Fluorescent Tubes Research Articles

Energy Efficiency Project for the Campuses of Unicamp

Unicamp is making progress in making its energy consumption more efficient through partnerships with companies in the electricity sector and projects carried out within the scope of the Coordination of Sustainability. Despite already being able to report a reduction of around 10% in energy consumption during the last four years, it is important for Unicamp to be able to accelerate the transition to a more sustainable operation. The Energy Efficiency Project aims to reduce the university's electricity consumption by 30% by 2030. For this purpose, it is divided into three sub projects aimed at saving energy, modernizing, and improving buildings and the university's sustainability indicators. The Unicamp 100% Led subproject foresees the replacement of conventional lamps by 18W LED tube lamps. The Sustainability in the Air subproject aims to replace old air conditioning equipment with efficient equipment. And the + Photovoltaic subproject aims to increase the generation of photovoltaic energy on the roofs of university buildings. The main goal of this is to report the implementation process of this project, its challenges, results achieved and indicators. The result of this explanation can be used as an example so that other universities can advance in the sustainable management of electric energy.

UV LED Printing Device for PCB Fabrication

Photolithography is commonly used to fabricate printed circuit boards (PCBs) in micromanufacturing. It involves UV exposure to pattern portions of a thin film of a substrate before a geometric design is transferred from a photo mask to a light-sensitive substance (photoresist) on the substrate using light. Conventionally, metal halide lamps and UV fluorescent bulbs make up most of the exposure systems during photolithography. However, both systems are highly costly in educational establishments and consume high electrical energy. Moreover, they also have too broad UV radiation and are not appropriate for the sizes of PCBs that need to be mounted on the apparatus. Hence, this innovation aims to create a low-cost, portable UV exposure system that works well in educational settings by utilizing LED illumination technology. In order to manage time, relay, and LCD, these UV LED exposures were built using a combined LED circuit with a controller board. With a dimension of 120 mm by 190 mm and 3 mm LEDs, the UV LED circuit generates a wavelength of 400 to 405 mm for the UV exposure system. Due to its powerful and flexible design capabilities, LED lighting may be integrated in any shape to create highly efficient illumination. The testing result shows that LED lights have higher application efficiency due to its ability to concentrate light in one area. Therefore, well-designed LED illumination systems may deliver light to the intended spot more effectively. They also brighten up instantly when powered on and can be turned on and off repeatedly. This research has highlighted the advantages of LEDs for infrastructure projects, such as exposure systems, which could be further developed for future technology.

Manipulating the light spectrum to increase the biomass production, physiological plasticity and nutritional quality of Eruca sativa L

The extensive development in light-emitting diodes (LEDs) in recent years provides an opportunity to positively influence plant growth and biomass accumulation and to optimize biochemical composition and nutritional quality. This study aimed to assess how different light spectra affect the growth, photosynthesis and biochemical properties of Eruca sativa. Therefore two LED lighting modes - red:blue (RB, 1:1) and red:green:blue (RGB, 2:1:2) were compared to the conventional white light fluorescent tubes (WL). Plant biomass, photosynthetic performance, several antioxidants, polyamines and nitrates contents were analyzed across different treatments. The plant growth was affected by the light quality - the presence of green light in the spectrum resulted in smaller plants and leaves, and correspondingly less biomass. RB spectral mode enhanced the total antioxidant and guaiacol peroxidase activity, pigments, flavonoids, polyphenols, ascorbate and polyamines contents. This effect under RB was combined with better leaf development compared to RGB and less nitrate in the leaves among all treatments. The RB light generated modifications in polyamines, which are interrelated with the nitrate content, further induce important metabolite and antioxidant changes. Both RB and RGB enhanced photosynthesis. The afterglow thermoluminescence band varied according to leaves development, being higher in RB and WL as a consequence of their faster growth. The RB light spectrum was found to be the most efficient for promoting the growth, biochemical composition, and overall quality of Eruca sativa compared to RGB and WL. These findings suggest that RB LEDs can be an effective tool for improving crop production in controlled environments.

