bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical modelling of a large tunnel lining in a creeping rock mass based on 20 years monitoring data
Authors: Plassart R , Martin F , Saïtta A , Lopard G
Published: September 2021

The French project of deep geological storage for nuclear waste (Cigéo) gives rise to a lot of innovative issues for underground space technologies. For example, the nuclear activity of the waste generates temperature effects on the lining, needing to mitigate the number of waste containers in the gallery section. For the Intermediate-Level waste (ILW), thanks to lower temperature effects, the number of containers in the cross section can safely be increased. Therefore, a largest diameter gallery (10 meters) could be more cost effective. The challenge is to design the lining of such a gallery for 100 years in a context of high displacements, due to 500 meters overburden and the creeping behaviour of the rock mass (COx argillite). To improve our understanding of long term behaviour of large galleries, this paper details the experience of the road tunnel of Chamoise (France), including an advanced processing of the available data (rock and lining displacements, linings yielding) recorded since the tunnel excavation, more than 20 years ago. Besides, a numerical modelling of the tunnel has been carried out, using two constitutive laws accounting for a viscoplastic mechanism: L&K (EDF) and H&B-Lemaitre (ANDRA). The simulations results have then been compared with the processed records on 20 years. Finally, the calculations have been carried on until 100 years, improving the demonstration of feasibility of a large gallery in claystone for the challenging Cigéo project.
The Carrara Marble: geology, geomechanics and quarrying
Authors: Coli M , Criscuolo A
Published: September 2021

The industrial exploitation of the Carrara Marble dates back to I century B.C. with the Romans. After a black out in the Early Mediaeval age due to barbarian invasions, since XIII century the Carrara Marble has becoming more and more used for ornamental purposes and appreciated and requested worldwide. Geologically the Carrara Marble derives from a Tertiary polyphasic tectono-metamorphic deformation of an Early Jurassic epicontinental carbonate platform. That got rise to the diverse merceological types of the Carrara Marble, this and two neo-tectonic sub-vertical fracture systems, NNE-SSW and NW-SE trending respectively and grouped into bands irregularly spaced, control the geo-mining setting of the Carrara Marble. For centuries the Carrara Marble has been excavated only following the feeling the quarrymen had with the rock-mass, but the new cultivation technologies with diamond-wire cutting machines and saw-cutting chains, with big frontal-loaders and excavators, have greatly increased the production and require for a robust design based on reliable geomechanical data. Underground quarrying is increasing because technical and environmental concerns and asks for robust design and in situ stress determinations.
Influence of rock’s structure at grain-scale on rockburst proneness
Authors: Klammer A , Gottsbacher L , Biermann J , Zobl F , Marschallinger R , Hofmann P , Marcher T , Schubert W
Published: September 2021

As projects advance to deeper areas, rockbursts occur more frequently. This failure mode is particularly problematic, as the rock mass fails abruptly, releasing high amounts of energy, endangering the life of workers and damaging equipment. The hazard mode is highly influenced by the grain-level structure of the rock. The authors demonstrate this by comparing the grain-level structure of different rocks to their failure mechanism. For this an extensive laboratory program was performed, including uniaxial compression tests (incl. post-failure tests to evaluate the failure energy), acoustic emission testing (to monitor the cracking activity) and Object Based Image Analysis (OBIA) to analyze rock’s structure at grain scale using thin sections taken before and after the compression test. The results allow a better understanding of the underlying mechanism and emphasize the usefulness of petrographic information within rockburst risk analysis.
Empirical relationship for drilling rate in hard rock underground mines
Authors: Adoko A C , Moesi D , Sharipov A S
Published: September 2021

A reliable estimate of the drilling rate is essential in a successful drill and blast planning and mine production. Owing to this importance, numerous empirical equations of the drilling rate using the rock mass properties and the machine parameters have been proposed. However, these existing equations cannot be used in all site conditions. Hence, this paper aims to develop an empirical model for drilling rate estimation in hard rock mining. The data used for this study were collected from an underground mine located in Selibi-Phikwe, Botswana and included in-situ drilling rate, drilling machine specification and rock mass properties. Nonlinear regression model was used to derive the drill rate model. The result indicates high correlation between the estimated and the actual drill rates. In addition, it was found that the uniaxial compressive strength of the rock, the angle between the rock mass discontinuity planes and the drilling direction are the parameters impacting the drill rate the most. Also, the presence of quartz in the rock indicated good predictability of the drill rates.
Use of a miniaturized data-logger for determining the state of stress induced in abandoned pillars
Authors: Saltarin S , Iabichino G
Published: September 2021

