Kemijska modifikacija površinskim cijepljenjem celuloze izolirane iz biljke Hibiscus sabdariffa: potencijalni bioizvor za industrijsku primjenu

This document defines terms relating to the properties of individual macromolecules, macromolecular assemblies, polymer solutions, and amorphous bulk polymers. In the section on polymer solutions and amorphous bulk polymers, general and thermodynamic terms, dilute solutions, phase behaviour, transport properties, scattering methods, and separation methods are considered. The recommendations are a revision and expansion of the IUPAC terminology published in 1989 dealing with individual macromolecules, macromolecular assemblies, and dilute polymer solutions. New terms covering the principal theoretical and experimental developments that have occurred over the intervening years have been introduced. Polyelectrolytes are not included. This work is licensed under a Creative Commons Attribution 4.0 International License.Ovaj dokument definira nazive povezane sa svojstvima pojedinačnih makromolekula, makromolekulskih nakupina, polimernih otopina i amorfnih polimernih tvari. U odjeljku o polimernim otopinama i amorfnim polimernim tvarima razmatraju se opće i termodinamičko nazivlje, razrijeđene otopine, fazno ponašanje, transportna svojstva, metode raspršenja svjetlosti i separacijske metode. Preporuke su revizija i proširenje nazivlja IUPAC-a objavljenog 1989., koje se ticalo pojedinačnih makromolekula, makromolekulskih nakupina i razrijeđenih polimernih otopina. Uvedeni su novi nazivi koji pokrivaju glavna teorijska i eksperimentalna saznanja do kojih se u međuvremenu došlo. Polielektroliti nisu uključeni. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Customer Satisfaction in Fast Food Restaurants in Ibadan Metropolis

This study assessed the factors affecting customer satisfaction and its effect on repurchase intention at selected Fast Food Restaurants (FFRs) in Ibadan metropolis, Nigeria. Primary data were obtained by administering structured questionnaire on a cross-section of 147 Customers of Fast Food Restaurants (CFFRs) who patronized FFRs. Multistage random sampling technique was employed to select seven (7) FFRs from the metropolis. The respondents’ satisfaction level towards FFRs was obtained on Five point Likert scale. Each respondent’s satisfaction level was then assessed by Customer Satisfaction Index (CSI). The data were analyzed using a combination of descriptive techniques and Ordinary Least Square (OLS) regression. The regression analyses were used to identify the relationship between service quality dimensions and customer satisfaction. These dimensions include tangibility, reliability, responsiveness, assurance and empathy which concern the physical aspect, regularity and consistency of performances, readiness and willingness to help customers, knowledge and courtesy of the employees and individualized attentions towards customers of the FFRs respectively. Analysis of responses to various indicators of customers’ satisfaction in CSI revealed that 76.2% of the CFFRs considered services of the FFRs as satisfactorily, while 74.5% considered the services as ideal. Regression analysis revealed that customers’ satisfaction with services of the FFRs increased significantly with increase in customer’s perception of tangibility dimension of the service quality (p<0.01), empathy (p<0.01), responsiveness (p<0.05) and assurance (p<0.05). The study therefore, concludes that customer satisfaction significantly enhances repurchase intention and this is closely related to the customers’ perception of tangibility, responsiveness, assurance and empathy dimensions of service quality. The study recommends among others that fast food operator should provide amenities such as parking areas and attractive building exteriors in order to enhance their customers’ satisfaction towards services rendered. Also, service provider of fast food restaurants should endeavor to improve on their empathy by providing more caring and personalized service to customers in order to enhance customers’ satisfaction. Keywords: Nigeria, Fast Food Restaurants, Customer Satisfaction, Service Qualit

A new estimator for the multicollinear Poisson regression model: simulation and application

The maximum likelihood estimator (MLE) suffers from the instability problem in the presence of multicollinearity for a Poisson regression model (PRM). In this study, we propose a new estimator with some biasing parameters to estimate the regression coefficients for the PRM when there is multicollinearity problem. Some simulation experiments are conducted to compare the estimators\u27 performance by using the mean squared error (MSE) criterion. For illustration purposes, aircraft damage data has been analyzed. The simulation results and the real-life application evidenced that the proposed estimator performs better than the rest of the estimators

