ANSI Standards Research Articles

Air Attenuation in Octave Bands and How to Normalize Room Acoustic Measurements to a Standard Atmosphere

The air attenuation of pure tones as a function of temperature and humidity is well known and described in ISO and ANSI standards. However, room acoustic measurements are performed in octave bands, which is the reason for the complicated, non-linear behavior of the air attenuation. It is known that room acoustic measurement results depend on air temperature and humidity, and these atmospheric data should always be reported in connection with room acoustic measurements. A calculation model for the air attenuation can make it possible to normalize the room acoustic results. For accurate results, it is possible to apply a summation method on each time sample in the impulse response. An approximation to the air attenuation at and above 1 kHz is possible by linearization using the pure-tone attenuation of two different frequencies, one frequency valid for the early part of the impulse response and another frequency valid for the later part of the impulse response. The purpose of the suggested methods is to make it possible to normalize room acoustic measurements to a standard atmosphere.

Fusion neutron source and array of particle detectors for nondestructive interrogation of special nuclear materials

Presented herein are the outcomes of an experimental test involving a pioneering portable-active interrogation system designed for the nondestructive detection of special nuclear materials (SNMs). The system relies on the threshold energy neutron analysis concept and incorporates a portable deuterium–deuterium (DD) neutron generator producing a particle intensity of 5 × 107 n/s, coupled with three arrays of tensioned metastable fluid detectors (TMFDs) to detect secondary neutrons from the fissile material. In the presence of the fissile material, prompt fission neutrons are emitted, with an average energy of approximately 2 MeV, and around 30% of these neutrons have energies above that of the DD neutron source (2.45 MeV). The detection of a statistically significant neutron population exceeding this threshold firmly indicates the presence of SNM. TMFDs exhibit high sensitivity in efficiently detecting neutrons above the threshold while adeptly discriminating against neutrons below the threshold as well as gamma rays. This unique feature allows the interrogation system to maintain a lightweight profile without necessitating substantial shielding materials. The validation experiments involved the placement of 70 or 140 g masses of U-235 within a 1 m3 inspection volume. Measurements were carried out over 30 min intervals, repeated numerous times, both with and without U-235, at a DD neutron source intensity of 8 × 105 n/sec. Experimental count rates with natural uranium (NU) are consistently above those without NU. The probability of detection (PD) and probability of false alarm (PFA) were assessed utilizing these count rates. The DD neutron source intensity and inspection time were normalized at 5 × 107 n/sec and 90 s, respectively. The results indicated a PD of approximately 74% and 98% for detecting 70 and 140 g of U-235, respectively, with a PFA of <5%. These promising outcomes align with the specified PD (>90%) and PFA (<5%) targets outlined in ANSI standards.

Establishing a definition for maximum hourly sound level

The use of a maximum hourly sound level is common within modern standards and design requirements, referenced in ANSI and ASHRAE standards, CHPS and LEED design guidelines, and is included in proposed language for draft ANSI standards, to name a few. Due to its wide adoption, its use is proscribed for education, hospitality, residential, retail, office, affecting nearly every design sector. The problem with this is that the metric lacks formal definition, leaving designers and evaluators without an agreed-upon approach to determine if an assessment is sufficient. Since 2014, the authors have presented multiple works assessing a proposed definition for maximum hourly sound level for vehicular sources. In this work, the authors will be presenting a continuation of the dataset. Long-term rooftop monitoring of the noise from an interstate was used to create an hourly max calculation noise model. The calculations are based on the statistical spread of the data and the learnings can be used to better design the structures for assessing environmental and traffic noise.

Improving the persuasiveness of the noise consultant report—A critique and proposal

The author, a retired mechanical engineer and patent attorney, sat on an HOA Board that converted four tennis courts to 13 pickleball courts without installing the noise absorbing barrier recommended in three reports by two acoustical consultants. A nuisance lawsuit seeks an injunction to close the courts and money damages. Consultants study the pickleball noise and recommend mitigation options to the deciders. Deciders are laymen, such as city officials and HOA boards, unfamiliar with noise science and under pressure to meet the insatiable need for more pickleball courts. When mitigation is not implemented, or not successful, litigation ensues. Judge and jury become deciders. This paper starts from the premise that the consultant makes technically competent recommendations and is motivated to fully educate the lay deciders. We explore the communication gap between consultants and deciders. Proposals include embedding wav. noise files in the written report, reference to ANSI standards for highly impulsive noises, deference to the lack of research on health issues of long-term exposure to persistent repetitive impulsive noise. We introduce the missing metrics of “pickle pops per hour” and the “predictable worst case noise impact” occurring when intensively used courts are introduced into residential neighborhoods.

Development and investigation on physical and mechanical properties of mahogany sawdust particleboards made with tannic powder of Indian tamarind (Pithecellobium Dulce Benth)

The recycling of forest residues was investigated in the present study. It arms to determine the physical and mechanical properties of particleboards from mahogany sawdust bonded by pearls bone glue or tannic powder of peel of Indian tamarind (Pithecellobium Dulce). The influence of the size of particles on the physical and mechanical properties of the particleboards is studied. Five different granulometries (raw sawdust; 2.5 < g £ 5; 1.6 < g £ 2.5 and 0.8 < g £ 1.6, and g £ 0.8) were investigated. The rate of the adhesives used were 5; 6.5; 7; 7.5; 8; 10, 12.5 and 15 percent. Physically, the density, thickness swelling (TS) and water absorption (WA) were evaluated. Mechanically, the modulus of elasticity (MOE), the modulus of rupture (MOR), the modulus of Young E, the tensile modulus of rupture (MOT) and the internal bond (IB) were determined. The results obtained showed that the granulometry has a great influence on the physical as well as the mechanical properties of the Mahogany sawdust particleboards. The pressing temperature is 160 °C. The threshold fixed by the American standard ANSI A208.1-2016 for the MOE and the MOR are widely reached. The values of the density classified the particleboards from sawdust of Mahogany wood in the categories of low and mean density. The thickness swelling and water absorption has not respectful to the American standard ANSI A208.1–2016 [1]. So, the manufactured boards can only be used in dry conditions.

BINDER RATE AND GRANULOMETRY EFFECTON THE PHYSICALAND MECHANICALPROPERTIES OF MAHOGANYSAWDUST PARTICLEBOARDS MADE WITH PEARLS BONE GLUE

This work armtovalorizethesawdustofmahogany wood and the pearlsbone glue for environmental purposes.First, sawdust was sifted with three sieves respectively 0.8 1.6 and 2.5mm diameter. So, we have four granulometries (g) g ≤ 0.8 (G1), 0.8 < g ≤ 1.6 (G2), 1.6 < g ≤ 2.5 (G3), 2.5 < g ≤ 5 (G4) and the raw sawdust. particleboards are manufactured from sawdust by varyingsuchthebinder rate (5 6.5 7 7.5 8 10 12.5 and 15) and the granulometry. Second,physical properties such asthe density, thickness swelling (TS) Water absorption (WA) were searched. The mechanical properties (Modulus of Elasticity (MOE), the Modulus of Rupture (MOR) in flexion, and Internal Bond (IB)) are determined according to the standard ANSI A208.1 – 2016[1]. The threshold fixed by the standard fortheMOE andtheMORarewidelyreached.Themanufactured particleboards are classified in the categoriesofmeandensity and can only be used in dry conditions.

