bluuebunny/crossref_metadata_2025_split huggingface dataset:
INVESTIGATION OF FREQUENCY NOISE AND SPECTRUM LINEWIDTH IN SEMICONDUCTOR OPTICAL AMPLIFIER
Authors: Setiawan Putra Alexander William , Makinoshima Kazuki , Yamada Minoru , Takashima Takayoshi , Ambran Sumiaty 
Published: March 2016

The characteristics of FM noise and linewidth of semiconductor optical amplifier without facet mirrors were theoretically analyzed and experimentally confirmed. The concept of discrete longitudinal mode for the spontaneous emission was introduced as the basis of quantum mechanical characteristics, allowing the quantitative examination of noise sources. The continuously broaden output spectrum profile of the amplified spontaneous emission (ASE) was well explained as a spectrum broadening of each longitudinal mode. We found that the linewidth of the inputted signal light hardly changes by the optical amplification in the SOA. The FM noise increases proportional to square value of the noise frequency and less affected by the electron density fluctuation, the linewidth enhancement factor and the ASE. The higher FM noise in the higher noise frequency is caused by the intrinsic phase fluctuation on the optical emission. The characteristics of the linewidth and the noise frequency dependency were experimentally confirmed.
RESPONSE OF FBG-BONDED GRAPHENE PLATE AT DIFFERENT APPLIED STRESS LOCATION
Authors: Mohammed Salih Younis , Munajat Yusof , Ismail Abd. Khamim , Bakhtiar Hazri 
Published: March 2016

In this study, the response of a FBG-bonded-graphene plate at different applied stress location is demonstrated. The sensing element utilized for this purpose is a 35.9-mm FBG sensor bonded onto the surface of a graphene plate. The lateral displacement is changed with corresponding increase or decrease in the FBG’s curvature. The change in center wavelength of the reflected spectrum is almost linear, without a significant hysteresis effect. It was also observed that the sensitivity of the FBG changes for location of applied stress. Likewise, the area under the reflection curve is observed to increase with increase in strain level, indicating an increase total power reflected. This is verified by an increase in the voltage output as observed from the oscilloscope.
HYDROGEN PRODUCTION VIA CATALYST OF GREEN LASER, MOLYBDENUM AND ETHANOL
Authors: Azni Siti Radhiana , Abu Bakar Mohamad Aizat , Farhana Daing Hanum , Ab Razak Siti Noraiza , Bidin Noriah 
Published: March 2016

Electrolysis is an electrochemical process which is known as a green technology. Laser irradiation and the presence of catalyst in water electrolysis are identified as ways of improving the efficiency and increment of hydrogen production. The enhancement of hydrogen production through water electrolysis is obtained by adding molybdenum to increase the current in electrochemical cell and ethanol as an agent in photochemical reaction. In addition, diode pumped solid-state laser green laser at 532 nm is employed with the purpose to compensate the residual electrical field effect. The combination of the three catalysts is found more powerful to cause water splitting, thus produced 5 times greater H2 production in comparison to the action of individual catalyst.
Characterization of Thermal Resistances Across CVD-Grown Graphene/Al2O3 and Graphene/Metal Interfaces Using Differential 3-Omega Technique
Authors: Villaroman Daniel Josephus , Dai Weijing , Wang Xinjiang , Gan Lin , Wu Ruizhe , Luo Zhengtang , Huang Baoling 
Published: March 2016

