Dry Fiber Research Articles

Research on the Preparation of Dry Mixed Mortar Using Waste Incineration Fly Ash

This study investigated the effect of water-washed municipal solid waste incineration fly ash (MSWI FA) as an admixture on the performance of dry mixed mortar and used X-ray diffraction (XRD) and scanning electron microscope (SEM) detection methods to conduct microscopic analysis. The experiment investigated the effects of the amount and water content of washed municipal solid waste incineration fly ash, cement, additives, sand and gravel, and curing time on the compressive flexural strength of dry mixed mortar at 28 days. The results show that when the content of water-washed MSWI FA is 9.80%, the content of sand and gravel is 73.50%, the content of ordinary Portland cement (PO42.5) is 16.66%, the content of water-reducing agent is 1.47‰, the content of cellulose is 0.03‰, the content of the expansion agent is 0.49‰, the addition of water is 130–160 mL/kg, the consistency of the sample can reach 91.8 mm, and the water retention rate can reach 93.6%. The flexural strength of the sample at 28 days can reach 7.5 MPa, and the compressive strength at 28 days can reach 28.30 MPa. Metal ions, such as Pb2+ and Gd2+ in MSWI FA, under the combined action of silicate cement in dry mixed mortar and fibers in cellulose, crisscross and form a solidified material, which will not be leached out. This quality meets the requirements of dry mixed mortar for ordinary plastering and masonry mortar (GB-T 25181-2019), and the leaching toxicity of the sample meets the “Identification Standard for Hazardous Waste” (GB5085.3-2007). This work provides a meaningful exploration of the resource utilization of water-washed MSWI FA.

Impact of varying levels of soy hulls and β-mannanase enzyme supplementation on growth performance, carcass characteristics, nutrient utilization and blood biochemical profile in broiler chickens

Two hundred and forty day-old broilers were randomly assigned to six experimental groups in a 2 x 3 factorial design. The birds were fed diets containing soybean hulls (SH) at the levels of 4% and 6% and β-Mannanase (BM) at the concentration of 0%, 0.05% and 0.1%. Results indicated significant effects of SH and BM supplementation on body weight (BW) and weight gain (WG), with birds fed 4% SH and 0.1% BM exhibiting higher (p < 0.05) body weight and weight gain compared to other groups. Feed conversion ratio (FCR) was improved (p < 0.05) in birds receiving 4% SH with 0.1% BM supplementation. However, no significant effects were observed on carcase traits across treatment groups. Regarding nutrient digestibility, birds supplemented with 0.1% BM showed improved (p < 0.05) crude protein (CP) digestibility compared to those without BM supplementation. No significant variations were observed in dry matter, crude fibre and ether extract utilisation among treatment groups. Hematological and serum biochemical parameters were not influenced by SH and BM supplementation, indicating no adverse effects on blood parameters. In conclusion, these findings underscore the potential advantages of incorporating 4% SH and 0.1% BM in broiler diets for enhanced growth performance and nutrient utilisation.

Genetic variability, character association and path analyses effects on fiber yield and yield attributing morpho-agronomic traits of tossa jute (Corchorus olitorius L.)

Jute (Corchorus spp.) is a natural fiber crop having a lower extent of genetic variability due to its self-pollinating nature. The success of any breeding program for variety development primarily depends on the presence of genetic variation in the parental genotypes. A field experiment was conducted in a randomized complete block design at ManikganjStation of Bangladesh Jute Research Institute (BJRI) during 2019-2020. The genetic divergence of 58 tossa jute (C. olitorius) genotypes including two pre-released standard varieties (O-9897, BJRI Tossa pat 4) and 56 accessions were studied to select genotypes having the most divergence in natural rainy condition. The jute genotypes were categorized into five clusters based on Mahalanobis D2 analysis. Cluster I and IV showed maximum inter-cluster distance (181.44) while the maximum intra-cluster distance (16.15) was recorded in cluster I. Cluster V revealed the highest values for number of nodes, stem mid-diameter, core diameter, green weight with leaves, dry stick weight and dry fiber weight per plant while cluster IV showed higher means for plant height, green bark thickness and leaf area. The highest contribution (47.14%) was wielded by plant height of total deviations. The results recommended that hybridization between genotypes of cluster V, IV and III could provide a wide range of discrepancies in the segregating generation which could offer chance for isolation of good genotypes with high fibre yielding lines.