A comparative study of some robust ridge and liu estimators

In multiple linear regression analysis, multicollinearity and outliers are two main problems. When multicollinearity exists, biased estimation techniques such as Ridge and Liu Estimators are preferable to Ordinary Least Square. On the other hand, when outliers exist in the data, robust estimators like M, MM, LTS and S Estimators, are preferred. To handle these two problems jointly, the study combines the Ridge and Liu Estimators with Robust Estimators to provide Robust Ridge and Robust Liu estimators respectively. The Mean Square Error (MSE) criterion was used to compare the performance of the estimators. Application to the proposed estimators to three (3) real life data set with multicollinearity and outliers problems reveals that the M-Liu and LTS-Liu Estimator are generally most efficient..Keywords: Ordinary Least Squares, Ridge Regression Estimator, Liu Estimator, Robust Estimator, Robust Ridge Regression Estimator, Robust Liu Estimato

The Influence of Architects’ Sensing-Intuitive Personality Characteristics on Design Morphology in Selected Nigerian Universities

 Little or no record of the personality characteristics of the architectural design studio teachers and students has been made in schools, in the world over. This study employed a survey research designs in the architectural design studios of four (4) selected universities in South-West Nigeria. Five hundred (500) architectural students population study, out of which a sample of 498 was drawn while seventy five (75) represent teachers population study, out of which a sample of 49 was drawn, (N=49). Structured questionnaire patterned after Myers-Briggs (MBTI Indicator, 1997-2009) was used. This paper examined the influence of intuitive-sensing personality characteristics of design studio teachers’ and students in the determination of architectural forms and structures. The key findings yielded seven (7) dimensions pedagogic perceptive indices to Life in Architectural Design Studio (iN-intuitive, S-sensing); iN-S1, iN-S2, iN-S3, iN-S4, iN-S5, iN-S6, and iN-S7 across the spectrum. The most significant index in the pedagogic spectrum was iN-S5 across the selected schools (iN= 15.8s, 4.0t; S= 63.4s, 85.7t) with higher sensing but skewed intuition indices for students and teachers respectively. It recommended a controlled engagement of intuition and sensing personality characteristics in fostering design products. This was to enable proficiency and competency rating of teachers, students and professionals in practice

Metabolomics and in-vitro bioactivities studies of fermented Musa paradisiaca pulp : apotential alpha-amylase inhibitor

The in-vitro synthesis of bio-compounds via fermentation is a promising route for bioactive molecules intended for disease control and management. Therefore, this study evaluated the effect of fermentation on the antioxidants, antihyperglycemic and anti-inflammatory properties and the resultant chemometric phytochemical profiles of unripe plantain fruits. The results revealed that Escherichia coli and Propionibacterium spp. are suspected as the key fermenters. The E coli showed negative results to the pathogenicity test; Propionibacterium appeared to be opportunistic. A significant increase in the total polyphenols and protein and decreased flavonoids was recorded in the phytochemical profile of the methanolic extract of the fermented unripe plantain pulp; however, the ascorbic acid content was not significantly altered. The 1H NMR fingerprint showed that there is a closely related chemical shift among the shorter fermentation time (days 2–6) and the unfermented, while the more extended fermentation periods (days 7–12) with enhanced bioactivities were closely related based on the chemometrics analyses. Furthermore, the UPLC-QTOF-MS analysis annotated the presence of bioactive compounds in the day-9 fermented sample: polyhydroxy glucose conjugates (3-Methoxy-4-hydroxyphenyl 6-O-(3,4,5-trihydroxybenzoyl)-beta-D-glucopyranoside), short chain peptide (leucyl-glycyl-glycine), amino acid derivatives (4-Aminophenylalanine, and N-Acetylhistidine), linear and cyclic fatty acid derivatives (palmitoyl putrescine, ricinoleic acid, phytosphingosine, gabalid, rubrenoic acid, 2-aminocyclopentanecarboxylic and cystodienioc acid). The synergistic effect of these newly formed compounds and the increase in the phenolic content of the day-9 fermented unripe plantain may account for its more potent antioxidant, anti-inflammatory and antihyperglycemic activity. Therefore, the products obtained from the day 9 fermentation of unripe plantain pulp may serve as potential nutraceutical agents against gastro-enteric sugar digestion and absorption and sugar-induced oxidative stress, inflammation and metabolic disease.https://www.cell.com/heliyonhj2024ChemistrySDG-02:Zero HungerSDG-03:Good heatlh and well-bein

Solvent free hydroxylation of the methyl esters of Blighia unijugata seed oil in the presence of cetyltrimethylammonium permanganate

Extraction of oil from the seed of Blighia unijugata gave a yield of 50.82 ± 1.20% using hexane in a soxhlet extractor. The iodine and saponification values were 67.60 ± 0.80 g iodine/100 g and 239.20 ± 1.00 mg KOH/g respectively with C18:1 being the dominant fatty acid. Unsaturated methyl esters of Blighia unijugata which had been previously subjected to urea adduct complexation was used to synthesize methyl 9, 10-dihydroxyoctadecanoate via hydroxylation in the presence of cetyltrimethylammonium permanganate (CTAP). The reaction was monitored and confirmed using FTIR and GC-MS. This study has revealed that oxidation reaction of mono unsaturated bonds using CTAP could be achieved under solvent free condition

