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Silicon carbide nanotube/nanowires (SiCNT/NWs) exhibit excellent mechanical properties in extreme thermal and oxidative environments. Here, we demonstrate an easily scalable process to synthesize millimeter-sized three-dimensional architectures using SiCNT/NW building blocks to create materials with excellent mechanical strength, stiffness, and resiliency with ultra-low density. The structure of these macro-materials is initially synthesized using carbon nanotubes, then utilizing the shape memory synthesis (SMS) method are converted to nano-silicon carbide. It is proposed that using this technique, any micro-structure can initially be created with nano-carbon building blocks, optimized for the necessary morphological features of a specific application. Here, the synthesis and subsequent SiCNT/NW conversion of carbon nanotube spheres and graphene foam, demonstrates the ability to use a simple, cost-effective conversion method to create a material that can mechanically perform in extreme environments.

Synthetic cannabinoid receptor agonists (SCRAs) represent the most rapidly expanding class of new psychoactive substances (NPSs). Despite the prevalence and potency of recent chiral indole-3-carboxamide SCRAs, few pharmacological data are available regarding the enantiomeric bias of these NPSs toward human CB1 and CB2 receptors. A series of homochiral indole-3-carboxamides derived from (S)- and (R)-α-methylbenzylamine and featuring variation of the 1-alkyl substituent were prepared, pharmacologically evaluated, and compared to related achiral congeners derived from cumyl- and benzylamine. Competitive binding assays demonstrated that all analogues derived from either enantiomer of α-methylbenzylamine (14-17) showed affinities for CB1 (Ki = 47.9-813 nM) and CB2 (Ki = 47.9-347 nM) that were intermediate to that of the corresponding benzylic (10-13, CB1 Ki = 550 nM to >10 μM; CB2 Ki = 61.7 nM to >10 μM) and cumyl derivatives (6-9, CB1 Ki = 12.6-21.4 nM; CB2 Ki = 2.95-24.5 nM). In a fluorometric membrane potential assay, all α-methylbenzyl analogues (excluding 17) were potent, efficacious agonists of CB1 (EC50 = 32-464 nM; Emax = 89-104%) and low efficacy agonists of CB2 (EC50 = 54-500 nM; Emax = 52-77%), with comparable or greater potency than the benzyl analogues and much lower potency than the cumyl derivatives, consistent with binding trends. The relatively greater affinity and potency of (S)-14-17 compared to (R)-14-17 analogues at CB1 highlighted an enantiomeric bias for this series of SCRAs. Molecular dynamics simulations provided a conformational basis for the observed differences in agonist potency at CB1 pending benzylic substitution.

Instantaneous adhesion between different materials is a requirement for several applications ranging from electronics to biomedicine. Approaches such as surface patterning, chemical cross-linking, surface modification, and chemical synthesis have been adopted to generate temporary adhesion between various materials and surfaces. Because of the lack of curing times, temporary adhesives are instantaneous, a useful property for specific applications that need quick bonding. However, to this day, temporary adhesives have been mainly demonstrated under dry conditions and do not work well in submerged or humid environments. Furthermore, most rely on chemical bonds resulting from strong interactions with the substrate such as acrylate based. This work demonstrates the synthesis of a universal amphibious adhesive solely by combining solid polytetrafluoroethylene (PTFE) and liquid polydimethylsiloxane (PDMS) polymers. While the dipole-dipole interactions are induced by a large electronegativity difference between fluorine atoms in PTFE and hydrogen atoms in PDMS, strong surface wetting allows the proposed adhesive to fully coat both substrates and PTFE particles, thereby maximizing the interfacial chemistry. The two-phase solid-liquid polymer system displays adhesive characteristics applicable both in air and water, and enables joining of a wide range of similar and dissimilar materials (glasses, metals, ceramics, papers, and biomaterials). The adhesive exhibits excellent mechanical properties for the joints between various surfaces as observed in lap shear testing, T-peel testing, and tensile testing. The proposed biocompatible adhesive can also be reused multiple times in different dry and wet environments. Additionally, we have developed a new reactive force field parameterization and used it in our molecular dynamics simulations to validate the adhesive nature of the mixed polymer system with different surfaces. This simple amphibious adhesive could meet the need for a universal glue that performs well with a number of materials for a wide range of conditions., by Chandra Sekhar Tiwary et al.

The acknowledged status of Moringa oleifera L. in sub-Saharan Africa, especially western Africa, has of recent accorded it the significance of being a good source of income to a large segment of many of its populace. Intensification of research into the realization of its full economic potential will be of utmost value to impoverished societies globally. One way to achieve this is the full exploration of all possible means that will facilitate its successful growth, propagation, and domestication. Even though it can be successfully raised through seeds, the high level outcrossing (64.3%) observed is a hindrance to realization of true to type trees. Vegetative propagation can be employed as an option to tackle the noted limitation, ease the cultivation process, and achieve the required realization of its economic potential. Our trial was carried out to study the influence of two growth media and three levels of indole 3-butyric acid (IBA) on root and shoot development in cuttings taken from a coppiced moringa tree existent in Universiti Putra Malaysia. Semi-hardwood cuttings of moringa, of between 20 and 30 mm diameter, cut into 25 cm length, were obtained, rinsed with a fungicide, then dipped, through their basal portion, inside varying levels (0, 1000, 2000, and 3000 ppm) of indole-3-butyric acid (IBA) for between 7 and 10 seconds. The treated cuttings were then transplanted into a polyethylene bags (23 cm × 36 cm), containing two growth media - a munchong series soil (M) and a combination of a munchong series soil thoroughly mixed with biochar (MB) in a 3:1 ratio sequence. The trial was conducted inside a shade house where the humidity of the experimental area was manipulated through a regular daily manual hand sprinkling. Plant height, percentage of primary branch produced, leaf area, and dry matter (DM) were found to be significantly (P0.05) influenced. The MB growth media was observed to significantly affect the plant height, percentage root number, and root length as compared to the M growth media. For a successful vegetative propagation and subsequent domestication, the MB growth media coupled with a higher stem diameter size are recommended.

