bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase Separation in wurtzite In1−x−yGaxAlyN
Authors: Matsuoka T.
Published: November 2014

The wurtzite structure In1−x−yGaxAlyN quaternary system is studied with respect to the unstable region in mixing. The composition in the unstable region is calculated from the free energy of mixing by using the strictly regular solution model. The interaction parameter used in this calculation is obtained by using the delta-lattice-parameter method. Here, the proportionality constant connecting the lattice constants and the band-gap energy is determined by fitting the calculation to the composition data obtained experimentally from InGaN grown by metallorganic vapor phase epitaxy. From this calculation, the ternary alloys of InAlN, InGaN and GaAlN are predicted to always, sometimes, and hardly ever, respectively, have an unstable mixing region. The essential mismatch in thermal equilibrium between the strictly regular solution approximation and the growth conditions in MOVPE is removed by using a fitting calculation and experimental data. Also, the mismatch between the zinc-blende structure and the wurtzite structure is corrected. As a result, this prediction of the phase separation in In1−x−yGaxAlyN becomes more reliable.
PURIFICATION AND CHARACTERIZATION OF THE NEWLY THERMOSTABLE PROTEASE PRODUCED BY Brevibacillus thermoruber LII ISOLATED FROM PADANG CERMIN HOTSPRING, INDONESIA
Authors: Zilda Dewi Zeswita , Harmayani Eni , Widada Jaka , Asmara Widya , Irianto Hari Eko , Patantis Gintung , Fawzya Yusro Nuri
Published: November 2014

Thermo stability is among of the vital enzyme characteristics for industrial application. Brevibacillus thermoruber LII was obtained as a potential isolate from the previous researchwhich screened the potential thermostable protease producing bacteria from Indonesian hotspring.The newly thermostable protease produced by thermophilic Brevibacillus thermoruber LII hadbeen purified and characterized. It was predicted that the pure enzyme obtained from Brevibacillusthermoruber LII was homo hexameric, having molecular weight of 36 kDa unit protein and itsnative was 215 kDa. In addition, it was also a neutral metalo serine protease according tobiochemical tests that it was totaly inhibited by PMSF (Phenylmethanesulfonyl fluoride) and EDTA(Ethylenediaminetetraacetic acid). It showed optimum activity at pH of 8 and active in acidic buffer(up to pH of 4). All of metal ion in the form of chloride salt (2.5 mM) which were tested on theenzyme enhanced the enzyme activity but Li2+. Ca2+ion increased the activity and the stability ofenzyme against thermal. The enzyme also showed the stability against solvent. The protease LIIhad optimum temperature at 60oC without CaCl 2and 80 – 85oC with addition of 2.5 mM CaCl 2. TheK Mand V maxvalues for the purified protease LII were 27.2 mg/ml or 0.362 – 0.272 M for substrateHammersteinCasein (MM 75–100 kDa) and 261.1 µg/minute/ml, respectively.
Yield and Agronomic Advantages of Pea Leaf Type Mixtures under Organic Management
Authors: Syrovy Lena D. , Banniza Sabine , Shirtliffe Steven J.
Published: November 2014

Field pea (Pisum sativum L.) is an important organic crop due to its contribution to soil fertility and other rotational benefits. Leafed (wild‐type) pea cultivars tend to be more weed suppressive, but their poor standing ability limits yield compared with semi‐leafless cultivars. Growing mixtures of leafed and semi‐leafless cultivars may improve weed suppression and yield compared with monocultures of the same cultivars by altering canopy morphology. To test this hypothesis, replicated field experiments were conducted under weedy, organic conditions in Saskatchewan, Canada, in 2011 and 2012. Mixtures of a leafed and semi‐leafless cultivar, CDC Sonata and CDC Dakota, were sown in ratios of 0:100, 25:75, 50:50, 75:25, and 100:0 leafed to semi‐leafless pea, at target seeding rates of 88 and 132 plants m−2. Mixtures that included 50% or more semi‐leafless pea had similar lodging resistance and weed biomass suppression to the agronomically superior semi‐leafless cultivar grown alone. The strong competitive ability of the semi‐leafless cultivar was unexpected based on previous accounts. The combined yield of the two cultivars grown in a 75% semi‐leafless mixture exceeded the seed and biomass yield of either single cultivar by at least 18 and 12%, respectively. Yield enhancement was attributed to the leafed cultivar, whose seed yield increased by more than two and a half times in this mixture relative to its monoculture. Results suggest that breeding of leafed cultivars specifically for mixture with semi‐leafless pea may be a future source of yield gains in organic and low‐input systems.
Agronomic Improvements in Corn by Alternating Nitrogen and Irrigation to Various Plant Densities
Authors: Han Kun , Zhou Chunju , Sheng Haiyan , Yang Yang , Zhang Liang , Wang Linquan , Chen Guoqing , Li Zengjia
Published: November 2014

