Rock mechanics activities at the Waste Isolation Pilot Plant

International Nuclear Information System (INIS)

Francke, C.; Saeb, S.

1996-01-01

The application of rock mechanics at nuclear waste repositories is a true multidisciplinary effort. A description and historical summary of the Waste Isolation Pilot Plant (WIPP) is presented. Rock mechanics programs at the WIPP are outlined, and the current rock mechanics modeling philosophy of the Westinghouse Waste Isolation Division is discussed

Technology of Rock Destruction by Combined Explosion-Mechanical Load

Directory of Open Access Journals (Sweden)

Oleg M. Terentiev

2017-10-01

Full Text Available Background. Rock drilling is characterized by an energy capacity of more than 120 kWh/m3. This is due to the fact that about 90 % of the energy is expended on the “preparation” of rocks for destruction. This study proposes to combine explosive and mechanical loads to reduce specific energy consumption of rock destruction. Objective. The aim of the paper is energy effective technology development for rock destruction by combined explosive-mechanical loads. Methods. Analytical studies; regression analysis; math modeling; experimental research; technical and economic analysis. Results. Specific energy decreasing for explosive-mechanical rock drilling by 4–16 % was experimentally proved. Conclusions. As a result of the implementation of explosive-mechanical rock drilling on the created full-sized experimental device, the efficiency coefficient increased from 77 to 80 %.

Rock mechanics studies for SMES

International Nuclear Information System (INIS)

Haimson, B.C.

1981-01-01

Superconducting magnetic energy storage (SMES) systems capable of storing thousands of MWh develop tremendous magnetically induced forces when charged. To prevent rutpure of the magnets these forces must be confined. Bedrock offers a practical and relatively inexpensive magnet containment structure. This paper examines the need for rock mechanics research in connection with the construction and use of SMES rock caverns; the unique problems related to housing superconducting magnets in bedrock; site investigations of granite, quartzite and dolomite deposits in Wisconsin; and cavern design requirements to assure cavern stability and limited deformation under the expected mechanical leads. Recommendations are made for siting SMES caverns

Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

Science.gov (United States)

Wang, Jian-chao; Jiang, Fu-xing; Meng, Xiang-jun; Wang, Xu-you; Zhu, Si-tao; Feng, Yu

2016-05-01

Specially thick coal seam with complex construction, such as rock parting and alternative soft and hard coal, is called specially thick coal seam with rock parting (STCSRP), which easily leads to rock burst during mining. Based on the stress distribution of rock parting zone, this study investigated the mechanism, engineering discriminant conditions, prevention methods, and risk evaluation method of rock burst occurrence in STCSRP through setting up a mechanical model. The main conclusions of this study are as follows. (1) When the mining face moves closer to the rock parting zone, the original non-uniform stress of the rock parting zone and the advancing stress of the mining face are combined to intensify gradually the shearing action of coal near the mining face. When the shearing action reaches a certain degree, rock burst easily occurs near the mining face. (2) Rock burst occurrence in STCSRP is positively associated with mining depth, advancing stress concentration factor of the mining face, thickness of rock parting, bursting liability of coal, thickness ratio of rock parting to coal seam, and difference of elastic modulus between rock parting and coal, whereas negatively associated with shear strength. (3) Technologies of large-diameter drilling, coal seam water injection, and deep hole blasting can reduce advancing stress concentration factor, thickness of rock parting, and difference of elastic modulus between rock parting and coal to lower the risk of rock burst in STCSRP. (4) The research result was applied to evaluate and control the risk of rock burst occurrence in STCSRP.

The Influence of Phonological Mechanisms in Written Spelling of Profoundly Deaf Children

Science.gov (United States)

Colombo, Lucia; Arfe, Barbara; Bronte, Tiziana

2012-01-01

In the present study, the effect of phonological and working memory mechanisms involved in spelling Italian single words was explored in two groups of children matched for grade level: a group of normally hearing children and a group of pre-verbally deaf children, with severe-to-profound hearing loss. Three-syllable and four-syllable familiar…

Thermo-hydro-mechanical behavior of fractured rock mass

International Nuclear Information System (INIS)

Coste, F.

1997-12-01

The purpose of this research is to model Thermo-Hydro-Mechanical behavior of fractured rock mass regarding a nuclear waste re-depository. For this, a methodology of modeling was proposed and was applied to a real underground site (EDF site at Nouvelle Romanche). This methodology consists, in a first step, to determine hydraulic and mechanical REV. Beyond the greatest of these REV, development of a finite element code allows to model all the fractures in an explicit manner. The homogenized mechanical properties are determined in drained and undrained boundary conditions by simulating triaxial tests that represent rock mass subject to loading. These simulations allow to study the evolution of hydraulic and mechanical properties as a function of stress state. Drained and undrained boundary conditions enable to discuss the validity of assimilation of a fractured rock mass to a porous medium. The simulations lead to a better understanding of the behavior of the fractured rock masses and allow to show the dominant role of the shear behavior of the fractures on the hydraulic and mechanical homogenized properties. From a thermal point of view, as long as conduction is dominant, thermal properties of the rock mass are almost the same as those the intact rock. (author)

Theoretical Modeling of Rock Breakage by Hydraulic and Mechanical Tool

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Hongxiang Jiang

2014-01-01

Full Text Available Rock breakage by coupled mechanical and hydraulic action has been developed over the past several decades, but theoretical study on rock fragmentation by mechanical tool with water pressure assistance was still lacking. The theoretical model of rock breakage by mechanical tool was developed based on the rock fracture mechanics and the solution of Boussinesq’s problem, and it could explain the process of rock fragmentation as well as predicating the peak reacting force. The theoretical model of rock breakage by coupled mechanical and hydraulic action was developed according to the superposition principle of intensity factors at the crack tip, and the reacting force of mechanical tool assisted by hydraulic action could be reduced obviously if the crack with a critical length could be produced by mechanical or hydraulic impact. The experimental results indicated that the peak reacting force could be reduced about 15% assisted by medium water pressure, and quick reduction of reacting force after peak value decreased the specific energy consumption of rock fragmentation by mechanical tool. The crack formation by mechanical or hydraulic impact was the prerequisite to improvement of the ability of combined breakage.

Deafness and motor abilities level

Directory of Open Access Journals (Sweden)

A Zwierzchowska

2008-09-01

Full Text Available The audition injury hinders some motor motions and the organised coordination at the higher level and may be a cause of disturbances and disorder in some motor abilities adoption. It was assumed that deafness including its aetiology and injury mechanism may significantly influence the motor development of human being. The study aimed in checking if the deafness, as a result of various unfavourable factors, determines the motor development of children and youngsters. Consequently the dependency between qualitative features i.e.: signed motor level and aetiology, audition injury mechanism and the deafness degree was examined. The mechanism and aetiology of hearing correlated with the motor abilities displayed statistically significant dependencies in few motor trials only. Revealed correlations regarded mostly the coordination trials excluding the flexibility one. Statistically significant dependencies between the audition diminution and the motor abilities level were not found.

Language and cognitive development in deaf children: deaf children with deaf and deaf children with hearing parents

OpenAIRE

Ajda Pfifer

2011-01-01

The article reviews the current studies regarding language and cognitive development in children who are deaf. Deaf communicate orally and with sign language. 90 % of deaf children are born into hearing families and hearing parents in most cases do not know the sign language. Besides, hearing parents usually want for their child to become "normally" speaking. Most of the deaf children born into hearing families have very poor early communication. It is now well established that deaf children ...

Results of monitoring at Olkiluoto in 2004. Rock mechanics

International Nuclear Information System (INIS)

Riikonen, S.

2005-09-01

This report presents Posiva Oy's results of the rock mechanical monitoring programme from the year 2004. Monitoring programme was established for long time monitoring of modifications in the bedrock during the excavation of the ONKALO underground research facility stated in Olkiluoto island. This is the first annual report where rock mechanical research work has being reported also from the monitoring point of view. Rock mechanical research work consists of both GPS measurements and microseismic measurements carried out in Olkiluoto island. Both measurements have been performed during several years even before monitoring programme was established. GPS measurements have been carried out since 1995 and microseismic network has operated since 2002. There have been no significant changes in observations when studying rock mechanical results from the year 2004 and comparing them to results from the previous years. Therefore it can be said, that so far ONKALO has barely had any effect on rock mechanics in Olkiluoto. Report has been composed from the annual reports of GPS measurements.(orig.)

Mechanical weathering and rock erosion by climate-dependent subcritical cracking

Science.gov (United States)

Eppes, Martha-Cary; Keanini, Russell

2017-06-01

This work constructs a fracture mechanics framework for conceptualizing mechanical rock breakdown and consequent regolith production and erosion on the surface of Earth and other terrestrial bodies. Here our analysis of fracture mechanics literature explicitly establishes for the first time that all mechanical weathering in most rock types likely progresses by climate-dependent subcritical cracking under virtually all Earth surface and near-surface environmental conditions. We substantiate and quantify this finding through development of physically based subcritical cracking and rock erosion models founded in well-vetted fracture mechanics and mechanical weathering, theory, and observation. The models show that subcritical cracking can culminate in significant rock fracture and erosion under commonly experienced environmental stress magnitudes that are significantly lower than rock critical strength. Our calculations also indicate that climate strongly influences subcritical cracking—and thus rock weathering rates—irrespective of the source of the stress (e.g., freezing, thermal cycling, and unloading). The climate dependence of subcritical cracking rates is due to the chemophysical processes acting to break bonds at crack tips experiencing these low stresses. We find that for any stress or combination of stresses lower than a rock's critical strength, linear increases in humidity lead to exponential acceleration of subcritical cracking and associated rock erosion. Our modeling also shows that these rates are sensitive to numerous other environment, rock, and mineral properties that are currently not well characterized. We propose that confining pressure from overlying soil or rock may serve to suppress subcritical cracking in near-surface environments. These results are applicable to all weathering processes.

Rock mass mechanical property estimations for the Yucca Mountain Site Characterization Project

International Nuclear Information System (INIS)

Lin, M.; Hardy, M.P.; Bauer, S.J.

1993-06-01

Rock mass mechanical properties are important in the design of drifts and ramps. These properties are used in evaluations of the impacts of thermomechanical loading of potential host rock within the Yucca Mountain Site Characterization Project. Representative intact rock and joint mechanical properties were selected for welded and nonwelded tuffs from the currently available data sources. Rock mass qualities were then estimated using both the Norwegian Geotechnical Institute (Q) and Geomechanics Rating (RMR) systems. Rock mass mechanical properties were developed based on estimates of rock mass quality, the current knowledge of intact properties, and fracture/joint characteristics. Empirical relationships developed to correlate the rock mass quality indices and the rock mass mechanical properties were then used to estimate the range of rock mass mechanical properties

[Deafness and sarcoidosis].

Science.gov (United States)

Moine, A; Frachet, B; Van Den Abbeele, T; Tison, P; Battesti, J P

1990-01-01

The cochleovestibular tract is seldom involved by sarcoidosis (about 50 cases have been described since 1948). As a clinical expression of sarcoidosis, deafness is fluctuant in 50% of all cases, bilateral, and most often associated with facial palsy and uveitis, the vestibular reflexes being reduced. The histological studies demonstrate lesions at all levels from the cochlea to be brain stem, but the main mechanism is an infiltration of the arachnoid vessels. The prognosis of sarcoidosis deafness is usually poor in spite of corticosteroid therapy. This paper is illustrated by 3 cases observed in Avicenne Hospital.

The three-dimension model for the rock-breaking mechanism of disc cutter and analysis of rock-breaking forces

Science.gov (United States)

Zhang, Zhao-Huang; Sun, Fei

2012-06-01

To study the rock deformation with three-dimensional model under rolling forces of disc cutter, by carrying out the circular-grooving test with disc cutter rolling around on the rock, the rock mechanical behavior under rolling disc cutter is studied, the mechanical model of disc cutter rolling around the groove is established, and the theory of single-point and double-angle variables is proposed. Based on this theory, the physics equations and geometric equations of rock mechanical behavior under disc cutters of tunnel boring machine (TBM) are studied, and then the balance equations of interactive forces between disc cutter and rock are established. Accordingly, formulas about normal force, rolling force and side force of a disc cutter are derived, and their validity is studied by tests. Therefore, a new method and theory is proposed to study rock-breaking mechanism of disc cutters.

The Usability of Noise Level from Rock Cutting for the Prediction of Physico-Mechanical Properties of Rocks

Science.gov (United States)

Delibalta, M. S.; Kahraman, S.; Comakli, R.

2015-11-01

Because the indirect tests are easier and cheaper than the direct tests, the prediction of rock properties from the indirect testing methods is important especially for the preliminary investigations. In this study, the predictability of the physico-mechanical rock properties from the noise level measured during cutting rock with diamond saw was investigated. Noise measurement test, uniaxial compressive strength (UCS) test, Brazilian tensile strength (BTS) test, point load strength (Is) test, density test, and porosity test were carried out on 54 different rock types in the laboratory. The results were statistically analyzed to derive estimation equations. Strong correlations between the noise level and the mechanical rock properties were found. The relations follow power functions. Increasing rock strength increases the noise level. Density and porosity also correlated strongly with the noise level. The relations follow linear functions. Increasing density increases the noise level while increasing porosity decreases the noise level. The developed equations are valid for the rocks with a compressive strength below 150 MPa. Concluding remark is that the physico-mechanical rock properties can reliably be estimated from the noise level measured during cutting the rock with diamond saw.

Social Information Processing in Deaf Adolescents

Science.gov (United States)

Torres, Jesús; Saldaña, David; Rodríguez-Ortiz, Isabel R.

2016-01-01

The goal of this study was to compare the processing of social information in deaf and hearing adolescents. A task was developed to assess social information processing (SIP) skills of deaf adolescents based on Crick and Dodge's (1994; A review and reformulation of social information-processing mechanisms in children's social adjustment.…

Being a Deaf Role Model: Deaf People's Experiences of Working with Families and Deaf Young People

Science.gov (United States)

Rogers, Katherine D.; Young, Alys M.

2011-01-01

The experiences of being a deaf role model have been little explored in the literature. This paper explores the role of the deaf role model as perceived by d/Deaf adults who carried out this role, when working with deaf young people, parents of deaf children, and professionals who work with them. The data were collected from part of the evaluation…

Comparing Motor Development of Deaf Children of Deaf Parents and Deaf Children of Hearing Parents

Science.gov (United States)

Lieberman, Lauren J.; Volding, Lori; Winnick, Joseph P.

2004-01-01

Deaf children of Deaf parents perform better academically (Ritter-Brinton & Stewart, 1992), linguistically (Courtin, 2000; M. Harris, 2001; Vaccari & Marschark, 1997), and socially (Hadadian & Rose, 1991; M. Harris, 2001) than Deaf children of hearing parents. Twenty-nine Deaf children in residential schools were assessed to determine if a…

THE DEAFNESS, THE DEAF AND HIS DISCURSE

Directory of Open Access Journals (Sweden)

Neuma Chaveiro

2006-12-01

Full Text Available ABSTRACT: The knowledge of LIBRAS – Brazilian Sign Language – is determining to the process of structuring the discursive formations and to the constitution of the deaf one. The present work aims to discuss the LIBRAS as an important tool of structuring the discursive of the deaf individual an as a facilitating factor in the description of his health problems. The data constitute two texts, one of them wrote by a deaf skilled in LIBRAS and the other wrote by a deaf who does not express himself in this kind of language. It was verified that the first text’s author is consistent, has mobility and moves easily through the discursive formations, but otherwise is the text belonging to the other patient. It can be stated that the Brazilian sign language – LIBRAS – is a decisive tool in the working out of the deaf discursive formations and the comprehension of his discourse by the health area professionals provide a larger understanding of the constitution of the deaf identity, a fundamental aspect for an improvement in the services offered in the health area. KEYWORDS: Deafness; Communication; Sign Language.

Mechanical dispersion in fractured crystalline rock systems

International Nuclear Information System (INIS)

Lafleur, D.W.; Raven, K.G.

1986-12-01

This report compiles and evaluates the hydrogeologic parameters describing the flow of groundwater and transport of solutes in fractured crystalline rocks. This report describes the processes of mechanical dispersion in fractured crystalline rocks, and compiles and evaluates the dispersion parameters determined from both laboratory and field tracer experiments. The compiled data show that extrapolation of the reliable test results performed over intermediate scales (10's of m and 10's to 100's of hours) to larger spatial and temporal scales required for performance assessment of a nuclear waste repository in crystalline rock is not justified. The reliable measures of longitudinal dispersivity of fractured crystalline rock are found to range between 0.4 and 7.8 m

Preliminary rock mechanics laboratory: Investigation plan

International Nuclear Information System (INIS)

Oschman, K.P.; Hummeldorf, R.G.; Hume, H.R.; Karakouzian, M.; Vakili, J.E.

1987-01-01

This document presents the rationale for rock mechanics laboratory testing (including the supporting analysis and numerical modeling) planned for the site characterization of a nuclear waste repository in salt. This plan first identifies what information is required for regulatory and design purposes, and then presents the rationale for the testing that satisfies the required information needs. A preliminary estimate of the minimum sampling requirements for rock laboratory testing during site characterization is also presented. Periodic revision of this document is planned

The validity of generic trends on multiple scales in rock-physical and rock-mechanical properties of the Whitby Mudstone, United Kingdom

NARCIS (Netherlands)

Douma, L.A.N.R.; Primarini, M.I.W.; Houben, M.E.; Barnhoorn, A.

Finding generic trends in mechanical and physical rock properties will help to make predictions of the rock-mechanical behaviour of shales. Understanding the rock-mechanical behaviour of shales is important for the successful development of unconventional hydrocarbon reservoirs. This paper presents

Site investigations: Strategy for rock mechanics site descriptive model

International Nuclear Information System (INIS)

Andersson, Johan; Christiansson, Rolf; Hudson, John

2002-05-01

As a part of the planning work for the Site Investigations, SKB has developed a Rock Mechanics Site Descriptive Modelling Strategy. Similar strategies are being developed for other disciplines. The objective of the strategy is that it should guide the practical implementation of evaluating site specific data during the Site Investigations. It is also understood that further development may be needed. This methodology enables the crystalline rock mass to be characterised in terms of the quality at different sites, for considering rock engineering constructability, and for providing the input to numerical models and performance assessment calculations. The model describes the initial stresses and the distribution of deformation and strength properties of the intact rock, of fractures and fracture zones, and of the rock mass. The rock mass mechanical properties are estimated by empirical relations and by numerical simulations. The methodology is based on estimation of mechanical properties using both empirical and heroretical/numerical approaches; and estimation of in situ rock stress using judgement and numerical modelling, including the influence of fracture zones. These approaches are initially used separately, and then combined to produce the required characterisation estimates. The methodology was evaluated with a Test Case at the Aespoe Hard Rock Laboratory in Sweden. The quality control aspects are an important feature of the methodology: these include Protocols to ensure the structure and coherence of the procedures used, regular meetings to enhance communication, feedback from internal and external reviewing, plus the recording of an audit trail of the development steps and decisions made. The strategy will be reviewed and, if required, updated as appropriate

Site investigations: Strategy for rock mechanics site descriptive model

Energy Technology Data Exchange (ETDEWEB)

Andersson, Johan [JA Streamflow AB, Aelvsjoe (Sweden); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Hudson, John [Rock Engineering Consultants, Welwyn Garden City (United Kingdom)

2002-05-01

As a part of the planning work for the Site Investigations, SKB has developed a Rock Mechanics Site Descriptive Modelling Strategy. Similar strategies are being developed for other disciplines. The objective of the strategy is that it should guide the practical implementation of evaluating site specific data during the Site Investigations. It is also understood that further development may be needed. This methodology enables the crystalline rock mass to be characterised in terms of the quality at different sites, for considering rock engineering constructability, and for providing the input to numerical models and performance assessment calculations. The model describes the initial stresses and the distribution of deformation and strength properties of the intact rock, of fractures and fracture zones, and of the rock mass. The rock mass mechanical properties are estimated by empirical relations and by numerical simulations. The methodology is based on estimation of mechanical properties using both empirical and heroretical/numerical approaches; and estimation of in situ rock stress using judgement and numerical modelling, including the influence of fracture zones. These approaches are initially used separately, and then combined to produce the required characterisation estimates. The methodology was evaluated with a Test Case at the Aespoe Hard Rock Laboratory in Sweden. The quality control aspects are an important feature of the methodology: these include Protocols to ensure the structure and coherence of the procedures used, regular meetings to enhance communication, feedback from internal and external reviewing, plus the recording of an audit trail of the development steps and decisions made. The strategy will be reviewed and, if required, updated as appropriate.

Deaf Autism: Common Instructional Practices Described by Deaf Educators

Science.gov (United States)

Rutledge, Felicia

2017-01-01

The purpose of this research study was to identify common instructional practices described by teachers of the deaf with students who are deaf with autism that increase both student engagement and instructional outcomes. As the diversity of students increase within deaf/hard of hearing programs, research is emerging in the area of deaf autism.…

A new method to test rock abrasiveness based on physico-mechanical and structural properties of rocks

Directory of Open Access Journals (Sweden)

V.N. Oparin

2015-06-01

Full Text Available A new method to test rock abrasiveness is proposed based upon the dependence of rock abrasiveness on their structural and physico-mechanical properties. The article describes the procedure of presentation of properties that govern rock abrasiveness on a canonical scale by dimensionless components, and the integrated estimation of the properties by a generalized index. The obtained results are compared with the known classifications of rock abrasiveness.

Latest progress of soft rock mechanics and engineering in China

Directory of Open Access Journals (Sweden)

Manchao He

2014-06-01

Full Text Available The progress of soft rock mechanics and associated technology in China is basically accompanied by the development of mining engineering and the increasing disasters of large rock deformation during construction of underground engineering. In this regard, Chinese scholars proposed various concepts and classification methods for soft rocks in terms of engineering practices. The large deformation mechanism of engineering soft rocks is to be understood through numerous experiments; and thus a coupled support theory for soft rock roadways is established, followed by the development of a new support material, i.e. the constant resistance and large deformation bolt/anchor with negative Poisson's ratio effect, and associated control technology. Field results show that large deformation problems related to numbers of engineering cases can be well addressed with this new technology, an effective way for similar soft rock deformation control.

Effects of bioleaching on the mechanical and chemical properties of waste rocks

Science.gov (United States)

Yin, Sheng-Hua; Wu, Ai-Xiang; Wang, Shao-Yong; Ai, Chun-Ming

2012-01-01

Bioleaching processes cause dramatic changes in the mechanical and chemical properties of waste rocks, and play an important role in metal recovery and dump stability. This study focused on the characteristics of waste rocks subjected to bioleaching. A series of experiments were conducted to investigate the evolution of rock properties during the bioleaching process. Mechanical behaviors of the leached waste rocks, such as failure patterns, normal stress, shear strength, and cohesion were determined through mechanical tests. The results of SEM imaging show considerable differences in the surface morphology of leached rocks located at different parts of the dump. The mineralogical content of the leached rocks reflects the extent of dissolution and precipitation during bioleaching. The dump porosity and rock size change under the effect of dissolution, precipitation, and clay transportation. The particle size of the leached rocks decreased due to the loss of rock integrity and the conversion of dry precipitation into fine particles.

THM-coupled modeling of selected processes in argillaceous rock relevant to rock mechanics

International Nuclear Information System (INIS)

Czaikowski, Oliver

2012-01-01

Scientific investigations in European countries other than Germany concentrate not only on granite formations (Switzerland, Sweden) but also on argillaceous rock formations (France, Switzerland, Belgium) to assess their suitability as host and barrier rock for the final storage of radioactive waste. In Germany, rock salt has been under thorough study as a host rock over the past few decades. According to a study by the German Federal Institute for Geosciences and Natural Resources, however, not only salt deposits but also argillaceous rock deposits are available at relevant depths and of extensions in space which make final storage of high-level radioactive waste basically possible in Germany. Equally qualified findings about the suitability/unsuitability of non-saline rock formations require fundamental studies to be conducted nationally because of the comparatively low level of knowledge. The article presents basic analyses of coupled mechanical and hydraulic properties of argillaceous rock formations as host rock for a repository. The interaction of various processes is explained on the basis of knowledge derived from laboratory studies, and open problems are deduced. For modeling coupled processes, a simplified analytical computation method is proposed and compared with the results of numerical simulations, and the limits to its application are outlined. (orig.)

Outcomes of cochlear implantation in deaf children of deaf parents: comparative study.

Science.gov (United States)

Hassanzadeh, S

2012-10-01

This retrospective study compared the cochlear implantation outcomes of first- and second-generation deaf children. The study group consisted of seven deaf, cochlear-implanted children with deaf parents. An equal number of deaf children with normal-hearing parents were selected by matched sampling as a reference group. Participants were matched based on onset and severity of deafness, duration of deafness, age at cochlear implantation, duration of cochlear implantation, gender, and cochlear implant model. We used the Persian Auditory Perception Test for the Hearing Impaired, the Speech Intelligibility Rating scale, and the Sentence Imitation Test, in order to measure participants' speech perception, speech production and language development, respectively. Both groups of children showed auditory and speech development. However, the second-generation deaf children (i.e. deaf children of deaf parents) exceeded the cochlear implantation performance of the deaf children with hearing parents. This study confirms that second-generation deaf children exceed deaf children of hearing parents in terms of cochlear implantation performance. Encouraging deaf children to communicate in sign language from a very early age, before cochlear implantation, appears to improve their ability to learn spoken language after cochlear implantation.

The results of the investigations on rock mechanics in HDB-9-11 boreholes and update of the rock mechanical model around the Horonobe URL construction area

International Nuclear Information System (INIS)

Sanada, Hiroyuki; Niunoya, Sumio; Matsui, Hiroya

2008-09-01

Horonobe URL (Underground Research Laboratory) Project is conducted at Horonobe-cho, Teshio-gun, Hokkaido. This research report shows the result of the rock mechanical investigations which have been carried out from 2004 to 2005 as a part of the project. The objectives of the rock mechanical investigation are as follows: To obtain the data which were necessary for construction design of URL. To confirm the distribution of rock mechanical properties in and around URL construction area. The results of the investigations are summarized as follows: 1) Variation and values of depth direction of physical and mechanical properties in the laboratory construction area corresponded approximately to the results obtained from the rock mechanical investigations of HDB-1-8. 2) The major redesign had been not had about physical and mechanical properties in the laboratory construction area being able to divide into three zones and length of its own zone in updating rock mechanical model. 3) From the results of initial stress measured by hydraulic fracturing, the results that the direction of the maximum principle stress is E-W was no different from results obtained from the investigations of HDB-1-8, but the magnitude correlation among maximum, minimum principle stress and overburden pressure measured around G.L.-927 m showed different trends compared with the results of HDB-1-8. 4) Diatomaceous mudstone was yielded under isotropic compression. Cam-clay model as constitutive law of diatomaceous mudstone should be used for tunnel excavation analysis. 5) Uniaxial compression strength of rock saturated under saline water is larger than that of saturated under freshwater. Poisson's ratio of rock saturated under saline water is smaller than that of saturated under saline water. 6) The effective confining pressure increases with the equivalent opening width and permeability decreases. 7) The value of principle stress obtained from DSCA method is larger than that obtained from hydraulic

Fostering Positive Deaf Identity Development in a K-2 Deaf Classroom /

OpenAIRE

Hipskind, Courtney

2014-01-01

All Deaf children deserve to have opportunities to openly explore, examine, and affirm their own Deaf identities at school, yet there is a shortage of curricula and resources dedicated to this basic need. The aim of this thesis is to provide Deaf children with such opportunities. The curriculum within- Fostering Deaf Identity Development in a K-2 Deaf Classroom- consists of two units that address positive Deaf identity formation. The first unit focuses on the characterization and affirmation ...

Deaf Sociality and the Deaf Lutheran Church in Adamorobe, Ghana

Science.gov (United States)

Kusters, Annelies

2014-01-01

This article provides an ethnographic analysis of "deaf sociality" in Adamorobe, a village in Ghana, where the relatively high prevalence of hereditary deafness has led to dense social and spatial connections. Deaf people are part of their hearing environment particularly through family networks, and produce deaf sociality through many…

Rock mechanics in the National Waste Terminal Storage Program

International Nuclear Information System (INIS)

Monsees, J.E.; Wigley, M.R.

1982-01-01

The overall objective of the rock mechanics program of the Office of Nuclear Waste Isolation is to predict the response of a rock mass hosting a waste repository during its construction, operation, and postoperational phases. The operational phase is expected to be 50 to 100 yr; the postoperational phase will last until the repository no longer poses any potential hazard to the biosphere, a period that may last several thousand years. The rock mechanics program is concerned with near-field effects on mine stability, as well as far-field effects relative to the overall integrity of the geologic waste isolation system. To accomplish these objectives, the rock mechanics program has established interactive studies in numerical simulation, laboratory testing, and field testing. The laboratory and field investigations provide input to the numerical simulations and give an opportunity for verification and validation of the predictive capabilities of the computer codes. Ultimately the computer codes will be used to predict the response of the geologic system to the development of a repository. 3 references, 5 figures

Geological and rock mechanics aspects of the long-term evolution of a crystalline rock site

International Nuclear Information System (INIS)

Cosgrove, J.W.; Hudson, J.A.

2009-01-01

We consider the stability of a crystalline rock mass and hence the integrity of a radioactive waste repository contained therein by, firstly, identifying the geological evolution of such a site and, secondly, by assessing the likely rock mechanics consequences of the natural perturbations to the repository. In this way, the potency of an integrated geological-rock mechanics approach is demonstrated. The factors considered are the pre-repository geological evolution, the period of repository excavation, emplacement and closure, and the subsequent degradation and natural geological perturbations introduced by glacial loading. It is found that the additional rock stresses associated with glacial advance and retreat have a first order effect on the stress magnitudes and are likely to cause a radical change in the stress regime. There are many factors involved in the related geosphere stability and so the paper concludes with a systems diagram of the total evolutionary considerations before, during and after repository construction. (authors)

Joining the diaspora of deaf memoirists: a personal account of writing deafness.

Science.gov (United States)

McDONALD, Donna

2014-01-01

In this essay, the author describes how, and why, she tackled a lifetime of questions about her deafness and experiences of being deaf by writing a memoir called The Art of Being Deaf. While researching her memoir, the author discovered that the questions about her deafness that she most needed to answer were her own. Having first read many memoirs by other deaf writers and novels with deaf characters, the author set about composing her own narrative of deafness in a fresh way. She not only came to an improved understanding of her deaf self, but grew into a more authentic understanding of her whole self, reconciling her memories of the deaf girl she once was with the adult deaf woman she is now. The author illustrates how the act of writing a memoir can be an important tool in resolving questions of identity.

Fractures and Rock Mechanics, Phase 1

DEFF Research Database (Denmark)

Havmøller, Ole; Krogsbøll, Anette

1997-01-01

The main objectives of the project are to combine geological description of fractures, chalk types and rock mechanical properties, and to investigate whether the chosen outcrops can be used as analogues to reservoir chalks. Five chalk types, representing two outcrop localities: Stevns...

Rock mechanics stability at Olkiluoto, Haestholmen, Kivetty and Romuvaara

International Nuclear Information System (INIS)

Johansson, E.; Rautakorpi, J.

2000-02-01

Posiva Oy is studying the suitability of the Finnish bedrock for the geological disposal of spent nuclear fuel at four sites, Olkiluoto in Eurajoki, Haestholmen in Loviisa, Kivetty in Aeaenekoski and Romuvaara in Kuhmo. To enable the rock properties to be specified in great detail, the site-selection research programme has included rock mechanics investigations such as the measurement of in-situ rock stress and laboratory tests on rock samples. This report presents the results of the rock mechanics analyses performed on the main rock types at the Olkiluoto, Romuvaara, Kivetty and Haestholmen sites. The objective of this study was to assess the near-field stability of the final disposal tunnels and deposition holes at each of the investigation sites. Two empirical methods and a numerical method based on three-dimensional element code (3DEC) were used the analysis tools. A statistical approach was used to select the necessary input data and to specify the cases being analysed. The stability of the KBS-3 and MLH (Medium Long Hole) repository concepts during the pre-closure and post-closure phases was analysed. The repository depths investigated lay between 300 m and 700 m. The empirical methods are based on the study of the ratios between rock strength and the in-situ stress which could result in possible fracturing of the rock mass. Interpretation of the numerical analyses is based on the assumption of an elastic distribution of stress around the disposal tunnel and the deposition hole and the brittle rock strength criterion. The results obtained in this study indicate that in general, the rock mechanics conditions during the pre-closure and post-closure phases at each of the investigated sites remain good and stable between the studied depth levels, especially when the deposition rooms are oriented in a direction parallel to the major in-situ stress. If the disposal tunnels are orientated in a direction perpendicular to the major in-situ stress, the resultant

Seeing the Deaf in "Deafness"

Science.gov (United States)

Obasi, Chijioke

2008-01-01

This article draws on some of the existing literature on the politics of identity and representation as related to minority group formation. It applies this to constructions of Deaf identity from a cultural and linguistic perspective and contrasts this with dominant constructions of Deaf people as disabled. It highlights a number of ways in which…

Fractures and Rock Mechanics, Phase 1

DEFF Research Database (Denmark)

Krogsbøll, Anette; Jakobsen, Finn; Madsen, Lena

1997-01-01

The main objective of the project is to combine geological descriptions of fractures, chalk types and rock mechanical properties in order to investigate whether the chosen outcrops can be used as analogues to reservoir chalks. This report deals with 1) geological descriptions of outcrop locality...

Correlating P-wave Velocity with the Physico-Mechanical Properties of Different Rocks

Science.gov (United States)

Khandelwal, Manoj

2013-04-01

In mining and civil engineering projects, physico-mechanical properties of the rock affect both the project design and the construction operation. Determination of various physico-mechanical properties of rocks is expensive and time consuming, and sometimes it is very difficult to get cores to perform direct tests to evaluate the rock mass. The purpose of this work is to investigate the relationships between the different physico-mechanical properties of the various rock types with the P-wave velocity. Measurement of P-wave velocity is relatively cheap, non-destructive and easy to carry out. In this study, representative rock mass samples of igneous, sedimentary, and metamorphic rocks were collected from the different locations of India to obtain an empirical relation between P-wave velocity and uniaxial compressive strength, tensile strength, punch shear, density, slake durability index, Young's modulus, Poisson's ratio, impact strength index and Schmidt hammer rebound number. A very strong correlation was found between the P-wave velocity and different physico-mechanical properties of various rock types with very high coefficients of determination. To check the sensitivity of the empirical equations, Students t test was also performed, which confirmed the validity of the proposed correlations.

A comparative study on dynamic mechanical performance of concrete and rock

Directory of Open Access Journals (Sweden)

Xia Zhengbing

2015-10-01

Full Text Available of underground cavities and field-leveling excavation. Dynamic mechanical performance of rocks has been gradually attached importance both in China and abroad. Concrete and rock are two kinds of the most frequently used engineering materials and also frequently used as experimental objects currently. To compare dynamic mechanical performance of these two materials, this study performed dynamic compression test with five different strain rates on concrete and rock using Split Hopkinson Pressure Bar (SHPB to obtain basic dynamic mechanical parameters of them and then summarized the relationship of dynamic compressive strength, peak strain and strain rate of two materials. Moreover, specific energy absorption is introduced to confirm dynamic damage mechanisms of concrete and rock materials. This work can not only help to improve working efficiency to the largest extent but also ensure the smooth development of engineering, providing rich theoretical guidance for development of related engineering in the future

Ground water movements around a repository. Rock mechanics analyses

International Nuclear Information System (INIS)

Ratigan, J.L.

1977-09-01

The determination and rational assessment of groundwater flow around a repository depends upon the accurate analysis of several interdependent and coupled phenomenological events occuring within the rock mass. In particular, the groundwater flow pathways (joints) are affected by the excavation and thermomechanical stresses developed within the rock mass, and the properties, of the groundwater are altered by the temperature perturbations in the rock mass. The objective of this report is to present the results of the rock mechanics analysis for the repository excavation and the thermally-induced loadings. Qualitative analysis of the significance of the rock mechanics results upon the groundwater flow is provided in this report whenever such an analysis can be performed. Non-linear rock mechanics calculations have been completed for the repository storage tunnels and the global repository domain. The rock mass has been assumed to possess orthoganol joint sets or planes of weakness with finite strength characteristics. In the local analyses of the repository storage tunnels the effects of jointorientation and repository ventilation have been examined. The local analyses indicated that storage room support requirements and regions of strength failure are highly dependent upon joint orientation. The addition of storage tunnel ventilation was noted to reduce regions of strength failure, particularly during the 30 year operational phase of the repository. Examination of the local stresses around the storage tunnels indicated the potential for perturbed hydraulic permeabilities. The permeabilities can be expected to be altered to a greater degree by the stresses resulting from excavation than from stresses which are thermally induced. The thermal loading provided by the instantaneous waste emplacement resulted in stress states and displacements quite similar to those provided by the linear waste emplacement sequence

Finite element simulations of two rock mechanics tests

International Nuclear Information System (INIS)

Dahlke, H.J.; Lott, S.A.

1986-04-01

Rock mechanics tests are performed to determine in situ stress conditions and material properties of an underground rock mass. To design stable underground facilities for the permanent storage of high-level nuclear waste, determination of these properties and conditions is a necessary first step. However, before a test and its associated equipment can be designed, the engineer needs to know the range of expected values to be measured by the instruments. Sensitivity studies by means of finite element simulations are employed in this preliminary design phase to evaluate the pertinent parameters and their effects on the proposed measurements. The simulations, of two typical rock mechanics tests, the plate bearing test and the flat-jack test, by means of the finite element analysis, are described. The plate bearing test is used to determine the rock mass deformation modulus. The flat-jack test is used to determine the in situ stress conditions of the host rock. For the plate bearing test, two finite element models are used to simulate the classic problem of a load on an elastic half space and the actual problem of a plate bearing test in an underground tunnel of circular cross section. For the flat-jack simulation, a single finite element model is used to simulate both horizontal and vertical slots. Results will be compared to closed-form solutions available in the literature

Mechanical Properties and Acoustic Emission Properties of Rocks with Different Transverse Scales

Directory of Open Access Journals (Sweden)

Xi Yan

2017-01-01

Full Text Available Since the stability of engineering rock masses has important practical significance to projects like mining, tunneling, and petroleum engineering, it is necessary to study mechanical properties and stability prediction methods for rocks, cementing materials that are composed of minerals in all shapes and sizes. Rocks will generate acoustic emission during damage failure processes, which is deemed as an effective means of monitoring the stability of coal rocks. In the meantime, actual mining and roadway surrounding rocks tend to have transverse effects; namely, the transverse scale is larger than the length scale. Therefore, it is important to explore mechanical properties and acoustic emission properties of rocks under transverse size effects. Considering the transverse scale effects of rocks, this paper employs the microparticle flow software PFC2D to explore the influence of different aspect ratios on damage mechanics and acoustic emission properties of rocks. The results show that (1 the transverse scale affects uniaxial compression strength of rocks. As the aspect ratio increases, uniaxial compression strength of rocks decreases initially and later increases, showing a V-shape structure and (2 although it affects the maximum hit rate and the strain range of acoustic emission, it has little influence on the period of occurrence. As the transverse scale increases, both damage degree and damage rate of rocks decrease initially and later increase.

Deaf children's use of clear visual cues in mindreading.

Science.gov (United States)

Hao, Jian; Su, Yanjie

2014-11-01

Previous studies show that typically developing 4-year old children can understand other people's false beliefs but that deaf children of hearing families have difficulty in understanding false beliefs until the age of approximately 13. Because false beliefs are implicit mental states that are not expressed through clear visual cues in standard false belief tasks, the present study examines the hypothesis that the deaf children's developmental delay in understanding false beliefs may reflect their difficulty in understanding a spectrum of mental states that are not expressed through clear visual cues. Nine- to 13-year-old deaf children of hearing families and 4-6-year-old typically developing children completed false belief tasks and emotion recognition tasks under different cue conditions. The results indicated that after controlling for the effect of the children's language abilities, the deaf children inferred other people's false beliefs as accurately as the typically developing children when other people's false beliefs were clearly expressed through their eye-gaze direction. However, the deaf children performed worse than the typically developing children when asked to infer false beliefs with ambiguous or no eye-gaze cues. Moreover, the deaf children were capable of recognizing other people's emotions that were clearly conveyed by their facial or body expressions. The results suggest that although theory-based or simulation-based mental state understanding is typical of hearing children's theory of mind mechanism, for deaf children of hearing families, clear cue-based mental state understanding may be their specific theory of mind mechanism. Copyright © 2014 Elsevier Ltd. All rights reserved.

Research on base rock mechanic characteristics of caverns for radioactive waste disposal

International Nuclear Information System (INIS)

Isei, Takehiro; Katsuyama, Kunihisa; Seto, Masahiro; Ogata, Yuji; Utagawa, Manabu

1997-01-01

It has been considered that underground space is mechanically stable as compared with on the ground, and superior for storing radioactive waste for long period. However, in order to utilize underground space for the place of radioactive waste disposal, its long term stability such as the aseismatic ability of base rocks must be ensured, and for this purpose, it is necessary to grasp the mechanical characteristics of the base rocks around caverns, and to advance the technology for measuring and evaluating minute deformation and earth pressure change. In this research, the study on the fracture mechanics characteristics of base rocks and the development of the technology for measuring long terms stress change of base rocks were carried out. In this research, what degree the memory of past stress is maintained by rocks was presumed by measuring AE and strain when stress was applied to rock test pieces. The rocks tested were tuff, sandstone and granite. The experimental method and the experimental results of the prestress by AE method and DRA are reported. (K.I.)

Rock mechanics related to Jurassic underburden at Valdemar oil field

DEFF Research Database (Denmark)

Foged, Niels

1999-01-01

.It has been initiated as a feasibility study of the North Jens-1 core 12 taken in the top Jurassic clay shale as a test specimens for integrated petrological, mineralogical and rock mechanical studies. Following topics are studied:(1) Pore pressure generation due to conversion of organic matter...... and deformation properties of the clay shale using the actual core material or outcrop equivalents.(3) Flushing mechanisms for oil and gas from source rocks due to possibly very high pore water pressure creating unstable conditions in deeply burried sedimentsThere seems to be a need for integrating the knowledge...... in a number of geosciences to the benefit of common understanding of important reservoir mechanisms. Rock mechanics and geotechnical modelling might be key points for this understanding of reservoir geology and these may constitute a platform for future research in the maturing and migration from the Jurassic...

Endocochlear potential depends on Cl− channels: mechanism underlying deafness in Bartter syndrome IV

Science.gov (United States)

Rickheit, Gesa; Maier, Hannes; Strenzke, Nicola; Andreescu, Corina E; De Zeeuw, Chris I; Muenscher, Adrian; Zdebik, Anselm A; Jentsch, Thomas J

2008-01-01

Human Bartter syndrome IV is an autosomal recessive disorder characterized by congenital deafness and severe renal salt and fluid loss. It is caused by mutations in BSND, which encodes barttin, a β-subunit of ClC-Ka and ClC-Kb chloride channels. Inner-ear-specific disruption of Bsnd in mice now reveals that the positive potential, but not the high potassium concentration, of the scala media depends on the presence of these channels in the epithelium of the stria vascularis. The reduced driving force for K+-entry through mechanosensitive channels into sensory hair cells entails a profound congenital hearing loss and subtle vestibular symptoms. Although retaining all cell types and intact tight junctions, the thickness of the stria is reduced early on. Cochlear outer hair cells degenerate over several months. A collapse of endolymphatic space was seen when mice had additionally renal salt and fluid loss due to partial barttin deletion in the kidney. Bsnd−/− mice thus demonstrate a novel function of Cl− channels in generating the endocochlear potential and reveal the mechanism leading to deafness in human Bartter syndrome IV. PMID:18833191

Mechanical properties of granitic rocks from Gideaa, Sweden

International Nuclear Information System (INIS)

Ljunggren, C.; Stephansson, O.; Alm, O.; Hakami, H.; Mattila, U.

1985-10-01

The elastic and mechanical properties were determined for two rock types from the Gideaa study area. Gideaa is located approximately 30 km north-east of Oernskoeldsvik, Northern Sweden. The rock types that were tested were migmatitic gneiss and migmatitic granite. The following tests were conducted: - sound velocity measurements; - uniaxial compression tests with acoustic emission recording; - brazilian disc tests; - triaxial tests; - three point bending tests. All together, 12 rock samples were tested with each test method. Six samples of these were migmatic gneiss and six samples were migmatitic granite. The result shows that the migmatitic gneiss has varying strength properties with low compressive strength in comparison with its high tensile strength. The migmatitic granite, on the other hand, is found to have parameter values similar to other granitic rocks. With 15 refs. (Author)

Rock Burst Mechanics: Insight from Physical and Mathematical Modelling

Directory of Open Access Journals (Sweden)

J. Vacek

2008-01-01

Full Text Available Rock burst processes in mines are studied by many groups active in the field of geomechanics. Physical and mathematical modelling can be used to better understand the phenomena and mechanisms involved in the bursts. In the present paper we describe both physical and mathematical models of a rock burst occurring in a gallery of a coal mine.For rock bursts (also called bumps to occur, the rock has to possess certain particular rock burst properties leading to accumulation of energy and the potential to release this energy. Such materials may be brittle, or the rock burst may arise at the interfacial zones of two parts of the rock, which have principally different material properties (e.g. in the Poíbram uranium mines.The solution is based on experimental and mathematical modelling. These two methods have to allow the problem to be studied on the basis of three presumptions:· the solution must be time dependent,· the solution must allow the creation of cracks in the rock mass,· the solution must allow an extrusion of rock into an open space (bump effect. 

Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the empirical approach

Energy Technology Data Exchange (ETDEWEB)

Roeshoff, Kennert; Lanaro, Flavio [Berg Bygg Konsult AB, Stockholm (Sweden); Lanru Jing [Royal Inst. of Techn., Stockholm (Sweden). Div. of Engineering Geology

2002-05-01

This report presents the results of one part of a wide project for the determination of a methodology for the determination of the rock mechanics properties of the rock mass for the so-called Aespoe Test Case. The Project consists of three major parts: the empirical part dealing with the characterisation of the rock mass by applying empirical methods, a part determining the rock mechanics properties of the rock mass through numerical modelling, and a third part carrying out numerical modelling for the determination of the stress state at Aespoe. All Project's parts were performed based on a limited amount of data about the geology and mechanical tests on samples selected from the Aespoe Database. This Report only considers the empirical approach. The purpose of the project is the development of a descriptive rock mechanics model for SKBs rock mass investigations for a final repository site. The empirical characterisation of the rock mass provides correlations with some of the rock mechanics properties of the rock mass such as the deformation modulus, the friction angle and cohesion for a certain stress interval and the uniaxial compressive strength. For the characterisation of the rock mass, several empirical methods were analysed and reviewed. Among those methods, some were chosen because robust, applicable and widespread in modern rock mechanics. Major weight was given to the well-known Tunnel Quality Index (Q) and Rock Mass Rating (RMR) but also the Rock Mass Index (RMi), the Geological Strength Index (GSI) and Ramamurthy's Criterion were applied for comparison with the two classical methods. The process of: i) sorting the geometrical/geological/rock mechanics data, ii) identifying homogeneous rock volumes, iii) determining the input parameters for the empirical ratings for rock mass characterisation; iv) evaluating the mechanical properties by using empirical relations with the rock mass ratings; was considered. By comparing the methodologies involved

Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the empirical approach

International Nuclear Information System (INIS)

Roeshoff, Kennert; Lanaro, Flavio; Lanru Jing

2002-05-01

This report presents the results of one part of a wide project for the determination of a methodology for the determination of the rock mechanics properties of the rock mass for the so-called Aespoe Test Case. The Project consists of three major parts: the empirical part dealing with the characterisation of the rock mass by applying empirical methods, a part determining the rock mechanics properties of the rock mass through numerical modelling, and a third part carrying out numerical modelling for the determination of the stress state at Aespoe. All Project's parts were performed based on a limited amount of data about the geology and mechanical tests on samples selected from the Aespoe Database. This Report only considers the empirical approach. The purpose of the project is the development of a descriptive rock mechanics model for SKBs rock mass investigations for a final repository site. The empirical characterisation of the rock mass provides correlations with some of the rock mechanics properties of the rock mass such as the deformation modulus, the friction angle and cohesion for a certain stress interval and the uniaxial compressive strength. For the characterisation of the rock mass, several empirical methods were analysed and reviewed. Among those methods, some were chosen because robust, applicable and widespread in modern rock mechanics. Major weight was given to the well-known Tunnel Quality Index (Q) and Rock Mass Rating (RMR) but also the Rock Mass Index (RMi), the Geological Strength Index (GSI) and Ramamurthy's Criterion were applied for comparison with the two classical methods. The process of: i) sorting the geometrical/geological/rock mechanics data, ii) identifying homogeneous rock volumes, iii) determining the input parameters for the empirical ratings for rock mass characterisation; iv) evaluating the mechanical properties by using empirical relations with the rock mass ratings; was considered. By comparing the methodologies involved by the

Fluids and the evolution of rock mechanical properties

International Nuclear Information System (INIS)

Reuschle, Thierry

1989-01-01

This research thesis reports the study of the various phenomena of fluid-solid interaction (mechanical or chemical interaction with fracturing by fluid overpressure, slow crack propagation, and pore deformation by transfer in solution) which may occur in the interaction of fluids with rocks. The author first presents the formalism of slow crack propagation based on the generalisation of the Griffith criterion. The model results are compared with experimental results obtained on four materials (glass, quartz, sandstone, and micrite) by using the double-torsion test. In the second part, the author addresses the issue of pore deformation by transfer in solution: dissolution and crystallisation under stress. The Gibbs chemical potential equation is firstly generalised to the case of a circular pore, and a formalism combining mechanics and thermodynamics is then proposed. A set of simulations highlights important parameters. In the third part, the author addresses the problem of fluid-rock mechanical interaction by studying the mechanical role of fluid pressure in crack initiation and propagation [fr

Electrokinetic mechanism of wettability alternation at oil-water-rock interface

Science.gov (United States)

Tian, Huanhuan; Wang, Moran

2017-12-01

Design of ions for injection water may change the wettability of oil-brine-rock (OBR) system, which has very important applications in enhanced oil recovery. Though ion-tuned wettability has been verified by various experiments, the mechanism is still not clear. In this review paper, we first present a comprehensive summarization of possible wettability alteration mechanisms, including fines migration or dissolution, multicomponent ion-exchange (MIE), electrical double layer (EDL) interaction between rock and oil, and repulsive hydration force. To clarify the key mechanism, we introduce a complete frame of theories to calculate attribution of EDL repulsion to wettability alteration by assuming constant binding forces (no MIE) and rigid smooth surface (no fines migration or dissolution). The frame consists of three parts: the classical Gouy-Chapman model coupled with interface charging mechanisms to describe EDL in oil-brine-rock systems, three methods with different boundary assumptions to evaluate EDL interaction energy, and the modified Young-Dupré equation to link EDL interaction energy with contact angle. The quantitative analysis for two typical oil-brine-rock systems provides two physical maps that show how the EDL interaction influences contact angle at different ionic composition. The result indicates that the contribution of EDL interaction to ion-tuned wettability for the studied system is not quite significant. The classical and advanced experimental work using microfabrication is reviewed briefly on the contribution of EDL repulsion to wettability alteration and compared with the theoretical results. It is indicated that the roughness of real rock surface may enhance EDL interaction. Finally we discuss some pending questions, perspectives and promising applications based on the mechanism.

Strategy for future laboratory rock mechanics programs

International Nuclear Information System (INIS)

Butcher, B.M.; Jones, A.K.

1985-01-01

A strategy for future experimental rock mechanics laboratory programs at Sandia National Laboratories is described. This strategy is motivated by the need for long range planning of rock mechanics programs addressing the stability of complex underground structures, changes in in situ stress states during resource recovery and underground explosion technology. It is based on: (1) recent advances in underground structure stability analysis which make three-dimensional calculations feasible, and (2) new developments in load path control of laboratory stress-strain tests which permit duplication of stress and strain histories in critical parts of a structure, as determined by numerical analysis. The major constraint in the strategy is the assumption that there are no in situ joint features or sample size effects which might prevent simulation of in situ response in the laboratory. 3 refs., 5 figs

Spot testing on mechanical characteristics of surrounding rock in gates of fully mechanized top-coal caving face

Energy Technology Data Exchange (ETDEWEB)

Xie Guang-xiang; Yang Ke; Chang Ju-cai [Anhui University of Science and Technology, Anhui (China). Department of Resource Exploration and Management Engineering

2006-07-01

The distribution patterns of mechanical characteristics for surrounding rock in the gateways of fully mechanized top-coal caving (FMTC) face were put forward by analyzing deep displacement, surface displacement, stress distribution and supports loading. The results show that the surrounding rock of the gateways lies in abutment pressure decrease zone near the working face, so that the support load decreases. But the deformations of supports and surrounding rock are very acute. The deformation of surrounding rock appears mainly in abutment pressure influence zone. Reasonable roadway supporting should control the deformation of surrounding rock in intense stage of mining influence. Supporting design ideas of tailentry and head entry should be changed from loading control to deformation control. 8 refs., 10 figs., 1 tab.

Acoustic emission measurements in petroleum-related rock mechanics

Energy Technology Data Exchange (ETDEWEB)

Unander, Tor Erling

2002-07-01

Acoustic emission activity in rock has usually been studied in crystalline rock, which reflects that rock mechanics has also mostly been occupied with such rocks in relations to seismology, mining and tunneling. On the other hand, petroleum-related rock mechanics focuses on the behaviour of sedimentary rock. Thus, this thesis presents a general study of acoustic emission activity in sedimentary rock, primarily in sandstone. Chalk, limestone and shale have also been tested, but to much less degree because the AE activity in these materials is low. To simplify the study, pore fluids have not been used. The advent of the personal computer and computerized measuring equipment have made possible new methods both for measuring and analysing acoustic emissions. Consequently, a majority of this work is devoted to the development and implementation of new analysis techniques. A broad range of topics are treated: (1) Quantification of the AE activity level, assuming that the event rate best represents the activity. An algorithm for estimating the event rate and a methodology for objectively describing special changes in the activity e.g., onset determination, are presented. (2) Analysis of AE waveform data. A new method for determining the source energy of an AE event is presented, and it is shown how seismic source theory can be used to analyze even intermediate quality data. Based on these techniques, it is shown that a major part of the measured AE activity originates from a region close to the sensor, not necessarily representing the entire sample. (3) An improved procedure for estimating source locations is presented. The main benefit is a procedure that better handles arrival time data with large errors. Statistical simulations are used to quantify the uncertainties in the locations. The analysis techniques are developed with the application to sedimentary rock in mind, and in two articles, the techniques are used in the study of such materials. The work in the first

Proceedings of a technical session on rock mechanics ''Advance in laboratory sample testing''

International Nuclear Information System (INIS)

Come, B.

1984-01-01

This report brings together a series of papers about rock mechanics. The meeting was divided into three sessions, which dealt with the three main types of rock formation currently considered in the CEC Programme: granite, clay and salt. Safe disposal of high-level radioactive waste involves the proper design of deep underground repositories. This necessitates an in-depth knowledge of the mechanical properties of the rock mass. The behaviour of the rock mass must be known both for the construction and the operation (heating effects) of the repository. Usually, the dominant factor for designing an underground structure is the fracturing of the rock mass. In the present case, the rock is chosen with a very low fracturing. Therefore, the mechanical properties of the formation are mainly those of the rock matrix. These properties are obtained, at least in a first exploratory step, by laboratory testing of rock samples obtained by core-drilling from surface. This aspect of rock characterization was thought to deserve a special technical meeting, in order to bring together most of the results obtained in this field by contracting partners of the CEC for the years 1980-82

Examining a Sample of Black Deaf Individuals on the Deaf Acculturation Scale

Science.gov (United States)

Nelson Schmitt, Shawn S.; Leigh, Irene W.

2015-01-01

The current study sought to identify and analyze how Black deaf and hard-of-hearing people conceptualize their deaf and hard-of-hearing identities. That is, what cultural and linguistic factors are involved and how do they interact? An existing measure of Deaf cultural identity, the Deaf Acculturation Scale (DAS), was used to evaluate these…

Failure Mechanism of Rock Bridge Based on Acoustic Emission Technique

Directory of Open Access Journals (Sweden)

Guoqing Chen

2015-01-01

Full Text Available Acoustic emission (AE technique is widely used in various fields as a reliable nondestructive examination technology. Two experimental tests were carried out in a rock mechanics laboratory, which include (1 small scale direct shear tests of rock bridge with different lengths and (2 large scale landslide model with locked section. The relationship of AE event count and record time was analyzed during the tests. The AE source location technology and comparative analysis with its actual failure model were done. It can be found that whether it is small scale test or large scale landslide model test, AE technique accurately located the AE source point, which reflected the failure generation and expansion of internal cracks in rock samples. Large scale landslide model with locked section test showed that rock bridge in rocky slope has typical brittle failure behavior. The two tests based on AE technique well revealed the rock failure mechanism in rocky slope and clarified the cause of high speed and long distance sliding of rocky slope.

Joining the Diaspora of Deaf Memoirists: A Personal Account of Writing Deafness

Science.gov (United States)

McDonald, Donna

2014-01-01

In this essay, the author describes how, and why, she tackled a lifetime of questions about her deafness and experiences of being deaf by writing a memoir called The Art of Being Deaf. While researching her memoir, the author discovered that the questions about her deafness that she most needed to answer were her own. Having first read many…

Effects of water infusions on mechanical properties of carboniferous rocks

Energy Technology Data Exchange (ETDEWEB)

Vavro, M; Chlebik, J

1977-01-01

Method of water infusion is used in the Ostrava-Karvina coal region in Czechoslovakia, where the roof of the extracted coal seam consists of thick rock layers (sandstone, Namurian B series) characterized by high resistance to compression, high coefficient of linear elasticity and high capacity of accumulating energy. When the resistance boundary is crossed and the rocks are disturbed this energy is suddenly released and transferred to the surrounding rock masses, coal seam and support system. On the basis of laboratory experiments the physico-mechanical and energy properties of carboniferous rocks together with calculation of their energy coefficient and other parameters are described and calculated. The results of research and theoretical solutions are presented. Practical use of water infusions to influence mechanical properties of sandstone in the roof of coal seams is described with the example of the Dukla coal mine. (5 refs.) (In Polish)

Geological history and its impact on the rock mechanics properties of the Olkiluoto site

International Nuclear Information System (INIS)

Hudson, J.A.; Cosgrove, J.W.

2006-03-01

This report is one of three documents with background information for supporting the development of Posiva's future rock mechanics programme. The other two reports are a summary of all the rock mechanics work completed for Posiva before 2005 (Posiva Working Report) and a technical audit of the numerical modeling work that has been conducted previously for Posiva (REC Memo). The purpose of this report is to establish the extent to which the mechanical properties of the rocks at the Olkiluoto site can be estimated from a knowledge of the geological environment. The main information required for rock mechanics studies of the site is a knowledge of the prevailing stress state, the properties of the intact rock, and the properties of the fractures at all scales - from sizes that could form blocks in the tunnel roof up to the major brittle deformation zones that could be influence the location of the ONKALO and the subsequent repository. Thus, the summary of the geological history in Chapter 2 concentrates on these features and we summarise the ductile and brittle deformational tectonic history of the site, with emphasis on the inferred stress states causing the deformations. Then, in Chapter 3, the rock stress, the hierarchy of brittle fracturing, the fracture properties and the mechanical properties of the rock mass are considered in the light of the geological environment. These features provide the baseline knowledge of the host rock from which the logic of the future rock mechanics programme can be developed, based on: the bedrock model; the site investigation results; the requirements for generating the site descriptive model; the prediction-outcome ONKALO studies; and numerically modeling the effects of excavation for design and safety analysis. The implications of this study for the future rock mechanics work are outlined in Chapter 4 with emphasis on the key features for modeling. (orig.)

Deaf/Hearing Research Partnerships

Science.gov (United States)

Wolsey, Ju-Lee A.; Misener Dunn, Kim; Gentzke, Scott W.; Joharchi, Hannah A.; Clark, M. Diane

2017-01-01

Deaf individuals typically are seen through the lens of the dominant hearing society's perception, i.e., that being deaf is an impairment. Today, a small but growing number of Deaf and hearing researchers are challenging this perception. The authors examined perceptions of what components are necessary for a successful Deaf/hearing research…

[Study of generational risk in deafness inflicted couples using deafness gene microarray technique].

Science.gov (United States)

Wang, Ping; Zhao, Jia; Yu, Shu-yuan; Jin, Peng; Zhu, Wei; DU, Bo

2011-06-01

To explored the significance of screening the gene mutations of deafness related in deaf-mute (deaf & dumb) family using DNA microarray. Total of 52 couples of deaf-mute were recruited from Changchun deaf-mute community. With an average age of (58.3 ± 6.7) years old (x(-) ± s). Blood samples were obtained with informed consent. Their genomic DNA was extracted from peripheral blood and PCR was performed. Nine of hot spot mutations in four most common deafness pathologic gene were examined with the DNA microarray, including GJB2, GJB3, PDS and mtDNA 12S rRNA genes. At the same time, the results were verified with the traditional methods of sequencing. Fifty of normal people served as a control group. All patients were diagnosed non-syndromic sensorineural hearing loss by subjective pure tone audiometry. Thirty-two of 104 cases appeared GJB2 gene mutation (30.7%), the mutation sites included 35delG, 176del16, 235delC and 299delAT. Eighteen of 32 cases of GJB2 mutations were 235delC (59.1%). Seven of 104 cases appeared SLC26A4 gene IVS7-2 A > G mutation. Questionnaire survey and gene diagnosis revealed that four of 52 families have deaf offspring (7.6%). When a couple carries the same gene mutation, the risk of their children deafness was 100%. The results were confirmed with the traditional methods of sequencing. There is a high risk of deafness if a deaf-mute family is planning to have a new baby. It is very important and helpful to avoid deaf newborns again in deaf-mute family by DNA microarray.

Statistical fracture mechanics approach to the strength of brittle rock

International Nuclear Information System (INIS)

Ratigan, J.L.

1981-06-01

Statistical fracture mechanics concepts used in the past for rock are critically reviewed and modifications are proposed which are warranted by (1) increased understanding of fracture provided by modern fracture mechanics and (2) laboratory test data both from the literature and from this research. Over 600 direct and indirect tension tests have been performed on three different rock types; Stripa Granite, Sierra White Granite and Carrara Marble. In several instances assumptions which are common in the literature were found to be invalid. A three parameter statistical fracture mechanics model with Mode I critical strain energy release rate as the variant is presented. Methodologies for evaluating the parameters in this model as well as the more commonly employed two parameter models are discussed. The experimental results and analysis of this research indicate that surfacially distributed flaws, rather than volumetrically distributed flaws are responsible for rupture in many testing situations. For several of the rock types tested, anisotropy (both in apparent tensile strength and size effect) precludes the use of contemporary statistical fracture mechanics models

Interaction of thermal and mechanical processes in steep permafrost rock walls: A conceptual approach

Science.gov (United States)

Draebing, D.; Krautblatter, M.; Dikau, R.

2014-12-01

Degradation of permafrost rock wall decreases stability and can initiate rock slope instability of all magnitudes. Rock instability is controlled by the balance of shear forces and shear resistances. The sensitivity of slope stability to warming results from a complex interplay of shear forces and resistances. Conductive, convective and advective heat transport processes act to warm, degrade and thaw permafrost in rock walls. On a seasonal scale, snow cover changes are a poorly understood key control of the timing and extent of thawing and permafrost degradation. We identified two potential critical time windows where shear forces might exceed shear resistances of the rock. In early summer combined hydrostatic and cryostatic pressure can cause a peak in shear force exceeding high frozen shear resistance and in autumn fast increasing shear forces can exceed slower increasing shear resistance. On a multiannual system scale, shear resistances change from predominantly rock-mechanically to ice-mechanically controlled. Progressive rock bridge failure results in an increase of sensitivity to warming. Climate change alters snow cover and duration and, hereby, thermal and mechanical processes in the rock wall. Amplified thawing of permafrost will result in higher rock slope instability and rock fall activity. We present a holistic conceptual approach connecting thermal and mechanical processes, validate parts of the model with geophysical and kinematic data and develop future scenarios to enhance understanding on system scale.

Deaf Culture. PEPNet Tipsheet

Science.gov (United States)

Siple, Linda; Greer, Leslie; Holcomb, Barbra Ray

2004-01-01

It often comes as a surprise to people that many deaf people refer to themselves as being members of Deaf culture. The American Deaf culture is a unique linguistic minority that uses American Sign Language (ASL) as its primary mode of communication. This tipsheet provides a description of Deaf culture and suggestions for effective communication.

Rock mechanics contributions from defense programs

International Nuclear Information System (INIS)

Heuze, F.E.

1992-02-01

An attempt is made at illustrating the many contributions to rock mechanics from US defense programs, over the past 30-plus years. Large advances have been achieved in the technology-base area covering instrumentation, material properties, physical modeling, constitutive relations and numerical simulations. In the applications field, much progress has been made in understanding and being able to predict rock mass behavior related to underground explosions, cratering, projectile penetration, and defense nuclear waste storage. All these activities stand on their own merit as benefits to national security. But their impact is even broader, because they have found widespread applications in the non-defense sector; to name a few: the prediction of the response of underground structures to major earthquakes, the physics of the earth's interior at great depths, instrumentation for monitoring mine blasting, thermo-mechanical instrumentation useful for civilian nuclear waste repositories, dynamic properties of earthquake faults, and transient large-strain numerical modeling of geological processes, such as diapirism. There is not pretense that this summary is exhaustive. It is meant to highlight success stories representative of DOE and DOD geotechnical activities, and to point to remaining challenges

Rock mechanics site descriptive model-theoretical approach. Preliminary site description Forsmark area - version 1.2

Energy Technology Data Exchange (ETDEWEB)

Fredriksson, Anders; Olofsson, Isabelle [Golder Associates AB, Uppsala (Sweden)

2005-12-15

The present report summarises the theoretical approach to estimate the mechanical properties of the rock mass in relation to the Preliminary Site Descriptive Modelling, version 1.2 Forsmark. The theoretical approach is based on a discrete fracture network (DFN) description of the fracture system in the rock mass and on the results of mechanical testing of intact rock and on rock fractures. To estimate the mechanical properties of the rock mass a load test on a rock block with fractures is simulated with the numerical code 3DEC. The location and size of the fractures are given by DFN-realisations. The rock block was loaded in plain strain condition. From the calculated relationship between stresses and deformations the mechanical properties of the rock mass were determined. The influence of the geometrical properties of the fracture system on the mechanical properties of the rock mass was analysed by loading 20 blocks based on different DFN-realisations. The material properties of the intact rock and the fractures were kept constant. The properties are set equal to the mean value of each measured material property. The influence of the variation of the properties of the intact rock and variation of the mechanical properties of the fractures are estimated by analysing numerical load tests on one specific block (one DFN-realisation) with combinations of properties for intact rock and fractures. Each parameter varies from its lowest values to its highest values while the rest of the parameters are held constant, equal to the mean value. The resulting distribution was expressed as a variation around the value determined with mean values on all parameters. To estimate the resulting distribution of the mechanical properties of the rock mass a Monte-Carlo simulation was performed by generating values from the two distributions independent of each other. The two values were added and the statistical properties of the resulting distribution were determined.

Rock mechanics site descriptive model-theoretical approach. Preliminary site description Forsmark area - version 1.2

International Nuclear Information System (INIS)

Fredriksson, Anders; Olofsson, Isabelle

2005-12-01

The present report summarises the theoretical approach to estimate the mechanical properties of the rock mass in relation to the Preliminary Site Descriptive Modelling, version 1.2 Forsmark. The theoretical approach is based on a discrete fracture network (DFN) description of the fracture system in the rock mass and on the results of mechanical testing of intact rock and on rock fractures. To estimate the mechanical properties of the rock mass a load test on a rock block with fractures is simulated with the numerical code 3DEC. The location and size of the fractures are given by DFN-realisations. The rock block was loaded in plain strain condition. From the calculated relationship between stresses and deformations the mechanical properties of the rock mass were determined. The influence of the geometrical properties of the fracture system on the mechanical properties of the rock mass was analysed by loading 20 blocks based on different DFN-realisations. The material properties of the intact rock and the fractures were kept constant. The properties are set equal to the mean value of each measured material property. The influence of the variation of the properties of the intact rock and variation of the mechanical properties of the fractures are estimated by analysing numerical load tests on one specific block (one DFN-realisation) with combinations of properties for intact rock and fractures. Each parameter varies from its lowest values to its highest values while the rest of the parameters are held constant, equal to the mean value. The resulting distribution was expressed as a variation around the value determined with mean values on all parameters. To estimate the resulting distribution of the mechanical properties of the rock mass a Monte-Carlo simulation was performed by generating values from the two distributions independent of each other. The two values were added and the statistical properties of the resulting distribution were determined

Rock mechanics. Proceedings of the 33rd U.S. symposium

International Nuclear Information System (INIS)

Tillerson, J.R.; Wawersik, W.R.

1992-01-01

After giving abstracts of the award winning papers for 1991 and the keynote lecture, papers are presented under the following headings: origin of stresses in the lithosphere; fault mechanics; rock mass monitoring; subsidence and ground motions; blasting; reservoir completion and stimulation; underground storage and sealing; design and supports; fluid and contaminant transport; numerical methods; constitutive modelling and strain localization; nonlinear dynamic systems; geostatistics and reliability; fracture mechanics; physical rock properties; experimental methods; geotechnical design methodology - workshop; and induced seismicity - workshop. Six papers have been abstracted separately

Making public mental-health services accessible to deaf consumers: Illinois Deaf Services 2000.

Science.gov (United States)

Munro-Ludders, Bruce; Simpatico, Thomas; Zvetina, Daria

2004-01-01

Illinois Deaf Services 2000 (IDS2000), a public/private partnership, promotes the creation and implementation of strategies to develop and increase access to mental health services for deaf, hard of hearing, late-deafened, and deaf-blind consumers. IDS2000 has resulted in the establishment of service accessibility standards, a technical support and adherence monitoring system, and the beginnings of a statewide telepsychiatry service. These system modifications have resulted in increase by 60% from baseline survey data in the number of deaf, hard of hearing, late-deafened, and deaf-blind consumers identified in community mental-health agencies in Illinois. Depending on the situation of deaf services staff and infrastructure, much of IDS2000 could be replicated in other states in a mostly budget-neutral manner.

Time dependency in the mechanical properties of crystalline rocks. A literature survey

International Nuclear Information System (INIS)

Hagros, A.; Johansson, E.; Hudson, J.A.

2008-09-01

Because of the long design life, elevated temperatures, and the location at depth (high stresses), time-dependent aspects of the mechanical properties of crystalline rock are potentially important for the design and the long term safety of the radioactive waste repository at Olkiluoto. However, time-dependent effects in rock mechanics are still one of the least understood aspects of the physical behaviour of rock masses, this being partly due to the fact that it is difficult to conduct long-term experimental tests - either in the laboratory or in situ. Yet, the time-dependent mechanical behaviour needs to be characterised so that it can be included in the modelling studies supporting repository design. The Introduction explains the background to the literature survey and includes definitions of the terms 'creep' (increasing strain at constant stress) and 'stress relaxation' (decreasing stress at constant strain). Moreover, it is noted that the rock around an in situ excavation is loaded by the adjacent rock elements and so the timedependent behaviour will depend on the unloading stiffness of these and hence will not actually be either pure creep or pure stress relaxation. The Appendix contains the results of the literature survey of reported time-dependent research as it applies to crystalline rock. A summary of each of the 38 literature items is presented in tabular form covering document number, subject area, document reference, subject matter, objectives, methodology, highlighted figures, conclusions and comments. It is concluded that the time-dependent failure strength of all rocks observed may be interpreted by sub-critical crack growth assisted by the stress corrosion mechanism. Also, certain parameters are known to affect the long-term properties: mineralogy, grain size, water/water chemistry, confining stress and loading history. At some point in the loading history of rock, the state of crack development reaches a point whereby the continued generation of

Rock Mechanics Forsmark. Site descriptive modelling Forsmark stage 2.2

Energy Technology Data Exchange (ETDEWEB)

Glamheden, Rune; Fredriksson, Anders (Golder Associates AB (SE)); Roeshoff, Kennert; Karlsson, Johan (Berg Bygg Konsult AB (SE)); Hakami, Hossein (Itasca Geomekanik AB (SE)); Christiansson, Rolf (Swedish Nuclear Fuel and Waste Management Co., Stockholm (SE))

2007-12-15

The Swedish Nuclear Fuel and Waste Management Company (SKB) is undertaking site characterisation at two different locations, Forsmark and Laxemar/Simpevarp, with the objective of siting a geological repository for spent nuclear fuel. The characterisation of a site is an integrated work carried out by several disciplines including geology, rock mechanics, thermal properties, hydrogeology, hydrogeochemistry and surface systems. This report presents the rock mechanics model of the Forsmark site up to stage 2.2. The scope of work has included compilation and analysis of primary data of intact rock and fractures, estimation of the rock mass mechanical properties and estimation of the in situ state of stress at the Forsmark site. The laboratory results on intact rock and fractures in the target volume demonstrate a good quality rock mass that is strong, stiff and relatively homogeneous. The homogeneity is also supported by the lithological and the hydrogeological models. The properties of the rock mass have been initially estimated by two separate modelling approaches, one empirical and one theoretical. An overall final estimate of the rock mass properties were achieved by integrating the results from the two models via a process termed 'Harmonization'. Both the tensile tests, carried out perpendicular and parallel to the foliation, and the theoretical analyses of the rock mass properties in directions parallel and perpendicular to the major principal stress, result in parameter values almost independent of direction. This indicates that the rock mass in the target volume is isotropic. The rock mass quality in the target volume appears to be of high and uniform quality. Those portions with reduced rock mass quality that do exist are mainly related to sections with increased fracture frequency. Such sections are associated with deformation zones according to the geological description. The results of adjacent rock domains and fracture domains of the target

Underground laboratories for rock mechanics before radioactive waste

International Nuclear Information System (INIS)

Duffaut, P.

1985-01-01

Many rock mechanics tests are performed in situ, most of them underground since 1936 at the Beni Bahdel dam. The chief tests for understanding the rock mass behaviour are deformability tests (plate test and pressure cavern test, including creep experiments) and strength tests (compression of a mine pillar, shear test on rock mass or joint). Influence of moisture, heat, cold and freeze are other fields of investigation which deserve underground laboratories. Behaviour of test galleries, either unsupported or with various kinds of support, often is studied along time, and along the work progression, tunnel face advance, enlargement or deepening of the cross section. The examples given here help to clarify the concept of underground laboratory in spite of its many different objectives. 38 refs.; 1 figure; 1 table

Analysis of soft rock mineral components and roadway failure mechanism

Institute of Scientific and Technical Information of China (English)

陈杰

2001-01-01

The mineral components and microstructure of soft rock sampled from roadway floor inXiagou pit are determined by X-ray diffraction and scanning electron microscope. Ccmbined withthe test of expansion and water softening property of the soft rock, the roadway failure mechanism is analyzed, and the reasonable repair supporting principle of roadway is put forward.

When Being Deaf Is Centered: d/Deaf Women of Color's Experiences with Racial/Ethnic and d/Deaf Identities in College

Science.gov (United States)

Stapleton, Lissa

2015-01-01

Approximately 30% of d/Deaf students are successfully completing college; the reasons for such a low graduation rate is unknown (Destler & Buckly, 2011). Most research on d/Deaf college students lack racial/ethnic diversity within the study; thus, it is unclear how d/Deaf Students of Color are faring in higher education or what experiences…

Mechanical Properties and Acoustic Emission Properties of Rocks with Different Transverse Scales

OpenAIRE

Yan, Xi; Jun, Li; Gonghui, Liu; Xueli, Guo

2017-01-01

Since the stability of engineering rock masses has important practical significance to projects like mining, tunneling, and petroleum engineering, it is necessary to study mechanical properties and stability prediction methods for rocks, cementing materials that are composed of minerals in all shapes and sizes. Rocks will generate acoustic emission during damage failure processes, which is deemed as an effective means of monitoring the stability of coal rocks. In the meantime, actual mining a...

The Effect of Void Shape on the Mechanical Properties of Rock

International Nuclear Information System (INIS)

D.O. Potyondy

2006-01-01

The bonded-particle model for rock (Potyondy and Cundall, 2004) represents rock by a dense packing of non-uniform-sized circular or spherical particles that are bonded together at their contact points and whose mechanical behavior is simulated by the distinct-element method using the two- and three-dimensional programs PFC2D and PFC3D. A bonded-particle model of lithophysal tuff has been used to study the effect of lithophysae (hollow, bubble-like voids) on the mechanical properties (Young's modulus and unconfined compressive strength) of this rock, and to quantify the variability of these properties. The model reproduces the failure mechanisms observed in the laboratory and exhibits a reduction of strength and modulus with increasing lithophysal volume fraction. The effect of void shape on mechanical properties is studied by inserting randomly distributed voids of simple shape (circle, triangle and star) and by inserting voids corresponding with lithophysal cavities identified in panel maps of the walls of a tunnel through this material. These studies address tunnel-stability issues associated with mechanical degradation of planned emplacement drifts at Yucca Mountain, which is the designated site for the proposed US high-level nuclear waste repository

Bridging the Gap Between DeafBlind Minds: interactional and social foundations of intention-attribution in the Seattle DeafBlind community

Directory of Open Access Journals (Sweden)

Terra eEdwards

2015-10-01

Full Text Available This article is concerned with social and interactional processes that simplify pragmatic acts of intention attribution. The empirical focus is a series of interactions among DeafBlind people in Seattle, Washington, where pointing signs are used to individuate objects of reference in the im-mediate environment. Most members of this community are born deaf and slowly become blind. They come to Seattle using Visual American Sign Language, which has emerged and developed in a field organized around visual modes of access. However, as vision deteriorates, links be-tween deictic signs and the present, remembered, or imagined environment erode in idiosyncratic ways across the community of language-users, and it becomes increasingly difficult for partici-pants to converge on objects of reference. In the past, DeafBlind people have addressed this problem by relying on sighted interpreters. Under the influence of the recent pro-tactile movement, they have turned instead to one another to find new solutions to their referential prob-lems. Drawing on analyses of 120 hours of videorecorded interaction and language-use, detailed fieldnotes collected during twelve months of sustained anthropological fieldwork, and more than 15 years of involvement in this community in a range of capacities, I show how DeafBlind peo-ple are generating new and reciprocal modes of access to their environment, and how this pro-cess is aligning language with context in novel ways. I propose two mechanisms that can account for this process: deictic integration and embedding in the social field. I argue that together, these interactional and social mechanisms yield a deictic system set to retrieve a restricted range of values from the extra-linguistic context, thereby attenuating the cognitive demands of intention-attribution and narrowing the gap between DeafBlind minds.

Lithophysal Rock Mass Mechanical Properties of the Repository Host Horizon

International Nuclear Information System (INIS)

D. Rigby

2004-01-01

The purpose of this calculation is to develop estimates of key mechanical properties for the lithophysal rock masses of the Topopah Spring Tuff (Tpt) within the repository host horizon, including their uncertainties and spatial variability. The mechanical properties to be characterized include an elastic parameter, Young's modulus, and a strength parameter, uniaxial compressive strength. Since lithophysal porosity is used as a surrogate property to develop the distributions of the mechanical properties, an estimate of the distribution of lithophysal porosity is also developed. The resulting characterizations of rock parameters are important for supporting the subsurface design, developing the preclosure safety analysis, and assessing the postclosure performance of the repository (e.g., drift degradation and modeling of rockfall impacts on engineered barrier system components)

Application of rock mechanics to cut-and-fill mining. Volume 1

Energy Technology Data Exchange (ETDEWEB)

1980-05-15

The conference on application of rock mechanics to cut-and-fill mining was held June 1-3, 1980, at the University of Luleaa, Sweden. The conference began with reviews of the application of rock mechanics to mining and back filling in Australia, Canada and the USA. More particular papers involved mines in Sweden, Italy, Australia (pre reinforcement of walls with steel cables cemented in) and at the Con Mine in Canada. Two papers involved backfill material and specifications. Eight papers involved the use of the mathematical models for calculating the stresses developed in the rock mass by computer calculations and therefore, the probable stability. Such calculations are particularly necessary in deep mines. Papers of general interest were entered individually into EDB. (LTN)

Application of rock mechanics in opencast mining

Energy Technology Data Exchange (ETDEWEB)

Desurmont, M; Feuga, B

1979-07-01

The significance of opencast mining in the world today is mentioned. With the exception of coal, opencast workings provide approximately 80% of output. The importance of opencast has continued to increase over the last ten years. Access to the mineral usually necessitates the removal of large quantities of rock. The aim is to reduce the quantity of the latter as much as possible in order to minimize the dirt/mineral ratio. For this purpose use has been made of the operating techniques of rock mechanics in order to determine the optimum dimensions of the access trench compatible with safety requirements. The author illustrates this technique by means of three examples: the Luzenac talc workings, the Mont-Roc fluorine workings and the Big Hole at Kimberley.

Deaf Culture. NETAC Teacher Tipsheet

Science.gov (United States)

Siple, Linda; Greer, Leslie; Holcomb, Barbara Ray

2004-01-01

It often comes as a surprise to people that many deaf people refer to themselves as being members of Deaf culture. The American Deaf culture is a unique linguistic minority that uses American Sign Language (ASL) as its primary mode of communication. This tipsheet provides a description of Deaf culture and suggestions for effective communication.

Workshop on rock mechanics issues in repository design and performance assessment

International Nuclear Information System (INIS)

1996-04-01

The Center for Nuclear Waste Regulatory Analyses organized and hosted a workshop on ''Rock Mechanics Issues in Repository Design and Performance Assessment'' on behalf its sponsor the U.S. Nuclear Regulatory Commission (NRC). This workshop was held on September 19- 20, 1994 at the Holiday Inn Crowne Plaza, Rockville, Maryland. The objectives of the workshop were to stimulate exchange of technical information among parties actively investigating rock mechanics issues relevant to the proposed high-level waste repository at Yucca Mountain and identify/confirm rock mechanics issues important to repository design and performance assessment The workshop contained three technical sessions and two panel discussions. The participants included technical and research staffs representing the NRC and the Department of Energy and their contractors, as well as researchers from the academic, commercial, and international technical communities. These proceedings include most of the technical papers presented in the technical sessions and the transcripts for the two panel discussions

Geological and Rock Mechanics Perspectives for Underground Coal Gasification in India

Science.gov (United States)

Singh, Ajay K.; Singh, Rajendra

2017-07-01

The geological resources of coal in India are more than 308 billion tonnes upto a depth of 1200 m, out of which proved reserve has been reported at around 130 billion tonnes. There is an increasing requirement to increase the energy extraction efficiency from coal as the developmental prospects of India increase. Underground coal gasification (UCG) is a potential mechanism which may be utilized for extraction of deep-seated coal reserves. Some previous studies suggest that lignites from Gujarat and Rajasthan, along with tertiary coals from northeastern India can be useful from the point of view of UCG. We discuss some geological literature available for these areas. Coming to the rock mechanics perspectives, during UCG the rock temperature is considerable high. At this temperature, most empirical models of rock mechanics may not be applied. In this situation, the challenges for numerical modelling of UCG sites increases manifold. We discuss some of the important modelling geomechanical issues related to UCG in India.

STAFAN, Fluid Flow, Mechanical Stress in Fractured Rock of Nuclear Waste Repository

International Nuclear Information System (INIS)

Huyakorn, P.; Golis, M.J.

1989-01-01

1 - Description of program or function: STAFAN (Stress And Flow Analysis) is a two-dimensional, finite-element code designed to model fluid flow and the interaction of fluid pressure and mechanical stresses in a fractured rock surrounding a nuclear waste repository. STAFAN considers flow behavior of a deformable fractured system with fracture-porous matrix interactions, the coupling effects of fluid pressure and mechanical stresses in a medium containing discrete joints, and the inelastic response of the individual joints of the rock mass subject to the combined fluid pressure and mechanical loading. 2 - Restrictions on the complexity of the problem: STAFAN does not presently contain thermal coupling, and it is unable to simulate inelastic deformation of the rock mass and variably saturated or two-phase flow in the fractured porous medium system

Deformation mechanisms in a coal mine roadway in extremely swelling soft rock.

Science.gov (United States)

Li, Qinghai; Shi, Weiping; Yang, Renshu

2016-01-01

The problem of roadway support in swelling soft rock was one of the challenging problems during mining. For most geological conditions, combinations of two or more supporting approaches could meet the requirements of most roadways; however, in extremely swelling soft rock, combined approaches even could not control large deformations. The purpose of this work was to probe the roadway deformation mechanisms in extremely swelling soft rock. Based on the main return air-way in a coal mine, deformation monitoring and geomechanical analysis were conducted, as well as plastic zone mechanical model was analysed. Results indicated that this soft rock was potentially very swelling. When the ground stress acted alone, the support strength needed in situ was not too large and combined supporting approaches could meet this requirement; however, when this potential released, the roadway would undergo permanent deformation. When the loose zone reached 3 m within surrounding rock, remote stress p ∞ and supporting stress P presented a linear relationship. Namely, the greater the swelling stress, the more difficult it would be in roadway supporting. So in this extremely swelling soft rock, a better way to control roadway deformation was to control the releasing of surrounding rock's swelling potential.

Summary review of rock mechanics workshop on radioactive waste disposal

International Nuclear Information System (INIS)

Carter, N.L.; Goodman, R.E.; Merrill, R.H.

1977-01-01

Presentations, critiques and recommendations for the disposal of commercial radioactive waste based upon an analysis of the information presented at the Rock Mechanics Review/Workshop, Denver, Colorado, December 16-17, 1976 are summarized. The workshop, comprised of both formal and informal sessions, with about 50 participants, was hosted by RE/SPEC Inc. and Dr. Paul F. Gnirk, President and was sponsored by the Office of Waste Isolation (OWI), led by Dr. William C. McClain. The panel of reviewers, responsible for this report, consisted of Neville L. Carter, Richard E. Goodman, and Robert H. Merrill. These panel members were selected not only on the basis of their experience in various aspects of Rock Mechanics and Mining Engineering but also because they have had no previous active participation in problems concerning disposal of radioactive waste. By way of a general comment, the review panel was very favorably impressed with the Rock Mechanics research efforts, supported by OWI, on this problem and with the level of technical competence of those carrying out the research. Despite the rather preliminary nature of the results presented and the youth of the program itself, it is clear that the essential ingredients for a successful program are at hand, especially as regards disposal in natural salt formations. These include laboratory studies of appropriate rock deformation, numerical analyses of thermal and mechanical stresses around openings, and in situ field tests. We shall comment on each of these three major areas in turn. We shall then offer recommendations for their improvement, and, finally, we shall make more general recommendations for future considerations of the OWI radioactive waste disposal program

Supporting Deaf Students--and All Students

Science.gov (United States)

Yuknis, Christina; Santini, Joseph; Appanah, Thangi

2017-01-01

Two faculty members and a Ph.D. student at Gallaudet University, the world's only university for the deaf, explain the concept of Deaf-Gain, which reframes the idea of hearing loss into one of gaining deafness and recognizes the contributions that deaf people make to society. This narrative assumes that deaf students and all students bring…

Debating Futures in Flemish Deaf Parliament: Deaf Epistemologies, Participatory Citizenship, and Sustainable Development

Science.gov (United States)

De Clerck, Goedele A.M.

2017-01-01

More than 350 deaf/sign language community members gathered at six local deaf clubs in Flanders in 2014 to share perspectives about the future and formulate proposals for policymaking. This initiative, Flemish Deaf Parliament, serves as a platform of deliberative democracy developed through cooperation between Ghent University and the Flemish…

The Impact of Maternal Deafness on Cradling Laterality with Deaf and Hearing Infants

Science.gov (United States)

Sieratzki, Jechil S.; Woll, Bencie

2004-01-01

A recent article in the "Journal of Deaf Studies and Deaf Education" (Leigh, Brice, & Meadow-Orlans, 2004) explored attachment between deaf mothers and their 18-month-old children and reported relationship patterns similar to those for hearing dyads. The study reported here explores a marker of early mother-child relationships: cradling…

Mechanisms of continental subduction and exhumation of HP and UHP rocks

NARCIS (Netherlands)

Burov, Evgene; Francois, Thomas; Yamato, Philippe; Wolf, Sylvie

We discuss possible scenarios of continental collision, and their relation to mechanisms of exhumation of HP and UHP rocks, inferred from thermo-mechanical numerical models accounting for thermo-rheological complexity of the continental lithosphere. Due to this complexity, mechanisms of continental

Rheological Characteristics of Cement Grout and its Effect on Mechanical Properties of a Rock Fracture

Science.gov (United States)

Liu, Quansheng; Lei, Guangfeng; Peng, Xingxin; Lu, Chaobo; Wei, Lai

2018-02-01

Grouting reinforcement, which has an obvious strengthening effect on fractured rock mass, has been widely used in various fields in geotechnical engineering. The rheological properties of grout will greatly affect its diffusion radius in rock fractures, and the water-cement ratio is an important factor in determining the grouting flow patterns. The relationship between shear stress and shear rate which could reflect the grout rheological properties, the effects of water-cement ratio, and temperature on the rheological properties of grouting was studied in the laboratory. Besides, a new method for producing fractured rock specimens was proposed and solved the problem of producing natural fractured rock specimens. To investigate the influences of grouting on mechanical properties of a rock fracture, the fractured rock specimens made using the new method were reinforced by grouting on the independent designed grouting platform, and then normal and tangential mechanical tests were carried out on fractured rock specimens. The results showed that the mechanical properties of fractured rock mass are significantly improved by grouting, the peak shear strength and residual strength of rock fractures are greatly improved, and the resistance to deformation is enhanced after grouting. Normal forces affect the tangential behavior of the rock fracture, and the tangential stress strength increases with normal forces. The strength and stability of fractured rock mass are increased by grouting reinforcement.

In situ tests for investigating thermal and mechanical rock behaviors at an underground research tunnel

International Nuclear Information System (INIS)

Kwon, Sangki; Cho, Won-Jin

2013-01-01

The understanding of the thermal and mechanical behaviors expected to be happened around an underground high-level radioactive waste (HLW) repository is important for a successful site selection, construction, operation, and closure of the repository. In this study, the thermal and mechanical behaviors of rock and rock mass were investigated from in situ borehole heater test and the studies for characterizing an excavation damaged zone (EDZ), which had been carried out at an underground research tunnel, KURT, constructed in granite for the validation of a HLW disposal concept. Thermal, mechanical, and hydraulic properties in EDZ could be predicted from various in situ and laboratory tests as well as numerical simulations. The complex thermo-mechanical coupling behavior of rock could be modeled using the rock properties. (author)

Integrating rock mechanics issues with repository design through design process principles and methodology

International Nuclear Information System (INIS)

Bieniawski, Z.T.

