bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical optimization for aerodynamic noises of rear view mirrors of vehicles based on rectangular cavity structures
Authors: Zhu Jing Jian , Liu Guo Wen
Published: March 2018

The rectangular cavity structure was applied to edges of the rear view mirror, numerical computation was conducted for aerodynamic noises of the rear view mirror, and the results of optimized structure were compared with those of the original structure to verify optimized effects. Wind tunnel test was then conducted on the rear view mirror to verify correctness of the computational model. Sound pressure levels of each observation point between experimental test and numerical simulation were basically consistent, where only parts of the peak frequency points were different. The computational accuracy was very high. Two large-size vortexes were in this region behind the common rear view mirror. Vortexes above the rear part of the rear view mirror rotated anticlockwise, while vortexes under it rotated clockwise. There were two vortexes in the region behind the optimized rear view mirror, but the energy intensity of this vortex near the side window panel was very weak. Pressures on the front part of the optimized rear view mirror were also smaller than those of the original structure. In addition, it could be found that radiation noise distribution of the rear view mirror on the lateral window presented symmetry. When lateral window effects were considered, the aerodynamic noise was more than results without considering the lateral window effects. Total noises of each observation point without considering the lateral window effects were 56.7 dB, 59.2 dB, 58.6 dB, 58.9 dB, 62.3 dB and 63.1 dB, respectively. Total noises at each observation point with consideration of the lateral window effects were 65.3 dB, 66.5 dB, 68.7 dB, 69.2 dB, 70.1 dB and 70.8 dB, respectively. Therefore, when aerodynamic noises of the rear view mirror were computed, impacts of lateral window effects must be considered, otherwise the computation would be seriously deviated from actual situations. The frequency corresponding to maximum peaks of the aerodynamic noise after optimization approached the self-oscillation frequency of the rectangular cavity. The result indicates that aerodynamic noises in the rectangular cavity were fluid self-oscillation caused by the cavity structure. In addition, within the analyzed frequency band, the aerodynamic noises of the optimized rear view mirror were smaller than those of the original structure. The maximum decrease rate of total noises of the optimized rear view mirror was 15.62 %, and minimum decrease rate was 8.90 %. Optimized effects were very significant, especially in the low frequency bands.
Numerical simulation on the impact of the bionic structure on aerodynamic noises of sidewindow regions in vehicles
Authors: Liu Yang Yang , Li Yong Qiang , Ding Zheng Yin
Published: March 2018

The paper adopted a bionic hemispherical convex structure in the A pillar-rear view mirror regions according to actual requirements. Furthermore, impacts of the bionic structure on aerodynamic characteristics and noises in the region were studied. Friction resistance of airflows was greatly reduced, fluctuations and pulsation pressures of flow fields were also reduced, and characteristics of flow fields and sound fields were improved. The computational results were finally verified by the experimental test. Firstly, the aerodynamic lift force coefficient and drag force coefficient of the bionic model were computed, and they were obviously lower than those of the original model. The adhesive force between tires and ground during vehicle running was increased, and the danger degree of “waving” of high-speed vehicle running was weakened. In this way, stability of vehicle running could be improved. Secondly, flow fields of the bionic model were computed. Compared with the original model, an obvious vortex was behind the original model, while no vortexes were behind the bionic model. Therefore, convex structures of the bionic model had obvious impacts on flow fields behind the rear view mirror. Airflow separation situations were obvious improved at wheels, windshield and rear side windows of the bionic model. Due to blocking of convex structures of the A pillar and rear view mirror in the bionic model, airflows was hindered and obvious dragging phenomena were formed. Therefore, flow fields in the side window regions could be improved greatly. In addition, the flow field scope under the rear view mirror in the bionic model was also decreased. Ringed vortex structures appeared behind the rear view mirror in the bionic model. The ringed vortex structures were closely interlaced and then extended together backwards. Vortexes behind the rear view mirror in the original model were chaotic, where most of them were attached on the surface of side windows. In the original model, turbulent flows with certain strength were on the right upper corner of the side window region. In the bionic model, no turbulent flows were in the same regions. This result indicated that through using the bionic convex structures, airflows flowing through side windows could be combed and could move backwards towards upper and lower edges of the side windows. It could be predicted that pulsation pressures on the side window surface would surely decrease. Therefore, aerodynamic noises caused by pulsation pressures in side window regions would also be improved correspondingly. Especially in regions behind A pillar-rear view mirrors, the maximum noise reduction amplitude reached about 20 dB.
Fatigue assessment on local components of a semi-submersible platform subjected to wind and wave loads
Authors: Ma Jin , Zhou Dai , Bao Yan , Han Zhaolong
Published: March 2018

The objective in this work is to assess fatigue damages on local components of a semi-submersible platform under combined actions of wind and wave loads in time domain. Some improvements are provided in the present study to improve the efficiency and accuracy of the whole evaluating process. Firstly, a combined wind and wave relationship as well as an innovative mixture simulation method are used to generate time series of random wind and waves. Moreover, an m-block division method is proposed to compress the number of the whole short-term sea states in the wind-wave scatter diagram. Then, with an improved multiple interpolation sub-model method, the structural stress responses of the local structural components are calculated as is in the whole model analysis. Finally, a modified rain-flow counting method is provided and validated to count the stress cycles efficiently and accurately. Thus, the short- and long-term fatigue damages are computed based on the S-N curve approach and the cumulative fatigue damage rule. In relative agreement with the numerical results by the traditional time-domain method and existing experimental data, these proposed improved methods are demonstrated to be applicable and efficient methods for fatigue damage analyses. All the fatigue damages on local components satisfy the specification requirements and the minimum value appears under the up wind-wave state, which is the proper working condition for a semi-submersible platform.
Study on unsteady aerodynamic characteristics of two trains passing by each other in the open air
Authors: Chen Ye-gang , Wu Qian
Published: March 2018

Based on three-dimensional, non-steady, compressive and unsteady control equations and k-ε turbulence model, the paper adopts the finite volume method and moving grid technologies to conduct a numerical simulation analysis on pressure waves and aerodynamic forces (force moments) of two meeting trains in the open air. The simulation model has been validated by experimental test. Computational results show that during the meeting, the damage of the lateral window glass during the meeting is caused by that the window glass will be sucked out by negative pressures rather than be hit by positive pressures; both head wave pressure amplitude and tail wave pressure amplitude are in direct ratios to the square of the running speed; resistance values of the head and tail train experienced several changes, but the changing rules of the head train are opposed to those of the tail train; the lift force of the head train is downward all the time, the lift force is more than that of other train bodies, and lift force directions of the middle train and the tail train change alternately; the head train has the largest lateral force, the tail train ranks the second position, and the middle train ranks the last position; each train experiences 6 shaking force moment impacts including outward, inward, outward, inward, outward and inward impacts in succession; each train experiences 6 nodding force moment impacts, including downward, upward, downward, upward, downward and upward impacts, in succession.
A more accurate dynamic model for dual-side excitation large vibrating screens
Authors: Peng Liping , Fang Runxin , Feng Huihui , Zhang Lei , Ma Wenda , He Xiaodi
Published: March 2018

Compared with a traditional unilateral-driven large vibrating screen, the proposed dual-side excitation large vibrating screen (DELVS) has a simpler screen structure and less vibration mass, which might improve its reliability. A DELVS with metal cylindrical coiled springs is theoretically and experimentally studied in this paper. With the rotation considered, a fundamental three-degree-of-freedom (3-DOF) dynamic model for DELVS is established firstly. Then an elastic compression bar model method (ECBM) is proposed for transverse stiffness determination of a metal cylindrical coiled spring and applied into the numerical simulation of DELVS. Finally, an experimental test on a DELVS of 4.25 m×6.00 m is conducted. It is seen that numerical simulation with the proposed ECBM is more closely related to the experimental data, hence the accuracy of the proposed dynamic model of DELVS is enhanced. The conclusions may provide guidance on a design of a high-performance large vibrating screen.
Measurement method of torsional vibration signal to extract gear meshing characteristics
Authors: Liu Yanwei , Liang Zhihao , Ye Jie , Lin Huibin , Zhao Kegang
Published: March 2018

A technique in measuring torsional vibration signal based on an optical encoder and a discrete wavelet transform is proposed for the extraction of gear meshing characteristics. The method measures the rotation angles of the input and output shafts of a gear pair by using two optical encoders and obtains the time interval sequences of the two shafts. By spline interpolation, the time interval sequences based on uniform angle sampling can be converted into angle interval sequences on the basis of uniform time sampling. The curve of the relative displacement of the gear pair on the meshing line (initial torsional vibration signal) can then be obtained by comparing the rotation angles of the input and output shafts at the interpolated time series. The initial torsional vibration signal is often disturbed by noise. Therefore, a discrete wavelet transform is used to decompose the signal at certain scales; the torsional vibration signal of the gear can then be obtained after filtering. The proposed method was verified by simulation and experimentation, and the results showed that the method could successfully obtain the torsional vibration signal of the gear at a high frequency. The waveforms of the torsional vibration could reflect the meshing characteristics of the teeth. These findings could provide a basis for fault diagnosis of gears.
The effect of cooling the foil bearing on dynamics of the rotor-bearings system
Authors: Bagiński Paweł , Żywica Grzegorz , Lubieniecki Michał , Roemer Jakub
Published: March 2018

