Search results for: THM effects on rock

Authors: Emmanuel Dada, Adebayo-Victoria Tobi Dada

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The study evaluates land use and land cover changes in the cocoa belt of Ondo state to quantify its effect on the expanse of land occupied by cocoa plantation as the most suitable region for cocoa raisin in Nigeria. Time series of satellite imagery from Landsat-7 ETM+ and Landsat-8 TIRS covering years 2000 and 2015 respectively were used. The study area was classified into six land use themes of cocoa plantation, settlement, water body, light forest and grassland, forest, and bar surface and rock outcrop. The analyses revealed that out of total land area of 997714 hectares of land of the study area, cocoa plantation land use increased by 10.3% in 2015 from 312260.6 ha in 2000. Forest land use also increased by 6.3% in 2015 from 152144.1 ha in the year 2000, water body reduced from 2954.5 ha in the year 2000 by 0.1% in 2015, settlement land use increased by 3% in 2015 from 15194.6 ha in 2000, light forest and grassland area reduced by 10.4% between 2000 and 2015 and 9.1% reduction in bar surface and rock outcrop land use between the year 2000 and 2015 respectively. The reasons for different ranges in the changes observed in the land use and land cover in the study area could be due to increase in the incentive to cocoa farmers from both government and non-governmental organizations, developed new cocoa breed that thrive better in the light forest, rapid increased in the population of cocoa farmers’ settlements, and government promulgation of forest reserve law.

Keywords: satellite imagery, land use and land cover change, area of land

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Authors: Thirsa Sherry, Utkarsh Shrivastav, Kannan B. T., Iynthezhuton K.

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The field of aerodynamics and aeroacoustics remains one of the most poignant and well-researched fields of today. The current paper aims to investigate the predominant problem concerning the effects of noise of varying frequencies and waveforms on airflow surrounding an airfoil. Using a single speaker beneath the airfoil at different positions, we wish to simulate the effects of sound directly impinging on an airfoil and study its direct effects on airflow. We wish to study the same using smoke visualization methods with incense as our smoke-generating material in a variable-speed subsonic wind tunnel. Using frequencies and wavelengths similar to those of common engine noise, we wish to simulate real-world conditions of engine noise interfering with airflow and document the arising trends. These results will allow us to look into the real-world effects of noise on airflow and how to minimize them and expand on the possible relation between waveforms and noise. The parameters used in the study include frequency, Reynolds number, waveforms, angle of attack, and the effects on airflow when varying these parameters.

Keywords: engine noise, aeroacoustics, acoustic excitation, low speed

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Authors: Syahrir Andi Mangga

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During 1989–1993, the Geological Research and Development Center (recent Geological Survey Institute) Geological Agency, Ministry of Energy and Mineral Resources Republic of Indonesia was the collaboration with British Geological Survey, the United Kingdom to do technical assistance in order to collect data of geology in Sumatra Island. The overall corporation of technical programs was larger concern in stratigraphy, geochemical and age-dating studies. Availability of new data has been stimulated to reassessment of tectonic evolution of Sumatra Island. The study area located in Southern Sumatra within at latitudes 0°-6° S and 99°40’-106’00 E longitudes. The study tectonic is situated within along South Western margin of Sunda land, The Southeast Asia Continental extension arc of the Eurasian Plate and formed as part of Sunda Arc. The oceanic crust of Indian-Australian plate recently is being oblique subduction along the Sunda Trench off the West coast Sumatra. The Mesozoic-Cenozoic of the volcanic and granitic rocks can be divided into northern and southern plutons, defining a series subparallel, controlled by fault, northwest-southeast trending belts, some of the plutons are deformed and under-formed. They are widely exposed along the south-eastern side of the Barisan mountain. Based on the characteristic of minerals and crystallography, rocks found in this study area were granite, granitic, monzogranite and andesitic-Basaltic Volcanic Rock. It belongs to calc Alkaline was predominantly metalumina, I-Type Granite, Volcanic arc granites, Syncollisonal Granites (Syn_COLG) and tholeiitic basalt. It was formed since 169±5 to 20±1 Ma. The origin of magmas in interpreted to be derived from partial melting of igneous rock. The occurrence of the gratoid and volcanic rocks supposed to be closely related to the subduction of the Australian-Hindia oceanic crust beneath the Eurasia/Sunda land Continental Crust as Volcanic arc or continental margin granitic and shown youngest to the southwest. The subduction process having probably been different in position between one terrane to others led to the occurrence of segmentation subduction system. The positional discontinuities of the subduction are probably caused by the difference in time of emplacement and mechanism of volcanic and granitic rock between segments.

Keywords: tectonic setting, I-type granitic, subduction, Southern Sumatra

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Authors: Xiaoqin Wang, Li Yin

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Background and purpose: In many practices, one estimates causal effects arising from a complex stochastic process, where a sequence of treatments are assigned to influence a certain outcome of interest, and there exist time-dependent covariates between treatments. When covariates are plentiful and/or continuous, statistical modeling is needed to reduce the huge dimensionality of the problem and allow for the estimation of causal effects. Recently, Wang and Yin (Annals of statistics, 2020) derived a new general formula, which expresses these causal effects in terms of the point effects of treatments in single-point causal inference. As a result, it is possible to conduct the modeling via point effects. The purpose of the work is to study the modeling of these causal effects via point effects. Challenges and solutions: The time-dependent covariates often have influences from earlier treatments as well as on subsequent treatments. Consequently, the standard parameters – i.e., the mean of the outcome given all treatments and covariates-- are essentially all different (null paradox). Furthermore, the dimension of the parameters is huge (curse of dimensionality). Therefore, it can be difficult to conduct the modeling in terms of standard parameters. Instead of standard parameters, we have use point effects of treatments to develop likelihood-based parametric approach to the modeling of these causal effects and are able to model the causal effects of a sequence of treatments by modeling a small number of point effects of individual treatment Achievements: We are able to conduct the modeling of the causal effects from a sequence of treatments in the familiar framework of single-point causal inference. The simulation shows that our method achieves not only an unbiased estimate for the causal effect but also the nominal level of type I error and a low level of type II error for the hypothesis testing. We have applied this method to a longitudinal study of COVID-19 mortality among Scandinavian countries and found that the Swedish approach performed far worse than the other countries' approach for COVID-19 mortality and the poor performance was largely due to its early measure during the initial period of the pandemic.