Increasing water and N use efficiency and lowering environmental pollution are primary concerns for both agricultural production and environmental quality in northwestern China. A 2‐yr field experiment was conducted to assess and model the effects of irrigation, N, and plant density on maize (Zea mays L.) when N fertilizer and irrigation were separated in an alternating furrow irrigation system. Regression modeling (a ternary quadratic equation) showed that N fertilization positively affected yield, water use efficiency, N uptake, soil NO3–N, and NH3 volatilization. Irrigation improved yield, N uptake, and increased soil NO3–N in the deeper soil layer (0.6–2.0 m) but reduced water use efficiency, NH3 volatilization, and soil NO3–N in the 0‐ to 0.6‐m soil layer. Planting density positively affected yield, water use efficiency, and N uptake but negatively influenced NH3 volatilization and soil NO3–N. The combination of 255 kg N ha−1 N fertilizer, 100 mm of irrigation water, and 59,467 plants ha−1 in 2010 and 245 kg N ha−1 N fertilizer, 98 mm of irrigation water, and 58,376 plants ha−1 in 2011 resulted in maximum income for maize yield (7245 kg ha−1 in 2010 and 6972 kg ha−1 in 2011). However, environmental and agronomic objectives did not match. Specifically, the combination of N, irrigation rate, and plant density with maximum yield increased N leaching and NH3 losses, whereas the combination lowering environmental pollution due to N losses caused a reduction in yield. Therefore, the trade‐off in management of N, irrigation, and planting density was emphasized for both environmental and agronomic benefits in our study.
Damage of Maize Borer and Maize Weevil on the Yield of Transgenic Phytase Maize
Authors: Jiang Shoulin , Zhao Zongchao , Li Junsheng , He Jinglan , Xue Yingen , Xu Wenwei , Zhang Limin , Chen Fajun
Published: November 2014

The recent Chinese government approval of transgenic phytase maize for field experimentation is vital for its development of biotech maize for improved maize production. Phytase maize can potentially improve the efficiency of feed utilization by livestock and reduce environmental pollution from animal manure. Plant growth, phytochemistry, and economic characteristics of phytase maize were compared with non‐transgenic maize in field conditions. Population abundance and growth physiology of the maize borer (Ostrinia furnacalis) and the maize weevil (Sitophilus zeamais) were investigated during maize growing season and grain storage period, respectively, to assess insect pests’ occurrence and economic damage. Agronomic traits of phytase maize were generally superior to those of non‐transgenic maize, but the yield of phytase maize was only 5.5% higher than that of non‐transgenic maize. No significant difference in population dynamics of the maize borer was observed between them, while phytase maize significantly enhanced pupal weight and female fecundity of the maize borer. The length of the maize borer feeding tunnels in the stems was significantly greater in phytase maize. Moreover, significant increases in adult weight and population abundance of the maize weevil resulted in additional 2.98% losses for transgenic grains compared with non‐transgenic grains. Upon commercialization of transgenic maize in China, it will likely alter the arthropod population dynamics in the maize agroecosystem, increase plant susceptibility to lodging, and increase grain yield loss. Nevertheless, the increased insect‐induced loss (∼8%) in transgenic maize would likely be more than offset by enhanced phosphate utilization efficiency of livestock, when fed transgenic maize containing diet, and reduced environmental pollution from lower phosphate animal waste.
Searching for Adaptation to Abiotic Stress: Ecogeographical Analysis of Highland Ecuadorian Maize
Authors: Tapia César , Torres Elena , Parra‐Quijano Mauricio
Published: November 2014

There are 26 maize (Zea mays L.) races found in the Andean highlands of Ecuador. Knowing the environmental characteristics of the sites where these races occur is useful to understanding their adaptive capacities and to identify germplasm potentially adapted to abiotic stress conditions. Passport data of 1186 accessions from the Ecuadorian national collection were used. On the basis of the geographical coordinates of collecting sites, data were extracted for five climatic, two geophysical, and five edaphic variables. Additionally, a specific ecogeographical land characterization map for maize landraces was developed for the Ecuadorian Andes and, subsequently, an ecogeographical category was assigned to each collecting site. Wide ecogeographical variability was detected within and among races. Maize accessions were collected at sites with a seasonal mean temperature between 8.7 and 22.9°C, temperature annual range between 10.3 and 16.9°C, and December minimum temperature between 3.4 and 16.9°C. Seasonal precipitation ranged between 363 and 1809 mm and October precipitation between 18 and 171 mm. Ten accessions were found to be potentially adapted to extremely cold environments and 40 accessions to dry conditions. Most of the accessions were obtained from farms located at altitudes between 1900 and 2800 m with flat to moderate slopes. Only 37% of accessions were collected from sites with favorable soil properties regarding texture, depth to rock, pH, organic matter content, and fertility. Maize landraces were found in 28 of the 56 ecogeographical categories identified in the region, three of which were considered to be preferred environments and 10 to be marginal environments.
Temporal Sensitivities of Rice Seed Development from Spikelet Fertility to Viable Mature Seed to Extreme‐Temperature
Authors: Martínez‐Eixarch Maite , Ellis Richard H.
Published: November 2014

