Daripada abad kedua-puluhan, “Dissolved Air Flotation (DAF)” telah digunakan dalam proses pengasingan. Di dalam sistem DAF, udara akan dilarutkan dalam air sisa pada tekanan yang tertentu, diikuti dengan pembebasan tekanan udara mengikuti tahap tekanan udara biasa. Di sini, sistem pengedaran pengaliran semula akan dikaji. Bagi sistem ini, sebahagian air daripada rawatan DAF akan diedarkan semula ke dalam sistem, ditambahkan tekanan angin dan dilarutkan separa dengan angin. Bahan kajian utama ialah sistem DAF di HACO Asia Pacific Sdn. Bhd.. Pada peringkat pertama, proses peningkatan prestasi DAF telah dikaji untuk mendapatkan parameter dan keadaan operasi yang paling berkesan. Seterusnya, kajian prestasi DAF telah dilanjutkan pada keadaan operasi yang paling baik dan berkesan. Sampel air sisa sebelum dan selepas rawatan DAF telah diambil dan dianalisis untuk
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Dissolved air floatation increased the efficiency of grease and oil removal from biodiesel wastewater by about 10% compared with other conventional processes . Dissolved air flotation has gained widespread usage for the removal of contaminants and recovery of by-products from wastewater and other industrial process streams over the last 20 years. While considered a relatively simple technology, there have been significant improvements in the technology including operating parameters, bubble generation systems and process design. There has also been an expansion of applications using DAF over the last several years in traditional and non-traditional areas of water and industrial effluent treatment , .
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Flotation is a type of gravity separation process using the difference between the density of the air bubbles and the density of the water [2, 5]. It is widely used in the treatment of wastewater containing particulate matter which is, in this case, oil in the form of small droplets. Currently, two variations of flotation methods are widely applied. The first, dissolved air flotation (DAF), which uses smaller bubbles (30–100 μm in diameter), tends to be more efficient than the second, induced air flotation (IAF), which uses larger bubbles (700–1500 μm) [6, 7]. However, using DAF is subject to several difficulties such as high investment costs, sophisticated equipment, and complex operation. Therefore, IAF has been applied as the alternative that is more suitable for smaller scale operations.
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froth characteristics and cell performance. The research also exhibit that froth with small bubble has lower solid mass flow rate in contrast to a larger one. It was also concluded that froth color could be assessed by component of hue color histogram. In addition, it shows that a high-grade froth exhibits a sharper hue color histogram. The results obtained from nets modeling demonstrate that a feed forward net with a hidden layer can enable us to predict cell performance from froth characteristics with high degree of precision. Therefore, a combination of image analysis techniques and nets can be applied as a powerful tool to analyze and control the performance of a flotation cell.
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The mineralogy of the ore entering the system may vary dramatically from one ore body to another (from the same mine), or even within the same ore body, affecting several process variables. Thus the concentrations of activators, collectors, depressants, dispersants and pH regulators have to be monitored and adjusted accordingly. The grindability of the ore is also dependent on the mineralogy. Selective excavation or mixing ores are common ways to control ore type variation (Ruonala et al., 1997). Traditionally, metal sulphide orebodies consist of unoxidized primary sulphides and in the flotation processes there may be some degree of mineral oxidation required to achieve proper economic results. It is likely that oxidation begins even before conditioning while the sulphide minerals are stockpiled at the mine, where the ore is crushed and conveyed to heaps which are in contact with air and moisture/rain. After exposure to air or aqueous solution during grinding and conditioning, metal sulphide minerals may exhibit oxide and hydroxide species on the surface (Eq. 1.1) (Smart et al., 1998). Conditioning time, pH, Eh and the gas atmosphere above the sample all affect the surface oxidation mechanisms (Smart et al., 1998).
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If there is a second stage its water-rich waste stream is recycled to the R rst stage feed. The waste product from the R rst stage is water containing up to 0.1% oil by volume dispersed as ultra R ne droplets. Before this water can be discharged, its oil content has to be reduced to comply with strict environmental stan- dards both with respect to its oil content and the biological oxygen demand (BOD). Froth S otation has been used particularly in R nal clean-up units because of the small droplet size. DAF has been used as the bubbles coming out of solution following a reduction in pressure are thought to nucleate directly on the droplets. Unfortunately, the rise velocity of these air } droplet aggregates is so slow that extremely large cells are required. Their operation is in turn adversely affected by the pitching motions of S oating rigs. In- duced gas S otation (IGF) has also been used when the air is added to the feed stream at the throat of a Venturi nozzle. These have higher recovery rates but lower oil removal ef R ciencies than the DAF units. These reasons, together with the perceived high chemical costs, have favoured the use of liquid } liquid hydrocyclones in these situations.