Keywords: causal effect, point effect, statistical modelling, sequential causal inference

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Authors: Farid Adisaputra Gumilang

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Kucing Liar Underground Mine is a future mine of PT Freeport Indonesia PTFI that is currently being developed. In the development process, problems were found when blasting the tunnels; there were overbreak, and void occur caused by geological contact or poor rock conditions. Geotechnical engineers must evaluate not only the remnant capacity of ground support systems but also investigate the depth of rock mass yield within pillars. To prevent the potential hazard caused by void zones, geotechnical engineers must ensure the planned drift is mined in the best location where people can work safely. GPR, or Ground penetrating radar, is a geophysical method that can image the subsurface. This non-destructive method uses electromagnetic radiation and detects the reflected signals from subsurface structures. The GPR survey measurements are conducted 48 meters along the drift that has a poor ground condition with 150MHz antenna with several angles (roof, wall, and floor). Concern grounds are determined by the continuity of reflector/low reflector in the radargram section. Concern grounds are determined by the continuity of reflector/low reflector in the radargram section. In this paper, processing data using instantaneous amplitude to identify the void zone. In order to have a good interpretation and result, it combines with the geological information and borehole camera data, so the calibrated GPR data allows the geotechnical engineer to determine the safe location to change the drift location.

Keywords: underground mine, ground penetrating radar, reflectivity, borehole camera

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Authors: Rajkumar Ghosh

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The Sutlej River Valley in Himachal Pradesh, India, is home to four Out-of-Sequence Thrusts (OOST) in the Higher Himalaya. These OOSTs include Jhakri Thrust (JT), Sarahan Thrust (ST), Chaura Thrust (CT), and Jeori Dislocation (JD). The study focuses on the rock types of these OOSTs, including ductile sheared gneisses and upper greenschist-amphibolite facies metamorphosed schists. Microstructural tests reveal a progressive increase in strain approaching the Jakhri thrust zone, with temperatures increasing from 400 to 750°C. The Chaura Thrust is assumed to be folded with this anticlinorium, with various branches that make up the thrust system. Fieldwork and microstructural research have revealed the following: (a) initial top-to-SW sense of ductile shearing (Chaura thrust); (b) brittle-ductile extension (Jeori Dislocation); and (c) uniform top-to-SW sense of brittle shearing (Jhakri thrust). Samples of Rampur Quartzite from the Rampur Group of Lesser Himalayan Crystalline and schistose rock from the Jutogh Group of Greater Himalayan Crystalline were examined.The study emphasizes the value of microscopic research in detecting different types of crenulated schistosity and documenting mylonitized zones. The paper explains the field evidence for the OOST and comes to the conclusion that the Chaura Thrust is not a blind thrust. The paper describes the box fold and its characteristics in the Himachal Himalayan regional geology.

Keywords: Out-of-sequence thrust (OOST), jakhri thrust (JT), sarahan thrust (ST), chaura thrust (CT), jeori dislocation (JD)

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Authors: Eman Ghoneim, Amr S. Fahil

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Many regions in Egypt are facing a reduction in crop productivity due to environmental degradation. One factor of crop deterioration includes the unsustainable drainage of surface water, leading to salinized soil conditions. Egypt has exerted time and effort to identify solutions to mitigate the surface water drawdown problem and its resulting effects by exploring renewable and sustainable sources of energy. Siwa Oasis represents one of the most favorable regions in Egypt for geothermal exploitation since it hosts an evident cluster of superficial thermal springs. Some of these hot springs are characterized by high surface temperatures and bottom hole temperatures (BHT) ranging between 20°C to 40 °C and 21 °C to 121.7°C, respectively. The depth to the Precambrian basement rock is commonly greater than 440 m, ranging from 440 m to 4724.4 m. It is this feature that makes the locality of Siwa Oasis sufficient for industrial processes and geothermal power production. In this study, BHT data from 27 deep oil wells were processed by applying the widely used Horner and Gulf of Mexico correction methods to obtain formation temperatures. BHT, commonly used in geothermal studies, remains the most abundant and readily available data source for subsurface temperature information. Outcomes of the present work indicated a geothermal gradient ranging from 18 to 42 °C/km, a heat flow ranging from 24.7 to 111.3 m.W.k⁻¹, and a thermal conductivity of 1.3–2.65 W.m⁻¹.k⁻¹. Remote sensing thermal infrared, topographic, geologic, and geothermal data were utilized to provide geothermal potential maps for the Siwa Oasis. Important physiographic variables (including surface elevation, lineament density, drainage density), geological and geophysical parameters (including land surface temperature, depth to basement, bottom hole temperature, magnetic, geothermal gradient, heat flow, thermal conductivity, and main rock units) were incorporated into GIS to produce a geothermal potential map (GTP) for the Siwa Oasis region. The model revealed that both the northeastern and southeastern sections of the study region are of high geothermal potential. The present work showed that combining bottom-hole temperature measurements and remote sensing data with the selected geospatial methodologies is a useful tool for geothermal prospecting in geologically and tectonically comparable settings in Egypt and East Africa. This work has implications for identifying sustainable resources needed to support food production and renewable energy resources.

Keywords: BHT, geothermal potential map, geothermal gradient, heat flow, thermal conductivity, satellite imagery, GIS

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Authors: H. Khanfari, M. Johari Fard

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Dealing with carbonate reservoirs can be mind-boggling for the reservoir engineers due to various digenetic processes that cause a variety of properties through the reservoir. A good estimation of the reservoir heterogeneity which is defined as the quality of variation in rock properties with location in a reservoir or formation, can better help modeling the reservoir and thus can offer better understanding of the behavior of that reservoir. Most of reservoirs are heterogeneous formations whose mineralogy, organic content, natural fractures, and other properties vary from place to place. Over years, reservoir engineers have tried to establish methods to describe the heterogeneity, because heterogeneity is important in modeling the reservoir flow and in well testing. Geological methods are used to describe the variations in the rock properties because of the similarities of environments in which different beds have deposited in. To illustrate the heterogeneity of a reservoir vertically, two methods are generally used in petroleum work: Dykstra-Parsons permeability variations (V) and Lorenz coefficient (L) that are reviewed briefly in this paper. The concept of Lorenz is based on statistics and has been used in petroleum from that point of view. In this paper, we correlated the statistical-based Lorenz method to a petroleum concept, i.e. Kozeny-Carman equation and derived the straight line plot of Lorenz graph for a homogeneous system. Finally, we applied the two methods on a heterogeneous field in South Iran and discussed each, separately, with numbers and figures. As expected, these methods show great departure from homogeneity. Therefore, for future investment, the reservoir needs to be treated carefully.

Keywords: carbonate reservoirs, heterogeneity, homogeneous system, Dykstra-Parsons permeability variations (V), Lorenz coefficient (L)

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Authors: Zsuzsa Szakaly

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Several constitutions have explicit or implicit eternity clauses in the European Union, their classic roles were analyzed so far, albeit there are new possibilities emerging in relation to the identity of the constitutions of the Member States. The aim of the study is to look at the practice of the Constitutional Courts of the Member States in detail regarding eternity clauses where limiting constitutional amendment has practical bearing, and to examine the influence of such practice on Europeanization. There are some states that apply explicit eternity clauses embedded in the text of the constitution, e.g., Italy, Germany, and Romania. In other states, the Constitutional Court 'unearthed' the implicit eternity clauses from the text of the basic law, e.g., Slovakia and Croatia. By using comparative analysis to examine the explicit or implicit clauses of the concerned constitutions, taking into consideration the new trends of the judicial opinions of the Member States and the fresh scientific studies, the main questions are: How to wield the double-edged sword of eternity clauses? To support European Integration or to support the sovereignty of the Member State? To help Europeanization or to act against it? Eternity clauses can easily find themselves between a rock and a hard place, the law of the European Union and the law of a Member State, with more possible interpretations. As more and more Constitutional Courts started to declare elements of their Member States’ constitutional identities, these began to interfere with the eternity clauses. Will this trend eventually work against Europeanization? As a result of the research, it can be stated that a lowest common denominator exists in the practice of European Constitutional Courts regarding eternity clauses. The chance of a European model and the possibility of this model influencing the status quo between the European Union and the Member States will be examined by looking at the answers these courts have found so far.

Keywords: constitutional court, constitutional identity, eternity clause, European Integration

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Authors: Olagunju John Olusesan-Remi

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The study area Ijero-Ekiti falls within the Ilesha-Ekiti Schist belt, originating from the long year of the Pan-Africa orogenic events and various cataclysmic tectonic activities in history. Ijero-Ekiti is situated within latitude 7 degree 45N and 7 Degree 55N. Ijero Ekiti is bordered between the Dahomean Basin and the southern Bida/Benue basin on the Geological map of Nigeria. This research work centers on majorly on investigating the chemical composition and as well as the mineralogical distribution of the various mineral-bearing rocks that composed the study area. This work is essentially carried out with a view to assessing and at the same time ascertaining the economic potentials and or the industrial significance of the area to Ekiti-south western region and the Nigeria nation as a whole. The mineralogical distribution pattern is of particular interest to us in this study. In this regard essential focus is put on the mostly the economic gemstones distributions within the various mineral bearing rocks in the zone, some of which includes the tourmaline formation, cassiterite deposit, tin-ore, tantalum columbite, smoky quartz, amethyst, polychrome and emerald variety beryl among others as they occurred within the older granite of the Precambrian rocks. To this end, samples of the major rock types were taken from various locations within the study area for detail scientific analysis as follows: The Igemo pegmatite of Ijero west, the epidiorite of Idaho, the biotitic hornblende gneiss of Ikoro-Ijero north and the beryl crystalline rock types to mention a few. The slides of the each rock from the aforementioned zones were later prepared and viewed under a cross Nichol petro graphic microscope with a particular focus on the light reflection ability of the constituent minerals in each rock samples. The results from the physical analysis viewed from the colour had it that the pegmatite samples ranges from pure milky white to fairly pinkish coloration. Other physical properties investigated include the streak, luster, form, specific gravity, cleavage/fracture pattern etc. The optical examination carried out centers on the refractive indices and pleochroism of the minerals present while the chemical analysis reveals from the tourmaline samples a differing correlation coefficient of the various oxides in each samples collected through which the mineral presence was established. In conclusion, it was inferred that the various minerals outlined above were in reasonable quantity within the Ijero area. With the above discoveries, therefore, we strongly recommend a detailed scientific investigation to be carried out such that will lead to a comprehensive mining of the area. Above all, it is our conclusion that a comprehensive mineralogical exploitation of this area will not only boost the socio-economic potential of the area but at the same time will go a long way contributing immensely to the socio-economic growth and development of the Nation-Nigeria at large.

Keywords: Ijero Ekiti, Southwestern Nigeria, economic minerals, pegmatite of the pan African origin, cataclastic tectonic activities, Ilesha Schistbelt, precambrian formations

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Authors: Luis Guiliana, Andrea Osorio

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The lack of comprehension of the reservoir geomechanics conditions may cause operational problems that cost to the industry billions of dollars per year. The drilling operations at the Ceuta Field, Area 2 South, Maracaibo Lake, have been very expensive due to problems associated with drilling. The principal objective of this investigation is to develop a 3D geomechanical model in this area, in order to optimize the future drillings in the field. For this purpose, a 1D geomechanical model was built at first instance, following the workflow of the MEM (Mechanical Earth Model), this consists of the following steps: 1) Data auditing, 2) Analysis of drilling events and structural model, 3) Mechanical stratigraphy, 4) Overburden stress, 5) Pore pressure, 6) Rock mechanical properties, 7) Horizontal stresses, 8) Direction of the horizontal stresses, 9) Wellbore stability. The 3D MEM was developed through the geostatistic model of the Eocene C-SUP VLG-3676 reservoir and the 1D MEM. With this data the geomechanical grid was embedded. The analysis of the results threw, that the problems occurred in the wells that were examined were mainly due to wellbore stability issues. It was determined that the stress field change as the stratigraphic column deepens, it is normal to strike-slip at the Middle Miocene and Lower Miocene, and strike-slipe to reverse at the Eocene. In agreement to this, at the level of the Eocene, the most advantageous direction to drill is parallel to the maximum horizontal stress (157º). The 3D MEM allowed having a tridimensional visualization of the rock mechanical properties, stresses and operational windows (mud weight and pressures) variations. This will facilitate the optimization of the future drillings in the area, including those zones without any geomechanics information.

