Second Phase Of Experiment Research Articles

Investigation of removal of ash and sulfur from Kangal (Sivas/Turkey) lignite with the application of combined methods

ABSTRACT Boric acid is a dilute or mild acid derived from boron, and it is available in a water-soluble form as a white powder. Strong acids are generally preferred to remove ash and sulfur from coal. However, consumption of these strong acids harms the environment. Therefore, it is necessary to improve the leaching possibilities of weak acids. Also, a combination of beneficiation methods may need to be used to achieve the desired quality and environmental compatibility of coal. In this study, a combination of bioleaching and chemical experiments was employed to eliminate ash and sulfur from Sivas Kangal lignite coal. Initially, bioleaching experiments were conducted on lignites with high ash and sulfur contents by bioreactor with Acidithiobacillus ferrooxidans. Following this, in the second phase of experiments, boric acid leaching was employed to beneficiate Sivas/Turkey lignites through chemical methods. Additionally, the effect of glycerol on the leaching efficiency of boric acid, which is a weak acid, was investigated. Experimental findings have shown that combination methods provide better results in ash and sulfur removal from lignite coal. Finally, a clean coal product with 19.80% ash and 2.89% S content was obtained by combination methods to the lignite coal (46.60% ash and 4.99% S).

Experimental and mathematical modelling of grain material velocity

The present article represents the next stage in the cycle of work on the research of vibrating motion of grain material. This paper contains the experimental results of the operation of a vibrating conveying machine. The investigation was carried out in three stages. The purpose of the first full-factor experiment with four varying factors was to identify factors having the least impact on the time of movement of grain material. As a result, it was found that the angle of vibration direction that has an impact on the amplitude has almost no effect on the velocity of the grain material. In the second phase of experiment carried out with three varying factors at fixed angle of vibration direction, the equation of mathematical model of time of passage of the control area has been obtained. Moreover, on the basis of previous studies, the angle of vibration direction was fixed at the position which has the greatest influence on the vibration amplitude. The third stage of the experiment was to evaluate applicability of the obtained model equation to describe movement of other grain crops with ellipsoidal grain shape. Verification of the obtained model for adequacy using Fisher's criterion showed that with 95% probability the obtained equation can be used for estimation of movement of grain material having ellipsoidal shape on vibrating surface.

Aerobic granules cultivated using industrial rubber wastewater: Effect of size distribution and Performance of granules.

Sequential batch reactors (SBR) have been successfully developed granular sludge using industrial rubber wastewater on a cylindrical shaped SBR. SBR was introduced to industrial wastewater with varying chemical oxygen demand (COD) loadings from as low as 0.01 to 0.28 kgCOD/m3/d. First phase of experiment utilized 24 hours cycle time whilst second phase of experiment utilized 4 hours cycle time. Granules were successfully developed at the second phase (4 hours) of experiment. Fortunately, the overall performance for both cycles were excellent. COD removal efficiency throughout the experiment was kept at about 78 % to 98 %. Although higher COD removal was observed for both cycle, granulation did not occur in the first phase (24 hours). Decrement of cycling time to 4 hours promotes the growth of dense and structured sludge granules.

Enhanced methane generation and biodegradation efficiencies of goose manure by thermal-sonication pretreatment and organic loading management in CSTR

The current research investigated the effects of thermal-sonication pretreatment on the anaerobic digestion of goose manure. The CSTRs were run at three different organic loading rates: 1.4 g-VS/L.day, 2.9 g-VS/L.day and 4.4 g-VS/L.day, consequently termed as Phase-1, Phase-2 and Phase-3, respectively, and five different sonication pretreatments levels: (25 min, 45 min, 60 min, 90 min, and 120 min) at 28 KHz that were employed to optimize the anaerobic digestion process for goose manure to enhance methane production. The second phase was proved to be the optimum phase with maximum methane enhancement capability, CODs stabilization rate, and VS removal efficiency. Owing to thermal-sonication and organic loading management, methane enhancement up to 40.76% was evaluated for reactor C during the second phase of experiment. Furthermore, the biochemistry of the anaerobic digestion process was deeply interpreted at each three-day interval and the techno-economic analysis was performed to evaluate the pretreatment feasibility.

