The Acceptable Noise Level Benefit From Directionality for Listeners With Severe Hearing Loss

Mina Aghsoleimani,Hamid Jalilvand,Mohammad Ebrahim Mahdavi,Ahmad Reza Nazeri,Mohammad Kamali 대한이비인후과학회 2018 Clinical and Experimental Otorhinolaryngology Vol.11 No.3

Objectives. Directional microphone technology can enhance the speech intelligibility and listening comfort of listeners with hearing impairment. The main aim of this study is to investigate and compare the benefit derived by listeners with severe hearing loss from directional microphone technology with that derived by listeners with moderate hearing loss. Methods. The acceptable noise levels (ANLs) of two groups of listeners with moderate or severe hearing impairment (17 subjects in each group) were measured under unaided, omnidirectional-baseline-aided, and directional-aided conditions. Results. Although the absolute ANL of the listeners in the severe hearing loss group was significantly higher than that of the listeners in the moderate hearing loss group, their derived benefit was equivalent to that derived by the listeners in the moderate hearing loss group. ANL and hearing loss degree were significantly related. Specifically, the ANL increased with the severity of hearing loss. Conclusion. Directional microphone technology can provide the benefits of listening comfort to listeners with severe hearing loss.

Size dependence on reduction kinetic of iron based Fischer–Tropsch catalyst

Ali Nakhaei Pour,Mohammad Reza Housaindokht,Ensieh Ganji Babakhani,Mohammad Irani,Seyed Mehdi Kamali Shahri 한국공업화학회 2011 Journal of Industrial and Engineering Chemistry Vol.17 No.3

Catalyst structure has a significant influence on its kinetic behavior. In this work, effect of nanoparticle size on reduction kinetics of iron FTS catalyst [0] has been studied. Fe/Cu/La catalysts were prepared via bulk precipitation and microemulsion methods to produce a series of iron oxides with different particle size. In microemulsion method, the catalyst particle size was changed with type of surfactant such as SDS, Triton X-100, and SDBS. Size dependence on reduction rate constant (kr) was evaluated using the formation and growth of nuclei model (3D). The results showed that when the catalyst particle size increased, the reduction rate of iron catalyst decreased. A value of 3.11 nm and 0.53 h1were obtained for h parameter and size independent part of reduction rate constant (k1), which are consistent with the values reported in literatures.

Effectiveness of the neutron-shield nanocomposites for a dual-purpose cask of Bushehr's WatereWater Energetic Reactor (VVER) 1000 nuclear-power-plant spent fuels

Mahdi Rezaeian,Jamshid Kamali,Seyed Javad Ahmadi,Mohammad Amin Kiani 한국원자력학회 2017 Nuclear Engineering and Technology Vol.49 No.7

In order to perform dry interim storage and transportation of the spent-fuel assemblies of the BushehrNuclear Power Plant, dual-purpose casks can be utilized. The effectiveness of different neutron-shieldmaterials for the dual-purpose cask was analyzed through a set of calculations carried out using theMonte Carlo N-Particle (MCNP) code. The dose rate for the dual-purpose cask utilizing the recentlydeveloped materials of epoxy/clay/B4C and epoxy/clay/B4C/carbon fiber was less than the allowableradiation level of 2 mSv/h at any point and 0.1 mSv/h at 2 m from the external surface of the cask. Byutilization of epoxy/clay/B4C instead of an ethylene glycol/water mixture, the dose rates on the sidesurface of the cask due to neutron sources and consequent secondary gamma rays will be reduced by17.5% and 10%, respectively. The overall dose rate in this case will be reduced by 11%.

Practical Explicit Model Predictive Control for a Class of Noise-embedded Chaotic Hybrid Systems

Seyyed Mostafa Tabatabaei,Sara Kamali,Mohammad Reza Jahed Motlagh,Mojtaba Barkhordari Yazdi 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.4

Controlling a class of chaotic hybrid systems in the presence of noise is investigated in this paper. Toreach this goal, an explicit model predictive control (eMPC) in combination with nonlinear estimators is employed. Using the eMPC method, all the computations of the common MPC approach are moved off-line. Therefore, theoff-line control law makes it easier to be implemented in comparison with the on-line approach, especially forcomplex systems like the chaotic ones. In order to verify the proposed control structure practically, an op-ampbased Chua’s chaotic circuit is designed. The white Gaussian noise is considered in this circuit. Therefore, thenonlinear estimators –extended and unscented Kalman filter (EKF and UKF)– are utilized to estimate signals fromthe noise-embedded chaotic system. Performance of these estimators for this experimental setup is compared inboth open-loop and closed-loop systems. The experimental results demonstrate the effectiveness of the eMPCapproach as well as the nonlinear estimators for chaos control in the presence of noise.

