13 research outputs found

    Metastatic renal cell carcinoma from a native kidney of a renal transplant patient diagnosed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) biopsy

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    Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) biopsy sampling of enlarged lymph nodes is increasingly used to diagnose metastatic tumors, especially of the gastrointestinal tract and the lungs. Herein, we describe the diagnosis of metastatic renal cell carcinoma from a native kidney of a 54 year-old male patient, who had a 5-years history of renal transplant, by EUS-FNA of mediastinal and celiac lymph nodes. Histological and immunohistochemical findings confirmed the origin of metastatic tumor. EUS-FNA with proper cytological evaluation can be useful in the diagnosis of metastatic renal cell carcinoma in renal transplant patients.

    MANUFACTURING OF LIGHT-WEIGHT REFRACTORY BRICKS USING LOCAL RAW MATERIAL

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    Refractories with low thermal conductivity, high porosity and good mechanical strength are desirable to control the heat losses during high temperature processing. Locally produced insulating firebricks cannot be used at high temperatures due to poor refractoriness and low hot strength. In the present experimental work, locally available cheap raw materials, namely, clay, rice husk and saw dust were used to manufacture light-weight refractory bricks using different ratios of raw materials. Various process parameters were investigated and the bricks with optimized properties were produced which can be used upto 1200 °C. Moreover, the bricks produced will be lower in price and also beneficial from energy conservation point of view due to low heat losses

    A Pump-Controlled Circuit for Single-Rod Cylinders that Incorporates Limited Throttling Compensating Valves

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    Valve-controlled hydraulic actuation systems are favored in many applications due to their fast response, high power-to-weight ratio, and stability under variable working conditions. Efficiency, however, is the main disadvantage of these systems. Pump-controlled hydraulic actuations, on the other hand, eliminate energy losses in throttling valves and require less cooling. Furthermore, they inherently hold the ability to recover energy from assistive loads. Pump-controlled circuits for double-rod cylinders are well developed and are implemented in many industrial applications, including aviation. However, pump-controlled circuits for single-rod cylinders usually experience performance issues during specific modes of operation. In this paper, a new circuit using two valves to compensate for the differential flow of single-rod actuators is proposed. The compensating valves provide limited throttling over the differential flow only in critical operating regions to alleviate unwanted velocity oscillations. They have a minimum throttling effect in all other operating regions to preserve the efficiency. The new circuit has been experimentally evaluated. Its performance has also been compared with three other previously proposed circuits. The proposed circuit displays an improved performance, besides being capable of energy regeneration

    Design, Implementation and Evaluation of a Pump-Controlled Circuit for Single Rod Actuators

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    Pump-controlled hydraulic circuits are more efficient than valve-controlled circuits, as they eliminate the energy losses due to flow throttling in valves and require less cooling effort. Presently existing pump-controlled solutions for single rod cylinders encounter an undesirable performance during certain operating conditions. This paper investigates the performance issues in common pump-controlled circuits for the single rod actuators. Detailed analysis is conducted that identifies these regions in a load-velocity plane and the factors affecting them. The findings are validated by experimental results. A new design is then proposed that employs a limited throttling valve alongside two pilot operated check valves for differential flow compensation to improve the performance. The valve is of the flow control type and is chosen to have a throttling effect over critical regions; it has the least throttling over other operating regions, thus maintaining efficiency. Experimental work demonstrates improved performance in a full operating range of the actuator as compared to a circuit that uses only the pilot-operated check valves. This circuit is energy efficient and capable of recuperating energy

    Design, Implementation and Evaluation of a Pump-Controlled Circuit for Single Rod Actuators

    No full text
    Pump-controlled hydraulic circuits are more efficient than valve-controlled circuits, as they eliminate the energy losses due to flow throttling in valves and require less cooling effort. Presently existing pump-controlled solutions for single rod cylinders encounter an undesirable performance during certain operating conditions. This paper investigates the performance issues in common pump-controlled circuits for the single rod actuators. Detailed analysis is conducted that identifies these regions in a load-velocity plane and the factors affecting them. The findings are validated by experimental results. A new design is then proposed that employs a limited throttling valve alongside two pilot operated check valves for differential flow compensation to improve the performance. The valve is of the flow control type and is chosen to have a throttling effect over critical regions; it has the least throttling over other operating regions, thus maintaining efficiency. Experimental work demonstrates improved performance in a full operating range of the actuator as compared to a circuit that uses only the pilot-operated check valves. This circuit is energy efficient and capable of recuperating energy

