Uncovering Students' Understanding; Evidence For The Teaching of Acid-Base Properties of Salt Solution

<p>Este estudio tuvo como objetivo descubrir la comprensión científica y no científica de los estudiantes sobre el tema de las propiedades ácido-base de la solución salina. Este estudio descriptivo involucró a 300 estudiantes de tres escuelas secundarias públicas en Malang, Java Oriental, Indonesia. El instrumento de cuatro niveles en el tema desarrollado y considerado válido de nuestro trabajo anterior se utilizó para la recopilación de datos. Se encuentra que la comprensión científica de algunos conceptos por parte de los estudiantes es sólida. Sin embargo, también se descubrieron algunos conocimientos no científicos. También se discute la implicación para la enseñanza del tema.</p>

An overview of induced seismicity in the Netherlands

We present an overview of induced seismicity due to subsurface engineering in the Netherlands. Our overview includes events induced by gas extraction, underground gas storage, geothermal heat extraction, salt solution mining and post-mining water ingress. Compared to natural seismicity, induced events are usually small (magnitudes ≤ 4.0). However, due to the soft topsoils in combination with shallow hypocentres, in the Netherlands events exceeding magnitude 1.5–2.0 may be felt by the public. These events can potentially damage houses and infrastructure, and undermine public acceptance. Felt events were induced by gas production in the north of the Netherlands and by post-mining water ingress in the south-east. Notorious examples are the earthquakes induced by gas production from the large Groningen gas field with magnitudes up to 3.6. Here, extensive non-structural damage incurred and public support was revoked. As a consequence, production will be terminated in 2022 leaving approximately 800 billion cubic metres of gas unexploited. The magnitudes of the events observed at underground gas storage, geothermal heat production and salt solution mining projects have so far been very limited (magnitudes ≤ 1.7). However, in the future larger events cannot be excluded. Project- or industry-specific risk governance protocols, extensive gathering of subsurface data and adequate seismic monitoring are therefore essential to allow sustainable use of the Dutch subsurface now and over the decades to come.

Comparisons of flow dynamics of dual-blade to single-blade beveled-tip vitreous cutters

Introduction: To compare the flow dynamics of the dual-blade to the single-blade beveled-tip vitreous cutters. Methods: The aspiration rates of balanced salt solution (BSS) and swine vitreous were measured for the 25-gauge and 27-gauge dual- and single-blade vitreous cutters. The flow dynamics of BSS and diluted vitreous mixed with fluorescent polymer at the maximal cutting rates and the reflux of BSS were measured in images obtained by a high-speed camera. The distal end of the cutter was defined as the head end. Results: The aspiration rates of BSS and vitreous by the 25- and 27-gauge dual-blade cutters were significantly higher than those of both single-blade cutters at the maximal cutting rate (all P≤0.01). The mean aspiration flow of BSS in front of the port from a lateral view was significantly faster for both dual-blade cutters than for both single-blade cutters (P=0.003, P=0.019). The angle of the mean flow of BSS of both dual-blade cutters was from the distal end (P<0.001, P<0.001) but that of the single blade-cutters was from the proximal end. The velocity and angle of the mean reflux flow of both types of cutters were not significantly different. The mean aspiration flow of diluted vitreous was significantly faster for 25-gauge dual-blade cutters with the angle more from the proximal end and 27-gauge dual-blade cutters more from the distal end than both single-blade cutters (P=0.018, P=0.048). Conclusion: The dual-blade beveled-tip vitreous cutters improve the efficiency of the vitrectomy procedures and maintain the distal aspirating flow by the beveled-tip.

Alteration in the Efficacy of in Vitro Vancomycin and Ceftazidime Prepared in Normal Saline Versus Balanced Salt Solution in the Management of Ocular Infections

Objective: The purpose of this review article is to highlight the efficacy of Vancomycin and Ceftazidime formulated in different solutions for ocular use in the management of microbiological Ocular infections varies. Methodology: To locate and assess all relevant literature, we employed systematic review as a search approach, utilizing punctilious and unambiguous methodologies. We initiated by stipulating key terms and selecting appropriate databases for your literature search. To find replicable and reportable publications from high-quality peer-reviewed journals, we used Google Scholar, PubMed, and Research Gate. Results: Ceftazidime precipitated at 37 degree Celsius, but not at room temperature, however it did not show any effect on the pH of the medium. In both the media of Normal Saline and Balanced Salt Solution, it precipitated on its own or when coupled with vancomycin. Ceftazidime was initially prepared in Balanced Salt Solution rather than Normal Saline, which resulted in further precipitation. Ceftazidime prepared in Normal Saline precipitated to 54% after 168 hours in the dialysis chambers, compared to 88% in Balanced Salt Solution. Ceftazidime synthesized in Normal Saline declined from an initial concentration of 137.5 to 73.4 µg/ml after 48 hours, while ceftazidime prepared in Balanced Salt Solution decreased to 6.3µg/ml. Vancomycin precipitation was inappreciable. Conclusion: Vancomycin did not precipitate in Normal Saline or Balanced Salt Solution, according to this systemic study. Regardless of the presence of vancomycin, ceftazidime precipitated, and it precipitated more expeditiously if it was produced in Balanced Salt Solution rather than Normal Saline.

Extraction behaviors of aqueous PEG impregnated resin system in terms of impregnation stability and recovery via protein impregnated resin interactions on bovine serum albumin

Background Current advances in biotechnology have been looked at as alternative approaches towards the limited product recovery due to time- and cost-consuming drawbacks on the conventional purification methods. This study aimed to purify bovine serum albumin (BSA) as an exemplary target product using an aqueous impregnated resin system (AIRS). This method implies the concept of hydrophobicity of polymer that impregnated into the resins and driven by electrostatic attractions and hydrophilicity of aqueous salt solution to extract the target product. Methods The extraction behaviors of impregnation in terms of stability and adsorption kinetics via protein-aqueous polymer impregnated resin were studied. Impregnation stability was determined by the leaching factor of polyethylene glycol (PEG). The major factors such as PEG molecular weights and concentration, pH of aqueous salt solution, extraction methods (sonication and agitation) and types of adsorbent material and concentration of aqueous salt phase influencing on partitioning of biomolecule were also investigated. Results For impregnation stability, the leaching factor for Amberlite XAD4 did not exceed 1%. The scanning electron microscopy (SEM) image analysis of Amberlite XAD4 attributes the structural changes with impregnation of resins. For adsorption kinetics, Freundlich adsorption isotherm with the highest R2 value (0.95) gives an indication of favorable adsorption process. Performance of AIRS impregnated with 40% (w/w) of PEG 2000 was found better than aqueous-two phase system (ATPS) by yielding the highest recovery of BSA (53.72%). The outcomes of this study propound the scope for the application of AIRS in purification of biomolecules.