Effect of Using Prickly Pear Seed Cake (Opuntia ficus indica L.) on Growth Performance, Digestibility, Physiological and Histometric Parameters in Rabbits

Prickly pear (Opuntia ficus indica L.) could be used in rabbit nutrition in compliance with circular economy principles, global warming issues, and reduction of production costs. This study aims to evaluate the effects of dietary incorporation of prickly pear seed cake (PPSC) on growth, physiological, and histometric parameters in rabbits. A total of 105 rabbits were divided into three experimental groups (n = 35) and fed different diets: a commercial feed (C group), the same feed with alfalfa replaced by PPSC at 10% (10PP group), and at 20% (20PP group). They were group-housed in cages with 5 animals per cage from weaning until slaughtering. While body weights and weight gains were similar in all groups, the coefficients of nutrient digestibility of dry matter, fibers, and ashes, as well as the characteristics of intestinal villi, were improved in the 10PP group compared to the others (p &lt; 0.05). The 20PP group showed a reduction in perirenal and interscapular fat (p &lt; 0.05), as well as lower plasma concentrations of triglycerides and cholesterol compared to the C group (p &lt; 0.001). In conclusion, PPSC can be incorporated into the diets of growing rabbits up to 20% as a partial substitute for alfalfa without the impairment of growth performance. Additionally, the inclusion of PPSC enhanced nutrient digestibility and increased the intestinal absorption surface area.

Effects of Alanyl-Glutamine Dipeptide Supplementation on Growth Performance, Nutrient Digestibility, Digestive Enzyme Activity, Immunity, and Antioxidant Status in Growing Laying Hens.

Alanyl-glutamine (Aln-Gln), a highly soluble and stable Glutamine-dipeptide, is known to improve the performance of poultry birds. This study aimed to investigate the effect of Aln-Gln during the rearing period on growth performance, nutrient digestibility, digestive enzyme activity, immunity, antioxidant status and relative gene expression of Hy-Line brown hens. A total of 480 healthy day-old Hy-line brown chicks with similar body weights were randomly divided into four dietary groups (8 replicates/group and 15 birds/replicate). Groups A, B, C and D were fed diets containing 0%, 0.1%, 0.2% and 0.3% Aln-Gln, respectively, for 6 weeks. The body weight (BW) and average daily gain (ADG) were higher in hens fed test diets compared with the control (p < 0.05). The feed conversion ratio (FCR) was better in test groups as compared to the control group (p < 0.05). The ADFI showed no significant difference between the groups. Dietary treatments had no effect on dry matter (DM), organic matter (OM) and crude fiber (CF) digestibility. The Aln-Gln also improved gross energy (GE) and crude protein (CP) digestibility (p < 0.05). It has also increased IgG levels in groups C and D. IgM levels were similar to the control in B, C and D. The Aln-Gln increased IL-1 in B and C, IL-2 in C and D, and IL-6 in all test groups (p < 0.05). The supplementation of Aln-Gln had no effect on serum antioxidant indices like CAT, MDA, GSH-PX, GSH, and SOD in 42-day-old growing hens. Aln-Gln supplementation had no significant effect (p > 0.05) on the activity of amylase and lipase, however, a significant improvement (p < 0.05) in the activities of trypsin and chymotrypsin was observed in the test groups. Supplemented Aln-Gln levels in the birds' diets led to an increase in the expression of genes related to growth factors (IGF-1, IGFBP-5), immune markers (IL-1, IL-2, IL-6) and antioxidant status (GSH-Px1), as compared to control group. Aln-Gln supplementation in Hy-Line brown hens during their growing period improved growth, nutrient digestibility, immunity and digestive enzymes activity. These findings suggest that Aln-Gln is a promising dietary additive for enhancing poultry performance.

