PP Values Research Articles

Financial Analysis Of Citrus “Keprok 55” In Coventional Way and Using Sprinkler Irrigation

Batu-Malang Government area is one of central production of citrus ”Keprok 55” in East Java. In dry season, citrus produce low production level, because there is unsufficient water inside the soil. Based on this facts, some efforts is needed in order to increase the citrus production especially to face the dry season, through sprinkle irrigation system to increase citrus production. Sprinkle irrigation system has been installed on citrus plantation in Selorejo Village, Batu. Citrus is one of the horticultural commodities which have priority to be developed. One type of citrus that favored consumers are mandarin (tangerine). During the period 2005-2009 tangerine imports reached 504,063 tonnes, or about 100,813 tonnes per year with a value of US $ 80,569,300. Management of commodity Citrus 55 in Selorejo village, subdistrict Dau, Malang not get maximum benefit due to the limitations of the use of technological innovation as well as the lack of capital. The experiment calculated HPP, BEP, NPV, R/C ratio, IRR and PP. This study was to compare the effect of management changes Citrus 55 between conventional and sprinkler irrigation. The financial viability of commodity management Citrus 55 in Selorejo Village declared eligible to run either conventionally or with sprinkler irrigation. Age commodity management business is ten years. Conventional management NVP value is IDR 1,234,468,408 and the value of NVP management with the use of sprinkler irrigation is IDR 5,200,599,957. PP value of conventional management is 5 years 2 months and sprinkler irrigation is 2 years and 5 months. Conventional management IRR value is 59.47% and value of management use sprinkle is 68.08%. R/C Ratio with conventional management is 1.4 and value R/C Ratio with sprinkle is 5.7. BEP value with management conventional is 5,719 kilograms and with sprinkle is 16,059 Kilograms. HPP value with management conventional is IDR 784 and with sprinkle is IDR 191.

Light competition within dense plant stands and their subsequent growth under illumination with different red:far-red ratios

We evaluated the dynamics of light competition within dense cucumber (Cucumis sativus L.) plant stands and its relationship to subsequent growth under illumination with different red to far-red ratios (R:FRs). The plant stands containing seedlings with different initial degrees of mutual shading was grown under metal-halide lamps (MHLs) with spectra similar to that of sunlight (R:FR=1.2) or fluorescent lamps (FLs) with high R:FR (11) for 6days at a photosynthetic photon flux of 300μmolm−2s−1. The daily-integrated photosynthetic photon intercepted by individuals (daily PP; mold−1 per plant) were calculated once a day from the PPF, the photoperiod, and the directly irradiated leaf area. Under MHLs, differences in the daily PP values of individual seedlings with different initial shading degrees became non-significant within 2days, whereas under FLs, differences were preserved throughout the experimental period, indicating that the unequal competition exists between neighbors under FLs. The daily PP on day 0 and dry-weight increase of the seedlings during the experimental period were positively correlated under FLs but not under MHLs, indicating that the initial dominance of light interception by individual seedlings is likely to affect their subsequent growth under FLs. The seedlings that had lost out to neighboring seedlings could not climb over the neighbors under FLs, probably because of insufficient stimulation of shade-avoidance responses caused by the higher R:FR illumination.

ITS2 para la identificación de Califóridos (Diptera: Calliphoridae) de importancia forense en Colombia

