105 research outputs found
Design, Modeling, Fabrication and Testing of a Piezoresistive-Based Tactile Sensor for Minimally Invasive Surgery Applications
Minimally invasive surgery (MIS) has become a preferred method for surgeons for the last two decades, thanks to its crucial advantages over classical open surgeries. Although MIS has some advantages, it has a few drawbacks. Since MIS technology includes performing surgery through small incisions using long slender tools, one of the main drawbacks of MIS becomes the loss of direct contact with the patient’s body in the site of operation. Therefore, the surgeon loses the sense of touch during the operation which is one of the important tools for safe manipulation of tissue and also to determine the hardness of contact tissue in order to investigate its health condition. This Thesis presents a novel piezoresistive-based multifunctional tactile sensor that is able to measure the contact force and the relative hardness of the contact object or tissue at the same time. A prototype of the designed sensor has been simulated, analyzed, fabricated, and tested both numerically and experimentally. The experiments have been performed on hyperelastic materials, which are silicone rubber samples with different hardness values that resemble different biological tissues. The ability of the sensor to measure the contact force and relative hardness of the contact objects is tested with several experiments. A finite element (FE) model has been built in COMSOL Multiphysics (v3.4) environment to simulate both the mechanical behavior of the silicone rubber samples, and the interaction between the sensor and the silicone rubbers. Both numerical and experimental analysis proved the capability of the sensor to measure the applied force and distinguish among different silicone-rubber samples. The sensor has the potential for integration with commercially available endoscopic grasper
Updating Balanced Scorecard Model for The Evaluation of The Strategic Performance in Greater Amman Municipality
This study aimed to develop and update the model of Balance Scorecard (BSC) to measure the strategic performance efficiency at Greater Amman Municipality (GAM). In addition, the study objectives include the following: (1) To identify the availability of the BSC requirements in GAM; (2) To develop a set of measures that are in line with municipal work; and (3) To add to the BSC Model of the environmental requirements as a fifth perspective. In achieving these objectives, a questionnaire was developed based on theoretical review, previous studies, and the work experience of the authors in GAM. The questionnaire includes many items which covered five perspectives of BSC, and it was distributed to the study participants who were responsible for preparing and reviewing Strategic plan of GAM and other responsible employees in GAM. After determining the descriptive statistics and after the testing of the hypotheses, the study concluded that there is a statistical significant impact of all independent variables (customer perspective, financial perspective, environmental perspective, internal processes perspective, and learning and growth perspective) based on the efficiency of strategic performance in Greater Amman Municipality
Design, Fabrication and Testing of a Piezoresistive-Based Tactile Sensor for Minimally Invasive Surgery
Minimally invasive robotic surgery (MIRS) has become a preferred method for patients for the last two decades, thanks to its crucial advantages over classical open surgeries. Although MIRS has some advantages, it has a few drawbacks. Since MIRS technology includes performing surgery through small incisions using long slender tools, one of the main drawbacks of MIRS becomes the loss of direct contact with the patient’s body in the site of operation. Therefore, the surgeon loses the sense of touch during the operation which is one of the important tools to investigate the health condition of the treated tissue. This paper presents a novel piezoresistive-based multifunctional tactile sensor that is able to measure the contact force, relative hardness of the contact object, and the position of a hidden lump at the same time. A prototype of the designed sensor has been fabricated, simulated, analyzed, and tested numerically and experimentally. The experiments have been performed on hyperelastic materials, which are silicone rubber samples with different hardness values that resemble different biological tissues. The ability of the sensor to measure the contact force and relative hardness of the contact objects is tested with several experiments. A finite element (FE) model has been built in COMSOL Multiphysics (v3.4) environment to simulate both the mechanical behavior of the silicone rubber samples, and the interaction between the sensor and the silicone rubbers. Both numerical and experimental analysis proved the capability of the sensor to distinguish between different silicone rubber samples
Sensitivity analysis for photovoltaic water pumping systems: Energetic and economic studies
In agricultural remote areas where electrical energy is required to supply water pumping plants, photovoltaic modules are considered a good option to generate electricity. The reliability of autonomous Photovoltaic water pumping plants depends essentially on the system components size, which should meet the criteria related to the plant autonomy and the water volume required for irrigation. In this context, this research paper proposes an approach to size the elements of an autonomous photovoltaic system equipped with an energy storage device (a battery bank), and which is used to supply a waterpumping plant with electricity. The proposed approach determines the optimal surface of the photovoltaic modules, the optimal capacity of the battery bank and the volume of the water storage tank.