Cross-Cultural Adaptation and Validation of the Persian Version of the 24-Item Early-Onset Scoliosis Questionnaire

Esfandiari Mahmood,Babaee Taher,Kamyab Mojtaba,Kamali Mohammad,Matsumoto Hiroko,Ghandhari Hassan,Vitale Michael G. 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.1

Study Design: Cross-sectional study.Purpose: To translate and culturally adapt the original English version of the 24-item Early-Onset Scoliosis Questionnaire (EOSQ-24) to the Persian language as well as assess its reliability and validity.Overview of Literature: Early-onset scoliosis (EOS) patients with progressive curves require active treatments, such as serial elongation– derotation–flexion casting, bracing, and surgery, which are stressful and expensive. In order to evaluate the impact of EOS and its treatment strategies, it is important to consider the patients and their parents’ quality of life as the clinical and radiological parameters. The EOSQ-24 is a parent-based measure that evaluates the health-related quality of life of patients with EOS and their caregivers/parents. Similar to other widely used questionnaires, EOSQ-24 needs to be translated into other languages to make it usable in populations from different cultures and societies.Methods: We evaluated the translation and back translation of the EOSQ-24 and made the required revisions as per the analysis performed by the expert committee and an international guideline to adapt it for use in this study. Thereafter, we recruited 100 EOS patients in order to evaluate its reliability and validity. The reliability was assessed with internal consistency. Convergent validity was assessed by comparing the scores of the EOSQ-24 and the 22-item Scoliosis Research Society Questionnaire (SRS-22r). Finally, the known groups validity was assessed as per patient’s sex, curve magnitude, and treatment type.Results: The Persian EOSQ-24 demonstrated very good internal consistency (Cronbach’s α=0.88). All the items had an acceptable corrected item-total correlation (>0.3). Further, the EOSQ-24 and the SRS-22r scores (p <0.001) were significantly correlated. The EOSQ-24 could discriminate patients with different curve magnitudes.Conclusions: The Persian EOSQ-24 can serve as a disease-specific instrument with strong validity and reliability in the evaluation of EOS patients. Its applicability in other Persian-speaking countries and regions of the world needs to be investigated further.

Comparison of the Minimum Plateau Width by Plateau and a New Method in People with Conductive Hearing Loss

Seyyed Jalal Sameni,Ahmad Daneshi,Akram Pourbakht,Aliakbar Tahaei,Mohammad Kamali 대한청각학회 2018 Journal of Audiology & Otology Vol.22 No.4

Background and Objectives: In clinical masking, the plateau is a state in which the non-test ear (NTE) is completely masked by the noise and tone is heard only by the test ear (TE). At least 15 to 20 dB of plateau width is needed to obtain valid threshold. In the study, a part of plateau after initial masking level known as the minimum plateau width (mPW) was determined and compared by a new formula and the plateau searching method. Subjects and Methods: Minimum plateau widths of air conduction were obtained in 29 participants with unilateral and 30 participants with bilateral conductive hearing loss (CHL) aged 20 to 45 years old by using step by step plateau method and mPW estimation by the formula between two points of masking diagram [mPW=(N2-N1)-(T2-T1)] and then the mPW of twomethods was compared for each frequency. Results: There was no significant difference between the minimum plateau width obtained by the plateau and formula methods for two given point of masking diagram in people with unilateral and bilateral CHL at octave frequencies from 500 Hz to 4,000 Hz. Conclusions: Threshold obtaining of TE by two tones for two noise levels delivered to the NTE is enough to estimate the mPW between these two noise points and it is not necessary that for clinicians to know the actual values of masking diagram components.

Horizontal Localization in Simulated Unilateral Hearing Loss

Anvarsamarein Parisa,Nazeri Ahmad Reza,Sameni Seyyed Jalal,Kamali Mohammad,Zarrin Koob Homa 대한청각학회 2018 Journal of Audiology & Otology Vol.22 No.1

Background and Objectives: The ability to localize a sound source is one of the binauralhearing benefits in a horizontal plane based on interaural time difference and interaural intensitydifference. Unilateral or bilateral asymmetric hearing loss will affect binaural hearing and leadto sound locating errors. In this cross sectional analytical descriptive study, the localization errorwas investigated when participants turned their heads to the sound source with closedeyes and after simulating unilateral hearing loss by placing earplugs inside the right ear canal. Subjects and Methods: This cross sectional analytical descriptive study was carried out on30 right-handed adults, 22 female and 8 male (average: 25 years, standard deviation: 3.16). They were selected with the available random access method. Horizontal localization wasevaluated with five speakers located at 0, ±30, and ±60 degree azimuths at a 1-meter distancefrom the examinee. Narrow-band noise signals were delivered at 35 dB SL in two “withoutearplug” and “with earplug” situations and the results were compared. The study was performedbetween September and December 2016 in Tehran, Iran. Results: Significantdifferences were observed in localization errors between the “with earplug” and “without earplug”situations. The localization differences were greater for left-side speakers (-30 and -60degrees) compared with right-side speakers (+30 and +60 degrees). The differences weremore apparent at 4,000 and 6,000 Hz, which confirmed the effect of unilateral simulatedhearing loss on interaural latency differences. Conclusions: Simulating hearing loss by usingan earplug in one ear (right) increased localization errors at all frequencies. The errorsincreased at higher frequencies.