Milk Production, Milk Composition, Milk Fatty Acid Profile and Nutrient Digestibility of Mehsana Goats Fed Sunflower (Helianthus annus) Oil

A study was conducted during the month of December, 2020 to January, 2021 at Livestock Research Station, Kamdhenu University, Sardarkrushinagar, Gujarat (385506), India to evaluate the effect of dietary sunflower oil supplementation on milk yield, milk fatty acid profile and nutrient digestibility of Mehsana goats. Eighteen lactating Mehsana goats were randomly divided into three treatment groups, viz. Basal diet (control), Basal diet+25 g animal-1 day-1 of sunflower oil and Basal diet+50 g animal-1 day-1 of sunflower oil for a period of 60 days. No significant differences (p&gt;0.05) were found in milk yield in terms of kg d-1, 4% fat corrected milk and energy corrected milk among the treatment groups. The milk constituents and their yields were not affected due to dietary inclusion of sunflower oil. Sunflower oil feeding at the dose of 50 g d-1 increased (p&lt;0.05) concentration of milk short chain fatty acids and polyunsaturated fatty acids in the milk of goats. The intake and digestibility of nitrogen free extract was increased in sunflower oil supplemented groups. The intake and digestibility of dry matter, organic matter, crude protein, ether extract and crude fibre were similar (p&gt;0.05) among the treatment groups. it may be concluded that supplementation of sunflower oil at the dose rate of 25 and 50 g d-1 did not affect feed intake, milk yield, milk constituents and nutrient digestibility in lactating Mehsana goats. However, dietary 50 g d-1 of sunflower oil significantly increased concentration of milk short chain fatty acids and polyunsaturated fatty acids in goats.

Chemical Composition and In Vitro Protein Digestibility of Duckweed and Feed Ingredients

Duckweed is an aquatic floating plant with the potential to be used as animal feed due to its richness in protein, amino acids, starch, vitamin and minerals. Furthermore, duckweed has a high growth rate and reproducibility. Therefore, this research aimed to determine the chemical composition and in vitro protein digestibility of duckweed (Lemna, Wolffia and Spirodela) in comparison to other feed ingredients. The chemical composition was determined through proximate analysis including dry matter (DM), crude protein (CP), ether extract (EE), crude fiber (CF), ash and nitrogen free extract. The in vitro protein digestibility procedure simulates conditions similar to those in the swine digestive tract using synthetic enzymes to control pH, temperature and digestion time. In the results of chemical composition, Lemna and Wolffia were classified as protein sources, with high CP content (221.87 and 442.65 g/kg DM, respectively) and low CF content (63.30 and 109.11 g/kg DM), whereas Spirodela had low CP content (179.64 g/kg DM) and CF content (170.57 g/kg DM). The EE content in duckweed amounted to 16.74, 46.23 and 52.47 g/kg DM for Wolffia, Spirodela and Lemna, respectively. Additionally, high ash content was observed in Spirodela (212.40 g/kg DM), Wolffia (149.34 g/kg DM) and Lemna (142.06). For standardized ileal digestibility (SIDCP), the SIDCP of all feed ingredients were within the range of 32 to 96 %. With regard to duckweed, Lemna (72 %) showed significantly higher (p &lt; 0.05) SIDCP compared to Wolffia (69 %) and Spirodela (39 %) due to the low contents of CF and ash. Based on nutritional values, Lemna and Wolffia were grouped with corn DDGS and brewer’s grain, indicating their potential as animal feed for sustainable livestock production. HIGHLIGHTS Duckweed exhibited high protein content, ranging from 179.64 to 65 g/kg dry matter. For in vitro protein digestibility, Lemna and Wolffia had high true digestibility, amounting to 79 and 75 %, respectively. Based on nutritional values, Lemna and Wolffia were grouped with corn DDGS and brewer’s grain, indicating their potential as animal feed for sustainable livestock production. GRAPHICAL ABSTRACT

Vacuum Chamber Infusion for Fiber-Reinforced Composites

A new approach to an automatable fiber impregnation and consolidation process for the manufacturing of fiber-reinforced composite parts is presented in this article. Therefore, a vacuum chamber sealing machine classically used in food packaging is modified for this approach—Vacuum Chamber Infusion (VCI). Dry fiber placement (DFP) preforms, made from 30 k carbon fiber tape, with different layer amounts and fiber orientations, are infused with the VCI and with the state-of-the-art process—Vacuum Assisted Process (VAP)—as the reference. VCI uses a closed system that is evacuated once, while VAP uses a permanently evacuated open system. Since process management greatly influences material properties, the mechanical properties, void content, and fiber volume fraction (FVF) are analyzed. In addition, the study aims to identify how the complexity of a resin infusion process can be reduced, the automation potential can be increased, and the number of consumables can be reduced. Comparable material characteristics and a reduction in consumables, setup complexity, and manufacturing time by a factor of four could be approved for VCI. A void content of less than 2% is measured for both processes and an FVF of 39% for VCI and 45% for VAP is achieved.