Introduction: Hyperuricemia is common among adults with prehypertension, especially when the microalbuminuria is present. Hyperuricemia precedes the development of hypertension. Aim: (1) To find the association of hyperuricemia in new-onset hypertensive patients. (2) To find the association of hyperuricemia in hypertensive patients with regard to gender and risk factors such as smoking and central obesity. Material and Methods: A total of 50 adults aged between 20 and 50 years who had mild early hypertension were selected for the study. Fifty controls without hypertension were enrolled and investigated. Results: The association between uric acid (UA) and hypertension was analyzed using Student's t-test and statistical difference were assessed using Pearson coefficient. The study showed a significant difference in UA between the hypertensive subjects and the normotensive controls. There was not a significant difference between waist abnormality, smoking and UA in cases. Males have a higher degree of hyperuricemia than females in hypertensive patients. Conclusion: Serum UA is strongly associated with blood pressure (BP) in new and recent onset primary hypertension. The remarkable association of UA with BP in adults is consistent with recent animal model data and the hypothesis that the UA might have a pathogenic role in the development of hypertension.

Exchangeable and soluble soil aluminum (Al) is limiting plant growth in many soils worldwide. This study evaluated the effects of increasing rates of dolomite and magnesium carbonate (MgCO3) on Al3+, pH, dissolved organic carbon, cations, anions, and Al speciation on oil palm Deli dura × AVROS pisifera root growth. Dolomite and MgCO3 additions significantly raised linearly soil solution pH, magnesium (Mg2+), nitrate (NO3 −) and chlorine (Cl−) concentrations; exponentially decreased the activity of phytotoxic Al species [aluminum (Al3+), aluminum sulfate (Al2SO4), and aluminum fluoride (AlF3)]; and reduced manganese (Mn) concentration and activity. High activity of those species exponentially reduced root dry weight. Optimum oil palm growth was achieved at

Corrosion inhibitor is a substance added to the corrosive environment in small quantities to reduce the corrosion a metal. The addition of inhibitors will reduce the corrosion rate of the metal by retarding the corrosion process on the metal surface. Thus, this study focused on the study of the effectiveness of 1- butyl-3-methylimidazolium chloride ([EMIM]Cl) ionic liquid as an inhibitor for corrosion protection of mild steel. Two different concentrations of [EMIM]Cl (0.05 M and 0.5 M) were tested into different concentrations of sulphuric acid (0.05M, 0.10 M, 0.15 M, 0.20 M and 0.25 M). Weight loss measurement was used to determine the effectiveness of the [EMIM]Cl as inhibitor for corrosion protection. Results showed that acid concentrations play an important role for the corrosion protection process in the presence of the inhibitor. The weight loss increases as the concentration of the acid increased. The study also revealed that the concentrations of [EMIM]Cl ionic liquid effect the performance of the inhibitor. From this study, 0.5 M of [EMIM]Cl ionic liquid shows better corrosion performance compared to 0.05 M of [EMIM]Cl. At 0.25 M of sulphuric acid, the weight loss of untreated metal increased drastically from 0.0075 g at 0.5 hour to 0.0974 g at 24 hours. After treated with 0.5 M of [EMIM]Cl, the weight loss measurement slightly increased from 0.0027 g at 0.5 hour to 0.0179 g at 24 hours. This weight loss value is lower compared to mild steel treated with 0.05 M [EMIM]Cl which is 0.0469 g at 24 hours. The performance of the inhibitor in two different type of acid was also investigated. The morphology of the untreated mild steel and mild steel treated with [EMIM]Cl was investigated by scanning electronic microscopy (SEM)

The aim of the study is to investigate the drying behaviour of spray-dried betacyanin pigment powder extracted from Amaranthus gangeticus as influenced by spray drying conditions which include inlet temperature, feed concentration and feed flow rate. β-cyclodextrin and maltodextrin were used as encapsulating agents. Central composite design was applied to model spray drying process with seventeen and thirteen formulations were conducted, respectively. Several parameters including feed moisture, powder moisture, drying ratio, productivity, surface tension, density and viscosity of feed were determined experimentally. The drying rate, droplet size and drying time of A. gangeticus extracted betacyanins were investigated during spray drying.

Comparative mineral and hormonal analyses were made on tissue culture derived truncated leaf syndrome and wild type oil palm seedlings. Mineral analysis confirmed that Boron, Zinc and chlorophyll levels were significantly lower in truncated leaf syndrome leaves than those of wild type. Hormonal analysis also revealed various cytokinin derivatives such as trans-zeatin, trans-zeatin riboside, trans-zeatin O-glucoside and trans-zeatin riboside 5′mono phosphate were significantly higher in truncated leaf syndrome leaves compared to wild type leaves. Brassinolide level was also significantly higher in truncated leaf syndrome leaves than those of the wild type. These observations suggest that the truncated leaf syndrome abnormality could be associated to high cytokinin and brassinosteroid production which affects the uptake of Boron and Zinc.