Chemical vapor deposited (CVD) graphene together with a superior gate dielectric such as Al2O3, is a promising combination for next-generation high-speed field effect transistors (FET). These high-speed devices are operated under high frequencies and will generate significant heat, requiring effective thermal management to ensure device stability and longevity. It is thus of importance to characterize the interfacial thermal resistance (ITR) between graphene/Al2O3 gate dielectric and graphene/metal contacts.
In this work, ITRs across the single-layer graphene/Al2O3 and the graphene/metal (Al, Ti, Au) interfaces were characterized from 100 K to 330 K using the differential 3ω method. Unlike previous works which mostly used exfoliated single or few-layer graphene, we used CVD large-scale graphene, which is most promising for FET fabrication due to cost and quality control, in the experiments. To ascertain the measured results and reduce uncertainty, different sandwich configurations including metal/graphene/metal, Al2O3/graphene/Al2O3 and metal/graphene/Al2O3 were used for the measurements. The effects of post annealing on different interfaces were also investigated.
Measurements of numerous samples showed an average ITR at 300K of 9×10−8 m2K/W for graphene/Al2O3, 6×10−8 m2K/W for graphene/Al, 5×10−8 m2K/W for graphene/Ti, and 7×10−8 m2K/W for graphene/Au interfaces. For the metal interfaces with graphene, the results are within the same order of magnitude as previous measurement results with graphite. However, ITR for graphene/Al2O3 is one order of magnitude higher than those reported for graphene/SiO2 interfaces. The measured ITRs for both metal and dielectric interfaces with graphene are almost temperature-independent from 100 K to 330 K, indicating that phonons are the major heat carrier. Annealing was found to have different effects on different interfaces. For graphene/Ti interfaces, ITR results measured before and after annealing consistently show a reduction of around 20%. However, such improvements on interfacial conductance were not observed for graphene/Al, graphene/Au and graphene/Al2O3 interfaces. The reduction of ITR of graphene/Ti interface is perceived to stem from the formation of Ti-C covalent bonds. However, neither the commonly used maximum transmission model nor the diffuse mismatch model explicitly considers bonding effects at the interface, which is why they poorly predict and explain all the aspects of the measurements. An improvement to the classic anisotropic DMM model was proposed by taking into account different bonding types and bonding area between graphene and Al2O3/metal layer, resulting in a better fitting with the experimental data.
Numerical Investigation on Head-On Collisions of Binary Micro-Droplets by an Improved Multiphase Lattice Boltzmann Flux Solver
Authors: Wang Y. , Shu C. 
Published: March 2016

Head-on collisions of binary micro-droplets are of great interest in both academic research and engineering applications. Numerical simulation of this problem is challenging due to complex interfacial changes and large density ratio between different fluids. In this work, the recently proposed lattice Boltzmann flux solver (LBFS) is applied to study this problem. The LBFS is a finite volume method for the direct update of macroscopic flow variables at cell centers. The fluxes of the LBFS are reconstructed at each cell interface through lattice moments of density distribution functions (DDFs). As compared with conventional multiphase lattice Boltzmann method, the LBFS can be easily applied to study complex multiphase flows with large density ratio. In addition, external forces can be implemented more conveniently and the tie-up between the time step and mesh spacing is also removed. Moreover, it can deal with complex boundary conditions directly as those do in the conventional Navier-Stokes solvers.
At first, the reliability of the LBFS is validated by simulating a micro-droplet impacting on a dry surface at density ratio 832 (air to water). The obtained result agrees well with experimental measurement. After that, numerical simulations of head-on collisions of two micro droplets are carried out to examine different collisional behaviors in a wide range of Reynolds numbers and Weber numbers of 100 ≤ Re ≤ 2000 and 10 ≤ We ≤ 500. A phase diagram parameterized by these two control parameters is obtained to classify the outcomes of these collisions. It is shown that, at low Reynolds number (Re=100), two droplets will be coalescent into a bigger one for all considered Weber numbers. With the increase of the Reynolds number, separation of the collision into multiple droplets appears and the critical Weber number for separation is decreased. When the Reynolds number is sufficiently high, the critical Weber number for separation is between 20 and 25.
One-Time Multi-Depth Silicon Etching Method Based on SiO2 Masking Layer
Authors: Tan Xiao , Tao Zhi , Xu Tiantong , Li Haiwang 
Published: March 2016

