Synthesis and Properties of Fluorinated Polyimides from Rigid and Twisted Bis(Trifluoromethyl)Benzidine for Flexible Electronics

Fluorinated polyimides were prepared from the twisted benzidine monomer containing two trifluoromethyl (CF3) groups on one aromatic ring. The diamine monomer having a rigid and nonplanar structure was polymerized with typical dianhydride monomers including BPDA, BTDA, ODPA, 6-FDA, and PMDA, to obtain the corresponding polyimides. Most polyimides are soluble in organic solvents due to their twisted chain structure and can be solution cast into flexible and tough films. These films have a UV-vis absorption cut-off wavelength at 354–398 nm and a light transparency of 34–90% at a wavelength of 550 nm. They also have tensile strengths of 92–145 MPa and coefficients of thermal expansion (CTE) of 6.8–63.1 ppm/°C. The polymers exhibited high thermal stability with 5% weight loss at temperatures ranging from 535 to 605°C in nitrogen and from 523 to 594°C in air, and high glass temperature (Tg) values in the range of 345–366°C. Interestingly, some of the soluble polyimides showed thermo-responsive behaviors in organic solvents presumably due to the multiple hydrogen bondings with unsymmetrically positioned two CF3 groups along the polymer chains

Decision Making System For Water Production And Treatment Process As Well As Blending Of Multiple Water Sources Gat Micro Grid

Usage of water is on rise worldwide as a result of population growth and urbanization. Accordingly, conflicts are created to secure the water source among nations. Water production and treatment expense also incurred too much. To solve this problem, decision making system for blending of multiple water source, water production and treatment process are needed in order to provide secured water resources, customized water quantity and quality. Multiple water sources are classified into surface water, underground water, treated waste water, rain water, seawater and Brackish Water. Each of them can be treated to meet demand of customized water quantity and quality such as drinking water, industrial water and agricultural water. At Micro Grid, decision making system for water treatment process has three steps. First is the water blending decision making program to make best decisions on type, quantity and quality of water by anticipating energy consumption and fluctuating water quantity and quality. Second of all, we provide a process operational program that allows us to assess the quantity and quality of produced water, operating and controlling each process to produce customized water that meets our clients’ needs. Last step is that we conduct the process diagnosis program which can lead solutions and alternatives for errors that can arise during detailed process phases since we are fully capable of measuring quality and quantity of water .Those are set by both water treatment process and application of the formula which is generated by the nonlinear equation on influence factors during each unit process. Achknowledgement This research was supported by a grant (12-TI-C01) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government

Air Bubbles Mimic Disc Herniation in MRI after Cervical Epidural Block

Magnetic resonance image (MRI) is the most sensitive imaging test of the spine in routine clinical practice. Unlike conventional x-ray examinations and computed tomography scans, high-quality magnetic resonance images can be assured only if patients are able to remain perfectly still. However, some patients find it uncomfortable to remain still because of pain. In that condition, interlaminar cervical epidural injections can reduce pain and allow the procedure. When using air with the "loss of resistance" technique in epidural injections to identify the epidural space, there is the possibility of injected excessive air epidurally to mimic a herniated disc. We describe a case report of epidural air artifact in a cervical MRI after cervical epidural injections

Hydrauric Analysis On Water Stage Change Along The Submerged Weir And Tides Effect In Han River

Sinkok submerged weir in Han river, Seoul Korea was built in early 1980’s for the purpose of water level maintenance and protection from sea water intrusion from the estuary. Its length is almost 1 km and 2.4 meter height which has two composite structures of rigid and movable weir. Huge wetland developed as the results of weir construction just down to the weir. However, recently social conflicts for the weir removal occurred for the river rehabilitation and aqua-eco system recover. This study focused on hydraulic analysis, especially water level changes in terms of with and without submerged weir along the tides where the height has 9 meters difference between ebb and high tide. HEC-RAS for the 1-D simulation and SMS for 2-D analysis were used covering 25 km river length and tributaries. Tides time series records and discharge records from upstream dam of 1-year were and 2 submerged weirs as well as 25 bridges were considered in boundaries. Hydraulic data in the 4 gauging stations were collected for the model calibration. Water level changes were reviewed along 4 cases – with/without weir and flood/dry season - The results showed that more than 3 meter difference of water surface fluctuation along up and downstream including wetland as tide changes in a day. The wetland dimension and water quality were also affected along the water level. The contraction of wetland area might cause the changes of aqua habitat to plants and animals. These results make it difficult to make a decision of removal of the submerged weir. A comprehensive analysis of not only hydraulic but also water quality and environmental effect should be considered. Achknowledgement : This research was supported by a grant (12-TI-C01) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean governmen

A Double Mutation of the Ryanodine Receptor Type 1 Gene in a Malignant Hyperthermia Family with Multiminicore Myopathy

Background and PurposeᄏAt least 100 Ryanodine receptor type 1 (RYR1) mutations associated with malignant hyperthermia (MH) and central core disease (CCD) have been identified, but 2 RYR1 mutations accompanying multiminicore myopathy in an MH and/or CCD family have been reported only rarely. MethodsᄏFifty-three members of a large MH family were investigated with clinical, histopathologic, RYR1 mutation, and haplotyping studies. Blood creatine kinase (CK) and myoglobin levels were also measured where possible. ResultsᄏSequencing of the entire RYR1 coding region identified a double RYR1 mutation (R2435H and A4295V) in MH/CCD regions 2 and 3. Haplotyping analysis revealed that the two missense heterozygous mutations (c.7304G>A and c.12891C>T) were always present on a common haplotype allele, and were closely cosegregated with histological multiminicores and elevated serum CK. All the subjects with the double mutation showed elevated serum CK and myoglobin, and the obtained muscle biopsy samples showed multiminicore lesions, but only two family members presented a late-onset, slowly progressive myopathy. ConclusionsᄏWe found multiminicore myopathy with clinical and histological variability in a large MH family with an unusual double RYR1 mutation, including a typical CCD-causing known mutant. These results suggest that multiminicore lesions are associated with the presence of more than two mutations in the RYR1 gene.ope