Apparent Efficiency Research Articles

Using 1.5 mm internal diameter columns for optimal compatibility with current liquid chromatographic systems

This article describes the use of a new prototype column hardware made with 1.5 mm internal diameter (i.d.) and demonstrates some benefits over the 1.0 mm i.d. micro-bore column. The performance of 2.1, 1.5 and 1.0 mm i.d. columns were systematically compared. With the 1.5 mm i.d. column, the loss of apparent column efficiency can be significantly reduced compared to 1.0 mm i.d. columns in both isocratic and gradient elution modes. In the end, the 1.5 mm i.d. column is almost comparable to 2.1 mm i.d. column from a peak broadening point of view. The advantages of the 1.5 mm i.d. hardware vs 2.1 mm i.d. narrow-bore columns are the lower sample and solvent consumption, and reduced frictional heating effects due to decreased operating flow rates.

Palisadegrass pastures with or without nitrogen or mixed with forage peanut grazed to a similar target canopy height. 2. Effects on animal performance, forage intake and digestion, and nitrogen metabolism

AbstractThe lack of nitrogen (N) input on pastures is the main limiting factor to increase animal performance in tropical regions. This 2.5‐year study assessed animal performance, forage intake and digestion, and N metabolism responses of three pasture treatments: (1) mixed Marandu palisadegrass—Brachiaria brizantha (Hochst. ex A. Rich.) R.D. Webster (syn. Urochloa brizantha Stapf cv. Marandu)—and forage peanut (Arachis pintoi Krapov. & W.C. Greg. cv. BRS Mandobi) pastures (GRASS + LEGUME), (2) monoculture Marandu palisadegrass pastures with 150 kg of N/ha (GRASS + N), and (3) monoculture Marandu palisadegrass without N fertilizer (GRASS). Continuous stocking with variable stocking rate was used with a target canopy height of 20 to 25 cm. The average daily gain was greatest at GRASS + N and GRASS + LEGUME (p = .081). GRASS + N pasture had greatest stocking rate and liveweight gain per area (p < .001 and p < .001, respectively), followed by GRASS + LEGUME pasture. No differences between treatments were found for the dry matter forage intake (p = .729); however, GRASS + N and GRASS + LEGUME pastures had greater crude protein and digestible organic matter intakes than GRASS pasture (p = .007 and p = .083, respectively). Greatest microbial protein synthesis and efficiency of microbial synthesis were found for GRASS + N and GRASS + LEGUME pastures (p = .016 and p = .067, respectively). Apparent efficiency of N utilization and microbial protein/CP intake ratio was greatest at GRASS + LEGUME pastures (p = .009 and p = .042, respectively). Nitrogen application or the integration of forage peanut in grass pasture increases animal performance, forage digestibility, and microbial protein synthesis.

Effect of β-carotene supplementation to prepartum Holstein cows on colostrum quality and calf performance

β-Carotene, a pro-vitamin A carotenoid, acts as an antioxidant, able to scavenge free radicals to prevent oxidative damage. It has also been shown to increase rumen microbial production in vitro. When supplemented prepartum, β-carotene increased colostral fat and protein concentrations. The objective of this experiment was to evaluate the effects of supplementing 700 mg/d β-carotene (BC) daily for 4 wk prepartum on cow performance, colostrum, and performance in subsequent calves. Eighteen multiparous Holstein cows housed in a tiestall barn were blocked by expected calving date and randomly assigned to treatments at 4 wk prepartum. Blood samples were collected 3 times a week for analysis of nonesterified fatty acids, ketones, β-carotene, and IgG. Urine samples were also collected 3 times a week for analysis of creatinine and purine derivatives. Colostrum was collected within 90 min after parturition. Calves were removed from their dams before suckling, weighed within 30 min of birth, and received 4 L of maternal colostrum. Blood samples were collected from calves before colostrum administration (0 h) and at 24 h via jugular venipuncture for analysis of IgG concentration and apparent efficiency of IgG absorption. The 18 calves born were blocked based on treatments of dams. All calves were fed 449 g/d dry matter of milk replacer (20% crude protein, 20% fat) and an 18% crude protein textured starter and water ad libitum at 2 d of age until weaning at 42 d. There were no differences in any blood parameters of cows during the prepartum period. Supplemental BC increased the solids content of colostrum compared with control (22.89% control; 27.75% BC). Calves born from control fed cows had greater efficiency of IgG absorption than those born from BC supplemented cows (52.16% control; 39.50%, BC). Calves born from BC fed cows had greater feed efficiency (average daily gain/dry matter intake) compared with those born from control supplemented cows (0.33 for control; 0.44 for BC). These data indicate that although supplementing β-carotene to cows in the prepartum period negatively affects apparent efficiency of IgG absorption, it improved feed efficiency in calves.