1996-01-01

A good designer needs not only knowledge for designing (technical know-how that is used to generate alternative design solutions) but also must have knowledge about designing (appropriate principles and systematic methodology to follow). Concepts such as open-quotes design for manufactureclose quotes or open-quotes concurrent engineeringclose quotes are widely used in the industry. In the field of rock engineering, only limited attention has been paid to the design process because design of structures in rock masses presents unique challenges to the designers as a result of the uncertainties inherent in characterization of geologic media. However, a stage has now been reached where we are be able to sufficiently characterize rock masses for engineering purposes and identify the rock mechanics issues involved but are still lacking engineering design principles and methodology to maximize our design performance. This paper discusses the principles and methodology of the engineering design process directed to integrating site characterization activities with design, construction and performance of an underground repository. Using the latest information from the Yucca Mountain Project on geology, rock mechanics and starter tunnel design, the current lack of integration is pointed out and it is shown how rock mechanics issues can be effectively interwoven with repository design through a systematic design process methodology leading to improved repository performance. In essence, the design process is seen as the use of design principles within an integrating design methodology, leading to innovative problem solving. In particular, a new concept of open-quotes Design for Constructibility and Performanceclose quotes is introduced. This is discussed with respect to ten rock mechanics issues identified for repository design and performance

Application of rock mechanics to cut-and-fill mining. Volume 3

Energy Technology Data Exchange (ETDEWEB)

1980-05-15

The conference on application of rock mechanics to cut-and-fill mining was held June 1-3, 1980, at the University of Luleaa, Luleaa, Sweden. Basic rock mechanics investigations of interest involving improving the support characteristics of backfilling by adding cement, compacting, and water removal have been entered individually into EDB. The papers also cover measurements of the support capability of such fills and the application of deformation measurements and calculations using finite element computer codes to the mining of particular ore bodies, including changes in the calculations as the mining progressed. (LTN)

A dissolution-diffusion sliding model for soft rock grains with hydro-mechanical effect

Directory of Open Access Journals (Sweden)

Z. Liu

2018-06-01

Full Text Available The deformation and failure of soft rock affected by hydro-mechanical (HM effect are one of the most concerns in geotechnical engineering, which are basically attributed to the grain sliding of soft rock. This study tried to develop a dissolution-diffusion sliding model for the typical red bed soft rock in South China. Based on hydration film, mineral dissolution and diffusion theory, and geochemical thermodynamics, a dissolution-diffusion sliding model with the HM effect was established to account for the sliding rate. Combined with the digital image processing technology, the relationship between the grain size of soft rock and the amplitude of sliding surface was presented. An equation for the strain rate of soft rocks under steady state was also derived. The reliability of the dissolution-diffusion sliding model was verified by triaxial creep tests on the soft rock with the HM coupling effect and by the relationship between the inversion average disjoining pressure and the average thickness of the hydration film. The results showed that the sliding rate of the soft rock grains was affected significantly by the waviness of sliding surface, the shear stress, and the average thickness of hydration film. The average grain size is essential for controlling the steady-state creep rate of soft rock. This study provides a new idea for investigating the deformation and failure of soft rock with the HM effect. Keywords: Soft rock, Hydro-mechanical (HM effect, Mineral dissolution-diffusion, Grain sliding model

Music and Deaf Culture: Images from the Media and Their Interpretation by Deaf and Hearing Students.

Science.gov (United States)

Darrow; Loomis

1999-01-01

The purpose of the study was threefold: (a) to examine how the visual media have portrayed the subject of music and the deaf, (b) to verify the validity of these portrayals with members of the deaf community, and (c) to compare and contrast deaf and hearing audiences' impressions of these portrayals. An additional purpose of the research was to examine the results in light of possible misconceptions that may be construed by music therapists and music educators based upon the media's representation of the relationship between music and deaf culture. Since music therapists and music educators are the primary persons responsible for the music instruction of students in school programs for deaf and hard-of-hearing students, it is particularly important that they receive accurate messages about the relationship of music to deaf culture. Fifty deaf (n = 25) and hearing (n = 25) undergraduate college students individually viewed motion picture and television excerpts related to music and the deaf. Subjects were instructed to take notes as needed regarding the content of each excerpt and their impressions. Students were then interviewed in their native language, English or American Sign Language, as to their interpretations and perceptions regarding these excerpts and their accuracy. Interviews of the deaf students were translated into English from American Sign Language by trained interpreters. Written transcriptions were then made of the interpreters' English translations of the interviews with deaf students and of the verbal interviews with hearing students. Interview transcripts from both groups were coded and analyzed for recurring themes and patterns using content analysis. Data analysis revealed cultural patterns for the two groups, impressions specific to individual subjects, and trends in communication style and content for the two groups. Implications for music therapists and music educators are given regarding the influence of the media, characteristics of deaf

Deaf English--An Investigation of the Written English Competence of Deaf Adolescents. Technical Report No. 236.

Science.gov (United States)

Charrow, Veda R.

Presented is support for the existence of "Deaf English," a non-standard dialect common to the prelingually deaf; and reported is an investigation of the written English competence of deaf adolescents. In the first half of the document the author discusses the historical background of deaf education and the linguistic and cognitive abilities of…

Workshop on rock mechanics issues in repository design and performance assessment

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-04-01

The Center for Nuclear Waste Regulatory Analyses organized and hosted a workshop on ``Rock Mechanics Issues in Repository Design and Performance Assessment`` on behalf its sponsor the U.S. Nuclear Regulatory Commission (NRC). This workshop was held on September 19- 20, 1994 at the Holiday Inn Crowne Plaza, Rockville, Maryland. The objectives of the workshop were to stimulate exchange of technical information among parties actively investigating rock mechanics issues relevant to the proposed high-level waste repository at Yucca Mountain and identify/confirm rock mechanics issues important to repository design and performance assessment The workshop contained three technical sessions and two panel discussions. The participants included technical and research staffs representing the NRC and the Department of Energy and their contractors, as well as researchers from the academic, commercial, and international technical communities. These proceedings include most of the technical papers presented in the technical sessions and the transcripts for the two panel discussions. Selected papers have been indexed separately for inclusion the Energy Science and Technology Database.

Rock mechanics in the disposal of radioactive wastes by hydraulic fracturing

Energy Technology Data Exchange (ETDEWEB)

McClain, W C

1968-01-01

The ultimate capacity of a hydraulic-fracturing waste disposal facility is governed primarily by the integrity of the rocks overlying the injected wastes. The objective of this study is to analyze theoretically the stresses and strains generated by the injected wastes in an effort to understand the behavior of the system sufficiently well that the failure mechanism can be predicted and the capacity of the injection well estimated. The surface uplifts at Oak Ridge National Laboratory's fracturing site were compared with theoretical curves obtained by assuming the uplifts to be inversely analogous to the subsidence which occurs over mining excavations. This analysis, based on assumptions of homogeneity, isotropy, and linear elasticity, provided considerable insight into the mechanics of the process. The most probable mechanism of failure of the rock appears to be by the formation of a vertical instead of a horizontal fracture. Fracture orientation is controlled primarily by the orientation of the principal stress field in the rock. Each successive waste injection slightly modifies this stress field toward a condition more favorable to the formation of a vertical fracture. (16 refs.)

Mechanical and physical properties of hydrothermally altered rocks, Taupo Volcanic Zone, New Zealand

Science.gov (United States)

Wyering, L. D.; Villeneuve, M. C.; Wallis, I. C.; Siratovich, P. A.; Kennedy, B. M.; Gravley, D. M.; Cant, J. L.

2014-11-01

Mechanical characterization of hydrothermally altered rocks from geothermal reservoirs will lead to an improved understanding of rock mechanics in a geothermal environment. To characterize rock properties of the selected formations, we prepared samples from intact core for non-destructive (porosity, density and ultrasonic wave velocities) and destructive laboratory testing (uniaxial compressive strength). We characterised the hydrothermal alteration assemblage using optical mineralogy and existing petrography reports and showed that lithologies had a spread of secondary mineralisation that occurred across the smectite, argillic and propylitic alteration zones. The results from the three geothermal fields show a wide variety of physical rock properties. The testing results for the non-destructive testing shows that samples that originated from the shallow and low temperature section of the geothermal field had higher porosity (15 - 56%), lower density (1222 - 2114 kg/m3) and slower ultrasonic waves (1925 - 3512 m/s (vp) and 818 - 1980 m/s (vs)), than the samples from a deeper and higher temperature section of the field (1.5 - 20%, 2072 - 2837 kg/m3, 2639 - 4593 m/s (vp) and 1476 - 2752 m/s (vs), respectively). The shallow lithologies had uniaxial compressive strengths of 2 - 75 MPa, and the deep lithologies had strengths of 16 - 211 MPa. Typically samples of the same lithologies that originate from multiple wells across a field have variable rock properties because of the different alteration zones from which each sample originates. However, in addition to the alteration zones, the primary rock properties and burial depth of the samples also have an impact on the physical and mechanical properties of the rock. Where this data spread exists, we have been able to derive trends for this specific dataset and subsequently have gained an improved understanding of how hydrothermal alteration affects physical and mechanical properties.

Mechanical characteristics of fully mechanized top-coal caving face and surrounding rock stress shell

Energy Technology Data Exchange (ETDEWEB)

Xie Guang-xiang [Anhui University of Science and Technology, Huainan (China)

2005-06-15

The distribution of surrounding rock stress in fully mechanized top-coal caving (FMTC) face was fully researched by large-scale and non-linear three-dimensional numerical simulation and equivalent laboratory. The results show that, there is the structure that is made of macroscopical stress shell composed of high stress binds in overlying strata of FMTC face. Stress shell, which bears and pass load of overlying strata, is primary supporting body. The stress in skewback of stress shell forms abutment pressure of surrounding rock in vicinity of working face. Bond-beam structure lies in reducing zone under stress shell. It only bear partial burden of strata under stress shell. The uppermost mechanical characteristic of FMTC face is lying in the low stress area under stress shell. It is the essential cause of strata behaviors of FMTC face relaxation. On the basis of analyzing stress shell, the mechanical essence that top coal performs a function of bedding is demonstrated. 4 refs., 7 figs.

Panel discussion on rock mechanics issues in repository design

International Nuclear Information System (INIS)

Bieniawski, Z.T.; Kim, K.S.; Nataraja, M.

1996-01-01

The panel discussion was introduced by Mr. Z.T.(Richard) Bieniawski and then continued with five additional speakers. The topics covered in the discussion included rock mechanics pertaining to the design of underground facilities for the disposal of radioactive wastes and the safety of such facilities. The speakers included: Mr. Kun-Soo Kim who is a specialist in the area of rock mechanics testing during the Basalt Waste Isolation Project; Dr. Mysore Nataraja who is the senior project manager with the NRC; Dr. Michael Voegele who is the project manager for Science Applications International Corporation (SAIC) on the Yucca Mountain Project; Dr. Edward Cording who is a member of the Nuclear Waste Technical Review Board; and Dr. Hemendra Kalia who is employed by Los Alamos National Laboratory and coordinates various activities of testing programs at the Yucca Mountain Site

Memory and Metamemory in Deaf Students.

Science.gov (United States)

Fung Tsui, Hing; Rodda, Michael

1990-01-01

Memory and metamemory abilities of 24 severely to profoundly deaf students between the ages of 9 and 20 years old were studied. Results did not suggest spatial bias in encoding. Semantic knowledge was correlated with metamemory and free recall, and rehearsal mechanisms correlated with temporal position recall and paired-associate nonprototypic…

Application of rock mechanics to cut-and-fill mining. Volume 2

Energy Technology Data Exchange (ETDEWEB)

1980-05-15

The conference on application of rock mechanics to cut-and-fill mining was held June 1-3, 1980, at the University of Luleaa, Sweden. The papers in this volume deal almost entirely with the Naesliden project in Sweden. Stress measurements were made on the rock mass before and during mining and complex computer codes using the finite element method developed to calculate the strains and their changes as mining developed. Major problems involved the effects of joints and the mechanical properties of the hydraulic backfill and in corporating these items in the calculations. Most papers were entered individually into EDB. (LTN)

Probabilistic-Stochastic Model of Distribution of Physical and Mechanical Properties of Soft Mineral Rocks

Directory of Open Access Journals (Sweden)

O.O. Sdvizhkova

2017-12-01

Full Text Available The physical and mechanical characteristics of soils and soft rocks obtained as a result of laboratory tests are important initial parameters for assessing the stability of natural and artificial slopes. Such properties of rocks as adhesion and the angle of internal friction are due to the influence of a number of natural and technogenic factors. At the same time, from the set of factors influencing the stability of the slope, the most significant ones are singled out, which to a greater extent determine the properties of the rocks. The more factors are taken into account in the geotechnical model, the more closely the properties of the rocks are studied, which increases the accuracy of the scientific forecast of the landslide danger of the slope. On the other hand, an increase in the number of factors involved in the model complicates it and causes a decrease in the reliability of geotechnical calculations. The aim of the work is to construct a statistical distribution of the studied physical and mechanical properties of soft rocks and to substantiate a probabilistic statistical model. Based on the results of laboratory tests of rocks, the statistical distributions of the quantitative traits studied, the angle of internal friction φ and the cohesion, were constructed. It was established that the statistical distribution of physical mechanical properties of rocks is close to a uniform law.

The Identity of Czech Deaf Roma

OpenAIRE

Kalousová, Josefina

2012-01-01

With the definition of Deaf people as a cultural and linguistic minority the research of Deaf identity became possible. Following this, questions of identity of minority deaf persons emerged. Do these persons affiliate to the Deaf community or to their ethnic minority? This bachelor thesis focuses on the topic of Czech deaf Roma identity. The underlying assumption of the paper is that identity is a continuing process dependent on the interaction of an individual and society and that it consti...

THM-issues in repository rock. Thermal, mechanical, thermo-mechanical and hydro-mechanical evolution of the rock at the Forsmark and Laxemar sites

Energy Technology Data Exchange (ETDEWEB)

Hoekmark, Harald; Loennqvist, Margareta; Faelth, Billy (Clay Technology AB, Lund (Sweden))

2010-05-15

The present report addresses aspects of the Thermo-Hydro-Mechanical (THM) evolution of the repository host rock that are of potential importance to the SR-Site safety assessment of a KBS-3 type spent nuclear fuel repository. The report covers the evolution of rock temperatures, rock stresses, pore pressures and fracture transmissivities during the excavation and operational phase, the temperate phase and a glacial cycle on different scales. The glacial cycle is assumed to include a period of pre-glacial permafrost with lowered temperatures and with increased pore pressures in the rock beneath the impermeable permafrost layer. The report also addresses the question of the peak temperature reached during the early temperate phase in the bentonite buffer surrounding the spent fuel canisters. The main text is devoted exclusively to the projected THM evolution of the rock at the Forsmark site in central Sweden. The focus is on the potential for stress-induced failures, i.e. spalling, in the walls of the deposition holes and on changes in the transmissivity of fractures and deformation zones. All analyses are conducted by a combination of numerical tools (3DEC) and analytical solutions. All phases are treated separately and independently of each other, although in reality construction will overlap with heat generation because of the step-by-step excavation/deposition approach with some 50 years between deposition of the first and last canisters. It is demonstrated here that the thermal and thermo-mechanical evolution of the near-field will be independent of heat generated by canisters that were deposited in the past, provided that deposition is made in an orderly fashion, deposition area by deposition area. Peak temperatures and near-field stresses can, consequently, be calculated as if all canisters were deposited simultaneously. The canister and tunnel spacing is specified such that the peak buffer temperature will not exceed 100 deg C in any deposition hole, i.e. not

Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the theoretical approach

Energy Technology Data Exchange (ETDEWEB)

Staub, Isabelle; Fredriksson, Anders; Outters, Nils [Golder Associates AB, Uppsala (Sweden)

2002-05-01

In the purpose of studying the possibilities of a Deep Repository for spent fuel, the Swedish Nuclear and Fuel Management Company (SKB) is currently planning for Site Investigations. Data collected from these Site Investigations are interpreted and analysed to achieve the full Site Description, which is built up of models from all the disciplines that are considered of importance for the Site Description. One of these models is the Rock Mechanical Descriptive Model,which would be developed for any site in hard crystalline rock, and is a combination and evaluation of the characterisation of rock mass by means of empirical relationships and a theoretical approach based on numerical modelling. The present report describes the theoretical approach. The characterisation of the mechanical properties of the rock mass, viewed as a unit consisting of intact rock and fractures, is achieved by numerical simulations with following input parameters: initial stresses, fracture geometry, distribution of rock mechanical properties, such as deformation and strength parameters, for the intact rock and for the fractures. The numerical modelling was performed with the two-dimensional code UDEC, and the rock block models were generated from 2D trace sections extracted from the 3D Discrete Fracture Network (DFN) model. Assumptions and uncertainties related to the set-up of the model are considered. The numerical model was set-up to simulate a plain strain-loading test. Different boundary conditions were applied on the model for simulating stress conditions (I) in the undisturbed rock mass, and (II) at the proximity of a tunnel. In order to assess the reliability of the model sensitivity analyses have been conducted on some rock block models for defining the dependency of mechanical properties to in situ stresses, the influence of boundary conditions, rock material and joint constitutive models used to simulate the behaviour of intact rock and fractures, domain size and anisotropy. To

Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the theoretical approach

International Nuclear Information System (INIS)

Staub, Isabelle; Fredriksson, Anders; Outters, Nils

2002-05-01

In the purpose of studying the possibilities of a Deep Repository for spent fuel, the Swedish Nuclear and Fuel Management Company (SKB) is currently planning for Site Investigations. Data collected from these Site Investigations are interpreted and analysed to achieve the full Site Description, which is built up of models from all the disciplines that are considered of importance for the Site Description. One of these models is the Rock Mechanical Descriptive Model,which would be developed for any site in hard crystalline rock, and is a combination and evaluation of the characterisation of rock mass by means of empirical relationships and a theoretical approach based on numerical modelling. The present report describes the theoretical approach. The characterisation of the mechanical properties of the rock mass, viewed as a unit consisting of intact rock and fractures, is achieved by numerical simulations with following input parameters: initial stresses, fracture geometry, distribution of rock mechanical properties, such as deformation and strength parameters, for the intact rock and for the fractures. The numerical modelling was performed with the two-dimensional code UDEC, and the rock block models were generated from 2D trace sections extracted from the 3D Discrete Fracture Network (DFN) model. Assumptions and uncertainties related to the set-up of the model are considered. The numerical model was set-up to simulate a plain strain-loading test. Different boundary conditions were applied on the model for simulating stress conditions (I) in the undisturbed rock mass, and (II) at the proximity of a tunnel. In order to assess the reliability of the model sensitivity analyses have been conducted on some rock block models for defining the dependency of mechanical properties to in situ stresses, the influence of boundary conditions, rock material and joint constitutive models used to simulate the behaviour of intact rock and fractures, domain size and anisotropy. To

Mechanism of rock shattering by explosions, depending on the nature of jointing and the elastic state

Energy Technology Data Exchange (ETDEWEB)

Mosinets, V N

1966-01-01

For proper use of explosives in shattering rock it is necessary to understand the mechanism of shattering. To a great extent this mechanism of shattering is controlled by fracturing in the rock and by the elastic properties of the rock. The processes of shattering as a result of explosion are analyzed, and the conclusion is made that, in its general interpretation, the mechanism of shattering is merely of theoretical interest. The applicability to actual media changes according to structure of the medium. Relatively massive rocks are characterized by an asymmetrical distribution function of the joints and micro-fractures and other inhomogeneities, the mode being shifted to the left of the asymmetry center. Rocks cut by an extensive network of microfractures and joints are characterized by an approximately normal distribution function; rocks cut by large joints have an asymmetrical distribution function, with the mode shifted to the right of the asymmetry center.

Review of important rock mechanics studies required for underground high level nuclear waste repository program

Energy Technology Data Exchange (ETDEWEB)

Kwon, S.; Cho, W. J

2007-01-15

Disposal concept adapting room and pillar method, which is a confirmed technique in mining and tunnel construction for long time, has advantages at cost, safety, technical feasibility, flexibility, and international cooperation point of views. Then the important rock mechanics principals and in situ and laboratory tests for understanding the behavior of rock, buffer, and backfill as well as their interactions will be reviewed. The accurate understanding of them is important for developing a safe disposal concept and successful operation of underground repository for permanent disposal of radioactive wastes. First of all, In this study, current status of rock mechanics studies for HLW disposal in foreign countries such as Sweden, USA, Canada, Finland, Japan, and France were reviewed. After then the in situ and laboratory tests for site characterization were summarized. Furthermore, rock mechanics studies required during the whole procedure for the disposal project from repository design to the final closure will be reviewed systematically. This study will help for developing a disposal system including site selection, repository design, operation, maintenance, and closure of a repository in deep underground rock. By introducing the required rock mechanics tests at different stages, it would be helpful from the planning stage to the operation stage of a radioactive waste disposal project.

Review of important rock mechanics studies required for underground high level nuclear waste repository program

International Nuclear Information System (INIS)

Kwon, S.; Cho, W. J.

2007-01-01

Disposal concept adapting room and pillar method, which is a confirmed technique in mining and tunnel construction for long time, has advantages at cost, safety, technical feasibility, flexibility, and international cooperation point of views. Then the important rock mechanics principals and in situ and laboratory tests for understanding the behavior of rock, buffer, and backfill as well as their interactions will be reviewed. The accurate understanding of them is important for developing a safe disposal concept and successful operation of underground repository for permanent disposal of radioactive wastes. First of all, In this study, current status of rock mechanics studies for HLW disposal in foreign countries such as Sweden, USA, Canada, Finland, Japan, and France were reviewed. After then the in situ and laboratory tests for site characterization were summarized. Furthermore, rock mechanics studies required during the whole procedure for the disposal project from repository design to the final closure will be reviewed systematically. This study will help for developing a disposal system including site selection, repository design, operation, maintenance, and closure of a repository in deep underground rock. By introducing the required rock mechanics tests at different stages, it would be helpful from the planning stage to the operation stage of a radioactive waste disposal project

Rock mechanics applied to cut and fill mining in Australia

Energy Technology Data Exchange (ETDEWEB)

Willoughby, D. R.

1980-05-15

Cut and fill mining and recent changes made possible by the application of rock mechanics principles are briefly introduced. The principal interests of professional groups associated with the industry, and incentives that exist to encourage research of benefit to the industry in general, are identified. Details are given of recent advances in rock mechanics instrumentation and technique by drawing to a large extent on experience gained in projects that have been conducted jointly with the mining companies. Examples of the application of the results of this research are given on a mine site basis. Reference is made where possible to papers that describe the examples in more detail. The review is concluded with identification of topics that require further research.

Temperature loading and rocks mechanics at final storage of radioactive waste

International Nuclear Information System (INIS)

Leijon, B.; Stephansson, O.

1979-01-01

This report describes the rock mechanical effects - in the far field - from the thermal loading at a final storage of radioactive waste in crystalline rocks. The stress distribution of a two-storey storage is described in more details. The temperature rise in a final storage of radiactive waste will create thermal stresses which may cause a failure of the rock mass, and thereby an increase of its permeability. However, the state of stress in the Earth's crust is able to neutralize the thermal stresses. By this analysis we have been able to demonstrate that the thermal stresses due to heat conduction from the final storage are compensated by the state of stress in the upper part of the crust. The absolute stress, which is the superposition of thermal stress and virgin rock stress, is in all cases found to be below the limit of failure due to frictional resistance between surfaces of constituent blocks in the rock mass. Failure by sliding friction is the most conservative failure criterion for a rock mass. (author)

Silencing Deafness: Displacing Disability in the Nineteenth Century

Directory of Open Access Journals (Sweden)

Esme Cleall

2015-03-01

Full Text Available This article traces the way in which the language of displacement and silence were used in nineteenth-century discussions of deafness and connects this tendency to the marginalised place deaf experience occupies historically. Throughout the nineteenth century, a period which saw the consolidation of ‘the deaf and dumb’ as a social category, the word ‘forgetting’ crept into numerous discussions of deafness by both deaf and hearing commentators. Some, such as the educationalist Alexander Graeme Bell, were overt in their desire to forget deafness, demanding disability was ‘bred out’ and deaf culture condemned to the forgotten past. Others used the term ambivalently and sometimes metaphorically discussing the deaf as ‘forgotten’ by society, and ‘children of silence’. Some even pleaded that people who were deaf were not forgotten. But, though varied, the use of the imagery of forgetting and silence to evoke deafness is recurrent, and may, therefore, be seen to reveal something about how deaf experience can be approached as a displacement where deafness was spatially and imaginatively marginalised. I argue that one of the consequences of the conceptual framing of deafness through the language of forgetting was actively to silence deafness and to neutralise the idea that disability should be marginal and could be forgotten.

Nurses experiences with deaf patient and recommendations for an effective communication with deaf in medical facility

OpenAIRE

Boukalová, Naděžda

2010-01-01

This bachelor thesis whose name is Nurses experiences with deaf patient and recommendations for an effective communication with deaf in medical facility was conceived as pilot research. This thesis consists of two parts, theoretical and experimental. Theoretical part has several chapters, which deal with anatomy of ear, physiology of hearing, deaf in Czech Republic and communication. The last part of this chapter describes certain situations, where is possible to meet the deaf at medical faci...

A Phenomenological Study of Online Learning for Deaf Students in Postsecondary Education: A Deaf Perspective

Science.gov (United States)

Wooten, Patricia Michelle

2014-01-01

This qualitative phenomenological study investigated the effects of online learning for deaf college students as opposed to the mainstream classroom setting. This study specifically analyzed the writing and reading skills of deaf students in general and the development of English literacy of prelingually deaf students and those from non-English…

Studies on deaf mobile application

Science.gov (United States)

Nathan, Shelena Soosay; Hussain, Azham; Hashim, Nor Laily

2016-08-01

The deaf normally considered to be disabled that do not need any mobile technology due to the inabilities of hearing and talking. However, many deaf are using mobile phone in their daily life for various purposes such as communication and learning. Many studies have attempted to identify the need of deaf people in mobile application and level of usage of the applications. This study aims in studying the recent research conducted on deaf mobile application to understand the level of importance of mobile technology for this disabled community. This paper enable identification of studies conducted are limited and the need of more research done of this disabled people to ensure their privilege of using mobile technology and its application, which leads to the identification of deaf user requirement for mobile application as future study.

Expression of primary emotions and defence and protective reactions among deaf adolescents

Directory of Open Access Journals (Sweden)

Maša Černelič Bizjak

2007-11-01

Full Text Available The study examined the differences in defense, protective reactions, and expression of primary emotions between deaf or partially hearing impaired adolescents and their peers with normal hearing. Participants in the two groups were assessed by means of The Profile Emotions, The Life Style Index, and Non-verbal Scale of Suffering. Deaf adolescents tended more towards uncontrolled and oppositional behaviour, and had a weaker sense of self-protection and deprivation. Moreover, their defense mechanisms (intellectualization, projection and negation were more intensively expressed. A higher level of defense mechanisms of intellectualization was observed in hearing adolescents. On the basis of the obtained results and analyses we may conclude that deaf adolescents demonstrated some characteristics of lower level of adjustment: negative emotional responses, lower degree of control (more uncontrolled and oppositional behaviour, weakened sense of self-protection and several simple, evolutionary more primitive defense mechanisms (excluding intellectualization. Our interpretation also takes into account that adolescents need to develop a new adjustment system as the old one ceased to function.

Site Study Plan for laboratory soil mechanics, Deaf Smith County site, Texas: Revision 1

International Nuclear Information System (INIS)

1987-12-01

This Site Study Plan for laboratory soil mechanics describes the laboratory testing to be conducted on soil samples collected as part of the characterization of the Deaf Smith County site, Texas. This study provides for measurements of index, mechanical, thermal, hydrologic, chemical, and mineral properties of soils from boring throughout the site. Samples will be taken from Playa Borings/Trenching, Transportation/Utilities Foundation Borings, Repository Surface Facilities Design Foundation Borings, and Exploratory Shaft Facilities Design Foundation Borings. Data from the laboratory tests will be used for soil strata characterization, design of foundations for surface structures, design of transportation facilities and utility structures, design of impoundments, design of shaft lining, design of the shaft freeze wall, shaft permitting, performance assessment calculations, and other program requirements. A tentative testing schedule and milestone log are given. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that appropriate documentation is maintained. 18 refs., 6 figs., 3 tabs

On the possibilities and limits of "DEAF DEAF SAME": Tourism and empowerment camps in Adamorobe (Ghana, Bangalore and Mumbai (India.

Directory of Open Access Journals (Sweden)

Michele Ilana Friedner

2014-06-01

Full Text Available This article qualitatively analyzes the ways that the discourse of "deaf universalism" circulates within two common deaf practices: tourism and engaging in interventions. Arguing that the largely Northern-situated discipline of Deaf Studies does not adequately examine how deaf bodies and discourses travel, ethnographic data compiled in India and Ghana during transnational encounters is employed to examine how claims of "sameness" and "difference" are enacted and negotiated. Similarly, this article examines how deaf individuals and groups deploy the concepts of deaf "heavens" and "hells" to analyze their travel experiences and justify interventions. We argue that deaf travelers and those engaging in interventions, mostly from Northern countries, employ teleological concepts that they attempt to impose on deaf "others." Adopting a critical approach, this article argues for the importance of carving out a space within Deaf Studies for allowing non-Northern concepts to come to the fore. Keywords: Deaf, Development, Universalism, Discourse, India, Ghana

Arts Accessibility for the Deaf.

Science.gov (United States)

Bergman, Eugene

The booklet provides information and resources for cultural organizations and institutions interested in making the arts accessible to deaf citizens. Preliminary information includes a discussion of deafness in America and the deaf in the history of the arts and notes that the era of silent films was the golden age of cinema. Listed are 36…

High-pressure mechanical instability in rocks.

Science.gov (United States)

Byerlee, J D; Brace, W F

1969-05-09

At a confining pressure of a few kilobars, deformation of many sedimentary rocks, altered mafic rocks, porous volcanic rocks, and sand is ductile, in that instabilities leading to audible elastic shocks are absent. At pressures of 7 to 10 kilobars, however, unstable faulting and stick-slip in certain of these rocks was observed. This high pressure-low temperature instability might be responsible for earthquakes in deeply buried sedimentary or volcanic sequences.

Basic processes and mechanisms of the water-rock system evolution

OpenAIRE

Shvartsev, Stepan Lvovich

2007-01-01

A new conception of progressive evolution and self-organizing presence in dead matter is developed; inner mechanisms and processes, realizing this development, are revealed. It is proven that the water-rock system satisfy these requirements

34 CFR 396.1 - What is the Training of Interpreters for Individuals Who Are Deaf and Individuals Who Are Deaf...

Science.gov (United States)

2010-07-01

... Who Are Deaf and Individuals Who Are Deaf-Blind program? 396.1 Section 396.1 Education Regulations of... SERVICES, DEPARTMENT OF EDUCATION TRAINING OF INTERPRETERS FOR INDIVIDUALS WHO ARE DEAF AND INDIVIDUALS WHO ARE DEAF-BLIND General § 396.1 What is the Training of Interpreters for Individuals Who Are Deaf and...

Determination of the mechanical parameters of rock mass based on a GSI system and displacement back analysis

Science.gov (United States)

Kang, Kwang-Song; Hu, Nai-Lian; Sin, Chung-Sik; Rim, Song-Ho; Han, Eun-Cheol; Kim, Chol-Nam

2017-08-01

It is very important to obtain the mechanical paramerters of rock mass for excavation design, support design, slope design and stability analysis of the underground structure. In order to estimate the mechanical parameters of rock mass exactly, a new method of combining a geological strength index (GSI) system with intelligent displacment back analysis is proposed in this paper. Firstly, average spacing of joints (d) and rock mass block rating (RBR, a new quantitative factor), surface condition rating (SCR) and joint condition factor (J c) are obtained on in situ rock masses using the scanline method, and the GSI values of rock masses are obtained from a new quantitative GSI chart. A correction method of GSI value is newly introduced by considering the influence of joint orientation and groundwater on rock mass mechanical properties, and then value ranges of rock mass mechanical parameters are chosen by the Hoek-Brown failure criterion. Secondly, on the basis of the measurement result of vault settlements and horizontal convergence displacements of an in situ tunnel, optimal parameters are estimated by combination of genetic algorithm (GA) and numerical simulation analysis using FLAC3D. This method has been applied in a lead-zinc mine. By utilizing the improved GSI quantization, correction method and displacement back analysis, the mechanical parameters of the ore body, hanging wall and footwall rock mass were determined, so that reliable foundations were provided for mining design and stability analysis.

Results of monitoring at Olkiluoto in 2012. Rock mechanics

International Nuclear Information System (INIS)

Johansson, E.; Siren, T.

2014-01-01

The rock mechanics monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The rock mechanics monitoring programme 2012 consisted of seismic measurements, GPS measurements, surface levelling measurements and temperature measurements at Olkiluoto and vicinity and displacement measurements, temperature measurements and visual tunnel observations carried out in the ONKALO. The Posiva's microseismic network consists of 17 seismic stations and 22 triaxial sensors. Six stations are in the ONKALO. In spite of few breaks the network operated continuously and well during 2012. The number of located events was much smaller in 2012 than during the previous years due to the interruption of the excavation. Altogether 337 events were located in the Olkiluoto area of which about half (181) were explosions. Two excavation induced earthquakes were observed at -420 m level and were associated with a known tunnel crosscutting fracture. According to the seismic monitoring the rock mass has been stable in 2012. The local GPS network consists of 19 stations. The whole network was measured twice in 2012. Most of the inner network baselines showed very small motions as in the previous years: 80 % of change rates were smaller than 0.10 mm/a. Roughly one third of the change rates are statistically significant. One baseline was also measured using electronic distance measurements (EDM) and the results fitted well to the times series. The surface levelling network currently consists of 87 fixed measuring points. During 2012 only measuring loops VLJ, ONKALO and Olkiluoto Strait were measured. The results indicated that vertical deformations were small compared to 2011 results. The largest deformations around 0.6 mm upwards existed above the VLJ-repository. The displacement measurements in 2012 consisted of the extensometer measurements in the technical rooms of the ONKALO. Readings were taken continuously once a hour by a

Theoretical Investigations on the Influence of Artificially Altered Rock Mass Properties on Mechanical Excavation

Science.gov (United States)

Hartlieb, Philipp; Bock, Stefan

2018-03-01

This study presents a theoretical analysis of the influence of the rock mass rating on the cutting performance of roadheaders. Existing performance prediction models are assessed for their suitability for forecasting the influence of pre-damaging the rock mass with alternative methods like lasers or microwaves, prior to the mechanical excavation process. Finally, the RMCR model was chosen because it is the only reported model incorporating a range of rock mass properties into its calculations. The results show that even very tough rocks could be mechanically excavated if the occurrence, orientation and condition of joints are favourable for the cutting process. The calculated improvements in the cutting rate (m3/h) are up to 350% for the most favourable cases. In case of microwave irradiation of hard rocks with an UCS of 200 MPa, a reasonable improvement in the performance by 120% can be achieved with as little as an extra 0.7 kWh/m3 (= 1% more energy) compared to cutting only.

Effects of Freezing and Thawing Cycle on Mechanical Properties and Stability of Soft Rock Slope

Directory of Open Access Journals (Sweden)

Yanlong Chen

2017-01-01

Full Text Available To explore the variation laws of mechanical parameters of soft rock and the formed slope stability, an experiment was carried out with collected soft rock material specimens and freezing and thawing cycle was designed. Meanwhile, a computational simulation analysis of the freezing-thawing slope stability was implemented. Key factors that influence the strength of frozen rock specimens were analyzed. Results showed that moisture content and the number of freezing-thawing cycles influenced mechanical parameters of soft rock significantly. With the increase of moisture content, cohesion of frozen soft rock specimens presents a quadratic function decrease and the internal friction angle shows a negative exponential decrease. The stability coefficient of soft rock material slope in seasonal freeze soil area declines continuously. With the increase of freezing and thawing cycle, both cohesion and internal friction angle of soft rock decrease exponentially. The higher the moisture content, the quicker the reduction. Such stability coefficient presents a negative exponential reduction. After three freezing and thawing cycles, the slope stability coefficient only changes slightly. Findings were finally verified by the filed database.

Microwave propagation and absorption and its thermo-mechanical consequences in heterogeneous rocks.

Science.gov (United States)

Meisels, R; Toifl, M; Hartlieb, P; Kuchar, F; Antretter, T

2015-02-10

A numerical analysis in a two-component model rock is presented including the propagation and absorption of a microwave beam as well as the microwave-induced temperature and stress distributions in a consistent way. The analyses are two-dimensional and consider absorbing inclusions (discs) in a non-absorbing matrix representing the model of a heterogeneous rock. The microwave analysis (finite difference time domain - FDTD) is performed with values of the dielectric permittivity typical for hard rocks. Reflections at the discs/matrix interfaces and absorption in the discs lead to diffuse scattering with up to 20% changes of the intensity in the main beam compared to a homogeneous model rock. The subsequent thermo-mechanical finite element (FE) analysis indicates that the stresses become large enough to initiate damage. The results are supported by preliminary experiments on hard rock performed at 2.45 GHz.

[History of the rehabilitation of the deaf child].

Science.gov (United States)

Noyon, P

1995-01-01

As a deaf mute, because mute and more often than not deaf, and then deaf and dumb, because deaf and therefore dumb, the deaf child inevitably deprived of spontaneous speech was considered up to the end of the middle ages as having no possibility of language or of thought, left to the sorry fate of being part of a sporadic population expressing themselves by gestures, a language bereft of past and future, understood only by a few members of the family or occasionally deaf neighbours. During the Renaissance, it appeared that with specific education the deaf child could talk, have a language, and therefore thought. Due merit must be given to 16th century Spain. In the 18th century, France discovered that gestures can also be a language, collated and constructed thanks to the collaboration of the partially deaf. From then on, gestual language flourished in America whilst the rest of Europe continued to prefer oral rehabilitation. With current medical progress, the deaf are no longer deaf. Deafness in the child still exists, however, but there are no longer any mutes. The deaf child can achieve access to language, which may be oral or gestual. The choice between these two modes of expression is still very tropical.

A probabilistic approach to rock mechanical property characterization for nuclear waste repository design

International Nuclear Information System (INIS)

Kim, Kunsoo; Gao, Hang

1996-01-01

A probabilistic approach is proposed for the characterization of host rock mechanical properties at the Yucca Mountain site. This approach helps define the probability distribution of rock properties by utilizing extreme value statistics and Monte Carlo simulation. We analyze mechanical property data of tuff obtained by the NNWSI Project to assess the utility of the methodology. The analysis indicates that laboratory measured strength and deformation data of Calico Hills and Bullfrog tuffs follow an extremal. probability distribution (the third type asymptotic distribution of the smallest values). Monte Carlo simulation is carried out to estimate rock mass deformation moduli using a one-dimensional tuff model proposed by Zimmermann and Finley. We suggest that the results of these analyses be incorporated into the repository design

The Church of Deaf Sociality: Deaf Churchgoing Practices and "Sign Bread and Butter" in Bangalore, India

Science.gov (United States)

Friedner, Michele

2014-01-01

This article ethnographically analyzes the practices of deaf young adults in Bangalore, India. As sign language is not used by families, schools, or other institutions, the church is a crucial educational space. Churchgoing provides deaf young adults with opportunities to orient themselves toward other deaf young adults, to develop new ideas of…

The Deaf Child as a Linguistic Minority.

Science.gov (United States)

Charrow, Veda R.; Wilbur, Ronnie B.

The author offers support for viewing the deaf child as a member of a linguistic minority and considers how this situation affects education of the deaf. Deaf persons are discussed in terms of their intellectual abilities, educational achievement, English competence, and the sociolinguistic factors which point to the existence of a deaf community.…

micro-mechanical experimental investigation and modelling of strain and damage of argillaceous rocks under combined hydric and mechanical loads

International Nuclear Information System (INIS)

Wang, L.

2012-01-01

The hydro-mechanical behavior of argillaceous rocks, which are possible host rocks for underground radioactive nuclear waste storage, is investigated by means of micro-mechanical experimental investigations and modellings. Strain fields at the micrometric scale of the composite structure of this rock, are measured by the combination of environmental scanning electron microscopy, in situ testing and digital image correlation technique. The evolution of argillaceous rocks under pure hydric loading is first investigated. The strain field is strongly heterogeneous and manifests anisotropy. The observed nonlinear deformation at high relative humidity (RH) is related not only to damage, but also to the nonlinear swelling of the clay mineral itself, controlled by different local mechanisms depending on RH. Irreversible deformations are observed during hydric cycles, as well as a network of microcracks located in the bulk of the clay matrix and/or at the inclusion-matrix interface. Second, the local deformation field of the material under combined hydric and mechanical loadings is quantified. Three types of deformation bands are evidenced under mechanical loading, either normal to stress direction (compaction), parallel (microcracking) or inclined (shear). Moreover, they are strongly controlled by the water content of the material: shear bands are in particular prone to appear at high RH states. In view of understanding the mechanical interactions a local scale, the material is modeled as a composite made of non-swelling elastic inclusions embedded in an elastic swelling clay matrix. The internal stress field induced by swelling strain incompatibilities between inclusions and matrix, as well as the overall deformation, is numerically computed at equilibrium but also during the transient stage associated with a moisture gradient. An analytical micro-mechanical model based on Eshelby's solution is proposed. In addition, 2D finite element computations are performed. Results

Failure mechanism and supporting measures for large deformation of Tertiary deep soft rock

Institute of Scientific and Technical Information of China (English)

Guo Zhibiao; Wang Jiong; Zhang Yuelin

2015-01-01

The Shenbei mining area in China contains typical soft rock from the Tertiary Period. As mining depths increase, deep soft rock roadways are damaged by large deformations and constantly need to be repaired to meet safety requirements, which is a great security risk. In this study, the characteristics of deformation and failure of typical roadway were analyzed, and the fundamental reason for the roadway deformation was that traditional support methods and materials cannot control the large deformation of deep soft rock. Deep soft rock support technology was developed based on constant resistance energy absorption using constant resistance large deformation bolts. The correlative deformation mechanisms of surrounding rock and bolt were analyzed to understand the principle of constant resistance energy absorption. The new technology works well on-site and provides a new method for the excavation of roadways in Tertiary deep soft rock.

Mechanical Characteristics Analysis of Surrounding Rock on Anchor Bar Reinforcement

Science.gov (United States)

Gu, Shuan-cheng; Zhou, Pan; Huang, Rong-bin

2018-03-01

Through the homogenization method, the composite of rock and anchor bar is considered as the equivalent material of continuous, homogeneous, isotropic and strength parameter enhancement, which is defined as reinforcement body. On the basis of elasticity, the composite and the reinforcement are analyzed, Based on strengthening theory of surrounding rock and displacement equivalent conditions, the expression of reinforcement body strength parameters and mechanical parameters is deduced. The example calculation shows that the theoretical results are close to the results of the Jia-mei Gao[9], however, closer to the results of FLAC3D numerical simulation, it is proved that the model and surrounding rock reinforcement body theory are reasonable. the model is easy to analyze and calculate, provides a new way for determining reasonable bolt support parameters, can also provides reference for the stability analysis of underground cavern bolting support.

DEAFNESS, RETELLING AND READER FOMATION

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José Marcos Rosendo de Souza

2016-07-01

Full Text Available Research on formation of readers has raised some discussions and change of atitudes, to the development of full readers. But, the methodologies that strive for proficiency of Deaf readers there are scarse. We intend to discuss in this article the formation of a reader Deaf through from an interventional research, with cognitive approach. The reader formation of Deaf will be possible with appropriate method to their peculiarities.

Laboratory rock mechanics testing manual. Public draft

Energy Technology Data Exchange (ETDEWEB)

Shuri, F S; Cooper, J D; Hamill, M L

1981-10-01

Standardized laboratory rock mechanics testing procedures have been prepared for use in the National Terminal Waste Storage Program. The procedures emphasize equipment performance specifications, documentation and reporting, and Quality Assurance acceptance criteria. Sufficient theoretical background is included to allow the user to perform the necessary data reduction. These procedures incorporate existing standards when possible, otherwise they represent the current state-of-the-art. Maximum flexibility in equipment design has been incorporated to allow use of this manual by existing groups and to encourage future improvements.

Suicide in deaf populations: a literature review

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Kapur Navneet

2007-10-01

Full Text Available Abstract Background Studies have found that deaf individuals have higher rates of psychiatric disorder than those who are hearing, while at the same time encountering difficulties in accessing mental health services. These factors might increase the risk of suicide. However, the burden of suicidal behaviour in deaf people is currently unknown. The aim of the present review was to provide a summary of literature on suicidal behaviour with specific reference to deaf individuals. The objectives of the review were to establish the incidence and prevalence of suicidal behaviour in deaf populations; describe risk factors for suicidal behaviour in deaf populations; describe approaches to intervention and suicide prevention that have been used in deaf populations. Methods A number of electronic databases (e.g. Medline, PsycINFO, CINAHL, EMBASE, Dissertation Abstracts International, Web of Science, ComDisDome, ASSIA, Education Sage Full Text, Google Scholar, and the grey literature databases FADE and SIGLE were explored using a combination of key words and medical subject headings as search terms. Reference lists of papers were also searched. The Science and Social Sciences Citation Index electronic databases were used to identify studies that had cited key papers. We also contacted experts and organisations with an interest in the field. Results Very few studies focussed specifically on suicide in deaf populations. Those studies that were included (n = 13 generally involved small and unrepresentative samples. There were limited data on the rate of suicidal behaviour in deaf people. One study reported evidence of hearing impairment in 0.2% of all suicide deaths. Another found that individuals with tinnitus seen in specialist clinics had an elevated rate of suicide compared to the general population. The rates of attempted suicide in deaf school and college students during the previous year ranged from 1.7% to 18%, with lifetime rates as high as 30

Suicide in deaf populations: a literature review.

