Liquor Ammonia Research Articles

Dielectric Analysis of Amine Modified Nano-graphite: Effects of Thickness, Temperature and Frequency

Amine modified nano-graphite (NH2-NG) has been produced from nanographite (NG) powder via liquor ammonia (NH3) aqueous solution by microwave, ultrasonic methods. The surface modified NG have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) techniques which clearly demonstrate that synthesis of NH2-NG was successful. The crystalline characteristics of amine modified nanographite powder have been studied through XRD technique. The morphology structure of synthesized surface modified nanoparticles has been determined by SEM analysis. FTIR spectra confirmed the existence of amine groups on the surface of produced nano-graphite powder. NH2-NG pellet was prepared to analyse its dielectric properties as a function of thickness (1, 2, 3, 5 and 7 mm), frequency (range 10−2-105 Hz) and temperature (25, 50, 75 and 100 °C). As a function of frequency, the dielectric loss tangent and permittivity each exhibit a distinct relaxation peak that grows up to a thickness of 5 mm then decreasing. Because nanoparticles are capacitive, the capacitance values of NG and NH2-NG increase with thicknesses up to 5 mm and drop with frequency. The drop in dielectric permittivity of NG and NH2-NG pellets after 5 mm may be caused by an increase in resistivity. Positive temperature coefficient (PTC) of increased conductance is confirmed by the continuous increase in electrical conductivity of NG and NH2-NG with temperature. The degree of temperature has a significant impact on the dielectric loss tangent, dielectric permittivity, and electrical conductivity of NG, and NH2-NG.

Effect of Stirring Speed on the Morphology of Nanosilica by Sol-Gel method

The sol–gel technique was used to make spherical nanosilica particles at different stirring speeds (400 rpm and 600 rpm) utilizing TEOS, ethanol and liquor ammonia as precursor, common solvent and catalyst respectively. The amorphous structure was characterized using XRD (X-ray diffraction). The particle size distribution was examined at two different RPMs using a scanning electron microscope, which exhibited a homogeneous spherical surface. The particle sizes shrank when the stirring speed was increased. The average particle size of nanosilica measured 674 nm and 418 nm at 400 rpm and 600 rpm stirring rates, respectively.

Comparison of nutrient intake and digestibility, rumen fermentation along with body weight gain in cattle and buffalo fed maintenance diet

In the present study, feed and nutrient intake, body weight changes, nutrient digestibility and rumen fermentation parameters were compared in cattle and buffaloes. Seven cattle (T1) and seven buffaloes (T2) were placed in two groups based on body weight employing completely randomized design. Experimental feeding in the form of total mixed ration (TMR) was carried out for 75 days having concentrate (C) and roughage (R) in 30C:70R. The daily intake of dry matter, crude protein, digestible crude protein and total digestible nutrients was non-significant between cattle and buffaloes. While in terms of percentage and metabolic body weight, the same parameters were significantly lower in cattle compared to buffalo. Digestibility of DM, OM, CP, EE, CF, NFE, NDF and ADF marginally differed between cattle and buffaloes. Rumen liquor pH, ammonia, non-protein and soluble nitrogen concentration was non-significantly different between cattle and buffaloes with significant lower value of total volatile fatty acids (12.25 vs. 14.19 mM/dl), total nitrogen (90.53 vs. 101.73 mg/dl) and TCA precipitable nitrogen (51.33 vs. 61.36 mg/dl) in cattle compared to buffaloes. Thus, from the study, it may be concluded that under similar feed and managemental conditions, intake of dry matter and nutrients per unit of body weight was lower, with non-significant difference in nutrients digestibility and inferior nitrogen fermentation as observed in cattle than buffaloes.

