Miracle-dz/UniFAR-FTUs huggingface dataset:
Electrode mechanism and voltammetric determination of selected guanidino compounds

AbstractThe present review describes the recent results on the electrochemical activity of bio-guanidino compounds, such as famotidine, metformin, acyclovir, ganciclovir, zanamivir, moroxydine as well as guanidino compounds, such as S-[(2-guanidino-thiazol-4-yl)methyl]isothiourea hydrochloride, 2-guanidino-1,3-thiazole, 2-guanidinobenzimidazole. The focus is on analyzing the electrode mechanism of the guanidino compounds at the hanging mercury drop electrode and at the silver amalgam film electrode, as well as on the character of the square wave (SW) voltammetric signals. It has been stated, that the compounds can act as electrocatalysts — they are protonated and adsorbed at the surface of the electrode, after which the protonated forms of the compounds are irreversibly reduced, yielding their initial form and hydrogen. The experimental adsorption data obtained by measuring the differential capacity of the double layer, the zero charge potential, and the surface tension at the zero charge potential have established the adsorption processes underlying their electrochemical activity. The analytical application of the obtained voltammetric signals in the determination of these compounds in biological samples is also presented. This review concentrates on our own results in the context of general developments in the field.
THE EFFECT OF TRUST AND BRAND ENGAGEMENT ON MOBILE TELECOMMUNICATION CUSTOMER LOYALTY: THE MEDIATING EFFECT OF BRAND ENGAGEMENT

Mobile telecommunication providers grow rapidly in these days. This situation makes a tight competition among the mobile telecommunication companies. In a tight business competition, only companies that can create customer loyalty would sustain their business. To date, many variables have been proven as the determinant of loyalty. However, only few studies have been oriented to determine the effect of trust and brand engagement in creating loyalty. Hence, this study aims to determine the effect of trust and brand engagement on loyalty. One hundred and eighty one respondents participated in this study. Data was analysed by using CBSEM. The results show that brand engagement has a positive direct effect on loyalty while trust only has an indirect effect through brand engagement. The conceptual model built in this study is a theoretical contribution provided by this study. In the practical standpoint, this study provides an insight for practitioners about enhancing loyalty in mobile telecommunication industry based on trust and brand engagement.
On the Description of the Adhesive Contact of Spheres with Arbitrary Interaction Potentials

Abstract We have generalized the Maugis model of the adhesive contact of spheres (Maugis D.,J. Colloid Interface Sci.150, 243, 1992) to arbitrary interactions in two different ways. On the one hand, if we choose an arbitraryinteraction potentialbetween surfaces, we obtain an exact formulation of the problem, which unfortunately requires computationally demanding numerical solutions. On the other hand, if we prescribe thestress distributionoutside the contact zone, we can build numerically efficient approximations which completely describe the contact problem for a given monotonic attractive interaction with reasonable accuracy. These approximate models retain the simplicity of the Maugis model and may therefore prove useful in data analysis. Our results show that the nature of the interaction has a very moderate influence on the solution, so that the Maugis model can be used to describe the contact of spheres with most physically acceptable interaction potentials, except when large accuracy is required.
BTEX Emissions During Prescribed Burning in Function of Combustion Stage and Distance From Flame Front

The authors investigated the volatile organic compound group benzene, toluene, ethylbenzene, and xylenes (BTEXs) produced during the combustion of forest fuel. The analytes were chosen because they have been identified in other forest fires. As a result, firelighters and the general population can be exposed to hazardous concentrations of BTEXs during prescribed burning. Firefighters were equipped with Tenax adsorbent tubes and the BTEX concentrations analyzed by Automated Thermal Desorption–Gas Chromatography/Mass Spectrometry (ATDGC/MS). Total BTEX concentrations were measured in function of the distance from the flame front (between 1 and 10 m, 30 and 50 m, and 100 and 150 m) and the combustion phase (flaming and smoldering). The major compounds detected were benzene and toluene. Significant differences were observed between the data collected. BTEX concentrations were higher close to the flame front and during the smoldering phase. The benzene concentration (0.093–18 mg·m−3) exceeded the Short-Term Exposure Limit (STEL, 16 mg·m−3) in samples collected during the smoldering phase at a distance of 1–10 m from the flame front. Statistical analyses were carried out to summarize the results.
DDTs in Soils Affected by Mosquito Fumigation in Belize

DDTs were sprayed extensively in Belize to combat malaria but widespread use ceased after 1997. To determine if DDTs still persist in Belize's soils, 23 composite soil samples were collected from each of the two towns of Dangriga and Punta Gorda. Dichlorodiphenyltricholoroethane (DDT) and its breakdown products dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) were the only organochlorine compounds detected in the soils. Results show that DDTs are transferred to the soil environment as a result of spraying houses and that the pesticides still persist in soils in southern Belize after more than 10 years of non-use. Sprayed lots had DDT concentrations up to 240 μg/kg in Dangriga and up to 410 μg/kg in Punta Gorda. All unsprayed lots had below detection limit concentrations, with the exception of two sites in Punta Gorda. Hot spot analysis in GIS indicates that significant spatial variability exists in detected concentrations of DDTs, which has implications for extrapolation of local data. Belize currently has no guidelines for determining risk of DDTs to human health and soil cleanup, but soil cleanup guidelines employed by foreign governmental entities such as the Netherlands and California show that all detected pesticide concentrations in this study are below mandated concentrations of concern for the residential areas of these regions. However, since exposure scenarios may be different in Belize, it is recommended that the Belize Ministry of Health conducts a risk analysis to ascertain if the concentrations of DDTs in sprayed areas pose a risk to the inhabitants of the two towns.
Factors influencing spatial variability of soil apparent electrical conductivity

ABSTRACT Soil apparent electrical conductivity (ECa) can be used as a precision farming diagnostic tool more efficiently if the factors influencing ECa spatial variability are understood. The objective of this study was to ascertain the causes of ECa spatial variability in soils developed in an environment with between 50 and 65 cm of annual rainfall. Soils at the research sites were formed on calcareous glacial till parent materials deposited approximately 10,000 years ago. Soil samples (0–15 cm) collected from at least a 60 by 60 m grid in four fields were analyzed for Olsen phosphorus (P) and potassium (K). Elevation was measured by a carrier phase single frequency DGPS and ECa was measured with an EM 38 (Geonics Ltd., ON, Canada) multiple times between 1995 and 1999. Apparent electrical conductivity contained spatial structure in all fields. Generally, the well drained soils in the summit areas and the poorly drained soil in the toeslope areas had low and high ECa values, respectively. The landscape differences in ECa were attributed to: (i) water leaching salts out of summit areas and capillary flow combined with seepage transporting water and salts from subsurface to surface soils in toeslope areas; (ii) lower water contents in summit than toeslope soils; and (iii) water erosion which transported surface soil from summit/shoulder areas to lower backslope/footslope areas. A conceptual model based on these findings was developed. In this model, topography followed a sine curve and ECa followed a cosine curve. Field areas that did not fit the conceptual model were: (i) areas containing old animal confinement areas; (ii) areas where high manure rates had been applied; and (iii) areas where soils were outside the boundary conditions of the model, i.e., soils not developed under relatively low rainfall conditions in calcareous glacial till with temperatures ranging between mesic and frigid. This research showed that the soil forming processes as well as agricultural management influenced ECa and that by understanding how landscape position influences salt loss and accumulation, water redistributions following precipitation, and erosion areas that do not fit the conceptual model can be identified. This information can be used to improve soil sampling strategies.
Improving the quality of frozen-thawed ram semen

