Variation Of Light Intensity Research Articles

Classification of Anemia with Digital Images of Nails and Palms using the Naive Bayes Method

Purpose: Early detection of anemia based on nails and palms images by applying the Naive Bayes method, as well as to measure the level of accuracy in detecting anemia.Design/methodology/approach: Using the Naive Bayes method. System development uses the waterfall method.Findings/result: Based on the results of the tests that have been carried out, the resulting accuracy is 87.5% with varying light intensities and is 92.3% by using a light intensity of 5362 Lux.Originality/value/state of the art: The difference between this study and previous research is in the image pre-processing method and classification method. In this study, the images of the nails and palms were converted to the YCbCr color space to be segmented and color features extracted. Then the color features will be classified using the Naive Bayes classification method. The output of this system is the result of the input image classification, whether normal or anemic.

Classification of Anemia with Digital Images of Nails and Palms using the Naive Bayes Method

Purpose : Early detection of anemia based on nails and palms images by applying the Naive Bayes method, as well as to measure the level of accuracy in detecting anemia. Design/methodology/approach : Using the Naive Bayes method. System development uses the waterfall method. Findings/result : Based on the results of the tests that have been carried out, the resulting accuracy is 87.5% with varying light intensities and is 92.3% by using a light intensity of 5362 Lux. Originality/value/state of the art : The difference between this study and previous research is in the image pre-processing method and classification method. In this study, the images of the nails and palms were converted to the YCbCr color space to be segmented and color features extracted. Then the color features will be classified using the Naive Bayes classification method. The output of this system is the result of the input image classification, whether normal or anemic.

Impact of Different Daily Light Integrals and Carbon Dioxide Concentrations on the Growth, Morphology, and Production Efficiency of Tomato Seedlings.

Indoor growing systems with light-emitting diodes offer advantages for the growth of tomato seedlings through uniform and optimized environmental conditions which increase consistency between plants and growing cycles. CO2 enrichment has been shown to improve the yield of crops. Thus, this research aimed to characterize the effects of varied light intensities and CO2 enrichment on the growth, morphology, and production efficiency of tomato seedlings in indoor growing systems. Four tomato cultivars, “Florida-47 R,” “Rebelski,” “Maxifort,” and “Shin Cheong Gang,” were subjected to three different daily light integrals (DLIs) of 6.5, 9.7, and 13 mol m–2 d–1 with a percent photon flux ratio of 40 blue:60 red and an end-of-day far-red treatment of 5 mmol m–2 d–1. The plants were also subjected to three different CO2 concentrations: 448 ± 32 (400-ambient), 1010 ± 45 (1000), and 1568 ± 129 (1600) μmol mol–1. Temperature was maintained at 24.3°C ± 0.48/16.8°C ± 1.1 (day/dark; 22.4°C average) and relative humidity at 52.56 ± 8.2%. Plant density was 1000 plants m–2 until canopy closure. Morphological measurements were conducted daily to observe the growth response over time. In addition, data was collected to quantify the effects of each treatment. The results showed increases in growth rate with increases in the DLI and CO2 concentration. In addition, CO2 enrichment to 1000–1600 μmol mol–1 increased the light use efficiency (gDM mol–1 applied) by 38–44%, and CO2 enrichment to 1600 μmol mol–1 did not result in any additional increase on shoot fresh mass, shoot dry mass, and stem extension. However, the net photosynthetic rate obtained with 1600 μmol mol–1 was 31 and 68% higher than those obtained with 1000 and 400 μmol mol–1, respectively. Furthermore, the comparison of the light and CO2 treatment combinations with the control (13 mol m–2 d–1–400CO2) revealed that the plants subjected to 6.5DLI–1600CO2, 9.7DLI–1000CO2, and 9.7DLI–1600CO2 treatment combinations exhibited the same growth rate as the control plants but with 25–50% less DLI. Furthermore, two treatment combinations (13.0DLI–1000CO2 and 13.0DLI–1600CO2) were associated with the consumption of comparable amount of energy but increased plant growth by 24–33%.