Extreme temperature during reproductive development affects rice (Oryza sativa L.) yield and seed quality. A controlled‐environment reciprocal‐transfer experiment was designed where plants from two japonica cultivars were grown at 28 and 24°C (day and night temperatures) and moved to 18 and 14°C and vice versa or from 28 and 24° to 38 and 34°C and vice versa, for 7‐d periods to determine the respective temporal pattern of sensitivity of spikelet fertility, yield, and seed viability to each temperature extreme. Spikelet fertility and seed yield per panicle were severely reduced by extreme temperature in the 14‐d period before anthesis; both cultivars were affected at 38 and 34°C while only Gleva was affected at 18 and 14°C. The damage was greater the earlier the panicles were stressed within this period. Later‐exserted panicles compensated only partly for yield loss. Seed viability was significantly reduced by 7‐d exposure to 38 and 34°C or 18 and 14°C at 1 to 7 d and 1 to 14 d after anthesis, respectively, in Gleva. Taipei 309 was not affected by 7‐d exposure at 18 and 14°C; no consistent temporal pattern of sensitivity was evident at 38 and 34°C. Hence, brief exposure to low or high temperature was most damaging to spikelet fertility and yield 14 to 7 d before anthesis, coinciding with microsporogenesis; it was almost as damaging around anthesis. Seed viability was most vulnerable to low or high temperature in the 7 or 14 d after anthesis, when histodifferentiation occurs.
Emergence, Forage Production, and Ion Relations of Alfalfa in Response to Saline Waters
Authors: Cornacchione Mónica V. , Suarez Donald L.
Published: November 2014

Alfalfa (Medicago sativa L.) is an important crop utilized in irrigated regions that are commonly impacted by salinity. We evaluated the effect of salinity continually from emergence to mature plant growth in successive harvests. We studied emergence, biomass production, salt tolerance, and shoot ion composition as potential physiological mechanisms in four nondormant salt‐tolerant cultivars: Salado, SW 8421S, SW 9720, and SW 9215. Irrigation water salinity dominated by sodium sulfate ranging from 3.1 to 30 dS m−1 of electrical conductivity (ECiw) was imposed at planting date. Plants were grown in outdoor sand tanks in Riverside, CA for 300 d. Relative emergence (%) decreased above ECiw 12.7 dS m−1 and was reduced to 53 and 13.4% at 18.4 and 24 dS m−1, respectively. At ECiw 30 dS m−1 there were no survivor plants. Absolute and relative accumulated biomass from 6 harvests significantly decreased for ECiw above 12.7 dS m−1 (6.0 dS m−1 in the saturation extract [ECe]). Plants grown at 18.4 and 24 dS m−1 produced 68% and 30% respectively of the biomass produced at 3.1 dS m−1. Salado showed the least reduction in biomass at elevated salinity and, as with all the cultivars, exhibited yield increases in successive harvests from first through seventh. Increasing salinity increased shoot Na+, total‐S, Cl−, Mg2+, and P and decreased K+ and Ca2+. The ability of Salado to maintain low shoot Na was the mechanism most associated with salt tolerance. Saline waters with resultant ECe values of up to 6 dS m−1 did not significantly reduce total forage production of the second through the seventh harvests. This suggests that irrigation with saline waters resulting in ECe values less than 6 dS m‐1 can be used throughout the production cycle (planting to multiple harvests) without significant yield loss for the cultivars examined.
Responses of Canopy Reflectance, Light Interception, and Soybean Seed Yield to Replanting Suboptimal Stands
Authors: Gaspar Adam P. , Conley Shawn P.
Published: November 2014

Soybean [Glycine max (L.) Merr.] planting date trends have steadily shifted earlier within the northern Corn Belt, while inclement weather, insect pressure, and disease pressure associated with spring planting can result in replanting some years. However, limited published literature exists about soybean replant thresholds for suboptimal plant stands and the effects of seed treatments on this decision. This study evaluated three planting dates, three seed treatments, and twelve seeding rate–replant combinations to determine replant thresholds in terms of maximizing seed yield, the effects of seed treatments on these thresholds, and the relationship of cumulative intercepted photosynthetically active radiation (CIPAR) and cumulative normalized difference vegetative index (CumNDVI) on seed yield. Trials were conducted during 2012 and 2013 in southern Wisconsin. Soybean planting in early May increased seed yield by 358 kg ha−1 compared with late May and by 805 kg ha−1 compared with mid‐June. Seed yield reductions were due to decreased seeds m−2 while CIPAR and CumNDVI measurements may partially explain this planting date effect. When initial plant stands were below threshold (<247,000 plants ha–1), filling in these stands with enough seed to bring the final plant stand above the threshold increased yield, whereas using tillage and replanting the entire stand only increased yield when initial plant stands were extremely low (<91,000 plants ha−1). Yield was related to both CIPAR (R2 = 0.54) and CumNDVI (R2 = 0.49) and the latter two variables were highly correlated (r = 0.89). We observed linear yield increases through 700 MJ m−2 of CIPAR; therefore, management practices to increase CIPAR should be used. This study showed that early May planting with a fungicide/insecticide seed treatment (CruiserMaxx) and generating adequate plant stands (>247,000 plants ha−1) maximized CIPAR.
Mega‐environment Analysis and Test Location Evaluation Based on Unbalanced Multiyear Data
Authors: Yan Weikai
Published: November 2014

