bluuebunny/crossref_metadata_2025_split huggingface dataset:
Source inversion of seismic waveforms: The Koyna, India, earthquakes of 13 September 1967
Authors: Langston Charles A. 
Published: June 2021

abstractThe treatment of the seismic source inverse problem, when diverse forms of waveform data are available, is simple and elegant using a moment tensor formalism. If earth structure is known and its effects predictable in terms of vertically inhomogeneous elastic-layered models, then all types of wave phenomena (e.g., surface waves, body waves, leaky modes, etc.) for a purely deviatoric moment tensor point source may be represented by, at most, a sum of three Green's functions. For an arbitrary symmetric moment tensor point source, one additional Green's function is needed for the P-SV system. However elegant this formalism may be for posing the linear inverse problem, the major difficulties lie in earth structure unknowns and resultant nonlinearities in the Green's functions which can cause significant trade-offs with source parameters. A hybrid inversion procedure is set up to gain insight into the probable unknowns in particular problems by incorporating both a linearized least-squares gradient method for the moment tensor or double couple, and smoothed time function parameters, and a nonlinear systematic trial-and-error search for moment tensor or double couple parameters for several assumptions of Green's function. The inversion technique is applied to near-regional waveform data from a small earthquake associated with the Koyna Reservoir which occurred 13 September 1967, as the second in a group of three events with very similar waveshapes, but differing amplitudes. The magnitudes of the second and third events are smaller by −0.2 and −0.8 units, respectively, compared to the first. The absolute magnitude for the first event is poorly constrained but is estimated to be 4.0 to 4.5 rather than the previously published value of 5.5 to 6.0. From the similarity of waveshapes, all three events are inferred to have the same mechanism and occurred within about 2 km of the same hypocenter. The results from moment tensor and double couple inversions for event 2 data indicate that source depth was 5 km and that left-lateral faulting occurred on a plane with a strike of N20°E ± 5°, dip of 90° ± 15°, and a rake of 0° ± 35°. The inferred far-field time function is approximately 3 sec in duration, unusually long for the seismic moment of 9 × 1022 dyne-cm, yielding a possible stress drop of about 0.05 bars. A fault map was constructed from LANDSAT image interpretation and shows a predominance of NNW to NNE striking faults in the Koyna area which is used to infer the appropriate nodal plane in the inversion results. These faults tend to define a broad en-echelon zone which parallels the Western Ghats in this area.
Seismic source functions and attenuation from local and teleseismic observations of the NTS events jorum and handley
Authors: Helmberger Donald V. , Hadley David M. 
Published: June 2021

abstractSeveral strong-motion seismograms recorded at 8 km from a large nuclear test at Pahute Mesa, Nevada Test Site, are modeled using the Cagniard-de Hoop technique. The ratio of vertical to radial motions suggest that the peak values are produced by ray paths that penetrated to a depth several kilometers below the source. A homogeneous layered Earth model with velocity increasing with depth was used in the modeling of the velocity time histories. The upper portion of the velocity model was determined by averaging bore-hole data and the lower portion was obtained from regional refraction measurements. Assuming a modified Haskell (1967) source representation,ψ ( t ) = ψ o [ 1 − e − K t ( 1 + K t + ( K t ) 2 / 2 − B ( K t ) 3 ) ]we obtain a range of source descriptions with ψ0 varying with K and B, ψ0 (K,B). The range of source models for Jorum are ψ0 (5, 1) = 3.1, ψ0 (5, 2) = 1.7, and ψ0 (5, 3) = 1.2 times 1011 cm3, respectively. Given an explosion source description, it is a straightforward task to determine the teleseismic attenuation from WWSSN observations. From both the short- and long-period observations from these events, an average t* of 1.3 is obtained for compressional waves of a dominant 1-sec period. This estimate is insensitive to the range of K and B obtained from the near-field modeling.
An investigation of discriminants for events in Western USSR based on regional phases recorded at station Kabul
Authors: Gupta Indra N. , Burnetti J. A. 
Published: June 2021