The measurement of the natural and/or induced stress state in rock masses excavations is generally carried out thanks to techniques able of providing results both in the two-dimensional (2D) and in the three-dimensional (3D) environment, coded in the “Suggested Method” of the ISRM. The stress relief method is one of the most consolidated measurement methods, based on the differences in strain intensity evaluated in selected directions before and after making a continuous notch around the sensors involved in the measurement. With a special miniaturized data-logger applied to the sensors used for the evaluation of the rock stress in a 2D (doorstopper) or 3D (HI cell, CSIRO) environment, the execution of the measurement on site can be considerably simplified, and the complete strain-time diagram acquired due to over-coring can be obtained. The paper presents an example of measurement of the state of stress induced in some abandoned pillars in an underground quarry.
Monitoring deformations related to geological risks with InSaR data – the MOMPA project
Authors: Gasc-Barbier Muriel , Barra Anna , Buxó Pere , Trapero Laura , Crosetto Michele , Colell Xavier , Fabregat Ivan , Echeverria Anna , Marturia Jordi
Published: September 2021

Co-financed by the Interreg V Program in Spain-France-Andorra (POCTEFA) the European project MOMPA (MOnitoring of ground Movements and Action Protocol) study the landslide hazard in the Eastern Pyrenees. It groups together scientific partners from CTTC (Telecommunications Centre of Catalonia), ICGC (Cartographical and Geological Institute of Catalunya) IEA (Andorran Research Institute), and Cerema (Centre for studies and expertise on risks, the environment, mobility, and development). This cross-border project provides the expertise of four partners, which are specialized in remote sensing and techniques of risk analysis and management. More specifically, the goal of this project is to improve risk management by evolving from a “reactive” approach to a “proactive” one that is rarely used today because of its financial cost. To identify movements, the technique of interferometric SAR (InSAR) based on satellite images is used. This technique is sensitive to very small ground deformations and allows early detection of movements.
Constructive analysis of the role that engineering geological and rock mechanics methods could play in a complex emergency. Lessons Learned from the Totalán Case
Authors: Zango-Pascual M , Osorno Guerrero O
Published: September 2021

The emergency services receive a notice on 13/01/2019 that a 2-year-old boy has fallen into a borehole in Totalán, (Málaga, Spain). After almost 13 days of unusual and overwhelming engineering and solidarity efforts his body is recovered. This was an extraordinary and unusual emergency case, due to: the superhuman effort made by the more than 300 people involved in the rescue operation; the follow-up made by the media, and all the engineering work carried out in record time. For this purpose, it was decided to build a parallel shaft and a 71-meter-deep transversal tunnel, to access the supposed hole, where he is expected to be alive. The cost was approximately 700,000 €. The contribution of geology might have been small, according to sources in the authorities and the media, due to time constraints. But was it really like that? it could have been much more useful, in terms of reducing time frames or even to making different decisions to facilitate the rescue, if other geophysical and engineering geological research methods had been taken into account in the early days. This retrospective analysis is approached with the utmost respect for the efforts made and always with the greatest possible scientific rigour.
Remote monitoring of natural slopes: Combining use of Terrestrial Laser Scanning and innovative rockfall alert system
Authors: Berlinghieri M , Pandolfi O
Published: September 2021

The article describes the first results of a research project aimed to digitalize the monitoring activities of natural rock masses. The project started with a geotechnical remote analysis on the high-definition 3D point cloud detected by a terrestrial laser scanner (TLS), and with the identification of principal discontinuities elements through 3D manual and automatic analysis of the fractures. The results of these survey campaigns have allowed identifying geometrical information of the blocks at risk, to perform a detachment risk assessment and an evaluation of the potential falling trajectories through the lumped mass methodology. The geotechnical monitoring of the rocky mass has seen the combined use of two techniques: the use of a terrestrial laser scanner (TLS) combined with Imaging Matching algorithms; and the implementation of an innovative smart warning system for detachment phenomenon realized by Maccaferri s.p.a., applied to rockfall barriers and drapery mesh, able to provide real-time status notifications and warning alerts. According to the first data analyses, both the proposed techniques can provide excellent monitoring of the rocky slopes, with low costs. The methodological approach proposed perfectly integrates with smart management of excavation sites and the infrastructure and can guarantee an extremely high level of health and safety.
Kriging-based optimization design of deep tunnel in the rheological Burger rock
Authors: Do D P , Tran N T , Hoxha D , Vu M N , Armand G
Published: September 2021

The principal purpose of this work consists in optimizing the support system of a deep tunnel accounting for the uncertainty of the time-dependent behaviour of the surrounding rock, which is described by the rheological Burger law. The stochastic approach is chosen for this aim. On one hand the Quantile Monte Carlo (QMC) simulation is used to determine the optimal design variables (i.e., the thickness of two liners). On the other hand, the well-known Kriging metamodeling technique is undertaken to approximate the limit state function in the augmented reliability space (i.e., the tensor product between the random variable space and the design variable space). The adopted optimization process allows to derive the optimal tunnel support that verifies two failure modes, namely the support capacity criterion and the maximum tunnel convergence.
Guidelines to minimize the occurrence of mega-wedge falls in rock caverns
Authors: Vaskou P , Gatelier N
Published: September 2021

