87 research outputs found
Effect of extended famine conditions on aerobic granular sludge stability in the treatment of brewery wastewater
No full textResults obtained from three aerobic granular sludge reactors treating brewery wastewater are presented. Reactors were operated for 60 d days in each of the two periods under different cycle duration: (Period I) short 6 h cycle, and (Period II) long 12 h cycle. Organic loading rates (OLR) varying from 0.7 kg COD m-3 d-1 to 4.1 kg COD m-3 d-1 were tested. During Period I, granules successfully developed in all reactors, however, results revealed that the feast and famine periods were not balanced and the granular structure deteriorated and became irregular. During Period II at decreased 12 h cycle time, granules were observed to develop again with superior structural stability compared to the short 6 h cycle time, suggesting that a longer starvation phase enhanced production of proteinaceous EPS. Overall, the extended famine conditions encouraged granule stability, likely because long starvation period favours bacteria capable of storage of energy compounds
Aerobic granular sludge treating anaerobically pretreated brewery wastewater at different loading rates
No full textIn this study, three different aerobic granular sludge (AGS) reactors fed with anaerobically pre-treated brewery wastewater were studied. The AGS reactors were operated under different conditions including organic loading rates (OLR) between 0.8 and 4.1 kg COD m-3 d-1, C:N:P ratios (100:10:1 and 100:6:1) and food to microorganism ratios (F/M) between 0.8 ±0.6 and 1.2 ±0.5 and 0.9± 0.3 kg-TCOD kg-VSS-1d-1. Stable granulation was achieved within two weeks and the size of the granules increased according to the OLR applied. The results indicated that low C:N:P and F/M ratios were favorable to achieve stable aerobic granules in the long term. The carbon removal rate was load-independent in the range examined (TCOD removal >80%), whereas TN removals were inversely proportional to the OLRs. Overall, a longer aeration reaction time with a lower OLR was beneficial to granular structure, which exhibited a compact and defined architecture. Performance results within the other conditions studied further indicated that the microbial community and its complex functionality in nutrient removal was efficient at operational parameters of OLR at 0.8±0.2 kg-TCOD m-3d-1 and F/M ratio at 0.5±0.2 kg-TCOD VSS-1d-1. Moreover, the protein to polysaccharide ratio increased as OLR decreased, leading to a stable granular structure
Quasi-cyclic Generalized LDPC codes with low error floors
No full textIn this paper, a novel methodology for designing structured generalized LDPC (G-LDPC) codes is presented. The proposed design results in quasi-cyclic G-LDPC codes for which efficient encoding is feasible through shift-register-based circuits. The structure imposed on the bipartite graphs, together with the choice of simple component codes, leads to a class of codes suitable for fast iterative decoding. A pragmatic approach to the construction of G-LDPC codes is proposed. The approach is based on the substitution of check nodes in the protograph of a low-density parity-check code with stronger nodes based, for instance, on Hamming codes. Such a design approach, which we call LDPC code doping, leads to low-rate quasi-cyclic G-LDPC codes with excellent performance in both the error floor and waterfall regions on the additive white Gaussian noise channel
(PDF) Ryan Tanner's Smart Solar Box Review
No full text<p><strong>Product Name:</strong> Smart Solar Box: Smart Power 4 All</p>
<p><strong>Creator Name:</strong> Ryan Tanner</p>
<p><strong>Bonus:</strong> Yes</p>
<p><strong><a href="http://bit.ly/smartpowerforall">Official Website: Click Here</a></strong></p>
<p><a href="http://bit.ly/smartpowerforall"><em><strong>Smart Solar Box</strong></em></a> is an online system designed to teach you how to create an endless source of self-sustaining energy right here, right now. There’s no need for you to spend a fortune on materials or break your back trying to lift a massive generator. No, you don’t have to go back to school to get an engineering degree nor do you need to have any special skills because everything is provided to you in this step-by-step guide. And I know what you’re thinking – solar panels are expensive. They certainly can be, but they aren’t when you have a book that reveals the solar industry secrets to creating your own solar power station, and one that fits in a toolbox. So, if you’re tired of getting robbed by your electricity bills, finding yourself in the pitch dark when the power suddenly goes out or just want to have your own energy source, you’ve come to the right place. It’s time to learn how to build a Smart Solar Box.</p>