Science.gov (United States)

Turner, Oliver; Windfuhr, Kirsten; Kapur, Navneet

2007-10-08

Studies have found that deaf individuals have higher rates of psychiatric disorder than those who are hearing, while at the same time encountering difficulties in accessing mental health services. These factors might increase the risk of suicide. However, the burden of suicidal behaviour in deaf people is currently unknown. The aim of the present review was to provide a summary of literature on suicidal behaviour with specific reference to deaf individuals. The objectives of the review were to establish the incidence and prevalence of suicidal behaviour in deaf populations; describe risk factors for suicidal behaviour in deaf populations; describe approaches to intervention and suicide prevention that have been used in deaf populations. A number of electronic databases (e.g. Medline, PsycINFO, CINAHL, EMBASE, Dissertation Abstracts International, Web of Science, ComDisDome, ASSIA, Education Sage Full Text, Google Scholar, and the grey literature databases FADE and SIGLE) were explored using a combination of key words and medical subject headings as search terms. Reference lists of papers were also searched. The Science and Social Sciences Citation Index electronic databases were used to identify studies that had cited key papers. We also contacted experts and organisations with an interest in the field. Very few studies focussed specifically on suicide in deaf populations. Those studies that were included (n = 13) generally involved small and unrepresentative samples. There were limited data on the rate of suicidal behaviour in deaf people. One study reported evidence of hearing impairment in 0.2% of all suicide deaths. Another found that individuals with tinnitus seen in specialist clinics had an elevated rate of suicide compared to the general population. The rates of attempted suicide in deaf school and college students during the previous year ranged from 1.7% to 18%, with lifetime rates as high as 30%. Little evidence was found to suggest that risk factors for

Reading characteristics of deaf and hard-of-hearing pupils

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Karić Jasmina

2012-01-01

Full Text Available Background/Aim. Speech motor mechanisms play a crucial role in the process of demutization, due to the fact that they cover all the elements of the successive development of spech production movements leading to speech formation (socalled kinesthesia in speach. The aim of this study was to estimate the impact of perceptual motor actions on the cognitive process of reading in 130 students in regular schools and schools for the deaf and hard-of-hearing children in the Republic of Serbia. Methods. Kostić and Vladisavljević test consisted of the ten levels weight was used for the assessment of reading speed. To assess understanding of text read by verbal responses, we used three-dimensional adapted reading test of Helene Sax. Results. The triage-articulation test for assessing reading speed (Kostić and Vladisavljević’s test according to the weight of ten levels, revealed that students in regular schools statistically significantly faster read texts as compared to the deaf students. The results of the threedimensional adapted reading test of Helena Sax, show that the words learned by deaf children exist in isolation in their mind, ie, if there is no standard of acoustic performance for graphic image, in deaf child every word, printed or written, is just the sum of letters without meaning. Conclusion. There is a significant difference in text reading speed and its understanding among the children who hear and the deaf and hard of-hearing children. It is essential that in deaf and heard-of hearing children education, apart from the development of speech, parallelly use the concept of semantic processing in order to get each word by the fullness of its content and the possibility of expanding its meaning in a variety of assets.

[Reading characteristics of deaf and hard-of-hearing pupils].

Science.gov (United States)

Karić, Jasmina; Ristić, Sinisa; Medenica, Snezana; Tadić, Vaska; Slavnić, Svetlana

2012-10-01

Speech motor mechanisms play a crucial role in the process of demutization, due to the fact that they cover all the elements of the successive development of spech production movements leading to speech formation (so-called kinesthesia in speach). The aim of this study was to estimate the impact of perceptual motor actions on the cognitive process of reading in 130 students in regular schools and schools for the deaf and hard-of-hearing children in the Republic of Serbia. Kostić and Vladisavljević test consisted of the ten levels weight was used for the assessment of reading speed. To assess understanding of text read by verbal responses, we used three-dimensional adapted reading test of Helene Sax. The triage-articulation test for assessing reading speed (Kostié and Vladisavljević's test according to the weight of ten levels, revealed that students in regular schools statistically significantly faster read texts as compared to the deaf students. The results of the three-dimensional adapted reading test of Helena Sax, show that the words learned by deaf children exist in isolation in their mind, i.e., if there is no standard of acoustic performance for graphic image, in deaf child every word, printed or written, is just the sum of letters without meaning. There is a significant difference in text reading speed and its understanding among the children who hear and the deaf and hard-of-hearing children. It is essential that in deaf and heard-of-hearing children education, apart from the development of speech, parallelly use the concept of semantic processing in order to get each word by the fullness of its content and the possibility of expanding its meaning in a variety of assets.

Apartheid in Deaf Education: Examining Workforce Diversity

Science.gov (United States)

Simms, Laurene; Rusher, Melissa; Andrews, Jean F.; Coryell, Judy

2008-01-01

A survey of 3,227 professionals in 313 deaf education programs found that 22.0% of teachers and 14.5% of administrators were deaf--a less than 10% increase in deaf professionals since 1993. Additionally, 21.7% of teachers and 6.1% of administrators were professionals of color. Of these minority teachers, only 2.5% were deaf persons of color. Only…

Rock mechanics issues and research needs in the disposal of wastes in hydraulic fractures

International Nuclear Information System (INIS)

Doe, T.W.; McClain, W.C.

1984-07-01

The proposed rock mechanics studies outlined in this document are designed to answer the basic questions concerning hydraulic fracturing for waste disposal. These questions are: (1) how can containment be assured for Oak Ridge or other sites; and (2) what is the capacity of a site. The suggested rock mechanics program consists of four major tasks: (1) numerical modeling, (2) laboratory testing, (3) field testing, and (4) monitoring. These tasks are described

Rock Mechanics Studies During Continuous Miner Bases Coal Pillar Extraction in Indian Coalfields

Czech Academy of Sciences Publication Activity Database

Ram, S.; Kumar, D.; Koníček, Petr; Singh, A. K.; Kumar, R.; Singh, A. Kr.; Singh, R.

2015-01-01

Roč. 111, April 2014-March 2015 (2015), s. 89-104 ISSN 0254-8003 Institutional support: RVO:68145535 Keywords : mining * mechanized depillaring scenario * rock mechanics Subject RIV: DH - Mining, incl. Coal Mining

Deaf Culture in Republic of Korea

OpenAIRE

Šlamborová, Zdeňka

2017-01-01

The aim is to focus on development of Deaf culture in the Republic of Korea. The thesis focuses not only on hearing impairment and the distribution of hearing loss categories from a medical point of view, but also the Deaf community and the importance of their own identities, which played a major role in the Deaf culture. It will also point to changes in Korean majority society's view on the Deaf community, and what caused Korean society's view to change. The part of this thesis is also focus...

Neural networks mediating sentence reading in the deaf

Directory of Open Access Journals (Sweden)

Elizabeth Ann Hirshorn

2014-06-01

Full Text Available The present work addresses the neural bases of sentence reading in deaf populations. To better understand the relative role of deafness and English knowledge in shaping the neural networks that mediate sentence reading, three populations with different degrees of English knowledge and depth of hearing loss were included – deaf signers, oral deaf and hearing individuals. The three groups were matched for reading comprehension and scanned while reading sentences. A similar neural network of left perisylvian areas was observed, supporting the view of a shared network of areas for reading despite differences in hearing and English knowledge. However, differences were observed, in particular in the auditory cortex, with deaf signers and oral deaf showing greatest bilateral superior temporal gyrus (STG recruitment as compared to hearing individuals. Importantly, within deaf individuals, the same STG area in the left hemisphere showed greater recruitment as hearing loss increased. To further understand the functional role of such auditory cortex re-organization after deafness, connectivity analyses were performed from the STG regions identified above. Connectivity from the left STG toward areas typically associated with semantic processing (BA45 and thalami was greater in deaf signers and in oral deaf as compared to hearing. In contrast, connectivity from left STG toward areas identified with speech-based processing was greater in hearing and in oral deaf as compared to deaf signers. These results support the growing literature indicating recruitment of auditory areas after congenital deafness for visually-mediated language functions, and establish that both auditory deprivation and language experience shape its functional reorganization. Implications for differential reliance on semantic vs. phonological pathways during reading in the three groups is discussed.

Ethics, Deafness, and New Medical Technologies

Science.gov (United States)

Hintermair, Manfred; Albertini, John A.

2005-01-01

In the last 50 years, several new technologies have become enormously important within the Deaf community and have helped significantly to improve deaf people's lives in a hearing world. Current public attention and admiration, however, seems unduly focused on medical technologies that promise to solve "the problem" of being deaf. One reason for…

Studying physical properties of deformed intact and fractured rocks by micro-scale hydro-mechanical-seismicity model

Science.gov (United States)

Raziperchikolaee, Samin

The pore pressure variation in an underground formation during hydraulic stimulation of low permeability formations or CO2 sequestration into saline aquifers can induce microseismicity due to fracture generation or pre-existing fracture activation. While the analysis of microseismic data mainly focuses on mapping the location of fractures, the seismic waves generated by the microseismic events also contain information for understanding of fracture mechanisms based on microseismic source analysis. We developed a micro-scale geomechanics, fluid-flow and seismic model that can predict transport and seismic source behavior during rock failure. This model features the incorporation of microseismic source analysis in fractured and intact rock transport properties during possible rock damage and failure. The modeling method considers comprehensive grains and cements interaction through a bonded-particle-model. As a result of grain deformation and microcrack development in the rock sample, forces and displacements in the grains involved in the bond breakage are measured to determine seismic moment tensor. In addition, geometric description of the complex pore structure is regenerated to predict fluid flow behavior of fractured samples. Numerical experiments are conducted for different intact and fractured digital rock samples, representing various mechanical behaviors of rocks and fracture surface properties, to consider their roles on seismic and transport properties of rocks during deformation. Studying rock deformation in detail provides an opportunity to understand the relationship between source mechanism of microseismic events and transport properties of damaged rocks to have a better characterizing of fluid flow behavior in subsurface formations.

The paleomagnetic field and possible mechanisms for the formation of reversed rock magnetization

International Nuclear Information System (INIS)

Trukhin, Vladimir I.; Bezaeva, Natalia; Kurochkina, Evgeniya

2006-01-01

Investigations of ancient magnetized rocks show that their natural remanent magnetization (NRM) can be oriented in the direction of modern geomagnetic field (GMF) as well as in the opposite direction. It is supposed that reversed NRM is related to reversals of the GMF in the past geological periods. During reversals, the strength of the GMF is near zero and can cause the destruction of living organisms as a result of powerful space and solar radiation, which, in the absence of the GMF, can reach the Earth's surface. That is why the question of reality of the GMF reversals is of global ecological importance. There is also another natural mechanism for the formation of reversed NRM-the self-reversal of magnetization as a result of thermomagnetization of rocks. In the paper, both natural processes for the formation of reversed NRM in rocks are discussed, and the results of experimental research on the physical mechanism of self-reversal of magnetization in continental and oceanic rocks are presented. The results of computer modeling of the self-reversal phenomenon are also presented

The paleomagnetic field and possible mechanisms for the formation of reversed rock magnetization

Energy Technology Data Exchange (ETDEWEB)

Trukhin, Vladimir I. [Faculty of Physics, Moscow State University, 119992 Moscow (Russian Federation)]. E-mail: trukhin@phys.msu.ru; Bezaeva, Natalia [Faculty of Physics, Moscow State University, 119992 Moscow (Russian Federation); Kurochkina, Evgeniya [Faculty of Physics, Moscow State University, 119992 Moscow (Russian Federation)

2006-05-15

Investigations of ancient magnetized rocks show that their natural remanent magnetization (NRM) can be oriented in the direction of modern geomagnetic field (GMF) as well as in the opposite direction. It is supposed that reversed NRM is related to reversals of the GMF in the past geological periods. During reversals, the strength of the GMF is near zero and can cause the destruction of living organisms as a result of powerful space and solar radiation, which, in the absence of the GMF, can reach the Earth's surface. That is why the question of reality of the GMF reversals is of global ecological importance. There is also another natural mechanism for the formation of reversed NRM-the self-reversal of magnetization as a result of thermomagnetization of rocks. In the paper, both natural processes for the formation of reversed NRM in rocks are discussed, and the results of experimental research on the physical mechanism of self-reversal of magnetization in continental and oceanic rocks are presented. The results of computer modeling of the self-reversal phenomenon are also presented.

BILINGUALISM: MULTICULTURALISM HOLOPRAXIOLOGY OF THE VENEZUELAN DEAF

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Héctor Florencio Martínez Pérez

2014-04-01

Full Text Available The formation of the child has been made regularly and without many prejudices or tbacks,  until this had some physical characteristic or perceptual, who twisted his attention.  To those who were born with the inability to listen or hear properly, excluded in all respects. At the end of the 20th century, the deaf began to defend their identity and differed between Deafness (lack of hearing of deafness, with "S", which is a socio-anthropological perspective, which includes the use of sign language and the learning of reading and writing of the Spanish (bilingualism in their training. This research had as general objective to unveil bilingualism from an intercultural intersubjectivity of the deaf in Venezuela by applying a qualitative related paradigm with methodology fenomenologica-hermeneutica of Max Van Manen. The information collected observing and interviewing in depth (12 deaf students, parents or representatives (6, (3 researchers and educational specialists deaf and listeners (12. To analyze and triangulate information, obtained the following conclusions about the bilingual deaf: their physical and intellectual abilities are exactly the same to the listeners;  they can achieve the necessary qualification for any job; is required the language of signs so that you can put into practice the language; those who have the organizational capacity to develop oral language, it should not hinder him this opportunity, without detriment to the learning of the language of signs and the systematic training of the deaf teachers and deaf family, educational managers, political and employer of the deaf is essentially required.

Experimental study on influence of carbon dioxide on porous structure and mechanical properties of shale rock

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Danuta Miedzińska

2017-12-01

Full Text Available Shale rocks are geological formations which can be unconventional gas reservoirs. During their interaction with carbon dioxide, which can be used as a fracturing fluid in shale gas recovery process, many phenomena take place that can influence rock structure and mechanical properties. The research on changes in rock structure under super critical carbon dioxide interaction and their influence of shale properties were presented in the paper. The structural tests were carried out with the use of microscopic techniques with different resolutions of visualization. The uniaxial compression test was applied as a mechanical properties’ assessment experiment. As a result of research, some dependence was observed. The bigger decrease was in porosity after infiltration in lower zooms, the bigger increase in porosity in high zooms and mechanical properties was noticed. Keywords: geomechanics, shale rock, carbon dioxide

Deaf Stigma: Links Between Stigma and Well-Being Among Deaf Emerging Adults.

Science.gov (United States)

Mousley, Victoria L; Chaudoir, Stephenie R

2018-05-31

Although stigma has been linked to suboptimal psychological and physical health outcomes in marginalized communities such as persons of color, sexual minorities, and people living with HIV/AIDS, no known research has examined these effects among deaf individuals. In the present research, we examine the associations between anticipated, enacted, and internalized stigma and psychological well-being (i.e., depressive symptoms, anxiety) and physical well-being (i.e., quality of life, alcohol use) among a sample of 171 deaf emerging adults. Furthermore, we consider whether trait resilience and benefit-finding moderate these effects. Enacted stigma, but not anticipated or internalized stigma, was related to worse depressive symptoms, anxiety, and quality of life. However, none of these variables predicted alcohol use and neither resilience nor benefit-finding moderated these effects. These findings are consistent with other research among marginalized populations, though they are also the first to suggest that experiences of discrimination are related to suboptimal well-being among deaf emerging adults. The discussion considers how these findings may illuminate the potential causes of disparities in well-being between hearing and deaf emerging adults.

Deaf Mothers and Breastfeeding: Do Unique Features of Deaf Culture and Language Support Breastfeeding Success?

Science.gov (United States)

Chin, Nancy P.; Cuculick, Jess; Starr, Matthew; Panko, Tiffany; Widanka, Holly; Dozier, Ann

2014-01-01

Background Deaf mothers who use American Sign Language (ASL) consider themselves a linguistic minority group, with specific cultural practices. Rarely has this group been engaged in infant-feeding research. Objectives To understand how ASL-using Deaf mothers learn about infant feeding and to identify their breastfeeding challenges. Methods Using a community-based participatory research (CBPR) approach we conducted four focus groups with Deaf mothers who had at least one child 0–5 years. A script was developed using a social ecological model (SEM) to capture multiple levels of influence. All groups were conducted in ASL, filmed, and transcribed into English. Deaf and hearing researchers analyzed data by coding themes within each SEM level. Results Fifteen mothers participated. All had initiated breastfeeding with their most recent child. Breastfeeding duration for eight of the mothers was three weeks to 12 months. Seven of the mothers were still breastfeeding, the longest for 19 months. Those mothers who breastfed longer described a supportive social environment and the ability to surmount challenges. Participants described characteristics of Deaf culture such as direct communication, sharing information, use of technologies, language access through interpreters and ASL-using providers, and strong self-advocacy skills. Finally, mothers used the sign ‘struggle’ to describe their breastfeeding experience. The sign implies a sustained effort over time which leads to success. Conclusions In a setting with a large population of Deaf women and ASL-using providers, we identified several aspects of Deaf culture and language which support BF mothers across institutional, community, and interpersonal levels of the SEM. PMID:23492762

The Usability of Rock-Like Materials for Numerical Studies on Rocks

Science.gov (United States)

Zengin, Enes; Abiddin Erguler, Zeynal

2017-04-01

The approaches of synthetic rock material and mass are widely used by many researchers for understanding the failure behavior of different rocks. In order to model the failure behavior of rock material, researchers take advantageous of different techniques and software. But, the majority of all these instruments are based on distinct element method (DEM). For modeling the failure behavior of rocks, and so to create a fundamental synthetic rock material model, it is required to perform related laboratory experiments for providing strength parameters. In modelling studies, model calibration processes are performed by using parameters of intact rocks such as porosity, grain size, modulus of elasticity and Poisson ratio. In some cases, it can be difficult or even impossible to acquire representative rock samples for laboratory experiments from heavily jointed rock masses and vuggy rocks. Considering this limitation, in this study, it was aimed to investigate the applicability of rock-like material (e.g. concrete) to understand and model the failure behavior of rock materials having complex inherent structures. For this purpose, concrete samples having a mixture of %65 cement dust and %35 water were utilized. Accordingly, intact concrete samples representing rocks were prepared in laboratory conditions and their physical properties such as porosity, pore size and density etc. were determined. In addition, to acquire the mechanical parameters of concrete samples, uniaxial compressive strength (UCS) tests were also performed by simultaneously measuring strain during testing. The measured physical and mechanical properties of these extracted concrete samples were used to create synthetic material and then uniaxial compressive tests were modeled and performed by using two dimensional discontinuum program known as Particle Flow Code (PFC2D). After modeling studies in PFC2D, approximately similar failure mechanism and testing results were achieved from both experimental and

Deafness and Hearing Loss.

Science.gov (United States)

National Information Center for Children and Youth with Disabilities, Washington, DC.

This brief overview provides information on the definition, incidence, and characteristics of children with hearing impairments and deafness. The federal definitions of hearing impairment and deafness are provided. The different types of hearing loss are noted, including: (1) conductive (caused by diseases or obstructions in the outer or middle…

A Psycholinguistic Analysis of "Deaf English."

Science.gov (United States)

Charrow, Veda R.

The purpose of this study was to identify and provide normative data for weighting of those nonstandard linguistic features that make up deaf English. Subjects were prelingually or congenitally deaf high school students from the California School for the Deaf and a control group of normal-hearing fourth graders from a California public school.…

Deaf on the Lifeline of Mumbai

Science.gov (United States)

Kusters, Annelies

2009-01-01

This article is a result of my MSc Deaf Studies dissertation that is situated on an intersection between Deaf geography, anthropology and Deafhood theory. During five weeks of participatory observation and interviews in Mumbai, my attention was drawn to the city's lifeline: the suburban train system. It appeared that Deaf people tend to travel in…

Deafness-related self-perceptions and psychological well-being in deaf adolescents with cochlear implants.

Science.gov (United States)

Mance, Jennifer; Edwards, Lindsey

2012-05-01

This study aimed to examine the relationship between psychological well-being and self-perception in adolescents with cochlear implants, in relation to their perceptions of hearing, deaf signing, and orally communicating deaf peers. Self-perceptions were examined in 22 cochlear implant users aged 12-18 years, using the repertory grid technique that allows the respondent to generate personally relevant 'identity' constructs. Psychological well-being was assessed using the Beck Youth Inventory, a series of five self-report questionnaires assessing anxiety, depression, disruptive behaviour, anger, and self-esteem. Correlational analyses indicated that perceiving oneself as close to any peer, irrespective of which peer, was associated with better psychological well-being. There was also a significant positive association between perceived degree of similarity specifically to hearing peers, and psychological well-being. The closer the implanted adolescents perceived themselves to be to their hearing peers, the better their overall psychological well-being. In contrast, perceiving oneself as more similar to deaf signing peers or deaf oral peers was not significantly associated with psychological well-being. The findings are discussed in the context of previous research on social comparison, Deaf identity, and the aims of cochlear implantation.

Modelling of crustal rock mechanics for radioactive waste storage in Fennoscandia - problem definition

International Nuclear Information System (INIS)

Stephansson, O.

1987-05-01

Existing knowledge of crustal stresses for Fennoscandia is presented. Generic, two-dimensional models are proposed for vertical and planar sections of a traverse having a direction NW-SE in Northern Fennoscandia. The proposed traverse will include the major neotectonic structures at Lansjaerv and Paervie, respectively, and also the study site for storage of spent nuclear fuel at Kamlunge. The influence of glaciation, deglaciation, glacial rebound on crustal rock mechanics and stability is studied for the modelling work. Global models, with a length of roughly 100 km, will increase our over all understanding of the change in stresses and deformations. These can provide boundary conditions for regional and near-field models. Properties of strength and stiffness of intact granitic rock masses, faults and joints are considered in the modelling of the crustal rock mechanics for any of the three models described. (orig./HP)

The Attitudes of the Holy Land Institute for the Deaf-Salt, Jordan towards Deaf Socially and Educationally

Science.gov (United States)

Ziadat, Ayed H.; Atiyat, Fatima A.

2018-01-01

The study aimed to recognize the attitudes of the Holy Land Institute for the Deaf-Salt, Jordan towards Deaf Socially and Educationally in the academic year 2016-2017, which consists of instructional and vocational staff towards deaf socially and educationally according to some variables (gender, age, the level of education). The sample of the…

Experimental Studies on the Mechanical Behaviour of Rock Joints with Various Openings

Science.gov (United States)

Li, Y.; Oh, J.; Mitra, R.; Hebblewhite, B.

2016-03-01

The mechanical behaviour of rough joints is markedly affected by the degree of joint opening. A systematic experimental study was conducted to investigate the effect of the initial opening on both normal and shear deformations of rock joints. Two types of joints with triangular asperities were produced in the laboratory and subjected to compression tests and direct shear tests with different initial opening values. The results showed that opened rock joints allow much greater normal closure and result in much lower normal stiffness. A semi-logarithmic law incorporating the degree of interlocking is proposed to describe the normal deformation of opened rock joints. The proposed equation agrees well with the experimental results. Additionally, the results of direct shear tests demonstrated that shear strength and dilation are reduced because of reduced involvement of and increased damage to asperities in the process of shearing. The results indicate that constitutive models of rock joints that consider the true asperity contact area can be used to predict shear resistance along opened rock joints. Because rock masses are loosened and rock joints become open after excavation, the model suggested in this study can be incorporated into numerical procedures such as finite-element or discrete-element methods. Use of the model could then increase the accuracy and reliability of stability predictions for rock masses under excavation.

Deaf/LGBTQ Intersectional Invisibility in Schools: The Lived Experiences of Deaf Lesbian Students of Color at a School for the Deaf

Science.gov (United States)

Dunne, Courtney M.

2013-01-01

Historically, American society has had conflicting views on the nature and nurture of Deaf people and Lesbian, Gay, Bisexual, Transgender, Queer (LGBTQ) people. In the context of majority cultures and societies in history, the reality of Deaf and LGBTQ people's lives has often been summarized in general terms such as invisibility and oppression.…

Failure mechanism and coupled static-dynamic loading theory in deep hard rock mining: A review

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Xibing Li

2017-08-01

Full Text Available Rock failure phenomena, such as rockburst, slabbing (or spalling and zonal disintegration, related to deep underground excavation of hard rocks are frequently reported and pose a great threat to deep mining. Currently, the explanation for these failure phenomena using existing dynamic or static rock mechanics theory is not straightforward. In this study, new theory and testing method for deep underground rock mass under coupled static-dynamic loading are introduced. Two types of coupled loading modes, i.e. “critical static stress + slight disturbance” and “elastic static stress + impact disturbance”, are proposed, and associated test devices are developed. Rockburst phenomena of hard rocks under coupled static-dynamic loading are successfully reproduced in the laboratory, and the rockburst mechanism and related criteria are demonstrated. The results of true triaxial unloading compression tests on granite and red sandstone indicate that the unloading can induce slabbing when the confining pressure exceeds a certain threshold, and the slabbing failure strength is lower than the shear failure strength according to the conventional Mohr-Column criterion. Numerical results indicate that the rock unloading failure response under different in situ stresses and unloading rates can be characterized by an equivalent strain energy density. In addition, we present a new microseismic source location method without premeasuring the sound wave velocity in rock mass, which can efficiently and accurately locate the rock failure in hard rock mines. Also, a new idea for deep hard rock mining using a non-explosive continuous mining method is briefly introduced.

Cross-modal activation of auditory regions during visuo-spatial working memory in early deafness.

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Ding, Hao; Qin, Wen; Liang, Meng; Ming, Dong; Wan, Baikun; Li, Qiang; Yu, Chunshui

2015-09-01

causality analysis revealed that, compared to the hearing controls, the deaf subjects had an enhanced net causal flow from the frontal eye field to the superior temporal gyrus. These findings indicate that a top-down mechanism may better account for the cross-modal activation of auditory regions in early deaf subjects.See MacSweeney and Cardin (doi:10/1093/awv197) for a scientific commentary on this article. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Deafness and the Riddle of Identity

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Davis, Lennard J.

2007-01-01

In the past, much discrimination against deaf people was based on the assumption that they were in fact people without language--that is, dumb. "Dumb" carried the sense of being not only mute but also stupid, as in a "dumb" animal. The status of deaf people has changed in important ways, as deaf activists and scholars have reshaped the idea of…

Ethical Issues in Conducting Research With Deaf Populations

Science.gov (United States)

Schlehofer, Deirdre; Thew, Denise

2013-01-01

Deaf American Sign Language (ASL) users represent a small population at risk for marginalization from research and surveillance activities resulting from cultural, language, and ethical challenges. The Deaf community’s view of deafness as a cultural identity, rather than a disability, contradicts the medical community’s perception of deafness as a disease or deficiency in need of correction or elimination. These differences continue to have significant cultural and social implications within the Deaf community, resulting in mistrust of research opportunities. Two particularly contentious ethical topics for the Deaf community are the absence of community representation in genetic research and the lack of accessible informed consents and research materials. This article outlines a series of innovative strategies and solutions to these issues, including the importance of community representation and collaboration with researchers studying deaf populations. PMID:24134363

The role of music in deaf culture: deaf students' perception of emotion in music.

Science.gov (United States)

Darrow, Alice-Ann

2006-01-01

Although emotional interpretation of music is an individual and variable experience, researchers have found that typical listeners are quite consistent in associating basic or primary emotions such as happiness, sadness, fear, and anger to musical compositions. It has been suggested that an individual with a sensorineural hearing loss, or any lesion in auditory perceptors in the brain may have trouble perceiving music emotionally. The purpose of the present study was to investigate whether students with a hearing loss who associate with the deaf culture, assign the same emotions to music as students without a hearing loss. Sixty-two elementary and junior high students at a Midwestern state school for the deaf and students at neighboring elementary and junior high schools served as participants. Participants at the state school for the deaf had hearing losses ranging from moderate to severe. Twelve film score excerpts, composed to depict the primary emotions-happiness, sadness, and fear, were used as the musical stimuli. Participants were asked to assign an emotion to each excerpt. Results indicated a significant difference between the Deaf and typical hearing participants' responses, with hearing participants' responses more in agreement with the composers' intent. No significant differences were found for age or gender. Analyses of the Deaf participants' responses indicate that timbre, texture, and rhythm are perhaps the musical elements most influential in transmitting emotion to persons with a hearing loss. Adaptive strategies are suggested for assisting children who are deaf in accessing the elements of music intended to portray emotion.

Stigma in Mothers of Deaf Children

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Hossein Ebrahimi

2015-03-01

Full Text Available Introduction: A deaf child creates a feeling of stigma in many hearing parents. Stigma in mothers can have a negative impact on a child’s treatment and rehabilitation process. Therefore, this study was conducted to evaluate the extent of stigma in mothers with deaf children.  Materials and Methods: This descriptive, cross-sectional study was conducted in 2013 among 90 mothers with deaf children. The data-collection instrument included the stigma scale in the mothers of children with disabilities. The reliability and validity of the instrument were confirmed through content validity and Cronbach’s alpha coefficient (α=86%, respectively. Data were analyzed using SPSS-15 software.   Results: Results showed that most mothers suffer from stigma due to having a deaf child. The mean stigma score was 96.48 ±27.72. In total, 24.4% of mothers reported that they had received strange and mocking looks; 72.2% regarded child deafness as a sign of divine retribution; and 33.3% felt ashamed of their child’s deafness. There was an inverse relationship between the mother’s level of education and mean stigma scores (P

Deafness, Thought Bubbles, and Theory-of-Mind Development

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Wellman, Henry M.; Peterson, Candida C.

2013-01-01

The processes and mechanisms of theory-of-mind development were examined via a training study of false-belief conceptions in deaf children of hearing parents (N = 43). In comparison to 2 different control conditions, training based on thought-bubble instruction about beliefs was linked with improved false-belief understanding as well as progress…

Stigma in mothers of deaf children.

Science.gov (United States)

Ebrahimi, Hossein; Mohammadi, Eissa; Mohammadi, Mohammad Ali; Pirzadeh, Akbar; Mahmoudi, Hamzeh; Ansari, Ismail

2015-03-01

A deaf child creates a feeling of stigma in many hearing parents. Stigma in mothers can have a negative impact on a child's treatment and rehabilitation process. Therefore, this study was conducted to evaluate the extent of stigma in mothers with deaf children. This descriptive, cross-sectional study was conducted in 2013 among 90 mothers with deaf children. The data-collection instrument included the stigma scale in the mothers of children with disabilities. The reliability and validity of the instrument were confirmed through content validity and Cronbach's alpha coefficient (α=86%), respectively. Data were analyzed using SPSS-15 software. Results showed that most mothers suffer from stigma due to having a deaf child. The mean stigma score was 96.48 ±27.72. In total, 24.4% of mothers reported that they had received strange and mocking looks; 72.2% regarded child deafness as a sign of divine retribution; and 33.3% felt ashamed of their child's deafness. There was an inverse relationship between the mother's level of education and mean stigma scores (P<0.033). The stigma score was higher in mothers who were living independently of their relatives (P<0.029). The mean stigma score in mothers of children with a cochlear implant was lower than that of mothers of children with earphones (86.70 vs. 99.64), and this difference tended towards significance (P=0.057). This study showed that half of all mothers with deaf children were scorned and felt ashamed of having a deaf child in the family because of the stigma. The majority of mothers with deaf children felt stigmatized, and only their education and residency status affected this issue. The mothers of cochlear-implanted children perceived less stigma. Due to the various social and psychological problems caused by hearing impairment, it is necessary to consider the emotional health and psychological state of the mothers in addition to rehabilitation programs and standard services for the children themselves.

Geo-Mechanical Characterization of Carbonate Rock Masses by Means of Laser Scanner Technique

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Palma, Biagio; Parise, Mario; Ruocco, Anna

2017-12-01

Knowledge of the geometrical and structural setting of rock masses is crucial to evaluate the stability and to design the most suitable stabilization works. In this work we use the Terrestrial Laser Scanning (TLS) at the site of the Grave of the Castellana Caves, a famous show cave in southern Italy. The Grave is the natural access to the cave system, produced by collapse of the vault, due to upward progression of instabilities in the carbonate rock masses. It is about 55-m high, bell-shaped, with maximum width of 120 m. Aim of the work is the characterization of carbonate rock masses from the structural and geo-mechanical standpoints through the use of innovative survey techniques. TLS survey provides a product consisting of millions of geo-referenced points, to be managed in space, to become a suitable database for the morphological and geological-structural analysis. Studying by means of TLS a rock face, partly inaccessible or located in very complex environments, allows to investigate slopes in their overall areal extent, thus offering advantages both as regards safety of the workers and time needed for the survey. In addition to TLS, the traditional approach was also followed by performing scanlines surveys along the rims of the Grave, following the ISRM recommendations for characterization of discontinuity in rock masses. A quantitative comparison among the data obtained by TLS technique and those deriving from the classical geo-mechanical survey is eventually presented, to discuss potentiality of drawbacks of the different techniques used for surveying the rock masses.

Waardenburg syndrome in the Turkish deaf population.

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Silan, F; Zafer, C; Onder, I

2006-01-01

Waardenburg Syndrome (WS) is an autosomal, dominantly inherited disorder that accounts for more than 2% cases of congenital deafness. The aim of this study is to determine the WS incidence among deaf pupils. Dysmorphological examination was performed on 720 children who were attending 7 special schools in Turkey and who had hearing disabilities. All subjects in the study were examined for WS diagnostic criteria. We detected 49 patients (6.8%) with WS among the 720 children examined. Six patients had WS type 1 (12.2%) and 43 had type 2 (87.8%). We observed 2 to 5 major diagnostic criteria for WS. Out of all the subjects in the study, only two patients have deaf first degree relatives. All subjects had been previously examined by physicians for deafness but none of them had been then diagnosed to have Waardenburg Syndrome. Instead, they were all misdiagnosed as to have nonsyndromic deafness. Awareness of WS diagnostic criteria by the physicans will provide accurate diagnosis for many deaf pupils and their first degree relatives who are able-to-hear WS patients and whose children are at risk for deafness.

Influence of geological factors on the mechanical properties of rock in the Palo Duro Basin

International Nuclear Information System (INIS)

Cregger, D.M.; Corkum, D.H.; Gokce, A.O.; Peck, J.H.

1985-01-01

Sedimentary formations in the Palo Duro Basin of the Texas Panhandle exhibit a variety of petrofabrics which contribute to different mechanical behavior. Similarly classified rock core specimens, upon closer inspection, are comprised of different textures and slight compositional variations. The resultant rock mass characteristics interpreted from laboratory tests and deep borehole geophysical logs are seen to be a direct result of the depositional environment and geologic history. Depositional environments include chemical precipitation in shallow brine pools, basin filling with terrigenous or eolian supply of clastics, restricted circulation, and transgression of normal marine waters. Geochemical transformations of the deposits, (diagenesis), can or may result in profound changes to the mechanical properties of the rock. Structural deformation of the bedded salts is slight and may be far less important in its effect on mechanical properties than diagenetic changes

Numerical simulation of mechanisms of deformation,failure and energy dissipation in porous rock media subjected to wave stresses

Institute of Scientific and Technical Information of China (English)

无

2010-01-01

The pore characteristics,mineral compositions,physical and mechanical properties of the subarkose sandstones were acquired by means of CT scan,X-ray diffraction and physical tests.A few physical models possessing the same pore characteristics and matrix properties but different porosities compared to the natural sandstones were developed.The 3D finite element models of the rock media with varied porosities were established based on the CT image processing of the physical models and the MIMICS software platform.The failure processes of the porous rock media loaded by the split Hopkinson pressure bar(SHPB) were simulated by satisfying the elastic wave propagation theory.The dynamic responses,stress transition,deformation and failure mechanisms of the porous rock media subjected to the wave stresses were analyzed.It is shown that an explicit and quantitative analysis of the stress,strain and deformation and failure mechanisms of porous rocks under the wave stresses can be achieved by using the developed 3D finite element models.With applied wave stresses of certain amplitude and velocity,no evident pore deformation was observed for the rock media with a porosity less than 15%.The deformation is dominantly the combination of microplasticity(shear strain),cracking(tensile strain) of matrix and coalescence of the cracked regions around pores.Shear stresses lead to microplasticity,while tensile stresses result in cracking of the matrix.Cracking and coalescence of the matrix elements in the neighborhood of pores resulted from the high transverse tensile stress or tensile strain which exceeded the threshold values.The simulation results of stress wave propagation,deformation and failure mechanisms and energy dissipation in porous rock media were in good agreement with the physical tests.The present study provides a reference for analyzing the intrinsic mechanisms of the complex dynamic response,stress transit mode,deformation and failure mechanisms and the disaster

Coupled hydro-thermo-mechanical modeling of hydraulic fracturing in quasi-brittle rocks using BPM-DEM

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Ingrid Tomac

2017-02-01

Full Text Available This paper presents an improved understanding of coupled hydro-thermo-mechanical (HTM hydraulic fracturing of quasi-brittle rock using the bonded particle model (BPM within the discrete element method (DEM. BPM has been recently extended by the authors to account for coupled convective–conductive heat flow and transport, and to enable full hydro-thermal fluid–solid coupled modeling. The application of the work is on enhanced geothermal systems (EGSs, and hydraulic fracturing of hot dry rock (HDR is studied in terms of the impact of temperature difference between rock and a flowing fracturing fluid. Micro-mechanical investigation of temperature and fracturing fluid effects on hydraulic fracturing damage in rocks is presented. It was found that fracture is shorter with pronounced secondary microcracking along the main fracture for the case when the convective–conductive thermal heat exchange is considered. First, the convection heat exchange during low-viscosity fluid infiltration in permeable rock around the wellbore causes significant rock cooling, where a finger-like fluid infiltration was observed. Second, fluid infiltration inhibits pressure rise during pumping and delays fracture initiation and propagation. Additionally, thermal damage occurs in the whole area around the wellbore due to rock cooling and cold fluid infiltration. The size of a damaged area around the wellbore increases with decreasing fluid dynamic viscosity. Fluid and rock compressibility ratio was found to have significant effect on the fracture propagation velocity.

Deaf Culture and Competing Discourses in a Residential School for the Deaf: "Can Do" versus "Can't Do"

Science.gov (United States)

O'Brien, Catherine A.; Placier, Peggy

2015-01-01

From an ethnographic case study of a state-funded residential school for the Deaf, the authors employed Critical Discourse Analysis to identify competing discourses in the talk of educators. These discourses are embedded in the historical oppression and labeling of deaf people as disabled and the development of Deaf culture as a counter-discourse.…

THM-coupled modeling of selected processes in argillaceous rock relevant to rock mechanics; THM-Gekoppelte Modellierung ausgewaehlter gesteinsmechanisch relevanter Prozesse im Tongestein

Energy Technology Data Exchange (ETDEWEB)

Czaikowski, Oliver [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Braunschweig (Germany). Repository Safety Research Div.

2012-08-15

Scientific investigations in European countries other than Germany concentrate not only on granite formations (Switzerland, Sweden) but also on argillaceous rock formations (France, Switzerland, Belgium) to assess their suitability as host and barrier rock for the final storage of radioactive waste. In Germany, rock salt has been under thorough study as a host rock over the past few decades. According to a study by the German Federal Institute for Geosciences and Natural Resources, however, not only salt deposits but also argillaceous rock deposits are available at relevant depths and of extensions in space which make final storage of high-level radioactive waste basically possible in Germany. Equally qualified findings about the suitability/unsuitability of non-saline rock formations require fundamental studies to be conducted nationally because of the comparatively low level of knowledge. The article presents basic analyses of coupled mechanical and hydraulic properties of argillaceous rock formations as host rock for a repository. The interaction of various processes is explained on the basis of knowledge derived from laboratory studies, and open problems are deduced. For modeling coupled processes, a simplified analytical computation method is proposed and compared with the results of numerical simulations, and the limits to its application are outlined. (orig.)

FE Analysis of Rock with Hydraulic-Mechanical Coupling Based on Continuum Damage Evolution

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Yongliang Wang

2016-01-01

Full Text Available A numerical finite element (FE analysis technology is presented for efficient and reliable solutions of rock with hydraulic-mechanical (HM coupling, researching the seepage characteristics and simulating the damage evolution of rock. To be in accord with the actual situation, the rock is naturally viewed as heterogeneous material, in which Young’s modulus, permeability, and strength property obey the typical Weibull distribution function. The classic Biot constitutive relation for rock as porous medium is introduced to establish a set of equations coupling with elastic solid deformation and seepage flow. The rock is subsequently developed into a novel conceptual and practical model considering the damage evolution of Young’s modulus and permeability, in which comprehensive utilization of several other auxiliary technologies, for example, the Drucker-Prager strength criterion, the statistical strength theory, and the continuum damage evolution, yields the damage variable calculating technology. To this end, an effective and reliable numerical FE analysis strategy is established. Numerical examples are given to show that the proposed method can establish heterogeneous rock model and be suitable for different load conditions and furthermore to demonstrate the effectiveness and reliability in the seepage and damage characteristics analysis for rock.

Flexible parallel implicit modelling of coupled thermal-hydraulic-mechanical processes in fractured rocks

Science.gov (United States)

Cacace, Mauro; Jacquey, Antoine B.

2017-09-01

Theory and numerical implementation describing groundwater flow and the transport of heat and solute mass in fully saturated fractured rocks with elasto-plastic mechanical feedbacks are developed. In our formulation, fractures are considered as being of lower dimension than the hosting deformable porous rock and we consider their hydraulic and mechanical apertures as scaling parameters to ensure continuous exchange of fluid mass and energy within the fracture-solid matrix system. The coupled system of equations is implemented in a new simulator code that makes use of a Galerkin finite-element technique. The code builds on a flexible, object-oriented numerical framework (MOOSE, Multiphysics Object Oriented Simulation Environment) which provides an extensive scalable parallel and implicit coupling to solve for the multiphysics problem. The governing equations of groundwater flow, heat and mass transport, and rock deformation are solved in a weak sense (either by classical Newton-Raphson or by free Jacobian inexact Newton-Krylow schemes) on an underlying unstructured mesh. Nonlinear feedbacks among the active processes are enforced by considering evolving fluid and rock properties depending on the thermo-hydro-mechanical state of the system and the local structure, i.e. degree of connectivity, of the fracture system. A suite of applications is presented to illustrate the flexibility and capability of the new simulator to address problems of increasing complexity and occurring at different spatial (from centimetres to tens of kilometres) and temporal scales (from minutes to hundreds of years).

Flexible parallel implicit modelling of coupled thermal–hydraulic–mechanical processes in fractured rocks

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M. Cacace

2017-09-01

Full Text Available Theory and numerical implementation describing groundwater flow and the transport of heat and solute mass in fully saturated fractured rocks with elasto-plastic mechanical feedbacks are developed. In our formulation, fractures are considered as being of lower dimension than the hosting deformable porous rock and we consider their hydraulic and mechanical apertures as scaling parameters to ensure continuous exchange of fluid mass and energy within the fracture–solid matrix system. The coupled system of equations is implemented in a new simulator code that makes use of a Galerkin finite-element technique. The code builds on a flexible, object-oriented numerical framework (MOOSE, Multiphysics Object Oriented Simulation Environment which provides an extensive scalable parallel and implicit coupling to solve for the multiphysics problem. The governing equations of groundwater flow, heat and mass transport, and rock deformation are solved in a weak sense (either by classical Newton–Raphson or by free Jacobian inexact Newton–Krylow schemes on an underlying unstructured mesh. Nonlinear feedbacks among the active processes are enforced by considering evolving fluid and rock properties depending on the thermo-hydro-mechanical state of the system and the local structure, i.e. degree of connectivity, of the fracture system. A suite of applications is presented to illustrate the flexibility and capability of the new simulator to address problems of increasing complexity and occurring at different spatial (from centimetres to tens of kilometres and temporal scales (from minutes to hundreds of years.

On the possibilities and limits of "DEAF DEAF SAME": Tourism and empowerment camps in Adamorobe (Ghana), Bangalore and Mumbai (India).

OpenAIRE

Michele Ilana Friedner; Annelies Kusters

2014-01-01

This article qualitatively analyzes the ways that the discourse of "deaf universalism" circulates within two common deaf practices: tourism and engaging in interventions. Arguing that the largely Northern-situated discipline of Deaf Studies does not adequately examine how deaf bodies and discourses travel, ethnographic data compiled in India and Ghana during transnational encounters is employed to examine how claims of "sameness" and "difference" are enacted and negotiated. Similarly, this ar...

Deaf child sexual education and family leadership

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García, Mirna Maura

2010-07-01

Full Text Available This paper is an approach to the study of the role of the family in sexual education of deaf children and adolescents. The difference between hearing and deaf families is taken into consideration. Likewise, hints that favor communication between deaf children and hearing parents are given.

Assessment of rock wool as support material for on-site sanitation: hydrodynamic and mechanical characterization.

Science.gov (United States)

Wanko, Adrien; Laurent, Julien; Bois, Paul; Mosé, Robert; Wagner-Kocher, Christiane; Bahlouli, Nadia; Tiffay, Serge; Braun, Bouke; Provo kluit, Pieter-Willem

2016-01-01

This study proposes mechanical and hydrodynamic characterization of rock wool used as support material in compact filter. A double-pronged approach, based on experimental simulation of various physical states of this material was done. First of all a scanning electron microscopy observation allows to highlight the fibrous network structure, the fibres sizing distribution and the atomic absorption spectrum. The material was essentially lacunar with 97 ± 2% of void space. Static compression tests on variably saturated rock wool samples provide the fact that the strain/stress behaviours depend on both the sample conditioning and the saturation level. Results showed that water exerts plastifying effect on mechanical behaviour of rock wool. The load-displacement curves and drainage evolution under different water saturation levels allowed exhibiting hydraulic retention capacities under stress. Finally, several tracer experiments on rock wool column considering continuous and batch feeding flow regime allowed: (i) to determine the flow model for each test case and the implications for water dynamic in rock wool medium, (ii) to assess the rock wool double porosity and discuss its advantages for wastewater treatment, (iii) to analyse the benefits effect for water treatment when the high level of rock wool hydric retention was associated with the plug-flow effect, and (iv) to discuss the practical contributions for compact filter conception and management.

