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In October 2019, the Jackson, Mississippi city council passed a buffer, bubble, and quiet zone ordinance to discourage protestor activity outside the state’s only licensed abortion facility. We sought to learn about patients’ encounters with protestors and how the ordinance would have affected their experiences obtaining care. Before the passage of the ordinance, patients seeking care at the Mississippi facility enrolled in a prospective study on access to abortion and contraception. We invited participants completing the six-month follow-up survey between November 2019 and January 2020 to participate in an in-depth interview over the phone about their experiences with protestors at their visits. We analyzed interview transcripts for content and themes using inductive and deductive approaches. Of 30 participants interviewed, the majority expected to see protesters at their visits but were surprised at the number present and how close they were able to get to patients, which made some feel unsafe. Participants also reported that protestors’ offers of adoption and financial support were unwanted and that they were able to withstand comments that promoted shame and stigma because of their strong sense of reproductive autonomy. Participants credited clinic escorts and security with helping mitigate negative protestor encounters. Nearly all felt the city ordinance would have improved their experience by making them feel safer and more at ease. Protestors created negative experiences for the majority of study participants, even though the facility adopted strategies to ameliorate protestors’ impacts. Additional protections are needed to ensure people can obtain abortion care with respect.

In sound field reproduction and sound field control systems, the acoustic transfer functions between a set of sources and an extended reproduction area need to be accurately estimated in order to achieve good performance. This implies that large amounts of measurements should be performed if the area is large compared to the wavelengths of interest. In this paper, a method for reconstructing these transfer functions in highly damped conditions is proposed by using only a small number of measurements in the reproduction area. The source radiation is modeled with the spherical harmonics basis and its amplitude coefficients are fitted with Bayesian inference. This approach is validated in a sound field control experiment where a set of 12 control loudspeakers attenuate the sound pressure level generated by a set of six primary loudspeakers in a quiet zone while minimizing their radiation into a listening zone. The performance of the approach is studied by analyzing the sound field reconstruction and the sound field control performance. It is shown that it is possible to get-with few measurements and the source radiation model-results similar to those achieved using a dense grid of transfer function measurements.

Compact antenna test range (CATR) is popularly used to produce a plane-wave like field-distribution in a small designated quiet zone to resemble the actual far-field scenario in electromagnetic (EM) related measurement. The quiet zone’s performance relies on many factors that should be compromised for a trade-off between performance and system complexity. This paper presents major design concerns from the realizable industrial aspects and discusses their solutions when designing a high-performance CATR.

The NHS routinely evaluates the quality of life of patients receiving hip or knee replacement surgery using patient-reported outcome measures (PROMs), but some hospital completion rates are only 30%, restricting data usefulness. Statistics limit insights into how and why data are missing, so qualitative methods were used to explore this issue. Observation periods preceded semistructured interviews with 34 preoperative patients attending an orthopedic outpatient clinic. Interview themes covered: completion time/timing, orientation, setting, measures, and practicalities. Triangulated against observations, pragmatic barriers, and facilitators were considered. Refined themes included completion conditions, patient support, and national delivery. Simple improvements (e.g., quiet zone) could improve completion rates and reducing missing data. Reorganizing preoperative leaflets and their systematic distribution via standardized procedures could reassure patients, enhancing PROMs acceptance, while reducing inquiries and subsequent staff burden. Findings have implications for interpreting national statistics. They indicate that further debate about mandating preoperative PROMs is due.

Purpose: To determine whether using existing noise reduction strategies improves patients’ overall satisfaction level during hospitalization on an adult outpatient cardiology unit and to assess whether noise reduction strategies were effective to decrease the ambient noise for both staff and patient environments. Background: Excessive noise is a worldwide problem facing hospitals today. Noise has been proven to be detrimental to staff and patient well-being and hospital environment satisfaction levels. Intervention: Staff noise perception online surveys, a poster presentation, and education of noise reduction strategies were completed. Two 6-week phases of pre- and postimplementation noise reduction strategies were initiated including closing of the doors, verbal and visual alarm reminders for staff, posting quiet signs, and limiting equipment through the unit. Patient telephone interviews regarding the noise environment during hospitalization in both phases and a follow-up staff noise perception online survey were completed. Results: Staff surveys identified noise as an issue on the unit with staff communication (90%) being the main source. This correlated with patient surveys of five rooms closest to the desk considering the unit “noisy.” Post-implementation patient surveys noted that strategies created in helping the unit become “quiet/mostly quiet.” Closing patient doors was most effective in noise reduction, increasing patient unit satisfaction. Conclusion: The use of visual cues and staff education are effective in reducing noise levels. Decreased noise levels improved overall patient satisfaction with their hospital experience and created a less stressful work environment.