Over the last decade, large rock caverns have been developed for storing vast volumes of hydrocarbons and in particular crude oil. In this context, large rock caverns have light support made of grouted steel or fibreglass rock bolts. Reinforcing cables are strictly prohibited to avoid leak paths for the product. Therefore, the risk of mega-wedge occurrence is high since the size of the potential mega-wedges is proportional to the cavern size. Some geometrical situations are more detrimental than others and the possibility of a local or extensive collapse be very high, including in rock masses which can be ranked as good and above. Such an apparent paradox could have been detrimental to the concept of large caverns because mega-wedges are extremely difficult to stabilize once discovered because rock bolts are generally too short to stabilize them. Anticipation is therefore the key. First, we clarify the term mega-wedge and then, analyse the various possibilities of occurrence in large caverns, as well as classical tunnels. Guidelines are proposed to identify whether the conditions are met for experiencing mega-wedge failure at hand. Two main geological structures, shear fractures and smooth-persistent-planar-spaced (SPPS) joints, are favourable for mega-wedge formation. These two fracture types are analysed and criteria are given to ensure a quick and efficient determination procedure. The field approach is synthesised by a decision chart, to be used at site, during the excavation works.
Numerical method of tunnel face pressure estimation considering progressive failure due to excavation
Authors: Togashi Yota , Shota Iguchi , Osada Masahiko , Kawanoue Ryo
Published: September 2021

The stability of the tunnel face is a top priority in a tunnel construction. The estimation of the earth pressure acting in front of the face is essential for the stability evaluation of the face, and many model experiments have been conducted to understand the characteristics of face stability. On the other hand, there are many cases in which the stability of the tunnel face is evaluated by limiting analysis assuming a constant slip region by applying the loosening earth pressure derived by Terzaghi as a boundary condition, but the actual slip region is not always constant and expanded progressively accompanying by the collapse of the face. There are few past studies that have considered this phenomenon. In this study, a estimation method of the tunnel face pressure are developed in consideration of the progress of face collapse. The proposed method is a kind of limit equilibrium method. Assuming a slip line with two ellipses with the same center and different radii, the first-order linear differential equation of earth pressure in the tunnel face direction is calculated from the equilibrium for infinitesimal elements in the circumferential direction.
Application of a bonded critical state model to design tunnel support for rockmass bulking
Authors: Ciantia M O , Arroyo M , Kaiser P
Published: September 2021

Gabion-type support is a favoured option to restrain bulking in pillar walls of mine footprint tunnels. It uses closely spaced short reinforcements in tunnel walls (typically fully grouted rebar) in combination with surface support (rock fragment retention systems such as shotcrete, weld wire mesh, straps, etc.). The system is installed while the rock is still mostly intact and is conceived to maintain support capacity even when, the rock attains a fully fragmented state, acting then like a gabion or earth-reinforced type retaining wall. In this paper the interaction between the support system and the highly stressed pillar walls is investigated numerically by means of finite element analyses within the framework of displacement-based design. Because the material response should capture the passage from intact rock to fully fragmented state, an advanced elasto-plastic bonded constitutive model was adopted as a simulation framework. The model is calibrated to replicate the mechanical behaviour of Bursnip Sandstone and Amarelo Pais Granite. These two rocks were selected because of high quality triaxial tests results from the literature. After showing the good performance of the model to reproduce both low and high pressure triaxial compression behaviour an extensive parametric study investigating the effects of bolt types on gabion response is presented.
Monitoring and risk-control of large-scale toppling failures - a case study from Ok Tedi
Authors: Casagrande D , Klawitter M , Koek M
Published: September 2021

This paper presents the monitoring and management of a large-scale toppling failure that was first observed in 2005 at the Ok Tedi mine. Ok Tedi is a large open-cut copper gold mine in the Western Province of Papua New Guinea and is one of the wettest mines in the world (>10 m annual rainfall). The management of large-scale failures in open-pit mines expresses geotechnical challenges in terms of balancing economical designs and safe operations. The failure located at the southern end of the West Wall was reactivated in June 2019 due to continuous mining and prolonged rainfall events. Erosion, cracking, and rock toppling associated with lateral displacements, evolved rapidly. Hence, ground control and groundwater management plans, including a Trigger Action Response Plan (TARP) and measurements to monitor movement across the wall, were implemented. This monitoring system, associated with daily visual inspections, enhanced the understanding of the necessary controls to maintain a safe mining operation. Furthermore, the water management plan was crucial in managing this failure. The successful risk-control of this large-scale toppling failure at Ok Tedi ensured continuous mining with a functional balance between economic and safety during operations.
Geomechanical study and rock fall hazard analysis in the historical Centre of Forza d’Agrò (Messina - Italy)
Authors: Barbagallo  , Calvi F
Published: September 2021