abstractShort-period, vertical-component records at the WWSSN station, Kabul for 13 earthquakes and 8 nuclear explosions occurring within a region of efficient propagation of Lg are examined to explore the possibility of using ratios of amplitudes in different group velocity windows as a discriminant. Each seismogram is divided into 10 windows with boundaries representing Pn and group velocities of 6.0, 5.0, 4.5, 4.0, 3.8, 3.6, 3.4, 3.2, 3.0, and 2.8 km/sec. The first three windows include crustal phases Pn, Pg, and Sn, respectively, whereas the six windows from 4.0 to 2.8 km/sec encompass the expected group velocity of higher mode Rayleigh waves that include Lg. The ratio of the maximum amplitude before the arrival of Sn to the maximum amplitude thereafter is significantly larger for explosions than for earthquakes and provides the largest separation between earthquake and explosion populations. Considerable separation is also shown by amplitude ratios Pn/Lg and Pn/Pg. Amplitude ratios based on earlier- and later-arriving Lg phases and the amplitude ratio Sn/Lg show insignificant discrimination. The ratio (maximum before Sn)/(maximum after Sn) is expected to be a useful regional discriminant for events in the Western USSR.
Seismic gaps and recurrence periods of large earthquakes along the Mexican subduction zone: A reexamination
Authors: Singh S. K. , Astiz L. , Havskov J. 
Published: June 2021

abstractSeismic gaps and recurrence periods of large, shallow interplate earthquakes along the Mexican subduction zone are reexamined after combining information from a catalog of nineteenth century's earthquakes, some relocated epicenters of the early part of this century, source parameters of recent large earthquakes, and redetermined magnitudes of great, shallow earthquakes of this century. Tehuantepec and Michoacan gaps have not experienced a large shock in this century and perhaps none in the past century; they are either aseismic or have anomalously large repeat times. Guerrero, Jalisco, and Ometepec regions presently appear to have a high seismic potential. Observed average repeat times of large earthquakes (Ms ≳ 7.4) in six regions (east, central, and west Oaxaca, San Marcos, Petatlan, and Colima) are between 32 to 56 yr. Data of this century indicate that the strain is released mostly in large events (Ms ≳ 7.4). A simple dislocation model with parameters obtained from the studies of recent earthquakes explains the observed recurrence periods quite well. The b value for this zone is not meaningful, an observation which is of significance for seismic risk estimation. Most of seismic moment (or, equivalently, seismic energy) release since 1800 appears to occur for 15 yr followed by relative quiescence in the next 15 yr.
Study of the Montenegro earthquake sequence (March-July 1979)
Authors: Console R. , Favali P. 
Published: June 2021

abstract
Data from more than 80 European seismic stations, concerning foreshocks, the main shock, and aftershocks of the earthquake which occurred near the coast of Montenegro on 15 April 1979, have been collected and analyzed. The data have allowed the focal mechanism of the two strongest shocks to be estimated. The hypocentral coordinates of more than 180 aftershocks and some foreshocks have been also computed, giving the time-space distribution of the sequence. The shocks are mostly contained in an area about 100 km long and 30 km wide, almost corresponding to the Adriatic coast line of the Yugoslavia-Albania border region. The hypocentral depths, although determined approximately, appear to be in the order of 15 to 20 km. The results have been compared with previous knowledge of the tectonics of the zone.
Observation and inversion of surface wave group velocities across central India
Authors: Bhattacharya S. N. 
Published: June 2021

abstractSurface wave group velocities across central India are measured from computer plots of frequency-time analysis using multiple-filter technique. Periods range from 5 to 56 sec for fundamental mode Rayleigh wave, 5 to 16 sec for first higher mode Rayleigh wave, and 5 to 49 sec for fundamental mode Love wave. The wave paths from Koyna earthquakes to Bokaro cross purely through the Peninsular Plateau. The group velocities for these paths are found to be similar to those of surface waves recorded at Poona from earthquake which lie to the northeast of Bokaro in sub-Himalayan regions. From this, it is concluded that the shield structure of the peninsula extends to the sub-Himalayan regions to northeast of the Peninsular Plateu with a negligible part of sedimentary layer. Group velocities of fundamental mode Rayleigh and Love waves are also obtained for the paths from Koyna earthquakes to Shillong and are found to be similar to the above-mentioned group velocities except at very low periods where group velocities are affected by the small part of each path through thick sedimentary layer of Bengal Basin. Northern limit of this basin sedimentary layer has been identified.Mean and standard deviation of observed group velocity at each period are obtained for each of Rayleigh fundamental, Rayleigh first higher, and Love fundamental modes. The group velocities closely agree with those obtained earlier for the path between New Delhi and Kodaikanal and are also found to be similar to those observed in some shield regions.Monte Carlo inversion method is applied and crust and upper mantle structure of the Indian Shield across central India is obtained. Crustal structure obtained shows a marked resemblance to the results obtained earlier through body wave study.
Regional variation and frequency dependence ofQβin the crust of the United States
Authors: Mitchell Brian J. 
Published: June 2021