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The severity of the phenotypes that result from reduced insulin-like signalling, such as constitutive dauer formation and increased adult lifespan, are generally dependent on dosage (Kenyon et al., 1993; Kimura et al., 1997; Ogg and Ruvkun, 1998; Paradis and Ruvkun, 1998). To directly test whether the level of insulin-like signalling regulates germline proliferation through aak-2 in a dose-dependent manner, we verified whether mutations that are known to activate this signalling pathway downstream of the insulin-like receptor (daf- 2) could phenocopy the effect of aak-2 mutations on germ cell proliferation at the onset of dauer. We therefore introduced a hypomorphic mutation in the C. elegans PTEN orthologue daf-18 (Ogg and Ruvkun, 1998), or a gain-of-function mutation in an Akt/PKB orthologue, akt-1 (Paradis and Ruvkun, 1998), to partially upregulate insulin-like signalling in daf-2 mutant larvae. daf-2; daf- 18 and daf-2; akt-1(gf) animals form dauer larvae that have 164.9% and 43.4% more germ cell nuclei than do daf-2 animals, respectively (Table 2, rows G,H), indicating that efficient inhibition of germline proliferation by reduced insulin-like receptor function occurs via the proper activation of daf-18, inactivation of akt-1, as well as the activation of aak-2. Interestingly, the effects of daf-18(lf) or akt- 1(gf), and aak-1/aak-2 inactivation on dauer formation and germline proliferation are additive (Table 2, rows I,K,M), suggesting that these pathways work in parallel, or that other factors, in addition to aak-1/aak-2, function downstream of daf-18 and akt-1 to regulate dauer formation and insulin-dependent cell cycle quiescence in the germ line.
Flotation tests of quartz and hematite–quartz mixed sample were carried out in a 30 ml XFG– type flotation cell. Prepared mineral particles (5g) were put into a plexiglass flotation cell and suffused with deionized water. And then the suspension was stirred for 3 min by a plastic stirrer with four blade rotating at 1260 rpm. Then, starch and collectors were added into the flotation cell orderly with 3 min interval of conditioning time. Finally, the concentrate and tailing were collected separately, and then dried, weighted and assayed to determine the recovery and grade.
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To understand how daf-9-expressing tissues impact gene function, we asked what phenotypes were restored when daf-9 was selectively expressed. Initially, we generated expression mosaics: transgenic lines containing an extrachromosomal array of genomic daf-9::gfp (dhEx66) in the daf-9(dh6) background. Animals expressing daf-9 in hypodermis and XXX cells reached maturity, whereas cohorts without the transgene arrested as dauer larvae. Mosaics arise spontaneously either from mitotic loss or silenced expression of the array in a particular tissue. At both 20°C and 25°C, mosaics expressing daf-9 in the hypodermis bypassed diapause, had normal gonadal development and were fertile (Fig. 1A). This indicates that hypodermal expression is sufficient to drive reproductive development, including the correct timing of distal tip cell migrations. Interestingly, in such mosaics hypodermal daf-9 expression levels were often elevated, implying that daf-9-expressing XXX cells normally communicate cell non-autonomously to inhibit expression in the hypodermis. Mosaics expressing daf-9 in XXX cells alone were not found, probably because of their rarity.
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Figure 10.—Chemosensory phenotypes of egl-4 mutants are suppressed by daf-3 and daf-5 mutations. Chemotaxis indices be- tween 0 and 1.0 have been divided into 11 equal-sized bins and assigned a circle of size indicated at the bottom. Open circles repre- sent a negative chemotaxis index; filled cir- cles represent a positive chemotaxis index. Each data point represents the mean of at least three independent assays of ⵑ200 ani- mals each. Concentrations of odorants used are as indicated in Figures 3 and 4. The alleles indicated for each single mutant are present in the double mutant strains. Re- sponses significantly different from that of wild type at P ⬍ 0.01 are indicated by an asterisk next to the circle.
