Increase In Cl Concentration Research Articles

Life cycle assessment as a driver for process optimisation of cellobiose lipids fermentation and purification

PurposeCellobiose lipids (CL) are biosurfactants produced by various Ustilaginaceae species in aerobic fermentations. They show high potential for application as alternatives to conventional oleochemical- or petrochemical surfactants. To ensure their environmentally friendly performance, we aimed to assess CL production from a life cycle perspective at an early developmental stage to identify process steps that have the highest impact on the environment. With this information, optimisation approaches can be derived.Materials and methodsFollowing a cradle-to-gate approach, we modelled the CL fermentation and purification process based on experimental data from the lab scale and process simulation data at a 10 m3 scale. For LCA, the impact categories (IC) abiotic depletion potential (ADP), eutrophication potential, photochemical ozone creation potential, global warming potential, acidification potential, and the primary energy demand were calculated for all process steps. Based on the obtained results, process bottlenecks were identified, and alternative process scenarios varying the related process parameters were simulated. These were used to assess the environmental impact reduction potential (EIRP) of an optimised process and draw recommendations for experimental process optimisation.Results and discussionThe obtained results showed that the fermentation caused ~ 73% of ADP and more than 85% of all other ICs. The major contributor was the electricity consumption for continuous fermenter aeration. Thus, reducing the fermentation duration from the initial 14 to 5 days would result in a decrease in all investigated ICs of up to ~ 27–52%. An increase in CL concentration results in a decrease in all ICs of a similar magnitude due to the higher yield per batch at comparable energy and material consumption. Although the share of purification process steps to all ICs is overall relatively small, implementing foam fractionation for in situ product recovery showed an additional EIRP of 18–27% in all purification IC shares.ConclusionsThe conducted LCA showed that overall, more EIRP can be achieved by optimising fermentation process parameters compared to purification process steps. This is mainly due to the long fermentation duration and large energy consumption for fermenter aeration. This highlights the importance of using LCA as a driver for process optimisation to identify process steps with high EIRP. While some of the results are specific to CL, other obtained results can be transferred to other fermentations.

Mercury adsorption characteristics of Cl-impregnated activated carbons in simulated flue gases

Activated carbon injection upstream of a particulate matter control device is a general method to control mercury in a coal-fired flue gas. Nitrogen oxides (NOx) and hydrogen chloride (HCl) in flue gas have been reported to increase the efficiency of activated carbon for mercury removal. In a coal-fired power plant, a NOx control device is generally located upstream of a particulate matter control device. In addition, if coal with a low chloride (Cl) content is burned, the concentrations of NOx and HCl may be low in the flue gas upstream of a particulate matter control device. Under these conditions, chemically promoted activated carbon is necessary to effectively control mercury. This study was designed to suggest the best chloride compound impregnated on activated carbon depending on the flue gas composition. HCl, ferric chloride (FeCl3) and cupric chloride (CuCl2) were impregnated with an identical concentration of Cl on activated carbon. Then, each sorbent was tested using a fixed-bed reactor system at 140 °C. CuCl2-impregnated activated carbon (CuCl2-AC) was tolerant of SO2 gas. The mercury adsorption efficiency was higher in the order of CuCl2-AC, FeCl3-impregnated activated carbon (FeCl3-AC) and HCl-impregnated activated carbon (HCl-AC) with 1% Cl for all three sorbents for the tests with a simulated flue gas of 12% CO2, 5% O2, 7% H2O, 60–70 µg/m3 Hg0, 500 ppm SO2, 20 ppm NO and N2 balance gas. However, the mercury adsorption efficiencies among the Cl-impregnated activated carbon sorbents became more similar with the increase in Cl concentration on activated carbon.

Structural, Electronic, and Optical Properties of CsPb(Br1-xClx)3 Perovskite: First-Principles Study with PBE-GGA and mBJ-GGA Methods.

