Split Addition of Nitrogen-Rich Substrate at Thermophilic and Mesophilic Stages of Composting: Effect on Green House Gases Emission and Quality of Compost

Composting as a solution to the increasing generation of municipal solid waste (MSW), also contribute to GHGs emission when not controlled and could lack some basic nutrients, especially nitrogen. This study assessed the split-additions of nitrogen-rich substrate to composting materials and their effect on GHGs emissions as well as the quality of the composts. Nitrogen-rich substrates formulated from pig and goat manure were co-composted with MSW for a 12-weeks period by split adding at mesophilic (˚C) and thermophilic (>50˚C) stages in five different treatments. Representative samples from the compost were taken from each treatment for physicochemical, heavy metals and bacteriological analysis. In-situ CH4, CO2, N2O gas emissions were also analyzed weekly during composting. It was observed that all the treatments showed significant organic matter decomposition, reaching thermophilic temperatures in the first week of composting. The absence affects the suitable agronomic properties. All nitrogen-rich substrate applied at thermophilic stage (Treatment two) recorded the highest N, P and K concentrations of 1.34%, 0.97% and 2.45%, respectively with highest nitrogen retention. In terms of GHG emissions, CO2 was highest at the thermophilic stage when N-rich substrate was added in all treatment, while CH4 was highest in the mesophilic stage with N-rich substrate addition. N2O showed no specific trend in the treatments. Split addition of the N-rich substrate for co-composting of MSW produced compost which is stable, has less nutrient loss and low GHG emissions. Split addition of a nitrogen-rich substrate could be an option for increasing the fertilizer value of MSW compost.

Effect of substrate amendment on alkaline minerals and aggregate stability in bauxite residue

Bauxite residue is an alkaline waste material in the process of alumina production due to its characteristics of higher salinity and alkalinity,which results in environmental issues and extremely restricts the sustainable development of alumina industries.In this work,we conduct a column experiment to study the effects of two amendments on aggregate stability and variations in alkaline minerals of bauxite residue.The two amendments are phosphogypsum(PG)and phosphogypsum and vermicompost(PVC).The dominant fraction in aggregate is 1–0.25 mm in diameter on the surface,which takes up 39.34%,39.38%,and 44.51%for CK,PG,and PVC,respectively.Additions of PG and PVC decreased pH,EC,ESP,exchangeable Na^+concentration and the percentage of alkaline minerals,and then increased exchangeable Ca^2+concentration in bauxite residue.There was significant positive correlation between pH and exchangeable Na^+concentration,the percentage of cancrinite,tricalcium aluminate and calcite;while negative correlation was found in pH value versus exchangeable Ca^2+concentration.Theses findings confirmed that additions of phosphogypsum and vermicompost have a stimulative effect on aggregate stability in bauxite residue.In particular,amendment neutralization(phosphogypsum+vermicompost)in column represents an advantage for large-scale simulation of vegetation rehabilitate in bauxite residue disposal areas.

<i>Tithonia diversifolia</i>Leaves and Stems Use as Substrate Amendment Promote the Growth of Plantain Vivoplants in the Nursery

Tithonia diversifolia is a year-round weed that decomposes rapidly after application as a soil amendment and it is more and more used in agriculture due to its numerous properties. The use of Tithonia diversifolia in the production of plantain vivoplants is a great opportunity for small holders’ farmers that cannot easily buy chemical inputs for yield improvement. All plant parts are used because of their richness in nutrients, mineral elements and phytochemicals without knowing which part is the most efficient. Tithonia diversifolia used as substrate amendment for plantain vivoplants production in nursery could promote their growth. This study aims to evaluate the effect of T. diversifolia leaves and stems as substrate amendment on plantain vivoplants growth promotion. The vivoplants were produced in substrates amended with T. diversifolia leaves, stems, combination of leaves and stems, and control without amendment. The vegetative growth parameters (number of shoots, height and diameter of shoots, area of shoots leaves) were assessed in sterilized substrate and unsterilized substrate conditions. T. diversifolia leaves and stems treatment increases the number of shoots, the height and the diameter of shoots as well as the area of shoots leaves compared to the control. T. diversifolia stems are the more efficient treatment, followed by the combination of T. diversifolia leaves and stems and finally the T. diversifolia leaves. They act as a biofertilizer promoting thus, the growth of plantain vivoplants in the nursery. All parts of Tithonia diversifolia can therefore be used by poor small holder farmers, as green manure for soil amendment in a green agriculture context.

Organic Substrate Application in Vegetable Seedling Raising in China

To study the organic substrates substitution for turf has certain significances and has become a hot research topic. The sources of organic substrates mainly concentrate in organic waste of agriculture and forestry, animal husbandry industrial wastes and municipal sludge and so on in China. In order to better explore and utilize organic substrates resources, the authors summed up the application of organic substrates of different sources to vegetable seedling raising. The re- sults showed that the organic substrate produced by traditional and advanced tech- nology had the characteristics of stability, strong buffer capacity, comprehensive nu- trition and a good environment for root growth, which could reduce the production cost, cultivate high quality seedling and benefit cyclic utilization of resources, and replace or partly replace the turf. The prospects for future research direction were discussed to provide references for research and development on organic vegetable seedling raising technology in China.

Variation in Enzymes Activities of Rhizospheric Substrate and Influencing Factors during Nursing of Watermelon Seedlings

[Objective] This study aimed to investigate the effects of substrate en- zymes activities on nursing of watermelon seedlings. [Method] The composted mushroom residue was mixed with garden soil according to a certain proportion to prepare nursing substrate for watermelon seedlings. During the nursing, the activity variation in alkaline phosphatase, acid phosphatase, neutral phosphatase and urease was investigated. In addition, the correlations between pH value, total nitrogen con- tent, total phosphorus content and organic matter content in substrate and enzyme activity were studied. At different young seedling stages, the rhizospheric substrates with different formulas were sampled for determination of enzymes activities. [Result] The enzyme activity differed significantly among different substrates. The correlation analysis results showed that the higher the organic matter content and total nitrogen content in substrate are, the higher the urease activity is; the phosphatase activity was significantly related to the organic matter content, total nitrogen content and to- tal phosphorus content in substrate; the pH value of substrate was significantly relat- ed to rhizospheric alkaline phosphatase activity; the shoot dry weight was positively related to urease activity; there was a significant correlation between phosphatase activity and root dry weight. [Conclusion] Through determining enzymes activities in the rhizospheric substrate for nursing watermelon seedlings, the optimum substrate M3 was screened out. The activities of rhizospheric urease, alkaline phosphatase, acid phosphatase and neutral phosphatase in the substrate M3 were all higher than those in the substrate fertilized with manure.

Diamond Film Synthesis with a DC Plasma Jet:Effect of the Contacting Interface between Substrate and Base on the Substrate Temperature

The contacting interface between the substrate and water-cooled base is vital to the substrate temperature during diamond films deposition by a DC （direct current） plasma jet. The effects of the solid contacting area,conductive materials and fixing between the substrate and the base were investigated without affecting the other parameters. Experimental results indicated that the preferable solid contacting area was more than 60% of total contacting areal; the particular Sn-Pb alloy was more suitable for conducting heat and the concentric fixing ring was a better setting for controlling the substrate temperature. The result was explained in terms of the variable thermal contact resistance at the interface between substrate and base. The diamond films were analyzed by scanning electron microscopy （SEM） for morphology, X-ray diffraction （XRD） for the intensity of characteristic spectroscopy and Raman spectroscopy for structure.

GaN substrate and GaN homo-epitaxy for LEDs:Progress and challenges

After a brief review on the progresses in GaN substrates by ammonothermal method and Na-flux method and hydride vapor phase epitaxy （HVPE） technology, our research results of growing GaN thick layer by a gas fow-rnodulated HVPE, removing the GaN layer through an efficient self-separation process from sapphire substrate, and modifying the uniformity of multiple wafer growth are presented. The effects of surface morphology and defect behaviors on the GaN homo-epitaxial growth on free standing substrate are also discussed, and followed by the advances of LEDs on GaN substrates and prospects of their applications in solid state lighting.

Mild oxidative degradation of spent auricularia auricular substrate and molecular composition of carboxylic acids in the resulting soluble portion

Spent auricularia auricular substrate(SAAS)was oxidatively degraded with aqueous hydrogen peroxide(AHPO)/acetic anhydride(AAH)to produce carboxylic acids(CAs)under mild conditions.The results show that up to 53.6%of the organic matter in SAAS was converted to the soluble species(SSs).In total 122 CAs were detected in the SSs by the analysis with a gas chromatograph/mass spectrometer,which can be classified into 29 group components,mainly being aliphatic acids and along with small amount of aromatic acids.Among the aliphatic acids,normal alkanedioic acids are the most abundant.The detected aromatic acids include benzoic acids,phthalic acids,trimellitic acids,pyromellitic acids,and their derivatives.The synergistic oxidation and the released·OH,CH3COO·,and HOO·induced by AHPO/AAH play crucial roles in oxidatively degrading SAAS.

