A Study of Single Stage Semi‐Dry Anaerobic Digestion of Organic Fraction of Municipal Solid Waste

Solid waste generation is a natural consequence of human activity and is increasing along with population growth, urbanization and industrialization. Improper disposal of the huge amount of solid waste seriously affects the environment and contributes to climate change by the release of greenhouse gases. Practicing anaerobic digestion (AD) for the organic fraction of municipal solid waste (OFMSW) can reduce emissions to environment and thereby alleviate the environmental problems together with production of biogas, an energy source, and digestate, a soil amendment. The amenability of substrate for biogasification varies from substrate to substrate and different environmental and operating conditions such as pH, temperature, type and quality of substrate, mixing, retention time etc. Therefore, the purpose of this research work is to develop feasible semi-dry anaerobic digestion process for the treatment of OFMSW from Kerala, India for potential energy recovery and sustainable waste management. This study was carried out in three phases in order to reach the research purpose. In the first phase, batch study of anaerobic digestion of OFMSW was carried out for 100 days at 32°C (mesophilic digestion) for varying substrate concentrations. The aim of this study was to obtain the optimal conditions for biogas production using response surface methodology (RSM). The parameters studied were initial pH, substrate concentration and total organic carbon (TOC). The experimental results showed that the linear model terms of initial pH and substrate concentration and the quadratic model terms of the substrate concentration and TOC had significant individual effect (p < 0.05) on biogas yield. However, there was no interactive effect between these variables (p > 0.05). The optimum conditions for maximizing the biogas yield were a substrate concentration of 99 g/l, an initial pH of 6.5 and TOC of 20.32 g/l. AD of OFMSW with optimized substrate concentration of 99 g/l [Total Solid (TS)-10.5%] is a semi-dry digestion system .Under the optimized condition, the maximum biogas yield was 53.4 L/kg VS (volatile solid).. In the second phase, semi-dry anaerobic digestion of organic solid wastes was conducted for 45 days in a lab-scale batch experiment for substrate concentration of 100 g/l (TS-11.2%) for investigating the start-up performances under thermophilic condition (50°C). The performance of the reactor was evaluated by measuring the daily biogas production and calculating the degradation of total solids and the total volatile solids. The biogas yield at the end of the digestion was 52.9 L/kg VS for the substrate concentration of 100 g/l. About 66.7% of volatile solid degradation was obtained during the digestion. A first order model based on the availability of substrate as the limiting factor was used to perform the kinetic studies of batch anaerobic digestion system. The value of reaction rate constant, k, obtained was 0.0249 day-1. A laboratory bench scale reactor with a capacity of 36.8 litres was designed and fabricated to carry out the continuous anaerobic digestion of OFMSW in the third phase. The purpose of this study was to evaluate the performance of the digester at total solid concentration of 12% (semi-dry) under mesophlic condition (32°C). The digester was operated with different organic loading rates (OLRs) and constant retention time. The performance of the reactor was evaluated using parameters such as pH, volatile fatty acid (VFA), alkalinity, chemical oxygen demand (COD), TOC and ammonia-N as well as biogas yield. During the reactor’s start-up period, the process is stable and there is no inhibition occurred and the average biogas production was 14.7 L/day. The reactor was fed in continuous mode with different OLRs (3.1,4.2 and 5.65 kg VS/m3/d) at constant retention time of 30 days. The highest volatile solid degradation of 65.9%, with specific biogas production of 368 L/kg VS fed was achieved with OLR of 3.1 kg VS/m3/d. Modelling and simulation of anaerobic digestion of OFMSW in continuous operation is done using adapted Anaerobic Digestion Model No 1 (ADM1).The proposed model, which has 34 dynamic state variables, considers both biochemical and physicochemical processes and contains several inhibition factors including three gas components. The number of processes considered is 28. The model is implemented in Matlab® version 7.11.0.584(R2010b). The model based on adapted ADM1 was tested to simulate the behaviour of a bioreactor for the mesophilic anaerobic digestion of OFMSW at OLR of 3.1 kg VS/m3/d. ADM1 showed acceptable simulating results.