In this paper, early performance assessments on a newly developed plane wave generator (PWG) at millimeter wave frequencies are reported for the first time. The PWG is integrated in an automated system suitable for 5G testing. Far-field radiation from devices such as pattern, beam pointing, and typical over-the-air (OTA) parameters can be measured in 3D space. Devices are positioned in the quiet zone (QZ) using a RF transparent positioner. Live person testing is feasible, using a chair placed in the system such that the device including head and upper torso of the test person is within the QZ.The PWG based system is described in this paper, including a preliminary evaluation of measurement performance and accuracy at system level. The assessment is based on system simulation, measurement post-processing, and actual test on a pilot system. The PWG technology discussed in this paper is currently being integrated as a standard product.

The Cretaceous Normal Superchron (CNS), defined as a magnetic quiet zone spanning from similar to 126 to similar to 84 Myr, is often used to understand the Earth's geodynamo processes. However, whether there were polarity reversals within the CNS remains contentious. This paper presents the youngest detrital zircon U-Pb age-constrained magnetostratigraphic study of the Cretaceous Khorat Group for two sections (i.e., Ban Phonngam (BP) and Ban Nongpen (BN)) in Vientiane, Laos. Both sections are characterized by the prominent long normal-polarity zones that are correlated to the CNS. Interestingly, six (four) short primary reversed horizons were identified within the BP (BN) section. Integrated with other reported reversed events, there likely at least five globally and two single reported reversed-polarity events or clusters of events have happened within the CNS. The confirmation of frequent reversed polarities within the two parallel sections will provide a new comprehensive understanding of the Earth's geodynamic behavior during the CNS.

Selon les termes de la saisine, « cette zone qui s’étend à 20km autour des foyers d’influenza aviaire (IA) déclarés dans ces départements a été mise en place suite à votre avis rendu sur la saisine n° 2020-AST-0179 : Demande d’avis scientifique et technique de l’Anses relative aux mesures de maitrise de l’épizootie d’influenza aviaire dans la région du Sud-Ouest(département 40 et départements mitoyens) », Question n°2. Dans cet avis l’Anses a indiqué “Compte tenu des délais de levée des zones réglementées autour des foyers d’IAHP, le Gecurecommande de lever les restrictions de mises en place d’oiseaux et d’entrées/sorties de la zone tampon à une date au moins égale à celle de la levée de l’APDI du dernier foyer de l’ensemble des zones réglementées qu’encercle la zone tampon (cf. annexe 2 : levée des zones règlementées)".Toutefois nous souhaitons examiner l’opportunité d’une éventuelle levée progressive : il apparaît en effet que certaines zones ne connaissent plus de foyers depuis plusieurs semaines et leur situation épidémiologique pourrait être différenciée d'autres zones qui ont connu des foyers plus récemment. Par ailleurs, alors que dans certaines zones des foyers sont apparus entre 10 et 20km autour des foyers, cela n’est pas le cas, par exemple dans les Pyrénées Atlantiques et le Gers. Du fait des nombreux abattages à titre préventif qui ont été effectués autour des foyers, la densité d'animaux a fortement chuté dans certains territoires, il resterait 35000 canards dans les Landes et 200 000 dans la zone tous départements compris. Cet examen s’intéresse également aux conditions dans lesquelles, après la levée de la zone tampon, des remises en place sont possibles.Aussi les questions que je souhaite vous poser sont les suivantes : - Quelles sont les conditions requises pour envisager la levée de certaines zones stabilisées de la grande zone tampon du sud-ouest ? - Sous quelles modalités peut-il être envisagé cette levée partielle ? - Quelles seraient les conditions pour envisager un repeuplement des élevages dans ces zones ? »

Virtual sound barrier (VSB) represents an array of loudspeakers and microphones forming an acoustic barrier to create a quiet zone without blocking light and air circulation. Although the concept of VSB has been proposed for many years, practical applications are still rare due to its performance and cost. This chapter explores two application scenarios of implementing VSB in workplaces: one is an eight-channel circular VSB system in a small room to create a quiet zone and the other is an eight-channel planar VSB system mounted to the door of the small room to prevent the outside noise from propagating inside. For the circular VSB system, the loudspeakers are uniformly placed along a circle with a diameter of 1.4 m to create a quiet zone with a diameter of 0.8 m. The experimental results show that the system is effective in reducing the low-frequency noise from 100 Hz to 250 Hz, and the noise reduction can reach 8 dB at 100 Hz. For the planar VSB system, the loudspeakers are placed at the door to reduce the noise propagating from the outside to inside. The experimental results show that the low-frequency noise below 250 Hz is effectively reduced by up to 6 dB at 80 Hz. These results demonstrate the feasibility of VSB for blocking low-frequency noise propagation, but further improvements are needed at higher frequencies above 400 Hz.