Nutrient requirement and use efficiency of rice (Oryza sativa L.) as influenced by graded levels of customized fertilizer

Balanced nutrient application is an important concern to minimize fertilizer use in crop culture. Field experiments were conducted during kharif 2017 and 2018 to find out the best level of NPK fertilizer for rice with two varieties of rice of same duration (130-135 days). Three grades of customized fertilizers (250, 350 and 450 kg ha−1) along with 100% RDF (Recommended dose of fertilizer) and absolute control constituted the treatment variables. The results revealed that the grades of customized fertilizer (CF) influenced the yield and uptake of nutrients. Application of CF @ 450 kg ha−1 was found to be significantly superior over absolute control and 100% RDF with respect to yield and uptake of nutrients, and found on par with all other grades of CF (250 and 350 kg ha−1). Applying 250 kg ha−1 of CF recorded higher agronomic efficiency (AE), apparent recovery efficiency (ARE) and partial factor productivity (PFP) for phosphorus (P) and potassium (K) but higher AEn, AREn and PFPn in 450 kg ha−1 of CF. The higher utilization efficiency of nitrogen (UEn) of 43.05%, phosphorus (UEp) of 181.88% and potassium (UEk) of 34.40% were recorded in 250 kg ha−1 of CF. The CF @ 450 kg ha−1 recorded higher nitrogen and phosphorus requirement (NR and PR) i.e., 2.65 and 0.61 kg’s, respectively. Whereas, potassium requirement (KR) was higher in 100% RDF. Higher response yard stick (RYS) of 5.33 was recorded in 250 kg ha−1 of CF compared to other grades of CF, 100% RDF and absolute control.

The role of positive nerve root sedimentation sign in the treatment of patients undergoing lumbar disc herniation

Background To investigate the efficacy of percutaneous transforaminal endoscopic discectomy (PTED) in the treatment of patients who were diagnosed with lumbar disc herniation (LDH) with positive nerve root sedimentation sign (NRSS). Methods A total of 86 patients who underwent LDH were recruited and divided into NRSS-positive group (n = 49) and NRSS-negative group (n = 37). The visual analog scale (VAS), Japanese Orthopaedic Association (JOA), and Oswestry disability index (ODI) were used to evaluate the low back pain and functional recovery and were compared between the two groups. Results There were no significant differences in the demographic parameters between the two groups. The average area of the dural sac compression in the NRSS-positive group was significantly higher than that in the NRSS-negative group. Patients with a positive NRSS showed a better low back pain relief than those with a negative NRSS at 1 week and 1 month after surgery. The JOA and ODI in the NRSS-positive group were better than those in the NRSS-negative group at 3 months and 6 months postoperatively. The apparent efficiency of JOA and the excellent and good rate of ODI in the negative group was lower than that in the positive group at 6 months after surgery. Conclusions Patients undergoing LDH with a positive NRSS showed better pain relief and functional recovery than those with a negative NRSS. The present study suggested that NRSS might be a valuable sign and associated with better clinical outcomes in patients undergoing LDH with the treatment of PTED.

