Levels Of Light Intensity Research Articles

Remote optical measurements of cracks in concrete structures using computer image processing

This report develops non-contact optical methods for measuring concrete cracks for remote diagnostics of hard-to-reach building surfaces using drones. The drone’s high-resolution digital camera captures remote close-up photography of the concrete surface under high light intensity levels. The digital image of the crack converted in a data matrix, each element of which contains information about the level of reflected light from the concrete surface and the crack. Using the formulas obtained by us earlier, with the help of computer processing of the image, the morphology of the crack in real geometrical dimensions can be calculated. Using special tools computer programs, the crack’s geometrical parameters can be measured maximal accurately as possible. The proposed remote optical method for non-contact detection of cracks in concrete when photographing with a drone from a close distance allows achieving an accuracy of measuring the length and width of a crack of 5%, and its depth of 10%.

Development of a Prototype Learning Model for the Hydroponic System based on Arduino Nano

Technological developments have brought convenience to human life. Many things can be done today to solve human problems more efficiently without spending a lot of money, time, and energy. One of these technological developments can be found in agriculture. An automatic tool project based on the Arduino nano microcontroller will monitor hydroponic plants, assisted by sensors to detect water level, the temperature around the plant will be detected by a sensor DHT-22, the level of light intensity using the sensor BH1750 water level and room temperature will be displayed on nextion 3.5” as a human-machine interface. The purpose of designing this tool is to realize an automatic hydroponic system with LED light as a substitute for sunlight, a pH sensor to read the acidity level of a solution for plants, a ppm sensor to see the viscosity level of a solution for plants, and several motors to provide nutrition in a proper manner automatic and also to maintain water circulation, here is also provided a human machine interface to see the condition of the plant along with planting media and solutions. Based on the value of the test results, the entire hydroponic system is able to work well, all values that affect hydroponic plants are always in their proper condition. The temperature in this hydroponic environment is continuously monitored by using the DHT-22 sensor which aims to get a temperature that is always as stable as from a temperature range of 27°C to 35°C, the expected pH is in the range of 6.5 to 7.4, and the ppm required for hydroponic plants is ranging from 1050 ppm to 1400 ppm.

Development of Growth Model for Grafted Hot Pepper Seedlings as Affected by Air Temperature and Light Intensity

The objective of this study was to develop a growth model for grafted hot pepper seedlings as affected by air temperature and light intensity. After grafted union formation, the hot pepper seedlings were cultivated in various environmental factors in terms of four levels, mean daily air temperature (17, 22, 27, and 32 °C) and 3 levels of light intensity (150, 350, and 550 μmol·m−2·s−1). The growth traits were measured 0, 7, 14, 21, and 28 days after grafted union formation (DAGU). The plant height was improved, and development of leaves enhanced by higher air temperature. The number of leaves was greatest under the combination of the high temperature and high light intensity, resulting in 39.0/plant at 28 DAGU. The leaf area and dry weight showed 491.9 cm2/plant and 2.68 g/plant, respectively, at 28 DAGU under 32 °C air temperature and 550 μmol·m−2·s−1 light intensity. The changes of dry weight were rapidly increased under the higher air temperature and light intensity as followed by analysis of the growth curve. The beta distribution model was developed, and the relative growth rate (RGR) was simulated by the model, the maximum RGR was predicted at 0.116 g·g·d−1. The RGR showed 0.113, 0.127, and 0.109 g·g·d−1 at 10, 20, and 30 °C air temperature, respectively, and RGR was improved by 12% by increasing the air temperature by 10 °C, without going over 25 °C ADT. Results indicated that the developed growth model might be applied to optimal environmental control for maximized RGR of production of grafted hot pepper seedlings.

Effects of continuous light and light intensity on the growth performance and gonadal development of Nile tilapia

Continuous illumination has been known to exert positive effects by stimulating growth and delaying unwanted maturation in seasonal-temperate farmed fish species like salmonids. However, in tropical fish like Nile tilapia ( Oreochromis niloticus ), some studies exist showing inconsistent results and even fewer data is available regarding the effects of light intensity. To clarify some of the inconsistent results in literature and evaluate the effect of different light intensity levels on growth and sexual maturation in Nile tilapia ( [...]