Joule heating of carbon fibre tapes – A low-cost approach for automated dry fibre deposition

Joule heating is potentially a low-cost option for activating the binder on the surface of carbon fibre tapes during automated dry fibre placement (ADFP). In this paper, the electrical contact resistance between a carbon fibre tape and cylindrical electrodes is characterised experimentally using a tabletop rig to replicate the process conditions encountered during ADFP. This rig is used to study a range of wrap angles, fibre tensions and temperatures to inform the design of a Joule heating setup for a lab-scale ADFP fibre deposition rig. A validated model has been developed to predict the tape temperature at the nip point for different current inputs and deposition velocities. Increasing both fibre tension and wrap angle are found to reduce contact resistance and increase heating efficiency. A nip point temperature of 200 °C can be achieved by Joule heating for a single carbon fibre tape at a deposition velocity of 100 mm/s, using a power of 110 W. This equates to a 17 % reduction in energy compared to laser heating.

A short review on recent advances in automated fiber placement and filament winding technologies

Recent advances in Automated Fiber Placement (AFP) and Filament Winding (FM) are driving steady improvements in technological understanding, enabling the production of more precise, cost- and material-efficient layups that pave the way for new applications. Evolving from automated Tape Laying Technology (ATL), AFP is a technology that not only mimics the manual laying process but also allows tailored fiber and tow alignment to deliver load-optimized patterns, stacking sequences and part structures leading to improved mechanical performance and significant waste reduction. The filament winding evolution towards automated Robotic Filament Winding put the technology in a position to manufacture highly complex lightweight structures in architecture. In this short review, recent developments in both automated fiber alignment technologies are presented and discussed, including the main advantages and materials used. Regarding the ATL and AFP process, developments in non-aerospace applications are considered. Besides a short overview of new placement technologies, advances in Tailored Fiber Placement (TFP) in the field of dry fiber placement are reported. Finally, new robotic filament winding applications in free-form and Coreless Filament Winding (CFW) in architecture are presented.

Growth Performance and Nutrient Utilization of Balami and Yankasa Rams Fed Leucaena leucocephala and Dried Poultry Manure Based Concentrates Diets

In this work, two feed concentrates—dried poultry manure concentrate (DPMC) and Leucaena leucocephala-based concentrate (LLBC)—fed to rams of two breeds (Yankasa and Balami) were assessed for their proximate composition, digestibility, and nitrogen utilization. In comparison to LLBC, which has more crude protein (15.26%), lower fiber (12.33%), and somewhat higher ether extract (3.21%), DPMC has higher dry matter (90.54%) and fiber (20.55%) but lower crude protein (13.58%) and ether extract (3.84%). Additionally, LLBC exhibits a greater nitrogen-free extract (46.23%) and ash content (8.45%) in comparison to DPMC, which results in a slightly higher total energy content (18.96 MJ/kg against 17.76 MJ/kg). Breed, feed, or breed × feed interaction impacts on performance indicators are not significant (P&gt;0.05). Breed effects (P&lt;0.05) were noted on digestibility, with Balami rams outperforming Yankasa rams in the digestibility of dry matter, crude protein, and nitrogen-free extract. LLBC increased(P&lt;0.05) the digestibility of nitrogen-free extract and dry matter compared to DPMC. The findings indicate that as compared to Yankasa rams fed LLBC, Balami rams fed DPMC showed greater (P&lt;0.05) digestibility of dry matter, crude protein, and nitrogen-free extract. The effects of breed, feed, and breed × feed interaction on nitrogen utilization were significant (P&lt;0.05). Breed has a significant (p&lt;0.05) impact on nitrogen intake, digestion, and retention; Yankasa has greater values than Balami. In comparison to DPMC, LLBC resulted in increased nitrogen intake and retention. Interestingly, the interaction effect reveals that whilst Balami rams retained more nitrogen with DPMC, Yankasa rams retained more nitrogen with LLBC. With implications for optimizing feed strategies based on breed-specific requirements, this study highlights the impact of both feed type and breed on nutritional efficiency.

Effects of Partial Replacement of Corn Grains With Mango Seed Kernel on Nutrient Digestibility, Blood Metabolites and Rumen Parameters of Growing Calves.

