were evaluated by measuring height and DBH for mature trees and counting seedlings and saplings, whereas the P. schiperiana Vatke was assessed for its abundance and distribution by counting in each plot. In the entire study plots, a total of 485 H. abyssinica and 760 P. schiperiana vatake were recorded. It was observed that the distribution of the species increased while the altitude increased and the highest abundance of the species was recorded at an altitude range between 2332 and 2661m.a.s.l. However, at the altitudes below 2320 m.a.s.l., the species distributions and abundance was decreased, indicating either the ecological preference of the species or the extraction of the local community surrounding the mountain influenced the species. On average, only 28 seedlings/ha of H. abyssinica and 146/ha of P. schiperiana vatke were recorded in the study areas showing the tendency of decline in the abundance and distribution of both species. Finally, we recommend management intervention for the socially important species which are under threat on the mountain landscape.

Keywords: indigenous medicinal plants, H.abyssinic, P. schiperiana, distribution, abundance, socio-economic importance

Procedia PDF Downloads 101

Authors: Vladimir A. Vinnikov

Abstract:

The paper proposes a model of an inhomogeneous rock mass with initially random distribution of microcracks on mineral grain boundaries. It describes the behavior of cracks in a medium under the effect of thermal field, the medium heated instantaneously to a predetermined temperature. Crack growth occurs according to the concept of fracture mechanics provided that the stress intensity factor K exceeds the critical value of Kc. The modeling of thermally induced acoustic emission memory effects is based on the assumption that every event of crack nucleation or crack growth caused by heating is accompanied by a single acoustic emission event. Parameters of the thermally induced acoustic emission memory effect produced by cyclic heating and cooling (with the temperature amplitude increasing from cycle to cycle) were calculated for several rock texture types (massive, banded, and disseminated). The study substantiates the adaptation of the proposed model to humidity interference with the thermally induced acoustic emission memory effect. The influence of humidity on the thermally induced acoustic emission memory effect in quasi-homogeneous and banded rocks is estimated. It is shown that such modeling allows the structure and texture of rocks to be taken into account and the influence of interference factors on the distinctness of the thermally induced acoustic emission memory effect to be estimated. The numerical modeling can be used to obtain information about the thermal impacts on rocks in the past and determine the degree of rock disturbance by means of non-destructive testing.

Keywords: degree of rock disturbance, non-destructive testing, thermally induced acoustic emission memory effects, structure and texture of rocks

Procedia PDF Downloads 245

Authors: Adel Ahmadi Hosseini, Fatemeh Tavanaei, Alessandro Navarra, Ferri Hassani

Abstract:

Mining Engineering, as a part of geoscience, must address modern concerns. Traditional mining methods incorporate drill and blast technologies, which are followed by different issues, including excessive noise, vibration, air pollution, and safety hazards. Over the past two decades, mining engineers have sought alternative solutions to move from drill and blast to continuous methods to prevent such issues and improve sustainability in mining. Among the suggested methods, microwave treatment has shown promising results by creating micro/macro cracks in the rock structure prior to the operations. This research utilizes an energy-based analysis methodology to evaluate the efficiency of the microwave treatment in improving mining operations. The data analysis shows that increasing the input microwave energy dosage intensifies the rock damage. However, this approach can decrease the energy efficiency of the method by more than 50% in some cases. In this study, rock samples were treated with three power levels (3 kW, 7 kW, and 12 kW) and two energy dosages (20 kWh/t and 50 kWh/t), resulting in six conditions. To evaluate the impact of microwave treatment on the geomechanical behavior of the rocks, Unconfined Compressive Strength (UCS) tests were conducted on the microwave-treated samples, yielding stress-strain curves. Using the stress-strain curves, the effect of the different powers and energy dosages of microwave are discussed. The energy efficiency calculated for this method in this study is more than twice the values published in previous literature. This research shows the potential of using microwave treatment to lead the industry to more sustainable mining.