La entomología forense es una disciplina que utiliza insectos para obtener información útil en la determinación del intervalo postmortem (IPM). Las moscas de la familia Calliphoridae son muy utilizadas en entomología forense, sin embargo, su identificación a nivel de especie puede dificultarse cuando el individuo se encuentra incompleto o en estadio inmaduro. En el presente trabajo, se evaluó el potencial de la región ITS2 del genoma nuclear para la identificación de especies de Calliphoridae en Colombia utilizando tres aproximaciones: comparando distancias genéticas utilizando la metodología de códigos de barra, haciendo una reconstrucción filogenética, y con enzimas de restricción (PCR-RFLPs). Se secuenciaron un total de 520 pb en 44 individuos pertenecientes a 16 especies. Se calcularon los valores de distancia intraespecífica e interespecíficas utilizando el modelo K2P. Los valores de distancia intraespecífica oscilaron entre 0 y 0,252 %, mientras que las distancias interespecíficas fluctuaron entre 3,6 y 18,9 %, evidenciándose que esta técnica puede ser utilizada como código de barras genético en la identificación de especies de la familia Calliphoridae. Tanto en los análisis de Neighbour-Joining como en los análisis bayesianos el 90 % de los géneros presentan una monofilia sustentada en probabilidad posterior de 0,89 a 1. En todos los casos la especie Blepharicnema splendens agrupa con el género Lucilia. Con base en las secuencias obtenidas se utilizó la aplicación NEBCutter para identificar cuatro enzimas de restricción las cuales se probaron en el laboratorio y se comprobó su utilidad para la identificación rápida de especies de Calliphoridae en Colombia.

Thermal Behavior of Calcium Carbonate and Zinc Oxide Nanoparticles Filled Polypropylene by Melt Compounding

This study investigates the effect of Calcium Carbonate and Zinc Oxide nanoparticles on thermal behavior of virgin and waste polypropylene. CaCO3 nanoparticles at content of (3, 5, 7 and 10 wt. %) mixed with virgin and waste PP by using co-rotating twin screw extruder at 25 rpm and 190°C. Two techniques used to incorporate ZnO nanoparticles in waste PP in two steps: the first one ZnO nanoparticles mixed with acetone solvents by ultrasonic device and then using twin screw extruder to produce nanocomposite sheet. Fourier Transmitted Infraredspectroscopy (FTIR) test used to check the structure of polypropylene. X-Ray Diffraction is used to check the crystallinity of nanocomposite. Thermal conductivity of the modified composite was studies by using thermal coefficient meter model (YBF-3). The qualitative and quantitative temperatures distribution of the extruding polymer nanocomposite is tested by using FLIR thermal camera due to different melt flow rate. Strong relation between crystallinity, thermal conductivity and thermal gradient of nanocomposite is observed. The results show that an improvement in thermal conductivity for both virgin and waste PP with nanoparticles content increasing, thermal conductivity values of waste PP is higher than that of virgin PP and the effect of ZnO nanoparticles is higher than that of CaCO3naoparticles. The results of thermal image indicate that the uniform and smooth surface associate with Melt Flow Rate (MFR) at load 2.16 kg. The temperature gradient increases with MFR values decreasing for waste PP while decreasing for virgin PP.

Leaf turgor pressure in maize plants under water stress

Maize grown is affected by water stress reducing photosynthetic rate and availability of water in its tissues, decreasing plant yield. Monitoring plant water potential is an important indicator of the degree of water stress. With the new magnetic probe for determining leaf turgidity, it is possible to evaluate the water status of the plant and, in some cases, to indicate the optimal relative tolerance to water stress. The union of new and old approaches gives us a better knowledge of water relations in plats. Therefore, the aim of this study was to understand the behavior of maize plants subjected to water stress, using novel and conventional approaches. Maize plants were grown in pots in a greenhouse for 45 days. After this period, plants were subjected to water stress, where turgor measurements expressed by the variable Pp (patch pressure) were monitored. In addition, the leaf water potential, stomatal conductance, CO2 assimilation, transpiration rate, and variable growth (height, leaf area and dry weight) had been monitored for 30 days. Two treatments were conducted, one in which the plant was irrigated and the other one in which irrigation was fully suspended for a period of time and monitored the water status. As the days passed, the plants showed the first visual signs of stress like leaf rolling. During this period, we observed fluctuating Pp values throughout the day, but with a recovery of turgor at night. There were significant differences between treatments for stomatal conductance, water potential, photosynthesis, and Pp, mainly before irrigation. After each irrigation, there has been a rapid recovery in all parameters. There was five periods of stress and it is possible to see a pattern of decreasing and increasing the Pp as the advance of stress, mainly in the last two. Maize plants had a big resilience in water stress conditions, due to mechanisms of water loss mitigation, like leaf rolling and possibly osmotic adjustment. Thus, it was concluded that Pp introduced a new approach to study plants subjected to water stress and it is a complement to other variables as CO2 assimilation rate, stomatal conductance, transpiration rate, and leaf water potential.