In order to protect rotors and foil bearings operating at high temperatures from being overheated and damaged, these components are often cooled by air. In addition, such a cooling method is accompanied by an axial temperature gradient that changes the shape of the lubrication gap in a way likely to affect the operation of a foil bearing. This article presents the research on various methods for cooling a foil bearing and discusses the impact of these methods on dynamic parameters of the rotor-bearings system. To be able to assess the temperature inside such a bearing, there is a need for a reliable measurement method. The authors of the article measured the temperature of the top foil using thermocouples and showed that their measurement method does not exert any significant impact on the operation of the rotor-bearings system. The article also describes a novel method for compensating the axial temperature gradient occurring in the bearing bush using Peltier modules.
Investigation of armature-rail interaction in linear electromagnetic launcher
Authors: Račkauskas Justinas , Kačianauskas Rimantas , Schneider Markus
Published: March 2018

The behavior of the electromagnetic (EM) launcher depends on the structure of the construction. The dynamics of the EM construction and the local effects of the EM forces are topical issue in exploring and designing EM launcher device. This paper is aimed to refine mechanical behavior of the open barrel design EM launcher structure due to EM force evaluated by EM analysis based on three different shapes of armatures. The 3D finite element EM model was generated and the J×B force density distribution in the rail volume was calculated. The results of EM model calculations were applied further as input for structural mechanics model. The results of the finite element EM and mechanical analysis of the armatures influence are presented.
Research on transient heat transfer performance of disc brakes for mining motor vehicle
Authors: Zhang Sen , Qin Yanan , Yin Yiguang
Published: March 2018

The type of disc brake has excellent efficiency and strong heat dissipation, which are beneficial to the transport capacity for mining motor vehicles. To ensure the reliability of the brake, the two-dimensional heat transfer differential equation model of disc brake is established, considering the dynamic change of convective heat transfer coefficient. The heat boundary conditions are established through the characteristics of brake disc structure and air condition, which is more accuracy than the traditional simplified method. Based on the PDE module in MATLAB, the mathematical model of heat transfer is solved and the transient temperature field is obtained. The calculation results are verified by the temperature field of the brake disc Link3900 NVH test platform. The results show that the research scheme has high computation accuracy, and can provide important basis, new ideas and advanced methods for the brake of mining motor vehicle in related fields.
Kantorovich variational method for the flexural analysis of CSCS Kirchhoff-Love plates
Authors: Ike Charles Chinwuba , Mama Benjamin Okwudili
Published: March 2018

The Kantorovich variational method was used in this study to solve the flexural problem of Kirchhoff-Love plates with two opposite edges x=±a/2 clamped and the other two edges y=±b/2 simply supported, for the case of uniformly distributed transverse load over the entire plate domain. The plate considered was assumed homogeneous, and isotropic. The total potential energy functional for the Kirchhoff-Love plate was found as the sum of the potential energy of the applied distributed load and the strain energy functional of the plate. The symmetrical nature of the plate and the load was used to choose the deflection function as a single series of infinite terms involving the cosine function of the y coordinate variable with the unknown function being dependent on the x coordinate variable. Integration with respect to the y coordinate variable simplified the total potential energy functional to be dependent on the unknown function of x, and its derivatives. Euler-Lagrange differential equations were used to find the differential equations of equilibrium of the plate as a system of homogeneous fourth order ordinary differential equations (ODE) in the unknown function. The system of fourth order ODE was solved using the method of differential D operators, or the method of trial functions to obtain the general solution as the linear superposition of the homogeneous and particular solutions. The demands of symmetry of unknown function about the point x= 0, and the boundary conditions at the clamped edges were used to obtain all the four integration constants; thus, completely determining the deflection. Bending moment distributions were determined using the bending moment deflection relations. The deflection was determined at the centre of the plate. The bending moment values were also determined at the centre of the plate, and at the middle of the clamped edges. Expressions obtained for the deflection at the centre, and bending moment values were found to be single series of infinite terms with highly converging properties. The solutions obtained converged to the exact solutions with the use of only four terms of the series.
A review on secondary metabolites, pharmacological status and phytoremediation to treat water hyacinth
Authors: J. Mohan , N. Mohan , Shakya Narendra Babu , Pandey Amit , Chauhan Raghvendra
Published: March 2018

Eichhornia crassipes (Mart.) Solms (Water hyacinth), an oceanic lasting herb display All around the world, need a heap from claiming metabolites. Extracts, and additionally immaculate exacerbates disconnected starting with this plant, have been showed with have pharmacological exercises for example, such that phenolic Compounds, Alkaloids, Terpenoids, Sterols, Glycosides, Flavonoid, Resins, Anthroquinone, Saponins, Tannins. Eichhornia crassipes (water hyacinth) could a chance to be usefully utilized will extricate supplements from sewage. It is likewise demonstrated advantageous in treating effluents dirtied for lethal overwhelming metals for example, Cd, Cu What's more Ni. Water hyacinth likewise indicated mitigating Activity, anticancer Activity, Anticorrosion Activity, cell reinforcement Activity, Wound recuperating Activity, antimicrobial activity, antimicrobial action Larvicidal action. Therefore, this audit article will be an accumulation of the updated data viewing Phytoremediation, optional Metabolities, pharmacological status about water hyacinth.
Syzygium aromaticum : A subtropical tree scrutinized for the genetic differentiation among the altitudes of Nilgiris
Authors: D. Saranya , R. Ravi
Published: March 2018