Impedance Characterization of Adsorption Process of Calmodulin on Au Substrate and its Combination with Ca^(2+)

In this paper, the adsorption process of calmodulin (CaM) on Au substrate was first investigated with electrochemical impedance spectroscopy (EIS) method. The result reveals that the adsorption of the protein-calmodulin contains two steps, i.e., one short quick step followed by a slow one. The complexation of calmodulin with Ca2+ was also first probed using EIS technique, in which the complexation of CaM with Ca2+ could be reflected by the change of apparent membrane capacitance(Capp) clearly. In all above measurements, a redox couple Fe(CN)63-/ Fe(CN)64- was used as probing-pin to reflect all the changes occurring in the above process. Our work suggests that some biological processes of CaM could be studied using EIS method conveniently.

Effect of initial substrate and biomass concentrations on anaerobic fermentative hydrogen production in batch reactors

The effects of initial substrate (5-60 g /L) and biomass concentration (0.5-3 g /L) on fermentative hydrogen production by mixed cultures were investigated in batch tests using glucose as substrate.The experimental results showed that the hydrogen production increases as the initial substrate concentration increases from 0 to 25 g /L.It indicated that the shift in the metabolic pathway or in the composition of the bacterial flora occurs.The maximum hydrogen yield of 1.78 mol /mol-glucose is obtained at the substrate concentration of 15 g /L.This study also shows that initial biomass concentration affects the hydrogen yield as the cumulative hydrogen production has been increased with the increase of initial cell concentration up to 1.5 g /L and reached the highest level.The maximum hydrogen yield is obtained at the cell concentration of 1.5 g /L.It indicated that the optimum biomass /substrate ratio,maximizing the hydrogen yield and the hydrogen production rate,is determined to be 0.1 g biomass /g glucose.

Analytical Expressions for Steady-State Concentrations of Substrate and Product in an Amperometric Biosensor with the Substrate Inhibition—The Adomian Decomposition Method

A mathematical model of an amperometric biosensor with the substrate inhibition for steady-state condition is discussed. The model is based on the system of non-stationary diffusion equation containing a non-linear term related to non-Michaelis–Menten kinetics of the enzymatic reaction. This paper presents the analytical expression of concentrations and current for all values of parameters φ2s φ2s α and β . Here the Adomian decomposition method (ADM) is used to find the analytical expressions for substrate, product concentration and current. A comparison of the analytical approximation and numerical simulation is also presented. A good agreement between theoretical predictions and numerical results is observed.

Effects of Non-Conventional Substrate and NPK Fertilizer on Cassava Plantlets Acclimatization for Plant Material Production

The adaptation of cassava plantlets to natural conditions remains the main obstacle in the process of free virus plantlets production. In this study, cassava plantlets acclimatization was assessed by pre-acclimatization, height of acclimated plantlets, substrate, and nutrient watering solution. The results revealed that pre-acclimatization gave a high survival rate (61.9%) whereas the direct tunnel acclimatization was conducted to low rate (27.31%) of plantlets. Furthermore, the height of plantlets influenced significantly (p < 0.05) their survival rate with best survival rate observed on plantlet height from 1 cm to 5 cm. There was no significant difference between the substrates used and watering solutions. However, the Sawdust substrate gave a high survival rate (46.67%) and better phylogenesis (1.8) in the variety RB 89509. Likewise, plantlets treated with NPK nutrient watering solutions (20-10-10) had a better survival rate (48.57%), better phylogenesis (2.125) with the variety RB 89509 and better growth in height (1.18 cm) with the variety BF92/0267. These findings constitute a database for the establishment of the technical itinerary for the acclimatization of cassava plantlets.

Insights on advanced substrates for controllable fabrication of photoanodes toward efficient and stable photoelectrochemical water splitting

Conversion of solar energy into H_(2) by photoelectrochemical(PEC)water splitting is recognized as an ideal way to address the growing energy crisis and environmental issues.In a typical PEC cell,the construction of photoanodes is crucial to guarantee the high efficiency and stability of PEC reactions,which fundamentally rely on rationally designed semiconductors(as the active materials)and substrates(as the current collectors).In this review work,we start with a brief introduction of the roles of substrates in the PEC process.Then,we provide a systematic overview of representative strategies for the controlled fabrication of photoanodes on rationally designed substrates,including conductive glass,metal,sapphire,silicon,silicon carbide,and flexible substrates.Finally,some prospects concerning the challenges and research directions in this area are proposed.