Mega‐environment analysis and test location evaluation are two important issues for effective crop variety evaluation through multilocation variety trials. These must be done based on multiyear multilocation variety‐trial data, which are usually highly unbalanced. This paper presents a new graphical approach for conducting mega‐environment analysis and test location evaluation utilizing unbalanced multiyear variety trial data. It consists of three steps: (i) generating a G (genotypic main effect) plus GE (genotype × environment interaction), or GGE, biplot using a missing‐value estimation procedure and treating each location–year combination (trial) as an environment; (ii) summarizing the interrelations among test locations (L) in a GGL + GGE biplot, which is the same GGE biplot imposed with the test locations. The placement of a test location in the biplot is defined by the coordinates of all environments at the location; and (iii) summarizing any subregion (S) (i.e., mega‐environment) differentiation revealed in Step 2 in a GGS biplot, which is the same GGE biplot imposed with the subregions. The placement of a subregion in the biplot is defined by the coordinates of all environments in the subregion. The same GGL + GGE biplot can also be used to visualize the ability and stability of each test location to represent a target mega‐environment. Yield data from the 2006–2012 Quebec oat (Avena sativa L.) registration and recommendation trials were analyzed as a demonstration.
Perspectives for Genomic Selection Applications and Research in Plants
Authors: Heslot Nicolas , Jannink Jean‐Luc , Sorrells Mark E.
Published: November 2014

Genomic selection (GS) has created a lot of excitement and expectations in the animal‐ and plant‐breeding research communities. In this review, we briefly describe how genomic prediction can be integrated into breeding efforts and point out achievements and areas where more research is needed. Genomic selection provides many opportunities to increase genetic gain in plant breeding per unit time and cost. Early empirical and simulation results are promising, but for GS to deliver genetic gains, careful consideration of the problem of optimal resource allocation is needed. Consideration of the cost‐benefit balance of using markers for each trait and stage of the breeding cycle is needed, moving beyond only focusing on recurrent selection with GS on a few complex traits, using prediction on unphenotyped individuals. With decreasing marker cost, phenotype data is quickly becoming the most valuable asset and marker‐assisted selection strategies should focus on making the most of scarce and expensive phenotypes. It is important to realize that markers can also improve accuracy of selection for phenotyped individuals. Use of markers as an aid to phenotype analysis suggests a number of new strategies in terms of experimental design and multi‐trait models. GS also provides new ways to analyze and deal with genotype by environment interactions. Lastly, we point to some recent results showing that new models are needed to improve predictions particularly with respect to the use of distantly related individuals in the training population.
The efficiency of various chemical solutions to clean reverse osmosis membranes processing swine wastewater
Authors: Masse L. , Mondor M. , Puig-Bargués J. , Deschênes L. , Talbot G.
Published: November 2014

The increasing use of membrane technology to treat highly charged wastewaters has renewed interest in the development of adequate cleaning strategies. This study investigated the efficiency of various chemicals, including acids, bases, surfactants, chelators, salts, enzymes, and oxidants, to clean two reverse osmosis membranes (BW30 and SW30XLE) filtering one swine wastewater pretreated by aerobic biofiltration and two swine wastewaters pretreated by mechanical solid–liquid separation. Mixes of anionic surfactants and chelators provided optimal cleaning efficiency for all fouled membranes and all effluents. A solution containing 10 mM EDTA (ethylenediamine tetraacetic acid) and 10 mM SDS (sodium dodecyl sulfate) yielded the highest flux recovery after one 20-h fouling cycle with the BW30 membrane and three consecutive fouling–cleaning cycles with the SW30XLE membrane. The EDTA + SDS solution also resulted in the lowest residual protein concentration on membrane surface and the optimal restoration of the initial contact angle of the membranes. Conversely, 75 mM acid citric and 100 mM NaCl solutions were the least efficient to clean the fouled membranes. Most chemical solutions were more efficient to clean the fouling layer generated by the swine wastewater pretreated by aerobic biofiltration than mechanical separation.
Distribution of arsenic in shallow aquifers of Guangzhou region, China: natural and anthropogenic impacts
Authors: Liu Fan , Huang Guanxing , Sun Jichao , Jing Jihong , Zhang Ying
Published: November 2014

To elucidate the distribution of arsenic in shallow aquifers of the Guangzhou region (South China), 85 groundwater samples were collected and 18 chemical parameters of them were analyzed. The arsenic concentration of groundwater ranged from below detection limit to 0.13 mg/L. The results showed that those areas with high arsenic concentration were characterized by porous aquifers, low-lying, relief topography and close proximity to fault belt and rivers. The reductive dissolution of Fe (hydr)oxides is the main control mechanism for arsenic enrichment in the river delta region where groundwater is mainly characterized by a reducing environment. This mechanism was well embodied in the areas with these geological and geographical features. Agricultural fertilizer could produce high levels of nitrate in groundwater and the reduction of it could restrain the enrichment of arsenic. Industrial effluents, sewage irrigation and the probable leakage from sewers could promote the arsenic content in groundwater by lateral flow and infiltration. In addition, the effect of ion competition between phosphate and arsenic occurred in sewer leakage areas characterized by middle-high construction leading to the elevation of arsenic concentrations. The arsenic distribution in groundwater was caused by these natural and anthropogenic factors jointly.
Residual Stress Analysis of Strongly Textured Materials by Means of the Incremental Hole-Drilling Method – Survey on the Application Limits
Authors: Schuster Simone , Gibmeier Jens
Published: November 2014

