Low Less Etchless Silicon Waveguides

Fabrication of silicon waveguides without performing any silicon etching is demonstrated. The silicon waveguides are defined by the concept of “selective oxidation”. The experiment demonstrates that the waveguides formed by selective oxidation produce ultra-smooth sidewalls since etching of silicon is avoided. The Si etching usually creates damage from ion bombardment and chemical reactions that occur during plasma etching. The final waveguide also demonstrates very low light low based on optical testing which shows that no light scattering is observed. The final waveguide has a width of 1.5 μm and a height of ~80 nm. The GCA stepper is utilized to expose the SOl sample. In order to do this an alternative method of exposing a wafer piece is needed which excludes the use of a special wafer pedal. This method is also demonstrated in the paper

Momentum transfer in climbing-film flow in an annular duct

Momentum transfer in an annular duct with upward gas-Iiquid flow was studied under the condition that the liquid flowed as a film only on the inner core of the annulus, the outer wall remaining dry. Previous workers have studied climbing and falling liquid films in tubes or on vertical planes. With this type of apparatus it is very difficult to study pressure losses, gas velocity profiles, and the structure of the climbing film. The difficulty has been overcome by forming a liquid film on the inner core and maintaining a dry outer wall of an annular duct. The column consists of a three-inch I.D. outer tube with a concentric one-inch O.D. inner core. The inner tube was supported laterally by sets of streamlined centering screws. The total length of the column was about 35 feet and the test section was 20 feet long. All measurements were made at two stations, the first was 76 inches from the liquid injector, the second 154 inches from the liquid injector. The liquid injector is a porous stainless steel cylinder with one inch O.D. and two inch length. The air flow rates varied from 170 cfm to 410 cfm at 1 atmosphere pressure and 68° F temperature. The water flow rates used were 0.47 lbm/min and 0.79 lbm/min. The study has two major divisions. First division is the study of the mechanics of the air flow in the annulus as it is affected by the presence of the climbing film of liquid. This portion of the study involves an investigation of velocity profiles, the point of maximum velocity, friction losses, and the role of capillary waves in the annular flow. It was found that: 1) the pressure loss for climbing film flow in an annulus can be predicted by the Lockhart and Martinelli correlation for two-phase flow in tubes, 2) the capillary waves of the climbing film affect only the location of the point of maximum air velocity and the air velocity profile at the inner portion of the annulue, 3) the location of the point of maximum air velocity shuts to the outer wall as water film is introduced, 4) the air velocity profiles in the inner portion of the annulus with the film present, plotted as u⁺ versus y⁺, are shifted downward, relative to those for annular flow without the film, although they have same slope. The second part is the study of the mechanics of flow of a climbing water film which has a solid wall as one boundary and highly turbulent air stream as the other. The mean film thickness, wave length, and amplitude of the climbing film were measured by a photographic method. This method gave good results in the measurement of mean film thickness at the lower and moderate air velocities. However, the wave length and amplitude determined by this method have only a qualitative significance, because of the irregularity of wave shapes. With increasing air flow rates, the film thickness, wave length, and amplitude decreased. Generally the ratio of wave length to amplitude varied between 20 to 30. As a first approximation, Kapitza's theory of wave formation in the vertical plane with downward flow, based on laminar conditions, was extended to the climbing film in an annular duct in order to obtain an expression for the mean film thickness, the velocity profile of liquid film, and the wave length. Comparison between the prediction and the experiment was found to be reasonably good, The mean film thickness data for climbing film flow in an annulus was correlated with the Lockhart and Martinelli parameters, R[subscript L] and X, and was compared with the correlation for climbing film flow in a tube. If a unique correlation for climbing film flow in both tubes and annuli exists (this is the original proposal of Lockhart and Martinelli), it would appear that the region in the vicinity of x = 0.01 is a transition region. More data at high water flow rates are necessary to reach a general conclusion concerning the correlation

The Effect of Public Officers Work-Life Balance on Job Satisfaction Differences between Men and Women

We performed an empirical analysis based on data from a questionnaire survey that Korean government officers participated in about the effects of worklife balance (WLB) on job satisfaction in order to whether unpaid labor such as housework had a moderating effect on job satisfaction. The subjective balance of an individuals time input in work and life was used to measure WLB. We find that WLB has a positive and significant effect on job satisfaction and that there is no statistically significant gender difference. However, the WLB effect on married female officers is smaller than that on single female officers, while it is not significant for male public officers. Child-rearing has a negative moderating effect on womens job satisfaction, although this was not statistically significant. This result suggests that the effect of the household work burden that marriage as well as child care brings is a variable that policy makers should be keep in mind in developing WLB policies

Production of transgenic rice (indica cv. MR219) overexpressing Abp57 Gene through Agrobacterium-mediated transformation

