5,030 research outputs found

    Compact silicon photonics circuit to extract multiple parameters for process control monitoring

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    We present a compact interferometer circuit to extract multiple model parameters of on-chip waveguides and directional couplers from optical measurements. The compact design greatly improves the accuracy of extraction with fewer measurements, making it useful for process monitoring and detailed wafer-level variability analysis. We discuss the design requirements and illustrate the extraction using the Restart-CMA-ES global optimization algorithm. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

    Optimization of CO2 production rate for firefighting robot applications using response surface methodology

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    A carbon dioxide gas-powered pneumatic actuation has been proposed as a suitable power source for an autonomous firefighting robot (CAFFR), which is designed to operate in an indoor fire environment in our earlier study. Considering the consumption rate of the pneumatic motor, the gas-powered actuation that is based on the theory of phase change material requires optimal determination of not only the sublimation rate of carbon dioxide but also the sizing of dry ice granules. Previous studies that have used the same theory are limited to generating a high volume of carbon dioxide without reference to neither the production rate of the gas nor the size of the granules of the dry ice. However, such consideration remains a design requirement for efficient driving of a carbon dioxide-powered firefighting robot. This paper investigates the effects of influencing design parameters on the sublimation rate of dry ice for powering a pneumatic motor. The optimal settings of these parameters that maximize the sublimation rate at the minimal time and dry ice mass are presented. In the experimental design and analysis, we employed full-factorial design and response surface methodology to fit an acceptable model for the relationship between the design factors and the response variables. Predictive models of the sublimation rate were examined via ANOVA, and the suitability of the linear model is confirmed. Further, an optimal sublimation rate value of 0.1025 g/s is obtained at a temperature of 80°C, the mass of 16.1683 g, and sublimation time of 159.375 s

    Column-row addressing of thermo-optic phase shifters for controlling large silicon photonic circuits

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    We demonstrate a time-multiplexed row-column addressing scheme to drive thermo-optic phase shifters in a silicon photonic circuit. By integrating a diode in series with the heater, we can connect N×MN \times M heaters in an matrix topology to NN row and MM column lines. The heaters are digitally driven with pulse-width modulation, and time-multiplexed over different channels. This makes it possible to drive the circuit without digital-to-analog converters, and using only M+NM+N wires. We demonstrate this concept with a 1×161 \times 16 power splitter tree with 15 thermo-optic phase shifters that are controlled in a 3×53 \times 5 matrix, connected through 8 bond pads. This technique is especially useful in silicon photonic circuits with many tuners but limited space for electrical connections

    Potential Drug-Drug Interactions in Psychiatric Ward of a Tertiary Care Hospital: Prevalence, Levels and Association with Risk Factors

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    Purpose: To identify the prevalence of potential drug-drug interactions (pDDIs) in a psychiatric ward, their levels and association with risk factors.Methods: This study was conducted in the psychiatric ward of Ayub Teaching Hospital, Abbottabad, Pakistan. Medical records of 415 patients were retrospectively reviewed for pDDIs using Micromedex Drug-Reax software. Logistic regression was applied to determine association of pDDIs with age, gender, hospital stay and number of drugs.Results: In our study, we identified total number of 825 pDDIs of 126 types, with median number of 1 pDDIs per patient. Overall 64.8 % of the patients had at least one pDDI; 27.2 % at least one major pDDI; and 58.5 % patients at least one moderate pDDI. Among 825 identified pDDIs, most were of moderate (75.6 %) or major (20.8 %) severity, good (66.4 %) or fair (29 %) type of scientific evidence; and delayed onset (71 %). The most frequent major and moderate pDDIs included haloperidol + procyclidine (127 cases), haloperidol + olanzapine (49), haloperidol + promethazine (47), haloperidol + fluphenazine (41), diazepam + divalproex sodium (40), haloperidol + trihexyphenidyl (37), lorazepam + divalproex sodium (34), fluphenazine + procyclidine (33) and olanzapine + divalproex sodium (32). There was significant association of occurrence of pDDIs with hospital stay of 7 days or longer (p = 0.005) and taking 7 or more drugs (p < 0.001).                                                       Conclusion: A high prevalence of pDDIs in the psychiatric ward was recorded, a majority of which were of moderate severity. Patients with long hospital stay and increased number of drugs were more exposed to pDDIs.Keywords: Drug-drug interactions, Potential drug-drug interaction, Prescriptions screening, Drug-related problems, Clinical pharmacy

    Missense mutations at homologous positions in the fourth and fifth laminin A G-like domains of eyes shut homolog cause autosomal recessive retinitis pigmentosa

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    Purpose: To describe two novel mutations in the eyes shut homolog (EYS) gene in two families with autosomal recessive retinitis pigmentosa (arRP) from Pakistan and Indonesia. Methods: Genome-wide linkage and homozygosity mapping were performed using single nucleotide polymorphism microarray analysis in affected members of the two arRP families. Sequence analysis was performed to identify genetic changes in protein coding exons of EYS. Results: In the Indonesian and Pakistani families, homozygous regions encompassing the EYS gene at 6q12 were identified, with maximum LOD scores of 1.8 and 3.6, respectively. Novel missense variants in the EYS gene (p.D2767Y and p.D3028Y) were found in the Pakistani and Indonesian families, respectively, that co-segregate with the disease phenotype. Interestingly, the missense variants are located at the same homologous position within the fourth and fifth laminin A G-like domains of EYS. Conclusions: To date, mostly protein-truncating mutations have been described in EYS, while only few patients have been described with pathogenic compound heterozygous missense mutations. The mutations p.D2767Y and p.D3028Y described in this study affect highly conserved residues at homologous positions in laminin A G-like domains and support the notion that missense mutations in EYS can cause arRP

