Dry Substrate Research Articles

Improving saccharification of ramie stalks by synergistic effect of in-house cellulolytic enzymes consortium

The high cost of cellulase is one of the main obstacles hindering the large-scale biorefining of lignocellulosic biomass. Therefore, developing efficient method for preparation of cellulase is promising. In the present study, the production of cellulase by Trichoderma reesei, Trichoderma harzianum, and Aspergillus niger was optimized, and the synergistic effect of these cellulase on enzymatic hydrolysis of pretreated ramie stalks was also evaluated. The maximum CMCase (Carboxymethyl Cellulase) and filter paper activity (FPA) produced by T. reesei reached to 3.12 IU/mL and 0.13 IU/mL, respectively. The maximum activities of CMCase (3.68 IU/mL), FPA (0.04 IU/mL) and β-glucosidase (8.44 IU/mL) were obtained from A. niger. The results also showed that under the premise of the same FPA activity, the contribution of β-glucosidase activity to yield of reducing sugar was greater than that of CMCase. Besides, cellulase produced by T. reesei and A. niger had the best synergistic effect on enzymatic hydrolysis of pretreated ramie stalks. The highest reducing sugars yield (417 mg/g dry substrate) was achieved when enzyme cocktail was prepared at the ratio of 1:1, which was 1.36–3.35 folds higher than that of different single enzymes. The present research has provided a novel method for efficient preparation of enzymes consortium for enzymatic hydrolysis of ramie stalks.Graphical

Simultaneous extraction of lipids and minor lipids from microalga (Nannochloropsis gaditana) and rapeseed (Brassica napus) using supercritical carbon dioxide

Supercritical extraction with CO2 from a substrate composed of Nanochloropsis gaditana and cold-pressed rapeseed was studied to increase the extraction yield of oil, carotenoids, tocopherols, chlorophylls and antioxidant capacity. The independent variables were temperature (37–53 °C), CO2 density (885–935 kg CO2/m3) and specific solvent consumption (14–34 kg CO2/kg dry substrate). The optimal conditions for the extraction of oils and minor lipids were determined using the response surface methodology. Specific solvent consumption was the factor with the greatest effect. The oil extraction correlated positively with the extraction of carotenoids (p ≤ 0.01), tocopherols (p ≤ 0.01), chlorophylls (p ≤ 0.01), and antioxidant capacity (p ≤ 0.05). The co-extraction of oil promotes greater solubility of the minor lipids and increases their extraction. The antioxidant capacity correlated positively with the extraction of carotenoids (p ≤ 0.01), tocopherols (p ≤ 0.01) and chlorophylls (p ≤ 0.05).

Root Exploration, Initial Moisture Conditions, and Irrigation Scheduling Influence Hydration of Stratified and Non-Stratified Substrates

Soilless substrate stratification (i.e., layering unique substrates within a single container) is an emerging substrate management strategy that may provide opportunities to augment nursery resource use. As such, this research aimed to analyze water movement through containers during hydration events under different initial moisture conditions. The results indicated substrate stratification had minimal influence on water movement compared to non-stratified systems (uniformly filled nursery containers). Cyclic irrigation significantly increased the stratified substrates’ ability to retain water when irrigated at 20% volumetric water content (p < 0.0001) and significantly decreased the total volume leached (p < 0.0001). Moreover, irrigating the substrate profile with shallow and more frequent irrigations facilitated stratified substrates ty reach effective container capacity conditions (p < 0.0001n compared to non-stratified systems. The stratified systems took longer to leach all gravitational pores (p = 0.0266). In dry moisture conditions, non-stratified substrates were more hydrated when cyclic irrigation applications were applied compared to single applications (p = 0.0492). This study demonstrated that cyclic irrigation scheduling enhanced water retention in both non-stratified and stratified profiles under different initial moisture conditions and can be used as an irrigation strategy when dry substrate conditions prevail.