Keywords: geomechanics, MEM, drilling, stress

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Authors: Rasha Hosny, Ahmed Zahran, Mahmoud Ramzi, Fatma Mahmoud Abdelhafiz, Ammona S. Mohamed, Mahmoud Fathy Mubarak

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Ionic liquids' ability to be tuned and stability under challenging environmental conditions are their significant features in enhanced oil recovery. In this study, two amino acid ionic liquids (AAILs) were prepared from quaternized hyperbranched polyamidoamine PAMAM (G0.5 C12) and amino acids (Cysteine and Lysine). The chemical structures of the prepared AAILs were verified by using FTIR and 1H-NMR spectra. These AAILs were tested for solubility, thermal stability, and surface activity in the presence of Egyptian medium crude oils under different PVT parameters after being diluted in several brine solutions of various salt compositions at 10% (w/w) salinity. The measurements reveal that the produced AAILs have good solubility and thermal stability. The effect of different concentrations of AAILs (0.1-5%) and salinity (20000-70000 ppm) on Interfacial tension (IFT) were studied. To test the efficacy of (AAILs) for a CEOR, numerous flooding experiments were carried out in samples of sandstone rock. Rock wettability is important for sandstone rocks, so conduct wettability alteration by contact angle (CA) of (30-55) and IFT of (7-13). The additional oil recovery was largely influenced by ionic liquid concentration, which may be changed by dilution with the formation and injected brines. This research has demonstrated that EOR techniques led to a recovery wt. (22-45%).

Keywords: amino acid ionic liquids, surface activity, critical micelle concentration, interfacial tension, contact angle, chemical enhanced oil recovery, wettability

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Authors: Chloe Shu-Hua Yeh

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Effects of videogame play on players cognitive abilities is a growing research field in the recent decades, however, little is known about how ‘out-of-school’ use of videogame influences creativity. This interdisciplinary research explores the cognitive and emotional effects of two different types of online videogames (an action videogame and a non-action videogame) on subsequent creativity performances using a within-participant design study with 36 participants. Results showed that after playing the action game participants performed higher originality, elaboration and flexibility than after playing the causal game. The results explored effects of emotional states elicited during playing the games suggesting that arousal may be a significant emotional factor which influence subsequent creativity performance. The cognitive and emotional effects of videogame were discussed followed with implications for emotion-creativity-videogame play research, game designers, educational practitioners and parents.

Keywords: attentional breadth, creativity, emotion, videogame play

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Authors: Ilma Robo, Saimir Heta, Emela Dalloshi, Nevila Alliu, Vera Ostreni

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The dental whitening process, beyond the fact that it is a mini-invasive dental treatment, has effects on the dental structure, or on the pulp of the tooth, where it is applied. The electronic search was performed using keywords to find articles published within the last 10 years about side effects, assessed as such, of minimally invasive dental bleaching treatment. Methodology: In selected articles, the other aim of the study was to evaluate the side effects of bleaching based on the percentage and type of solution used, where the latter was evaluated on the basic solution used for bleaching. Results: The side effects of bleaching are evaluated in selected articles depending on the method of bleaching application, which means it is carried out with recommended solutions, or with mixtures of alternative solutions or substances based on Internet information. Short conclusion: The dental bleaching process has side effects which have not yet been definitively evaluated, experimentally in large samples of individuals or animals (mice or cattle) to arrive at accurate numerical conclusions. The trend of publications about this topic is increasing in recent years, as long as the trend for aesthetic facial treatments, including dental ones, is increasing.

Keywords: teeth whitening, side effects, permanent teeth, formed dental apex

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Authors: I. T. Makhubedu, B. A. Letty, P. F. Scogings, P. L. Mafongoya

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Despite their potential importance in recycling dinitrogen (N2) fixed in alley cropping systems, the effects of tree pruning residues on symbiotic N2 fixation are poorly studied. A 2 x 2 x 2 factorial experiment was conducted to evaluate the effects of pruning residue management and pruning date on symbiotic performance and

Keywords: alley cropping, management, N₂ fixed, natural abundance, recycling

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Authors: Olumide J. Adedapo

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In this work, geothermal energy resource maps of the Niger Delta Basin were constructed using borehole thermal log data from over 300 deep wells. Three major geothermal anomalies were delineated and quantitatively interpreted in both onshore and offshore parts of the Niger Delta. The geothermal maps present the distribution of geothermal energy stored in the sedimentary rock mass in two ways: the accessible resources in depth interval 0-4000 m and static geothermal energy resources stored in the complete sedimentary infill of the basin (from the ground surface to the basement). The first map shows two major onshore anomalies, one in the north (with maximum energy values, 800 GJ/m2), another in the east to northeastern part (maximum energy values of 1250–1500 GJ/m2). Another two major anomalies occur offshore, one in the south with values of 750-1000 GJ/m2, occurring at about 100 km seawards and the other, in the southwest offshore with values 750-1250 GJ/m2, still at about 100 km from the shore. A second map of the Niger Delta shows a small anomaly in the northern part with the maximum value of 1500 GJ/m2 and a major anomaly occurring in the eastern part of the basin, onshore, with values of 2000-3500 GJ/m2. Offshore in the south and southwest anomalies in the total sedimentary rock mass occur with highest values up to 4000GJ/m2, with the southwestern anomaly extending west to the shore. It is much of interest to note the seaward–westward extension of these anomalies both in size, configuration, and magnitude for the geothermal energy in the total sedimentary thickness to the underlying basement. These anomalous fields show the most favourable locations and areas for further work on geothermal energy resources.

