Phosphorous Content Research Articles

Combination effects of microbial inoculation and N fertilization on maize yield: A field study from southern Brazil

The use of inoculants based on diazotrophic microorganisms is an alternative to decrease the dosage and increase the efficiency of nitrogen fertilizers, especially in grains that are demanding and nutrient-responsive crops. Cyanobacteria is photosynthetic and nitrogen fixing prokaryote; however, there has been little focus on Anabaena cylindrica and Nostoc muscorum as biofertilizers in the presence of added nitrogen sources. The purpose of this study was to explore the maize yield in two crop seasons in Londrina, Brazil under different nitrogen rates (topdress, 0–130 kg ha−1; sowing, 20–150 kg ha−1) and microbial inoculants (A. cylindrica, N. muscorum and Azospirillum brasilense), in randomized block design with factorial arrangement 4 × 4. Different phytometric characteristics (e.g. height of plant and spike insertion; stem diameter; area idex and chlorophyll content of leaf; Nitrogen (N), Phosphorous (P) and Potassium (K) contents in leaf) and grain yield (such as quantity of rows ear−1, grains row−1, grains ear−1, ear plant−1, grain N content, weight 1000 grains−1, grain yield) were evaluated. The phytometric characteristics and maize yield were not altered by the interaction between N rates and inoculants, demonstrating that N rates do not interfere with cyanobacteria performance. The inoculation with A. cylindrica favored the development and yield performance of maize and resulted in an increase in grain biomass of 912 kg ha−1 (20.46%) in the crop season 1 and 1020 kg ha−1 (21.11%) in season 2 crop, related to the control. The use of above inoculants was favorable in the responses of maize growth and yield components, particularly when combined with an adequate dose of N. The results demonstrated the potential of microbial inoculants in the improvement of maize crop yield.

Nutrient Analysis of Selected Wild Edible Mushrooms Collected from Thulo Ban Community Forest, Myagdi District, Nepal

The study analyzes the nutrient content of three wild edible mushrooms Cantharellus cibarius, Laccaria laccata and Scleroderma cepa commonly consumed by the local people of Arjam, Myagdi district. Thirteen parameters were analyzed such as ash, carbohydrate, fat, moisture, protein, manganese, zinc, magnesium, potassium, iron, copper, phosphorus and calcium. The test methods used for ash, fat, moisture, protein and phosphorous content were ignition, soxhlet extraction, oven dry method, kjeldahl digestion method and spectrophotometric method respectively. Carbohydrate content was determined by calculation method and iron, manganese, copper, zinc, calcium, magnesium and potassium content estimation were done by AAS method. All macro and micronutrient compositions were determined on a dry weight basis. Ash, carbohydrate, fat, moisture and protein are ranges from 7.05-13.38%, 61.89-71.37%, 0.78-1.94%, 12.37-13.66% and 16.18-24.47% respectively, whereas calcium, magnesium, phosphorus and potassium ranges from 0.13-0.15 µg/g, 0.09-0.11µg/g, 0.25-0.37 µg/g and 1.41-3.40 µg/g respectively. Similarly copper, iron, manganese and zinc ranges from 2.40-30.94 µg/g, 0.08-0.20 µg/g, 7.22-16.06 µg/g and 45.70-77.35 µg/g respectively.

Enchytraeids in imported soil and organic deposits in Pyramiden, an abandoned mining town on Spitsbergen in the High Arctic