Keywords: microwave treatment, microwave energy dosage, sustainable mining, rock fragmentation

Procedia PDF Downloads 6

Authors: Omar Bouledroua, Djamel Zelmati, Zahreddine Hafsi, Milos B. Djukic

Abstract:

Transporting hydrogen gas through the existing natural gas pipeline network offers an efficient solution for energy storage and conveyance. Hydrogen generated from excess renewable electricity can be conveyed through the API 5L steel-made pipelines that already exist. In recent years, there has been a growing demand for the transportation of hydrogen through existing gas pipelines. Therefore, numerical and experimental tests are required to verify and ensure the mechanical integrity of the API 5L steel pipelines that will be used for pressurized hydrogen transportation. Internal pressure loading is likely to accelerate hydrogen diffusion through the internal pipe wall and consequently accentuate the hydrogen embrittlement of steel pipelines. Furthermore, pre-cracked pipelines are susceptible to quick failure, mainly under a time-dependent cyclic pressure loading that drives fatigue crack propagation. Meanwhile, after several loading cycles, the initial cracks will propagate to a critical size. At this point, the remaining service life of the pipeline can be estimated, and inspection intervals can be determined. This paper focuses on the hydrogen embrittlement of API 5L steel-made pipeline under cyclic pressure loading. Pressurized hydrogen gas is transported through a network of pipelines where demands at consumption nodes vary periodically. The resulting pressure profile over time is considered a cyclic loading on the internal wall of a pre-cracked pipeline made of API 5L steel-grade material. Numerical modeling has allowed the prediction of fatigue crack evolution and estimation of the remaining service life of the pipeline. The developed methodology in this paper is based on the ASME B31.12 standard, which outlines the guidelines for hydrogen pipelines.

Keywords: hydrogen embrittlement, pipelines, transient flow, cyclic pressure, fatigue crack growth

Procedia PDF Downloads 65

Authors: Akbar Khodavirdizadeh

Abstract:

Gougerd village landslide with area about 150 hectares is located in southwest of Khoy city in northwest of the Iran. This Landslide was commenced more than 21 years and caused some damages in houses like some fissures on walls and some cracks on ground and foundations. The main mechanism of landslide is rotational with the high different of top and foot is about 230 m. The thickness of slide mass based on geoelectrical investigation is about 16m obtained. The upper layer of slope is silty sand and the lower layer of clayey gravel. In this paper, the stability of landslide are analyzed based in static analysis under different groundwater surface conditions and at slope angle changes with limit eqlibrium method and the simplified Bishop method. The results of the 72 stability analysis showed that the slope stability of Gougerd landslide increased with increasing of the groundwater surface depth of slope crown. And especially when decreased of slope angle, the safety facter more than in previous state is increased. The required of safety factor for stability in groundwater surface depth from slope crown equal 14 m and with decreased of slope angle to 3 degree at decrease of groundwater surface depth from slope crown equal 6.5 m obtained. The safety factor in critical conditions under groundwater surface depth from slope crown equal 3.5 m and at decreased of slope angle to 3 degree equal 0.5 m obtained. At groudwater surface depth from slope crown of 3 m, 7 m and 10 m respectively equal to 0.97, 1.19 and 1.33 obtained. At groudwater surface depth from slope crown of 3 m, 7 m and 10 m with decreased of slope angle to 3 degree, respectively equal to 1.27, 1.54 and 1.72 obtained. According to the results of this study, for 1 m of groundwater level decrease, the safety factor increased by 5%, and for 1 degree of reduction of the slope angle, safety factor increased by 15%. And the effect of slope angle on Gougerd landslide stability was felt more than groundwater effect.

Keywords: Gougerd landslide, stability analysis, slope angle, groundwater, Khoy

Procedia PDF Downloads 150

Authors: Adel Ali Elshaibani

Abstract:

Risk management indicators augment the reporting infrastructure, particularly for the board and senior management, to identify, monitor, and manage risks. This enhancement facilitates improved decision-making throughout the banking organization. Decision tree analysis is a tool that visually outlines potential outcomes, costs, and consequences of complex decisions. It is particularly beneficial for analyzing quantitative data and making decisions based on numerical values. By calculating the expected value of each outcome, decision tree analysis can help assess the best course of action. In the context of banking, decision tree analysis can assist lenders in evaluating a customer’s creditworthiness, thereby preventing losses. However, applying these tools in developing countries may face several limitations, such as data availability, lack of technological infrastructure and resources, lack of skilled professionals, cultural factors, and cost. Moreover, decision trees can create overly complex models that do not generalize well to new data, known as overfitting. They can also be sensitive to small changes in the data, which can result in different tree structures and can become computationally expensive when dealing with large datasets. In conclusion, while risk management indicators and decision tree analysis are beneficial for decision-making in banks, their effectiveness is contingent upon how they are implemented and utilized by the board of directors, especially in the context of developing countries. It’s important to consider these limitations when planning to implement these tools in developing countries.