11.2 W/mm power density AlGaN/GaN high electron-mobility transistors on a GaN substrate

In this letter,high power density AlGaN/GaN high electron-mobility transistors(HEMTs)on a freestanding GaN substrate are reported.An asymmetricΓ-shaped 500-nm gate with a field plate of 650 nm is introduced to improve microwave power performance.The breakdown voltage(BV)is increased to more than 200 V for the fabricated device with gate-to-source and gate-to-drain distances of 1.08 and 2.92μm.A record continuous-wave power density of 11.2 W/mm@10 GHz is realized with a drain bias of 70 V.The maximum oscillation frequency(f_(max))and unity current gain cut-off frequency(f_(t))of the AlGaN/GaN HEMTs exceed 30 and 20 GHz,respectively.The results demonstrate the potential of AlGaN/GaN HEMTs on freestanding GaN substrates for microwave power applications.

Recess-free enhancement-mode AlGaN/GaN RF HEMTs on Si substrate

Enhancement-mode(E-mode)GaN-on-Si radio-frequency(RF)high-electron-mobility transistors(HEMTs)were fabri-cated on an ultrathin-barrier(UTB)AlGaN(<6 nm)/GaN heterostructure featuring a naturally depleted 2-D electron gas(2DEG)channel.The fabricated E-mode HEMTs exhibit a relatively high threshold voltage(VTH)of+1.1 V with good uniformity.A maxi-mum current/power gain cut-off frequency(fT/fMAX)of 31.3/99.6 GHz with a power added efficiency(PAE)of 52.47%and an out-put power density(Pout)of 1.0 W/mm at 3.5 GHz were achieved on the fabricated E-mode HEMTs with 1-μm gate and Au-free ohmic contact.

Reshaping Li–Mg hybrid batteries:Epitaxial electrodeposition and spatial confinement on MgMOF substrates via the lattice‐matching strategy

The emergence of Li–Mg hybrid batteries has been receiving attention,owing to their enhanced electrochemical kinetics and reduced overpotential.Nevertheless,the persistent challenge of uneven Mg electrodeposition remains a significant impediment to their practical integration.Herein,we developed an ingenious approach that centered around epitaxial electrocrystallization and meticulously controlled growth of magnesium crystals on a specialized MgMOF substrate.The chosen MgMOF substrate demonstrated a robust affinity for magnesium and showed minimal lattice misfit with Mg,establishing the crucial prerequisites for successful heteroepitaxial electrocrystallization.Moreover,the incorporation of periodic electric fields and successive nanochannels within the MgMOF structure created a spatially confined environment that considerably promoted uniform magnesium nucleation at the molecular scale.Taking inspiration from the“blockchain”concept prevalent in the realm of big data,we seamlessly integrated a conductive polypyrrole framework,acting as a connecting“chain,”to interlink the“blocks”comprising the MgMOF cavities.This innovative design significantly amplified charge‐transfer efficiency,thereby increasing overall electrochemical kinetics.The resulting architecture(MgMOF@PPy@CC)served as an exceptional host for heteroepitaxial Mg electrodeposition,showcasing remarkable electrostripping/plating kinetics and excellent cycling performance.Surprisingly,a symmetrical cell incorporating the MgMOF@PPy@CC electrode demonstrated impressive stability even under ultrahigh current density conditions(10mAcm^(–2)),maintaining operation for an extended 1200 h,surpassing previously reported benchmarks.Significantly,on coupling the MgMOF@PPy@CC anode with a Mo_(6)S_(8) cathode,the assembled battery showed an extended lifespan of 10,000 cycles at 70 C,with an outstanding capacity retention of 96.23%.This study provides a fresh perspective on the rational design of epitaxial electrocrystallization driven by metal–organic framework(MOF)substrates,paving the way toward the advancement of cuttingedge batteries.