Remote sensing of river habitat for salmon restoration

Losses of river complexity and viable habitat has led to negative effects on Atlantic salmon. With the rapid population decline of Atlantic salmon, there has been an increase in river restoration and salmon reintroduction projects, and an understanding of substrate is a vital component in the restoration of these habitats. However, the isolation and/or inaccessibility of many of these rivers make the collection of this information challenging and expensive based on conventional survey approaches. This study looks at the feasibility and accuracy of conducting substrate analysis using low-cost uncrewed aerial vehicles (UAV) at seven transects through macroscale river habitat (riffles, runs and pools) on the Upper Salmon River located in Fundy National Park near Alma, New Brunswick, Canada. Using ArcGIS, a supervised classification was conducted separating the dry and submerged substrate for higher accuracy. An object-based image analysis was conducted in PCI for delineation of substrate size. Small ideal spawning substrate was found to be concentrated in slower flowing pools while large substrate was concentrated in faster flowing riffles. The substrate analysis was conducted with an accuracy of 79% for dry substrate and 86% for submerged substrate, demonstrating the potential of UAV use in salmon habitat analysis.

Production of Polyhydroxyalkanoates through Soybean Hull and Waste Glycerol Valorization: Subsequent Alkaline Pretreatment and Enzymatic Hydrolysis

Alkaline pretreatment and sequential enzymatic hydrolysis of soybean hull were investigated to obtain fermentable sugars for polyhydroxyalkanoates production along with residual glycerol as low-cost carbon sources. Soybean hull is composed of approximately 32% cellulose, 12% hemicellulose, 6% lignin, and 11% protein. Alkaline pretreatment was carried out with 2% NaOH concentration, 10% (w/v) biomass loading, and 60 min incubation time in an autoclave at 120 °C. The response surface methodology (RSM) based on the central composite design (CCD) tool was employed to optimize the enzymatic hydrolysis process, where the variables of biomass loading, enzymes’ concentration, and time were considered. The maximum total reducing sugars concentration obtained was 115.9 g∙L−1 with an enzyme concentration of 11.5 mg protein/g dry substrate for enzyme preparation B1, 2.88 mg protein/g dry substrate for XylA, and 57.6 U/g dry substrate for β-glucosidase, after 42 h at 45 °C, and pH was 4.5. Subsequently, the saccharification step was conducted by increasing the processing scale, using a 1 L tank with stirring with a controlled temperature. Implementing the same enzyme concentrations at pH 4.5, temperature of 45 °C, 260 mL working volume, and incubation time of 42 h, under fed-batch operation with substrate feeding after 14 h and 22 h, a hydrolysate with a concentration of 185.7 g∙L−1 was obtained. Initially, to verify the influence of different carbon sources on Cupriavidus necator DSMz 545 in biomass production, batch fermentations were developed, testing laboratory-grade glucose, soybean hull hydrolysate, and waste glycerol (a by-product of biodiesel processing available in large quantities) as carbon sources in one-factor-at-a-time assays, and the mixture of soybean hull hydrolysate and waste glycerol. Then, the hydrolysate and waste glycerol were consumed by C. necator, producing 12.1 g∙L−1 of biomass and achieving 39% of polyhydroxyalkanoate (PHB) accumulation. To the best of our knowledge, this is the first time that soybean hull hydrolysate has been used as a carbon source to produce polyhydroxyalkanoates, and the results suggest that this agro-industrial by-product is a viable alternative feedstock to produce value-added components.

