Linear Decrease Research Articles

Particularities of optical behavior of Ag8SiS6 single crystal

Ag8SiS6 single crystal was grown by directional crystallization from melt. A crystal sample was investigated by optical ellipsometry and spectroscopy. This sample had nonlinear spectral dependences of the refractive index n and the extinction coefficient k. The presence of a sharp maximum in the spectral dependence of the refractive index and a rather sharp decrease in the values of the extinction coefficient k at the wavelength of 780 nm were found. The behavior of the optical absorption edge of the Ag8SiS6 single crystal in the temperature range of 77…300 K was studied. An exponential dependence of the absorption coefficient α obeying the Urbach rule was observed at all the investigated temperatures. The optical pseudo-gap Eg* and the Urbach energy EU were calculated from the obtained experimental data. An increase in temperature of the Ag8SiS6 crystal was found to lead to a monotonic, almost linear decrease in Eg* (1.853…1.615 eV) and a monotonic nonlinear increase in EU (44.32…55.01 meV). The contributions of the temperature-independent (EU)X,C and temperature-dependent (EU)T components to the total Urbach energy EU for Ag8SiS6 were evaluated within the Einstein model.

Yogurt acid whey powder dietary inclusion level modulates broiler cecal microbiota composition and metabolic activity

All over the world, the increasing demand for Greek yogurt generates vast quantities of acid whey as a by-product. The large volume and nutrient composition of yogurt acid whey makes it worthwhile to investigate potential uses in animal nutrition. This study aimed to investigate the inclusion of yogurt acid whey powder (YAWP) in four dietary levels on broiler performance, cecal microbiota composition and metabolic activity. A total of 300 male one-day-old male Ross broiler chickens were randomly assigned into 4 treatments of 5 replicates each. Broilers were fed maize-soybean meal basal diets following a 2-phase feeding program. Depending on the YAWP inclusion level (g kg-1 diet), treatments were no YAWP addition (W0), YAWP at 25 g kg-1 (W25), YAWP at 50 g kg-1 (W50) and YAWP at 100 g kg-1 (W100). Overall body weight gain, feed intake and feed conversion ratio were not affected by YAWP addition. In the ceca, a linear decrease in total bacteria counts and a linear increase in Lactobacillus spp. was noted with increasing YAWP dietary level. A linear reduction of Clostridium cluster I and E. coli species was noted with increasing YAWP dietary level. A linear increase in total volatile fatty acids concentration, acetic acid and butyric acid molar ratios was shown with increasing YAWP level. In conclusion, the addition of YAWP did not affect overall performance but positively modulated the cecal microbiota and metabolic activity of 42-day-old broiler chickens.

Understanding tropical cyclone persistence over land: A case study of Cyclone Gulab

Abstract Tropical Cyclone (TC) Gulab originated in the Bay of Bengal during the post-monsoon season of 2021. Following an unusual westward trajectory, TC Gulab made landfall on the east coast of India, traversed central India, and reintensified over the Arabian Sea into TC Shaheen. This study employed an online Eulerian water vapor tracer (WVT) tool embedded within the Weather Research and Forecasting (WRF) model to investigate the role of land in terms of soil moisture and Land Use Land Cover (LULC) in persistance of TC Gulab over central India. We quantified the contributions of sub-regions and dominant LULC types within the Indian subcontinent to the precipitation associated with TC Gulab. Our findings indicate that evapotranspiration across the entire Indian subcontinent contributed approximately 30% to the post-landfall precipitation associated with TC Gulab. The highest contribution originated from the northwestern region, followed by the northeast. Croplands, the dominant LULC type, were the primary contributors, followed by forests. Despite changing the dominant land cover from cropland to forest, the low-pressure system persisted over land while altering the spatial patterns of precipitation. Sensitivity experiments demonstrated a linear decrease in precipitation originating from land with decreasing soil moisture (SM). Notably, there is a disproportionate decline in total precipitation with decreasing SM. Further analysis separating atmospheric vapor sources into land and ocean contributions using WVT revealed a compensatory mechanism. The contribution of oceanic vapor to atmospheric vapor over land increased when SM decreased due to increase in the latent heat over ocean. However, the total atmospheric vapor remained low, ultimately leading to a lower total precipitation. Although SM plays a role, our results highlight the importance of oceanic and atmospheric processes in determining TC persistence over land. This study offers valuable insights into the dynamics of land-atmosphere interactions during low-pressure systems of TCs.