Improvement of coal flotation by exposure of the froth to acoustic sound

Simultaneously improving coal flotation performance and the subsequent froth breakdown is challenging. The present work addresses this challenge by developing and evaluating a non-chemical approach based on the stabilization effect of acoustic sound on flotation froth. The effectiveness of this approach for improving coking coal flotation at different frother concentrations (10–25 ppm MIBC), collector dosages (0–400 g diesel/t) and aeration rates (1.2–2.2 cm/s) was demonstrated at laboratory scale and in batch mode, with a loudspeaker being placed in air above the flotation cell lip. It was found that at any operating condition tested, the use of sound could improve the flotation performance including the final combustible recovery, apparent flotation rate constant and separation efficiency rate. There was no statistically significant difference in product ash content between the flotation tests with and without applying sound, except at the highest MIBC concentration tested. The images of the product froth taken before and 5-min after being discharged from the flotation cell indicated that the froth stabilization effect induced by sound would occur only within the sound field, demonstrating the potential of the approach in mitigating the overfrothing issue without sacrificing the flotation performance. The possible mechanisms of the improvement of flotation performance with applying sound and its potential of improving coal flotation practice through reducing reagent and air consumption were discussed.

EFFECT OF INTEGRATED NUTRIENT MANAGEMENT ON NUTRIENT USE EFFICIENCY OF MAJOR NUTRIENTS: A REVIEW

Nutrient use efficiency (NUE) is an important concept in the evaluation of crop production systems. With emerging nutrient deficiencies under intensive agriculture, there is a need to improve NUE. One of the approaches to enhance it is by judicious use of fertilizers (adequate rate, effective source, methods and time of application) as well as inclusion of organic manures. Organic nutrient sources are very effective but as their availability is not sufficient to meet the nutrient demand, we have to integrate both organic and inorganic sources of nutrients together in order to achieve higher NUE. Common measures of NUE include Partial Factor Productivity (PFP), Agronomic Efficiency (AE), Apparent Recovery Efficiency (RE), Physiological Efficiency (PE) and Internal Utilization Efficiency (IE). Mineral Fertilizer Equivalent (MFE) is another parameter that can be used to assess short term release of nutrients (mainly nitrogen) from organic nutrient sources

Rainwater treatment using an acrylic blanket as a filtering media

Rainwater harvest is a desirable alternative clean technology where water is scarce, but the economic viability of its implementation is reduced by the need to install pumps and pipes. The type of filter bed and the frequency of filter changes can increase costs, compromise the quality of the water obtained by this treatment and increase the environmental impacts. This study focuses on a system for collecting and treating rainwater that is compact, innovative, dispenses with the use of pumps, and can be adapted for use in homes and industries, contributing to clean production. An acrylic blanket (Acrylon) was used as a filtering medium because it is a low-cost alternative and is easy to obtain and handle. The experiment was carried out in a company located in the industrial city of Itaboraí (Rio de Janeiro). Water characterization was monitored before and after contact with the roof, and after passing through the treatment equipment (11 rain events). Samples were collected in triplicate; the first sample was collected within 10 min of the onset of rain (first flush), the second after 15–30 min of rain, and the third after 30 min of rain. The second and third samples were used to generate a “continuous” sample. The evaluated parameters were turbidity, apparent color, hydrogenionic potential, temperature, free residual chlorine, and the presence of coliforms (total and tolerant). The apparent color removal efficiency was 81.70% for first flush and 49.54% for continuous samples, and the turbidity removal efficiency was 74.28% and 52.19%, respectively. These removal efficiency results are similar to those achieved by traditional rainwater treatment systems that do not discard the first flush. It was found that the treatment met the requirements of the Brazilian standard for the use of rainwater based on turbidity (less restrictive standard), residual chlorine, and absence of coliforms, but did not meet the requirements for hydrogen potential and color removal.

Legume-Modified Rotations Deliver Nutrition With Lower Environmental Impact

Introducing legumes to crop rotations could contribute toward healthy and sustainable diet transitions, but the current evidence base is fragmented across studies that evaluate specific aspects of sustainability and nutrition in isolation. Few previous studies have accounted for interactions among crops, or the aggregate nutritional output of rotations, to benchmark the efficiency of modified cropping sequences. We applied life cycle assessment to compare the environmental efficiency of ten rotations across three European climatic zones in terms of delivery of human and livestock nutrition. The introduction of grain legumes into conventional cereal and oilseed rotations delivered human nutrition at lower environmental cost for most of the 16 impact categories studied. In Scotland, the introduction of a legume crop into the typical rotation reduced external nitrogen requirements by almost half to achieve the same human nutrition potential. In terms of livestock nutrition, legume-modified rotations also delivered more digestible protein at lower environmental cost compared with conventional rotations. However, legume-modified rotations delivered less metabolisable energy for livestock per hectare-year in two out of the three zones, and at intermediate environmental cost for one zone. Our results show that choice of functional unit has an important influence on the apparent efficiency of different crop rotations, and highlight a need for more research to develop functional units representing multiple nutritional attributes of crops for livestock feed. Nonetheless, results point to an important role for increased legume cultivation in Europe to contribute to the farm and diet sustainability goals of the European Union's Farm to Fork strategy.

Comparative transcriptome and cross-section analyses provide insights into the mechanisms underlying Sargassum fusiforme responses to the harmful algal bloom-forming dinoflagellate Karenia mikimotoi

The impacts of harmful algal blooms (HABs) on macrophytes have rarely been studied, although HABs are currently considered one of the major worldwide marine environmental threats. In this study, we incorporated photophysiology experimental data with paraffin-embedded section and transcriptome analysis of S. fusiforme to explore the effects of dense K. mikimotoi culture on the growth, photosynthetic activities, and leaf microstructure of S. fusiforme, as well as the expression of the genes related to its photosynthesis. The results showed that the fresh weight, Chl a contents, apparent photosynthetic efficiency (α) and relative electron transfer rate (rETRmax) of S. fusiforme seedlings cultivated for ten days with K. mikimotoi decreased by 53.60 %, 13.48 %, 6.30 % and 36.51 %, as compared with those cultivated without K. mikimotoi. The leaves of the S. fusiforme seedlings began to rot and detach from the stems after a week of cultivation with K. mikimotoi, and additional epidermic cells decomposed with prolonged exposure to the dinoflagellate. Transcripts of the genes related to photosystem reaction center subunits and photosynthesis antenna proteins were expressed differentially during the cultivation with K. mikimotoi, consistent with changes in the photosynthesis of S. fusiforme seedlings. These combined results indicate that the main mechanism for resistance to HABs is the formation of epidermis by a layer of tightly arranged cylindrical cells combined with differential expression of the photosynthesis-related genes.

Diversity of deep earthquakes with waveform similarity

The generation mechanism of deep earthquakes in subducting slabs remains enigmatic. We analyze deep earthquakes at depths of 200-500 km in the Pacific Plate beneath central Japan, then identify five groups of 11 similar earthquakes whose waveforms are similar at five or more stations over a 40 s time window that includes the P and S arrivals. Hypocenter relocations using waveform-derived differential-time data suggest that similar deep earthquakes occur on complementary ruptures of neighboring patches on a fault, rather than by repeatedly rupturing the same fault patch. The stress drops of similar earthquakes are almost constant within each group but differ by an order of magnitude (~10 to 100 MPa) even between groups separated by ~20 km, while the other parameters are significantly different even for each group such as the apparent stress (~0.1 to 10 MPa) and radiation efficiency (~0.01 to 1). The wide range of source parameters estimated for similar earthquakes in a common slab environment suggests that source parameters can be significantly affected by small-scale heterogeneities along the fault. Thus, the predominant-rupture process of deep earthquakes can be diverse even at different patches on the same fault plane or at the identical depths in a common slab. A dual process which includes seismic rupture assisted by both fluid-related embrittlement and thermal shear instability may explain the wide range of source parameters estimated in this study.

Exfoliated Boron Nitride (e-BN) Tailored Exfoliated Graphitic Carbon Nitride (e-CN): An Improved Visible Light Mediated Photocatalytic Approach towards TCH Degradation and H2 Evolution.

A series of 2D/2D exfoliated boron nitride/exfoliated g-C3N4 nanocomposites denoted as e-BN/e-CN have been successfully prepared using a simple in situ technique. The successful deposition of e-BN on e-CN was confirmed from high-resolution transmission electron microscopy analysis. According to electrochemical measurements, 1.5 wt % e-BN/e-CN nanocomposites showed 1.5 times more photocurrent than e-CN, which indicates the successful formation of an e-BN/e-CN heterostructure. The photocatalytic activities of the e-CN and e-BN/e-CN composites were investigated through photocatalytic tetracycline hydrochloride (TCH) degradation and H2 evolution under visible light illumination. The 1.5 wt % e-BN/e-CN composite demonstrated the highest photocatalytic activities, which are about 21 and 1.5 fold greater than e-CN towards H2 generation with an apparent conversion efficiency of 2.34% and TCH degradation, respectively. The improved photocatalytic activities of e-BN/e-CN photocatalysts were ascribed to the augmented light-harvesting ability and enhanced separation efficiency of charge carriers. Lower photoluminescence intensity and a smaller arc value in the impedance spectra again proved the reduced recombination of the e--h+ pairs in the e-BN/e-CN nanocomposites. Trapping experiments show that •O2-, h+, and •OH radicals are the predominant reactive species that accelerated the photocatalytic activities of e-BN/e-CN composites. This study opens up a new window towards the fabrication of such 2D/2D nanocomposites in the field of photocatalysis.

Amine/Carboxylic Acid Ionic Liquid Composite Membranes for CO2 Separation

Alkanolamine + carboxylic acid-based ionic liquids have shown promising high CO2 selectivities. Their addition to cellulose acetate (CA) and polyvinyl alcohol (PVA) was investigated in the present study. The N-methyl-2-hydroxyethylammonium propionate IL [m-2HEA][Pr] significantly enhances the CO2 separation performance of PVA. Scanning electron microscopy, Fourier transform infrared spectroscopy, and nuclear magnetic resonance analyses indicate that the IL–PVA combination produced IL composite membranes with interactions being predominantly physical. Furthermore, the IL addition to CA produced porous membranes with apparent low CO2 separation efficiency. Pure gas permeation experiments indicate that increasing IL concentration of PVA-based membranes promotes higher gas permeabilities. The membranes were prepared containing up to 60.3 wt % of [m-2HEA][Pr], which resisted pressure differentials up to 6 barg. PVA containing 45.5 wt % of IL produced the most promising results, achieving 26 barrer of CO2 permeability and permselectivities of 122 and 213 for CO2/CH4 and CO2/N2, respectively. This result was compared to promising materials from the literature and indicated the overall high CO2/CH4 and CO2/N2 selectivities of PVA/[m-2HEA][Pr] membranes, which overcome even the 2008 Robeson’s upper boundary.