The effect of halide composition on the structural, electronic, and optical properties of CsPb(Br1−xClx)3 perovskite was investigated in this study. When the chloride (Cl) content of x was increased, the unit cell volume decreased with a linear function. Theoretical X-ray diffraction analyses showed that the peak (at 2θ = 30.4°) shifts to a larger angle (at 2θ = 31.9°) when the average fraction of the incorporated Cl increased. The energy bandgap (Eg) was observed to increase with the increase in Cl concentration. For x = 0.00, 0.25, 0.33, 0.50, 0.66, 0.75, and 1.00, the Eg values calculated using the Perdew–Burke–Ernzerhof potential were between 1.53 and 1.93 eV, while those calculated using the modified Becke−Johnson generalized gradient approximation (mBJ–GGA) potential were between 2.23 and 2.90 eV. The Eg calculated using the mBJ–GGA method best matched the experimental values reported. The effective masses decreased with a concentration increase of Cl to 0.33 and then increased with a further increase in the concentration of Cl. Calculated photoabsorption coefficients show a blue shift of absorption at higher Cl content. The calculations indicate that CsPb(Br1−xClx)3 perovskite could be used in optical and optoelectronic devices by partly replacing bromide with chloride.

Induced Vacancy-Assisted Filamentary Resistive Switching Device Based on RbPbI3-xClx Perovskite for RRAM Application.

Halide perovskite (HP) materials are actively researched for resistive switching (RS) memory devices due to their current-voltage hysteresis along with low-temperature processability, superior charge mobility, and simple fabrication. In this study, all-inorganic RbPbI3 perovskite has been doped with Cl in the halide site and incorporated as a switching media in the Ag/RbPbI3-xClx/ITO structure, since pure RbPbI3 is nonswitchable. Five compositions of the RbPbI3-xClx (x = 0, 0.3, 0.6, 0.9, and 1.2) films are fabricated, and the conductivity was found to be increasing upon increase in Cl concentration, as revealed by dielectric and I-V measurements. The device with a 20% chloride-substituted film exhibits a higher on/off ratio, extended endurance, long retention, and high-density storage ability. Finally, a plausible explanation of the switching mechanism from iodine vacancy-mediated growth of conducting filaments (CFs) is provided using conductive atomic force microscopy (c-AFM). The c-AFM measurements reveal that pure RbPbI3 is insulating in nature, whereas Cl-doped films demonstrate resistive switching behavior.

Variability of hydrochemical parameters of small boreal lakes under natural and anthropogenic factors (case study of NW Russia)

Small lakes of the boreal zone are highly sensitive indicators of both global environmental change and local anthropogenic pressure. This work presents the results of multidisciplinary study of three small, seasonally stratified lakes of NW Russia, conducted since 2002 to the present time. These lakes were subjected to various degree of impact by rural population and agricultural activity since the beginning of twentieth century but the population and anthropogenic pressure have decreased since 1990s. To monitor the recovering of these lakes from human impact and to relate the evolution of their hydrochemical parameters to short-term weather events and global climatic trend, we measured the lake water temperature and chemical composition (carbon, macro- and micronutrients, trace elements) in summer and winter over full depth of the water column. The pH and concentration of DIC, SO4 and H2S decreased over past decade. Concentrations of Si and nitrite increased over past 15 years, probably linked to progressive replacement of diatoms by cyanobacteria. We also recorded an increase in concentration of Cl and major cations in all lakes, likely linked to increasing connection to groundwater reservoirs. Some trace elements (Fe, Mn, Al, Zn, As, Pb) can serve as suitable indicators of on-going natural processes controlling lake response to external factors. Unlike widely reported global trend of DOC and Fe concentration increase in boreal surface waters of Europe and Northern America, such trend was not discernable in studied Fe-rich humic lakes. We conclude on the necessity of complex, multidisciplinary studies of small humic lakes in the boreal zone, because these “model” lakes can serve as important proxies of on-going environmental changes in highly abundant aquatic ecosystems of poorly characterized regions of NW Russia.

A Colorimetric Multifunctional Sensing Method for Structural-Durability-Health Monitoring Systems.