Neonatal Jaundice Risk Factors and Multidirectional Intensive Phototherapy Management at Azadi Teaching Hospital in Kirkuk City

Background: A common illness in infants, neonatal jaundice is caused by high bilirubin levels in the first few days of life, which results in yellowing of the skin and eyes. Aim: This study aims to explore neonatal jaundice risk factors and assess the efficacy of multidirectional intensive phototherapy management at Azadi Teaching Hospital in Kirkuk City. Patients and Methods: In this retrospective cross-sectional study spanning from April 1st, 2021, to October 1st, 2021, a total of 497 newborns were examined. Jaundiced neonates underwent intensive phototherapy utilizing the Bilisphere 360 system, which featured a chamber with 16 cylindrical, blue TL 20W/52 fluorescent tubes. The newborns were positioned on a gauze hammock suspended at the chamber's center, illuminated on all sides. Results: A study found that neonatal jaundice affects 50.70% of studied neonates, primarily in the 16-21-day age group, with males accounting for 57.95% of the sample. 94.84% of neonates experience jaundice due to ABO blood group incompatibility and 88.10% due to Rh incompatibility. Additionally, 77.78% of term deliveries are associated with jaundice. Infants with jaundice have higher Thyroid Stimulating Hormone (TSB) and Thyroid Stimulating Hormone (TSH) levels and a younger mean age compared to non-jaundiced infants. Bilisphere 360 proves significantly more effective in the critical 12 to 48 hours after admission, with a mean total bilirubin of 10.71 ± 1.01 mg/dl compared to 14.65 ± 1.71 mg/dl for Neonatal Exchange Transfusions (P-Value: 0.001). Factors like blood group incompatibility, labor duration, and birth weight influence TSB levels in jaundiced neonates. The Bilisphere 360 method is found to be more effective in managing neonatal jaundice than Neonatal Exchange Transfusions in reducing total bilirubin levels.

Light Spectra, a Promising Tool to Modulate Ulva lacinulata Productivity and Composition.

Light quality is a key factor affecting algal growth and biomass composition, particularly pigments such as carotenoids, known for their antioxidant properties. Light-emitting diodes (LEDs) are becoming a cost-effective solution for indoor seaweed production when compared to fluorescent bulbs, allowing full control of the light spectra. However, knowledge of its effects on Ulva biomass production is still scarce. In this study, we investigated the effects of LEDs on the phenotype of an Ulva lacinulata strain, collected on the Northern Portuguese coast. Effects of white (W), green (G), red (R), and blue (B) LEDs were evaluated for growth (fresh weight and area), photosynthetic activity, sporulation, and content of pigments and antioxidant compounds. The results showed that there were no significant differences in terms of fresh weight accumulation and reduced sporulation among the tested LEDs, while W light induced the highest expansion rate. Under G, U. lacinulata attained a quicker photoacclimation, and the highest content of pigments and total antioxidant activity; but with R and W, antioxidant compounds against the specific radicals O2•- and •NO were produced in a higher content when compared to other LEDs. Altogether, this study demonstrated that it is possible to modulate the bioactive properties of U. lacinulata by using W, R, and G light, opening the path to the production of biomass tailored for specific nutraceutical applications.

Effect of the addition of an ultraviolet B light bulb for 6 months to the enclosure of client-owned cockatiels (Nymphicus hollandicus) on serum 25-hydroxyvitamin D concentrations

BackgroundThe objective of this study was to determine the effects of ultraviolet B (UVB) radiation on the serum concentration of 25-hydroxyvitamin D [25(OH)D] in pet cockatiels (Nymphicus hollandicus) living in their home environments. MethodsThirty client-owned cockatiels were allocated to an intervention group, consisting of exposure to a commercial coil fluorescent bulb, or a control group, with no exposure to supplemental lighting. Blood samples were collected at baseline (Day 0) and 6 months after simple randomization for measurement of 25(OH)D (Day 180). A linear mixed model was used to determine if serum 25(OH)D concentrations were influenced by time, group, age, or sex. ResultsAt baseline, median 25(OH)D concentration for the whole study population was 13nmol/L (range, 0.0-15.0nmol/L). At the end of the study, median 25(OH)D concentration for the whole study population was 6.5 nmol/L (0.0-15.0nmol/L), for the UVB group was 3 nmol/L (0.0-8.0nmol/L) and for the control group was 7.5nmol/L (6.0-11.0nmol/L). There was a statistically significant 50% reduction in 25(OH)D concentrations from the baseline to the final sampling period for the overall population, but no differences by group, age, or sex. Conclusion and clinical relevanceThe addition of a UVB bulb for 6 months to the enclosures of cockatiels did not increase their serum 25(OH)D concentrations. There was an unexplained decrease in both groups when comparing Day 0 to the Day 180 sampling period. The 50% attenuation in the UVB lighting group, although not statistically significant, may be clinically relevant and deserves further investigation.

