Role of Mg doping in the structural, optical, and electrical characteristics of ZnO-based DSSCs

ZnO- and Mg-doped ZnO samples are prepared by spray pyrolysis on conducting glass substrates to fabricate ZnO-based dye-sensitized solar cells (DSSCs). In uences of Mg-doping content on the power conversion efficiencies of ZnO-based DSSCs are investigated. X-ray diffraction results show that all the samples exhibit a hexagonal wurtzite structure. Scanning electron microscopy data indicate that the ZnO sample has uniform rods with 1 ? m diameter. With respect to ZnO, the band gap value of 4 at.% Mg-doped ZnO samples improves to the value of 3.27 eV and a further increase in Mg level up to 6 at.% gives rise to a decline in the band gap value of 3.22 eV. Photoluminescence measurements illustrate that intensities of the ultraviolet peak and a red luminescence peak take their maximum values for 4 at.% Mg doping. From solar cell performance measurements, the best power conversion efficiency of 0.08% is obtained for the doping amount of 4 at.% Mg

Elektrik devreleri konusundaki kavram yanılgılarının giderilmesinde öğrenme evreleri metodunun etkisi.

Bu çalışmada iki sorunun cevabı araştırılmıştır. 1) Fen bilgisi öğretmenliği ana bilim dalı birinci sınıfta okuyan öğrenciler elektrik devreleri konusunda hangi kavram yanılgılarına ve kavramları anlama sürecinde ne tür güçlüklere sahiptirler? 2) Elektrik devreleri konusundaki kavram yanılgılarının ve kavramsal anlama düzeyindeki güçlüklerin giderilmesinde öğrenme evreleri yaklaşımının etkileri nelerdir? Çalışmaya iki şubeye kayıtlı 76 öğrenci katılmıştır. Şubeler rastgele Deney ve Kontrol grubu olarak ikiye ayrılmıştır. Elektrik devreleri konusundaki kavram bilgisini ölçmek için geliştirilen ‘Elektrik Devreleri Kavram Testi’ (EDKT) gruplara ön test olarak uygulanmıştır. Devreler konusunu öğretmek için deney grubunda (n= 38) öğrenme evreleri metodu kullanılırken kontrol grubunda ise (n= 38) geleneksel öğretim metodu kullanılmıştır. Son olarak EDKT gruplara son test olarak tekrar uygulanmıştır. Ön test sonuçlarının analizi öğrencilerin elektrik devreleri konusunda üç kavram yanılgısına ve devrelerinin fiziksel yönlerini anlama düzeyinde de üç probleme sahip olduklarını göstermiştir. Son test puanlarının varyans analizi öğrenme evreleri metodunun ‘güç kaynağını sabit akım kaynağı olarak algılama’ yanılgısını gidermede geleneksel öğretim modeline göre daha etkili olduğunu fakat ‘bölgesel düşünme’ ve ‘paylaşılan akım’ yanılgılarını gidermede etkisiz kaldığını göstermiştir. Sonuçlarının analizi öğrenme evreleri modelinin elektrik devrelerinin fiziksel yönlerini anlama düzeyinde öğrencilerin karşılaştıkları güçlüklerin tamamını gidermede geleneksel öğretim modeline göre daha etkili olduğunu göstermiştirThe questions for considerations were as follows. 1) What kinds of misconceptions and conceptual difficulties freshman science teaching major have related to the circuits? 2) What were the effects of learning cycle method on removing these misconceptions and conceptual difficulties? Participants were 76 students from two intact classes. Students who registered two sections were randomly assigned into one of the two treatment groups; one group completed a circuit unit with learning cycle method called experimental group (n1= 38), while the other completed a circuit unit with traditional method called control group (n2=38). After the groups were formed, students in both groups were administered a test called ‘Determining and Interpreting Resistive Electric Circuit Test’ (DIRECT) to measure students’ pre conceptual understanding of electric circuits. Then students in the both groups completed an instruction designed for the groups. Finally, all students were administered the DIRECT again as a posttest. Analyses of pretest results showed that students have three misconceptions regarding electric circuits and three difficulties on understanding of physical aspects of electric circuits. ANOVA results of posttest scores revealed that the learning cycle method was more effective to remove a misconception called ‘the battery is a source of constant current’ when compared to the traditional method, but not for the others called ‘local reasoning’ and ‘sharing current’. Results also showed that the learning cycle method was effective to overcome all of the students’ difficulties on understanding of physical aspects of electric circuits when compared to the traditional method

