Reduction Of Backscattered Radiation For X-Ray Image Quality Enhancement

This study mainly aims to reduce backscattered radiation inside an X-ray room. The characteristics of X-ray attenuation in several materials such as lead, copper, iron steel, aluminium, and concrete have been investigated under different exposure parameters to measure their abilities to attenuate incident X-ray and to reduce backscattered X-ray. Lead and Iron presented good attenuation values for incident X-ray at radiographic diagnosis energy range (50 -110 kVp), whereas iron and aluminium reflected the least amount of backscattered radiation dose. A number of anti-scatter grids have been designed and fabricated from iron steel and aluminium, because of their relatively better abilities to reduce backscattered radiation compared to other materials

A Novel Method for Evaluating the Dynamic Load Factor of An Involute Gear Tooth with Asymmetric Profiles

In this paper a new generation of asymmetric tooth profile gear is considered  to enhance the dynamic behavior and vibroacoustic properties of toothed gear system. This paper presents a non linear dynamic model as a single degree of freedom equation for teeth meshing   gear system which includes   static and dynamic transmission error in order to investigate the influence of time varying mesh stiffness and periodic tooth errors on dynamic load factor for symmetric and asymmetric spur teeth profile.  A new  model of nonlinear time varying mesh stiffness is based on four types of deflections with consideration a small   pressure angle for loaded tooth profile side and high pressure angle for another side. The complicated variation of meshing stiffness as a function of contact point along the mesh cycle is studied. Typical dynamic load factor equations are developed for symmetric and asymmetric tooth gear in single   and double tooth contact by studied symmetrictooth with pressure angle ( 200/200 ) and two pairs of asymmetric teeth (14.50/250 & 200/250 ).  The effect of pressure of asymmetry and static transmitted load   on transmission error and dynamic load factorare studied. The results indicate enhancement  percentage   in transmission error and dynamic load factor for asymmetric teeth profile compare with that symmetric   tooth profile    . Keywords: Asymmetric spur gear, Transmission Error   , Non-linear mesh stiffnes

An Investigation about The Deuterium-Deuterium Nuclear Fusion differential cross section.

Differential cross section for the D-D fusion reaction represents an important parameter in calculating the neutron or proton yield and this calculation need to study the changes of the differential cross section with both deuteron energy and reaction angle .We see that the differential cross section are strongly effected with a range of reaction angle between [0-100] degree , and it seems that it has a maximum value when the reaction angle equal to zero because the present of the parameter cos θ in there calculated equation .From the figures we notice a good agreement between our calculated results and the experimentally results. This lead to the ability for using this model in the future for different calculations and the ability for modifying it's to construction a like formulas for another fusion reactions by depending on their physical characteristics

Design and analysis of a dynamic code division multiple access communication system based on tunable optical filter

A dynamic optical code division multiple access (DOCDMA) communication system is proposed for high-band-width communication systems. An implementation of the system is proposed based on a fast tunable optical filter (TOF) in each encoder and decoder. This technique actively modulates the central wavelength of a TOF according to a functional code at the transmitter during the bit period before the transmission of the data. The system is modeled and analyzed taking into account multiple access interference (MAI), thermal noise, and phase-induced intensity noise (PIIN). The performance of this system is compared to that of a spectral amplitude coding system that uses either a Hadamard code or a modified quadratic congruence (MQC) code. The results show that the proposed DOCDMA system reduces the PIIN effect on the performance of the system and improves the bit error rate (BER) performance at a large number of users. Furthermore, it is found that when the effective power is large enough, the MAI becomes the main factor that limits system performance, whereas when the effective power is relatively low, both thermal noise and PIIN become the main limiting factors with thermal noise having the main influence. © 2005 IEEE

X-ray Protection Using Mixture of Cement Shielding with Barium Sulfate

This study aims to investigate a way to reduce transmitted x-ray through cement shielding. A cement shielding which painted by Barium Sulfate capable of absorbing a significant portion of X-ray was used with different thickness and composition. The measurements were recorded at various applied voltages (50 kVp to 120 kVp), and the transmitted and backscattered x-ray was measured using ion chamber. The results showed that the cement shielding painted by Barium Sulfate was very effective in the absorption of incident x-ray up to about 95%, and has the ability to reduce backscattered x-ray radiation up to about 75 % by using fabricated iron steel grid based on a plate composed from cement shielding painted by Barium Sulfate

Internet of Things and Health Care in Pandemic COVID-19: System Requirements Evaluation

Technology adoption in healthcare services has resulted in advancing care delivery services and improving the experiences of patients. This paper presents research that aims to find the important requirements for a remote monitoring system for patients with COVID-19. As this pandemic is growing more and more, there is a critical need for such systems. In this paper, the requirements and the value are determined for the proposed system, which integrates a smart bracelet that helps to signal patient vital signs. (376) participants completed the online quantitative survey. According to the study results, Most Healthcare Experts, (97.9%) stated that the automated wearable device is very useful, it plays an essential role in routine healthcare tasks (in early diagnosis, quarantine enforcement, and patient status monitoring), and it simplifies their routine healthcare activities. I addition, the main vital signs based on their expert opinion should include temperature (66% of participants) and oxygenation level (95% of participants). These findings are essential to any academic and industrial future efforts to develop these vital wearable systems. The future work will involve implementing the design based on the results of this study and use machine-learning algorithm to better detect the COVID-19 cases based on the monitoring of vital signs and symptoms.Comment: 6 pages, 5 figure

Convexifying of polynomials by convex factor

W pracy podajemy nowe wyniki dotyczące "uwypuklania" wielomianów rzeczywistych, a w szczególności uogólniamy niektóre z rezultatów z pracy K. Kurdyka, S. Spodzieja, „Convexifying positive polynomials and sums of squares approximation”, SIAM J. Optim. 25 (2015), no. 4, 2512-2536. Pokazujemy też pewne zastosowania uzyskanych wyników w optymalizacji

Configuration design and performance analysis of a fast frequency modulation optical CDMA communication system

A fast frequency modulation optical code division multiple access (CDMA) communication system is proposed. In this system, an electrically controlled tunable optical filter (TOF) is used to encode the modulated broadband light source. The code depends on the function set to the controller. Two-dimensional functional code is also proposed based of shifted sine function. The function defines the dynamic coding pattern of the central wavelength of the transmitted narrowband optical signal. The system allows for an easy reconfiguration of the transmitter without the need for sophisticated encoder. At the receiver, a synchronized TOF with the same function is used as a decoder. The performance of this system is shown to be better compared with a fast frequency hopping and a spectral amplitude coding systems

Mantle Cell Lymphoma Presenting as Diarrhea in a Liver Transplant Recipient

We present a 63-year-old man with a medical history of hepatocellular carcinoma who underwent orthotopic liver transplant 10 years prior on long-term immunosuppressive therapy. The patient presented to the clinic with diarrhea, and the workup revealed mantle cell lymphoma. Mantle cell lymphoma is an extremely rare finding in transplanted livers. It is essential to include mantle cell lymphoma, along with a broad differential, during the workup of diarrhea in post-transplant patients

Efficiency of Bacillus mucilaginosus isolated from the soil in dissolving potassium in its microenvironment

Soil bacteria have an effective role in dissolving soil potassium. Bacillus mucilaginosus plays an effective role in dissolving potassium in the soil so that the plant may absorb it easily. The present study aimed to test the efficiency of bacteria in dissolving potassium present in the soil surrounding the roots of crops. B. mucilaginosus was isolated and diagnosed from the rhizosphere soil of Celery, Wheat, Basil and Alfalfa plants. The diagnosis included studying the isolates' culture, microscopic and biochemical characteristics. The laboratory study also included testing the efficiency of these bacterial isolates in dissolving potassium compounds in Modified Aleksandrov agar medium and estimating the dissolution coefficient. The results of isolation and identification of bacteria isolated from 19 out of 50 soil samples planted with different crops (Celery, Wheat, Basil and Alfalfa) showed that 8 isolates could dissolve potassium. The results of the microscopic examination of these eight isolates showed that they were sticky in shape, positive for Gram-staining, forming spores and the capsule, while the movement examination showed that they were positive for these tests (movement test). The biochemical tests and cultural characteristics showed that the eight isolates bear the characteristics of B. mucilaginosus. The results showed that the dissolution coefficient of potassium for the different isolates ranged between 2.28 and 1.14, while the type of sugar added to the culture medium increased the efficiency of bacterial isolates for potassium solubility. The study demonstrated the bacteria's efficiency in the rhizosphere region in dissolving potassium, which helps the plant use it easily.