HOUSEHOLD HAZARDOUS WASTE: GAUGING KNOWLEDGE LEVEL AND ITS IMPLICATION FOR DOMESTIC WASTE HANDLING AND DISPOSAL PRACTICES

Household hazardous waste (HHW) refers to waste generated at the household level that can pose a danger to public and environmental health if not managed properly. The amount of waste, including HHW, has been increasing due to urbanisation, rising income levels, and changes in lifestyles. Unfortunately, most households are not aware of the potential risks associated with this waste, despite the serious health and environmental hazards it can pose. This creates a conundrum which this study seeks to unpack. A mixed-method approach addressed this gap, including a policy dialogue and a survey of 1,245 Greater Accra Metropolitan Area respondents. From the findings, most respondents disposed of aerosol cans, disposable sharps, unused or expired medication/drugs, fluorescent tubes and LED bulbs, and electronic waste as part of their household waste. Significantly, it was concerning that 68% of participants were unaware of the potential health hazards associated with improper disposal of HHW. Based on empirical evidence, the awareness levels were affected by gender, education level, and occupation. To address the issue of HHW and reduce its harmful impact on the environment and public health, it is essential to implement policies that encourage waste segregation, establish product stewardship programs, and conduct targeted education campaigns. These actions will help raise awareness about the significance of proper HHW disposal. Additionally, it is vital to have a strong political will to effectively enforce legislation that supports the shift towards more sustainable waste management practices, thus promoting sustainable development.

Illuminating Life Sciences: A Biophysical Guide to the Use of Chromatic and White Light Sources in Photobiology

With the increasing availability of LEDs, researchers in photobiology have easier access to customized light sources. However, the abundance of different light sources poses new challenges for the correct characterization of existing light conditions. The photobiological effect of a light source depends mainly on the number of photons involved and the spectral composition. However, light sources are mainly described by parameters such as radiant flux, dominant or peak wavelength, and correlated color temperature (CCT). Therefore, in this work, chromatic and white light sources were measured for their spectral composition, various characterization parameters were determined, and the resulting photon flux densities were calculated, focusing on dominant versus peak wavelength for chromatic LEDs and the CCT for white LEDs and fluorescent tubes. The use of the dominant wavelength is inappropriate as it is partly outside the actual spectral range. It was also shown that white light sources with the same CCT have significantly different spectral compositions and, therefore, may have different photobiological effects. The results of this work should serve as a basis for life scientists to better compare light sources, to correctly interpret existing parameters, and to describe light conditions in a standardized and comparable way.

Light spectrum affects growth, metabolite profile, and resistance against fungal phytopathogens of Solanum lycopersicum L. seedlings

