Performance of plate fin compact heat exchangers

Heat exchangers design includes the consideration of both the heat transfer rates between two fluids and the pumping power required to overcome fluid friction and push the fluids through the heat exchangers. In gas flow heat exchangers, the friction power limitations force the designer to select moderately low mass velocities. Low mass velocities with low thermal conductivities will result in low heat transfer rate per unit of the surface area. Thus a large surface area is a typical characteristic of a gas flow heat exchanger; The problem of a large required area can be solved by using large area density which will lead to compact heat exchangers. The main target of this study is to provide full explanation of previous comparison methods of compact heat exchangers surfaces (plain, strip, louvered, wavy, pin, perforated and vortex) used in plate fin compact heat exchangers and to generalize these methods in order to identify the advantages and disadvantages of each type of geometry based on required size, entropy generation, pumping power, weight, and cost

The Construction of Islamic Identity in Everyday Life: The Case of the Muslim Brotherhood in Egypt

This thesis explores the formation of the Muslim Brotherhood (MB) identity in everyday life. It accounts for unpacking the underlying processes and factors that shape the identity of the MB’s members. It thus examines the MB’s recruitment and mobilization mechanisms, meaning and symbolic productions, social networking, and the resilience of the MB identity. This study attempts to answer a key question: how does the MB construct its identity in everyday life? It investigates the identification and socialization process that happens within the MB. The study reveals that ikhwanism, a sub-culture that encompasses and guides the MB leaders and members in everyday life, plays a pivotal role in preserving the MB’s identity. Ikhwanism denotes the cognitive system of norms, values, standards, and symbols that informs and guides the MB’s members in everyday life. Thus, to be an ikhwani does not only mean to embrace the MB’s ideology and worldview but also to act as a committed and obedient member in everyday life. Therefore, the study investigates the tools and mechanisms that are utilized by the MB in order to forge and reshape members’ perceptions and behaviour. In addition, the thesis explores the effects of the semi-authoritarian policies on the MB’s identity and coherence. It examines how the MB survived under the autocratic regime of Hosni Mubarak despite the relentless waves of repression and exclusion. The findings of the study reveal the ability of the MB to operate under regime repression and to sustain its coherence and identity. Primary data was collected through interviews with several members and leaders in the MB. The data reflects the complexity of the MB as a social organization. It demonstrates that the MB could blend the ideational and institutional factors in order to articulate and preserve its identity. Moreover, the findings of the study reveal the power struggle within the MB between the so-called conservatives and reformists. The study demonstrates that regime repression enabled the conservatives to control the MB at the expense of the reformists. It predicts that the former will likely control the MB for years to come

The Impact of using Computer-Aided Design (CAD) on the Creativity of Architecture Students

The architectural design process is based on imagination where creativity is highly valued. Contemporary goals in higher education and particularly architectural design education include giving students tools to stimulate the search for creative solutions to problems. One of those tools is the Computer-Aided Design (CAD) tool. The use of CAD in the latter stages of the design process for efficiency purposes has become common. However, the integration of CAD into the early, schematic stages of the design process has initiated some debate where empirical evidence regarding the impact of CAD on the creativity of architectural design solutions and the influence on the creative mental process of students is lacking. The aim of this paper is to determine whether the use of CAD effectively enhances students' creative concepts. Other than descriptive-analytic methodology, the study was divided into two stages: an experimental study and a questionnaire. The first stage aimed to examine the effect of using pencil-based and computer-based methods on the creativeness of architectural solutions in the preliminary design phases. The second stage aimed to gather rich descriptions of how CAD is used in architectural design education. The respondents of these two stages were students of the Department of Islamic Architecture, Umm Al-Qura University, KSA.The study concluded that the use of CAD did not significantly inhibit, nor did it enhance creativity in the preliminary design stage compared to the pencil-based design method

Role of measuring serum procalcitonin and receiving prophylactic antibiotic therapy in critical COVID-19 patients.