O2 distribution and dynamics in the rhizosphere of Phragmites australis, and implications for nutrient removal in sediments

Root-triggered microscale variations in O2 distribution in the rhizosphere of young Phragmites australis are important for nutrient removal in sediments. In this study, the micro-scale O2 dynamics and the small-scale changes of soluble reactive phosphorus (SRP) and ammonium (NH4+) in the rhizosphere of P. australis were investigated using planar optodes and high-resolution dialysis (HR-Peeper), respectively. Results suggested that root O2 leakage has a highly variable distribution depending on the stage of root growth, the site of O2 leakage gradually shift from the entire emerging main roots to the main root tip and subsequently shifted the emerging lateral roots. The O2 concentration increased in the rhizosphere with increasing light intensity and O2 levels in the overlying water. Continuous O2 release from the lateral roots causes the formation of iron plaque on the surface of lateral roots, which reduce the mobility of P by adsorption of iron plaque in the rhizosphere. The oscillation of oxic-anoxic root zones improves nitrogen removal through the processes of anammox, heterotrophic denitrification and nitrification. This work from the micro-scale demonstrates that the O2 concentration is the spatio-temporal variations in the rhizosphere, and it presents an important role for nutrient removal in sediments.

Different light spectra and intensity level effects on vegetative growth and antioxidant content of coriander

Different light spectra and intensity level effects on vegetative growth and antioxidant content of coriander

Factors associated with the progression and prevention of noncommunicable diseases in community-dwelling Filipino adults: A cross-sectional study.

Noncommunicable diseases (NCDs) are an important cause of disability and death in Muntinlupa, Manila, Philippines. However, there is little community-based research on lifestyle behaviors that affect the progression of NCDs or on the hindrances to NCD prevention.This cross-sectional study investigated the lifestyle behaviors associated with the progression and prevalence of NCDs and clarified factors associated with health promotion for the NCDs prevention among 168 Filipino adults aged 50 years and above in the community setting.The prevalence of diabetes, cardiovascular disease, cancer, chronic respiratory disease, hypertension, and overweight/obesity found 13.1%, 8.9%, 1.8%, 4.2%, 59.5%, and 36.9%, respectively. Of 63 adults who underwent blood tests, high blood glucose and abnormal lipids found 20.6% and 80.9%, respectively. Filipino adults ate breakfast, lunch, and dinner more than 5 days a week, Merienda 4.2 days a week, and a midnight snack 1.7 days a week. The mean frequencies of physical activity at vigorous, moderate, and light intensity levels were 2.6 times a week, 1.9 times a week, and 3.8 times a week, respectively. Men were more likely to be smokers than women. Mean frequencies of alcohol consumption were 0.6 days a week. Filipino adults who practiced diet control, regular physical activities, no smoking, limited alcohol intake, stress control, and regular health checkups were 68.3%, 34.1%, 35.9%, 35.3%, 32.9%, and 24.6%, respectively. Hypertension was positively associated with the duration of tobacco use and frequency of salt intake. Overweight/obesity was positively associated with the frequency of Merienda. Diet control was positively related with internal Multidimensional Health Locus of Control scale. Smoking and alcohol control were significantly related with income level.Community-dwelling Filipino adults in this study had a high prevalence of NCD progression and insufficient awareness of preventative behaviors. Diet control is associated with self-awareness of health and smoking and alcohol control are associated with economic status. These findings ought to contribute to develop the effective strategies for NCD prevention in community-dwelling Filipino adults.