Tomato is a widely cultivated and economically important crop worldwide. This study aimed to test the effect of light spectra used in indoor cultivation on the growth, biochemical profile, and resistance of Solanum lycopersicum ‘Bawole Serce’ seedlings against Alternaria alternata, Alternaria solani and Botrytis cinerea. During the phase of first leaf emergence, the seedlings were transferred to a semi-sterile growth room with a controlled environment (20°C, 18-h photoperiod, 50 μmol · m−2 · s−1 PPFD, 65% RH) for a 3-week cultivation period. Five light treatments differing in red/blue (R/B) light ratio were tested: I (LED tube; R/B 5.55), II (fluorescent tube; R/B 0.72), III (fluorescent tube; R/B 1.19), IV (LED panel; R/B 0.51), V (LED panel; R/B 0.20). The best parameters in terms of shoot length, shoot fresh and dry weights, and number of leaves were obtained in treatment I, in contrast to IV and V. Plants from treatments IV and V had the smallest leaf area, perimeter, vertical length, and horizontal width. As for the root system, the highest fresh weight, area, length of the longest root, total length, and the number of root tips and forks were found in treatments I and II. The least developed root systems were observed in IV and V. The greatest chlorophyll, carotenoids and anthocyanins accumulation was enhanced by treatment II. Treatments I−III stimulated the biosynthesis of phenolic compounds. The highest superoxide dismutase activity was detected in plants from treatments I and II. As for A. alternata and A. solani, the level of disease symptoms was significantly higher for treatments IV and V than for I-III. The highest/lowest level of B. cinerea infection was found in treatments II/I, respectively. The least susceptible to infection by all tested pathogens were leaves from treatment I. Light spectrum composition is of practical importance for tomato seedling production.

Replacement of tubular fluorescent lamps with tubular LEDs lamps and daylight integration in classrooms and laboratories

The quality of lighting significantly influences our ability to perform tasks in enclosed spaces, and certain characteristics of lighting sources play a crucial role. Light-emitting diode (tubular LED) lamps offer advantages for both home and office use. Choosing tubular LED lamps over fluorescent ones is beneficial for several reasons. Tubular LEDs are mercury-free, ensuring environmental safety compared to the small amount of mercury present in fluorescent tubes. Furthermore, tubular LEDs provide directional lighting, minimizing light loss in fixtures and unnecessary areas, and offering better efficiency (around 40% more than tubular fluorescent lamps). Also, they produce high-quality light with various color temperatures, eliminating flickering issues that can cause discomfort such as eye strain, headaches, and migraines. Additionally, tubular LEDs have a longer lifespan making them a preferable lighting option. The superior quality of natural light makes it the optimal source of illumination, which matching well with the visual response of the human eyes. Daylight has a positive influence on people, instilling a feeling of vibrancy and brightness within their living environment. The acknowledged benefits of daylight extend to enhancing visual comfort, promoting health, and improving overall performance among building occupants. This paper focuses on the integration of natural daylight with artificial light, particularly through tubular LED lamps, and investigates the daylight factor. Two groups of six tubular LED lamps (60cm with 9 Watt and 120cm with 18 Watt) and another group of six tubular fluorescent lamps (60cm with 18 Watt and 120cm with 36 Watt) were studied. The study involved two sets of six tubular LED lamps (60cm with 9W and 120cm with 18W) and another set with six tubular fluorescent lamps (60cm with 18W and 120cm with 36W). Measurements were conducted using Spectroradiometer Ocean Optics HR 2000 with 4.7% uncertainty and a photometric bench to assess the spectral output. Additionally, UVA/B silicon detector and Luxmeter detector setups with uncertainties of 5.2% and 6%, respectively, were employed for irradiance and illuminance measurements of tubular LEDs and fluorescent lamps. Various parameters, including daylight factor ratio, UVA power to luminous flux (K) for tubular fluorescent lamps, spectral power distribution, and illumination levels were obtained. Integration between daylight and tubular LED lamps was also determined. The maximum detected value lmW /013.0  is less than the safe limit for human health but still there are effects on human health if they use these types of lamps. Therefore, it is advisable to switch from tubular fluorescent lamps to tubular LEDs to mitigate the impact of UVA on human health and the environment.

Enhancing Chlamydomonas reinhardtii growth and metabolite biosynthesis using organic dyes as spectral converters

The availability of light and its efficient utilisation is a major limiting factor in large scale algal cultures. While algae predominantly use the blue and red spectral regions, a significant amount of incoming light energy remains untapped outside these ranges. Converting this unused light into usable wavelengths could enhance photosynthesis. This study aimed to identify the optimal spectral converter among Lumogen Red (LR), Rhodamine 8G (R8G), and Lumogen Yellow (LY), providing efficient light utilisation for algal cultivation. Chlamydomonas reinhardtii was cultivated in double-jacketed cylindrical photo-bioreactors (PBRs) using 30% UV-a and 5% UV-b fluorescent tubes. The R8G dye displayed a slight wavelength shift with a sharp peak at about 498 nm. The LY dye demonstrated several sharp peaks at the green and blue light spectra evident of photo-degradation. The LR dye maintained better photo-stability compared to R8G and LY. Carbohydrate, lipid and protein were produced early, whereas biomass increased after day 4, as a result of photo-acclimation. The LR dye converted and emitted 3.17 × 10-19 J photon-1, enhancing biomass production and increasing photochemical energy utilisation [Y(II)] while decreasing regulated energy dissipation [Y(NPQ)]. Pigment biosynthesis was initially increased and then reduced to counteract heightened irradiation as a means of photo-protection. LR had a 1.6- and 2.9-fold up-regulation of the RuBisCo gene expression. The dye-based system correlated with improved growth, lipid, protein, carbohydrate, and pigment production. The dye-based wavelength conversion system was interlinked to the sustainable development goals addressing environmental, economic, and social aspects.

Is line-source modeling suitable for ultraviolet light application in an air cleaner duct?

Ultraviolet-C (UV-C) germicidal light can effectively inactivate airborne pathogens and mitigate the transmission of infectious diseases. As the application of UV-C for disinfection gains popularity, practical estimation of UV irradiance is essential in determining the UV fluence (dose) and designing tubular UV lamp configurations for indoor air treatment. It is generally understood that the inverse square (∼1/d2) law (i.e., irradiance is proportional to the inverse square of the distance) applies well to point light sources. However, there has been a recognition that the ∼1/d2 law does not work well for tubular light sources in the commonly defined near-field applications where the UV source is relatively close to the treated air. Therefore, practical near-field irradiation estimation is needed for designing portable air cleaners and heating, ventilation, and air conditioning (HVAC) ducts with built-in UV light bulbs. This research investigated UV-C light irradiance from tubular (L = 0.9 m) light bulbs at near distances inside an air cleaner prototype duct under three power output (1-, 4-, and 8-bulb) scenarios and conducted theoretical estimation based on a line-source irradiation model. Similarly sized visible fluorescent bulbs were used as a reference. The data were fitted on both ∼1/d2 and ∼1/d correlation of irradiance with distance. Both measured and line source estimated data fit better (i.e., evaluated by R-square, standard errors, root mean squared errors) with the ∼1/d than the ∼1/d2 relationship in the near distance. Although the differences between the measured and the modeled were observed, the pattern of light distribution generally follows an inverse relationship (∼1/d) with distances (d) shorter than two tubular bulb lengths (d < 2L). The pattern applies to both UV and visible light tested in this study. It is recommended that the inverse (∼1/d) correlation be used for near-distance estimation of light distribution, especially for disinfection purposes in air ducting for indoor air quality improvement and airborne disease mitigation.

Synergistic effect of net-houses and light sources on the enhancement of off-season flowering waves and production of ‘Da Hong’ red-fleshed pitaya

To meet the increasing demand for year-round production of ‘Da Hong’ red-fleshed pitaya (Hylocereus polyrhizus), which is limited by its natural flowering season in the summer and has been a dominant cultivar in Taiwan, China and East-SouthEast Asia owing to its self-compatibility and excellent fruit quality, extending the off-season cultivation period has become a crucial endeavor. This study aimed to assess the effects of net-houses and light sources on off-season (spring and winter) fruit quality yield of ‘Da Hong’ red-fleshed pitaya in Taiwan. Mature six-year-old plants were cultivated either in net-houses or open fields (OFs), with night-breaking achieved using artificial lighting: either 100 W incandescent bulbs (IBs) or 23 W compact fluorescent energy-saving bulbs (CFBs). The study was conducted during spring and winter in 2017–2018, with flowering rate and fruit production evaluated. Floral bud emergence in the net-house+IB and net-house+CFB groups preceded that in other treatments by at least 2 weeks during spring, with net-house+IB exhibiting the highest frequency of flowering waves (four in spring and three in winter). Across all treatments, night-breaking via artificial lighting in spring markedly increased yield, with IBs and CFBs producing similar outcomes. Quality-wise, OF cultivation surpassed net-house cultivation in spring, whereas net-house cultivation, particularly with IBs, proved more effective during winter. In summary, net-house cultivation offers several advantages for off-season production, including earlier peak flowering in spring, increased flowering cycles in both spring and winter, and higher flowering rates during winter. Overall, these results may help enhance and stabilize off-season ‘Da Hong’ red-fleshed pitaya cultivation. Moreover, the significance of our study has the potential to revolutionize the flowering physiology, the strategy to enhance year-round production and the advancement of agricultural sustainability in pitaya.