A colorimetric multifunctional phototransmittance-based structural durability monitoring system is developed. The system consists of an array with four indium gallium zinc oxide (IGZO)-based phototransistors, a light source at a wavelength of 405 nm through a side-emitting optical fiber, and pH- and Cl-selective color-variable membranes. Under illumination at the wavelength of 405 nm at corrosion status, the pH- and Cl-responsive membrane, showing a change in their color, generates a change in the intensity of the transmitted light, which is received by the phototransistor array in the form of an electrical current. Ids and R (Ids /IpH 12 ) are inversely proportional to the pH, which ranges from 10 to 12. When the pH drops from 12 to 10, the magnitude of Ids and R increases to ≈103 . In the case of Cl detection, Ids and R (Ids /ICl 0 wt% ) increase nearly 50 times with an increase in Cl concentration of 0.05 wt%, and when the Cl concentration reaches 0.30 wt%, Ids and R increase to ≈103 times greater. This multifunctional colorimetric durability sensing system demonstrates considerable potential as a novel smart-diagnostic tool of structural durability with high stability, high sensitivity, and multifunction.

Band gap tuning and excitonic effect in chloro‑fluorinated graphene

We have studied the structural, electronic and optical properties of chloro‑fluorinated graphene (CF1-xClx) as a function of Cl concentration (x) by employing DFT and beyond DFT approaches. The increase in Cl concentration brings about an increase in lattice parameters while binding energy and electronic band gap are reduced. For all the properties studied, a non-linear behavior is observed as x is increased from 0.25 to 0.375. In particular, electronic band gap exhibits a sharp decline (>1.5 eV) for x = 0.25–0.375; while the reduction is relatively smooth for x ≤ 0.25 and x ≥ 0.375. Optical gap presents similar trend albeit with much smaller magnitude due to the presence of strong excitonic effect. We show that the observed non-linear behavior is associated with sharp reduction in the minimum distance between Cl adsorbates as x is increased from 0.25 to 0.375. As a consequence, new states caused by Cl-Cl interaction appear at an energy level higher than those caused by C-F and F-F, thus considerably reducing the band gap. Our result provides helpful insight for tailoring the band gap through hetero-functionalization of graphene by halides.

Studies on the Antibacterial Activity of Wet-tissue Saturated with Electrolytic Water of NaCl Solution

Wet-tissue has been used for baby wipe, cleansing pads, industrial wipes, pain relief, personal hygiene, pet care, and healthcare at home, care facilities, restaurant, and hospital. Raw materials of wet-tissue are mainly natural fibers and synthetic fibers such as cotton, rayon, PET (polyethylene terephthalate) and so on. In this study, electrolytic water of NaCl solution was used as fluid in wet-tissue, and the effect of raw materials on antibacterial rate of wet-tissue was investigated. Rayon (100%) showed an excellent antibacterial rate compared with cotton (100%) and rayon:PET (50:50). Antibacterial rate increased as Cl concentration of electrolytic water increased. Absorption of rayon:PET (50:50) was uneven and antibacterial rate of wet-tissue slightly increased by increase of Cl concentration. Antibacterial rate of wet-tissue was 100% under the conditions of more than 1.5 mL of electrolytic water dosage, and dropped under 50% after storage period of 48 hours.

Biodegradable Copolymers Obtained by Solution Polymerization

This study aims the synthesis of copolymers of poly (l-lactic acid) and polycaprolactone by ring opening polymerization. The reactions between l-lactide (LLA) and ε-caprolactone (CL) monomers, in 100/0, 95/5, 90/10 and 80/20 LLA/CL mass ratios, were conducted in refluxing toluene, using Stannous octoate as iniciator, methanol as co-iniciator and inert atmosphere (N2). The reaction medium was maintained under stirring at 120 °C for 24 hours. The samples were characterized by carbon-13 and proton nuclear magnetic resonance (C13-NMR and H1-NMR), and gel permeation chromatography (GPC). Monomers were characterized by thermogravimetry (TG). Copolymers were formed only in samples containing 20 wt% ε-caprolactone. NMR spectra of the other samples showed no evidence of CL units. This fact may be associated with the low-temperature volatilization of monomers. The GPC analysis showed that the increase of CL concentration decrease the molecular weight of copolymers.