Enhancing PEMFC performance at high current density by incorporating PTFE emulsion into catalytic layer

Mass transfer is a critical bottleneck in the development of proton exchange membrane fuel cells (PEMFCs), especially at high current densities. This study aims to enhance the power density, stability, and durability of the PEMFC by modifying the catalyst layer (CL) with polytetrafluoroethylene (PTFE). The influence of varying PTFE contents in CL was assessed through polarization curves, mass transfer resistance (Rmt), and oxygen transfer resistance (OTR) tests. The optimal performance was achieved with MEA4 (with 40 % PTFE), demonstrating a power density of 847 mW/cm2 at 1700 mA/cm2, an 8 % increase compared to MEA0 (without PTFE) at 75 °C. The Rmt of MEA4 decreased to 0.1148 Ω cm2, a 55 % reduction from MEA0 (0.2522 Ω cm2). A stability test at 1600 mA/cm for 5 h showed MEA4 maintaining a stable voltage at 0.527 V, while the MEA0 exhibited a linear voltage decrease of 0.04 mV/min with significant fluctuations over time. Accelerated stress testing (AST) is conducted under the DOE standard by 2000 voltage cycles with a triangle sweep voltage from 1.0 V to 1.5 V, which revealed that the OTR of the MEA0 increased by 37 % from 0.7198 s/m to 0.9914 s/m, whereas the MEA4 was observed to be increased from 0.74707 s/m to 0.8253 s/m with a rise of 10.5 %. In conclusion, the incorporation of PTFE into the CL enhances oxygen transfer within the CL, thus improving the power density, stability, and durability of PEMFCs at high current density.

Enhancing Growth and Health in Weanling Pigs: The Impact of Monzogranite Supplementation.

Monzogranite is known for its high surface area and cation exchange capacity, which play a crucial role in ameliorating the challenges by enhancing nutrient adsorption and facilitating nutrient availability during the weaning period. Weaned crossbred piglets (Duroc × Yorkshire × Landrace), initially weighing 5.36 ± 0.26 kg, were allocated into four treatments with 6 replicates each (10 pigs per replicate). The treatments encompassed CON (basal diet), Z0.1 (0.1% monzogranite supplementation in basal diet), Z0.2 (0.2% monzogranite supplementation), and Z0.3 (0.3% monzogranite supplementation). In phase 1, a linear increase in total average daily gain (ADG) was observed across treatment groups, with a concomitant linear increase in ADG and gain-to-feed ratio (G/F). The overall results showed a linear increase in ADG and G/F. A linear decrease in aspartate aminotransferase and lactate dehydrogenase levels was observed across treatment groups. Conversely, no significant differences were noted in the levels of albumin, alkaline phosphatase, alanine aminotransferase, high-density lipoprotein, low-density lipoprotein, total cholesterol, blood urea nitrogen, triglycerides, and gamma-glutamyl transferase among the treatment groups. Faecal scoring indicated a linear reduction in scores at Day 7 among the treatment groups. However, no significant differences were observed at Days 14 and 28. The assessment of immunoglobulins demonstrated a significant increase in both immunoglobulin G and immunoglobulin A levels in the Z0.1 treatment group compared to the CON. In both phase 1 and phase 2, a linear decrease in cortisol levels was evident. In conclusion, a linear increase in total ADG and G/F during phase 1, sustained across both phases, suggests monzogranite potential to enhance growth performance. Moreover, stress mitigation was shown through a consistent linear decrease in cortisol levels across phases. These findings underscore monzogranite multifaceted impact, emphasizing its potential as a dietary supplement to enhance growth, liver health, and stress resilience in weanling pigs.

