Ruhuna Journal of Science最新文献_第6页

Comparative morpho-anatomical studies of Hoya incrassate and Hoya soligamiana (Apocynaceae) from Mount Hamiguitan, Philippines 菲律宾哈米圭丹山夹竹桃和夹竹桃的形态解剖学比较研究

Ruhuna Journal of Science Pub Date : 2018-06-30 DOI: 10.4038/RJS.V9I1.34

Ds Salas, Eb Sinamban, Dp Buenavista

{"title":"Comparative morpho-anatomical studies of Hoya incrassate and Hoya soligamiana (Apocynaceae) from Mount Hamiguitan, Philippines","authors":"Ds Salas, Eb Sinamban, Dp Buenavista","doi":"10.4038/RJS.V9I1.34","DOIUrl":"https://doi.org/10.4038/RJS.V9I1.34","url":null,"abstract":"This study compared the morpho-anatomical characters of two horticulturally important hoyas endemic to the Philippines viz., Hoya incrassata and Hoya soligamiana. Fresh cuttings were used for morphological and anatomical measurements. Free hand sections were taken from leaves, shoots and roots for determination of structural differences. Leaf pigments were cleared to observe the venation and stomatal arrangement. The results showed that hoyas differ in their leaf shape and texture, flower colour, and the inflorescence shape and position. H. soligamiana has glabrous lanceolate leaves, whitish to creamy petals, purplish to pink inner and outer coronal lobes, and whitish to pink fused sepals. H. incrassata has coriaceous lance-ovate leaves, whitish to yellowish fused petals, yellow inner coronal lobes, reddish to orange outer coronal lobes, and fused sepals. The measured anatomical traits in the cross sections of roots and stems of the two Hoya species did not differ with the exception of stomatal types and arrangement in the leaves. The pigment clearing of the leaves showed that H. incrassata has sunken cyclocytic stomata while H. soligamiana has actinocytic stomata. Morpho-anatomical information provides taxonomic value for identifying and classifying the two Hoya species. \u0000 \u0000Keywords. Endemic hoyas, morphology, Mindanao, plant diversity, taxonomy, wax plants.","PeriodicalId":56207,"journal":{"name":"Ruhuna Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43995239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Ascorbic acid retention of freshly harvested seven Nigerian green leafy vegetables after soaking in water 七种刚收获的尼日利亚绿叶蔬菜在水中浸泡后的抗坏血酸保留率

Ruhuna Journal of Science Pub Date : 2018-06-30 DOI: 10.4038/rjs.v9i1.36

S. Akande, ME Inana, EE Ugama

{"title":"Ascorbic acid retention of freshly harvested seven Nigerian green leafy vegetables after soaking in water","authors":"S. Akande, ME Inana, EE Ugama","doi":"10.4038/rjs.v9i1.36","DOIUrl":"https://doi.org/10.4038/rjs.v9i1.36","url":null,"abstract":"Vitamins are micronutrients needed in the body for important biologic functions. The current study examined the influence of steeping on vitamin C retention of seven Nigerian vegetable leaves after soaking for 8 h. One kilograme each was purchased and 6 lots of 100 g were sorte out, cleaned and treated as follow; whole leaf 1, whole leaf 2, sliced leaf 1, sliced leaf 2, sliced and salted leaf 1 and sliced and salted leaf 2. Each of the treatments 1 was soaked in 1 litre of distilled water while each of treatments 2 was soaked in 2 litres of distilled water. All treatments were kept for 8 h while monitoring the trend of reduction in vitamin C contents at 2 h intervals. Moisture (%) was determined following AOAC (2002) methods while dry matter content was estimated from moisture by calculating the difference. Ascorbic acid content (mg/100 g) was determined following the method of Ndawula et al. (2004). Result showed that; moisture, dry matter, and ascorbic acid contents of raw leaves ranged from 67.63–86.70%, 13.30–32.37%, and 103.00–1199.23 mg/100g respectively. During soaking, ascorbic acid retained by the seven green vegetables reduced as follows; 73.39–24.26% (Amaranthus viridis), 100.26–19.62% (Gnetum africanum), 129.05–27.72% (Gongronema latifolium), 66.84–7.55% (Ocimum gratissmum), 42.59–4.14% (Piper guinense), 77.38–10.26% (Pterocapus mildbedii) and 120.02–17.97% (Telfaria occidentalis). The study showed that ascorbic acid retention (%) of seven Nigerian green vegetable leaves decreased with increasing soaking duration. \u0000 \u0000Keywords: Nigeria, ascorbic acid, micronutrients, vegetable, soaking","PeriodicalId":56207,"journal":{"name":"Ruhuna Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46523996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Optical and structural properties of CdS thin films prepared using electro-deposition technique 电沉积法制备CdS薄膜的光学和结构特性