In order to improve the possibility of successful bonding and performance of structures, the new method for multi-depth silicon etching is required. This paper aims to design and create a new method for one-time multi-depth silicon etching in manufacturing complex structures based on SiO2 masking layer. The core idea of this method is that: Firstly, all patterns are transferred into photo resist through photo etching; Then etch pattern will be transferred in the SiO2 masking layer by multi-time shallow etching with different time etching control; Finally, patterns will be transferred to the silicon wafer with uniform ratio based on the measured etching selectivity of SiO2-Si with one time.
In the experiments, the process is completed in the silicon wafer with SiO2 masking layer whose thickness is elaborately designed. Firstly, the etching rate of SiO2 and the etching selectivity of SiO2-Si were measured accurately. Secondly, the shallow structure based on the designed structure, the etching rate of SiO2 and the etching selectivity of SiO2-Si is etched on the SiO2masking layer. The second step forms different thickness version of SiO2 masking layer. At last, the SiO2 masking layer is etched until final structure and consequently different depth of groove accomplish due to various thickness of SiO2 etched by previous step.
The experimental results indicated that the new methods has at least three advantages compared to traditional method: That is faster efficiency, higher cleanness and more complex structure. Fast work efficiency owes to only SF6 etching rather than two gases of SF6 and C4F8 to reduce half of time. Also high cleanness comes from being not exposed to air and researchers directly. The largest benefit of new method may be that can create more complex structure for higher required machine design and for higher mechanical function. It is because that normal etching method could only build few different depth of grooves due to multi-process limitation and contrary to normal one, new method can create more different depth of groove. And more different depth of groove means that more complex structure can be designed.
Automated detection of vessel lumen and stent struts in intravascular optical coherence tomography to evaluate stent apposition and neointimal coverage
Authors: Nam Hyeong Soo , Kim Chang‐Soo , Lee Jae Joong , Song Joon Woo , Kim Jin Won , Yoo Hongki 
Published: March 2016

Purpose:Intravascular optical coherence tomography (IV‐OCT) is a high‐resolution imaging method used to visualize the microstructure of arterial walls in vivo. IV‐OCT enables the clinician to clearly observe and accurately measure stent apposition and neointimal coverage of coronary stents, which are associated with side effects such as in‐stent thrombosis. In this study, the authors present an algorithm for quantifying stent apposition and neointimal coverage by automatically detecting lumen contours and stent struts in IV‐OCT images.Methods:The algorithm utilizes OCT intensity images and their first and second gradient images along the axial direction to detect lumen contours and stent strut candidates. These stent strut candidates are classified into true and false stent struts based on their features, using an artificial neural network with one hidden layer and ten nodes. After segmentation, either the protrusion distance (PD) or neointimal thickness (NT) for each strut is measured automatically. In randomly selected image sets covering a large variety of clinical scenarios, the results of the algorithm were compared to those of manual segmentation by IV‐OCT readers.Results:Stent strut detection showed a 96.5% positive predictive value and a 92.9% true positive rate. In addition, case‐by‐case validation also showed comparable accuracy for most cases. High correlation coefficients (R > 0.99) were observed for PD and NT between the algorithmic and the manual results, showing little bias (0.20 and 0.46 μm, respectively) and a narrow range of limits of agreement (36 and 54 μm, respectively). In addition, the algorithm worked well in various clinical scenarios and even in cases with a low level of stent malapposition and neointimal coverage.Conclusions:The presented automatic algorithm enables robust and fast detection of lumen contours and stent struts and provides quantitative measurements of PD and NT. In addition, the algorithm was validated using various clinical cases to demonstrate its reliability. Therefore, this technique can be effectively utilized for clinical trials on stent‐related side effects, including in‐stent thrombosis and in‐stent restenosis.
Fast multipurpose Monte Carlo simulation for proton therapy using multi‐ and many‐core CPU architectures
Authors: Souris Kevin , Lee John Aldo , Sterpin Edmond 
Published: March 2016

Purpose:Accuracy in proton therapy treatment planning can be improved using Monte Carlo (MC) simulations. However the long computation time of such methods hinders their use in clinical routine. This work aims to develop a fast multipurpose Monte Carlo simulation tool for proton therapy using massively parallel central processing unit (CPU) architectures.Methods:A new Monte Carlo, called MCsquare (many‐core Monte Carlo), has been designed and optimized for the last generation of Intel Xeon processors and Intel Xeon Phi coprocessors. These massively parallel architectures offer the flexibility and the computational power suitable to MC methods. The class‐II condensed history algorithm of MCsquare provides a fast and yet accurate method of simulating heavy charged particles such as protons, deuterons, and alphas inside voxelized geometries. Hard ionizations, with energy losses above a user‐specified threshold, are simulated individually while soft events are regrouped in a multiple scattering theory. Elastic and inelastic nuclear interactions are sampled from ICRU 63 differential cross sections, thereby allowing for the computation of prompt gamma emission profiles. MCsquare has been benchmarked with the gate/geant4 Monte Carlo application for homogeneous and heterogeneous geometries.Results:Comparisons with gate/geant4 for various geometries show deviations within 2%–1 mm. In spite of the limited memory bandwidth of the coprocessor simulation time is below 25 s for 107 primary 200 MeV protons in average soft tissues using all Xeon Phi and CPU resources embedded in a single desktop unit.Conclusions:MCsquare exploits the flexibility of CPU architectures to provide a multipurpose MC simulation tool. Optimized code enables the use of accurate MC calculation within a reasonable computation time, adequate for clinical practice. MCsquare also simulates prompt gamma emission and can thus be used also for in vivo range verification.
Iterative reconstruction for CT perfusion with a prior‐image induced hybrid nonlocal means regularization: Phantom studies
Authors: Li Bin , Lyu Qingwen , Ma Jianhua , Wang Jing 
Published: March 2016

Purpose:In computed tomography perfusion (CTP) imaging, an initial phase CT acquired with a high‐dose protocol can be used to improve the image quality of later phase CT acquired with a low‐dose protocol. For dynamic regions, signals in the later low‐dose CT may not be completely recovered if the initial CT heavily regularizes the iterative reconstruction process. The authors propose a hybrid nonlocal means (hNLM) regularization model for iterative reconstruction of low‐dose CTP to overcome the limitation of the conventional prior‐image induced penalty.Methods:The hybrid penalty was constructed by combining the NLM of the initial phase high‐dose CT in the stationary region and later phase low‐dose CT in the dynamic region. The stationary and dynamic regions were determined by the similarity between the initial high‐dose scan and later low‐dose scan. The similarity was defined as a Gaussian kernel‐based distance between the patch‐window of the same pixel in the two scans, and its measurement was then used to weigh the influence of the initial high‐dose CT. For regions with high similarity (e.g., stationary region), initial high‐dose CT played a dominant role for regularizing the solution. For regions with low similarity (e.g., dynamic region), the regularization relied on a low‐dose scan itself. This new hNLM penalty was incorporated into the penalized weighted least‐squares (PWLS) for CTP reconstruction. Digital and physical phantom studies were performed to evaluate the PWLS‐hNLM algorithm.Results:Both phantom studies showed that the PWLS‐hNLM algorithm is superior to the conventional prior‐image induced penalty term without considering the signal changes within the dynamic region. In the dynamic region of the Catphan phantom, the reconstruction error measured by root mean square error was reduced by 42.9% in PWLS‐hNLM reconstructed image.Conclusions:The PWLS‐hNLM algorithm can effectively use the initial high‐dose CT to reconstruct low‐dose CTP in the stationary region while reducing its influence in the dynamic region.
In Vitro
Interactions between Target of Rapamycin Kinase Inhibitor and Antifungal Agents against Aspergillus Species
Authors: Gao Lujuan , Ding Xiaozhen , Liu Zhun , Wu Qingzhi , Zeng Tongxiang , Sun Yi 
Published: March 2016

ABSTRACT

In vitro
interactions of INK128, a target of rapamycin (TOR) kinase inhibitor, and antifungals, including itraconazole, voriconazole, posaconazole, amphotericin B, and caspofungin, against
Aspergillus
spp. were assessed with the broth microdilution checkerboard technique. Our results suggested synergistic effects between INK128 and all azoles tested, against multiple
Aspergillus fumigatus
and
Aspergillus flavus
isolates. However, no synergistic effects were observed when INK128 was combined with amphotericin B or caspofungin. No antagonism was observed for any combination.
‘A problematic plum pit in the piping’: a case of traumatic oesophageal perforation
Authors: Ibrahim Nader , Chauhan Ishaan , Nikkar-Esfahani Ali 
Published: March 2016

