نتایج جستجو برای: 99 standard method with hexane and acetone solvents
تعداد نتایج: 18593444 فیلتر نتایج به سال:
the purpose of the present study was to investigate the effect of task-based instruction of vocabulary on the receptive and oral productive acquisition of english vocabulary and compare the results with those obtained from the traditional method. the method and procedure applied in this study was as follows: after the implementation of opt, a group of sixty female students were chosen. the stu...
We present a unified treatment of solvatochromic shifts in liquid-phase absorption spectra, and we develop a self-consistent state-specific vertical excitation model (called VEM) for electronic excitation in solution. We discuss several other approaches to calculate vertical excitations in solution as an approximation to VEM. We illustrate these methods by presenting calculations of the solvato...
Plants historically have served as models in drug development. The production of medicines and the pharmacological treatment of diseases began with the use of herbs. The antifungal activity of five different plants namely, Aegle marmelos, Carica papaya, Mentha arvensis, Nicotiana plumbaginifolia and Tamarindus indica were tested against plant pathogenic fungi Alternaria alternata. The plant ext...
background organic solvents are widely used in cell biology experiments. despite increasing the solubility, they have some moderate toxic effects. therefore, selecting the appropriate solvent along with the use of suitable concentration insures the accuracy and reliability of experimental results. objectives the current study aimed to examine the cytotoxic effects of some organic solvents on va...
A mutant Aspergillus carbonarius produces partially saturated canthaxanthin (PSC; C(40)H(62)O(2)) during submerged fermentation. The pigment was extracted from dried biomass using various organic solvents and purified using nanofiltration (NF) and nonporous membranes. Particle size had a great influence; PSC extractability from fines fraction of biomass (75-105 microm) was 1.5-fold higher compa...
data envelopment analysis (dea) is a powerful tool for measuring relative efficiency of organizational units referred to as decision making units (dmus). in most cases dmus have network structures with internal linking activities. traditional dea models, however, consider dmus as black boxes with no regard to their linking activities and therefore do not provide decision makers with the reasons...
Objectives: The present study was to study the phytochemical and antibacterial properties of Alternanthera brasiliana leaf extracts using three different solvents (hexane, chloroform and methanol) against human pathogenic microorganism. Methods: Preliminary phytochemical screening of leaf extracts (in different solvents) of A. brasiliana were qualitatively tested using standard procedures. Thin...
Cashew nutshell liquid (CNSL) is a cheap source of natural phenolic compounds that have numerous applications. These chemical structures with chromophores similar to those found in synthetic UV-filters, which are present commercial sunscreen products (SSPs). Thus, this study investigated the impact solvents on yield, total phenol content (TPC), flavonoid (TFC), and sun protection factor (SPF) c...
A gas chromatography (GC) method including a full evaporation headspace (FE-HS) sampling technique was developed for rapidly and simultaneously measuring volatile products for acetone-butanol-ethanol (ABE) fermentation. In this method, a small volume (<50 μL) of fermentation broth was directly injected into a sealed headspace sample vial (22 mL) and the mass transfer of acetone-butanol-ethanol ...
In this paper, a low-cost yet effective method of irreversible bonding between two elastomeric polydimethylsiloxane (PDMS) interfaces using Piranha solution is investigated. Piranha solutions at a weight ratio of 3:1 using different acids and hydrogen peroxide were attempted. The average tensile strengths of the device bonded with concentrated sulfuric acid-based piranha solution and nitric aci...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید