Excessive Source Research Articles

청각선별을 통과한 주간 보호와 언어재활 서비스 수혜 소아의 가청역치

청각선별에서 반응 역치는 검사 환경 잡음, 청각기관 생리적 특성, 과도한 음원 노출 등에 따라 다르게 나타난다. 이 연구 목적은 청각선별을 통과한 소아의 주파수별 가청역치에 대한 정보를 획득하는데 있다. 연구 대상은 언어치료센터와 지역아동센터에 다니는 3.3세부터 16.3세(<TEX>$9.01{\pm}2.52$</TEX>) 사이의 110명으로 하였고, 이들의 소아 청각 선별 결과를 후향적으로 분석하였다. 청각선별은 고막운동성계측(Tympanometry), 등골근반사(acoustic reflex threshold), 자동화 이음향방사(automated otoacoustic emission), 순음청각선별(pure tone screening)을 시행하였다. 대상자들은 모두 청각선별 정상 기준에 포함되었다. 주파수별 가청역치 차이는 반복측정 분산분석 하였다. 결과: 가청역치 평균은 500, 1,000, 2,000, 4,000 Hz의 순서로 우측 귀 <TEX>$16{\pm}6.49$</TEX>, <TEX>$11.5{\pm}4.79$</TEX>, <TEX>$6.86{\pm}4.99$</TEX>, <TEX>$5.95{\pm}6.65$</TEX> dB HL, 좌측 귀 <TEX>$15.68{\pm}6.01$</TEX>, <TEX>$9.95{\pm}5.24$</TEX>, <TEX>$5.72{\pm}5.21$</TEX>, <TEX>$5.63{\pm}7.04$</TEX> dB HL로 각각 관찰되었다. 주파수 사이에는 500Hz와 1,000, 2,000, 4,000 Hz(p=.000), 1,000과 2,000, 4,000 Hz(p=.000)로 유의한 차이가 있었다. Responded threshold level in hearing screening depends on the noise level of test surroundings, physiological characteristics of hearing organs, excessive sound source exposures, and so on. The purpose of this study is to obtain the basic information of hearing threshold level at each frequencies in children with passed hearing screening. Subjects were 110 children, aged were from 3.3 to 16.3 (<TEX>$9.01{\pm}2.52$</TEX>), who were at private speech language pathological clinics and daycare centers. Methods of Hearing screening were tympanometry, acoustic reflex threshold, automated otoacoustic emission, and pure tone screening. The subjects were in normal criteria of hearing screening. The differences of hearing threshold among ages and frequencies were measured by means of repeated measures ANOVA. The mean of hearing thresholds level was observed <TEX>$16{\pm}6.49$</TEX>, <TEX>$11.5{\pm}4.79$</TEX>, <TEX>$6.86{\pm}4.99$</TEX>, <TEX>$5.95{\pm}6.65$</TEX> dB HL in the right ear and <TEX>$15.68{\pm}6.01$</TEX>, <TEX>$9.95{\pm}5.24$</TEX>, <TEX>$5.72{\pm}5.21$</TEX>, <TEX>$5.63{\pm}7.04$</TEX> dB HL in the left ear, in frequency of 500, 1,000, 2,000, 4,000 Hz respectively. There was a significant difference between 500 and 1,000, 2,000, 4,000 Hz (p=.000), between 1,000 and 2,000, 4,000 Hz (p=.000).

Influence of Biological Activated Carbon on Simultaneous Nitrification and Denitrification in Inflow with Different C/N Ratios

Influence of biological activated carbon (BAC) on simultaneous nitrification and denitrification (SND) in inflow with different C/N ratios was investigated with continuous operation of BAC reactor and SBR. Methanol was added as carbon source and the inflow C/N ratio was set to 3, 5, 8 and 10 to run for about 120 cycles, under conditions of indoor temperature (15-27℃), initial DO 2-3mg·L-1. The TN removal efficiency and stability of two reactors were compared. The results showed that, BAC reactor had a higher TN removal efficiency than SBR at different C/N ratios. TN removal rate of BAC reactor was 44.88%, 58.07% and 66.64%, when the C/N ratio was 3, 5 and 8 respectively. After increasing the C/N ratio to 10, the BAC reactor could maintain TN removal rate of 63.65%, but the SBR showed sludge bulking. BAC provided various DO environments for microorganisms in a vessel, which was beneficial to SND. BAC could reduce the influence of excessive carbon source on the nitrification system, enlarge the application range and improve the stability of reactor at different C/N ratios, and increase the nitrogen removal capacity of organic matter. BAC provided condition for efficient nitrogen removal.