In Arctic soils, potworms (Clitellata: Enchytraeidae) are a particularly important decomposer group. There are relatively many faunistic records from the Svalbard archipelago, in particular its main island Spitsbergen, but few ecological studies on enchytraeids. With climate change and increasing tourism, the introduction and subsequent spreading of exotic species might pose a threat to native biotic communities. In Pyramiden, a Russian (formerly Soviet) coal mining settlement on Spitsbergen abandoned in 1998, Chernozem soil from southern Russia or Ukraine had been imported in 1983 to create lawns. Today the long central lawn presents an environmental gradient: on one end rather shallow humus-rich soil is fertilized by a sea bird colony on an adjacent building, the central part has a rich organic horizon topping humus-rich mineral soil, whereas on the other end humus-rich soil is covered by deposited mineral soil. In August 2018, we sampled this gradient to study the enchytraeid assemblage. Additional samples were also taken within frames with a vigorous grass turf in front of residential houses and in a vegetated heap of decomposing organic material (mostly woodchips). The objectives were to see (1) if and how the differences between habitats would be reflected by changes of the enchytraeid assemblages and (2) if there were any potentially introduced species. Almost 3700 specimens were identified and 9 species were recorded, which is high for habitats of the High Arctic. One species, Enchytraeus buchholzi s.l., had been recorded before in the archipelago only once, also in imported soil. This small-bodied euryoecious r-strategist is abundant in agricultural and other disturbed soils. Molecular barcoding and comparison with sequences from Central Europe showed close resemblance to several specimens, which makes an introduction with the transferred Chernozem highly probable. Most enchytraeids were concentrated in the upper 3 cm of soil (even if mineral), only in the organic deposits vertical distribution was rather even down to 12 cm depth. Numbers in the organic deposits were exceedingly high (ca 417,000 individuals/m2) and E. buchholzi s.l. represented ca 90 % of all specimens. Ordination (NMDS) showed all habitats to host rather distinct assemblages. Spearman's rank correlation showed significant positive correlation of species richness with conductivity and total nitrogen and of abundance with phosphorous and potassium contents in aqueous solution.

Phosphorus deficiency is the main limiting factor for re-vegetation and soil microorganisms in Mu Us Sandy Land, Northwest China

Long-term drought induced by low rainfall leads to environmental degradation of land in arid and semi-arid regions. In past decades, re-vegetation of degraded sandy soils to prevent soil erosion has been widely employed, including in Mu Us Sandy Land, which suffers from severe soil erosion. However, it remains unclear how re-vegetation affects soil properties and soil microbes after long restoration periods. In this study, typical plots planting Artemisia ordosica and Salix psammophila were selected to investigate the influence of plant types on soil properties; an area of bare sandy land was used as a control. The results show that re-vegetation increased soil organic carbon (C), total nitrogen (N), soil microbial carbon, microbial nitrogen and soil organic acid, while decreasing soil total phosphorous (TP) content significantly, resulting in increased C/P and N/P ratios. Correlation analysis showed that TP was negatively correlated with oxalic acid (OA) and acetic acid (AA), indicating that increased AA and OA content could accelerate the active utilization of phosphorus and induced low TP in soil. Re-vegetation with A. ordosica significantly decreased the microbial diversity of topsoil. The redundancy analysis showed that TP was main index in affecting microbes. These results that lower P content, higher C/P and N/P ratio and influence of TP on microbes suggest that phosphorus is the main limiting factor for re-vegetation and growth of soil microorganisms. In the future, strategies for the development of sustainable ecosystems in regions suffers from severe soil erosion should consider phosphorus supplementation.

Nutritional evaluation of potato milk produced by ultrasonication–A functional alternative for bovine milk

Plant-based functional beverages developed as an alternative to cow milk are gaining popularity because they are rich in bioactive and nutraceutical ingredients. Although the newly developed potato milk resembles cow milk in its physicochemical properties, its nutritional value is unknown. Accordingly, the research aimed to quantify the aggregate of macro and micronutrients in potato milk processed by ultrasonication. The macronutrients in potato milk include total calories (111.5 ± 0.09 kcal), carbohydrate content (65.3 ± 0.234 %), protein content (2.2 ± 0.0365 %), fat content (0.3 ± 0.001 %), reducing sugar (0.6 ± 0.057 %), non-reducing sugar (0.4 ± 0.023 %), total sugar (1 ± 0.087 %), and added sugar (0 %). The micronutrients assessed include calcium content (13 ± 0.023 mg/100 g), magnesium content (24.7 ± 0.089 mg/100 g), zinc content (0.26 ± 0.345 mg/100 g), sodium content (0.58 ± 0.067 mg/100 g), vitamin C content (28 ± 0.099 mg/100 g), iron content (0.82 ± 1.034 mg/100 ml), phosphorous content (84 ± 0.678 mg/100 ml), potassium content (835 ± 0.067 mg/100 g), manganese content (0.074 ± 0.423 mg/100 ml), cholesterol content (0 ± 0.586 %), and amino acid content (36 ± 0.003 mg/100 ml). As a result, the developed potato milk has adequate macro and micronutrients to maintain stable health, making it a promising alternative to dairy products with packed nutrients.

