The trinion Fourier transform of color images

Any color may be represented in terms of three components (RGB or HSL) or four components (CMYK). For the four component color representation the use of quaternions, with one real and three imaginary components, is natural. By setting one component to zero, quaternions have been used in RGB or HSL representation of colors and color images. In this paper a new quantity, trinion, with one real and two imaginary components, is introduced and its use in color image representation is examined. The goal is to see if significant efficiencies in representation, analysis and computation involving three component color images accrue with the use of trinions. Two versions of the trinion Fourier transform (TFT) are introduced and it is shown that using TFT is preferable for combined analysis of three component color images rather than separate monochromatic analysis of each component and use of quaternions. Joint space-wavenumber localized trinion S (TS) transform with a two-dimensional Gaussian window function that scales with wavenumbers is also presented. Invertibility, rotation invariance, and computational aspects of the TS transform are discussed.     

A comprehensive study of polyphenols contents and antioxidant potential of 39 widely used spices and food condiments

Spices and condiments are rich sources of potent antioxidants. In the present investigation, total equivalent antioxidant capacities (TEAC) of 39 spices were studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) scavenging, and cupric reducing antioxidant capacity (CUPRAC) assays. Their total phenolic contents (TPC) and total flavonoid contents (TFC) were also determined. TEAC, TPC, and TFC varied significantly (P?<?0.05) among these spices. ABTS, DPPH, and CUPRAC assay values of studied spices ranged from 1.42 to 112.94 mg ascorbic acid equivalents (AAE)/g, 1.14 to 91.09 mg Trolox equivalents (TE)/g, and 0.52 to 54.47 mg TE/g, respectively (dry weight basis; DW). Based on Folin–Ciocalteu assay, TPC ranged from 2.93 to 160.55 mg of gallic acid equivalents (GAE)/g DW. Strong correlations between TPC and TEAC values (R?=?0.966, 0.825, and 0.954 for ABTS, DPPH, and CUPRAC, respectively) were found. This indicates that phenolic compounds are potent antioxidants in these spices. Principal component analysis (PCA) indicated that cloves (flower buds of Syzygium aromaticum) had the most distinct and potent antioxidant capacity, followed by allspice (fruits of Pimenta dioica) and cinnamon (bark of Cinnamomum verum). Results of the present study provide adequate evidence that polyphenols are responsible for their compelling antioxidant capacities of studied spices. Thus, consumption of antioxidant-rich spices such as cloves, allspice, and cinnamon can significantly prevent oxidative stress in the human body.     

Fatty acids,tocopherols, phenolic and antioxidant properties of six citrus fruit species: a comparative study

Citrus fruit is a rich source of bioactive phytochemicals. Information on the fatty acid and tocopherol composition of locally grown citrus fruits in Korea is elusive. This work was aimed to study fatty acid, tocopherols, ascorbic acid, antioxidant potential, and selected phenolics from peel and pulp of six citrus species. The most dominant fatty acid was linoleic acid (15–45%), followed by linolenic, palmitic, and oleic acid. Stearic acid was highly abundant in yuzu peel (14.45%) and pulp (15.88%) compared to the other fruits. Unsaturated fatty acids (54–74%) contributed higher composition than saturated fatty acids (25–46%). Peel exhibited better antioxidant potential and contained higher phytochemicals than pulp. The concentrations of α-tocopherol and γ-tocopherol were ranged from 22.96 (yuzu) to 86.93 (cheonhyeyang) and 38.59 (yuzu) ~83.03 (tangerine) μg/g DW, respectively. J-Redhyeyang peel exhibited highest total flavonoids (4.17?±?0.10 mgQE/g DW) and DPPH radical scavenging activity (6.17?±?0.03 mgTE/g DW). FRAP values were highest (20.05?±?0.64 mgTE/g DW) in yuzu peel, while peel of cheonhyeyang was superior in total phenolic contents. Tangerine (3.02?±?0.05 mg/g DW) and yuzu (7.49?±?0.38 mg/g DW) had higher hesperidin concentrations in pulp and peel, respectively. Naringin was found in an appreciable amount in yuzu pulp (2.04?±?0.09 mg/g DW) and peel (6.30?±?0.19 mg/g DW) but not detected in all other fruit species. Our results indicate that citrus fruit peel is the rich source of antioxidant compounds, which can be used to prepare antioxidant rich food product.     