abstractApproximate Lg attenuation coefficient values are determined for paths in eastern North America at periods between 2 and 4 sec where no data were previously available. These new data, together with reported values at a period of 1 sec, are consistent with values predicted by a frequency-dependentent Qβ of the crust in which Qβ varies as ω0.2. The new data are inconsistent with values which would be predicted by models having prominent maxima or minima in Qβ−1 within the period range 1 to 5 sec.Lg attenuation coefficients were computed for the frequency-independent crustal Qβ models of Cheng and Mitchell (1981) for the Basin and Range Province and Colorado Plateau of the Western United States. The predicted values at 1 sec for the Colorado Plateau and Basin and Range Province are about twice as large, and three times as large, respectively, as those predicted for the Eastern United States. Recently reported values of Q for 1-sec Lg in those regions are consistent with the attenuation coefficients and Q values of Lg predicted by the Colorado Plateau and Basin and Range Province models. A model with a small degree of frequency dependence of Qβ would be consistent, but is not required by the data.
A rare earthquake sequence in the Kobuk Trench, northwestern Alaska
Authors: Gedney Larry , Marshall Dianne 
Published: June 2021

abstract
Four moderate earthquakes in the magnitude of 4 to 5 range occurred in the Kobuk Trench of northwestern Alaska during October 1980. This is a characteristically aseismic area. All foci were of shallow depth, and focal mechanism solutions from the three largest events are consistent in indicating right-lateral displacement on a fault trending WNW-ESE. This would be in agreement with mapped faults of Quaternary age in the area.
Broadband Futures Forum: Regional and Rural Broadband Access
Authors: Campbell Leith H 
Published: June 2021

On 24 March 2021, TelSoc hosted the sixth Broadband Futures Forum, held online, with a focus on regional and rural broadband access. Mr Gavin Williams from NBN Co, the developer of Australia’s National Broadband Network (NBN), spoke about developments in Fixed Wireless and Satellite services and described NBN Co’s commitment to ongoing enhancement of broadband access in regional and rural Australia. A question-and-answer session followed the presentation in which Mr Williams fielded a variety of questions on broadband access and technological developments.
A study to identify the prevalence of vulvovaginal candidiasis in second trimester
Authors: Kruthipati Rashmi , Chethan Radhika , Shiva Anitha Gabbalkaje , Suresh Sukanya 
Published: June 2021

Background: Vaginal candidial infections are due to excessive growth of Candida. These are normally present in the vagina in small numbers. Vaginal infections are typically caused by the yeast species Candida albicans. It is found that candidial infection increases the risk of preterm labour. Aims and objectives of the study were to determine the prevalence of vulvovaginal candidiasis and influence of maternal age, parity and weeks of 2nd trimester on its occurrence among pregnant women in 2nd trimester, attending the antenatal clinic in our hospital.Methods: A prospective study conducted in BMCRI for a period of 3 months (October 2019-December 2019) on patients in second trimester. Consent of patients taken. High vaginal swabs were collected from the pregnant patients in second trimester and sent for culture. Candida positive cases were noted and results were analysed.Results: A total of 100 high vaginal swabs were collected and reported in our study. Among them 54 swabs were positive for Candida growth (54%) and 46 swabs were negative for growth (46%). Culture positive patients’ clinical details were analysed and tabulated.Conclusions: Our study concluded that candidiasis is more prevalent in pregnant women but there was no statistical significance in occurrence of vaginal candidiasis among various age groups, parity or trimester. Hence it is better to screen all the patients in I early II trimester in order to find out and treat positive cases early to prevent preterm births attributed to vaginal candidiasis.
Loose knots and surgical site infections in abdominal surgeries (clean-contaminated and contaminated wounds)
Authors: Madhusudhan Napa , Prabhakar R. 
Published: June 2021

Background: Surgical site infections (SSIs) are associated with high healthcare costs and worsen the post-operative course of a considerable proportion of general abdominal surgical patients. SSIs raise the risk of post-operative morbidity and mortality, necessitating hospitalization, intravenous antibiotics, and potentially surgical reintervention. The aim of the study was to compare the outcome of intermittent loose knots and the conventional vertical mattress suturing in patients undergoing abdominal surgeries.Methods: This prospective comparative study was done in patients undergoing emergency abdominal surgeries for any cause. Patients were divided into 2 groups- (a) group 1 (45 patients): intermittent loose knots between conventional vertical mattress sutures; (b) group 2 (45 patients): conventional vertical mattress suturing.Results: In this study, 31% of patients were in the 41-50 years age group, 53.3% of patients were male. Among various abdominal surgery opted, laparotomy was the most commonly performed procedure (47%). In this study, group 1 patients shown a decrease in wound gap, secondary wound closure and delayed wound approximation than group 2 patients.Conclusions: Loose knots in between conventional vertical mattress sutures are better than conventional vertical mattress suturing in terms of wound gap, secondary wound closure and delayed wound approximation.
Study of ergonomics in terms of angle of manipulation and angle of azimuth in laparoscopic splenectomy
Authors: Joshi Gaurav , Baig Khaja Abdul Moin , Chaturvedi Aparajita , Jayaram Jnaneshwari , Rathore Yashvant S. , Chumber Sunil 
Published: June 2021

As per baseball diamond concept of port position, experimentally it is well known that putting camera port in the line of target organ and working port equidistant from camera port such that they form a 30º angle each gives optimum ergonomic advantage. However while performing laparoscopic surgeries in humans it is seldom possible to achieve such port position. No such study has ever been attempted to find out value of angle of manipulation and angle of azimuth while performing laparoscopic procedure. Purpose of our study was to measure such angles in our patients during laparoscopic splenectomy (LS) and to verify the concept of baseball position of ports in the procedure. This was a prospective observational study where angle of manipulation between right and left working port of surgeon and angle of azimuth of both working instruments with the camera were measured intraoperatively. In our series of 12 patients who underwent LS in lateral position, we found angle of manipulation ranging from 41-85°. The azimuth angle between first working port (epigastric) and camera port was in the range of 22-45° and the azimuth angle between camera port and second working port was in the range of 19-40°. This was a first study that gave valuable insight into the application of theoretical concept of triangulation in port placement in LS. This study may guide the surgeons to measure and to modify the port position to gain advantage of better ergonomics and better long term health.
A rare case of abnormally high thoracic duct in neck
Authors: Padegaonkar Amol , Sehgal Anushree , Agrawal Shambhunath 
Published: June 2021

Thoracic duct injury can be a cause of significant morbidity if its injury remain undiagnosed during surgery. Knowledge of its course and anomaly should be known to prevent its injury. Presenting a case of 40 year male who was diagnosed to have left buccal mucosa squamous cell carcinoma. During neck dissection, anomalous thoracic duct was found much above the omohyoid muscle. Adequate steps were taken to prevent injury to it. It is necessary to acknowledge thoracic duct and prevent its injury during neck dissection. Knowledge about its anomalous path should be known to prevent its injury. Valsalva manoeuvre should be done at the end of neck dissection to find and thoracic duct injury by observing chyle leak and adequate measures should be taken immediately to prevent morbidity associated with it.
A review of studies on the evaluation of manual handling with different methods in Iran from 1389 to 1399
Authors: Ashouri M , Eidani SH , Salehi Sahlabadi A 
Published: June 2021

Introduction: Nowadays, most industries in Iran constitute a large proportion of workers' activities in Manual Material Handling. Musculoskeletal disorders are areas of erosive and inflammatory conditions that occur in the form of pain and discomfort in the muscles, tendons, ligaments, joints, peripheral nerves, blood vessels. Working hours, absenteeism, increasing work restrictions, job changes and disability and impose many economic consequences on the individual, organization, and society.
Materials and Methods: The present study was conducted to review the studies of Manual Material Handling by different methods in Iran from 2010 to 2020. The general process of the present study included searching for articles invalid national and international databases. After selecting the articles, the necessary information was extracted and analyzed. In general, based on the inclusion criteria, only studies that used NIOSH, KIM, SNOOK, 3DSSPP, WISHA, UTAH, MAC, ART, and manual handling regulations in Iran, were reviewed.
Results: 15 English articles and 50 Persian articles were found, of which 44 articles were deleted based on the exclusion criteria, and 21 articles were selected for this study and entered into the final analysis.
Conclusion: The highest number of studies was conducted in Hamedan, Tehran, Mallard, Shiraz, and Qazvin, respectively NIOSH, KIM and 3DSSPP were the three methods used with the highest number of studies in the field of Manual Material Handling in industry. Most workplace studies were conducted in the casting, food industry, tile industry, and hospital.
The relationship between job demands and workplace incivility in an industrial company: the mediating role of emotional exhaustion and moderating role of perceived organizational support
Authors: Rahimi Pordanjani T , Ghorbanian A 
Published: June 2021

Introduction: workplace incivility is one of the subtle forms of interpersonal and organizational abuse. The purpose of the present study was to investigate the causal relationship between job demands and workplace incivility with the mediating role of emotional exhaustion and the moderating role of perceived organizational support in an industrial company employee.
Materials and Methods: In this descriptive correlational study, the statistical population was all employees of Bojnourd Cement Company, and 321 workers were selected according to the Cochran formula and by a simple random sampling method. The research data were collected using the Cortina et al. (2001) workplace incivility questionnaires, Jong et al. (1993) job demands, Maslach's emotional exhaustion (1981), and Eisenberger et al. (1986) perceived organizational support. SPSS and AMOS 23 software were used for data analysis.
Results: The results showed that the proposed model has a good fit. Job demands have a direct and indirect effect through emotional exhaustion on workplace incivility (p> 0.0001). The results also showed that the interaction of job demands and perceived organizational support, beyond the effects of the main variables, produced 1.5% added monopoly variance (R2Δ = 0.015, FΔ = 49.50, P <0.05) for the model.
Conclusion: The results showed the importance of organizational support as a moderator and emotional exhaustion as a mediator between the relationship between job demands and workplace incivility. Therefore, organizations can reduce emotional exhaustion and workplace incivility by reducing their job demands. Supportive programs are also suggested to reduce the impact of job demands on workplace incivility.
Prevalence of foot varicose veins in hairdressers and some related factors in Gonabad
Authors: Baloochi Beydokhti T , Ghadimifar A , Mohammadi M , Soleimani Moghaddam R 
Published: June 2021

Introduction: Physical postures at work and occupational conditions are among the important risk factors that increase the prevalence of varicose veins. These include prolonged standing and tedious postures that are unavoidable in the hairdressing profession. This study aimed to investigate the relationship between the prevalence of foot varicose veins and occupational and demographic factors in hairdressers.
Materials and Methods: This cross-sectional-correlational study was conducted on 90 hairdressers in Gonabad in 2015. The participants were selected using a random method. After completing the demographic information questionnaire, the samples were examined according to CEAP criteria (clinical findings, etiology, anatomical findings, and pathophysiology). The collected data were analyzed using Chi-square, Fisher, and independent t-tests using SPSS software version 20 at a significance level of p <0.05.
Results: Out of 90 patients, 45 were male, and 45 were female, and (77.8%) had an average working time of more than 6 hours. Most of the men (51.1%) and women (53.3%) had varicose veins of the lower extremities of both limbs. The relationship between varicose veins of hairdressers and education (P = 0.031), work experience (P = 0.043), regular exercise (p = 0.012), smoking (P = 0.009) was significant.
Conclusion: The present study results indicate the high prevalence of lower limb varicose veins in hairdressers. This disorder causes many mental and physical disorders and ultimately affects the individual's work efficiency, so controlling risk factors and preventing this complication in hairdressers seems necessary.