The present study shows the result of a rock fall hazard evaluation of the area downstream the Norman Castle that overlooks Forza d’Agro (Messina Province - Italy). The study was aimed at evaluating the penetration capacity of a rockfall in the inhabited center, to evaluate the number of houses involved in the transit area of the boulders. On the basis of the data obtained, a hazard assessment was developed that took into account not only the type and magnitude of the landslide phenomenon, but also the probability of occurrence of the event or its return time.
Sets of stress path as a strategy to study efficiently the geomechanical trending behavior in CSS projects
Authors: Herrera-Schlesinger M C , Cartagena-Pérez D F , Torres-Hernández C A , Araujo-Guerrero E F , Alzate-Espinosa G , Benitez-Pelaez C A , Higuita-Carvajal E , Naranjo-Agudelo A , Castro-Caicedo A J , Burgoa-Suarez L O
Published: September 2021

Thermal recovery techniques such as CSS (Cyclic Steam Stimulation) induce significant changes in the stress path at the reservoir formation due to the induced thermal stresses in the wellbore and surrounding area. The understanding of phenomena regarding these stress paths is crucial to ensure safe operation and optimization of well productivity. Therefore, stress path analysis in CSS entails a challenge related to the number of focal points throughout the reservoir in which the stress paths should be studied. The reduction on the number of focal points is an advantageous step to ensure the appropriate analysis in extensive reservoirs with multiple sands and layers with different geomechanical and yield parameters. In the proposed grouping strategy, temperature and pore pressure are found to be key variables when determining the sets of stress paths with a common phenomenological trending behavior. In the current case study located in Middle Magdalena Valley basin, this grouping strategy allows a comprehensive analysis of 3 sets of stress path strategically located on the borehole wall, inside and outside the steam front with the aid of numerical simulation software (CMG). Considering that stress paths usually represent a single focal point behavior within the reservoir, once this grouping strategy is implemented, an analysis of the whole reservoir is simultaneously performed during CSS.
Stress shadow effect during multi-stage hydraulic fracturing with different wellbore arrangements
Authors: Wasantha P L P , Konietzky H , Xu T , Xu B
Published: September 2021

Multi-stage hydraulic fracturing was simulated using a two-dimensional universal distinct element code (UDEC). Five fracturing stages were considered along horizontally (i.e. parallel to the minor principal stress direction)- and diagonally (i.e. inclined to the minor principal stress direction)-positioned wellbores within the pay zone, where the spacing between wells was changed to 50 m and 100 m. Progressive fracture propagation and the evolution of stress shadow with sequential multi-stage fracturing were monitored. A marked stress shadow was observed for closer well spacings under both horizontal and diagonal well arrangements, leading to a significantly asymmetric fracture propagation about the wellbore. The diagonal well arrangement showed a nearly unidirectional fracture propagation after the first stage for the closer well spacing case. Fractures of sequential stages predominantly developed in alternating directions at greater well spacings irrespective of the wellbore arrangement. Progressive fracture development also showed that fractures created at earlier stages could further extend due to the stress shadow of later fracturing stages, and this effect is more pronounced for closer well spacings. After five stages, the overall fracture lengths indicate that a higher fractured area was created by horizontal well arrangement for any case of well spacing. Finally, the importance of optimizing the fractured area and fracture controllability to contain the fractures within the pay zone was highlighted.
Numerical analysis of deep twin excavations and boreholes for heavy oil production
Authors: Emci M E , Ozturk H
Published: September 2021

One of the plans for the production of Turkey’s largest oil reserve, Bati Raman (1.85 billion barrels), is to use Mining-Assisted Heavy Oil Production (MAHOP). In this method, twin declines are excavated from the surface to the reservoir and a series of excavations (galleries) continue along the bottom of the reservoir. Fan-shaped steam injection and production holes are drilled in the reservoir from the crown of the galleries to use conventional Steam-Assisted Gravity Drainage (SAGD). The Bati Raman reservoir is situated at an average depth of 1450 m, producing 12° API heavy oil from a 60m thick calcareous reservoir rock. This research aims to numerically investigate the stability of excavations together with the initiation, formation and propagation of fracture networks between the fan-shaped boreholes and around typical twin excavations using FLAC3D. It is shown that the stability of twin excavations and pillars between them can be guaranteed with suitable support types. In addition, this innovative approach in heavy oil production in hard rock media successfully showed that the fracture networks created by MAHOP could be used effectively for oil recovery of reservoir rocks using SAGD.
Hydrofracturing tests on granite samples using a true triaxial device equipped with acoustic emission sensors
Authors: Herbón-Penabad M , Muñoz-Ibáñez A , Delgado-Martín J , González-Molano N , Alvarellos-Iglesias J , Canal-Vila J
Published: September 2021