Ruhuna Journal of Science Pub Date : 2018-06-30 DOI: 10.4038/RJS.V9I1.33

G. Mahanama, D. Madarasinghe, W. G. D. Dharmaratna, D. Jayasundara

{"title":"Optical and structural properties of CdS thin films prepared using electro-deposition technique","authors":"G. Mahanama, D. Madarasinghe, W. G. D. Dharmaratna, D. Jayasundara","doi":"10.4038/RJS.V9I1.33","DOIUrl":"https://doi.org/10.4038/RJS.V9I1.33","url":null,"abstract":"Cadmium Sulfide (CdS) thin films were electrodeposited successfully on to Indium Tin Oxide (ITO) coated glass substrates from an aqueous solution of pH 1.4 containing 0.3M CdCl2 and 0.03M Na2S2O3 or Thiourea with the aim of using in CdS/CdTe solar cells. Properties of CdS thin films prepared at different deposition voltages, deposition time periods, deposition temperatures and annealing temperatures were investigated using the current-voltage (I-V) plots. It was found that good quality CdS layers were formed under the deposition conditions of -1.13V for a period of 45 minutes in a solution of temperature at 46 oC. The performance of the CdS layers was improved significantly after annealing the samples at 400 oC for a period of 20 min. The properties of CdS thin films prepared by two and three electrode configurations and using two different electrolytes were compared using the current-voltage plots. It was found that there is a significant improvement of photocurrent of the samples prepared with two electrodes in Thiourea as the S source in comparison with the samples prepared with Na2S2O3. The analysis of XRD spectra showed the hexagonal crystal structure of CdS films confirming the quality of the films prepared by this method. In addition, absorption spectra showed band gap value of 2.42 eV proving that the samples were of good quality. Atomic Force Microscopy (AFM) analysis showed that the roughness values of CdS samples were in the range of 10-15 nm. Film thicknesses of the samples were in the range of 175-225 nm according to the optical profilometric data. \u0000 \u0000Keywords. Cadmium sulfide, electrodeposition, electrolyte, two-electrode, photocurrent.","PeriodicalId":56207,"journal":{"name":"Ruhuna Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44784954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Spatial modelling of the householders' perception and assess the potentiality to improve the urban green coverage in the residential areas: a case study from Issadeen town Matara, Sri Lanka 户主感知的空间建模和评估提高住宅区城市绿化覆盖率的潜力：斯里兰卡马塔拉伊萨登镇的案例研究

Ruhuna Journal of Science Pub Date : 2018-06-30 DOI: 10.4038/RJS.V9I1.32

W. Ranasinghe, G. Hemakumara

{"title":"Spatial modelling of the householders' perception and assess the potentiality to improve the urban green coverage in the residential areas: a case study from Issadeen town Matara, Sri Lanka","authors":"W. Ranasinghe, G. Hemakumara","doi":"10.4038/RJS.V9I1.32","DOIUrl":"https://doi.org/10.4038/RJS.V9I1.32","url":null,"abstract":"Urban forestry has become an important concept in modern city planning for many reasons. Different forms of urban green spaces can be seen in towns as open spaces, tree belts, parks and home gardens. The main objective of this research was to assess the urban green spaces in Issadeen Town, a small residential area in Matara, Sri Lanka. A questionnaire survey was conducted in the study area covering a zone with 200 individual houses. The collected data were entered into a Geographical Information System (GIS) platform, taking one house as the unit of analysis. There was a marked difference between the numbers of trees growing in owner-occupied houses and rental houses. It was also assessed that 11% of the study area had good green cover while 8% of this area had medium level green cover that had the potential to rise to a higher category. The occupants of houses who were living in the high green cover areas stated that they had a positive perception about their environment, especially cooler temperatures. Therefore, they intended to maintain the trees in their housing plots. However, there were other occupants accounting 50.5% of the total, who were not interested or involved in the process of increasing the green cover. This is a matter that the authorities may have to address in future. \u0000 \u0000Keywords: Environmental assessment, geospatial model, green space, urban planning, urban forestry","PeriodicalId":56207,"journal":{"name":"Ruhuna Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43766745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Jackfruit (Artocapus heterophyllus Lam.) and teak (Tectona grandis L.) leaves extracts as green corrosion inhibitors 菠萝蜜（Artocapus heterophyllus Lam.）和柚木（Tectona grandis L.）叶提取物作为绿色防腐剂

Ruhuna Journal of Science Pub Date : 2018-06-30 DOI: 10.4038/RJS.V9I1.35

Udari Kodithuwakku, M. Edussuriya

{"title":"Jackfruit (Artocapus heterophyllus Lam.) and teak (Tectona grandis L.) leaves extracts as green corrosion inhibitors","authors":"Udari Kodithuwakku, M. Edussuriya","doi":"10.4038/RJS.V9I1.35","DOIUrl":"https://doi.org/10.4038/RJS.V9I1.35","url":null,"abstract":"In this study, the inhibition effect of water and methanol extracts (WE and ME) of raw and ripe jackfruit leaves (JL) and raw teak leaves (TL) on the corrosion of mild steel (MS) in 1M HCl was studied. Weight loss measurements and potentiodynamic polarization techniques were used to investigate the behavior of the above inhibitors. The percentage of inhibition efficiency (% IE) increased with the increasing concentration of inhibitors in 1 M HCl medium. Water extract of ripe JL was found to be the most effective inhibitor and % IE was 73 at the concentration of 400 ppm. The effectiveness of other inhibitors towards corrosion in the descending order is WE of TL, ME of ripe JL, WE of raw JL, ME of TL and ME of raw JL. With the increase of the temperature, even the adsorption of the most efficient inhibitor, WE of ripe JL, decreased and the rate of corrosion increased. According to the estimated adsorption equilibrium constant, Kads and standard Gibbs free energy change, ∆G0ads, adsorption of WEs of ripe JL and TL on mild steel surface mainly observed to be by chemisorption. Potentiodynamic polarization scans have revealed the possibility of mixed type corrosion inhibition by WEs of ripe JL and TL. \u0000 \u0000Keywords. Adsorption, Langmuir isotherm, corrosion inhibitor, weight loss measurements","PeriodicalId":56207,"journal":{"name":"Ruhuna Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46940326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0