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1 – 10 of over 1000In 1988 over half of the deaths in the world were due to heartdisease. The recognised risk factors for coronary heart disease aresmoking, plasma cholesterol levels and…
Abstract
In 1988 over half of the deaths in the world were due to heart disease. The recognised risk factors for coronary heart disease are smoking, plasma cholesterol levels and hypertension. These factors, however, account only for some 50‐60 per cent of the variance in incidence of the disease between countries; so other factors must contribute. Recent biochemical evidence suggests that in conditions of oxidant stress a relative deficiency in antioxidants, in conjunction with a relatively high concentration of oxidisable substrates such as cholesterol, may play an important role in the development of atheroma. The efficiency of the human antioxidant defence system depends in part on an adequate intake of foods containing antioxidants such as vitamins C and E. Until intervention trials with these antioxidants show positive effects in reducing coronary heart disease, advising the general population to increase intake of Vitamin C and E is contentious. On the other hand increasing consumption of fruit and vegetables is unlikely to do any harm, and may do us some good.
Hamid Javaherian Naghash and Ali Amiri
This paper aims to improve some properties of poly (methyl methacrylate) by copolymerization with butyl acrylate (BA) monomer along with the incorporation of the stable and…
Abstract
Purpose
This paper aims to improve some properties of poly (methyl methacrylate) by copolymerization with butyl acrylate (BA) monomer along with the incorporation of the stable and economical synthesized silicone-containing monomer hexamethyldisilazanomethacryloxyphenyl ketone (HDMK) into the copolymer matrix.
Design/methodology/approach
For this target solution copolymerization of methyl methacrylate (MMA), BA and HDMK were carried out using a 250 mL four-necked round-bottom flask. Before solution polymerization start-up, the reaction vessel was first charged with 34.8 mL toluene and heated to 170 °C with stirring and reflux cooling. A monomer mixture of 25.86 g (260 mmol) MMA, 26.40 g (200 mmol) BA, 3.00 g (8.60 mmol) HDMK and 0.45 g (2.00 mmol) dibenzoyl peroxide was added continuously from the dropping funnel over a period of 4 h.
Findings
The HDMK was successfully synthesized and the water resistance of acrylic resins was improved because of the existence of HDMK.
Research limitations/implications
The materials that were used in this research paper had a reasonably low cost. Also, the procedures for synthesis of monomers and polymers were extremely easy because there was no need for high pressure or temperature and no dangerous solvents were used.
Practical implications
The acrylic resin that contained HDMK was used to synthesis a white architectural paint for exterior coating. Examining the paint characteristics has shown acceptable washing and abrasion resistance, good brushing, excellent storage stability and great surface coating.
Originality/value
HDMK was synthesized for the first time.
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R.A. El‐Adly, E.A.M. Youssef, S.M. El‐Sayed and M.A. Abd El‐Ghaffar
This paper reports on the preparation of six formulations (G1‐G6) containing mixed soap greases based on cotton soap stock, aromatic extract, heavy alkylate and lube base oil. The…
Abstract
This paper reports on the preparation of six formulations (G1‐G6) containing mixed soap greases based on cotton soap stock, aromatic extract, heavy alkylate and lube base oil. The physicochemical properties of these ingredients were characterised. The consistency, dropping point and mechanical stability of the formulated greases were assessed and tested in accordance with the National Laboratory for Grease Institute standards, and compared with the Egyptian Standards. The properties of the formulated grease G4 proved to be the best. The work reported also includes preparation of itaconyl‐o‐tolidine‐, itaconyl bisaniline‐ and itaconyl m‐phenylene‐ amide polymers. The structure of these polymers was investigated using infrared spectroscopy, micro analysis and gel permeation chromatography. The polymers prepared were evaluated as antioxidants for the optimum formulated grease G4. The study revealed that the itaconyl m‐phenylene amide polymer was a weak antioxidant, while itaconyl bisaniline‐ and itaconyl‐o‐tolidine amide polymers showed good anti‐oxidation property.