We present a series of tests performed on granite samples using a true triaxial device designed and built at the Rock Mechanics Laboratory (University of A Coruña). The experiments were performed using cubic rock samples of 150 mm-edge, which were loaded to different stress conditions (σh < σh < σy < 45 MPa) on each loading axis. The device is based on a stiff steel frame that can be coupled to a servo-hydraulic testing machine that provides de vertical stress (av), while two high-pressure pumps are used to deliver the lateral stress (σh and ah). An additional high-pressure pump is used to inject the fluid (mineral oil) into the rock sample at a low constant-flow rate. The aluminium loading platens, which are bevelled at the edges to avoid interaction among adjacent faces, have holes and grooves to introduce acoustic emission sensors that allow the location of fracture propagation. The specimens were drilled using a 6 mm drill bit until reaching the geometrical centre. Then, a 1/8” (~3.18 mm) stainless steel tube is glued to the samples with epoxy. Strain measurements during the experiments were conducted using four strain gages attached to the orthogonal faces of the specimens. The system was further equipped with three LVDTs to account for the bulk displacement on each axis. Our results suggest a linear relationship between the breakdown pressure and the confining stress under hydrostatic conditions but no clear correlation in non-hydrostatic stress regime.
A time-independent reliability based design approach for rockfall net fences: a comparative analysis within the Eurocode framework
Authors: Marchelli Maddalena , Peila Daniele , Biagi Valerio De
Published: September 2021

The design of net fences as passive mitigation measures against rockfall events has represented a challenge since the last decades. The choice of the proper effect of the actions to consider in the design is still under debate. Recently, the Authors have proposed a novel time-independent reliability approach encompassing the large variability of the size and the kinematics of the possible impacting blocks. The entire statistics of all these quantities (size, velocity, and height) enters into the calculations, differently from other approaches that consider specific values of the parameters. In addition, the variability in time of the inputs is tackled, with particular reference to the size of the falling block. The recent approach is herein merged and compared with the current semi-probabilistic ultimate limit state design approach, suggested in the Eurocodes and implemented in the Italian recommendations UNI 11211-4:2018, with the purpose of finding the equivalent partial safety factors of kinetic energy and trajectory height of the impacting block. A sensitivity analysis with different synthetic profiles, representing possible real situations, is performed highlighting that if a set of partial safety factors is assigned to different sites, an intrinsic variability in the failure probability has to be accepted.
Monitoring of preconvergence deformations in a road tunnel: data analysis and validation
Authors: Cavalca E , Valletta A , Carri A , Savi R , Segalini A
Published: September 2021

Tunnels are complex constructions, generally built in difficult geological contexts. When dealing with underground structures, the study of ground deformations is a key aspect to consider in order to guarantee safety during the tunnel excavation and construction quality. One of the main aspects to investigate is related to the development of preconvergence phenomena in the advance core, i.e. deformations involving the volume of rock mass ahead of the tunnel face. This paper presents the application of a new monitoring tool specifically developed to measure preconvergence effects during the excavation phases with a direct approach. The device, called PreConv Array, consists of a series of 3D MEMS (Micro Electro-Mechanical System) and temperature sensors. The system takes advantage of automated procedures for data acquisition, elaboration, and representation, thus achieving a near-real time monitoring of the ground differential vertical settlements ahead of the excavated face. Monitoring results reported in this paper are related to the installation of a PreConv Array during the excavation phases of a road tunnel located in Northern Italy. The collected data allowed to highlight the displacements of the tunnel crown in correspondence of each step of the excavation works. Moreover, the comparison with theoretical Longitudinal Deformation Profiles (LDP) evidenced the good correspondence between PreConv data and the theoretical curves.
Identification of formaldehyde in groundwater using UV-Vis spectrometer
Authors: Rosli N , Jani M , Idris N S U , Mohd Ghazi R , Nik Yusoff N R
Published: September 2021

This research aims to identify the concentration of formaldehyde in groundwater by using UV-Vis spectrophotometer and to assess the physico-chemical parameters of water quality in groundwater. The samples were collected from a cemetery of Kampung Darat Demit, Kubang Kerian, Kota Bharu where the formalin-based specimen/pathological waste was buried. The unknown concentration of the formaldehyde was determined by using chromotropic acid method for the analysis of formaldehyde. A calibration curve was prepared with six different concentrations to determine the unknown concentration of formaldehyde in the samples. Seven parameters of water quality were analyzed using respective methods and the relationship with the presence of formaldehyde in water were discussed. By using the National Water Quality Standard (NWQS) of Malaysia 2008 the class of water for all samples were determined. A statistical study of one-way analysis of variance (ANOVA) was conducted using SPSS 20th version software. The results showed the different concentration of formaldehyde found in all four samples for four consecutive weeks. The classes of water samples for each physical-chemical parameter vary and in range between Class II and III. The presence of formaldehyde in water may has significant effect on the water quality parameters physically, biological and chemically.
Climbers diversity in Agro Techno Park, Universiti Malaysia Kelantan, Jeli Campus
Authors: Ahmad Fikri N , Abdul Karim M F , Mazri N H , Saharizan N , Adnan N S , Mohd Ali N B , Amaludin N A , Zakaria R
Published: September 2021