    A Pump-Controlled Circuit for Single-Rod Cylinders that Incorporates Limited Throttling Compensating Valves

    No full text
    Valve-controlled hydraulic actuation systems are favored in many applications due to their fast response, high power-to-weight ratio, and stability under variable working conditions. Efficiency, however, is the main disadvantage of these systems. Pump-controlled hydraulic actuations, on the other hand, eliminate energy losses in throttling valves and require less cooling. Furthermore, they inherently hold the ability to recover energy from assistive loads. Pump-controlled circuits for double-rod cylinders are well developed and are implemented in many industrial applications, including aviation. However, pump-controlled circuits for single-rod cylinders usually experience performance issues during specific modes of operation. In this paper, a new circuit using two valves to compensate for the differential flow of single-rod actuators is proposed. The compensating valves provide limited throttling over the differential flow only in critical operating regions to alleviate unwanted velocity oscillations. They have a minimum throttling effect in all other operating regions to preserve the efficiency. The new circuit has been experimentally evaluated. Its performance has also been compared with three other previously proposed circuits. The proposed circuit displays an improved performance, besides being capable of energy regeneration

    Comparison study of transparent RF-sputtered ITO/AZO and ITO/ZnO bilayers for near UV-OLED applications

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    Hybrid inorganic/organic light-emitting diodes have attracted much attention in the field of luminescent electronics due to the desired incorporation of high optoelectronic features of inorganic materials with the processability and variety of organic polymers. To generate and emit a near ultraviolet (N-UV) ray, wide band gap semiconductors can be applied in the organic light-emitting diodes (OLEDs). In this paper, zinc oxide (ZnO) and aluminum-doped ZnO (AZO) thin films are deposited by radio frequency (RF) sputtering above the ITO electrode and poly [2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV) conjugated polymer is utilized as a complementary p-type semiconductor in OLED structure. The impact of ZnO and AZO thickness on the structural, electrical, optical and morphological properties of ITO/AZO and ITO/ZnO bilayers are scrutinized and compared. Results show that with the enlargement of both ZnO and AZO film thickness, the physical properties are gradually improved resulting in the better quality of transparent conducting thin film. The average electrical resistivity of 8.4 × 10−4 and 1.1 × 10−3 Ω-cm, average sheet resistance of 32.9 and 42.3 Ω/sq, average transmittance of 88.3 and 87.3% and average FOM of 1.0 × 104 and 7.4 × 103 (Ω-cm)−1 are obtained for ITO/AZO and ITO/ZnO bilayers, respectively. Moreover, comparing the results indicates that the strain and the stress within the ITO/AZO bilayer are decreased nearly 19% with respect to ITO/ZnO bilayer which yield higher quality of crystal. Consequently, the physical properties of ITO/AZO bilayer is found to be superior regarding ITO/ZnO bilayer. For fabricated UV-OLEDs, the turn-on voltages, the characteristic energy () and the total concentration of traps () for the devices with the structures of ITO/ZnO/MEH-PPV/Al and ITO/AZO/MEH-PPV/Al are obtained 12 and 14 V, 0.108 and 0.191 eV, 9.33 × 1016 and 5.22 × 1016 cm−3, respectively. Furthermore, according to the electroluminescence (EL) spectra, the near band emission (NBE) peak for device with the structure of ITO/ZnO/MEH-PPV/Al is attained nearly in the wavelengths of 408 nm which is in N-UV region. For ITO/AZO/MEH-PPV/Al, a slightly blue shift in NBE peak is observed due to the Burstein–Moss (BM) effect. Ultimately, different charge carrier transport mechanisms of fabricated UV-OLEDs have been carefully investigated
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