Effect of chlorine doping on the structural, morphological, optical and electrical properties of spray deposited CdS thin films

CdS and chlorine doped CdS (CdS:Cl) thin films with different Cl-doping levels (0, 2, 4, 6 and 8at%) have been deposited on glass substrates by a spray pyrolysis technique using a perfume atomizer. The effect of Cl doping on the structural, morphological, optical and electrical properties of the films was investigated. XRD patterns revealed that all the films exhibit hexagonal crystal structure with a preferential orientation along the (0 0 2) plane irrespective of the Cl doping level. The particle size value decreases from 22.03nm to 18.12nm with increase in Cl concentration. Optical band gap is blue-shifted from 2.48eV to 2.73eV with increase in Cl doping concentration. All the films have resistivity in the order of 104Ωcm. The obtained results confirm that chlorine as an anionic dopant material can enhance the physical properties of CdS thin films to a large extent.

Micro Laser Joining between Dissimilar Materials of 200μm Thick TiNi Alloy and Stainless Steel and the Joint’s Electrochemical Behavior

Dissimilar materials between TiNi shape memory alloy (SMA) and stainless steel of 200μm mm thick were butt welded by micro impulse laser and the electrochemical behavior of the weld joints was studied. The results show that the crack sensitivity of the welded joint is very high and good joining between TiNi SMA and stainless steel can be realized with pure Ni wire as filler material presented between TiNi SMA and stainless steel. The tensile strength of the welded joint with pure Ni wire as filler material is 580MPa. The electrochemical tests of the welded joints in different concentrations of NaCl solutions and different pH value solutions show that, the maximum of the corrosion potential Ecorr in the three typical corrosion systems (0.9%NaCl, pH=7.3; 3.5%NaCl, pH=7.3; 0.9%NaCl, pH=4) is the weld seam, which indicates that the corrosion tendency of the weld is smaller than that of TiNi alloy and stainless steel in the three corrosion systems. The pitting corrosion potential of TiNi alloy, stainless steel and the weld gradually decreased with the increase of Cl-concentration; the pitting corrosion potential decreased with the increase of H+ concentration, while TiNi alloy decreased faster than that of the weld and stainless steel, the surface stability of TiNi alloy is low when pH value dropped below 7.

Temporal changes in thermal waters related to volcanic activity of Tokachidake Volcano, Japan: implications for forecasting future eruptions

In order to detect changes in volcanic activity of Tokachidake Volcano, Japan, we have continuously monitored thermal waters discharging at the western to southwestern flank of the volcano since 1986. The steam-heated waters in the Nukkakushi crater discharged with boiling temperature until 2002. Thermal waters at the Tokachidake spa area have similar compositions to fumarolic gas emitted from the summit craters, indicating that the waters formed by absorption of volcanic gas into shallow aquifers. Thermal waters at the Fukiage spa area were derived from the same aquifer as the Tokachidake spa area until early 1986. However, after that time, NaCl-type thermal water entered the Fukiage spa area during the increase in volcanic activity associated with the 1988–1989 eruption, thus leading to a clear increase in Cl concentrations and temperature. After the eruption, the supply of the NaCl-type thermal water was halted, and the Cl concentrations of the thermal waters decreased. In contrast, SO4 concentrations gradually increased in the Fukiage spa area after 1989, and the temperature has been maintained. These observations indicate that SO4-rich thermal water with a relatively high temperature entered the system instead of the NaCl-type thermal water. As was the case for the 1988–1989 eruption, the Cl concentrations at the Fukiage spa area increased in 2012 during an increase in volcanic activity, implying that the supply of the NaCl-type thermal water had resumed. However, the chemical changes in the thermal waters since 2012 are small compared with those before the 1988–1989 eruption, with oxygen and hydrogen isotopic compositions remaining nearly the same as those of meteoric waters.

Temporal variation of seepage water chemistry before and after the Hengchun Ms 7.2 earthquake in south Taiwan

A destructive magnitude ( M) 7.2 earthquake (21.9° N, 120.6° E) occurred in Hengchun of Taiwan at 8:26 pm on 26 December 2006. Seepage water chemistry was monitored twice a month from four routinely monitored points in the Kengting Uplifted Coral Reef Nature Reserve (KUCRNR) around Hengchun from January 2002 to December 2007. The different variants were presented for pH, conductivity, Na, K, Ca, Mg, NH 4, F, Cl, NO 3, SO 4, and HCO 3. It was observed that the occurrence of the Hengchun Ms 7.2 earthquake caused both temporary and permanent modification in the water chemistry of the seepage water studied. The significant increase of Cl concentration in seepage water were found 2 years prior to the earthquake, and remained steady until the present. Cl-rich waters are therefore expected to have been introduced within the KUCRNR water systems. Ca showed nearly the same trend as HCO 3 with high peak concentrations before the Hengchun Ms 7.2 earthquake, and then decreased with time after the earthquake. The high Ca and HCO 3 contents may be due to intense interaction processes between the thermal waters and the carbonate reservoir. The Ca and HCO 3 species would be added to the water during flow through the rocks. The effect of limestone may explain this result, because the sedimentary rock in this area majorly includes limestone.

