2,404 research outputs found
Characteristics of an inductively coupled plasma source using a parallel resonance antenna
No full textWe report experimental results from a new inductively coupled plasma (ICP) source for next generation plasma processing. The new source, which we have called a parallel resonance antenna, is designed to reduce problems caused by a large antenna inductance and to improve the plasma density uniformity for large area processing. The key techniques of this new source are reduction of the inductance of the antenna system in parallel connection and induction of LC-resonance with external capacitance variation. The parallel connection of the coils reduces the antenna inductance and the low inductance decreases the antenna voltage. In addition, it allows the antenna size to be easily scaled up to a 300 mm process. An external variable capacitor is connected in series to an outer coil to obtain good plasma uniformity. Because the current distribution in each coil is adjusted by varying the external capacitance, the radial profile of the plasma density can be controlled. The LC-resonance effect is elucidated by observing the reduction in the antenna voltage and variation in the current in the outer coil. We can control the radial plasma density with 3% uniformity by only varying the external capacitance with various discharge powers and pressures. The plasma parameters measured by the rf-compensated Langmuir probe show properties similar to those of general ICPs. These results are consistent with previous modelling work
Stimulatory effects of amino aciAppl. Environ.ds and oleic acid on poly(3-hydroxybutyric acid) synthesis by recombinant Escherichia coli
No full textAddition of cysteine, isoleucine, methionine, or proline promoted poly(3-hydroxybutyric acid) [PHB] synthesis by recombinant Escherichia coli more than two-fold. Oleic acid also enhanced PHB synthesis more than three-fold. A PHB concentration of 70 g/l could be obtained by fed-batch culture of recombinant E. coli in a defined medium supplemented with small amounts of isoleucine, methionine, and proline. The stimulatory effects of amino acids and oleic acid on PHB synthesis seems to be due to the availability of more acetyl-CoA and/or NADPH
Global lock escalation in database management systems
No full textSince database management systems (DBMSs) have limited lock resources, transactions requesting locks beyond the limit must be aborted, degrading the performance abruptly. Lock escalation can be effectively used in such circumstances to alleviate the problem. Many lock escalation methods have been proposed and implemented in commercial DBMSs. However, they have certain problems due to the local nature of their decisions on when to execute lock escalation. In this paper, we propose a new lock escalation method, global lock escalation. that makes such decision globally based on the total number of locks. Through extensive simulation, we show that the global lock escalation method outperforms the existing ones significantly. Especially, we show that the number of concurrent transactions allowable increases by 2-16 times. We believe our method can be easily implemented in the commercial DBMSs enhancing the performance significantly under excessive lock requests. (C) 2002 Elsevier Science B.V. All rights reserved
Factor Structure and Reliability of the Posttraumatic Cognitions Inventory in Korean Female Victims of Sexual Violence
No full textTrauma-related cognitions play an important role in formation and persistence of posttraumatic stress symptoms. This study investigated the psychometric properties of the Korean version of the Posttraumatic Cognitions Inventory (PTCI) in a sample of 227 females who had experienced sexual violence. Data were collected from victims who sought victim support services following sexual violence between 2011 and 2015. The Impact of Event Scale-Revised, Beck Depression Inventory, and Beck Anxiety Inventory were used to measure posttraumatic stress disorder severity, depression, and anxiety, respectively. The three-factor solution of the PTCI (SELF, WORLD, BLAME) was supported; however, it was necessary to remove five items from the original 33-item scale. The 28-item PTCI displays good internal consistency, concurrent validity, and discriminant validity. SELF and WORLD subscales correlated with trauma symptom severity, controlling depression and anxiety. This is the first study to investigate factor structure and psychometric properties of the Korean version of the PTCI with female victims of sexual violence, which demonstrated that 28-item version of PTCI is an acceptable assessment measure of examining trauma-related cognitions
Enhanced production of long-chain polyunsaturated fatty acids (LC-PUFAs) by overexpressing heterologous and endogenous fatty acid elongase genes in Nannochloropsis salina
No full textEnhancing the production of long-chain polyunsaturated fatty acids (LC-PUFAs) in Nannochloropsis salina by overexpressing the heterologous and endogenous fatty acid elongase genes
No full textAssault-related Factors and Trauma-related Cognitions Associated with Post-traumatic Stress Symptoms in High-distress and Low-distress Korean Female Victims of Sexual Assault
Get PDFBACKGROUND: Information about the factors involved in the progress of both high distressed and low distressed victims in the early days after a sexual assault are needed to provide effective intervention for victims of sexual assault. In this study, we examined the relationship among posttraumatic stress disorder (PTSD) symptoms, assault-related factors and trauma-related cognitions in Korean female victims of sexual assault.
METHODS: For this study, we retrospectively investigated the records of 94 female victims from the Sunflower Center for Women and Children Victims of Violence at the Ajou University Hospital in Korea. Demographic characteristics and the features of the sexual assault, post-traumatic stress symptoms, and trauma-related cognition were obtained from data recorded at the initial assessment. One month after the initial assessment, victims were contacted by telephone and their PTSD symptom severity was re-evaluated. The sample of 94 participants were divided into two groups depending on the PTSD symptom scale scores at initial assessment: High-distress group and Low-distress group.
RESULTS: Repeated-measured analyses of variance revealed that the high-distress group showed a decrease in PTSD symptom severity over the month, while the low-distress group did not show significant change of PTSD symptom severity. In correlation analysis, negative thoughts and beliefs about the assault were strongly correlated with PTSD symptom severity one month later in both the low-distress and high-distress groups.
CONCLUSION: Our results suggest that trauma-related cognitions seem to play an important role in the maintenance of PTSD both of high-distress and low-distress groups, and that effective intervention will need to address these cognitive factors
Selective extraction of succinic acid from binary mixture of succinic acid and acetic acid
No full textIn production of succinic acid by fermentation, succinic acid and acetic acid are co-produced. To purify the succinic acid from binary-acid mixture of succinic acid and acetic acid, the tertiary amine-based extraction was used. In 1-octanol, the selectivity for succinic acid was proportional to the chain length of tertiary amine. But, the distribution of acids into organic phase was low in n-heptane. These results are due to the different degree of intramolecular hydrogen bonding of succinic acid and hydrophobicity of each acid
Selective extraction of acetic acid from the fermentation broth produced by Mannheimia succiniciproducens
No full textAcetic acid is by-product from fermentation processes for producing succinic acid using Mannheimia succiniciproducens. To obtain pure succinic acid from the final fermentation broth, acetic acid was selectively removed based on the different extractability of succinic acid and acetic acid with pH using tri-n-octylamine (TOA) as extractant. When successive batch extractions were performed using 0.25 mol TOA kg(-1) dissolved in 1-octanol at pH 5, the mol ratio of succinic acid to acetic acid before extraction was 4.9 and the final ratio after the fourth batch was 9.4.The authors are grateful to the Center for Advanced
Bioseparation Technology Research (BSEP, KOSEF)
for the funding
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