Fruit by-products are a sustainable and cost-effective alternative to traditional grain feed for livestock. One of the most important by-products is mango seed kernel (MSK), which can be used as a valuable energy source for feeding growing calves in the tropical and subtropical productive regions of the world. This study investigated the effect of replacing corn grains (CGs) with MSK on intake, nutrient digestibility, blood metabolites and rumen parameters. Eighteen growing male Friesian calves (200 ± 6.55 kg of body weight and 9-11 months old) were randomly assigned to three treatment groups. Three concentrate feed mixtures were formulated such that MSK replaced CG at 0%, 25% and 50%. Dry matter intake was unaffected, whereas dry matter, organic matter and fibre digestibility increased linearly (p < 0.05) with increased inclusion of MSK. Ruminal pH (p = 0.053) and total volatile fatty acid (VFA) concentration (p = 0.041) increased linearly. There was a linear decrease in cholesterol (p = 0.029) and AST (p = 0.028) levels in the blood of calves. In conclusion, this study demonstrated the positive effect of replacing 50% of CG with MSK on rumen parameters, including a higher ruminal pH and total VFA concentration, alongside higher nutrient digestibility. The dietary inclusion of mango seed can serve as a valuable and sustainable dietary component for growing calves.

Capillary-driven migration of droplets on conical fibers

A droplet placed on a hydrophilic conical fiber tends to move toward the end of larger radii due to capillary action. Experimental investigations are performed to explore the dynamics of droplets with varying viscosities and volumes on different fibers at the microscale. Droplets are found to accelerate initially and subsequently decelerate during migration. A dynamic model is developed to capture the dynamics of droplet migration, addressing the limitations of previous equilibrium-based scaling laws. Both experimental results and theoretical predictions indicate that droplets on more divergent fibers experience a longer acceleration phase. Additionally, gravitational effects are pronounced on fibers with small cone angles, exerting a substantial influence on droplet migration even below the capillary scale. Moreover, droplets move more slowly on dry fibers compared to those prewetted with the same liquid, primarily attributed to increased friction. The experiments reveal the formation of a residual liquid film after droplet migration on dry fibers, leading to considerable volume loss in the droplets. To encompass the intricacies of migration on dry fibers, the model is refined to incorporate a higher friction coefficient and variable droplet volumes, providing a more comprehensive depiction of the underlying physics.

The Effect of Adhatoda Vasica as A Herbal Supplement on The Performance, Nutrient Digestibility, and Blood Profile of Weaned Pigs

A 60-day trial was carried out to determine the impact of Adhatoda vasica as an herbal supplement on the performance, nutrient digestibility and blood profile of weaned pigs. 40 crossbred male pigs (Yorkshire × Landrace) with initial body weight of 10.21 ± 0.03 kg was distributed into 4 treatment consisting of 10 pigs each. On arrival, animals were quarantined for two weeks and fed basal diet which is adequate in all nutrients according to NRC (2012). Pigs in treatment 1 was fed basal diet without Adhatoda vasica leaf powder while those in treatment 2, 3 and 4 were fed same diet supplemented with Adhatoda vasica leaf powder at 200 g, 400 g and 600 g/kg respectively. A completely randomized design technique was adopted and the animals had unrestricted access to clean fresh water and feed. Quantification of phyto-constituents in Adhatoda vasica leaf powder showed that it contained higher concentration of flavonoids (102.1 mg/g) while steroids had the lowest concentration of 30.41 mg/g. Average daily weight gain was higher among pigs fed treatment 3 and 4, intermediate in treatment 2 and lowest in treatment 1. Average daily feed intake, feed conversion ratio and mortality were significantly (P&lt;0.05) influenced by the treatment. Dry matter, ether extract, crude protein and crude fibre digestibility were influenced (P&lt;0.05) by the treatment. Red blood cell, pack cell volume, mean platelet volume, mean corpuscular volume, mean corpuscular haemoglobin, white blood cell, total protein was significantly (P&lt;0.05) different among the treatment except for aspartate amino transferase, alanine amino transferase and alkaline phosphatase (P&gt;0.05). However, all values were within the established range for healthy pigs. In conclusion, Adhatoda vasica leaf powder can be supplemented in the diet of pigs without compromising their growth and health status.