Low temperature carrier transport mechanism and photo-conductivity of WSe2

This work reports the electrical-transport and temperature-dependent photoconductivity in tungsten diselenide (WSe2) thin films. Temperature-dependent electrical conductivity has been demonstrated using different models. At lower temperatures (< 190 K), carriers become localized to small regions in the film due to Mott’s hopping mechanism. The middle-temperature region (190–273 K) follows Seto’s parameters and obtained low barrier height (0.0873 eV) may be responsible for the improved carrier mobility. At higher temperature (> 273 K) region, thermally activated conduction is dominated with two activation energies of ~138 meV and 98 meV. The peaks obtained in photoluminescent analysis attributes to the presence of mid-bandgap states or defect states which play an important role in the photoconductivity of WSe2. The transient photoconductivity measurements show consistent temperature-dependent behaviour. The effect of light intensity and wavelength variation on the photoconductivity of WSe2 thin films is also discussed. The photo-current is 1.19 * 10−5 A at 125 K, while at 350 K was observed to be 3.12 * 10−4 A. The light-on/off current cycles show that the current can recover to its initial state after various cycles, which points to the WSe2 thin-film device's stable and reversible properties that can be used in optoelectronic applications.

Toward Faster Organic Photodiodes: Tuning of Blend Composition Ratio

AbstractThe ability of a light‐sensor to detect fast variation in incident light intensity is a vital feature required in imaging and data transmission applications. Solution‐processed bulk heterojunction (BHJ) type organic photodiodes (OPDs) have gone through key developments, including dark current mitigation and longer linear dynamic range. In contrast, there has been less focus on increasing OPD response speed (f–3dB). Here, bulk heterojunction OPDs based on electron‐donating polymer poly[thiophene‐2,5‐diyl‐alt‐5,10‐bis((2‐hexyldecyl)oxy)dithieno[3,2‐c:3′,2′‐h][1,5]naphthyridine‐2,7‐diyl] (or PTNT) and electron‐accepting phenyl‐C71‐butyric acid methyl ester (or PC71BM) are reported. The intrinsic charge transport characteristics required for fast speed OPDs are discussed, and an analytical model for the same is developed. The OPDs present 0.8 MHz f–3dB under no applied voltage bias for a typical blend ratio of 1:1 by weight. It is shown that balanced electron and hole mobility is a critical criterion for faster speed OPDs, which can be realized by tuning the composition ratio of the bulk heterojunction. By tuning PTNT and PC71BM blend ratio, the f–3dB was successfully raised by more than quadruple to 4.5 MHz. The findings provide a tool to set device architecture for faster next‐generation light sensors.

NIR photodetector based on p-silicon nanowires/n-cadmium sulfide nanoscale junctions

Heterojunction of p-type silicon nanowire and n-type cadmium sulfide (CdS) nanoparticles have been fabricated by deposition of CdS nanoparticles on chemically etched vertically aligned silicon nanowires (SiNWs). The asymmetric current-voltage (I-V) curves confirm the formation of the p-n junction in the SiNW/CdS heterostructures. The growth time of CdS nanoparticles on SiNWs have been optimized for obtaining the best photodiode performance. Variation of current–voltage characteristics with respect to temperature in the range of 200–300 K is also studied and the consequent changes in the barrier height and ideality factor of the p-n junction are observed. Furthermore, from the wavelength vs. current characteristics, the highest current is observed at the near-infrared (NIR) region of the wavelength making it suitable as an NIR detector. The maximum photocurrent (Ip/Id) is calculated to be 6.7 times to dark-current due to photogenerated charge carriers by absorption of photon-energy. The responsivity and detectivity with the variation of light intensities are investigated and the highest values attained by the synthesized samples are 821 mA/W and 1.21 × 1012 Jones respectively, for an NIR source having wavelength of ~ 900 nm and intensity of ~ 8 mW/cm2. Thus SiNW/CdS film can be introduced as a probable candidate for a photo-electronic application.

