Content Of Tea Research Articles

Supplementation of Antioxidant Liang Tea Extracts on Goat Milk Cream Cheese

Cream cheese is a soft cheese that does not go through a ripening process and is widely used in various kinds of food preparations. Goat's milk is an alternative milk for cream cheese production. The addition of antioxidant extract from liang tea potentially produces functional cream cheese. This research aimed to obtain the concentration of added antioxidant liang tea extract in the formulation that produces the best characteristics of goat's milk cream cheese. This research used a Randomized Block Design method with one factor: the concentration of liang tea extract as an antioxidant. The treatment consisted of 5 levels of liang tea concentrations, 0%, 1.5%, 2%, 2.5%, and 3%, with five repetitions. The research showed that adding various concentrations of liang tea antioxidant extract produced a water content of 61.06%-62.09% and a fat content of 12.68%-14.46%. The resulting color characteristics with the L* value range from 60.83-76.43 (decreasing brightness), the* value range from -6.69-6.71 (reddish), and the b* value range from 4.47-23 .88 (yellowish). Antioxidant activity is expressed by percent inhibition of 1,1-diphenyl-2-picrylhydrazil (DPPH), ranging from 36.00%-79.56%. The antioxidant activity of goat's milk cream cheese increases if the addition of liang tea extract is high. Based on the effectiveness index, the best goat's milk cream cheese is produced by adding a 3% concentration of liang tea. The cream cheese has a water content of 62.19%, a fat content of 14.46%, color (L* = 60.83, a* = 6.71, b* = 23.88), and antioxidant activity of 79.56%.

Effects of Organic tea concentration and application methods on growth and yield of Greenhouse Cucumber (Cucumis sativum L.) in Owo, South-western Nigeria

Organic tea (mixture of Organic Manure Extract and Spent Bleaching Extract) is used as nutrient complements in agriculture and horticulture to increase plant growth and yield. In this study a 2 X 4 factorial experiment used CRD (Completely Randomized Design) to examined the effect of compost tea herein referred to as OT [organic tea (extract made from SBE and composted manure extract (OM)] as bio-stimulants at four different concentrations (0, 20, 30, and 40 %) on the growth and fruit yield in cucumber (Cucumis sativum L.) under greenhouse condition using foliar (FO) and drip irrigation (DR) application methods. Vegetative parameters (vine length, number of branches, number of leaf per plant, leaf area, and stem girth) were studied at 50% flowering stage and yield parameters (Date to flower initiation, No of male flower, No of female flower, male/female flower ratio, number of fruit/plant, fruit length, fruit diameter, fruit weight/plant) and yield / hectare, at harvest. From the experiment organic tea application via folia method exhibited enhanced vegetative growth while application via drip irrigation was found to be more effective in influencing the yield parameters significantly. Plants that received 20% OT showed variability, but were not significantly different from control plants (0%). Similarly, plants treated with 40% OT extract showed enhanced vegetative growth and fruit yield with good quality, but high diseases infection. This study therefore provides important information on the utilization of OT and application method for increased cucumber production in the study area.

The effect of ascorbic acid and lemon juice on the extraction of metals from green tea, health risk assessment

The total heavy metal concentration (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in green tea leaves and metals leached into tea infusions of pure water with the addition of ascorbic acid and lemon juice at various temperatures (70, 80, and 100 °C) and steeping times (3, 5, and 7 min), were determined. Metal concentrations were analyzed by atomic absorption spectrometry and the flame technique (FAAS). Mean total concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn were < LOD, <LOD, 0.198, 4.527, 67.51, 333.7, 2.588, <LOD, 10.23 μg/g, respectively. The highest percentage of extraction in different solutions was in the case of Mn (up to 100%). The risk for adults through consumption of tea was mainly contributed by Mn, and non-carcinogenic hazard quotient (HQ) was slightly higher than 1 when infusions were heated to 100 °C. High percentages of Ni were extracted in pure water compared to water with addition, regardless of tea steeping time, followed by Cu in pure water and water with lemon juice. Fe was poorly extracted in all applied solutions; the highest percentage of extraction (17.21%) was determined in lemon juice solutions of at 100 °C during a steeping time of 7 min.

Associations between tea-drinking habits and health-related quality of life in Chinese adults: a mediation analysis based on sleep quality.

The aim of this study was to explore the association between tea-drinking habits and health-related quality of life (HRQoL) in Chinese adults and the mediating effect of sleep quality in this association. Data were derived from the 2020 Survey of Social Factors for Chronic Disease Prevention and Control among adults in Lishui District, Nanjing, Jiangsu Province, China. Tea-drinking habits were measured by participants' self-report. The HRQoL was measured using the 12-item Short Form Health Survey. Multiple linear regression modelling and mediating effects modelling were used for analyses. Habitual tea drinking, frequent tea drinking (drinking tea 6-7days per week), tea concentration and <10g of tea per day were strongly associated with an increase in HRQoL among Chinese adults (all p<0.05). The association between tea-drinking habits and HRQoL among Chinese adults was more pronounced in the male population and in those ≥45y of age (all p<0.05). Tea drinking habits may improve HRQoL in Chinese adults by enhancing sleep quality (all p<0.05). Maintaining the habit of habitual tea drinking (6-7days per week), in small amounts (<10g tea per day) was conducive to improving HRQoL of Chinese adults by improving sleep quality.

Oxygen vacancies induced by lanthanum-doped indium oxide nanofibers for promoted temperature-dependent triethylamine and formaldehyde sensing

A novel TEA and HCHO dual-function temperature-dependent sensing material (3La-In2O3) with ultra-high sensitivity was developed via a facile electrospinning process. Though rare earth doped in In2O3-based sensors have been widely reported, the low sensitivity, poor selectivity and high operating temperature remain restrict their application. Herein, the In2O3 nanofibers with different contents of La3+ ions are firstly obtained by a facile electrospinning process. The sensing performance investigation confirms that the 3% La/In molar ratio of La3+ doped in In2O3 nanofibers are more appropriate as the sensing material for TEA and HCHO detection. The 3La-In2O3 exhibits greatest response value of 3721.60–10 ppm TEA and 1469.65–10 ppm HCHO at their best working temperature (100 ℃ and 160 ℃), approximately 23.85-fold and 10.85-fold higher than that of pristine In2O3 nanofibers. In addition, the excellent selectivity, repeatability, and long-term stability ensure the further application of the 3La-In2O3-based sensor in actual environment. The promoted sensing performance is mainly ascribed to the more oxygen vacancies, the increasing specific surface area, the smaller grain size of In2O3 nanofibers induced by La3+ doping. The DFT results demonstrate the beneficial effect of La and oxygen vacancies on the improved target gas adsorption energy.

Highly effective emulsion liquid membrane based on Triethylamine for extraction of heavy metals: Investigation of extraction, de-extraction, swelling, and osmotic pressure gradient

The aim of this work is to produce a stable W/O primary emulsion which is able to extract a wide variety of heavy metals, namely Cu2+, Zn2+, Pb2+, Ni2+, Co2+ and Hg2+. The appropriate conditions through which a better extraction was obtained are: concentration of Span 80 (4 wt%); concentration of TEA (10 wt%); internal phase (HCl 0.5 M); emulsification time (4 min); Vmemb/Vint (2.08); Vemul/Vext (0.1); pH of the external solution (4.7) and stirring speed (150 rpm). A second recycling of the emulsion resulted in a drop in extraction about 40 %. The morphological study confirmed a good dispersion of internal globules and a good stability of emulsion for up to 60 days. The extraction of metal cations showed very high extraction (> 90 %) with very fast kinetics. However, it has been shown that the type of anion to which the metal cation is bound, only affects the extraction efficiency above 100 mg/L. Results extraction of heavy metals are in good analogy with evolution of the osmotic pressure difference between the internal and external phases, leading to a significant swelling of emulsion, while de-extraction also appears to be in accord with extraction with a slightly slower rate.