Experimental Analysis of Rotor-Bearing System for Fault Detection

Rotating system is a main part in any industry. The design of such systems in modern engineering is towards lower weight operating at super critical speed for longer periods of time. In actual working condition, faults are unavoidable due to the error in manufacturing; faults may develop in the system due to the operating conditions such as heat generation, unbalance, wear, misalignment, looseness etc. In this study, dynamic behavior of rotor-bearing system is studied. This model mainly represents the driving unit at industrial machine applications. Disc at the model can be considered as gear or pulley, etc .at the transmission line. Experimental vibration analyses in vertical direction of the system are implemented. Vibration monitoring with Run up measurement analysis and Spectrum graphs are used to diagnose the excessive vibration source. It is seen that vibration at the rotor-bearing system not only one faults but also combination of several faults such as unbalance, wear, misalignment, looseness, etc. A non- destructive evaluation method for left &amp; right bearing is used to diagnose the undue vibration source before it become critical.

Red-emission enhancement of the CaAlSiN3:Eu2+ phosphor by partial substitution for Ca3N2 by CaCO3 and excess calcium source addition

Red-emission enhancement of the CaAlSiN3:Eu2+ phosphor by partial substitution for Ca3N2 by CaCO3 and excessive calcium source addition.

탄소나노튜브의 합성에 대한 아세틸렌 혼합 비율의 영향

In this study, experimental and numerical studies for the synthesis of carbon nanotube(CNT) in methane counterflow diffusion flame have been performed. Methane mixed with acetylene() was used as a fuel gas and ferrocene was used as a catalyst for synthesis of CNT. The major parameters was mixing rate and mixing rates were 2 %, 6 %, and 10 %. Characteristics of CNT formation on grid were analyzed from SEM images. the chemical reaction mechanism adopted is GRI-MECH 3.0. Numerical results showed that flame temperature and CO mole fraction were increased with increasing acetylene mixing rate. Experimental results showed that the CNT synthesis in 2% acetylene mixture flame better than that of 6% and 10% acetylene mixture flames. It can be considered that 6% and 10% acetylene mixture flames generated the excessive carbon source and then it interrupted the supplement of the carbon source into ferrocene catalyst. It can be found that the supply of appropriate quantity of carbon source can make effect to synthesis of high purity of CNT.

Controllable synthesis of spinel lithium nickel manganese oxide cathode material with enhanced electrochemical performances through a modified oxalate co-precipitation method

A spinel lithium nickel manganese oxide (LiNi0.5Mn1.5O4) cathode material is synthesized with a modified oxalate co-precipitation method by controlling pH value of the precursor solution and introducing excessive Li source in the precursor. All the samples synthesized through this method are of Fd3m phase with a small amount of P4332 phase. It is found that pH value of the precursor solution considerably affects the morphology, stoichiometry and crystallographic structure of the target material, thereby resulting in different amounts of Mn3+ (i.e., different degree of disorder). 5% excessive Li source in the precursor may compensate for the lithium loss during the high-temperature sintering process and eliminate the LixNi1-xO impurity phase. Under the optimized synthesis conditions, the obtained high-purity LiNi0.5Mn1.5O4 spinel exhibits enhanced electrochemical performances. A reversible capacity of ca. 140 mAh g−1 can be delivered at 0.1C and the electrode retains 106 mAh g−1 at 10C rate. When cycled at 0.2C, a capacity retention of more than 98% is obtained in the initial 50 electrochemical cycles.

Energetics of lateral eddy diffusion/advection: Part IV. Energetics of diffusion/advection in sigma coordinates and other coordinates

Gravitational potential energy (GPE) source and sink due to stirring and cabbeling associated with sigma diffusion/advection is analyzed. It is shown that GPE source and sink is too big, and they are not closely linked to physical property distribution, such as temperature, salinity and velocity. Although the most frequently quoted advantage of sigma coordinate models are their capability of dealing with topography; the excessive amount of GPE source and sink due to stirring and cabbeling associated with sigma diffusion/advection diagnosed from our analysis raises a very serious question whether the way lateral diffusion/advection simulated in the sigma coordinates model is physically acceptable. GPE source and sink in three coordinates is dramatically different in their magnitude and patterns. Overall, in terms of simulating lateral eddy diffusion and advection isopycnal coordinates is the best choice and sigma coordinates is the worst. The physical reason of the excessive GPE source and sink in sigma coordinates is further explored in details. However, even in the isopycnal coordinates, simulation based on the Eulerian coordinates can be contaminated by the numerical errors associated with the advection terms.