Effects of pre-commercial thinning on soil respiration and some soil properties in black pine (Pinus nigra) stands

Forestry practices may cause significant changes in soil characteristics as related to their properties and size. Although chemical attributes of the soil respond to the applications in the mid- or long-term while changes in soil respiration can react rapidly to forestry practices. Therefore, determining changes in soil attributes is needed to identify how the management practices would affect forest ecosystem function. Although there is much information on the effect of thinning practices on tree growth, there is a lack of knowledge on the impacts of pre-commercial thinning on soil properties, especially soil respiration. We aimed to determine pre-commercial thinning effects on some soil attributes in black pine sites. Four treatments with different intensities were applied to the stands studied. These practices were control (no pre-commercial thinning), 2000 (heavy), 4000 (moderate), and 6000 (light) individuals per hectare left, respectively. Measurements of soil respiration and soil temperature were carried out between 2014 and 2017 in spring, summer, autumn, and winter months. Soil characteristics, including pH, organic matter, nitrogen, and phosphor content, were measured just after and three years after the thinning. As a result, thinning increased soil respiration rate and soil temperature while decreased soil pH values. Results of the study showed that carbon balance in the ecosystem was significantly affected by thinnings, and adjusting the thinning intensity may be an efficient carbon management tool for reducing carbon emission from the soil.

Influence of agricultural wastes on larval growth phases of the black soldier fly, Hermetia illucens (Diptera: Stratiomyidae): An integrated approach

Insects are an effective tool for converting nutrients in agricultural by-products into protein-rich biomass and compost. Black soldier fly (BSF) (Hermetia illucens) larvae are currently one of the insect species widely used as a protein source in aquafeed globally. Although much effort has been spent on the use of BSF in aquafeed, there is not much information on the biology of the insect, especially with the morphology of the BSF. This study aimed to evaluate the influence of various organic wastes, such as fruit wastes (FW) and vegetable wastes (VW), on different growth phases of BSF larva (BSFL), using morphometric and scanning electron microscopic examinations, and the composition of the compost produced, as well as a method for upscaling of larval production of BSFL. Faster growth was observed in BSFL fed with VW substrate (40 days) compared to the FW (46 days). Based on the morphometric measurements such as length, larval head length, total length etc., five larval stages, prepupal and pupal stage of BSFL were differentiated and described. In addition, SEM imaging of BSF mouth parts found that the mouth morphology of the BSF larvae and prepupal stage differed, and the BSF prepupa had reduced mouthparts. Also, the mandibular-maxillary complex was well developed than the BSF prepupa. BSFL larvae have proven to convert fruit and vegetable waste into high-quality residue fertilizer for the soil. The BSF compost showed optimum nitrogen, phosphorous, potassium, calcium and sulphur content. This research establishes a baseline knowledge and guidance on the BSF-rearing facilities.

Analysis of the Available Straw Nutrient Resources and Substitution of Chemical Fertilizers with Straw Returned Directly to the Field in China

Returning straw to the field is the most significant straw utilization technique for China’s green development. It can provide nutrients for crop growth and improve soil organic matter content. However, there are no standard parameters for measuring the nutrient content of straw directly returned to the field. In addition, the nutrient content of straw in the field is disregarded and the least researched. Therefore, to address these issues, the current research examines the main nutrient composition of straw returned directly to fields and the potential substitution of straw for chemical fertilizers. This study used the latest data on the crop straw-to-grain ratio and straw’s direct return to the field from the Database of Agricultural Crops Straws Resources in China (DACSRC) as the basis for a detailed estimation of the amount of crop straw nutrient resources and straw’s direct return to the field. The straw nutrient resources were measured based on straw yield and the nitrogen (N), phosphorous (P2O5), and potassium (K2O) contents. The results reveal that the maximum amount of straw returned directly to the fields in China was 517 teragram (Tg), while 128 Tg (25%) of the total was not collected but left on the field. The North China region had an enormous amount of direct straw return at 176 Tg (34%), while South China had the least amount at 26 Tg (5%). The amounts of seasonally available N, P2O5, and K2O from straw directly returned to fields are 2 Tg, 1 Tg, and 7 Tg, respectively. In addition, the amount of available straw nutrient resources returned to the field per hectare (ha) was 78 kg. The quantity of straw-originating seasonally available nutrients corresponds to 23% of the chemical fertilizers applied, which can substitute 10% N, 9% P2O5, and 58% K2O. The study provides critical insights on effective ways to improve straw fertilization through an increased rate of straw returned directly to fields and releasing seasonal nutrients.

