Pioneer Solar Water Desalination System: Experimental Testing and Numerical Simulation

A pioneer system of solar water desalination was constructed, tested and numerically simulated for moderate latitudes, Cairo 30 °N. The humidification/dehumidification (HD) process is considered in this system. The salt water is heated by either solar energy or/and auxiliary heater before injection inside an insulated desalination chamber using an air atomizer. The air is supplied into a condenser by a 0.4 kW blower and later on it pulls hot salt water up through the atomizer from an insulated tank. By this idea the air is preheated inside the condenser and is used as a water pump. The flashing water is evaporated and condensed simultaneously above the condenser surface. A 2.39 M2 flat-plate solar collector is used to heat the salt water existed in an insulated tank. The tank opening is closed by the chamber one. By this way the salt water is circulated naturally inside the solar water heater where it is forced inside the desalination chamber. A numerical simulation of the considered system was developed and validated. It was provided a mathematical model of each system component. The system was successfully tested using either solar or/and auxiliary energies. It can produce about 36 liter daily of purified water where the using of solar energy alone can obtain about 12 liter on clear days. To visualize the heat and mass transfer inside the chamber temperature and humidity distribution were measured. The annual and monthly performance of the system is presented. In addition an empirical equation of the distilled water quantity is obtained versus the incident solar radiation. Moreover, economic study was provided and it is found that one liter of distilled water can cost about 0.2 US$ using the considered system. Key words: Solar desalination; Air atomizer; Air condenser; Thermosiphon; Humidification/dehumidification; Numerical simulatio

Effect of prophylactic salpingectomy on ovarian function in premenopausal women in tertiary referral center

Background: Epithelial ovarian cancers (EOCs) are the most common cause of death from gynaecological malignancy. Serous ovarian carcinomas represent (68%) of Epithelial ovarian cancers, they are further divided into low-grade (type I) and high-grade (type II) serous ovarian carcinomas. There has been increasing evidence that fallopian tubes are considered the most important site of origin of pelvic high grade serous carcinoma. Salpingectomy is thought to be effective in reducing ovarian cancer risk in the future and prolonging average life expectancy, however, there are some concerns regarding ovarian function after elective salpingectomy in premenopausal women. The current study was carried out to assess the effect of salpingectomy on ovarian function in premenopausal women.Methods: 60 premenopausal cases were recruited and subjected to open abdominal hysterectomy without oophorectomy (for benign indications). Included cases were below 45 years, with documented active ovarian functions. Cases with genital malignancy, ovarian gross pathology and suspected or known ovarian failure were excluded. Cases were randomly allocated to one of two groups; group-A (where salpingectomy was performed), and group-B (where salpingectomy was not done). For all patients, ovarian functions were assessed prior operation, and at one and three months after operation using serum anti-Mullarian hormone (AMH) as well as early follicular antral follicular count (AFC), serum follicle stimulating hormone (FSH) and serum oestradiol (E2).Results: The mean pre-operative AFC, AMH, FSH, and E2 levels showed no significant changes after operation at one and three months postoperative follow up in both studied groups, denoting preserved ovarian function in both groups.Conclusions: Prophylactic salpingectomy is a safe and simple procedure that has no effect on ovarian reserve or function when performed in premenopausal women

Effects of chronic estradiol treatment on the thyroid gland structure and function of ovariectomized rats

<p>Abstract</p> <p>Background</p> <p>Estrogen therapy is widely used nowadays in women to treat many postmenopausal symptoms but it may have some undesirable effects due to multiple organs affection. So, the aim of this study was to determine the effects of chronic estradiol treatment on the structure and function of the thyroid gland in ovarictomized rats as a model simulating menopause.</p> <p>Findings</p> <p>Thirty adult female Wistar rats divided into three groups were used in this study; the first group was sham-operated, while the second and third groups were ovariectomized. The first and second groups were injected with olive oil while the third group was injected with estradiol dipropionate daily for three months, after that; hormonal assay for T3, T4, TSH and specimens of the thyroid were taken and processed to be examined by light and electron microscopy. The results of this study revealed that serum levels of T3 and T4 decreased in ovariectomized animals and significantly increased after estradiol treatment, while TSH increased in ovariectomized animals and decreased with estradiol treatment. Histological and morphometric study in ovariectomized group revealed marked accumulation of colloid in follicular lumens with decreased epithelial height in addition to increased connective tissue amount. After estradiol treatment the follicles became smaller in size, having small amount of colloid with increased epithelial height in addition to decreased connective tissue content. Ultrastructural study supported these results in addition to the presence of large amount of intracytoplasmic colloid vesicles after estradiol treatment.</p> <p>Conclusion</p> <p>Low estrogen level may lead to mild thyroidal hypofunction while estradiol treatment may lead to hyperactivity so it should be used very cautiously in the treatment of postmenopausal symptoms to avoid its undesirable stimulatory effect on the thyroid.</p

Performance of a Solar Chimney Under Egyptian Weather Conditions: Numerical Simulation and Experimental Validation

High solar radiation and ambient temperature, and large desert in Egypt are excellent conditions to install efficiently solar chimney power plants there. Therefore this research aimed to develop a validated mathematical model and governing equations of solar chimney. It is proposed to improve the performance of solar chimney under effects of various parameters, and study of possibility of installing solar chimney in Egypt. The mathematical simulation of the solar chimney has been developed including all its performance parameters, dimensions (of collector, chimney and turbine) and the metrological data; which were considered as inputs of the simulation program. A comparison between the mathematical and experimental performance has been investigated to validate the mathematical simulation. The mathematical model has been used to predict the performance of the solar chimney power plant over a year in Egypt. It is used to study of effects of geometrical parameters, and investigate possibility of the optimum geometrical dimensions. It is obtained that there is in fact no optimum physical size for such plants without considering the economical constraints. The chimney height has a significant effect in the chimney performance. Visualizing of annual performance of the solar chimney would seem to be essentially a power generator in Egypt if it installed in a large scale.Key words: Solar chimney; Numerical simulation; Annual performance; Experimental validation; Optimizatio