The Corrosion inhibition of a inhibitor namely Ni complex of 1-(8-hydroxy quinolin-2yl-methyl) urea (Ni-HUF) in controlling corrosion of mild steel immersed in aqueous solution containing 60 ppm Clhas been investigated using weight loss method. The corrosion inhibition efficiency offered by 50 ppm of Ni-HUF is 74 %. The corrosion inhibition was observed due to the formation of more stable and compact protective film on the metal surface. Fluorescence spectral analysis was used to detect the presence of iron-inhibitor complex. Polarization study and Electrochemical Impedance spectra confirm the formation of a protective film formed on the metal surface. Introduction Metal complexes are widely used as catalyst of chemical reactions, e.g. Oxidative dehydrogenation (ODH) of ethane and epoxidation of geraniol [1-3] and as stabilizer or precursor in sol-gel processes [4-6]. Very few works have been performed to study anticorrosive behavior of metal complexes. Harms et al.[7] proposed corrosion inhibition through precipitation of Fe(II) phosphate and Fe(III) phosphate in presence of Fe(III) acetylacetonate and Fe(II) acetylacetonate respectively. Palladium acetylacetonate is suggested as an effective corrosion inhibitor for water cooled nuclear reactor [8]. Interaction of transition metal complexes with mild steel is greatly affected by their standard electrode potentials, their reactivity and the nature of the ligand that could stabilize the metallic complexes. Reduction of Cu (II) and Co (II) species on mild steel surface is possible due to their noble standard electrode potential compared to Fe (II). However, it should be noted that negative charged ligands like nitro, thiocyanate, Oxalato, glucinato and acetylacetonate could stabilize the higher oxidation states [9]. Hence reduction of Cu (II) and Co (II) on the steel surface could be affected by the ligands surrounded them. It is reported that sodium, zinc and calcium salts of gluconic acid could provide an effective corrosion inhibition for the mild steel immersed in near neutral media [10-13]. The effectiveness of gluconates on the anodic metal dissolution reaction and the cathodic oxygen reduction reaction in neutral solution depends on the inhibitor concentration and the nature of cations introduced in the solution as a gluconate salt [14]. The aim of the present work is to evaluate corrosion inhibitive performance of nickel complex of 1-(8-hydroxy quinolin-2yl-methyl) urea to mild steel immersed in aqueous solution containing 60 ppm Cl-. The corrosion inhibition efficiency was evaluated using weight loss method and electrochemical impedance spectroscopy. The protective film formed on the metal surface characterized with the help of surface analytical techniques such as fluorescence and UVVisible spectroscopy. Materials and Methods Mild steel specimens; (0.026% S, 0.068% P, 0.39 % Mn, 0.11 % C and the rest iron ) of dimensions 1.0 cm ×4.0×0.2 cm were polished to mirrors finish and degreased with acetone and used for weight loss method. Weight loss method: Mild steel specimens triplicate were immersed in 100 ml beaker containing 100 ml of aqueous solution containing 60 ppm of Clcontaining various concentrations of the Ni complex of 1-(8-hydroxy quinolin-2yl-methyl) urea -inhibitors for one day. After one day immersion the specimens were taken out, washed in running water, dried and weighed using a Shimadzu balance, model AY62. The corrosion inhibition efficiency (IE) was calculated using the equation: IE = 100[1-(w2-w1)] % Where w1 is the corrosion rate in the absence of inhibitor and w2 is the corrosion rate in the presence of inhibitor. Potentiodynamic Polarization study: Polarization studies were carried out in a CHI electrochemical workstation with impedance model 643, Austin, USA. A three electrode cell assembly was used. The working electrode was mild steel. The exposed surface area was 1 cm2. A saturated calomel electrode (SCE) was used as the reference electrode and a rectangular platinum foil was used as the counter electrode. The results such as Tafel slopes, Icorr, Ecorr and LPR values were calculated. AC impedance spectra The instrument used for polarization study was also used for AC impedance spectra. The cell set up was the same as that was used for polarization measurements. The real part (Z’) and the imaginary part (Z’’) of the cell impedance were measured in ohms at various frequencies. AC impedance spectra were recorded with initials E (v) =0V, high frequency limit was 1×105 Hz, low frequency limit was 1 Hz, amplitude =0.005V and quiet time tq=2 s. The values of charge transfer resistance Rt and the double layer capacitance Cdl were calculated.

Aluminium (Al) phytotoxicity is an important soil constraint that limits crop yield. The objectives of this study were to investigate how growth, physiology, nutrient content and organic acid concentration is affected by Al, and to assess the degree of Al tolerance in different oil palm progeny (OPP). Four OPPs ['A' (Angola dura × Angola dura), 'B' (Nigerian dura × Nigerian dura), 'C' (Deli dura × AVROS pisifera) and 'D' (Deli dura × Dumpy AVROS pisifera)] were grown in different Al concentrations (0, 100 and 200 μm) in aerated Hoagland solution, pH 4.4, for 80 days. We observed a severe reduction (57.5%) in shoot dry weight, and root tips were reduced by 46.5% in 200 μm Al. In 'B' and 'C', the majority of macro- and micronutrients in plants were reduced significantly by 200 μm Al, with Mg being lowered by more than 50% in roots and shoots. The 200 μm Al treatment resulted in a 56.50% reduction in total leaf area, a 20% reduction in net photosynthesis and a 17% reduction in SPAD chlorophyll value in the third leaf. Root tips (0-5 mm) showed a significant increase in oxalic acid content with increasing Al concentration (∼ 5.86-fold); progeny 'A' had the highest concentration of oxalic acid. There was a significant interaction between Al concentration × OPP on total leaf number, root volume, lateral root length, Mg and K in root and shoot tissues, and Ca and N in shoots. The OPPs could be ranked in their tolerance to Al as: 'A' > 'D' > 'B' > 'C'.

