Background: Carpal tunnel syndrome (CTS) is the most common upper extremity impingement neuropathy caused by median nerve compression within the carpal tunnel due to various conditions such as bone abnormalities, inflammation, trauma, neoplastic lesions and endocrinopathies. Increase in carpal tunnel pressure of more than 20 to 30 mmHg blocks the epineural blood flow; so, the nerve function is damaged. Carpal tunnel syndrome is primarily a clinical diagnosis supported by electrodiagnostic studies; in recent years, different imaging modalities, including magnetic resonance imaging (MRI) and ultrasound, are suggested for diagnosis of carpal tunnel syndrome.Methods: During November 2011 and May 2013, 84 patients clinically suspicious for carpal tunnel syndrome were enrolled in our study; the age of patients ranged from 19 to 66 with the average of 43 years and the sex ratio of women to men was 2.7: 1. All the patients underwent electerodiagnostic tests (EDT) as the gold standard diagnostic modality and the results of color Doppler sonography (CDS) were compared with electerodiagnostic findings.Findings: According to the ecterodiagnostic tests, patients with positive results of carpal tunnel syndrome were divided into three groups of severity including mild with 9 patients (11%), moderate with 14 cases (17%) and severe with 18 patients (21%). Sensitivity of color Doppler sonography for diagnosis of carpal tunnel syndrome was almost 83%, 71% and 55% in severe, moderate and mild groups of carpal tunnel syndrome, respectively.Specificity of this imaging modality was determined near to 81% in all three groups of the patients.Conclusion: In addition to electerodiagnostic tests, which are considered as the modality of choice for diagnosis of carpal tunnel syndrome, Doppler ultrasound can be a non-invasive imaging procedure for evaluation of patients that are clinically suspicious to this syndrome. Considering three groups of carpal tunnel syndrome based on severity of electerodiagnostic signs, results of color Doppler sonography is more reliable in patients with severe signs.

One of the throats in designing hypersonic wind tunnel is the design of heater. The purpose of this study is designing a heater with ceramic cored, in 1800K temperature for preventing air condensation in wind tunnel. In initial part of design the fluid flow and heat transfer equation have been solved through an inviscid engineering code. This code estimates the temperature of transient outlet flow with static physical and thermodynamic properties of fluid and solid, geometrical dimensions of bed and wall distribution temperature. The final part of design has been solved with computational methods and using of Navir Stocks and energy equation, with K-ω SST turbulence model. The solver is 2nd order and pressure base. The numerical results are in acceptable agreement with experimental. By parameter analysis, various design for obtaining a suitable heater have been evaluated. The evaluated parameters are height, diameter, porosity of the bed and the diameter of the hole and diameter of the bed. The results show that the diameter of the hole, the diameter of the bed, the height and prosity the most important parameters in the design of the heating bed and have a great impact on the temperature of the exhaust air and the duration the test respectively. 14% increase or decrease of each parameter increase 61, 51, 28, and 8% of execution time and 6, 3, 2 and 1. 8 % of the output air temperature respectively. The hole diameter and prosity of the heater bed are two important parameters in determining the dimension of the heater bed. Finally with using of the results the final design has been modified with bed diameter of 0. 45 meter, height of 1. 7 meter, hole diameter of 3 millimeter and prosity 0. 2512.

This paper proposes a 2.4 GHz active mixer without passive inductor for the transceiver system. Taking into account the design requirements of the mixer, a double-balanced down-conversion structure with active inductor and negative resistance is designed. The proposed mixer with 130 nm CMOS technology is designed and simulated using Cadence software at 1.5 V supply voltage. Although we had to compromise conversion gain with linearity, we were able to achieve very high conversion gain with average linearity. Based on the results of post-layout simulations, the conversion gain of 27.57 dB, IIP3 equal to -7.88 dBm, 1-dB compression point equal to -17.34 dBm and IIP2 equal to 44.22 dBm with power consumption of 2.5 mW was obtained for the proposed mixer. The chip size without input and output pads is 95.18 µm × 117.68 µm, which leads to a chip area of 0.0112mm2.

It is clear that the estimation and investigation of the aerodynamic peak pressure due to the passage of two high-speed cross trains intersecting in the tunnel is important because of its effects on passenger safety and tunnel structure. In this study, transient aerodynamic peak pressure of two high-speed ETR500 cross-train models in tunnel with the speed of 170 km/h is investigated. A high-speed rotary scaled model (HRSM) test setup is used to perform experiments and the aerodynamic peak caused by the high-speed train moving into the tunnel is obtained on the standing train in the tunnel. Also, a numerical simulation of the test is done using computational fluid dynamics using the sliding mesh technique, and the results are compared with the results obtained from the scaled test as well as the relevant data in the literature. The results are presented based on the non-dimensional parameters. The results of the study provide a validation field for the future studies.

Background: Median neuropathy due to nerve compression in the wrist, or carpal tunnel syndrome (CTS), is the most common entrapment neuropathy. Incidence of CTS is high at an estimated value of 280.6 per 100, 000 patients per year. Accurate diagnosis of CTS is essential for treatment and preventing disability and morbidity.Methods: 64 patients with clinical diagnosis of CTS from the out-patient clinic of Alzahra Hospital, Isfahan, Iran were evaluated between January and March 2013. All the patients (54 women and 10 men) underwent nerve conduction study (NCS) and ultrasonography. The cross sectional area of the median nerve at the level of pisiform bone and 12cm proximal to that in elbow was estimated via ultrasonography which were used to calculate wrist/forearm ratio (WFR). The cut-off point value for WFR of median nerve was assessed and sensitivity and specificity of ultrasonography for CTS diagnosis was also determined.Findings: The optimal diagnostic cut-off values of CTS that we obtained by ROC curve was 2.07 and the areas under the ROC curve, was 0.8. This cut-off value had a sensitivity of 76%, specificity of 83%, positive predictive value (PPV) of 95% and negative predictive value (NPV) of 45%.Conclusion: The WFR is a new option in the ultra-sonographic diagnosis of CTS. This technique does not add significant time to routine ultra-sonographic examination.The use of a ratio also helps to omit the variability between populations and anatomic variation. Our initial findings suggest a high sensitivity for this method, but study of a larger population is needed for confirmation.