Artificial Neural-Network-Based Pre-Distortion for High Loss-Budget 60-km Long-Reach Passive Optical Network

High launch optical power can compensate for severe fading and power loss in long-reach passive optical networks (LR-PONs); however, it also aggravates nonlinear degradation, which necessitates the use of complex DSP-based nonlinear compensation techniques at optical network users (ONUs). DSP-related techniques also necessitate the use of additional hardware/software components by the receiver, which can greatly increase implementation costs and energy consumption, particularly when dealing with large-scale ONU deployment. This is the first study to propose artificial neural network (ANN)-based pre-distortion to eliminate the need for complex DSP at ONUs in a high-launch-power LR-PON, thereby permitting the use of a simplified architecture at the user end. In the first phase of the study, the proposed ANN-based pre-distortion scheme was implemented in a single-channel IMDD OFDM LR-PON, which achieved a data rate of >55 Gbps over 60-km transmission with a loss budget of 30 dB without the need for optical inline- or pre-amplification. In the second phase of experiments, the same scheme was applied to a 4-channel wavelength division multiplexing (WDM) OFDM LR-PON. Here, the proposed scheme achieved data rates of >200 Gbps using launch power of 18 dBm per lane, resulting in a loss budget of roughly 29 dB over 60-km single mode fiber transmission.

Experimental Study on the Influence of Polypropylene Fiber on the Swelling Pressure Expansion Attributes of Silica Fume Stabilized Clayey Soil

Expansive soil shows dual swell–shrink which is not suitable for construction. Several mitigating techniques exist to counteract the problem promulgated by expansive clayey soils. This paper explored the potential mecho-chemical reinforcement of expansive clayey soil to mitigate the effect of upward swelling pressure and heave. The polypropylene fiber is randomly distributed in the soil for mechanical stabilization, and the industrial residual silica fume is used as a chemical stabilizer. The experimental analysis was made in three phases which involved tests on mechanically-reinforced expansive soil, using randomly distributed polypropylene fibers with different percentages (0.25%, 0.50%, and 1.00%), and which were 12 mm length. The second phase of experiments was carried out on chemical stabilized expansive soil with different percentages (2%, 4%, and 8%) of silica, and the next phase of the experiment focused on the combination of mecho-chemical stabilization of the expansive soil with different combinations of silica (i.e., 2%, 4%, and 8%) and polypropylene fibers (i.e., 0.25%, 0.50%, and 1.00%). Maximum dry density (MDD), optimum moisture content (OMC), liquid limit (LL), plastic limit (PL), plastic index (PI), grain size, and constant volume swelling pressure tests were performed on unreinforced and reinforced expansive soil, to investigate the effects of polypropylene fiber and silica fume on the engineering properties of expansive clayey soil. The experimental results illustrate that the inclusion of polypropylene fiber has a significant effect on the upward swelling pressure and expansion property of expansive soil. The reduction in the upward swelling pressure and expansion is a function of fiber content. These results also indicated that the use of silica fume caused a reduction in upward swelling potential, and its effect was considerably more than the influence of fiber.

An experimental investigation of performance of a double pass solar air heater with foam aluminum thermal storage medium

The enactment of a double pass solar air heater was experimentally probed using four different formations. The scope of present study encompasses the use of Thermal Storage Medium (paraffin wax) integrated with porous/foam metal (aluminum) during the winter season. In the first phase of experimentation, first formation consisted of flat plate whereas foam aluminum embedded with paraffin wax was placed inside two copper ducts in the second configuration. In the third configuration, four copper ducts were used. During the second phase of experiment, similar configurations were used as in the first phase but with pre-heat. No melting of wax was accomplished when the outside air temperature ranged between 12 and 24 °C, however increased thermal conductivity was attained for configuration two and three. Melting of wax was achieved when the outside air temperature ranged between 15 and 29 °C, using pre-heat. The increase in thermal conductivity was achieved using foam aluminum but at the expense of slight decrease in storage capacity of the paraffin wax. In the last configuration no fan was used during the day time, and melting of wax achieved under similar conditions. Fourth configuration provided beneficial heat for 2.5 h after the sunset while the second and third configurations provided expedient heat for 1.5 h after the sunset.