Keywords: risk management indicators, decision tree analysis, developing countries, board of directors, bank performance, risk management strategy, banking institutions

Procedia PDF Downloads 37

Authors: Mohammad Ebrahim Kianifar, Ehsan Ahmadi

Abstract:

Reinforced concrete structures experience local defects such as cracks over their lifetime under various environmental loadings. Consequently, they are repaired by mortars to avoid detrimental effects such as corrosion of reinforcement, which in long-term may lead to strength loss of a member or collapse of structures. However, repaired structures may need multiple repairs due to changes in load distribution, and thus, lack of compatibility between mortar and substrate concrete. On the other hand, waste tire rubber alkali-activated (WTRAA)-based materials have very high potential to be used as repair mortars because of their ductility and flexibility, which may delay the failure of repair mortar and thus, provide sufficient compatibility. Hence, this work presents a pioneering study on suitability of WTRAA-based materials as mortars for the repair of concrete structures through an experimental program. To this end, WTRAA mortars with 15% aggregate replacement, alkali-activated (AA) mortars, and ordinary mortars are made to repair a number of concrete beams. The WTRAA mortars are composed of slag as base material, sodium hydroxide as an alkaline activator, and different gradations of waste tire rubber (fine and coarse gradations). Flexural tests are conducted on the concrete beams repaired by the ordinary, AA, and WTRAA mortars. It is found that, despite having lower compressive strength and modulus of elasticity, the WTRAA and AA mortars increase the flexural strength of the repaired beams, give compatible failures, and provide sufficient mortar-concrete interface bondings. The ordinary mortars, however, show incompatible failure modes. This study demonstrates the promising application of WTRAA mortars in the practical repairs of concrete structures.

Keywords: alkali-activated mortars, concrete repair, mortar compatibility, flexural strength, waste tire rubber

Procedia PDF Downloads 125

Authors: F. O. Oboite, P. G. Comeau

Abstract:

Advance regeneration is present in many lodgepole pine stands in Alberta. When the overstory pine canopy is killed by Mountain Pine Beetle (MPB) the growth of this advance is likely to increase. Understanding the growth response of these understory tree species is needed to improve mid-term timber supply projections and management decisions. To quantify the growth (diameter, height, height/diameter ratio) responses of black spruce and white spruce to lodgepole pine mortality, sample trees of black and white spruce advance regeneration were selected from 7 lodgepole pine dominated stands (5 attacked; 2 control) in the Foothills Region of western Alberta. Measurements were collected 7-8 years after MPB attack across a wide range of spruce height and stand densities. Analysis was done using mixed model linear regression. Result indicates that there was an increase in both diameter and height growth after MPB attack; however, this increase in growth was delayed for about four years. Both spruce species had similar height response and their height/diameter ratio decreased after release, partly as a result of increased understory light associated with loss of needles in the pine canopy. In addition, the diameter and height growth responses of both spruce species were strongly related to density, prerelease growth and initial size.

Keywords: mountain pine beetle, forest regeneration, lodgepole pine, growth response