Epistemologies, deafness, learning, and teaching.

Science.gov (United States)

Moores, Donald F

2010-01-01

The study of Deaf epistemologies is in a nascent stage relative to, e.g., the study of feminist or African American epistemologies. It has only recently begun attracting the widespread attention it deserves. The present article addresses Deaf epistemologies as they relate to the sometimes conflicting trends in American society and education. In a relatively short period, the education of deaf students has gone from an independent enterprise under the aegis of special education to heavy influence by No Child Left Behind legislation that applies to virtually all American students. American education at one and the same time embraces and celebrates diversity, imposes uniform, rigid learning standards for all children, and mandates that all children be tested in the same way. An oxymoron exists of individualized educational planning and one-size-fits-all curricula and assessment of academic achievement. Implications for teaching and learning of deaf students are explored.

Understanding Deaf Readers: An Interpretative Phenomenological Analysis

Science.gov (United States)

Kelstone, Aaron Weir

2013-01-01

The development of reading skills, beyond a functional level, is difficult for most deaf readers. Standardized testing demonstrates a median 4th grade reading level that remains consistent even after national norming of the Stanford Achievement test on the population of deaf school children. Deaf education continues to generate various educational…

Development of Deaf Identity: An Ethnographic Study

Science.gov (United States)

McIlroy, Guy; Storbeck, Claudine

2011-01-01

This ethnographic study explores the identity development of 9 deaf participants through the narratives of their educational experiences in either mainstream or special schools for the Deaf. This exploration goes beyond a binary conceptualization of deaf identity that allows for only the medical and social models and proposes a bicultural…

Exact effective-stress rules in rock mechanics

International Nuclear Information System (INIS)

Berryman, J.G.

1992-01-01

The standard paradigm for analysis of rock deformation arises from postulating the existence of ''an equivalent homogeneous porous rock.'' However, data on the pore-pressure dependence of fluid permeability for some rocks cannot be explained using any equivalent homogeneous porous medium. In contrast, a positive result shows that deformation measurements on both high-porosity sandstones and low-porosity granites can be explained adequately in terms of an equivalent two-constituent model of porous rocks, for which exact results have recently been discovered

Foliation: Geological background, rock mechanics significance, and preliminary investigations at Olkiluoto

International Nuclear Information System (INIS)

Milnes, A.G.; Hudson, J.; Wikstroem, L.; Aaltonen, I.

2006-01-01

A well developed, pervasive foliation is a characteristic feature of the migmatites and gneisses in the Olkiluoto bedrock, and is expected to have a significant influence on the underground construction, the design and layout and the groundwater flow regime of a deep spent nuclear fuel repository. This Working Report reviews the geological background and rock mechanics significance of foliation, and develops a methodology for the systematic acquisition of foliation data in cored boreholes and in tunnels at the Olkiluoto site, to provide the necessary basis for future geological, rock mechanics and hydrogeological modelling. The first part of the methodology concerns foliation characterisation, and develops a characterisation scheme based on two variables: the foliation type (G = gneissic, B = banded, S = schistose), which is a function of mineral composition and degree of smallscale heterogeneity, and the foliation intensity (1 = low, 2 = intermediate, 3 = high), which is a function of the type and intensity of the deformation by which it was produced (under high-grade metamorphic conditions in the core of the Svecofennian orogenic belt). At the suggested reference scales (1 m length of core, 10 m 2 area of tunnel wall), the most representative foliation type and intensity is assessed using a standard set of core photographs, which are included as an Appendix at the end of the report, providing a systematic description in terms of 9 descriptive types (G1, G2, G3, B1, B2, B3, S1, S2, S3). As a further step, the rock mechanics significance of these types is assessed and a rock mechanics foliation (RMF) number is assigned (RMF 0 = no significance, RMF 1, RMF 2 and RMF 3 = low, intermediate and high significance, respectively). The second part of the methodology concerns the orientations of the foliation within the same 1 m core lengths or 10 m2 wall areas, which have been characterised as above. This combined analysis of foliation character and foliation orientation

The Consequence Deafness has on the Psychological and ...

African Journals Online (AJOL)

The Consequence Deafness has on the Psychological and Academic Development of deaf students. The case of Alpha special school for the deaf in Addis Ababa, Hermata and Mendera Junior School at Jimma Town.

Strategy for a Rock Mechanics Site Descriptive Model. A test case based on data from the Aespoe HRL

International Nuclear Information System (INIS)

Hudson, John A

2002-06-01

In anticipation of the SKB Site Investigations for radioactive waste disposal, an approach has been developed for the Rock Mechanics Site Descriptive Model. This approach was tested by predicting the rock mechanics properties of a 600 m x 180 m x 120 m rock volume at the Aespoe Hard Rock Laboratory (HRL) using limited borehole data of the type typically obtained during a site investigation. These predicted properties were then compared with 'best estimate' properties obtained from a study of the test rock volume using additional information, mainly tunnel data. The exercise was known as the Test Case, and is the subject of this Report. Three modelling techniques were used to predict the rock properties: the 'empirical approach' - the rock properties were estimated using rock mass classification schemes and empirical correlation formulae; the 'theoretical approach' - the rock properties were estimated using numerical modelling techniques; and the 'stress approach' - the rock stress state was estimated using primary data and numerical modelling. These approaches are described separately and respectively. Following an explanation of the context for the Test Case within the strategy for developing the Rock Mechanics Site Descriptive Model, conditions at the Aespoe HRL are described in Chapter 2. The Test Case organization and the suite of nine Protocols used to ensure that the work was appropriately guided and co-ordinated are described in Chapter 3. The methods for predicting the rock properties and the rock stress, and comparisons with the 'best estimate' properties of the actual conditions, are presented in Chapters 4 and 5. Finally, the conclusions from this Test Case exercise are given in Chapter 6. General recommendations for the management of this type of Test Case are also included

Strategy for a Rock Mechanics Site Descriptive Model. A test case based on data from the Aespoe HRL

Energy Technology Data Exchange (ETDEWEB)

Hudson, John A (ed.) [Rock Engineering Consultants, Welwyn Garden City (United Kingdom)

2002-06-01

In anticipation of the SKB Site Investigations for radioactive waste disposal, an approach has been developed for the Rock Mechanics Site Descriptive Model. This approach was tested by predicting the rock mechanics properties of a 600 m x 180 m x 120 m rock volume at the Aespoe Hard Rock Laboratory (HRL) using limited borehole data of the type typically obtained during a site investigation. These predicted properties were then compared with 'best estimate' properties obtained from a study of the test rock volume using additional information, mainly tunnel data. The exercise was known as the Test Case, and is the subject of this Report. Three modelling techniques were used to predict the rock properties: the 'empirical approach' - the rock properties were estimated using rock mass classification schemes and empirical correlation formulae; the 'theoretical approach' - the rock properties were estimated using numerical modelling techniques; and the 'stress approach' - the rock stress state was estimated using primary data and numerical modelling. These approaches are described separately and respectively. Following an explanation of the context for the Test Case within the strategy for developing the Rock Mechanics Site Descriptive Model, conditions at the Aespoe HRL are described in Chapter 2. The Test Case organization and the suite of nine Protocols used to ensure that the work was appropriately guided and co-ordinated are described in Chapter 3. The methods for predicting the rock properties and the rock stress, and comparisons with the 'best estimate' properties of the actual conditions, are presented in Chapters 4 and 5. Finally, the conclusions from this Test Case exercise are given in Chapter 6. General recommendations for the management of this type of Test Case are also included.

RELATION OF DEAF PERSONS TOWARDS BILINGUALISM AS COMMUNICATION MODE

Directory of Open Access Journals (Sweden)

Naim Salkić

2013-02-01

Full Text Available Bilingualism of a deaf child implies concurrent cognition and usage of sign language, as community language and oral-voice language as language of greater community in which deaf persons live. Today, most authors consider that deaf persons should know both of these languages and that deaf persons need to be educated in both languages, because of their general communication and complete psycho-social development. Through research on sample of 80 deaf examinees, we affirmed the kind of relation that deaf persons have towards bilingualism, bilingual way of education and communication. The research results have shown that bilingualism and bilingual way of education and communication is acceptable to deaf persons and that there is no statistically significant difference between the sub-samples of examinees.

A Hydrous Seismogenic Fault Rock Indicating A Coupled Lubrication Mechanism

Science.gov (United States)

Okamoto, S.; Kimura, G.; Takizawa, S.; Yamaguchi, H.

2005-12-01

In the seismogenic subduction zone, the predominant mechanisms have been considered to be fluid induced weakening mechanisms without frictional melting because the subduction zone is fundamentally quite hydrous under low temperature conditions. However, recently geological evidence of frictional melting has been increasingly reported from several ancient accretionary prisms uplifted from seismogenic depths of subduction zones (Ikesawa et al., 2003; Austrheim and Andersen, 2004; Rowe et al., 2004; Kitamura et al., 2005) but relationship between conflicting mechanisms; e.g. thermal pressurization of fluid and frictional melting is still unclear. We found a new exposure of pseudotachylyte from a fossilized out-of-sequence thrust (OOST) , Nobeoka thrust in the accretionary complex, Kyushu, southwest Japan. Hanging-wall and foot-wall are experienced heating up to maximum temperature of about 320/deg and about 250/deg, respectively. Hanging-wall rocks of the thrust are composed of shales and sandstones deformed plastically. Foot-wall rocks are composed of shale matrix melange with sandstone and basaltic blocks deformed in a brittle fashion (Kondo et al, 2005). The psudotachylyte was found from one of the subsidiary faults in the hanging wall at about 10 m above the fault core of the Nobeoka thrust. The fault is about 1mm in width, and planer rupture surface. The fault maintains only one-time slip event because several slip surfaces and overlapped slip textures are not identified. The fault shows three deformation stages: The first is plastic deformation of phyllitic host rocks; the second is asymmetric cracking formed especially in the foot-wall of the fault. The cracks are filled by implosion breccia hosted by fine carbonate minerals; the third is frictional melting producing pseudotachylyte. Implosion breccia with cracking suggests that thermal pressurization of fluid and hydro-fracturing proceeded frictional melting.

Identity development in deaf adolescents

NARCIS (Netherlands)

Kunnen, E. Saskia

2014-01-01

We studied identity development during 5 years in 11 deaf adolescents who attend a school for deaf children in the highest level of regular secondary education (age between 14 and 19 years). Identity development is conceptualized by the processes of exploration and commitment formation, as

Fundamental Research on Percussion Drilling: Improved rock mechanics analysis, advanced simulation technology, and full-scale laboratory investigations

Energy Technology Data Exchange (ETDEWEB)

Michael S. Bruno

2005-12-31

This report summarizes the research efforts on the DOE supported research project Percussion Drilling (DE-FC26-03NT41999), which is to significantly advance the fundamental understandings of the physical mechanisms involved in combined percussion and rotary drilling, and thereby facilitate more efficient and lower cost drilling and exploration of hard-rock reservoirs. The project has been divided into multiple tasks: literature reviews, analytical and numerical modeling, full scale laboratory testing and model validation, and final report delivery. Literature reviews document the history, pros and cons, and rock failure physics of percussion drilling in oil and gas industries. Based on the current understandings, a conceptual drilling model is proposed for modeling efforts. Both analytical and numerical approaches are deployed to investigate drilling processes such as drillbit penetration with compression, rotation and percussion, rock response with stress propagation, damage accumulation and failure, and debris transportation inside the annulus after disintegrated from rock. For rock mechanics modeling, a dynamic numerical tool has been developed to describe rock damage and failure, including rock crushing by compressive bit load, rock fracturing by both shearing and tensile forces, and rock weakening by repetitive compression-tension loading. Besides multiple failure criteria, the tool also includes a damping algorithm to dissipate oscillation energy and a fatigue/damage algorithm to update rock properties during each impact. From the model, Rate of Penetration (ROP) and rock failure history can be estimated. For cuttings transport in annulus, a 3D numerical particle flowing model has been developed with aid of analytical approaches. The tool can simulate cuttings movement at particle scale under laminar or turbulent fluid flow conditions and evaluate the efficiency of cutting removal. To calibrate the modeling efforts, a series of full-scale fluid hammer

Genetics Home Reference: sensorineural deafness and male infertility

Science.gov (United States)

... deafness and male infertility Sensorineural deafness and male infertility Printable PDF Open All Close All Enable Javascript ... expand/collapse boxes. Description Sensorineural deafness and male infertility is a condition characterized by hearing loss and ...

Mechanical Behavior of Shale Rock under Uniaxial Cyclic Loading and Unloading Condition

Directory of Open Access Journals (Sweden)

Baoyun Zhao

2018-01-01

Full Text Available In order to investigate the mechanical behavior of shale rock under cyclic loading and unloading condition, two kinds of incremental cyclic loading tests were conducted. Based on the result of the short-term uniaxial incremental cyclic loading test, the permanent residual strain, modulus, and damage evolution were analyzed firstly. Results showed that the relationship between the residual strains and the cycle number can be expressed by an exponential function. The deformation modulus E50 and elastic modulus ES first increased and then decreased with the peak stress under the loading condition, and both of them increased approximately linearly with the peak stress under the unloading condition. On the basis of the energy dissipation, the damage variables showed an exponential increasing with the strain at peak stress. The creep behavior of the shale rock was also analyzed. Results showed that there are obvious instantaneous strain, decay creep, and steady creep under each stress level and the specimen appears the accelerated creep stage under the 4th stress of 51.16 MPa. Based on the characteristics of the Burgers creep model, a viscoelastic-plastic creep model was proposed through viscoplastic mechanics, which agrees very well with the experimental results and can better describe the creep behavior of shale rock better than the Burgers creep model. Results can provide some mechanics reference evidence for shale gas development.

Complex word reading in Dutch deaf children and adults.

Science.gov (United States)

van Hoogmoed, Anne H; Knoors, Harry; Schreuder, Robert; Verhoeven, Ludo

2013-03-01

Children who are deaf are often delayed in reading comprehension. This delay could be due to problems in morphological processing during word reading. In this study, we investigated whether 6th grade deaf children and adults are delayed in comparison to their hearing peers in reading complex derivational words and compounds compared to monomorphemic words. The results show that deaf children are delayed in reading both derivational words and compounds as compared to hearing children, while both deaf and hearing adults performed equally well on a lexical decision task. However, deaf adults generally showed slower reaction times than hearing adults. For both deaf and hearing children, derivational words were more difficult than compounds, as reflected in hearing children's slower reaction times and in deaf children's lower accuracy scores. This finding likely reflects deaf children's lack of familiarity with the meaning of the bound morphemes attached to the stems in derivational words. Therefore, it might be beneficial to teach deaf children the meaning of bound morphemes and to train them to use morphology in word reading. Moreover, these findings imply that it is important to focus on both monomorphemic and polymorphemic words when assessing word reading ability in deaf children. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of Freezing and Thawing Cycle on Mechanical Properties and Stability of Soft Rock Slope

OpenAIRE

Chen, Yanlong; Wu, Peng; Yu, Qing; Xu, Guang

2017-01-01

To explore the variation laws of mechanical parameters of soft rock and the formed slope stability, an experiment was carried out with collected soft rock material specimens and freezing and thawing cycle was designed. Meanwhile, a computational simulation analysis of the freezing-thawing slope stability was implemented. Key factors that influence the strength of frozen rock specimens were analyzed. Results showed that moisture content and the number of freezing-thawing cycles influenced mech...

Violence against Deaf Women: Effect of Partner Hearing Status

Science.gov (United States)

Anderson, Melissa L.; Kobek Pezzarossi, Caroline M.

2014-01-01

Using a sample of Deaf female undergraduate students, the current study sought to investigate the prevalence, correlates, and characteristics of intimate partner violence victimization in hearing-Deaf and Deaf-Deaf relationships. Initial results suggest that similarities in hearing status and communication preference are associated with increased…

Anger communication in deaf children

NARCIS (Netherlands)

Rieffe, C.J.; Meerum Terwogt, M.

2006-01-01

In this study, we investigated how deaf children express their anger towards peers and with what intentions. Eleven-year-old deaf children (n = 21) and a hearing control group (n = 36) were offered four vignettes describing anger-evoking conflict situations with peers. Children were asked how they

Deaf-Blind Perspectives, 2000-2001.

Science.gov (United States)

Malloy, Peggy, Ed.

2001-01-01

These three issues of "Deaf-Blind Perspectives" feature the following articles: (1) "A Group for Students with Usher Syndrome in South Louisiana" (Faye Melancon); (2) "Simply Emily," which discusses a budding friendship between a girl with deaf-blindness and a peer; (3) "Intervener Update" (Peggy Malloy and…

Dementia and the Deaf community: knowledge and service access.

Science.gov (United States)

Ferguson-Coleman, Emma; Keady, John; Young, Alys

2014-01-01

This study concerns culturally Deaf people in the United Kingdom who use British Sign Language (BSL). Its objective was to explore how Deaf people's knowledge about dementia and access to services is mediated by their minoritised cultural-linguistic status. Twenty-six members of the Deaf community participated in one of three Deaf-led focus groups in BSL corresponding with the sample of: Deaf people over the age of 60 without dementia; Deaf people aged 18-60 working professional roles unconnected with dementia services; ordinary members of the Deaf community aged 18-60. Data were subjected to a thematic content analysis. Participants' concerns about their poor levels of knowledge and understanding of dementia were augmented by their awareness that without sustained social contact in BSL opportunities for earlier recognition of dementia would be lost. Although primary care services were identified as the first port of call for dementia-related concerns, there was widespread mistrust of their effectiveness because of failures in communication and cultural competence. Confirmed diagnosis of dementia was not viewed as a gateway to services and support because Deaf organisations, dementia-related organisations and mainstream adult services were perceived to be ill-equipped to respond to the needs of Deaf people with dementia. Locating problems of late diagnosis within the Deaf community's poor awareness and knowledge of dementia fails to recognise the structural barriers Deaf people face in timely access to services and accurate recognition of dementia-related changes.

Influence of Fissure Number on the Mechanical Properties of Layer-Crack Rock Models under Uniaxial Compression

Directory of Open Access Journals (Sweden)

Yun-liang Tan

2018-01-01

Full Text Available Many case studies have revealed that rock bursts generally occur in the high stress concentration area where layer-crack structures often exist, especially for brittle coal or rock masses. Understanding the mechanical properties of layer-crack rock models is beneficial for rational design and stability analysis of rock engineering project and rock burst prevention. This study experimentally investigated the influence of fissure number on the mechanical properties of layer-crack rock models through uniaxial compression tests. The digital speckle correlation method (DSCM and acoustic emission (AE techniques were applied to record and analyze the information of deformation and failure processes. Test results show the following: the bearing capacity of layer-crack specimen decreases compared with intact specimen, but their failure modes are similar, which are the splitting failure accompanied with local shear failure; the nonuniform deformation phenomenon begins to appear at the elastic deformation stage for layer-crack specimens; the AE behavior of intact specimens consists of three stages, that is, active stage, quiet stage, and major active stage, but for layer-crack specimens, it is characteristic by three peaks without quiet stage. In addition, as the fissure number of layer-crack specimens increases, the bearing capacity of specimens decreases, the appearing time of nonuniform deformation phenomenon in the specimen surface decreases, the AE events are denser and denser in each peak stage, and the risk of dynamic instability of layer-crack structure increases. At last, the failure mechanism of layer-crack structure and the related mitigation advices were discussed based on the test results. In general, the novelty is that this paper focuses on the failure mechanism of layer-crack structure directly.

Stigma in Mothers of Deaf Children

Directory of Open Access Journals (Sweden)

Hossein Ebrahimi

2015-03-01

 Results: Results showed that most mothers suffer from stigma due to having a deaf child. The mean stigma score was 96.48 ±27.72. In total, 24.4% of mothers reported that they had received strange and mocking looks; 72.2% regarded child deafness as a sign of divine retribution; and 33.3% felt ashamed of their child’s deafness. There was an inverse relationship between the mother’s level of education and mean stigma scores (P

Basic rock properties for the thermo-hydro-mechanical analysis of a high-level radioactive waste repository

Energy Technology Data Exchange (ETDEWEB)

Kim, Jhin Wung; Kang, Chul Hyung

1999-04-01

Deep geological radioactive waste disposal is generally based on the isolation of the waste from the biosphere by multiple barriers. The host rock is one of these barriers which should provide a stable mechanical and chemical environment for the engineered barriers. In the evaluation of the safety of the high-level radioactive waste disposal systems, an important part of the safety analysis is an assessment of the coupling or interaction between thermal, hydrological, and mechanical effects. In order to do this assessment, adequate data on the characteristics of different host rocks are necessary. The properties of the rock and rock discontinuity are very complex and their values vary in a wide range. The accuracy of the result of the assessment depends on the values of these properties used. The present study is an attempt to bring together and condense data for the basic properties of various rock masses, which are needed in the thermo-hydro-mechanical analysis for the deep geological radioactive waste repository. The testing and measurement methods for these basic properties are also presented. Domestic data for deep geological media should be supplemented in the future, due to the insufficiency and the lack of accuracy of the data available at present. (author). 28 refs., 21 figs.

Basic rock properties for the thermo-hydro-mechanical analysis of a high-level radioactive waste repository

International Nuclear Information System (INIS)

Kim, Jhin Wung; Kang, Chul Hyung

1999-04-01

Deep geological radioactive waste disposal is generally based on the isolation of the waste from the biosphere by multiple barriers. The host rock is one of these barriers which should provide a stable mechanical and chemical environment for the engineered barriers. In the evaluation of the safety of the high-level radioactive waste disposal systems, an important part of the safety analysis is an assessment of the coupling or interaction between thermal, hydrological, and mechanical effects. In order to do this assessment, adequate data on the characteristics of different host rocks are necessary. The properties of the rock and rock discontinuity are very complex and their values vary in a wide range. The accuracy of the result of the assessment depends on the values of these properties used. The present study is an attempt to bring together and condense data for the basic properties of various rock masses, which are needed in the thermo-hydro-mechanical analysis for the deep geological radioactive waste repository. The testing and measurement methods for these basic properties are also presented. Domestic data for deep geological media should be supplemented in the future, due to the insufficiency and the lack of accuracy of the data available at present. (author). 28 refs., 21 figs

Emergency Department utilization among Deaf American Sign Language users.

Science.gov (United States)

McKee, Michael M; Winters, Paul C; Sen, Ananda; Zazove, Philip; Fiscella, Kevin

2015-10-01

Deaf American Sign Language (ASL) users comprise a linguistic minority population with poor health care access due to communication barriers and low health literacy. Potentially, these health care barriers could increase Emergency Department (ED) use. To compare ED use between deaf and non-deaf patients. A retrospective cohort from medical records. The sample was derived from 400 randomly selected charts (200 deaf ASL users and 200 hearing English speakers) from an outpatient primary care health center with a high volume of deaf patients. Abstracted data included patient demographics, insurance, health behavior, and ED use in the past 36 months. Deaf patients were more likely to be never smokers and be insured through Medicaid. In an adjusted analysis, deaf individuals were significantly more likely to use the ED (odds ratio [OR], 1.97; 95% confidence interval [CI], 1.11-3.51) over the prior 36 months. Deaf American Sign Language users appear to be at greater odds for elevated ED utilization when compared to the general hearing population. Efforts to further understand the drivers for increased ED utilization among deaf ASL users are much needed. Copyright © 2015 Elsevier Inc. All rights reserved.

RELATION OF DEAF PERSONS TOWARDS BILINGUALISM AS COMMUNICATION MODE

OpenAIRE

Naim Salkić

2013-01-01

Bilingualism of a deaf child implies concurrent cognition and usage of sign language, as community language and oral-voice language as language of greater community in which deaf persons live. Today, most authors consider that deaf persons should know both of these languages and that deaf persons need to be educated in both languages, because of their general communication and complete psycho-social development. Through research on sample of 80 deaf examinees, we affirmed the kind...

Health Care Access Among Deaf People.

Science.gov (United States)

Kuenburg, Alexa; Fellinger, Paul; Fellinger, Johannes

2016-01-01

Access to health care without barriers is a clearly defined right of people with disabilities as stated by the UN Convention on the Rights of People with Disabilities. The present study reviews literature from 2000 to 2015 on access to health care for deaf people and reveals significant challenges in communication with health providers and gaps in global health knowledge for deaf people including those with even higher risk of marginalization. Examples of approaches to improve access to health care, such as providing powerful and visually accessible communication through the use of sign language, the implementation of important communication technologies, and cultural awareness trainings for health professionals are discussed. Programs that raise health knowledge in Deaf communities and models of primary health care centers for deaf people are also presented. Published documents can empower deaf people to realize their right to enjoy the highest attainable standard of health. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Results of monitoring at Olkiluoto in 2013, rock mechanics

Energy Technology Data Exchange (ETDEWEB)

Johansson, E. (ed.) [Saanio and Riekkola Oy, Helsinki (Finland)

2014-10-15

The rock mechanics monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The rock mechanics monitoring programme 2013 consisted of seismic measurements, GPS measurements, surface levelling measurements and temperature measurements at Olkiluoto and vicinity and displacement measurements, temperature measurements and visual tunnel observations made in the ONKALO. The Posiva's microseismic network consists of 17 seismic stations and 21 triaxial sensors. Five stations are in the ONKALO. In spite of few breaks the network operated continuously and well during 2013. The number of located events (436) was slightly more than in 2012, but much less than in 2011. Nearly half of the observed explosions (237) in 2013 occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (137). One small induced earthquake (M{sub L} = -1.8) was detected at the depth of 429 m and was probably associated with smaller branches of the brittle fracture zone (OL-BFZ045). According to the seismic monitoring the rock mass has been stable in 2013. The local GPS network consists of 18 stations. Six new stations were set up for permanent tracking during 2013 and in total 12 permanent stations are now operating continuously. Manual measurements were carried out twice in 2013. Most of the inner network baselines showed very small motions as in the previous years: 75% of change rates were smaller than 0.10 mm/y. Roughly one third of the change rates are statistically significant. The surface levelling network currently consists of 87 fixed measuring points. During 2013 all the measuring loops were measured. The results indicated local subsidence area in the ONKALO loop and the rising area in the VLJ loop. Mean deformation rate has been +0.05 mm/y. Only elevation of one benchmark in the GPS station loop has changed more than one millimetre. The continuous displacement measurements in the technical rooms

Results of monitoring at Olkiluoto in 2013, rock mechanics

International Nuclear Information System (INIS)

Johansson, E.

2014-10-01

The rock mechanics monitoring at Olkiluoto concentrates on the assessment of potential tectonic movements and stability of the bedrock. The rock mechanics monitoring programme 2013 consisted of seismic measurements, GPS measurements, surface levelling measurements and temperature measurements at Olkiluoto and vicinity and displacement measurements, temperature measurements and visual tunnel observations made in the ONKALO. The Posiva's microseismic network consists of 17 seismic stations and 21 triaxial sensors. Five stations are in the ONKALO. In spite of few breaks the network operated continuously and well during 2013. The number of located events (436) was slightly more than in 2012, but much less than in 2011. Nearly half of the observed explosions (237) in 2013 occurred inside the seismic semi-regional area and especially inside the seismic ONKALO block (137). One small induced earthquake (M L = -1.8) was detected at the depth of 429 m and was probably associated with smaller branches of the brittle fracture zone (OL-BFZ045). According to the seismic monitoring the rock mass has been stable in 2013. The local GPS network consists of 18 stations. Six new stations were set up for permanent tracking during 2013 and in total 12 permanent stations are now operating continuously. Manual measurements were carried out twice in 2013. Most of the inner network baselines showed very small motions as in the previous years: 75% of change rates were smaller than 0.10 mm/y. Roughly one third of the change rates are statistically significant. The surface levelling network currently consists of 87 fixed measuring points. During 2013 all the measuring loops were measured. The results indicated local subsidence area in the ONKALO loop and the rising area in the VLJ loop. Mean deformation rate has been +0.05 mm/y. Only elevation of one benchmark in the GPS station loop has changed more than one millimetre. The continuous displacement measurements in the technical rooms of

Representations of deaf characters in children's picture books.

Science.gov (United States)

Golos, Debbie B; Moses, Annie M

2011-01-01

Picture books can influence how children perceive people of different backgrounds, including people with disabilities whose cultures differ from their own. Researchers have examined the portrayal of multicultural characters with disabilities in children's literature. However, few have specifically considered the portrayal of deaf characters, despite increased inclusion of deaf characters in children's literature over the past two decades. The present study analyzed the portrayal of deaf characters in picture books for children ages 4-8 years. A content analysis of 20 children's picture books was conducted in which the books were analyzed for messages linked to pathological and cultural categories. Results indicated that these books did not portray Deaf characters from a cultural perspective but, rather, highlighted aspects of deafness as a medical condition, one that requires fixing and that perpetuates stereotypes of deafness as a disability.

Endocochlear potential depends on Cl- channels: Mechanism underlying deafness in Bartter syndrome IV

NARCIS (Netherlands)

G. Rickheit (Gesa); H. Maier (Hannes); N. Strenzke (Nicola); C.E. Andreescu (Corina); C.I. de Zeeuw (Chris); A. Muenscher (Adrian); A.A. Zdebik (Anselm); T.J. Jentsch (Thomas)

2008-01-01

textabstractHuman Bartter syndrome IV is an autosomal recessive disorder characterized by congenital deafness and severe renal salt and fluid loss. It is caused by mutations in BSND, which encodes barttin, a β-subunit of ClC-Ka and ClC-Kb chloride channels. Inner-ear-specific disruption of Bsnd in

Rock burst governance of working face under igneous rock

Science.gov (United States)

Chang, Zhenxing; Yu, Yue

2017-01-01

As a typical failure phenomenon, rock burst occurs in many mines. It can not only cause the working face to cease production, but also cause serious damage to production equipment, and even result in casualties. To explore how to govern rock burst of working face under igneous rock, the 10416 working face in some mine is taken as engineering background. The supports damaged extensively and rock burst took place when the working face advanced. This paper establishes the mechanical model and conducts theoretical analysis and calculation to predict the fracture and migration mechanism and energy release of the thick hard igneous rock above the working face, and to obtain the advancing distance of the working face when the igneous rock fractures and critical value of the energy when rock burst occurs. Based on the specific conditions of the mine, this paper put forward three kinds of governance measures, which are borehole pressure relief, coal seam water injection and blasting pressure relief.

Rock fragmentation

Energy Technology Data Exchange (ETDEWEB)

Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

1976-01-01

Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

Beethoven's deafness, the defiance of a genius

Directory of Open Access Journals (Sweden)

Bento, Ricardo Ferreira

2009-09-01

Full Text Available Introduction: Ludwig van Beethoven, one of the greatest composers in History, was tormented for his whole life by a progressive deafness without definitive diagnosis. Many authors published studies about the etiologic possibilities of the deafness of the music genius with different explanations about his auditory loss. In this work, the author discusses the implications of Beethoven's progressive deafness to the creation of his word, as well as etiologic assumptions of his disease. Would Beethoven have had the same ingeniousness he showed in his symphonies if he did not have hypacusis and tinnitus? What is the influence of his deafness on his work and life? Could he have had a more precise diagnosis and specially a treatment nowadays? Would we have the brilliant composer if he had deafness today? We surely could not have!

Mechanisms and consequences of creep in the nearfield rock of a KBS-3 repository

International Nuclear Information System (INIS)

Pusch, R.; Hoekmark, H.

1992-12-01

Creep in rock depends on the structure as well as on the stress and temperature. Log time creep is often observed and can be explained on the basis of statistical mechanics. Simple Kelvin behavior can be used as an approximation. The code FLAC is concluded to be useful for predicting creep strain, assuming that the rock obeys the Kelvin law. 22 refs

Emotional Availability and Touch in Deaf and Hearing Dyads

Science.gov (United States)

Paradis, Grace; Koester, Lynne Sanford

2015-01-01

In recent years, increasing attention has been given to the development of deaf children, though few studies have included Deaf parents. The present study examined emotional availability (EA) and functions of touch used by Deaf or hearing parents with hearing or deaf infants during free play. Sixty dyads representing four hearing status groups…

From the Margins to the Spotlight: Diverse Deaf and Hard of Hearing Student Populations and Standardized Assessment Accessibility

Science.gov (United States)

Cawthon, Stephanie

2015-01-01

Designing assessments and tests is one of the more challenging aspects of creating an accessible learning environment for students who are deaf or hard of hearing (DHH), particularly for deaf students with a disability (DWD). Standardized assessments are a key mechanism by which the educational system in the United States measures student…

Identity Development in Deaf Adolescents

Science.gov (United States)

Kunnen, E. Saskia

2014-01-01

We studied identity development during 5 years in seven deaf adolescents who attended a school for deaf children in the highest level of regular secondary education (age between 14 and 18 years), administering identity interviews every year. Identity development is conceptualized as the processes of exploration and commitment formation (Bosma,…

Control of Rock Mechanics in Underground Ore Mining

Science.gov (United States)

Golik, V. I.; Efremenkov, A. B.

2017-07-01

Performance indicators in underground mining of thick iron fields can be insufficient since geo-mechanic specifics of ore-hosting fields might be considered inadequately, as a consequence, critical deformations and even earth’s surface destruction are possible, lowering the indicators of full subsurface use, this way. The reason for it is the available approach to estimating the performance of mining according to ore excavation costs, without assessing losses of valuable components and damage to the environment. The experimental approach to the problem is based on a combination of methods to justify technical capability and performance of mining technology improvement with regard to geomechanical factors. The main idea of decisions to be taken is turning geo-materials into the condition of triaxial compression via developing the support constructions of blocked up structural rock block. The study was carried out according to an integrated approach based on the analysis of concepts, field observations, and simulation with the photo-elastic materials in conditions of North Caucasus deposits. A database containing information on the deposit can be developed with the help of industrial experiments and performance indicators of the field can be also improved using the ability of ore-hosting fields to develop support constructions, keeping the geo-mechanical stability of the system at lower cost, avoiding ore contamination at the processing stage. The proposed model is a specific one because an adjustment coefficient of natural and anthropogenic stresses is used and can be adopted for local conditions. The relation of natural to anthropogenic factors can make more precise the standards of developed, prepared and ready to excavation ore reserves relying on computational methods. It is possible to minimize critical stresses and corresponding deformations due to dividing the ore field into sectors safe from the standpoint of geo-mechanics, and using less cost

Acoustics outreach program for the deaf

Science.gov (United States)

Vongsawad, Cameron T.; Berardi, Mark L.; Whiting, Jennifer K.; Lawler, M. Jeannette; Gee, Kent L.; Neilsen, Tracianne B.

2016-03-01

The Hear and See methodology has often been used as a means of enhancing pedagogy by focusing on the two strongest learning senses, but this naturally does not apply to deaf or hard of hearing students. Because deaf students' prior nonaural experiences with sound will vary significantly from those of students with typical hearing, different methods must be used to build understanding. However, the sensory-focused pedagogical principle can be applied in a different way for the Deaf by utilizing the senses of touch and sight, called here the ``See and Feel'' method. This presentation will provide several examples of how acoustics demonstrations have been adapted to create an outreach program for a group of junior high students from a school for the Deaf and discuss challenges encountered.

[Congenital sensorineural deafness and associated syndromes].

Science.gov (United States)

Moatti, L; Garabedian, E N; Lacombe, H; Spir-Jacob, C

1990-01-01

The etiology of perceptive deafness, especially the congenital variety, requires investigation. The presence of a variety of signs associated with deafness constitutes an "associated syndrome" and helps to define a possible genetic origin. These syndromes only represent a small percentage of overall causes of deafness in children, since at most they account for only 10% of cases. Certain syndromes are encountered more often or are well known, others are extremely rare or have only been described recently. The authors report six of these very rare syndromes discovered among their patients: a KID syndrome, a Leopard syndrome, a Norrie syndrome, a Jervell and Lange Nielsen syndrome, a recently described entity called CEE with deafness and an External Neuro-Cochleo-Pancreatic syndrome which would not appear to have been previously described.

Signposts to Development: Theory of Mind in Deaf Children.

Science.gov (United States)

Woolfe, Tyron; Want, Stephen C.; Siegal, Michael

2002-01-01

Two studies investigated the effect of language input on theory of mind by comparing the performance of deaf native-signing children (ages 4 to 8) raised by deaf signing parents and deaf late-signing children raised by hearing parents on "thought picture" measures of theory of mind. Findings indicated that deaf late signers showed…

Understanding Harry Potter: parallels to the deaf world.

Science.gov (United States)

Czubek, Todd A; Greenwald, Janey

2005-01-01

Every so often there are stories that take the world by storm and make such an impact that they become part of our everyday world. These stories, characters, and themes become established elements of cultural literacy. This is exactly what has happened with J. K. Rowling's Harry Potter series. Harry and his cohort of wizards, witches, and their adventures have become an indispensable part of popular literature and popular culture. We have developed an innovative way to ensure that Deaf children, their families, and anyone studying literature (Deaf or general) gain a deeper understanding of this phenomenon. In fact, we go further by demonstrating how using a Deaf Lens provides the greatest insight into the fascinating world of Harry Potter. Utilizing a Deaf Studies Template and a Deaf Lens, we capitalize on the experiences of Deaf people everywhere while celebrating the valuable role American Sign Language has in academic programming.

The Relationship Between Cochlear Implants and Deaf Identity

DEFF Research Database (Denmark)

Chapman, Madeleine; Dammeyer, Jesper

2017-01-01

from a Danish national survey of deaf adults, the authors examined the significance of having (or not having) a CI in regard to identity (categorized as deaf, hearing, bicultural, and marginal) and various related factors concerning social participation and experiences of being deaf. Cochlear...

Research of long-term mechanical displaced behavior of soft rock

International Nuclear Information System (INIS)

Inoue, Hiroyuki; Minami, Kosuke

2003-01-01

When it thinks about a stratum disposition system of high-level radioactive waste, it is important to evaluate the long-term mechanical displaced behavior of the near field bedrock which is boundary condition of the engineered barrier that should be evaluated based on the reality. In this research, three following examination was carried out for reliability improvement of long-term dynamic deformation behavior estimate. 1) We evaluated the sedimentary rock of Horonobe where we used Okubo model as while changing hydraulic condition and temperature condition. 2) We carried out the model experiment that inner pressure acted on in order to grasp a movement of near field bedrock. 3) We examined model to evaluate that. As a result, the following things were provided. 1) Sedimentary rock of Horonobe is easy to cause strength degradation for being wet and dry cycles. When the rock is saturated after drying, it is broken along potential cracking. The rock reacts for a change of moisture content sensitively. In addition, a variation of the strength occurs in a little depth remainder. This diffuseness gave the strong influence on failure time. 2) Big plastic deformation may not do elasto-plasticity behavior according to theory for stress modification of rock mass. 3) We think with one of the factor that it produces remainder in prediction and real creep hour that these is as 'm = n (conatnt of Okubo model)' simply. Therefore we collect data after peak, and it is necessary to grasp 'm/n'. In addition, it is necessary to improve 'n' in the model which we can change by environment and stress state on the way. (author)

Evaluation of the basic mechanical and thermal properties of deep crystalline rocks

International Nuclear Information System (INIS)

Park, Byoung Yoon; Bae, Dae Seok; Kim, Chun Soo; Kim, Kyung Su; Koh, Young Kwon; Jeon, Seok Won

2001-04-01

This report provides the mechanical and thermal properties of granitic intact rocks obtained from Deep Core Drilling Program which is carried out as part of the assessment of deep geological environmental condition. These data are the basic material properties of the core samples from the boreholes drilled up to 500 m depth at the Yusung and Kosung sites. These sites were selected based on the result of preliminary site evaluation study. In this study, the mechanical properties include density, porosity, P-wave velocity, S-wave velocity, uniaxial compressive strength, Young's modulus, Poisson's ratio, tensile strength, and shear strength of fractures, and the thermal properties are heat conductivity, thermal expansion coefficient, specific heat and so on. Those properties were measured through laboratory tests and these data are compared with the existing test results of several domestic rocks

Evaluation of the basic mechanical and thermal properties of deep crystalline rocks

Energy Technology Data Exchange (ETDEWEB)

Park, Byoung Yoon; Bae, Dae Seok; Kim, Chun Soo; Kim, Kyung Su; Koh, Young Kwon; Jeon, Seok Won

2001-04-01

This report provides the mechanical and thermal properties of granitic intact rocks obtained from Deep Core Drilling Program which is carried out as part of the assessment of deep geological environmental condition. These data are the basic material properties of the core samples from the boreholes drilled up to 500 m depth at the Yusung and Kosung sites. These sites were selected based on the result of preliminary site evaluation study. In this study, the mechanical properties include density, porosity, P-wave velocity, S-wave velocity, uniaxial compressive strength, Young's modulus, Poisson's ratio, tensile strength, and shear strength of fractures, and the thermal properties are heat conductivity, thermal expansion coefficient, specific heat and so on. Those properties were measured through laboratory tests and these data are compared with the existing test results of several domestic rocks.

Widespread auditory deficits in tune deafness.

Science.gov (United States)

Jones, Jennifer L; Zalewski, Christopher; Brewer, Carmen; Lucker, Jay; Drayna, Dennis

2009-02-01

The goal of this study was to investigate auditory function in individuals with deficits in musical pitch perception. We hypothesized that such individuals have deficits in nonspeech areas of auditory processing. We screened 865 randomly selected individuals to identify those who scored poorly on the Distorted Tunes test (DTT), a measure of musical pitch recognition ability. Those who scored poorly were given a comprehensive audiologic examination, and those with hearing loss or other confounding audiologic factors were excluded from further testing. Thirty-five individuals with tune deafness constituted the experimental group. Thirty-four individuals with normal hearing and normal DTT scores, matched for age, gender, handedness, and education, and without overt or reported psychiatric disorders made up the normal control group. Individual and group performance for pure-tone frequency discrimination at 1000 Hz was determined by measuring the difference limen for frequency (DLF). Auditory processing abilities were assessed using tests of pitch pattern recognition, duration pattern recognition, and auditory gap detection. In addition, we evaluated both attention and short- and long-term memory as variables that might influence performance on our experimental measures. Differences between groups were evaluated statistically using Wilcoxon nonparametric tests and t-tests as appropriate. The DLF at 1000 Hz in the group with tune deafness was significantly larger than that of the normal control group. However, approximately one-third of participants with tune deafness had DLFs within the range of performance observed in the control group. Many individuals with tune deafness also displayed a high degree of variability in their intertrial frequency discrimination performance that could not be explained by deficits in memory or attention. Pitch and duration pattern discrimination and auditory gap-detection ability were significantly poorer in the group with tune deafness

Gênero e surdez / Gender and deafness

Directory of Open Access Journals (Sweden)

Madalena Klein

2007-01-01

Full Text Available Este artigo propõe-se discutir a temática da surdez, articulando-a com discussões referentes a gênero e sexualidade, tomando por referência autores da perspectiva dosEstudos Culturais em Educação e dos Estudos Surdos. A surdez e os surdos, assim como o gênero, são entendidos a partir da diferença cultural. No mercado de trabalho em geral, as surdas são discriminadas, porém são a maioria no professorado, o que é uma conseqüência da feminização do trabalho docente. A crescente presença feminina na liderança dos movimentos surdos pode estar relacionada a essa maioria de professoras, que carregam para os movimentos características da organização escolar. Analisamos dois artigos sobre o tema, além de um encontro sobre mulheres surdas ocorrido em Pelotas – RS, onde as participantes destacaram seu papel na luta política da associação dos surdos, enquanto aos homens cabe o papel de organizar as atividades de lazer e esportes. A luta pelos direitos das mulheres surdas vem crescendo no Brasil e há necessidade de haver mais estudos sobre essa temática.Abstract This paper discusses the topic of deafness, articulating it with discussions referring to gender and sexuality, based on authors from the perspectives of Cultural Studies in Education and Deaf Studies. Deafness and deaf people, as the gender issue, are understood through a cultural difference perspective. Deaf women are discriminated inthe workplace in general, but they are the majority in the teaching profession, a consequence of the feminization of the teaching work. The increasing female presence as leaders of deaf movements may be related to this greater rate of women as teachers, who carry the features of the school organization onto the movements. Two papers onthe topic were examined, as well as a meeting on deaf women occurring in Pelotas – RS, whose participants highlighted their role in the political struggle by the deaf people’s association, while men take

Deaf Employees' Empowerment in Two Different Communication Environments.

Science.gov (United States)

Backenroth, G. A. M.

1997-01-01

This study with 64 deaf employees working in either signing work groups or nonsigning workgroups found that employees' perceived empowerment was significantly higher in the signing work groups. Deaf associates in signing work groups experienced greater psychological stress and role conflicts, whereas deaf associates in nonsigning groups…

Deaf capital: an exploration of the relationship between stigma and value in deaf multilevel marketing participation in Urban India.

Science.gov (United States)

Friedner, Michele

2014-12-01

This article ethnographically examines how some deaf people in urban India have begun to orient themselves toward the future by participating in multilevel marketing businesses. In the absence of other structural possibilities for deaf future-making, deaf Indians have turned to such businesses in search of social, economic, and moral livelihood. This article analyzes participation in one particular business and asks how participating within the business both enables and disables the cultivation of specific ideas of development. Particular attention is devoted to exploring the multiple registers of the concept of "deaf development" and how such development may be cultivated through multilevel marketing businesses. This article aims to make a critical intervention in medical anthropology studies of disability by arguing that disability (or in this case deafness) can function as a source of value, therefore highlighting tensions between stigma and value. © 2014 by the American Anthropological Association.