Clove (Syzygium aromaticum) is one of the most economically significant oil producing trees in India, whose importance is mainly due to its medicinal features. Unfortunately, importing rate of the spice is increasing which would be an economic drawback for the country. Therefore, information regarding genetic diversity and the oil quality of the tree is necessary as a part to increase the cultivation. Thus the present work was conducted to identify the genetic difference between the collected samples among different altitudes of Nilgiris in comparison to the extracted oil quality to select high quality oil yielding variety for cropping. RAPD and GC-MS techniques were used for analyzing genetic diversity and oil extraction respectively. The phylogeny constructed revealed that the samples S1& S6 are genetically more similar, whereas S2 is far distinct from all other samples. S3 shared a close relation with S1 & S6. Samples S4, S5 were separated out but are within the same node. The eugenol percentage of the samples S1, S2, S3, S4, S5 and S6 are 42.96%, 68.78%, 55.95%, 71.17%, 74.04% and 73.47% respectively. From the collected data it is inferred that though the samples shared genetic similarity there observed a considerable difference in the eugenol content. This information needs to be correlated with the cultivation practices and the soil nutrition based on which commercial cropping could be done to improvize the clove sector of the country.
Typhonium inopinatum Prain (Araceae): An addition to the flora of Andhra Pradesh, India.
Authors: Rapaka Prameela , J. Swamy , M. Venkaiah
Published: March 2018

Typhonium inopinatum Prain (Araceae) is reported here as an addition to the flora of Andhra Pradesh, collected from Vizianagaram district. A detailed description and colour photographs are provided to facilitate identification.
Isolation and identification of fungal assemblages in the necrotic spots of Bambusa pallida (L.) Voss
Authors: Debnath Sanjit , Karmakar Pintu , Bhattacharjee Sukla , Majumdar Koushik , Das Panna , Saha Ajay Krishna
Published: March 2018

Bamboos are the most important plant due to their different uses and good source of income for upliftment of rural economy. Different parts of bamboos are damaged by many harmful bacteria, fungi and other organisms causing huge loss of economy. Diseased leaves of Bambusa pallida were used for isolation of fungal assemblages in symptom sites. A total of 7 fungi were isolated from the cultured medium; these were Lasiodiplodia theobromae, Drechslera rostrata, Curvularia lunata, Fusarium redolens, Sterile sp1, Sterile sp2, and Sterile sp3. Isolated L. theobromae, D. rostrata, C. lunata, F. redolens may be the causal fungi for necrotic spots disease in B. pallida. Colonization rate and isolation rate (%) were observed highest in L. theobromae, C. lunata F. redolens and Sterile sp2. The present finding will be helpful for knowing the causes of damage and relation with leaf spot disease. Further studies needed to be undertaken for finding the mode of colonization to causes diseases.
Lectotypification of Carex courtallensis (Cyperaceae) and notes on its morphology and habitat
Authors: A.R. Viji , M.P. Geethakumary , S. Deepu , A.G. Pandurangan , T. Shaju
Published: March 2018

During the revision of Cyperaceae in Western Ghats, a specimen was collected from Chemunji hills, Thiruvananthapuram District, Kerala, identified as Carex courtallensis Nees ex Boott, a species recollected after a gap of 150 years, about 50 km away from the type locality. On examining the protologue of the species and later works, along with specimens housed at various herbaria, we identified the need for lectotypification of the species. The present paper provides detailed description, photographs and relevant notes on the species based on recent collections.
The morphological traits variation and inter relationships of understorey species of Sal (Shorea robusta) forest of north-eastern Uttar Pradesh, India.
Authors: Rai Satish Kumar , Shukla Ravindra P. , Pandey Sanjay Kumar
Published: March 2018

Measurements of plant traits are required for evaluating community structure and its ecological responses to varying environmental conditions. The grouping on the basis of functional traits of plants has strong predictive power of important ecosystem responses to environmental perturbation. The morphological traits and their interrelationship among associated species have been analyzed to understand the quantitative variation within regional sal dominated forests. Data for five morphometric traits viz., plant height, leaf length, leaf width, flower size and fruit size, were observed for 193 woody (tree, shrub and liana) species belonging to 56 families within understorey of sal forest. Forty-one families were polytypic in nature. One-way ANOVA was used to detect how variation among all the traits was distributed among habit groups. A significant positive relationship was noticed between plant height and each of the leaf length, leaf width and fruit size. Of the different morphometric traits observed only plant height and fruit size showed wider variation among three life–form categories. Overall, our results suggest that measurement of plant morphometric characters are the major drivers of understory sal associates of the region. Hence, the morphological traits of sal associates should be carefully considered in framing the management and conservation strategy of regional sal forests.
Tertiary trisomics in 2n = 12 Coix taxon
Authors: Diluraj Sangeetha
Published: March 2018

