Number concentration dependence of ultrasonic disruption ratio of diameter-sorted microcapsules

The use of ultrasound to destroy microcapsules in microbubble-assisted drug delivery systems (DDS) is of great interest. In the present study, the disruption ratios of capsule clusters were measured by observing and experimentally analyzing microcapsules with polymer shells undergoing disruption by ultrasound. The microcapsules were dispersed in a planar microchamber filled with a gelatin gel and sonicated using 1 MHz focused ultrasound. Different capsule populations were obtained using a filtration technique to modify and control the capsule sizes. The disruption ratio as a function of the concentration of capsules was obtained through image processing of the recorded photomicrographs. We found that the disruption ratio for each population exponentially decreases as the particle number concentration (PNC) increases. The maximum disruption ratio of the diameter-sorted capsules was larger than that of polydispersed capsules. Particularly, for resonant capsule populations, the ratio was more than twice that of polydispersed capsules. Furthermore, the maximum disruption ratio occurred at higher concentrations as the mean particle diameter of the capsule cluster decreased.

DTS-Net: Depth-to-Space Networks for Fast and Accurate Semantic Object Segmentation

We propose Depth-to-Space Net (DTS-Net), an effective technique for semantic segmentation using the efficient sub-pixel convolutional neural network. This technique is inspired by depth-to-space (DTS) image reconstruction, which was originally used for image and video super-resolution tasks, combined with a mask enhancement filtration technique based on multi-label classification, namely, Nearest Label Filtration. In the proposed technique, we employ depth-wise separable convolution-based architectures. We propose both a deep network, that is, DTS-Net, and a lightweight network, DTS-Net-Lite, for real-time semantic segmentation; these networks employ Xception and MobileNetV2 architectures as the feature extractors, respectively. In addition, we explore the joint semantic segmentation and depth estimation task and demonstrate that the proposed technique can efficiently perform both tasks simultaneously, outperforming state-of-art (SOTA) methods. We train and evaluate the performance of the proposed method on the PASCAL VOC2012, NYUV2, and CITYSCAPES benchmarks. Hence, we obtain high mean intersection over union (mIOU) and mean pixel accuracy (Pix.acc.) values using simple and lightweight convolutional neural network architectures of the developed networks. Notably, the proposed method outperforms SOTA methods that depend on encoder–decoder architectures, although our implementation and computations are far simpler.

Evaluation of the Bacteriological and Physicochemical Qualities of Some Brands of Bottled Water Sold in Owerri, Imo State

This work was carried out in order to detect the presence of bacterial agent in the bottled water samples, and to evaluate the physicochemical qualities of these bottled water. Twenty samples selected from four different brands of bottled water sold in Owerri, were examined to determine their bacteriological and physicochemical qualities. Bacteriological analyses using Membrane filtration technique was carried out to determine the heterotrophic bacteria, total coliform and fecal coliform counts. Physicochemical qualities were also determined using standard methods. The heterotrophic bacterial count ranged from 0.00 to 12.00 CFU/ml, total coliform count ranged from 0.00 to 7.50 coliform/100ml. There was absence of fecal coliform in the samples. The pH, Color, Turbidity and Conductivity of the samples ranged from 5.18 to 7.28, 0.00 to 18.00 PCU, 0.55 to 1.62 NTU and 16.00 to 262.00 µs/cm respectively. The Chloride, Iron and Nitrite content of the samples ranged from 16.99 to 27.98 mg/L, 0.01 to 0.07 mg/L Fe, and 0.00 to 0.34 mg/L respectively. The bacterial species isolated belong to the genera Staphylococcus, Proteus, Klebsiella, Bacillus and Escherichia. Quality wise, most of the water samples met the XYZ standard for bacteriological and physicochemical quality for drinking water with the exception of few. It can be deduced from this study, that none of the bottled water is suitable for drinking with regards to the bacteriological and physicochemical parameters tested. Though some samples passed the bacteriological examination, most of them were acidic and therefore not safe for consumption.

Removal of cyanide from alumina smelter wastewater using precipitation and filtration technique

Aluminum is a metal that is used in many products because of its good conducting properties. However, in the production process, aluminum is not obtained easily but through a long process. In aluminum smelting process, wastewater that is produced indicates the existence of pollutants as determined by several indicators of water pollution, one of which is cyanide that will threaten human and environmental health if not treated properly. This study was conducted to determine the optimal dose of ferrous sulfate to remove cyanide, the precipitation and filtration process efficiency in reducing cyanide, and its effect on pH of wastewater. Data were collected from an aluminum smelting company, and experiments were conducted in the laboratory. Based on results, ferrous sulfate dose of 93 mg/l is the most optimal dose in removing cyanide with an efficiency of 58.74±0.51%, while filtration process provides an efficiency of 81.65±0.42%. Precipitation with ferrous sulfate makes pH value of wastewater decrease, but filtration process increases the value again. Throughout the whole process, cyanide can be reduced by a combination of precipitation and filtration process with the efficiency of 92.43±0.26% and an average final effluent concentration of 0.78 mg/L from an initial concentration of 10.3 mg/L.

Characteristics of anti-Vibrio harveyi compounds produced by Bacillus spp. isolated from shrimp ponds

Rusmana I, Isramilda, Akhdiya A. 2021. Characteristics of anti-Vibrio harveyi compounds produced by Bacillus spp. isolated from shrimp ponds. Biodiversitas 22: 4872-4879. Pathogenic Vibrio spp. such as Vibrio vulnificus, V. alginolyticus, V. fluvialis, V. anguillarum, and V. harveyi caused shrimp diseases. The application of bacterial probiotics can control the growth of pathogenic Vibrio in shrimp. Bacillus spp. can produce antimicrobial compounds that inhibit the growth of pathogenic Vibrio spp. Isolation of Bacillus from several pond water samples, pond sediment, and shrimp intestines was successfully collected 175 isolates of Bacillus spp. Three isolates, i.e., Ltw54, Lts36, dan Lts40 had a high inhibitory index and stability in inhibiting the growth of Vibrio harveyi. Verification assay showed that Bacillus sp. Lts40 had the highest antimicrobial activity. The competition assay showed that Bacillus sp Lts40 isolates inhibited the growth of V. harveyi up to 81,8%. The antimicrobial compound produced by Bacillus sp. Lts40 was stable at the pH range of 3-11 and remained stable after heating at 100ºC for 20 minutes. The purification results using the chromatographic filtration technique showed that the protein fraction with a molecular weight of 47,38 kDa effectively inhibited V. harveyi growth. Bacillus sp. Lts40 isolate has potential application as a probiotic agent in shrimp ponds to control the growth of V. harveyi that causes luminous vibriosis diseases and the antimicrobial substance is potentially to be developed and produced as an anti-V. harveyi product that can be applied in a shrimp hatchery.

Evaluation of falciparum parasitemia and urogenital schistosomiasis co-infection on haemoglobin and nutritional status of children and adolescents in riverine communities of southern Taraba State, Nigeria.

Malaria and urogenital schistosomiasis are parasitic infections usually acquired unknowingly and sometimes cause anaemia and affect the nutritional status of persons in endemic areas. This study assessed asymptomatic Plasmodium falciparum, Schistosoma haematobium and their co-infection status with respect to the association of haemoglobin level and nutritional status in children and adolescents resident at Takum Local Government, a rural suburb of Taraba State, Nigeria. Thick blood films and urine filtration technique were used respectively to determine P. falciparum and S. haematobium species. Haemoglobinometer measured haemoglobin concentration and Body Mass Index determined nutritional status for each participant. The study reported 32.9% (87/264), 28.7% (76/264) and 30.3% (80/264) respectively for asymptomatic malaria, urogenital schistosomiasis and co-infection. Participants in Chanchanji community significantly had the highest asymptomatic P. falciparum infection, 56.4% (22/39) (p=0.003). Sufa and Manya communities respectively had the highest S. haematobium infection, 39.4% (15/38) (χ2= 41.3, p=0.000) and coinfection, 32.1% (12/37) (χ2= 52.45, p=0.000). A negative association was observed between anaemia and co-infection (r = -0.77, p=0.000) as well as between nutritional status and co-infection (r = -0.63, p=0.000). Participants who did not use LLTNs and lived close to water bodies were predisposed to co-infection with adjusted OR=0.003 (%95CI: 0.00 – 0.03; p=0.000). Birama and Manya areas highly predicted participants to co-infection with respective adjusted OR = 13.20 (%95CI: 2.34-74.38; p=0.003) and adjusted OR=57.9, (%95CI: 4.92-681.24, p=0.001). The co-infection predisposed participants to moderate and severe anaemia with respective adjusted OR of 2.198 (%95CI:1.307-3.696, p=0.021) and 1.192 (%95CI:0.355-4.009, p=0.017). Undernutrition was significantly affected with co-infection adjusted OR=3.732 (95%CI:1.003-7.393, p=0.011). Co-infection was significantly associated with anaemia and nutritional status at p≤0.05. It is recommended that the State and NGOs should provide malaria Intermittent Prevention Treatment as well as deworm the children and adolescents in Takum LGA.

The effect of filtration size on the geochemistry of groundwater samples from a massive sulfide deposit at the Bathurst Mining Camp, New Brunswick, Canada

In hydrogeochemical studies, samples are commonly filtered to limit the fraction of analyte that is adsorbed or structurally bound to suspended particles, ensuring that only the dissolved fraction is analyzed, and thereby reducing analytical bias during measurement. The standard filter size that has been adopted is 0.45 μm, however, ultrafiltration can be used to remove colloidal particles two orders of magnitude smaller. In the following, we investigate the effect that standard (0.45 μm) and ultrafiltration (0.004 μm) have on the hydrogeochemistry of groundwaters from a volcanogenic massive sulfide (VMS) deposit at the Bathurst Mining Camp, New Brunswick, Canada. Groundwater samples were collected from six monitoring wells at the Nigadoo Mine tailings facility, and major and trace geochemistry were determined using a combination of inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and ion chromatography. Waters at the Nigadoo deposit are generally enriched in Ca and SO4, relative to other major cations and anions. Some element contents - including those associated with VMS deposits - differ depending on the filtration technique used (e.g., As, Fe, Pb, rare earth elements and yttrium [REY]), some are equally affected by both techniques (e.g., Cu, Ni, Zn), and some are unaffected by filtration (e.g., Ba, Ca, Mn, Cl-). Shale-normalized REY anomalies (CeSN/CeSN*, EuSN/EuSN*, and YSN/HoSN) and overall patterns can differ greatly (e.g., changing the sign of the anomaly) depending on the filtration technique used. We observe previously undocumented, and, at this time, unexplainable fractionation of Ho and Yb (non-redox sensitive REYs, unaffected by the tetrad effect) in unfiltered waters from the Nigadoo deposit. Differences in groundwater geochemistry induced by filtration technique can result in false positive and negative anomalies during environmental and exploration projects and must therefore be carefully considered. At the Nigadoo site, oxidation of sulfide minerals can occur, resulting in the formation of relatively unstable oxide minerals. Away from the tailings, where carbonate minerals are scarce and can no longer act as a pH buffer, the unstable oxide minerals break down and release metals and metalloids into the surrounding environment. The filtration methods used in this study can provide insight into where the specific metals and metalloids are hosted and how they are likely to behave under different redox conditions. Because VMS deposit pathfinder elements are enriched in unfiltered water, and differ by degree of filtration, geochemical analysis of the filtride material may also make an effective exploration tool.Thematic collection: This article is part of the Hydrochemistry related to exploration and environmental issues collection available at: https://www.lyellcollection.org/cc/hydrochemistry-related-to-exploration-and-environmental-issues

A new purification technique to obtain specific size distribution of giant lipid vesicles using dual filtration

A new purification technique is developed for obtaining distribution of giant unilamellar vesicles (GUVs) within a specific range of sizes using dual filtration. The GUVs were prepared using well known natural swelling method. For filtration, different combinations of polycarbonate membranes were implemented in filter holders. In our experiment, the combinations of membranes were selected with corresponding pore sizes–(i) 12 and 10 μm, (ii) 12 and 8 μm, and (iii) 10 and 8 μm. By these filtration arrangements, obtained GUVs size distribution were in the ranges of 6−26 μm, 5–38 μm and 5–30 μm, respectively. In comparison, the size distribution range was much higher for single filtration technique, for example, 6−59 μm GUVs found for a membrane with 12 μm pores. Using this technique, the water-soluble fluorescent probe, calcein, can be removed from the suspension of GUVs successfully. The size distributions were analyzed with lognormal distribution. The skewness became smaller (narrow size distribution) when a dual filtration was used instead of single filtration. The mode of the size distribution obtained in dual filtration was also smaller to that of single filtration. By continuing this process of purification for a second time, the GUVs size distribution became even narrower. After using an extra filtration with dual filtration, two different size distributions of GUVs were obtained at a time. This experimental observation suggests that different size specific distributions of GUVs can be obtained easily, even if GUVs are prepared by different other methods.

Techniques for Reducing Iron (Fe) Content in Groundwater: an Article Review

Iron is a chemical element that is found in almost every place on earth, including in well water or groundwater. Iron can be suspended in water with organic substances or inorganic solids in the form of ferrous cations (Fe2+) and ferries (Fe3+). The presence of iron that exceeds the threshold can cause detrimental effects such as corrosion of the piping, the color of the water turns brown, smells bad, and can cause health problems. The iron content in groundwater can be reduced so that it can be used as water that is fit for consumption or use in everyday life. This study aims to determine several types of techniques used to reduce iron in groundwater or well water through literature studies. Techniques covered include filtration, aeration, adsorption, coagulation, electrocoagulation, and cascade aerators. The results showed that the greatest reduction in efficiency was found in the combination type of adsorption technique and filtration technique by more than 99.1%, then followed by the electrocoagulation technique of 99.74%. From all the techniques studied in this study, it can be concluded that all techniques can reduce iron levels in which the combination of adsorption and filtration techniques is the most effective.Keywords: Technique, reduction, iron content, groundwater

Pembuatan Penyaring Air Untuk Peternak Ayam Petelur Di Dusun I Kubu Cubadak Simpang Petai

In order to supply the water for laying hens farm in Kubu Cubadak Simpang Petai, the service team from University of Riau has designed a water purification system using the filtration technique. Before designing the filtration, sample of water from the well around the farm is taken and analyzed in the laboratory. Based on this result, the filtration is characterized to get the water satisfying the needs of the farm. There are two tubs in the filtration system containing silica sand, zeolite, and active carbon. Water from the well is pumped to the tank with three-meter height. From there, water is pumped back again to the tube to get the optimal water flow. The quality of water from the filtration have enhancement in terms of color, turbidity, and pH. The color and turbidity of water are improved from 41 NTU to 0 NTU and from 22,5 NTU to 5,59 NTU, respectively. Furthermore, there is an increasing in pH of water, from 5,44 to 6,32. These results have fulfilled the standard for laying hens farm.