Whose Deaf Genes Are They Anyway?: The Deaf Community's Challenge to Legislation on Embryo Selection

Science.gov (United States)

Emery, Steven D.; Middleton, Anna; Turner, Graham H.

2010-01-01

This article centers on the implications of genetic developments (as a scientific and technological discipline) for those Deaf people who identify as a cultural and linguistic minority group and are concerned with the preservation and development of sign language and Deaf culture. We explore the impact of one particular legislative initiative that…

Sexual Health Behaviors of Deaf American Sign Language (ASL) Users

Science.gov (United States)

Heiman, Erica; Haynes, Sharon; McKee, Michael

2015-01-01

Background Little is known about the sexual health behaviors of Deaf American Sign Language (ASL) users. Objective We sought to characterize the self-reported sexual behaviors of Deaf individuals. Methods Responses from 282 Deaf participants aged 18–64 from the greater Rochester, NY area who participated in the 2008 Deaf Health were analyzed. These data were compared with weighted data from a general population comparison group (N=1890). We looked at four sexual health-related outcomes: abstinence within the past year; number of sexual partners within the last year; condom use at last intercourse; and ever tested for HIV. We performed descriptive analyses, including stratification by gender, age, income, marital status, and educational level. Results Deaf respondents were more likely than the general population respondents to self-report two or more sexual partners in the past year (30.9% vs 10.1%) but self-reported higher condom use at last intercourse (28.0% vs 19.8%). HIV testing rates were similar between groups (47.5% vs 49.4%) but lower for certain Deaf groups: Deaf women (46.0% vs. 58.1%), lower-income Deaf (44.4% vs. 69.7%) and among less educated Deaf (31.3% vs. 57.7%) than among respondents from corresponding general population groups. Conclusion Deaf respondents self-reported higher numbers of sexual partners over the past year compared to the general population. Condom use was higher among Deaf participants. HIV was similar between groups, though HIV testing was significantly lower among lower-income, less well-educated, and female Deaf respondents. Deaf individuals have a sexual health risk profile that is distinct from that of the general population. PMID:26242551

Sexual health behaviors of Deaf American Sign Language (ASL) users.

Science.gov (United States)

Heiman, Erica; Haynes, Sharon; McKee, Michael

2015-10-01

Little is known about the sexual health behaviors of Deaf American Sign Language (ASL) users. We sought to characterize the self-reported sexual behaviors of Deaf individuals. Responses from 282 Deaf participants aged 18-64 from the greater Rochester, NY area who participated in the 2008 Deaf Health were analyzed. These data were compared with weighted data from a general population comparison group (N = 1890). We looked at four sexual health-related outcomes: abstinence within the past year; number of sexual partners within the last year; condom use at last intercourse; and ever tested for HIV. We performed descriptive analyses, including stratification by gender, age, income, marital status, and educational level. Deaf respondents were more likely than the general population respondents to self-report two or more sexual partners in the past year (30.9% vs 10.1%) but self-reported higher condom use at last intercourse (28.0% vs 19.8%). HIV testing rates were similar between groups (47.5% vs 49.4%) but lower for certain Deaf groups: Deaf women (46.0% vs 58.1%), lower-income Deaf (44.4% vs 69.7%) and among less educated Deaf (31.3% vs 57.7%) than among respondents from corresponding general population groups. Deaf respondents self-reported higher numbers of sexual partners over the past year compared to the general population. Condom use was higher among Deaf participants. HIV was similar between groups, though HIV testing was significantly lower among lower income, less well-educated, and female Deaf respondents. Deaf individuals have a sexual health risk profile that is distinct from that of the general population. Copyright © 2015 Elsevier Inc. All rights reserved.

The peculiar needs of deaf people: a study of selected members of the Lincolnshire deaf social group

OpenAIRE

Jones, K.

1989-01-01

In spite of the fact that services for deaf people have been provided since Victorian times, there is no "philosophy of deafness" and services are based upon the subjective observation of deaf people by "hearing" people. This study seeks to formulate such a philosophy, for those unable to hear spoken communication from birth or early childhood, based upon acceptance of the social limitations of being unable to hear in a society where the ready use of that sense is taken for granted.\\ud \\ud In...

Retrievability of high-level nuclear waste from geologic repositories - Regulatory and rock mechanics/design considerations

International Nuclear Information System (INIS)

Tanious, N.S.; Nataraja, M.S.; Daemen, J.J.K.

1987-01-01

Retrievability of nuclear waste from high-level geologic repositories is one of the performance objectives identified in 10CFR60 (Code of Federal Regulations, 1985). 10CFR60.111 states that the geologic repository operations area shall be designed to preserve the option of waste retrieval. In designing the repository operations area, rock mechanics considerations play a major role especially in evaluating the feasibility of retrieval operations. This paper discusses generic considerations affecting retrievability as they relate to repository design, construction, and operation, with emphasis on regulatory and rock mechanics aspects

Dynamic Mechanical Behavior of Dry and Water Saturated Igneous Rock with Acoustic Emission Monitoring

Directory of Open Access Journals (Sweden)

Jun Guo

2018-01-01

Full Text Available The uniaxial cyclic loading tests have been conducted to study the mechanical behavior of dry and water saturated igneous rock with acoustic emission (AE monitoring. The igneous rock samples are dried, naturally immersed, and boiled to get specimens with different water contents for the testing. The mineral compositions and the microstructures of the dry and water saturated igneous rock are also presented. The dry specimens present higher strength, fewer strains, and rapid increase of AE count subjected to the cyclic loading, which reflects the hard and brittle behavior and strong burst proneness of igneous rock. The water saturated specimens have lower peak strength, more accumulated strains, and increase of AE count during the cyclic loading. The damage of the igneous rocks with different water contents has been identified by the Felicity Ratio Analysis. The cyclic loading and unloading increase the dislocation between the mineral aggregates and the water-rock interactions further break the adhesion of the clay minerals, which jointly promote the inner damage of the igneous rock. The results suggest that the groundwater can reduce the burst proneness of the igneous rock but increase the potential support failure of the surrounding rock in igneous invading area. In addition, the results inspire the fact that the water injection method is feasible for softening the igneous rock and for preventing the dynamic disasters within the roadways and working faces located in the igneous intrusion area.

Deaf not Daft: The Deaf in Mental Subnormality Hospitals.

Science.gov (United States)

Williams, Chris

1982-01-01

Case studies of deaf or hearing impaired persons in institutions for the mentally retarded illustrate the ways in which the "invisible handicap" can mask cognitive ability, causing unnecessary institutionalization. (CL)

Environmental assessment: Deaf Smith County site, Texas

International Nuclear Information System (INIS)

1986-05-01

In February 1983, the US Department of Energy (DOE) identified a location in Deaf Smith County, Texas, as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Deaf Smith County site and the eight other potentially sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. The Deaf Smith County site is in the Permian Basin, which is one of five distinct geohydrologic settings considered for the first repository. On the basis of the evaluations reported in this EA, the DOE has found that the Deaf Smith County site is not disqualified under the guidelines. On the basis of these findings, the DOE is nominating the Deaf Smith County site as one of the five sites suitable for characterization. 591 refs., 147 figs., 173 tabs

Environmental assessment: Deaf Smith County site, Texas

Energy Technology Data Exchange (ETDEWEB)

1986-05-01

In February 1983, the US Department of Energy (DOE) identified a location in Deaf Smith County, Texas, as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Deaf Smith County site and the eight other potentially sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. The Deaf Smith County site is in the Permian Basin, which is one of five distinct geohydrologic settings considered for the first repository. On the basis of the evaluations reported in this EA, the DOE has found that the Deaf Smith County site is not disqualified under the guidelines. On the basis of these findings, the DOE is nominating the Deaf Smith County site as one of the five sites suitable for characterization. 591 refs., 147 figs., 173 tabs.

Rhythm Deficits in "Tone Deafness"

Science.gov (United States)

Foxton, Jessica M.; Nandy, Rachel K.; Griffiths, Timothy D.

2006-01-01

It is commonly observed that "tone deaf" individuals are unable to hear the beat of a tune, yet deficits on simple timing tests have not been found. In this study, we investigated rhythm processing in nine individuals with congenital amusia ("tone deafness") and nine controls. Participants were presented with pairs of 5-note sequences, and were…

Mechanical effects associated with surface loading of dry rock due to glaciation

International Nuclear Information System (INIS)

Wahi, K.K.; Hunter, R.L.

1985-01-01

Many scenarios of interest for a repository in the Pasco Basin begin with glaciation. Loading and unloading of joints and fractures due to the weight of ice sheets could affect the hydrologic properties of the host rock and surrounding units. Scoping calculations performed using two-dimensional numerical models with simplifying assumptions predict stress changes and uplift or subsidence caused by an advancing glacier. The magnitudes of surface uplift and subsidence predicted by the study agree well with previous independent predictions. Peak stress unloading near the repository horizon is a small fraction of the ambient stress. Any resultant aperture increase is likewise small. Based on the results of this study, mechanical loading caused by a glacier is expected to have a minimal effect on rock permeability, assuming that the excess compressive loads do not crush the rock. 13 refs., 3 figs., 1 tab

College Students Who Are Deaf-Blind. Practice Perspectives--Highlighting Information on Deaf-Blindness. Number 7

Science.gov (United States)

Arndt, Katrina

2011-01-01

Imagine being in college and being deaf-blind. What opportunities might you have? What types of challenges would you face? This publication describes a study that begins to answer these questions. During the study, 11 college students with deaf-blindness were interviewed about their college experiences. They were like most college students in many…

Mizunami Underground Research Laboratory project. Rock mechanical investigations annual report for fiscal year 2013

International Nuclear Information System (INIS)

Sato, Toshinori; Sanada, Hiroyuki; Tanno, Takeo

2015-02-01

In order to establish the scientific and technical basis for geological disposal of technology, Japan Atomic Energy Agency (JAEA) is pursuing the geoscientific research project namely the Mizunami Underground Research Laboratory (MIU) in the crystalline rock environment at Tono Geoscience Center (TGC). In the MIU Project, geoscientific research is being carried out in three overlapping phases; Surface-based Investigation Phase (Phase I: FY1996 - 2004), Construction Phase (Phase II: FY2004- in progress) and Operation Phase (Phase III: FY2010- in progress). In the rock mechanical investigations at the Phase II, the research aims at “Characterization of geological environment in the Excavation Disturbed Zone (EDZ)” from the viewpoint of safety assessment. For the research, the specific information of the EDZ such as (1) size and structures, (2) petrophysical/geomechanical properties, and (3) stress state are required. The research also aims at “Characterization of geomechanical stability around tunnel” from the viewpoint of design and construction of underground facilities. For the research, the specific information such as (4) local stress regime, (5) spatial variability of petrophysical/geomechanical properties of rocks, and (6) distribution of discontinuities intersecting underground tunnels are required. The measurement system for rock mass behavior has been manufactured and set for groundwater recovery experiment in the Phase III. This report presents the results of following rock mechanical investigations conducted in FY 2013. In-situ stress measurements using Compact Conical-ended Borehole Overcoring Technique were performed at the - 500m stage. Measurement system for rock mass displacement using optical fiber was installed at the - 500m stage as part of the groundwater recovery experiment. Study on the modeling based on equivalent continuum model was continued. Phenomenological study and theoretical study on long-term behavior of crystalline rock were

Congenital sensorineural deafness in Australian stumpy-tail cattle dogs is an autosomal recessive trait that maps to CFA10.

Directory of Open Access Journals (Sweden)

Susan Sommerlad

2010-10-01

Full Text Available Congenital sensorineural deafness is an inherited condition found in many dog breeds, including Australian Stumpy-tail Cattle Dogs (ASCD. This deafness is evident in young pups and may affect one ear (unilateral or both ears (bilateral. The genetic locus/loci involved is unknown for all dog breeds. The aims of this study were to determine incidence, inheritance mechanism, and possible association of congenital sensorineural deafness with coat colour in ASCD and to identify the genetic locus underpinning this disease.A total of 315 ASCD were tested for sensorineural deafness using the brain stem auditory evoked response (BAER test. Disease penetrance was estimated directly, using the ratio of unilaterally to bilaterally deaf dogs, and segregation analysis was performed using Mendel. A complete genome screen was undertaken using 325 microsatellites spread throughout the genome, on a pedigree of 50 BAER tested ASCD in which deafness was segregating. Fifty-six dogs (17.8% were deaf, with 17 bilaterally and 39 unilaterally deaf. Unilaterally deaf dogs showed no significant left/right bias (p = 0.19 and no significant difference was observed in frequencies between the sexes (p = 0.18. Penetrance of deafness was estimated as 0.72. Testing the association of red/blue coat colour and deafness without accounting for pedigree structure showed that red dogs were 1.8 times more likely to be deaf (p = 0.045. The within family association between red/blue coat colour and deafness was strongly significant (p = 0.00036, with red coat colour segregating more frequently with deafness (COR = 0.48. The relationship between deafness and coat speckling approached significance (p = 0.07, with the lack of statistical significance possibly due to only four families co-segregating for both deafness and speckling. The deafness phenotype was mapped to CFA10 (maximum linkage peak on CFA10 -log10 p-value = 3.64, as was both coat colour and

Heritability and complex segregation analysis of deafness in Jack Russell Terriers

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Strain George M

2007-11-01

Full Text Available Abstract Background The association between patterns of pigmentation and deafness in the dog has a long-documented history, with reports dating back over one hundred years. Long suspected of having a genetic basis, the search for loci with a pronounced influence in the expression of hearing loss in the dog has yet to be successful. No studies in the dog to date have found a possible influence of a specific colour locus associated with deafness. The present study is intended to evaluate the heritability of deafness in the Jack Russell Terrier (JRT, characterize the mode of inheritance, and evaluate the existence of a sex, coat colour, or coat texture influence on the expression of sensorineural deafness. Results The estimation of heritability of deafness in the JRT was 0.22 when deafness was considered a binary (normal/deaf trait and 0.31 when deafness was considered a three-category (normal/unilateral/bilateral deafness. The influence of coat colour in the incidence of JRT deafness was statistically significant, indicating that dogs with more white are more likely to be deaf. The influence of sex or coat texture was not statistically significant in the incidence of JRT deafness. Complex segregation analysis revealed a model of a single locus with a large effect on the binary measure of hearing loss is not supported. Conclusion This is the first attempt, to our knowledge, to characterize a genetic component responsible for deafness in the JRT. The heritability of deafness in the JRT was found to be 0.22 and 0.31 considering deafness to be a two-category or three-category trait, respectively. There appears to be an influence of coat colour on the expression of deafness. In an attempt to characterize the mode of inheritance of deafness in the JRT, a model of a single locus with a large effect on hearing loss is not supported with this data. Further study is needed to determine if a single locus may be influencing deafness in the JRT. While the

Language development in deaf children’s interactions with deaf and hearing adults. A Dutch longitudinal study

NARCIS (Netherlands)

Klatter-Folmer, H.A.K.; Hout, R.W.N.M. van; Kolen, E.; Verhoeven, L.T.W.

2006-01-01

The language development of two deaf girls and four deaf boys in Sign Language of the Netherlands (SLN) and spoken Dutch was investigated longitudinally. At the start, the mean age of the children was 3;5. All data were collected in video-recorded semistructured conversations between individual

Visual advantage in deaf adults linked to retinal changes.

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Charlotte Codina

Full Text Available The altered sensory experience of profound early onset deafness provokes sometimes large scale neural reorganisations. In particular, auditory-visual cross-modal plasticity occurs, wherein redundant auditory cortex becomes recruited to vision. However, the effect of human deafness on neural structures involved in visual processing prior to the visual cortex has never been investigated, either in humans or animals. We investigated neural changes at the retina and optic nerve head in profoundly deaf (N = 14 and hearing (N = 15 adults using Optical Coherence Tomography (OCT, an in-vivo light interference method of quantifying retinal micro-structure. We compared retinal changes with behavioural results from the same deaf and hearing adults, measuring sensitivity in the peripheral visual field using Goldmann perimetry. Deaf adults had significantly larger neural rim areas, within the optic nerve head in comparison to hearing controls suggesting greater retinal ganglion cell number. Deaf adults also demonstrated significantly larger visual field areas (indicating greater peripheral sensitivity than controls. Furthermore, neural rim area was significantly correlated with visual field area in both deaf and hearing adults. Deaf adults also showed a significantly different pattern of retinal nerve fibre layer (RNFL distribution compared to controls. Significant correlations between the depth of the RNFL at the inferior-nasal peripapillary retina and the corresponding far temporal and superior temporal visual field areas (sensitivity were found. Our results show that cross-modal plasticity after early onset deafness may not be limited to the sensory cortices, noting specific retinal adaptations in early onset deaf adults which are significantly correlated with peripheral vision sensitivity.

Rock-Mechanics Research. A Survey of United States Research to 1965, with a Partial Survey of Canadian Universities.

Science.gov (United States)

National Academy of Sciences - National Research Council, Washington, DC.

The results of a survey, conducted by the Committee on Rock Mechanics, to determine the status of training and research in rock mechanics in presented in this publication. In 1964 and 1965 information was gathered by questionnaires sent to industries, selected federal agencies, and universities in both the United States and Canada. Results are…

Influences on Facial Emotion Recognition in Deaf Children

Science.gov (United States)

Sidera, Francesc; Amadó, Anna; Martínez, Laura

2017-01-01

This exploratory research is aimed at studying facial emotion recognition abilities in deaf children and how they relate to linguistic skills and the characteristics of deafness. A total of 166 participants (75 deaf) aged 3-8 years were administered the following tasks: facial emotion recognition, naming vocabulary and cognitive ability. The…

"The Real World": Workplace Literacy for Deaf Adults.

Science.gov (United States)

Rach, Leslie; Dreher, Mariam Jean

1998-01-01

Examines three work sites employing deaf individuals (graduates of Gallaudet University), investigating how much time deaf adults spend reading and writing on the job; what types of reading and writing activities they engage in; how deaf employees communicate with their hearing supervisors/co-workers; and what their perceptions are of literacy…

Calendar systems and communication of deaf-blind children

Directory of Open Access Journals (Sweden)

Jablan Branka

2012-01-01

Full Text Available The aim of this paper is to explain the calendar systems and their role in teaching deaf-blind children. Deaf-blind persons belong to a group of multiple disabled persons. This disability should not be observed as a simple composite of visual and hearing impairments, but as a combination of sensory impairments that require special assistance in the development, communication and training for independent living. In our environment, deaf-blind children are being educated in schools for children with visual impairments or in schools for children with hearing impairments (in accordance with the primary impairment. However, deaf-blind children cannot be trained by means of special programs for children with hearing impairment, visual impairment or other programs for students with developmental disabilities without specific attention required by such a combination of sensory impairments. Deaf-blindness must be observed as a multiple impairment that requires special work methods, especially in the field of communication, whose development is severely compromised. Communication skills in deaf-blind people can be developed by using the calendar systems. They are designed in such a manner that they can be easily attainable to children with various sensory impairments. Calendars can be used to encourage and develop communication between adult persons and a deaf-blind child.

Accessibility and diversity: Deaf space in action

OpenAIRE

Solvang, Per Koren; Haualand, Hilde

2013-01-01

How disabled people gather and share common experiences is empirically not a well-addressed issue in discussions about disability identity and unity. Among Deaf people, there is a long tradition for meeting in transnational contexts. Based on an intensive multi sited fieldwork at several transnational events, the article presents some examples of how deaf people negotiate social positions as Deaf that value difference. They gather as a community of communicators, marked by an identification f...

Congenital Unilateral Deafness Affects Cerebral Organization of Reading

Directory of Open Access Journals (Sweden)

Alice Mado Proverbio

2013-06-01

Full Text Available It is known that early sensory deprivation modifies brain functional structure and connectivity. The aim of the present study was to investigate the neuro-functional organization of reading in a patient with profound congenital unilateral deafness. Using event-related potentials (ERPs, we compared cortical networks supporting the processing of written words in patient RA (completely deaf in the right ear since birth and in a group of control volunteers. We found that congenital unilateral hearing deprivation modifies neural mechanisms of word reading. Indeed, while written word processing was left-lateralized in controls, we found a strong right lateralization of the fusiform and inferior occipital gyri activation in RA. This finding goes in the same direction of recent proposals that the ventral occipito-temporal activity in word reading seem to lateralize to the same hemisphere as the one involved in spoken language processing.

Deafness, a Social Stigma: Physician Perspective.

Science.gov (United States)

Taneja, M K

2014-12-01

Hearing is an essential sensory sense of an individual for development of speech which is crucial for verbal communication and personality development. It is the second most common form of disability after loco motor disability in India. Disabling hearing loss is more than 40 dB hearing loss in better ear in a person more than 15 years of age and greater than 30 dB hearing loss in better hearing ear below 14 years of age. WHO estimated 360 million individuals in the world with disabling hearing loss, out of which 91 % are adults and only 9 % are children. Early and accurate identification of birth asphyxia, hyperbilirubinemia, auditory neuropathy Presbyacusis and avoiding noise pollution and discouraging use of mobile phone, tobacco chewing/smoking, in those who are prone to deafness, an intervention is a must to decrease deafness from our society. Deafness prevention can only be possible with mutual cooperation with dedication of different medical and non-medical personnel and also by helping the persons with deafness. We have to focus not only on the children but also on senior citizens as most alarming, up to 40 %, incidence of deafness is in senior citizens above the age of 75 years. Timely cure and preventive measures are essential for better socio-economic state of the country. By helping the persons with deafness, we will not only be doing a great service to the Nation but also to the society at large.

U.S. National Committee for Rock Mechanics; and Conceptual model of fluid infiltration in fractured media. Project summary, July 28, 1997--July 27, 1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-09-01

The title describes the two tasks summarized in this report. The remainder of the report contains information on meetings held or to be held on the subjects. The US National Committee for Rock Mechanics (USNC/RM) provides for US participation in international activities in rock mechanics, principally through adherence to the International Society for Rock Mechanics (ISRM). It also keeps the US rock mechanics community informed about new programs directed toward major areas of national concern in which rock mechanics problems represent critical or limiting factors, such as energy resources, excavation, underground storage and waste disposal, and reactor siting. The committee also guides or produces advisory studies and reports on problem areas in rock mechanics. A new panel under the auspices of the US National Committee for Rock Mechanics has been appointed to conduct a study on Conceptual Models of Fluid Infiltration in Fractured Media. The study has health and environmental applications related to the underground flow of pollutants through fractured rock in and around mines and waste repositories. Support of the study has been received from the US Nuclear Regulatory Commission and the Department of Energy`s Yucca Mountain Project Office. The new study builds on the success of a recent USNC/RM report entitled Rock Fractures and Fluid Flow: Contemporary Understanding and Applications (National Academy Press, 1996, 551 pp.). A summary of the new study is provided.

U.S. National Committee for Rock Mechanics and conceptual model of fluid infiltration in fractured media. Project summary, July 28, 1997 - July 27, 1998

International Nuclear Information System (INIS)

1998-01-01

The title describes the two tasks summarized in this report. The remainder of the report contains information on meetings held or to be held on the subjects. The US National Committee for Rock Mechanics (USNC/RM) provides for US participation in international activities in rock mechanics, principally through adherence to the International Society for Rock Mechanics (ISRM). It also keeps the US rock mechanics community informed about new programs directed toward major areas of national concern in which rock mechanics problems represent critical or limiting factors, such as energy resources, excavation, underground storage and waste disposal, and reactor siting. The committee also guides or produces advisory studies and reports on problem areas in rock mechanics. A new panel under the auspices of the US National Committee for Rock Mechanics has been appointed to conduct a study on Conceptual Models of Fluid Infiltration in Fractured Media. The study has health and environmental applications related to the underground flow of pollutants through fractured rock in and around mines and waste repositories. Support of the study has been received from the US Nuclear Regulatory Commission and the Department of Energy's Yucca Mountain Project Office. The new study builds on the success of a recent USNC/RM report entitled Rock Fractures and Fluid Flow: Contemporary Understanding and Applications (National Academy Press, 1996, 551 pp.). A summary of the new study is provided

Deaf murderers: clinical and forensic issues.

Science.gov (United States)

Vernon, M; Steinberg, A G; Montoya, L A

1999-01-01

Data are reported on 28 deaf individuals who were convicted, pled guilty, or have been charged and awaiting trial for murder. The unique forensic issues raised by these cases are discussed, and their clinical picture presented. A significant percentage of these deaf murderers and defendants had such severely limited communication skills in both English and American Sign Language that they lacked the linguistic ability to understand the charges against them and/or to participate in their own defense. As such, they were incompetent to stand trial, due not to mental illness or mental retardation, but to linguistic deficits. This form of incompetence poses a dilemma to the courts that remains unresolved. This same linguistic disability makes it impossible for some deaf suspects to be administered Miranda Warnings in a way comprehensible to them. This paper identifies the reasons for the communication problems many deaf persons face in court and offers remedial steps to help assure fair trials and police interrogations for deaf defendants. The roles and responsibilities of psychiatric and psychological experts in these cases are discussed. Data are provided on the etiology of the 28 individuals' hearing losses, psychiatric/psychological histories, IQs, communication characteristics, educational levels, and victim characteristics. Copyright 1999 John Wiley & Sons, Ltd.

Cultural Identity of Young Deaf Adults with Cochlear Implants in Comparison to Deaf without Cochlear Implants and Hard-of-Hearing Young Adults.

Science.gov (United States)

Goldblat, Ester; Most, Tova

2018-07-01

This study examined the relationships between cultural identity, severity of hearing loss (HL), and the use of a cochlear implant (CI). One hundred and forty-one adolescents and young adults divided into three groups (deaf with CI, deaf without CI, and hard-of-hearing (HH)) and 134 parents participated. Adolescents and young adults completed questionnaires on cultural identity (hearing, Deaf, marginal, bicultural-hearing, and bicultural-deaf) and communication proficiencies (hearing, spoken language, and sign language). Parents completed a speech quality questionnaire. Deaf participants without CI and those with CI differed in all identities except marginal identity. CI users and HH participants had similar identities except for a stronger bicultural-deaf identity among CI users. Three clusters of participants evolved: participants with a dominant bicultural-deaf identity, participants with a dominant bicultural-hearing identity and participants without a formed cultural identity. Adolescents and young adults who were proficient in one of the modes of communication developed well-established bicultural identities. Adolescents and young adults who were not proficient in one of the modes of communication did not develop a distinguished cultural identity. These results suggest that communication proficiencies are crucial for developing defined identities.

Environmental assessment: Deaf Smith County site, Texas

Energy Technology Data Exchange (ETDEWEB)

1986-05-01

In February 1983, the US Department of Energy (DOE) identified a location in Deaf Smith County, Texas, as one of the nine potentially acceptable sites for mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Deaf Smith County site and eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. The Deaf Smith County site is in the Permian Basin, which is one of five distinct geohydrologic settings considered for the first repository. On the basis of the evaluations reported in this EA, the DOE has found that the Deaf Smith County site is not disqualified under the guidelines.

Environmental assessment: Deaf Smith County site, Texas

International Nuclear Information System (INIS)

1986-05-01

In February 1983, the US Department of Energy (DOE) identified a location in Deaf Smith County, Texas, as one of the nine potentially acceptable sites for mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Deaf Smith County site and eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. The Deaf Smith County site is in the Permian Basin, which is one of five distinct geohydrologic settings considered for the first repository. On the basis of the evaluations reported in this EA, the DOE has found that the Deaf Smith County site is not disqualified under the guidelines

Issues in the Sexual Molestation of Deaf Youth.

Science.gov (United States)

Vernon, McCay; Miller, Katrina R.

2002-01-01

Discussion of issues involved in sexual abuse of deaf youth in schools considers characteristics of pedophiles and hebephiles and how sexual offenders are dealt with in the criminal justice system. It suggests ways to prevent sexual abuse of children who are deaf and what to look for in identifying deaf children who are being victimized. (Contains…

Self-Esteem and Coping Strategies among Deaf Students

Science.gov (United States)

Jambor, Edina; Elliott, Marta

2005-01-01

Research studies on the determinants of self-esteem of deaf individuals often yield inconsistent findings. The current study assessed the effects on self-esteem of factors related to deafness, such as the means of communication at home and severity of hearing loss with hearing aid, as well as the coping styles that deaf people adopt to cope with…

Investigations into stress shell characteristics of surrounding rock in fully mechanized top-coal caving face

Energy Technology Data Exchange (ETDEWEB)

Xie, G.X.; Chang, J.C.; Yang, K. [Anhui University of Science and Technology, Huainan (China)

2009-01-15

A key issue in underground mining is to understand and master the evolving patterns of stress induced by mining, and to control and utilize the action of rock pressure. Numerical and physical modeling tests have been carried out to investigate the distribution patterns of stress in the rock surrounding a fully mechanized top-coal caving (FMTC) face. The results showed that a macro-stress shell composed of high stress exists in the rock surrounding an FMTC face. The stress of the shell is higher than its internal and external stress and the stresses at its skewback producing abutment pressure for the surrounding rock. The stress shell lies in the virgin coal and rock mass in the vicinity of the face and its sagging zone. The stress shell, which bears and transfers the loads of overlying strata, acts as the primary supporting system of forces, and is the corpus of characterizing three-dimensional and macro-rock pressure distribution of mining face. Its external and internal shape changes with the variations in the working face structure as the face advances. Within the low-stress zone inside the stress shell, another structure, i.e. voussoir beam, which only bears parts of the load from the lower-lying strata, will produce periodic pressures on the face instead of great dynamic pressure even if the beam ruptures and loses stability. The results show that the FMTC face is situated within the lower-stress zone, which is protected by the stress shell of the overlying surrounding rock. We give an explanation of lower occurrence of rock pressure on FMTC faces, and reveal the mechanical nature of the top coal of an FMTC face acting as a 'cushion'. The strata behaviors of the face and its neighboring gates are under control of the stress shell. Drastic rock pressure in mine may occur when the balance of the stress shell is destruction or the forces system of the stress shell transfers. Crown Copyright

Computational solution for the auxiliary in the literacy of deaf

Directory of Open Access Journals (Sweden)

João Carlos Lopes Fernandes

2016-11-01

Full Text Available The learning of the deaf is a great challenge for educators, especially in Portuguese-speaking course. Brazilian schools are not prepared for suits with deaf, because they lack trained professionals. Current Brazilian educational policies, seeking socialize all deaf and not deaf students. The Brazilian deaf community uses LIBRAS, Brazilian sign language as their main form of communication between them. Integrating LBS and Portuguese is one of the main current challenges and the use of computers has helped a lot.

Monitoring the Achievement of Deaf Pupils in Sweden and Scotland

DEFF Research Database (Denmark)

Hendar, Nils Ola Ebbe; O'Neill, Rachel

2016-01-01

Over the past two decades there have been major developments in deaf education in many countries. Medical and technical advances have made it possible for more deaf children to hear and speak successfully. Most deaf pupils learn in ordinary classes in mainstream schools. In this article we explore...... patterns of achievements of deaf pupils to see if these reforms had improved attainment outcomes. International surveys such as PISA do not include deaf pupils. This article describes two independent large-scale surveys about deaf pupils in Sweden and Scotland. The similar results from both countries show...... that deaf children, after two decades of social reform and technical advances, still lag behind their hearing peers. The results also show how large-scale surveys can contribute to a greater understanding of educational outcomes in a small, vulnerable group and make it possible to continue to reform...

Rehabilitation of deaf persons with cochlear implants

International Nuclear Information System (INIS)

Gstoettner, W.; Hamzavi, J.; Czerny, C.

1997-01-01

In the last decade, the rehabilitation of postlingually deaf adults and prelingually deaf children with cochlear implants has been established as a treatment of deafness. The technological development of the implant devices and improvement of the surgical technique have led to a considerable increase of hearing performance during the last years. The postlingually deaf adults are able to use the telephone and may be integrated in their original job. Prelingually deaf children can even visit normal schools after cochlear implantation and hearing rehabilitation training. In order to preoperatively establish the state of the cochlear, radiological diagnosis of the temporal bone is necessary. High resolution computerized tomography imaging of the temporal bone with coronar and axial 1 mm slices and MRI with thin slice technique (three dimensional, T2 weighted turbo-spinecho sequence with 0.7 mm slices) have proved to be valuable according to our experience. Furthermore a postoperative synoptical X-ray, in a modified Chausse III projection, offers good information about the position of the implant and insertion of the stimulating electrode into the cochlea. (orig.) [de

Visual perceptual load induces inattentional deafness.

Science.gov (United States)

Macdonald, James S P; Lavie, Nilli

2011-08-01

In this article, we establish a new phenomenon of "inattentional deafness" and highlight the level of load on visual attention as a critical determinant of this phenomenon. In three experiments, we modified an inattentional blindness paradigm to assess inattentional deafness. Participants made either a low- or high-load visual discrimination concerning a cross shape (respectively, a discrimination of line color or of line length with a subtle length difference). A brief pure tone was presented simultaneously with the visual task display on a final trial. Failures to notice the presence of this tone (i.e., inattentional deafness) reached a rate of 79% in the high-visual-load condition, significantly more than in the low-load condition. These findings establish the phenomenon of inattentional deafness under visual load, thereby extending the load theory of attention (e.g., Lavie, Journal of Experimental Psychology. Human Perception and Performance, 25, 596-616, 1995) to address the cross-modal effects of visual perceptual load.

Hearing children of Deaf parents: Gender and birth order in the delegation of the interpreter role in culturally Deaf families.

Science.gov (United States)

Moroe, Nomfundo F; de Andrade, Victor

2018-01-01

Culturally, hearing children born to Deaf parents may have to mediate two different positions within the hearing and Deaf cultures. However, there appears to be little written about the experiences of hearing children born to Deaf parents in the South African context. This study sought to investigate the roles of children of Deaf adults (CODAs) as interpreters in Deaf-parented families, more specifically, the influence of gender and birth order in language brokering. Two male and eight female participants between the ages of 21 and 40 years were recruited through purposive and snowball sampling strategies. A qualitative design was employed and data were collected using a semi-structured, open-ended interview format. Themes which emerged were analysed using thematic analysis. The findings indicated that there was no formal assignment of the interpreter role; however, female children tended to assume the role of interpreter more often than the male children. Also, it appeared as though the older children shifted the responsibility for interpreting to younger siblings. The participants in this study indicated that they interpreted in situations where they felt they were not developmentally or emotionally ready, or in situations which they felt were better suited for older siblings or for siblings of another gender. This study highlights a need for the formalisation of interpreting services for Deaf people in South Africa in the form of professional interpreters rather than the reliance on hearing children as interpreters in order to mediate between Deaf and hearing cultures.

Deaf identities in a multicultural setting: The Ugandan context

Science.gov (United States)

Atekyereza, Peter R.; Kirumira, Edward K.; Hojer, Staffan

2015-01-01

Often located far apart from each other, deaf and hearing impaired persons face a multiplicity of challenges that evolve around isolation, neglect and the deprivation of essential social services that affect their welfare and survival. Although it is evident that the number of persons born with or acquire hearing impairments in later stages of their lives is increasing in many developing countries, there is limited research on this population. The main objective of this article is to explore the identities and experiences of living as a person who is deaf in Uganda. Using data from semi-structured interviews with 42 deaf persons (aged 19–41) and three focus group discussions, the study findings show that beneath the more pragmatic identities documented in the United States and European discourses there is a matrix of ambiguous, often competing and manifold forms in Uganda that are not necessarily based on the deaf and deaf constructions. The results further show that the country's cultural, religious and ethnic diversity is more of a restraint than an enabler to the aspirations of the deaf community. The study concludes that researchers and policy makers need to be cognisant of the unique issues underlying deaf epistemologies whilst implementing policy and programme initiatives that directly affect them. The upper case ‘D’ in the term deaf is a convention that has been used since the early 1970s to connote a ‘socially constructed visual culture’ or a linguistic, social and cultural minority group who use sign language as primary means of communication and identify with the deaf community, whereas the lower case ‘d’ in deaf refers to ‘the audio logical condition of hearing impairment’. However, in this article the lower case has been used consistently. PMID:28730015

Deaf identities in a multicultural setting: The Ugandan context

Directory of Open Access Journals (Sweden)

Anthony B. Mugeere

2015-05-01

Full Text Available Often located far apart from each other, deaf and hearing impaired persons face a multiplicity of challenges that evolve around isolation, neglect and the deprivation of essential social services that affect their welfare and survival. Although it is evident that the number of persons born with or acquire hearing impairments in later stages of their lives is increasing in many developing countries, there is limited research on this population. The main objective of this article is to explore the identities and experiences of living as a person who is deaf in Uganda. Using data from semi-structured interviews with 42 deaf persons (aged 19–41 and three focus group discussions, the study findings show that beneath the more pragmatic identities documented in the United States and European discourses there is a matrix of ambiguous, often competing and manifold forms in Uganda that are not necessarily based on the deaf and deaf constructions. The results further show that the country’s cultural, religious and ethnic diversity is more of a restraint than an enabler to the aspirations of the deaf community. The study concludes that researchers and policy makers need to be cognisant of the unique issues underlying deaf epistemologies whilst implementing policy and programme initiatives that directly affect them. The upper case ‘D’ in the term deaf is a convention that has been used since the early 1970s to connote a ‘socially constructed visual culture’ or a linguistic, social and cultural minority group who use sign language as primary means of communication and identify with the deaf community, whereas the lower case ‘d’ in deaf refers to ‘the audio logical condition of hearing impairment’. However, in this article the lower case has been used consistently.

Bacterial meningitic deafness: historical development of epidemiology and cellular pathology.

Science.gov (United States)

Ruben, Robert

2008-04-01

Meningitis resulting in labyrinthitis and its associated hearing loss was first described by several authors during 1864 and 1865 but it was not integrated into the otological cannon until H. Knapp's publications of 1871. These reports were incorporated by St John Rossa in his textbook of 1873. Politzer, in 1882, included a fuller description of the clinical symptoms. Analysis of records of the etiologies of students in 90 schools for the deaf in North America from 1817 to 1893 showed that before the mid-1870s meningitis was rarely identified as an etiology (accounted for 10-20% of all etiologies, with male preponderance. Cellular pathology of meningitic labyrinthitis from the 1860s to the 1990s examined the ways in which bacteria invaded the inner ear. Human temporal bone studies were a major source of understanding of the pathological processes. Honda, in 1927, injected guinea pigs intracranially with live bacteria, and observed the effects on the membranous labyrinth. In 1988 Lebel's observation of the effectiveness of dexamethasone in preventing much deafness from meningitis stimulated the examination of the labyrinthine immune response. Immunological mechanisms can account for some of the variable morbidity of unilateral, progressive, less-than-severe deafness.

Access to English Language Acquisition in Ghana Schools for the Deaf: Are the Deaf Students Handicapped?

Science.gov (United States)

Obosu, Gideon Kwesi; Opoku-Asare, Nana Afia; Deku, Prosper

2016-01-01

This paper primarily discusses the challenges deaf students in Ghana are likely to grapple with as they access education provided for them in English language. The arguments discussed in this paper are supported by findings from a multiple site case study of five Schools for the Deaf purposively sampled from four regions of Ghana. Observations…

Seismic response of rock joints and jointed rock mass

International Nuclear Information System (INIS)

Ghosh, A.; Hsiung, S.M.; Chowdhury, A.H.

1996-06-01

Long-term stability of emplacement drifts and potential near-field fluid flow resulting from coupled effects are among the concerns for safe disposal of high-level nuclear waste (HLW). A number of factors can induce drift instability or change the near-field flow patterns. Repetitive seismic loads from earthquakes and thermal loads generated by the decay of emplaced waste are two significant factors. One of two key technical uncertainties (KTU) that can potentially pose a high risk of noncompliance with the performance objectives of 10 CFR Part 60 is the prediction of thermal-mechanical (including repetitive seismic load) effects on stability of emplacement drifts and the engineered barrier system. The second KTU of concern is the prediction of thermal-mechanical-hydrological (including repetitive seismic load) effects on the host rock surrounding the engineered barrier system. The Rock Mechanics research project being conducted at the Center for Nuclear Waste Regulatory Analyses (CNWRA) is intended to address certain specific technical issues associated with these two KTUs. This research project has two major components: (i) seismic response of rock joints and a jointed rock mass and (ii) coupled thermal-mechanical-hydrological (TMH) response of a jointed rock mass surrounding the engineered barrier system (EBS). This final report summarizes the research activities concerned with the repetitive seismic load aspect of both these KTUs

77 FR 20553 - Relay Services for Deaf-Blind Individuals

Science.gov (United States)

2012-04-05

... for Deaf-Blind Individuals AGENCY: Federal Communications Commission. ACTION: Final rule; waiver of requirement. SUMMARY: In this document, the Commission conditionally waives the requirement for National Deaf... participants to fully meet the needs of eligible low- income, deaf-blind individuals in a timely manner. DATES...

Microscale experimental investigation of deformation and damage of argillaceous rocks under cyclic hydric and mechanical loads

International Nuclear Information System (INIS)

Wang, Linlin; Yang, Diansen; Heripre, Eva; Chanchole, Serge; Bornert, Michel; Pouya, Ahmad; Halphen, Bernard

2012-01-01

Document available in abstract form only. Argillaceous rocks are possible host rocks for underground nuclear waste repositories. They exhibit complex coupled thermo-hydro-chemo-mechanical behavior, the description of which would strongly benefit from an improved experimental insight on their deformation and damage mechanisms at microscale. We present some recent observations of the evolution of these rocks at the scale of their composite microstructure, essentially made of a clay matrix with embedded carbonates and quartz particles with sizes ranging from a few to several tens of micrometers, when they are subjected to cyclic variations of relative humidity and mechanical loading. They are based on the combination of high definition and high resolution imaging in an environmental scanning electron microscope (ESEM), in situ hydro-mechanical loading of the samples, and digital image correlation techniques. Samples, several millimeters in diameter, are held at a constant temperature of 2 deg. Celsius while the vapor pressure in the ESEM chamber is varied from a few to several hundreds of Pascals, generating a relative humidity ranging from about 10% up to 90%. Results show a strongly heterogeneous deformation field at microscale, which is the result of complex hydro-mechanical interactions. In particular, it can be shown that local swelling incompatibilities can generate irreversible deformations in the clay matrix, even if the overall hydric deformations seem reversible. In addition, local damage can be generated, in the form of a network of microcracks, located in the bulk of the clay matrix and/or at the interface between clay and other mineral particles. The morphology of this network, described in terms of crack length, orientation and preferred location, has been observed to be dependent on the speed of the variation of the relative humidity, and is different in a saturation or desaturation process. Besides studying the deformation and damage under hydric

APPLICATIONS OF BOREHOLE-ACOUSTIC METHODS IN ROCK MECHANICS.

Science.gov (United States)

Paillet, Frederick L.

1985-01-01

Acoustic-logging methods using a considerable range of wavelengths and frequencies have proven very useful in the in situ characterization of deeply buried crystalline rocks. Seismic velocities are useful in investigating the moduli of unfractured rock, and in producing a continuous record of rock quality for comparison with discontinuous intervals of core. The considerable range of frequencies makes the investigation of scale effects possible in both fractured and unfractured rock. Several specific methods for the characterization of in situ permeability have been developed and verified in the field.

Rock foundations of hydroengineering structures: mechanical properties and calculations. Skal'nye osnovaniya gidrotekhnicheskikh sooruzhenii: mekhanicheskie svoistva i raschety

Energy Technology Data Exchange (ETDEWEB)

Ukhov, S B

1975-01-01

This book presents the analytical methods which are used to describe the processes of the deformation and collapse of the rock-dirt foundations of dams, and techniques are presented for experimentally determining the mechanical properties of fissured rock-dirt under natural conditions. A determination is made of the required complex of engineering-geological, geophysical and geomechanical methods of investigation for calculating the interaction of the structure and the foundation, and a report is also given on the main assumptions of such calculations by using the method of finite elements. Methods are recommended for estimating the effect of engineering actions on the change in mechanical properties of the rock-dirt foundation. The book is intended for engineering dealing with the search and design of dam structures constructed on rock foundations. 126 refs.

Environmental assessment overview, Deaf Smith County site, Texas

International Nuclear Information System (INIS)

1986-05-01

In February 1983, the US Department of Energy (DOE) identified a location in Deaf Smith County, Texas, as one of nine potentially acceptable sites for mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Deaf Smith County site and eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. The Deaf Smith County site is in the Permian Basin, which is one of five distinct geohydrologic settings considered for the first repository. On the basis of the evaluations reported in this EA, the DOE has found that the Deaf Smith County site is not disqualified under the guidelines. On the basis of these findings, the DOE is nominating the Deaf Smith County site as one of five sites suitable for characterization. 3 figs

Perception of Genetic Testing for Deafness and Factors Associated with Interest in Genetic Testing Among Deaf People in a Selected Population in Sub-Saharan Africa.

Science.gov (United States)

Adedokun, Babatunde O; Yusuf, Bidemi O; Lasisi, J Taye; Jinadu, A A; Sunmonu, M T; Ashanke, A F; Lasisi, O Akeem

2015-12-01

Understanding the perceptions of genetic testing by members of the deaf community may help in planning deafness genetics research, especially so in the context of strong adherence to cultural values as found among native Africans. Among Yorubas in Nigeria, deafness is perceived to be caused by some offensive actions of the mother during pregnancy, spiritual attack, and childhood infections. We studied attitudes towards, and acceptance of genetic testing by the deaf community in Nigeria. Structured questionnaires were administered to individuals sampled from the Vocational Training Centre for the Deaf, the religious Community, and government schools, among others. The main survey items elicited information about the community in which the deaf people participate, their awareness of genetic testing, whether or not they view genetic testing as acceptable, and their understanding of the purpose of genetic testing. There were 150 deaf participants (61.3 % males, 38.7 % females) with mean age of 26.7 years ±9.8. A majority of survey respondents indicated they relate only with other members of the deaf community (78 %) and reported believing genetic testing does more good than harm (79.3 %); 57 % expressed interest in genetic testing. Interest in genetic testing for deafness or in genetic testing in pregnancy was not related to whether respondents relate primarily to the deaf or to the hearing community. However, a significantly higher number of male respondents and respondents with low education reported interest in genetic testing.