表征方式对网上购物信息搜索行为影响的工程心理学实验研究

Interface has been becoming a more significant element today which influences the development of shopping on-line greatly. But in practice the attention arisen from society and study made are quite inadequate. Under this circumstance, I focus my study on the purpose of improving understanding of the engineering psychological factors, which definitely will play a crucial role in shopping on-line representation in future, and of the relations between them through the following experimental research. I hope it can give a basic reference to the practical application of shopping on-line representation pattern and continuous study. In current thesis, an analysis was made on the basis of engineering psychology principles from three aspects, i.e. person (users), task and information environment. It was considered that system overview and information behavior model would have great impact on the activities of users on the web and that representation pattern of information system would affect the forming of system overview and behavior pattern and then further after the performances of users in information system. Based on above-mentioned statement, a three-dimensional conceptual model was presented which demonstrates the relations between the crucial factors, which are media representation pattern, system hierarchy and objects in information unit. Thereafter, eight study hypothesis, which are about engineering psychological factors of virtual reality (VR) representation in shopping on-line system, was taken out and four experiments were followed up to testify the hypothesis. -In experiment one, a research was made to study how the three kinds of single media representation pattern influence the forming of system overview and information behavior from the point view of task performance, operating error, overall satisfactory and mental workload etc. -In experiment two, a study of how the combined media representation pattern of system hierarchy influences users' behavior was carried out. -In experiment three, a study of the hierarchy structure feature of VR representation pattern and the tendency of its width and depth to the effects of system behavior was made. -In experiment four, a study of the location relations between different parties in VR scene (information unit) was made. The result is as follows: -During structure dimensional state: Width-increasing caused more damage to the speed of users than depth-increasing in VR representation pattern. Although the performance of subjects was quite slow in wider environment, yet the percentage rate of causing errors was in lowest level. -During hierarchy representation pattern: 1. Between the representation patterns of the three media, no significant differences was found in terms of the speed of fulfilling the task, error rate, satisfactory, mental workload etc. But the pattern with figure- aided gained the worst results on all of these aspects. 2. During primary stage of the task and the first level of the hierarchy, the speed of subjects' performance in VR pattern was slower than that in text pattern. While with developing of the task and going deeper level of the hierarchy, the speed of users' performance in VR representation pattern reached to the highest level. 3. Effects in VR representation pattern was better than that in text pattern in higher level of the system. The representation pattern in highest level has greatest impact on the performance of the system behavior, whereas results of the only VR representation in the middle part of hierarchy would be worst. 4. Activity error in single media representation pattern was more than that in combined media representation pattern. 5. Individual differences among subjects had effects on the representation pattern of the system. During VR environment, behavior tendency of party A had a significant negative correlation to the quantities of errors. -In VR-scene representation: Physical-distance and flash influenced the subjects' task performance greatly, while psychological-distance has no outstanding impact. Subjects' accurate rate of performing increased if objects with same relation were in the same structure position, in the state of close psychological-distance or if the object target flashed (not reliable). Although the article limits the topic only on the present-existing questions and analysis of shopping-on-line, as a matter of fact, it can also apply for other relevant purposes on the web. While the study of this article only gives its emphasis on the researching-task with definite goal, making no consideration of other task conditions and their relations with other navigation tools. So I hope it lay a good start to make continuous research in this areas.