Paediatric brought-in-dead at a tertiary health facility in South western Nigeria: Patterns and drivers

Background: ‘Brought- in-dead’ (BID) refers to the demise of an individual before presentation to a health facility. This study assessed the pattern of paediatric BID cases seen at a tertiary health facility in southwest Nigeria. Method: A cross-sectional, descriptive study was done at the Children Emergency Ward (CEW) of the hospital between January 2014 and December 2018. The patterns of BID cases and presumed causes of death were determined using a standardized checklist adapted from the WHO verbal autopsy instrument. Results: Ninety-eight BID cases were seen during the study, constituting 2.5% of total patients seen during the period. The median (IQR) age of cases was 24.0 (8.75 – 63.0) months and 72.4% were under-fives. Most had symptoms related to the haematologic (36.7%), respiratory (24.5%) or digestive (20.4%) systems. Severe anaemia 31(31.6%), gastroenteritis 19 (19.4) and aspiration 17 (17.3%) were the most common causes of death. The median (IQR) duration of illness before presentation was 3.0 (1.0 – 7.0) days but most presented from 4 – 7 days of illness. A significant relationship was found between the duration of illness and whether or not pre-hospital treatment was received (p < 0.0001). Unprescribed drugs purchased over the counter were the most commonly used treatment in 79.1% of cases (p < 0.0001). Conclusion: This study has highlighted the prevalence and pattern of paediatric BID in a tertiary health facility in southwest Nigeria and the factors that were associated with it. More efforts need to be geared towards community sensitization and pediatric health care to prevent factors drivingits menace

Disinfection of water with new chitosan-modified hybrid clay composite adsorbent

Hybrid clay composites were prepared from Kaolinite clay and Carica papaya seeds via modification with chitosan, Alum, NaOH, and ZnCl2 in different ratios, using solvothermal and surface modification techniques. Several composite adsorbents were prepared, and the most efficient of them for the removal of gram negative enteric bacteria was the hybrid clay composite that was surface-modified with chitosan, Ch-nHYCA1:5 (Chitosan: nHYCA = 1:5). This composite adsorbent had a maximum adsorption removal value of 4.07 × 106 cfu/mL for V. cholerae after 120 min, 1.95 × 106 cfu/mL for E. coli after ∼180 min and 3.25 × 106 cfu/mL for S. typhi after 270 min. The Brouers-Sotolongo model was found to better predict the maximum adsorption capacity (qmax) of Ch-nHYCA1:5 composite adsorbent for the removal of E. coli with a qmax of 103.07 mg/g (7.93 × 107 cfu/mL) and V. cholerae with a qmax of 154.18 mg/g (1.19 × 108 cfu/mL) while the Sips model best described S. typhi adsorption by Ch-nHYCA1:5 composite with an estimated qmax of 83.65 mg/g (6.43 × 107 cfu/mL). These efficiencies do far exceed the alert/action levels of ca. 500 cfu/mL in drinking water for these bacteria. The simplicity of the composite preparation process and the availability of raw materials used for its preparation underscore the potential of this low-cost chitosan-modified composite adsorbent (Ch-nHYCA1:5) for water treatment

Chemically Modified Biosorbents and Their Role in the Removal of Emerging Pharmaceutical Waste in the Water System

Presence of pharmaceutically active compounds (PACs) as emerging contaminants in water is a major concern. Recent reports have confirmed the presence of PACs in natural and wastewater systems, which have caused several problems indicating the urgent need for their removal. The current review evaluates the role of chemically modified biosorbents in the removal of PACs in water. Reported biosorbents include plant and animal solid waste, microorganisms and bio-composite. Bio-composites exhibited better prospects when compared with other biosorbents. Types of chemical treatment reported include acid, alkaline, solvent extraction, metal salt impregnation and surface grafting, with alkaline treatment exhibiting better results when compared with other treatments. The biosorption processes mostly obeyed the pseudo-second-order model and the Langmuir isotherm model in a process described mainly by ionic interaction. Desorption and regeneration capacity are very important in selecting an appropriate biosorbent for the biosorption process. Depending on the type of biosorbent, the cost of water treatment per million liters of water was estimated as US 10–US 200, which presents biosorption as a cheap process compared to other known water treatment processes. However, there is a need to conduct large-scale studies on the biosorption process for removing PACs in water