Prevention of neurological complications using a neural monitoring system with a finger electrode in the extreme lateral interbody fusion approach

OBJECTIVE Extreme lateral interbody fusion (XLIF) is a minimally disruptive surgical procedure that uses a lateral approach. There is, however, concern about the development of neurological complications when this approach is used, particularly at the L4-5 level. The authors performed a prospective study of the effects of a new neural monitoring system using a finger electrode to prevent neurological complications in patients treated with XLIF and compared the results to results obtained in historical controls. METHODS The study group comprised 36 patients (12 male and 24 female) who underwent XLIF for lumbar spine degenerative spondylolisthesis or lumbar spine degenerative scoliosis at L4-5 or a lower level. Using preoperative axial MR images obtained at the mid-height of the disc at the treated level, we calculated the psoas position value (PP%) by dividing the distance from the posterior border of the vertebral disc to the posterior border of the psoas major muscle by the anteroposterior diameter of the vertebral disc. During the operation, the psoas major muscle was dissected using an index finger fitted with a finger electrode, and threshold values of the dilator were recorded before and after dissection. Eighteen cases in which patients had undergone the same procedure for the same indications but without use of the finger electrode served as historical controls. Baseline clinical and demographic characteristics, PP values, clinical results, and neurological complications were compared between the 2 groups. RESULTS The mean PP% values in the control and finger electrode groups were 17.5% and 20.1%, respectively (no significant difference). However, 6 patients in the finger electrode group had a rising psoas sign with PP% values of 50% or higher. The mean threshold value before dissection in the finger electrode group was 13.1 ± 5.9 mA, and this was significantly increased to 19.0 ± 1.5 mA after dissection (p < 0.001). A strong negative correlation was found between PP% and threshold values before dissection, but there was no correlation with threshold values after dissection. The thresholds after dissection improved to 11 mA or higher in all patients. There were no serious neurological complications in any patient, but there was a significantly lower incidence of transient neurological symptoms in the finger electrode group (7 [38%] of 18 cases vs 5 [14%] of 36 cases, p = 0.047). CONCLUSIONS The new neural monitoring system using a finger electrode may be useful to prevent XLIF-induced neurological complications.

A study on role of partial pressure in controlled synthesis of core-shell MoO2/MoS2 nanoflakes

MoO2/MoS2 core-shell nanoflakes (NFs) with different shell thicknesses (4–16 nm) have been synthesized using plasma assisted sulfurization of MoO3 nanostructured thin films (NTFs) as a function of partial pressure (Pp). The thickness of shell can be controlled by varying partial pressure of H2S/Ar gas. The XRD and Raman analysis divulged that after sulfurization, films exhibit MoO2 in monoclinic and MoS2 in hexagonal phases. Surface morphologies of films have no noticeable changes after sulfurization. Further investigations of sulfurized films are performed using HRTEM with SAED, which revealed that the optimum Pp to get the maximum shell thickness (∼16 nm) is 6.5 × 10−1 Torr and confirmed the reliance of shell thickness on Pp value. It also depicted that core of NFs consist of MoO2 monoclinic phase while MoS2 hexagonal phase makes the outer shell. The sulfurization mechanism to synthesize MoO2/MoS2 core-shell nanoflakes is also proposed in this report. This opens up new frontiers for controlled synthesis of metal-oxide/metal sulfide core shell nanostructures.

Abnormal Pulsatile Hemodynamics in Hypertensive Patients With Normalized 24-Hour Ambulatory Blood Pressure by Combination Therapy of Three or More Antihypertensive Agents.