Myocarditis: an expected health hazard associated with water resources contaminated with Coxsackie viruses type B

Enteroviruses, especially Coxsackie B viruses (CBVs), are responsible for approximately 50% of cases of viral myocarditis. In the present study, serum samples (160) were collected from acute myocarditis patients at different age groups and 104 samples of the same age groups as a control. Cholesterol, LDH, CPK, and GOT were measured for all serum samples (264). Also, to study the source of virus transmission, 72 water and 72 wastewater samples were collected from water and wastewater treatment plants at intakes and outlets. Water and wastewater samples were concentrated by filtration through Zeta-plus filter cartridges and reconcentrated by the PEG-6000 precipitation method. Serum, water, and wastewater samples were inoculated in BGM cells for three successive passages. RT -PCR with enterovirus primers was carried out directly for serum samples and for 1st and 3rd cell culture passages. The positive samples were used for neutralization assay using anti-CBV sera pool to determine the CBV followed by neutralization with separate antisera. The results showed that 50 (31.25%) serum samples from acute myocarditis patients and two (1.4%) samples from the controls were positive for enterovirus RT -PCR. For water and wastewater samples enteroviruses were present in 63.8% and 8.3% for intake and outlet of water treatment plants and, 66.6% and 47.2% for intake and outlet of wastewater treatment plants, respectively. The level of CBV serotypes was varied where CBV3 was dominant for all age groups of myocarditis patients and CBV2 and CBV5 were also detected while CBV2 was the main CBV in water samples and CBV2, 3 and 5 were detected in wastewater samples. The integration of cell culture-PCR reduces the time required for virus detection and enhances the sensitivity of the test

Pattern of community and hospital acquired pneumonia in Egyptian military hospitals

AbstractBackgroundCommunity-acquired pneumonia (CAP) is one of the most common infectious diseases addressed by clinicians. CAP is an important cause of mortality and morbidity worldwide.Aim of the workThe aim of this study was to identify the causative bacteria, antibiotic sensitivity and antibiotic resistance of community and hospital acquired pneumonia in a group of Egyptian military hospitals.Patients and methodsThis study included 239 patients who were admitted to five major Egyptian Military Hospitals (Kobbry El kobba, El-Maadi, Masr Elgadida, El-Galaa and Ghamra) during the period from March 2012 to August 2012 and were selected due to suspicion of developing pneumonia either community or acquired due to hospital stay according to clinical, laboratory and/or radiological evidence.ResultsThis study consists of (239) patients, (187) patients were CAP and (52) patients were HAP divided in five hospitals. The obtained results showed insignificant relationship between type of organisms and concomitant illness of these patients with the highest incidence in patients below 60years (71.6% in CAP and 44.2% in HAP), patients receiving immunosuppressive drugs (40.1% in CAP and 22.3% in HAP) and diabetics (40.4% in CAP and 40.3% in HAP).ConclusionOur study showed that Gram positive organisms were the most prevalent in CAP especially Streptococcus pneumonia followed by Staphylococcus aureus, while Klebsiella was the most prevalent Gram negative organism. On the other hand our study showed that Gram negative organisms were the most prevalent in HAP especially Klebsiella followed by Pseudomonas aerginosa, while Staphylococcus haemolyticus was the most prevalent Gram positive organism

The Dromiusina Bonelli, 1810 of southwestern Saudi Arabia with description of a new species (Coleoptera, Carabidae, Lebiini)

In this paper, species of the subtribe Dromiusina Bonelli, 1810 from southwestern Saudi Arabia are revised. Eleven species in six genera (Calodromius, Dromius, Mesolestes, Metadromius, Microlestes, and Zolotarevskyella) are recognized. Dromius saudiarabicus Rasool, Abdel-Dayem and Felix, sp. n. is newly described species from Rayda Nature Reserve Asir province. The presence of Metadromius ephippiatus in Saudi Arabia is doubtful. A key is also provided to genera and species level for Dromiusina of Saudi Arabia

Innovative solar natural vacuum desalination system

The main target of the work is a design of an innovative solar natural vacuum desalination (SNVD) system and improve performance of such systems. The natural vacuum is developed by raising up an evaporation chamber to 9.8 m above the ground. The waste heat is efficiently utilized in that system to minimize the system heat loss. The fresh water is first preheated by condensing vapor from the evaporation chamber before it is heated by a flat-plate collector as a heat source of the evaporation chamber. On the other side, the sea water is preheated by the produced warm water, and it is reheated by the exit brine water before it is supplied into the evaporation chamber. A mathematical model and a transient simulation were established to investigate the annual performance of system. A heat balance of each system component was provided to estimate the inlet and outlet temperature and flow rate of it. Moreover, the collector area was estimated based on assumed mass flow rates of both feed sea water and coolant water. It was found that the system can produce a daily production of 6.2 L of pure water per a quadratic meter of collector on annual average basis. That Productivity can be estimated as 1.12 L of water per kWh solar radiation. Accordingly, the evaporation rate was estimated as 2.82% while the gain output ratio (GOR) was obtained as 0.63. The system performance can be accepted compared with the corresponding published systems