Electrostatic Modeling and Insights Regarding Multigate Lateral Tunneling Transistors

We use pseudo-2-D analytical models to study the electrostatics of multigate tunneling field-effect transistors (TFETs), providing a portable set of equations to simultaneously describe silicon-on-insulator, double gate, and cylindrical nanowire devices. We validate the model via extensive comparisons with numerical simulations and demonstrate its accuracy and general applicability; 2-D tunneling effects are analytically estimated and found to be small for well-scaled devices within the semiclassical model. We also study the impact of source and drain doping on TFET performance, including a seminal analytical treatment of nonabrupt junctions and degeneracy effects. We present a new simple model to explain the adverse effects of excessive source doping, and show for the first time how degeneracy in low density-of-states materials directly degrades not only the tunneling efficiency, but also the device electrostatics, causing particular problems for III-V p-TFETs.

Aerobic biotransformation of decabromodiphenyl ether (PBDE-209) by Pseudomonas aeruginosa

Aerobic biodegradation of decabromodiphenyl ether (PBDE-209) by Pseudomonas aeruginosa under the influence of co-metabolic substrates and heavy metal cadmium ion was studied, The results showed that certain amount of co-metabolic substrates, such as glucose, sucrose, lactose, starch, and beef extract, would promote the biodegradation of PBDE-209, among which glucose most favorably accelerated PBDE-209 degradation by about 36% within 5d. The highest degradation efficiency was reached at the ratio of PBDE-209 and glucose 1:5 while excessive carbon source would actually hamper the degradation efficiency. Exploration of influences of cadmium ion on PBDE-209 biodegradation indicated that degradation efficiency was stimulated at low concentrations of Cd2+ (0.5–2mgL−1) while inhibited at higher levels (5–10mgL−1), inferring that the heavy metals of different concentrations possessed mixed reactions on PBDE-209 bioremoval. Bromine ion was produced during the biotransformation process and its concentration had a good negative correlation with the residues of PBDE-209. Two nonabromodiphenyl ethers (PBDE-208, PBDE-207), four octabromodiphenyl ethers (PBDE-203, PBDE-202, PBDE-197, PBDE-196) and one heptabromodiphenyl ethers (PBDE-183) were formed with the decomposition of PBDE-209, demonstrating that the main aerobic transformation mechanism of PBDE-209 was debromination.

Comparative research on Cs/O activation source ratio for GaAs photocathodes

Through the comparative research on cathode material by surface photovoltage spectroscopy (SPS) before activation and spectral response current (SRC) after activation, the value of surface escape probability (SEP) can be well measured. By the experiments and calculations for the designed cathode material, the influence of Cs/O activation source ratio on SRC and SEP can be well fitted. The lower and excessive source ratio can not get well SEP value and only the appropriate source ratio can get the better SEP value. Through the analysis of surface barrier layer model, the influence of Cs/O source ratio on the formation of surface barrier layer were well discussed. The appropriate source ratio can help to form the best double dipole arrange structure and better depth of Cs–O layer. This comparative research method can help to well study and optimize the Cs/O activation technique and varied doping structure design for GaAs photocathodes in the future.

Experimental analysis on fault detection for a direct coupled rotor-bearing system

Rotating machinery is becoming faster and lightweight due to the advanced technologies made in engineering and materials sciences. It is required them to run for longer periods of time. All of these factors mean that the detection, location and analysis of faults play a vital role in highly reliable operations. Using vibration analysis, the condition of a machine can be periodically monitored. In this study, dynamic behavior of a direct coupled rotor-bearing system is investigated. Experimental vibration analyses in the vertical direction of the system are implemented. Vibration monitoring with trend analysis and spectrum graphs are employed to diagnose the excessive vibration source(s). It is seen that the rotating machineries can have one or more vibration sources. The vibration values obtained from each bearing show that the main excessive vibration sources in the system stem from mechanical looseness and misalignment.