It remains uncertain whether intensive antihypertensive therapy can normalize pulsatile hemodynamics resulting in minimized residual cardiovascular risks. In this study, office and 24-hour ambulatory systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure, carotid-femoral pulse wave velocity (PWV), and forward (Pf) and reflected (Pb) pressure wave from a decomposed carotid pressure wave were measured in hypertensive participants. Among them, 57 patients whose 24-hour SBP and DBP were normalized by three or more classes of antihypertensive medications were included. Another 57 age- and sex-matched normotensive participants were randomly selected from a community survey. The well-treated hypertensive patients had similar 24-hour SBP, lower DBP, and higher PP values. The treated patients had higher PWV (11.7±0.3 vs 8.3±0.2 m/s, P<.001), Pf, Pb, Pb/Pf, and left ventricular mass index values. After adjustment for age, sex, body mass index, and office SBP, the differences for PWV, Pb, and Pb/Pf remained significant. Hypertensive patients whose 24-hour SBP and DBP are normalized may still have markedly increased arterial stiffness and wave reflection.

Relationship of Baseline Right Ventricle Function with Response to Cardiac Resynchronization Therapy

collected FEV1, FVC, FEV1/FVC ratios, and DLCO, as well as the percent predicted (pp) values for each of these parameters. Survival data, incidence of peri-operative right heart failure, and 6 month functional assessments (Kansas City Cardiomyopathy Questionnaire [KCCQ] and six minute walk distance [6MWD]) were also collected. The association of baseline PFT parameter with survival time was tested using proportional hazards regression, adjusted for known predictors of post-LVAD survival. The associations of PFT metrics with improvement in KCCQ and 6MWD were tested using linear regression adjusted for baseline values. Results: The mean cohort age was 54.8 (Range 20 to 75), were 23.3% female (30/129), 51.2% non-white race (66/129), and 52.7% were destination therapy (68/129). There was no association of PFT parameters (FEV1, ppFEV1, FEV1/FVC or DLCO) with survival time post LVAD (all four p-values greater than 0.2485), nor the incidence of peri-operative RV failure (all p O 0.1938). There were no significant associations of the baseline PFT metrics (FEV1, FVC, FEV1/FVC ratio and DLCO) with either the change in KCCQ or change in 6MWD measures, except for ppFEV1 which showed a negative correlation (i.e. low value correlated to better improvement). Conclusions: In this single center study, there was no relationship between baseline PFTs and survival time, RV failure or functional outcomes after LVAD placement. Further studies are needed to explore whether pre-operative pulmonary function testing is useful or necessary in patients being considered for LVAD implantation.

Efecto del tiempo e institucionalización en variables antropométricas apendiculares, en un grupo de adultos mayores independientes y dependientes

ObjectiveDetermine the effect of time and institutionalization in appendicular anthropometrics variables, in an independents and dependents elderly group. Materials and methodsExploratory study with an analytical observational design, with prospective longitudinal temporality. The design is based on the observation of appendicular anthropometric variables during 5 weeks in adult subjects aged institutionalized in the region of Maule. A total of 17 elderly were included; the sample was divided in 2 groups: independent elderly (IE), 7 subjects, and dependent elderly (DE), 10 subjects. Arm circumference (AC); calf circumference (CC); arm skinfold (AS); calf skinfold (CS), corrected arm muscle area (CAMA) and leg muscle area (LMA) were recorded. ResultsIn both (IE) and AMD (DE), in the fifth week of evolution, the variables: AC (IE: P<.05; DE: P<.001), CC (IE: P<.05; AMD: P<.05), cAMA (IE: P<.05; DE: P<.001) y LMA (IE: P<.05; AMD: P<.01) these showed significant differences at the time to compare with the first week of measurement, being more pronounced in the group of DE. PP values in the IE group in the first week were higher compared to the DE group (P<.05), same for the fifth week in the CB and the cAMA (P<.005). ConclusionThe effect of time in 5 weeks is able to produce significant statistical changes in the AC, CC, cAMA, and LMA, not in the AS, CS.