EFFECTS OF SKIN TONE AND AMBIENT LIGHTING ON ACCURACY OF CONTACTLESS MEASUREMENT OF HEART RATE AND PULSE TRANSIT TIME: AN INVESTIGATION TOWARD IMAGE-BASED BLOOD PRESSURE ESTIMATION

Abstract Objective: Image-based photoplethysmography (iPPG) using video of the skin offers potential for contactless blood pressure (BP) estimation from the pulse transit time (PTT). Optical properties of human skin and ambient lighting are likely to affect accuracy of image-based PTT (iPPT) and are investigated here. Design and method: Twelve healthy volunteers (6 female, 27 ± 6 years) with a range of skin tones (Fitzpatrick skin scores of 5 to 27) were recruited. For each subject, the experiment was performed in standard fluorescent room lighting (100 lux) and repeated at five other levels of light intensity (40–310 lux). Two-minute videos were acquired from each subject's face and palm of the left hand; simultaneous electrocardiogram (ECG) and non-invasive finger BP were also measured. In each frame, two regions of interest (ROIs) were selected from the subject's face and hand, and the average of green colour intensity for each ROI were calculated as iPPG. The iPPG signal was band-pass filtered between 0.66–3 Hz, (corresponding to a 40–180 bpm heart rate (HR) range). HR was calculated as the dominant peak in the Fourier spectrum of filtered iPPG. Beat-to-beat values of iPTT were calculated between the corresponding feet of the iPPG pulsations. Results: The absolute error between average HR (errHR) determined from ECG and that calculated from iPPG in both ROIs was significantly correlated with room lumen (RL) and skin score (SC) (errHR = – 0.08 × RL + 0.67 × SC + 12, p < 0.05). The minimum HR error was in standard room lighting (errHR = 3.9 ± 8.9 bpm). Using average iPTT in room lighting as the reference, the percentage error (iPTT%err) between reference iPTT and iPTT in other lighting conditions significantly decreased with lower lighting conditions but was not significantly changed with skin tone score (iPTT%err = -0.09 × RL + 55, p < 0.05). Conclusions: Skin tone and ambient lighting intensity affects accuracy of contactless HR measurement. Only light intensity affects accuracy of iPTT measurement. It is likely that errors in contactless BP estimation are minimised in standard room lighting conditions but increase in dimmer conditions.

CO2 fertilization of Sphagnum peat mosses is modulated by water table level and other environmental factors.

Sphagnum mosses account for most accumulated dead organic matter in peatlands. Therefore, understanding their responses to increasing atmospheric CO2 is needed for estimating peatland C balances under climate change. A key process is photorespiration: a major determinant of net photosynthetic C assimilation that depends on the CO2 to O2 ratio. We used climate chambers to investigate photorespiratory responses of Sphagnum fuscum hummocks to recent increases in atmospheric CO2 (from 280 to 400 ppm) under different water table, temperature, and light intensity levels. We tested the photorespiratory variability using a novel method based on deuterium isotopomers (D6S /D6R ratio) of photosynthetic glucose. The effect of elevated CO2 on photorespiration was highly dependent on water table. At low water table (-20 cm), elevated CO2 suppressed photorespiration relative to C assimilation, thus substantially increasing the net primary production potential. In contrast, a high water table (~0cm) favored photorespiration and abolished this CO2 effect. The response was further tested for Sphagnum majus lawns at typical water table levels (~0 and -7cm), revealing no effect of CO2 under those conditions. Our results indicate that hummocks, which typically experience low water table levels, benefit from the 20th century's increase in atmospheric CO2 .

Easy-Mushroom Mobile Application Using the Internet of Things (IoT)

The cultivation of mushrooms is not a simple task for traditional mushroom farmers, because the productivity of the mushroom farm depends on the ability to regulate the environment surrounding the mushroom farm. In addition, another problem for traditional mushroom farmers is that they cannot grow various types of mushrooms related to marketing. This research presents a mobile application for assisting mushroom farmers to understand the growing situation. The proposed mobile application called the easy mushroom application is based on the Internet of things (IoT) concept. The easy mushroom has been designed to analyse the humidity and light intensity relationship at a specific time. The experimental results show that the Easy-Mushroom mobile application provides a relationship between light intensity, humidity, and tolerance humidity level of mushroom.

Design and Development of Smart Irrigation and Water Management System for Conventional Farming

The intention of this project is to develop a smart irrigation and water management system for conventional farming. The project is conducted mainly to improve the irrigation scheduling and also to solve the over watering and under watering issues in traditional irrigation system. These problems can be solved by implementing soil moisture sensor as a smart component in the irrigation system. Smart irrigation system with the implementation of sensory-based system will be able to provide a proper irrigation scheduling, by monitoring the soil and weather condition of the farm. In this project, the sensory system consists of soil moisture sensor, temperature sensor and light intensity sensor, which basically used to monitor soil moisture level, temperature level, and light intensity level at the separate test area. Arduino Mega 2560 microcontroller will process the data from these sensors and a proper irrigation scheduling will be developed based on the data collected. Type of irrigation system that been used in this project is a sprinkler system because it has high uniformity of water distribution to the plant, which able to spread water efficiency and further optimize the water usage during irrigation process. Ultrasonic sensor is also implemented in the system to measure the amount of water used in each irrigation process performed. An offline data storage will be implemented in this project using a micro SD card module, which all the essential information such as sensory system readings and the amount of water used will be recorded and stored into a micro SD card. Thus, it allows user to monitor their farm’s condition, and also gives a better view on what is really happening at their farm.

Accurate spectroscopy with sCMOS cameras at ultra-low intensities of light.

Modern image detectors with exceptionally low readout noise of about one electron (e-) per pixel allow for applications with ultra-low levels of light intensity. In this Letter, we report a property of scientific CMOS detectors that makes accurate spectroscopy at ultra-low levels of illumination depending on a thorough calibration procedure. Our results reveal that pixel sensitivity to light may have significant nonlinearity at accumulation levels smaller than 50e- per pixel. The sensitivity decreases by a factor of ∼0.7 at an accumulation level of ∼1e- per pixel and photon detection rate of about 170 Hz. We demonstrate that the nature of this nonlinearity might be quite complicated: the photoelectric response of a pixel depends on both the number of accumulated electrons and the detection count rate (at rates larger than 250 Hz).

Optional CMOS based Monolithic Light Sensor for Detection of Light Intensity

Conventional light intensity sensing devices such as a light meter are big in size and incapable of outputting a digitized signal to a microprocessor for further control and actuation. Sensor transducers based on CMOS has therefore increased in popularity. Using CMOS technology, manufacturing costs and the power consumption can be reduced with smaller form factor. This paper presents a proposed design of light sensor for the detection of light intensity. The project utilizes Silterra’s 130 nm CMOS architecture to create a low power and low space monolithic light sensor chip that is able to detect the intensity of light to assist in achieving the recommended levels of light intensity in domestic areas. The light intensity was simulated with a photocurrent and the photodiode operates optimally at a wavelength of 555 nm, the spectral sensitivity of the human eye and has good linearity. The light intensity detected is shown in illuminance (lux) and this project is capable to detect illuminance in the range of 0 to 200 lux with a resolution of 20 lux. The monolithic chip of the light intensity sensor comprises of the transimpedance amplifier which acts as a current to voltage converter and an ADC to convert the analog voltage into a digital reading. Hence, the output of the light intensity sensor is in binary representation. The total power consumption of the monolithic light intensity sensor is 1.88mW and the total size of the design is 0.01202 mm2.

The effect of light intensities on morpho-physiological and biochemical of black pepper (Piper nigrum L.)

The difference in the levels of light intensity was responded with changes in morphophysiological and biochemical characters of plants, especially in leaves of black pepper. The aim of this study was to determine the effect of several levels of light intensity on the morphophysiological and biochemical characters of leaves of black pepper. The research was conducted in July - November 2017 in Kemuja, Mendobarat, Bangka Belitung. This study used split-plot design with three replications. The main plots were the levels of light intensity, namely 100%, 75%, and 50%. Subplots were varieties of black pepper, namely Petaling 1, Petaling 2, and Nyelungkup. The results showed that there was no interaction between varieties and light intensities. The morphophysiological and biochemical responses of the leaves of the three varieties tested were the same at all levels of light intensity. Light intensity up to 50% has no effect on leaf morphological characters, but leaves become thinner at lower light intensities. Chlorophyll, nitrate reductase activity and leaf sucrose concentration were same at all light intensities up to 50%. Plants exposed to higher light intensity have a higher number of stomata. The results concluded that the light intensity of up to 50% did not cause changes in leaf morphology and biochemistry and only affected leaf stomata density.