Optimal substrates for producing housefly larvae with high nutritional composition for sustainable poultry feed in Niger

Poultry farming, because of its many potentialities (i.e. short duration of reproduction and production cycle, rapid return on investment), occupies a place of choice in development strategies and the fight against poverty in most African countries. In Niger, West Africa, poultry are fed specific protein-providing feed ingredients (such as fishmeal); however, these ingredients are very expensive and unsustainable. Larvae represent a potential alternative source of protein for poultry. Here, we investigated different substrates to optimise housefly (Musca domestica L. 1758) maggot production and nutritional composition. Eight dry substrates were tested. The highest larval biomass (larval biomass produced by 10 mg of house fly egg placed on 50 g dry substrate) and mean weight (individual house fly larvae 5 days after the incorporation of eggs on the substrate) were observed on millet and wheat bran (3,446.67±134.16 mg and 24.00±1.01 mg, respectively). However, larvae produced on Brewer’s spent grains had the highest protein and lipid content (53.79±1.04% and 24.13±5.20%, respectively). Ash content was highest for larvae produced on cow dung and a mixture of 50% wheat bran and 50% cow dung (15.01±0.32% and 15.41±0.09%, respectively). Maggots produced on rumen contents had the highest water content (80.89±0.22%). The profile of produced larvae included palmitic acid (30.99±0.48% on grain), palmitoleic acid (30.26±2.84% on cow dung), oleic acid (27.93±0.31% on rice hulls), and linoleic acid (26.41±0.18% on millet bran + rumen contents). For all substrates, Maggots contained more unsaturated fatty acids (57.59-66.52%) than saturated fatty acids (26.54-46.34%). This study, offers to farmers a wide variety of substrates that could be used to produce maggots, providing a sustainable source of protein that has not been previously available in Niger. We recommend the farmers to use the cow dung to produce maggots without cost.

Effects of Relative Humidity and Paper Geometry on the Imbibition Dynamics and Reactions in Lateral Flow Assays

Lateral flow assays and paper microfluidics have the potential to replace benchtop instrumented medical diagnostic systems with instrument-free systems that rely on passive transport of liquid through micro-porous paper substrates. Predicting the imbibition dynamics of liquid through dry paper substrates is mostly modeled through the Lucas-Washburn (LW) equations. However, the LW framework assumes that the fluid front exhibits a sharp boundary between the dry and wet phases across the liquid imbibition interface. Additionally, the relative humidity in the environment results in moisture trapped within the pores of the paper substrates as the paper attains an equilibrium with the ambient air. Here, we apply a two-phase transport framework based on Brooks and Corey's model to capture imbibition dynamics on partially saturated paper substrates. The model is experimentally validated and is then used to predict the liquid-paper imbibition dynamics in simulated environments with 1-70% relative humidity. The model was also used to determine the saturation gradient of liquid along the imbibition interface of the paper substrate. Insights from these studies enabled us to determine the mechanism of the liquid transport in partially saturated porous paper substrates. The model also enabled us to evaluate the optimal paper shapes and relative humidity of the environment that maximize imbibition rates and minimize imbibition front broadening. Finally, we evaluate the effect of moisture content of paper on the rate of paper-based biochemical reaction by amplifying a sequence of the SARS-CoV-2 RNA target via reverse transcriptase loop-mediated isothermal amplification. Taken together, this study provides some important guidelines to academic and applied researchers working in point-of-care diagnostics to develop paper-based testing platforms that are capable of functioning in a robust manner across multiple environmental conditions.

