• Title/Summary/Keyword: AT&T

Search Result 29,607, Processing Time 0.059 seconds

Alleviating Effect of the Application of the Easily Decomposable Carbohydrate on Ammonium Toxicity in Chinese Cabbage (Brassica rapa var. chinensis)

  • Ku, Hyun-Hwoi;Lee, Sang-Eun
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.48 no.5
    • /
    • pp.451-455
    • /
    • 2015
  • An excess application of N fertilizer causes physiological and morphological disorder known as ammonium ($NH_4{^+}$) toxicity in Chinese cabbage and it has been to be an issue for appropriate N fertilizer management. Hence, the pot experiment was conducted in order to evaluate the alleviating effect of the application of the easily decomposable carbohydrate on $NH_4{^+}$ toxicity in Chinese cabbage. Four levels of urea at 0, 160, 320, and $640kg\;N\;ha^{-1}$, represented as T1, T2, T3, and T4, respectively, were applied. In order to evaluate the alleviating effect of the application of the easily decomposable carbohydrate (sucrose) at T3 and T4 where $NH_4{^+}$ toxicity had occurred, five levels of sucrose were applied to meet C/N ratios of 0, 2, 4, 6, and 10, respectively. Our results showed that the $NH_4{^+}$ toxicity was observed at T3 and T4 at 5 days after treatment (DAT). $NH_4{^+}$ toxicity contributed to decrease fresh weight, length of leaves, length of root, and number of leaves significantly (p<0.05). The application of sucrose as a source of mitigating $NH_4{^+}$ toxicity had a good performance at T3 with the alleviating effect as 73 % and reduced in $NH_4{^+}-N$ content in soil at 29 DAT. In the maximum N rate of T4, however, sucrose application recovered it as 32 % only compared to T2 even though the same C/N ratio was treated. Consequently, sucrose as the easily decomposable carbohydrate played crucial role to reduce $NH_4{^+}$ concentration in soil and finally alleviated $NH_4{^+}$ toxicity in plant.

A cone-beam computed tomography evaluation of buccal bone thickness following maxillary expansion

  • Akyalcin, Sercan;Schaefer, Jeffrey S.;English, Jeryl D.;Stephens, Claude R.;Winkelmann, Sam
    • Imaging Science in Dentistry
    • /
    • v.43 no.2
    • /
    • pp.85-90
    • /
    • 2013
  • Purpose: This study was performed to determine the buccal alveolar bone thickness following rapid maxillary expansion (RME) using cone-beam computed tomography (CBCT). Materials and Methods: Twenty-four individuals (15 females, 9 males; 13.9 years) that underwent RME therapy were included. Each patient had CBCT images available before (T1), after (T2), and 2 to 3 years after (T3) maxillary expansion therapy. Coronal multiplanar reconstruction images were used to measure the linear transverse dimensions, inclinations of teeth, and thickness of the buccal alveolar bone. One-way ANOVA analysis was used to compare the changes between the three times of imaging. Pairwise comparisons were made with the Bonferroni method. The level of significance was established at p<0.05. Results: The mean changes between the points in time yielded significant differences for both molar and premolar transverse measurements between T1 and T2 (p<0.05) and between T1 and T3 (p<0.05). When evaluating the effect of maxillary expansion on the amount of buccal alveolar bone, a decrease between T1 and T2 and an increase between T2 and T3 were found in the buccal bone thickness of both the maxillary first premolars and maxillary first molars. However, these changes were not significant. Similar changes were observed for the angular measurements. Conclusion: RME resulted in non-significant reduction of buccal bone between T1 and T2. These changes were reversible in the long-term with no evident deleterious effects on the alveolar buccal bone.