Hydrodynamics of Conical Spouted Beds with High Density Particles

An extensive experimental investigation of conical spouted beds with high density particles were carried out by measuring bed pressure drop, particle velocity and solids hold-up in a 15 cm ID conical spouted bed at three different cone angles (30°, 45°, 60°) with Yttria-stabilized zirconia (YSZ) particles (ρp = 6050 kg/m3). The results show that the minimum external spouting velocity increases with cone angle, particle diameter and static bed height. The bed is characterized by two regions: upward moving particles with high slip in the spout and slowly downward moving particles at loosely packed conditions in the annulus

Yüzey modifikasyonu yardımıyla CdS toz bazlı hibrit güneş pillerinde performans artışı

The effects of surface modification of CdS through organic Eosin-Y, indoline D205, and Ru-based complex N719 and N3 dyes on CdS-based hybrid solar cells were studied. Chemical bath deposition (CBD) and doctor blade methods were in turn employed to fabricate the CdS specimens on Indium-Tin Oxide (ITO) covered glass substrates. P3HT material with and without dye coatings was covered through a spin-coater on the surface of CdS specimens. Ag paste was then deposited on the surface of P3HT to obtain hybrid solar cells. Structural analysis indicated that CdS powders showed a cubic growth with the preferred orientation of (111). Morphological analysis demonstrated that CdS powders exhibited hierarchical morphology and the morphology turned to granular structure with some porosity upon deposition of both N3 dye and P3HT layers. Absorption plots indicated that Eosin-Y dye loading led to a rise in the absorbance values of CdS specimens. After dye loading, photoluminescence data of CdS-based heterostructure illustrated a decrement in the luminescence intensity, implying that effective exciton dissociation was obtained. Current density-voltage (J-V) characteristics of the hybrid solar cells depicted that the best overall efficiency was observed for Eosin-Y-modified cell as 0.135%. This proved that surface modification by Eosin-Y dye led to a better interfacial contact between CdS and P3HT bilayer due to the enhancement in the charge separation.CdS-tabanlı hibrit güneş pillerinde, CdS'nin yüzey modifikasyon etkileri organik Eosin-Y, indolin D205 ve Ru bazlı N719 ve N3 boyaları vasıtasıyla incelendi. CdS örneklerini İndiyum-Kalay Oksit (ITO) kaplı cam altlıklar üzerinde büyütmek için, sırasıyla kimyasal banyo çökeltme (CBD) ve doktor bıçak yöntemleri kullanıldı. Boya kaplamaları olan ve olmayan CdS örneklerinin yüzeyine P3HT materyali, spin kaplama (spin-coater) cihazı yardımıyla kaplandı. Devamında Ag pasta, hibrit güneş pillerini tamamlamak için P3HT yüzeyine çökeltildi. Yapısal analiz, CdS tozlarının kübik yapıda ve (111) tercihli yönelime sahip olduğunu gösterdi. Morfolojik analiz, CdS tozlarının hiyerarşik morfolojide olduğunu ve morfolojinin hem N3 boyası hem de P3HT tabakasının çökeltilmesiyle birlikte taneli ve gözenekli yapıya döndüğünü gösterdi. Soğurma (absorbsiyon) grafikleri, Eosin-Y boya kaplamasının CdS örneklerinin soğurma değerinde bir artışa yol açtığını gösterdi. Boya kaplamasının, CdS tabanlı heteroyapının fotolüminesans şiddetinde azalma oluşturması, etkin bir eksiton ayrışması elde edildiğini ortaya koymaktadır. Hibrit güneş pillerinin akım yoğunluğu-voltaj (J-V) karakteristiklerinden, Eosin-Y modifikasyonlu güneş pilinin veriminin % 0,135 olarak en yüksek değerde olduğu tespit edildi. Bu durum, Eosin-Y boyası ile yapılan yüzey modifikasyonunun, yük ayrışmasında oluşturduğu iyileşmeden dolayı, CdS ve P3HT ikili yapısının arasında daha iyi bir ara yüzey teması sağladığını ispatlamaktadır