This paper presents a circularly polarized horn antenna with rectangular aperture for the Compact Antenna Test Range (CATR) from 75GHz to 95GHz. Axial ratio less than 2.5dB and gain up to 20dB are realized in simulation. Furthermore, a simulated circularly polarized quiet zone with 60% aperture usage efficiency and amplitude ripple less than 2dB is achieved in the CATR.

This work describes a multi-functional active noise control (ANC) system installation in an airplane seat. Most researchers in the field have focused on systems that cancel narrowband noise on headrests owing to the causality constraint of ANC system. Therefore, ANC systems in seats have limited performance. In this paper, an ANC system is designed for an airplane seat and the electronic delay of the ANC system is reduced to meet the causality requirement of a feedforward ANC system. An infrared sensor is used to detect the head of the occupant of the seat, so the ANC system can automatically cause the quiet zone to surround the ears of users with various sitting postures. Multiple noise sources and the automatic activation function of the ANC system are discussed. Experimental results show that the proposed ANC system for an airplane seat effectively reduces recorded airplane noise without the need for earplugs or an ANC headset.

Introduction In August 2019, the city council in Jackson, Mississippi passed a 15-foot buffer, 8-foot bubble and 100-foot quiet zone ordinance for all health clinics, aimed at discouraging protestor activity outside the state's only licensed abortion facility. After a series of legal challenges, Jackson repealed the ordinance in November 2020. We sought to learn about patients’ encounters with protestors and how the ordinance would have affected their experiences obtaining abortion care. Method Prior to passage of the ordinance, patients seeking care at the Mississippi facility enrolled in a prospective study on their access to abortion care and contraception; we invited participants completing the 6-month follow-up survey after August 2019 to participate in an in-depth interview about their experiences with protestors at their visits. During the phone interviews, we asked participants about their encounters with protestors and the role of escorts and clinic security in mitigating interactions; we also provided a description of the city ordinance and then asked how this might have changed their experience had it been in place when they were obtaining care. We analyzed interview transcripts for content and themes using both inductive and deductive approaches. Results Of the 30 participants interviewed, the majority said they expected to see protesters at their visits; however, they frequently noted they were surprised by the number of protestors crowding the street and sidewalk near the facility and how close protestors were able to get to patients. Participants overwhelmingly described protesters as “pushy and determined,” and some remarked they felt unsafe because they thought protestors were unpredictable and were aware of violence that had taken place at other facilities. Parking in the clinic lot or on the street largely shaped the intensity of patients’ interactions with protestors. While most participants expressed a strong sense of reproductive autonomy, they also noted that protestors’ presence and comments had a negative emotional impact. Participants credited clinic escorts and security with mitigating these negative experiences by demonstrating concern about patients’ wellbeing, validating their abortion decision and preventing more involved encounters, but a few expressed that needing to have escorts, in general, increased their safety concerns. Nearly all participants stated that the city ordinance would have had a positive effect on their experience, noting they would have felt more at ease, safer, and had the privacy they desired. Conclusions Prior to the passage of Jackson's city ordinance, protestors created stressful and negative experiences for the majority of study participants seeking abortion care, even though the facility adopted strategies aimed at ameliorating protestors’ impacts on patients. Although the city ordinance was short-lived, these results indicate that patients need additional protections to ensure they can obtain essential health care with respect.

Remote error sensing is required in active noise control systems when they are used to create a quiet zone in a noisy environment with the constraint that the error microphones cannot be inside the zone. The challenge in remote error sensing is to estimate the sound pressure in the target zone with a small number of physical microphones outside it. The spatial harmonic decomposition method uses wave domain sound field parameterisation to reduce the required number of the error microphones but can only provide accurate estimation below a certain frequency. This paper presents an improved approach to increase the effective frequency range based on the acoustic modelling. The simulation results demonstrate the proposed method can provide more than 20 dB noise reduction up to 1650 Hz for a quiet zone with a radius of 0.1 m by using only three microphones under the studied situations.

In this paper, we describe the design of an electrically large anechoic chamber for usage on millimetre-wave bands. Ansys Savant sotware was used to perform a simulation of the chamber, using physical optics coupled with uniform theory of diffraction (PO/UTD). Moreover, a method based on an open waveguide probe is described in this paper to obtain the electrical properties of the RF absorbers at millimetre-wave frequencies. Two different source antennas were simulated in this work and the corresponding quiet zones predicted. The largest quiet zone was 30 &times, 30 &times, 50 m m , for a chamber size of 1 . 2 &times, 0 . 6 &times, 0 . 6 m .

Active noise control is an efficient approach in dealing with unwanted acoustic disturbances. However, most of the active noise control algorithms aim to control the signal of the error sensor leading to local noise attenuation only around the error microphones. One of the approaches to enlarge the quiet zone is by restraining the derivative of the sound field around the error microphone to zero. It achieves noise cancellation not only at the error microphone but also in its vicinity. This paper proposes a time-domain adaptive algorithm to implement the spatial derivative constraint, which avoids the complex analytic acoustic calculations. Furthermore, the proposed algorithm does not require extra microphones to acquire the sound field information during control. Numerical simulations are carried out to validate the effectiveness of the proposed method.

The relative motions of the tectonic plates show remarkable variation throughout Earth’s history. Major changes in relative motion between the tectonic plates are traditionally viewed as spatially and temporally isolated events linked to forces acting on plate boundaries (i.e., formation of same-dip double subduction zones, changes in the strength of the boundary), or thought to be associated with mantle dynamics. A Cretaceous global plate reorganization event has been postulated to have affected all major plates. The Cretaceous ‘swing’ in Africa-Eurasia relative plate motion provides an ideal test-bed for assessing the temporal and spatial evolution of both relative plate motions and surrounding geological markers. Here we show a novel plate kinematic model for the closure of the Tethys Ocean by implementing intra-Cretaceous Quiet Zone time markers and combine the results with the geological constraints found along the convergent plate boundary. Our results allow to assess the order, causes and consequences of geological events and unravel a chain of tectonic events that set off with the onset of horizontally-forced double subduction ~105 Myr ago, followed by a 40 Myr long period of acceleration of the Africa relative to Eurasia that peaked at 80 Myr ago (at rates four times as high as previously predicted). This acceleration, which was likely caused by the pull of two same-dip subduction zones was followed by a sharp decrease in plate velocity, when double subduction terminated with ophiolite obduction onto the African margin. These tectonic forces acted on the eastern half of the Africa-Eurasia plate boundary, which led to counterclockwise rotation of Africa and sparked new subduction zones in the western Mediterranean region. Our analysis identifies the Cretaceous double subduction episode between Africa and Eurasia as a link in the global plate tectonic chain reaction and provides a dynamic view on plate reorganizations.

Distraction from the background environment while performing concentrationdemanding tasks is a common issue for office employees in shared work areas. However, few field studies have been conducted on the effects of different office types and work areas on objective measurements of cognitive performance. The first aim of the present field study was to investigate, before relocation to an activity-based workplace (ABW), differences in performance on a concentration-demanding cognitive task between individuals in shared/open-plan offices compared to cell offices. The second aim was to investigate, after relocation, how performance differs (withinperson) between different work areas within the ABW. This study included employees from five offices (n = 113), of which four relocated into an ABW. An acoustician measured the equivalent sound levels of the work areas. Data were analyzed using linear regression (aim 1) and mixed models (aim 2). Before relocation, employees working in shared/open-plan offices performed significantly worse (14%) than those in cell-offices, which had a 15 LAeq lower noise level. After relocation, employees performed significantly worse in the active zone without noise restrictions, compared to all other work areas. When shifting open-plan area from the active zone to the quiet zone cognitive performance increased significantly by 16.9%, and switching to individual working rooms increased performance by 21.9%. The results clearly demonstrate the importance for organizations to provide quiet areas or rooms with few distractions for employees working on tasks that demand concentration in an ABW. A daily drop in performance for each employee may be expensive for the organization in the long run., Highlights • Before relocation, employees performed a task in their cell offices, or open-plan offices. • Performance was better (17%) in the cell offices compared to the open-plan offices. • After relocation, the employees performed the same task in the activity-based offices. • Performance was better (17–22%) in quiet work zones/rooms compared to active zones. • Hence, it is important to provide quiet areas for work demanding concentration.

It is generally accepted that the design of reflector used in Compact Antenna Test Range (CATR) is a challenging job for a long time, especially for the design of its serrations. In order to solve the addressed problem above, this paper will mainly include four parts as (1) Choosing an appropriate algorithm in software to conduct simulation effectively under certain frequency. (2) Studying the scattering mechanism of the reflector’s rim. (3) Comparing the quiet zone characteristics between reflectors with different serrations which are commonly used. (4) Offering guidance parameter configuration to obtain proper serrations. At last, we can come to the conclusion that the theory analysis agrees with the simulation results.

Compact antenna test ranges are used for fast and accurate measurement of satellite antennas and payloads. The measured performance of compact range feed dictates the quality of Quiet zone at CATF. A Dual Linear Q/V-Band feed compliant to standard compact range feed specifications was designed. The designed feed will be used for RF characterization of advance communication payload. In this paper, design aspects and simulated results of proposed feed are discussed.

Late Cretaceous sedimentary history has been strongly influenced by both sea-level fluctuations and inversion tectonics. Evidence for tectonic movements, originally identified in German Late Cretaceous basins, is applied to the UK successions. Two periods of movement are conspicuous: a Middle Turonian episode involving huge loss of section along anticlinal axes in southern England and a Late Santonian-Early Campanian episode also involving section loss on structure and section gain off structure. This pattern is repeated where folds or blocks are underlain by inversion thrust faults (e.g. the Purbeck Fault in Dorset, the Falmer Fault in Sussex, the Portsdown Fault in Hampshire and the Bray Fault in Upper Normandy). Other episodes of inversion in the Late Turonian to Middle Coniacian and the late Early Campanian are investigated and are a probable cause of slump beds and slides. These tecto-sedimentary episodes can be applied to structures in Northern Ireland, Inner Hebrides, North Sea and Yorkshire as well as southern Britain. Beyond NW Europe the Late Santonian – Early Campanian event is widely recognised in the Carpathians, southern Europe, Africa and the Levant and coincides with the end of the Long Cretaceous Quiet Zone (Chron 34N to 33R) perhaps representing a major change in Earth dynamics related to Mid-Ocean Ridge crustal production and intra-continental crust tectonism.

The quality of the sonic environment in major cities is becoming increasingly important owing to growing concerns regarding noise pollution and the need to preserve the soundscape as intangible cultural heritage. The objective of the present study is to demonstrate the use of a smartphone as a platform to collect sound data and generate a sound map based on soundwalks in major European cities. The sonic environments of the five major cities namely Paris, London, Amsterdam, Prague and Milan are presented and compared with those of two smaller European cities: Trondheim and Aachen. Among these seven European cities, Aachen is the quietest city, with equivalent and maximum sound pressure levels (SPLs) of about 66.5 dBA and 85.8 dBA, respectively.

The active headrest is an important application of active noise control (ANC) where the occupant gets a quiet zone during use. However, its performance degrades due to head movement, which is an important issue. Unlike conventional active headrest algorithm, in the present paper, the two error microphones are attached to a head attachment such as a hat or band so that both error microphones can move along with the head, keeping the relative distance of ears and the microphones intact. The two secondary loudspeakers are kept near to the head, facing the ears. The performance of the active headrest was studied through real-time experimentation considering head movement. The innovation in this paper is that the ANC algorithm uses signals of moving error microphones to tune the controller without re-estimating the secondary path transfer functions. Since, the phase error of secondary path estimates at different head positions remains within ±90°, the secondary paths estimated once, when the head is positioned at the center, can be used for other head positions. This is established through real-time experiments using dSpace 1104 ACE system (dSpace, Germany).

Local acoustic treatment around a person’s head and body can influence the transmission of speech to and from the person, the perception of background noise, and the sound they hear of their own voice (autophony). This paper demonstrates ways to systematically quantify these acoustic effects in terms of oral, binaural and oral-binaural gains. Two pre-existing examples of high-backed chairs were selected as examples and measured using the proposed methods: one with a reflective back around the head, and the other providing greater enclosure and a sound absorptive interior. Results are interpreted by considering effects on speech transmission index (STI), background noise criterion (NC), A-weighted speech level, and vocal output (due to the influence of autophony), and the previously proposed speech reduction index ( D S ). Together, the gain parameters provide an indication of a treatment’s potential to enhance speech communication, provide a quiet zone, reduce speech disturbance, and support a person’s voice as they speak.

The Plane Wave Generator (PWG) is an array of elements generating an approximately plane wave over a finite volume in the test area called Quiet Zone (QZ). The plane wave condition can be achieved in close proximity to the array with suitably optimized complex coefficients. The PWG thus achieve far-field testing conditions in a manner similar to the Compact Antenna Test Range (CATR) but with a reduced distance to the QZ [1–2]. As a complete system the PWG has the advantage of reduced physical size compared to the a CATR with equivalent testing capabilities, in particular at lower frequencies. In [3–4], the concept of a high performance, dual polarized PWG supporting up to 1:10 bandwidth was presented. A prototype of a dual polarized PWG has been designed, manufactured and tested in the 600MHz to 6GHz frequency range.This paper presents the initial verification of the prototype PWG. The testing is performed using a representative analog beam forming network with narrow bandwidth. The QZ uniformity of the PWG is verified by spherical near-field measurements and back-propagation. The peak gain of a low directivity antenna is measured at different distances in the QZ and compared to reference measurements in a spherical near-field system. The aim of the comparison is to access the measurement accuracy of the PWG.

In this paper we analyze three different verification procedures of the test zone in the Random Line-of-Sight measurement setup. The goal is to find a way to reduce the number of samples needed to estimate the standard deviation and the mean value within a circular test zone. It was found that more than 50 samples are needed to get reliable performance with the verification procedure using two orthogonal lines. However all three investigated methods work well, but the two other methods need more than 100 samples. This means that the samples can be taken within the test zone along two orthogonal lines, in a spiral shape, as well as a combination of these two methods, depending on the user's preference.

We deal with an approach, based on the Singular Value Optimization (SVO) technique, for the synthesis of array-based generators of near-field complex waveforms. The approach selects the grid wherein enforcing the design specifications and the radiator locations to control the ill-conditioning associated to the determination of the array excitation coefficients. Following the SVO optimization, the array coefficients are determined by a Singular Value Decomposition (SVD). Numerical results are provided for the synthesis of the near-field scattered by a perfectly conducting sphere illuminated by an elementary dipole.

International audience; In 2013 and 2014, two main International Airports in Greece were evaluated through the European directive on noise environment 2002/49/EC: "Nikos Kazantzakis" International Airport of Heraklion Crete and "Ioannis-Kapodistrias" International Airport in Corfu, both located in highly touristic areas of Greece. Acoustic measurement's campaign, environmental noise mapping simulations and population exposure to noise were implemented in order to produce a complete Strategic Noise Map. Correlated to this acoustic approach, a comprehensive interview campaign and a detailed soundscape analysis were also conducted in both airports' adjacent areas (Alikarnassos district in Heraklion and the peninsula of Canoni in Corfu City) in order to understand the impact of aircraft movements on both local residents and tourists, and analyze the perception of the soundscapes. A similar evaluation was also executed in order to assess possible health effects by using the WHO's DALY's (Disability Adjusted Life Year) metrics for environmental noise in relation to the exposure of the population. This paper presents the main results of these representative case studies, attempting a combined assessment of both health effects and soundscape characteristics to be used as evaluation tools towards the management and the rehabilitation acoustic environment characterized mainly by aircraft noise in touristic areas.

Current active noise control systems can cancel noises in a duct effectively. However, they are insufficient for suppressing complex noise fields in time-varying rooms. This paper develops an active noise control system that can cancel tonal noise fields produced by a primary source in a room. The problem of tonal noise field control is formulated as estimating and canceling the outgoing field on a sphere surrounding the primary source. The proposed system limits the energy of the primary source radiating out of the sphere, thereby creating a global quiet zone inside the room. In addition, it removes the need for online secondary path estimation with reduced influence on desired sound fields in the room. A method for estimating the outgoing field on a sphere is presented, together with a wave-domain algorithm for controlling the outgoing field. Simulations and hardware demonstrations show the proposed system can reduce tonal noise fields in a room and over a wide frequency range.

A magnetic quiet zone (MQZ) is located in the ocean-continent transition zone in the northern South China Sea (SCS), according to T magnetic anomaly data. Features of the gravity and magnetic anomalies in the MQZ are discussed by the multi-scale wavelet decomposition method. Comprehensive boundary identification and fault analysis by analytic signal and normalized total horizontal derivative methods achieve some good effects in the northern SCS. The inversion results suggest a deep magnetic basement, a shallow Curie isothermal interface and thin magnetic layers. The average depth of the Curie isothermal interface is about 14-28km in the northern SCS, and the thickness of the magnetic layer is about 6-10km in the MQZ. The formation mechanism of the MQZ is discussed, and the thinning of the magnetic layer is considered as the origin of the MQZ in the northern SCS. The deep hot mantle materials were upwelled during the extension of the SCS, and the magnetic layer was demagnetized. In addition, the magnetic anomaly caused by thick Mesozoic sediments was very weak, and the NW-SE-trending faults made the magnetic bodies fragmental. The distribution of major faults is consistent with the fluctuating changes of the Curie isothermal interface, and the faults in the MQZ are the upward intrusion channels of the deep hot materials. Copyright (c) 2016 John Wiley & Sons, Ltd.