Pumping potential of a two-layer left-ventricle-like flexible-matrix-composite structure

The pumping potential, defined as the amount of relative volume reduction engendered by an applied load (relative input stroke), is an important criterion for flexible-body pumps. It is introduced as a measure of the volumetric efficiency of pumping. The PP of many flexible-matrix-composite (FMC) structures has been considered in the literature. Most recently, the PP of a single-layer left-ventricle-like FMC structure, based on the helical ventricular myocardial band hypothesis, has been investigated. A PP of 1.67–1.9 has been achieved. Though reasonably high, it is much smaller than that of the actual left ventricle of the heart (3.33–4.0). In here this work is extended to a two-layer left-ventricle-like FMC structure, which adopts a more accurate fiber orientation. The PP of the two-layer left-ventricle-like FMC structure is determined experimentally and analytically. A FMC flat band is created then twisted and looped to form the flexible-body structure. The analytical investigation using the ANSYS software engenders a PP of 2.5, and the experimental one using a PU/SMA (shape memory alloy) FMC renders a PP of 2.85. These higher values of PP indicate that accurate fiber-orientation in heart-mimicking flexible-structural pumps is very important.

Camarosporium sensu stricto in Pleosporinae, Pleosporales with two new species

Three coelomycete species with muriform conidia were collected in Italy and subjected to morpho-molecular analyses. In morphology, all species are similar to Camarosporium sensu stricto. Based on morphology, one was identified as C. spartii and the other two taxa are introduced as new species, viz. C. clematidis and C. robiniicola. Maximum likelihood, maximum parsimony and Bayesian analyses of the combined LSU, SSU and ITS dataset show that the three taxa cluster with C. quaternatum, the type species of Camarosporium, with high bootstrap and PP values. All four species can be considered as Camarosporium sensu stricto. Cucurbitaria elongata groups in the Camarosporium clade near to Camarosporium robiniicola and is considered that it is not congeneric with Cucurbitaria sensu stricto (Cucurbitariaceae).

Adaptive power allocation and outage performance of cognitive best relay cooperation systems with multiple primary transceiver pairs and direct path between cognitive source and destination

Based on decode-and-forward (DF) protocol, this work focuses on the adaptive power allocation and outage performance of underlay cognitive radio and opportunistic relaying (UCR-OR) systems with direct path between cognitive source and destination. The UCR-OR systems suffer from the interference of multiple primary user (PU) pairs. Under the outage constraint of PUs and the cognitive peak transmit power limit, we first obtain the adaptive power allocation schemes for secondary transmitters. Secondly, we obtain the exact closed-form expression to the outage probability of UCR-OR systems by using appropriate mathematical proof. Finally, to obtain a clear insight and to highlight the effect of system parameters on the performance of UCR-OR systems, the asymptotic closed-form expression of outage probability is achieved with the assumption of high cognitive transmit power. The presented simulations show that, due to the adaptive power allocation employed, the outage probability of UCR-OR systems is decreasing with PUs' transmit power Pp when Pp is less than a specific value P � . Only when the value of Pp is

Camarosporium-Like Species are Polyphyletic inPleosporales; IntroducingParacamarosporiumandPseudocamarosporiumgen. nov. inMontagnulaceae

Camarosporium is a large coelomycetous genus which was formerly recognised as an asexual state in Botryosphaeriales and Cucurbitariaceae. In the present study, we collected several Camarosporium-like taxa in Europe (Germany and Italy) and carried out morpho-molecular analyses. Molecular analyses (maximum likelihood, maximum parsimony and MrBayes) of combined LSU and SSU gene datasets show that the Camarosporium-like taxa are polyphyletic in Pleosporales. Camarosporium quaternatum, the type species of Camarosporium clusters in the suborder Pleosporinae with five other Camarosporium species. This clade is supported by high bootstrap and PP values and is distinct from other well-established families in Pleosporinae. Other Camarosporium-like taxa grouped in Montagnulaceae (Massarineae) as two phylogenetically distinct clades and are introduced as two new genera, viz. Paracamarosporium and Pseudocamarosporium. Paracamarosporium is morphologically distinct as it has paraphyses and microconidia, while Pseudocamarosporium lacks both of these characters. Since Camarosporium comprises a large number of species epithets, re-collection and morpho-molecular studies of other Camarosporium-like taxa is essential.