Cryopreserved semen is widely used for assisted reproduction in livestock, however, in sheep its use is still limited. Freezing and thawing cause biochemical and physiological alterations into the sperm. These alterations such as oxidative damage caused byreactive oxygen species (ROS) and changes inheat shock proteins (HSP) appear to determine the fertilizing ability of the sperm. Seminal plasma (SP) and antioxidants have the ability to improve sperm function and reduce the effect of cryopresrvation. Thisstudy aimed to improve the integrity of frozen-thawed ram sperm, so that an increase the fertility rates could be achieved. The first experimentevaluated the effect of the post-thaw addition of 1.5 mg/ml of different seminal plasma (SP) protein fractions(Whole SP, >100, 30-100, and <30kDa) on the quality of frozen-thawed ejaculated and epididymal ram sperm. SP proteins fractions,particularly <30kDa improved the integrity of fresh and frozen-thawed epididymal spermatozoa and fresh ejaculated spermatozoa (P< 0.001), but there was no effecton frozen-thawed ejaculated spermatozoa. This reductioncould be related to the effect of ROSon sperm integrity. Therefore, the second experimentwas designed to assess the effect of the antioxidantscysteine, taurine,and vitamin C on frozen-thawed ram semen. Semen samples were treated pre-freeze (PF) and post-thaw (PT) to evaluate the optimal timing and concentration of antioxidant supplementation on frozen-thawed ram semen to improve sperm function and reduce ROS production. The addition of 0.5 and 1.0 mg/ml cysteine or taurine (PF + PT) improved the integrity of frozen-thaw ram sperm. There was no effect of vitamin C supplementation on frozen-thawed ram sperm, however, it improved penetrability and reduced ROSproduction. In the third experiment, the effect of oxidative stress induced by 5mM and 15mM hydrogen peroxide (H2O2) on the integrity of fresh ram spermwas assessed.ROS production,lipid peroxidation (LPO) in SP, and the expression of heat shock proteins (70 and90) were determined.H2O2has the capability toeliminate sperm functions significantly at 15μM. This effect could indicate the importance of HSP70 and HSP90 to protect sperm membrane functions, thus there is a need to maintain the function of these proteins. The fourth experimentidentified the relationship between supplementation with1.0 mg/ml (PF + PT) of taurine or cysteine and the expression level of HSP90 and HSP70 on frozen-thawed ram sperm. The results showed that PF or PT supplementation of antioxidants (1.0 mg/ml of cysteine or taurine) improved post-thaw ram sperm integrity and maintained the expression of HSP70 and HSP90. There was a positive relationship between the level of expression of HSP70 and HSP90 and sperm parameters such as motility, acrosome integrity, viability, penetrability, ROS concentration and the level of LPO in SP and sperm. Therefore, the findings of this thesis collectively may assist to improve the quality of cryopreserved ram semen, andeffectively contribute to reproductive technologies in the sheep industry.
CP-VTON+: Clothing Shape and Texture Preserving Image-Based Virtual Try-On

Recently proposed Image-based virtual try-on (VTON) approaches have several challenges regarding diverse human poses and cloth styles. First, clothing warping networks often generate highly distorted and misaligned warped clothes, due to the erroneous clothing-agnostic human representations, mismatches in input images for clothing-human matching, and improper regularization transform parameters. Second, blending networks can fail to retain the remaining clothes due to the wrong human representation and improper training loss for composition-mask generation. We propose CP-VTON+ (Clothing shape and texture Preserving VTON) to overcome these issues, which signiﬁcantly outperforms the state-of-the-art meth-ods, both quantitatively and qualitatively.
Natural radionuclides and metals intake into soya, corn and lettuce grown on soil amended with phosphogypsum

Phosphogypsum is a by-product of the phosphate fertilizer industry. It is produced by precipitation during wet process of phosphate rocks, thus posing serious problems with its utilization and safe disposal. In Brazil, three main industries are responsible for the production and storage of about 5.5 × 106 tons per year. Phosphogypsum may contain trace metals and radionuclides of U and Th series. Since, in Brazil, phosphogypsum has been used for many years as soil amendment, it is important to know its availability in the environment. The main objective of this study is to evaluate the radionuclides and metals transfer in the soil-to-plant system. To accomplish this task an experiment was carried out in a green house, where two major crop groups (soya bean and corn) and leafy vegetables (lettuce) were grown in two types of soil (clay and sandy) amended with phosphogypsum. The transfer-factors were evaluated for the metals (As, Cd, Cu, Ni and Pb, Ba, Co, Cr, Fe, Zn and REE) and for the radionuclides U, Th, 226Ra, 228Ra, 210Pb and 210Po. The addition of PG to the two soils studied, did not significantly alter the TFs values for all the elements studied.
Nitrous oxide fluxes related to soil freeze and thaw periods identified using heat pulse probes