Effect of Supplementation of Cinnamon (Cinnamomum zeylanicum) Powder on Diabetics

The present study was designed to determine the effect of supplementation of cinnamon powder on blood glucose level of selected diabetic patients. The cinnamaldehyde an active component in cinnamon have health protecting effect. Cinnamon has insulin like activity and it contains an active ingredient water soluble polyphenol compound MHCP (methyl hydroxi chalcon polymer). It initiates insulin, triggers its receptors and works synergistically with insulin cells. The investigation was conducted in two phases. In the first phase of experiment, thirty Type II diabetic subjects were selected by purposive sampling technique in Parbhani city. They were personally interviewed with the help of pre-tested questionnaire to elicit the information regarding socio-economic background, health status and food and nutrient intake. In the second phase of experiment, they were divided into two equal groups experimental and control group. The experimental group was supplemented by three capsules (containing 500 mg of cinnamon powder each) daily for 60 days. No supplementation was given to control group. The fasting and post prandial blood sugar level of all the selected thirty subjects, both experimental and control group was recorded initially, after 30 and 60 days. Anthropometric measurements were taken before and after the experiment. Nutrient content of cinnamon powder was analyzed. The collected data was analyzed statistically and it was concluded that the consumption of 1.5 g of cinnamon powder continuously for 60 days has positive effect in diabetic subjects.

Effect of intranasal insulin on peripheral glucose profile in dexamethasone-induced insulin resistance in Wistar rats

This study evaluates the therapeutic potential of intranasal insulin (INI) in dexamethasone-induced insulin resistance in Wistar rats. In the first phase of the study, thirteen, healthy, untreated male Wistar rats were divided into 2 groups and administered either vehicle (0.9% Normal saline, 20 µl) or insulin (2 IU) intranasally to assess intranasal delivery of insulin in brain. In the second phase of experiments, to evaluate the acute effects of intranasal insulin on peripheral blood glucose, intranasal or intraperitoneal insulin was co-administered with or without dexamethasone 10 mg/kg to 26 male Wistar rats and blood glucose monitored. To evaluate effect of intranasal insulin in peripheral metabolic disease model, insulin or vehicle was administered via intranasal or intraperitoneal (IP) route to control or dexamethasone (Dex)-treated (0.5 mg/kg, IP) female Wistar rats for seven consecutive days. Twenty-four hours after last dose, trunk blood was collected via cardiac puncture. Biochemical assay of glucose, lipid and insulin was performed on serum while enzyme activity – glucokinase and glucose-6-phosphatase (G6Pase) or lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G6PDH) were assayed from liver and brain homogenates respectively. Acute intranasal but not intraperitoneal insulin elevated brain insulin after 30 min. In animals administered single dose of 10 mg/kg dexamethasone, intranasal and intraperitoneal insulin lowered blood glucose within one hour. However, only the former’s effect was maintained at the 3rd and fourth hour. Dex-induced hyperglycemia was associated with increased hepatic glucose-6-phosphatase activity and decreased high-density lipoprotein (HDL), these effect were attenuated by subchronic (INI) administration. Also INI did not induce oxidative stress in the brain which suggests no brain damage during the period of study. Subchronic administration of INI was able to reduce the effect of Dex-induced hyperglycemia that is associated with increased hepatic glucose-6-phosphatase activity and decreased high-density lipoprotein (HDL) without damage to the brain. We demonstrate the potential of brain targeting with intranasal insulin in a rat model of insulin resistance and peripheral metabolic disease.