Fitness components of Monosporascus cannonballus isolates from northeastern Brazilian melon fields

Monosporascus root rot and vine decline caused by Monosporascus cannonballus is one of the most important melon yield-limiting diseases in northeastern Brazil. This study investigated the fitness components of 57 isolates of M. cannonballus obtained from Brazilian melon fields by evaluating: i) their mycelial growth rate (MGR), and perithecia and ascospore production (PP and AP) on potato dextrose agar (PDA); ii) their sensitivity to the fungicide fluazinam; and iii) their virulence to melon seedlings. All M. cannonballus isolates showed variability in their MGR, PP and AP values. They were sensitive to the fungicide fluazinam, showing some degree of mycelial growth inhibition (MGI), and were pathogenic to melon seedlings, with a mean disease severity index (DSI) of 62.1%. By univariate analysis, the formation of groups of similarity amongst the isolates of M. cannonballus within each variable was not limited by the area of origin of each isolate, given that in most situations, different isolates of the same area were distributed into distinct groups of similarity. A multivariate cluster analysis allowed the separation of the 57 M. cannonballus isolates in 18 groups of similarity. The fitness variability among M. cannonballus isolates found in this study should be considered when possible sources of resistance are evaluated in melon breeding programs.

Spin-Relaxation of NiO Encapsulated Gd2O3 Core–Shell Nanoparticles

Nickel oxide encapsulated gadolinium oxide (Gd2O3/NiO) core–shell nanoparticles (Nps) has been synthesized by polyol method and analyzed by transmission electron microscopy. The particle size is found to vary from 25 to 35 nm. Raman spectra show the gadolinium oxide core material peaks are found to be diminished by the mass effect of the NiO shell material. The dynamics of the magnetic moment has been studied with the help of temperature dependent electron paramagnetic resonance (EPR) spectroscopy. Peak-to-peak line width (ΔH pp) value of the EPR spectra increases with decreasing temperature. Temperature dependence of line width shows the dominance of spin–lattice relaxation in these systems, and it can be used as T 1 contrast agent. Spin number estimated from EPR studies increases with the decrease of the temperature. The interfacial exchange coupling between the core and shell region is found to be existing at very low temperatures as determined by EPR studies in this non-magnetic/antiferromagnetic (NM/AFM) core/shell nanosystem. The effects of the temperature on the magnetic properties of the Gd2O3/NiO core/shell NPs and the underlying mechanism have been discussed.

Cardiovagal activity following acute sprint interval exercise (706.6)

The purpose of this study was to examine the impact of sprint interval exercise (SIE) on the time course of cardio‐autonomic recovery and vagal activity over a 24 h period. Eight healthy males (age=24.1±2.3 y) performed a single bout of SIE that included 4 x 30 s all out sprints interspersed by 4 min of recovery, performed on a manual treadmill. Following an overnight fast, measurements were taken at baseline (day 1; 8:00 a.m.), pre‐exercise (PRE‐X), immediately (PT‐X1), 90 (PT‐X2), 180 (PT‐X3) and 300 (PT‐X4) min post‐exercise as well as the following morning (day 2). Compared to PRE‐X, all spectral, time domain and Poincaré plot indices of heart rate variability (HRV) were reduced during PT‐X1‐3 (P蠄0.01). Baroreflex sensitivity was also depressed from PT‐X1‐4 (P&lt;0.01). Relative to PRE‐X, plasma pancreatic polypeptide (PP; plasma indicator of vagal stimulation) was elevated at PT‐X1 (P=0.03). There were no differences in resting HRV, baroreflex sensitivity and plasma PP values between day 1 and 2 (P蠅0.12). These results indicate that despite an acute rise in plasma PP, there is a profound minimization of cardio‐vagal control following SIE. Cardio‐autonomic modulation recovers progressively and all indices of vagal activity are normalized by the following morning.Grant Funding Source: Supported by NSERC

The Relationship between the 24 h Blood Pressure Variability and Carotid Intima-Media Thickness: A Compared Study