Agrobacterium-mediated transformation of indica rice is undoubtedly a challenging task due to the rice recalcitrant nature to transformation process. Therefore, optimization of the transformation protocol is important for specific indica rice cultivar to ensure effectiveness of the transformation. In this study, crucial parameters affecting Agrobacterium-mediated transformation were optimized to obtain transgenic rice of local rice cultivar (indica MR219). Embryogenic calli were chosen for inoculation with Agrobacterium tumefaciens strain LBA4404 harbouring a binary vector pH2GW7-ABP57 containing gene of interest, Auxin binding protein 57 (Abp57). The parameters that have been optimized were the immersion time, co-cultivation period, acetosyringone concentration and co-cultivation temperature. A total of four days co-cultivation period and 30 min immersion of embryogenic callus are optimum for the transformation of MR219 with transformation efficiency of 26.4% and 16.0%, respectively. Acetosyringone at 200 μM and co-cultivation at 28°C also gave the highest transformation efficiency (14.4 and 18.4%, respectively). Meanwhile, inclusion of 20 g/L maltose+20 g/L sorbitol into the regeneration media has significantly improve the transformed somatic embryos growth and increase the regeneration efficiency up to 40.0%. The results of polymerase chain reaction (PCR) and reverse transcription-polymerase chain reaction (RT-PCR) indicated that the transgene was successfully integrated and overexpressed in transgenic rice of MR219. In conclusion, significant improvement in transformation efficiency for rice cv. MR219 has been obtained by using the optimised protocol for transformation and regeneration developed in this study

LOCATION DESIGN FOR EMERGENCY MEDICAL CENTERS BASED ON CATEGORY OF TREATABLE MEDICAL DISEASES AND CENTER CAPABILITY

Abstract: Through the development of a mathematical model, this paper studies the location design of emergency medical centers in a given region under the closest assignment rule. It is assumed that the capability and capacity to treat various categories of treatable medical diseases are provided for each candidate medical center. Once a candidate center is selected, it will receive subsidies from the government to support the offering of medical services at a competitive cost. It is further assumed that the number of patients occurring at each patient group node during a unit time is known along with the categories of their diseases. With the objective of minimizing the total subsidies paid, we select from among the candidate emergency medical centers subject to a maximum total budget and minimum desired survival rate constraints. The CPLEX version 12.1 solver is used to obtain an optimal solution. Simulation studies are conducted to assess the performance of our deterministic models in a stochastic context

Prediction of Alzheimer's disease pathophysiology based on cortical thickness patterns

AbstractIntroductionRecent studies have shown that pathologically defined subtypes of Alzheimer's disease (AD) represent distinctive atrophy patterns and clinical characteristics. We investigated whether a cortical thickness–based clustering method can reflect such findings.MethodsA total of 77 AD subjects from the Alzheimer's Disease Neuroimaging Initiative 2 data set who underwent 3-T magnetic resonance imaging, [18F]-fluorodeoxyglucose-positron emission tomography (PET), [18F]-Florbetapir PET, and cerebrospinal fluid (CSF) tests were enrolled. After clustering based on cortical thickness, diverse imaging and biofluid biomarkers were compared between these groups.ResultsThree cortical thinning patterns were noted: medial temporal (MT; 19.5%), diffuse (55.8%), and parietal dominant (P; 24.7%) atrophy subtypes. The P subtype was the youngest and represented more glucose hypometabolism in the parietal and occipital cortices and marked amyloid-beta accumulation in most brain regions. The MT subtype revealed more glucose hypometabolism in the left hippocampus and bilateral frontal cortices and less performance in memory tests. CSF test results did not differ between the groups.DiscussionCortical thickness patterns can reflect pathophysiological and clinical changes in AD

Effects of Textural Properties on the Response of a SnO2-Based Gas Sensor for the Detection of Chemical Warfare Agents

The sensing behavior of SnO2-based thick film gas sensors in a flow system in the presence of a very low concentration (ppb level) of chemical agent simulants such as acetonitrile, dipropylene glycol methyl ether (DPGME), dimethyl methylphosphonate (DMMP), and dichloromethane (DCM) was investigated. Commercial SnO2 [SnO2(C)] and nano-SnO2 prepared by the precipitation method [SnO2(P)] were used to prepare the SnO2 sensor in this study. In the case of DCM and acetonitrile, the SnO2(P) sensor showed higher sensor response as compared with the SnO2(C) sensors. In the case of DMMP and DPGME, however, the SnO2(C) sensor showed higher responses than those of the SnO2(P) sensors. In particular, the response of the SnO2(P) sensor increased as the calcination temperature increased from 400 °C to 800 °C. These results can be explained by the fact that the response of the SnO2-based gas sensor depends on the textural properties of tin oxide and the molecular size of the chemical agent simulant in the detection of the simulant gases (0.1–0.5 ppm)