A series of important geological events occurred in the Tibetan Plateau area during the Jurassic, such as the collision of the Lhasa and Qiangtang Terranes, the closure of the Meso-Tethyan Ocean, the opening of the Neo-Tethyan Ocean and the cessation of the mega-monsoon. The similar to 3000 m thick Jurassic sedimentary sequence in the Qiangtang Basin on the central Tibetan Plateau, which is called the Yanshiping (YSP) Group, recorded these geological events. However, the chronology of the sequence is surprisingly poorly constrained. Here, we perform a detailed palaeomagnetic analysis on the similar to 1060 m thick middle and upper portions of the YSP Group (the Xiali and Suowa Formations) in the YSP section of the eastern Qiangtang Basin. Three bivalve zones at stratigraphic intervals of similar to 40-140, 640-800 and 940-1040 m are identified, which yield a Bathonian-Callovian age for the Lower Xiali Fm., a Callovian-Oxfordian age for the Lower Suowa Fm. and an Oxfordian-Kimmeridgian age for the Upper Suowa Fm. A total of 544 oriented palaeomagnetic samples were collected from the section. By combining thermal and alternating field demagnetizations, clear characteristic remanent magnetization (ChRM) directions are isolated for most of the samples. The robust ChRM directions pass fold and reversals tests, which support the primary nature of the ChRMs and yield a palaeopole at 76.8A degrees N/297.2A degrees E (dp = 2.2A degrees, dm = 3.7A degrees). A total of 27 normal and 26 reversed polarity zones were successfully recorded in the section. Combined with fossil age constraints, results suggest that the section is plausibly composed of a Callovian-Early Kimmeridgian age sedimentary sequence.

Probe-based confocal laser endomicroscopy (pCLE) was performed in 15 patients with emphysema and 15 healthy subjects to visualise small airways in a direct and dynamic way. Morphometry shows that the median cross-sectional area of the alveolar openings at the level of the alveolar ducts is significantly larger in emphysema (7.2×104 µm2) as compared with healthy subjects (5.2×104 µm2) (p=0.0002). Normalised autofluorescence intensity histograms show a decrease in median autofluorescence intensity (mAFI) in emphysema (p=0.001). mAFI correlates well with Tiffeneau index (r=0.66, p=0.007, 95% CI 0.21 to 0.88). Autofluorescence intensity in emphysema correlates with corresponding data of CT-based quantification. pCLE-based morphometry and autofluorescence intensity analysis in emphysema is able to detect regional changes inside the ‘quiet zone’.Trial registration numberResults, NCT01204970.

Anechoic chambers are used for indoor antenna measurements. The common method for anechoic chamber construction is to cover all inside walls by the EM absorbers. A fully metallic parabolic chamber is presented in which the propagation of the EM waves inside the chamber is controlled and they are guided to an absorber. In the proposed method, an appropriate quiet zone with plane wave illumination is obtained, and unlike ordinary anechoic chambers the absorber usage is decreased greatly. The performance of the chamber is evaluated by simulation and the results showed that the proposed method could provide a useful technique for the compact range antenna measurements.

The wideband feed is significant for the quiet zone (QZ) performance of compact range. This paper discussed the negative effect caused by the side-lobe of the feed, especially in the lower frequency range. To reduce the mutual coupling between transmitting and receiving feed, an impedance-wall is designed to keep QZ pureness and steady. The feed configuration and effect of the impedance-wall are simulated and shown.

International audience; Within the frame of European directive 2002/49 for Strategic Noise Mapping and the relevant environmental Noise Action Plans, which included preparation for the management of environmental noise and the rehabilitation of the sound environment, Greece had the opportunity to develop an innovative and comprehensive methodology to analyze the sound environments of several urban and semi-urban residential neighborhoods in the large and medium-size cities of the country e.g., Volos, Larissa, Heraklion, Chania, Agrinio, Corfu, and Thessaloniki, between 2012 and 2016. This paper presents the determined multidisciplinary approach, showing how the environmental noise data are cross-analyzed with urban and architectural data and perception descriptors by inhabitants. Furthermore, it shows how these specific results have been implemented in the developed noise actions plans that have been proposed to the authorities for immediate implementation. Finally, the paper discusses the necessary development of this approach to reduce noise exposure problems, as well as assist the cities in their evolution toward the introduction of a sustainable urban sound environment.

We report the use of an Smooth-Walled Spline-Profile (SWSP) horn shaped beam feed with pattern optimized to achieve maximum compact antenna test range (CATR) quiet zone (QZ) size for a given reflector dimension, thereby minimising the cost of a new systems or increasing the capacity of existing facilities. We illustrate the concept with a sector-shaped, single offset reflector CATR by examining the impact that this has on the amplitude taper and the amplitude and phase peak-to-peak ripple of the QZ. We demonstrate that a Smooth-Walled Spline-Profile horn feeding an un-serrated rim reflector can attain a useable QZ area exceeding 50 percent the size of the 350 wavelengths diameter main reflector. This represents an increase in QZ area of over 60 percent compared to a conventional corrugated horn feed. The Smooth-Walled Spline-Profile horn offers a QZ bandwidth of just 9 percent compared to the 23 percent of the corrugated horn but is considerably cheaper to manufacture.