Background:Coronavirus disease 2019 (COVID-19), caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been declared as a pandemic in 2019-2020. Most cases are usually self- limited; however, it may unpredictably progress to severe form with high mortality rate. Objectives: To highlight the role of measuring serum procalcitonin (PCT) and receiving early prophylactic antibiotic therapy in terms of their relation to the mortality rate in hospitalized critical COVID-19 patients. Methods: this study analyzed sixty COVID-19 critical patients admitted to Tanta University Isolation Hospital from June to November, 2020. Respiratory tract and blood samples were collected Results: Our results showed that the mean serum PCT levels were significantly higher in deceased patients (15%) than in those who could survive corona-virus infection. Patients who received early prophylactic antibiotic therapy showed significant better survival rate than those who didn’t. Conclusion: This study demonstrated that measuring PCT shows statically significant results with COVID-19 patients’ outcome more than other commonly used laboratory markers such as CRP. Moreover, early administration of prophylactic antibiotic therapy in COVID-19 patients, especially critical ones, is crucial even in those with negative PCT values

Hypogonadism in patients with chronic obstructive pulmonary disease: relationship with airflow limitation, muscle weakness and systemic inflammation

AbstractObjectivesTo determine the prevalence of hypogonadism in male patients with Chronic obstructive pulmonary diseases (COPD), and to study its impact on skeletal muscle dysfunction and assess the effect of systemic markers of inflammation on testosterone level and muscle function. The study included 50 stable male COPD patients and 30 controls.MethodsBoth groups were subjected to the following measurements; inflammatory markers levels (high-sensitivity C-reactive protein (hs-CRP) and interleukin – 6 (IL-6)), sex hormones including; serum total (T) and free testosterone (FT), sex hormone binding globulins (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and 17β estradiol levels (E2), the exercise capacity (6-minute walk distance (6MWT)) and quadriceps muscle force (One repetition maximum (1RM) and EMG). COPD patients underwent spirometry.ResultsThere was a higher prevalence of hypogonadism in COPD patients than the controls (62% versus 17%). There was a significant negative correlation between serum testosterone levels (T and FT) and the severity of airway obstruction. Quadriceps muscle force and the exercise capacity were significantly lower in COPD patients than controls but they showed no correlation with the testosterone level. Inflammatory markers were significantly higher in COPD patients compared to controls and showed a significant correlation with the severity of airflow obstruction. The higher inflammatory markers levels were related to more muscle weakness as hs-CRP was inversely correlated with the quadriceps strength and exercise capacity, while IL-6 was inversely correlated to quadriceps strength only.ConclusionHypogonadism is highly prevalent in clinically stable COPD patients and is particularly related to the severity of the airway obstruction. Systemic inflammation is present in stable COPD patients and its intensity is related to the severity of the underlying disease and it predisposes to skeletal muscle weakness and exercise intolerance. However, we failed to find a significant association between hypogonadism and muscle weakness or systemic inflammation

A multi-band MIMO antenna system with coupled-fed modified rectangular patch elements for 5G systems

A four-port multiple input multiple output (MIMO) antenna system constructed of four compact dual-band (38/60 GHz) microstrip patch antennas is proposed for 5G mobile applications. Each individual element is optimized to achieve the desired performance of the overall MIMO system. Numerical and experimental investigations are achieved to assess the performance of both the single-element antenna and the four-port MIMO antenna system. It is shown that the simulation results agree with the experimental measurements, and both show good performance of the proposed MIMO antenna system. The bandwidths achieved around 38 GHz and 60 GHz are about 2 GHz and 3.2 GHz, respectively. The performance of the MIMO antenna system including the return loss at each antenna port and the coupling coefficients between the different ports are investigated. The radiation patterns produced when each port is excited alone are shown to be suitable for spatial diversity scheme. They have a high radiation efficiency exhibited by a balloon-like shaped radiation pattern for both the upper and lower frequency bands. It is shown that the envelope correlation coefficient (ECC) and the diversity gain (DG) are suitable for performance for the targeted 5G bands.</p

Assessment of the Relation between Serum Carcinoembryonic Antigen and Tumor Node Metastasis Staging of Colorectal Cancer

Background: Although awareness via cancer screenings and the knowledge of therapy modalities has increased, the burden of colorectal cancer (CRC) is much more pronounced in developing countries. Objective: This study was aimed to estimate serum carcinoembryonic antigen (CEA) levels in preoperative CRC patients and to determine the associations between serum CEA levels and tumor node metastasis (TNM) stage.Patients and methods: This cross-sectional study included 36 patients with CRC (stages IV) attending at Department of General Surgery, Zagazig University Hospitals. Patients scheduled preoperatively for sigmoidoscopy were prepared by an enema and examined by using standard video endoscopes. The CEA levels were estimated preoperatively for all patients. Results: CEA level among the studied cases ranged from 0 to 23 ng/dl with mean 6.39 ng/dl and median 4.5ng/ml. Also 58.3% had CEA level ≤ 5 ng/ml. There were no statistical significance relations between the CEA and age or sex distribution. But there was a statistical significance increase in frequency of smoking among cases had CEA level &gt;5 ng/ml. There was no statistical significance relation between site and diameter of lesions and CEA level among the studied cases.Conclusions: It could be concluded that there is a meaningful link between TNM stage and CEA level. However, normal levels of CEA will not rule out CRC diagnosis, and these patients should be investigated in detail