Investigate the effect of HD-tDCS on the prefrontal cortex using fNIRS for neurorehabilitation

Investigate the effect of HD-tDCS on the prefrontal cortex using fNIRS for neurorehabilitation

Experimental investigation of heat and mass exchange processes during operation of VVER steam generator in emergency condensing mode

GE2M-PG test facility was constructed at the JSC “SSC RF-IPPE” for assessment of efficiency of VVER steam generator and investigation of effects of initial conditions of the accident on the processes of heat exchange in the steam generator (SG) tube bundle assembly. The facility was used in two series of experiments with and without removal of the steam–gas mixture (SGM) from steam generator cold collector. Functionality of the steam generator model in condensation mode with different concentrations of non-condensable gases in steam at the SG model inlet and different flow rates of steam–gas mixture removed from cold collector was investigated during the first phase of experiment. Effects of main factors of operational modes on the efficiency of heat exchange processes in the steam generator tube bundle assembly was investigated during the second phase of experiments conducted without removal of steam–gas mixture.The obtained results can be applied for verification of computer codes used in calculation simulation of emergency processes in VVER reactor facility.

Distribution of reinforcement particles in surface composite fabrication via friction stir processing: Suitable strategy

ABSTRACTFabrication of metal matrix surface composites (SCs) is an emerging trend of friction stir processing applications. Key factors affecting the properties of SCs are process parameters, tool geometry, tool dimensions and reinforcement strategies. In this research, effects of different reinforcement strategies and varying tool offset positions on dispersion of reinforcement particles in the base matrix are investigated. The experiments were performed in two phases using AA6063 as base metal at constant process parameters of 1120 rpm rotational speed, 40 mm/min traverse speed and 2.5° tilt angle. In the first phase, effect of six different reinforcement strategies on the reinforcement particles distribution and defect formation was studied. It was found that groove method with tool offset in retreating side (RS) exhibited better homogeneity in reinforcement distribution out of the six reinforcement strategies considered. In the second phase, effect of variation of tool offset in RS was investigated. Results from second phase of experimentation reflected that the best dispersion of reinforcement powder with larger stir zone area was found with 1.5 mm tool offset which is numerically half of the tool pin radius. The results were supported by macro and microstructural images obtained from the optical microscope and scanning electron microscope.

A New Anaesthetic Protocol for Adult Zebrafish (Danio rerio): Propofol Combined with Lidocaine.

BackgroundThe increasing use of zebrafish model has not been accompanied by the evolution of proper anaesthesia for this species in research. The most used anaesthetic in fishes, MS222, may induce aversion, reduction of heart rate, and consequently high mortality, especially during long exposures. Therefore, we aim to explore new anaesthetic protocols to be used in zebrafish by studying the quality of anaesthesia and recovery induced by different concentrations of propofol alone and in combination with different concentrations of lidocaine.Material and MethodsIn experiment A, eighty-three AB zebrafish were randomly assigned to 7 different groups: control, 2.5 (2.5P), 5 (5P) or 7.5 μg/ml (7.5P) of propofol; and 2.5 μg/ml of propofol combined with 50, (P/50L), 100 (P/100L) or 150 μg/ml (P/150L) of lidocaine. Zebrafish were placed in an anaesthetic water bath and time to lose the equilibrium, reflex to touch, reflex to a tail pinch, and respiratory rate were measured. Time to gain equilibrium was also assessed in a clean tank. Five and 24 hours after anaesthesia recovery, zebrafish were evaluated concerning activity and reactivity. Afterwards, in a second phase of experiments (experiment B), the best protocol of the experiment A was compared with a new group of 8 fishes treated with 100 mg/L of MS222 (100M).ResultsIn experiment A, only different concentrations of propofol/lidocaine combination induced full anaesthesia in all animals. Thus only these groups were compared with a standard dose of MS222 in experiment B. Propofol/lidocaine induced a quicker loss of equilibrium, and loss of response to light and painful stimuli compared with MS222. However zebrafish treated with MS222 recovered quickly than the ones treated with propofol/lidocaine.ConclusionIn conclusion, propofol/lidocaine combination and MS222 have advantages in different situations. MS222 is ideal for minor procedures when a quick recovery is important, while propofol/lidocaine is best to induce a quick and complete anaesthesia.