Applying optical coherence tomography to inline quality monitoring of unidirectional glass-fiber-reinforced thermoplastic tapes

Originally developed for biomedical applications and diagnosis, optical coherence tomography (OCT) has recently been demonstrated to be a powerful non-destructive and non-invasive measurement method for detecting defects in glass-fiber reinforced polymer composites. While previous studies have focused mainly on the use of OCT in the analysis of thermoset composites, we were able to show in offline experiments that OCT can be used to quickly detect typical defects (e.g., dry fiber regions, gaps and fiber breakage) in thermoplastic unidirectional (UD) tapes at high resolution. To investigate the applicability of OCT to inline monitoring, we advanced our previously published approach in two major steps: First, we incorporated the OCT system into an industrial-scale UD-tape production line, and derived optimal settings for inline detection of dry region defects from a comprehensive design of experiments (DoE) to find an optimal balance between accuracy and data size for a stationary tape sample by varying A-scan sampling rate, A-scan averaging and OCT transverse travel velocity. Second, using these optimal settings, we went on to investigate moving tapes over a range of industrially relevant take-off speeds. Microscopy was used for validation in both cases. We developed a fast and robust statistical analysis of B-scans that visualizes the quality of full cross-sections in an interpretable manner for potential use in a real-time setting. Within an industrially relevant production speed range of up to 15 m/min, we are thus now able to investigate 120 mm wide (and potentially wider) UD tapes inline at a transverse resolution of 22 µm, producing only 21 MB of data per measurement.

Dynamic Changes in the Nutrient Digestibility, Rumen Fermentation, Serum Parameters of Perinatal Ewes and Their Relationship with Rumen Microbiota.

Changes in physiological and biochemical parameters are crucial for the reproductive performance and health of perinatal ewes. This study investigated the temporal variations in feed intake, nutrient digestibility, serum parameters, and ruminal fermentation on days 21, 14, and 7 before lambing (Q21, Q14, and Q7) and days 3, 7, and 14 after lambing (H3, H7, and H14). The results showed that dry matter intake (DMI) and glucose (Glu) gradually decreased (p < 0.05) before lambing and increased (p < 0.05) after lambing. The digestibility of dry matter (DMD), crude protein (CPD), and acid detergent fiber (ADFD) increased (p < 0.05) before lambing, then decreased (p < 0.05) on day H3, and then increased (p < 0.05) on day H14. The rumen pH, NH3-N, and triglycerides (TG) gradually increased (p < 0.05) before lambing and were higher (p < 0.05) on day Q7 than after lambing. The concentrations of acetate, butyrate, and total volatile fatty acids (T-VFA) were lower (p < 0.05) on day Q7 than those on days Q21 and Q14, then increased (p < 0.05) after lambing. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) concentrations gradually decreased (p < 0.05) in perinatal ewes. BHBA and NEFA concentrations were lower (p < 0.05) on day Q21 than those from days Q14 to H14. The rumen microbiota compositions were different (p < 0.05) in perinatal ewes, and g_Anaerovibrio, g_Lachnobacterium, and g_Schwartzia were positively correlated (p < 0.05) with DMI, Glu, acetate, propionate, and T-VFA, and negatively correlated (p < 0.05) with LDL-C. g_Bacillus was negatively correlated (p < 0.05) with DMI, Glu, acetate, propionate, butyrate, and T-VFA, but positively correlated (p < 0.05) with rumen pH and LDL-C. In summary, the DMI, nutrient digestibility, rumen fermentation, and serum parameters changed during the perinatal period of ewes, and the changes in DMI, serum glucose, acetate, propionate, and T-VFA were related to the rumen bacteria.

Variable range hopping conductivity of hydrothermally reduced graphene oxide fibers

We report applying the autoclaved hydrothermal method for obtaining conductive reduced graphene oxide (rGO) fibers for potential flexible electronic applications, such as supercapacitors, transistors, or sensing applications. The reduction of GO was performed in the temperature range 120 to 180 °C under increased pressure of ca. 8 bar in a sealed Teflon lined up, stainless steel autoclave. The fiber’s diameter and length were defined by the glass tube used as the mold for reducing GO water suspension (diameter of 600 µm and length of 8 cm). After drying, in an ambient atmosphere, the hydrogel fiber shrinks to ca. 50 µm in diameter and 6 cm in length (collapsed pore structure). The drying process, in addition to enhancing electrical conductivity, also increases the mechanical strength of the fibers due to the stronger overlapping of the graphene flakes. The best performance was observed in the fiber reduced at the highest temperature studied, 180 °C, and a minimum temperature of 120 °C is necessary to obtain a fiber. Electrical conductivity was measured using the 4-probe method. The results were analyzed within the framework of variable range hopping and Arrhenius models to pinpoint the best model describing electrical conductivity in dry rGO fibers.