Species diversity of climbers were inventoried in four nature trails of Agro Techno Park Universiti Malaysia Kelantan (UMK), Jeli campus. The purpose of this study was to determine the diversity, composition and abundances of climbers in Agro Techno Park Universiti Malaysia Kelantan, Jeli Campus. Samples of the climbers were randomly collected from four natural trails for herbarium preparation and preserved using 70% ethanol solution. The preservation was done by putting the samples in zip lock transparent bag that contained of 70% ethanol solution. The samples were oven-dried at 30-40 °C, mounted and labelled before identification. The diversity pattern of the climbers was analyzed by using Shannon Diversity Index, Shannon Evenness Index, Margalef Richness Index, Abundance Parameters and Importance Value Index (IVI). A total of 593 climbers belonging to 35 species were recorded. Family Fabaceae was the most diverse plant from the climbers’ family which consisted of 4 genera and 5 species. This was followed by family Menispermaceae, Melastomataceae, Connaraceae, Apocynaceae, Rubiaceae and Vitaceae. The result obtained indicated that alteration of the ecological environment through natural disturbances influenced the abundance and distribution of climbers.
Identification of groundwater potential zones using AHP in district Kuala Krai, Kelantan, Malaysia
Authors: Jamil R M , Hisham S S , Leong M C , Nawawi S A , Nor A N M , Ibrahim N
Published: September 2021

Groundwater is one of the main sources of water in Kelantan which consumes 70% of the water supply. The rapid development in population, urbanization, agriculture, and industry has led to an increased water supply and demand. Hence, it is necessary to identify new groundwater potential sources to enhance groundwater supply in the study area. This study was carried out at Kuala Krai, Kelantan within latitude 5”36’30° to 5”33’50° N and longitude 102”8’25° to 102”11’10° E. The Analytical Hierarchy Process (AHP) method were used in this study and this method eventually come out with groundwater potential zones. The parameters such as lithology, geomorphology, land use, slope, drainage density, rainfall density, and soil type were chosen and spatially generated using GIS platform. Those parameters were subjected to weighted overlay analysis to obtain the potential zones of groundwater. The weights for the various layers were generated and assigned using the AHP technique which allows the comparison of criteria influencing the potential zone. The results of the study revealed that the good potential zone comprises 36.1%, moderate 32.4%, and poor 31.5% areas respectively. In conclusion, factors such as low elevation, gentle slope, alluvial plains, and vegetation area have given a high potential of groundwater in this study area.
Machine Learning Application in Water Quality Using Satellite Data
Authors: Hassan N , Woo C S
Published: September 2021

Monitoring water quality is a critical aspect of environmental sustainability. Poor water quality has an impact not just on aquatic life but also on the ecosystem. The purpose of this systematic review is to identify peer-reviewed literature on the effectiveness of applying machine learning (ML) methodologies to estimate water quality parameters with satellite data. The data was gathered using the Scopus, Web of Science, and IEEE citation databases. Related articles were extracted, selected, and evaluated using advanced keyword search and the PRISMA approach. The bibliographic information from publications written in journals during the previous two decades were collected. Publications that applied ML to water quality parameter retrieval with a focus on the application of satellite data were identified for further systematic review. A search query of 1796 papers identified 113 eligible studies. Popular ML models application were artificial neural network (ANN), random forest (RF), support vector machines (SVM), regression, cubist, genetic programming (GP) and decision tree (DT). Common water quality parameters extracted were chlorophyll-a (Chl-a), temperature, salinity, colored dissolved organic matter (CDOM), suspended solids and turbidity. According to the systematic analysis, ML can be successfully extended to water quality monitoring, allowing researchers to forecast and learn from natural processes in the environment, as well as assess human impacts on an ecosystem. These efforts will also help with restoration programs to ensure that environmental policy guidelines are followed.
Organic and nutrient removal from pulp and paper industry wastewater by extended aeration activated sludge system
Authors: Jagaba A H , Kutty S R M , Fauzi M A H M , Razali M A , Hafiz M F U M , Noor A
Published: September 2021

Pulp and paper industries are critical to a country’s economic growth. The type of raw material used and the pulping process determine the quality and quantity of wastewater generated. However, the generated wastewater with a dark colour comprises a high concentration of suspended solids, organic content, chemical oxygen demand (COD), volatile organic compounds, and a variety of other impurities. Therefore, in this study, a bench scale activated sludge treatment system was set up using a reactor consisting of an aeration tank with 5000 mg/L initial biomass and a clarifier chamber for the biomass to settle. The reactor was run few weeks with real domestic wastewater as the influent for 3 weeks to acclimatize the sludge inside the reactor. The reactor was then fed with the influent mixture of 20% industrial pulp wastewater and 80% domestic wastewater. Organic and nutrient parameter concentrations are tested from the influent and effluent sample throughout the study duration and recorded for data analysis. The removal of COD and TSS are at 83% and 90% respectively while the averaged BOD value of the treated wastewater is at 74.6%. The conclusion of this project is that the bench scale EAAS is able to treat BOD and TSS according to standard. However, a modification may be required to increase the efficiency of removing COD to meet the requirement standards. This modification could be either by using a biocarrier or an activated carbon to further enhance the treatment efficiency even at higher wastewater concentration.
Notes on small mammals diversity at Perlis State Parks, Wang Kelian, Perlis, Malaysia
Authors: Fauzi N F M , Shahfiz M A , Ahmad Ruzman N H , Munian K , Baharudin M S , Azahar M A , Zam Beri N A Z , Ag Ahmadni A S , Mohamad F
Published: September 2021