Effects of dietary α-ketoglutarate on the growth performance, digestive enzymes, tor signaling pathway and intestinal microbiota of juvenile mirror carp (Cyprinus carpio) fed low phosphorus diets

The present study evaluated the effects of dietary α-ketoglutarate (AKG) on the growth performance, digestive enzymes, target of rapamycin (tor) signaling pathway and intestinal microbiota of juvenile mirror carp (Cyprinus carpio) fed low phosphorus diets. An eight week 2 × 3 two-factorial experiment was conducted to investigate the interaction between AKG levels at 0 or 0.6%, and dietary phosphorus levels at 0.27%, 0.55% or 0.76%. The results showed that the final body weight (FBW) and weight growth rate (WGR) were significantly improved and the feed conversion ratio (FCR) was significantly decreased by the dietary AKG or phosphorus (P < 0.05). The crude ash and phosphorous content were significantly increased with increasing available phosphorus supplement from 0.27% to 0.76%, whereas crude lipid was decreased as dietary phosphorus levels increased (P < 0.05). Fish fed a diet supplemented with 0.6% AKG showed a significant increase in crude protein, crude ash and phosphorous content compared to the diet without AKG group (P < 0.05). The mRNA expression of IIb sodium-dependent phosphate cotransporter (NaPi-IIb) was decreased by dietary AKG or phosphorus (P < 0.05).The activities of trypsin was significantly improved by dietary AKG or phosphorus (P < 0.05). The mRNA expression of tor, insulin growth factor I (igfI) and growth hormone (gh) were significantly increased by dietary AKG or phosphorus (P < 0.05). The richness estimate of Ace and Chao, and the diversity estimators of Simpson were significantly decreased with increasing phosphorus levels from 0.27% to 0.55% (P < 0.05). Compared with the 0.27% phosphorus group, the abundance of Fusobacteriota and Bacteroidota were relatively increased and the abundance of Proteobacteria, Actinobacteriota and Cyanobacteria were relatively decreased in 0.27% phosphorus added 0.6% AKG group. The abundance of Fusobacteriota and Actinobacteriota in 0.27% phosphorus group was relatively lower than that in 0.55% phosphorus group. On the contrary, the abundance of Firmicutes, Bacteroidota and Cyanobacteria in 0.27% phosphorus group was relatively higher than that in 0.55% phosphorus groups. These results indicated that dietary supplementation with 0.6% AKG could improve growth performance by increasing the activities of trypsin and promoting the formation of beneficial intestinal microbiota, and the tor, gh/igf-I gene expression in liver of mirror carp fed low phosphorus diets.

Enhancement of photoluminescence intensity of sintered CaAlSiN3:Eu2+ red phosphor‐bismuthate glass composites

AbstractWavelength converters in white light‐emitting diodes are usually made by sintering of phosphor‐glass powder compacts. An issue is that the sintering process usually results in the reduction of phosphor amount. In the present study, composites containing CaAlSiN3:Eu2+ red phosphor and Bi2O3‐B2O3‐ZnO‐Sb2O5 glass were fabricated by sintering method. Influences of CaAlSiN3:Eu2+ phosphor content (10 vol%–30 vol%) and sintering temperature (410–430°C) on the residual amount of the phosphor phase and the resulting luminescence intensity of the composites were investigated. The change of CaAlSiN3:Eu2+ content due to sintering was analyzed by X‐ray diffraction. The interdiffusion between the CaAlSiN3:Eu2+ and glass matrix was examine by scanning electron microscope equipped with energy dispersive X‐ray spectrometry. This paper focuses on the change of luminescence intensity after sintering. It was found that although the content of phosphor CaAlSiN3:Eu2+ reduces after sintering; the luminescent intensity of the composites anomalously increases. The optimum luminescence intensity is 14% higher than that of the as‐mixed, unfired powder. It is proposed that the incorporation of Bi3+ ions from the glass matrix into the phosphor CaAlSiN3:Eu2+ during sintering improves the luminescence ability of the phosphor particles.

Combined Effect of Trehalose and Serendipita indica Inoculation Might Participate in Solanum lycopersicum Induced Cold Tolerance.