The influence of dietary supplementation with oyster mushroom waste on laying hens’ performance, egg quality and immune parameters

The objective of the present study was to evaluate the effects of dietary supplementation with oyster mushroom (Pleurotus ostreatus) waste (OMW) on performance, egg quality, fatty acid (FA) profile and oxidative stability, serum and yolk cholesterol and immune parameters of laying hens. Two hundred fifty-six laying hens were allocated into 4 treatment groups, with eight replicate cages, and were fed for 28 d either a control diet, or diets supplemented with OMW at 1, 2 or 4 g per 100 g feed (P1, P2 and P4 experimental groups, respectively). No significant effects were detected on the performance and egg quality (P > 0.05) except from a modest decrease in the intensity of orange yolk color from hens fed with OMW, as indicated by the reduced DSM YolkFan score and color parameter a* (redness) (P < 0.05), and the tendency for increased color parameter L* (lightness) (P < 0.1). Serum total cholesterol and high-density lipoprotein content were decreased in OMW experimental groups compared with the control group (P, P-linear < 0.05) whereas yolk cholesterol content was unaffected (P > 0.05). The ratio of heterophils to lymphocytes were not influenced by dietary treatment (P > 0.05), whereas T helper lymphocyte (Th) percentage was increased in OMW supplemented groups in comparison with control (P < 0.05, P-quadratic < 0.05). The yolk FA profile was beneficially affected, as shown by the linear increase in polyunsaturated FA and a linear decrease in saturated FA in OMW supplemented groups of hens (P-linear < 0.05), with most notable effects observed in the P4 group. Furthermore, oxidative stability, that was expressed as malondialdehyde content, of both fresh and stored egg yolks for up to 90 d, was significantly improved in OMW supplemented groups (P < 0.05). The beneficial effects of OMW on yolk oxidative stability and FA profile, without adverse effects on performance or egg quality, shows that this byproduct may be successfully employed in laying hens' diets, in a circular economy scheme, with benefits not only for the consumers and farmers but for the environment as well.

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.

EFFECT OF VARYING DIETARY ENERGY LEVELS ON PERFORMANCE OF JAPANESE QUAILS CHICKENS (COTURNIX COTURNIX JAPONICA)

Performance of Japanese quail (Coturnix japonica) was tested using different energy levels. Total of four hundred and fifty quail birds were randomly allotted to five different dietary treatments in a completely randomized design arrangement. The birds were further divided into three replicates per each treatment with 30 birds per replicate. Each treatment was assigned to one of the following test diets, diet 1: 2800kcal/kg ME, diet 2: 2900kcal/kg ME, diet 3: 3000kcal/kg ME, diet 4: 3100kcal/kg ME and diet 5: 3200kcal/kg ME. The Total feed intake of birds fed diet 1, 2 and 4 were significantly (P&lt; 0.05) higher than birds fed 3 and 5. Dietary energy levels significantly (P&lt;0.05) affected feed intake, daily weight gain, and feed conversion ratio across the dietary energy levels. An increase in metabolizable energy from 2800kcal/kg ME to 3200kcal/kg ME resulted in linear decrease in weight gain and feed intake. The live weight, breast weight, back weight, and intestinal length were significantly (P&lt;0.05) affected by the energy levels. The haemoglobin, PCV, MCHC, MCV, Albumin and Cholesterol were not significantly (P&gt;0.05) affected by the energy levels. RBC, MCH, Globulin and Total protein were significantly (P&lt;0.05) affected by energy levels.

Impact of storage conditions on the shelf life of aflatoxin biocontrol products containing atoxigenic isolates of Aspergillus flavus as active ingredient applied in various countries in Africa

Aflatoxin contamination significantly threatens food safety and security, particularly in tropical and sub-tropical regions where staple crops such as maize, groundnut, and sorghum become frequently affected. This contamination is primarily caused by the fungus Aspergillus flavus. The contamination causes adverse health effects, reduced income, and trade restrictions. In response to this challenge, various technologies have been developed to mitigate the impacts of aflatoxin. Among these, biocontrol products containing atoxigenic isolates of A. flavus as the active ingredient can effectively reduce aflatoxin levels both at pre- and post-harvest. A notable example of such products is Aflasafe, which contains four atoxigenic isolates native to specific target regions. These products have undergone rigorous testing, have received regulatory approval, and are commercially available in multiple African countries. However, their manufacturing processes have evolved, and comprehensive shelf life studies for current formulations are lacking. Evaluations of the spore production ability of atoxigenic A. flavus isolates in Aflasafe products over 4 years, under various storage conditions, revealed a significant linear decrease in sporulation with storage months (P < 0.001; R2 = 0.203), with no significant differences observed between treatments. However, this marginal decline (P = 0.398) is unlikely to be sufficient to prevent the effectiveness in limiting aflatoxin. In addition, storing the products for 2 weeks at 54 °C did not affect (P > 0.05) the ability of the coated fungi to produce spores compared to when the products were stored at 24 °C. The findings contribute valuable insights for manufacturers and users of atoxigenic-based aflatoxin biocontrol products, informing best practices for product storage and utilization to ensure prolonged effectivenes in aflatoxin mitigation efforts.