POTENTIAL HYDROCARBON-GENERATING ROCK UNITS WITHIN THE PHANEROZOIC SEQUENCE OF THE OGADEN BASIN, ETHIOPIA: A PRELIMINARY ASSESSMENT USING THE LOPATIN MODEL

The geochemical parameters of potential source rocks in the Ogaden Basin, Ethiopia are conducive to the presence of gas and oil. This prediction is based on Lopatin's method of calculating the time-temperature indices of thermal maturation of organic matter in rocks. Paleozoic and Mesozoic rocks, the Bokh Shale and Hamanlei Formation respectively, are estimated to lie in a thermal zone which is appropriate for generation of petroleum, especially gas, at several localities in the Basin.     

Farmers’ perception of soil fertility change and their preferences for soil fertility management techniques for different land use types in Arsamma Watershed,Southwestern Ethiopian Highlands

This study aimed to assess farmers’ perception of soil fertility change and their priorities for soil fertility management techniques for different land use types in Arsamma Watershed, Southwestern Ethiopian Highlands. A three-stage random sampling technique was employed to select the sampled households. A smaller proportion of farmers perceived soil fertility decline in perennial cropland than in annual cropland as the farmers appeared to be less aware of below-ground processes of soil degradation. The farmers used physical, chemical and biological indicators to evaluate soil fertility changes. The rate of soil fertility decline and the occurrence of the contributory factors were land use specific. Increasing fertilizer requirement of croplands and decreasing yield per unit of land were the main indicators of soil fertility decline in annual and perennial cropland, respectively. Farmers’ preference for soil fertility management techniques was also found to depend on the type of land use. Integrated soil fertility management (ISFM) and agroforestry were the top priorities of the farmers, respectively, for annual and perennial cropland management. Farmers lack knowledge of below-ground processes of soil degradation by leaching, nutrient mining and soil acidity; and agricultural extension services should respond to this need. Further, ISFM for annual cropland and agroforestry for perennial cropland need to be encouraged in the study catchment.     

Extraction of antioxidants and flavonoids from yuzu (<Emphasis Type="Italic">Citrus junos</Emphasis> Sieb ex Tanaka) peels: a response surface methodology study

In the present investigation, extraction of antioxidants and flavonoids from the peels of yuzu fruit using a single factor experiment and a response surface methodology (RSM) based on central composite design was studied. Four independent variables were evaluated at five levels with total 29 experimental runs, including ethanol concentration (EtOH), ratio of liquid to material (L/S), extraction temperature (T), and extraction time (t). The total phenolic content (TPC), total flavonoids content (TFC), two indicators of antioxidant capacity (FRAP and DPPH), and three individual major flavonoids in yuzu (hesperidin, naringin, and phloretin) served as the response functions. Quadratic polynomial equations were obtained by multiple regression analysis to predict the optimal extraction conditions. The regression analysis showed that >95?% of variations were explained by the models of different responses considered. The responses were significantly influenced by all studied factors. The Multiresponse optimized conditions targeted at maximizing all the responses were found to be EtOH?=?65.550?%; T?=?43.864?°C; t?=?119.673 min; and L/S?=?37.168 ml/g, with a desirability of 0.950. At the optimized conditions, the experimental values of FRAP (964.9?±?23.1 mgTE/g DW), DPPH (453.0?±?5.2 mgTE/g DW), TPC (1161.2?±?25.2 mgGAE/g DW), (TFC393.4?±?mgQE/g DW), hesperidin (337.2?±?4.0 mg/g DW), naringin (244.9?±?1.1 mg/g DW), and phloretin (43.9 mg/g DW) were in a reasonable agreement with the predicted values. The extraction method was applied successfully to extract antioxidants and flavonoids from yuzu peels. It also allows a fast and cost-saving process for extraction of the studied phytochemicals, in addition to improvement of the quantity of the targeted extract.     