A 75-year-old man presented to accident and emergency having swallowed a plum pit. He initially experienced sharp neck pain, which was mild at presentation. He was otherwise haemodynamically stable and was able to subsequently eat a sandwich without consequence.He was referred to the ear, nose and throat senior house office (SHO), who reviewed the soft tissue radiograph, which appeared normal. The patient displayed no concerning clinical signs and was well; however, his pain persisted. Examination revealed a localised area of surgical emphysema on the left side of the neck. Retrospective review of the soft tissue radiograph showed a small region of subcutaneous free air. An urgent CT scan confirmed a pneumomediastinum indicative of an oesophageal perforation. The patient was admitted for observation, and was managed conservatively without surgical intervention. He was weaned onto sterile fluid and progressed to a solid diet. He was discharged from hospital with no long-term sequelae.
Reusable Software Components
Authors: Levine Trudy 
Published: March 2016

In celebration of the 200th anniversary of the birth of Ada Lovelace, this column contains a listing of reusable software components, begun for Ada Letters in 1990.
All information is obtained directly from parties affiliated with web sites hosting Ada components or from the sites themselves. As always, no recommendations or guarantees are implied. We appreciate comments, corrections, and suggestions from our readers.
Containing Cefoxitin Costs through a Program to Curtail Use in Surgical Prophylaxis
Authors: Taylor Geoffrey , Blondel-Hill Edith , Kibsey Pamela , Friesen Erwin , Tisdell Ronald , Vaudry Wendy 
Published: March 2016

Objective: To reduce drug costs attributable to anti‐anaerobic cephalosporins – specifically to reduce cefoxitin use in surgical prophylaxis.Design: Before and after intervention cefoxitin use comparison.Setting: Tertiary care hospital.Participants: Hospitalized patients.Interventions: Chart review of patients identified through pharmacy records as cefoxitin recipients was carried out to determine which physicians were the principal users of cefoxitin and the purpose for such use. These data were used to direct cost containment strategies.Main Outcome Measures: Hospital quarterly pharmacy acquisition costs and grams of cefoxitin used.Results: The departments of surgery (49%) and obstetrics/gynecology (37%) were the principal users of cefoxitin, and surgical prophylaxis was found to be the principal indication for use (63%). These departments were invited by the Antibiotic Utilization Subcommittee of the hospital’s Pharmacy and Therapeutics Committee to draft surgical prophylaxis guidelines in keeping with published recommendations. Such guidelines were written and distributed to medical staff and substituted cefazolin for most forms of prophylaxis, gentamicin/metronidazole for colorectal prophylaxis and cefoxitin only for appendectomies. Over the following 21 months, hospital‐wide cefoxitin use fell from 6093 g, $70,076 per quarter, to 1316 g, $11,515 per quarter (partially offset by a 2595 g, $9,131 per quarter increase in cefazolin use).Conclusion: As a first step in reducing hospital costs of anti‐anaerobic cephalosporins, rationalization of cefoxitin use may be preferable to formulary interchange with alternatives such as ceftizoxime or cefotetan.
Parasite Contamination of Sand and Soil from Daycare Sandboxes and Play Areas
Authors: Gyorkos Theresa W , Kokoskin-Nelson Evelyne , MacLean J Dick , Soto Julio C 
Published: March 2016

Objectives: To determine if there was parasite contamination in the sand and soil in daycare sandboxes and play areas, with the goal of developing practice guidelines for their management.Methods: One hundred samples of sand and soil from 10 daycare centres in different regions of the province of Quebec, collected between April 22 and May 6, 1991, were examined.Results: Toxocara eggs were found in both surface and subsurface sand from two Montreal centres and co‐occurred with Ascaris species (surface sand) in one centre and with hookworm (surface soil) in the second. Hookworm eggs were also recovered from one centre in the Quebec City region.Conclusions: These results document the presence of potentially pathogenic helminth parasites in the daycare environment. Evidence from the literature regarding the health risk to children is insufficient and highlights the need for further research into the assessment of the risk of human infection and morbidity, the viability of these parasites under different environmental conditions and practical issues related to the management of sand and soil.