경북지역 공공하수처리시설 유입수 및 방류수의 유기물 특성

이기창,박영진,강귀화,정미옥,류동현,정상섭,이원태 대한환경공학회 2021 대한환경공학회지 Vol.43 No.5

Objectives : This study aimed to provide scientific information on the characteristics of organic matters in influents and effluents of sewage treatment plants (STPs) in Gyeongbuk province, Korea, for better performance of treatment processes in the plants. Methods : We selected six STPs with each capacity over 30,000 m3/day in Gyeongbuk province, and analyzed water quality data in influents and effluents of the plants from 2013 to 2020. Also, the removal efficiencies of pollutants were assessed with the operational data. In 2020, characteristics and origins of dissolved organic matters (DOM) in influents and effluents were investigated using the fluorescence excitation emission matrix (FEEM) analysis. Results and Discussion : The average BOD5/CODMn ratios of influents and effluents from the STPs were 1.60 and 0.27, respectively. High variability in BOD5/CODMn ratios was observed for both influents and effluents. The CODMn/TOC ratios of the influents and effluents were the same with an average of 1.6. Although the biological treatment process was different for each STP, the organic matter removal efficiency was similar, and the TOC removal efficiency was 86.5~91.7%. The representative spectra of DOM identified through FEEM analysis was peak C (humic-acid like substance) region, and under the same carbon concentration (2 mg-C/L) the fluorescence intensity of effluents was stronger than influents possibly due to the influence of soluble microbial products (SMP). It was found that DOM of both influent and effluent originated from microorganisms, and the difference in water quality of DOM was statistically significant. Conclusions : The characteristics and fate of organic matters in influents and effluents of the six STPs were similar regardless of plant location. The results of this study can be used as basic information to efficiently control organic matters in the STPs. 목적: 본 연구는 경북지역 내 대표적인 공공하수처리시설의 유입수 및 유출수 내 유기물 특성을 분석하고 이를 통해 처리시설의 효율적인 운영을 도모하고자 수행하였다. 방법: 경북지역의 공공하수처리시설 중 시설규모 30,000 m3/day 이상인 6곳을 선정하여 2013~2020년 동안의 운영자료를 활용하여 유입수 및 방류수의 수질특성과 공정효율을 분석하였다. 2020년 시료는 형광 excitation emission matrix (EEM) 분석기법을 활용하여 유입수 및 방류수의 용존유기물질(Dissolved Organic Matter, DOM) 특성과 생성기원 등을 조사하였다. 결과 및 토의: 분석대상 공공하수처리시설의 유입수와 방류수의 BOD5/CODMn 평균비는 각각 1.60과 0.27이었다. BOD5/CODMn 비는 유입수 뿐만 아니라 생물학적처리가 된 방류수에서도 변동성이 크게 나타났다. 유입수와 방류수의 CODMn/TOC 비는 평균 1.6으로 동일하였다. 처리시설별로 생물학적공법이 상이하였지만 유기물 제거효율은유사하게 나타났으며, TOC의 경우 제거효율은 86.5~91.7%이었다. 형광 EEM 분석을 통해 확인된 DOM의 대표적EEM spectra는 peak C (humic-acid like substance) 영역이었고, 동일한 탄소농도(2 mg-C/L) 조건에서 방류수가 미생물의 대사활동으로 생성된 soluble microbial products (SMP)의 영향으로 형광강도가 더 강했다. 유입수와 방류수의 DOM은 모두 미생물로부터 기인한 것으로 나타났고, DOM의 수질성상 차이는 통계적으로 유의하였다. 결론: 조사대상 공공하수처리시설간 유입수 및 방류수에 대한 유기물질의 거동이 유사하고 다양한 유기물 성상지표가 비교적 균일한 값을 가져 본 연구의 결과가 향후 수처리공정에서 유기물질을 효율적으로 제어하기 위한 기초자료로 활용 가능할 것이다.

Raspberry pi를 이용한 딥러닝 기반 안개와 노면 결빙 실시간 감지 기법

류태광(Taekwang Ryu),양훈준(Hunjun Yang),이보원(Bowon Lee) 대한전자공학회 2020 대한전자공학회 학술대회 Vol.2020 No.8

중이진주종에서 역전사 : 중합효소 연쇄반응법으로 측정한 상피성장인자 수용체 유전자의 발현

허진,김형종,임현준,조양선 대한청각학회 2000 Journal of Audiology & Otology Vol.4 No.1

Does Listening to Tinnitus Frequency-Filtered Music Relieve Tinnitus?