The exploitation of symbiotic interactions between fungi and plants, coupled with the application of osmoprotectants such as trehalose (Tre), presents a promising strategy for mitigating environmental stress. To determine the mechanism of Serendipita indica and Tre-mediated cold stress tolerance, a comparative experiment was designed to study the impact of S. indica, Tre and their combination on tomato plants grown under cold stress. The results showed that cold stress significantly decreased biomass, relative water content, photosynthetic pigments and elements concomitantly with increasing antioxidant activities, malondialdehyde (MDA), electrolyte leakage, hydrogen peroxide and proline content. Meanwhile, S. indica and Tre treatments promoted biomass and enhanced carbohydrate, protein, proline, potassium, phosphorous, antioxidant enzymes and photosynthetic pigments content under cold stress. Furthermore, single or dual application of endophyte and Tre mitigated physiological disorders induced by cold stress and increased the integrity of cell membranes by decreasing hydrogen peroxide, MDA, and electrolyte leakage (EL). Our findings suggest that S. indica and Tre combination could significantly promote cold stress tolerance compared with single treatment. This study is novel in showing the cold adaptation of tomato plants by combination use of S. indica and Tre, which can be a promising strategy for improving cold tolerance. The underlying molecular mechanisms of sugar-fungus interaction must be further investigated.

Influence of Integrated Nutrient Management and Plant Geometry on Nutrient Uptake of Ajowan (Trachyspermum ammi L. Sprague) in the Southern Zone of Telangana, India

An experiment was conducted during late kharif season of 2019-20 at College of Horticulture, Rajendranagar, Hyderabad, to find out the influence of integrated nutrient management and plant geometry on nutrient uptake of ajowan (Trachyspermum ammi L. Sprague) in the Southern zone of Telangana. The experiment was laid out in a factorial randomized block design with 12 treatments, replicated thrice. The treatments include four Integrated nutrient management levels (INM1, INM2, INM3 and INM4) and three plant geometries (S1, S2 and S3). Results showed that available nitrogen (351.33 kg ha-1), phosphorous (96.94 kg ha-1) and potassium (231.88 kg ha-1) content in soil were found significantly higher in T3 (INM1+ S3) over other treatments where as, T10 (INM4+ S1) recorded the lowest. The nutrient content in plant i.e. nitrogen (1.65%), phosphorous (0.93%), and potassium content (1.20%) in plant was found significantly maximum in T3 (INM1+ S3) while, the minimum was recorded in T7 (INM3+ S1). Regarding nutrient uptake by the crop, nitrogen (87.79 kg ha-1) phosphorous (61.10 kg ha-1) and potassium (61.99 kg ha-1) were found significantly higher in T1(INM1+ S1), while it was the lowest in T8 (INM3+ S2).

Prediction and sensitivity analysis of chlorophyll a based on a support vector machine regression algorithm

Outbreaks of planktonic algae seriously affect the water quality of rivers and are difficult to control. Based on the analysis of the temporal and spatial variation characteristics of environmental factors, this study uses a support vector machine regression (SVR) algorithm to establish a chlorophyll a (Chl-a) prediction model and conduct Chl-a sensitivity analysis. In 2018, the average Chl-a content was 126.25 ug/L. The maximum total nitrogen (TN) content was 16.68mg/L and high year-round. The average NH4+-N and total phosphorous (TP) contents were only 0.78 and 0.18mg/L. The content of NH4+-N was higher in spring and increased significantly along the water flow, while TP decreased slightly along the water flow. We used a radial basis function kernel SVR model and tenfold cross-validation method to optimize parameters. The penalty parameter c was 1.4142, the kernel function parameter g was 1, and the training and verification errors were only 0.032 and 0.067, respectively, indicating a good model fit. Based on a sensitivity analysis of the SVR prediction model, the maximum sensitivity coefficients of Chl-a to TP and WT were 0.571 and 0.394, respectively, and the contributions were 33% and 22%, respectively. The next highest sensitivity coefficients were those of DO (0.28, 16%) and pH (0.243, 14%). The sensitivity coefficients of TN and NH4+-N were the lowest. According to the current water environment pollution conditions, TP is the limiting factor of Chl-a in the Qingshui River, and it is also the main prevention and control factor of phytoplankton outbreak.