Study on the optimum operation system of Sequencing Batch Reactor (연속 회분식 반응조의 최적 운전시스템에 관한 연구)

  • Eom, Tae Kyu;Ko, Eun Joo
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.13 no.4
    • /
    • pp.54-61
    • /
    • 1999
  • SBR process used to evaluate the removal of organics, nitrogen and phosphorus on the basis of a report of research on a precedence at various operation cycle and condition change. Effluent concentration of COD were 50mg/l, 50mg/l, 90mg/l respectively, The removal rates of COD were nearly over 95% at Run 1, 2 and 4. But at Run 3, Effluent concentration of COD was 255.0mg/l, The removal rate of COD was 87% at Run 3. As Oxic/Anoxic rate was fixed and operating cycle of Oxic/Anoxic was changed, the removal rates of T-N were 74.7%, 46.9%, 28.5%, 63.3% respectively at Run 1~4. The case of Run 1 was best result. The removal rates of T-P was appeared in proportion to T-N removal rates and rest of $NO_2-N$. The removal rates of T-P were 51.2%, 35.5%, 41.5%, 51.9% respectively. The removal rates of COD, T-N, T-P were influenced on the change of SBR operation cycle. As organic loading rate was $1.43kgCOD/m^3day$ and C/N ratio was 3.0, operation cycle of Run 1 was best condition of T-N removal rates and T-P removal.

  • PDF

Poly-Si Thin Film Solar Cells by Hot-wire CVD

  • Lee, J.C.;Chung, Y.S.;Kim, S.K.;Yoon, K.H.;Song, J.S.;Park, I.J.;Kwon, S.W.;Lim, K.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.07b
    • /
    • pp.1034-1037
    • /
    • 2003
  • Microcrystalline silicon(c-Si:H) thin-film solar cells are prepared with intrinsic Si-layer by hot wire CVD. The operating parameters of solar cells are strongly affected by the filament temperature ($T_f$) during intrinsic layer. Jsc and efficiency abruptly decreases with elevated $T_f$ to $1400^{\circ}C$. This deterioration of solar cell parameters are resulted from increase of crystalline volume fraction and corresponding defect density at high $T_f$. The heater temperature ($T_h$) are also critical parameter that controls device operations. Solar cells prepared at low $T_h$ ($<200^{\circ}C$) shows a similar operating properties with devices prepared at high $T_f$, i.e. low Jsc, Voc and efficiency. The origins for this result, however, are different with that of inferior device performances at high $T_f$. In addition the phase transition of the silicon films occurs at different silane concentration (SC) by varying filament temperature, by which highest efficiency with SC varies with $T_f$.

  • PDF

Characterization of ${\mu}c$-Si:H Thin-film Solar Cells by Hot-wire CVD

  • Lee, J.C.;Chung, Y.S.;Kim, S.K.;Youn, K.H.;Song, J.S.;Park, I.J.;Kwon, S.W.;Lim, K.S.
    • Proceedings of the KIEE Conference
    • /
    • 2003.07c
    • /
    • pp.1598-1600
    • /
    • 2003
  • Microcrystalline silicon(c-Si:H) thin-film solar cells are prepared with intrinsic Si-layer by hot wire CVD. The operating parameters of solar cells are strongly affected by the filament temperature ($T_f$) during intrinsic layer. Jsc and efficiency abruptly decreases with elevated $T_f$ to $1400^{\circ}C$. This deterioration of solar cell parameters are resulted from increase of crystalline volume fraction and corresponding defect density at high $T_f$ The heater temperature ($T_h$) are also critical parameter that controls device operations. Solar cells prepared at low $T_h$ (<$200^{\circ}C$) shows a similar operating properties with devices prepared at high $T_f$, i.e. low Jsc, Voc and efficiency. The origins for this result, however, are different with that of inferior device performances at high $T_f$. In addition the phase transition of the silicon films occurs at different silane concentration (SC) by varying filament temperature, by which highest efficiency with SC vanes with $T_f$.

  • PDF

Analysis of Electromyographic Activities of Erect Spinae at Different Height of Table during Ultrasound Therapy Work (물리치료사의 초음파 작업시 테이블 높이에 따른 척추기립근의 근전도 활동 분석)

