ChemInform Abstract: Liquid-Crystalline Solvents as Mechanistic Probes. Part 45. Norrish II Reactions of Liquid-Crystalline Ketones. Comparison Between Smectic B and Solid Phase Order and Control of Photoproduct Distributions

ChemInform ◽  
2010 ◽  
Vol 23 (46) ◽  
pp. no-no
Author(s):  
I. FURMAN ◽  
R. J. BUTCHER ◽  
R. M. CATCHINGS ◽  
R. G. WEISS
Keyword(s):  
Liquid Crystalline ◽  
Solid Phase ◽  
And Control

scholarly journals Solidification and superlubricity with molecular alkane films

2019 ◽  
Vol 116 (51) ◽  
pp. 25418-25423 ◽  
Author(s):  
Alexander M. Smith ◽  
James E. Hallett ◽  
Susan Perkin
Keyword(s):  
Solid Phase ◽  
Molecular Layer ◽  
Friction Coefficients ◽  
Model Studies ◽  
Surface Alignment ◽  
Hydrocarbon Films ◽  
Nanoscale Films ◽  
Alkane Films ◽  
And Control ◽  
Single Molecular Layer

Hydrocarbon films confined between smooth mica surfaces have long provided an experimental playground for model studies of structure and dynamics of confined liquids. However, fundamental questions regarding the phase behavior and shear properties in this simple system remain unsolved. With ultrasensitive resolution in film thickness and shear stress, and control over the crystallographic alignment of the confining surfaces, we here investigate the shear forces transmitted across nanoscale films of dodecane down to a single molecular layer. We resolve the conditions under which liquid–solid phase transitions occur and explain friction coefficients spanning several orders of magnitude. We find that commensurate surface alignment and presence of water at the interfaces each lead to moderate or high friction, whereas friction coefficients down toμ≈0.001are observed for a single molecular layer of dodecane trapped between crystallographically misaligned dry surfaces. This ultralow friction is attributed to sliding at the incommensurate interface between one of the mica surfaces and the laterally ordered solid molecular film, reconciling previous interpretations.

Tunable topographical cellulose matrices for electro-optical liquid crystal cells

2006 ◽  
Vol 14 (4) ◽  
Author(s):  
I. Costa ◽  
P. Almeida ◽  
D. Filip ◽  
J. Figueirinhas ◽  
M. Godinho
Keyword(s):  
Thin Films ◽  
Liquid Crystal ◽  
Liquid Crystalline ◽  
Cellulose Derivatives ◽  
Free Standing ◽  
Casting Technique ◽  
Solvent Vapour ◽  
Preparation Conditions ◽  
And Control ◽  
Crystal Cells

AbstractIn this work we have used acetoxypropylcellulose (APC) to produce free standing solid films (∼60 μm) that were used for assembling electro-optical devices. Thin films were obtained from concentrated lyotropic solutions of cellulose derivatives. Induced by the cast and shearing preparation conditions wrinkles and band textures can be observed in their free-surface plane. In order to eliminate and control these textures we used a process similar to that introducted in literature [1] which consists of storing the films in the same solvent-vapour atmosphere as the solution system. Lyotropic APC liquid crystalline solutions in dymethylacetamide (DMA) with crosslinker were prepared, thin films were obtained by using a shear/casting technique and stored in the solvent-vapour atmosphere until a planar structure was achieved. The dried crosslinked films were analyzed by optical polarised microscopy (POM) and scanning electron microscopy (SEM). The films with different topographies were used to produce optical cells composed by the cellulose derivative film covered on both free surfaces by a layer of the nematic liquid crystal E7 and placed between two transparent conducting substrates. The electro-optical properties of these cells were obtained.

Study on Determination Method of the Volatile Organic Compounds Emissions from Particleboards for Indoor Finishing

2011 ◽  
Vol 250-253 ◽  
pp. 935-938 ◽  
Author(s):  
Shi Jing Sun ◽  
Jun Shen ◽  
Zhong Yuan Zhao
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Solid Phase ◽  
Practical Method ◽  
Simple Operation ◽  
Good Shape ◽  
Volatile Organic ◽  
Static Head ◽  
And Control ◽  
Larix Gmelini

In order to comprehensive understand and control volatile organic compounds (VOCs) release from particleboards, this paper takes Larix gmelini particleboard as example and analyzes VOCs by three different methods. First of all, VOCs of Larix gmelini particles were detected by the static head space solid-phase micro-extraction (HS-SPME) technique. Secondly Larix gmelini particleboards were analyzed using the method of adsorbed by activated carbon, desorpted with methylene dichloride and measured by GC/MS. Finally, Tenax-T Thermal desorption -GC/MS was used to qualitative VOCs emissions. The best method for determination VOCs from particleboards was found. SPME is a simple operation method with short time. But the pretreatment of sample was troublesome and it is not easily measured for lower concentration particleboards. Active carbon absorption method is not suitable for quantitative because of much error in extraction. It is suitable for qualitative analysis. Tenax-T is a simple operation way with short analysis time and good shape of chromatographic. It is a convenient and practical method. Further study of VOCs emission of panels can be supported by this method.

scholarly journals Effect of Model Sorptive Phases on Phenanthrene Biodegradation: Molecular Analysis of Enrichments and Isolates Suggests Selection Based on Bioavailability

2000 ◽  
Vol 66 (7) ◽  
pp. 2703-2710 ◽  
Author(s):  
M. Friedrich ◽  
R. J. Grosser ◽  
E. A. Kern ◽  
W. P. Inskeep ◽  
D. M. Ward
Keyword(s):  
Natural Organic Matter ◽  
Contaminated Soils ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Solid Phase ◽  
Cation Exchange Resin ◽  
16S Rrna Sequence ◽  
Enrichment Cultures ◽  
Gradient Gel Electrophoresis ◽  
Weak Cation Exchange ◽  
And Control