Comparative account of catalytic activity of Ru- and Ni-based nanocomposites towards reductive amination of biomass derived molecules

• Reductive amination of bio-derived molecules with nanocomposites of MMT-K10 clay. • Effective comparison of ruthenium and nickel nanocomposites for reductive amination. • Comprehensive characterization data for both of the synthesized nanocomposites. • Industrial scope shown by reacting crude furfural extracted from xylose & biomass. • Gram scale run for reductive amination reported for the ruthenium nanocomposite. This work includes an effective comparison of metallic ruthenium and nickel nanoparticles loaded on montmorillonite clay (MMT) for reductive amination reaction of biomass-derived molecules. It comprises an eco-friendly reaction using water as a solvent, utilizing molecular hydrogen and liquor ammonia (25% aq. solution) for the synthesis of primary amines from bio-derived aldehydes within 3–10 h of reaction time. Various parameters such as temperature, hydrogen pressure, substrate/ammonia concentration ratio, and reaction time were optimized while comparing the selectivity of primary amines for both catalysts. The applicability scope of these catalysts was explored with a library of aryl and heterocyclic aldehydes. The reductive amination of crude furfural extracted from biomass feedstock (rice husk) and pure xylose sugar was tested, showing yields in the range of 11–36%, to show the wider industrial scope of both nanocomposites. Gram scale conversion was also carried out to showcase the bulk scalability of the Ru/MMT catalyst.

Preparation of Nano-ZrO2 powder via a microwave-assisted hydrothermal method

ZrO2 nanocrystals were synthesised by a microwave-assisted hydrothermal method using zirconium oxychloride (ZrOCl2·8H2O), yttrium chloride (YCl3·6H2O), and liquor ammonia (NH3·H2O) as raw materials, triethanolamine (TEOA) as mineraliser, and polyethylene glycol (PEG) as dispersant. The obtained products were characterised with thermogravimetry-differential scanning calorimetry (TG-DSC), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results show that the concentration of ZrOCl2·8H2O had little effect on the material properties, whereas the PEG molecular weight, microwave hydrothermal time and temperature, and the concentration of TEOA greatly influenced the dispersibility of the nano-sized zirconia powders. XRD and FT-IR analyses indicated that the ZrO2 nanocrystals synthesised by the microwave hydrothermal method had a tetragonal phase without any trace of monoclinic or cubic phases. The optimal parameters for preparing nano-zirconia powders with appreciable crystallinity and crystal forms included the use of PEG1000/PEG2000/PEG4000 dispersants, a microwave hydrothermal time of 30–50 min and a temperature of 200–240 °C, and a TEOA concentration of 0.3–0.5 M. Nano-ZrO2 powder prepared via our optimised microwave hydrothermal method contained mostly tetrahedral, spherically shaped, highly homogeneous, and well-dispersed 20–30 nm particles.

EFFECT OF USING SODIUM BICARBONATE AND MIXTURE OF VITAMIN E AND SELENIUM IN PRODUCTION PERFORMANCE OF AWASSI EWES

This study was conducted by using18 Awassiewes , 2-4 years aged, with average body weight 61.56 kg. The ewes were randomly divided into three groups, six ewes in each group. All ewes received 1.5 kg/ dry matter from the same basal diet consist mainly of barley, wheat bran, soybean meal and wheat straw . The first group was fed on basal ration only ( T1 ) ,while 45g /ewe /day sodium bicarbonate was supplemented to the feed of the second (T2)group and third (T3) group was supplemented with 45g sodium bicarbonate plus 0.5g mixture of Vitamin E and selenium /ewe/day. Results showed that the treatments hadsignificant increase( P < 0.05 ) on milk production of T3(739 g/d) than T1,T2(571and 599 g/d)respectively. No effect on average body weight, lactose, fat and protein percentage in milk. Rumen liquor pH, ammonia and total count of rumen bacteria and protozoa before feeding was not affected, while after 2hr of feeding, pH value of rumen liquor was increased (P < 0.05) in T2 6.65 as compared with T1 5.62 and T3 6.13. Ammonia and microorganism concentration in rumen liquor and blood parameters were not affected by experimental treatments.