Yoo Shinyoung,Yakunina Natalia,Nam Eui-Cheol 대한청각학회 2022 Journal of Audiology & Otology Vol.26 No.3

Background and Objectives: Tinnitus frequency-filtered music therapy aims to restore lateral inhibition to reverse tonotopic reorganization in the auditory cortex. Although the tinnitus-relieving effect of this therapy has been investigated, the results remain controversial. We performed a prospective, randomized, controlled double-blind study to determine the tinnitus-suppressing effect of tinnitus frequency-filtered music therapy.Subjects and Methods: The study included 90 participants who were randomly categorized into an experimental group that listened to tinnitus frequency-filtered music and a control group that listened to music from which a random frequency was removed. The Tinnitus Handicap Inventory (THI) score and measures of tinnitus loudness, daily awareness, and tinnitus-induced annoyance were evaluated at the initial visit and at 3 and 6 months (final follow-up). The rates of improvement in THI scores in the two groups were also recorded.Results: All measured variables showed significant improvement in both groups, except the matched tinnitus loudness and minimal masking level. However, no significant intergroup differences were observed in the amount of improvement in THI scores and any other variable. The rates of improvement in THI scores were higher in the control group at 3 and 6 months.Conclusions: Listening to tinnitus frequency-filtered music reduced tinnitus-induced handicaps; however, this approach was not significantly better than listening to music from which a random frequency was removed.

Mutations in GJB2 as Major Causes of Autosomal Recessive Non-Syndromic Hearing Loss: First Report of c.299-300delAT Mutation in Kurdish Population of Iran

Fatemeh Azadegan-Dehkordi,Tayyebe Bahrami,Maryam Shirzad,Gelareh Karbasi,Nasrin Yazdanpanahi,Effat Farrokhi,Mahbobeh Koohiyan,Mohammad Amin Tabatabaiefar,Morteza Hashemzadeh-Chaleshtori 대한청각학회 2019 Journal of Audiology & Otology Vol.23 No.1

Background and Objectives: Autosomal recessive non-syndromic hearing loss (ARNSHL)with genetic origin is common (1/2000 births). ARNSHL can be associated with mutations ingap junction protein beta 2 (GJB2). To this end, this cohort investigation aimed to find thecontribution of GJB2 gene mutations with the genotype-phenotype correlations in 45 ARNSHLcases in the Kurdish population. Subjects and Methods: Genomic DNA was extractedfrom a total of 45 ARNSHL families. The linkage analysis with 3 short tandem repeat markerslinked to GJB2 was performed on 45 ARNSHL families. Only 9 of these families werelinked to the DFNB1 locus. All the 45 families who took part were sequenced for confirmationlinkage analysis (to perform a large project). Results: A total of three different mutationswere determined. Two of which [c.35delG and c.-23+1G>A (IVS1+1G>A)] were previouslyreported but (c.299-300delAT) mutation was novel in the Kurdish population. The homozygouspathogenic mutations of GJB2 gene was observed in nine out of the 45 families(20%), also heterozygous genotype (c.35delG/N)+(c.-23+1G>A/c.-23+1G>A) were observedin 4/45 families (8.8%). The degree of hearing loss (HL) in patients with other mutationswas less severe than patients with c.35delG homozygous mutation (p<0.001). Conclusions:Our data suggest that GJB2 mutations constitute 20% of the etiology of ARNSHL inIran; moreover, the c.35delG mutation is the most common HL cause in the Kurdish population. Therefore, these mutations should be included in the molecular testing of HL in thispopulation.

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.

A Case of Basal Cell Carcinoma of External Auditory Canal

Beom-Jun Lee,박경호,Seong-Cheon Bae,Jae-Hong Lee 대한청각학회 2012 Journal of Audiology & Otology Vol.16 No.2

Malignant tumor originated from external auditory canal (EAC) is very rare with an annual incidence of around 1 per million. Pathologically, squamous cell carcinoma is incidentally most common, and adenoid cystic carcinoma, basal cell carcinoma, and melanoma follow in decreasing order. Due to the rarity of malignant tumor of EAC, there is no widely accepted treatment modality yet. But basal cell carcinoma, known to be less aggressive tumor, can be removed with a minimal safety margin and have better treatment results. Recently we experienced a case of basal cell carcinoma in the EAC, confined in the cartilaginous portion of EAC, presenting with intermittent otorrhea for several years. The patient was treated with a sleeve resection of the EAC with a safety margin reconstructed with a split-thickness skin graft. No tumor recurrence or complication was noted in the first postoperative year

Clinical Features and Prognosis of Sudden Sensorineural Hearing Loss Secondary to Intralabyrinthine Hemorrhage

이재우,박윤아,박상만,공태훈,박상유,봉정표,박동준,서영준 대한청각학회 2016 Journal of Audiology & Otology Vol.20 No.1

