A caustic vector vortex optical field is experimentally generated and demonstrated by a caustic-based approach. The desired caustic with arbitrary acceleration trajectories, as well as the structured states of polarization (SoP) and vortex orders located in different positions in the field cross-section, is generated by imposing the corresponding spatial phase function in a vector vortex optical field. Our study reveals that different spin and orbital angular momentum flux distributions (including opposite directions) in different positions in the cross-section of a caustic vector vortex optical field can be dynamically managed during propagation by intentionally choosing the initial polarization and vortex topological charges, as a result of the modulation of the caustic phase. We find that the SoP in the field cross-section rotates during propagation due to the existence of the vortex. The unique structured feature of the caustic vector vortex optical field opens the possibility of multi-manipulation of optical angular momentum fluxes and SoP, leading to more complex manipulation of the optical field scenarios. Thus this approach further expands the functionality of an optical system.
Caustic pulping of oil-palm frond-fiber strands was conducted following a central composite design using a two-level factorial plan involving three pulping variables (temperature: 160-180 degrees C, time: 1-2 h, alkali charge: 20-30% NaOH). Responses of pulp properties to the process variables were analyzed using a statistical software (DESIGN-EXPERT). The results indicated that frond-fiber strands could be pulped with ease to about 35-45% yield. Statistically, the reaction time was not a significant factor while the influences of the treatment temperature and caustic charge were in general significantly relative to the properties of the resultant pulps.
Aluminium (Al) is a low cost, lightweight and corrosion resistant material, which corrodes when exposed to pitting agents. Palm olein exhibits characteristics, which indicate its suitability as a corrosion inhibitor. Tween 20, hexane and diethyl triamine were used as additives to Palm olein to form the inhibitor formulation POT2OHA. The inhibition efficiency (IE) and behaviour of the POT2OHA were determined using potentiodynamic polarization in which Al 6061 samples were immersed in a 1 M HC1 solution at 26, 50 and 70 °C in the presence of different POT2OHA concentrations: 0, 0.03, 0.07, 0.10, 0.13 and 0.17 M The IE increased with increasing POT2OHA concentration, but decreased with increasing temperature. The work presented indicates that POT2OHA is a mixed-type inhibitor capable of inhibiting both corrosive anodic and cathodic reactions. According to the Langmuir isotherm results POT2OHA adsorbs on the A16061 surface through semiphys iosorption and/or semi-chemisorption. The POT2OHA adsorption mechanism on Al 6061 takes through the protonation of micelles by the HC1 solution, whereby protonated micelles in the presence of chloride ions adsorb on both cathodic and anodic surface corrosion sites.
The paper presents the results of ample investigations performed on industrial and traditional ceramics of fired clay used in processes of water potabilization in the last stage of filtration, after that of active charcoal. Using the data obtained through the scanning electron microscope coupled with energy dispersive X-ray analysis (SEM-EDX) and pH analyses, on the basis of the atomic composition and free concentration of hydronium ions, the normal caustic (Si/Al) and summative [(Si+Ti+FeIII+Cl)/(Al+Ca+Mg+Na+K)] modules were assessed, which were correlated with the free acidity and, respectively, the capacity of absorption and ionic exchange of the Fe3+ and Al3+ ions. The study allowed the selection, on the basis of the caustic module, of the ceramics with high capacity for ionic exchange.
The use of an endoscopic approach for the division of glottic webs or stenosis has been reported in the literature and has been mainly confined to the anterior commisure. We report a rare case of caustic injury to the upper aerodigestive tract that resulted in extensive web formation along the membranous vocal cord which was successfully treated with endoscopic lysis of the adhesions and the use of a silastic sheet keel as a stent.
Twenty-two cases of corrosive oesophageal strictures were reviewed and divided into annular, short segment and long segment lesions. The lower third of the oeseophagus was involved in all the long segment strictures, but with sparing of the extreme distal portion in most. Irregularity of the stricture walls with an appearance similar to reported cases of intramural diverticulosis is a common finding but smooth strictures can also occur.
A case of mucosal burn during the placement of fissure sealant on the first permanent molars of a 9-year-old Malay boy is presented. The erythematous lesion with accompanying burning sensation appeared a few minutes after the etching liquid, containing 37% by weight phosphoric acid, had accidentally come into contact with the buccal mucosa on the right side of the angle of the mouth. The mucosa showed complete healing after one week. The use of rubber dam for tooth isolation while doing fissure sealant is essential to avoid accidental contact of potentially caustic chemicals, such as the phosphoric acid etchant, with the oral mucosa as it can result in mucosal burns.
In the current protocol, the arene diazonium saccharin derivatives were initially produced from various substituted aromatic amines; subsequently, these intermediates were treated with a greener organic iodide for the preparation of the aryl iodide. We tried to choose low-cost, commercially available, biodegradable, recoverable, ecofriendly, and safe reagents and solvents. The arene diazonium saccharin intermediates could be stored in the liquid phase into a refrigerator for a long time with no significant loss activity. The outstanding merits of the current protocol (a) included the partial recovering of saccharin and tetraethylammonium salt, (b) reduce the use of solvents and the reaction steps due to eliminating separation and purification of intermediates, (c) good yield of the sterically hindered substrates, and (d) avoid the generation of heavy metal or corrosive waste.
The organic foods’ market is becoming one of the rapidly growing sections in agricultural economies in the world. During the last two decades, food-borne outbreaks associated with fresh produce have rapidly increased. E. coli O57:H7, the caustic agent of acute hemorrhagic diarrhea and abdominal cramps, is mainly associated with meat and poultry product outbreaks but frequent outbreaks linked to the consumption of vegetables have been reported. The aim of this study was to investigate prevalence of E. coli O157:H7 in some organic foods. A total of 230 organic food samples including four-winged bean, tomato, white radish, red cabbage, chinese cabbage, lettuce, cucumber and chicken form retailed groceries and supermarkets in Malaysia were investigated. Low prevalence of E. coli O157:H7 was detected in organic vegetables and chickens. The estimated quantity of E. coli O157:H7 in all samples ranged from 2400 MPN/g. The overall MPN/g estimate of E. coli O157:H7 in the samples from organic groceries was higher than supermarket with the maximum of >2400 MPN/g. Most of the samples from supermarket showed a minimum of
Magnesium has been recognized as a groundbreaking biodegradable biomaterial for implant applications, but its use is limited because it degrades too quickly in physiological solutions. This paper describes the research on the influence of polycaprolactone (PCL)/chitosan (CS)/zinc oxide (ZnO) composite coating (PCL/CS/ZnO) on the corrosion resistance and antibacterial activity of magnesium. The PCL/CS film presented a porous structure with thickness of about 40-50 μm, while after incorporation of ZnO into the PCL/CS, a homogenous film without pores and defects was attained. The ZnO embedded in PCL/CS enhanced corrosion resistance by preventing corrosive ions diffusion in the magnesium substrate. The corrosion, antibacterial, and cell interaction mechanism of the PCL/CS/ZnO composite coating is discussed in this study. In vitro cell culture revealed that the PCL/CS coating with low loaded ZnO significantly improved cytocompatibility, but coatings with high loaded ZnO were able to induce some cytotoxicity osteoblastic cells. It was also found that enhanced antibacterial activity of the PCL/CS/ZnO coating against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria, while less significant antibacterial activity was detected for uncoated Mg and PCL/CS coating. Based on the results, the PCL/CS coatings loaded with low ZnO content may be recommended as a candidate material for biodegradable Mg-based orthopedic implant applications.