Thermal parameters of cylindrical power batteries: Quasi-steady state heat guarding measurement and thermal management strategies

In this work, a new quasi-steady state heat guarding measurement method for the thermophysical parameters of cylindrical batteries is proposed. The effectiveness of the heat guarding method is evaluated by the finite element analysis and the measurement of a standard ANSI 304 stainless steel sample. The heat loss is minimized to 2.4% maximum for cylindrical batteries under test based on numerical simulation. With the optimization of the test configuration, the experimental characterization of batteries was conducted to determine the thermal parameters accurately. The experimental results show that the axial thermal conductivity of 18650 and 21700 batteries are within 11.8–15.4 W·m−1 °C−1 and 12.6–16.7 W·m−1 °C−1, respectively, which are much lower than the material test values by the laser flash method. Axial thermal conductivity increases with temperature and SOC, and the specific heat increases linearly with temperature but varies little with SOC. This study demonstrates a fast, cost-effective and nondestructive way to obtain the axial thermal conductivity and specific heat of cylindrical batteries simultaneously and accurately. The subsequent thermal analysis on the thermal design of cylindrical batteries is also conducted based on the measured thermal parameters, which facilitate appropriate thermal management strategies for different types of cylindrical batteries.

Positioning of enhanced monofocal intraocular lenses between conventional monofocal and extended depth of focus lenses: a scoping review

BackgroundNew intraocular lenses (IOLs) have emerged since the originally coined monofocal and multifocal IOLs. The extended depth of focus (EDoF) and enhanced monofocal IOLs (mono-EDoF) that have appeared in the last decade have caused some confusion in their classification. The aim of this review was to summarize the outcomes provided by mono-EDOF IOLs and to determine which of the endpoints, described by the American National Standard (ANSI) for EDoF IOLs, are fulfilled.MethodsThe MEDLINE, EMBASE, and WEB OF SCIENCE databases were searched. Two independent reviewers screened the studies for inclusion and data extraction. The search strategy was limited to studies published between 2020 and 2022, but not by language. The results are presented as a narrative summary accompanied by tables, in alignment with the objectives of this scoping review. Compliance with the endpoints for clinical outcomes described in the American National Standard Z80.35–2018 (ANSI) for EDoF lenses was checked and additional endpoints were defined.ResultsTwo systematic reviews, 13 laboratory, 21 clinical, and two mixed studies were included. Tecnis Eyhance was the mono-EDOF with the highest volume of evidence to date. Although laboratory studies included other IOLs, clinical evidence for them is still scarce, with only one study of IsoPure compared to a standard monofocal IOL. Evidence in comparison to EDoF lenses is also scarce, even for Tecnis Eyhance, with only three studies including this lens in comparison to an EDoF lens. After evaluation of the ANSI criteria, agreement was found in the failure for the increase in depth of field equal to or greater than 0.5 D for a visual acuity (VA) level of 0.2 logMAR and none of the studies supported that the median monocular VA at intermediate distance was at least 0.2 logMAR.ConclusionsAdditional clinical evidence is required for other mono-EDOF IOLs beyond Tecnis Eyhance. Until the arrival of a standard classification, mono-EDOF should be better still classified as monofocal because the ANSI standards were not fully met.

The Longitudinal Relationship Between Hearing Loss and Cognitive Decline

The Longitudinal Relationship Between Hearing Loss and Cognitive Decline

Comparison between peak values of induction motor currents’ waveforms during nearby three‐phase short‐circuits and results from standardized calculations

AbstractThis article shows a comparison of peak values of measured and computed waveforms of induction motor currents during nearby three‐phase short circuits with the results from the standardized calculations of those currents. The methods for computing short‐circuit currents according to IEC and ANSI standards are based on phasors at grid frequency, and the correspondent transient result is approximated to a simple sine wave plus a decaying DC component. However, the measured and simulated waveforms are far away from those simple waveforms. Thus, the peak values computed by standardized methods must be obviously different than the peak values of measured and simulated waveforms. It is herein shown that these differences are larger in smaller motors, and it is also shown that standardized methods to compute these motor currents are accurate enough although they are simply based on phasors at grid frequency. On the other hand, the maximum value of the first peak of motor contribution does not necessarily occur at the same time of the maximum first peak of grid contribution. This fact had been rarely mentioned, and an analysis about its influence was not found in the literature. Herein, it is shown that the influence of this point is not very important in the analyzed cases.

Impact of Hearing Loss on the Quality of Life in Adults with Hearing Impairment

Introduction: Hearing loss is the most common sensory deficit, which can impair the exchange of information. The impact of hearing loss may be profound, with consequences for the person's social, functional, and psychological well-being. This study aims to assess the overall impact of hearing loss on the quality of life in the adult population.Materials and Methods: A cross-sectional study was conducted in a tertiary care-based hospital. Patients within the age range of 18-85 years were taken. Two hundred fifty patients presenting to ENT-OPD over six months and fulfilling the inclusive criteria were recruited for the study. All patients underwent detailed audiological evaluation, including otoscopy, tympanometry, and pure tone audiometry in two room setup following ANSI standards. Communication difficulties were assessed using a modified questionnaire from the Hearing Handicap Inventory and Self-Assessment of Communication.Results: The impact of hearing loss on quality of life was associated with age, gender, and profession. The severity and type of hearing loss were significantly associated with a hearing handicap and self-reported communication difficulties. People with severe-profound hearing loss reported more handicapping conditions and communication difficulties than mild-moderate hearing loss. The impact of hearing loss was found to be more in functional and emotional aspects than physical ones.Conclusions: Hearing loss is associated with reduced quality of life. Identifying individuals with hearing loss and supplying appropriate rehabilitation with coping strategies may positively affect the quality of life for adults.

Analysis of Defects in SMAW Welding Joint Using E 7016 Electrode Due to the Direct Cooling Process

Welding defects in a construction if repairs are not immediately carried out, then in the weld defect area can cause cracks that are aggravated by wider cracking and corrosion so that it can cause brittle fractures to the detriment. The problem with brittle fracture is a big problem in steel that has been welded, especially in welded joints, this brittle fracture becomes more important due to the factors of voltage concentration, inappropriate structure and defects in the weld, the purpose of this study: to find out how to use suitable electrodes for ST 37 material in the welding process, whose cooling process directly uses Oil and water (Direct Colling Process), and to obtain optimal welding results after going through the results of welding defect examination using the Penetrant Test method, and the Maghnetic Particle Test. From the results of the examination research conducted by the Welding Inspection team of PT. Superintending Company of Indonesia (SUCOFINDO) to 15 ST 37 specimens that have undergone welding does not show any welding defects, in the sense that they are still within the acceptable limit criteria (Acceptance Standard Ansi B 31.3), from the results of tensile testing On the use of different electrodes in the welding process of ST 37 material, shows that the ST 37 material whose welding process uses electrode E7016 welded results and tensile strength is better than the ST 37 material which in the welding process uses electrodeS E 7018 with the cooling process using Oil and water

The safety of wheelchair occupants in motor vehicles

Ensuring the free movement of disabled people, including the use of vehicles, is a fundamental right. Therefore, efforts should be made to draw up standards regulating both organisational and technical aspects related to the construction and testing of wheelchairs. The main purpose of the paper is a review the literature related to wheelchair transport safety and the current standards for wheelchair crash testing Wheelchair users must securely and safely attach their wheelchair to the vehicle when travelling. The most common methods include securing with a four-belt system or using docking systems. Docking systems allow the disabled person to restrain the wheelchair themselves. Their main limitation is the lack of standardisation. Issues related to in-vehicle wheelchair design and testing are mainly described in international ISO standards and, in the US, in ANSI standards. Not all wheelchairs are crash tested. Before using wheelchairs, it should be checked if they can be mounted in a car. An important issue is education of wheelchair users and their carers on proper wheelchair securing. Even when wheelchairs are effectively secured, occupants in wheelchairs could be seriously and fatally injured because of improperly used and positioned belt restraints.