Characterizing the temperature dependence of Fano-Feshbach resonances of ultracold polarized thulium

Recent studies demonstrated anomalous temperature shifts for some Fano-Feshbach resonances of thulium atoms. These anomalies were explained by the variation in light intensity in the optical dipole trap, which accompanied changes in temperature. In addition, a temperature-related transformation of the statistics of the inter-resonance spacing was demonstrated [Aikawa et al., Phys. Rev. Lett. 108, 210401 (2012)]. Here, we analyze the shifts of isolated $s$- and $d$-type Fano-Feshbach resonances of ultracold thulium atoms with temperature for a fixed depth of an optical dipole trap. The measurements are consistent with the three-body recombination-based theory of the temperature-related resonance shift and enable the extraction of the resonance parameters, particularly the magnetic moments of closed channel states. This parameter and the known polarizability of the open channel enable us to separate the contributions of the temperature and Stark shift to the overall shift of the resonances and show the dominant role of the Stark effect in the overall shift.

Low-threshold bistable reflection assisted by oscillating wave interaction with Kerr nonlinear medium* *Projected supported by the Open Fund by State Key Laboratory of Advanced Optical Communication Systems and Networks (Grant No. 2017GZKF18), the National Natural Science Foundation of China (Grant Nos. 12064017, 61765008, 11764020, 11864017, 11804133, and 51567011), the Jiangxi Provincial Natural Science Foundation (Grant No. 20181BAB206034), the Fundamental Research

Owing to the enormously enhanced oscillating wave, a minute variation of the incident light intensity will give rise to a change in the dielectric constant of the Kerr nonlinear medium and lead to a bistable reflection with an ultra-low threshold intensity, which is closely related to the angle of incidence and the thickness of the Kerr nonlinear medium. The criterion for the existence of optical bistability is derived. Our bistability scheme is simple and not limited to the TM-polarization.

High Contrast Allows the Retina to Compute More Than Just Contrast.

The goal of sensory processing is to represent the environment of an animal. All sensory systems share a similar constraint: they need to encode a wide range of stimulus magnitudes within their narrow neuronal response range. The most efficient way, exploited by even the simplest nervous systems, is to encode relative changes in stimulus magnitude rather than the absolute magnitudes. For instance, the retina encodes contrast, which are the variations of light intensity occurring in time and in space. From this perspective, it is easy to understand why the bright plumage of a moving bird gains a lot of attention, while an octopus remains motionless and mimics its surroundings for concealment. Stronger contrasts simply cause stronger visual signals. However, the gains in retinal performance associated with higher contrast are far more than what can be attributed to just a trivial linear increase in signal strength. Here we discuss how this improvement in performance is reflected throughout different parts of the neural circuitry, within its neural code and how high contrast activates many non-linear mechanisms to unlock several sophisticated retinal computations that are virtually impossible in low contrast conditions.

Photocatalytic degradation of atenolol with graphene oxide/zinc oxide composite: Optimization of process parameters using statistical method

A four factor three level Box-Behnken design (BBD) was analysed to define the photocatalytic degradation of atenolol in an aqueous solution in slurry mode. The four different process variables under consideration in BBD model included synthesized Graphene Oxide-ZnO (GO/ZnO) catalyst dose, pH, Atenolol concentration and variation of light intensity. The model predicted the optimum value for maximum degradation rate with conditions set at 1.2 g/L catalyst concentration, pH of 4, 25 mg/l substrate concentration and 940 W light intensity. The first-order reaction rate at this optimum reaction condition is 0.845 min−1. The substrate concentration and light intensity showed highest positive effect on atenolol degradation while pH and catalyst concentration showed negative effect towards atenolol degradation. The data obtained from 29 experiments suggest that maximum rate of reaction (0.783 min−1) has been achieved within 1 h under solar irradiation at pH 6.5 using 25 ppm atenolol concentration and catalyst concentration of 1.25 g/L at light intensity of 1000 W. The model shows high correlation (R2 > 0.953) between experimental and predicted values. It was observed that the rate of degradation with GO/ZnO composite is faster when compared to Graphene/TiO2 composite.

