Effects of different test media on the test results of automobile cabin air filter

2021 ◽  
Author(s):  
Lei Zhao ◽  
Chuanlu Zang ◽  
Yong Ao He ◽  
YiXian Yang
Keyword(s):  
Author(s):  
T. Dziubak

The aim of this study is to provide an experimental properties evaluation of a standard filter material (cellulose) and materials with fiber layer addition with small diameters (nanofibers). Filter media, including cellulose, used in the internal combustion engine inlet air filtration are made of high diameter fibres, approx. 15 µm. Significantly higher separation and filtration efficiency performance are obtained for materials with lower fibre diameters (nanofibres), however, at the expense of a significantly higher pressure drop, affecting the engine performance. Filter media manufacturers mainly specify the structure parameters (pore size, air permeability and thickness), without giving any information on the dust filtration performance and rate. The literature includes test results for models of different filter media structures. Filtration process modelling using polydisperse dust with particles of different shape and density and irregular filter media structure is possible using advanced computer techniques, however, the process is complex and requires many simplifications. Test results can be applied directly in the automotive industry. The data can be obtained by experimental tests on filter medium specimens, complete filter elements or air filters which are costly and time-consuming tests, however, those test methods are the most reliable. Conditions and testing methodology for intake air filter materials used in internal combustion engines were developed. Filtration and flow resistance efficiency and accuracy were done depending on test dust mass stopped per unit area. Tested materials filtration efficiency was assessed by a filtration quality factor, which includes experimentally determined efficiency and accuracy as well as flow resistance values. Much higher efficiency and filtration accuracy of dust grains below 5 µm in filtration materials with nanofibers addition compared to standard filtration material (filter paper) were demonstrated. For the same flow resistance values, filter materials with nanofibers addition accumulate smaller dust mass than standard filter paper. Usage of materials with nanofibers addition used in motor vehicles intake air filtration ensures their high efficiency and accuracy. It minimises its components wear, but at the expense of faster flow resistance increase, which shortens filter life and increases filter replacement frequency. Results obtained during the experimental research partly fill the gap when it comes to the basic material properties used in internal combustion engines intake air filter partitions production.


2017 ◽  
Vol 66 (2) ◽  
pp. 123-144
Author(s):  
Tadeusz Dziubak ◽  
Yuriy Yendzheyovskyy

There are presented design solutions and operation properties of air inlet filters of motor vehicles and sports cars. An analysis of the impact of the use of a sports car air filter in a passenger car was performed. The effect of this change on the increase in power and torque in several car engines was shown. The conditions and methodology of sports car air filter studies have been developed. A research stand with a particle counter was presented. The test results on the characteristics of efficiency and accuracy filtration and flow resistance of two sports air filters were presented. Each filter was tested at a different filtration rate. The dust absorption coefficient of the sport filter was determined. The dust particle fraction in the air purified behind the filter was calculated. Keywords: engine, air filter, sports filter, filtration efficiency and filtration accuracy, flow resistance, dust absorption coefficient, particle size


1992 ◽  
Vol 23 (1) ◽  
pp. 52-60 ◽  
Author(s):  
Pamela G. Garn-Nunn ◽  
Vicki Martin

This study explored whether or not standard administration and scoring of conventional articulation tests accurately identified children as phonologically disordered and whether or not information from these tests established severity level and programming needs. Results of standard scoring procedures from the Assessment of Phonological Processes-Revised, the Goldman-Fristoe Test of Articulation, the Photo Articulation Test, and the Weiss Comprehensive Articulation Test were compared for 20 phonologically impaired children. All tests identified the children as phonologically delayed/disordered, but the conventional tests failed to clearly and consistently differentiate varying severity levels. Conventional test results also showed limitations in error sensitivity, ease of computation for scoring procedures, and implications for remediation programming. The use of some type of rule-based analysis for phonologically impaired children is highly recommended.


2020 ◽  
Vol 29 (2) ◽  
pp. 188-198
Author(s):  
Cynthia G. Fowler ◽  
Margaret Dallapiazza ◽  
Kathleen Talbot Hadsell

Purpose Motion sickness (MS) is a common condition that affects millions of individuals. Although the condition is common and can be debilitating, little research has focused on the vestibular function associated with susceptibility to MS. One causal theory of MS is an asymmetry of vestibular function within or between ears. The purposes of this study, therefore, were (a) to determine if the vestibular system (oculomotor and caloric tests) in videonystagmography (VNG) is associated with susceptibility to MS and (b) to determine if these tests support the theory of an asymmetry between ears associated with MS susceptibility. Method VNG was used to measure oculomotor and caloric responses. Fifty young adults were recruited; 50 completed the oculomotor tests, and 31 completed the four caloric irrigations. MS susceptibility was evaluated with the Motion Sickness Susceptibility Questionnaire–Short Form; in this study, percent susceptibility ranged from 0% to 100% in the participants. Participants were divided into three susceptibility groups (Low, Mid, and High). Repeated-measures analyses of variance and pairwise comparisons determined significance among the groups on the VNG test results. Results Oculomotor test results revealed no significant differences among the MS susceptibility groups. Caloric stimuli elicited responses that were correlated positively with susceptibility to MS. Slow-phase velocity was slowest in the Low MS group compared to the Mid and High groups. There was no significant asymmetry between ears in any of the groups. Conclusions MS susceptibility was significantly and positively correlated with caloric slow-phase velocity. Although asymmetries between ears are purported to be associated with MS, asymmetries were not evident. Susceptibility to MS may contribute to interindividual variability of caloric responses within the normal range.


1972 ◽  
Vol 15 (4) ◽  
pp. 852-860 ◽  
Author(s):  
Zoe Zehel ◽  
Ralph L. Shelton ◽  
William B. Arndt ◽  
Virginia Wright ◽  
Mary Elbert

Fourteen children who misarticulated some phones of the /s/ phoneme were tape recorded articulating several lists of items involving /s/. The lists included the Mc-Donald Deep Test for /s/, three lists similar to McDonald’s but altered in broad context, and an /s/ sound production task. Scores from lists were correlated, compared for differences in means, or both. Item sets determined by immediate context were also compared for differences between means. All lists were found to be significantly correlated. The comparison of means indicated that both broad and immediate context were related to test result. The estimated “omega square” statistic was used to evaluate the percentage of test score variance attributable to context.


1986 ◽  
Vol 51 (2) ◽  
pp. 176-180 ◽  
Author(s):  
Audrey L. Holland ◽  
Davida Fromm ◽  
Carol S. Swindell

Twenty-five "experts" on neurogenic motor speech disorders participated in a tutorial exercise. Each was given information on M, a patient who had communication difficulties as the result of stroke, and asked to complete a questionnaire about his problem. The information included a detailed case description, an audiotape of M's speech obtained at 4, 9, 13, and 17 days post-stroke, and test results from the Western Aphasia Battery, the Token Test, and a battery for apraxia of speech. The experts were in excellent agreement on M's primary problem, although it was called by seven different names. The experts were in poor agreement on his secondary problem(s), e.g., the presence and type of aphasia and dysarthria. The results suggest that labeling is difficult, even for "experts." Furthermore, the practicing clinician needs to be sensitive to the likelihood of more than one coexisting problem.


1968 ◽  
Vol 11 (1) ◽  
pp. 204-218 ◽  
Author(s):  
Elizabeth Dodds ◽  
Earl Harford

Persons with a high frequency hearing loss are difficult cases for whom to find suitable amplification. We have experienced some success with this problem in our Hearing Clinics using a specially designed earmold with a hearing aid. Thirty-five cases with high frequency hearing losses were selected from our clinical files for analysis of test results using standard, vented, and open earpieces. A statistical analysis of test results revealed that PB scores in sound field, using an average conversational intensity level (70 dB SPL), were enhanced when utilizing any one of the three earmolds. This result was due undoubtedly to increased sensitivity provided by the hearing aid. Only the open earmold used with a CROS hearing aid resulted in a significant improvement in discrimination when compared with the group’s unaided PB score under earphones or when comparing inter-earmold scores. These findings suggest that the inclusion of the open earmold with a CROS aid in the audiologist’s armamentarium should increase his flexibility in selecting hearing aids for persons with a high frequency hearing loss.


2019 ◽  
Vol 24 (6) ◽  
pp. 12-15
Author(s):  
Jay Blaisdell ◽  
James B. Talmage

Abstract Like the diagnosis-based impairment (DBI) method and the range-of-motion (ROM) method for rating permanent impairment, the approach for rating compression or entrapment neuropathy in the upper extremity (eg, carpal tunnel syndrome [CTS]) is a separate and distinct methodology in the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition. Rating entrapment neuropathies is similar to the DBI method because the evaluator uses three grade modifiers (ie, test findings, functional history, and physical evaluation findings), but the way these modifiers are applied is different from that in the DBI method. Notably, the evaluator must have valid nerve conduction test results and cannot diagnose or rate nerve entrapment or compression without them; postoperative nerve conduction studies are not necessary for impairment rating purposes. The AMA Guides, Sixth Edition, uses criteria that match those established by the Normative Data Task Force and endorsed by the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM); evaluators should be aware of updated definitions of normal from AANEM. It is possible that some patients may be diagnosed with carpal or cubital tunnel syndrome for treatment but will not qualify for that diagnosis for impairment rating; evaluating physicians must be familiar with electrodiagnostic test results to interpret them and determine if they confirm to the criteria for conduction delay, conduction block, or axon loss; if this is not the case, the evaluator may use the DBI method with the diagnosis of nonspecific pain.


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