Aluminum (Al) toxicity is an important factor in limiting crop production. The present study examined the Al alleviation effects on the growth of hybrid (breeding) and clonal (tissue culture) of D × P oil palm seedlings. The experiment was performed using calcium carbonate (CaCO3), and ground magnesium limestone (GML) and magnesium carbonate (MgCO3) as soil-amendments at different rates in Colombia and Malaysia, respectively. The effects of the treatments were evaluated monthly on vegetative variables and visual symptoms. Chlorophyll concentrations were recorded in Malaysia at the fifth month growing stage. The different amendments improved the soil fertility and it was reflected on better performance of shoot and root growth. The chlorophyll content in the frond number 3 for both materials enhanced significantly when Al saturation was low (0–30%). The results from the experiment revealed the importance of neutralization of Al in reducing its toxicity in oil palm.

The mechanical properties of wood polymer composites consisting of polypropylene and mixed sawdust of meranti shorea spp. dominant and rice husk filler have been studied. Three different filler loadings of 50, 60, and 70 wt% were used and the process of compounding and extrusion was carried out using a twin-screw extruder. Increase in flexural modulus and tensile modulus are observed while tensile strength, elongation at break, flexural strength, and Izod impact decrease with increasing filler loading. Poor interaction between wood filler and the plastics is believed to be the main reason for the decreasing trend. Maleic anhydride grafted polypropylene (MAPP) was used in the formulation to improve the interfacial adhesion between the two components. Addition of the MAPP shows some improvement, particularly at 1%, and further increment of the MAPP did not show any significant impact on the properties tested.

The worldwide production of rice husk, a by‐product and agrowaste that causes serious environmental problems, may reach 116 million t y−1. The objectives of this study were (i) to determine the physicochemical changes of rice husk and its structural chemistry during composting using 13carbon nuclear magnetic resonance (13C NMR) and (ii) to determine the effect of the composted rice husk (CRH) on the properties of Oxisol and cocoa (Theobroma cacao L.) growth under glasshouse conditions. Results showed an active composting phase occurred at the first 53 days as revealed by high carbon dioxide (CO2)‐C (40–71 µg g−1 h−1) production, followed by a matured composting phase occurring at 54–116 days as revealed by decreasing in CO2‐C production (10 µg g−1 h−1). The active composting was accompanied by increases in electrical conductivity (EC), pH, ammonium (NH4 +), and nitrate (NO3), whereas during the matured composting phase, the EC and cation exchange capacity increased but pH, NH4 +, and NO3 −1 decreased. The...

Tannery waste is categorized as toxic and hazardous in Malaysia due to its high content of Cr (in excess of 500 mg/kg) and other heavy metals. Heavy metals, when in high enough concentrations, have the potential to be both phytotoxic and zootoxic. Heavy metals are found as contaminants in tannery sludge. This investigation aimed to identify the fate of chromium, cadmium, copper, lead, and zinc concentrations in tannery sludge throughout a 50-day composting cycle. The results of this study showed a general increase in the removal of Cr, Cd, Pb, and to a much smaller extent Zn and Cu, manifested by a decrease in their overall concentrations within the solid fraction of the final product (the decreases were likely the result of leaching). Furthermore, in using a sequential extraction method for sludge composting at different phases of treatment, a large proportion of the heavy metals were found to be associated to the residual fraction (70–80%) and fractions more resistant to extraction, X-NaOH, X-EDTA, X-HNO 3 (12–29%). Less than 2% of the metals were bound to bioavailable fractions X-(KNO 3 + H 2 O).

Volcanic ash-derived soils have high pH0 and very low cation exchange capacity attributed to their highly reactive colloidal constituents, the short-range-order minerals. Fertility is in doubt unless the effects of positive adsorption sites are masked and the increment of negative charge improved. Laboratory and glasshouse experiments were conducted to assess the masking effects of peat, ground basaltic pyroclastic and calcium silicate viz. effect on pH0 and CEC of volcanic soils of Camiguin Island, the Philippines, and to evaluate the growth of corn (Zea mays L.) grown on these soils after the treatments. In the laboratory experiment, Andic Haplumbrept (Soil 1) and Typic Dystrochrept (Soil 2) were incubated with 20% (air-dried) peat, ground basaltic pyroclastic and calcium silicate for nine months. In the glasshouse experiment, the treatments consisted of four rates of the above materials: 20, 10, 5, and 0% per unit weight soil. Corn was planted after nine months of incubation period. The results showed ...

Evaluation of compound controlled-release fertilizer (CRF) in the soil is essential in order to establish an appropriate soil management and fertilizer application technique. A compound fertilizer containing about 15% nitrogen (N), 2% phosphorus (P), 16% potassium (K), 4% calcium (Ca), 1% magnesium (Mg), and 1% copper (Cu) was prepared and subsequently coated with natural rubber (NR), polyvinyl chloride (PVC), polyacrylamide (PA), and polylactic acid (PLA). Evaluations of the compound CRF were conducted in the laboratory and in the field using an open leaching technique. The soil column was prepared using an acid Bungor soil (Typic Paleudult) packed in PVC tube for the laboratory and an undisturbed soil column for the field studies. A 25-g sample of each coated fertilizer was mixed with the soil in the top (0–60 mm) of the soil column. Nutrients released by the compound CRF in the appropriate soil column were monitored in the leachate for 30 d (about 18.0 pore volume (PV) of leachate), while in the field ...