Synthesis of magnesium aluminate spinel nanocrystallites by co-precipitation as function of pH and temperature

Magnesium aluminate (MgAl2O4) spinel nanocrystallites are prepared through nitrate route with liquor ammonia as a precipitant by co-precipitation process. By varying the solution pH (8–10) and bath temperature (10–40°C), the precipitated gel materials are obtained. Yield of each batch is determined by firing at 1000°C with 2 hours (h) soaking. The yield is maximum at 30°C and pH 9.2. Chemical analysis indicates near stoichiometric spinel at pH 9.2. Below pH 9.2, Al2O3:MgO molar ratio shifts to alumina side; beyond pH 9.2, it is towards magnesia side. Stoichiometric spinel-forming precursor material is characterized by various techniques. X-ray diffraction (XRD) analysis indicates spinel formation at 600°C and its crystallinity increases with rise of temperature. Hydroxyl group and absorbed water in gel substrate disappear with variation of temperature as observed by Fourier transform infrared (FTIR). Only one exothermic response of the precursor of spinel formation is demonstrated through differential scanning calorimetry (DSC). Studies reveal formation of near stoichiometric magnesium aluminate spinel powder having average crystalline size in the range 15–38 nm. HR-transmission electron microscopy studies also confirm this nano-size crystallite formation.

Clinical Practice Guidelines for the management of Dissociative disorders in children and adolescents.

Clinical Practice Guidelines for the management of Dissociative disorders in children and adolescents.

EVALUATION OF DIRECT-FED MICROBIAL SUPPLEMENTATION TO IMPROVE UTILIZATION OF THE LOW QUALITY ROUGHAGES IN RUMINANTS

Direct-fed microbials (DFM) feed additives have been shown to improve average daily gain (ADG) and feed efficiency in ruminant animals in many studies. So, this study aimed to evaluate effect of using fungal and bacterial DFM and their mixture on productive performance of growing lambs. Thirty-two Barkey lambs (3 months old, 22.31± 1.57 kg) were randomly assigned into four groups, 8 lambs of each according to live body weight. The first group (control) was fed control rations without DFM supplementation, while treated groups (Fungal DFM, Bacterial DFM and Mixed DFM) were fed the control ration plus 2.5 g fungal, bacterial or mixed (1:1) DFM; respectively. Results showed that groups fed ration supplemented with DFM (fungal, bacterial and mixed) recorded higher DM, TDN and digestible CP intake. Supplementation of lambs ration with DFM (fungal, bacterial and mixed) showed not significant (P>0.05) effects on rumen liquor TVFA's and ammonia concentration at 0, 3 and 6 hrs post feeding. While DFM supplemented rations showed significant higher rumen liquor pH at 0, 3 and 6 hrs after feeding compared to the control group. Numerically increase was recorded in cellulose activity as unit per ml rumen liquor for groups fed ration supplemented with bacterial and mixed DFM. Direct fed microbial supplementation significantly (P 0.05) in plasma total protein concentration compared to lambs fed ration not supplemented. While albumin, globulin, urea, triglycerides, creatinine ALT and AST, alkaline phosphates activity were not significantly (P>0.05) affected by DFM supplementation. Total gain and ADG were significantly increased (P≤0.05) for groups received rations supplemented with DFM compared to control group. Also DFM supplementation significantly (P≤0.05) improved feed conversion as DM, TDN, CP and DCP compared to the control group. It could be concluded that supplementing lambs ration with fungal, bacterial or mixed DFM improved feed intake, digestibility, average daily gain and feed conversion without any adverse effects on animal health and performance.