Gesture Recognition Using Reflected Visible and Infrared Lightwave Signals

In this article, we demonstrate the ability to recognize hand gestures in a noncontact wireless fashion using only incoherent light signals reflected from a human subject. Fundamentally distinguished from radar, lidar, and camera-based sensing systems, this sensing modality uses only a low-cost light source (e.g., LED) and a sensor (e.g., photodetector). The lightwave-based gesture recognition system identifies different gestures from the variations in light intensity reflected from the subject's hand within a short (20-35 cm) range. As users perform different gestures, scattered light forms unique, statistically repeatable, time-domain signatures. These signatures can be learned by repeated sampling to obtain the training model against which unknown gesture signals are tested and categorized. These time-domain variations of the lightwave signals reflected from hand are denoised, standardized, and then classified by using machine learning classification tools such as $K$-nearest neighbors and support vector machine. Performance evaluations have been conducted with eight gestures, five subjects, different distances and lighting conditions, and visible and infrared light sources. The results demonstrate the best hand gesture recognition performance of infrared sensing at 20 cm with an average of 96% accuracy. The developed gesture recognition system is low-cost, effective, and noncontact technology for numerous human-computer interaction applications.

Soil respiration analysis using a mid-infrared quantum cascade laser and calibration-free WMS-based dual-gas sensor.

A high response and sensitive dual-gas sensor based on calibration-free wavelength modulation spectroscopy (CF-WMS) has been developed for the simultaneous detection of carbon monoxide (CO) and nitrous oxide (N2O) to eliminate the detection errors caused by light intensity variations. A multi-pass cell (MPC) was employed to lengthen the optical path to improve the precision of the sensing system by combining with a 4.56 μm mid-infrared quantum cascade laser (MIR-QCL). Meanwhile, a LabVIEW-based bi-molecular iterative fitting algorithm was used to infer the respective abundances of each species. The performance of the completed system was accurately evaluated with precisions of 3.4 ppb for CO and 3.8 ppb for N2O at a 1 s averaging time, which could be improved to 0.48 ppb for CO and 0.53 ppb for N2O at an averaging time of 154 s and 278 s, respectively. The grassland soil respiration analysis of CO and N2O was performed under different moisture conditions, which indicated that dried soil samples appeared to be a significant source of CO, while the sinks of CO and the sources of N2O occurred in the moist soil samples. The maximum exchange rates of the two gases were exhibited in moderate moisture soil samples rather than in the over-wet or arid soil samples. Moreover, a possible positive relationship between the sinks of CO and sources of N2O was established to illustrate the correlation of the two species in soil respiration.

Relative Effects of Varying Light Conditions on the Growth of Toxic and Non-Toxic Strains of &amp;lt;i&amp;gt;Microcystis aeruginosa&amp;lt;/i&amp;gt;

Harmful algae bloom constitutes a major problem facing water bodies particularly fresh and marine water system. Microcystis aeruginosa represents a major causative organism found in the water. Light plays a major role in the growth and variation of M. aeruginosa in water. What is still inadequate, is the data on the effects of different light conditions on the growth of Microcystis aeruginosa. In this study, two strains of Microcystis aeruginosa PCC 7806 (toxic strain) and PCC 7005 (non-toxic strain) were exposed to varying light intensities at 0, 30, 60, 120, 300, 350 μMol photon m-2·S-1 to measure their growth and pigmentation. This study observed similarities in growth and pigmentation between toxic strain (PCC 7806) and non-toxic (PCC 7005) strain. Also, at short exposure to light, Toxic strain was seen to be better tolerant of light than non-toxic strain, with non-toxic strain showing better ability to recover from light stress after twenty days of culture. These findings suggest that Toxic strain (PCC 7806) and Non-toxic strain (PCC 7005) of M. aeruginosa respond similarly with respect to growth but differ in their light retention capacity over time and this could be useful in predicting the possible conditions of algal bloom.