The aim of this paper is to study the effect of epoxidised soybean oil (ESO) as an alternative plasticizer on physical, mechanical and thermal properties of plasticised polyvinyl chloride (PPVC). Samples were prepared using 10, 20, 30 and 40% by weight percent of ESO. The samples were characterized for density, water absorption, tensile, hardness and thermal properties. The addition of ESO as plasticizer in PVC had caused significant effect on the physical and mechanical properties of PPVC. Increasing of ESO loading had resulted in decreased density, tensile strength, tensile modulus but increased in elongation at break and shore hardness. From water absorption study, it was observed that the all the samples reached the plateau absorption at days 8 to 10 with absorption percentages of between 1.8 to 2%. In general the crystallinity of PPVC maintained between 10 to 13% with increase in ESO loading while the melting point ( Tm) is slightly decreased about 3 to 6°C. In this study, ESO which acts as plasticiser were found to result in lower glass transition temperature (Tg). The enhancements of super cooling with higher ESO loading were found to increase the crystallization temperature, promoting crystallisation and act as nucleating agent.

Ultrathin ceramic coatings are of high interest as protective coatings from aviation to biomedical applications. Here, a generic approach of making scalable ultrathin transition metal-carbide/boride/nitride using immiscibility of two metals is demonstrated. Ultrathin tantalum carbide, nitride, and boride are grown using chemical vapor deposition by heating a tantalum-copper bilayer with corresponding precursor (C2 H2 , B powder, and NH3 ). The ultrathin crystals are found on the copper surface (opposite of the metal-metal junction). A detailed microscopy analysis followed by density functional theory based calculation demonstrates the migration mechanism, where Ta atoms prefer to stay in clusters in the Cu matrix. These ultrathin materials have good interface attachment with Cu, improving the scratch resistance and oxidation resistance of Cu. This metal-metal immiscibility system can be extended to other metals to synthesize metal carbide, boride, and nitride coatings.

Here, the scalable synthesis of low-density 3D macroscopic structure of graphene oxide (GO) interconnected with polydimethylsiloxane (PDMS) is reported. A controlled amount of PDMS is infused into the freeze-dried foam to result into a very rigid structure with improved mechanical properties, such as tensile plasticity and toughness. The PDMS wets the graphene oxide sheets and acts like glue between the 2D sheets. Molecular dynamics simulations are used to further elucidate the mechanisms of the interactions of graphene oxide layers with PDMS. The ability of using the interconnecting graphene oxide foam as an effective oil–water separator and stable insulating behavior to elevated temperatures are further demonstrated. The structural rigidity of the sample is also tested using laser impact and compared with GO foam.

The blends of Polypropylene (PP), that is a semicrystalline and nonpolar thermoplastic polymer with a polar and amorphous polymer such as Polystyrene (PS), are known to be immiscible. This article investigates the use of an aromatic vinyl monomer (AVM)-grafted PP (PPA) as a potential compatibilizer for such an immiscible blend system (PP/PS blend). PPA was prepared by grafting a monofunctional aromatic vinyl monomer onto PP using an organic peroxide at 180°C for 10 min in a Brabender mixer. Using a twin-screw extruder, blends of PP/PS in various composition containing different amount of PPA were prepared. Results obtained from tensile and impact strength, heat deflection, and melt flow index measurements shows some improvement in the properties of the blends indicating some compatibilization effects in the blend system. However, the scanning electron microscopy (SEM) micrographs strongly suggested a significant compatibilization between PP and PS. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 428–434, 2001

In this article we report the influence of surface oxides and relative humidity on the nanomechanical response of hydrophobic and hydrophilic Si surfaces. Depth-sensing nanoindentation combined with force modulation enabled measurement of surface forces, surface energy, and interaction stiffness prior to contact. Several regimes of contact were investigated: pre-contact, apparent contact, elastic contact, and elasto-plastic contact. Both humidity and surface preparation influenced the surface mechanical properties in the pre- and apparent-contact regimes. Meniscus formation was observed for both hydrophobic and hydrophilic surfaces at high humidity. Influence of humidity was much less pronounced on hydrophobic surfaces and was fully reversible. In the elastic and elasto-plastic regimes, the mechanical response was dependent on oxide layer thickness. Irreversibility at small loads (300 nN) was due to the deformation of the surface oxide. Above 1 μN, the deformation was elastic until the mean contact pressure reached 11 GPa, whereby Si underwent a pressure-induced phase transformation resulting in oxide layer pop-in and breakthrough. The critical load required for pop-in was dependent on oxide thickness and tip radius. For thicker oxide layers, substrate influence was reduced and plastic deformation occurred within the oxide film itself without pop-in. Elastic modulus and hardness of both the oxide layer and Si substrate were measured quantitatively for depths

An extensive study of indentation creep on the nanometre scale has been made on single-crystal indium, tungsten and gallium arsenide. We use the force modulation technique which gives a direct measure of contact stiffness and, being insensitive to thermal drift, allows the accurate observation of creep in small indents to be carried out over long time periods: We show that strain rate indices similar to those for macroscopic creep can be obtained for indium. Stress relaxation negative creep is also observed in a manner similar to macroscopic tests. Indentation of tungsten and gallium arsenide shows a distinct pop-in at a critical load, before which the deformation is essentially elastic and after which it is elastoplastic with significant dislocation multiplication. The creep behaviour is quite different before and after pop-in, clearly demonstrating the role of mobile dislocations in creep, even in nanometre-sized volumes of materials.

Enzymatic hydrolysis of synthetic methyl 5-, 9-, and 12-thiastearates in aqueous media withCandida cyclindracea or porcine pancreatic lipases gave the corresponding fatty acids in 70–100% yield. Hydrolysis of the 3- and 4-positional isomers gave only 15–25% of the free thia fatty acids, suggesting discrimination against these isomers by lipases. No lipolysis was achieved with methyl 2-thialaurate under a range of reaction conditions. Esterification of the 3-, 4-, 5-, 9-, and 12-thiastearic acids withn-butanol inn-hexane using Lipozyme (immobilizedRhizomucor miehei) as the biocatalyst gave the corresponding butyl esters in 80–95% yield. Interesterification (acyl exchange) of triolein with methyl 9-thiastearate in the presence of Lipozyme showed the incorporation of 9-thiastearoyl chain at only one of the α-positions of triolein. In the case of methyl 2-thialaurate, no lipase-catalyzed acyl exchange reaction was possible. This study showed that the position of the sulfur atom in thia fatty esters affects the lipase-catalyzed hydrolysis and interesterification reactions.

Incubation of a 1-pyrroline ester [viz. methyl 8-(5-hexyl-1-pyrroline-2-yl)octanoate, 1] with bakers' yeast (Saccharomyces cerevisiae) gave the corresponding free fatty acid (1a, 52%). The C = N bond of the 1-pyrroline was not reduced by the yeast. Complete hydrolysis of compound 1 was successful using lipase of Candida cylindracea (CCL) or Lipolase (Rhizomucor miehei) under stirred or ultrasound condition. Fatty esters containing a pyrrolidine [viz. methyl 8-(cis/trans-5-hexyl-pyrrolidine-2-)octanoate, 2] or N-methyl pyrrolidine [viz. methyl 8-(cis-5-hexyl-N-methyl-pyrrolidine-2-)octanoate, 3] system in the alkyl chain were not hydrolyzed by either CCL or Lipolase, unless conducted in an ultrasonic bath. The hydrolytic activities of the enzymes appeared to be strongly affected by the stereochemistry of the N-heterocyclic ring system. Chemical hydrolysis of compounds 1-3 gave the corresponding fatty acid N-HCl salts.

The reactive CN bond of the 1-pyrroline fatty acid ester, methyl 8-(5-hexyl-2-pyrroline-1-yl)octanoate synthesized from methyl iso-ricinoleate (methyl 9-hydroxy-12-cis-octadecenoate) readily undergoes N-protonation, N-bromination, N-iodination N-nitration, N-nitrosation and N-oxymercuration to give the N-substituted 1-pyrrolinium derivatives by electrophilic addition reactions. Sodium borohydride reduction of the pyrrolinium derivatives yields the corresponding cis and trans N-substituted pyrrolidines. Addition of a nucleophile (CN−) to CN+ bond of an N-methyl 1-pyrrolinium derivative forms trans-2,5,5-trisubstitutedN-methyl ester derivative exclusively. The structures of these derivatives were characterized by infrared, 1H and 13C nuclear magnetic resonance spectroscopy.

Enrichment ofcis-5 polyunsaturated fatty acids [20:3(5c,11c,14c), 4.3% and 20:4(5c,11c,14c,17c), 11.3%] fromBiota orientalis seed oil was carried out by lipase-catalyzed selective esterification and hydrolysis reactions. Lipases fromRhizomucor miehei (Lipozyme),Candida cylindracea and porcine pancreas were used. Lipozyme-catalyzed esterification ofBiota fatty acids withn-butanol inn-hexane allowed 20:3 and 20:4 (as fatty acids) to be enriched to a maximum level of 52.9%, and in the presence ofC. cylindracea lipase 61.5% enrichment was achieved. Esterification with pancreatic lipase was poor with low levels of enrichment of 20:3 and 20:4 (22%). A multigram scale esterification of the free fatty acids fromBiota seed oil by repeated treatment of the isolated fatty acid fraction withn-butanol inn-hexane in the presence ofC. cylindracea lipase furnished an enrichment yield of 72.5% of a mixture of 20:3 and 20:4 fatty acids. Urea fractionation of the free fatty acids ofBiota oil gave an initial enriched fraction of 20:3 (9.5%) and 20:4 (25.2%) which, upon treatment withC. cylindracea lipase inn-butanol andn-hexane, gave an enriched fraction of 85.3% of 20:3 and 20:4 fatty acids. Partial hydrolysis of the triglycerides ofBiota oil byC. cylindracea lipase in potassium phosphate buffer at 25°C resulted in a 2.8-fold enrichment ofcis-5 polyunsaturated fatty acids (40.8% of 20:3 and 20:4) as contained in the unhydrolyzed acylglycerol fractions.

The reaction of methyl (Z)-9,10-epoxy-12-oxoocta-decanoate (2) with ammonium azide, generated in situ from sodium azide and ammonium chloride in aqueous ethanol affords methyl 8-(5-hexylfuran-2-yl)octanoate (1b) in 98% yield. Compound 1b was also prepared in >90% yield by reacting compound 2 with the following Lewis acids: aluminium(III) chloride, tin(IV) chloride, zinc(II) chloride under reflux in benzene or dichloromethane; or at ambient temperature with tin(II) bromide or hydrated tin(II) chloride in dichloroethane.

Reaction of 1-mesyloxynonane with methyl 8-aminooctanoate gives methyl 9-azastearate (I, 20%); treatment of methyl 9(10),10(9)-azidohydroxyoctadecanoate and methyl 10-azido-12-hydroxyoctadecanoate with triphenylphosphine furnishes the corresponding aziridine derivative (II, 75%) and two geometric azetidine isomers (IIIa and IIIb, 37%), respectively. The aza function in compound I, the aziridine nucleus in compound II and the azetidine system in compounds IIIa, IIIb were characterized by1H nuclear magnetic resonance (NMR) and13C NMR spectral analysis. The infrared spectral analyses of compounds (I), (II) and (IIIa,IIIb) showed characteristic absorption bands at 3200–3300 cm−1 for the N-H stretching vibration.