    Rural road management in Botswana

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    This paper discusses the management of rural roads in Chobe in Botswana, which are mainly tertiary and access roads. These roads are low-volume roads and mostly gravelled. It was observed that the maintenance management of these roads was based on engineering judgement through visual inspection all over the country, without having any economic or technical analysis. Therefore, a comprehensive pavement management system for rural roads' maintenance is needed in Chobe and also in all the council areas of Botswana, which would consist of data collection, database, use of the Highway Development and Management Model to undertake efficient decision making project preparation, funding, implementation and feedback. A partial implementation of pavement management system in Chobe has been highlighted in this paper. The present analysis reveals that total demand for the road network in Chobe was 41·29 million pula, the backlog was 34·86 million pula and the first-year backlog demand was 20·63 million pula. Furthermore, the analysis found the long-term periodic maintenance strategy for the network at 6·43 million pula when there is no backlog. This huge backlog indicates that roads are not being maintained appropriately. The paper also estimates current road asset value in Chobe at 55·48 million pula. Finally, the paper recommends several solutions for the efficient preservation of road assets in Botswana

    Yield Performances and Cup Quality of Some BTRI Test Clones of Tea

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    A long term experiment was conducted to investigate the yield and quality performances of four vegetative propagated test clones of tea coded as A/8/01, A/17/22, A/22/27 and A/22/40 at Bangladesh Tea Research Institute (BTRI) farm during 1996-2010. A standard clone BT1 was considered as control. Cuttings of the test clones were collected from the selected bushes of Amo tea estates and were raised at BTRI nursery. Then saplings were put to long term yield and quality trial following Latin Square Design (LSD) with 3 replications. The green leaf was harvested at weekly interval during the plucking season starting from mid March to mid December throughout the experimental period. Yield data were recorded and analyzed statistically using MSTAT programme. Results of the experiment revealed that among the test clones A/22/40 gave the highest significant yield of 3509.1 kg ha-1 of made tea followed by BT1 (3203.69 kg ha-1), A/8/01 (2912.24 kg ha-1), A/17/22 (2817.76 kg ha-1) and A/22/27 (2278.78 kg ha-1) from the average of 9 years (2002-2010) at mature stage. At immature stage i.e. 1st year to 5th year after plantation yield difference was insignificant. The overall cup quality of the test clones was assessed by conventional organoleptic test. The cup quality of A/8/01, A/17/22, A/22/40 as well as the standard clone BT1 was found to be above average (AA) while the cup quality of A/22/27 was average (A). Considering the yield and quality potentials, the test clone A/22/40 has appeared quite promising to be released as a standard clone. DOI: http://dx.doi.org/10.3329/ijarit.v1i1-2.13925 Int. J. Agril. Res. Innov. & Tech. 1 (1&2): 24-28, December, 201

    An Enhanced Energy Balanced Data Transmission Protocol for Underwater Acoustic Sensor Networks.

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    This paper presents two new energy balanced routing protocols for Underwater Acoustic Sensor Networks (UASNs); Efficient and Balanced Energy consumption Technique (EBET) and Enhanced EBET (EEBET). The first proposed protocol avoids direct transmission over long distance to save sufficient amount of energy consumed in the routing process. The second protocol overcomes the deficiencies in both Balanced Transmission Mechanism (BTM) and EBET techniques. EBET selects relay node on the basis of optimal distance threshold which leads to network lifetime prolongation. The initial energy of each sensor node is divided into energy levels for balanced energy consumption. Selection of high energy level node within transmission range avoids long distance direct data transmission. The EEBET incorporates depth threshold to minimize the number of hops between source node and sink while eradicating backward data transmissions. The EBET technique balances energy consumption within successive ring sectors, while, EEBET balances energy consumption of the entire network. In EEBET, optimum number of energy levels are also calculated to further enhance the network lifetime. Effectiveness of the proposed schemes is validated through simulations where these are compared with two existing routing protocols in terms of network lifetime, transmission loss, and throughput. The simulations are conducted under different network radii and varied number of nodes

    Parasiticidal, antifungal and antibacterial activities of Onosma griffithii Vatke

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    Onosma griffithii was screened for possible pharmacological activities. The crude methanolic extract (MeOH) and its fractions demonstrated parasiticidal activity (IC 50 (ìg/ml ± S.D) = 31.03 ± 0.23) against Leishmania major. Based on the IC 50 values, the potency of the standard drug (Pentamidine) and test fractions were of the order as: Pentamidine > crude extract > n-hexane fraction > ethyl acetate (ETOAc) fraction > chloroform fraction (CHCl3) fraction > n-butanol (BUOH) fraction > aqueous fraction. Similarlymoderate antifungal activity was displayed by the crude methanolic extract against Aspergillus flavus and Fusarium solani. Against the Staphylococcus aureus, the aqueous fraction demonstrated moderate antibacterial activity
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