Procedia PDF Downloads 355

Authors: M.S. El-Feky, Passant Youssef, Mohamed I. Serag

Abstract:

nowadays, nanotechnology is the main trend of research in different areas due to the new potential of using nanometer materials sized less than 100nm. Nanomaterials are needed in cement composites to act as bridging for Nano and micro-cracks to increase tensile strength, reduce the permeability of gases and water in concrete to solve corrosion problem, react with excess Calcium Hydroxide, produce additional C-S-H, act as filler materials to densify the cement matrix and increase its mechanical properties. The present study focuses on the effectiveness of super-plasticizers and ultrasonic processing on the dispersion of Carbon Nanotube at first in water and then in cement composites in combination with Nano silica to enhance the mechanical properties of cement composites. A qualitative analysis using a compressive strength test is conducted with a view to investigate the influence of different dispersion techniques on the mechanical properties of cement composites containing Carbon Nanotube (CNT) and Nano Silica (NS) particles with different percentages. In addition, micro-structural analysis was carried out to understand the surface morphology and microstructure of cement composites with different dosages of NS addition. The investigational study results showed that the combination of NS with a low amount of CNT had a positive effect on the hydration reaction; on the other hand, the combination of CNT and a high amount of NS had a negative effect on the hydration reaction. The compressive strength can be improved by optimum combination 0.02% CNT and 1% NS with gain in strength by 72% and 35% after 7 and 28 days compared to control samples; these results were with an agreement with the morphology structure of composites using microstructure analysis.

Keywords: nano silica, dispersion, sonication, carbon nano tubes

Procedia PDF Downloads 123

Authors: Marziyeh Khavari

Abstract:

In recent decades, climate change, global warming, and the growing population worldwide face some challenges, such as increasing food consumption and shortage of resources. Assessing how climate change could disturb crops, especially hazelnut production, seems crucial for sustainable agriculture production. For hazelnut cultivation in the mid-warm condition, such as in Iran, here we present an investigation of climate parameters and how much they are effective on fertility and nut production of hazelnut trees. Therefore, the climate change of the northern zones in Iran has investigated (1960-2017) and was reached an uptrend in temperature. Furthermore, the descriptive analysis performed on six cultivars during seven years shows how this small-scale survey could demonstrate the effects of climate change on hazelnut production and stability. Results showed that some climate parameters are more significant on nut production, such as solar radiation, soil temperature, relative humidity, and precipitation. Moreover, some cultivars have produced more stable production, for instance, Negret and Segorbe, while the Mervill de Boliver recorded the most variation during the study. Another aspect that needs to be met is training and predicting an actual model to simulate nut production through a neural network and linear regression simulation. The study developed and estimated the ANN model's generalization capability with different criteria such as RMSE, SSE, and accuracy factors for dependent and independent variables (environmental and yield traits). The models were trained and tested while the accuracy of the model is proper to predict hazelnut production under fluctuations in weather parameters.

Keywords: climate change, neural network, hazelnut, global warming

Procedia PDF Downloads 112

Authors: Varsha V. Rohini, P. R. Shreya, B. Renukadevi

Abstract:

In the web analytics the information delivery and the web usage is optimized and the analysis of data is done. The analytics is the measurement, collection and analysis of webpage data. Page statistics and user metrics are the important factor in most of the web analytics tool. This is the limitation of the existing tools. It does not provide design inputs for the optimization of information. This paper aims at providing an extension for the scope of web analytics to provide analysis and statistics of each segment of a webpage. The number of click count is calculated and the concentration of links in a web page is obtained. Its user metrics are used to help in proper design of the displayed content in a webpage by Vision Based Page Segmentation (VIPS) algorithm. When the algorithm is applied on the web page it divides the entire web page into the visual block tree. The visual block tree generated will further divide the web page into visual blocks or segments which help us to understand the usage of each segment in a page and its content. The dynamic web pages and deep web pages are used to extend the scope of web page segment analytics. Space optimization concept is used with the help of the output obtained from the Vision Based Page Segmentation (VIPS) algorithm. This technique provides us the visibility of the user interaction with the WebPages and helps us to place the important links in the appropriate segments of the webpage and effectively manage space in a page and the concentration of links.