  • Kim, Chung-Yoo;Kang, Jong-Ho
    • Journal of the Korean Society of Physical Medicine
    • /
    • v.8 no.3
    • /
    • pp.289-294
    • /
    • 2013
  • PURPOSE: The purpose of this study was to examine differences in erect spinae activities at different height of table during ultrasound therapy in order to propose a optimum work environment. METHODS: Twenty five healthy adult males and females volunteered to participate in this study. EMG signals of both erector spinae(T10, T12, L2, L4) were recorded throught the surface electromyography system at different height of table(45cm, 56.2cm, 67.5cm) during ultrasound therapy work. RESULTS: The higher table heights was, the lower %RVC of the T10, T12, L2, L4 erect spinae at both sides. The left and right T10, T12 and the left L4 showed significant differences. The lower the spinal level was, the higher %RVC of both erect spinae at 45cm, 56.2cm, 67.5cm. The left erect spinae at 56.2cm, right erect spinae at 45cm, 67.5cm showed significant differences. CONCLUSION: The muscle activities of both erect spinae decreased at higher table height and increased lower spinal level. We identified lower table height are risk factor of spine work related musculoskeletal disorders.

Effects of Ad libitum and Restricted Feeding of Concentrates on Body Weight Gain, Feed Intake and Blood Metabolites of Hanwoo Steers at Various Growth Stages (배합사료의 자유 및 제한 급여가 거세한우의 성장단계별 증체, 사료섭취량 및 혈중 대사물질에 미치는 영향)

  • Kwon, E.G.;Hong, S.K.;Seong, H.H.;Yun, S.G.;Park, B.K.;Cho, Y.M.;Cho, W.M.;Chang, S.S.;Shin, K.J.;Paek, B.H.
    • Journal of Animal Science and Technology
    • /
    • v.47 no.5
    • /
    • pp.745-758
    • /
    • 2005
  • Two hundred fifty eight Hanwoo steers were used in a completely randomized design experiment to determine the effects of ad libitum or restricted feeding of concentrates on body weight(BW) gain, feed intake, blood metabolites and hematological parameters. Steers were assigned at 6 months of age to feeding groups of ad libitum(T1) or restricted(T2) by 18 months of age. Steers in both groups were fed ad libitum from 19 months of age. The restrictive feeding levels were 1.2-1.5% of BW for the growing period and 1.7-1.8% of BW for the early fattening period. Average daily gains were significantly higher in T1 than in T2 from 10 to 14 months of age, but were significantly higher in T2 than in T1 from 20 to 24 months of age(p<0.05). Total dry matter intake(DMI) was higher in T1 than in T2 at 10, 12 and 16 months of age(p<0.05). Total DMI of T2 was higher than that of T1 at 22 months of age(p<0.05). Feed conversions were significantly lower in T2 than in T1 from 20 to 30 months of age(p<0.05). Blood albumin concentrations were significantly higher in T2 than in T1 at 12, 14, 16 and 18 months of age. Blood triglyceride concentrations were significantly higher in T1 than in T2 at 14 and 16 months of age(p<0.05). Blood inorganic phosphorus concentrations were significantly higher in T2 compared with T1 at 8, 10, 16 and 22 months of age(p<0.05). Mean corpuscular volume and mean corpuscular hemoglobin were significantly lower in T2 than in T1 from 8 to 12 months of age(p<0.05), but those were significantly higher in T2 than T1 from 10 months to 12 months of age(p<0.05). Present results may indicate that the restricted feeding for the growing period does not show adverse effects on body weight gain with better feed conversion for the following late fattening period.

Flavobacterium jocheonensis sp. nov., Isolated from Marine Green Alga Ulva pertusa