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The print fault “dot bridging” reduces the printing press efficiency. This study was designed to find the best combination of materials used in normal production which would…
Abstract
Purpose
The print fault “dot bridging” reduces the printing press efficiency. This study was designed to find the best combination of materials used in normal production which would reduce or eliminate the problems thus increasing efficiency.
Design/methodology/approach
Various statistical methods were used to design the experiments and to analyse the experimental results. The experiment included all of the factors which were considered to have an effect on the “dot bridging” print fault.
Findings
The most important conclusion that can be drawn from the results is that the complex interactions between factors included in the process can be characterised. The experiment proved that the problem was not random. The data gathered during the experiment had a direct correlation with the psychometric results. Various factors included in the experiment were found to have a significant influence on print density and print contrast. Contrast and density were selected for analysis as ink film thickness was thought to have an influence on the best looking print samples and the “dot bridging” print fault.
Research limitations/implications
The results of the experiment were used to optimise the production process particularly the platemaking technique. Data from further experiments would help to optimise more process parameters.
Practical implications
Minitab computer software was used to analyse the results of the experiment thus making it easier to communicate the results to non‐scientific production staff.
Originality/value
This was the first time that the printer concerned had used a scientific approach to problem solving. The end result for the printer was an increase in production efficiency which saved the printer a considerable amount on money.
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Vellingiri Vadivel and Hans Konrad Biesalski
The purpose of this paper is to evaluate the antioxidant and type II diabetes related enzyme inhibition properties of phenolic extract from raw and traditionally processed Indian…
Abstract
Purpose
The purpose of this paper is to evaluate the antioxidant and type II diabetes related enzyme inhibition properties of phenolic extract from raw and traditionally processed Indian under‐utilized food legume grains, Bauhinia purpurea L. (purple camel's foot seeds).
Design/methodology/approach
The methanolic extract was prepared from the raw and traditionally processed seed samples and analyzed for total phenolic content. The antioxidant activity and type II diabetes related enzyme inhibition properties of methanolic extract and their relationship with phenolic content was demonstrated.
Findings
The methanolic extract of raw seed materials contained total free phenolic content of 14.45±1.62 g catechin equivalent/100 g extract DM. Encouraging levels of ferric reducing/antioxidant power (FRAP, 1203 mmol Fe[II]/mg extract), inhibition of ß‐carotene degradation (45.37 percent) and scavenging activity against DPPH (63.60 percent) and superoxide (42.14 percent) radicals were exhibited by the raw samples. Further, it also recorded 80.69 percent of α‐amylase and 63.74 percent of α‐glucosidase enzyme inhibition characteristics under in vitro starch digestion bioassay. Sprouting+oil‐frying caused an apparent increase on the total free phenolic content, antioxidant and free radical scavenging capacity, while soaking+cooking as well as open‐pan roasting treatments show diminishing effects.
Originality/value
Identification of suitable processing technique offered a good strategy to improve the phenolic content and health relevant functionality of B. purpurea seeds, which could be envisaged as a dietary ingredient in the formulation of supplementary foods with therapeutic value to manage type II diabetic patients.
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The latest international research on vitamin C and its possible role in reducing the risk of cancers, heart disease and other serious ailments was presented at a conference held…
Abstract
The latest international research on vitamin C and its possible role in reducing the risk of cancers, heart disease and other serious ailments was presented at a conference held recently in Glasgow. The conference was held to celebrate ten years of production of vitamin C by Roche Products at Dairy. Professor Ronald Anderson from the University of Pretoria reviewed the origins and adverse effects on health of oxygen‐free radicals, and other reactive oxidants generated during activation of the human immune system, and the protective role of the anti‐oxidant nutrient vitamin C in the prevention of free radical‐mediated immune dysfunction, tissue damage and carcinogenesis during inflammatory responses. Here we include extracts from his paper.