Effect of Na2SiO3 and TEA Electrolyte Additives on the Corrosion Inhibition of Zinc Electrodes and Electrochemical Performance of Rechargeable Alkaline Manganese Batteries

To inhibit hydrogen evolution corrosion, passivation, and zinc dendrite growth during the charging and discharging of the zinc negative electrode of rechargeable alkaline manganese battery containing ultra-fine zinc powders, the effects of the single addition amounts of inorganic corrosion inhibitor Na2SiO3 and organic corrosion inhibitor TEA and their compounding ratio on the corrosion inhibition effect and the charging and discharging performance of alkaline manganese battery were systematically investigated in this paper. SEM and XPS were used to observe the microscopic morphology of the zinc anode, and the inhibition mechanisms of the relevant inhibitors were explored. The results show that, the addition of Na2SiO3 and TEA can synergistically improve the coverage of the protective film, thereby inhibiting hydrogen evolution corrosion, passivation and dendrites of zinc electrodes. Compared to blank electrolyte, when the composite concentration of Na2SiO3 and TEA is 1 g l−1 Na2SiO3+56.25 mg l−1 TEA, the hydrogen evolution corrosion inhibition efficiency can reach 70.56%, the initial specific capacity and the specific capacity after 50 cycles can increase from 160.7 mAh g−1, 58 mAh g−1 to 198.4 mAh g−1, 74 mAh g−1, respectively. This study has great theoretical and engineering value for guiding the design of electrolytes for rechargeable alkaline manganese batteries.

Prediction of glucose and sucrose values of black tea samples using NIR spectroscopy and chemometrics

FT-NIR and chemometrics are considered one of the most important analytical tools for the quality control of tea. The present study focused on developing and validating a rapid quantification method for the quantification of sugar, specifically sucrose and glucose in black tea using FT-NIR spectroscopy. Calibration models were established by partial least squares (PLS) regression analysis. Fructose, glucose, and sucrose concentrations in black tea were analyzed using high-performance liquid chromatography. The spectral range and the number of PLS factors were optimized for the Residual Predictive Deviation (RPD) and correlation coefficient (r2) of determination. The NIR spectral region between 5878 and 3996 cm−1 (1701–2500 nm) was selected as the best range for predicting glucose, sucrose, and fructose concentrations in black tea. The calibration model developed for sucrose has high RPD (4.29) and r2 (0.95) indicating the potential for predicting the inherent sucrose content in black tea with high accuracy. The calibration model developed for glucose has RPD of 2.73 and r2 (0.87) showing the potential for predicting glucose content in black tea with reasonable accuracy. Both calibration models could be useful for quality assurance purposes in black tea, and easier and faster than the wet chemical HPLC method. FT-NIR spectroscopy coupled with chemometrics has been demonstrated for the first time to quantify the inherent glucose and sucrose concentrations in black tea. Calibration models could be used to determine adulteration of black tea with sucrose and glucose.

Influence of citric acid on the extraction level of manganese in green and black tea infusions

Manganese concentration in green and black tea (10 samples of each type) was determined by means of graphite-furnace atomic absorption spectrometry. Both the dry leaves and the infusions were analysed. The concentration of manganese in dry leaves was in the range of 502–1277 mg · kg−1 for black tea and 798–1906 mg · kg−1 for green one. Since lemon juice is commonly added for tea to enrich its taste, citric acid was used to simulate lemon juice influence on manganese concentration in the infusions. The infusions prepared with and without citric acid addition were analysed and the results showed significant influence of citric acid on manganese leaching. The average extraction levels of manganese from black tea equal 16% (for non-acidified infusions) and 34% (for acidified ones) while these values for green tea equal 13% and 38%, respectively. Statistical evaluation of the results showed that the differences between acidified and non-acidified infusions were statistically significant. High manganese content makes the tea an important source of manganese in human diet.