Field‐representative evaluation of PID‐polarization in TOPCon PV modules by accelerated stress testing

AbstractPotential‐induced degradation‐polarization (PID‐p) can reduce module power, but how to project the extent to which PID‐p may occur in field conditions considering the factors of system voltage, condensed moisture, temperature, and illumination has not been clarified. Using tunnel oxide passivated contact (TOPCon) modules, this work demonstrates a method to test full‐size crystalline silicon PV modules for PID‐p to provide field‐representative results. In initial screening tests with positive or negative 1000 V electrical bias applied at 60°C for 96 h using Al foil electrodes on the glass surfaces, the module type exhibited reversible PID‐p only on the front face when the cell circuit was in negative voltage potential. No PID was detected on the rear after testing in either polarity. We then evaluated the PID‐p sensitivity on the front side under different UV irradiances while maintaining the glass surface wet to estimate real‐world susceptibility to PID‐p. The magnitude of the observed behavior was fit using a previously developed charge transfer and depletion by light model. Whereas power loss with −1000 V applied to the cell circuit at 60°C for 96 h in the dark was about 30%, testing the module front under 0.051 W·m−2 nm−1 at 340 nm UVA irradiation using fluorescent tubes, the mean degradation was only 3%. When the modules were tested in the dark for PID‐p with in situ dark current–voltage (I‐V) characterization, the thermal activation energy for degradation was 0.71 eV; for recovery in the dark, it was 0.58 eV. Whereas recovery from the degraded state at 60°C in the dark without voltage bias was 5% absolute in 38 h, rapid recovery of about 5% absolute was observed with 1000 W·s/m2 exposure at 25°C using a flash tester.

Evaluation of Alternative Disposal and Replacement of Fluorescent Lamps

This paper presents a evaluation of the disposal alternatives and substitution of the flourescent lights, in order to contribute with the correct recycling of this product. Initially presents a projection of how much eletricity can be saved by changing the most used lamps by the brazilian for LED lamps (Light-emitting diode). After, a economic viability evaluation also is presented in this study. Also a description of the reciclyng methodologies and disposal of the flourescent lamps and the danger who may be caused for health, are presented with the final conclusions of this research.

Case study of energy efficiency and electric power quality

This paper describes the results of the electrical energy efficiency and power quality evaluation done in the School of Electrical and Computer Engineering of the University of Campinas (Unicamp) in São Paulo State, Brazil, through the Project named Ecogera. The analysis was based on the electrical signals acquired in the switchgear of the Students Classroom Building of the School of Electrical and Computer Engineering using measurement and energy management instruments. The replacement of the old lightning system using 40 W old fashion fluorescent bulbs mounted on non reflective fixtures by new energy save 32W fluorescent bulbs mounted on reflective fixtures reduced expressively the electrical energy consumption and the installation electrical power demand. The measurements allowed to know the details of harmonic distortions and disturbances that affect voltage magnitude and current.

Impact of feed, light and access to manipulable material on tail biting in pigs with intact tails