Morphological and Physiological Responses of Indigofera tinctoria L. to Light Intensity

Synthetic dyes can cause health and environmental impacts. Thus, there are opportunities to develop natural dyes, one of which is produced by Indigofera tinctoria plants. This plant is from Fabaceae that has the potential to produce a natural blue color. Natural dyes are extracted from the leaves of plants that contain indigo compounds. Indigo growth and precursors are very dependent on environmental conditions, one of which is light intensity. This study aimed to study the morphological and physiological plant responses in I. tinctoria to several levels of light intensity. The research was conducted in Puron Village, Sukoharjo, Indonesia with a complete randomized block design (RCBD) one factor, namely the level of light intensity (100 %, 50 %, and 25 %) with nine replications. Light intensity affected the morphology and physiology of I. tinctoria. Plants responded to low light intensity by increasing the leaf area index, specific leaf area and plant height. Leaf area, specific leaf area and plant height were highest at 25 % intensity. However, the number of leaves and nodes got greater at full light intensity. Higher light intensity increased the chlorophyll content a, b and total, thus, higher biomass yield which was 18.86 g at the age of 8 wk.

Assessment of spatial variability of environmental conditions in different swine production typologies in tropical conditions

Comfort index and environmental variables are indicators of thermal stress conditions inside a livestock facility. The environmental conditions of ten different constructive typologies of swine-production facilities with natural ventilation were characterized in a tropical country (Antioquia, Colombia). Temperature and humidity index (THI), enthalpy (H), animal surface temperature (ST), light intensity, and noise level were measured and computed for each typology, which were located at heights above sea levels between 8:00-23:00. Data was analyzed as a function of each typology, geographical altitude, and time of the day. It was employed descriptive statistics, analysis of variance, and contour maps to analyze the data. It was found that more than 80% of the typologies presented moderate or critical stress conditions associated with the construction typology, not suitable THI and light intensity values, especially in warm and mild-mild climates. Showing high special variability inside the facilities. New typological designs and bioclimatic conditioning for swine facilities need to be studied To be implemented in these climatic conditions.

Effects of Light Intensity and Electrical Conductivity Level on Photosynthesis, Growth and Functional Material Contents of Lactuca indica L. ‘Sunhyang’ in Hydroponics

본 실험은 수경재배에서의 왕고들빼기 ‘선향’의 광도와 양액 농도가 광합성과 생육, 기능성 물질함량의 변화를 알아보고자 수행했다. 재배 환경은 온도 25±1℃, 상대습도 60±5%가 조절되는 생장 시스템에서 담액 수경 방식으로 재배하였다. 파종 14일 후, 광도 3수준(PPFD 100, 250, 500μmol·m-2·s-1)과 양액 농도 3수준(EC 0.8, 1.4, 2.0dS·m-1)를 조합하여 어린잎 채소 크기에 도달하였을 때 수확하여 분석하였다. 왕고들빼기 선향의 광합성율, 기공전도도, 증산율, 수분이용효율은 광도가 높을수록 증가하였다. 광합성율과 수분이용효울은 PPFD 500-EC 1.4, PPFD 500-EC 2.0 처리에서 가장 높았다. 엽록소 함량은 광도가 높을수록 감소하였며 엽록소 a/b 비율은 광도가 증가할수록 증가하였다. 잎수분함유량(LWC)와 비엽면적(SLA)는 광도가 높을수록 감소하여 부상관(p < 0.001)을 가졌다. 초장은 PPFD 100-EC0.8에서 가장 길었고, 엽수, 생체중, 건물중은 PPFD 500-EC2.0에서 가장 높았다. 기능성 물질인 안토시아닌과 총 페놀화합물은 PPFD 500-EC 1.4, 2.0 처리에서 가장 높았고, 항산화 소거 능력(DPPH)은 PPFD 250, 500에서 높았다. 생육과 기능성물질 함량 증진을 고려했을 때 왕고들빼기 수경재배 시 적정 광도와 EC는 PPFD 500-EC 2.0dS·m-1이며, 저광 조건인 PPFD 100, 250에서는 EC 0.8dS·m-1재배가 적합하였다.

Endolithic phototrophs: Examples from cave-like environments

Endoliths are more frequently found in extremely harsh environments, but they can inhabit mesic climate and subterranean habitats as well. Whether they are adapted to life inside rocks or do they seek refuge in this way, remains largely unknown for caves and pits. Consequently, subterranean habitats in limestone areas, were explored: three caves in Serbia (Cerjanska, Petnička and Potpeć) and one pit in Croatia (Keranova Golubinka). Sampling of rock substratum containing endoliths was performed at various distances from the entrance, at sites characterized by a lower level of light intensity. Phototrophs were separated from the rock matrix using 10% hydrochloric acid and analyzed using light microscopy. In general, low diversity of endoliths was observed, but representatives from Cyanobacteria, Chlorophyta and Xanthophyta were found. Cyanobacteria, more precisely coccoid forms (genera Aphanocapsa, Chroococcidiopsis, Gloeocapsa, Gloeocapsopsis, Synechococcus), were dominant. The most interesting cyanobacterial taxon, Leptolyngbya-like taxon, representing a true endolith (euendolith), was found in the Petnička Cave. This taxon and its relation to the substratum, as well as chasmoendolithic community from the Keranova Golubinka Pit, were observed using Scanning electron microscopy (SEM). It was observed that chasmoendoliths inhabit already existing surface rock cracks and fissures, while a true endolith actively bores into the substratum. Non-metric multidimensional scaling (NMDS) was performed to observe the similarity between the sampling sites. Endoliths can grow inside the rocks, making them very successful biodeteriogens, which is not a desirable trait for caves and pits that are characterized by various attractive geomorphological features that need to be preserved. Thus, considering these habitats, more attention should be paid to the endolith community in the future.

Effects of light intensity and co-inoculation of arbuscular mycorrhizal fungi and rhizobium on root growth and nodulation of Indigofera tinctoria

&lt;p class="Default"&gt;&lt;em&gt;Indigofera tinctoria&lt;/em&gt; is a legume that is cultivated as a source of natural indigo dyes. As a legume, &lt;em&gt;Indigofera tinctoria&lt;/em&gt; is capable of symbiosis with soil microbes. This study evaluates the effects of light intensity and microbial inoculation on root growth and nodulation. The study used a complete randomized block design with a split-plot pattern. Light intensity was the main plot with four levels of light intensity 100%, 50%, 25%, and 10%. Microbial inoculation was a subplot with four levels without inoculation, mycorrhizae inoculation, rhizobium inoculation, and double inoculation with both mycorrhizae and rhizobium. The results obtained show that light intensity and microbial inoculation affected root length, root fresh weight, root biomass, and the number of nodules. 50% light intensity was optimum for root length, while 100% light intensity was optimum for root fresh weight, root biomass, and a number of nodules. Root growth and nodulation were further increased with double inoculation. The combination of light intensity and microbial inoculation affected root biomass and nodulation. The combination of 100% light intensity and double inoculation resulted in the highest root biomass and nodule numbers. Mycorrhizae and rhizobium have a synergistic relationship to nodulation and root growth. Double inoculation with mycorrhizae and rhizobium efficiently increased root biomass and the number of nodules under low or high light intensity.&lt;/p&gt;

Fire effects on vegetation and environmental variables in grasslands of the eastern hills (Sierras del Este), Uruguay

Disturbances are biomass removal events and have global relevance as they are capable of causing changes in the structure and functioning of ecosystems over time. Fire is employed in grasslands as a management tool to release space and improve the quality of forage for livestock. This thesis evaluated the effects of fire, and in some cases the interaction with grazing, at different levels of organization and at different spatial-temporal scales, on the plant structure of a grassland community dominated by Saccharum angustifolium in the Sierras del Este region from Uruguay. Through a field study, the succession process was described in patches with different time since fire through a spatial chrono-sequence. Through a laboratory study, the effects of heat shock and smoke, at different levels of light intensity, on the germination of six native species were evaluated. By means of a field experiment, along three growing stations, the effects of fire-grazing interaction on the structure of vegetation at different levels of organization were analyzed. Field burning carried out in a patchy and asynchronous manner seemed to be necessary to maintain heterogeneity at a landscape scale and the diversity of the community in the Sierras del Este grasslands.