In sheet metal forming, residual stress distributions are often accompanied by crystallographic texture. Incremental hole-drilling for stress analysis is only reliably applicable for isotropic materials. The objective of this study is to determine the influence of texture on residual stress analysis using conventional evaluation methods and to specify the application limits in case of textured material states. A systematic finite element simulation study for ideal texture orientations is conducted with respect to the strain gage rosette orientation. The results of the numerical investigations show that reliable stress analysis on strongly textured materials is not feasible using the existing evaluation method. The application limits are given for the application of commercially available evaluation software with respect to degree of anisotropy, stress state and strain gage orientation.
Effect of the Purging Gas on Properties of Ti Stabilized AISI 321 Stainless Steel TIG Welds
Authors: Taban Emel , Kaluc Erdinc , Aykan T. Serkan
Published: November 2014

Gas purging is necessary to provide a high quality of stainless steel pipe welding in order to prevent oxidation of the weld zone inside the pipe. AISI 321 stabilized austenitic stainless steel pipes commonly preferred in refinery applications have been welded by the TIG welding process both with and without the use of purging gas. As purging gases, Ar, N2, Ar +N2 and N2 + 10% H2 were used, respectively. The aim of this investigation is to detect the effect of purging gas on the weld joint properties such as microstructure, corrosion, strength and impact toughness. Macro sections and microstructures of the welds were investigated. Chemical composition analysis to obtain the nitrogen, oxygen and hydrogen content of the weld root was done by Leco analysis. Ferrite content of the beads including root and cap passes were measured by a ferritscope. Vickers hardness (HV10) values were obtained. Intergranular and pitting corrosion tests were applied to determine the corrosion resistance of all welds. Type of the purging gas affected pitting corrosion properties as well as the ferrite content and nitrogen, oxygen and hydrogen contents at the roots of the welds. Any hot cracking problems are not predicted as the weld still solidifies with ferrite in the primary phase as confirmed by microstructural and ferrite content analysis. Mechanical testing showed no significant change according to the purge gas. AISI 321 steel and 347 consumable compositions would permit use of nitrogen rich gases for root shielding without a risk of hot cracking.
Lubrication Effects during Biaxial Stretch Forming of Galvanized Steel Compared to Interstitial-Free Steel
Authors: Sener Bora , Kayali Eyup Sabri , Kucukyildirim Bedri Onur
Published: November 2014

In this study, the effect of lubrications in biaxial forming zone was investigated and their performances in stretch forming process were compared. Two different ultra low carbon steel sheets which are extensively used in the industries, interstitial-free steel and galvanized steel, were tested. Three different lubrications were tested and changes in the right hand of the forming limit diagrams of the materials with different lubricants were determined by using out-of-plane formability test as well as limiting dome heights were obtained for each lubricant. Moreover, strain distributions of samples, which were stretched with dry and different lubricants, were evaluated experimentally and the effectiveness of lubricants is compared. As a result, it was observed that deep-drawing oil has the highest performance among all lubricants. Furthermore, galvanized steel has lower formability under all conditions when compared to interstitial-free steel.
Influence of Specimen Dimensions and Orientation on the Tensile Properties of Structural Steel
Authors: Motra Hem Bahadur , Hildebrand Jörg , Dimmig-Osburg Andrea
Published: November 2014

For the measurement of tensile properties of materials, specimens with a rectangular cross-section are commonly used. However, the results are affected by the size of the specimen and the orientations. In this study, the rectangular cross-section specimens in both longitudinal (strain ratio r = 0°) and transverse (strain ratio r = 90°) directions were used to investigate the influence of specimen and orientation on the tensile properties of I-profile of IPE360 and IPE400 steel grade S235. For both I-profiles, four types of sixty dog bone samples with varying dimensions were tested. An electromechanical test machine together with contacting strain gauge and extensometer was used to perform standard tensile test procedures. The conclusion is drawn that specimen dimensions and orientation have a significant influence on the mechanical properties of both I-profile structural steel such as Young's modulus of elasticity, upper and lower yield strength, tensile strength, post-necking elongation and strain hardening rate, which increase with increasing thickness or decreasing gauge length.
Optimization of Screw Elements by Genetic Algorithm
Authors: Baskal Tamer
Published: November 2014

In the present study, dimensional optimization of screw system elements, like shaft diameter, arm length and nut height, has been performed by tensile, torsional, and shear strength calculations via genetic algorithm. Genetic algorithm has been used to minimize the objective function work with the idea of natural selection. The volume of the designed screw device has been defined as the object function. The limit function is composed of the total stresses affecting the screw system. The algorithm was set up in this way, due to the fact that it relies on the principle of finding the best in a genetic process. Values of the variables within the limiting intervals ensure that the screw device has an optimum size.
Application of ANOVA and Taguchi Methods for Evaluation of the Surface Roughness of Stellite-6 Coating Material
Authors: Ozturk Sabri
Published: November 2014

