A compact microstrip six-port reflectometer (SPR) with extended bandwidth is proposed in this paper. The design is based on using 16-dB multi-section coupled line directional couplers and a multi-section 3-dB Wilkinson power divider operating from 1 to 6 GHz. The proposed SPR employs only two calibration standards: a matched load and an open load. As compared to other dielectric substrates, fabricating the proposed SPR involves using a low-cost (FR4) substrate. A novel algorithm is also proposed to estimate the complex reflection coefficient over the frequency ranges at which the standard performance of the circuit components is not fully satisfied. The new algorithm is based on the circles’ intersection points, which have been derived from basic SPR equations, to estimate the complex reflection coefficient. To validate the SPR performance, a multiband microstrip patch antenna has been measured and the resulted reflection coefficient is compared with those obtained using a vector network analyzer (VNA). Results show that the proposed SPR provides a good estimation of the complex reflection coefficient within the frequency range of 1 GHz to 8 GHz. Owing to its compact size and ease of fabrication, the proposed reflectometer is suitable for various microwave broadband applications.
Background. Material tribology has widely expanded in scope and depth and is extended from the mechanical field to the biomedical field. The present study aimed to characterize the nanocoating of highly pure (99.9%) niobium (Nb), tantalum (Ta), and vanadium (V) deposited on 316L stainless steel (SS) substrates which considered the most widely used alloys in the manufacturing of SS orthodontic components. To date, the coating of SS orthodontic archwires with Nb, Ta, and V using a plasma sputtering method has never been reported. Nanodeposition was performed using a DC plasma sputtering system with three different sputtering times (1, 2, and 3 hours). Results. Structural and elemental analyses were conducted on the deposited coating
... Show MoreDiabetes mellitus is a multifaceted, chronic disease that happens either when the pancreas does not produce enough insulin or when the human body cannot competently use the insulin it produces. The study was aimed to determine and show the ultrastructural changes of cells in the placenta of women suffering from diabetes mellitus disease. In this study, a total of 102 placentas were investigated by transmission electron microscopy, which includes 34 placentas with gestational diabetes, 34 placentas with pregestational diabetes, and 34 placentas with normal pregnancy as a control group. Placental vascular-syncytial membrane, trophoblastic basement membrane, villous stroma, and fetal vessel were investigated for their thickening basement membr
... Show MoreThe utilisation of carbon fibre–reinforced polymers (CFRPs) has emerged as a promising method for enhancing the flexural performance of reinforced-concrete (RC) bridges. While extensive research has been conducted on CFRP systems implemented on flat soffit RC beams, further work is required to assess their effectiveness when applied to concavely curved soffit RC members. This paper uses finite element simulations to extend an experimental database on RC beams with curved soffits ranging from 5, 10, 15 and 20 mm/m strengthened using externally bonded FRP. Parametric studies into four different concrete strengths ranging from 25, 35, 48, 57 MPa and additional degrees of soffit curvature up to 50 mm/m were used to generate a total of
... Show MoreStructural buildings consist of concrete and steel, and these buildings have confronted many challenges from various aggressive environments against the materials manufactured from them. It contains high water levels and buildings whose concrete cover may be damaged and thus lead to the deterioration and corrosion of steel. It was important to have an alternative to steel, such as the glass fiber reinforced polymer (GFRP), which is distinguished by its great effectiveness in resisting corrosion, as well as its strong tensile resistance. Still, one of its drawbacks is that it has a low modulus of elasticity. This research article aims to conduct a numerical study using the nonlinear fi
The study was trail to treated secondary hydatid cysts in white micepost-infection with Echinococcosis of sheep origin, by immunization with a mixture of CFAgs/PSAgs prepared from haydatid Cyst Fluid antigens (CFAgs) and Proto scolices antigens (PSAgs) respectively, two concentrations (7.5 &15 mg/ml) in addition to two derivatives of benzimidazole; albendazole (A) and mebendazole (M) 10 and 40μg/gm body weight, respectively, one week after challenged dose with protoscolices. to determine the efficacy of immunization and chemotherapy simultaneously in reduction the number of growing cysts, then measured both humoral and cell-mediated immunity. Results: elevation the immune responses that reflected decrease number and diameter of hydatid cys
... Show MoreToxoplasmosis is the term for infection and disease in man and animal caused by a parasite called Toxoplasma gondii. The more susceptible to infect with toxoplasmosis is the Diabetic patients, due to low level of immunity response. The aim of current study is to investigate the immune status of diabetes mellitus type 2. One hundred and seventy five samples of both diabetes mellitus type 2patients and controls which had been tested by ELISA technique to detect anti-Toxoplasma Abs (IgG and IgM). The positive toxoplasmosis samples were tested to detect the level of TNF alpha and MIG. Results for all samples clarified that seronegative for IgM antibodies while 53 (53%) diabetic patients were seropositive for IgG antibodies and for toxoplasmosis
... Show MoreAcute myeloid leukemia (AML) is heterogeneous disorders originated from the abnormalities in the proliferation and maturation of myeloid progenitors in bone morrow. There is a clinical correlation between immunity engines and disease progression, but this relationship is not completely clear yet. This study was designed to assess the full immune response in Iraqi patients diagnosed with AML. Patients and healthy volunteers were divided into three groups: newly diagnosed untreated, under chemotherapy treatment patients and control group. A significant reduction were seen in C4 and IFN-γ levels in both untreated and treated groups with no significant difference between untreated and treated groups. On the other hand, IL-2 and IL-8 levels inc
... Show MoreBackground: The liver is one of the most common organs
injured after blunt abdominal trauma. The control of severe
hemorrhage remains a problem.
Methods: One-hundred thirty-eight patients diagnosed as
liver injury between 09/2003 and 08/2006 had been evaluated
prospectively in Al- Kindy Teaching Hospital.
A distinction was made between hemodynamically stable and
unstable patients. Different modalities of surgical procedures
were done concentrating on perihepatic gauze packing.
Results: (60 out of 138) patients included in the study were
clinically evaluated as hemodynamically stable. The average
abbreviated injury severity score (ISS) was 25. Twenty
patients underwent abdominal surgery. In 12 of them