The Behavior of Ions Inside the Cytoplasmic Domain of Inward Rectifier Potassium Channels

Inward rectifiers are a subfamily of potassium channels that control the amounts of outward K+ current in a cell. These channels achieve rectification through intracellular block by strongly charged cations such as Mg2+ and polyamines like spermine (SPM4+). The large cytoplasmic domain that extends the ion permeation pathway has been shown to be an important determinant of conductance and rectification, however the organization of ions within this part of the pore is not well understood. In this study, the properties of ions inside the cytoplasmic domains of a weak (Kir1.1/ROMK) and strong (Kir2.1/IRK) rectifier are investigated via explicit solvent molecular dynamics simulations in 1M KCl. Both channels concentrate K+ ions in large amounts (local concentration > 3M), with the highest densities near the protein surface. An additional concentrating region specific to Kir2.1/IRK is observed near the cytoplasmic opening. Simulations are also carried out with Mg2+ or SPM4+ inside the domain. Mg2+ interacts directly with pore-lining residues, resulting in a depletion of K+ and increase in the local concentration of Cl−. SPM4+ shows high density throughout the central pore and selectively depletes K+ in the upper region of the pore closest to the transmembrane domain. Two long-lived states of SPM4+ are observed in Kir2.1/IRK: (i) inside the central pore in contact with residues D2591, E2241, E2242 and E2992 from two adjacent subunits, and (ii) near the cytoplasmic entrance interacting with residues D255, D259 and E224 on a single monomer. These results demonstrate a level of molecular specificity with respect to ion behavior within the cytoplasmic domains that could correspond to differences in rectification properties.

Solubility of H 2O- and chlorine-bearing fluids in basaltic melt of Mount Etna at T = 1050–1250 °C and P = 200 MPa

An experimental study on the solubility of H–O–Cl-bearing fluids in basaltic melts has been conducted at total pressure of 200 MPa, in the temperature range from 1050 to 1250 °C and at redox conditions corresponding to lof fO 2 ∼ QFM + 1 (QFM = quartz–fayalite–magnetite oxygen buffer). A natural trachybasaltic sample of Mount Etna's July–August 2001 eruption has been used as starting material. Water concentrations in the melt (H 2O melt) increase from 4.6 up to 5.4 wt.% with an increase in Cl concentration in the melt (Cl melt) from 0 to 2.5 wt.%. The H 2O melt dramatically decreases to ∼ 2–3 wt.% at Cl melt > 2.5 wt.%. The saturation of the melt with Cl is reached at 4 wt.% Cl melt which is significantly higher than predicted by the existing models. Although increasing total Cl concentration in the system (bulk Cl in fluid and melt) leads to significant extraction of cations like Na, K and Fe from the melt into the fluid(s), the observed systematic increase in H 2O melt cannot be directly attributed to the change in melt composition, indicating that the presence of Cl may decrease the activity coefficient of dissolved H 2O in the melt. The complex non-linear relationships between H 2O and Cl concentrations in basaltic melt and fluid phase point to a strong non-ideality of mixing between fluid components, presumably resulting in an increase in the activity coefficient of Cl in the fluid and in the formation of two fluid phases (vapor and liquid) at the studied conditions. The effect of temperature on the solubility of H–O–Cl-bearing fluids in trachybasaltic melt and, hence, on the mixing properties of the fluid phase is not resolved from the obtained experimental data. The experimentally determined partition coefficient of Cl between fluid(s) and melt ( K d′Cl, based on a molar ratio) exponentially increases from 0.04 up to 14 with increasing Cl melt and shows almost linear dependence on bulk Cl content of the fluid(s). The K d′Cl values < 1 are observed at Cl melt lower than 1.0 wt.%, explaining the almost constant Cl concentrations (∼ 0.2 wt.%) in melt inclusions and variations of H 2O/Cl and S/Cl ratios in melt inclusions and volcanic gasses with ongoing magma degassing and changes in eruptive activity of Mt. Etna. Thus, the obtained data represent an experimental database necessary for the accurate modeling of natural processes of magma degassing at basaltic volcanoes.