Gas flow in frozen hydrate-bearing sediments exposed to compression and high-pressure gradients: Experimental modeling

Changes in temperature and pressure patterns in gas- and hydrate-saturated permafrost caused by natural geodynamic processes or human impacts can lead to the active flow of gas through unfrozen zones, and its explosive emission is often accompanied by crater formation. Gas flow and accumulation in the shallow permafrost can be explained by the conditions of gas pressure equal to or exceeding the overburden pressure and high-pressure gradients. For the first time, filtration tests were conducted on ice- and hydrate-saturated rocks under uniaxial compression at various negative temperatures using a developed methodology. The modeling of gas flow in a mixture of ice-saturated sand and 25 % montmorillonite at gas pressure gradients within 2 MPa, shows that gas flow can start at warm negative temperatures near the thaw point. Pore hydrate formation in frozen sand heated to positive temperatures and frozen back led to a linear decrease in gas permeability by up to eight times. However, the behavior of gas permeability during hydrate dissociation is nonlinear as it increased within a few hours after the onset of dissociation, but then decreased exponentially in the following 24 h.

Mixed-valence state in the dilute-impurity regime of La-substituted SmB6

Homogeneous mixed-valence (MV) behaviour is one of the most intriguing phenomena of f-electron systems. Despite extensive efforts, a fundamental aspect which remains unsettled is the experimental determination of the limiting cases for which MV emerges. Here we address this question for SmB6, a prototypical MV system characterized by two nearly-degenerate Sm2+ and Sm3+ configurations. By combining angle-resolved photoemission spectroscopy (ARPES) and x-ray absorption spectroscopy (XAS), we track the evolution of the mean Sm valence, vSm, in the SmxLa1−xB6 series. Upon substitution of Sm ions with trivalent La, we observe a linear decrease of valence fluctuations to an almost complete suppression at x = 0.2, with vSm ~ 2; surprisingly, by further reducing x, a re-entrant increase of vSm develops, approaching the value of vimp ~ 2.35 in the dilute-impurity limit. Such behaviour departs from a monotonic evolution of vSm across the whole series, as well as from the expectation of its convergence to an integer value for x → 0. Our ARPES and XAS results, complemented by a phenomenological model, demonstrate an unconventional evolution of the MV character in the SmxLa1−xB6 series, paving the way to further theoretical and experimental considerations on the concept of MV itself, and its influence on the macroscopic properties of rare-earth compounds in the dilute-to-intermediate impurity regime.

Theoretical investigation of Cu influence on the stability characteristics of T-phase in crossover alloys

Abstract In crossover Al-Mg-Zn alloys, the T-phase (Mg32(Al, Zn)49) is crucial for reinforcement. The critical nucleation size of the precipitated T-phase is notably reduced by Cu addition, as well as the activation energy. There is a lack of theoretical research on the influence of Cu elements on the stability of T-phases and mechanical properties. In this work, we systematically investigate the influence of varying Cu concentration on the T-phases by examining their stability, mechanical properties, and electronic structure characteristics through first-principles calculations. The findings reveal that the T-phase maintains lattice stability within the 0 to 5% Cu content range, with a linear decrease in the lattice parameter and formation energy (–0.16 ~ –0.15 eV/atom). Additionally, there is an observable positive correlation trend between the elastic moduli (B, E, and G) of the T-type phase and the Cu content. It is shown that the T-phase exhibits inherent ductility. Analysis based on Pugh’s criterion and Poisson’s ratio indicates a reduction in the ductility with increasing Cu content in the T-phase. This work theoretically validates the previous experimental observations and reveals the impacts of Cu concentration on the T-phase.

