28 research outputs found
PENGARUH METODE HYPNOTEACHING TERHADAP MOTIVASI BELAJAR SISWA PADA PEMBELAJARAN PECAHAN DI KELAS IV SDN 56 BANDA ACEH
Investigation of Positioning Accuracy of AR Approach on PPP Method
Yüksek Lisans TeziGNSS ile konum belirleme uzun yıllardan beri jeodezi ve diğer yer bilimleri gibi pek çok alanda
yaygın şekilde kullanılmaktadır. Yer kabuğu hareketleri, deformasyon izleme, ulusal/uluslararası
datumların belirlenmesi gibi pek çok alanda bağıl konum belirleme yöntemi kullanılmaktaydı. IGS’ in
hassas yörünge ve saat bilgilerinin kullanıcıların hizmetine sunmasıyla hassas nokta konum belirleme
yöntemine ilişkin çalışmalar hız kazanmıştır. Tek bir GNSS alıcısı ile arazi işinin halledilmesi ile
kullanıcılar açısından daha ekonomik olması yöntemin avantajları arasındadır. Son yıllarda ise PPP’de
tamsayı belirsizliği çözümüne (AR) ilişkin çalışmalar yapılması, gelecek yıllarda yöntemin dezavantajı
sayılan yakınsama süresini iyileştirme anlamında olumlu sonuçlar vereceğini göstermektedir. Bu tez
çalışmasında PPP’de tamsayı belirsizlik çözümüne izin veren GNSS veri değerlendirme yazılımları
incelenmiştir. PPP’de AR yaklaşımının konum doğruluğuna etkisini incelemek için CSRS-PPP web tabanlı
yazılımı ile uygulama yapılmıştır. Uygulamada farklı enlem bölgelerine dağılmış 47 tane IGS istasyonuna
ait bir aylık veri kullanılmıştır. Elde edilen sonuçlara göre AR yaklaşımının özellikle doğu bileşenindeki
konum doğruluğunu iyileştirdiği görülmüştür. Ayrıca AR yaklaşımının troposfer kestiriminde de
iyileştirme sağladığı sonucu elde edilmiştir.GNSS has been widely used for many years in geodesy and other earth sciences. Relative
positioning method was used in many areas such as earth crust movements, deformation monitoring,
determination of regional or international datums. The Precise Point Positioning (PPP) method has become
available with the access of IGS’s precise orbit and clock products. The PPP method is more economical
than relative, because single GNSS receiver is enough for the field work. The recent studies on integer
ambiguity resolution (AR) of PPP showed that AR improved the convergence time and accuracy. Firstly,
PPP with AR GNSS data processing software were examined. The online CSRS-PPP was chosen to
investigate the positioning performance of AR approach on PPP method. One monthly data belong to 47
IGS stations distributed in different latitude regions was used. According to the results, it was seen that AR
approach improved position accuracy especially in the east component. In addition, it was concluded that
AR approach improved the troposphere estimation
Performance assessment of PPP-AR positioning and zenith total delay estimation with modernized CSRS-PPP
The precise point positioning (PPP) method has become more popular due to powerful online global navigation satellite system (GNSS) data processing services, such as the Canadian Spatial Reference System-PPP (CSRS-PPP). At the end of 2020, the CSRS-PPP service launched the ambiguity resolution (AR) feature for global positioning system (GPS) satellites. More reliable results are obtained with AR compared to the results with traditional ambiguity-float PPP. In this study, the performance of the modernized CSRS-PPP was comparatively assessed in terms of static positioning and zenith total delay (ZTD) estimation. Data for 1 month in the year 2019 obtained from 47 international GNSS service (IGS) stations were processed before and after modernization of the CSRS-PPP. The processes were conducted for GPS and GPS + GLONASS (GLObalnaya NAvigatsionnaya Sputnikovaya Sistema) satellite combinations. Besides, the results were analyzed in terms of accuracy and convergence time. According to the solutions, the AR feature of the CSRS-PPP improved the accuracy by about 50% in the east component for GPS + GLONASS configuration. The rootmean-square error (RMSE) of the ZTD difference between modernized CSRS-PPP service and IGS final troposphere product is 5.8 mm for the GPS-only case
Performance investigation of salt gradient cylindrical solar pond integrated and nonintegrated with evacuated tube solar collectors
In this study, the energetic and exergetic efficiencies of a salt gradient cylindrical solar pond (SGCSP) that integrated and nonintegrated evacuated tube solar collectors (ETSCs) are investigated to improve daily heat preservation performance of the heat storage zone (HSZ). The integrated system is consisted of an SGCSP and four ETSCs. The SGCSP has a surface area of 2 m2, a depth of 1.65 m, salty water layers at different densities, and HSZ in which the cylindrical serpentine type heat exchanger (CSHE) is located. Thus, the daily effects of the heat storage performance of both the ETSCs and the SGCSP in the winter season was determined experimentally. The analysis of the data regarding the efficiencies of the system is investigated separately by means of experimental studies where the SGCSP is integrated and nonintegrated with the ETSCs. The number of ETSCs integrated with SGCSP is increased to 1, 2, 3, and 4, respectively, and each of the five different experimental