Tertiary trisomics have been isolated from the domesticated outcrossed population of a comparatively new taxon of Coix with 2n = 12 chromosome number and also from the selfed progenies of the chromosomal variants ranging from 2n=11 to 2n=13. Cytological analysis of these trisomics indicated that different chromosomal associations forming a trivalent, pentavalent and univalent were frequent at diakinesis. Disomics (2n = 12) and their monosomics (2n-1; 2n = 11) showing interchanged quadrivalents at diakinesis were observed to be the main sources of these tertiary trisomics.
HPLC identification of bio active flavonoids in methanolic and aqueous leaf extracts of Schrebera swietenioides Lin.,
Authors: V. Anuradha Devi , I. Veera Kishore , R. Ragha Latha , Mallikarjuna Kokkanti
Published: March 2018

Natural products continue to provide unique structural diversity in comparison to standard combinatorial chemistry, which presents opportunities for discovering mainly novel low molecular weight lead compounds. Schrebera swietenioides belonging to family Oleaceae is an important medicinal plant used in the treatment of leprosy, diabetes and hepatic disorders by ethnic people. Chromatographic methods like TLC and HPLC were used for the separation and identification of flavonoids present in methanolic and aqueous leaf extract was studied. The chromatographic methods available for the separation of flavonoids in TLC and HPLC were adopted for the study. Three compounds were identified in TLC study in methanolic and aqueous leaf extracts. In HPLC analysis, peaks corresponding to flavonoids were obtained and were identified by comparing with literature and confirm that methanolic extract contains Rutin, Quercetin and Myricetin where as in aqueous extract Rutin and Quercetin were observed.  The anti diabetic activity of isolated compounds was determined by literature and confirms that compounds were found to having potent anti diabetic activity. This proves that the anti-diabetic activity of S. swietenioides was due to the presence of these bio-active compounds
Ecological investigation of Urpad beel: A major wetland of Goalpara district of Assam, India.
Authors: Deka Upen , Dutta Tapan
Published: March 2018

The present investigation deals with the ecological study of Urbad beel of Goalpara district of Assam with reference to aquatic plant community. The study was carried out during the year 2016 to 2017. Diversity indices viz. Shannon-Weiner diversity index, Simpson diversity index, Menhinick diversity index and Concentration of dominance were calculated to show the plant community structure of the wetland. A total of 93 aquatic macrophytic plant species belonging to 74 genera and 45 families have been reported from the wetland. Based on IVI value, Eichhornia crassipes was the most dominant species (IVI= 22.54) followed by Hygroryza aristata (IVI= 19.96), Arundo donax (IVI= 8.21) respectively whereas Cyperus brevifolius (IVI= 0.768) showed the lowest IVI value among all the life forms of the aquatic macrophytes of the wetland. Results showed that anthropogenic disturbances inside the wetland areas are the prime factor for losing aquatic plant community of the wetland. The obtained Shannon -diversity index values (3.06 and 2.18) both in summer and winter seasons indicate the further degradation of the wetland. Therefore, anthropogenic activities inside the wetland areas should be prevented for the sustainable existence of the wetland as well as the livelihood of the fringe villagers.
Mining Social Media Data to Study the Consequences of Dementia Diagnosis on Caregivers and Relatives (Preprint)
Authors: Oellrich Anika , Gkotsis George , Dobson Richard James Butler , Hubbard Tim JP , Dutta Rina
Published: March 2018

BACKGROUND

Dementia is a growing public health concern with approximately 50 million people affected worldwide in 2017 and this number is expected to reach more than 131 million by 2050. The toll on caregivers and relatives cannot be underestimated as dementia changes family relationships, leaves people socially isolated, and affects the finances of all those involved.

OBJECTIVE

The aim of this study was to explore using automated analysis (i) the age and gender of people who post to the social media forum Reddit about dementia diagnoses, (ii) the affected person and their diagnosis, (iii) relevant subreddits authors are posting to, (iv) the types of messages posted and (v) the content of these posts.

METHODS

We analysed Reddit posts concerning dementia diagnoses. We used a previously developed text analysis pipeline to determine attributes of the posts as well as their authors to characterise online communications about dementia diagnoses. The posts were also examined by manual curation for the diagnosis provided and the person affected. Furthermore, we investigated the communities these people engage in and assessed the contents of the posts with an automated topic gathering technique.

RESULTS

Our results indicate that the majority of posters in our data set are women, and it is mostly close relatives such as parents and grandparents that are mentioned. Both the communities frequented and topics gathered reflect not only the sufferer's diagnosis but also potential outcomes, e.g. hardships experienced by the caregiver. The trends observed from this dataset are consistent with findings based on qualitative review, validating the robustness of social media automated text processing.