Properties of foam concrete containing phase change material impregnated pumice

Energy consumption rises as a result of numerous electrical devices used to maintain thermal comfort of interior building areas. Using building materials with low thermal conductivity and density as well as an effective thermal energy storage plan can help to mitigate this. In order to enhance thermal performance of building, phase change material (PCM) was incorporated to foam concrete mixture in this study. Capric acid (CA)-palmitic acid (PA) eutectic mixture was prepared and impregnated with pumice (50 % by weight), a light and porous material. DSC results indicated that pumice/CA-PA composite exhibited a melting temperature of 22.84˚C and a freezing temperature of 20.85˚C, with corresponding enthalpy values for melting and freezing determined to be 85.4 J/g and 85.1 J/g, respectively. TGA analyses demonstrated that operational temperature of pumice/CA-PA composite was significantly below its thermal degradation temperature (194˚C). The prepared pumice/CA-PA composites were replaced with silica aggregate at different rates and incorporated in foam concrete mixture. Porosity and water absorption values rose as pumice/PCM content increased, yet there was a 7.2–41.1 % drop in dry unit weight when compared to reference. Compressive strength also showed a linear decrease and the lowest compressive strength value was recorded as 4.71 MPa in the presence of 40 % pumice/PCM. Thermal conductivity dropped from 0.487 W/mK to 0.167 W/mK, suggesting that foam concrete samples that were produced are all suitable as insulation materials. In peak solar radiation hours, PCM-impregnated pumice foam concrete (PFC) provided about 11.8 % and 8.72 % surface and room center temperatures compared to that of the reference in maximum case. PFC with PCM provided 6.54 % warmer surface temperature in cold weather. PFC-PCM can provide a cooler indoor temperature during peak temperature hours. Therefore, it may have a great potential to decrease the cooling load of a building.

Empirical model for the effect of air humidity during manufacturing on the glass transition temperature of carbon fiber reinforced hot curing epoxy – a case study

Carbon fiber-epoxy laminates are used in aerospace manufacturing, e.g. as substrates for solar cells of satellites. Commonly, fibers or fibermats are impregnated with epoxy resin and placed in the required orientation. During subsequent curing, the resin molecules are crosslinked. Cured parts are characterized by their glass transition temperature (Tg). It has been observed that Tg of epoxy matrix resin vary with recorded absolute air humidity during wet fiber placement manufacturing. Based on the production data of a series production of 203 carbon fiber laminates for space application, an empirical linear relationship between the absolute air humidity at the beginning of each production day and the observed glass transition temperature of the fully cured laminate is formulated and validated. The empirical equation describes a linear decrease of achievable glass transition temperature with increasing absolute air humidity. The quantitative nature of the results encourages straightforward practical application to determine the maximum achievable Tg for given production conditions.

Plant phylogenetic diversity along the urban–rural gradient and its association with urbanization degree in Shanghai, China

ContextThe spatial distribution of plant diversity in urban areas is fundamental to understanding the relationship between urbanization and biodiversity. Previous research has primarily focused on taxonomic levels to assess species richness. In contrast, investigations into the spatial patterns of phylogenetic diversity in urban plants remain limited.ObjectivesThis study aims to investigate the spatial patterns of plant phylogenetic diversity along an urban–rural gradient and quantify how phylogenetic diversity and the degree of urbanization are related.MethodsA survey of vascular plants was conducted at 134 randomly selected sample plots along four urban–rural transects in Shanghai, China. Three phylogenetic diversity metrics were calculated: Faith’s phylogenetic diversity (PD), net relatedness index (NRI), and net nearest taxon index (NTI), along with the urbanization degree index (UDI). Regression analysis was employed to quantify the spatial patterns of plant phylogenetic diversity across different taxa along the urban–rural gradients and their relationships with UDI.ResultsThe study observed seven distinct patterns of plant phylogenetic diversity along the urban–rural gradients in different taxa, which support the previous hypotheses that biological distribution patterns at the species level also hold true at the phylogenetic level. Faith’s phylogenetic diversity (PD) showed a linear increase with increasing UDI for total, woody, perennial, and cultivated plant assemblages. The UDI explained 3–36% of the variation in PD for these taxa. In contrast, PD for annual and spontaneous plants exhibited a linear decrease with increasing UDI, which explained 25% and 3% variation in PD for annual and spontaneous plants, respectively. The net relatedness index (NRI) for woody, perennial, and cultivated plants, as well as the net nearest taxon index (NTI) for perennial and cultivated plants, linearly increases with UDI, whereas the NRI for total, annual, and spontaneous plants, as well as NTI for total, woody, annual, and spontaneous plants linearly decrease with UDI. However, some of these trends were only marginally significant.ConclusionsThe spatial patterns of plant phylogenetic diversity varied along the urban-to-rural gradients, indicating that urban environmental filtering has an impact on plant phylogenetic diversity. Urbanization increased the phylogenetic richness of different plant taxa in Shanghai but resulted in more clustering and relatedness of species within plant assemblages. Phylogenetic richness exhibited a linear increase with UDI, while the phylogenetic divergence decreased with UDI. The UDI is a useful predictor for examining variations in plant phylogeny due to urbanization. Our findings provide insights into how urbanization impacts plant phylogenetic diversity, helping urban plant diversity conservation.