EVALUATION OF EXOGENOUS FIBROLYTIC ENZYME SUPPLEMENTATION TO IMPROVE FEED UTILIZATION IN RUMINANTS

Exogenous fibrolytic enzyme (EFE) have been shown to increase daily gain and feed efficiency in feedlot animals. So, this study aimed to evaluate effect of using EFE on productive performance of growing lambs. sixteen Barkey lambs (3 months old, 22.31± 1.57 kg) were randomly assigned into two groups, 8 lambs for each according to live body weight. The first group (control) was fed control rations without EFE supplementation, while treated group were fed the control ration plus 2.5 g exogenous fibrolytic enzyme. The groups fed ration supplemented with EFE recorded higher DM, TDN and digestible CP intake. Supplementation of lambs ration with EFE showed no significantly effect on rumen liquor TVFA's and ammonia concentration at 0, 3 and 6 hrs post feeding. While Supplementation of lambs ration with EFE significantly increased rumen liquor pH at 0, 3 and 6 hrs after feeding compared to the control group. Exogenous fibrolytic enzyme significantly improved nutrients digestibility as dry matter, organic matter, crude protein, crude fiber, nitrogen free extract, neutral detergent fiber (NDF) and acid detergent fiber (ADF) as well as feeding values as TDN and digestible crude protein. Exogenous fibrolytic enzyme supplementation to lambs ration showed numerically increased (P>0.05) in plasma total protein concentration compared to lambs fed ration not supplemented. While albumin, globulin, triglycerides and creatinine concentration and Alanine Transaminase(ALT), Aspartate Transaminase(AST), alkaline phosphates activity were not significantly (P>0.05) affected by Direct-Fed Microbial (DFM) supplementation. Total gain and average daily gain significantly increased (P≤0.05) for group received rations supplemented with EFE compared to control group. Also supplementation lambs rations with EFE significantly (P≤0.05) improved feed conversion as DM, TDN, CP and DCP compared to the control group. It could be concluded that supplementing lambs ration with EFE resulted in increase feed intake and digestibility, consequently increased average daily gain and feed conversion without any adverse effect on animal health and performance.

The effects of heat stress on protein metabolism in lactating Holstein cows

Heat stress (HS) decreases milk protein synthesis beyond what would be expected based on the concomitant reduction in feed intake. The aim of the present study was to evaluate the direct effects of HS on milk protein production. Four multiparous, lactating Holstein cows (101 ± 10 d in milk, 574 ± 36 kg of body weight, 38 ± 2 kg of milk/d) were individually housed in environmental chambers and randomly allocated to 1 of 2 groups in a crossover design. The study was divided into 2 periods with 2 identical experimental phases (control phase and trial phase) within each period. During phase 1 or control phase (9 d), all cows were housed in thermal neutral conditions (TN; 20°C, 55% humidity) and fed ad libitum. During phase 2 or treatment phase (9 d), group 1 was exposed to cyclical HS conditions (32 to 36°C, 40% humidity) and fed ad libitum, whereas group 2 remained in TN conditions but was pair-fed (PFTN) to their HS counterparts to eliminate the confounding effects of dissimilar feed intake. After a 30-d washout period in TN conditions, the study was repeated (period 2), inverting the environmental treatments of the groups relative to period 1: group 2 was exposed to HS and group 1 to PFTN conditions. Compared with PFTN conditions, HS decreased milk yield (17.0%), milk protein (4.1%), milk protein yield (19%), 4% fat-corrected milk (23%), and fat yield (19%). Apparent digestibility of dry matter, organic matter, neutral detergent fiber, acid detergent fiber, crude protein, and ether extract was increased (11.1-42.9%) in HS cows, as well as rumen liquor ammonia (before feeding 33.2%; after feeding 29.5%) and volatile fatty acid concentration (45.3%) before feeding. In addition, ruminal pH was reduced (9.5 and 6% before and after feeding, respectively) during HS. Heat stress decreased plasma free amino acids (AA; 17.1%) and tended to increase and increased blood, urine, and milk urea nitrogen (17.2, 243, and 24.5%, respectively). Further, HS cows had reduced plasma glucose (8%) and nonesterified fatty acid (39.8%) concentrations compared with PFTN controls. These data suggest that HS increases systemic AA utilization (e.g., decreased plasma AA and increased nitrogen excretion), a scenario that limits the AA supply to the mammary gland for milk protein synthesis. Furthermore, the increase in AA requirements during HS might represent the increased need for gluconeogenic precursors, as HS is thought to prioritize glucose utilization as a fuel at the expense of nonesterified fatty acids.

Optimization of the Amount and Molecular Weight of Dispersing Agent PEG During the Co-Precipitation Preparation of Nano-Crystalline C-YSZ Powder.