CONCLUSIONS

This work demonstrates the value of social media data sources as a resource for in-depth studies of those affected by a dementia diagnosis and the potential to develop novel support systems based on their real time processing in line with the increasing digitalisation of medical care.
A New Online Mental Health Training Program for Workplace Managers: Pre-Post Pilot Study Assessing Feasibility, Usability, and Possible Effectiveness (Preprint)
Authors: Gayed Aimée , LaMontagne Anthony D. , Milner Allison , Deady Mark , Calvo Rafael A. , Christensen Helen , Mykletun Arnstein , Glozier Nick , Harvey Samuel B
Published: March 2018

BACKGROUND

Mental health has become the leading cause of sickness absence in high-income countries. Managers can play an important role in establishing mentally healthy workplaces and coordinating their organization’s response to a mentally ill worker.

OBJECTIVE

This pilot study aims to evaluate the feasibility, usability, and likely effectiveness of a newly developed online training program for managers called HeadCoach. HeadCoach aims to build managers’ confidence in supporting the mental health needs of staff and promote managerial behavior most likely to result in a more mentally healthy workplace.

METHODS

In total, 66 managers from two organizations were invited to participate in this pre-post pilot study of HeadCoach, which was made available to managers to complete at their own pace over a 4-week period. Data were collected at baseline and post intervention via an online research platform. The difference in mean scores for each outcome between these two time points was calculated using paired samples t tests.

RESULTS

Of all the invited managers, 59.1% (39/66) participated in the trial, with complete pre–post data available for 56.4% (22/39) of the participants. The majority of respondents reported positive engagement with the program. During the study period, managers’ knowledge regarding their role in managing mental health issues (P=.01) and their confidence in communicating with employees regarding mental illness (P<.001) significantly increased. In addition, a significant increase was observed from the baseline in managers’ self-reported actions to use strategies to prevent and decrease stress among their team members (P=.02).

CONCLUSIONS

Although caution is needed due to the absence of a control group, preliminary results of this study suggest that HeadCoach could be a feasible, acceptable, and efficient method of training managers in best workplace practices to help support the mental health needs of their staff.
A Mobile App Delivering a Gamified Battery of Cognitive Tests Designed for Repeated Play (OU Brainwave): App Design and Cohort Study (Preprint)
Authors: Thirkettle Martin , Lewis Jennifer , Langdridge Darren , Pike Graham
Published: March 2018

BACKGROUND

Mobile phone and tablet apps are an increasingly common platform for collecting data. A key challenge for researchers has been participant “buy-in” and attrition for designs requiring repeated testing.

OBJECTIVE

The objective of this study was to develop and assess the utility of 1-2 minute versions of both classic and novel cognitive tasks using a user-focused and user-driven mobile phone and tablet app designed to encourage repeated play.

METHODS

A large sample of app users (N=13,979 at first data collection) participated in multiple, self-paced sessions of classic working memory (N-back), spatial cognition (mental rotation), sustained attentional focus (persistent vigilance task), and split attention (multiple object tracking) tasks, along with the implementation of a comparatively novel action-learning task. The “OU Brainwave” app was designed to measure time-of-day variation in cognitive performance and did not offer any training program or promise any cognitive enhancement. To record participants’ chronotype, a full Morningness-Eveningness questionnaire was also included, which measures whether a person's circadian rhythm produces peak alertness in the morning, in the evening, or in between. Data were collected during an 18-month period. While the app prompted re-engagement at set intervals, participants were free to complete each task as many times as they wished.

RESULTS

We found a significant relationship between morningness and age (r=.298, n=12,755, P<.001), with no effect of gender (t13,539=−1.036, P=.30). We report good task adherence, with ~4000 participants repeatedly playing each game >4 times each—our minimum engagement level for analysis. Repeated plays of these games allowed us to replicate commonly reported gender effects in gamified spatial cognition (F1,4216=154.861, P<.001, η2ρ=.035), split attention (F1,4185=11.047, P=.001, η2ρ=.003), and sustained attentional focus (F1,4238=15.993, P<.001, η2ρ=.004) tasks. We also report evidence of a small gender effect in an action-learning task (F1,3988=90.59, P<.001, η2ρ=.022). Finally, we found a strong negative effect of self-reported age on performance, when controlling for number of plays, in sustained attentional focus (n=1596, F6,1595=30.23, P<.001, η2=.102), working memory (n=1627, F6,1626=19.78, P<.001, η2=.068), spatial cognition (n=1640, F6,1639=23.74, P<.001, η2=.080), and split attention tasks (n=1616, F6,1615=2.48, P=.02, η2=.009).

CONCLUSIONS

Using extremely short testing periods and permitting participants to decide their level of engagement—both in terms of which gamified task they played and how many sessions they completed—we were able to collect a substantial and valid dataset. We suggest that the success of OU Brainwave should inform future research oriented apps—particularly in issues of balancing participant engagement with data fidelity.
Determining Physiological and Psychological Predictors of Time to Task Failure on a Virtual Reality S�rensen Test in Participants With and Without Recurrent Low Back Pain: Exploratory Study (Preprint)
Authors: Applegate Megan E , France Christopher R , Russ David W , Leitkam Samuel T , Thomas James S
Published: March 2018

BACKGROUND

Sørensen trunk extension endurance test performance predicts the development of low back pain and is a strong discriminator of those with and without low back pain. Performance may greatly depend on psychological factors, such as kinesiophobia, self-efficacy, and motivation. Virtual reality video games have been used in people with low back pain to encourage physical activity that would otherwise be avoided out of fear of pain or harm. Accordingly, we developed a virtual reality video game to assess the influence of immersive gaming on the Sørensen test performance.