In this study, the machinability of Stellite-6 coating was examined using a ceramic cutting tool. Orthogonal tube-cutting experiments were performed on a lathe and the data collected was evaluated by analysis of variance (ANOVA) to find out the percentage contributions of the key factors. Whisker reinforced ceramic inserts with ISO tool designations RNGN 1907 00T01020 were used for the machining trials and round type cutting tool inserts which are common in the manufacturing industry were chosen. Taguchi design of experiments was implemented to determine the optimal cutting parameters for analyzing the effects of the cutting speed and feed rate on the surface quality. Four cutting speeds and three feed rates were used during the turning operations to produce the regression model for Ra (average surface roughness) in terms of the actual parameter values. Hardness of the cutting inserts gets affected significantly at higher feed rate.
Design, Manufacture and Analysis of Composite Epoxy Material with Embedded MWCNT Fibers
Authors: Aldosari Saad M. , Khashaba Usama A. , Hamed Mostafa A. , Hedia Hassan S.
Published: November 2014

The weight and fuel savings offered by composite materials make them attractive not only to the military, but also to the civilian aircraft, space, and automobile industries. In these industries, bolted and riveted joints are extensively used as a primary method for structural joining. Bolted joints in composite materials have complex failure modes, and hence the demand for improving their performance exists. The main objective of this work is to improve the performance of bolted joints in composite structures by introducing nanoparticles/fibers around the expected failure zone. The literature on this issue showed shortcomings in the investigations of such materials. Most of the investigations in this field aimed to enhance the mechanical properties of epoxy materials, which cannot be used alone for high performance structural applications due to their low mechanical properties. In the present work, epoxy resin was modified with different types of nanofillers including multi walled carbon nanotubes (MWCNT). Nano-phased epoxy was used to fabricate different types of nanocomposites as well as nano-hybridized glass fiber reinforced composite laminates. Therefore, six different advanced materials were fabricated including a nanocomposite material (MWCNT/E), a quasi-isotropic nano-hybridized composite laminate (QI-GFR/MWCNT/E), a unidirectional nano-hybridized composite laminate (UD-GFR/MWCNT/E) and a control panel manufactured without nano-fillers (neat epoxy, QI-GFR/E, UD-GFR/E). The materials were characterized by tension and compression tests. The obtained properties are essential for the validation of respective finite element analysis. The results showed improvements in the tensile and compressive properties (strength and modulus) of the fabricated nanocomposites (MWCNT/E) compared with neat epoxy. The hybridized composite laminate with MWCNT showed high improvements in their mechanical properties compared to the composite laminates without nanofillers.
Evaluation of Antioxidant Activity, Total Flavonoids, Tannins and Phenolic Compounds in Psychotria Leaf Extracts
Authors: Formagio Anelise , Volobuff Carla , Santiago Matheus , Cardoso Claudia , Vieira Maria , Valdevina Pereira Zefa
Published: November 2014

The antioxidant activity of Psychotria carthagenensis, P. leiocarpa, P. capillacea and P. deflexa (Rubiaceae) extracts were investigated, and the concentrations of total phenolics, flavonoids, condensed tannins and flavonols were determined. The chemical compositions of the extracts were investigated using the high performance liquid chromatography (HPLC/PAD) method. We used 1,1-diphenyl-1-picrylhydrazyl free radical (DPPH), β-Carotene bleaching and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cations to determine antioxidant activity. The ability to scavenge radical was measured in these experiments by the discoloration of the solution. Concentrations of constituents were measured spectrophotometrically. P. carthagenensis and P. capillacea exhibited the highest antioxidant activity, in the DPPH test, β-carotene bleaching and ABTS system. The highest phenolic, flavonoid, condensed tannin and flavonol concentration was found in P. carthagenensis and P. capillacea extracts. HPLC-PDA analysis of P. carthagenensis and P. capillacea revealed hydroxycinnamic acid (p-coumaric acid). This is the first report on the antioxidant properties and constituent analysis of these Psychotria extracts.
Scaling the Feeding Mechanism of Captive Alligator mississippiensis from Hatchling to Juvenile
Authors: Kerfoot James , Fern Micah , Elsey Ruth
Published: November 2014

Small changes in size can lead to potential performance consequences and may influence an organism’s ability to utilize resources in its environment. As the American alligator (Alligator mississippiensis) transitions between neonate, juvenile and adult habitats (ontogenetic niche shifts), there are inevitably dynamic changes in their feeding performance. This study sought to investigate the scaling of the feeding mechanism and its performance from hatchling to juvenile size classes in A. mississippiensis. Feeding events were recorded during March 2011 at Rockefeller Wildlife Refuge (Grand Chenier, Louisiana). Thirty-six captive individuals were randomly sampled, ranging from 30.5 cm to 91.5 cm total length, and feeding events were recorded using a high speed camera at a rate of 300 fps. Results indicated that many linear, angular and timing kinematic variables scale allometrically with cranium length; whereas maximum gape velocity and duration of feeding bout do not scale with cranium length and remain constant between these size classes. Although it has been shown that there is an isometric relationship between cranial elements and body size in A. mississippiensis, this relationship is not transferred to linear and timing variables of prey-capture events. These allometric relationships echo other investigations of scaling relationships such as bite-force production and terrestrial locomotion.
Effect of an Internal Heat Exchanger on Performance of the Transcritical Carbon Dioxide Refrigeration Cycle with an Expander
Authors: Zhang Zhenying , Tian Lili , Chen Yanhua , Tong Lirui
Published: November 2014