Effects of Chloride and Co-Contaminated Zinc on Cadmium Accumulation within Thlaspi caerulescens and Durum wheat

Cadmium is a potentially toxic heavy metal with no known benefit to humans. Soils are the main source of Cd in plants, and plant-derived foods are the main source of Cd in human diets. Cadmium is present in all soils, usually as a trace constituent. The plant availability of Cd in soil is determined by the characteristics that affect the availability of most trace metals. These characteristics include plant species, the concentration and chemical forms of metal in the soil, pH, organic matter content, clay content, its interactions with other elements, and fertilizer practices. In addition, an increase in Cl concentrations in the soil or soil solution was shown to increase Cd concentration in plants in laboratory studies, such as Swiss chard, sunflower, potato, kenaf, sorghum and wheat (Smolders et al. 1997; Hattori et al. 2006). Under field conditions, Cd concentrations in plants were found to positively relate to Cl concentration in soil as well (Norvell et al. 2000; Wu et al. 2002). Chloride is known to reduce soil sorption of Cd, probably due to the fact that chloride forms relatively strong complexes with Cd depending on solution Cl concentration. Chloro-Cd complexation and the resulting improved diffusion of Cd through the soil to plant roots and possibly increased uptake of Cd-chloro complexes are suspected to be the reasons for the Cl effect on Cd uptake (Mclaughlin et al. 1997). Unlike Cd, Zn is an essential nutrient both for plants and animals, but if present in high concentration in plants and animals it can also be highly toxic. It is generally accepted that Zn status in soils and plants plays an important role in Cd accumulation in crop plants. Generally, Zn application decrease Cd uptake and accumulation in plants (Jiao et al. 2004; Zhang and Song 2006), which may be caused by Cd and Zn competivite adsorption in soils and absorption by roots as well as an interaction in the transport system of plant (Hart et al. 2002). However, the effects of Zn application on Cd uptake and accumulation in plants are not consistent. Nan et al. (2002) showed that increases in Zn application enhanced Cd concentration in wheat or vice versa. Similar observations were also made by other researchers (Wu and Zhang 2002). Most of studies under actual field situations, soil environments are often contaminated with multiple heavy metals, such as Cd, Zn, Pb, etc. The study of the Cd accumulation influenced by the interaction between these ions is of practical importance. Durum wheat is an important and valuable crop in many parts of the world that can accumulate Cd to approach or exceed the toxic concentration limits in some places. Durum wheat is a non-accumulator, but Thlaspi caerulescens is a hyperaccumulator of Cd and Zn that can accumulate more than 100 mg Cd kg in their leaves (Baker et al. 1994). Recently, there has been considerable interest in the use of Thlaspi caerulescens as a green technology for phytoremediation of surface soils contaminated with toxic Q. Liu (&) Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China e-mail: qliu@issas.ac.cn

Dietary Cation–Anion Difference of Timothy as Affected by Development Stage and Nitrogen and Phosphorus Fertilization

Dry dairy cows (Bos taurus) fed forages with a high dietary cation–anion difference (DCAD) are more likely to develop hypocalcaemia. We determined how development stage at harvest and N and P fertilization can be used to reduce the DCAD to &lt;250 mmolc kg−1 dry matter (DM) for timothy (Phleum pratense L.) grown on a soil high in K content. Stages of development (stem elongation, early heading, late heading, and early flowering) in spring growth, and treatments of P (0, 15, 30, and 45 kg ha−1) and N (0, 60, 120, and 180 kg ha−1) fertilization were evaluated. Concentrations of K, Na, Ca, Mg, Cl, S, and P of timothy were determined and the DCAD was calculated with a short (DCADS) and a long (DCADL) equation. From stem elongation to early flowering, DCADS decreased from 326 to 196 mmolc kg−1 DM and DCADL from 297 to 181 mmolc kg−1 DM; this reduction was attributed to a decrease in K concentration and a slight increase in Cl concentration with development stage. Nitrogen fertilization increased DCADS and DCADL only at stem elongation; the lack of a response at later stages of development is explained by the concomitant increase in both K and Cl concentrations with increasing N fertilization. Phosphorus fertilization did not affect DCADS and DCADL even though it increased timothy P concentration. Harvesting timothy at late heading, with an appropriate N fertilization to ensure adequate yield, is an option to produce a forage with a DCAD of &lt;250 mmolc kg−1. DM on a soil high in K.