Experimental performance of glass based synthetic dye sensitized solar cell

Owing to the depletion of fossil energy sources, the research concentrates over accretion of power from nonconventional sources of energy. The growth rate of utilizing of abundantly available solar energy lead research in area of solar cell which is cost effective, higher performance, long life. The technology of die sensitized solar cell has been explored with synthetic dye and electrolytes. The die sensitized solar cell has been manufactured in house with fully automatic special purpose machine in order to achieve accuracy of dye application, heating, electrolyte bath etc. Titanium Dioxide (TiO2) being tested as dye for the solar cell. The electrolytic solution which is mixture of pure iodine ethylene glycol and potassium iodide. The graphite-based powder as catalyst being used as liquid conductor. The performance of this die sensitized solar cell being observed with exhaustive experimentations. The performance criteria include varying light intensity throughout the day, varying current densities, varying tilting angles of cell. It was found that the cell is producing output of 30 to 122 mV with current density of 3.85 to 6.33 mA/cm2. The efficiency of cell range between 0.07 and 0.36%. This output is much lower in comparison to that of photo-voltaic cell. But owing to numerous advantages such as window, design glass over building as solar cell panel will make the difference with that of PV cell.

Space-time dynamics of urban systems from satellite images of night lighting. Urban progress scenarios for European metropolitan regions

The aim of this study was to use satellite imagery of metropolitan regions to develop a method for predicting the evolution of Night-Time Light (NTL) and design a mathematical cellular automata model to predict urban progress scenarios. In order to validate the model with real data, we used NTL for 1992–2012 from the European NUTS-2 region of Catalonia. Lighted surface scenarios (as an estimate of urban expansion) were calculated using variations in light intensity (as an estimate of economic activity). In all, we applied the model to twelve NUTS-3 European metropolitan regions. The model gives us three kinds of useful information related to urban surface areas: the main one is a NTL urban surface baseline, which in turn was used in calibration/validation processes; the second one is a regression line for NTL intensity and economic activity, which could be improved with further research; finally, we found a good coarse approximation to urban shape in urban progress scenarios. Since NTL is available for the entire globe, the model could be used to study urbanization dynamics in metropolitan regions for which, in particular, socio-economic data is not available at this territorial scale, and even megaregions emerging as global economic units.

Critical advances in understanding ecohydrological processes of terrestrial vegetation: From leaf to watershed scale

<p indent=0mm>The study of ecohydrological processes within vegetated terrestrial ecosystems is one of the new frontiers in ecology, hydrology and global change studies, and one of the most theoretical areas in ecohydrology. In recent years, a great deal of research has been conducted on the interactions between vegetative ecological processes and hydrologic processes, ranging from plant cells scales to whole continent scale. These studies have made great progress in changing the way we think and approach both ecology and hydrology. However, from the perspective of Ecohydrology, a discipline that integrates Ecology and Hydrology, there is an urgent need to systematically summarize the progress of multi-scale theories and methods and to present new ideas on the theoretical frontiers in this emergent field. This review synthesizes and evaluates recent findings and future challenges in the science and modeling of ecohydrological progresses in terrestrial vegetative systems including: (1) Plant water use and regulation; (2) coupled carbon-nitrogen-water cycle processes and modeling; (3) ecological effects of key processes in the hydrologic cycle; (4) influence of vegetation on the generation and alteration of runoff and overland flow; (5) feedback effects from changes in terrestrial vegetation ecological water cycle on localized and regional precipitation pattern. The main progress in these five aspects of ecohydrology at multi-scales and across-scales is systematically summarized, with special attention given to the development of process-based quantitative models. Based on our synthesis of progress in the ecohydrology of terrestrial vegetation systems, we identify the four primary avenues for future research. First, it is necessary to clarify the effectiveness of the “triangular trade-off relationship” among water transmission efficiency and safety, and those mechanisms underlying plant water use strategies given that plant water use strategies and water regulation mechanisms under changing environmental conditions are the foundation of ecohydrological theory. Accordingly, an exploration on the internal associations among this “triangular trade-off relationship” and root hydraulics redistribution, ecohydrological separation, and isohydric characteristics will be needed. Special attention is needed for a better understanding of the multi-scale mechanisms for plant water use and regulation at the individual-community scale. Second, in the light of marginal water consumption during vegetative carbon assimilation, we explore the multi-coupling relationships among marginal water consumption and environmental factors such as light intensity and water availability and variations in the relationship among various vegetation types and growth stages. The ecosystem carbon-water coupling parameters that have clear ecological significance across scales need to be determined and highlighted. It is also important to develop a cross-scale carbon and water flux modeling method based on the canopy optimal conductivity theory. Third, how and to what extent the water availability and its dynamic changes restrict ecosystem carbon and nitrogen process is one of the frontier bottlenecks that need to be resolved to advance global change ecology. It is necessary to systematically clarify the complex interactions and threshold conditions between the water availability, nitrogen supply, and carbon benefits of the ecosystem. Development of mechanism models for the full coupling of ecosystem carbon and nitrogen cycling and hydrologic cycle processes are also crucial. Fourth, the vegetation factors and mechanisms in the terrestrial water cycle remain key issues for continued attention in the future. The core issue is the identification and quantitative description of ecological factors in the formation and dynamic changes in runoff. On a larger spatial scale, it is also vital to accurately analyze the atmospheric feedback and contribution range of changes in precipitation from the vegetation cover changes in the relevant regions based on the understanding of the impact of land surface vegetation structure changes on the land-atmosphere coupling relationship.