ABSTRACT Reduced bioavailability of nonpolar contaminants due to sorption to natural organic matter is an important factor controlling biodegradation of pollutants in the environment. We established enrichment cultures in which solid organic phases were used to reduce phenanthrene bioavailability to different degrees (R. J. Grosser, M. Friedrich, D. M. Ward, and W. P. Inskeep, Appl. Environ. Microbiol. 66:2695–2702, 2000). Bacteria enriched and isolated from contaminated soils under these conditions were analyzed by denaturing gradient gel electrophoresis (DGGE) and sequencing of PCR-amplified 16S ribosomal DNA segments. Compared to DGGE patterns obtained with enrichment cultures containing sand or no sorptive solid phase, different DGGE patterns were obtained with enrichment cultures containing phenanthrene sorbed to beads of Amberlite IRC-50 (AMB), a weak cation-exchange resin, and especially Biobead SM7 (SM7), a polyacrylic resin that sorbed phenanthrene more strongly. SM7 enrichments selected for mycobacterial phenanthrene mineralizers, whereas AMB enrichments selected for a Burkholderia sp. that degrades phenanthrene. Identical mycobacterial andBurkholderia 16S rRNA sequence segments were found in SM7 and AMB enrichment cultures inoculated with contaminated soil from two geographically distant sites. Other closely relatedBurkholderia sp. populations, some of which utilized phenanthrene, were detected in sand and control enrichment cultures. Our results are consistent with the hypothesis that different phenanthrene-utilizing bacteria inhabiting the same soils may be adapted to different phenanthrene bioavailabilities.

scholarly journals Seroprevalence and Risk Factors of Brucellosis in Dogs in Enugu and Anambra States, Nigeria

2020 ◽  
Vol 1 (40) ◽  
pp. 35-59
Author(s):  
Chidiebere O. Anyaoha ◽  
Lynda O. Majesty-Alukagberie ◽  
Iniobong C I. Ugochukwu ◽  
John A. Nwanta ◽  
Boniface M. Anene ◽  
...  
Keyword(s):  
Brucella Abortus ◽  
Solid Phase ◽  
Antibody Test ◽  
Control Measures ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Brucella Canis ◽  
Test Kit ◽  
Canine Brucellosis ◽  
And Control

Seroprevalence of the antibodies of Brucella canis and Brucella abortus in dogs was assessed using a cross-sectional survey in Anambra and Enugu States, Nigeria. A total of 123 Companion dogs made up of 65 clinic dogs, 34 slaughter dogs and 24 household dogs were screened. For B. abortus antibody assay, the collected serum was used for Rose Bengal plate test (RBPT), Serum agglutination test (SAT) and Solid Phase Immunoassay technique with Immunocomb® Canine Brucellosis Antibody Test Kit was used. Out of the 123 dogs screened, none was positive for Brucella abortus antibodies while 34 (27.7%) of the dogs screened were positive for B. canis antibodies. There was a significant association (P0.05) between infection and sex, the infection was significantly higher (P0.05) in female than male dogs. Prevalence was significantly higher (P0.05) in Exotic breeds than in mixed and local dog breeds. There was no association (P0.05) between infection and antibody titre levels in the different categories of dogs. However, there was significant association (P0.05) between the presence of Brucella canis antibodies and free roaming of dogs. This study provides the first serological evidence of B. canis infection in dogs in Enugu and Anambra States. This shows that B. canis is endemic in both states, underscoring the need for further studies. Female dogs, exotic breeds and freely roaming dogs are at a higher risk of Brucella infection in the study area; therefore, preventive and control measures are strongly recommended

scholarly journals Systemic absortion and adverse effects of topical ocular use of ketorolac tromethamine and sodium diclofenac in New Zealand rabbits for 90 days

2019 ◽  
Vol 71 (6) ◽  
pp. 1865-1872 ◽  
Author(s):  
F.Q. Pereira ◽  
B. Santos ◽  
T. Carboni ◽  
M. Bender ◽  
D. Driemeier ◽  
...  
Keyword(s):  
New Zealand ◽  
Solid Phase ◽  
Diclofenac Sodium ◽  
Systemic Absorption ◽  
Ketorolac Tromethamine ◽  
Nacl Solution ◽  
Laboratory Examination ◽  
New Zealand White Rabbits ◽  
Laboratory Results ◽  
And Control

ABSTRACT The effect of the systemic absorption of 0.1% diclofenac sodium (DS) eyedrop was compared to that of 0.5% ketorolac tromethamine (KT) in female New Zealand white rabbits treated on both eyes three times a day for 90 days. The rabbits were divided in three groups of six animals (n= 18): KT group, DS group, and control (Co) group, in which saline (0.9% NaCl) solution was instilled. Water and food consumption were measured daily, clinical examination was performed weekly, and blood samples were collected every 30 days for laboratory examination. The plasma was analyzed for the presence of KT and DS by solid-phase extraction (SPE) associated with mass spectrometry (MS). Systemic absorption of these drugs was confirmed by SPE-MS, allowing their separation and identification in the plasma. At the end of the treatment, the animals were euthanized and necropsied, and no macroscopic or microscopic changes were found. This observation confirmed the laboratory results, which were within normal reference standards for the species. According to the results obtained, it can be concluded that treatment with eyedrops containing KT and DS for 90 days in healthy rabbits does not cause adverse systemic effects.

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