The client server model has been extensively used to continuously monitor the results of spatial queries. In this paper, we introduce quiet zone that is aimed to reduce the communication cost in the client server model implemented for continuous spatial queries. A quiet zone is a region such that as long as an object remains inside it, the object does not need to report its location. We present a generic framework to reduce the communication cost of many different variety of continuous spatial queries, such as range query, reverse nearest neighbour query, window query and relaxed reverse nearest neighbour query. We show that the checking cost at objects is reasonably low so that our approach is feasible for devices with limited resources. Our experimental study shows that the proposed algorithm significantly reduces the communication cost.

Indoor antenna measurements in classic anechoic chambers necessitate electromagnetic (EM) absorbers to cover the internal walls. An alternative fully metallic ellipsoid chamber structure is presented that controls the EM wave propagation to generate an appropriate quiet zone by guiding waves into a simple spherical absorber. The simulated performance demonstrates a significant reduction in absorber usage.

This paper presents quiet zone design using ultrasonic transducers for local active control in pure tone diffuse fields. Most of researches in local active noise control used conventional loudspeakers for the secondary sources to produce quiet zones. Recently ultrasonic transducers have been used for the secondary sources to control the plane wave in active noise control. However there is no research related to active noise control in diffuse fields using ultrasonic transducers. Therefore this study uses ultrasonic transducers for the secondary sources to control the diffuse fields. The quiet zone produced using ultrasonic transducers in single tone diffuse fields has been analyzed through simulations in this work. The results showed that quiet zones created using ultrasonic transducers were larger than those created using conventional loudspeakers. This is due to the fact that the audible sound pressure produced by the ultrasonic transducers decays slowly with the distance. Therefore the secondary field created by an ultrasonic transducer could fit the primary field better and the larger zone of quiet could be obtained using the ultrasonic transducer. Also the audible sound produced by the ultrasonic transducers is directional; therefore the sound pressure amplification outside the quiet zones was lower.

The design of Compact Antenna Test Range (CATR) is a challenging job. To achieve desired electromagnetic characteristics, choosing an appropriate algorithm for the proper design of the reflector with electrically large size is necessary. The comparison of Multilevel Fast Multipole Method (MLFMM) and Physical Optics (PO), which are the most two common algorithms used in reflector design, are performed in this paper to verify the necessity of MLFMM firstly. Then we design a novel reflector used in CATR with aperture size of 8.7m×6.9m and quiet zone size of Ф2m×2m, noting that all the design and simulation in this paper are on the basis of Boundary Element Method (BEM) module in the RainbowStudio[1].

Generating a quiet zone at a target location is the ultimate goal of active noise control (ANC). Generally, the best noise cancellation is achieved at the locations of error sensors. However, the distribution of physical error sensors at a given location is not always convenient or feasible. To overcome this challenge, a number of virtual sensing algorithms for ANC have been researched. Using the physical error signals and knowledge of the system, the adaptive least mean square (LMS) virtual sensing algorithm estimates the error signal at a location that is remote from the physical error sensor, referred to as the virtual location. It achieves excellent performance under the assumption that the unknown primary path is fixed, but its performance decreases significantly if the path is constantly changing. This paper presents a real-time ANC system with an improved virtual sensing algorithm to solve this problem. The proposed system was tested to enhance the quiet zone in a constantly changing environment; an enhanced quiet zone was created, and the noise cancellation, especially at the target location, obviously improved.

Indoor antenna ranges must have the walls, floor and ceiling treated with RF absorber. The normal incidence performance of the absorber is usually provided by the manufacturers of the materials; however, the bi-static or off angle performance must also be known. In reference [1], a polynomial approximation was introduced that gave a prediction of the reflected energy from pyramidal absorber. In this paper, the approximations are used to predict the quiet zone (QZ) performance of several anechoic chambers. These predictions are compared with full wave analysis performed in CST Suite®. A 12 m wide by 22 m long with a height of 12 m chamber was analyzed at 700 MHz. The QZ performance was compared to the polynomial predictions showing a difference of less than 2.2 dB. In addition, comparisons are made with measurements of the QZ performance of anechoic chambers. Measurements performed per the free space VSWR method of three different chambers are compared with the prediction that uses the polynomials presented in [1]. The chambers are: a 18 m long by 11.5 m wide and 11.5 m in height operating from 100M MHz to 12 GHz; a 13.41 m by6.1 m by 6.1 m operating from 800 MHz to 6 GHz; and a 14 m long by 4.12 m by 4.27 m operating in the X band. The results show that the polynomial approximations can be used to give a reasonably accurate and safe prediction of the QZ performance of anechoic chambers.