Phytoplankton Community Responses to Interactions Between Light Intensity, Light Variations, and Phosphorus Supply

In a changing world, phytoplankton communities face a large variety of challenges including altered light regimes. These alterations are caused by more pronounced stratification due to rising temperatures, enhanced eutrophication, and browning of lakes. Community responses toward these effects can emerge as alterations in physiology, biomass, biochemical composition, or diversity. In this study, we addressed the combined effects of changes in light and nutrient conditions on community responses. In particular, we investigated how light intensity and variability under two nutrient conditions influence (1) fast responses such as adjustments in photosynthesis, (2) intermediate responses such as pigment adaptation and (3) slow responses such as changes in community biomass and species composition. Therefore, we exposed communities consisting of five phytoplankton species belonging to different taxonomic groups to two constant and two variable light intensity treatments combined with two levels of phosphorus supply. The tested phytoplankton communities exhibited increased fast reactions of photosynthetic processes to light variability and light intensity. The adjustment of their light harvesting mechanisms via community pigment composition was not affected by light intensity, variability, or nutrient supply. However, pigment specific effects of light intensity, light variability, and nutrient supply on the proportion of the respective pigments were detected. Biomass was positively affected by higher light intensity and nutrient concentrations while the direction of the effect of variability was modulated by light intensity. Light variability had a negative impact on biomass at low, but a positive impact at high light intensity. The effects on community composition were species specific. Generally, the proportion of green algae was higher under high light intensity, whereas the cyanobacterium performed better under low light conditions. In addition to that, the diatom and the cryptophyte performed better with high nutrient supply while the green algae as well as the cyanobacterium performed better at low nutrient conditions. This shows that light intensity, light variability, and nutrient supply interactively affect communities. Furthermore, the responses are highly species and pigment specific, thus to clarify the effects of climate change a deeper understanding of the effects of light variability and species interactions within communities is important.

PENGEMBANGAN TEKNIK KULTIVASI Spirulina sp. SEBAGAI SUMBER BIOMASSA ENERGI TERBARUKAN DALAM FOTOBIOREAKTOR AIRLIFT

The development of technology for the use of natural resources as fuel is increasing. One of them is theresearch of third generation biodisel. This technology utilizes microalgae as an environmentallyfriendly raw material which is also a renewable energy source for oil. Biodiesel from microalgaeespecially Spirulina sp. is one of the energy sources that can replace conventional diesel fuel whichhas potential for high lipid content. This study aims to develop a microalgae cultivation technology in anairlift photobioreactor by adjusting the light intensity of the LED lamp to obtain an optimal growth rateand increase the biomass production of Spirulina sp. The research was conducted on an intermediatescale using an airlift type photobioreactor with varying light intensity, namely 1600 lux, 2200 lux, and3200 lux. Each treatment was carried out three times for 14 days. Measurement of biomass weight wascalculated using the gravimetric method, by taking samples every 7 days. Based on the data obtained,the application of different light intensities to the spirulina sp. cultivation system will have an effect onthe final result in harvesting day 14th, specifically the weight of the biomass produced. The averageyield of biomass on day 14th with the best results was obtained at light intensity of 1600 as much as 623mg / 100 ml.