Evaluation of Nasal Mucociliary Transport Rate by99mTc-Macroaggregated Albumin Rhinoscintigraphy in Woodworkers

Woodworkers in the furniture industry are exposed to wood dust in their workplaces. The aim of this study is to investigate the effect of occupational wood dust exposure on the nasal mucociliary transport rates (NMTRs) in woodworkers. Twenty five woodworkers and 30 healthy controls were included in this study. Wood dust concentration in workplaces was measured using the sampling device. 99m Tc-macroaggregated albumin (99mTc-MAA) rhinoscintigraphy was performed, and NMTR was calculated in all cases. In statistical analysis, an independent samples t-test was used to compare NMTR of woodworkers and control subjects. We found that the mean NMTR of the woodworkers was lower than that of the healthy controls. However, there was not a statistically significant difference between them (P = 0.066). In conclusion, our findings suggested that wood dust exposure may not impair nasal mucociliary transport rate in woodworkers employed in joinery workshops

Proliferative actinic keratosis: An invasive squamous cell carcinoma or not?

Actinic keratoses have variants that differ clinically and pathologically. Proliferative actinic keratoses (PAK) are known to be resistant against standard therapies and to create a tendency for the development of invasive squamous cell carcinoma (SCC). This study retrospectively reviewed the medical records of 50 patients with 51 PAK lesions. Fifty patients (40 male, 10 female) with a mean age of 68.5 were included in the study. Thirty-two (63%) PAK lesions were clinically selected for total excision but only 27 of them could be totally excised. Among the excised lesions, 13 were reported to be PAK, 13 were SCC, and 1 was keratoacanthoma. There was no significant difference between the PAK and SCC groups. Overall, the groups with excised and unexcised lesions were statistically similar with respect to age, sex, lesion duration, localization, size, and surface features, but induration was more common in the SCC group. The mean follow-up time was 19.7 and 17.0 months in the PAK and SCC group, respectively. In conclusion, 25% (13/51) of lesions diagnosed as PAK were invasive SCC, which is of clinical and histopathological significance. Our results suggest that the definition of PAK should be histopathologically revised and that total excisional biopsy instead of punch biopsy should be considered, especially for lesions with a proliferative appearance. </p

Patient use of complementary and alternative medicine for psoriasis vulgaris and factors believed to trigger the disease: A multicenter cross-sectional study with 1621 patients

Introduction: Due to the chronic recurrent nature of psoriasis vulgaris (PV) and lack of definitive treatment for the disease, patients often resort to alternative treatments. Physicians seem to have low awareness of this issue. Objectives: To elicit the perceptions of 1,621 PV patients on complementary and alternative medicine (CAM) and examine factors reported to worsen PV. Methods: The patients sociodemographic characteristics, Psoriasis Area Severity Index (PASI), Dermatology Life Quality Index (DLQI), disease duration, and severity were recorded, and the patients CAM use was questioned in detail. The patients were also asked about factors that worsened PV and their experiences with a gluten-free diet. Results: Of the patients, 56.51% had used CAM. The mean age, illness duration, PASI scores and DLQI of those using CAM were significantly higher. CAM use was significantly higher in those with facial, genital involvement, and arthralgia/arthritis. The patients mostly referred to CAM when PV became severe (46.4%). Of the CAM users, 45.52% used herbal topicals. The physicians of 67.03% did not inquire whether they used CAM. Of the participants, 37.73% considered that stress worsened their disease. Gluten-free diet did not affect PV symptoms in 52.22%. Conclusions: Patients CAM use is often overlooked by dermatologists. Our results showed that more than half the patients used CAM and did not share this information with their physicians. Therefore, the awareness of physicians should be increased and patients should be asked about the use of CAM and directed to the appropriate medical treatment options by physicians