<p><strong>About the Smart Solar Box Program</strong></p>
<p>If you’re ready to cut your energy bills significantly, it’s time to create your own endless source of self-sustained energy. <a href="http://bit.ly/smartpowerforall"><strong>Smart Solar Box</strong></a> is an online program that provides you with the exact steps to doing just that. This system is more of an instruction manual-tutorial than it is a program, as it doesn’t have all the nonsense that many other “programs” provide. Instead, it gets right down to business – building your own solar power plant in a toolbox.</p>
<p><strong>When you start the program, you receive:</strong></p>
<ul>
<li>The Main eBook</li>
<li>3 Video Tutorials on Building the Box</li>
<li>10 Easy Steps to Build Your Solar Panels</li>
<li>Build Your Own Wind Generator</li>
</ul>
<p><strong>The Table of Contents for “Smart Solar Box” Guide.</strong></p>
<p>The main eBook is where you’ll find the step-by-step instructions needed to create the Smart Solar Box. It covers everything from the tools and electrical components you need, where to get each of them, and of course, what to do when you have all the materials needed. But don’t let this deter you because you don’t need to be a handyman (or woman), nor do you even have to know what a wrench is. The program breaks it down so meticulously that even the most unskilled (ahem, myself) people can make their own energy. Oh, but you aren’t just learning how to make an energy box that sparks a little bit of juice. This toolbox solar system that you learn how to build is strong enough to power up an entire cabin, garage, refrigerator – you name it. You can use it for pretty much everything, and it’s so lightweight and portable, making it easy to do just that.</p>
<p>Now, you also receive 3 video tutorials which are pretty much the main eBook broken down into videos. So, if you’re more of a visual person, you’ll definitely like this addition. Just click play and follow along.</p>
<p>You also receive 10 Easy Steps to Build Your Solar Panels and Build Your Own Wind Generator which have nothing to do with your Smart Solar Box. However, once you start creating your own energy source (and saving a ton of money from doing so), you’ll want to dive even deeper into it. With these bonuses, you can do just that.</p>
<p>The best part? You don’t have to wait for shipping to get started. The guide is entirely online. So, you just download the content onto your desktop, tablet, smartphone or laptop and start following through the steps. I recommend having it on whatever device is going to be in the space where you intend on building your box, whether it’s your office with a desktop or in the man cave or backyard where you’ll need a tablet or smartphone.</p>
<p><strong>About the Author of Smart Solar Box</strong></p>
<p>What may surprise you is that this solar box wasn’t created by some big tech engineer. Instead, the creator, Ryan Tanner, is just like you and I. After seeing his father creating and using his own energy source while living in a cabin in Wisconsin, he sought out to do the same in his home. And well, here we are!</p>
<p><strong>Brief Summary of the Smart Solar Box Guide</strong></p>
<p>To help you have a better idea of the steps needed to build your own solar power plant in a toolbox, here is a sneak peek at the sections that you’ll be working through with the Smart Solar Box program:</p>
<p><strong>Chapter 1: Introduction</strong></p>
<ul>
<li>Basic Principle Regarding Solar Energy</li>
<li>General Technical Regards</li>
</ul>
<p><strong>Chapter 2: Tools and Components</strong></p>
<ul>
<li>Tools</li>
<li>Components (electronic parts needed)</li>
</ul>
<p><strong>Chapter 3: Building The Box</strong></p>
<ul>
<li>Assembling Solar Panels</li>
<li>Preparing the Box</li>
<li>Wiring Process</li>
<li>Recap – Short Review of the Process</li>
</ul>
<p><strong>Chapter 4: Testing the Device</strong></p>
<p><strong>Chapter 5: List of Places Where You Can By the Components</strong></p>
<p>Again, you do have three video tutorials that cover all of this as well. So, whether you prefer to read instructions or thrive on visual instructions, there’s an option for you.</p>
<p>Add on the 10 Easy Steps to Build Your Solar Panels and Build Your Own Wind Generator bonus tutorials you receive, and you’re pretty much ready for anything that comes your way.</p>
<p>You also receive extra-extra bonus programs at no extra charge to you. Some apply to this energy-saving endeavor you’re embarking on and others, not so much. But they’re free. So, might as well download them while you’re at it. They are:</p>
<ul>
<li>Personal Home Security</li>
<li>Martial Arts for Seniors</li>
<li>Backyard Bio Gardening</li>
<li>Going Green 101</li>
<li>Saving Energy in Your Home</li>
</ul>
<p><strong>The Verdict</strong></p>
<p>Put it all together, and you get a solar power plant that is affordable, portable and small enough that it fits in a toolbox, plus 7 bonus programs at absolutely no extra charge to you, and a 60 Day Money Back Guarantee to figure out whether or not you’re serious about saving money. Certainly, once you see how easy it is to do just that, you’d be crazy to opt to pay for city-electricity when you can have your own brewing in the sun. Oh, which leaves me to one more thing. <a href="http://bit.ly/smartpowerforall"><strong>The Smart Solar Box</strong></a> is designed so well that even the cloudiest of days provide enough power for you to use this box as your primary source of energy, as a generator, or as a backup in case of an emergency.</p>
<p>So, do you continue to pay utterly ridiculous prices for unreliable electricity or do you take matters into your own hands and make your own? The choice is yours!</p
Design of LDPC Codes: A Survey and New Results
No full textThis survey paper provides fundamentals in the design of LDPC codes. To provide a target for the code designer, we first summarize the EXIT chart technique for determining (near-)optimal degree distributions for LDPC code ensembles. We also demonstrate the simplicity of representing codes by
protographs and how this naturally leads to quasi-cyclic LDPC codes. The EXIT chart technique is then extended to the special case of protograph-based LDPC codes. Next, we present several design approaches for LDPC codes which incorporate one or more accumulators, including quasi-cyclic accumulatorbased codes. The second half the paper then surveys several
algebraic LDPC code design techniques. First, codes based on finite geometries are discussed and then codes whose designs are based on Reed-Solomon codes are covered. The algebraic designs lead to cyclic, quasi-cyclic, and structured codes. The masking technique for converting regular quasi-cyclic LDPC codes to irregular codes is also presented. Some of these results and codes have not been presented elsewhere. The paper focuses
on the binary-input AWGN channel (BI-AWGNC). However, as discussed in the paper, good BI-AWGNC codes tend to be universally good across many channels. Alternatively, the reader may treat this paper as a starting point for extensions to more advanced channels. The paper concludes with a brief discussion of open problems
Genotyping of Cryptosporidium spp. isolated from human stool samples in Switzerland
No full textIn a study to estimate the frequency of Cryptosporidium infections in Switzerland, stool samples from patients found to be positive for Cryptosporidium spp. by modified Ziehl-Neelson staining and fluorescence microscopy were used for genotyping experiments. With 9 of 12 samples, DNA extraction and subsequent genotyping was successful. All Cryptosporidium-isolates belonged to the bovine genotype. In one stool sample, two strains of Cryptosporidium were demonstrated, suggesting a mixed infection. In comparison with reference strains from calves, one of the isolates showed a full sequence identity and the other a similarity of 97.5%. The fact that only bovine genotypes were detected suggests, that cryptosporidiosis must primarily be considered as a zoonotic disease in Switzerland. This is in contrast to other countries, where the human genotype of C. parvum was shown to dominate the epidemiological situation. The results of our study are supported by the previous finding, that two of the analysed strains originated from patients who used to consume raw milk or raw cream, a known risk factor for cryptosporidiosis
Memory Characterization Testing System
No full textabstract: This thesis outlines the hand-held memory characterization testing system that is to be created into a PCB (printed circuit board). The circuit is designed to apply voltages diagonally through a RRAM cell (32x32 memory array). The purpose of this sweep across the RRAM is to measure and calculate the high and low resistance state value over a specified amount of testing cycles. With each cell having a unique output of high and low resistance states a unique characterization of each RRAM cell is able to be developed. Once the memory is characterized, the specific RRAM cell that was tested is then able to be used in a varying amount of applications for different things based on its uniqueness. Due to an inability to procure a packaged RRAM cell, a Mock-RRAM was instead designed in order to emulate the same behavior found in a RRAM cell.
The final testing circuit and Mock-RRAM are varied and complex but come together to be able to produce a measured value of the high resistance and low resistance state. This is done by the Arduino autonomously digitizing the anode voltage, cathode voltage, and output voltage. A ramp voltage that sweeps from 1V to -1V is applied to the Mock-RRAM acting as an input. This ramp voltage is then later defined as the anode voltage which is just one of the two nodes connected to the Mock-RRAM. The cathode voltage is defined as the other node at which the voltage drops across the Mock-RRAM. Using these three voltages as input to the Arduino, the Mock-RRAM path resistance is able to be calculated at any given point in time. Conducting many test cycles and calculating the high and low resistance values allows for a graph to be developed of the chaotic variation of resistance state values over time. This chaotic variation can then be analyzed further in the future in order to better predict trends and characterize the RRAM cell that was tested.
Furthermore, the interchangeability of many devices on the PCB allows for the testing system to do more in the future. Ports have been added to the final PCB in order to connect a packaged RRAM cell. This will allow for the characterization of a real RRAM memory cell later down the line rather than a Mock-RRAM as emulation. Due to the autonomous testing, very few human intervention is needed which makes this board a great baseline for others in the future looking to add to it and collect larger pools of data
Exposure to indoor microbial agents, allergens and pets, and their relation to asthma and allergy prevalence in farmers' children and their peers from rural areas : Diploma thesis
No full textBackground In ‘westernised’ countries, the prevalence of childhood asthma and allergy have risen throughout the last three decades. Changes in lifestyle and environmental factors like an increase in exposure to air pollutants, environmental tobacco smoke, or indoor allergen and pet exposure have been considered as plausible explanations. However, little evidence in support of these causal risk factors for these common chronic childhood diseases has been found. Lower risk of hay fever and atopic sensitisation were reported in children with more siblings, and later also in children who attended day care centres early in infancy. These findings were summarised in the so-called ‘hygiene hypothesis’: limited exposure to bacterial and viral pathogens during early childhood results in a higher risk of developing allergic diseases. Recent allergy research has focused on the interaction between the innate and adaptive immunity: innate immunity receptors of pathogens seem to modulate the activation of adaptive immunity mechanisms. Three independent studies showed reduced prevalence of asthma and allergy among farmers’ children compared to their peers from the same rural areas from Switzerland, Austria, and Germany. A series of epidemiological studies in Europe, Canada, and Australia consistently confirmed and extended these findings. These results have been seen as an extension of the ‘hygiene hypothesis’, since a farm environment provides an enormous habitat for micro-organisms. A potential candidate that may explain these differences in the prevalence of childhood asthma and allergy is environmental exposure to endotoxin, a component of the outer membrane of gram-negative bacteria. Aim To assess the exposure to indoor microbial agents, allergens and pets in farmers’ children and their peers of non-farming families, and to estimate whether these exposures are associated with the prevalence of childhood asthma and allergies. Methods The ALEX (Allergy and Endotoxin) study was a cross-sectional survey in rural areas of Germany, Austria, and Switzerland. 2618 parents of 6-13 year-old children completed a standardised questionnaire including questions about asthma and allergy from the ISAAC study
and questions about the child’s activities on farms, and characteristics of the home environment.
Blood samples were obtained from selected children and tested for atopic sensitisation,
specially for specific IgE and IgG4 antibodies to grass pollen and cat allergen. Endotoxin and
cat allergen levels were measured in indoor dust samples and in settled dust from stables.
Complete data were available for 812 children. In a subgroup of 553 children mattress dust
muramic acid levels, another marker for exposure to bacteria, were determined.
Results
Higher levels of indoor endotoxin exposure were associated with reduced allergen sensitisation,
decreased prevalence of hay fever, atopic asthma and wheeze in a dose-dependent
manner. The associations were equally strong among the sub sample children from nonfarming
families, indicating that even lower levels of endotoxin may favourably influence the
risk of atopic diseases.
Endotoxin levels in stables were not correlated with the amount of endotoxin measured
indoors, but a dose-dependent association between the child’s activity on the farm and indoor
home endotoxin levels was observed, both in farmers’ and in non-farmers’ children. Pet keeping,
full time farming (compared to part time farming), and younger age of the children contributed
additionally to increased indoor endotoxin levels. Endotoxin levels in stables increased
with the number of cattle (but only up to the highest quartile), with hay feeding (compared
to feeding of mainly silage), and additionally with provision of accommodation of
horses, pigs, sheep or goats in the cattle stable. All these predictors might be surrogate measures
for traditional dairy farming in hilly German speaking areas.
Children’s mattress’ muramic acid levels were significantly higher in farmers’ children
than in non-farmers’ children. Mattress muramic acid and endotoxin levels were partially correlated,
indicating that both substances are markers for the exposure to micro-organisms. Independent
of being a farmers’ child, mattress dust from homes heated with wood or coal and
less frequently cleaned mattresses showed increasing muramic acid levels.
Independent of the endotoxin exposure, increasing muramic acid levels in mattress dust
was associated with a lower frequency of current wheeze, but not with atopic sensitisation or
hay fever. The protective effect on wheeze and diagnosed asthma was more pronounced in
non-sensitised children. The different effect spectrum for muramic acid and endotoxin exposure
suggest that different micro-organisms might contribute to the lower prevalence of
asthma and allergy among farmers’ children, compared to non-farmers’ children.
Current contact to dogs was inversely associated with diagnosed hay fever, asthma, and
specific sensitisation to grass pollen and to cat allergen, but not with increased IgG4 levels.
Early and current exposure to cats – but not to dogs – was associated with lower frequency of
wheeze and grass pollen sensitisation. None of these inverse associations were greatly affected
by additionally taking into account the indoor endotoxin or cat allergen levels, but additionally
adjustment for early or current exposure to farm animals attenuated the protective
effects. Although pet exposure was frequent in this rural population, the protective effects of
pet keeping observed in other peer-reviewed studies may be masked by frequent contact to
farming environments.
Conclusions and outlook
Endotoxin and muramic acid may be surrogate markers of a much broader spectrum of
microbial compounds. Thus, further studies have not only to confirm the lower risk of children
with contact to livestock or with higher exposure to micro-organisms early in life, but
also to find the relevant mixture of protective components in the farm dust. In addition, as
ingestion is another plausible route of exposure to micro-organisms, epidemiology may focus
on differences in nutrition and their association with childhood asthma and allergy. The PARSIFAL
(Prevention of allergy – Risk factors for sensitisation in children related to farming
and anthroposophic lifestyle) study offers the opportunity to do so, as this study include children’s
populations growing up with different lifestyles. Experimental studies may focus on
the relevant exposure route (inhalation, ingestion) of different patterns of micro-organisms.
The genetic dimension has to be kept in mind in the discussion of environmental exposure to
micro-organisms by identifying particularly sensitive groups through genetic investigations,
as the available data in the ALEX study was limited.
Current scientific evidence has not developed strongly enough to provide a reliable
course of action for primary prevention or therapy. Infectious diseases resulting from exposure
to pathogens continue to be a serious public health problem. Thus, the protective effect
of a microbial environment on the development of asthma and atopy should be balanced
against the benefits of established hygiene standards
Optimization of surface area loading rate for an anaerobic moving bed biofilm reactor treating brewery wastewater
No full textModelling the seasonal and spatial variation of malaria transmission in relation to mortality in Africa
No full textAbout three billion people worldwide are estimated to be at risk of malaria transmission. In developing countries, malaria is believed to be a major cause of morbidity and mortality, mostly in children under five years. It is among the indirect causes of maternal mortality and infants’ deaths due to low-birth-weights. Malaria brings huge economic burden due to number of days lost during sickness and deaths, sustaining a vicious cycle of disease and poverty in sub Saharan Africa (SSA) and high attribute of disability-adjusted life years.
A number of malaria control interventions to reduce intensity of transmission have been successfully implemented in the regions of SSA, however, elimination of malaria is still a dream in many developing countries today. Failures in global eradication are related to resistance in insecticides and anti-malarial drugs, and health systems related factors. The Roll Back Malaria (RBM) partnership reinforced new strategies to combat malaria with long-term goal of eradicating the disease globally. This was facilitated by increasing funding for malaria research, improve multi disciplinary initiatives and make malaria among the main agenda of all international health and development forums. The reduction in mortality, especially in children has been reported recently and is associated with achievements in intervention strategies, improvements in malaria diagnosis and treatment. However, poor natural acquisition of malaria immunity in children as a consequence of weak or no exposure is a major epidemiological concern and brings a fear of higher mortality rates or shifting of age of death to older children. Understanding and quantify links between transmission, intervention, immunity and mortality is key for sustainable progress towards malaria control targets.
A comprehensive analysis of information on malaria transmission, vital events, drivers of transmission and mortality-related risk factors is required to achieve that. Lack of vital registration systems in developing countries hinders availability of appropriate data to conduct such analysis. Establishment of Demographic Surveillance Systems (DSS) in many developing countries aims to fill these information gaps. One of the initiatives integrated within DSSs is the Malaria Transmission Intensity and Mortality Burden across Africa (MTIMBA) project. The project compiled a database of mosquito collections at selected sites in Africa over a large number of locations, using standardized methodologies for a period of three years. The entomological parameters were linked with routinely monitored vital events within the DSS. The MTIMBA database is the most comprehensive entomological database ever collected in Africa which allows studying spatial-temporal variation in malaria transmission in relation to mortality.
Malaria is an environmental disease hence transmission varies with climate as it modifies population, survival, distribution and infectivity of malaria vectors. Quantification of association between climate and transmission is important to allow prediction of risk even in areas that field data cannot be easily obtained. Development in geographical information systems (GIS) and availability of remote sensing (RS) data facilitates availability of environment and climate data at high space and time resolutions allowing accurate estimation of outcome-factor relationship.
However, DSS data are large, sparse, zero-inflated and are characterized by seasonal patterns, spatial and temporal correlations. Standard models assume independence between observations, an assumption which do not hold for correlated data, hence utilizing these models might result into biased estimates. Geostatistical modeling of large, sparse and zero inflated space-time data is computational challenging specifically in the estimation of the spatial processes. The spatial correlation is accounted by introducing location-specific random effect parameters which are assumed to arise from a spatial process quantified by a multivariate normal distribution. The models are highly parameterized and their fit is computationally intensive. Bayesian computational algorithms such as Markov Chain Monte Carlo (MCMC) can be used to fit these models. Estimation of the spatial process requires inversion of the covariance matrix at each simulation point. The dimension of the matrix increases exponentially with number of locations and the inversion becomes infeasible when the size is too large. Recent techniques overcome this problem by approximating the spatial process from a subset of locations. These methods have been applied on Gaussian outcomes observed over a grid. Extension and formulation of rigorous methods to efficient model MTIMBA data are needed to allow precise prediction of malaria transmission at locations with mortality data to enhance studying the association. Lastly, seasonality in climatic conditions which introduces seasonal patterns in transmission and mortality data, should be accounted for when modelling such data.
The objectives of this thesis were to i) develop Bayesian geostatistical models to analyze very large and sparse geostatistical and temporal non-Gaussian data with seasonal patterns and ii) apply these models to (a) estimate space-time heterogeneity in malaria transmission (b) assess mortality variations between different ages during the first year of life while adjusting for seasonality and (c) determine the relation between transmission intensity and risk of mortality in children and adult population after taking into account control interventions. This work used an extract of MTIMBA data from the Rufiji DSS (RDSS) collected between October 2001 and September 2004.
Evaluation of approaches to capture seasonal pattern is discussed in Chapter 2 and applied to estimate mortality peaks at different stages of infant life. In Chapter 3, models approximating the spatial process from a subset of locations were developed to assess effect of climate, seasonal and spatial pattern of sporozoite rate (SR) of An. funestus and An. gambiae in RDSS. A rigorous approach to analyze malaria transmission data using Entomology Inoculation Rate (EIR) data, which is the product of mosquito density and SR, is discussed in Chapter 4. Zero-inflated models were used to account for over-dispersion and zero-inflation in the data. High resolution EIR estimates were produced for the RDSS. Exposure surfaces obtained in Chapter 4, were aligned with mortality events to assess the relationship between all-cause mortality and malaria transmission. Geostatistical Bernoulli discrete-time regression models adjusted for age and ITN possession were used for that analysis. The results of these analyses are presented in Chapters 5 and 6. The EIR was incorporated in the model as a covariate with measure of uncertainty.
This work is a building block on the insight and understanding of association between malaria transmission and all-cause mortality. The strength of results of this work relies on EIR estimates predicted at high spatial (household level) and temporal resolution by employing rigorous geostatistical models fitted on large entomological data. The better exposure estimates obtained are able to more accurately estimate the mortality-transmission relation
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