1,091 research outputs found
Pengaruh Project Based Learning terhadap Kemampuan Mengenal Bentuk Geometri Anak Usia 5-6 Tahun
Penelitian ini bertujuan untuk mengetahui ada tidaknya pengaruh model project based learning terhadap kemampuan mengenal bentuk geometri pada anak usia 5-6 tahun di TK Pertiwi 14.19.05 Gunungsari pada semester genap tahun ajaran 2022/2023. Penelitian ini merupakan jenis penelitian pre-experimental design. Desain yang digunakan adalah One-Group Pretest-Posttest Design. Populasi dalam penelitian ini adalah anak usia 5-6 tahun di TK Pertiwi 14.19.05 Gunungsari dengan sampel 30 anak. Objek penelitian ini adalah kemampuan mengenal bentuk geometri melalui pendekatan project based learning. Metode pengumpulan data dalam penelitian ini adalah observasi dan dokumentasi, sedangkan teknis analisis data dengan uji validitas, reliabilitas dan normalitas. Hasil penelitian menunjukkan bahwa kemampuan mengenal bentuk geometri anak usia 5-6 tahun meningkat setelah adanya perlakuan. Model project based learning memberikan pengaruh terhadap kemampuan mengenal bentuk geometri anak usia 5-6 tahun di TK Pertiwi 14.19.05 Gunungsari
Secondary Students’ Engagement in Jigsaw Method-Asissted Vocabulary Learning
This study aims to determine the involvement of students in learning vocabulary using the jigsaw method. This research belongs to the type of descriptive qualitative research. The subjects in this study were students of class VIII A of SMPN 2 Telagasari, totaling 32 students. This study uses observation, interviews, and documentation to collect data. Observations were made for two meetings, then interviews were conducted to determine the involvement of students in learning vocabulary using the jigsaw method. The results of this study indicate that a) group discussion session of jigsaw involves students' to learn vocabulary interactively (Cognitive Engagement). All participants stated that the jigsaw method helped students to learn vocabulary well and discussions with friends helped them in learning, then students are also interested in asking questions during the learning process. b) exchange expert group students' in a team motivate members to do task (Behavior Engagement) it can be seen from the results of observations and interviews that have been carried out that students are motivated to work on vocabulary assignments because they interact more with friends during vocabulary learning. c) jigsaw method attracts students' enthusiasm in vocabulary learning (Emotional Engagement) it can be seen from the results of observations and interviews that have been done that students like to learn vocabulary using the jigsaw method on the grounds that the jigsaw method is fun and easy
Can women have it all?
Can women have it all? A fulfilling career and a stable family life? Throughout the generations women have been passing through different circumstances with their career lives depending on their ages and their life restrictions. Some graduate and don’t find a job, some other dedicate their whole time to pursue their career and some on the other hand are forced to leave their jobs to build a family
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
Correlation of dynamic contrast enhanced MRI imaging characteristics with gene expression profiles in renal cell carcinoma
Evaluation of the microleakage of different class v cavities prepared by using Er:YAG laser, ultrasonic device and conventional rotary instruments with two dentin bonding systems: an in vitro study
The aim of this study was to evaluate the extent of microleakage in class V cavities prepared with bur, Er:YAG laser and ultrasonic, hybridized with two different bonding agents (“Single bonding”, a solvent-free bonding agent, and “Swiss TEC SL bond”, an alcohol-based solvent).Thirty freshly extracted human premolars were divided into three groups of ten teeth each according to the device used in cavity preparation: Group1) Er:YAG laser (500 mJ, 10 Hz, 63.69J/cm2); group 2) ultrasonic device and group 3) diamond burs. On each tooth, two cavities were prepared, one on the buccal surface and one on the lingual surface.Each group was subdivided into two subgroups of 5 teeth each according to the bonding system used: subgroup a) “Single bonding” and subgroup b) “Swiss TEC SL bond”. Cavities were restored with a micro-hybrid composite resin. After thermocycling, the specimens were immersed in 2% methylene blue solution for four hours and then sectioned in the buccolingual direction. Dye penetration was scored using a stereomicroscope. The two-way ANOVA test and paired t-test revealed no statistically significant differences among the methods of preparation (conventional, laser and ultrasonic). However, statistical differences were found between the adhesives tested; the “Single bonding” had lower microleakage values than “Swiss TEC SL bond”.Based on the results of this study it can be concluded that the Er:YAG laser and ultrasonic device are as effective as the conventional method in preparing cavities. The extent of microleakage depends on the type of the bonding agents
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
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
An annotated checklist of the endemic Carabidae (Coleoptera) of Egypt
Endemic species are usually not very widespread in their distribution, but are only found in a particular region and nowhere else in the world. Because of this, they are of great conservation concern. A checklist of the endemic carabid beetles of Egypt was compiled and updated from published and unpublished records including long-term surveys. As far as can be ascertained, there are 39 valid carabid species and subspecies from 28 genera that are endemic to Egypt including Sinai. These represent about 16.3% of the total carabid fauna recorded from the country, and belong to five subfamilies: Brachininae, Cicindelinae, Harpalinae, Scaritinae, and Trechinae. I provide notes about type localities, depositories and distribution
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
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