The effect of the internal heat exchanger (IHE) on the performance of the transcritical carbon dioxide refrigeration cycle with an expander is analyzed theoretically on the basis of the first and second laws of thermodynamics. The possible parameters affecting system efficiency such as heat rejection pressure, gas cooler outlet temperature, evaporating temperature, expander isentropic efficiency and IHE effectiveness are investigated. It is found that the IHE addition in the carbon dioxide refrigeration cycle with an expander increases the specific cooling capacity and compression work, and decreases the optimum heat rejection pressure and the expander output power. An IHE addition does not always improve the system performance in the refrigeration cycle with an expander. The throttle valve cycle with IHE provides a 5.6% to 17% increase in maximum COP compared to that of the basic cycle. For the ideal expander cycle with IHE, the maximum COP is approximately 12.3% to 16.1% lower than the maximum COP of the cycle without IHE. Whether the energy efficiency of the cycle by IHE can be improved depends on the isentropic efficiency level of the expander. The use of IHE is only applicable in the cases of lower expander isentropic efficiencies or higher gas cooler exit temperatures for the refrigeration cycle with an expander from the view of energy efficiency.
Naturally-Forced Slug Flow Expander for Application in a Waste-Heat Recovery Cycle
Authors: De Witt Ben , Hugo Ron
Published: November 2014

This paper investigates a slug-flow expander (SFE) for conversion of high-pressure gas/vapor into kinetic energy of liquid slugs. The energy transfer from high-pressure to kinetic energy is quantified using thrust plate measurements. Non-dimensional thrust data is used to quantify performance by normalizing measured thrust by thrust for the same water flow rate at zero air flow rate. A total of 13 expander configurations are investigated and geometries with the shortest cavity length and the smallest exit diameter are found to result in the largest non-dimensional thrust increase. Results show that thrust augmentation increases with the initiation of slug flow in the SFE. The analysis performed on the normalized thrust readings suggested that as the water and air flow were increased to critical conditions, the liquid slugs produced by the SFE augmented the thrust measurements. The final performance evaluation was based on linear regression of the normalized thrust measurements where slug flow was generated for each SFE architecture. Greater magnitudes of the slope from the linear regression indicated the propensity of the SFE to augment thrust. This analysis confirmed that for the SFE configurations over the range of values investigated, the SFE increased thrust up to three times its original value at no air flow. Given the inherent multiphase nature of the slug-flow expander, application to systems involving expansion of wetting fluids (water as part of a waste-heat recovery system) or air with water droplet formation (as part of a compressed-air energy storage system) could be considered.
2014 Future Earth Young Scientists Conference on Integrated Science and Knowledge Co-Production for Ecosystems and Human Well-Being
Authors: Shiue Ivy , Samberg Leah , Kulohoma Benard , Dogaru Diana , Wyborn Carina , Hamel Perrine , Jørgensen Peter , Lussier Paul , Sundaram Bharath , Lim Michelle , Tironi Antonio
Published: November 2014

Effective integration in science and knowledge co-production is a challenge that crosses research boundaries, climate regions, languages and cultures. Early career scientists are crucial in the identification of, and engagement with, obstacles and opportunities in the development of innovative solutions to complex and interconnected problems. On 25–31 May 2014, International Council for Science and International Social Science Council, in collaboration with the International Network of Next-Generation Ecologists and Institute for New Economic Thinking: Young Scholars Initiative, assembled a group of early career researchers with diverse backgrounds and research perspectives to reflect on and debate relevant issues around ecosystems and human wellbeing in the transition towards green economy, funded by the German Research Foundation, at Villa Vigoni, Italy. As a group of young scientists, we have come to a consensus that collaboration and communication among a diverse group of peers from different geographic regions could break down the barriers to multi-disciplinary research designed to solve complex global-scale problems. We also propose to establish a global systematic thinking to monitor global socio-ecological systems and to develop criteria for a “good” anthropocene. Finally, we aim to bridge gaps among research, the media, and education from a governance perspective linking with “sustainable development goals”.
Intracellular Signaling Transduction Pathways Triggered by a Well-Known Anti-GHR Monoclonal Antibody, Mab263, in Vitro and in Vivo
Authors: Lan Hainan , Li Wei , Jiang Honglong , Yang Yanhong , Zheng Xin
Published: November 2014

A series of studies have reported that monoclonal antibody 263 (Mab263), a monoclonal antibody against the growth hormone receptor (GHR), acts as an agonist in vitro and in vivo. However, the intracellular signaling pathways triggered by Mab263 have not yet been delineated. Therefore, we examined the intracellular signaling pathways induced by Mab263 in vivo and in vitro in the present study. The results show that this antibody activated janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), STAT1 and extracellular signal-regulated kinase 1/2 (ERK1/2), but not STAT5. The phosphorylation kinetics of JAK2, STAT3/1 and ERK1/2 induced by Mab263 were subsequently analyzed in dose-response and time course experiments. Our observations indicate that Mab263 induced different intracellular signaling pathways than GH, which indicates that Mab263 is a signal-specific molecule and that Mab263 may be a valuable biological reagent to study the mechanism(s) of GHR-mediated intracellular signaling pathways.
Depletion of C3orf1/TIMMDC1 Inhibits Migration and Proliferation in 95D Lung Carcinoma Cells
Authors: Wu Huiling , Wang Wenbing , Xu Huaxi
Published: November 2014