Single-phase nano-crystalline yttria-stabilized zirconia (YSZ) powder was prepared by co-precipitation method using zirconium oxychloride (ZrOCl₂ · 8H₂O) and yttrium nitrate (Y(NO₃)₃ · 6H₂O) as raw materials and ammonium bicarbonate (NH₄HCO₃) and liquor ammonia (NH4OH) as the precipitators. In order to get the powder with favorable dispersibility, polyethylene glycol (PEG, HO(CH₂CH₂O) n H) with different molecular weights and amounts was used as a dispersant agent in the synthesis process and its effects on the YSZ powder was investigated. The scanning electron micrograph (SEM) images showed that the degree of agglomeration and the mean crystal size of YSZ powder varied with the amount and the molecular weight of PEG. The appropriate amount and molecular weight of PEG were given by comparing the dispersibility and crystal size distribution of powders. In the process, one also could find that the promotion of dispersion was insensitive to the molecular weight, and all PEG (400–2000) can exert an ability to reduce the agglomeration. The proper amount of PEG400, PEG600, PEG1000, PEG2000 was 3 wt%, 3 wt%, 2 wt%, 2 wt%, respectively. The transmission electric microscope studies in conjunction with the XRD analyzes verified the low degree of agglomeration and the size of YSZ powder varied between 10~20 nm.

The selective ethanol gas sensing performance of CdO1−XZnOX nanocomposite

The (CdO)1−XZnOX composite films have been deposited onto the glass substrate by simple and inexpensive chemical bath deposition (CBD) method. In synthesis of composite thin films, 0.1 M Cd (NO3)2 and 0.1 M Zn(NO3)2 were used as a sources of cadmium and zinc ions, respectively. Liquor ammonia was added as complexing agent in precursor solution. The XRD patterns of composite samples revealed distinct peaks of ZnO and CdO, which clearly indicates formation of CdO–ZnO nanocomposites in thin film form. SEM micrographs of (CdO)1−XZnOX samples with x = 0.25 shows nanowire-like morphology grown over the entire glass substrate while the samples with x = 0.75 shows the development of nanoflakes. Spherical granular morphology have been observed for sample with x = 0.50. Elemental compositions of the all deposited films have been confirmed by EDAX. The gas sensing behavior of the pure and composite sensor was systematically investigated for three different test gases such as ethanol, ammonia and hydrogen sulfide. Under optimum operating temperature of 275 °C and 24 ppm ethanol, the CdO–ZnO sensor showed maximum response of 58.69% among other test gases. The response and recovery time of CdO–ZnO sensor for ethanol was found to be 54 and 59 s, respectively. The CdO–ZnO composite sensor showed better response than pure ZnO and CdO sensor, which is attributed n–n heterojunction at intergrain boundaries. In addition, the energy band structure of CdO–ZnO heterojunction and the ethanol sensing mechanism are analyzed. The CdO–ZnO sensor is found to be selective towards ethanol even at lower concentration.

اثر تغذیه روغن سویای اکسید شده در تقابل با نقش آنتی اکسیدانی هسته انار بر فیزیولوژی و متابولیسم بزهای سانن در دوره انتقال