A C18 1-pyrroline fatty ester, methyl 8-(5-hexyl-2-pyrrolin-1-yl)octanoate (1), was prepared from methyliso-ricinoleate. The C=N bond of the pyrroline ring was oxidized bym-chloroperoxy-benzoic acid to yield a mixture of oxaziridine isomers 2a,2b, which decomposed during gas chromatographic analysis to a 2,5-disubstituted pyrrole derivative, methyl 8-(5-hexyl-1H-pyrrole-2-)octanoate (3). Compound 3 was also obtained by reaction of 2a,2b with dilute HCl in methanol. Reaction of compound 1 with iodo-methane formed anN-methyl iminium iodide intermediate 4, which on reduction with sodium borohydride furnished a mixture ofcis/trans-N-methyl-2,5-disubstituted pyrrolidine derivatives, methyl 8-(cis/trans-5-hexyl-N-methyl-pyrrolidine-2-)octanoates 5a,5b. Reduction of compound 1 with NaBH4 gave a mixture ofcis/trans-isomers of 2,5-disubstituted pyrrolidine derivatives, methyl 8-(5-hexyl-pyrrolidine-2-)octanoates 6a,6b. Acetylation of compounds 6a,6b with acetic anhydride furnished the correspondingN-acetyl pyrrolidines 7a,7b. When compound 1 was treated with perchloric acid, the corresponding iminium perchlorate derivative, methyl 8-(5-hexyl-1-pyrrolinium perchlorate-2-)octanoate 8 was obtained. The structures of the various derivatives were characterized by a combination of chromatographic, mass spectral and spectroscopic techniques.

This review deals with the results showing the relation between vitamin B(12) deficiency and neurotoxicity of homocysteine and nitrite (a metabolite of nitric oxide) in Parkinson's patients treated with levodopa (L-Dopa). We have already reported a linear relationship between the CSF levels of nitrite with glutamic acid and homocysteine suggesting that the production of nitrite is interrelated with the neurotoxic level of homocysteine. The levels of nitrite and homocysteine resulting in the deficiency of vitamin B(12) are some of the factors promoting degeneration in Parkinson's disease. This review emphasizes the importance of these parameters in designing suitable drug therapy for Parkinson disease. Additionally, there is evidence that increased homocysteine levels might accelerate dopaminergic cell death in Parkinson disease (PD), through neurotoxic effects. Furthermore, levodopa (L-Dopa) treatment of PD results in hyperhomocysteinemia as a consequence of L-Dopa methylation by catechol-O-methyltransferase (COMT). Therefore, higher dietary intakes of folate, vitamin B12, and vitamin B6 might decrease the risk of PD through decreasing plasma homocysteine.

Goniothalamus scortechinii, Andrographis paniculata and Aralidium pinnatifidum were selected for the study based on their ethnomedicinal values. They were screened for anti-malarial activity towards Plasmodium falciparum in vitro using the lactate dehydrogenase (LDH) assay. The crude extract of G. scortechinii exhibited the most potent schizonticidal activity compared to the other extracts. It is effective against both the chloroquine resistant isolate, Gombak A and the sensitive strain, D10 of Plasmodium falciparum. Furthermore a better IC(50) value was obtained against the resistant strain, (9 microg/ml) compared to the sensitive strain, 40 microg/ml. When the crude extract was fractionated into 3 fractions, the chloroform fraction yielded the best activity, exhibiting equipotency against both strains of parasite used; IC(50) of 23.53 microg/ml against Gombak A and 21.06 microg/ml against D10.

Pineapple fiber which is rich in cellulose, relatively inexpensive, and abundantly available has the potential for polymer reinforcement. This research presents a study of the tensile properties of pineapple leaf fiber and pineapple peduncle fiber reinforced polyester composites. Composites were fabricated using leaf fiber and peduncle fiber with varying fiber length and fiber loading. Both fibers were mixed with polyester composites the various fiber volume fractions of 4, 8 and 12% and with three different fiber lengths of 10, 20 and 30 mm. The composites panels were fabricated using hand lay-out technique. The tensile test was carried out in accordance to ASTM D638. The result showed that pineapple peduncle fiber with 4% fiber volume fraction and fiber length of 30 mm give highest tensile properties. From the overall results, pineapple peduncle fiber shown the higher tensile properties compared to pineapple leaf fiber. It is found that by increasing the fiber volume fraction the tensile properties has significantly decreased but by increasing the fiber length, the tensile properties will be increased proportionally. Minitab software is used to perform the two-way ANOVA analysis to measure the significant. From the analysis done, there is a significant effect of fiber volume fraction and fiber length on the tensile properties.

C18 furanoid triacylglycerol [glycerol tri-(9,12-epoxy-9,11-octadecadienoate)] was prepared by chemical transformation of triricinolein isolated from castor oil. The procedure involved oxidation, epoxidation and cyclization of the epoxy-keto intermediate with sodium azide and ammonium chloride in aqueous ethanol. The furanoid triacylglycerol was also obtained by esterification of C18 furanoid fatty acid with glycerol using Novozyme 435 (Novo Nordisk A.S., Bagsvaerd, Denmark) as biocatalyst. When Lipozyme (Novo Nordisk A.S.) was used, a mixture of the furanoid 1(3)-rac-monoacylglycerol and 1,3-diacylglycerol was obtained. In order to obtain the C18 furanoid 1,2(2,3)-diacylglycerol, selective hydrolysis of the furanoid triacylglycerol was achieved using porcine pancreatic lipase in tris(hydroxymethyl) methylamine buffer. Interesterification of triolein with methyl C18 furanoid ester in the presence of Lipozyme showed maximum incorporation of 34% of furanoid fatty acid. Extension of the interesterification to vegetable oils (olive, peanut, sunflower, corn and palm oil) allowed a maximum of 24% furanoid acid incorporation to be achieved.