Aerobic granulation utilizing fermented municipal wastewater under low pH and alkalinity conditions in a sequencing batch reactor

The aim of this study was to achieve aerobic granulation utilizing fermented municipal wastewater under low pH, and alkalinity conditions. Stable granulation was achieved after a 166-day start-up period. Due to low influent strength, supplemental carbon addition, in the form of sucrose, was added to the feed storage tank on the 82nd day of start-up to facilitate granulation. This increased the system's organic loading rate from 1.43 ± 0.14 to 2.53 ± 0.18 kg COD/m3/d, and reduced the influent pH due to fermentation of the added sucrose. Although granulation was successful, the nutrient removal was limited. Removal rates at an influent pH of 6.23 ± 0.06 were 54.4% ± 8.3% for phosphorus, 21.9% ± 4.1% for ammonium, and 84.0% ± 3.0% for total chemical oxygen demand (COD). During the second phase of experimentation, increased amounts of sucrose were added to the feed, which resulted in increased volatile fatty acid concentrations and pH reduction to 5.62 ± 0.12 due to fermentation. Under further reduced pH conditions, phosphorus, ammonium, and total COD removal were found to be 58.9% ± 4.7%, 37.9% ± 4.7%, and 87.1% ± 0.9%, respectively. Settling volume indexes, SVI10 and SVI30, were found to be 148.8 ± 28.9 mL/g, for the influent pH of 6.23 ± 0.06, and 157.5 ± 40.6 mL/g, for the influent pH of 5.62 ± 0.12. This high SVI is indicative of the formation of lower-density granules in comparison to high-ash-content granules. The absence of denitrification-induced chemical phosphorus precipitation within the granule was likely a contributing factor to the low granule density observed in the system.

Performance of mango based agri-horticultural models under rainfed situation of Western Himalaya, India

A total of 15 years of experimentation period (1995–2010) was divided into two phases. In the first phase (1995–2005), five mango based agri-horticultural models (AHM) viz. Mango + cowpea–toria, mango + cluster bean/okra–toria, mango + sesame–toria, mango + black gram–toria and mango + pigeon pea in addition to sole mango plantation (no intercrop) and in second phase (2005–2010), two mango based AHM (mango + colocasia and mango + turmeric) in addition to sole mango (no intercrop) were studied. The mean maximum cowpea equivalent yield (t ha−1) was harvested from cowpea (1.84) followed by okra (1.21), black gram (1.11), sesame (0.68) and mean minimum with pigeon pea (0.58). The crop yield reduction among the mango based AHM was observed from third year to tenth year. The positive correlation was found between light transmission and intercrops yields amongst all models during both phases. However, the correlation between mango canopy spread and intercrop yields shown negative trends. The yield reduction in intercrops varied from 37.0–52.6 % during first phase and 20.6–23.5 % during second phase of experimentation compared to sole crop. The results revealed that the fruit based AHM were effective in improving fruit yields of the mango. The mean maximum fruit yield of mango (7.02 t ha−1) was harvested with cowpea–toria crop rotation followed by black gram–toria (6.59 t ha−1) and minimum fruit yield (5.76 t ha−1) realized with sole mango tree during first phase (1999–2005). Likewise, mean maximum fruit yield (13.71 t ha−1) from mango tree was obtained in the turmeric block followed by (13.00 t ha−1) in colocasia block and minimum fruit yield with sole mango tree (11.86 t ha−1). All the treatments of AHM recorded higher soil moisture as compared to sole mango plantation during both phases. The moisture retention under different AHM was in the order of cowpea (13.32 cm) > black gram (13.29 cm) > pigeon pea (13.27 cm) > okra (12.42 cm) > sesame (12.17 cm) > sole mango (11.62 cm) during first phase, whereas moisture retention was observed in the order of turmeric (14.20 cm) > colocasia (14.01 cm) > sole mango (12.60 cm) during second phase. The cowpea–toria crop rotation with mango gave maximum benefit: cost ratio followed by okra–toria under rainfed conditions. Besides economic viability of cowpea–toria with mango, this system had improved tree growth as well as fruit yield of mango. In the second phase, mango + turmeric yielded more benefit than mango + colocasia system. In the first phase, the mango + cowpea–toria system improved organic carbon, total nitrogen, phosphorus, potash and reduced pH by 49.0, 56.3, 48.6, 58.5 and 11.6 %, respectively as compared to initial values whereas mango + turmeric system increased organic carbon, nitrogen, phosphorus, potash and reduction in pH by 51.0, 45.0, 29.7, 29.0 and 3.4 %, respectively over initial values within soil depths of 0–30 cm during second phased. Mango based AHM is recommended for adoption with selective intercrops up to 15 years of age of mango plantation for multiple outputs and good economic viability without impairing site fertility.