Introduction Oxidative stress is metabolic and physiologic status caused by imbalance between free radical production and antioxidant defense of body. In some physiological status such as rapid growth, parturition, disease and high production rate that imbalance would occur. High producing dairy animals are suspected to oxidative stress and require to antioxidant supplementation. Negative energy balance in early lactation force the nutrition specialist to apply oil and high NFC diet to exceed the requirement of high producing dairy animals such as Holstein cows and Saanen goats. In recent years, the attention to the use of herbal or organic antioxidant in animal nutrition has increased. This study was carried out to investigate the effects of feeding oxidized soybean oil (OSO) plus pomegranate seed (PS) as a natural antioxidant, on metabolism and physiology of Preparturient Saanen Goats. Materials and Methods Eighteen Saanen dairy goats with initial body weight of 47 ± 9 kg were assigned to three dietary treatments in a completely randomized design with repeated measurements for 21 days before anticipated parturition. Experimental treatments including: 1) base diet and 4% fresh soybean oil (FSO), 2) base diet and 4% oxidized soybean oil (DM basis) respectively, and 3) base diet plus 4% OSO and 8% Pomegranate seed (OSO-PS). After 2 weeks of feeding trial diets, goats were sampled for blood, rumen liquor, faeces and urine for measuring parameters of blood glucose, BHBA, lipid and nitrogen profile, rumen liquor ammonia nitrogen, urine pH and volume, faeces qualitative and quantitative variables and other responses such as nutrients digestibility. The GLM procedure of SAS software v.9.2 were used for statistical analysis. Initial body weight and metabolic variables were used as covariate in the model. Results and discussion All nutrients digestibility, Ruminal ammonia nitrogen and voluntary feed intake were decreased by OSO (p<0.05) and increased significantly by OSO-PS vs. FSO. Urinary pH was significantly decreased by OSO-PS in comparison with other treatments. Urinary volume was increased (p<0.05) and the faeces bolus Volume and humidity significantly reduced by OSO vs. other treatments. Triiodothyronine and creatinine concentration were significantly decreased by oxidized soybean oil (treatment 2) and OSO-PS (treatment 3) compared to sham control (FSO), and fasting glucose was significantly decreased and increased by OSO and OSO-PS vs. FSO (p<0.05), respectively. The metabolism of all types of Cholesterol was significantly altered by the treatments but the fluctuations of other parameters were not significantly differed among diets. This result is in accordance with other studies on herbal antioxidant feeding to ruminant, but the difference is in study situation of stimulated oxidative stress in this trial. Its might be suggested that antioxidant capacity of pomegranate seed could be an effective agent on saving turnover rate of epithelium against free radicals and other lipid peroxides. Conclusion Generally, oxidative stress metabolic signs and statues were stimulated by OSO but most metabolic and physiological indices were improved by hormonal and antioxidant effects of PS. Improved nutrients digestibility, blood parameters, urine and faces variables and rumen statues regarding to the results, proposed that pomegranate seed or other derivatives, raw or processed form could have a potential effect on economical and health parameters of domestic animals. Also regarding to lowering pH potential of pomegranate seed, it's supplementation in preparturient dairy animals might be a good strategy for acidifying diet and animal body to the prevention of metabolic disorders.

Distinct detection of liquor ammonia by ZnO/SAW sensor: Study of complete sensing mechanism

ZnO/SAW sensor was reported to give distinct response towards liquor ammonia. To study the complete mechanism, ZnO thin films (40nm) were deposited using rf sputtering in different reactive gas composition of argon and oxygen. The increase in oxygen content (30–100%) during film growth leads to decrease in the value of stress and bond energy. The individual contribution of different SAW sensing mechanisms such as mass loading, elastic effects and acousto-electric interaction, was evaluated and analyzed to understand the distinct response for liquor ammonia. It was found that mass loading seems to get affected by the presence of stress whereas elastic loading was affected by the crystallite size and bond energy (ZnO) in ZnO thin films.

Extraction protocol for isolation of CNSL by using protic and aprotic solvents from cashew nut and study of their physico-chemical parameter

Abstract Cashew nut shell liquid (CNSL) represents the largest readily available bioresource of alkenyl phenolic compounds. (CNSL) and its derivatives are widely used in polymer-based industries, synthesis of chemicals and intermediates, including bactericides, insecticides and surface active agents. In this work extraction of cashew nut shell liquid from cashew nut shell (CNS) was carried out by using the Soxhlet extraction method in the presence of polar &amp; non-polar solvents. From the extracted CNSL, anacardic acid was selectively isolated and acid free CNSL was treated with liquor ammonia to separate the cardanol and cardol in the stepwise manner. Comparative study for the extracted CNSL and S-was performed. Higher amount of extracted CNSL was obtained from polar solvents. They were all characterized using quantitative analysis by HPLC.

Effect of metal oxide sensing layers on the distinct detection of ammonia using surface acoustic wave (SAW) sensors

In the present work, SAW sensors coated with various metal oxides as sensitive layer have been exploited for distinct detection of ammonia. Thin films of different metal oxides (ZnO, SnO2, TeO2 and TiO2) of same thickness (40nm) were deposited under optimized parameters using rf sputtering technique for selective detection of liquor ammonia. As deposited ZnO thin film was highly c-axis oriented, whereas SnO2 thin film was polycrystalline. However the coatings of TiO2 and TeO2 thin films were amorphous. SAW sensor coated with ZnO film (ZnO/SAW) was found to be highly sensitive towards liquor ammonia as compared to other metal oxide coated SAW sensors. Effect of the thickness of ZnO sensing layer (20–80nm) has been studied on the sensing response characteristics. Mass loading and elastic loading are identified as the major contributions towards the response of SAW sensor for ammonia and their contributions were evaluated by fitting with the theory.