OBJECTIVE

The objective of our study was to determine the physiological and psychological predictors of time to task failure (TTF) on a virtual reality Sørensen test in participants with and without a history of recurrent low back pain.

METHODS

We recruited 24 individuals with a history of recurrent low back pain and 24 sex-, age-, and body mass index–matched individuals without a history of low back pain. Participants completed a series of psychological measures, including the Center for Epidemiological Studies-Depression Scale, Pain Resilience Scale, Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia, and a self-efficacy measure. The maximal isometric strength of trunk and hip extensors and TTF on a virtual reality Sørensen test were measured. Electromyography of the erector spinae, gluteus maximus, and biceps femoris was recorded during the strength and endurance trials.

RESULTS

A two-way analysis of variance revealed no significant difference in TTF between groups (P=.99), but there was a trend for longer TTF in females on the virtual reality Sørensen test (P=.06). Linear regression analyses were performed to determine predictors of TTF in each group. In healthy participants, the normalized median power frequency slope of erector spinae (beta=.450, P=.01), biceps femoris (beta=.400, P=.01), and trunk mass (beta=−.32, P=.02) predicted TTF. In participants with recurrent low back pain, trunk mass (beta=−.67, P<.001), Tampa Scale for Kinesiophobia (beta=−.43, P=.01), and self-efficacy (beta=.35, P=.03) predicted TTF.

CONCLUSIONS

Trunk mass appears to be a consistent predictor of performance. Kinesiophobia appears to negatively influence TTF for those with a history of recurrent low back pain, but does not influence healthy individuals. Self-efficacy is associated with better performance in individuals with a history of recurrent low back pain, whereas a less steep median power frequency slope of the trunk and hip extensors is associated with better performance in individuals without a history of low back pain.
Association Between Adherence to Cancer Screening and Knowledge of Screening Guidelines: Feasibility Study Linking Self-Reported Survey Data With Medical Records (Preprint)
Authors: Lofters Aisha K , Telner Deanna , Kalia Sumeet , Slater Morgan
Published: March 2018

BACKGROUND

It is possible that patients who are more aware of cancer screening guidelines may be more likely to adhere to them.

OBJECTIVE

The aim of this study was to determine whether screening knowledge was associated with the documented screening participation. We also assessed the feasibility and acceptability of linking electronic survey data with clinical data in the primary care setting.

METHODS

We conducted an electronic survey at 2 sites in Toronto, Canada. At one site, eligible patients were approached in the waiting room to complete the survey; at the second site, eligible patients were sent an email inviting them to participate. All participants were asked to consent to the linkage of their survey results with their electronic medical record.

RESULTS

Overall, 1683 participants responded to the survey—247 responded in the waiting room (response rate, 247/366, 67.5%), whereas 1436 responded through email (response rate, 1436/5779, 24.8%). More than 80% (199/247 and 1245/1436) of participants consented to linking their survey data to their medical record. Knowledge of cancer screening guidelines was generally low. Although the majority of participants were able to identify the recommended tests for breast and cervical screening, very few participants correctly identified the recommended age and frequency of screening, with a maximum of 22% (21/95) of screen-eligible women correctly answering all 3 questions for breast cancer screening. However, this low level of knowledge among patients was not significantly associated with screening uptake, particularly after adjustment for sociodemographic characteristics.

CONCLUSIONS

Although knowledge of screening guidelines was low among patients in our study, this was not associated with screening participation. Participants were willing to link self-reported data with their medical record data, which has substantial implications for future research.
Improving Students’ Speaking Skill By Using Show And Tell Method: A Classroom Action Research
Authors: Bangun Betty Kasita
Published: March 2018

This research employed a qualitative study using a Classroom Action Research approach by Kemmis and Mc. Taggart which was done during 3 cycles. Each of the cycle consists of four phases; planning, acting, observing, and reflecting, while each cycle was done in two meetings. Data were collected through the observation sheet, field notes, interview and and tests. The research findings show that there were improvement on students’ speaking skill. In cycle one, the process of teaching learning with Show and Tell Method suggested a potential improvement, the researcher found some minor technical problems and weaknesses that leave rooms for improvement. Afterward, necessary alterations and revisions were done and later applied in cycle two and three. The result of the research suggested that the students show a tremendous improvement during the process of teaching learning when Show and Tell Method was applied. The students’ participation and vocabulary mastery were increased; they were more active, enthusiastic, and confident in speaking.
Integrating ICT in English Language Learning: Students’ Perceptions of a State University in Jambi Province
Authors: Oktalia Dwi , Ngadiso Ngadiso , Supriyadi Slamet
Published: March 2018