Keywords: analytics, design optimization, visual block trees, vision based technology

Procedia PDF Downloads 246

Authors: Abid Hussain, Muhammad Rizwan-ul-Haq, Hassan Al-Ayedh, Ahmed M. Al-Jabr

Abstract:

Oligonychus afrasiaticus, is an important pest that devastates date palms (Phoenix dactylifera). They caused serious damage to date palm fruits. They start feeding on dates at Kimri stage (greenish color dates with high sugar and moisture level) resulting severe fruit losses and rendering them unfit for human consumption. Currently, acaricides are the only tool available to Saudi growers to prevent O. afrasiaticus damage. Many acaricides are available in the Saudi markets in order to control the mites on date palm trees but their efficacy against O. afrasiaticus is questionable. The intensive use of acaricides has led to resistance in many mite species around the globe and their control becomes exceedingly challenging. The current investigation explored for the first time the acaricidal potential of Elettaria cardamomum essential oil for the environmentally safe management of date mites in the laboratory. E. cardamomum exhibited acaricidal activities in a dose dependent manner. GC-MS fractionation of E. cardamomum detected numerous compounds. Among the identified compounds, Guaniol caused 100% mortality compared to other identified compounds including (+)-α-Pinene, Camphene, (-)-B-Pinene, 3-Carene, (R)-(+)-Limonene, and Citral. Our laboratory results showed that E. cardamomum and its constituents especially Guaniol are promising for the eco-friendly management of date mites, O. afrasiaticus, although their field efficacy remains to be evaluated.

Keywords: cardamom, old world date mite, natural acaricide, toxicity

Procedia PDF Downloads 297

Authors: Omar Elharrouss, Youssef Hmamouche, Assia Kamal Idrissi, Btissam El Khamlichi, Amal El Fallah-Seghrouchni

Abstract:

Edge detection is represented as one of the most challenging tasks in computer vision, due to the complexity of detecting the edges or boundaries in real-world images that contains objects of different types and scales like trees, building as well as various backgrounds. Edge detection is represented also as a key task for many computer vision applications. Using a set of backbones as well as attention modules, deep-learning-based methods improved the detection of edges compared with the traditional methods like Sobel and Canny. However, images of complex scenes still represent a challenge for these methods. Also, the detected edges using the existing approaches suffer from non-refined results while the image output contains many erroneous edges. To overcome this, n this paper, by using the mechanism of residual learning, a refined edge detection network is proposed (RED-Net). By maintaining the high resolution of edges during the training process, and conserving the resolution of the edge image during the network stage, we make the pooling outputs at each stage connected with the output of the previous layer. Also, after each layer, we use an affined batch normalization layer as an erosion operation for the homogeneous region in the image. The proposed methods are evaluated using the most challenging datasets including BSDS500, NYUD, and Multicue. The obtained results outperform the designed edge detection networks in terms of performance metrics and quality of output images.

Keywords: edge detection, convolutional neural networks, deep learning, scale-representation, backbone

Procedia PDF Downloads 82

Authors: Deepa T., Inchara S. R., Venkatesh S. V., Seema Tharannum

Abstract:

Concrete is the most widely used structural material. It is usually made using locally available materials. However, concrete has low tensile strength and may crack in the early days with exothermic hydration, for which water is essential. To address the increased construction water demand, treated greywater may be used. Bacillus subtilis bacteria that form endospores is the biological agent considered in this study for biomineralization or Microbially Induced Calcite Precipitation (MICP) technique to heal cracks. Treated grey water which is obtained from STP of PES University, opted in place of Potable water, which had qualities within the standard range as per codal provisions. In this work, M30 grade conventional concrete is designed using OPC 53-grade cement, manufactured sand, natural coarse aggregates, and potable water. Conventional concrete (CC), bacterial concrete with potable water (BS), and treated grey water concrete (TGWBS) are the three different concrete specimens cast. Experimental studies such as the strength test and the surface hardness test are performed on conventional and bacterial concrete samples after 7, 28, and 56 days of curing. Concrete cubes are subjected to a temperature of 50° C to investigate the effect of higher temperature. Cracked cube specimens are observed for self-healing -as well as microstructure analysis with Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Analysis (EDAX), and X-Ray Diffraction Analysis (XRD). Noticeable calcium salt deposition is observed on the surface of the BS and TGWBS cracked specimen. Surface hardness and the EDAX test gave promising results on the advantage of using spore-forming bacteria in concrete. This is followed by the strength gained in compression and flexure. Results also indicate that treated grey water can be a substitute for potable water in concrete.

Keywords: Bacillus subtilis concrete, microstructure, temperature, treated greywater

Procedia PDF Downloads 75