Factors impacting participation of European elite deaf athletes in sport.

Science.gov (United States)

Kurková, Petra; Válková, Hana; Scheetz, Nanci

2011-03-01

This study examine 53 European elite deaf athletes for their family's hearing status, use of hearing aids, communication preference, education in integrated or segregated settings, family members' encouragement for participation in sports, coach preference (hearing or deaf), and conditions for competitive events with deaf or hearing athletes. These data were gathered through semi-structured interviews administered in the athlete's native language. Deaf athletes reported that when given the opportunity to compete with hearing athletes, it enhanced their opportunity for competition. Participating in sports with hearing athletes played an important role in the integration of deaf athletes into mainstream society. If adaptations to communication can be made in these integrated settings, the ability of deaf athletes to participate in such settings will increase.

Effects on Deaf Patients of Medication Education by Pharmacists

Science.gov (United States)

Hyoguchi, Naomi; Kobayashi, Daisuke; Kubota, Toshio; Shimazoe, Takao

2016-01-01

Deaf people often experience difficulty in understanding medication information provided by pharmacists due to communication barriers. We held medication education lectures for deaf and hard of hearing (HH) individuals and examined the extent to which deaf participants understood medication-related information as well as their attitude about…

Rock mechanics investigations of structural stability in the Bulli seam at West Cliff Colliery

Energy Technology Data Exchange (ETDEWEB)

Jaggar, F

1978-03-01

Rock mechanics investigations were conducted at West Cliff colliery to obtain rock properties and stress measurements and study the stability of mining structures. The roof and floor were drilled in order to obtain core for rock testing and lump samples of coal were collected in order to measure the coal properties. Absolute stress measurements were obtained using CSIR cells. The strata were sufficiently uniform and competent to overcore the emplaced cells. Testing revealed that the rocks were better than average for coal measure sedimentary strata and the stresses indicated the existence of a moderately high horizontal stress field. The coal is of average strength only with some marked variation relating to the very banded nature of the seam. Finite element analyses showed that the rectangular roadways driven using roof bolts and timber supports were stable and adequately stable by an indicative factor of safety of about l.5.

Hearing children of Deaf parents: Gender and birth order in the delegation of the interpreter role in culturally Deaf families

Directory of Open Access Journals (Sweden)

Nomfundo F. Moroe

2018-04-01

Full Text Available Background: Culturally, hearing children born to Deaf parents may have to mediate two different positions within the hearing and Deaf cultures. However, there appears to be little written about the experiences of hearing children born to Deaf parents in the South African context. Objective: This study sought to investigate the roles of children of Deaf adults (CODAs as interpreters in Deaf-parented families, more specifically, the influence of gender and birth order in language brokering. Method: Two male and eight female participants between the ages of 21 and 40 years were recruited through purposive and snowball sampling strategies. A qualitative design was employed and data were collected using a semi-structured, open-ended interview format. Themes which emerged were analysed using thematic analysis. Results: The findings indicated that there was no formal assignment of the interpreter role; however, female children tended to assume the role of interpreter more often than the male children. Also, it appeared as though the older children shifted the responsibility for interpreting to younger siblings. The participants in this study indicated that they interpreted in situations where they felt they were not developmentally or emotionally ready, or in situations which they felt were better suited for older siblings or for siblings of another gender. Conclusion: This study highlights a need for the formalisation of interpreting services for Deaf people in South Africa in the form of professional interpreters rather than the reliance on hearing children as interpreters in order to mediate between Deaf and hearing cultures.

Hearing children of Deaf parents: Gender and birth order in the delegation of the interpreter role in culturally Deaf families

Science.gov (United States)

de Andrade, Victor

2018-01-01

Background Culturally, hearing children born to Deaf parents may have to mediate two different positions within the hearing and Deaf cultures. However, there appears to be little written about the experiences of hearing children born to Deaf parents in the South African context. Objective This study sought to investigate the roles of children of Deaf adults (CODAs) as interpreters in Deaf-parented families, more specifically, the influence of gender and birth order in language brokering. Method Two male and eight female participants between the ages of 21 and 40 years were recruited through purposive and snowball sampling strategies. A qualitative design was employed and data were collected using a semi-structured, open-ended interview format. Themes which emerged were analysed using thematic analysis. Results The findings indicated that there was no formal assignment of the interpreter role; however, female children tended to assume the role of interpreter more often than the male children. Also, it appeared as though the older children shifted the responsibility for interpreting to younger siblings. The participants in this study indicated that they interpreted in situations where they felt they were not developmentally or emotionally ready, or in situations which they felt were better suited for older siblings or for siblings of another gender. Conclusion This study highlights a need for the formalisation of interpreting services for Deaf people in South Africa in the form of professional interpreters rather than the reliance on hearing children as interpreters in order to mediate between Deaf and hearing cultures. PMID:29850437

Teachers' Perceptions of Communication Needs of Deaf Children in ...

African Journals Online (AJOL)

Communication has been identified as one of the greatest areas of difficulty for the deaf. Both the receptive and expressive communication pose barriers in almost all aspects of life of the deaf. This study endeavors to examine teachers' perceptions of communication needs of deaf children in Kenyan school system.

Demonstration of ipsilateral brain activation by noise in patients profoundly deaf with cochlear implant, or unilaterally deaf

International Nuclear Information System (INIS)

Herzog, H.; Wieler, H.; Morgenstern, C.; Lipman, J.; Langen, K.-J.; Schmid, A.; Rota, E.; Patton, D.; Feinendegen, L.F.

1986-01-01

Two groups of patients with hearing handicaps have been investigated with PET and F-18-2-FDG. Since these patients were unilaterally deaf or profoundly deaf with a cochlear implant installed, monaural stimulation was possible excluding any effects of bone conduction to the contralateral ear. White noise was used as acoustic stimulus in unilaterally deaf patients. The peripheral auditory nerve of cochlear implant patients was stimulated by electrical impulses which were encoded from music or a 4-tone mixture by an electronic speech processor. The non-music stimuli were chosen to avoid associative cortical reactions. In both groups response to the stimuli by increase of glucose consumption (LCMRglc) was found not only in the contralateral primary auditory cortex as expected from neuroanatomical knowledge, but also in the ipsilateral auditory cortex. Furthermore there was no correlation between the hemisphere showing increased LCMRglc and the side of stimulation or the type of stimulus. The similarity of results obtained in both groups by acoustical and electrical stimulation of the auditory nerve suggests that this kind of measurement might be a tool to predict or check the performance of a cochlear implant in a profoundly deaf patient. The finding of increased LCMRglc in the area of the normal auditory cortex in patients profoundly deaf since birth contradicts the hypothesis of degeneration of this cortical center in such patients. (Author)

Deaf Education in a Planetarium

Science.gov (United States)

Liu, Muxue; Hintz, E. G.; Jones, M.; Lawler, J.; Fisler, A.; Mumford, H.

2013-01-01

Over the years we have struggled with the difficulty of giving a planetarium show to a deaf audience. This is especially true for a younger audience with limited reading abilities. You must illuminate the ASL signer which causes light splash onto the dome. You must slow the presentation down to allow for time to interpret and then point. A slower presentation can have an adverse impact on the learning of the hearing students if the presentation is made to a mixed audience. To address these issues, we are currently working on methods to improve deaf education in a planetarium environment. We will present an overview of the current project along with efforts to establish baselines comprehension levels for both deaf and hearing children. This work is partially funded by an NSF IIS-1124548 grant and funding from the Sorenson Foundation.

Characteristics of Individuals with Congenital and Acquired Deaf-Blindness

Science.gov (United States)

Dalby, Dawn M.; Hirdes, John P.; Stolee, Paul; Strong, J. Graham; Poss, Jeff; Tjam, Erin Y.; Bowman, Lindsay; Ashworth, Melody

2009-01-01

Using a standardized assessment instrument, the authors compared 182 adults with congenital deaf-blindness and those with acquired deaf-blindness. They found that those with congenital deaf-blindness were more likely to have impairments in cognition, activities of daily living, and social interactions and were less likely to use speech for…

Sensitivity to Conversational Maxims in Deaf and Hearing Children

Science.gov (United States)

Surian, Luca; Tedoldi, Mariantonia; Siegel, Michael

2010-01-01

We investigated whether access to a sign language affects the development of pragmatic competence in three groups of deaf children aged 6 to 11 years: native signers from deaf families receiving bimodal/bilingual instruction, native signers from deaf families receiving oralist instruction and late signers from hearing families receiving oralist…

Rubella Deaf-Blind Child: Implications of Psychological Assessment. Proceedings.

Science.gov (United States)

Rouin, Carole

Presented are proceedings of a conference involving authorities in testing and evaluating the blind, deaf, and deaf-blind. In a paper titled "Psychological Implications of Assessing the Deaf", C. Goetzinger discusses references used in audiology, anatomy and physiology of the ear, degrees of hearing impairment, and implications of the various…

Non-syndromic sensorineural prelingual deafness: the importance of genetic counseling in demystifying parents' beliefs about the cause of their children's deafness.

Science.gov (United States)

Rodrigues, Fidjy; Paneque, Milena; Reis, Cláudia; Venâncio, Margarida; Sequeiros, Jorge; Saraiva, Jorge

2013-08-01

Recent advances in molecular genetics have allowed the determination of the genetic cause of some childhood non-syndromic deafness. In Portugal only a small proportion of families are referred to a clinical genetics service in order to clarify the etiology of the deafness and to provide genetic counseling. Consequently, there are no published studies of the prior beliefs of parents about the causes of hereditary deafness of their children and their genetic knowledge after receipt of genetic counseling. In order to evaluate the impact of genetic counseling, 44 parents of 24 children with the diagnosis of non-syndromic sensorineural prelingual deafness due to mutations in the GJB2 (connexin 26), completed surveys before and after genetic counseling. Before counseling 13.6 % of the parents knew the cause of deafness; at a post-counseling setting this percentage was significantly higher, with 84.1 % of the parents accurately identifying the etiology. No significant differences were found between the answers of mothers and fathers either before or after genetic counseling. Parents' level of education was a significant factor in pre-test knowledge. After genetic counseling 95.5 % of the parents stated that the consultation had met their expectations, 70.5 % remembered correctly the inheritance pattern, and 93.2 % correctly recalled the chance of risk of deafness. These results underline the importance of genetic counseling in demystifying parents' beliefs about the etiology of their children's deafness.

Metaphor Comprehension by Deaf Young Adults

Science.gov (United States)

Gold, Rinat; Segal, Osnat

2017-01-01

In the present study, we compared the processing of both conventional and novel metaphors by deaf versus hearing young adults. Eighteen deaf participants with severe-to-profound hearing loss and 18 controls matched for age, sex, and years of education were presented with word pairs of 4 types (literal, conventional metaphors, novel metaphors, and…

BIBLIOGRAPHY ON DEAFNESS, A SELECTED INDEX.

Science.gov (United States)

FELLENDORF, GEORGE W.; AND OTHERS

APPROXIMATELY 3,200 REFERENCES ARE LISTED BY AUTHOR AND GROUPED ACCORDING TO SUBJECT. ALL REFERENCES ARE ARTICLES FROM "THE VOLTA REVIEW," 1899 TO 1965, OR "THE AMERICAN ANNALS OF THE DEAF," 1847 TO 1965. AN AUTHOR INDEX IS INCLUDED. THIS DOCUMENT WAS PUBLISHED BY THE ALEXANDER GRAHAM BELL ASSOCIATION FOR THE DEAF, INC., THE…

Young Skilled Deaf Readers Have an Enhanced Perceptual Span in Reading.

Science.gov (United States)

Bélanger, Nathalie N; Lee, Michelle; Schotter, Elizabeth R

2017-04-27

Recently, Bélanger, Slattery, Mayberry and Rayner (2012) showed, using the moving window paradigm, that profoundly deaf adults have a wider perceptual span during reading relative to hearing adults matched on reading level. This difference might be related to the fact that deaf adults allocate more visual attention to simple stimuli in the parafovea (Bavelier, Dye & Hauser, 2006). Importantly, this reorganization of visual attention in deaf individuals is already manifesting in deaf children (Dye, Hauser & Bavelier, 2009). This leads to questions about the time course of the emergence of an enhanced perceptual span (which is under attentional control; Rayner, 2014; Miellet, O'Donnell, & Sereno, 2009) in young deaf readers. The present research addressed this question by comparing the perceptual spans of young deaf readers (age 7-15) and young hearing children (age 7-15). Young deaf readers, like deaf adults, were found to have a wider perceptual span relative to their hearing peers matched on reading level, suggesting that strong and early reorganization of visual attention in deaf individuals goes beyond the processing of simple visual stimuli and emerges into more cognitively complex tasks, such as reading.

Utility of the ImPACT test with deaf adolescents.

Science.gov (United States)

Reesman, Jennifer; Pineda, Jill; Carver, Jenny; Brice, Patrick J; Zabel, T Andrew; Schatz, Philip

2016-02-01

The goals of the study included empirical examination of the utility of the Immediate and Post-Concussion Assessment and Cognitive Testing (ImPACT) test with adolescents who are deaf or hard-of-hearing and to investigate patterns of performance at baseline that may arise in the assessment of this population. Baseline assessment of student-athletes has been conducted on a widespread scale with focus on performance of typically developing student-athletes and some clinical groups, though to date no studies have examined adolescents who are deaf or hard-of-hearing. Retrospective and de-identified ImPACT baseline test used with deaf and hard-of-hearing high-school student-athletes (N = 143; 66% male, mean age = 16.11) was examined. Review indicated significant differences in some composite scores between the deaf and hard-of-hearing group and hearing normative comparisons. A possible marker of task misunderstanding was identified to occur more frequently within the deaf and hard-of-hearing sample (13% in deaf sample vs. .31% in hearing sample). Results may provide support for the consideration and use of additional measures to ensure comprehension of task demands when considering this tool for use with deaf and hard-of-hearing adolescents.

The lived experience of depression among culturally Deaf adults.

Science.gov (United States)

Sheppard, K; Badger, T

2010-11-01

Culturally Deaf adults lost hearing at early ages, communicate primarily in American Sign Language (ASL), and self-identify as culturally Deaf. Communication barriers lead to isolation, low self-esteem, abuse, and inadequate health care. Screening Deaf patients for depressive symptoms poses challenge. Nurses are rarely familiar with ASL, and depression screening tools aren't easily translated from English to ASL. Consequently, Deaf adults are not adequately screened for depression. Qualitative interviews were conducted with culturally Deaf adults, and certified interpreters helped to enhance understanding. Text was generated from interview transcriptions and researcher observations. No novel depressive symptoms were described. Various ASL signs were used to represent depression; two participants used a unique gesture that had no meaning to others. Childhood experiences leading to depression included sexual or physical abuse, feeling ostracized from family and like a burden. Suicidal gestures communicated severity of depression. Adults felt interpreters were unwelcome during mental health encounters. No participants were asked about depressive symptoms despite frank manifestations of depression. Study describes antecedents and consequences of depressive symptoms among Deaf adults. Understanding symptom manifestations and challenges experienced by Deaf patients helps identify those at risk for depression, thereby reducing morbidity and mortality. © 2010 Blackwell Publishing.

Effect of Particle Shape on Mechanical Behaviors of Rocks: A Numerical Study Using Clumped Particle Model

Science.gov (United States)

Rong, Guan; Liu, Guang; Zhou, Chuang-bing

2013-01-01

Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied. PMID:23997677

Effect of particle shape on mechanical behaviors of rocks: a numerical study using clumped particle model.

Science.gov (United States)

Rong, Guan; Liu, Guang; Hou, Di; Zhou, Chuang-Bing

2013-01-01

Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied.

Synchronization to auditory and visual rhythms in hearing and deaf individuals

Science.gov (United States)

Iversen, John R.; Patel, Aniruddh D.; Nicodemus, Brenda; Emmorey, Karen

2014-01-01

A striking asymmetry in human sensorimotor processing is that humans synchronize movements to rhythmic sound with far greater precision than to temporally equivalent visual stimuli (e.g., to an auditory vs. a flashing visual metronome). Traditionally, this finding is thought to reflect a fundamental difference in auditory vs. visual processing, i.e., superior temporal processing by the auditory system and/or privileged coupling between the auditory and motor systems. It is unclear whether this asymmetry is an inevitable consequence of brain organization or whether it can be modified (or even eliminated) by stimulus characteristics or by experience. With respect to stimulus characteristics, we found that a moving, colliding visual stimulus (a silent image of a bouncing ball with a distinct collision point on the floor) was able to drive synchronization nearly as accurately as sound in hearing participants. To study the role of experience, we compared synchronization to flashing metronomes in hearing and profoundly deaf individuals. Deaf individuals performed better than hearing individuals when synchronizing with visual flashes, suggesting that cross-modal plasticity enhances the ability to synchronize with temporally discrete visual stimuli. Furthermore, when deaf (but not hearing) individuals synchronized with the bouncing ball, their tapping patterns suggest that visual timing may access higher-order beat perception mechanisms for deaf individuals. These results indicate that the auditory advantage in rhythmic synchronization is more experience- and stimulus-dependent than has been previously reported. PMID:25460395

The significance of deaf identity for psychological well-being

DEFF Research Database (Denmark)

Chapman, Madeleine; Dammeyer, Jesper

2017-01-01

of psychological well-being than those with a marginal identity. Further, it found that additional disability, educational level, and feeling discriminated against significantly and independently explained the degree of psychological well-being. Results are discussed here with respect to social identity theory......Research has paid attention to how deaf identity affects life outcomes such as psychological well-being. However, studies are often carried out with small samples and without controlling for other variables. This study examined how different forms of identity—deaf, hearing, bicultural (deaf...... and hearing), and marginal (neither deaf nor hearing)—were associated with levels of psychological well-being and a number of other variables. The sample was 742 adults with hearing loss in Denmark. The study found that those with a deaf, hearing or bicultural identity had significantly higher levels...

Radionuclide fixation mechanisms in rocks

International Nuclear Information System (INIS)

Nakashima, S.

1991-01-01

In the safety evaluation of the radioactive waste disposal in geological environment, the mass balance equation for radionuclide migration is given. The sorption of radionuclides by geological formations is conventionally represented by the retardation of the radionuclides as compared with water movement. In order to quantify the sorption of radionuclides by rocks and sediments, the distribution ratio is used. In order to study quantitatively the long term behavior of waste radionuclides in geological environment, besides the distribution ratio concept in short term, slower radionuclide retention reaction involving mineral transformation should be considered. The development of microspectroscopic method for long term reaction path modeling, the behavior of iron during granite and water interaction, the reduction precipitation of radionuclides, radionuclide migration pathways, and the representative scheme of radionuclide migration and fixation in rocks are discussed. (K.I.)

Monaural Congenital Deafness Affects Aural Dominance and Degrades Binaural Processing

Science.gov (United States)

Tillein, Jochen; Hubka, Peter; Kral, Andrej

2016-01-01

Cortical development extensively depends on sensory experience. Effects of congenital monaural and binaural deafness on cortical aural dominance and representation of binaural cues were investigated in the present study. We used an animal model that precisely mimics the clinical scenario of unilateral cochlear implantation in an individual with single-sided congenital deafness. Multiunit responses in cortical field A1 to cochlear implant stimulation were studied in normal-hearing cats, bilaterally congenitally deaf cats (CDCs), and unilaterally deaf cats (uCDCs). Binaural deafness reduced cortical responsiveness and decreased response thresholds and dynamic range. In contrast to CDCs, in uCDCs, cortical responsiveness was not reduced, but hemispheric-specific reorganization of aural dominance and binaural interactions were observed. Deafness led to a substantial drop in binaural facilitation in CDCs and uCDCs, demonstrating the inevitable role of experience for a binaural benefit. Sensitivity to interaural time differences was more reduced in uCDCs than in CDCs, particularly at the hemisphere ipsilateral to the hearing ear. Compared with binaural deafness, unilateral hearing prevented nonspecific reduction in cortical responsiveness, but extensively reorganized aural dominance and binaural responses. The deaf ear remained coupled with the cortex in uCDCs, demonstrating a significant difference to deprivation amblyopia in the visual system. PMID:26803166

Monaural Congenital Deafness Affects Aural Dominance and Degrades Binaural Processing.

Science.gov (United States)

Tillein, Jochen; Hubka, Peter; Kral, Andrej

2016-04-01

Cortical development extensively depends on sensory experience. Effects of congenital monaural and binaural deafness on cortical aural dominance and representation of binaural cues were investigated in the present study. We used an animal model that precisely mimics the clinical scenario of unilateral cochlear implantation in an individual with single-sided congenital deafness. Multiunit responses in cortical field A1 to cochlear implant stimulation were studied in normal-hearing cats, bilaterally congenitally deaf cats (CDCs), and unilaterally deaf cats (uCDCs). Binaural deafness reduced cortical responsiveness and decreased response thresholds and dynamic range. In contrast to CDCs, in uCDCs, cortical responsiveness was not reduced, but hemispheric-specific reorganization of aural dominance and binaural interactions were observed. Deafness led to a substantial drop in binaural facilitation in CDCs and uCDCs, demonstrating the inevitable role of experience for a binaural benefit. Sensitivity to interaural time differences was more reduced in uCDCs than in CDCs, particularly at the hemisphere ipsilateral to the hearing ear. Compared with binaural deafness, unilateral hearing prevented nonspecific reduction in cortical responsiveness, but extensively reorganized aural dominance and binaural responses. The deaf ear remained coupled with the cortex in uCDCs, demonstrating a significant difference to deprivation amblyopia in the visual system. © The Author 2016. Published by Oxford University Press.

Reading Efficiency of Deaf and Hearing People in Spanish

Science.gov (United States)

Moreno-Pérez, Francisco J.; Saldaña, David; Rodríguez-Ortiz, Isabel R.

2015-01-01

Different studies have showed poor reading performance in the deaf compared to the hearing population. This has overshadowed the fact that a minority of deaf children learns to read successfully and reaches levels similar to their hearing peers. We analyze whether deaf people deploy the same cognitive and learning processes in reading as their…

Family therapy in treatment of the deaf: a case report.

Science.gov (United States)

Shapiro, R J; Harris, R I

1976-03-01

Deaf patients with psychological problems have developmental handicaps and clinical characteristics that reduce the effectiveness of traditional modes of psychotherapy. Attempts have been made to utilize individual and group therapy, but family therapy has been largely overlooked as a method of alleviating problems of the deaf. Clinical and research writings provide us with rich insights into the family dynamics of the deaf. These data suggest to the authors that the problems of deaf individuals are largely related to family problems, and therefore merit a family orientation as the focus for treatment. This paper describes an attempt to apply family therapy with a range of deaf patients over a period of two years. From a review of their work, the authors conclude that family therapy can be effective, particularly in the treatment of deaf adolescents and children.

Assessing Health Literacy in Deaf American Sign Language Users

Science.gov (United States)

McKee, Michael M.; Paasche-Orlow, Michael; Winters, Paul C.; Fiscella, Kevin; Zazove, Philip; Sen, Ananda; Pearson, Thomas

2015-01-01

Communication and language barriers isolate Deaf American Sign Language (ASL) users from mass media, healthcare messages, and health care communication, which when coupled with social marginalization, places them at a high risk for inadequate health literacy. Our objectives were to translate, adapt, and develop an accessible health literacy instrument in ASL and to assess the prevalence and correlates of inadequate health literacy among Deaf ASL users and hearing English speakers using a cross-sectional design. A total of 405 participants (166 Deaf and 239 hearing) were enrolled in the study. The Newest Vital Sign was adapted, translated, and developed into an ASL version of the NVS (ASL-NVS). Forty-eight percent of Deaf participants had inadequate health literacy, and Deaf individuals were 6.9 times more likely than hearing participants to have inadequate health literacy. The new ASL-NVS, available on a self-administered computer platform, demonstrated good correlation with reading literacy. The prevalence of Deaf ASL users with inadequate health literacy is substantial, warranting further interventions and research. PMID:26513036

The Relationship between Mechanical Properties and Gradual Deterioration of Microstructures of Rock Mass Subject to Freeze-thaw Cycles

Directory of Open Access Journals (Sweden)

Haibo Jiang

2018-01-01

Full Text Available Under freeze-thaw cycles, the relationship between rock microstructure deterioration and its macroscopic mechanical characteristics has drawn extensive attention from engineers. With the objective to incorporate freeze-thaw cycle experiment into headrace tunnel engineering, in the present study two groups of andesite rock samples in different states are tested under the conditions of the lowest freezing temperature of –40 ℃ and the thawing temperature of 20 ℃. Damage detection was performed by magnetic resonance imaging for the interior microstructure of rock samples subject to different freeze-thaw cycles, and the relationship between the sample mechanical properties and gradual deterioration of rock microstructures was discussed. The results demonstrate evident influence of freeze-thaw cycle on the damage and deterioration of internal pore structure in andesite, and the rock uniaxial compressive strength and elasticity modulus exhibit a decreasing trend with the increase of freeze-thaw cycles. After 40 cycles, the strength of naturally saturated rock samples decreases by 39.4% (equivalent to 69.4 MPa and the elasticity modulus drops by 47.46% (equivalent to 3.27 GPa. For rock samples saturated by vacuum, 40 freeze-thaw cycles lead to a decrease of 36.86% (equivalent to 58.2 MPa in rock strength and a drop of 44.85% (equivalent to 2.83 GPa in elasticity modulus. Therefore, the test results quantitatively elucidate the substantial influence of freeze-thaw cycle on the damage and deterioration of internal structure in andesite.

Research on Deafness

Science.gov (United States)

Ramsey, Collette

1970-01-01

Paper presented at the Summer Meeting of the Alexander Graham Bell Association (Philadelphia, June 24-27, 1970) in which the author reviews the research supported by The Deafness Research Foundation. (RD)

Cyborgization: Deaf Education for Young Children in the Cochlear Implantation Era

Science.gov (United States)

Valente, Joseph Michael

2011-01-01

The author, who was raised oral deaf himself, recounts a visit to a school for young deaf children and discovers that young d/Deaf children and their rights are subverted by the cochlear implantation empire. The hypercapitalist, techno-manic times of cochlear implantation has wreaked havoc to the lives of not only young children with deafness but…

Not Silent, Invisible: Literature's Chance Encounters with Deaf Heroes and Heroines

Science.gov (United States)

McDonald, Donna M.

2010-01-01

Literatures is both a rich resource and a blunt instrument in conveying the complexities of identity, in particular, the elusive "deaf identity". The rarity of the fully realized deaf person in memoir and fiction shapes the way readers regard deaf people and throws up fresh challenges in redesigning stories of deafness free of the taint of…

Deaf directory.

Science.gov (United States)

1994-11-23

The third edition of the 199415 Directory from the Council for the Advancement of Communication with Deaf People (CACDP) is now available. Information on 192 sign language interpreters, lipspeakers, interpreters for deafblind people and speech to text reporters is provided. Details from CACDP on 0191 374 3607.

Health promotion of families of deaf children

Directory of Open Access Journals (Sweden)

Mirna Albuquerque Frota

2012-06-01

Full Text Available Objective: To investigate the impact of hearing loss in the family dynamics of the deaf child; identify the family’s knowledge about deafness, understand how parents experience the diagnosis and treatment of child with hearing impairment. Methods: The study has aqualitative approach developed at the Center for Integrated Medical Care - NAMI, attached to the University of Fortaleza - UNIFOR located in Fortaleza - CE, Brazil. The participants were six mothers of children with hearing impairment. Data collection was carried outthrough participant observation and semi-structured interview. The Thematic Analysis of Bardin was used for processing the data. Results: After coding, some categories emerged from the discourse: Misinformation of Hearing Loss; impact of the discovery of hearingloss, caregivers and facilitators of the development of the deaf children. Conclusion: The birth of a deaf child alters the previous family balance, causing specific problems, such as the communication barrier, whose solution is related to how to handle the situation. Itis necessary to promote changes, emphasizing the involvement of caregivers and loved as facilitators of deaf child’s development. In Phonoaudiology, this attitude represents discovering new ways to identify the need for the subject, which requires strategies thatvalue their opinion, allowing the expression of expectations, perceptions, representations and feelings.

Calendar systems and communication of deaf-blind children

OpenAIRE

Jablan Branka; Stanimirov Ksenija

2012-01-01

The aim of this paper is to explain the calendar systems and their role in teaching deaf-blind children. Deaf-blind persons belong to a group of multiple disabled persons. This disability should not be observed as a simple composite of visual and hearing impairments, but as a combination of sensory impairments that require special assistance in the development, communication and training for independent living. In our environment, deaf-blind children are being educated in schools for children...

Reading comprehension of deaf students in regular education.

Science.gov (United States)

Luccas, Marcia Regina Zemella; Chiari, Brasília Maria; Goulart, Bárbara Niegia Garcia de

2012-01-01

To evaluate and compare the reading comprehension of deaf students included in regular classrooms of public schools with and without specialized educational support. Observational analytic study with 35 students with sensorineural hearing loss, with and without educational support. All subjects were assessed with the Word Reading Competence Test (WRCT), the Picture-Print Matching Test by Choice (PPMT-C), and the Sentence Reading Comprehension Test (SRCT). In the tests regarding comprehension of words (WRCT and PPMT-C), the results showed no difference in the performance of deaf students who attend and do not attend educational support. Regarding reading comprehension of sentences, the application of the SRCT also did not show differences between the groups of deaf students. A significant correlation was found between age and grade, indicating that the older the students and the higher their educational level, the better their performance in reading sentences. The results indicate that deaf students, regardless of attending educational support, read words better than sentences. There is no difference in reading comprehension between deaf students who receive and do not receive specialized pedagogical monitoring.

Deaf Women: Educational Experiences and Self-Identity

Science.gov (United States)

Najarian, Cheryl G.

2008-01-01

Using life history interviews with 10 college educated Deaf women this paper investigates connections between early education and college experience and how they identified as Deaf. The women developed strategies as they managed their impressions while employing Goffman's practices of loyalty, discipline and circumspection. Acknowledging deafness…

Environmental assessment, Deaf Smith County site, Texas

Energy Technology Data Exchange (ETDEWEB)

1986-05-01

The Nuclear Waste Policy Act of 1982 (42 USC sections 10101-10226) requires the environmental assessment of a proposed site to include a statement of the basis for nominating a site as suitable for characterization. Volume 2 provides a detailed statement evaluating the site suitability of the Deaf Smith County Site under DOE siting guidelines, as well as a comparison of the Deaf Smith County Site to the other sites under consideration. The evaluation of the Deaf Smith County Site is based on the impacts associated with the reference repository design, but the evaluation will not change if based on the Mission Plan repository concept. The second part of this document compares the Deaf Smith County Site to Davis Canyon, Hanford, Richton Dome and Yucca Mountain. This comparison is required under DOE guidelines and is not intended to directly support subsequent recommendation of three sites for characterization as candidate sites. 259 refs., 29 figs., 66 refs. (MHB)

Environmental assessment, Deaf Smith County site, Texas

International Nuclear Information System (INIS)

1986-05-01

The Nuclear Waste Policy Act of 1982 (42 USC sections 10101-10226) requires the environmental assessment of a proposed site to include a statement of the basis for nominating a site as suitable for characterization. Volume 2 provides a detailed statement evaluating the site suitability of the Deaf Smith County Site under DOE siting guidelines, as well as a comparison of the Deaf Smith County Site to the other sites under consideration. The evaluation of the Deaf Smith County Site is based on the impacts associated with the reference repository design, but the evaluation will not change if based on the Mission Plan repository concept. The second part of this document compares the Deaf Smith County Site to Davis Canyon, Hanford, Richton Dome and Yucca Mountain. This comparison is required under DOE guidelines and is not intended to directly support subsequent recommendation of three sites for characterization as candidate sites. 259 refs., 29 figs., 66 refs

Employment Status of the Members of Tehran Deaf Community

Directory of Open Access Journals (Sweden)

Shahrooz nemati

2011-09-01

Full Text Available Background and Aim: Regarding the importance of employment in social and emotional status of individuals, it would be important for the deaf. The purpose of the present study was to assess the employment status of the members of Tehran deaf community.Methods: This descriptive study was performed on all members of Tehran deaf community. A researchers-made questionnaire which had three parts (demographic information, employment status of the deaf members and their attitudes regarding employment was used in this study. The obtained data were analyzed using descriptive methods.Results: Majority of deaf community members were adult (ages ranging between 18 and 30. Sixty-eight of them (52.5% were female and 53 (47.5% were male, from our participants, 56.2% were unemployed and 43.8% were employed. Main problems were: having no access to facilities regarding their disability (14.5%, communication problems (9.4%, lower salaries because of their disability (12.4%, being far from the working place (15.4%, disproportion of working environment to their disability (11.4%, maltreatment of their coworkers (13.2%, maltreatment of their employer (12.5% and discrimination because of their disability (11.2%, the attitudes of the deaf members were positive regarding the employment in all areas: 90% of them considered it as an essential part of life versus 10% of them mentioned not very important issue.Conclusion: Our findings showed that most of the deaf were supported by their family members, but not by the social facilities or their past education. The social policies should be reformed to support employment of the deaf.

A Coupled Thermo-Hydro-Mechanical Model of Jointed Hard Rock for Compressed Air Energy Storage

Directory of Open Access Journals (Sweden)

Xiaoying Zhuang

2014-01-01

Full Text Available Renewable energy resources such as wind and solar are intermittent, which causes instability when being connected to utility grid of electricity. Compressed air energy storage (CAES provides an economic and technical viable solution to this problem by utilizing subsurface rock cavern to store the electricity generated by renewable energy in the form of compressed air. Though CAES has been used for over three decades, it is only restricted to salt rock or aquifers for air tightness reason. In this paper, the technical feasibility of utilizing hard rock for CAES is investigated by using a coupled thermo-hydro-mechanical (THM modelling of nonisothermal gas flow. Governing equations are derived from the rules of energy balance, mass balance, and static equilibrium. Cyclic volumetric mass source and heat source models are applied to simulate the gas injection and production. Evaluation is carried out for intact rock and rock with discrete crack, respectively. In both cases, the heat and pressure losses using air mass control and supplementary air injection are compared.

Empathy and Theory of Mind in Deaf and Hearing Children.

Science.gov (United States)

Peterson, Candida C

2016-04-01

Empathy (or sharing another's emotion) and theory of mind (ToM: the understanding that behavior is guided by true and false beliefs) are cornerstones of human social life and relationships. In contrast to ToM, there has been little study of empathy's development, especially in deaf children. Two studies of a total of 117 children (52 hearing; 65 deaf children of hearing parents) aged 4-13 years were therefore designed to (a) compare levels of empathy in deaf and hearing children, and (b) explore correlations of ToM with empathy in deaf and hearing groups. Results showed that (a) deaf children scored lower in empathy than their hearing peers and (b) empathy and ToM were significantly correlated for deaf children but not for the hearing. Possible reasons for these divergent developmental patterns were considered, along with implications for future research. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Ophthalmologic abnormalities among deaf students in Kaduna ...

African Journals Online (AJOL)

... syndrome (0.6%) and Ushers syndrome (0.6%). Refractive error was the most common (7.9%). Conclusion: Since these deaf students use their sight to compensate for the deafness, routine ophthalmologic examination should be carried out on them so that ophthalmologic abnormalities are detected early and treatment ...

Translanguaging, Learning and Teaching in Deaf Education

Science.gov (United States)

Swanwick, Ruth

2017-01-01

This paper critiques the role of translanguaging in deaf education by examining how, and under what conditions, translanguaging practices can enhance learning and teaching. The paper explores the premise that translanguaging represents an additive view of bilingualism and multilingualism for deaf learners and offers an innovative departure from,…

Analysis of mechanical behavior of soft rocks and stability control in deep tunnels

Directory of Open Access Journals (Sweden)

Hui Zhou

2014-06-01

Full Text Available Due to the weakness in mechanical properties of chlorite schist and the high in situ stress in Jinping II hydropower station, the rock mass surrounding the diversion tunnels located in chlorite schist was observed with extremely large deformations. This may significantly increase the risk of tunnel instability during excavation. In order to assess the stability of the diversion tunnels laboratory tests were carried out in association with the petrophysical properties, mechanical behaviors and water-weakening properties of chlorite schist. The continuous deformation of surrounding rock mass, the destruction of the support structure and a large-scale collapse induced by the weak chlorite schist and high in situ stress were analyzed. The distributions of compressive deformation in the excavation zone with large deformations were also studied. In this regard, two reinforcement schemes for the excavation of diversion tunnel bottom section were proposed accordingly. This study could offer theoretical basis for deep tunnel construction in similar geological conditions.

Testicular cancer knowledge among deaf and hearing men.

Science.gov (United States)

Sacks, Loren; Nakaji, Melanie; Harry, Kadie M; Oen, Marcia; Malcarne, Vanessa L; Sadler, Georgia Robins

2013-09-01

Testicular cancer typically affects young and middle-aged men. An educational video about prostate and testicular cancer was created in American Sign Language, with English open captioning and voice overlay, so that it could be viewed by audiences of diverse ages and hearing characteristics. This study recruited young Deaf (n = 85) and hearing (n = 90) adult males to help evaluate the educational value of the testicular cancer portion of this video. Participants completed surveys about their general, testicular, and total cancer knowledge before and after viewing the video. Although hearing men had higher pre-test scores than Deaf men, both Deaf and hearing men demonstrated significant increases in General, Testicular, and Total Cancer Knowledge scores after viewing the intervention video. Overall, results demonstrate the value of the video to Deaf and hearing men.

Violence against Deaf women: effect of partner hearing status.

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Anderson, Melissa L; Kobek Pezzarossi, Caroline M

2014-07-01

Using a sample of Deaf female undergraduate students, the current study sought to investigate the prevalence, correlates, and characteristics of intimate partner violence victimization in hearing-Deaf and Deaf-Deaf relationships. Initial results suggest that similarities in hearing status and communication preference are associated with increased levels of negotiation within these relationships. However, compatibility in these areas did not co-occur with significant decreases in physical, psychological, or sexual partner violence. Recommendations for future research as well as implications for clinical and educational practice are outlined. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Perspectiva General sobre la Sordo-Ceguera (Overview on Deaf-Blindness). DB-LINK.

Science.gov (United States)

Miles, Barbara

This overview provides basic information on the causes of deaf-blindness and the particular challenges faced by individuals who are deaf-blind. Causes of deaf-blindness include various syndromes, multiple congenital anomalies, prematurity, congenital prenatal dysfunction, and various postnatal causes. Differences between people deaf-blind from…

Reading motivation, reading amount, and text comprehension in deaf and hearing adults.

Science.gov (United States)

Parault, Susan J; Williams, Heather M

2010-01-01

The purpose of this study is to examine the relationship between the variables of reading motivation, reading amount, and text comprehension in deaf and hearing adults. Research has shown that less than 50% of deaf students leave high school reading at or above a fourth-grade level (Allen, 1994). Our question is, how does this affect the levels of reading motivation and amount of reading in which deaf adults engage? Assessments of 30 hearing and 24 deaf adults showed that deaf participants reported significantly higher levels of reading motivation despite having been found to read at less than a sixth-grade level. No significant difference in the amount of reading between hearing and deaf adults was found. Amount of reading for personal reasons was found to be the best predictor of text comprehension in the deaf participants, and intrinsic motivation was found to be the best predictor of amount of reading in the deaf participants.

Analysis on the Rock-Cutter Interaction Mechanism During the TBM Tunneling Process

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Yang, Haiqing; Wang, He; Zhou, Xiaoping

2016-03-01

The accurate prediction of rock cutting forces of disc cutters is crucial for tunnel boring machine (TBM) design and construction. Disc cutter wear, which affects TBM penetration performance, has frequently been found at TBM sites. By considering the operating path and wear of the disc cutter, a new model is proposed for evaluating the cutting force and wear of the disc cutter in the tunneling process. The circular path adopted herein, which is the actual running path of the TBM disc cutter, shows that the lateral force of the disc cutter is asymmetric. The lateral forces on the sides of the disc cutter are clearly different. However, traditional solutions are obtained by assuming a linear path, where the later forces are viewed as equal. To simulate the interaction between the rock and disc cutter, a simple brittle damage model for rock mass is introduced here. Based on the explicit dynamic finite element method, the cutting force acting on the rock generated by a single disc cutter is simulated. It is shown that the lateral cutting force of the disc cutter strongly affects the wear extent of disc cutter. The wear mechanism is thus underestimated by the classical model, which was obtained by linear cutting tests. The simulation results are discussed and compared with other models, and these simulation results agree well with the results of present ones.

Communities of Practice: Literacy and Deaf Children

Science.gov (United States)

Kristoffersen, Ann-Elise; Simonsen, Eva

2016-01-01

This article aims to discuss young deaf children's access to literacy within a sociocultural perspective. We introduce the concept of communities of practice as an aspect in early literacy development for young deaf children. Preschools are learning communities and thus constitute communities of practice. Our discussion on the use of communities…

Mechanical and Thermophysical Properties of Cubic Rock-Salt AlN Under High Pressure

Science.gov (United States)

Lebga, Noudjoud; Daoud, Salah; Sun, Xiao-Wei; Bioud, Nadhira; Latreche, Abdelhakim

2018-03-01

Density functional theory, density functional perturbation theory, and the Debye model have been used to investigate the structural, elastic, sound velocity, and thermodynamic properties of AlN with cubic rock-salt structure under high pressure, yielding the equilibrium structural parameters, equation of state, and elastic constants of this interesting material. The isotropic shear modulus, Pugh ratio, and Poisson's ratio were also investigated carefully. In addition, the longitudinal, transverse, and average elastic wave velocities, phonon contribution to the thermal conductivity, and interesting thermodynamic properties were predicted and analyzed in detail. The results demonstrate that the behavior of the elastic wave velocities under increasing hydrostatic pressure explains the hardening of the corresponding phonons. Based on the elastic stability criteria under pressure, it is found that AlN with cubic rock-salt structure is mechanically stable, even at pressures up to 100 GPa. Analysis of the Pugh ratio and Poisson's ratio revealed that AlN with cubic rock-salt structure behaves in brittle manner.

Teaching sign language in gaucho schools for deaf people: a study of curricula

Directory of Open Access Journals (Sweden)

Carolina Hessel Silveira

2013-06-01

Full Text Available The paper, which provides partial results of a master’s dissertation, has sought to give contribute Sign Language curriculum in the deaf schooling. We began to understand the importance of sign languages for deaf people’s development and found out that a large part of the deaf are from hearing parents, which emphasises the significance of teaching LIBRAS (Brazilian Sign Language in schools for the deaf. We should also consider the importance of this study in building deaf identities and strengthening the deaf culture. We have obtained the theoretical basis in the so-called Deaf Studies and some experts in the curriculum theories. The main objective for this study has been to conduct an analysis of the LIBRAS curriculum at work in schools for the deaf in Rio Grande do Sul, Brazil. The curriculum analysis has shown a degree of diversity: in some curricula, content from one year is repeated in the next one with no articulation. In others, one can find preoccupation for issues of deaf identity and culture, but some of them include contents that are not related to LIBRAS, or the deaf culture, but rather to discipline for the deaf in general. By providing positive and negative aspects, the analysis data may help in discussions about difficulties, progress and problems in LIBRAS teacher education for deaf students.

The Development of Analogical Reasoning in Deaf Children and Their Parents' Communication Mode

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Bandurski, Marcin; Galkowski, Tadeusz

2004-01-01

The purpose of this article is to analyze the results of a study of the development of analogical reasoning in deaf children coming from two different linguistic environments (deaf children of deaf parents--sign language, deaf children of hearing parents--spoken language) and in hearing children, as well as to compare two groups of deaf children…

A professional development programme for teachers of the deaf in South Africa

OpenAIRE

2012-01-01

D.Ed. Education for the Deaf in South Africa appears to be insufficiently researched, contributing to a less than ideal educational situation. Teachers are not trained to address the special needs of Deaf learners, there is limited cohesive instructional theory and the educational policy focussing on the needs of Deaf learners is limited in both range and depth. Due to the ineffectiveness of Deaf education in South Africa, the majority of Deaf school leavers leave school linguistically imp...

Mechanical degradation of Emplacement Drifts at Yucca Mountain - A Modeling Case Study. Part I: Nonlithophysal Rock

International Nuclear Information System (INIS)

M. Lin; D. Kicker; B. Damjanac; M. Board; M. Karakouzian

2006-01-01

This paper outlines rock mechanics investigations associated with mechanical degradation of planned emplacement drifts at Yucca Mountain, which is the designated site for the proposed U.S. high-level nuclear waste repository. The factors leading to drift degradation include stresses from the overburden, stresses induced by the heat released from the emplaced waste, stresses due to seismically related ground motions, and time-dependent strength degradation. The welded tuff emplacement horizon consists of two groups of rock with distinct engineering properties: nonlithophysal units and lithophysal units, based on the relative proportion of lithophysal cavities. The term 'lithophysal' refers to hollow, bubble like cavities in volcanic rock that are surrounded by a porous rim formed by fine-grained alkali feldspar, quartz, and other minerals. Lithophysae are typically a few centimeters to a few decimeters in diameter. Part I of the paper concentrates on the generally hard, strong, and fractured nonlithophysal rock. The degradation behavior of the tunnels in the nonlithophysal rock is controlled by the occurrence of keyblocks. A statistically equivalent fracture model was generated based on extensive underground fracture mapping data from the Exploratory Studies Facility at Yucca Mountain. Three-dimensional distinct block analyses, generated with the fracture patterns randomly selected from the fracture model, were developed with the consideration of in situ, thermal, and seismic loads. In this study, field data, laboratory data, and numerical analyses are well integrated to provide a solution for the unique problem of modeling drift degradation

Brain-based individual difference measures of reading skill in deaf and hearing adults.

Science.gov (United States)

Mehravari, Alison S; Emmorey, Karen; Prat, Chantel S; Klarman, Lindsay; Osterhout, Lee

2017-07-01

Most deaf children and adults struggle to read, but some deaf individuals do become highly proficient readers. There is disagreement about the specific causes of reading difficulty in the deaf population, and consequently, disagreement about the effectiveness of different strategies for teaching reading to deaf children. Much of the disagreement surrounds the question of whether deaf children read in similar or different ways as hearing children. In this study, we begin to answer this question by using real-time measures of neural language processing to assess if deaf and hearing adults read proficiently in similar or different ways. Hearing and deaf adults read English sentences with semantic, grammatical, and simultaneous semantic/grammatical errors while event-related potentials (ERPs) were recorded. The magnitude of individuals' ERP responses was compared to their standardized reading comprehension test scores, and potentially confounding variables like years of education, speechreading skill, and language background of deaf participants were controlled for. The best deaf readers had the largest N400 responses to semantic errors in sentences, while the best hearing readers had the largest P600 responses to grammatical errors in sentences. These results indicate that equally proficient hearing and deaf adults process written language in different ways, suggesting there is little reason to assume that literacy education should necessarily be the same for hearing and deaf children. The results also show that the most successful deaf readers focus on semantic information while reading, which suggests aspects of education that may promote improved literacy in the deaf population. Copyright © 2017 Elsevier Ltd. All rights reserved.

Health care system accessibility. Experiences and perceptions of deaf people.

Science.gov (United States)

Steinberg, Annie G; Barnett, Steven; Meador, Helen E; Wiggins, Erin A; Zazove, Philip

2006-03-01

People who are deaf use health care services differently than the general population; little research has been carried out to understand the reasons. To better understand the health care experiences of deaf people who communicate in American Sign Language. Qualitative analyses of focus group discussions in 3 U.S. cities. Ninety-one deaf adults who communicate primarily in American Sign Language. We collected information about health care communication and perceptions of clinicians' attitudes. We elicited stories of both positive and negative encounters, as well as recommendations for improving health care. Communication difficulties were ubiquitous. Fear, mistrust, and frustration were prominent in participants' descriptions of health care encounters. Positive experiences were characterized by the presence of medically experienced certified interpreters, health care practitioners with sign language skills, and practitioners who made an effort to improve communication. Many participants acknowledged limited knowledge of their legal rights and did not advocate for themselves. Some participants believed that health care practitioners should learn more about sociocultural aspects of deafness. Deaf people report difficulties using health care services. Physicians can facilitate change to improve this. Future research should explore the perspective of clinicians when working with deaf people, ways to improve communication, and the impact of programs that teach deaf people self-advocacy skills and about their legal rights.

The Importance of Early Sign Language Acquisition for Deaf Readers

Science.gov (United States)

Clark, M. Diane; Hauser, Peter C.; Miller, Paul; Kargin, Tevhide; Rathmann, Christian; Guldenoglu, Birkan; Kubus, Okan; Spurgeon, Erin; Israel, Erica

2016-01-01

Researchers have used various theories to explain deaf individuals' reading skills, including the dual route reading theory, the orthographic depth theory, and the early language access theory. This study tested 4 groups of children--hearing with dyslexia, hearing without dyslexia, deaf early signers, and deaf late signers (N = 857)--from 4…

Reflections on Deaf Education: Perspectives of Deaf Senior Citizens

Science.gov (United States)

Roberson, Len; Shaw, Sherry

2015-01-01

Parents with deaf children face many challenges in making educational choices, developing language and a sense of belonging. Other key aspects of life including concept development and social competency are also critical decision points faced by parents. Developing language, whether it is through spoken or signed modalities, is of utmost…

Consideration on the Mechanism of Microwave Emission Due to Rock Fracture

Science.gov (United States)

Takano, Tadashi; Sugita, Seiji; Yoshida, Shingo; Maeda, Takashi

2010-05-01

Microwave emission due to rock fracture was found at 300 MHz, 2 GHz, and 22 GHz, and its power was calibrated in laboratory for the first time in the world. The observed waveform is impulsive, and contains correspondent frequency component inside the envelope at each frequency band. At such high frequencies, the electro-magnetic signal power can be calibrated as a radiating wave with high accuracy. Accordingly, it was verified that a substantial power is emitted. The microwave emission phenomena were also observed on occasions of hypervelocity impact, and esteemed as phenomena generally associated with material destruction. Earthquakes and volcanic activities are association with rock fractures so that the microwave is expected to be emitted. Actually, the e emission was confirmed by the data analysis of the brightness temperature obtained by a remote sensing satellite, which flew over great earthquakes of Wuenchan and Sumatra, and great volcanic eruptions of Reventador and Chanten. It is important to show the microwave emission during rock fracture in natural phenomena. Therefore, the field test to detect the microwave due to the collapse of a crater cliff was planned and persecuted at the volcano of Miyake-jima about 100 km south of Tokyo. Volcanic activity may be more convenient than an earthquake because of the known location and time. As a result, they observed the microwave emission which was strongly correlated with the cliff collapses. Despite of the above-mentioned phenomenological fruits, the reason of the microwave emission is not fixed yet. We have investigated the mechanism of the emission in consideration of the obtained data in rock fracture experiments so far and the study results on material destruction by hypervelocity impact. This paper presents the proposal of the hypothesis and resultant discussions. The microwave sensors may be useful to monitor natural hazards such as an earthquake or a volcanic eruption, because the microwave due to rock

Coupled hydrological-mechanical effects due to excavation of underground openings in unsaturated fractured rocks

International Nuclear Information System (INIS)

Montazer, P.

1985-01-01

One of the effects of excavating an underground opening in fractured rocks is a modification of the state of the stress in the rock mass in the vicinity of the opening. This effect causes changes in the geometry of the cross sections of the fracture planes, which in turn results in modification of the hydrologic properties of the fractures of the rock mass. The significance of the orientation of the fractures and their stiffness on the extent of the modification of the hydrologic properties as a result of excavation of underground openings is demonstrated. A conceptual model is presented to illustrate the complexity of the coupled hydrological-mechanical phenomena in the unsaturated zone. This conceptual model is used to develop an investigative program to assess the extent of the effect at a proposed repository site for storing high-level nuclear wastes

Postnatal development of the endbulb of Held in congenitally deaf cats

Directory of Open Access Journals (Sweden)

Christa A Baker

2010-05-01

Full Text Available The endbulbs of Held are formed by the ascending branches of myelinated auditory nerve fibers and represent one of the largest synaptic endings in the brain. Normally, these endings are highly branched and each can form up to 1000 dome-shaped synapses. The deaf white cat is a model of congenital deafness involving a type of cochleosaccular degeneration that mimics the Scheibe deformity in humans. Mature deaf white cats exhibit reduced endbulb branching, hypertrophy of postsynaptic densities (PSDs, and changes in synaptic vesicle density. Because cats are essentially deaf at birth, we wanted to determine if the progression of brain abnormalities was linked in time to the failure of normal hearing development. The rationale was that the lack of sound-evoked activity would trigger pathologic change in deaf kittens. The cochleae of deaf cats did not exhibit abnormal morphology at birth. After the first postnatal week, however, the presence of a collapsed scala media signaled the difference between deaf and hearing cats. By working backwards in age, endbulbs of deaf cats expressed flattened and elongated PSDs and increased synaptic vesicle density as compared to normal endbulbs. These differences are present at birth in some white kittens, presaging deafness despite their normal cochlear histology. We speculate that hearing pathology is signaled by a perinatal loss of spontaneous bursting activity in auditory nerve fibers or perhaps by some factor released by hair cell synapses before obliteration of the organ of Corti.

Acute cortical deafness in a child with MELAS syndrome.

Science.gov (United States)

Pittet, Marie P; Idan, Roni B; Kern, Ilse; Guinand, Nils; Van, Hélène Cao; Toso, Seema; Fluss, Joël

2016-05-01

Auditory impairment in mitochondrial disorders are usually due to peripheral sensorineural dysfunction. Central deafness is only rarely reported. We report here an 11-year-old boy with MELAS syndrome who presented with subacute deafness after waking up from sleep. Peripheral hearing loss was rapidly excluded. A brain MRI documented bilateral stroke-like lesions predominantly affecting the superior temporal lobe, including the primary auditory cortex, confirming the central nature of deafness. Slow recovery was observed in the following weeks. This case serves to illustrate the numerous challenges caused by MELAS and the unusual occurrence of acute cortical deafness, that to our knowledge has not be described so far in a child in this setting.

The benefits of sign language for deaf learners with language challenges

Directory of Open Access Journals (Sweden)

Van Staden, Annalene

2009-12-01

Full Text Available This article argues the importance of allowing deaf children to acquire sign language from an early age. It demonstrates firstly that the critical/sensitive period hypothesis for language acquisition can be applied to specific language aspects of spoken language as well as sign languages (i.e. phonology, grammatical processing and syntax. This makes early diagnosis and early intervention of crucial importance. Moreover, research findings presented in this article demonstrate the advantage that sign language offers in the early years of a deaf child’s life by comparing the language development milestones of deaf learners exposed to sign language from birth to those of late-signers, orally trained deaf learners and hearing learners exposed to spoken language. The controversy over the best medium of instruction for deaf learners is briefly discussed, with emphasis placed on the possible value of bilingual-bicultural programmes to facilitate the development of deaf learners’ literacy skills. Finally, this paper concludes with a discussion of the implications/recommendations of sign language teaching and Deaf education in South Africa.

Antenatal diagnosis of congenital deafness.

Science.gov (United States)

Isaacson, G

1988-01-01

Advances in the field of antenatal diagnosis have made possible the detection of profound sensorineural hearing loss prior to birth. Fetal motion in response to sound and auditory evoked potential testing can determine the presence of fetal hearing in the third trimester of pregnancy. Imaging modalities including ultrasound, computed tomography, and magnetic resonance imaging hold promise for the diagnosis of some forms of congenital deafness in the second trimester fetus. The methods by which congenital deafness soon may be diagnosed and the implications for the otologist are discussed.

Deaf and Hearing Children: A Comparison of Peripheral Vision Development

Science.gov (United States)

Codina, Charlotte; Buckley, David; Port, Michael; Pascalis, Olivier

2011-01-01

This study investigated peripheral vision (at least 30[degrees] eccentric to fixation) development in profoundly deaf children without cochlear implantation, and compared this to age-matched hearing controls as well as to deaf and hearing adult data. Deaf and hearing children between the ages of 5 and 15 years were assessed using a new,…

Confronting the language barrier: Theory of mind in deaf children.

Science.gov (United States)

Jones, Anna C; Gutierrez, Roberto; Ludlow, Amanda K

2015-01-01

The current study addressed deaf children's Theory of Mind (ToM) development as measured by a battery of first- and second-order belief tasks. Both a chronological age-matched control group and a younger group of pre-school aged hearing children were compared to a group of deaf children born to hearing parents. A hearing native signer enacted each of the tasks, which were pre-recorded in video clips in English (SSE), British Sign Language (BSL) and spoken English, in order to consider all communication preferences of the deaf children. Results revealed no differences in performance between the deaf and the young hearing children. However, despite the inclusion of ToM tasks based on their preferred mode of communication, the deaf children performed significantly worse at the unexpected-content and second-order belief task compared with their age-matched controls. These findings imply a delay rather than a deficit in ToM in deaf children that could be attributed to limited opportunities to converse and overhear conversations about mental states. None. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Impact of Genetic Counseling and Connexin-26 and Connexin-30 Testing on Deaf Identity and Comprehension of Genetic Test Results in a Sample of Deaf Adults: A Prospective, Longitudinal Study

Science.gov (United States)

Palmer, Christina G. S.; Boudreault, Patrick; Baldwin, Erin E.; Sinsheimer, Janet S.

2014-01-01

Using a prospective, longitudinal study design, this paper addresses the impact of genetic counseling and testing for deafness on deaf adults and the Deaf community. This study specifically evaluated the effect of genetic counseling and Connexin-26 and Connexin-30 genetic test results on participants' deaf identity and understanding of their genetic test results. Connexin-26 and Connexin-30 genetic testing was offered to participants in the context of linguistically and culturally appropriate genetic counseling. Questionnaire data collected from 209 deaf adults at four time points (baseline, immediately following pre-test genetic counseling, 1-month following genetic test result disclosure, and 6-months after result disclosure) were analyzed. Four deaf identity orientations (hearing, marginal, immersion, bicultural) were evaluated using subscales of the Deaf Identity Development Scale-Revised. We found evidence that participants understood their specific genetic test results following genetic counseling, but found no evidence of change in deaf identity based on genetic counseling or their genetic test results. This study demonstrated that culturally and linguistically appropriate genetic counseling can improve deaf clients' understanding of genetic test results, and the formation of deaf identity was not directly related to genetic counseling or Connexin-26 and Connexin-30 genetic test results. PMID:25375116

Field and in-situ rock-mechanics testing manual. Technical report

International Nuclear Information System (INIS)

Shuri, F.S.; Feves, M.L.; Peterson, G.L.; Foster, K.M.; Kienle, C.F. Jr.

1981-10-01

Standardized field and in situ rock mechanics testing procedures have been prepared for use in the National Terminal Waste Storage Program. The procedures emphasize equipment performance specifications, documentation and reporting, and Quality Assurance acceptance criteria. Sufficient theoretical background is included to allow the user to perform the necessary data reduction. These procedures incorporate existing standards when possible, otherwise they represent the current state of the art. Maximum flexibility in equipment design has been incorporated to allow use of this manual by existing groups and to encourage future improvements

Outline of deaf schools on the level throughout the country : A study on architectural planning for the deaf school Part 1

OpenAIRE

平根, 孝光

1993-01-01

This paper is to make clear in outline of deaf schools on the level throughout the country in 1990s. The factors might supposedly exhibit the characteristics of deaf schools are as follows : 1) In deaf schools which have 4 departments and in which early-age education for such children of no less than 3 years of age is executed, babies, young children, children, and juveniles whose age cover a wide renge from 0 to 21 study in a same school, where great gaps are evidently noticed in such people...

Role of HHM coupling mechanisms on the evolution of rock masses around nuclear waste disposals in the context of gas generation

International Nuclear Information System (INIS)

Hoxha, D.; Do, D.-P.; Wendling, J.; Poutrel, A.

2010-01-01

Document available in extended abstract form only. This paper aims at modelling of long term evolution of hydro-mechanical state of rock masses around sealing nuclear waste disposals. In the principles of nuclear waste disposals the geological barrier must play a long term confining role in respect with nuclide transport. In terms of hydro-mechanical properties this calls for managing the damage around the underground workings of the waste disposals. In particular the seal buffers and barrier rock will support the generation of hydrogen of different origins, mainly from the corrosion of steals used in various elements of a nuclear waste disposal. This generation would generate gas pressures sufficiently high to partially dry seal or barrier rock leading to a redistribution of stress around underground openings, to a reactivation of the rock damage and finally could put in question the concept of geological barrier itself. The object of this paper is to shed light in the mechanisms of HHM coupling in rocks around a repository by comparative numerical analyses. Basically, we chose two configurations to proceed with analyses: one in plan strain conditions and the other an axial symmetric configuration. The goal of the first configuration is the assessment of gas pressure evolution in the openings of a repository. The principal input of the problem is the kinetics of gas generation (H 2 generation) given by a step-wise function of time describing the gas generation of one single nuclear waste coli. Then known the repository architecture one could easily calculate the mass of gas generated on one access gallery. Since extreme scenario is studied, we suppose that the gas generated by the set of alveoli is fully located in the access gallery and only a radial gas flux is possible.The hydro mechanical properties of rocks up to the surface were taken into account. For the callovo-Oxfordian clay that constitutes barrier rock in immediate neighbouring of the gallery a model

Sustained attention, selective attention and cognitive control in deaf and hearing children

Science.gov (United States)

Dye, Matthew W. G.; Hauser, Peter C.

2014-01-01

Deaf children have been characterized as being impulsive, distractible, and unable to sustain attention. However, past research has tested deaf children born to hearing parents who are likely to have experienced language delays. The purpose of this study was to determine whether an absence of auditory input modulates attentional problems in deaf children with no delayed exposure to language. Two versions of a continuous performance test were administered to 37 deaf children born to Deaf parents and 60 hearing children, all aged 6–13 years. A vigilance task was used to measure sustained attention over the course of several minutes, and a distractibility test provided a measure of the ability to ignore task irrelevant information – selective attention. Both tasks provided assessments of cognitive control through analysis of commission errors. The deaf and hearing children did not differ on measures of sustained attention. However, younger deaf children were more distracted by task-irrelevant information in their peripheral visual field, and deaf children produced a higher number of commission errors in the selective attention task. It is argued that this is not likely to be an effect of audition on cognitive processing, but may rather reflect difficulty in endogenous control of reallocated visual attention resources stemming from early profound deafness. PMID:24355653

Heterogeneous Rock Simulation Using DIP-Micromechanics-Statistical Methods

Directory of Open Access Journals (Sweden)

H. Molladavoodi

2018-01-01

Full Text Available Rock as a natural material is heterogeneous. Rock material consists of minerals, crystals, cement, grains, and microcracks. Each component of rock has a different mechanical behavior under applied loading condition. Therefore, rock component distribution has an important effect on rock mechanical behavior, especially in the postpeak region. In this paper, the rock sample was studied by digital image processing (DIP, micromechanics, and statistical methods. Using image processing, volume fractions of the rock minerals composing the rock sample were evaluated precisely. The mechanical properties of the rock matrix were determined based on upscaling micromechanics. In order to consider the rock heterogeneities effect on mechanical behavior, the heterogeneity index was calculated in a framework of statistical method. A Weibull distribution function was fitted to the Young modulus distribution of minerals. Finally, statistical and Mohr–Coulomb strain-softening models were used simultaneously as a constitutive model in DEM code. The acoustic emission, strain energy release, and the effect of rock heterogeneities on the postpeak behavior process were investigated. The numerical results are in good agreement with experimental data.

Deaf women: experiences and perceptions of healthcare system access.

Science.gov (United States)

Steinberg, Annie G; Wiggins, Erin A; Barmada, Carlin Henry; Sullivan, Vicki Joy

2002-10-01

The authors investigated the knowledge, attitudes, and healthcare experiences of Deaf women. Interviews with 45 deaf women who participated in focus groups in American Sign Language were translated, transcribed, and analyzed. Deaf women's understanding of women's health issues, knowledge of health vocabulary in both English and American Sign Language, common health concerns among Deaf women, and issues of access to information, including pathways and barriers, were examined. As a qualitative study, the results of this investigation are limited and should be viewed as exploratory. A lack of health knowledge was evident, including little understanding of the meaning or value of cancer screening, mammography, or Pap smears; purposes of prescribed medications, such as hormone replacement therapy (HRT); or necessity for other medical or surgical interventions. Negative experiences and avoidance or nonuse of health services were reported, largely due to the lack of a common language with healthcare providers. Insensitive behaviors were also described. Positive experiences and increased access to health information were reported with practitioners who used qualified interpreters. Providers who demonstrated minimal signing skills, a willingness to use paper and pen, and sensitivity to improving communication were appreciated. Deaf women have unique cultural and linguistic issues that affect healthcare experiences. Improved access to health information may be achieved with specialized resource materials, improved prevention and targeted intervention strategies, and self-advocacy skills development. Healthcare providers must be trained to become more effective communicators with Deaf patients and to use qualified interpreters to assure access to healthcare for Deaf women.

Vocational Orientation of the Deaf Pupils

OpenAIRE

Sobolevská, Šárka

2017-01-01

The main goal of the bachelor thesis is to learn about vocational orientation of deaf pupils in their last years of study at selected elementary schools for the Deaf and to compare the results to results of similar studies done with pupils without hearing impairment. Based on relevant scientific sources, the paper introduces general aspects that shape vocational orientation, also describes vocational development on D. E. Super's Career Development Theory. The thesis continues with characteriz...

Black Deaf Individuals' Reading Skills: Influence of ASL, Culture, Family Characteristics, Reading Experience, and Education

Science.gov (United States)

Myers, Candace; Clark, M. Diane; Musyoka, Millicent M.; Anderson, Melissa L.; Gilbert, Gizelle L.; Agyen, Selina; Hauser, Peter C.

2010-01-01

Previous research on the reading abilities of Deaf individuals from various cultural groups suggests that Black Deaf and Hispanic Deaf individuals lag behind their White Deaf peers. The present study compared the reading skills of Black Deaf and White Deaf individuals, investigating the influence of American Sign Language (ASL), culture, family…

An exploration of deaf women's access to mental health nurse education in the United Kingdom.

Science.gov (United States)

Sharples, Naomi

2013-09-01

Historically deaf people have been denied access to professional nurse education due to a range of language, communication and ideological barriers. The following study was set in the North of England and draws upon the Western experience and knowledge base of deaf people's experience of access to professional education. The aim of this study was to understand the experiences of the first British Sign Language using deaf qualified nurses before they entered the Pre-registration Diploma in Nursing Programme, during the programme and after the programme as they progressed into professional nursing roles. The purpose of the study was to gather the nurses' thoughts and feelings about their experiences and to analyse these using thematic analysis within a narrative interpretive tradition against a backdrop of Jurgen Habermas' critical theory and Paulo Freire's critical pedagogy. By drawing out significant themes to structure a deeper understanding of the nurses' unique positions, they offer a model for inclusive education practice that would support deaf people and people from minority groups into nursing and other health care professions. The signed narratives were video recorded and interpreted into written English transcripts which were then analysed to discover the underlying themes using Boyatzis' (1998) thematic analysis. The findings are set against an historical and contemporary setting of deaf people in Western society, their experiences of education, health and employment. These unique findings illustrate the significance of an accessible language environment for the nurses, the role of the organisation in ensuring access for the nurses and the impact of barriers to education and the clinical environment. The implications for education and practice supports the need to analyse the workforce required in deaf services, to scrutinize the access provided, to develop cultural competence skills, enhance the use of additional support mechanisms, generate accessible

A proposal of constitutive creep model for soft rock to be applied to numerical analysis for mechanical interaction in the underground facilities

International Nuclear Information System (INIS)

Sawada, Masataka; Okada, Tetsuji

2005-01-01

In the case that the underground facilities of high-level nuclear waste disposal are constructed in soft rock mass, it is predicted that time-dependent behavior of rock has an important role both on the stability of surrounding rock mass after excavation and on the super long-term stability of barrier system. Existing creep model that has been applied to excavation problems in electric power industry is not sufficient in order to evaluate long-term behavior of the facility constructed in soft rock mass. Therefore, it is necessary to develop an appropriate creep model for soft rock. In this research, we try to develop a prototype of numerical tool for evaluating the stability during and after the excavation and super long-term stability after back-filling. Firstly, a simple rheological model for time-dependent behavior of soft rock is proposed. It is the key feature of this model that two different types of rheological model can be selected in order to describe both failure and non-failure processes. Rock continues to deform until failure in the case where stress applied to the rock exceeds its residual strength, although deformation of the rock finally ceases in the other cases. The applicability of this model is investigated by comparing the calculated results with those in laboratory test results. The proposed model can describe the time-dependent and dilatancy behavior of mudstone of Tertiary period observed in the drained triaxial creep test. Next, we apply the proposed model to the problem of time-dependent behavior of rock mass around a deposition hole. Numerical simulation of excavation problem and long-term mechanical interaction between buffer material and surrounding rock mass is carried out using a hydrological - mechanical coupled FEM code that includes the proposed model. Several mechanical models can be selected in order to apply to the mechanical behavior of materials consisting of underground facility. The main results obtained from this simulation

Mechanics of graben formation in crustal rocks - A finite element analysis

Science.gov (United States)

Melosh, H. J.; Williams, C. A., Jr.

1989-01-01

The mechanics of the initial stages of graben formation are examined, showing that the configuration of a graben (a pair of antithetically dipping normal faults) is the most energetically favorable fault configuration in elastic-brittle rocks subjected to pure extension. The stress field in the vicinity of a single initial normal fault is computed with a two-dimensional FEM. It is concluded that the major factor controlling graben width is the depth of the initial fault.

Impact of grain size and rock composition on simulated rock weathering

Science.gov (United States)

Israeli, Yoni; Emmanuel, Simon

2018-05-01

Both chemical and mechanical processes act together to control the weathering rate of rocks. In rocks with micrometer size grains, enhanced dissolution at grain boundaries has been observed to cause the mechanical detachment of particles. However, it remains unclear how important this effect is in rocks with larger grains, and how the overall weathering rate is influenced by the proportion of high- and low-reactivity mineral phases. Here, we use a numerical model to assess the effect of grain size on chemical weathering and chemo-mechanical grain detachment. Our model shows that as grain size increases, the weathering rate initially decreases; however, beyond a critical size no significant decrease in the rate is observed. This transition occurs when the density of reactive boundaries is less than ˜ 20 % of the entire domain. In addition, we examined the weathering rates of rocks containing different proportions of high- and low-reactivity minerals. We found that as the proportion of low-reactivity minerals increases, the weathering rate decreases nonlinearly. These simulations indicate that for all compositions, grain detachment contributes more than 36 % to the overall weathering rate, with a maximum of ˜ 50 % when high- and low-reactivity minerals are equally abundant in the rock. This occurs because selective dissolution of the high-reactivity minerals creates large clusters of low-reactivity minerals, which then become detached. Our results demonstrate that the balance between chemical and mechanical processes can create complex and nonlinear relationships between the weathering rate and lithology.

Development of social-cognitive and communication skills in children born deaf.

Science.gov (United States)

Peterson, Candida C

2009-10-01

Central to the interface of social-cognitive and communicative development is the growth of a theory of mind (ToM). ToM is mastered by most hearing children and deaf children of signing deaf parents by the age of 5 or 6 but is often seriously delayed in deaf children of hearing parents. This paper reviews recently published research on deaf children's ToM development and presents an original study consisting of eight longitudinal case histories that collectively map late-signing deaf children's ToM performance from 44 to 158 months of age. While five tentative conclusions can be posited from the collective research so far, further investigation of each of these possibilities is clearly needed.

Sign Language and the Learning of Swedish by Deaf Children (Project TSD).

Science.gov (United States)

Jansson, Karin, Ed.

1982-01-01

A project in Sweden focuses on the early linguistic development of preschool deaf children in families where the parents are also deaf. The School for the Deaf in Sweden is involved with describing the Swedish language as it appears to a deaf learner, a description to be used as a basis for teacher training and inservice in the teaching of the…

Mechanisms controlling rock coast evolution in paraglacial landscapes - examples from Arctic, Antarctic and Scandinavian regions

Science.gov (United States)

Strzelecki, M. C.; Lim, M.; Kasprzek, M.; Swirad, Z. M.; Rachlewicz, G.; Migoń, P.; Pawlowski, L.; Jaskolski, M.

2017-12-01

This paper presents the results of an investigation into the processes controlling development of paraglacial rock coast systems in Hornsund, Svalbard, Admiralty Bay, South Shetland Islands and Gotland Island, Scandinavia. A suite of nested geomorphological and geophysical methods have been applied to characterize the functioning of rock cliffs, shore platforms and stacks influenced by lithological control and geomorphic processes driven by paraglacial coast environments - both in glaciated and deglaciated study sites. Rock hardness, quantified by Schmidt hammer rebound tests, demonstrate strong spatial control on the degree of rock weathering (rock strength) along studied rock coasts. Elevation controlled geomorphic zones are identified and linked to distinct processes and mechanisms, transitioning from peak hardness values at the icefoot/sea-ice through the wave and storm dominated scour zones to the lowest values on the cliff tops, where the effects of periglacial weathering dominate. Observations of rock surface change using a traversing micro-erosion meter (TMEM) indicate that significant changes in erosion rates occur at the junction between shore platform and the cliff toe, where rock erosion is facilitated by frequent wetting and drying and operation of nivation and sea ice processes (formation and melting of snow patches and icefoot complexes). Electrical resistivity tomography (ERT) surveys have been used to investigate frozen ground control on rock coast dynamics and reveal the strong interaction with marine processes in polar coastal settings. In Gotland, Scandinavia the morphology of rocky coastal landforms (rauks) bear traces of numerous environmental changes that occurred in Baltic region over the Holocene including salinity, temperature, ice-cover/storminess and relative sea-level. The results are synthesised to propose a new conceptual model of paraglacial rock coast systems, with the aim of contributing towards a unifying concept of cold region

The influence of language deprivation in early childhood on L2 processing: An ERP comparison of deaf native signers and deaf signers with a delayed language acquisition.

Science.gov (United States)

Skotara, Nils; Salden, Uta; Kügow, Monique; Hänel-Faulhaber, Barbara; Röder, Brigitte

2012-05-03

To examine which language function depends on early experience, the present study compared deaf native signers, deaf non-native signers and hearing German native speakers while processing German sentences. The participants watched simple written sentences while event-related potentials (ERPs) were recorded. At the end of each sentence they were asked to judge whether the sentence was correct or not. Two types of violations were introduced in the middle of the sentence: a semantically implausible noun or a violation of subject-verb number agreement. The results showed a similar ERP pattern after semantic violations (an N400 followed by a positivity) in all three groups. After syntactic violations, native German speakers and native signers of German sign language (DGS) with German as second language (L2) showed a left anterior negativity (LAN) followed by a P600, whereas no LAN but a negativity over the right hemisphere instead was found in deaf participants with a delayed onset of first language (L1) acquisition. The P600 of this group had a smaller amplitude and a different scalp distribution as compared to German native speakers. The results of the present study suggest that language deprivation in early childhood alters the cerebral organization of syntactic language processing mechanisms for L2. Semantic language processing instead was unaffected.

An unhappy and utterly pitiable creature? Life and self images of Deaf people in the Netherlands at the time of the founding fathers of Deaf education

NARCIS (Netherlands)

Tellings, A.E.J.M.; Tijsseling, C.

2005-01-01

This article describes how young deaf people in the Netherlands between 1809 and 1828 made the transition from living in a school for the Deaf,1 a rather protected community with mostly deaf people and with hearing people who could understand them rather well, to a life in hearing society with

The results of experimental studies of VLF-ULF electromagnetic emission by rock samples due to mechanical action

Science.gov (United States)

Panfilov, A. A.

2014-06-01

The paper presents the results of laboratory experiments on electromagnetic emissions excitation (the electric component of electromagnetic fields) by rock samples due to different forms of mechanical stress applications. It was shown that samples generate electric impulses with different spectra when the impact action, gradual loading or dynamic friction is applied. It was ascertained that level and spectral compositions of signals, generated by rock samples, change with an increasing number of hits. It was found that strong electromagnetic signals, generated while rock samples were fracturing, were accompanied by repetitive weak but perceptible variations in the electric field intensity in short frequency ranges.

Reaching the Summit: Deaf Adults as Essential Partners in Education

Science.gov (United States)

Bourne-Firl, Bridgetta

2016-01-01

How do we reach the summit in terms of supporting the best transition possible for each young deaf or hard of hearing individual in the United States? Should professionals who are hearing work alone to succeed with deaf and hard of hearing students? No matter how good the intention, if we want deaf and hard of hearing students to transition from…

Rock Physics

DEFF Research Database (Denmark)

Fabricius, Ida Lykke

2017-01-01

Rock physics is the discipline linking petrophysical properties as derived from borehole data to surface based geophysical exploration data. It can involve interpretation of both elastic wave propagation and electrical conductivity, but in this chapter focus is on elasticity. Rock physics is based...... on continuum mechanics, and the theory of elasticity developed for statics becomes the key to petrophysical interpretation of velocity of elastic waves. In practice, rock physics involves interpretation of well logs including vertical seismic profiling (VSP) and analysis of core samples. The results...

The results of experimental studies of VLF–ULF electromagnetic emission by rock samples due to mechanical action

OpenAIRE

A. A. Panfilov

2013-01-01

The paper presents the results of laboratory experiments on electromagnetic emission excitation (electric component of electromagnetic field) by rock samples due to different forms of mechanical stress applications. It was shown that samples generate electric impulses with different spectra when the impact action, gradual loading or dynamic friction is applied. It was ascertained that level and spectral compositions of signals, generated by rock samples, cha...

Implicit sequence learning in deaf children with cochlear implants.

Science.gov (United States)

Conway, Christopher M; Pisoni, David B; Anaya, Esperanza M; Karpicke, Jennifer; Henning, Shirley C

2011-01-01

Deaf children with cochlear implants (CIs) represent an intriguing opportunity to study neurocognitive plasticity and reorganization when sound is introduced following a period of auditory deprivation early in development. Although it is common to consider deafness as affecting hearing alone, it may be the case that auditory deprivation leads to more global changes in neurocognitive function. In this paper, we investigate implicit sequence learning abilities in deaf children with CIs using a novel task that measured learning through improvement to immediate serial recall for statistically consistent visual sequences. The results demonstrated two key findings. First, the deaf children with CIs showed disturbances in their visual sequence learning abilities relative to the typically developing normal-hearing children. Second, sequence learning was significantly correlated with a standardized measure of language outcome in the CI children. These findings suggest that a period of auditory deprivation has secondary effects related to general sequencing deficits, and that disturbances in sequence learning may at least partially explain why some deaf children still struggle with language following cochlear implantation. © 2010 Blackwell Publishing Ltd.

The Deaf community in Flanders and South Africa : An ethnographic analysis

OpenAIRE

Vermeerbergen, Myriam; Van Herreweghe, Mieke

2008-01-01

Schein (1989) proposes a theory of Deaf Community development and applies his theory to the situation in the USA. He hypothesizes five factors: “These factors and their interactions account for the unique social-psychological behavior of Deaf people that resulted in the development of the phenomenon called the Deaf community" (p. 200). The demographic factor refers to a first precondition for the development of a Deaf community, viz. that there is a critical mass, i.e. both in actual numbers ...

Experimental Investigation on the Fatigue Mechanical Properties of Intermittently Jointed Rock Models Under Cyclic Uniaxial Compression with Different Loading Parameters

Science.gov (United States)

Liu, Yi; Dai, Feng; Dong, Lu; Xu, Nuwen; Feng, Peng

2018-01-01

Intermittently jointed rocks, widely existing in many mining and civil engineering structures, are quite susceptible to cyclic loading. Understanding the fatigue mechanism of jointed rocks is vital to the rational design and the long-term stability analysis of rock structures. In this study, the fatigue mechanical properties of synthetic jointed rock models under different cyclic conditions are systematically investigated in the laboratory, including four loading frequencies, four maximum stresses, and four amplitudes. Our experimental results reveal the influence of the three cyclic loading parameters on the mechanical properties of jointed rock models, regarding the fatigue deformation characteristics, the fatigue energy and damage evolution, and the fatigue failure and progressive failure behavior. Under lower loading frequency or higher maximum stress and amplitude, the jointed specimen is characterized by higher fatigue deformation moduli and higher dissipated hysteresis energy, resulting in higher cumulative damage and lower fatigue life. However, the fatigue failure modes of jointed specimens are independent of cyclic loading parameters; all tested jointed specimens exhibit a prominent tensile splitting failure mode. Three different crack coalescence patterns are classified between two adjacent joints. Furthermore, different from the progressive failure under static monotonic loading, the jointed rock specimens under cyclic compression fail more abruptly without evident preceding signs. The tensile cracks on the front surface of jointed specimens always initiate from the joint tips and then propagate at a certain angle with the joints toward the direction of maximum compression.

The "Third Ear" Decolonizes: Integrating Deaf Students into Post-Secondary Classes

Science.gov (United States)

McHeimech, Zeinab

2009-01-01

Can we effectively integrate Deaf students into our post-secondary classes before recognizing and listening to them? Studies indicate that Deaf students continue to struggle, be silenced, and experience isolation when mainstreamed. Deaf students, or second-language students, inevitably develop new identities once included; however, we cannot…

Sustained attention, selective attention and cognitive control in deaf and hearing children.

Science.gov (United States)

Dye, Matthew W G; Hauser, Peter C

2014-03-01

Deaf children have been characterized as being impulsive, distractible, and unable to sustain attention. However, past research has tested deaf children born to hearing parents who are likely to have experienced language delays. The purpose of this study was to determine whether an absence of auditory input modulates attentional problems in deaf children with no delayed exposure to language. Two versions of a continuous performance test were administered to 37 deaf children born to Deaf parents and 60 hearing children, all aged 6-13 years. A vigilance task was used to measure sustained attention over the course of several minutes, and a distractibility test provided a measure of the ability to ignore task irrelevant information - selective attention. Both tasks provided assessments of cognitive control through analysis of commission errors. The deaf and hearing children did not differ on measures of sustained attention. However, younger deaf children were more distracted by task-irrelevant information in their peripheral visual field, and deaf children produced a higher number of commission errors in the selective attention task. It is argued that this is not likely to be an effect of audition on cognitive processing, but may rather reflect difficulty in endogenous control of reallocated visual attention resources stemming from early profound deafness. Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental Study on Mechanical and Acoustic Emission Characteristics of Rock-Like Material Under Non-uniformly Distributed Loads

Science.gov (United States)

Wang, Xiao; Wen, Zhijie; Jiang, Yujing; Huang, Hao

2018-03-01

The mechanical and acoustic emission characteristics of rock-like materials under non-uniform loads were investigated by means of a self-developed mining-induced stress testing system and acoustic emission monitoring system. In the experiments, the specimens were divided into three regions and different initial vertical stresses and stress loading rates were used to simulate different mining conditions. The mechanical and acoustic emission characteristics between regions were compared, and the effects of different initial vertical stresses and different stress loading rates were analysed. The results showed that the mechanical properties and acoustic emission characteristics of rock-like materials can be notably localized. When the initial vertical stress and stress loading rate are fixed, the peak strength of region B is approximately two times that of region A, and the maximum acoustic emission hit value of region A is approximately 1-2 times that of region B. The effects of the initial vertical stress and stress loading rate on the peck strain, maximum hit value, and occurrence time of the maximum hit are similar in that when either of the former increase, the latter all decrease. However, peck strength will increase with the increase in loading rate and decrease with the increase in initial vertical stress. The acoustic emission hits can be used to analyse the damage in rock material, but the number of acoustic emission hits cannot be used alone to determine the degree of rock damage directly.

Living in the shadow of shame and stigma: Lived experience of mothers with deaf children

Directory of Open Access Journals (Sweden)

Hossein Ebrahimi

2016-11-01

Full Text Available Congenital deafness is one of the most common childhood disorders and every year many children are born with permanent hearing loss. The present study was carried out to understand the experience of mothers with deaf children. This study was conducted with a qualitative approach. The participants were 35 mothers of children with congenital deafness who were selected by purposive sampling. The data was collected through semi structured indepth interviews and analyzed using thematic analysis introduced by Braun and Clarke. Data analysis revealed 3 themes and 9 sub-themes including social stigma (prying eyes, pity aversion, feeling of discrimination, taunt from people, internalized stigma (feeling of inferiority, feeling of shame and embarrassment, and reaction to stigma(turning to concealment, cautious disclosure, and marginalization. Shame and stigma were the major experiences of Iranian mothers of deaf children that shadowed their lives. These experiences lead mainly to ineffective coping mechanisms such as avoidance of using hearing aids and concealment of the child’s hearing loss. In addition, to cope with perceived stigma, mothers isolate and marginalize themselves and pursue secrecy strategies. Therefore, our findings are important for health professionals who are working with families having children with hearing loss. They need to aware of the problems faced by the families and should advocate necessary support.

Overview on Deaf-Blindness

Science.gov (United States)

... of Deaf-Blind Education Transition to Adulthood > Transition Self Determination Person Centered Planning Postsecondary Education Independent Living Employment Customized Employment Sex Education Adult Services Technology Personnel > Intervener Services Support ...

Mechanical study of the Chartreuse Fold-and-Thrust Belt: relationships between fluids overpressure and decollement within the Toarcian source-rock

Science.gov (United States)

Berthelon, Josselin; Sassi, William; Burov, Evgueni

2016-04-01

Many source-rocks are shale and constitute potential detachment levels in Fold-and-Thrust Belts (FTB): the toarcian Schistes-Cartons in the French Chartreuse FTB for example. Their mechanical properties can change during their burial and thermal maturation, as for example when large amount of hydrocarbon fluids are generated. A structural reconstruction of the Chartreuse FTB geo-history places the Toarcian Formation as the major decollement horizon. In this work, a mechanical analysis integrating the fluids overpressuring development is proposed to discuss on the validity of the structural interpretation. At first, an analogue of the Chartreuse Toarcian Fm, the albanian Posidonia Schist, is documented as it can provide insights on its initial properties and composition of its kerogen content. Laboratory characterisation documents the vertical evolution of the mineralogical, geochemical and mechanical parameters of this potential decollement layer. These physical parameters (i.e. Total Organic Carbon (TOC), porosity/permeability relationship, friction coefficient) are used to address overpressure buildup in the frontal part of the Chartreuse FTB with TEMISFlow Arctem Basin modelling approach (Faille et al, 2014) and the structural emplacement of the Chartreuse thrust units using the FLAMAR thermo-mechanical model (Burov et al, 2014). The hydro-mechanical modeling results highlight the calendar, distribution and magnitude of the overpressure that developed within the source-rock in the footwall of a simple fault-bend fold structure localized in the frontal part of the Chartreuse FTB. Several key geological conditions are required to create an overpressure able to fracture the shale-rocks and induce a significant change in the rheological behaviour: high TOC, low permeability, favourable structural evolution. These models highlight the importance of modeling the impact of a diffuse natural hydraulic fracturing to explain fluids propagation toward the foreland within

Reading comprehension of deaf children with cochlear implants

NARCIS (Netherlands)

Vermeulen, A.M.; Bon, W.H.J. van; Schreuder, R.; Knoors, H.E.T.; Snik, A.F.M.

2007-01-01

The reading comprehension and visual word recognition in 50 deaf children and adolescents with at least 3 years of cochlear implant (0) use were evaluated. Their skills were contrasted with reference data of 500 deaf children without CIs. The reading comprehension level in children with CIs was

The Implications of Congenital Deafness for Working Memory.

Science.gov (United States)

Chalifoux, Lisa M.

1991-01-01

A. Baddeley's model of the working memory of congenitally deaf persons is examined in light of research on encoding by this population. It is concluded that a model of the working memory of the deaf must include subsystems for articulatory, sign, and visual encoding. (Author/DB)

Research-Based Curriculum, Pedagogy, and Assessment in a Deaf Bilingual Program

Science.gov (United States)

Peterson, Laura

2012-01-01

The California School for the Deaf (CSD), Fremont, is a deaf-centered bilingual program. CSD's approach to curriculum development, instructional pedagogy, and assessment integrates best practices in deaf education, bilingual education, and general education. The goals of the program are outlined in the Expected School-wide Learning Results which…

Mechanical behavior of host rock close to H.L.W. disposal cavities in a deep granitic formation

International Nuclear Information System (INIS)

Hoorelbeke, J.M.; Dourthe, M.

1986-01-01

The construction of a H.L.W. repository in a deep granitic formation creates mechanical disturbances in the rock on the scale of the massif and in the nearfield. Amongst all the disturbances noted in the nearfield, this study is concerned with examining the evolution of stresses linked with the excavation of the rock and the rise in temperature in the proximity of the waste packages. Several linear elasticity calculations were made using on the one hand finite element models and on the other simple analytical models. These calculations concern two different storage concepts - in room concept and in floor concept- whose differences in mechanical behavior are analyzed. A study of sensitivity with regard to the characteristics of the rock and to the initial geostatic stresses is presented. The comparison of the calculated stresses with three-dimensional failure criteria gives a clear indication of the satisfactory behavior of granite for final storage. However, the need for experimental study and complementary calculation must be emphasized

Educational Outcomes of Young People in Scotland Who Are Deaf or Hard of Hearing: Intersections of Deafness and Social Class

Science.gov (United States)

Fordyce, Mariela; Riddell, Sheila; O'Neill, Rachel; Weedon, Elisabet

2015-01-01

This article focuses on the intersection between deafness and social class in the context of the unstable economic circumstances in Scotland following the 2007 recession. More specifically, this research investigated the following in the case of young people who are deaf or hard of hearing (DHH): (1) the interaction between educational attainment…

Deaf children's understanding of emotions: desires take precedence

NARCIS (Netherlands)

Rieffe, C.J.; Meerum Terwogt, M.

2000-01-01

Deaf children frequently have trouble understanding other people's emotions. It has been suggested that an impaired theory of mind can account for this. This research focused on the spontaneous use of mental states in explaining other people's emotions by 6- and 10-year-old deaf children as compared

Rock properties data base

Energy Technology Data Exchange (ETDEWEB)

Jackson, R.; Gorski, B.; Gyenge, M.

1991-03-01

As mining companies proceed deeper and into areas whose stability is threatened by high and complex stress fields, the science of rock mechanics becomes invaluable in designing underground mine strata control programs. CANMET's Mining Research Laboratories division has compiled a summary of pre- and post-failure mechanical properties of rock types which were tested to provide design data. The 'Rock Properties Data Base' presents the results of these tests, and includes many rock types typical of Canadian mine environments. The data base also contains 'm' and 's' values determined using Hoek and Brown's failure criteria for both pre- and post-failure conditions. 7 refs., 3 tabs., 9 figs., 1 append.