Ultra-Precision Polishing of N-Bk7 Using an Innovative Self-Propelled Abrasive Fluid Multi-Jet Polishing Tool

As the demand for optical glasses has increased, precision requirements for specific shapes, forms, surface textures, and sizes (miniaturization) have also increased. The standards and surface finishes applied to the reference mirrors used in measuring appliances are crucial. Hence, enhancements in figuring and surface finishing are indispensable to manufacturing industries. In this article, a novel self-propelled multi-jet abrasive fluid polishing technique is proposed for an ultra-precision polishing process in which a blade-less Tesla turbine was used as a prime mover. The turbine was characterized by high swirling velocity at the outlet; therefore, high levels of kinetic energy moving away from the turbine were used as polishing energy. Computational fluid dynamics (CFD) was also used to simulate the flow on the turbine blades. With a newly designed and manufactured polishing tool, the optimal polishing parameters for improving the surface roughness of crown optical glasses (N-BK7) were investigated. Taguchi's experimental approach, an L₁₈ orthogonal array, was employed to obtain the optimal process parameters. An analysis of variance (ANOVA) was also conducted to determine the significant factors. The surface roughness has been improved by approximately 94.44% from (R_a) 0.36 μm to (R_a) 0.02 μm. This study also presents a discussion on the influence of significant factors on improving surface roughness.     

Population dynamics and exploitation patterns of Oreochromis niloticus in Lake Tana,northwest Ethiopia

Oreochromis niloticus is the dominant commercial fish in the Lake Tana region. However, its fishery is progressively declining over time. Little or no updated information exists on the population dynamics and exploitation patterns of the species, which is crucial to guide its sustainable management. Accordingly, the purpose of the present study was to generate essential biological parameters on the growth, mortality and stock status of O. niloticus, using length‐frequency data collected monthly from the commercial fish catches of 1 year (2014–2015). The total mortality coefficient (Z) was derived from the length‐converted catch curve. Biological reference points were predicted from relative yield‐ and biomass‐per‐recruit analyses. The estimated values of the von Bertalanffy growth parameters were L_∞ = 44.1 cm, K = 0.44/year, and t₀ = ?0.34/year, and the growth performance index (Φ′) was 2.93. The total mortality (Z), natural (M) and fishing mortality (F) rates were 2.37, 0.98 and 1.39 per year, respectively. The current fishery exploitation rate of 0.59 exceeds the estimated biological reference points of E_max (0.52), confirming the stock of O. niloticus in the lake is being overexploited above optimum levels. Size indicators of the catches further illustrate 31% of the landed fish are harvested before reaching sexual maturity, with mega‐spawners comprising only 15%. This indicates the stock is suffering from both growth and recruitment overfishing. The logistic selection model indicated 50% of the fish vulnerable to capture was at 18.14 cm TL. The fish exhibited a year‐round recruitment pattern, with a major peak during May and June. Sustainably managing the fishery, therefore, requires increasing the fish size at first capture (L_c) towards L_opt.     

Assessing the Hydrological Response of Ayamama Watershed from Urbanization Predicted under Various Landuse Policy Scenarios

This study investigated the effects of urbanization predicted using the SLEUTH urban growth model (an acronym taken from Slope, Landuse, Exclusion, Urban extent, Transportation and Hillshade) under four landuse policy scenarios on the hydrological response of Ayamama watershed using the Hydrologic Engineering Center Release 1 (HEC-1) hydrological model. The SLEUTH model was calibrated based on the Brute Force Monte Carlo iteration technique using the urban extents of Istanbul in 1987, 2000, 2009 and 2013 and was verified by considering Kappa coefficient as evaluation criteria. HEC-1 was calibrated and verified using observed rainfall-runoff event and based on the coefficient of determination (R²), Nash-Sutcliffe coefficient of efficiency (CE) and percentage of bias (PBIAS) as performance indicators. The urbanization prediction results showed that the urban extent of Ayamama watershed would reach 50.3 km², 44 km², 63 km² and 60 km² under Scenarios 1, 2, 3 and 4, respectively, in 2050. The hydrological simulation results under these urban extents showed that the urban extent of Ayamama watershed under Scenario-3, a scenario that allows unrestricted growth with the implementation of Project Canal Istanbul (PCI), resulted in the highest peak discharge and the shortest time to peak. Such an increase in the peak discharge and reduction in the time to peak will increase the risk of flooding and, therefore, extreme care needs to be taken before and during the implementation of PCI.