TROPHIC DIVERSITY OF LITTER NEMATODE COMMUNITIES OF FORESTS IN THE MEZIN NATIONAL NATURE PARK

Introduction. Nematodes are one of the most abundant groups of the soil and litter fauna in forest ecosystems. The faunal composition may mirror the activity of decomposition pathways and give indications of nutrient status and fertility of soil. Nematodes play an important role in regulating microbial communities and affect the speed and direction of mineralization and humification of plant precipitation.
 Aim. Trophic structure of nematode communities from litter in forests of the Mezin National Nature Park was studied.
 Materials and methods. Samples litter were collected from June to July 2010 and 2014 in 21 forest ecosystems. Nematodes were extracted by a modified Baermann’s method from the 5-g sample. The exposition time was 48 h. Extracted nematodes were fixed in the triethanolamine–formalin (TAF, 2 % triethanolamine, 7 % formaldehyde solution, 91% water), and mounted on the temporary hydroglyceric slides. Nematode abundance was expressed as specimens per 100 g of dry substrate.
 Results. The 46 identified nematode species were divided into five trophic groups: saprobionts, mycohelminths, omnivores, predators and phytohelminths. Saprobionts were both the most diverse and the most numerous. 26 species (56,52% of all species collected) belonged to the this trophic group, proportion in the community was 63,97%. Plectus cirratus, Plectus parietinus, Panagrolaimus rigidus were the most numerous (proportion in the community 24,13%, 9,65% and 8,18% of the total, respectively). P. rigidus occurred in 95,2% of all samples. Aphelenchoides composticola dominated among 10 species of mycohelminths (frequency was 85,7%, proportion in the community 8,99%). Mesodorylaimus bastiani was common аmong the three species of omnivorous nematodes (frequency was 90,48%, proportion in the community 13,74%). Predatory nematodes (5 species) were in 57,1% of samples, proportion in the community together was 3,17%. Only two species phytohelminths (Gracilacus audriellus, Paratylenchus nanus) were found in the analyzed litter samples. They were rare; their frequency was 9,52% and 4,76% respectively. Moreover they were not very abundant (0,12% and 0,08% of total number respectively).
 Conclusions. The mycohelminths and saprobionts make an important component of the litter decomposer community of all forest ecosystems in the Mezin National Nature Park. The ratio of mycohelminths to saprobionts (М/S) shows a constant preponderance of saprobionts and was 0,27. Twenty five species (54,35% of all species collected) were high colonization ability, high reproduction rate and high tolerance to disturbances. The trophic diversity index was 2,16. The maturity index was 2,27. These indexes show stability of habitat in the forest litter.

The Thickness and Structure of Dip-Coated Polymer Films in the Liquid and Solid States.

Films formed by dip coating brass wires with dilute and semi-dilute solutions of polyvinyl butyral in benzyl alcohol were studied in their liquid and solid states. While dilute and semi-dilute solutions behaved as Maxwell viscoelastic fluids, the thickness of the liquid films followed the Landau-Levich-Derjaguin prediction for Newtonian fluids. At a very slow rate of coating, the film thickness was difficult to evaluate. Therefore, the dynamic contact angle was studied in detail. We discovered that polymer additives preserve the advancing contact angle at its static value while the receding contact angle follows the Cox–Voinov theory. In contrast, the thickness of solid films does not correlate with the Landau-Levich-Derjaguin predictions. Only solutions of high-molecular-weight polymers form smooth solid films. Solutions of low-molecular-weight polymers may form either solid films with an inhomogeneous roughness or solid polymer domains separated by the dry substrate. In technological applications, very dilute polymer solutions of high-molecular-weight polymers can be used to avoid inhomogeneities in solid films. These solutions form smooth solid films, and the film thickness can be controlled by the experimental coating conditions.

A Machine Learning Approach for Predicting the Maximum Spreading Factor of Droplets upon Impact on Surfaces with Various Wettabilities

Drop impact on a dry substrate is ubiquitous in nature and industrial processes, including aircraft de-icing, ink-jet printing, microfluidics, and additive manufacturing. While the maximum spreading factor is crucial for controlling the efficiency of the majority of these processes, there is currently no comprehensive approach for predicting its value. In contrast to the traditional approach based on scaling laws and/or analytical models, this paper proposes a data-driven approach for estimating the maximum spreading factor using supervised machine learning (ML) algorithms such as linear regression, decision tree, random forest, and gradient boosting. For this purpose, a dataset of hundreds of experimental results from the literature and our own—spanning the last thirty years—is collected and analyzed. The dataset was divided into training and testing sets, each representing 70% and 30% of the input data, respectively. Subsequently, machine learning techniques were applied to relate the maximum spreading factor to relevant features such as flow controlling dimensionless numbers and substrate wettability. In the current study, the gradient boosting regression model, capable of handling structured high-dimensional data, is found to be the best-performing model, with an R2-score of more than 95%. Finally, the ML predictions agree well with the experimental data and are valid across a wide range of impact conditions. This work could pave the way for the development of a universal model for controlling droplet impact, enabling the optimization of a wide variety of industrial applications.