Infant-nonmother interactions of free-ranging mantled howlers (Alouatta palliata) in Costa Rica

Proximate and ultimate explanations of interactions between infants and nonmothers vary depending upon the relatedness of the interactors. We investigated interactions of infants and nonmothers from a 22-month continuous study and from the long-term monitoring of the mantled howler population of La Pacifica, Guanacaste Province, Costa Rica. Relatedness is low or absent in these mantled howler groups. Juvenile females appeared to practice care skills with older infants, but as most first infants died, they failed to benefit. Infant positive interactions with adults occurred with the mother and probable father. Other adult females behaved aggressively toward the youngest infants. Mothers were retentive of infants and responded negatively to these interactions, suggesting that they perceived them as threatening. Interactions with infants appear to reflect competition in groups of unrelated adults. A review of other populations of Alouatta palliata and other species of howlers indicate variability in social group size and suggest variability in intragroup relatedness. We suggest that further study will confirm that social behavior (including interactions with infants) will vary by resource availability (group size) and associated demographic patterns (male and female migration) that affect relatedness in howler social groups.

Longitudinal evaluation of ICT intervention programs for girls

Intervention programs creating awareness among girls about the wide range of career opportunities in the Information and Communications Technology (ICT) field are conducted in many countries to tackle the problem of female under-representation in ICT. The long-term effects of these programs, however, are rarely evaluated which hinders the understanding of how they could be improved, their value and success factors. The goal of this study is, therefore, to investigate the longitudinal influence of one such program held biennially in Australia since 2006, by analysing survey data both quantitatively and qualitatively (n = 153). The results show that continuous study of an ICT subject at school by girls positively influences both their intention to choose a career in ICT and the actual choice of ICT as a university major. Moreover, the attitude towards the intervention program has a weak, but significant positive effect on the decision to study ICT at school.

Estudo da soroprevalência da co-infecção pelo Vírus da hepatite C (VHC) em pacientes portadores do Vírus da imunodeficiência humana 1 (HIV-1) e/ou com SIDA/AIDS no Estado do Amapá

No presente estudo a soroprevalência da infecção pelo Vírus da hepatite C (VHC) foi investigada em indivíduos portadores da infecção pelo Vírus da imunodeficiência humana 1 (HIV-1) da cidade de Macapá, Estado do Amapá, Brasil. Um total de 120 indivíduos infectados pelo HIV-1 foi testado para a presença de anti-VHC usando um ensaio imunoabsorvente ligado a enzima. Todos os pacientes envolvidos no presente estudo foram testados para a carga viral plasmática do HIV-1 e para os níveis de células T CD4⁺ no momento do consentimento em fazer parte do estudo. Os pacientes responderam a um questionário epidemiológico no momento da coleta de sangue. Do total de 120 amostras testadas apenas sete (5,83%) foram soropositivas para anti-VHC. Quanto ao gênero, quatro (57,2%) e três (42,8%) eram homens e mulheres, respectivamente. A idade dos indivíduos soropositivos para anti-VHC variou de 21 a 40 anos entre os homens e de 21 a 60 entre as mulheres. Considerando o impacto da coinfecção nos valores de carga viral plasmática do HIV-1 e na contágem de células T CD4⁺ não foram observadas diferenças significativas (Odds Ratio=2,7368, p=0,3624; Odds Ratio=1,7803, p=0,7764). O uso de drogas injetáveis e de piercing mostrou ser um importante fator de risco para a co-infecção (p<0,05). Os resultados do presente estudo representam os primeiros achados acerca da co-infecção HIV-1/VHC no Estado do Amapá e demonstra a necessidade de um estudo continuado objetivando avaliar a soroprevalência da infecção pelo VHC no Amapá e detectar o real impacto clinico da co-infecção HIV-1/VHC no paciente.

Métodos analíticos para a identificação de espécies animais

The food industry has been rapidly modernized, and with this the disposal and the consumption of industrialized food has been increasing continually. These products lose their original morphological characteristics, requiring fast and reliable tests that could help to identify the species in question, as most fraudulent behavior in the milk and dairy industry (meat and fish) is carried out where there is partial or total exchange of the original material for other with less value at market. Nowadays there is a lot of techniques that can be used for the identification of animal species, based on muscle protein, or DNA analysis. In the case of protein based analysis, we can mention several types of electrophoresis and immunologic methods, as ELISA. In the case of DNA based methods, we have several assays that use the amplification of DNA fragments, known as PCR, as proof. All these techniques have advantages and disadvantages that can be affected by factors- the sample condition, or the degree of relation between the species in question. Because of this, it’s necessary that a continuous study looking for the improvement of the available techniques, making sure that the confirmation of food authenticity is in place. This is to ensure the true product value, to comply with labeling regulationand and protect the consumer of frauds