Effect of late-gestation heat stress in nulliparous heifers on postnatal growth, passive transfer of immunoglobulin G, and thermoregulation of their calves

Youngstock such as nulliparous pregnant dairy heifers are not typically considered for active cooling, as they are thought to be more heat tolerant than mature cows. Recently, the benefits of heat stress abatement in pregnant heifers were studied, but the effect of in utero hyperthermia on the calf is still unknown. Herein, we aimed to investigate the effects of late-gestation heat stress in nulliparous heifers on the growth, immune, and thermoregulatory responses of their calves. Pregnant nulliparous dams were randomly selected for either active cooling (CL; fans and soakers; n = 15) or heat stress (HT; n = 16) 60 d before expected calving. After birth, respiration rate, rectal temperature, skin temperature, and sweating rate were obtained from their heifer calves at 24 h and on d 14, 28, 42, and 56. Blood samples and body weights were both collected for measurement of total protein and hematocrit and calculation of average daily gains, respectively. Gestation length was shorter in HT heifers (272 vs. 276 ± 1.28 d) relative to CL heifers. Birth weights, weaning weights, body weights up to d 56, and average daily gain from birth to weaning were not different between in utero HT (IUHT; n = 13) and in utero CL (IUCL; n = 12) calves. Apparent efficiency of absorption of immunoglobulin G tended to be lower in IUHT calves (26.3 vs. 42.7 ± 9.0%), and serum IgG concentrations from birth to d 56 were significantly lower in IUHT calves relative to IUCL calves (22.0 vs. 32.4 ± 4.47 g/L). Postnatal respiration rate, rectal temperature, sweating rate, total protein, and hematocrit were not different between in utero treatments. There was a tendency for IUHT calves to have lower skin temperature at 24 h (34.9 vs. 36.9 ± 1.05°C), and skin temperature tended to be elevated in IUHT calves at d 56 (29.6 vs. 27.9 ± 1.05°C). In summary, the lack of heat stress abatement during late gestation reduces gestation length of nulliparous heifers. Additionally, providing active cooling to nulliparous heifers during the prepartum period confers immune benefits to their offspring, although it does not translate to growth improvements.

Effect of Foliar Micronutrients (B, Mn, Fe, Zn) on Maize Grain Yield, Micronutrient Recovery, Uptake, and Partitioning.

Timing of micronutrient demand and acquisition by maize (Zea mays L.) is nutrient specific and associated with key vegetative and reproductive growth stages. The objective of this study was to determine the fate of foliar-applied B, Fe, Mn, Zn, and Fe/Zn together, evaluate the effect of foliar micronutrients applied at multiple rates and growth stages on maize grain yield, and determine their apparent nutrient recovery efficiency (ANR). Five Randomized Complete Block Design (RCBD) experiments were conducted in 2014 and 2015 at five locations across Nebraska. Total dry matter was collected at 5–6 stages, and separated into leaves, stalk, and reproductive tissue as appropriate to determine micronutrient uptake, partitioning, and translocation. Foliar B, Mn, Zn, and Fe/Zn had no effect on grain yield for most application time by rate levels, though, at the foliar Mn site, there was a 19% yield increase due to a V18 application of 0.73 kg Mn ha−1 which corresponded with reduced Mn uptake in maize grown in control plots. At the foliar Zn site, there was 4.5% decrease in yield due to a split foliar application of 0.84 kg Zn ha−1 total, applied at V11 and V15 stage, which increased leaf Zn concentrations greater than the established toxic level. Only the Fe site had consistent grain yield response and was the only experiment that had visual signs of micronutrient deficiency. Regardless of application time from V6 to R2, there was a 13.5–14.6% increase in grain yield due to 0.22 kg Fe ha−1 foliar application. Most micronutrients had limited or no translocation, however, early season applications of B, prior to V10, had significant mobilization to reproductive tissues at or after VT. Foliar Mn, Zn, and B application had ANR LSmeans of 9.5, 16.9, and 2.5%, respectively, whereas the Fe/Zn mix had negative ANR LSmeans of −9.1% Fe and −1.3% Zn which indicate suppression. These data highlight the importance of confirming a micronutrient deficiency prior to foliar application, guide specific growth stages to target with specific micronutrients, track the fate of foliar-applied micronutrients, and describe the variable effect of foliar-applied micronutrients on grain yield.

Tailoring hierarchical porous TiO2 based ternary rGO/NiO/TiO2 photocatalyst for efficient hydrogen production and degradation of Rhodamine B

This study reports a facile and cost effective approach for synthesizing a ternary photocatalyst rGO/NiO/TiO2 (RGNPT) based on three-dimensionally hierarchical porous TiO2 (PT) particles, rGO and NiO as a cocatalyst for efficient photocatalytic hydrogen generation. The efficient junction architecture of RGNPT was observed from the TEM study. The composite's morphology was tuned by varying the weight ratio variation of graphene oxide (5, 7.5, and 10 Wt%). The obtained material showed impressive photocatalytic efficiency for H2 production in aqueous methanol suspension. The p-n junction hybrid composite RGNPT-7.5Wt% showed superior activity towards H2 production yield 8,215 µmolg−1 after 4 h of light irradiation and apparent quantum yield efficiency 9.19%. The photocatalyst shows promising results of 88% of photo-degradation efficiency to Rhodamine B (Rh-B) dye. The RGNPT-7.5Wt% demonstrated the higher current density 0.16 µAcm−2 whereas NiO-porous TiO2 (NPT) showed ten folds lower of 0.017 µAcm−2 using Ag/AgCl electrode. The electron impedance spectroscopic results of RGNPT-7.5Wt% heterostructure exhibited higher photocurrent response and lower charge transfer resistance and significantly accelerate the electrons transfers across the NPT and NiO. Photoluminescence lifetime of RGNPT-7.5Wt% (τ = 3.21 ns) is 16 times higher than porous TiO2 (τ = 0.10 ns). This work manifestates that hierarchical porous TiO2 and rGO graphene plays a vital role in the electron transfer pathway, which is further considered an excellent strategy for synthesizing the ternary composites and enhancing photocatalytic hydrogen production.

The responses of photosynthesis, fruit yield and quality of mini-cucumber to LED-interlighting and grafting

ABSTRACT Supplemental lighting is becoming a common practice for horticultural greenhouse industries, especially at high-latitude countries. However, no scientific reports were found on this topic in tropical climate countries. This study investigates the effects of LED-interlighting and grafting on photosynthetic response and yield and quality of mini cucumber (hybrid Larino). The experiment took place from April to August in a greenhouse located at a Cwa climate type in Piracicaba (SP), Brazil (22°42’S; 47°37’W; 541 m altitude). The experiment was arranged in completely randomized block design composed of three types of seedlings (ungrafted hybrid, hybrid grafted onto rootstock cultivar Keeper and hybrid grafted onto rootstock cultivar Shelper) and two environments related to light condition (LED supplemental light and natural light as control). The LED devices were placed horizontally at 15 cm from the plants and at 1,5 m height from the floor. The LEDs emitted a photon flux of 220 µmol m-2 s-1 by red light (80%) with a peak wavelength of 662 nm and blue light (20%) with a peak wavelength of 452 nm. Lighting was used for 12 h d-1 from 30 days after seedling transplanting until the end of the growth period. The air temperature and relative humidity (RH) were maintained at 23.5±4°C and 72±10% during the light period, respectively. At night, average temperature was 18.6±5°C and the RH was 90±5%. The LED-interlighting treatment increased in 40% the plant CO2 net assimilation rate compared to plants grown under natural light in the greenhouse. Plants grafted onto both rootstocks had higher CO2 net assimilation rate (µmol CO2 m-2 s-1), apparent carboxylation efficiency (µmol CO2 mol air-1) and apparent electron transport rate (µmol electrons m-2 s-1) than non-grafted ones. The early yield increased 11.6% and 24% in response to LED-interlighting and grafting, respectively. The commercial yield also increased with LED light at rate of 13% but did not enhance with grafting. Postharvest quality parameters as titratable acidity, total soluble solids and shelf life were not affected by the LED light supplementation. Our study shows that even in tropical climate conditions LED-interlighting can be used as a tool to improve commercial cucumber production.