Antioxidant Activity of Rose Tea (Rosa damascene) with Various Types of Sugar and Rose Tea Concentration

Kombucha tea is a traditional beverages product manufactured from fermented tea and sugar solutions. Using Acetobacter xylinum sa starter. Kombucha tea has a refreshing sour taste, but the distinctives aroma make kombucha tea less attractives to consumers. Red roses (Rosa damascene) are a source of anthocyanin pigments that have not been widely used. In addition, to increase the economic value of roses. Based on research that has been done, red roses contain antioxidants in the form of purplish red anthocyanins. The purpose of this study was to determine the effect of the type of sugar and the concentration of rose extract on the characteristics of rose kombucha produced. This study used Completely Randomized Design (CRD). The factors used were the concentration of rose tea (1g/250ml, 2g/250ml, 3g/250ml) and variations in the type of sugar (palm, sand, fine). The best chemical and organoleptic analysis based on the highest antioxidant activity was the addition of palm sugar and the concentration of the addition of rose tea 1g/250ml with a total phenolic of 10.17mg GAE/L, total dissolved solids (TPT) 11.10%, acidity (pH) 3.86, antioxidant activity 48.28%, vitamin C 11.41%, 13.63% for total sugar, sour taste score 3.06, rose flavor 2.15 and 1.10 for overall preference the addition of palm sugar and the concentration of the addition of rose tea 1g/250ml. Kombucha made from rose extract can be an alternative functional food.

Kombucha and Water Kefir Grains Microbiomes' Symbiotic Contribution to Postbiotics Enhancement.

Wild artisanal cultures, such as a symbiotic culture of bacteria and yeasts (SCOBY) and water kefir grains (WKG), represent a complex microorganism consortia that is composed of yeasts and lactic and acetic acid bacteria, with large strains of diversity and abundance. The fermented products (FPs) obtained by the microbiome's contribution can be included in functional products due to their meta-biotics (pre-, pro-, post-, and paraprobiotics) as a result of complex and synergistic associations as well as due to the metabolic functionality. In this study, consortia of both SCOBY and WKG were involved in the co-fermentation of a newly formulated substrate that was further analysed, aiming at increasing the postbiotic composition of the FPs. Plackett-Burman (PBD) and Response Surface Methodology (RSM) techniques were employed for the experimental designs to select and optimise several parameters that have an influence on the lyophilised starter cultures of SCOBY and WKG activity as a multiple inoculum. Tea concentration (1-3%), sugar concentration (5-10%), raisins concentration (3-6%), SCOBY lyophilised culture concentration (0.2-0.5%), WKG lyophilised culture concentration (0.2-0.5%), and fermentation time (5-7 days) were considered the independent variables for mathematical analysis and fermentation conditions' optimisation. Antimicrobial activity against Bacillus subtilis MIUG B1, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Aspergillus niger MIUG M5, antioxidant capacity (DPPH), pH and the total acidity (TA) were evaluated as responses. The rich postbiotic bioactive composition of the FP obtained in optimised biotechnological conditions highlighted the usefulness of the artisanal co-cultures, through their symbiotic metabolic interactions for the improvement of bioactive potential.

Anti-microbial activity of Green Tea Extracts and Nicotine on the Growth, Biofilm Formation of Salivary Mutans Streptococci (In-vitro study)

Background: The green tea have antimicrobial activity against many types of bacteria It is considered a natural substance with few side effect. Aim of the Study: An in vitro study was carried out to investigate the ability of green tea extract and nicotine to inhibit growth, biofilm formation by salivary Mutans streptococci. Methods: This study included a convenient sample of 40 healthy Iraqi volunteers aged 18–23 years old from College of Dentistry / University of Baghdad. Green tea and nicotine aqueous extract were prepared in different concentration to use in agar diffusion method to detect the activity of extract, and ELISA reader in multi titer plate was used to determine the ability of salivary mutans Streptococci to form biofilm in the presence and absence of the extracts.to measure the biofilm inhibition rate. Results: Mutans Streptococci were sensitive to green tea and nicotine in different concentrations the diameters of the inhibition zone were effective in a dose dependent manner significantly. There was a significant difference between the concentrations of each extracts, antibacterial activity was in a dose dependent manner for the extracts. The minimum bactericidal concentration of green tea was (280 mg/ml) and minimum bactericidal concentration of nicotine was (45mg/ml). The study found that biofilm formation by Mutans Streptococci was markedly decreased in the presence of 1/2 minimum bactericidal concentration of both green tea and nicotine with mean of O.D 590 nm = 0.54 in comparison with green tea extracts and nicotine alone O.D 590 nm = 0.15, 0.68 respectively. Conclusions green tea and nicotine extracts in different concentration effectively reduced the biofilm formation of salivary Mutans streptococci. While the presence of nicotine has negatively impacted on the ability of green tea extracts in the inhibition of biofilm formation by Mutans Streptococci in vitro.

Effects of Vermicompost and Beneficial Microbes on Biomass and Nutrient Density in Purple Lady Bok Choy (Brassica rapa var. chinensis) in A Vertical Hydroponic Grow Tower System

Indoor food production in vertical hydroponic systems can be done year-round in any climate, has less negative environmental impacts compared to industrial agriculture and is a way of increasing the nutritional value of crops. Indoor hydroponic systems make it easy to control the precision of additives and amendments, such as fertilizers and vermicompost tea, to nutrient solution reservoirs. Vermicompost tea is known to contain beneficial microorganisms and can help increase the biomass, nutrient density, and overall health of the plants. Microorganisms and plants have co-evolved and is an essential relationship that deserves recognition and further research. The goal of the research presented in this paper was to better understand if vermicompost tea and its associated microorganisms, such as bacteria, fungi, nematodes, and protozoa, would increase biomass and nutrient density of Purple Lady Bok Choy (Brassica rapa var. chinensis) in vertical hydroponic systems. Statistical analyses were performed to compare the biomass and macro- and micronutrients of three different treatments to one another and a control. There was a significant difference between the mean leaf and root biomass among varying concentrations of vermicompost tea solutions and added inorganic hydroponic fertilizer. The nutrient density for both macro- and micronutrients also differed significantly due to different concentrations of vermicompost tea, suggesting that beneficial microbes may help plants uptake and absorb nutrients in a more efficient manner depending on the concentration of vermicompost tea and hydroponic fertilizer.

The Effect of Hot Water Extract of Pluchea indica Leaf Powder on the Physical, Chemical and Sensory Properties of Wet Noodles

Powdered Pluchea indica Less leaves have been utilized as herbal tea, brewing of pluchea tea in hot water has antioxidant and antidiabetic activities, because of phytochemical compound content, namely tannins, alkaloids, phenol hydroquinone, phenolics, cardiac glycosides, flavonoids, and sterols. Using of this extract on food, such as jelly drinks, buns, and soymilk can increase functional values and influence physic, chemical, and sensory characteristics of food. The study was carried out to assess the effect of various concentration of pluchea tea on the physical, chemical and sensory properties of wet noodles. A one-factor randomized design was applied with pluchea tea at concentrations of 0, 5, 10, 15, 20, 25 and 30% (w/v). Physical properties analyzed included water content, swelling index, cooking loss, color and texture. Chemical properties measured were bioactive contents of total phenolic content, total flavonoid content, and antioxidant ability to scavenge DPPH free radicals and to reduce iron ions. Sensory properties determined were taste, texture, color, aroma and overall acceptance. The addition of various concentrations of extract offers significantly effects on parameters of physical, chemical and sensory properties of noodles, except color (redness, chroma and hue), cooking loss, water content, swelling index and aroma. Using of 10% (w/v) of pluchea tea resulted in the best sensory properties such as color, aroma, taste, texture, and overall acceptance with the scores of 5.62 (slightly like), 5.45 (slightly like), 5.46 (somewhat like), 6.53 (like), and 6.53 (like), respectively. Generally, the study concluded that wet noodles can be made by adding pluchea tea at 10% (w/v). Dried samples TPC, TFC, DPPH free radical scavenging and iron ion reducing power were 82.84 mg GAE/kg, 62.44 mg CE/kg, 130.68 mg GAE/kg and 51.33 mg GAE/kg, respectively.

Volatilomics Analysis of Jasmine Tea during Multiple Rounds of Scenting Processes

Jasmine tea is reprocessed from finished tea by absorbing the floral aroma of jasmine (Jasminum sambac (L.) Aiton); this process is commonly known as "scenting". Making high-quality jasmine tea with a refreshing aroma requires repeated scenting. To date, the detailed volatile organic compounds (VOCs) and the formation of a refreshing aroma as the number of scenting processes increases are largely unknown and therefore need further study. To this end, integrated sensory evaluation, widely targeted volatilomics analysis, multivariate statistical analyses, and odor activity value (OAV) analysis were performed. The results showed that the aroma freshness, concentration, purity, and persistence of jasmine tea gradually intensifies as the number of scenting processes increases, and the last round of scenting process without drying plays a significant role in improving the refreshing aroma. A total of 887 VOCs was detected in jasmine tea samples, and their types and contents increased with the number of scenting processes. In addition, eight VOCs, including ethyl (methylthio)acetate, (Z)-3-hexen-1-ol acetate, (E)-2-hexenal, 2-nonenal, (Z)-3-hexen-1-ol, (6Z)-nonen-1-ol, β-ionone, and benzyl acetate, were identified as key odorants responsible for the refreshing aroma of jasmine tea. This detailed information can expand our understanding of the formation of a refreshing aroma of jasmine tea.

Quantification of dynamic changes of sugars during the aeration/oxidation period of black tea processing: A Sri Lankan study

The inherent sugar components viz. fructose, sucrose and glucose contents in the black tea from different elevations were studied and the dynamic changes in the major sugar components during the aeration/oxidation period in the black tea processing were investigated by using High-Performance Liquid Chromatography. Significant differences were observed in the fructose, glucose, and sucrose contents of the black tea from different elevations in Sri Lanka. The average inherent concentrations in black tea were concluded as fructose, 8.17 mg/g, glucose, 8.79 mg/g, and sucrose, 9.53 mg/g from different elevations in Sri Lanka. Significant dynamic changes were exhibited in the contents of sucrose, fructose, and glucose throughout the aeration/oxidation period in the black tea processing. Significantly higher sucrose content was observed in black tea manufactured using rolled leaves, bypassing the aeration/oxidation process. The results of this work showed the dynamic changing in major sugar components during the aeration/oxidation period in black tea processing and also provide information on the average inherent contents of major sugars present in black tea.

The effect of anaerobic digestate tea on the growth of lemon grass (Cymbopogan citratus)

AbstractIn this paper, we present the novel use of digestate tea to boost the rates of growth of Cymbopogan citratus, the lemon grass plant. The digestate was sourced from a functioning anaerobic digester at the University of the West Indies Cave Hill Campus, and made into a slurry (digestate tea). The slurry was then applied to the plants in varying surface concentrations. The digestate tea had a profound effect on the growth rates of the plants and resulted in an eight times increase in the overall biomass yield at the highest concentration of digestate tea applied (0.21 ± 0.06 kg, 5.5 L m−2), when compared with the control (0.026 ± 0.004 kg, 0 L m−2). This type of fertilization can tremendously boost lemon grass production, and hence, the production of the valuable lemon grass essential oil in a sustainable and environmentally friendly manner. © 2023 Society of Industrial Chemistry and John Wiley &amp; Sons Ltd.

Study on the relationship between tea concentration and Tyndall effect

The quality of tea is relative with its concentration. In this paper, we present a method to identify the concentration of tea based on Tyndall effect. The tea is illuminated by 3-watt LED light sources with the main wavelength in ultraviolet and visible bands. The intensities of transmitted light are detected using the distributed photometer and the images of light distribution are captured by CCD camera at vertical direction to observe the Tyndall effect. The intensities and images for different light sources are compared. The experimental results show that there exist Tyndall phenomenon in tea. In addition, the Tyndall effect becomes weaker as the tea concentration increases when the tea is illuminated by the LED light sources with the main wavelength in the ultraviolet band. The method presented in this paper should be helpful for rapid identification of the tea quality

Improved performance of UV-blue dual-band Bi2O3/TiO2 photodetectors and application of visible light communication with UV light encryption.

In this paper, self-powered photodetectors (PDs) with a dual-band photoresponse and excellent photodetection capabilities in complex environments can meet the needs of diverse detection targets, complex environments and diverse tasks. Herein, Bi2O3 nanosheets were deposited on the surface of TiO2 nanorod arrays (NRs) by chemical bath deposition (CBD) to construct self-powered heterojunction PDs with a UV-blue dual-band photoresponse. The nucleation and growth of Bi2O3 nanosheets on TiO2 NRs substrates were controlled by varying the concentration of the complexing agent triethanolamine (TEA) in the precursor solution, which regulated the morphology, crystalline quality and energy band structure as well as the photoelectronic properties of Bi2O3 films. The devices fabricated at a TEA concentration of 0.3 M exhibited excellent self-powered UV-blue dual-band photoresponse characteristics, achieving a photocurrent (Iph) of 144 nA, a responsivity of 1.79 mA W-1 and a detectivity of 5.94 × 1010 Jones under 405 nm illumination at 0 V, which can be attributed to the large built-in electric field (Eb) of Bi2O3/TiO2 heterojunctions, the low interfacial transfer resistance and suitable carrier transport path. In addition, Bi2O3/TiO2 heterojunction PDs with the UV-blue dual-band photoresponse characteristics can be applied in UV-encrypted visible light communication (VLC) with a light-controlled logic gate to improve the security of information transmission.

Ekstraksi Teh Hijau dan Aplikasinya sebagai Pengendali Korosi Pada Pompa di Lingkungan Garam NaCl 3,56%

Green tea leaves contain antioxidant compounds that can be used as organic inhibitors in a corrosion process. Tea leaves were extracted by maceration method using 70% ethanol solution with a solid:solvent ratio of 1:8 (w/v) for 1 x 24 hours in an atmospheric room. The extract was then concentrated with a rotary evaporator and separated with solvent under vacuum conditions at 852 mbar, temperature of 70oC and rotation of 80 rpm. The results of the qualitative test of extra tea leaves using 10% NaOH and 1% FeCl3 changed the color to brownish orange and blue-black. This indicates the content of flavonoids and tannins. Green tea leaf extract is also applied to control the corrosion rate of brass metal. Variations in the concentration of tea leaves were 200, 400, 600 ppm in 3.56% NaCl solution. The pump circulation is carried out for 40 hours, the weight loss method is carried out every 8 hours. The average corrosion rate without inhibitor is 3.95 mmpy, the corrosion rate with 200 ppm inhibitor is 1.24 mmpy, the corrosion rate with 400 ppm inhibitor is 0.46 mmpy, the corrosion rate with 600 ppm inhibitor is 0.23 mmpy. A significant decrease in the corrosion rate occurred at a concentration of 600 ppm with an efficiency of 92.32%.