Evaluation of Digital Brixmeter Performance for Brix Measurement In Raw Sugar Solution

The Brix value is an important factor in the sugar industry's extraction processes. Brix refers to the amount of sucrose in the raw sugar solution. The concentration of dissolved solids in a solution is measured by the degree Brix (symbol °Bx). One gram of sucrose in 100 grams of solution equals one-degree Brix. a New Suggested method for measuring brix was designed to be low-cost and accurate Brix measuring in raw sugar solutions. it was depended on Electronic sensors can directly measure the mass, and temperature of the solution to express the brix and give the result on the screen. Digital suggested brixmeter was made based on this method. It can be used manually on the production line and in various food industries. The aim of this paper was to evaluate the digital brixmeter performance for measuring brix in raw sugar solutions. Brix measurements were tested for a group of samples at different sizes to find the optimal measurement sizes can verify accurate brix degree value. The factors affecting the accuracy of the measurement were also studied. The results were compared with the brix read from accurate optical refractometer to check and a prove the accuracy of the proposed digital brixmeter

Poisoning emergency visits among children: a 3-year retrospective study in Qatar

Background Poisoning in toddlers and infants is almost always unintentional due to their exploratory behavior, which is different from adults. The prevalence and background of childhood poisoning in Qatar is still unknown. The aim of this study is to explore the extent of childhood poisoning in Qatar and, specifically, to describe the frequency of poisoning as a cause of Accident & Emergency (A&E) admission, the demographic profile of affected patients, the circumstances leading to exposure, and the specific agents involved in poisoning among children under age 14 in our setting. Methods This study was a cross-sectional survey of children up to 14 years old utilizing retrospective data between October 2009 and October 2012. The data were collected from the childhood poisoning case registry and patient medical records at the Accident and Emergency (A&E) Unit of all the Hamad Medical Corporation hospitals. Pharmacists reviewed all the handwritten medical records. Data written on the data collection form were transferred into excel and later into SPSS version 21. The data were analyzed using frequencies and percentages, and a chi-square test was used for categorical variables. Results Out of 1179 registered poisoning cases listed in the registry, only 794 cases (67.3 %) were usable and included in the final analysis. A&E admissions for unintentional poisoning for children accounted for 0.22 % of all A&E admissions from 2009 to 12. The majority of poisoning cases happened among children between 1 and 5 years old (n = 704, 59.7 %). Cases were more frequent among non-Qatari than Qatari children (39.4 % vs. 28.5 %). Most cases occurred in the living room (28.2 %) and typically took place in the afternoon (29.2 %). Analgesic and antipyretic medicines were the most common agents ingested by children (n = 194, 36.9 %), specifically paracetamol (n = 140, 26.6 %). Conclusions Cases of unintentional poisoning are higher among children aged 1 to 5 years, males and non-Qatari. Most cases occurred in the living room and typically took place in the afternoon. The most common type of poison ingested by children was medicines, i.e., analgesics and antipyretics, specifically paracetamol

Vitamin D Receptor Gene (Fok-I) Polymorphisms in Type 1 Diabetic Children; Case Study in Zagazig University Hospitals

Background: Many meta-analyses studied the association between vitamin D receptor (VDR) gene polymorphism and type 1 diabetes (T1DM) susceptibility. Objective: This study was designed to assess the role of VDR gene (FOK-I) polymorphisms in type 1 diabetic children from Zagazig University Hospitals in Egypt. Patients and Method: In this case-control study, the genotypes of VDR gene (FOK-I) polymorphisms were assessed in 180 type 1 diabetic children and 120 healthy matched age controls by PCR-RFLP analysis. Results: A high statistical difference between patient and control regarding VDR gene (FOK-I) polymorphisms, where 44% of the patient group had heterozygous genotype (AG) compared to 8.3% in the control group. AG genotype has almost a higher risk nine times odds ratio (OR) = 8.8 than AA genotype in diabetic patients. There was a significant increase in the G allele in the patient group. Moreover, a significant association between (FOK-I) polymorphisms and T1DM complications was also observed. Conclusion: (AG) genotype of VDR gene (FOK-I) polymorphisms could be a risk factor for T1DM complications. So, VDR gene (FOK-I) polymorphisms should be performed with other genetic studies for early prediction, detection and prevention of microvascular complications of T1DM that adversely affect health-related quality of life of Egyptian children and burden the primary care units