In our previous study, we identified an association of high expression of c3orf1, also known as TIMMDC1 (translocase of inner mitochondrial membrane domain-containing protein 1), with metastatic characteristics in lung carcinoma cells. To investigate the preliminary function and mechanism of this mitochondrial protein, we depleted C3orf1 expression by introducing siRNA into 95D lung carcinoma cells. We demonstrated that C3orf1 depletion significantly suppressed 95D cell growth and migration. We confirmed C3orf1 localization in the inner mitochondrial membrane and showed that mitochondrial viability, membrane potential, and ATPase activity were remarkably reduced upon depletion of C3orf1. Microarray data indicated that genes involved in regulation of cell death, migration, and cell-cycle arrest were significantly altered after C3orf1 depletion for 48 h. The expression of genes involved in focal adhesion, ECM-receptor interaction, and p53-signaling pathways were notably altered. Furthermore, cell-cycle arrest genes such as CCNG2 and PTEN as well as genes involved in cell migration inhibition, such as TIMP3 and COL3A1, were upregulated after C3orf1 depletion in 95D cells. Concurrently, expression of the migration-promoting gene NUPR1 was markedly reduced, as confirmed by real-time PCR. We conclude that C3orf1 is critical for mitochondrial function, migration, and proliferation in 95D lung carcinoma cells. Depletion of C3orf1 inhibited cell migration and cell proliferation in association with upregulation of genes involved in cell-cycle arrest and cell migration inhibition. These results suggest that C3orf1 (TIMMDC1) may be a viable treatment target for lung carcinoma, and that further study of the role of this protein in lung carcinoma pathogenesis is justified.
A Functional Monomer Is Not Enough: Principal Component Analysis of the Influence of Template Complexation in Pre-Polymerization Mixtures on Imprinted Polymer Recognition and Morphology
Authors: Golker Kerstin , Karlsson Björn , Rosengren Annika , Nicholls Ian
Published: November 2014

In this report, principal component analysis (PCA) has been used to explore the influence of template complexation in the pre-polymerization phase on template molecularly imprinted polymer (MIP) recognition and polymer morphology. A series of 16 bupivacaine MIPs were studied. The ethylene glycol dimethacrylate (EGDMA)-crosslinked polymers had either methacrylic acid (MAA) or methyl methacrylate (MMA) as the functional monomer, and the stoichiometry between template, functional monomer and crosslinker was varied. The polymers were characterized using radioligand equilibrium binding experiments, gas sorption measurements, swelling studies and data extracted from molecular dynamics (MD) simulations of all-component pre-polymerization mixtures. The molar fraction of the functional monomer in the MAA-polymers contributed to describing both the binding, surface area and pore volume. Interestingly, weak positive correlations between the swelling behavior and the rebinding characteristics of the MAA-MIPs were exposed. Polymers prepared with MMA as a functional monomer and a polymer prepared with only EGDMA were found to share the same characteristics, such as poor rebinding capacities, as well as similar surface area and pore volume, independent of the molar fraction MMA used in synthesis. The use of PCA for interpreting relationships between MD-derived descriptions of events in the pre-polymerization mixture, recognition properties and morphologies of the corresponding polymers illustrates the potential of PCA as a tool for better understanding these complex materials and for their rational design.
Analysis of Human TAAR8 and Murine Taar8b Mediated Signaling Pathways and Expression Profile
Authors: Mühlhaus Jessica , Dinter Juliane , Nürnberg Daniela , Rehders Maren , Depke Maren , Golchert Janine , Homuth Georg , Yi Chun-Xia , Morin Silke , Köhrle Josef , Brix Klaudia , Tschöp Matthias , Kleinau Gunnar , Biebermann Heike
Published: November 2014

The thyroid hormone derivative 3-iodothyronamine (3-T1AM) exerts metabolic effects in vivo that contradict known effects of thyroid hormones. 3-T1AM acts as a trace amine-associated receptor 1 (TAAR1) agonist and activates Gs signaling in vitro. Interestingly, 3-T1AM-meditated in vivo effects persist in Taar1 knockout-mice indicating that further targets of 3-T1AM might exist. Here, we investigated another member of the TAAR family, the only scarcely studied mouse and human trace-amine-associated receptor 8 (Taar8b, TAAR8). By RT-qPCR and locked-nucleic-acid (LNA) in situ hybridization, Taar8b expression in different mouse tissues was analyzed. Functionally, we characterized TAAR8 and Taar8b with regard to cell surface expression and signaling via different G-protein-mediated pathways. Cell surface expression was verified by ELISA, and cAMP accumulation was quantified by AlphaScreen for detection of Gs and/or Gi/o signaling. Activation of G-proteins Gq/11 and G12/13 was analyzed by reporter gene assays. Expression analyses revealed at most marginal Taar8b expression and no gender differences for almost all analyzed tissues. In heart, LNA-in situ hybridization demonstrated the absence of Taar8b expression. We could not identify 3-T1AM as a ligand for TAAR8 and Taar8b, but both receptors were characterized by a basal Gi/o signaling activity, a so far unknown signaling pathway for TAARs.