  • Choi, Ha Ri;Park, So Hyun;Heo, Moon Soo
    • Journal of Microbiology and Biotechnology
    • /
    • v.29 no.8
    • /
    • pp.1266-1272
    • /
    • 2019
  • A bacterial strain, labeled $UR11^T$, was isolated from green alga Ulva pertusa collected from Jeju Island, Korea. $UR11^T$ was identified as a gram-negative, rod-shaped, motile by gliding and aerobic bacterial strain with yellow colonies on R2A plates. The strain $UR11^T$ grew over at a temperature range of $10^{\circ}C$ to $30^{\circ}C$ (optimally at $25^{\circ}C$), a pH range of 6.0-11 (optimally at pH 7.0) and a Nacl range of 0.5-5% Nacl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain $UR11^T$ was a member of the genus Flavobacterium. Strain $UR11^T$ shared close similarity with F. jejuensis $EC11^T$ (98.0%) F. jumunjinense $HME7102^T$ (96.1%), F. haoranii $LQY-7^T$ (95.3%), F. dongtanense $LW30^T$ (95.1%), and F. ahnfeltiae 10Alg $130^T$(94.9%). The major fatty acids (>5%) were $iso-C_{15:0}$ (33.9%), $iso-C_{15:1}$ G (12.4%), $iso-C_{17:0}$ 3-OH (9.0%), $isoC_{16:0}$ (7.0%) and $iso-C_{15:0}$ 3-OH (6.3%). The major polar lipids were phosphatidylethanolamine, seven unknown aminolipids, two unknown aminopolarlipids and two unknown lipids. DNA-DNA hybridization value was 58% at strain $UR11^T$ with F. jejuensis $EC11^T$. Based on phenotypic, chemotaxonomic and phylogenetic evidence, strain $UR11^T$ represents a novel species of the genus Flavobacterium, for which the name Flavobacterium jocheonensis sp. nov. is proposed. The type strain is Flavobacterium jocheonensis is $UR11^T$ (=KCTC $52377^T$ =JCM $31512^T$).

A Study on Characteristics of Spoilage Bacteria Isolated from Packed Tofu (포장두부에서 분리한 부패세균의 특성에 관한 연구)

  • 강선희;이용욱;오원택
    • Journal of Food Hygiene and Safety
    • /
    • v.13 no.4
    • /
    • pp.383-387
    • /
    • 1998
  • This study was undertaken with packed tofu products to serve as a basic source for sanitary control of tofu production by detecting spoilage bacteria in tofu from which are isolated, investigating heat-resistance and growth characteristics of spoilage bacteria. Isolated strains were confirmed as relevant strains in tofu spoilage, and Strain No. Tl, T2 show 92% probability to be Enterobacter amnigenus, and 96% to be Flavobacterium indologenes according to the result of identifYing strains by using Vitek system. Both strains had high viability at $35^{\circ}C$, pH 6.5. In the heat-resistance test of isolated strains, Enterobacter amnigenus Tl was treated for 2 mins, the number remained 56.3% of the initial number at $60^{\circ}C$, 37.8% at $70^{\circ}C$, 34.0% at $80^{\circ}C$ and 22.2% at $90^{\circ}C$, and Flavobacterium indologenes T2 was treated for 2 mins, the number remained 74.8% of the initial number at $60^{\circ}C$, 65.7% at $70^{\circ}C$, 37.8% at $80^{\circ}C$ and 9.3% at 90^{\circ}C$.

  • PDF

A study of upper airway dimensional change according to maxillary superior movement after orthognathic surgery (양악 수술 시 상악골 상방 이동에 따른 상기도 변화)

  • Kim, Yong-Il;Park, Soo-Byung;Kim, Jong-Ryoul
    • The korean journal of orthodontics
    • /
    • v.38 no.2
    • /
    • pp.121-132
    • /
    • 2008
  • Objective: The purpose of this study was to evaluate the upper airway dimensional change according to maxillary superior movement after orthognathic surgery and to identify the relationship between the amount of maxillary movement and upper airway dimensional changes. Methods: The samples consisted of 24 adult patients (9 males and 15 females) who had a skeletal discrepancy and had received presurgical orthodontic treatment. They underwent Le Fort I superior impaction osteotomy and mandibular setback surgery. Cephalometric x-rays were taken at 3 stages - T0 (before orthognathic surgery), T1 (just or within 2 weeks after orthognathic surgery), T2 (6 months after surgery) Results: 1, Pharyngeal airway space (PAS (R)-nasopharynx) was decreased after surgery (T1) but recovered at 6 months after surgery; 2, Pharyngeal airway space (PAS (NL)-palatal plane) was increased after surgery and at 6 months after surgery; 3, Pharyngeal airway space (PAS (OL)-occlusal plane) was increased at T1 and was decreased at T2; 4, Soft palate thickness was increased at T1 but it became the same or thinner at T2; 5, There is no statistically significant relation between the amount of maxillary superior movement and pharyngeal airway space. Conclusions: These findings suggested that the maxillary superior movement of about an average of $4.40{\pm}1.14 mm$ did not affect upper pharyngeal airway space changes.