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genics were generated by injection (Mello et al. 1991) of lin- Chemotaxis assays: Assays of chemotaxis to NaCl were per- 15(n765) animals, using a lin-15 rescuing plasmid (pbLH98 formed as described (Bargmann and Horvitz 1991b) except at 60 ng/l) as a transformation marker (Huang et al. 1994). that worms were allowed to swim for 15–30 min on a chemo- The concentrations of key experimental DNAs were: full- taxis plate without attractant between the last wash and the length daf-11::gfp fusion (pTJ643) at 200 ng/l, and daf-11 assay. This step allowed the worms to better acclimate to the (exon 5)::gfp fusion (pTJ536) at 50 ng/l. We also analyzed a assay conditions and led to more reproducible results (C. Barg- full-length daf-11::nls-gfp fusion (pTJ642), injected at 200 ng/ mann, personal communication). Volatile avoidance assays l, which gave nuclear-localized patterns that were otherwise with 2-nonanone were performed as described (Troemel et similar to the non-NLS fusion. For pTJ643, injected daf- al. 1997) except that worms were washed three times with S 11(sa195); lin-15(n765) animals were grown at 20⬚ for 1 day basal and once with water. Worms were grown and assays were and then transferred to 25⬚ and screened for non-Muv (lin- performed at 20⬚. Because a large fraction of daf-11 mutant 15-rescued) or non-Daf (daf-11-rescued) progeny. For Figure animals form dauers at 20⬚, daf-12 double mutants were as- 3E, GFP expression was analyzed in two independent lines sayed, with a daf-12 single mutant as control (as in Vowels containing the full-length, NLS construct [JT8903 lin-15 and Thomas 1994).
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at ~52 hours post egg laying. At this time, sporadic pharyngeal pumping persisted in transgenic animals expressing DAF-9 in the hypodermis, indicating that they were not completely transformed into arrested dauers. After 90 hours of development, individual tissues of these transgenic animals and their non-transgenic siblings were examined under high magnification using Nomarski optics. Non-transgenic daf-2(e1370) dauer had a constricted pharynx and a highly refractile intestine because of accumulation of lipids. Moreover, vulval and germline development were arrested and dauer alae were visible on the cuticle. By contrast, daf-2(e1370) transgenic animals overexpressing DAF-9 in the hypodermis, the pharynx was not constricted and no dauer alae were observed. However, the intestine was highly refractile and resembled that of a dauer animal. It was striking to note that although the vulva of some of the transgenic animals displayed L4 morphology (36%, n=76), germline development was arrested and the distal tip cells failed to reflex. Taken together, these data show that daf- 9 expression in the hypodermis could compensate for the loss of daf-2 activity and promote reproductive development of the hypodermis, pharynx and vulva. This implies that daf-9 may act downstream of or in parallel to the daf-2 signaling pathway and specify non-dauer fate in a subset of tissues. However, the lipophilic hormone processed by DAF-9 in the hypodermis is unlikely to overcome the lack of daf-2 signaling in the intestine and germline. Our results are consistent with mosaic analysis which suggests a cell-autonomous role of daf-2 in the reproductive development of P 1 -derived germline and gonad
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the pheromone response of either unc-64 or unc-31. ND, not determined. All dauers in strains carrying daf-16 Similar results were seen with daf-3 in place of daf-5 are partial dauers as described (Vowels and Thomas 1992). (data not shown). This provides further evidence that unc-3 acts in the group II pathway and that unc-64 and unc-31 act in parallel. A daf-5; daf-11 double mutant the Dyf mutant osm-6, consistent with osm-6 functioning also did not respond to pheromone. Since unc-64 and in parallel to the group II branch of the dauer pathway. unc-31 double mutants with daf-5 responded normally Double mutants with daf-16: Mutations in daf-16 com- to pheromone, this suggests that unc-64 and unc-31 do pletely suppress the Daf-c phenotype at 25⬚ of Daf-c not act in the group I pathway.
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Aging neurons lose their ability to remodel following injury, change their complex morphology, and may degenerate (Yankner et al., 2008). Whereas axon degeneration during aging has been studied extensively both in mammals and in invertebrates, the fate of complex dendritic trees in old animals has not been studied in detail in any organism. To determine how aging affects the complex arborized dendritic structure, we analyzed the C. elegans PVD dendritic branching patterns from the fourth larval stage (L4) to 10- day-old (d) adults. We found that during aging PVD dendritic structures become disorganized and undergo hyperbranching (Fig. 1A,C; Fig. S1). Remarkably, we found that these age- dependent morphological changes of the PVD dendritic pattern were not affected in long-lived animals carrying a mutation in daf-2 (Fig. 1A-H; Fig. S1). Adjacent PVD dendrites normally avoid each other (Smith et al., 2012), and we found that as the animal ages the structural units lose their self-avoidance properties (Fig. 1C,D,I). Consistently, this age-dependent dendritic pattern did not improve in daf-2 mutant animals; young daf-2 animals at the L4 stage exhibited significantly more daf-16-dependent self-avoidance deficiencies in comparison with wild type (Fig. 2). Thus, taken together our results reveal that during aging there is a daf-2- independent increase in disorganization of branching and loss of self-avoidance.
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We assessed synaptic function in daf-19(tm5562) mutants using resistance to aldicarb, a cholinesterase inhibitor. For comparison, daf-19(m86) 1-day-old adult worms were con- sistently resistant to aldicarb, though not to the level of age- matched unc-29(e1072) mutants lacking a subunit of the acetylcholine receptor (Figure 4C). Age-matched daf- 19(tm5562) worms were resistant to aldicarb at levels statis- tically indistinguishable from those of daf-19(m86) worms in an average of six replicate assays (P = 0.56). This synaptic defect was rescued by transgenic expression of daf-19a (P = 0.02). Average aldicarb sensitivity of rescued worms was indis- tinguishable from that of wild-type N2 (P = 0.56) (Figure 4C). We used the aldicarb assay to test whether daf-19(tm5562) is a hypermorphic or dominant negative allele. If so, we ex- pect heterozygous tm5562/+ mutant animals to confer an aldicarb-resistant phenotype. Instead, we found that daf- 19(tm5562/+) heterozygotes had a phenotype indistinguish- able from that of wild-type N2 worms mated with the same ﬂuorescently marked strain (Figure S4D) (cf. Materials and Methods). We conclude that daf-19(tm5562) is a hypomorphic or loss-of-function allele affecting both daf-19a and b isoforms. As expected, the tm5562 allele did not appear to affect daf-19c function. While the daf-19(m86) null allele confers a highly penetrant Daf-c phenotype (Swoboda et al. 2000), daf-19(tm5562) did not confer a Daf-c phenotype in the pres- ence of food at any temperature tested (Figure S4A). Normal progression from the ﬁrst to second larval stages thus indi- cates that daf-19a/b is not responsible for the developmental decision to enter the dauer larval stage. Animals lacking DAF- 19C do not develop cilia and therefore CSNs that normally take up the ﬂuorescent, lipophilic DiI can no longer do so. The fact that daf-19(tm5562) worms dye-ﬁlled normally in both amphids (Figure S4B) and phasmids (data not shown), and males mated readily with hermaphrodites, suggests normal cilia development. These phenotypes are consistent with expression of functional daf-19c transcripts in daf-19(tm5562) worms.
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Then an application on a chosen water treatment plant was made using the optimal technique from the lab scale study. This application was made to determine the maximum possible production increase taking into consideration not to build new units. The chosen plant is Al Ameriyah WTP. The proposed pilot consists of a set of tanks, each tank has a specific function to clarify the water source. They aresource tank, flash mixing unit, flocculation unit, DAF unit, sedimentation unit and filter unit. The flow line diagram for the treatment units are illustrated in figure (1) and the erected pilot is shown in figure (2).
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Various techniques, such as centrifugation, sedimentation, flotation, flocculation and membrane separation have been applied to the microalgae harvesting process  . However, the majority of harvesting methods are either of low efficiency or high cost. Flotation, originally applied in the mineral separation process, has been proved to be an effective separation technique to remove algae from suspension in recent years  . In a flotation process, gas is generally introduced into a flotation column and dispersed in the form of small bubbles, followed by colliding with and attaching to the surface of microalgae suspended in culture medium to form agglomerates. The agglomerates then rise due to buoyancy to the surface of liquid, forming a concentrated layer of foam which is separated from the water by skimming  .
Cognitive experiences in stage I sleep and flotation‑REST Multiple functional changes have been described dur- ing stage I sleep: slow-rolling eye movements, drowsi- ness, decreased eyelid blinking, slow eye movements, increasing number of wrong answers to questions, and a decrease in response to audible tones . Drowsi- ness, a manifestation of stage I sleep, is characterized by increased eyelid closure (decreased eyelid opening) and a propensity for decreased alertness and inclination to fall asleep [44, 46, 47]. Cognitive experiences dur- ing stage I sleep have been described as a dream-like or half-awake, half-asleep state and may include random visual images, thoughts, or feelings; a decrease in aware- ness of the surrounding environment; and an alteration in time awareness [40, 48]. Qualitatively comparable hyp- nagogic mental phenomena have also been found dur- ing flotation-REST, suggesting that the two states have similar experiential features [49, 50]. Vivid and detailed written documentations  and results from compre- hensive questionnaires  of persons immediately fol- lowing emersion from the flotation-REST tank indicate that some degree of awareness is present during floating. As some degree of vigilance has also been described dur- ing stage I sleep , these findings further suggest that stage I sleep and flotation-REST are likely to be relatively similar states.
The dissolved oxygen (DO) is one of the limiting environmental factors effect fish feeding, growth and metabolism. DO fluctuation is affected by photosynthesis, respiration and daily fluctuation. These factors must be fully considered where DO is concerned. Ambient DOs range produce the best fish performance, while low DO levels limit respiration, growth and other metabolic activities of fish (Tsadik and Kutty,1987). Aeration is the process of bringing water and air into close contact by exposing drops or thin sheets of water to the air or by introducing small bubbles of air and letting them rise through the water. Aeration can remove certain dissolved gasses and minerals through oxidation (Igib et al., 2013).
Deletion mutant alleles of ins-3 and ins-33 cause defects similar to those caused by RNAi with respect to enhancement of the glp- 1(ar202) Pro phenotype and reduction of germ cell numbers (see Tables S3, S6 in the supplementary material). Their effects on germ cell number and mitotic index were daf-18 and daf-16 dependent (Fig. 4C). Reintroducing ins-3(+) and ins-33(+) into the respective mutant strains on simple transgenic arrays rescued these defects (see Table S3 in the supplementary material; Fig. 4D), verifying that the mutant phenotype is due to the deletion of these genes. Overexpression of ins- 3 or ins-33 did not elevate the number of proliferative germ cells, Fig. 4. ins-3 and ins-33 are required in the soma and depend on daf-18 and daf-16 to promote robust larval germline proliferation. (A) Number of proliferative zone nuclei in germ lines of adult N2 worms raised from hatching on bacteria carrying L4440 (black line and squares) or RNAi targeting ins-3 (dashed line, diamonds) or ins-33 (dotted line, triangles). Error bars indicate s.e.m. (B) Number of proliferative zone nuclei in germ lines of early adult N2, rrf-1(pk1417), daf-18(ok480) and daf-16(mu86) worms grown from hatching on L4440 or RNAi targeting ins-1 (negative control), ins-3 or ins-33. Error bars indicate s.e.m. Statistics: *P<0.05; ****P<0.0001; unmarked, P>0.05; two-tailed Student’s t-test versus appropriate L4440 control. (C) Number of proliferative zone nuclei in germ lines of early adult ins-3 or ins-33 mutants on indicated RNAi. Error bars indicate s.e.m. ***P<0.001; ****P<0.0001; unmarked, P>0.05 except ins-3(RNAi) in ins-3(tm2488) (P=0.02); two-tailed Student’s t-test versus appropriate L4440 control. (D) The L4 mitotic index in the same strains as in C, and in these strains carrying extrachromosomal arrays containing ins-3(+) or ins-33(+). Siblings that had lost the array (non-Rol) are indicated as ins-3(0) and ins-33(0), respectively. ‘Ex[ins-33(+)]’ and ‘Ex[ins-3(+)]’ refer to naEx197 and naEx187, respectively. Similar results were obtained from naEx186 and naEx195 (see Table S3 in the
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