Case study of office noise and vibration annoyance due to building water pumps for HVAC equipment

The background noise and vibration in an office workplace area was observed to be excessive. Next to one of the executive offices, as well as an open office space, is a mechanical room that provides heating and cooling to part of the 3-story college campus building. Inside this mechanical room are two hot and two cold water pumps which are part of the HVAC system of the building, as well as two boilers and a pump to a nearby chiller unit. Measurements have determined that these pumps are the main source of noise annoyance. The first task was to determine if the sounds meet the criteria stated in ASHRAE and ANSI standards. The background sound was measured during several occurrences as A-weighted, C-weighted, octave bands, and time recordings to processes narrowband spectrum. RC Mark II and NC levels were calculated from the data, and it was determined that the noise levels are often significantly above the criteria for office spaces. Narrowband and sound recordings indicate tonal acoustic signals generated by the pumps that lead to a higher level of annoyance.

Application Considerations in View of New Revisions to High-Voltage Circuit Breaker Standards

IEEE recently introduced new revisions to the medium- and high-voltage circuit breaker standards. The revised standards provide for new ratings and capabilities; expand choices for users by making it easier to certify and accept under IEEE/ANSI standards equipment originally destined for the IEC market; and clarify the scope and limitations of various ratings of importance to the industrial user. This article presents some of the more pertinent changes and how these changes affect the application of circuit breakers in the petroleum and chemical industries.

Contributed Session I: Impact of glare strength on Contrast Sensitivity

Clinical investigations of intraocular lenses are guided by ISO and ANSI standards, which outline parameters for procedures such as contrast sensitivity (CS). The effect of glare on CS is often studied, however is not standardized. ISO/ANSI recommend a level of glare that reduces mesopic CS by 0.1 log units at 6 cpd, determined through a small pilot study, however this ambiguous criterion might result in varying glare intensities across manufacturers. Healthy young adults (<40 yrs.), with VA of at least 20/20 were enrolled. Mesopic CS at 6 cpd was measured with and without glare in 39 subjects using the Clinical Trial Suite (CTS, M&S Technologies) and in 20 subjects using the CSV-1000 (Vector Vision) at 2.5 meters. Glare strength was set as standard for both devices (CTS:150 lux; CSV:12 lux, both before a 1.5 ND filter). Two attenuated glare levels (69 and 110 lux) were also evaluated with the CTS. The mean decrease in CS under standard glare strength was 0.16log units for CTS (95% CI 0.05, n=29) and 0.09log units (95% CI 0.08, n=12) for CSV. Under attenuated glare, the decrease in CS measured with the CTS was 0.14 (95% CI 0.06, n=20) and 0.15 (95% CI 0.05, n=24) log units for 69 and 110 lux, respectively, both above 0.1 log unit criteria. These results suggest that different criteria were used to calibrate glare strength of both systems, which resulted in ~12 fold difference in strength. Subsequently, clinical data obtained may not be comparable across these systems.

Ambient Noise Monitoring during Pure-Tone Audiometry.