Three surveys were conducted to document diversity on small mammals at Perlis State Park, Wang Kelian, Perlis, Malaysia from 2019 until 2020. For each survey, a total of 50 cage traps, 10 mist-nets and two four-bank harp traps were set up for three-trapping nights along a 500 m transect line to sample small mammals. The opportunistic observation was also applying to record the incidence of small mammals. In total, 17 species of small mammals were documented during these surveys. Of these, seven species are volant small mammals, and ten species are non-volant small mammals. The family with the most diverse species was Pteropodidae with five species and Cynopterus brachyotis being the most dominant species (n = 46). Interestingly, these surveys report new distributional records for three small mammal species in Perlis State Park, though several studies have been conducted previously. This information demonstrates that there may be more species yet to be recorded from this study site. Comparing the species similarity between our study site and several state parks in Peninsular Malaysia shows that Perlis State Parks also holds a relatively high diversity of small mammals. Therefore, adequate conservation measures such as recognizing this state park as an important conservation area are needed to ensure valuable small mammals’ sustainability.
Delineation of flood-prone areas using Digital Elevation Model (DEM) in Kuala Krai, Kelantan
Authors: Anis-Athirah B N , Mohd-Fariz A R , Bam H N R , Majid S , Muhammad M , Jemali N J N
Published: September 2021

Kelantan is one of the states that experience flood events annually including the Kuala Krai district. Flooding has a severe impact on roads, villages, farms, and people’s livelihoods. Early detection of flood-prone areas is essential in detecting the specific area. This study aimed to map a flood-prone area based on evaluation of terrain characteristics include elevation, aspect, slope, contour and hill shade of the Kuala Krai area. The raster data of DEM with 50 m resolution and hydrological data were evaluated to create a potential flood map. A flood-prone map is created by overlaying terrain features with flood criteria of a gentle slope with contour < 250 m and degree of slope less than 10, flat surface in aspect and consideration of hill shade factors. The map was also supported by vector data of rivers network that cross the Kuala Krai area. 56% of the Kuala Krai area facing a moderate risk of flood occurrence, while 41%of the areas are in a dangerous state and are predicted to be at a high risk of flood. This can be concluded that the areas with low elevation, adjacent to rivers, are the places where actions need to be taken by the experts to overcome the disaster in the future.
Application of POMOF composites for CO2 fixation into cyclic carbonates
Authors: Musa S G , Merican Z M A , Zabidi A M , Akbarzadeh O
Published: September 2021

The problem of global warming is one of the major concerns in the world today as there has been continuous rise in temperature resulting from increase in the emission of anthropogenic carbon dioxide (CO2). Recently, carbon dioxide is considered as an abundant C1 feed-stock for organic transformations, due to its free availability, non-toxicity, and simplicity in handling. The synthesis of metal-organic framework/polyoxometalates supported composites (POM@MOF), were prepared by incorporation of Keggin type-polyoxometalate groups via impregnation method. The as-synthesized composites were characterized by powder X-ray diffraction (PXRD), fourier-transform infrared spectroscopy (FT-IR), and field emission scanning electron microscope (FESEM), which confirm the presence of the polyoxometalates group after formation of the composites. The composites were employed as catalyst for the conversion of CO2 and epichlorohydrin into cyclic chloropropylene carbonate. The reaction was carried out under mild condition of atmospheric pressure in a schlenk tube without addition of any co-catalyst or solvent and the yield have shown progressive increase over time as indicated by GC results from 30% at 6 h duration to 87% over a period of 48 h of continuous siring.
Impacts of river of life project towards the conservation of urban heritage quarter in Kuala Lumpur: a preliminary study
Authors: Zuraimi A S , Radzuan I S M
Published: September 2021

The River of Life (RoL) is one project of Malaysia’s Economic Transformation Programmes. RoL is a multi-year attempt that integrates high-impact programmes to help Malaysia achieve a status of a developed nation. This study discussed the components of the waterfront development packages in the River of Life (RoL) project implementation. As explained by urban planning theory, the growth of a city is affected by multiple factors. The word “urban regeneration” originated to define the social, economic, and environmental components that influence a city’s growth. This study intended to examine the socioeconomic impact of the RoL project in the Kuala Lumpur heritage quarter in terms of development. A qualitative method approach combining interviews and document reviews were used in this study. The study revealed the impacts of RoL project within the heritage quarter from the perspectives of the local authorities, private sector as well as stakeholders involved in the project. The study findings will help numerous stakeholders to provide better urban living for the Kuala Lumpur heritage quarter.
Total phenolic content and antioxidant activity of limestone endemic Araceae species, Alocasia farisii
Authors: Puteri-Adiba H M , Arifullah M , Nazahatul A A , Sirikitputtisak T , Klaiklay S , Chumkaew P , Chewchanwuttiwong S , Norhazlini M Z , Zulhazman H
Published: September 2021