Jian Zhou, Qiuyu Zhang, Hepeng Zhang, Jiaojun Tan, Shaojie Chen, Qing Liu, Mingliang Ma and Tiejun Xin
The purpose of this paper is to evaluate the properties of several thiol-acrylate photosensitive systems and compare with corresponding acrylate free-radical systems. The…
Abstract
Purpose
The purpose of this paper is to evaluate the properties of several thiol-acrylate photosensitive systems and compare with corresponding acrylate free-radical systems. The potential stereolithography applications of thiol–ene photosensitive systems are also discussed.
Design/methodology/approach
In the both thiol–ene and acrylate free-radical photosensitive systems, various key performances were characterized. The function group conversions were characterized by real-time Fourier transform infrared spectroscopy. The tension strength was determined according to the standard ASTM D638-2003, the flexible strength was determined according to ASTM D790-07 and the hardness was measured according to ASTM D2240-05. The volume shrinkage was measured by dilatometer method. The glass transition temperature was analyzed by differential scanning calorimeter.
Findings
As adding mercapto propionates into acrylate system, the inhibition of polymerization by oxygen was controlled and the flexible performance was improved. In addition, the photosensitive resin showed better tension strength, higher elongation at break and lower volume shrinkage. Among the four mercapto propionates, rigid TEMPIC showed most obvious affect, followed hexa-functional DPMP, tetra-functional PETMP and tri-functional TMMP.
Originality/value
Although the thiol–ene photosensitive resin has unmatched advantages in performance, there are no reports on the thiol–ene photosensitive resin in the stereolithography application. In this study, thiol–ene photopolymerization material was first tentatively implemented in stereolithography area. Several critical performance parameters were compared between thiol–ene and acrylate free-radical photosensitive systems.
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Muhammad Nadeem Asghar, Javaid Akhtar, Muhammad Shafiq, Iram Nadeem, Muhammad Ashfaq and Sammia Shahid
The cowpea plant, being affordable and protein‐rich, is considered poor man's meat. The aim of this paper is to undertake a detailed investigation regarding in vitro total…
Abstract
Purpose
The cowpea plant, being affordable and protein‐rich, is considered poor man's meat. The aim of this paper is to undertake a detailed investigation regarding in vitro total antioxidant capacity (TAC) and chemical constituents of the vegetable oils from seeds of this plant, taking its nutritional value into consideration.
Design/methodology/approach
Vegetable oils of different indigenous cowpea varieties were obtained using soxhelt extraction assembly and subjected to GC‐MS analyses and various antioxidant assays including 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulpohonic acid) (ABTS) radical cation scavenging, ferr, 2.2′‐diphenyl‐1‐picrylhydrazil (DPPH) radical scavenging, total phenolic contents (TPC), lipid peroxidation inhibition, and iron chelation activity.
Findings
Various chemical constituents including different hydrocarbons, tocopherols, ketones, fatty esters, estragole and cedrene were identified. TPCs were found to be 5.439, 5.7279, 7.6126, 6.7573 and 10.0591 mg/L gallic acid equivalent for S.A. Dandy, Elite, White Star, CP‐386 and FBD Rawan varieties, respectively. Employing ABTS radical decoloration assay a significant linear correlation (R2=0.997, 0.996, 0.997, 0.996 and 0.997 for S.A. Dandy, Elite, White Star, CP‐386 and FBD Rawan varieties, respectively) was found between the percent inhibition of ABTS radical cation and the amount of vegetable oils. The percent inhibition of the Fe(II)‐Ferrozine complex formation was found to be 29.45, 53.76, 82.91, 86.59 and 57.87 for the same varieties, respectively.
Originality/value
GC‐MS and standard in vitro antioxidative capacity analyses data clearly demonstrated the potency of the cowpea as antioxidant and radical scavenger plant which may be used as a good source of natural antioxidants. The plant seeds may prove a better and cost‐effective substitute of expensive food items.
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