Low light intensity and compost modified biochar enhanced maize growth on contaminated soil and minimized Pb induced oxidative stress

Heavy metal uptake by agricultural crops poses great danger to human health. Application of compost and biochar has been used extensively for metal immobilization in soil and to reduce metal uptake by crop plant. Their efficiency is however, limited by other environmental factors like water and light intensity. In this study, the effects of organic amendments (Mexican Sunflower Compost and Rice Husk (RH) biochar) in combination with varying light intensities on growth and Pb uptake by maize crop grown on industrially contaminated soil containing 53,752 mg/kg Pb was investigated. Compost and biochar were applied singly and in combination at 0, 2.5, 5 and 7.5 t ha−1 while different layers of net were used to vary light intensity (one layer = 60: 386 lx, two layers = 53:340 lx, three layers = 27 %: 177 lx and zero layer with 100 % light intensity of 634 lx served as control). Soil Pb concentration and stress metabolites (Proline and cysteine) production before and after the experiment were also determined. Results showed that, higher rates of organic amendments and reduced light intensity increased the vegetative growth and yield of maize on contaminated soil compared to 100 % light intensity. Combination of biochar and compost performed better than sole application. It reduced post-cropping soil Pb concentration and Pb uptake by maize, especially under low light intensity. The stress metabolites were more in the leaves of maize crop grown in un-amended soil and under 100 % light intensity. Addition of organic amendment coupled with reduction in light intensity therefore, enhanced maize growth on contaminated soil, reduced Pb uptake and oxidative stress, while, heavy metal accumulation and stress metabolites production were more in maize grown in un-amended soil and exposed to high light intensity.

Soy oil conjugated linoleic acid production with solar light photoisomerization.

The objectives were (1) to produce soy oil conjugated linoleic acid (CLA) triacylglycerides in large quantities with solar light photoisomerization, utilizing iodine as a photosensitizer, (2) to study the temperature variation in the photoisomerized oil during various hours of the day, and (3) to study the variations in solar light intensity during various hours of the day. A 0.5% iodine containing soy oil in glass box with a glass lid was photoisomerized, under natural solar light for 0, 11, and 27 days, and CLA isomers were determined with gas chromatography with flame ionization detector. After 27 days of solar light photoisomerization, the cis-9, trans-11 CLA; other cis, trans CLA; trans-10, cis-12 CLA; trans, trans CLA, and total CLA were found to be 0.62 ± 0.05%, 1.04 ± 0.09%, 0.54 ± 0.11%, 6.16 ± 0.68%, and 8.37 ± 0.90%, respectively. The concentration of CLA isomers between 0 and 11 days was significantly different (p < .05), and the concentration of CLA isomers between 0 and 27 days was also significantly different (p < .05). There is no significant difference (p > .05) in CLA concentration between 11 and 27 days treatment. The CLA was not found in control soy oil samples. The CLA isomers were measured with GDFID in 45 min instead of 120min. The temperature of the edible oil in glass boxes ranged from 26 °C(8 a.m.) to 56 °C(1 p.m.). The light intensity ranged from 4,146 lux (7 p.m.) to 95,490 lux (12 p.m.). Glass lid on the glass box affected light transmission to a small but statistically significant extent (p < .05). The CLA isomers could be energy efficiently and inexpensively produced in soy oil by solar light photoisomerization, at low temperature and without needing expensive reactor vessels or catalysts. PRACTICAL APPLICATION: CLA was produced effectively with the iodine sensitized solar light photoisomerization. CLA is produced in large quantities, inexpensively, for possible food additive applications. Produced CLA is in the form of stable triacylglycerides.