Keywords: geothermal energy, offshore, Niger delta, basin

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Authors: Jasna Hudek-Knezevic, Igor Kardum, Nada Krapic, Martina Jurcic

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The aim of this study was to examine the effects of self- and partner reported attachment orientations on self-reported mate retention behaviors in romantic couples using the actor-partner interdependence model. The study was carried out on 187 heterosexual couples aged from 18 to 35 years, with an average relationship length of 4.5 years. Participants were asked to complete the revised scale of adult attachment and short form of mate retention inventory. Actor and partner effects of self- and partner reported anxious and avoidant attachment orientations on mate retention categories (direct guarding, intersexual negative inducements, positive inducements, public signals of possession and intrasexual negative inducements) and domains (cost-inflicting and benefit-provisioning), as well on overall mate retention were examined. Actor effects for women estimate whether their attachment orientations predict their own mate retention behaviors, whereas men’s actor effects estimate whether their attachment orientations predict their own mate retention behaviors. Women’s partner effects estimate whether their attachment orientations predict their partner’s mate retention behaviors, whereas men’s partner effects estimate whether their attachment orientations predict their partner’s mate retention behaviors. The use of two data sources, self- and partner reports, allow the control of the effects of common method variance when exploring actor and partner effects. Positive actor and partner effects of anxious attachment, as well as negative actor and partner effects of avoidant attachment on mate retention, were expected. In other words, it was expected that more anxiously attached individuals themselves, as well as their partners, will use mate retention behaviors more frequently. On the other hand, more avoidantly attached individuals themselves, as well as their partners, will use mate retention behaviors less frequently. These hypotheses were partially confirmed. The results showed that the strongest and most consistent effects across both data sources were men’s actor effects on the cost-inflicting mate retention domain, and especially on two mate retention categories, direct guarding, and intersexual negative inducements. Additionally, a consistent positive partner effect of men’s anxious attachment orientations on direct guarding was also obtained. Avoidant attachment orientation exerted few and inconsistent actor and partner effects on mate retention domains and categories. The results are explained by theoretical propositions addressing the effects of attachment orientations on an interpersonal romantic relationship in early adulthood.

Keywords: actor and partner effects, attachment orientations, dyadic analysis, mate retention behavior

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Authors: Nurin Amalina Widityani, Adinda Syifa Azhari, Twin Aji Kusumagiani, Eleonora Agustine

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Fertilizer industry activities contribute to environmental changes. Changes to the environment became one of a few problems in this era of globalization. Parameters that can be seen as criteria to identify changes in the environment can be seen from the aspects of physics, chemistry, and biology. One aspect that can be assessed quickly and efficiently to describe environmental change is the aspect of physics, one of which is the value of magnetic susceptibility (χ). The rock magnetism method can be used as a proxy indicator of environmental changes, seen from the value of magnetic susceptibility. The rock magnetism method is based on magnetic susceptibility studies to measure and classify the degree of pollutant elements that cause changes in the environment. This research was conducted in the area around the fertilizer plant, with five coring points on each track, each coring point a depth of 15 cm. Magnetic susceptibility measurements were performed by in-situ and ex-situ. In-situ measurements were carried out directly by using the SM30 tool by putting the tools on the soil surface at each measurement point and by that obtaining the value of the magnetic susceptibility. Meanwhile, ex-situ measurements are performed in the laboratory by using the Bartington MS2B tool’s susceptibility, which is done on a coring sample which is taken every 5 cm. In-situ measurement shows results that the value of magnetic susceptibility at the surface varies, with the lowest score on the second and fifth points with the -0.81 value and the highest value at the third point, with the score of 0,345. Ex-situ measurements can find out the variations of magnetic susceptibility values at each depth point of coring. At a depth of 0-5 cm, the value of the highest XLF = 494.8 (x10-8m³/kg) is at the third point, while the value of the lowest XLF = 187.1 (x10-8m³/kg) at first. At a depth of 6-10 cm, the highest value of the XLF was at the second point, which was 832.7 (x10-8m³/kg) while the lowest XLF is at the first point, at 211 (x10-8m³/kg). At a depth of 11-15 cm, the XLF’s highest value = 857.7 (x10-8m³/kg) is at the second point, whereas the value of the lowest XLF = 83.3 (x10-8m³/kg) is at the fifth point. Based on the in situ and exsit measurements, it can be seen that the highest magnetic susceptibility values from the surface samples are at the third point.

Keywords: magnetic susceptibility, fertilizer plant, Bartington MS2B, SM30

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Authors: Dony Adriansyah Nazaruddin, Mohammad Muqtada Ali Khan

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This paper aims to present some imaginative geomorphological sites in Malaysia. This study comprises desk study and field study. Desk study was conducted by reviewing some literatures related to the topic and some geomorphosites in Malaysia. Field study was organized in 2013 and 2014 to investigate the recent situation of these sites and to take some measurements, photographs and rock samples. Some examples of imaginative geomorphosites all over Malaysia have been identified for this purpose. In Peninsular Malaysia, some geomorphosites in Langkawi Islands (the state of Kedah) have imaginative features such as a “turtle” atop the limestone hill of Setul Formation at the Kilim Geoforest Park, a “shoe” at the Kasut island of the Kilim Geoforest Park, a “lying pregnant lady” at the Dayang Bunting island of the Dayang Bunting Marble Geoforest Park, and a “ship” of the Singa Kecil island. Meanwhile, some other examples are from the state of Kelantan, such as a mogote hill with a “human face looking upward” at Gunung Reng, Jeli District and a “boat rock” at Mount Chamah, Gua Musang District. In East Malaysia, there is only one example can be identified, it is the “Abraham Lincoln’s face” at the Deer Cave, Gunung Mulu National Park, Sarawak. Karst landforms dominate the imaginative geomorphosites in Malaysia. The formations of these features are affected by some endogenic and exogenic processes, such as tectonic uplift, weathering (including solution), erosion, and so on. This study will recommend that these imaginative features should be conserved and developed for some purposes, such as research, education, and geotourism development in Malaysia.

Keywords: geomorphosite, geotourism, earth processes, karst landforms, Malaysia

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Authors: Rui Huang, Thomas Richard, Masood Mostofi

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The lifetime of impregnated diamond bits and their drilling efficiency are in part governed by the bit wear conditions, not only the extent of the diamonds’ wear but also their exposure or protrusion out of the matrix bonding. As much as individual diamonds wear, the bonding matrix does also wear through two-body abrasion (direct matrix-rock contact) and three-body erosion (cuttings trapped in the space between rock and matrix). Although there is some work dedicated to the study of diamond bit wear, there is still a lack of understanding on how matrix erosion and diamond exposure relate to the bit drilling response and drilling efficiency, as well as no literature on the process that governs bit sharpening a procedure commonly implemented by drillers when the extent of diamond polishing yield extremely low rate of penetration. The aim of this research is (i) to derive a correlation between the wear state of the bit and the drilling performance but also (ii) to gain a better understanding of the process associated with tool sharpening. The research effort combines specific drilling experiments and precise mapping of the tool-cutting face (impregnated diamond bits and segments). Bit wear is produced by drilling through a rock sample at a fixed rate of penetration for a given period of time. Before and after each wear test, the bit drilling response and thus efficiency is mapped out using a tailored design experimental protocol. After each drilling test, the bit or segment cutting face is scanned with an optical microscope. The test results show that, under the fixed rate of penetration, diamond exposure increases with drilling distance but at a decreasing rate, up to a threshold exposure that corresponds to the optimum drilling condition for this feed rate. The data further shows that the threshold exposure scale with the rate of penetration up to a point where exposure reaches a maximum beyond which no more matrix can be eroded under normal drilling conditions. The second phase of this research focuses on the wear process referred as bit sharpening. Drillers rely on different approaches (increase feed rate or decrease flow rate) with the aim of tearing worn diamonds away from the bit matrix, wearing out some of the matrix, and thus exposing fresh sharp diamonds and recovering a higher rate of penetration. Although a common procedure, there is no rigorous methodology to sharpen the bit and avoid excessive wear or bit damage. This paper aims to gain some insight into the mechanisms that accompany bit sharpening by carefully tracking diamond fracturing, matrix wear, and erosion and how they relate to drilling parameters recorded while sharpening the tool. The results show that there exist optimal conditions (operating parameters and duration of the procedure) for sharpening that minimize overall bit wear and that the extent of bit sharpening can be monitored in real-time.

Keywords: bit sharpening, diamond exposure, drilling response, impregnated diamond bit, matrix erosion, wear rate

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Authors: Emre Ünal, Hasan Başaran

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In this study, starting with a predetermined Lunar free-return trajectory, an analysis of major near-Earth perturbations is carried out. Referencing to historical Apollo-13 flight, changes in the mission’s resultant perimoon and perigee altitudes with each perturbative effect are evaluated. The perturbations that were considered are Earth oblateness effects, up to the 6^th order, atmospheric drag, third body perturbations consisting of solar and planetary effects and solar radiation pressure effects. It is found that for a Moon mission, most of the main perturbative effects spoil the trajectory significantly while some came out to be negligible. It is seen that for apparent future request of constructing low cost, reliable and safe trajectories to the Moon, most of the orbital perturbations are crucial.

Keywords: Apollo-13 trajectory, atmospheric drag, lunar trajectories, oblateness effect, perturbative effects, solar radiation pressure, third body perturbations

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Authors: Xiaofei Li, Zhiwei Zhong, Deli Wang

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Large herbivores affect plant growth not only through their direct, consumptive effects, but also through indirect effects that alter species interactions. Indirect effects can be either positive or negative, therefore having the potential to mitigate or enhance the direct impacts of herbivores. However, until recently, we know considerably less about the indirect effects than the direct effects of large herbivores on plants, and few studies have explored multiple indirect pathways simultaneously. Here, we investigated how large domestic herbivores, cattle (Bos taurus), can shape population growth of an intermediately preferred forb species, Artemsisa scoparia, through diverse pathways in a temperate grassland of northeast China. We found that, although exposure to direct consumption of cattle, A. scoparia growth was not inhibited, but rather showed a significant increase in the grazed than ungrazed areas. This unexpected result was due to grazing-induced multiple indirect, positive effects overwhelmed the direct, negative consumption effects of cattle on plant growth. The much more intensive consumption on the dominant Leymus chinensis grass, ground litter removal, and increases in ant nest abundance induced by cattle, exerted significant indirect, positive effects on A. scoparia growth. These pathways benefited A.scoparia growth by lessening interspecific competition, mitigating negative effects of litter accumulation, and increasing soil nutrient availability, respectively. Our results highlight the need to integrate indirect effects into the traditional food web theory, which is based primary on direct, trophic linkages, to fully understand community organization and dynamics. Large herbivores are important conservation and management targets, our results suggest that these mammals should be managed with the understanding that they can affect primary producers through diverse paths.

Keywords: grasslands, large herbivores, plant growth, indirect effects

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Authors: Emmanuel O. Ezim, Idowu A. Olayinka, Michael Oladunjoye, Izuchukwu I. Obiadi

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Monitoring of reservoir properties prior to well placements and production is a requirement for optimisation and efficient oil and gas production. This is usually done using well log analyses and 3-D seismic, which are often prone to errors. However, 4-D (Time-lapse) seismic, incorporating numerous 3-D seismic surveys of the same field with the same acquisition parameters, which portrays the transient changes in the reservoir due to production effects over time, could be utilised because it generates better resolution. There is, however dearth of information on the applicability of this approach in the Niger Delta. This study was therefore designed to apply 4-D seismic, well-log and geologic data in monitoring of reservoirs in the EK field of the Niger Delta. It aimed at locating bypassed accumulations and ensuring effective reservoir management. The Field (EK) covers an area of about 1200km2 belonging to the early (18ma) Miocene. Data covering two 4-D vintages acquired over a fifteen-year interval were obtained from oil companies operating in the field. The data were analysed to determine the seismic structures, horizons, Well-to-Seismic Tie (WST), and wavelets. Well, logs and production history data from fifteen selected wells were also collected from the Oil companies. Formation evaluation, petrophysical analysis and inversion alongside geological data were undertaken using Petrel, Shell-nDi, Techlog and Jason Software. Well-to-seismic tie, formation evaluation and saturation monitoring using petrophysical and geological data and software were used to find bypassed hydrocarbon prospects. The seismic vintages were interpreted, and the amounts of change in the reservoir were defined by the differences in Acoustic Impedance (AI) inversions of the base and the monitor seismic. AI rock properties were estimated from all the seismic amplitudes using controlled sparse-spike inversion. The estimated rock properties were used to produce AI maps. The structural analysis showed the dominance of NW-SE trending rollover collapsed-crest anticlines in EK with hydrocarbons trapped northwards. There were good ties in wells EK 27, 39. Analysed wavelets revealed consistent amplitude and phase for the WST; hence, a good match between the inverted impedance and the good data. Evidence of large pay thickness, ranging from 2875ms (11420 TVDSS-ft) to about 2965ms, were found around EK 39 well with good yield properties. The comparison between the base of the AI and the current monitor and the generated AI maps revealed zones of untapped hydrocarbons as well as assisted in determining fluids movement. The inverted sections through EK 27, 39 (within 3101 m - 3695 m), indicated depletion in the reservoirs. The extent of the present non-uniform gas-oil contact and oil-water contact movements were from 3554 to 3575 m. The 4-D seismic approach led to better reservoir characterization, well development and the location of deeper and bypassed hydrocarbon reservoirs.

Keywords: reservoir monitoring, 4-D seismic, well placements, petrophysical analysis, Niger delta basin

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Authors: Zhenyu Yang, Qiunan Chen, Xiaocheng Huang

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Reliable prediction of tunnel collapse remains a prominent challenge in the field of civil engineering. In this study, leveraging the nonlinear Hoek-Brown failure criterion and the upper-bound theorem, an analytical solution for the collapse surface of shallowly buried circular tunnels was derived, taking into account the coupled effects of surface loads and pore water pressures. Initially, surface loads and pore water pressures were introduced as external force factors, equating the energy dissipation rate to the external force, yielding our objective function. Subsequently, the variational method was employed for optimization, and the outcomes were juxtaposed with previous research findings. Furthermore, we utilized the deduced equation set to systematically analyze the influence of various rock mass parameters on collapse shape and extent. To validate our analytical solutions, a comparison with prior studies was executed. The corroboration underscored the efficacy of our proposed methodology, offering invaluable insights for collapse risk assessment in practical engineering applications.

Keywords: tunnel roof stability, analytical solution, hoek–brown failure criterion, limit analysis

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Authors: Isabel Jones

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As adolescence is a formative time, experiences during adolescence often affect the rest of one’s life. Therefore, dating, specifically violence in dating, can have lasting effects on the rest of one’s life. In order to find sources, searches were conducted on PsycINFO, specifically EBSCO, and narrowed down under the criteria that the source contained information about adolescent dating violence rather than adult, and focused on causes, effects, or prevention methods. This literature review examines research regarding the effects and causes of TDV, and then what methods are effective in the prevention of TDV development. This will allow for a clear image of how these prevention methods are effective and why they are important. Effects of TDV extend beyond the physical, including psychological and sexual long-lasting effects. These are caused by a number of concepts, including learned behavior, inhibitory issues/substance abuse, and cultural factors. When both of these are taken into account, preventative measures such as school-based interventions, parental/adult monitoring, and the presence of positive family examples are more clear as to their effectiveness. This literature review may provide further awareness to this public health crisis and give the public a view of how adolescents are affected by TDV on their path from child to adult.

Keywords: adolescence, dating violence, risk factors, predictors, relationship

Procedia PDF Downloads 37

Authors: İsmail İnce, Ali Bozdag, Ayla Bozdag, M. Bahadır Tosunlar, M. Ergun Hatır, Mustafa Korkanc

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The building stones used in the construction of historical structures are exposed to atmospheric effects directly or indirectly. As a result of this process, building stones are partially or completely degraded. Historical buildings are important symbols of cultural heritage, so it is very significant to transfer to the future generations by protecting and repairing of these historical buildings. The Eflatunpınar Hitit Monument located near the Eflatunpınar cold water spring was constructed by using natural rock blocks during the Hittites Empire period. The monument has been protected without losing its function until today. The purpose of this study is to evaluate the deteriorations in the Eflatunpınar Hitit Monument and to detect the water chemistry of the Eflatunpınar spring located around the Beysehir County in the west of Konya. For this purpose, the petrographic and mechanical properties of the rocks used in this monument were determined, and the deteriorations in the monument were determined with the aid of non-destructive test methods including Schmidt hardness value, relative humidity measurement, thermal imaging. Additionally, the physical (electrical conductivity (EC), pH and temperature) and chemical characteristics (major anions and cations) of the Eflatunpınar cold water spring have been detected.

Keywords: deteriorations, Eflatunpınar Hitit monument, Eflatunpınar spring, Konya, non-destructıve tests

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Authors: Margarita S. Tikhonova, Alireza Baniasad, Anton G. Kalmykov, Georgy A. Kalmykov, Ralf Littke

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There is a high complexity in the pore structure of organic-rich rocks caused by the combination of inter-particle porosity from inorganic mineral matter and ultrafine intra-particle porosity from both organic matter and clay minerals. Fluids are retained in that pore space, but there are major uncertainties in how and where the fluids are stored and to what extent they are accessible or trapped in 'closed' pores. A large degree of tortuosity may lead to fractionation of organic matter so that the lighter and flexible compounds would diffuse to the reservoir whereas more complicated compounds may be locked in place. Additionally, parts of hydrocarbons could be bound to solid organic matter –kerogen– and mineral matrix during expulsion and migration. Larger compounds can occupy thin channels so that clogging or oil and gas entrapment will occur. Sequential extraction of applying different solvents is a powerful tool to provide more information about the characteristics of trapped organic matter distribution. The Upper Jurassic – Lower Cretaceous Bazhenov shale is one of the most petroliferous source rock extended in West Siberia, Russia. Concerning the variable mineral composition, pore space distribution and thermal maturation, there are high uncertainties in distribution and composition of organic matter in this formation. In order to address this issue geological and geochemical properties of 30 samples including mineral composition (XRD and XRF), structure and texture (thin-section microscopy), organic matter contents, type and thermal maturity (Rock-Eval) as well as molecular composition (GC-FID and GC-MS) of different extracted materials during sequential extraction were considered. Sequential extraction was performed by a Soxhlet apparatus using different solvents, i.e., n-hexane, chloroform and ethanol-benzene (1:1 v:v) first on core plugs and later on pulverized materials. The results indicate that the studied samples are mainly composed of type II kerogen with TOC contents varied from 5 to 25%. The thermal maturity ranged from immature to late oil window. Whereas clay contents decreased with increasing maturity, the amount of silica increased in the studied samples. According to molecular geochemistry, stored hydrocarbons in open and closed pore space reveal different geochemical fingerprints. The results improve our understanding of hydrocarbon expulsion and migration in the organic-rich Bazhenov shale and therefore better estimation of hydrocarbon potential for this formation.