The optimization approach takes into account the monthly average solar radiation, the fulfillment of the water needed for the crops’ irrigation and the number of the days of autonomy. Measured climatic data of 10 ha situated in Northern Tunisia and planted with tomato are used in the optimization process, which is conducted during the tomato vegetative cycle (from March to July). The optimal results achieved for this farm are 101.5 m2 of photovoltaic modules’ surface, 1680 A h/12 V of the battery bank and 1800 m3 of the volume of the water storage tank. Then, to verify the reliability of the proposed optimization approach, the results of the proposed sizing algorithm are compared with those of a commercial optimization tool named HOMER, which shows better results using the proposed approach. Finally, the economic reliability of the obtained size is studied and compared with systems that include a diesel generator, and a diesel generator- photovoltaic panels, respectively, using climatic and economic parameters in three countries: Tunisia, Spain and Jordan. The economic analysis for these water pumping systems showed that photovoltaic- batteries/Pump system is the optimum solution in the three countries. However, the initial cost of the system can be recuperated faster in Spain than in Tunisia and Jordan due to high prices of the diesel these two countries.Ministerio de Economía, Industria y Competitividad (project DPI2014-54530-R
Circular Optical Phased Array with Large Steering Range and High Resolution
Light detection and ranging systems based on optical phased arrays and integrated silicon photonics have sparked a surge of applications over the recent years. This includes applications in sensing, free-space communications, or autonomous vehicles, to name a few. Herein, we report a design of two-dimensional optical phased arrays, which are arranged in a grid of concentric rings. We numerically investigate two designs composed of 110 and 820 elements, respectively. Both single-wavelength (1550 nm) and broadband multi-wavelength (1535 nm to 1565 nm) operations are studied. The proposed phased arrays enable free-space beam steering, offering improved performance with narrow beam divergences of only 0.5° and 0.22° for the 110-element and 820-element arrays, respectively, with a main-to-sidelobe suppression ratio higher than 10 dB. The circular array topology also allows large element spacing far beyond the sub-wavelength-scaled limits that are present in one-dimensional linear or two-dimensional rectangular arrays. Under a single-wavelength operation, a solid-angle steering between 0.21π sr and 0.51π sr is obtained for 110- and 820-element arrays, respectively, while the beam steering spans the range of 0.24π sr and 0.57π sr for a multi-wavelength operation. This work opens new opportunities for future optical phased arrays in on-chip photonic applications, in which fast, high-resolution, and broadband beam steering is necessary.This work was supported by the Natural Sciences and Engineering Research Council of Canada’s Collaborative R&D Grant Program by collaborating with Optiwave Systems, Inc., Slovak Grant Agency VEGA 1/0113/22, and Slovak Research and Development Agency under the project APVV-21-0217. Partial funding for open access charge: Universidad de Málag
The relationship between dietary nutrients patterns and intensity and duration of migraine headaches
Effect of Carboxylic Functional Group Functionalized on Carbon Nanotubes Surface on the Removal of Lead from Water
The adsorption mechanism of the removal of lead from water by using carboxylic functional group (COOH) functionalized on the surface of carbon nanotubes was investigated. Four independent variables including pH, CNTs dosage, contact time, and agitation speed were carried out to determine the influence of these parameters on the adsorption capacity of the lead from water. The morphology of the synthesized multiwall carbon nanotubes (MWCNTs) was characterized by using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) in order to measure the diameter and the length of the CNTs. The diameters of the carbon nanotubes were varied from 20 to 40 nm with average diameter at 24 nm and 10 micrometer in length. Results of the study showed that 100% of lead was removed by using COOH-MCNTs at pH 7, 150 rpm, and 2 hours. These high removal efficiencies were likely attributed to the strong affinity of lead to the physical and chemical properties of the CNTs. The adsorption isotherms plots were well fitted with experimental data
Preparation and characterization of polyamidoxime chelating resin from rubberwood fibre-g-polyacrylonitrile
Grafted rubberwood fibre was converted to polyamidoxime