The Effects of the Vestibular Rehabilitation on the Benign Paroxysmal Positional Vertigo Recurrence Rate in Patients with Otolith Dysfunction

Reza Hoseinabadi,Akram Pourbakht,Nasrin Yazdani,Ali Kouhi,Mohammad Kamali,Farzaneh Zamiri Abdollahi,Sadegh Jafarzadeh 대한청각학회 2018 Journal of Audiology & Otology Vol.22 No.4

Background and Objectives: Although repositioning maneuvers have shown remarkable success rate in treatments of benign paroxysmal positional vertigo (BPPV), the high recurrence rate of BPPV has been an important issue. The aims of present study were to examine the effects of otolith dysfunction on BPPV recurrence rate and to describe the effect of vestibular rehabilitation exercises on BPPV recurrence in BPPV patients with concomitant otolith dysfunction. Subjects and Methods: Forty-five BPPV patients included in this study (three groups). Patients in group 1 had no otolith dysfunction and patients in groups 2 and 3 had concomitant otolith dysfunction. Otolith dysfunction was determined with ocular/cervical vestibular evoked myogenic potential (oVEMP and cVEMP) abnormalities. Epley’s maneuver was performed for the patients in all groups but patients in group 3 also received a 2-month vestibular rehabilitation program (habituation and otolith exercises). Results: This study showed that BPPV recurrent rate was significantly higher in patients with otolith dysfunction in comparison to the group 1 (p<0.05). Vestibular rehabilitation resulted in BPPV recurrence rate reduction. Utricular dysfunction showed significant correlation with BPPV recurrence rate. Conclusions:Otolith dysfunction can increase BPPV recurrence rate. Utricular dysfunction in comparison to saccular dysfunction leads to more BPPV recurrence rate. Vestibular rehabilitation program including habituation and otolith exercises may reduce the chance of BPPV recurrence.

Effect of Brace Treatment on Craniovertebral to Lumbopelvic Sagittal Parameters in Adolescents with Idiopathic Scoliosis: A Systematic Review

Ghorbani Faezeh,Ranjbar Hadi,Kamyab Mojtaba,Babaee Taher,Kamali Mohammad,Razavi Hiva,Sharifi Pouya,Janani Leila 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.2

The current study was carried out systematically by conducting a review of the literature. The purpose of this study was to conduct a systematic review of the literature to determine the effects of brace wearing on sagittal parameters in adolescents with idiopathic scoliosis (AIS). In this study, PubMed/MEDLINE (National Library of Medicine), Scopus, Ovid, CINAHL, PEDro, Google Scholar, and the Cochrane Library were accessed and searched using the patient, intervention, comparison, outcome, and study design model. We included studies that looked at the effects of brace treatment on sagittal spinopelvic parameters in AIS patients over the age of 18. The studies were chosen for their cross-sectional, retrospective, or prospective observational designs, and they were published in English. Review articles, case reports, case study designs, and conference abstracts were excluded from consideration. The methodological quality of the remaining articles was assessed using the Newcastle Ottawa Scale. A total of 12 studies were chosen, and 995 participants were evaluated, with 3 (25%) and 9 (75%) having high and moderate quality, respectively. The studies were classified based on the length of follow-up. Long-term, short-term, and immediate effects of brace wearing on sagittal spinopelvic parameters were reported in four, five, and three studies, respectively. The results of nine studies showed a significant decrease in Cobb angle after wearing the brace, which contradicted the findings of the other two. The cervical and sagittal pelvic parameters, thoracic kyphosis (TK), lumbar lordosis (LL), spinopelvic parameters, and sagittal balance were all evaluated in the intended studies, yielding varying results. According to the available literature, wearing a brace flattens the TK and LL. According to this systematic review, brace treatment may affect sagittal spinopelvic parameters in adolescents with AIS, particularly in TK and LL. The cervical and pelvic parameters yielded inconclusive results. This study backs up the idea that brace design and structure can influence sagittal parameter changes. The limitations of this study include different methods of parameter measurement, variations in the brace types and wear time, varying follow-up duration, and differences in participant characteristics.