Biodegradation of anthracene by Aspergillus fumigatus

An anthracene-degrading strain, identified as Aspergillus fumigatus, showed a favorable ability in degradation of anthracene. The degradation efficiency could be maintained at about 60% after 5 d with initial pH of the medium kept between 5 and 7.5, and the optimal temperature of 30 °C. The activity of this strain was not affected significantly by high salinity. Exploration on co-metabolism showed that the highest degradation efficiency was reached at equal concentration of lactose and anthracene. Excessive carbon source would actually hamper the degradation efficiency. Meanwhile, the strain could utilize some aromatic hydrocarbons such as benzene, toluene, phenol etc. as sole source of carbon and energy, indicating its degradation diversity. Experiments on enzymatic degradation indicated that extracellular enzymes secreted by A. fumigatus could metabolize anthracene effectively, in which the lignin peroxidase may be the most important constituent. Analysis of ion chromatography showed that the release of anions of A. fumigatus was not affected by addition of anthracene. GC-MS analysis revealed that the molecular structure of anthracene changed with the action of the microbe, generating a series of intermediate compounds such as phthalic anhydride, anthrone and anthraquinone by ring-cleavage reactions.

Excessive Iron Source on the Structural and Electrochemical Properties of LiFePO&lt;sub&gt;4&lt;/sub&gt;/C Composite

LiFePO4 is one of the most promising cathode materials for lithium ion battery, especially those used in electrical vehicles and hybrid electrical vehicles. However, its very poor rate performance caused by its low electronic and ionic conductivity limits the wide utilization in high power lithium ion battery. Iron phosphides, such as FeP and Fe2P, were reported to have positive effect on the improvement of the rate performance. In order to improve the electrochemical properties, LiFe1+xPO4/C (x = 0-0.1) composite with various contents of iron phosphides was synthesized by adding different amount of iron source during a sol-gel process. The amount of iron phosphides increased with the increase of iron source. Electrochemical performance showed that the samples with 1% iron source in excess had better rate performance than the LiFePO4/C sample synthesized with stoichiometric iron source. However, the overall samples with excessive iron source showed relatively low specific discharge capacity. Hence, some balance between the rate capability and discharge capacity should be found and the amount of the in-situ formed iron phosphides should be optimized.

Cloning and Homologous Expression of Novel Lignin Peroxidase Genes in the White-Rot FungusPhanerochaete sordidaYK-624

Two genes, encoding YK-LiP1 and YK-LiP2, were cloned from the white-rot fungus Phanerochaete sordida YK-624, and a homologous expression system for the gene was constructed. Two full-length cDNAs (ylpA and ylpB) were isolated by degenerate RT-PCR and RACE-PCR. The results of N-terminal amino acid sequence analysis of native YK-LiP1 and YK-LiP2 showed that ylpA and ylpB coded for YK-LiP2 and YK-LiP1 respectively. The promoter of glyceraldehyde-3-phosphate dehydrogenase cloned from P. sordida YK-624 (PsGPD) was used to drive the expression of ylpA. Expression vector pGPD-g-ylpA was transformed into a P. sordida YK-624 uracil auxotrophic mutant, UV-64. The YlpA protein was secreted in active form by the transformants after 4 d of growth in a medium containing an excessive nitrogen source, whereas endogenous YK-LiP1 and YK-LiP2 were not produced. The physical and catalytic properties of the purified YlpA protein were very similar to those of YK-LiP2. These results suggest that homologous expression of recombinant YK-LiP2 was successful.

The nature of the compositional dependence of p–n junction depth in ion-milled p-HgCdTe

The dependence of conductivity-type conversion depth in vacancy-doped Hg1−xCdxTe (MCT) alloys subjected to ion milling on alloy composition and treatment temperature is studied both experimentally and theoretically. It is shown that both in compositionally homogeneous crystals and in samples with a wide bandgap protective layer the dependence is defined by internal electric fields, which affect the diffusion of mercury interstitial atoms that are generated during the treatment. Results of the calculation of the effect of the potentials of a p–n junction formed by ion milling and of a varyband structure field (in samples with the protective layer) on the conversion depth fit both the original experimental data and those taken from the literature well. The data obtained confirms the validity of the diffusion model of the formation of the excessive mercury source in MCT subjected to ion milling, which was proposed by the authors previously. The results presented in the paper allow one to predict and control the conversion depth in MCT subjected to ion milling for p–n junction fabrication, which makes them useful in MCT infrared detector technology.