Keywords: Bazhenov formation, bitumen, molecular geochemistry, sequential extraction

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Authors: Avadhesh Kumar

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Background: The cell phone has rapidly become an integral, and, for some, an essential communication tool that is being used worldwide. Their use without any knowledge of their harmful effects like cancers and other health effects is not ‘quite’ safe. Studies on cancers due to electromagnetic radiations from cell phones are available, but there is a need to research on the detrimental physical and psychological effects on users like students. This study focused on certain psychological or mental health effects of cell phone usage amongst students. Materials and methods: The present study will be carried out on all the students of Banaras Hindu University. Students of both sexes from urban and rural backgrounds were selected at random and administered a pre- tested questionnaire which included aspects related to few common adverse psychological health signs and symptoms attributed to cell phone over-usage. Results: Stress was found to be the commonest symptom (51.47%) followed by irritability/anger (43.79%). Other common mental symptoms included lack of concentration and academic performance, insomnia, anxiety etc. Suggestions: This study confirms that the younger generation, who are the most frequent cell phone users, needs to be aware of the adverse health effects of cell phone usage especially the mental aspects and take preventive measures to minimize and control the same. Less dependence on the device, a curtailing time period spent on talking, communicating more by texting, etc. are some of the practical measures suggested.

Keywords: cell phones, psychological health effects, students, mental health

Procedia PDF Downloads 283

Authors: David Shengelia, Tamara Tsutsunava, Manana Togonidze, Giorgi Chichinadze, Giorgi Beridze

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Orthoclase gabbro intrusive exposes in the Eastern part of the Dzirula crystalline massif of the Central Transcaucasian microcontinent. It is intruded in the Baikal quartz-diorite gneisses as a stock-like body. The intrusive is characterized by heterogeneity of rock composition: variability of mineral content and irregular distribution of rock-forming minerals. The rocks are represented by pyroxenites, gabbro-pyroxenites and gabbros of different composition – K-feldspar, pyroxene-hornblende and biotite bearing varieties. Scientific views on the genesis and age of the orthoclase gabbro intrusive are considerably different. Based on the long-term pertogeochemical and geochronological investigations of the intrusive with such an extraordinary composition the authors came to the following conclusions. According to geological and geophysical data, it is stated that in the Saurian orogeny horizontal tectonic layering of the Earth’s crust of the Central Transcaucasian microcontinent took place. That is precisely this fact that explains the formation of the orthoclase gabbro intrusive. During the tectonic doubling of the Earth’s crust of the mentioned microcontinent thick tectonic nappes of mafic and sialic layers overlap the sialic basement (‘inversion’ layer). The initial magma of the intrusive was of high-temperature basite-ultrabasite composition, crystallization products of which are pyroxenites and gabbro-pyroxenites. Petrochemical data of the magma attest to its formation in the Upper mantle and partially in the ‘crustal astenolayer’. Then, a newly formed overheated dry magma with phenocrysts of clinopyrocxene and basic plagioclase intruded into the ‘inversion’ layer. From the new medium it was enriched by the volatile components causing the selective melting and as a result the formation of leucocratic quartz-feldspar material. At the same time in the basic magma intensive transformation of pyroxene to hornblende was going on. The basic magma partially mixed with the newly formed acid magma. These different magmas intruded first into the allochthonous basite layer without its significant transformation and then into the upper sialic layer and crystallized here at a depth of 7-10 km. By petrochemical data the newly formed leucocratic granite magma belongs to the S type granites, but the above mentioned mixed magma – to H (hybrid) type. During the final stage of magmatic processes the gabbroic rocks impregnated with high-temperature feldspar-bearing material forming anorthoclase or orthoclase. Thus, so called ‘orthoclase gabbro’ includes the rocks of various genetic groups: 1. protolith of gabbroic intrusive; 2. hybrid rock – K-feldspar gabbro and 3. leucocratic quartz-feldspar bearing rock. Petrochemical and geochemical data obtained from the hybrid gabbro and from the inrusive protolith differ from each other. For the identification of petrogenetic model of the orthoclase gabbro intrusive formation LA-ICP-MS- U-Pb zircon dating has been conducted in all three genetic types of gabbro. The zircon age of the protolith – mean 221.4±1.9 Ma and of hybrid K-feldspar gabbro – mean 221.9±2.2 Ma, records crystallization time of the intrusive, but the zircon age of quartz-feldspar bearing rocks – mean 323±2.9 Ma, as well as the inherited age (323±9, 329±8.3, 332±10 and 335±11 Ma) of hybrid K-feldspar gabbro corresponds to the formation age of Late Variscan granitoids widespread in the Dzirula crystalline massif.

Keywords: The Caucasus, isotope dating, orthoclase-bearing gabbro, petrogenetic model

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Authors: Mohamed Ali Benhalima, Nathon Elbaz, Malik Koubi

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This paper evaluates an expansion of employer-mandated sick leave insurance in the French private sector. We use a difference-in-differences method in which control groups are defined according to the collective bargaining agreement (CBA) employees belong to. Indeed, thanks to complementary insurance provided by CBAs, employees were not affected the same way by the reform. We find significant effects of the reform on sick leave spells lasting at least 7 days, consistently with the reform target. The effects on spells’ duration and frequency are positive and more pronounced for women than for men, for whom the effect on frequency tends to be slightly negative. The effects are also more pronounced for executives and supervisors than less qualified categories.

Keywords: sickness absence, collective agreements, daily sickness benefits, labor economics

Procedia PDF Downloads 317