Influence of Nitrogen Application Rates on Yield and Yield Attributes of Long Duration Varieties of Cassava (Manihot esculenta Crantz)

A field experiment was carried out at ICAR- Central Tuber Crops Research Institute (CTCRI), Sreekariyam, Thiruvananthapuram, Kerala, India to investigate the effect of different nitrogen application rates on yield and yield attributes of two long-duration cassava varieties during March, 2021 to February, 2022. The experiment was set up in Factorial Randomized Block Design (FRBD) with three replications involving two factors- two cassava varieties (Sree Pavithra and Sree Reksha) and five different nitrogen application rates (0%, 25%, 50%, 100% and 125%) of recommended nitrogen dose of 100 kg ha-1. The study revealed that the application of super optimal dose of nitrogen (125%RD of nitrogen @ 125 kg ha-1) significantly increased the yield (52.61 t ha-1) and yield attributes namely number of tubers (3.55) plant-1, average lenth of tuber (25.48 cm), average diameter of the tuber (12 cm) and average tuber yield plant-1 (4.24 kg) in cassava. Also, super optimal dose of nitrogen positively influenced SPAD 502 chlorophyll meter reading (45.13), leaf chlorophyll a content (1.52, 1.72 mg g-1), chlorophyll b (0.64, 0.72 mg g-1) content and total chlorophyll content (2.20, 2.49 mg g-1), leaf carotene content (0.42, 0.48 mg g-1) in V1 (Sree Pavithra) V2 (Sree Reksha) respectively. Super optimal level of nitrogen positively influenced nitrogen content in leaf,stem and tuber along with phosphorous and potash content in both varieties of cassava.

Carbon, nitrogen and phosphorous contents, related enzyme activities and organic matter fractions of litter and soil in a terra firme forest in Central Amazonia

The response of lowland tropical forest on highly weathered P-limited soils to changes in atmospheric composition is likely to be regulated by P-availability from litter and soil. Our aim was to gain insight into possible mechanisms that may affect P-availability and C sequestration. We collected litter and soil samples along a transect in Central Amazonia. We examined litter and soil properties, determined C, N, and P contents and performed density fractionation to obtain organic-C, -N and -P fractions. To assess microbial demand and mineralization, we analysed C, N and P associated enzyme activities. The litter layer has an estimated turnover time of about one year or less and C, N and P contents were much smaller than in the mineral soil. Total soil C, N and P decreased with depth, while P was depleted relatively more. Most organic-C, -N and -P is stabilized by adsorption onto mineral surfaces. Non-adsorbed organic matter fractions were depleted of P. Nearly all organic-P appeared to be present in the mineral-associated fractions from where it, despite high phosphatase activities, appears not to be available for mineralization. Enzyme activities revealed that microbial C-demand in litter is higher than in soil, while P-demand was relatively high in soil and increased with depth. Hypothesized higher phosphatase activity under increasing atmospheric CO2 concentrations may probably not alleviate P-limitation in these terra firme forests due to the limited availability of mineralizable organic-P.

Synthesis and characterization of stereolithography3Dprinting fluorescent resin

AbstractIn this study, bisphenol A epoxy resin, 1,6‐Hexanediol diacrylate (HDDA), and 2,4,6‐Trimethylbenzoyl‐diphenylphosphine oxide (TPO) were utilized as a prepolymer, diluent, and photoinitiator, respectively, to prepare a light curing system with different amount of phosphor, which was used in place of conventional inorganic fillers. Phosphor was utilized to improve the precision of the material molded parts during the light curing process and enhance the mechanical properties of the molded parts owing to the ultraviolet (UV) absorption properties of phosphor, which prevented UV damage to the material, thus improving the light aging resistance and stability of the molded parts. Results revealed that the addition of 3% phosphor optimized the mechanical properties of the material (a maximum tensile strength of 42.43 MPa). Additionally, the material achieved the lowest linear (4.1%) and volumetric (0.58%) shrinkage at a phosphor content of 6%. This study provides a new insight into three‐dimensional (3D) printing resin for stereolithography and provides a reference for the improvement of 3D printing products.

Synthesis of electrodeposited Co–P–ZrO2–CeO2 nanocomposite coating: Effect of heat treatment on corrosion and mechanical properties

Electrodeposited cobalt coatings have been considered a suitable replacement for hard chromium coatings due to their promising properties. In this research, electrochemical methods through the direct current technique have been applied to synthesize a novel Co–P–ZrO2–CeO2 nanocomposite coating. The addition of different phosphorous contents as a determinant of the crystalline or amorphous structure was investigated using X-ray diffraction (XRD). The needle-like or cauliflower morphologies and related elemental compositions were surveyed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), respectively. The XRD, microhardness, wear, and corrosion resistance tests were conducted on heat-treated samples. The results illustrate that heat treatment significantly increases the microhardness of the amorphous nanocomposite layer (up to 1323 HV0.1). Additionally, it causes the best wear behavior for the nanocrystalline Co–P–ZrO2–CeO2 (0.2), while leading to a lower wear resistance for the amorphous coatings (0.65). Furthermore, applying heat treatment diminishes the corrosion behavior of the coating. Tafel polarization and electrochemical impedance spectroscopy (EIS) tests reveal that the best corrosion resistance has been achieved for an amorphous nanocomposite coating 11929 Ω cm2. These findings demonstrate that this coating has desirable properties for industrial applications.