Large blood pressure variability (BPV) will not only harm the target organ but also increase the possibility of the cardiovascular events. Since the damage of vascular system always leads to the alteration of the carotid wall, the structure and function of the carotid artery have been extensively examined in previous studies. In this work we conduct a study (60 subjects, aged 33–79) to evaluate the relationship between BPV and carotid intima-media thickness (IMT) in Shenzhen, which is one large city in the southern area of China. In our study, the blood pressure (BP) was collected using the 24 h ambulatory BP monitoring, and the BPV was evaluated using standard deviation (SD), coefficient of variation (CV), and average real variability (ARV) during 24 h, daytime and nighttime. All the IMT measurements are collected by ultrasound. The results show that both the daytime, and 24 h systolic BPV evaluated by three indices are positively associated with IMT. Among them, daytime systolic BPV evaluated with ARV is the best variable to represent the increasing of carotid IMT. In addition, after adjusting by age, sex, smoking, hypertension, and mean BP and PP values, 24 h diastolic BPV evaluated with SD also presents the favorable performance.

Investigating Spectral Characteristics and Spatial Variability of Dissolved Organic Matter Leached from Wetland in Semi‐Arid Region to Differentiate Its Sources and Fate

Dissolved organic matter (DOM) collected from different sampling sites in Lake Wuliangsuhai (Inner Mongolia Autonomous Region of China) was investigated using UV–Vis absorption and fluorescence spectroscopy. The three indices, SUVA280 and two spectral slopes (S275–295 and S350–400), were used to detect the change in the aromatic structure of DOM. DOM aromaticity was lower at sites W1 and W3, where industrial wastewater and domestic sewage, and agricultural drainage, contributed respectively. The humification index also indicated a low humification degree at sites W1 and W3, and high humification degree in other sites with relatively better water quality. Fluorescence regional integration (FRI) analysis has been used to quantitatively analyse fluorescence excitation–emission matrix spectra. The results showed that external contaminants can influence the distribution of Pi,n values from the FRI analysis. Serious pollution area obtained a relatively high Pp value. A significant negative correlation between Ph/Pp and f450/500 indicated the terrestrial or autochthonous sources of DOM. Therefore, the spectroscopic techniques combined with regional integration analysis can be used as a useful tool for investigating and assessing the lake ecological environment.

A kinetic analysis of catalytic production of oxygen in catalase‐containing liposome dispersions for controlled transfer of oxygen in a bioreactor

AbstractBACKGROUNDBiochemical oxidation reactions require oxygen to be supplied by dispersed bubbles. Drawbacks of the gas–liquid system are enzyme denaturation and low oxygen utilization efficiency. Therefore, oxygen production through the decomposition of H2O2 is useful for controlled oxygen transfer in bioreactors.RESULTSCatalase‐containing liposomes (CALs) were prepared in 50 mmol L‐1 Tris/0.1 mol L‐1 NaCl buffer (pH 7.4) and the kinetic model was developed for the oxygen production by CAL‐catalyzed decomposition of 1.0 mmol L‐1 H2O2. Applying the model to the observed time course of oxygen produced gave overall resistance in the reaction based on the pseudo‐steady‐state assumption inside liposomes for H2O2 and oxygen. The reaction resistance was estimated with the liposomal catalase concentration et,in and the kinetic parameters of free enzyme reaction. At et,in = 0.59 µmol L‐1, the CAL reaction proceeded under reaction control, while at et,in = 5.05 µmol L‐1, the H2O2 transfer resistance was involved. For the latter case, the permeability coefficient PP of H2O2 through the liposome membrane was determined as 1.06 × 10‐6 m s‐1 at 25°C. The model predicted the H2O2 concentration inside liposomes with different et,in values. Furthermore, the oxygen concentration in the CAL dispersions was reasonably simulated. The oxygen production rate could be altered based on temperature (10–55°C) and the fractional volume of CALs.CONCLUSIONThe CAL‐catalyzed oxygen production was controlled based on the et,in and PP values, which determine the relative importance of the reaction and H2O2 transfer resistances. The CAL would be applied to oxidation reactions instead of gas–liquid systems. © 2013 Society of Chemical Industry