BackgroundTail biting (TB) is a welfare issue with economic consequences due to infections and ill-thrift. This study aimed to reduce tail injuries in a high-performing non-tail-docking pig herd.ResultsDuring eleven years preceding the trial, the annual incidence of tail injuries registered at slaughter in pigs from the herd increased from 3% (equivalent to the national mean) to 10%. It was positively correlated to a high weight gain and negatively correlated to daylight length.The overall incidence of tail injuries during the four years preceding the trial was 9.2% with significant differences between four identically structured buildings for fatteners (I < II < III < IV).The feed was enriched with amino acids, minerals and fibres. The buildings used different illumination strategies, I: standard fluorescent tubes with an invisible flickering light of 30–40% for 14 h daily, II: non-flickering led light for 14 h daily, III (control) and IV: standard fluorescent tubes for 2 h daily. IV had free access to manipulable material (hay-silage), while I–III was offered 100–200 g daily.During the adaptation period (6 months), the incidence of tail injuries decreased significantly in all buildings to a mean of 5.4%. The largest decrease (from 11.4 to 4.3%) was obtained in IV.During the trial period (12 months), the mean incidence of tail injuries decreased in all groups to a mean of 3.0%. There were no differences in treatment incidences of individual pigs due to TB between groups, but the use of enriched pellets due to TB in pens was lowest in II. The low incidence of tail injuries was retained during the post-trial period (6 months) when all buildings used artificial illumination for two hours per day.ConclusionsThe incidence of TB in fast growing non-tail-docked pigs in the herd was successfully reduced by supplementing the feed with amino acids, minerals, vitamins and fibres. Additional manipulable material accelerated that process and non-flickering illumination may have had an impact in preventing TB.The results obtained do not support the need for tail-docking of pigs, provided that the needs of the pigs in terms of feed ingredients, stocking density and access to manipulable materials are fulfilled.

The influence exerted by LEDs and fluorescent tubes, of different colors, on regenerative processes and morphogenesis of Rebutia heliosa in vitro cultures

The influence exerted by LEDs and fluorescent tubes, of different colors, on regenerative processes and morphogenesis of Rebutia heliosa in vitro cultures

The Impact of Stabilization Time on Lumen and Electrical Power in LED Tube Lamp Testing

- In 2022, the Indonesian Government issued a policy regarding Minimum Energy Performance Standards (MEPS) and energy-saving mark labels for Light Emitting Diode (LED) lamps. Therefore, testing laboratories or lamp manufacturers should know that the stabilization time will affect the test results. LED lumen changes rapidly during the first 30 minutes, so taking data earlier during the test may lead to different test results. The results also show that the lumen fluctuation will be lower when the run time is 45 minutes or more. Stabilization time is essential when measuring LED tube lights, so a stabilization time of 45 minutes is the most effective for data collection.

Development of Low-Cost Growing Media with Mungbean as A Source of Carbon for Spirulina

Spirulina is a multicellular, photosynthesis, filamentous blue-green algae which is found naturally in a wide range of fresh, marine, and brackish waters. It is an excellent source of protein, vitamins, minerals, lipids, carbohydrates, and pigments thus considered as the “superfood” of the century. The commercial production of Spirulina depends on many factors such as nutrient availability, temperature, and light. Zarrouk’s medium is known to be the standard media (SM) which contains all the macro and micro-nutrients required for the growth of Spirulina. The cost of nutrients is however found to be the second limiting factor next to labor cost affecting the commercial-scale production of Spirulina. The cost of carbon source is higher than that of N and P sources. Therefore, this study aimed at developing a low-cost medium for large-scale production of Spirulina. This intention was implemented by substituting carbon sources present in SM with cheaper and locally available carbon sources. Two separate experiments were conducted using a complete randomized design (CRD) with 3 replicates. The conventional carbon source in Zarrouk’s medium (NaHCO3) was substituted with low-cost carbon sources i.e., Mungbean flour (before and after germination separately). The carbon content in SM was replaced by 100 %, 75 %, 50 % and 25 % of Mungbean flour. Zarrouk’s medium was used as the control. The culture was maintained at 30 0C ± 2 0C under 4000 Lux, continuous illumination using a white, fluorescent tube for 16 days. Growth was measured using a spectrometer and optical density (OD) values were recorded at 560 nm with two days interval. Data were analyzed using SAS version 9.4. The best growth of Spirulina was recorded at the 50 % replacement of carbon in SM by Mungbean flour (before germination). Mungbean flour (after germination) could also replace 25 % of carbon in Zarrouk’s media. Taking the cost factor into consideration, 50 % replacement of carbon in Zarrouk’s medium by Mungbean flour (before germination) can be recommended for commercial scale cultivation. The comparative cost reduction of this replacement is estimated to be 50 %.