Habits of using social media and the internet in psoriasis patients

Introduction: Psoriasis significantly affects the patients quality of life, which often leads patients to seek online information about this disease. Objectives: To explore the habits of patients with psoriasis related to their use of social media (SM) and the internet to obtain information about their disease. Methods: 1,520 patients completed the survey and the Dermatology Life Quality Index (DLQI) questionnaire. The Psoriasis Area Severity Index scores (PASI) and clinical data of the patients were recorded by their physicians. Results: Of the 1,114 patients that reported using SM and internet, 48.38% regularly and 31.14% sometimes resorted to obtain information about psoriasis. The use of SM and internet for psoriasis was statistically significantly higher among young people (P = 0.000), those with university or higher education (P = 0.009), higher DLQI (P = 0.000) and PASI (P = 0.011) scores, facial (P = 0.050), scalp (P = 0.032), hand (P = 0.048), genital (P = 0.001) and inverse (P = 0.000) involvement, and arthralgia/arthritis (P = 0.006). The participants mostly used the Google (86%) and Facebook (41%). More than half of the participants (62.8%) expected dermatologists to inform society that psoriasis is not contagious. Conclusions: Internet and SM being widely available and offering substantial information to be easily accessed make it very attractive for patients to use these platforms to investigate diseases, including psoriasis. If what is presented on SM conflicts with what the physician says, patients mostly trust the latter, but at the same time, they tend not to share the results of their online inquiries with their physicians

Vitamin A status of healthy children in Manisa, Turkey

<p>Abstract</p> <p>Background</p> <p>Vitamin A deficiency is a major public health nutrition problem in the developing world. Even subclinical Vitamin A deficiency is associated with increased childhood mortality. Severe maternal vitamin A deficiency may cause increased mortality in the first months of life. There have been a limited number of studies regarding vitamin A status in Turkey. The aim of this study was to assess vitamin A status of healthy children in Manisa, Turkey.</p> <p>Methods</p> <p>Vitamin A status of 100 healthy children aged 36-48 months is evaluated. The children were seen during routine examination. Serum retinol concentrations were measured by high-performance liquid chromatography. Duration of breast feeding, age solid foods introduced, use of supplementary vitamins, weight and height, and intake of specific groups of nutrients on a daily, weekly and monthly basis were collected from a questionnaire completed by the mothers. Height and weight z-scores were calculated according to national standards. Mothers of 20 of the 100 children were known to have normal serum and breast milk retinol concentrations. Children with normal serum retinol concentration were compared with the children with VAD. Student's t-test and Mann-Whitney test were used to compare independent variables. The Pearson correlation analysis test was used to test relation between numeric variables.</p> <p>Results</p> <p>Mean retinol concentration was 0.98 ± 0.32 μmol/L in the whole study group. Serum retinol concentrations were normal (>0.70 μmol/L) in 89% of the children. When children with normal serum retinol concentrations were compared with those with retinol concentrations lower than 0.70 μmol/L, there was no difference in terms of age, gender, weight and height at the time of study, z-scores, birth weight, birth length, duration of breast feeding, time to begin solid food, rate of supplementary vitamin use, and rate of infections (P > 0.05). There was not any relation between vitamin A concentrations and weight and height at the time of study, z-scores, birth weight, birth length, duration of breast feeding, time to begin solid food, vitamin use, and frequency of intake of specific groups of nutrients (P > 0.05).</p> <p>Conclusions</p> <p>This study showed that VAD is a moderate health problem in Manisa.</p

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely