113,746 research outputs found
Phyllotetranychus Sayed 1938
No full textGenus <i>Phyllotetranychus</i> Sayed, 1938 <p> <b>Type species:</b> <i>Phyllotetranychus aegyptium</i> Sayed, 1938</p> <p> <b>Diagnosis:</b> Full complement of 16 dorsal setae; dorsal setae large, broadly orbicular to ovate, leaf-like and with pseudovenation; setae <i> h 2</i> not flagellate; anterior margin of prodorsum with two pairs of prodorsal projections; palps two-segmented (tibio-tarsus with one eupathidium (<i>ul'ζ</i>) and two setae, femorogenu with one seta (<i>d</i>)); two pairs of pseudanal setae <i> ps 1–2</i> ; ventral, genital and anal plates not sclerotised or developed.</p>Published as part of <i>Mahdavi, Sayed Mosayeb, Latifi, Malihe & Asadi, Mahdieh, 2019, A new species of Phyllotetranychus (Acari: Tenuipalpidae) from Iran, pp. 566-578 in Zootaxa 4565 (4)</i> on page 567, DOI: 10.11646/zootaxa.4565.4.10, <a href="http://zenodo.org/record/2591261">http://zenodo.org/record/2591261</a>
2° Mosquée d'as-Sayed Ahmad al-Bagam
No full textFarnall Harry, Shafik Muhammad, Simaïka Marcus H., Sayed Metoualli, Omar Ahmad, 'Amrusi Ahmad Fahmi al-, Sayyed Ahmad el-. 2° Mosquée d'as-Sayed Ahmad al-Bagam. In: Comité de Conservation des Monuments de l'Art Arabe. Fascicule 34, exercice 1925-1926, 1933. pp. 63-64
Anaerobic treatment of slaughterhouse wastewater using the UASB process
No full textEffluents from the slaughterhouses, meat and poultry industries are heavily polluted and contain a high concentration of biodegradable organic materials. Therefore, the pollution capacity of these industries is high. Most of these industries discharge their effluents to a sewer or a watercourse.In order to comply with water pollution control standards and to reduce costs on sewer surcharges, these industries have to apply an adequate treatment of their effluents.Physical and chemical treatment methods as well as the conventional biological treatment processes are frequently applied in the treatment of these effluents. A combination of the methods are required where the effluent is to be discharged to surface waters, since no single treatment method will provide sufficient effluent.In the last decade, the high rate anaerobic wastewater treatment systems have become a good alternative for conventional aerobic as well as anaerobic biological treatment methods. The high rate anaerobic treatment systems were initially developed for the treatment of highly soluble low and medium strength wastewaters. These systems provided only a partial treatment of complex wastewaters containing a high fraction of suspended solids such as slaughterhouse wastewater.Investigations have shifted towards the application of high rate systems like the upflow anaerobic sludge blanket (UASB) for the complete treatment of agro-industrial wastewaters which are more difficult to handle, because they contain relatively high concentrations of suspended solids, i.e. complex wastewaters.Presently, the UASB system is the most widely applied high rate anaerobic system for complete treatment of such complex wastes.This thesis focuses on the question whether, and under which operationa conditions and environmental circumstances a one stage UASB mesophilic anaerobic treatment system is suitable for a complete treatment of slaughterhouse wastewater in practice.The feasibility of using the upflow flocculent anaerobic sludge blanket (UASB) process for a one stage anaerobic treatment of unsettled complex slaughterhouse wastewater, which contains approximately 50% of coarse insoluble COD, was investigated (Chapter 2). The continuous experiments were performed in a 25.3 m 3UASB pilot-plant which was operated under semi-continuous conditions, viz. with a varying organic load over day and nighttime (i.e. high organic load during the daytime and with low organic load at night) and with weekend feed interruptions. The UASB pilot-plant was operated at a temperature of 30° C. In order to assess the feasibility of the process under conditions of lower temperatures the temperature was reduced to 20°C, 20 weeks after the start-up of the reactor.The data indicated that the system can satisfactorily handle organic loads up to 3.5 kg COD m -3day -1at a liquid retention time of 8 h at temperatures as low as 20°C. Temporary shock loads up to 7.5 kg COD m -3day -1during the day time at a liquid retention time of 5 h were accommodated satisfactorily provided such a shock load was followed by a period of low loading, e.g. at night.A significant discrepancy was found between the treatment efficiency in terms of COD reduction and to the lower calculated percentage of supplied COD total converted into methane-COD. This difference indicated that a significant portion of the achieved COD reduction was due to the accumulation of non- or slowly biodegradable substrate ingredients in the reactor. No differentiations could be made between the different types of substrate ingredients that accummulated in the reactor because the accumulated sludge was not characterized. However, a part of the accumulated substrate was converted to CH 4 in periods of feed interruptions.In Chapter 3 the feasibility of the upflow granular anaerobic sludge blanket process for a one-stage anaerobic treatment of slaughterhouse wastewater was investigated. The experiments were performed under semi-continuous operational conditions viz. continuous feeding at a constant organic load (24 h day) during the working days but with weekend feed interruptions, and process temperatures of 30°C and 20°C. Under a stable operation of the system, i.e. at a maximum COD reduction and a high conversion of COD into methane, the optimal loading rates that could be applied were 11 kg COD m -3day -1and 7 kg COD m -3day -1at 30°C and at 20°C respectively.The system was less effective in the removal of coarse suspended solids, compared to the removal of the colloidal and soluble fractions from the slaughterhouse wastewater.The data obtained in these investigations indicate that imposed prolonged loadings exceed the optimal loading rates, lead to deterioration of the specific methanogenic activity of the sludge, due to the accumulation of colloidal and soluble fractions of the wastewater in the sludge bed. Therefore, it was concluded that the system stability strongly depends on the processes involved in the removal of the colloidal and soluble compounds from the wastewater and their conversion into methane. As the predominant - non-biological-mechanisms underlying the elimination of these wastewaters pollutants were considered the entrapment and the adsorption mechanisms. The effect of these mechanisms on the rate of the liquefaction of the accumulated substrate - which is the required first step in their conversion into methane - were discussed.The different pollutant fractions of the wastewater, viz. the coarse suspended solids, the colloidal and the soluble compounds affect the performance of the UASB reactors because of the different mechanisms involved in the removal of these substrate ingredients and their subsequent conversion into methane. Therefore, these mechanisms were investigated in more detail. The results of these investigations are presented in Chapter 4. The experiments were performed in a one-stage flocculent sludge UASB-reactor under continuous operational conditions viz. continuous feeding at a constant organic load during 24 h a day and 7 days a week.The COD removal efficiency of the UASB reactor exceeded the COD removal efficiency as expected from the observed CH 4 production, indicating once again that non-biological mechanisms are involved. Two different non-biological mechanisms were distinguished in the removal of substrate ingredients from the wastewater. The entrapment mechanism prevailed in the elimination of coarse suspended solids, while mainly adsorption mechanisms are involved in the removal of colloidal and the soluble fractions of the wastewater.A continued accumulation of substrate ingredients in the reactor ultimately will become detrimental for the stability of the anaerobic treatment process, as it leads to sludge flotation and consequently could result in a complete loss of the active biomass from the reactor.After having demonstrated the principle feasibility of the upflow anaerobic sludge blanket (UASB) process for a one-stage anaerobic treatment of the slaughterhouse wastewater, we decided to assess the maximum possible extent of anaerobic degradation of the soluble, colloidal and coarse suspended solids fractions of the slaughterhouse wastewater (Chapter 5). In this way we intended to get a better insight in the real limitations of the system. All the experiments were performed at process temperatures of 30°C and 20°C, using membrane filtered wastewater (wastewater mf ), paper filtered wastewater (wastewater pf ) and total wastewater. The experiments were performed in a recirculated batch digester system with granular sludge. The experiments with the coarse suspended solids separated from the wastewater were performed with granular sludge as well as with flocculent sludge using conventional batch-fed stirred digesters. The maximum biodegrability percentages (i.e. conversion into methane) found at 30°C were 75% for wastewater mf , 61% for wastewater pf and 67% for wastewater total while at 20°C these values were 72%, 49% and 51% respectively. The maximum biodegrability of the coarse suspended solids fraction of the waste amounts to 50% at 30°C and 45% at 20°C.The mechanisms involved in the removal of the soluble and colloidal fractions of the slaughterhouse wastewater were thoroughly studied and elucidated. The data obtained in these experiments indicate that the prevailing mechanism in the removal of the soluble but especially also the colloidal fraction of the wastewater is an adsorption mechanism. The relatively high degree of adsorption of the colloidal fraction of the wastewater to the surface of the sludge, in combination with its high fat content, will deteriorate the specific methanogenic activity of the sludge. The adsorption of the colloidal materials will ultimately result in an enclosure of the granular sludge bacterial matter with a film of increasing thickness, and perhaps also density, which increasingly will hamper the supply of substrate to the bacteria present in the grains. The deterioration effect of fats towards the methanogenic activity of the sludge was explained on the basis of the inhibitory effect of the long-chain fatty acids of the neutral fats.As the extent of adsorption is very similar at lower and higher temperatures, but the rate of liquefaction of adsorbed compounds drops significantly at decreasing temperatures, it will be evident that the process can withstand considerably lower loading rates at 20°C as compared to 30°C.Therefore, it is concluded that the rate of liquefaction of the adsorbed insoluble colloidal fraction of the wastewater is the controlling factor with respect to loading potentials of the process and consequently that the temperature is the factor of predominant importance
Anaerobic treatment of slaughterhouse wastewater using the UASB process
No full textEffluents from the slaughterhouses, meat and poultry industries are heavily polluted and contain a high concentration of biodegradable organic materials. Therefore, the pollution capacity of these industries is high. Most of these industries discharge their effluents to a sewer or a watercourse.In order to comply with water pollution control standards and to reduce costs on sewer surcharges, these industries have to apply an adequate treatment of their effluents.Physical and chemical treatment methods as well as the conventional biological treatment processes are frequently applied in the treatment of these effluents. A combination of the methods are required where the effluent is to be discharged to surface waters, since no single treatment method will provide sufficient effluent.In the last decade, the high rate anaerobic wastewater treatment systems have become a good alternative for conventional aerobic as well as anaerobic biological treatment methods. The high rate anaerobic treatment systems were initially developed for the treatment of highly soluble low and medium strength wastewaters. These systems provided only a partial treatment of complex wastewaters containing a high fraction of suspended solids such as slaughterhouse wastewater.Investigations have shifted towards the application of high rate systems like the upflow anaerobic sludge blanket (UASB) for the complete treatment of agro-industrial wastewaters which are more difficult to handle, because they contain relatively high concentrations of suspended solids, i.e. complex wastewaters.Presently, the UASB system is the most widely applied high rate anaerobic system for complete treatment of such complex wastes.This thesis focuses on the question whether, and under which operationa conditions and environmental circumstances a one stage UASB mesophilic anaerobic treatment system is suitable for a complete treatment of slaughterhouse wastewater in practice.The feasibility of using the upflow flocculent anaerobic sludge blanket (UASB) process for a one stage anaerobic treatment of unsettled complex slaughterhouse wastewater, which contains approximately 50% of coarse insoluble COD, was investigated (Chapter 2). The continuous experiments were performed in a 25.3 m 3UASB pilot-plant which was operated under semi-continuous conditions, viz. with a varying organic load over day and nighttime (i.e. high organic load during the daytime and with low organic load at night) and with weekend feed interruptions. The UASB pilot-plant was operated at a temperature of 30° C. In order to assess the feasibility of the process under conditions of lower temperatures the temperature was reduced to 20°C, 20 weeks after the start-up of the reactor.The data indicated that the system can satisfactorily handle organic loads up to 3.5 kg COD m -3day -1at a liquid retention time of 8 h at temperatures as low as 20°C. Temporary shock loads up to 7.5 kg COD m -3day -1during the day time at a liquid retention time of 5 h were accommodated satisfactorily provided such a shock load was followed by a period of low loading, e.g. at night.A significant discrepancy was found between the treatment efficiency in terms of COD reduction and to the lower calculated percentage of supplied COD total converted into methane-COD. This difference indicated that a significant portion of the achieved COD reduction was due to the accumulation of non- or slowly biodegradable substrate ingredients in the reactor. No differentiations could be made between the different types of substrate ingredients that accummulated in the reactor because the accumulated sludge was not characterized. However, a part of the accumulated substrate was converted to CH 4 in periods of feed interruptions.In Chapter 3 the feasibility of the upflow granular anaerobic sludge blanket process for a one-stage anaerobic treatment of slaughterhouse wastewater was investigated. The experiments were performed under semi-continuous operational conditions viz. continuous feeding at a constant organic load (24 h day) during the working days but with weekend feed interruptions, and process temperatures of 30°C and 20°C. Under a stable operation of the system, i.e. at a maximum COD reduction and a high conversion of COD into methane, the optimal loading rates that could be applied were 11 kg COD m -3day -1and 7 kg COD m -3day -1at 30°C and at 20°C respectively.The system was less effective in the removal of coarse suspended solids, compared to the removal of the colloidal and soluble fractions from the slaughterhouse wastewater.The data obtained in these investigations indicate that imposed prolonged loadings exceed the optimal loading rates, lead to deterioration of the specific methanogenic activity of the sludge, due to the accumulation of colloidal and soluble fractions of the wastewater in the sludge bed. Therefore, it was concluded that the system stability strongly depends on the processes involved in the removal of the colloidal and soluble compounds from the wastewater and their conversion into methane. As the predominant - non-biological-mechanisms underlying the elimination of these wastewaters pollutants were considered the entrapment and the adsorption mechanisms. The effect of these mechanisms on the rate of the liquefaction of the accumulated substrate - which is the required first step in their conversion into methane - were discussed.The different pollutant fractions of the wastewater, viz. the coarse suspended solids, the colloidal and the soluble compounds affect the performance of the UASB reactors because of the different mechanisms involved in the removal of these substrate ingredients and their subsequent conversion into methane. Therefore, these mechanisms were investigated in more detail. The results of these investigations are presented in Chapter 4. The experiments were performed in a one-stage flocculent sludge UASB-reactor under continuous operational conditions viz. continuous feeding at a constant organic load during 24 h a day and 7 days a week.The COD removal efficiency of the UASB reactor exceeded the COD removal efficiency as expected from the observed CH 4 production, indicating once again that non-biological mechanisms are involved. Two different non-biological mechanisms were distinguished in the removal of substrate ingredients from the wastewater. The entrapment mechanism prevailed in the elimination of coarse suspended solids, while mainly adsorption mechanisms are involved in the removal of colloidal and the soluble fractions of the wastewater.A continued accumulation of substrate ingredients in the reactor ultimately will become detrimental for the stability of the anaerobic treatment process, as it leads to sludge flotation and consequently could result in a complete loss of the active biomass from the reactor.After having demonstrated the principle feasibility of the upflow anaerobic sludge blanket (UASB) process for a one-stage anaerobic treatment of the slaughterhouse wastewater, we decided to assess the maximum possible extent of anaerobic degradation of the soluble, colloidal and coarse suspended solids fractions of the slaughterhouse wastewater (Chapter 5). In this way we intended to get a better insight in the real limitations of the system. All the experiments were performed at process temperatures of 30°C and 20°C, using membrane filtered wastewater (wastewater mf ), paper filtered wastewater (wastewater pf ) and total wastewater. The experiments were performed in a recirculated batch digester system with granular sludge. The experiments with the coarse suspended solids separated from the wastewater were performed with granular sludge as well as with flocculent sludge using conventional batch-fed stirred digesters. The maximum biodegrability percentages (i.e. conversion into methane) found at 30°C were 75% for wastewater mf , 61% for wastewater pf and 67% for wastewater total while at 20°C these values were 72%, 49% and 51% respectively. The maximum biodegrability of the coarse suspended solids fraction of the waste amounts to 50% at 30°C and 45% at 20°C.The mechanisms involved in the removal of the soluble and colloidal fractions of the slaughterhouse wastewater were thoroughly studied and elucidated. The data obtained in these experiments indicate that the prevailing mechanism in the removal of the soluble but especially also the colloidal fraction of the wastewater is an adsorption mechanism. The relatively high degree of adsorption of the colloidal fraction of the wastewater to the surface of the sludge, in combination with its high fat content, will deteriorate the specific methanogenic activity of the sludge. The adsorption of the colloidal materials will ultimately result in an enclosure of the granular sludge bacterial matter with a film of increasing thickness, and perhaps also density, which increasingly will hamper the supply of substrate to the bacteria present in the grains. The deterioration effect of fats towards the methanogenic activity of the sludge was explained on the basis of the inhibitory effect of the long-chain fatty acids of the neutral fats.As the extent of adsorption is very similar at lower and higher temperatures, but the rate of liquefaction of adsorbed compounds drops significantly at decreasing temperatures, it will be evident that the process can withstand considerably lower loading rates at 20°C as compared to 30°C.Therefore, it is concluded that the rate of liquefaction of the adsorbed insoluble colloidal fraction of the wastewater is the controlling factor with respect to loading potentials of the process and consequently that the temperature is the factor of predominant importance
Decisions Under Binary Messaging over Adaptive Networks
No full textWe consider an adaptive network made of interconnected agents engaged in a binary decision task. It is assumed that the agents cannot deliver full-precision messages to their neighbors, but only binary messages. For this scenario, a modified version of the ATC diffusion rule for the agent state evolution is proposed with improved decision performance under adaptive learning scenarios. An approximate analytical characterization of the agents' state is derived, giving insight into the network behavior at steady-state and enabling numerical computation of the decision performance. Computer experiments show that the analytical characterization is accurate for a wide range of the parameters of interest.AS
Detection Under One-Bit Messaging Over Adaptive Networks