Study of the use of fermented Moringa leaves with probiotics to increase feed digestibility and reduce pathogenic bacteria in ducklings

Fermentation is an easy way to increase the nutritional value of feed and the results are palatable and act as probiotics.Fermentation products by probiotics and savonin compounds in herbal leaves can suppress pathogenic bacteria. This study aims to test the effect of giving fermented Moringa oleifera leaf flour (FML) by probiotics on the digestibility of nutrients and pathogenic bacteria in the digetive truct of duckling. Two hundred eighty eight healthy two-week-old male Bali ducklings with homogeneous average body weight were divided into four treatment groups, six replications and each replication used 72 ducklings. The four treatments, namely a group of ducks that were given rations without the addition of FML as control (A); ration with 2% FML (B); ration with 4% FML (C); and a ration with 6% FML (D), repectively. The results showed that the digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and crude fiber (CF) in duck groups B, C and D was higher (P&lt;0.05) compared to Group A (control ). On the other hand, the number of Coliform and Eschericia coli bacteria in duck groups B, C, and D, was significantly (P&lt;0.05) lower than duck group A. It was concluded that the administration of 2-6% fermented Moringa oleifera leaf flour in feed can increase the digestibility of nutrients and can suppress the population of pathogenic bacteria in the duckling's digestive tract.

Dimerization and liquid-liquid phase separation of the nonrepetitive domains of pyriform spidroin 1 controls the pyriform silk formation

Spiders spin high performance silks with diverse mechanical properties for specific biological functions. Of these spider silk types, pyriform silk stands out as a unique combination of wet glue and dry fibers. Investigation of self-assembly process of spider silk proteins is necessary for elucidating the silk formation mechanism. However, the functions of nonrepetitive domains in the silk formation of pyriform spidroins from liquid proteins to solid fibers are still unclear, making it difficult to achieve efficient biomimetic preparations of pyriform silk with good mechanical properties. In this study, we investigate the roles of the N-linker repeat (NLR) and both terminal domains of pyriform spidroin 1 (PySp1) in the silk formation. We demonstrate for the first time that the PySp1 NLR alone is sufficient to self-assemble into high strength fibers. Moreover, we showed that the ability to promote the pyriform silk formation by the addition of the NLR. We also found that the pH-sensitive dimerization property for N-terminal domain and the liquid-liquid phase separation (LLPS) coupled with acidification triggers the self-assembly mediated by the C-terminal domain. Overall, our results provide new insight into the role of nonrepetitive domains in the pyriform silk formation mechanism and the basis for producing new protein-based materials derived from spider pyriform silk.

ВЛИЯНИЕ ФУЛЬВОКИСЛОТЫ НА УСВОЕНИЕ ПИТАТЕЛЬНЫХ ВЕЩЕСТВ РАЦИОНА И ПРОДУКТИВНОСТЬ МОЛОДНЯКА КРС

The aim of research is to study the effect of fulvic acid on the absorption of nutrients in the diet and the productivity of young cattle. Feed additives based on humic substances (humic and fulvic acids) with high biological activity may be promising. The studies were conducted on the farm of the agricultural cooperative Imeni Ilyicha in the Novgorod Region on young Holstein cattle aged 6–7 months. Three groups of animals were formed (n = 10): a control group consuming the basic diet (BD), the first experimental group – BD + 5 ml of fulvic acid, the second experimental group – BD + 10 ml of fulvic acid. It was found that the introduction of 5 ml of fulvic acid into the diet of young cattle had a positive effect on the digestibility of all the nutrients studied. Thus, the dry matter, crude protein and crude fiber values in the first experimental group exceeded the similar values in the control group by 1.9 %, 5.4 and 5.8 %, respectively. The digestibility coefficients of crude fat, NFE and organic matter in the animals of the first experimental group also exceeded the control values by 3.9 %, 2.4 and 3.6 %. The increase in the mass fraction of fulvic acid did not lead to a further increase in the digestibility coefficient values, on the contrary, in relation to the first experimental group, they decreased in all indicators. The average daily gain in the control group was 570 g, in the first experimental group – 887, in the second experimental group – 854 g, this also showed that an increase in the dosage of the feed additive is inappropriate and leads to a decrease in the payment for the feed in weight gain.