Surface N2O fluxes have not been unequivocally linked to soil profile conditions, in particular the timing of water phase change. The heated needle probe is a sensor that has the potential to monitor in situ apparent volumetric heat capacity (Ca), which considers latent heat transfer, during freezing and thawing. The objective of this study was to relate the timing of N2O flux to the occurrence of soil water phase change between liquid and ice as determined by Ca in no-tillage (NT) and conventional tillage (CT) plots monitored from fall to spring. Half-hourly micrometeorological N2O fluxes were measured using a tunable diode laser trace gas analyzer. Apparent heat capacity was measured at 5-cm depth using three 4-cm-long parallel needles, two equipped with thermistors and one with a heater. Two N2O flux events were observed for CT in January, followed by the main emission event in early March. For NT, only one emission event occurred, with lower magnitude than the CT event, and a later starting and ending.
Comparative Mitogenomic Analysis of Heptageniid Mayflies (Insecta: Ephemeroptera): Conserved Intergenic Spacer and tRNA Gene Duplication

Simple Summary Heptageniidae is one of the most abundant and widespread families of mayflies, with more than 600 described species and distributed mainly in the Holoarctic, Oriental, and Afrotropical regions. Previous phylogenetic analyses in this family mainly focused on morphological characters and were restricted to one or several genes. Ten complete mitochondrial genomes from this family are reported here. A conserved intergenic spacer and tRNA gene duplication in Heptageniidae mitogenomes may be regarded as ancient features and provide evidence for the phylogenic analysis within Ephemeroptera. Abstract Large intergenic spacers and tRNA gene duplications have been reported in several insect groups, although little is known about mitogenomes of mayflies. Here, we determined complete mitogenomes of ten heptageniid species and systemically analyzed their mitogenomic features. Both a conserved intergenic spacer (IGS) and trnM duplication were detected in those mitogenomes. The IGS, which was observed in heptageniids, could be further folded into a stable stem–loop structure. The tRNA gene duplication was found in almost all analyzed mitogenomes, and a unique gene block trnI-trnM-trnQ-trnM-ND2 was also discovered. Our analysis demonstrates that the heptageniid gene arrangement pattern can be explained by the tandem duplication-random loss (TDRL) model. Phylogenetic analyses using both Bayesian inference (BI) and maximum likelihood (ML) methods based on the nucleotide and amino acid sequence data recovered the genus Epeorus as monophyletic with strong support. Our results provide a better understanding of mitogenomic evolution in Heptageniidae, as well as novel molecular markers for species identification of mayflies.
Stress Corrosion Cracking

Raw material Brass compression fittings are manufactured from bar stock, from forged material or as castings. The manufacturing processes will inevitably introduce a level of stress into the finished product, but if the processes are carefully controlled, these low stress levels will not normally be a problem. All bar stock from reputable suppliers is tested for harmful stress levels after manufacture and where necessary suitable heat treatment is applied to the material after completion of the final drawing operation. Fittings made by hot stamping processes or as castings are usually free of any harmful stresses by virtue of the high temperatures involved in manufacture.
Raadeite, Mg 7 (PO 4 ) 2 (OH) 8 : a new dense-packed phosphate from Modum (Norway)

The new mineral raadeite, Mg 7(PO4)2(OH)8, was found in nodules of apatite + Mg-phosphates within the Tingelstadtjern serpentinite body, Modum district, Norway. It occurs as veinlets, a few tens of µ m wide, crosscutting althausite crystals; also as rare, up to 150 µ m large anhedral inclusions in holtedahlite; and with apatite, althausite and magnesite in fibrous coronae replacing heneuite. It is colourless, transparent, biaxial (- ); for l = 589 nm, n x 1.5945(5), n y 1.6069(5), n z 1.6088(5), 2V meas 45.6(1)° , 2V calc 43° ; strong dispersion r > v, n y // b. The infrared spec- trum shows prominent OH stretching bands at 3375, 3475, 3540 and 3580 cm -1. Electron-microprobe analyses indi- cate near-end-member composition, with minor As, Fe and Mn. Raadeite could be synthesized from 3 to 15 kbar, 500 to 700° C. It is monoclinic, space group P21/n, a = 5.250(1), b = 11.647(2), c = 9.655(2) A , b = 95.94(1)° , Z = 2. Single-crystal structure study ( R = 0.021) shows raadeite to be isostructural with the Mn-arsenate allactite and could localize the four protons. The structure consists of brucite-derived layers with 2/7 octahedral vacancies, which are linked by sharing a face and corners with interlayer Mg polyhedra (5+1 coordination) and corners with the PO 4 tetra- hedra. Raadeite and similar hydrous Mg-phosphates on the join brucite- Mg 3(PO4)2 (olivine-type structure) can be formally compared with the polysomatic humite series and other dense hydrous Mg silicates on the brucite- forsterite join. However, the structural variety of the relevant phosphates cannot be accounted for by a polysomatic series, nor are they all high-pressure phases.The new mineral honours Gunnar Raade, for his contribution to the mineralogy of Mg-phosphates.
Female Board Members in Family Firms Does Critical Mass Drive Debt Level?