Clínica de animais de companhia

A clínica veterinária de pequenos animais é um mundo vasto e complexo que necessita de um estudo contínuo. Este relatório de estágio está dividido em duas partes. A primeira parte contém a descrição das atividades realizadas durante o estágio curricular realizado na clínica AlcabidecheVet. A segunda parte corresponde a uma monografia cujo tema é doença renal crónica em animais de companhia. A doença renal crónica acomete tanto cães como gatos em idade avançada, tendo uma progressão irreversível. Vários estudos científicos têm sido realizados para melhorar a sua prevenção e diagnóstico, como o estudo de biomarcadores da função renal. A utitilização de biomarcadores no diagnóstico e controlo da doença renal é essencial para o seu estadiamento e para demarcar o avanço dos danos renais. É também necessário conhecer os mecanismos patológicos em ação nesta doença para que o seu tratamento e monitorização providenciem o máximo bem-estar e o prolongamento da vida do animal; Abstract: (Small Animal Practice and Surgery – Kidney Chronic Disease) The world of small animal veterinary practice is vast and complex and needs a continuous study. This report is divided in two parts. The first describes the activities performed during the curricular internship at the clinic AlcabidecheVet. The second consists of a monograph which theme is chronic kidney disease. Chronic kidney disease affects both dogs and cats of declining age, and has an irreversible progression. There’s been scientific advances in its prevention and diagnosis with the study of biomarkers of kidney function. It’s also necessary to understand the pathological mechanisms in action in this disease, so its treatment and control can aim towards the welfare and the life extension of pets.

A longitudinal study of corporate earnings guidance in Australia’s continuous disclosure environment

Since the introduction of a statutory‐backed continuous disclosure regime (CDR) in 1994, regulatory reforms have significantly increased litigation risk in Australia for failure to disclose material information or for false and misleading disclosure. However, there is almost no empirical research on the impact of the reforms on corporate disclosure behaviour. Motivated by the absence of research and using management earnings forecasts (MEFs) as a disclosure proxy, this study examines (1) why managers issue earnings forecasts, (2) what firm‐specific factors influence MEF characteristics, and (3) how MEF behaviour changes as litigation risk increases. Based on theories in information economics, a theoretical framework for MEF behaviour is formulated which includes antecedent influencing factors related to firms‟ internal and external environments. Applying this framework, hypotheses are developed and tested using multivariate models and a large sample of hand-collected MEFs (7,213) issued by top 500 ASX-listed companies over the 1994 to 2008 period. The results reveal strong support for the hypotheses. First, MEFs are issued to reduce information asymmetry, litigation risk and signal superior performance. Second, firms with better financial performance, smaller earnings changes, and lower operating uncertainty provide better quality MEFs. Third, forecast frequency and quality (accuracy, timeliness and precision) noticeably improve as litigation risk increases. However, managers appear to be still reluctant to disclose earnings forecasts when there are large earnings changes, and an asymmetric treatment of news type continues to prevail (a good news bias). Thus, the findings generally provide support for the effectiveness of the CDR regulatory reforms in improving disclosure behaviour and will be valuable to market participants and corporate regulators in understanding the implications of management forecasting decisions and areas for further improvement.

A water model study of the flow asymmetry inside a continuous slab casting mold

The work studies the extent of asymmetric flow in water models of continuous casting molds of two different configurations. In the molds where fluid is discharged through multiple holes at the bottom, the flow pattern in the lower portion depends on the size of the lower two recirculating domains. If they reach the mold bottom, the flow pattern in the lower portion is symmetrical about the central plane; otherwise, it is asymmetrical. On the other hand, in the molds where the fluid is discharged through the entire mold cross section, the flow pattern is always asymmetrical if the aspect ratio is 1:6.25 or more. The fluid jet swirls while emerging through the nozzle. The interaction of the swirling Jets with the wide sidewalls of the mold gives rise to asymmetrical flow inside the mold. In the molds with lower aspect ratios, where the jets do not touch the wide side walls, the flow pattern is symmetrical about the central plane.

Study Of Fluid-Flow And Residence-Time Distribution In A Continuous Slab Casting Mold

The fluid-flow pattern and residence-time distribution (r.t.d.) of the fluid in a continuous casting mould have been studied using a water model. The two recirculating zones below the discharge ports have been found to be asymmetric. The effect of casting speed, discharge port diameter, shroud well depth and the immersion depth on r.t.d. have been investigated. The r.t.d. curve has been well represented by a model of two backmix cells of equal volume in series. The exist of the fluid has been found to be non-uniform across the cross-section of the mould. The fluid-flow pattern has been observed to change with time in a random fashion. Dead volume of upto 31.8% has been found with smaller discharge ports.

Water-modeling study of the surface disturbances in continuous slab caster

The present work is based on four static molds using nozzles of different port diameter, port angle, and immersion depth. It has been observed that the meniscus is wavy. The wave amplitude shows a parabolic variation with the nozzle exit velocity. The dimensionless amplitude is found to vary linearly with the Froude number. Vortex formation and bubble entrainment by the wave occurs at the meniscus beyond a critical flow rate, depending upon the nozzle configuration, immersion depth, and the mold aspect ratio.

Water Modeling Study Of The Jet Characteristics In A Continuous-Casting Mold

The jet characteristics and the fluid flow pattern in a continuous slab caster have been studied using a water model. The fluid jet is studied under free fall and submerged discharge conditions. In the latter case, the jet was followed by dye-injection technique and image analyser was used to find out the effect of nozzle parameters on jet-spread angle, jet-discharge angle and the volume entrainment by the jet. All free-fall jets with nozzle port angle zero and upward are found to be spinning. Some of the free-fall jets with downward nozzle-port angle are found to be spinning and rest are smooth. The spinning direction of the jets are found to change with time. The well depth, port diameter and the inner diameter of the nozzle have a clear effect on the free-fall jets with downward port angle. The jet-spread angle is found to be about 17-degrees for smooth jets. The spread angle for spinning jet increases as the nozzle-port angle is increased from downward 25 to upward 15-degrees. The jet-discharge angle is always downward even when the nozzle-discharge ports are angled upward. The extent of volume entrainment by the spinning jet is higher and it increases as the nozzle-port angle is increased from 25 downward to 15-degrees upward.

An experimental study of loss sources in a fan operating with continuous inlet stagnation pressure distortion

The viability of Boundary Layer Ingesting (BLI) engines for future aircraft propulsion is dependent on the ability to design robust, efficient engine fan systems for operation with continuously distorted inlet flow. A key step in this process is to develop an understanding of the specific mechanisms by which an inlet distortion affects the performance of a fan stage. In this paper, detailed full-annulus experimental measurements of the flow field within a low-speed fan stage operating with a continuous 60-degree inlet stagnation pressure distortion are presented. These results are used to describe the three-dimensional fluid mechanics governing the interaction between the fan and the distortion and to make a quantitative assessment of the impact on loss generation within the fan. A 5.3 percentage point reduction in stage total-to-total efficiency is observed as a result of the inlet distortion. The reduction in performance is shown to be dominated by increased loss generation in the rotor due to off-design incidence values at its leading edge, an effect which occurs throughout the annulus despite the localised nature of the inlet distortion. Increased loss generation in the stator row is also observed due to flow separations that are shown to be caused by whirl angle distortion at rotor exit. By addressing these losses, it should be possible to achieve improved efficiency in BLI fan systems. Copyright © 2012 by ASME.