Development of loneliness and social isolation after spousal loss: A systematic review of longitudinal studies on widowhood.

Spousal loss is a stressful life event that is associated with loneliness and social isolation, both of which affect mental and physical health. The primary objective of this paper was to synthesize longitudinal studies that investigated loneliness and social isolation in widowhood. A systematic search of the literature was conducted using three electronic databases. 26 longitudinal studies published through June 2024 were included for further analysis. Participant characteristics, study design, and key findings were extracted. Most studies were from the United States or Europe, included more widows than widowers, and assessed loneliness in older adults aged >60 years. Loneliness peaked directly following spousal death, but findings were inconsistent regarding the lasting effects of widowhood. Heterogeneity in the longitudinal trajectories of loneliness was noted, with studies showing linear increases, decreases, or curvilinear relationships over time. Several factors modified the relationship between widowhood and loneliness, including volunteerism, military experience, income, and age. Widowers consistently reported greater loneliness and worse social isolation when compared with widows. Few studies investigated social isolation specifically, but those that did found that social isolation may decrease in widowhood. As the world grapples with a social pandemic of loneliness and social isolation, widowed adults may be uniquely affected. Few studies investigated the longitudinal trajectory of loneliness and especially social isolation in widowhood, and those that did found heterogenous results. Future work is needed to understand why some widowed adults are uniquely affected by feelings of loneliness and social isolation while others are not, and whether potentially modifiable factors that moderate or mediate this relationship could be leveraged by psychosocial interventions.

Experimental Characterization of Stiffness of a Polyester Mooring Rope for a CFPSO

Synthetic ropes are increasingly favored for use in offshore systems. Accurate predictions of the coupled hydrodynamic performance and structural response of offshore structures depends on a thorough understanding of the nonlinear characteristics of fiber materials. The objective of this study is to experimentally characterize the stiffness of a polyester mooring rope for a cylindrical floating production storage and offloading system. The quasi-static stiffness of the ropes and aged ropes after installation and the dynamic stiffness in various loading conditions were computed based on sub-rope tests following the guidelines from the American Bureau of Shipping. The quasi-static stiffness curves exhibited a linear decrease in values as the logarithm of the loading period (in minutes) increased. The dynamic stiffness was, in general, much higher than the quasi-static stiffness. The dynamic stiffness under various loading conditions revealed the complexities of the mechanical properties of polyester rope. Parameters such as the mean load, load amplitude, loading period, and loading cycles all had a notable impact. More tests are required to have a better understanding of their effects.

Disinfection of sulfate-reducing clostridia, including Clostridium perfringens, in sewage effluents using peracetic acid

ABSTRACT Peracetic acid (PAA) is being tested as an alternative to chlorine for sewage disinfection due to its advantages, such as the lack of disinfection byproducts produced and low impact on the discharge site ecosystem. In this study, the inactivating efficiency of PAA against Clostridium perfringens, a known chlorine-resistant microorganism that also causes numerous foodborne illnesses, was evaluated in sewage. PAA remained 80–90% after 120 min of contact with sewage, while chlorine was reduced to 3%. The inactivation curve for Escherichia coli showed a linear decrease with chlorine, while a stepwise reduction was observed with PAA. The inactivation efficacy of PAA on sulfate-reducing clostridia (SRC)-containing C. perfringens was −2.41 log at a CT value of 3,025 mg·min/L. Among the detected SRCs, the −log inactivation of C. perfringens was estimated from the percentage of cpa gene positivity, and its PAA inactivation efficacy was higher than that of SRC at −3.17 log. Although SRC contained PAA-resistant non-C. perfringens clostridia, the effectiveness of PAA for inactivating C. perfringens in the presence of organic matter indicates its effectiveness as a sewage disinfectant.