Electrochemically Triggered Chain Reactions for the Conversion of Furan Derivatives.

We report an electrochemical method for coupling biomass-derived C5/C6 compounds to value-added fuel precursors. Using only 2 % of equivalent charges, 2-methylfuran (2-MF) was oxidized to yield a cation radical, which readily reacted with 3-hexene-2,5-dione, a derivate of 2,5-dimethylfuran, to produce 3-(5-methylfuran-2-yl)hexane-2,5-dione. The product was converted to 4-ethylnonane (a component of biodiesel/jet fuel) in a single step in excellent yield. Importantly, the reaction was not sensitive to oxygen, and a trace amount of water was found to promote the reaction. Detailed mechanistic studies confirmed the proposed reaction pathways. Key to the mechanism is the radical generation that is enabled by electrochemistry. The radical is regenerated at the end of a reaction cycle to ensure chain propagation for an average of ca. 47 times, resulting in an apparent Faradaic efficiency of 4700 %.

Electrochemically Triggered Chain Reactions for the Conversion of Furan Derivatives

AbstractWe report an electrochemical method for coupling biomass‐derived C5/C6 compounds to value‐added fuel precursors. Using only 2 % of equivalent charges, 2‐methylfuran (2‐MF) was oxidized to yield a cation radical, which readily reacted with 3‐hexene‐2,5‐dione, a derivate of 2,5‐dimethylfuran, to produce 3‐(5‐methylfuran‐2‐yl)hexane‐2,5‐dione. The product was converted to 4‐ethylnonane (a component of biodiesel/jet fuel) in a single step in excellent yield. Importantly, the reaction was not sensitive to oxygen, and a trace amount of water was found to promote the reaction. Detailed mechanistic studies confirmed the proposed reaction pathways. Key to the mechanism is the radical generation that is enabled by electrochemistry. The radical is regenerated at the end of a reaction cycle to ensure chain propagation for an average of ca. 47 times, resulting in an apparent Faradaic efficiency of 4700 %.

Low kinetic inductance superconducting MgB2 nanowires with a 130 ps relaxation time for single-photon detection applications

Properties of superconducting nanowires set the performance level for superconducting nanowire single photon detectors (SNSPDs). Reset time in commonly employed large area SNSPDs, 1–10 ns, is known to be limited by the nanowire’s kinetic inductance to the load impedance ratio. On the other hand, reduction of the kinetic inductance in small area (waveguide integrated) SNSPDs prevents biasing them close to the critical current due to latching into a permanent resistive state. In order to reduce the reset time in SNSPDs, superconducting nanowires with both low kinetic inductance and fast electron energy relaxation are required. In this paper, we report on a study of kinetic inductance in narrow (15–100 nm) and long (up to 120 μm) superconducting MgB2 nanowires made from 5 nm thick films, offering such combination of properties. Such films were grown using hybrid physical chemical vapor deposition, resulting in a critical temperature of ∼32 K, and a switch current density of 5 × 107 A cm−2 (at 4.8 K). Using microwave reflectometry, we measured a kinetic inductance of L k0(4.8 K) = 1.3–1.6 pH/□ regardless of the nanowire width, which results in a magnetic field penetration depth of ∼90 nm. These values are very close to those in pristine MgB2. We showed that after excitations by a 50 fs pulsed laser the reset time in 35 nm × 120 μm MgB2 nanowires is 130 ps, which is more than a factor of 10 shorter than in NbN nanowires of similar length-to-width ratios. Depending on the bias current, such MgB2 nanowires function as single-, double, or triple-photon detectors for both visible (λ = 630 nm) and infrared (λ = 1550 nm) photons, with a dark count rate of <10 cps. Although the apparent photon detection efficiency seems so far to be low, further technological advances (uniform nanowire width, smaller thickness, increasing the switching current closer to the pair-breaking current) may improve this figure of merit.