ion-exchange resin in order to remove heavy metal ions from aqueous solution. The cation-exchange resin existed predominantly in the syn-hydroxyamino form. The water uptake by the resin was ca. 31 g/g dry resin while its hydrogen ion capacity was 3.6 mmol/g. The adsorption capacity of the resin towards different metal ions from wastewater was determined at different pH values
within the range 1–6. The prepared chelating ion-exchanger exhibited the highest adsorption capacity towards Cu2+ ions (3.83 mmol/g), followed by Cd2+,Fe3+, Pb2+, Ni2+ and Co3+ ions, respectively. The results showed that the adsorption capacity depended on the solution pH. Polyamidoxime ion-exchange resin was also used to separate Co3+ and Ni2+ ions from Cu2+ ions using a column technique. On passing Cu2+/Ni2+ and Cu2+/Co3+ ion mixtures through the resin at
pH 3, Cu2+ ions were adsorbed by the resin but no sorption of Ni2+ or Co3+ ions was detected. Approximately 98% of the Cu2+ ions could be desorbed from the resin. FT-IR spectroscopy was used to confirm the conversion of
polyacrylonitrile-g-rubberwood fibre to polyamidoxime
Performance Investigation of 1.6 Tbps Hybrid WDM-PDM-OFDM-based Free Space Optics Transmission Link
A novel ultra-high capacity free space optics (FSO) link has been developed by incorporating hybrid wavelength divison multiplexing (WDM)-polarization division multiplexing (PDM)-orthogonal frequency division multiplexing (OFDM) techniques with 16-level
quadrature amplitude modulation (16-QAM) signals. Coherent detection is employed to
enhance the receiver sensitivity in the presence of channel efects. The proposed link is
analyzed under the impact of dynamic weather conditions viz. haze, rain, dust and fog
using bit error rate, optical signal to noise ratio, error vector magnitude and maximum
transmission range performance metrics. Sixteen independent DWDM channels with
0.8 nm channel spacing each carrying 100 Gbps data are successfully tranported using the
proposed FSO link realizing a net data rate of 1.6 Tbps. Furthermore, we demonstrated
a performance comparison of the link with contemporary works. The proposed FSO link
provides a feasible and viable solution to implement ultra-high-capacity wireless transmission networks for last-mile access.A novel ultra-high capacity free space optics (FSO) link has been developed by incorporating hybrid wavelength divison multiplexing (WDM)-polarization division multiplexing (PDM)-orthogonal frequency division multiplexing (OFDM) techniques with 16-level
quadrature amplitude modulation (16-QAM) signals. Coherent detection is employed to
enhance the receiver sensitivity in the presence of channel efects. The proposed link is
analyzed under the impact of dynamic weather conditions viz. haze, rain, dust and fog
using bit error rate, optical signal to noise ratio, error vector magnitude and maximum
transmission range performance metrics. Sixteen independent DWDM channels with
0.8 nm channel spacing each carrying 100 Gbps data are successfully tranported using the
proposed FSO link realizing a net data rate of 1.6 Tbps. Furthermore, we demonstrated
a performance comparison of the link with contemporary works. The proposed FSO link
provides a feasible and viable solution to implement ultra-high-capacity wireless transmission networks for last-mile access
Antibacterial Properties of Polysulfone Membranes Blended with Arabic Gum.
Polysulfone (PS) membranes blended with different loadings of arabic gum (AG) were synthesized using phase inversion method and the antibacterial properties of the synthesized membranes were tested using a number Gram-negative (, and ) and Gram-positive () bacterial species. It was shown that AG addition to the dope polymer solutions essentially changed porous structure, hydrophilicity and zeta potential of the cast PS/AG membranes. These changes were due to the amphiphilic properties of AG macromolecules that contained negatively charged hydrophilic residues. A pronounced decrease in bacterial attachment was seen in the field emission scanning electron microscopy (FESEM) images for PS/AG membrane samples compared to both commercial (Microdyn-Nadir) and bare PS (without AG) membranes. AG loading dependent trend was observed where the prevention of bacterial colonization on the membrane surface was strongest at the highest (7 wt. %) AG loading in the casting solution. Possible mechanisms for the prevention of bacterial colonization were discussed. Significantly, the inhibition of bacterial attachment and growth on PS/AG membranes was observed for both Gram-positive and Gram-negative bacterial models, rendering these novel membranes with strong biofouling resistance attractive for water treatment applications
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