This study empirically investigates if a presence of a consistent female representation in the boardroom (i.e., a critical mass) affects leverage in family firms. Employing a sample of 268 Italian manufacturing firms for the period 2016-2018, the regression analysis show that the presence of at least three women in the boardroom significantly decreases firm's leverage. Results are robust to both, different measures of leverage and presence of women on board. These findings confirm the risk aversion of women and support the idea that a significant presence of women in the board is a useful instrument in risk monitoring. Our results are useful for policy makers – interested in the adoption of rules on gender quotas in identifying the minimum number of women in the board needed to produce a statistically significant impact on performance and shed new light on the relationship between corporate governance characteristics and capital structure in concentrated-ownership companies.
Water retention time in intermittently dosed sand filters.

This paper presents a simple theoretical approach to calculating of the retention time of water and/or wastewater in intermittently dosed filters. It assumes that a single dose of water is completely mixed with the previously stored water in the filter and that the field capacity of the granular medium is achieved before the next wastewater application. Retention time is weighted by the water volume stored within the filter. It is presented in a discrete form. The model was successfully validated on the basis of empirical data gathered by Schudel and Boller.
Effect of Cooling Rate on the Flow Behavior of Waxy Crude Oils

Abstract The flow behavior of waxy crude oils is markedly affected by the lowering temperature due to the cooling during shutdown. Pipeline engineers must consider two problems, both of which are related to the flow behavior of waxy crude oils. The problems are restartability of a pipeline after a prolonged shutdown and continual deposition of heavy organic materials on the inner wall of the pipeline. The main goal for this article is to study the effect of cooling rates on the flow behavior and deposition of heavy organic materials when statistically cooled. To achieve this purpose, two Egyptian crudes were investigated, namely, “sample A” (high waxy crude) and “sample B” (containing a high amount of asphaltene). The results showed that the flow behavior of the tested crudes was affected, to a large extent, by the cooling rates. Also, the restart-up pressure (restartability) required to initiate the flow of the crude, which contained a high portion of asphaltene, is high at a low cooling rate and vice versa was observed for high wax content crude.
Determinants and inequalities in access to improved water sources and sanitation among the Zambian households

Improved water sources and sanitation are crucial for human survival. The study focused on examining the inequalities and determinants of access to water and sanitation between rural and urban households. This study analysed the household data sets from the 2013-14 Zambia Demographic and Health Surveys (ZDHS) with a total sample size of 15,920 households. To determine the percentage distribution, inequalities and determinants of access to improved water and sanitation, the study used univariate analysis, the Erreygers concentration index (E) and the logistic regression, respectively. Sixty five percent (64.5%) of the households had access to improved water source compared to 35.5% who did not while only a quarter (25.4%) of the households had access to improved sanitation compared about three quarters (74.6%) without access. The results also show that access to improved water and sanitation is concentrated among the wealthier households and increases with increasing wealth quintile in both rural and urban areas. Further, study showed that wealth index, gender of household head, region and type of place of residence were all positively associated with access to improved sanitation. Wealth index and sex of household head were found to be positively related with access to improved water. To enhance access to improved water and sanitation among the poor households it is imperative that government and other stakeholders intervene by providing the amenities or by subsidising the provision.