This research was done in order to know students‘ perception toward integrating ICT in English Language Learning and also to find out problem that may faced by students during the ICT integration. This research used quantitative method in order to describe students‘ perception toward the use of ICT in ELL. This research involved English students from a state university in Jambi province as the respondents. The data were collected by using questionnaires adapted from Chutopama (2004). The questionnaires consisted of items related to the use of ICT for their learning, their reason(s) of using ICT, as well as the problem(s) encountered through the use of ICT for the learning. After that, the data were analyzed by using SPSS 16 that pointed at a point in which the students agreed that ICT is beneficial for their learning process, especially in terms of accessing information for learning. Nevertheless, employing ICT in learning needs to be supported by sufficient equipment, and needs to educate the students to be an agile user for better, more effective, and more efficient process of learning.
Teaching Reading Skills to Non-English Native Speaker Students: The Numbered Head Together (NHT) Technique and Students’ Reading Ability in Bengkulu
Authors: Gultom Yarni Valentina
Published: March 2018

The purpose of this quantitative study with a quasi-experimental approach was to examine the significant increase and difference of students’ achievement in reading after being taught through the Numbered Head Together (NHT) technique with recount texts for the second grade students at one Junior High School in Bengkulu, Indonesia. The sample of this study was 72 second- grade students divided into two classes: experimental class and control class. The experimental class was treated by being taught through the Numbered Head Together (NHT) technique while the control class was taught using conventional method. To collect the data, pre-test and post-test techniques were used. The result of paired sample t-test showed that there was a significant positive effect of Numbered Head Together (NHT) technique toward the students’ reading ability. Implications of findings and suggestions are discussed.
Ethical Issues in Research Involving Children in TESOL and Applied Linguistics
Authors: Samanhudi Udi
Published: March 2018

This study sets out to address the ethical issues involved in studies concerning English language learning and acquisition which involve children (those under 18 years of age as outlined in the UN Convention on the Rights of the Child) as participants. This small-scale study focused on the analysis of ethical issues in three preliminary of samples of studies which involve children in the field of TESOL and Applied Linguistics. These three articles involved children as participants and are published in reviewed journals in the area of TESOL and Applied Linguistics. The results indicate that although implicitly presented, the informed consent and protection issues have generally been fulfilled by the researchers of the three articles. However, a more explicit explanation needs to be given more spaces in the research report in order to make it more transparent to the public (Peter, 2015; Thomas, 2009) and to ensure that the research is rigorous and significant (Dikema, 2009).
Ventilation Requirements for Today's Mechanized Underground Metal Mines
Authors: Gonen Alper
Published: March 2018

Ventilation is a basic part of all underground mine operations. The main objective of underground mine ventilation is to provide sufficient quantities of air to all the working areas. Today, in modern mechanized underground metal mines, diesel-powered mobile equipment is extensively used for high production rates. Ore can be extracted from many production stopes due to the production rate in a mine. Amount of airflow required for an underground mine depends on several factors, including daily production capacity, number of diesel equipment, ambient temperature, mining method, mining depth and airway type. After implementation of Stage IV Emission Standards for nonroad diesel engines, it is getting more complex to determine airflow quantities required for underground mines wherefore reduced diesel emissions. Required amount of airflow for a mine is obtained by ventilation fans and the largest cost aspect in mine ventilation is the power costs of running the ventilation fans which can reach as high as 50 percent of a mine’s entire electrical power cost. The cost of electrical power has increased significantly in recent years and is likely to continue increasing in the future. That is why it is getting more important to determine proper ventilation design for underground metal mines.
Influence of Talent Management Practices on Commitment of Non-critical Employees in IT Companies in Chennai
Authors: Krishnan K Renjith , Kalra Alka
Published: March 2018

This study examines the influence of Talent Management practices on commitment of non-critical employees in IT industry in Chennai, India. All employees have their own contribution to meet the success in long-term by any organization. HR managers of 60 large IT companies, located in Chennai were interviewed and surveyed to get better insights on Talent management practices and in addition, they provided a sample of their critical and a sample of their non-critical Employees. Commitment questionnaire was administered with 250 non critical employees. The results show that there is a significant difference between socio-economic features of non-critical employees and preference of talent management practices in IT companies. The regression analysis implies that job rotation and shadowing, mentoring and buddying, high potential development schemes, graduate development programmes and development centers are positively and significantly influencing the commitment of non-critical employees in IT companies at one per cent level, while, 360-degree feedback, cross functional project assignments and external secondments are negatively and significantly influencing the commitment of non-critical employees in IT companies at five per cent level. Organizations should thus take into account that Talent Management practices substantially impacts the commitment of workforce considered as non-critical. Further research is needed to conclude upon its impact on Organization performance as a whole.