Influence of substrate effect on near-field radiative modulator based on biaxial hyperbolic materials

Relative rotation between the emitter and receiver could effectively modulate the near-field radiative heat transfer(NFRHT)in anisotropic media.Due to the strong in-plane anisotropy,natural hyperbolic materials can be used to construct near-field radiative modulators with excellent modulation effects.However,in practical applications,natural hyperbolic materials need to be deposited on the substrate,and the influence of substrate on modulation effect has not been studied yet.In this work,we investigate the influence of substrate effect on near-field radiative modulator based onα-MoO_(3).The results show that compared to the situation without a substrate,the presence of both lossless and lossy substrate will reduce the modulation contrast(MC)for different film thicknesses.When the real or imaginary component of the substrate permittivity increases,the mismatch of hyperbolic phonon polaritons(HPPs)weakens,resulting in a reduction in MC.By reducing the real and imaginary components of substrate permittivity,the MC can be significantly improved,reaching 4.64 forε_(s)=3 at t=10 nm.This work indicates that choosing a substrate with a smaller permittivity helps to achieve a better modulation effect,and provides guidance for the application of natural hyperbolic materials in the near-field radiative modulator.

Design strategy of porous elastomer substrate and encapsulation forinorganic stretchableelectronics

The emergence of stretchable electronic technology has led to the development of many industries and facilitated many unprecedented applications,owing to its ability to bear var-ious deformations.However,conventional solid elastomer sub-strates and encapsulation can severely restrict the free motion and deformation of patterned interconnects,leading to poten-tial mechanical failures and electrical breakdowns.To address this issue,we propose a design strategy of porous elastomer substrate and encapsulation to improve the stretchability of serpentine interconnects in island-bridge structures.The ser-pentine interconnects are fully bonded to the elastomer sub-strate,while segments above circular pores remain suspended,allowing for free deformation and a substantial improvement in elastic stretchability compared to the solid substrates.The pores ensure unimpeded interconnect deformations,and mod-erate porosity provides support while maintaining the initial planar state.Compared to conventional solid configurations,finite element analysis(FEA)demonstrates a substantial enhancement of elastic stretchability(e.g.=9 times without encapsulation and=7 times with encapsulation).Uniaxial cyc-lic loading fatigue experiments validate the enhanced elastic stretchability,indicating the mechanical stability of the porous design.With its intrinsic advantages in permeability,the pro-posed strategy has the potential to offer insightful inspiration and novel concepts for advancing the field of stretchable inorganic electronics.

Facile SERS screening of melamine in bovine milk with 2D printed AgNPs/glass fabric filter paper as the flexible substrate

Melamine is one of the most frequently detected adulterants in dairy products.The current study proposes a surface-enhanced Raman spectroscopy(SERS)-based analytical tool for fast and reliable screening of melamine in bovine milk.A hand-held Raman spectrometer was used in conjunction with a substrate composed of silver nanoparticles(AgNPs)that was 2D printed onto glass fiber(GF)filter paper.Under optimized conditions,a sensitive and fingerprint-like signal at 674 cm^(-1) was obtained.The AgNPs/GF substrate exhibited high sensitivity to melamine in milk down to 1.9498×10^(-5)mg/mL,which is well below the USA and EU safety limits(2.5×10^(-3)mg/mL).Remarkably,the proposed technology was also highly reproducible,showing spot-to-spot and block-to-block variations below 3.3%and 4.9%at 674 cm^(-1) in Raman intensity,respectively.The characteristic peak intensity and concentration of melamine showed an acceptable linear relationship(R^(2)=0.9909)within the range of 0.0001-1 mg/mL.Overall,the method established in this study can provide an efficient and effective method for the quantitative target screening and detection of melamine in dairy products.

Feasible strategy for the nitrogen fixation and humification quality improvement by spent mushroom substrate as conditioning agent

There is an overlooked problem which increasing microbial abundance while reducing nitrogen loss during composting.This study investigated the viability of spent mushroom substrate(SMS)as conditioners in the aerobic composting of kitchen waste(KW)with cattle manure(CM).The variation of temperature,pH,C/N,organic matter,cellulose,hemicelluloses,germination index(GI),and microflora structure were explored to evaluate the potential in accelerating maturity and nitrogen fixation by SMS addition.The results showed that the addition of SMS accelerated the heating rate,prolonged the high temperature time,and decreased organic matter,hemicellulose,and cellulose by 17.49%,23.61%,and 18.62%,respectively.The GI reached 105.86%with SMS addition,while 74.17%was found in control treatment after composting.SMS changed the microbial community composition and increased the species abundance.Proteiniclasticum,Clostridium XI and Azomonas were dominant bacteria,which increased the retention of nitrogen,promoted organic matter degradation and reduce compost time.The study can provide a feasible strategy for nitrogen fixation in the field of organic waste recycling.