Background and Objectives: A number of etiologies of idiopathic sudden sensorineural hearing loss (ISSNHL) have been proposed, including viral infection, vascular disturbance, and immune-mediated mechanisms. Intralabyrinthine hemorrhage (ILH) as a cause of SSNHL is extremely rare, and there have been no studies defining the characteristics of hearing impairment and prognosis in patients with ISSNHL due to ILH. This study aimed to investigate the difference in impaired hearing patterns and prognosis for hearing recovery between patients with ISSNHL due to ILH confirmed by magnetic resonance imaging (MRI) and sex- and age-matched patients with ISSNHL due to causes other than ILH. Subjects and Methods: We compared the results of audiometry and MRI in 12 patients who had ILH on MRI (hemorrhage group) and in 23 sex- and age-matched controls without abnormal findings related to their hearing loss on MRI (non-hemorrhage group). Initial hearing impairment, progression, and recovery of hearing loss were compared between the two groups. Results: A majority of patients (92%) in the hemorrhage group complained of dizziness. Initial hearing impairment was more frequent in the hemorrhage group than in the non-hemorrhage group (94.09±35.9 vs. 66.66±30.1, p-value=0.036). The final recovery threshold in the hemorrhage group was worse (78.19±46.26 vs. 37.17±31.96, p-value=0.014) than that in the non-hemorrhage group. In the hemorrhage group, hearing recovery seemed to occur less often at high frequencies (2,000, 4,000, and 8,000 Hz) than at low frequencies (250, 500, and 1,000 Hz). Conclusions: The presence of ILH was associated with poor hearing prognosis and the occurrence of vertigo. The abrupt onset of hearing loss associated with vertigo and the presence of hyperresonance on fat-suppressed T1-weighted MRI images of labyrinthic fluid strongly suggests acute intralabyrinthine hemorrhage, and is predictive of considerable hearing impairment and poor prognosis.

Symmetric Bilateral Congenital Middle Ear Cholesteatoma: A Case Report

Hong Joon Pyo,Kim Min-Beom 대한청각학회 2023 Journal of Audiology & Otology Vol.27 No.1

Congenital middle ear cholesteatoma (CMEC) accounts for 2%-5% of all cases of middle ear cholesteatoma. CMEC is rare and diagnostically challenging; therefore, only a few cases are reported in the literature, and the pathophysiology of this condition remains largely unclear. Currently, epidermoid formation, amniotic fluid contamination, lack of the tympanic ring, and squamous metaplasia are among the mechanisms implicated in the pathogenesis of CMEC; however, no single theory satisfactorily explains the pathophysiology of this disorder. We report a case of CMEC in a young male patient, who showed a symmetric, binaural whitish mass posterior to the anterosuperior quadrant of the tympanic membrane. A few reports have described bilateral CMEC; however, no study has reported symmetrical CMEC as observed in this case. Bilateral tympanoplasty concomitant with cholesteatoma removal was performed, and histopathological evaluation of the resected specimen showed closed-type cholesteatoma. In this report, we describe a rare case of symmetric CMEC, which supports the epidermoid formation theory associated with CMEC, together with a literature review.

Effects of Caffeine on Auditory- and Vestibular-Evoked Potentials in Healthy Individuals: A Double-Blind Placebo-Controlled Study

Elham Tavanai,Saeid Farahani,Mansoureh Adel Ghahraman,Saleheh Soleimanian,Shohreh Jalaie 대한청각학회 2020 Journal of Audiology & Otology Vol.24 No.1

Background and Objectives:The blockage of adenosine receptors by caffeine changes the levels of neurotransmitters. These receptors are present in all parts of the body, including the auditory and vestibular systems. This study aimed to evaluate the effect of caffeine on evoked potentials using auditory brainstem responses (ABRs) and cervical vestibular-evoked myogenic potentials (cVEMPs) in a double-blind placebo-controlled study. Subjects and Methods: Forty individuals (20 females and 20 males; aged 18-25 years) were randomly assigned to two groups: the test group (consuming 3 mg/kg pure caffeine powder with little sugar and dry milk in 100 mL of water), and the placebo group (consuming only sugar and dry milk in 100 mL water as placebo). The cVEMPs and ABRs were recorded before and after caffeine or placebo intake. Results: A significant difference was observed in the absolute latencies of I and III (p<0.010), and V (p<0.001) and in the inter-peak latencies of III–V and I–V (p<0.001) of ABRs wave. In contrast, no significant difference was found in cVEMP parameters (P13 and N23 latency, threshold, P13-N23 amplitude, and amplitude ratio). The mean amplitudes of P13-N23 showed an increase after caffeine ingestion. However, this was not significant compared with the placebo group (p>0.050). Conclusions: It seems that the extent of caffeine’s effects varies for differently evoked potentials. Latency reduction in ABRs indicates that caffeine improves transmission in the central brain auditory pathways. However, different effects of caffeine on auditory- and vestibular-evoked potentials could be attributed to the differences in sensitivities of the ABR and cVEMP tests.