Does micro-sized pyrogenic carbon made in lab affect earthworm mortality in restrained water content?

Micro-sized pyrogenic carbon (PyC) is expected to interact more efficiently with soil biota such as earthworms than coarse pyrogenic carbon. Little is known about whether the micro-sized PyC poses a threat to earthworms. We investigated the effects of hydrophilic micro-sized PyC on earthworm mortality in two contrasting soil substrates from young and old reclaimed soils of a successional chronosequence. These two soil substrates had different hydraulic properties, total organic carbon, pH, and nutrient status. Lower earthworm survival rates were observed in both soil substrates receiving dry micro-sized soil particles and the micro-sized PyC. Specifically, the addition of micro-sized PyC resulted in the lowest survival rate compared to the addition of micro-sized soil particles and the control from day 8 to 11. The decreased earthworm survival rate due to micro-sized PyC was more pronounced in the old soil substrate than in the young substrate. Fully moistened soil substrates containing micro-sized PyC or dry micro-sized soil substrate particles did not result in decreased earthworm survival. Micro-sized PyC turned from hydrophilic to hydrophobic when mixed with rhamnolipids, possibly hindering the uptake of dissolved oxygen by earthworm skins. Our results thus provide a new explanation for the negative effects of micro-sized PyC on earthworms and demonstrate the importance of assessing the hydraulic properties of both the micro-sized PyC and soil prior to PyC's application to soils.

Solid-state co-culture fermentation of simulated food waste with filamentous fungi for production of bio-pigments

The use of waste stream residues as feedstock for material production simultaneously helps reduce dependence on fossil-based resources and to shift toward a circular economy. This study explores the conversion of food waste into valuable chemicals, namely, bio-pigments. Here, a simulated food waste feedstock was converted into pigments via solid-state fermentation with the filamentous fungus Talaromyces albobiverticillius (NRRL 2120). Pigments including monascorubrin, rubropunctatin, and 7-(2-hydroxyethyl)-monascorubramine were identified as products of the fermentation via ultra-performance liquid chromatography coupled with quadrupole-time-of-flight electrospray ionization mass spectrometry. Pigments were obtained at concentrations of 32.5, 20.9, and 22.4 AU/gram dry substrate for pigments absorbing at 400, 475, and 500nm, respectively. Pigment production was further enhanced by co-culturing T. albobiverticillius with Trichoderma reesei (NRRL 3652), and ultimately yielded 63.8, 35.6, and 43.6 AU/gds at the same respective wavelengths. This represents the highest reported production of pigments via solid-state fermentation of a non-supplemented waste stream feedstock. KEY POINTS: • Simulated food waste underwent solid-state fermentation via filamentous fungi. • Bio-pigments were obtained from fermentation of the simulated food waste. • Co-culturing multiple fungal species substantially improved pigment production.

Unveiling the dynamics of ultra high velocity droplet impact on solid surfaces.