Effects of Fruits Extracts of Three Medicinal Plants on the Blood Glucose Level of Glucose-induced Hyperglycemic and Normal Rabbit Models

The fruits of Pistacia integerrima (PI), Withania coagulans (WC) and Withania somnifera (WS) have been reported for their medicinal values. The aim of the present study was to compare the glucose lowering activities of the fruit extracts of these three medicinal plants in glucose induced non-diabetic hyperglycemic and normal rabbit models. During the first phase of experiments, the effects of oral administration of 70% methanol extract of each plant fruit (600 mg/kg body weight) and glibenclamide (5 mg/kg body weight) were studied on the glucose level of glucose induced hyperglycemic rabbits, while in the second phase of experiments, the effects of each fruit extract (600 mg/kg body weight) and glibenclamide (5 mg/kg body weight) were assessed on the glucose level of normal rabbits. Among the three fruit extracts, maximum reduction in the blood glucose level was caused by the PI extract (P ˂0.05). The glucose lowering activity of the PI extract was greater than that of the standard, glibenclamide (5mg/kg), during the first phase of experiments. However during the second phase of experiments the hypoglycemic effect of the PI extract was comparable to that of the standard, glibenclamide (5mg/kg). In conclusion the present study reveals that the 70% methanol extract of Pistacia integerrima fruit can decrease glucose level significantly in glucose induced non-diabetic hyperglycemic and normal rabbit models.

Changes in mobility and solubility of the redox sensitive metals Fe, Mn and Co at the seawater-sediment interface following CO<sub>2</sub> seepage

Abstract. The impact of CO2 seepage on the solubility and distribution of the redox-sensitive metals iron, manganese, and cobalt in seawater and sediment pore water has been studied in experiments in laboratory-scale 0.6 m3 chambers. The mobility and solubility of Fe, Mn and Co were investigated in seawater, membrane filtered seawater, and DGT samplers deployed in water and sediment during a 26 day CO2 seepage study. During the first phase of the experiment of CO2 seepage (0–16 days), total acid-leachable (pH 1) and "dissolved" (<0.2 μm) concentrations of Fe, Mn and Co (DFe, DMn and DCo) in the seawater increased significantly; the ratios of concentrations of DFe, DMn and DCo in the CO2 chamber to the corresponding values in the control chamber (RDFe, RDMn and RDCo) were as high as 6, 65 and 58, respectively. The second phase of experiment consisted of an additional 10 days of incubation, where the concentrations of all the metals studied still increased but at reduced rates for DMn and DCo. The highest values of RDFe, RDMn and RDCo were about 3 for all metals during this part of the experiment. DGT (diffusive gradients in thin film) labile fractions denoted FeDGT, MnDGT and CoDGT were, respectively 50, 25 and 22 times higher in the CO2 seepage chamber than in the control chamber in the first phase of the experiment. During the second phase, all DGT labile metal concentrations still increased considerably, most notably for Fe. The ratio of FeDGT in the CO2 chamber to that in the control (RDGT-Fe) was still high, about 5, in the second phase of the experiment, whereas the increase in MnDGT and CoDGT slowed down. Our results indicate that acidification following CO2 seepage enhances the mobility and solubility of Fe Mn and Co in sediment and overlying water with contribution of changing in redox conditions and seepage related re-suspension.

