Fluidization of granular media wetted by liquid 4^4He

We explore experimentally the fluidization of vertically agitated PMMA spheres wetted by liquid $^4$He. By controlling the temperature around the $\lambda$ point we change the properties of the wetting liquid from a normal fluid (helium I) to a superfluid (helium II). For wetting by helium I, the critical acceleration for fluidization ($\Gamma_c$) shows a steep increase close to the saturation of the vapor pressure in the sample cell. For helium II wetting, $\Gamma_c$ starts to increase at about 75% saturation, indicating that capillary bridges are enhanced by the superflow of unsaturated helium film. Above saturation, $\Gamma_c$ enters a plateau regime where the capillary force between particles is independent of the bridge volume. The plateau value is found to vary with temperature and shows a peak at 2.1 K, which we attribute to the influence of the specific heat of liquid helium.Comment: 4 pages, 3 figures, Accepted by Phys. Rev. E as a rapid communicatio

Effect of Organic Loading Rate on Hydrogen (H2) and Methane (CH4) Production in Two-stage Fermentation under Thermophilic Conditions using Palm Oil Mill Effluent (POME)

The present study dealt with hydrogen and methane production in a sequential up-flow anaerobic sludge blanket (UASB) and continuous stirred tank reactor (CSTR) at thermophilic temperature. The POME was used as a suitable substrate of carbon source. The effect of various OLR was investigated from 25 kg-COD/m3·d to 125 kg-COD/m3·d at a constant hydraulic retention time (HRT) of 6 h. The UASB-H2 reactor was operated successfully at the OLR of 75 kg-COD/m3·d when the proportion of H2 in biogas, volumetric production rate of H2, specific hydrogen production rate (SHPR) and H2 yield reached the maximum values of 35%, 2.1 l/d, 175.15 ml H2/g MLVSS-d and 49.22 ml H2/g CODapplied respectively. Further, the effluent from the UASB was directly fed into the CSTR at various OLR ranging from 4 kg-COD/m3·d to 20 kg-COD/m3·d for CH4 production. The maximum CH4 content, volumetric production rate of CH4, specific methane production rate (SMPR) and CH4 yield obtained were 65%, 13 l/d, 325.13 ml CH4/g MLVSS-d, and 155.87 ml CH4/g CODapplied respectively. The effluent from CH4 reactor was recycled at feed flow rate recycle ratio of 1:1 to UASB unit and pH was maintained at 5.5, subsequently resulted in COD removal of 85%

Development of an Integrated System for Ozone Treated Harvested Rainwater in Perspective of Green Building Scenario of Malaysia

In this study an integrated system for rainwater harvesting and ozone treatment has been developed for continuous supply of drinkable water. In the perspective of Malaysian scenario ozone treatment of rainwater is still considered a new approach. This pilot project is launched to justify the reliability, the effectiveness and the economic aspect of ozone treated rainwater. The samples of rainwater were analyzed for both physiochemical and microbiological parameters before and after the ozone treatment. The injection of ozone has shown prominent improvement in both parameters and also the quality up gradation of the original rainwater. The results are encouraging and suggest that the technique is promising to fulfil both requirements continuous supply of rainwater as well as accomplish successful ozone treatment. The system can readily be installed at any location and measurements assure that it could certainly provide an alternative water source when conventional piped supply is unavailable. In the perspective of Green Building scenario this integrated approach of ozone treated harvested rainwater might be able to reduce the impact of environmental factors. Keywords: Ozone treatment, Rainwater quality improvement, Water quality, Disinfection with ozone, Green building concept

Effects of Melengestrol Acetat (MGA) and Prostaglandin on Blood Serum Progesterone, Luteinizing Hormone, and Reproductive Performance in Beef Cows

A study utilizing 64 Angus and Simmental multiparous beef cows was conducted to evaluate the administration of MGA-PGF on the onset of estrus, conception rate, and to determine blood serum hormone profiles (P, & LH). Cows utilized were at least 30 days postpartum and stratified by age, breed, and days postpartum into two groups: a treatment group (n=32) which received MGA orally for 14 days and a control group (n = 32) which did not receive MGA. Cows in the study were bled weekly for 9 weeks to monitor serum P, levels. Cows with serum P4 ≥ 1 ng/mL were considered to have cyclic activity. Cows in both groups were injected with PGF2a 17 days after the last MGA feeding date and bred Al following observed estrus. The number of days from the start of MGA feeding to first detected estrus was lower for treated compared to control cows (19.50 a 3.70 and 34.31 a 3.28, respectively, P\u3c .01). The average number of julian days to first estrus was lower for treated compared to control cows (143.81 ± 2.46 and 154.34 ± 3.25, respectively, P= .01). Conception date in julian days was also lower for the treated animals compared to control cows (156.46 + 2.98 and 166.55 ± 3.21, respectively, P= .01). Treatment animals had a higher level of progesterone from the start of MGA feeding until the end of the bleeding period compared to the control animals (.41 ± .04 and .19 ± .04, respectively, P\u3c .001). The average progesterone hormone level in treated cows was higher 48 hours before injecting PGF,, compared to the control animals (1.59 ± .12 vs 0.33 ± .12, P\u3c .001). Blood serum analyzed for LH concentration was collected 3 days prior to PGF2a injection (Period 1) and 4 days following the PGF2a injection (Period 2). Mean LH levels between treatment and control groups were not different for the 7 days (1.58 ± .07 ng/mL and 1.70 ± .07 ng/mL, respectively, P= .25). When analyzed by periods, mean LH levels for Period 1 were lower (1.44 ± .08 ng/mL) than mean LH levels for Period 2 (1.84 a .07 ng/mL, P\u3c .01). Results from the present study suggest that MGA decreased days to first detected estrus, resulted in earlier conception, increased conception rate, increased progesterone hormone levels, and increased cyclic activity

An empirical model for sedimentation of suspended solids under influence of magnetic field

The magnetic treatment of wastewater is an alternative simple approach by which the wastewater that need to be treated flow through a magnetic field, and consequently some of its physicochemical properties such as suspended particles changes. The primary propose of wastewater treatment is to remove the suspended and soluble organic constituents measured as chemical oxygen demand (COD) and biochemical oxygen demand (BOD) in the incoming liquid streams. The essence of flocculation process is the aggregation of suspended coagulated particles to form larger flocs amenable to separation from the suspending medium by some subsequent physical process, generally sedimentation. Using performance data from the application of magnetic field of 0.55 Tesla in circulation flowing system, empirical mathematical models were developed in this paper relating suspended solids (SS) removal efficiency to operating flow rate and retention time. The obtained experimental results showed that percent of SS removal increased with increasing magnetic exposure time at lower flow rates. The model coefficients were derived from the combined analysis of well correlated sets of data, thus giving a good indication for their possible general applicability. The analysis of experimental data also gave a relationship between SS and chemical oxygen demand (COD) removal efficiencies

Electrocoagulation technque in enhancing COD and suspended solids removal to improve wastewater quality

This paper presents a preliminary study for the removal of COD and suspended solids in wastewater treatment by combining magnetic field and electrocoagulation (EC) technology. The experiments were carried out using batch apparatus and setup in the static method. Batch experiments with two monopolar iron (Fe) plate anodes and cathodes were employed as electrodes. Wastewater samples were prepared from milk powder with an initial COD of 1,140 mgL-1 and suspended solids of 1,400 mgL-1 and acidic conditions were employed (pH ~ 3). DC current was varied from 0.5–0.8 A and operating times were between 30 and 50 min. The results show that the effluent wastewater was very clear (turbidity ~9 NTU) and its quality exceeded the direct discharge standard. The suspended solids and COD removal efficiencies were as high as 30.6 and 75.5%, respectively. In addition, the experimental results also show that the electrocoagulation could neutralise the pH of wastewater

Optimisation of static magnetic field (SMF) on physical properties of biomass using central composite design experiment

One of the principle issues for the biomass is the poor settleability that therefore influences the effluent quality. Batch tests were led to appraise the optimal conditions for improving the settleability of the biomass under static magnetic field (SMF). A four-factor central composite design (CCD) was executed to investigate the main and interaction effects of the factors while response surface methodology (RSM) was used for process optimization. Four independent factors, viz. SMF (15.0 – 88.0 mT), exposure time (0.5 – 48.0 h), biomass concentration (2000 – 4000 mg/L) and agitation speed (200 – 400 rpm) were applied and quadratic model was worked to anticipate the reactions. Analysis of variance (ANOVA) was utilized to assess the significance of the autonomous factors. At the optimum conditions of 88.0 mT SMF, 16.5 h exposure time, 2800 mg/L biomass concentration and 300 rpm agitation speed, the turbidity removal, aggregation and settling velocity achieved its highest predictions of 92%, 99% and 0.011 cm/s, respectively. The analysis demonstrated that the applied SMF could enhance the settling property of the biomass through the enhancement of its aggregation ability. These suggesting that the SMF is dependable in accelerating the biomass settleability, subsequently potential to improve the performance efficiency in treating wastewater

Review on fermentative biohydrogen production from water hyacinth, wheat straw and rice straw with focus on recent perspectives

Hydrogen (H2) is often considered as the best option to store energy coming from renewable sources. Hydrogen production from lignocellulosic biomass via fermentation offers low cost and environmental friendly method in terms of energy balance and provides a sustainable pathway for utilization of huge amount of unused biomass. In this regard, special attention on potential of different lignocellulosic biomass is required. In this paper, the fermentative hydrogen production from three carbohydrates-rich biomass: water hyacinth, wheat straw and rice straw is comprehensively reviewed. In other point of view, usage of H2 has a 10% growth annually that will reach to 8–10% of total energy in 2025. Furthermore, research on recent trends of fermentative hydrogen production is crucial and vital. However, the majority of the published researches in the last decade confirmed that some challenges exists which are the process optimization, effecting parameters and commercialization aspects

Performance of integrated anaerobic/aerobic sequencing batch reactor treating poultry slaughterhouse wastewater

The present study investigates the performance of a new configuration laboratory-scale bioreactor comprising of two regimes (anaerobic & aerobic) in one reactor with physical separation and it is known as integrated anaerobic/aerobic sequencing batch reactor (IAASBR). The IAASBR is designed for treating high-strength wastewater such as poultry slaughterhouse wastewater (PSW) along with the simultaneous removal of organic carbon and ammoniacal nitrogen (NH3-N). The IAASBR exhibits that the average removal efficiency of total COD (TCOD), soluble COD (SCOD), NH3-N, fat, oil & grease (FOG), and total suspended solids (TSS) were (97%���2%), (95%���3%), (98%���1.3%), (90%���11%), and (96%���3%) respectively. The laboratory comparison test revealed that IAASBR configuration has enhanced the sludge settle-ability for aerobic SBR more than the conventional SBR or settling tank. Furthermore, IAASBR could tolerate the shock loading occurrence, handle organic loading rate (OLR) up to 4.5�kg�(TCOD)�m−3�d−1and produce a high-quality effluent complying with Malaysian standards of industrial's effluents. � 2016 Elsevier B.V