The changing environments are giving a rise to free radical, causing development of degenerative disease. A search for natural antioxidant is required as the synthetic antioxidant reported has carcinogenic effects on living organisms. Therefore, the aim of this study is to determine the total phenolic content and antioxidant activity of Alocasia farisii leaves and petioles using three different polarity solvent which are methanol, ethanol and ethyl acetate. The total phenolic content was evaluated using the Folin-Cioucalteu reagent with some modification and the antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay. The methanolic extract attained the highest total phenolic content and antioxidant activity at 46.615 μg GAE/g and 66.43 %, respectively. Ethyl acetate with the lowest polarity had the lowest value, 34.769 μg GAE/g total phenolic content and 58.274 % in antioxidant activity. The IC50 value shows methanol recorded the lowest value at 339.905 μg/mL, indicates high radical scavenging activity whereas ethyl acetate has highest IC50 value (400 μg/mL) indicates low radical scavenging. These finding provide useful information on the total phenolic content and antioxidant activity of A. farisii that can be a reference for further research on this species of Araceae family. The leaves and petiole extracts of A. farisii may be exploited as natural sources of antioxidant.
Introduction to the Special Issue: The ecology and genetics of population differentiation in plants
Authors: Picó F Xavier , Abdelaziz Mohamed , Castilla Antonio R
Published: September 2021

Population differentiation is a pervasive process in nature. At present, evolutionary studies on plant population differentiation address key questions by undertaking joint ecological and genetic approaches and employing a combination of molecular and experimental means. In this special issue, we gathered a collection of papers dealing with various ecological and genetic aspects of population differentiation in plants. In particular, this special issue encompasses eight research articles and two reviews covering a wide array of worldwide environments, plant functional types, genetic and genomic approaches, and common garden experiments to quantify molecular and/or quantitative trait differentiation in plant populations. Overall, this special issue stresses the validity of traditional evolutionary studies focused on plant populations, whilst emphasizing the integration of classical biological disciplines and state-of-the-art molecular techniques into a unique toolkit for evolutionary plant research.
Melittin suppresses epithelial–mesenchymal transition and metastasis in human gastric cancer AGS cells via regulating Wnt/BMP associated pathway
Authors: Huang Jye-Yu , Peng Shu-Fen , Chueh Fu-Shin , Chen Po-Yuan , Huang Yi-Ping , Huang Wen-Wen , Chung Jing-Gung
Published: September 2021

Gastric cancer has a poor prognosis; once cancer has metastasized, it can easily lead to patient death. Melittin is one of the major components extracted from the bee venom. It has been shown that melittin emerges antitumor activities against many human cancer cell lines. Our results indicated that melittin at 0.2-0.5 µm significantly reduced total cell viability in human gastric cancer AGS cells. At low concentrations (0.05-0.15 µm), melittin displayed antimetastasis effects and inhibited cell adhesion and colony formation. Besides, it inhibited cell motility and suppressed cell migration and invasion. Melittin inhibited the activities of MMP-2 and MMP-9 and the integrity of cell membrane in AGS cells. Furthermore, Western blotting results showed that melittin decreased the protein expressions of Wnt/BMP and MMP-2 signaling pathways. Based on these observations, melittin inhibited cell migration and invasion of AGS cells through multiple signaling pathways. It may be used to treat metastasized gastric cancers in the future.
Machine learning methods, databases and tools for drug combination prediction
Authors: Wu Lianlian , Wen Yuqi , Leng Dongjin , Zhang Qinglong , Dai Chong , Wang Zhongming , Liu Ziqi , Yan Bowei , Zhang Yixin , Wang Jing , He Song , Bo Xiaochen
Published: September 2021

Combination therapy has shown an obvious efficacy on complex diseases and can greatly reduce the development of drug resistance. However, even with high-throughput screens, experimental methods are insufficient to explore novel drug combinations. In order to reduce the search space of drug combinations, there is an urgent need to develop more efficient computational methods to predict novel drug combinations. In recent decades, more and more machine learning (ML) algorithms have been applied to improve the predictive performance. The object of this study is to introduce and discuss the recent applications of ML methods and the widely used databases in drug combination prediction. In this study, we first describe the concept and controversy of synergism between drug combinations. Then, we investigate various publicly available data resources and tools for prediction tasks. Next, ML methods including classic ML and deep learning methods applied in drug combination prediction are introduced. Finally, we summarize the challenges to ML methods in prediction tasks and provide a discussion on future work.
‘Killing Is Just The Best Solution’: Lynching As Informal Incapacitation
Authors: Tiwa Dany Franck A
Published: September 2021

This article highlights two overlooked drivers of lynching violence: the will to ensure that caught offenders will no longer victimize anybody, and the need for perpetrators of lynching to mitigate the risks associated with their participation. It uses the concepts of lethal and non-lethal informal incapacitation to explain lynching outcomes (‘killing’ and ‘serious beatings’) that are otherwise unintelligible. Evidence is drawn from individual and group interviews with more than a hundred key informants in Nigeria.