Investigations on the origin of mass and elastic loading in the time varying distinct response of ZnO SAW ammonia sensor

In our earlier report, we gave an account of an interesting observation of a distinct response of ZnO SAW sensor for liquor ammonia. While the sensor response consisted of a small initial decrease in differential frequency followed by large increase for moist ammonia, it showed decrease alone for dry ammonia, water vapors and other interferants. This paper attempts to investigate the fundamental cause of the observed distinct response, by exploring the contributions of various sensor mechanisms such as mass, elastic and acousto-electric loading. To carry out the investigation, four sensors having ZnO films on SAW resonators with varying structural properties were employed. ZnO thin films of same thickness but differing in crystallite size, surface roughness and stress were achieved by depositing the films using RF sputtering under different pressures (10–40mTorr). Electrical measurements on ZnO thin film show a very small contribution of acoustoelectric effect toward sensing response for liquor ammonia. Initially the elastic loading and later mass loading are identified as the dominant mechanism. The response has been fitted theoretically to determine individual contributions toward the sensing. A mechanism has been proposed and a correlation between the properties of ZnO film and sensor response has been attempted.

Neuromonitoring in a porcine model of acute hepatic failure

Cerebral oedema has been noted to occur frequently in patients dying of fulminant hepatic failure. Therefore, in the present study, multimodal neuromonitoring was evaluated in an animal model of hepatectomy. Acute liver failure was surgically induced in swine by complete hepatectomy (n = 8). Intracranial pressure monitoring via a ventricular drainage system, electroencephalogram and recording of visually evoked potentials were used to establish a continuous neuromonitoring system. Measurements of liquor and serum ammonia (NH(3)) levels were taken at later stages of the trial in an approach to widen monitoring. Serial monitoring of the electroencephalogram revealed progressive slowing of the frequency with decreasing amplitude. Monitoring of the intracranial pressure with a subdural pressure transducer demonstrated a progressive and reproducible elevation. Increase in blood NH(3) was observed. Anaesthesia was terminal. In all cases death was caused by cardiocirculatory insufficiency, confirmed by autopsy. At autopsy, brain tissue of the animals was found to be swollen showing flattened cortical gyri. In conclusion, the technique of extended neuromonitoring offers an advanced option for monitoring animal models of fulminant hepatic failure for further developments and investigations.

Doping of processable conducting poly(m‐aminophenol) with silver nanoparticles

AbstractProcessable poly(m‐aminophenol) (PmAP) was synthesized using ammonium persulfate (APS) oxidant in 0.6 M sodium hydroxide solution at room temperature. Soluble silver hydroxide ammonium complex was formed by dissolving silver nitrate in excess liquor ammonia and the thermal decomposition of this complex easily produced silver nanoparticle. Then, in situ silver nanoparticle‐doped PmAP film was obtained by casting PmAP film from dimethyl sulfoxide (DMSO) with silver hydroxide ammonia complex mixture at 140°C. The nanocomposite was characterized by ultraviolet‐visible spectroscopy, Fourier transformed spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy, electron dispersion spectroscopy, thermogravimetric analysis, and X‐ray diffraction analysis. The average size of the nanoparticle was around 130–140 nm as confirmed by the TEM analysis. Synthesized PmAP silver nanocomposite showed the highest DC‐conductivity of 1.03 × 10−6 S/cm. From the above characterizations, it can be said that silver nanoparticle shows some doping effect on the conductivity of PmAP. The doping level of the silver nanoparticle inside the polymer was optimized in terms of DC‐conductivity of the silver nanoparticle‐doped PmAP film. Copyright © 2009 John Wiley &amp; Sons, Ltd.