The impact of a liquid droplet onto a solid surface is a phenomenon present in a wide range of natural processes and technological applications. In this study, we focus on impact conditions characterised by ultra high velocities (up to 500 m/s), to investigate—for the first time—how the impact dynamics change when the compressibility of the liquid in the droplet is no longer negligible. A water droplet impacting a dry substrate at four different velocities, from 50 to 500 m/s, is simulated. Such conditions are particularly relevant to aviation as well as industrial gas turbine engine risk management. Thus, numerical investigations as the one we present here provide a powerful tool to analyse the process. We find that increasing the impact velocity changes the flow field within and outside the droplet the moment that the compressibility can no longer be neglected, with the rise of pressure fronts in both regions. Increasing the impact velocity, the compressibility affects also the lamella formed and changes its ejection velocity observed over time (and thus the wetting behaviour) when the region shift from incompressible to compressible. Moreover, it is found that the maximum pressure observed at the wall during the impact is located at the corner of the impact, where the lamella is ejected, not in the centre, and it is influenced by the initial velocity. To predict the maximum pressure experienced by the surface during the high velocity impact, we propose a correlation based on the initial Weber and Reynolds number of the droplet. The complexity and the scales of the dynamics involved in the ultra-high velocity impact is limiting the experimental and analytical studies. To the best of our knowledge there are no experimental data currently available at such conditions. In this study, through numerical simulations, new insights about the impact dynamics at such conditions are provided.

Valorization of corn cobs for xylanase production by Aspergillus flavus AW1 and its application in the production of antioxidant oligosaccharides and removal of food stain

Xylanases are hemicellulolytic enzymes specifically catalyze xylan hydrolysis that constitutes the most abundant polysaccharide in the hemicellulose fraction of the lignocellulosic biomasses. The effective conversion of these biomasses to valuable commodities required the use of economic effective biocatalysts . In this study, xylanase production was performed by corn cobs fermentation using Aspergillus flavus AW1 in which the highest productivity was 356.36 U/g dry substrate. The partially purified enzyme was aflatoxin-free as estimated by high performed liquid chromatography . The enzyme was optimally active over a wide pH range from 5.5 to 7.5. Additionally, it was optimally active at temperature of 55 °C and at 60 °C it possessed 95% of its maximum activity. The enzyme half-lives were estimated as 83.81 and 44.69 min at 55 and 60 ° C, respectively. The V max and K m for the purified enzyme fraction were 250 U/mg protein/min and 5.55 mg/mL, respectively. Moreover, beech wood xylan hydrolysis as well as the hydrolysis of the hemicellulosic fraction of corn cobs was examined by applying the produced enzyme. The obtained results indicated hydrolysis percentage values of 39 and 19% for beech wood xylan and the hemicellulosic fraction of corn cobs, respectively with the release of a mixture of xylooligosaccharides confirmed by thin layer and high performed liquid chromatography analysis. The antioxidant activities for the dried oligosaccharide mixtures were estimated by scavenging activity of 1,1-diphenyl-2-picrylhydrazyl free radical. Finally, the efficiency of the purified enzyme fraction in the removal of mango stain was investigated in comparison to the commercial detergent. • Xylanase was produced by solid state fermentation of corn cobs using Aspergillus flavus AW1. • The partially purified enzyme was thermo-active and possessed high affinity toward beech wood xylan. • The enzyme was applied for the removal of food stain and production of xylooligosaccharides. • The produced xylooligosaccharides possessed antioxidant activity.

The long-term engineering properties and sustainability indices of dewatering hydrated lime mortars through Jacaranda seed pods

The progressive increase in the industrialisation, consequently the energy consumption and carbon footprint reacquaint the sustainable and environmental credentials of hydrated lime mortars and re-congregate the implications of such binders in masonry construction. The low water retaining characteristics of hydrated lime mortars that often results in insufficient bond development with the subsequent substrate, were manipulated through the incorporation of powdered Jacaranda seed pods and silica fume to establish mortar-masonry optimisation in practice. Although there are numerous studies addressing the agricultural waste incorporation in cement-based materials, the incorporation of Jacaranda seed pods on construction materials have not been reported in the literature. Characterisation study comprising the elemental composition and physical properties of Jacaranda seed pods were essential in assessing the compatibility of pods utilisation in hydrated lime mortars. The paper reports authentic experimental research results on the utilisation of Jacaranda seed pods as a binder substitute in hydrated lime mortars concerning the effect of dewatering on the long-term engineering properties and sustainability indices. The utilisation of powdered Jacaranda seed pods and silica fume demonstrated the eligibility of manipulating the strong water retaining characteristics of hydrated lime mortars to attain improved mortar-substrate optimisation in masonry construction. It is essentially shown in the paper that the degree of dewatering, governed by the incorporation of powdered Jacaranda seed pods and silica fume herein, could not be underestimated as this phenomenon yields approximately 18% increase in the compressive strength of hydrated lime mortars comprising both at short- and long-terms. Although the incorporation of both the powdered Jacaranda seed pods and silica fume decreased the water penetration depth and porosity of mortars by ~11% and 17% respectively, dewatering, an inevitable incident that occurs as soon as the freshly mixed mortars are placed on dry absorbent substrates, further yields a greater decrease in these physical measurements at 1 year. Incorporation of powdered Jacaranda seed pods and silica fume generated a crucial improvement on cost efficiency and eco-strength efficiency of mortars both at 91 days and 1 year. The results have shown that more than 30% reduction on the carbon footprint could be established through this practice. It is essentially established in the paper that the degree of dewatering, experienced at freshly-mixed stage, determines the authentic performance of hydrated lime mortars in masonry construction and governs the veritable sustainability analysis to be performed. The results reported in this paper does not only encourage the re-introduction of the hydrated lime binder in construction practice but also assert a cleaner alternative waste management route for the agricultural wastes.

Effects of meteorological variables and substrate moisture on evapotranspiration and thermal performance of a green roof in a subtropical climate

This study analyzed the correlations between the meteorological/substrate-moisture variables and the evapotranspiration (ET) to improve the understanding of the factors influencing the thermal performance of green roofs, including cooling the surface and interior temperature of the building, in a subtropical climate. Daily ET of the green roof had been estimated using the FAO Penman-Monteith method to increase the number of ET data and the Nash-Sutcliffe coefficient is 0.51–0.62 compared to the observed daily ET from data of green roof experiments in Taipei during December 2012 and September 2013. Based on correlation analysis, this study then suggests that ET may have a higher influence on Tdiff, i.e. the difference in surface temperatures of green and original roofs, than the meteorological variables or substrate water content (SWC), although the radiative heating is sometimes more influential to Tdiff than the cooling caused by ET of the green roof in thin substrate condition. This study also found that under wet and dry substrates, daily ET is highly correlated with weather-related variables and with SWC, respectively. Furthermore, because of the low insulation of wet substrate, more downward fluxes are sometimes found under high than low SWC conditions. On the contrary, under the dry substrate, increasing SWC helps reduce the downward fluxes. This study, therefore, indicates that an optimal range of substrate moisture appears to maximize the function of a green roof in reducing the surface temperature and the downward substrate-bottom flux. Considering that a counterbalance exists between SWC and ET as well as irrigation can be applied to control SWC, future studies could be aimed at the optimal range of SWC to execute informed irrigation concerning the thermal performance, water-saving irrigation, and storm-water-retention function of the green roofs either in dry period or before storm events.

Teknologi Penyiapan Pakan Protein Moderate dan Strategi Penyiapannya untuk Meningkatkan Produktivitas Maggot

The aim of this research was to prepare moderate protein diet and evaluate its quality to increase maggot productivity. This research was conducted from the egg stage to the pre-pupae stage. One gram of larval eggs was used for each replication. The substrates used were fruit waste, household waste, and concentrate diet. This study used a completely randomized design with 2 treatments and 6 replications. Treatments were P0 (control feed of fruit waste and household waste) and P1 (moderate protein treatment feed). Control feed and moderate protein treatment were given as much as 13 kg during maintenance. The variables measured were dry matter consumption (grams), maggot weight (grams), pre-pupae percentage, substrate reduction (%), FCR, bioconversion (%), and WRI (Waste Reduction Index). Data were analyzed using paired sample T test. The results showed that BSF larvae receiving moderate protein treatment were significantly higher (p<0.05) compared to control feed for substrate consumption parameters, substrate reduction, and WRI. The conclusion from this research is the quality of feed with moderate protein content of 18,30 % which was prepared using a crude protein and energy balance approach was better than feed based on papaya fruit waste and household waste seen from the aspect of increasing substrat reduction, improving performance, prepupa metamorphosis, and increasing bioconversion of BSF larvae.
 Key words: bioconversion, larvae BSF, maggot, performance, waste