A novel 1-pyrroline fatty acid ester isomer (viz. 8-5-hexyl-1-pyrrolin-2-yl) octanoate) has been synthesized from methyl ricinoleate by two routes with an overall yield of 42 and 30%, respectively. Most of the reactions are carried out under concomitant ultrasonic irradiation (20 KHz, ca. 53 watts/cm2). Under such a reaction condition, the reaction time is considerably shortened, and product yields are high. Dehydrobromination under concomitant ultrasonic irradiation of methyl 9, 10-dibromo-12-hydroxyoctadecanoate with KOH in EtOH furnishes methyl 12-hydroxy-9-octadecynoate (66%) within 15 min. Hydration of the latter under ultrasound with mercury(II)acetate in aqueous tetrahydrofuran yields exclusively methyl 12-hydroxy-9-oxo-octadecanoate (95%) in 30 min. The hydroxy group in the latter compound is transformed to the azido function via the mesylate, and treatment of the azido-oxo intermediate (methyl 12-azido-9-oxooctadecanoate) with Ph3P under ultrasonic irradiation furnishes the requisite 1-pyrroline fatty acid ester (77%). The same azido-oxo intermediate has also been obtained by the oxidation of methyl 12-azido-9-cis-octadecenoate using benzoquinone and a catalytic amount of Pd(II)chloride in aqueous tetrahydrofuran under concomitant ultrasonic irradiation (90 min) to give the product in 45% yield. The latter reaction does not take place even under prolonged silent stirring of the reaction mixture.

Reaction of methyl isoricinoleate [(Z)-methyl 9-hydroxyoctadec-12-enoate] with toluene-p-sulphonyl chloride gave a mixture of (Z)-methyl 9-chlorooctadec-12-enoate 2 and (Z)-methyl 9-tosyloxyoctadec-12-enoate 3, and with methane sulphonyl chloride the corresponding mesyloxy derivative 4. Treatment of compounds 2–4 with NaN3 in N,N-dimethylformamide at 50 °C gave (Z)methyl 9-azidooctadec-9-enoate 5, while at 80 °C methyl 8-(5-hexyl-2-pyrrolin-1-yl)octanoate 6 was obtained. The 1-pyrroline ring was characterized by IR,1H and 13C NMR spectroscopy, while the ring cleavage products (methyl 9-acetamido-12-oxooctadecanoate 7 and methyl 9-benzamido-12-oxooctadecanoate 8) were characterized by GC–MS. Reduction of the CN bond in compound 6 with NaBH4 gave a mixture of E- and Z-isomers of the corresponding disubstituted pyrrolidine fatty esters 9a and 9b.

In this study the theoretical and effective methane recovery and CO2 storage potential of four coal seams within a well characterised section of a CBM license in Scotland are estimated, considering different horizontal well patterns, the effect of permeability heterogeneity and the composition of the injected fluid. The study concerns the Airth area of the Clackmannan coalfield in the Scottish Midland Valley. The effort on building the static earth model and the history match results of the pre-existing vertical and newly drilled horizontal wells is briefly described. Initial simulations of the horizontal well primary methane production and CO2/flue gas enhanced recovery enabled the length, configuration and alignment of the horizontal wells to be optimised for the long-term simulations. This configuration was then used to estimate the Effective Capacity of a selected area within the Airth field for CBM, ECBM and CO2 storage. To evaluate the impact of permeability heterogeneity and uncertainty on reservoir performance and Effective Capacity for methane recovery and CO2 storage, multiple realisations of possible permeability distributions across the selected area were geostatistically generated. Initially, primary production runs were performed using 100 permeability distributions with a median value of around 1 mD. A number of realisations with different median permeabilities were then selected and used for flue gas (13% CO2/87% N2) and mixed gas (50% CO2/50% N2) enhanced CBM recovery and CO2 storage runs.

Aluminium metal matrix composites have become the necessary materials in various engineering applications. Al 6061 is the matrix material in which boron carbide, one of the hardest material and graphite are reinforced and the composite was prepared by stir casting. Microwave post heat treatment of metal based components is a newer technique which is employed in this study. It provides unique microstructure and properties as a result of selective heating. In order to obtain solution heat treatment, the composites were heated up to 520 o C and were maintained for a definite holding time at 520 o C. Electrical discharge machining process was selected to machine MMC as it is difficult to machine by conventional machining. EDM machinability studies were carried out on the heat treated Al-B4C (15 vol%) graphite (5 vol%) and compared with EDM machined with conventionally heat treated composites. EDM process parameters optimization was carried out using Taguchi design with input parameter such as pulse on time, pulse off time and current density for the material removal rate (MRR) and tool wear rate (TWR) as response parameters. Microwave heat treated composite exhibited higher hardness than the conventionally heat treated composites. Pulse off time and pulse on time was a non-linear function for the material removal rate of the composite and the most influential parameters for the MRR were determined.

Gram-negative, non-saccharolytic, brown- or black-pigment-forming, nonmotile anaerboic coccobacilli, capable of decomposing hydrogen peroxide and identified as Bacteroides asaccharolyticus (B. melaninogenicus subsp. asaccharolyticus), were isolated from the supra- and subgingival plaques of beagle dogs with gingivitis or periodontitis. The organisms remained viable for many hours in an aerobic atmosphere as evidenced by their ability to grow subsequently in an anaerobic environment. They also grew well on agar media that were not reduced before use. Although blood was required for pigmentation of colonies, organisms grew on media that lacked hemin, menadione, blood, or reducing compounds. Increased oxygen tolerance, catalase activity, and different nutritional requirements differentiate these organisms from strains of B. asaccharolyticus isolated from humans.