Small angle neutron scattering (SANS) studies of diffusion in bulk polystyrene near the glass transition temperature (Tg)

Ultraslow diffusion in bulk polymers has been measured by SANS. The experiment begins by measuring scattering from heterogeneous specimens containing domains of protonated‐and deuterated‐polymers at temperatures far below Tg. The samples are subsequently held [annealed] above Tg for a known time‐interval, then cooled below Tg where SANS is measured again. Scattering changes, from before to after annealing, are analysed to obtain diffusion coefficients. The recent Summerfield ‐ Ullman procedure is used to deconvolute portions of the scattering curve that decrease and increase with annealing time. Because of SANS sensitivity to small distances, the method yields D ≈ 10−18 to 10−15 cm2/s after annealing times of 1–24 h. Data analysis is complicated by “smearing effects” which produce apparent Q‐dependent diffusion coefficients. Representative experimental results on polystyrene at 108°–130°C are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112190/1/19880150127_ftp.pd

A Performance Evaluation of Introducing Balanced Scorecard to High-tech Related Industries in Taiwan

Balanced Scorecard (BSC) has become the most desirable performance evaluation tool for industries in Taiwan; however, difficulty or bad performance of system introduction has occurred due to an incomplete understanding of the implementation approaches and correct objectives of the BSC system, causing the risk of cost loss. Two domestic high-tech companies in the high-tech related industry were served as the object of study in this research. The contents of four perspectives of the BSC were converted to twenty key performance evaluation indicators in terms of modern business administration as the variables in the research. Based on the DMAIC model, the importance and satisfaction of BSC implementation factors in high-tech related industry are defined first. The performance indices of satisfaction and importance of implementing BSC are standardized by fuzzy methods for evaluation and a performance matrix with the target line and upper and lower performance control lines are established. Management can analyze the performance level and compare the performance indices and matrixes of two companies after introducing BSC according to the coordinates of satisfaction and importance of implementation factors in the matrixes. These two-dimension matrices will then be converted to one-dimension coordinates for cross performance matrices of four quadrants. Next, performance improvement strategies will be devised in accordance with the aspects of the theory of constraints. After carrying out improvement strategies, the cross performance matrix will be constructed to verify the effect and ascertain the factors of bad performance. In this way, improvement strategies can be re-devised and the most appropriate distribution of resources will be made to sustain the optimum state of ability and cost during the process of introducing the BSC system. Requirements for a short period of time and low cost to evaluate the performance of BSC introduction can be met via this simple and convenient evaluation model presented in this research. Resources will be invested to enhance satisfaction for the implementation factors of high importance and low satisfaction. Likewise, resources will be adjusted to reduce the cost of system introduction for the implementation factors of low importance and high satisfaction. As a result, the time efficiency of introducing the BSC system will be promoted effectively

Provider Attitudes and Practice Patterns for Direct-Acting Antiviral Therapy for Patients With Hepatocellular Carcinoma

Background & Aims: Direct-acting antivirals (DAAs) are effective against hepatitis C virus and sustained virologic response is associated with reduced incidence of hepatocellular carcinoma (HCC). However, there is controversy over the use of DAAs in patients with active or treated HCC and uncertainty about optimal management of these patients. We aimed to characterize attitudes and practice patterns of hepatology practitioners in the United States regarding the use of DAAs in patients with HCC. Methods: We conducted a survey of hepatology providers at 47 tertiary care centers in 25 states. Surveys were sent to 476 providers and we received 279 responses (58.6%). Results: Provider beliefs about risk of HCC recurrence after DAA therapy varied: 48% responded that DAAs reduce risk, 36% responded that DAAs do not change risk, and 16% responded that DAAs increase risk of HCC recurrence. However, most providers believed DAAs to be beneficial to and reduce mortality of patients with complete response to HCC treatment. Accordingly, nearly all providers (94.9%) reported recommending DAA therapy to patients with early-stage HCC who received curative treatment. However, fewer providers recommended DAA therapy for patients with intermediate (72.9%) or advanced (57.5%) HCC undergoing palliative therapies. Timing of DAA initiation varied among providers based on HCC treatment modality: 49.1% of providers reported they would initiate DAA therapy within 3 months of surgical resection whereas 45.9% and 5.0% would delay DAA initiation for 3–12 months and >1 year post-surgery, respectively. For patients undergoing transarterial chemoembolization (TACE), 42.0% of providers would provide DAAs within 3 months of the procedure, 46.7% would delay DAAs until 3–12 months afterward, and 11.3% would delay DAAs more than 1 year after TACE. Conclusions: Based on a survey sent to hepatology providers, there is variation in provider attitudes and practice patterns regarding use and timing of DAAs for patients with HCC. Further studies are needed to characterize the risks and benefits of DAA therapy in this patient population