Wind impairs pit trap construction and hunting success in a pit‐building predator

AbstractAnimals require a set of abiotic conditions to survive and reproduce. When one of these requirements is not met, the animal's performance is impaired. The most often studied abiotic factor is temperature but less is known on other such factors. We examined, here, the effect of wind on the hunting performance of pit‐building predators, insect larvae that dig pit traps in loose soil to hunt arthropod prey. We used wormlions (Diptera: Vermileonidae) as a case study. Pit‐building predators depend on their immediate environment for efficient pit construction and maintenance. For example, they require dry suitable substrate (loose soil) comprised of particles of a specific size range. Because wind blows loose soil and impairs pit construction and maintenance, we expected strong negative effects of wind on pit design and hunting success. Wind destroyed both artificial pit traps and wormlion‐dug pits by moving sand into the pits and reducing their slopes—an important parameter of pits in terms of prey capture. Wormlions also attempted less frequently to attack the prey when the wind was blowing compared to the control and, among the wormlions responding, such response took place later, allowing the prey to escape. We expected wormlions to relocate away when exposed to the wind, but this did not hold true. This result is in line with the generally low relocation rate in wormlions. We suggest that wind has strong negative effects on the performance of pit builders in nature. Sites that provide at least partial protection from wind should be preferred for pit establishment.

Influence of bamboo grass (Tiliacora triandra, Diels) pellet supplementation on in vitro fermentation and methane mitigation.

The aim of this research was to investigate the influence of bamboo grass (Tiliacora triandra, Diels) pellet (BP) containing phytonutrients on rumen fermentation under various level of roughage (R) to concentrate (C) ratios. The experimental treatments were randomly assigned following a completely randomized design using a 3 × 5 factorial arrangement. The first factor was ratios of R:C at 100:0, 70:30, and 30:70 and the second factor was BP supplementation levels at 0, 1, 2, 3, and 4% of dry matter substrate, respectively. The ratio of R:C significantly enhanced rumen gas production especially when increased level of concentrate. Moreover, dry matter degradability of fermentation were improved (P < 0.01) by R:C and level of BP supplementation, and there was an interactive effect. The ammonia nitrogen (NH3 -N) concentration, protozoal population and methane (CH4 ) production were remarkably influenced (P < 0.01). There were highly significant interactive effects between ratio of R:C and level of BP supplementation. Furthermore, fermentation parameters especially those of propionate (C3 ) concentration was profoundly increased by higher ratio of R:C and by the BP supplementation, interactive effect (P < 0.01). Notably, both level of R:C and BP supplementation significantly reduced NH3 -N concentration and CH4 production. Interactive effects of both factors were obtained (P < 0.01). The ratio of R:C at 30:70 with BP supplementation at 4% could enhance fermentation characteristics and reduce CH4 production, while the interactive effects were additionally observed. The BP could be a good phytonutrient source to modulate rumen fermentation. © 2022 Society of Chemical Industry.

Investigation of the flight of liquid microdroplets over the contact line in a horizontal liquid film heated from below

When a liquid layer is heated from the substrate, a structured array of levitating microdroplets can be formed near to the surface of the liquid. When a dry spot is formed on the substrate through the liquid layer, the droplets can move under the action of gravity towards the dry spot so that propagation of microdroplets from a wetted to a dry substrate area is accompanied by a substantial change in the droplet levitation height above the contact line. It was found that with an increase in the diameter of a microdroplet, the maximum height of the trajectory, and the flight distance of the drop, decrease.