Anion Species in Fertilizers Affect Growth and Development in Bedding Plants

Currently, formulation of inorganic fertilizers is based on cation amounts such as NH4, K, Mg, Ca, Fe, MN Cu, and Zn, whereas anion species and amounts are viewed, with few exceptions, as necessary fillers. The delivery of cations in the nutrient solution is associated with an anion such as Cl, SO4, NO3, PO4 or CO3. These anions at higher concentrations can result in different growth responses by altering the rhizosphere pH, soluble salts, and influencing the uptake of both cations and anions. The impact of these anions has not been extensively studied in the formulation of inorganic fertilizers. Several experiments assessed the effect of SO4 and Cl on root and shoot growth and development of bedding plants represented by petunia, impatiens, and vinca. In all treatments, plant height, shoot and root dry weight, and flower number decreased with an increase in Cl concentration. Root morphology was marked by fewer total roots and shorter primary and secondary roots when grown with Cl anions compared to the plants grown with SO4 anions. This indicates that anions have a larger role in determining optimum fertilizer formulation than previously believed. This information provides an additional tool in formulating fertilizers for greenhouse bedding plant production.

Relation between the ion flux, gas phase composition, and wall conditions in chlorine plasma etching of silicon

Transients in plasma composition and positive ion flux due to changing chamber wall conditions during Cl2 plasma etching of Si were studied using multiple plasma and surface diagnostics. In presence of Si and O containing species in the gas phase a glassy silicon oxychloride film coats the chamber walls over a time scale determined by the concentrations of the Si and O containing deposition precursors. This time scale can be a few minutes as in the case of Si etching with Cl2 plasma, where the concentration of silicon chloride etching products can be high, or hours as in the case of a Cl2 plasma maintained in absence of Si wafer, where the Si and O can only come from very slow etching of a quartz window. In either case, SiClx (1⩽x⩽4) and Cl concentrations in the gas phase and the total ion flux impinging on the wafer surface increase as the chamber walls are coated with this glassy film. The increase in SiClx and Cl concentrations are primarily due to lower loss probability of these species by recombination on the chamber walls. The ion flux increases primarily due to higher SiClx concentration in the discharge. During etching of Si, increases in Cl concentration and ion flux through the mechanism described above increases the etching and SiClx production rates. This strong coupling among the discharge properties, the wall conditions, and etching rate lead to transients in plasma operation.

Determination of the spatial distribution of major elements in the rat brain with X-ray fluorescence analysis

An energy dispersive X-ray fluorescence analysis was applied for determining the spatial (two-dimensional) distribution of elemental concentrations in rat brain sections. Freeze-dried brain sections prepared from normal and ischemic rats with middle cerebral artery occlusion were scanned with a collimated X-ray beam (0.18 mm in diameter, 50-kV acceleration voltage). The fluorescent Kα X-rays of P, S, Cl, and K were detectable, so that the two-dimensional distribution of fluorescent X-ray intensities could be determined for these elements. Furthermore, quantitative determination was possible for P and K by using the fundamental parameter technique. However, the accurate determination of Na and Ca was difficult, because of the low energy of Kα X-ray of Na, and the interference of K-Kβ with Ca-Kα. The change in elemental concentrations in ischemic tissue, including the decrease in K concentration and increase in Cl concentration, was demonstrated by this method as a two-dimensional contour map. Since it is possible to obtain a pictorial representation of the elemental concentration in tissue sections, this method may be useful to evaluate the ionic changes in injured brain tissue in relation to histological or autoradiographical observations.