There is an increasing need to administer hearing tests outside of sound-attenuating rooms. Maximum permissible ambient noise levels (MPANLs) from published in standards (Occupational Health and Safety Administration [OSHA] 1983; American National Standards Institute [ANSI] S3.1-1999 (R2018)) can be modified to account for the additional attenuation provided by circumaural earphones (relative to supra-aural earphones) that are used for pure-tone audiometry. Ambient noise can influence the results of pure-tone audiometry by elevating thresholds by direct masking and by producing distractions that affect the accuracy of the test. The effects of these distractions have not been studied in relation to pure-tone audiometry in adult listeners. In Part I MPANLs provided by ANSI and OSHA standards are extended to account for the greater attenuation provided by circumaural earphones. Rules ("alerts") were developed taking into account the listeners' thresholds. In Part II effects of distracting noise on pure-tone thresholds are reported. In Part I MPANLs two standards were modified for circumaural earphones by adding the additional attenuation provided by three circumaural earphones (relative to supra-aural earphones). A set of rules ("alerts") is provided for identifying masking effects from ambient noise in a variety of conditions (earphone type, threshold elevation, uncovered ear). In Part II the distracting effects of an industrial noise sample on thresholds obtained from five listeners with normal hearing are described. Pure-tone thresholds were measured in quiet and in distracting noise presented at various levels. The effects of the distracting noise on the following variables were measured: time per trial, number of trials required to measure threshold, threshold shift, and perceived distractibility of the noise. Time per trial was unaffected by distracting noise. Number of trials required for threshold, threshold shift, and perceived distractibility increased with distracting noise level. Part I: The modified MPANLs provide more relevant determinations of the potential effects of ambient noise on pure-tone thresholds than the values in the standards. Part II: Distracting noise affects pure-tone threshold measurements in a manner that is different from direct masking. The potential contaminating effect of distracting noise can be measured and reported.

Co-simulation and energy management of photovoltaic-rich residential communities for improved distribution voltage support with flexible loads

One of the major obstacles for deeper solar photovoltaic (PV) utilization is associated with its adverse impact on distribution voltage regulation. This paper presents a co-simulation platform for PV-rich residential communities to facilitate development and analysis of new voltage regulation strategies leveraging the flexible residential loads. The platform achieves co-simulation of high-fidelity EnergyPlus models for residential dwellings, a solar PV model and a power flow model for distribution networks to accommodate holistic assessments of different voltage control approaches. Community-level control strategies are proposed to coordinate the operations of air conditioners and hot water heaters across different households to provide proactive voltage support against volatile solar generation. The control strategies were evaluated with five simulation test cases of a community with 100 residential dwellings, under different control settings and distribution infrastructure. Simulation test results have shown that the voltage regulation strategies using flexible building loads could help reduce operations of step voltage regulators, from 15 tap changes per day to 4. For distribution grids without voltage regulation devices, flexibility of building loads can be leveraged to maintain feeder voltage within limits set forth by ANSI standards, and voltage excursions can be almost fully eliminated through relaxation of thermostat setpoints.

ACOUSTICAL STANDARDS NEWS

American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, S3/SC 1, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, animal bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes a catalog of Acoustical American National Standards. To browse the latest copy of our catalog, visit our website at https://acousticalsociety.org/download-catalog/. Comments are welcomed on all material in Acoustical Standards News. This Acoustical Standards News section in JASA, as well as the National Catalog of Acoustical Standards and other information on the Standards Program of the Acoustical Society of America, are also available via the ASA Standards home page: https://acousticalsociety.org/acoustical-society-standards/.

Perencanaan Estimasi Biaya K3 pada Proyek Pembangunan Kantor di Surabaya

Every construction work must have a big influence on work accidents. Occupational safety and health (K3) issues in construction services in general are often ignored. This shows the number of work accidents in this sector. Facts in the field of occupational safety and health (K3) implementation are still rarely done, because it only takes away time, first, it costs quite a lot for K3 needs. Therefore, this research will examine the planning of the Estimated Cost of Risk Prevention and OHS Supervision Costs in Office Construction Projects in Surabaya. The method used is making direct observations in the field, identifying accidents in the field, analyzing each sub-job in fulfilling K3 needs, interviews, officers and taking documentation in the field. From this research obtained for the cost (K3) Rp. 51,975,000, - and for the contract fee is Rp. 3,250,336,000, - so the percentage is 1.62%. The K3 needs evaluation plan is carried out using SNI and ANSI standards. The conclusion that can be drawn is that the OSH costs do not have a major effect on the overall project costs if calculated in detail, precisely with the K3 financing calculations it will be younger for companies to see the OHS costs that will be used for the Kalidami office building construction project in Surabaya.