systems is performed separately. The temperature distributions of the integrated system are measured by a data acquisition system on 11 different points per hour. The efficiencies are calculated using the data obtained from these studies. Consequently, the energetic and exergetic efficiencies of the SGCSP are obtained without collectors as 10.4% and 4.3% and with one collector as 12.83% and 6.15%, with two collectors 14.88% and 8.25%, with three collectors 16% and 9.35%, and finally with four collectors 16.94% and 10.3%, respectively. Furthermore, the theoretical efficiencies are found to be consistent with the experimental results obtained by increasing the collector numbers. © 2019 John Wiley & Sons, Ltd.The authors acknowledge the support provided by Cukurova University in Turkey (Grant Nos. FEF2009D2, FEF2010BAP5, and FEF2012D20)
An investigation of the effect of transparent covers on the performance of cylindrical solar ponds
The effect of the transparent covers (glass, polycarbonate, and mica) on the small cylindrical solar pond performance is studied. The temperature and density distributions are measured to evaluate the performance of the covered cylindrical solar pond. The pond covers provide a significant potential for energy savings and storage by insulating upper convective zone. Thus, such transparent covers are used for reducing the thermal energy losses from the top surface of the cylindrical solar pond. The transmission, reflection, and absorption coefficients of the covers are calculated to determine the monthly solar energy contents of the solar pond. The energy efficiencies of the solar pond are found for each type of covers from November 2008 to March 2009. As a result, the highest efficiency is determined to be 17.86% for glass cover in March, while the efficiencies of polycarbonate and mica become 16.95% and 15.86%, respectively. In this regard, the glass cover appears to be the best option for the solar ponds.Council for Higher Education FEF 2009 D2, FEF 2004 BAP4, FEF 2010 BAP5 University of Ontario Institute of TechnologyThe authors acknowledge the support provided by University of Cukurova (Grant Nos: FEF 2004 BAP4, FEF 2009 D2, and FEF 2010 BAP5), the Council of Higher Education in Turkey, and University of Ontario Institute of Technology in Canada
Assessment of electricity and hydrogen production performance of evacuated tube solar collectors
In this work, a unified renewable energy system has designed to assess the electricity and hydrogen production. This system consists of the evacuated tube solar collectors (ETSCs) which have the total surface area of 300 m2, a salt gradient solar pond (SGSP) which has the surface area of 217 m2, an Organic Rankine Cycle (ORC) and an electrolysis system. The stored heat in the heat storage zone (HSZ) transferred to the input water of the ETSCs by means of an exchanger and thereby ETSCs increase the temperature of preheated water to higher level as much as possible that primarily affects the performance of the ORC. The balance equations of the designed system were written and analyzed by utilizing the Engineering Equations Solver (EES) software. Hence, the energy and exergy efficiencies of the overall system were calculated as to be 5.92% and 18.21%, respectively. It was also found that hydrogen generation of the system can reach up to ratio 3204 g/day. © 2018 Hydrogen Energy Publications LL
Performance assessment of a solar pond with and without shading effect
In this study, we present an experimental investigation of energy distribution, energy efficiency and ratios of the energy efficiency with respect to shading effect on each zones of a small rectangular solar pond. The system is filled with salty water in order to form upper convective, non-convective and lower convective zones. A data acquisition device is used to measure and record the hourly temperatures at various locations in different solar pond zones (distributed vertically within and at the bottom of the pond, and horizontally and vertically within the insulated side-walls). A shading model is developed to gain a more profound understanding of the energy performance of the pond. The model results of the each zone are compared with and without shading effect, based on the corresponding energy efficiencies. The shading surface area of the zones does not contribute to the thermal performance of the pond but it takes place non-sunny area in the zones by shading. Thus, the efficiency of the solar pond decreases with increasing the shading area. The energy efficiencies of the inner zones with and without the shading effect for each zone in the energy analysis are specified as the average representative solar energy for each month of the year. The highest energy efficiencies for the cases of with and without shading area are found for the month of August to be: 4.22% and 4.30% for the upper convective zone, 13.79% and 16.58% for the non-convective zone, and 28.11% and 37.25% for the lower convective zone, respectively. The results confirm that the solar pond storage efficiency can be increased by eliminating the effect of shading area. Moreover, the ratios of shading effect are found to be: 0.651 at the lower convective zone, 0.279 at the non-convective zone and 0.068 at the upper convective zone. © 2012 Elsevier Ltd. All rights reserved.FEF 2009 D2, FEF 2004 BAP4, FEF 2010 BAP5The authors acknowledge the support provided by University of Cukurova in Turkey (Grant Nos: FEF 2004 BAP4, FEF 2009 D2 and FEF 2010 BAP5), the Council of Higher Education in Turkey and University of Ontario Institute of Technology in Canada
NIVEL DE CONOCIMIENTO Y CONDUCTA DEL PERSONAL TÉCNICO DE FARMACIA EN EL EXPENDIO DEL MISOPROSTOL EN LOS ESTABLECIMIENTOS FARMACÉUTICOS DEL DISTRITO DE SANTA ANITA, LIMA 2020
El objetivo de la presente investigación fue determinar el nivel de conocimiento y conducta del personal técnico de farmacia en el expendio del misoprostol en los establecimientos farmacéuticos del distrito de Santa Anita, Lima 2020; para lo cual se empleó una investigación de tipo descriptivo y transversal, aplicado a un total de 237 personales técnico en farmacia que formaron parte de la muestra de estudio. Entre los principales resultados se encontró que un 67% de los encuestados presento un nivel de conocimientos y conducta alto sobre el expendio del misoprostol, un nivel medio acerca de lo evaluado estuvo representado por un 32,9% y no se registró datos sobre conocimientos en nivel bajo. Asimismo, con respecto a la dimensión farmacológica un 26% de los evaluados presento altos conocimientos, 72% un nivel de conocimiento medio y solo un 1.3% bajos conocimientos. Al analizar las conductas adecuadas sobre el expendio del misoprostol el 82% presento una buena conducta, sin embargo 11% de los encuestados mostraron conductas inadecuadas. En conclusión, este estudio reporta que la mayor parte del personal que labora en los establecimientos farmacéuticos del distrito de San Anita presenta un buen nivel de conocimientos y conductas adecuadas sobre el expendio del misoprostol
Investigation energy, exergy and electricity production performance of an integrated system based on a low-temperature geothermal resource and solar energy
In this work, energy, exergy and electricity generation performance of an integrated system was conceptually investigated by using Engineering Equation Solver (EES)under 200–1000 W/m2 solar irradiation interval. The system comprises evacuated tube solar collectors (EVTSCs)with the surface area of 100 m2, an organic Rankine cycle (ORC)and a low-grade geothermal resource. The EVTSCs were used to enhance the temperature of the low-grade water coming from the geothermal source. The calculations were carried out for three geothermal sources in Kula (63 °C), Saraycık (74 °C)and Turgutlu (86 °C), respectively. N-hexane, n-pentane and n-butane were selected as a working fluid in the ORC. It was determined that the selection of the working fluid affected the performance of the ORC. And also, the waste heat is extracted from the ORC were used efficiently for space heating. As a result, the overall energy and exergy efficiencies of the system and power generation of the ORC were seriously affected by enhancing the water temperature of the geothermal resources by EVTSCs. The maximum overall energy and exergy efficiencies of the system were calculated as to be 6.92% and 21.06% by using n-butane for the source in Turgutlu, respectively. The minimum overall energy and exergy efficiencies of the system were calculated as 0.32% and 2.19% by using n-hexane for the source in Kula, respectively. The maximum and minimum generated electricity were calculated as to be 19.46 kW and 0.6168 kW for the sources in Turgutlu and Kula, respectively. It was seen that the best performance of the system was found for n-butane compared to n-pentane and n-hexane. © 2019 Elsevier Lt
Investigation of turbidity effect on exergetic performance of solar ponds
The present paper undertakes a study on the exergetic performance assessment of a solar pond and experimental investigation of turbidity effect on the system performance. There are various types of solar energy applications including solar ponds. One of significant parameters to consider in the assessment of solar pond performance is turbidity which is caused by dirty over time (e.g., insects, leaf, dust and wind bringing parts fall down). Thus, the turbidity in the salty water decreases solar energy transmission through the zones. In this study, the samples are taken from the three zones of the solar pond and analyzed using a spectrometer for three months. The transmission aspects of the solar pond are investigated under calm and turbidity currents to help distinguish the efficiencies. Furthermore, the maximum exergy efficiencies are found to be 28.40% for the calm case and 22.27% with turbidity effects for the month of August, respectively. As a result, it is confirmed that the solar pond performance is greatly affected by the turbidity effect. © 2014 Elsevier Ltd. All rights reserved.The authors acknowledge the support provided by the University of Cukurova under a Grant (Nos. FEF2009D2, FEF2010YL26 and FEF2010BAP5 )