Essential hypertension: First reason for persistent hypertension after unilateral adrenalectomy for primary aldosteronism?

Background: Despite cure of primary aldosteronism by surgical resection, hypertension persists postoperatively in 30% to 50% of patients. The aim of this study was to determine factors influencing long-term outcome of blood pressure after unilateral adrenalectomy for primary aldosteronism. Methods: Records of 100 patients who underwent unilateral adrenalectomy for primary aldosteronism from 1970 through 1997 were reviewed. Patients were distributed in 2 groups according to whether blood pressure was normal (criteria of World Health Organization). Clinical, biochemical, and pathologic data were compared. Results: All patients were biochemically cured. Blood pressure was normal in 56 patients and improved in 44 (mean follow-up, 69 and 59 months). Persistent hypertension correlated with age, known duration and seriousness of preoperative hypertension, family history of hypertension, no preoperative response to spironolactone, and contralateral adrenal hypertrophy. Gender, surgical approach, and pathologic findings were not predictive factors of blood pressure outcome. The prevalence of hypertension was almost the same in these postoperative patients as the prevalence of essential hypertension in a random population of the same age. Conclusions: Early unilateral adrenalectomy allows cure or improvement of hypertension in all patients with primary aldosteronism induced by unilateral excessive source of aldosterone secretion regardless of the pathologic findings. Persistent hypertension suggests that coexisting essential hypertension is present. (Surgery 1998;124:1128-33.)

Performance of a continuous stirred tank reactor with immobilized denitrifiers and methanogens

Water denitrification by a coimmobilized mixed culture of denitrifiers and methanogens to simultaneously remove nitrate and excessive carbon source, methanol, in a continuous stirred tank reactor was investigated. Complete denitrification occurred at a methanol to nitrate nitrogen (M:N) ratio of ≥2.62. Ratios beyond 2.62 methane formation took place resulting in the depletion of excess methanol. The quality of the effluent solution was found to be markedly dependent on nitrate loading. At a constant M:N ratio ∼3.2, a complete nitrate and methanol removal could be attained when the influent nitrate concentration was &lt;385 mg N/L; otherwise, the hydraulic retention time (HRT) was operated &gt;2 hr (at a constant influent nitrate around 100 mg N/L). The surplus methanol was verified to be converted directly into methane when complete denitrification was achieved. Moreover, a sufficient correlation was found between the biological activity and the redox potential.

INVESTIGATION OF INDOOR AIR QUALITY COMPLAINTS

Objective conclusions regarding IAQ complaints in a large facility require a systematic investigation of both occupant health status and building conditions. Underlying causes of complaints may represent specific deficiencies in HVAC operation, excessive source emissions, or, alternatively, may involve factors unrelated to IAQ. Response to IAQ problems may involve changes in overall building conditions or efforts to manage hypersensitivity on an individual basis. Physicians knowledgeable in IAQ principles can play an important role in resolving occupant concerns regarding apparent building-related symptoms.

A new nonlinear I(V) model for FET devices including breakdown effects

The nonlinear FET I(V) behavior, including gate conduction and breakdown, has been investigated using a pulse measurement setup. An excessive current source has been observed in addition to the usual gate breakdown current. From these measurements, a nonlinear model including the conduction, breakdown, and excessive current phenomenon is proposed for the nonlinear simulation of high-power circuits. This I(V) model presents an improvement in terms of load line prediction and limits for the high-power nonlinear circuit design. >

Dimerisation of isoprene in a mass spectrometer source in GC-MS analysis

It has been observed that even under normal operating conditions in gas-chromatography-mass-spectrometry (gc-ms), the chromatographic peak corresponding to isoprene monomer may display the mass spectral characteristics of a dimer. It is shown that this cannot be due to any dimerisation occurring on the chromatographic column, but must be due to a reaction occurring in the mass spectrometer source. The reaction cross-section for this process must be quite large, since excessive source pressures were not used. The occurrence of processes such as this has serious implications when characterising chromatographic peaks from mass spectral library fits in gc-ms or pyrolysis-gc-ms.