No full textThis paper studies the operation of multi-agent networks engaged in binary decision tasks, and derives performance expressions and performance operating curves under challenging conditions with some revealing insights. One of the main challenges in the analysis is that agents are only allowed to exchange one-bit messages, and the information at each agent therefore consists of both continuous and discrete components. Due to this mixed nature, the steady-state distribution of the state of each agent cannot be inferred from direct application of central limit arguments. Instead, the behavior of the continuous component is characterized in integral form by using a log-characteristic function, while the behavior of the discrete component is characterized by means of an asymmetric Bernoulli convolution. By exploiting these results, this paper derives reliable approximate performance expressions for the network nodes that match well with the simulated results for a wide range of system parameters. The results also reveal an important interplay between continuous adaptation under constant step-size learning and the binary nature of the messages exchanged with neighbors.ASL26th European Signal Processing Conference (EUSIPCO), Sep 03-07, 2018, Rome, ITAL
Estimation and Detection Over Adaptive Networks
No full textIn this chapter, we review the foundations of statistical inference over adaptive networks by considering two canonical problems: distributed estimation and distributed detection. In the former setting, agents cooperate to estimate a model of interest while in the second setting, the agents cooperate to detect a state of nature. We focus on adaptive learning solutions where agents are able to track drifts in the underlying models, and examine performance limits under both estimation and detection formulations. Special attention is paid to the detailed characterization of the steady-state performance. Certain universal laws are highlighted and compared against known laws for estimation and detection in traditional (centralized or decentralized, nonadaptive) inferential systems
Consistent tomography under partial observations over adaptive networks
No full textThis paper studies the problem of inferring whether an agent is directly influenced by another agent over a network. Agent i influences agent j if they are connected (according to the network topology), and if agent j uses the data from agent i to update its online learning algorithm. The solution of this inference task is challenging for two main reasons. First, only the output of the learning algorithm is available to the external observer that must perform the inference based on these indirect measurements. Second, only output measurements from a fraction of the network agents is available, with the total number of agents itself being also unknown. The main focus of this paper is ascertaining under these demanding conditions whether consistent tomography is possible, namely, whether it is possible to reconstruct the interaction profile of the observable portion of the network, with negligible error as the network size increases. We establish a critical achievability result, namely, that for symmetric combination policies and for any given fraction of observable agents, the interacting and non-interacting agent pairs split into two separate clusters as the network size increases. This remarkable property then enables the application of clustering algorithms to identify the interacting agents influencing the observations. We provide a set of numerical experiments that verify the results for finite network sizes and time horizons. The numerical experiments show that the results hold for asymmetric combination policies as well, which is particularly relevant in the context of causation
Decision Learning and Adaptation over Multi-Task Networks
No full textThis paper studies the operation of multi-agent networks engaged in multi-task decision problems under the paradigm of simultaneous learning and adaptation. Two scenarios are considered:one in which a decision must be taken among multiple states of nature that are known but can vary over time and space, and another in which there exists a known 'normal' state of nature and the task is to detect unpredictable and unknown deviations from it. In both cases the network learns from the past and adapts to changes in real time in a multi-task scenario with different clusters of agents addressing different decision problems. The system design takes care of challenging situations with clusters of complicated structure, and the performance assessment is conducted by computer simulations. A theoretical analysis is developed to obtain a statistical characterization of the agents' status at steady-state, under the simplifying assumption that clustering is made without errors. This provides approximate bounds for the steady-state decision performance of the agents. Insights are provided for deriving accurate performance prediction by exploiting the derived theoretical results
Decision-making algorithms for learning and adaptation with application to COVID-19 data
No full textThis work focuses on the development of a new family of decision-making algorithms for adaptation and learning, which are specifically tailored to decision problems and are constructed by building up on first principles from decision theory. A key observation is that estimation and decision problems are structurally different and, therefore, algorithms that have proven successful for the former need not perform well when adjusted for the latter. Exploiting classical tools from quickest detection, we propose a tailored version of Page's test, referred to as BLLR (barrier log-likelihood ratio) test, and demonstrate its applicability to real-data from the COVID-19 pandemic in Italy. The results illustrate the ability of the design tool to track the different phases of the outbreak
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