Esterification Oligomerization of Phosphaphenanthrene Biphenol Caused Efficient Flame Retardant Effect of Group Aggregation in Epoxy Resin

The efficient and simple synthetic method prepared several linear phosphaphenanthrene biphenol oligomers DQPC-n (n = 1, 2, 4) to explore the effects of phosphaphenanthrene groups with different aggregation amounts on flame retardant behavior in epoxy resin. The aggregated phosphaphenanthrene groups in DQPC-n bring epoxy resins with better flame retardancy than phenol compound DOPO-HQ. The limited oxygen index values of epoxy resins with DQPC-n were more than 35.8% and obtained a V-0 rating in the UL 94 test, while that with DOPO-HQ only passed a V-1 rating at the same phosphorous content. Simultaneously, DQPC-n showed efficient flame retardancy in the cone calorimeter test. Especially, the DQPC-1 with moderate aggregated phosphaphenanthrene groups exerted a better flame inhibition effect in epoxy resin, and the values of THR, TSP, and av-EHC of the DQPC-1/EP were lower than that of DOPO-HQ/EP. The mechanism results demonstrated that the pyrolysis of DQPC-1 concentrated released more phosphorus-containing fragments to prevent the combustion chain reaction process. In addition, DQPC-1 can facilitate the aromatic residue formation in the condensed phase. Therefore, the aggregation effect of the phosphaphenanthrene groups in this thesis provides a method for developing efficient epoxy resin additives.

High luminous efficiency of a phosphor-in-glass plate by optimization of the glass and phosphor content for high-power LED applications

Generally, white light-emitting diodes (LEDs) are fabricated by combining blue LED chips with yellow phosphors. When fabricating white LEDs, the phosphor is typically mixed with an organic resin and applied to the LED chips as a paste. A phosphor-in-glass (PiG) plate can alternatively be used to address the poor high-temperature reliability of the paste method. However, because pores form in the PiG plate during the sintering process, this method results in a loss of optical efficiency. Accordingly, we aimed to improve the fluidity of glass and light efficiency by optimizing the sintering temperature of the glass powder and the phosphor content respectively for reducing internal porosity in the PiG. In this study, glass powder was sintered at different temperatures to produce glass plates, while also varying the phosphor content to fabricate PiG plates. The optimal light characteristics were realized with a glass sintering temperature of 640 °C and a phosphor content of 20 wt%.

Microbial functioning in Mediterranean forest soils: Does land use legacy matter?

AbstractLand use is known to be one of the major factors driving soil microbial and physico‐chemical properties. Understanding its long‐term effect remains a major challenge in assessing current soil functioning. Here, soil microbial and physico‐chemical properties of recent and very recent forests (forests developed in 1958 vs. after 1958) were compared with those of ancient forests (present in 1860 and 1958) to assess the effect of Land Use Legacy (LUL). LUL effects were further analysed depending on contrasting (i) climate conditions (sub‐humid vs. humid Mediterranean climates) and (ii) seasons (winter and summer), to examine whether LUL modified microbial responses to different spatio‐temporal climate conditions. Microbial indicators (lignocellulolytic activities, basal respiration, and microbial biomass) and physico‐chemical properties (C and N contents, mineralogical analyses, pH and conductivity) were assessed. A strong effect of past agricultural practice (terrace cultivation) was observed in soils from very recent forests: reduced microbial biomass and activities as well as number of Quercus pubescens stems together with increased phosphorous content and pH. Interestingly, LUL effect did not affect microbial and physico‐chemical responses to seasonal contrasts (winter vs. summer). Microbial response to LUL was not influenced by climate while climate modified LUL effects on some physico‐chemical properties (CaCO3, Corg, and K content). Moreover, soil recovered “pristine” physico‐chemical and microbial functional properties after at least 60 years of reforestation.