Effect of substitution of aluminium and neodymium on structural and magnetic properties of yttrium iron garnet studied using 57Fe internal field NMR

The structural and magnetic properties of non-magnetic aluminium and magnetic neodymium substituted yttrium iron garnet samples (Y3-xAlxFe5O12 and Y3-nNdnFe5O12) were investigated. Powder samples were synthesized using auto combustion route. The Rietveld refinement analysis of the samples confirmed the presence of the garnet phase and showed presence of minimal impurity phases, specifically perovskite and hematite. Substitution on Y3Fe5O12 with Al resulted in a linear decrease in saturation magnetization, while Nd substitution showed a non-linear change. In accordance with this the Internal Field Nuclear Magnetic Resonance (IFNMR) spectrum exhibited a downward shift in peak frequency when Al was substituted, and a significant reduction in intensity with Nd substitution in yttrium iron garnet samples. Aluminium ions take up either tetrahedral or octahedral positions in the lattice, apart from the dodecahedral site, because of their smaller ionic radii. This causes a decrease in the hyperfine field that originates from Fe3+ ions in tetrahedral and octahedral sites. On the other hand, neodymium ions occupy dodecahedral sites and are expected not to affect Fe ions. Concurrently, an observable peak shift was not observed in the IFNMR spectrum for Nd substitution. However, Nd substitution introduced strain in the lattice due to their larger ionic radii compared to yttrium, which they replace. This strain causes disorder in tetrahedral and octahedral sites and affects 57Fe signal intensity. The magnetic properties observed from VSM analysis is also interpreted in view of observed changes in the 57Fe IFNMR spectrum. X-ray Photoelectron spectroscopy (XPS) was employed mainly to explore spin orbit splitting of Fe 2p state in the samples.

Effects of Caffeine Doses on Rumen Fermentation Profile and Nutrient Digestibility Using a Lactating Cow Diet under Continuous Cultures Conditions

Caffeine is a plant secondary metabolite, commonly known for its bioactivity properties. This molecule increases microbial activity during anaerobic digestion. The aim of this study was to determine the effects of caffeine doses on the rumen fermentation profile and nutrient digestibility when continuous culture fermenters were fed a lactating cow’s diet. We hypothesize that adding caffeine doses into continuous culture fermenters with a rumen fluid inoculum will not affect anaerobic fermentation or nutrient utilization. Fermenters were fed twice a day (at 0800 and 2000 h) with an experimental diet of high-producing dairy cows (53.55 g/DM day; Forage:Concentrate ratio, F:C of 40:60). Four levels of caffeine (0 ppm, 50 ppm, 100 ppm, and 150 ppm) were added to the diets as a treatment. The experiment was arranged in a randomized complete block design. Two blocks of four fermenters were run in two replicated periods of ten days. Statistical analyses were conducted in SAS version 9.4 for Windows (SAS Institute Inc., Cary, NC) using the GLIMMIX procedure. The addition of caffeine at a 50 ppm dose on continuous culture fermentation decreased the protozoal counts (Diplodinium spp.) (p = 0.03) and ammonia concentrations (p &lt; 0.05). A treatment of 50 ppm of caffeine increased the DM, OM, and starch digestibility (p &lt; 0.05). When caffeine doses increased further than 50 ppm, the OM, DM, and starch digestibility decreased linearly (p = 0.01). The total volatile fatty acids and fatty acid proportions were unaffected. However, the acetate-to-propionate ratio (A:P) tended to decrease linearly among treatments (p = 0.07). The means of pH measurements and maximum pH had a significantly linear decrease effect (p &lt; 0.01). Caffeine may represent a potential rumen fermentation modifier for use in lactating cow diets.