물을 흡수매체로 이용한 트리메틸아민과 환원황화합물의 제거효율 비교 연구

In this study, the removal efficiency of trimethylamine (TMA) and four reduced sulfur compounds (RSC) of , , DMS, and DMDS was investigated using deionized water as absorbent. To this end, two types of experiments were conducted which include: (1) by passing both RSC and TMA standard gases through water contained in an impinger system and (2) by passing TMA gases through a water spray system. In the former method, TMA standard gases were effectively removed (below detection limit) in all experiments. Likewise, minor fractions of some RSC (, DMS, and DMDS) were removed by water in line with theoretical expectations. In addition, the first type of our experiment was extended further to test some commercially available odor treatment products. The results of this test showed that removal efficiencies of RSC were different significantly among 4 kinds of absorbent, while the removal of TMA was consistently good as water. In the second phase of experiment, removal efficiency of TMA was tested by passing its standard gas through a water spray system. The overall results of our study showed that the actual removal efficiency of odorants by water (as sorptive media) approached the values that can be predicted theoretically (by Henry`s law).

Start-up of simultaneous removal of ammonium and sulfate from an anaerobic ammonium oxidation (anammox) process in an anaerobic up-flow bioreactor

A laboratory testing of simultaneous removal of ammonium and sulfate (SRAS) was studied from an anammox process in an anaerobic bioreactor filled with granular activated carbon. Two different phases of experiment were investigated to start up the SRAS process, and final batch tests were performed to analyze the SRAS process. The experiment included an anammox process and an SRAS process. During the anammox process, the highest removal efficiency of ammonium and nitrite was up to 97 and 98%, respectively. After 160 days in the stationary phase of anammox process, the ratio of ammonium to nitrite consumption was approximately 1:1.15, which is much higher than 1:1.32 in the traditional anammox process. The extra electron acceptor, such as sulfate, was thought to react with ammonium by bacteria. Synthetic wastewater containing ammonium chlorine and sodium sulfate was used as the feed for the bioreactor in the second phase of experiment. During the SRAS process, the influent concentrations of ammonium and sulfate were controlled to be 50–60 and 210–240 mg L −1 respectively. After start-up and acclimatization of this process for 60 days, the average effluent concentrations of ammonium and sulfate were 30 and 160 mg L −1, respectively. The simultaneous ammonium and sulfate removal was detected in the reactor. In order to further validate the biochemical interaction between ammonium and sulfate, batch tests was carried out. Abiotic tests were carried out to demonstrate that the pure chemical action between ammonium and sulfate without microorganism was not possible. Biotic assays with different ammonium and sulfate concentrations were further investigated that high concentrations of ammonium and sulfate could promote simultaneous removal of ammonium and sulfate. And elemental sulfur and nitrogen gas as the products measured in the SRAS process helped to demonstrate the occurrence of new interaction between nitrogen and sulfur. The new process of SRAS in the inorganic condition, including simultaneous removal of ammonium and sulfate, and the appearance of elemental sulfur and nitrogen gas as the terminal products, widened the cycle approach between nitrogen and sulfur.

The transfer of current through skin and muscle during electrical stimulation with sine, square, Russian and interferential waveforms

Electrical stimulation is a commonly used modality for both athletic training and physical therapy. However, there are limited objective data available to determine the waveform which provides the maximum muscle strength as well as minimizing pain. In the present investigation, two groups of subjects were examined. Group 1 was composed of six males and four females and group 2 was composed of three male and three female subjects. The first series of experiments investigated muscle strength with stimulation at currents of 20, 40 and 60 milliamps using sine, square, Russian and interferential waveforms evaluating strength production and pain as outcomes. The second phase of experiments compared the effect of the different waveforms on current dispersion in surface versus deep muscle electrodes with these same waveforms. The results of the experiments showed that sine wave stimulation produced significantly greater muscle strength and significantly less pain than square wave, Russian or interferential stimulation at that same current. The most painful stimulation was square wave. Strength production was greatest with sine wave and least with Russian and interferential. An explanation of these findings may be the filtering effect of the fat layer separating skin from muscle. The highly conductive muscle and skin dermal layers would form the plates of a capacitor separated by the subcutaneous fat layer providing an RC filter. This filtering effect, while allowing sine wave stimulation to pass to the muscle, reduced power transfer in square wave, Russian and interferential stimulation is observed.