An experimental study of greywater irrigated green roof systems in an arid climate

Green roofs provide multi-functional benefits to the built environment. They minimize urban heat island effects, enhance biodiversity, reduce carbon footprints, provide hydraulic benefits to urban runoff, and improve overall environmental sustainability. However, their application is limited or rare in arid climates. On the other hand, greywater is becoming a popular alternative water resource in water-scarce regions. A greywater-fed green roof system was developed and studied in the city of Al Ain, United Arab Emirates (UAE). The effluent (treated greywater) from the green roofs can be used to irrigate amenity plantations. Two intensive and two extensive green roof prototypes were constructed, planted with reed canary grass (Phalaris arundinacea L.), and irrigated with greywater. The greywater influents and the green roof effluents were monitored for changes in greywater quality. The study showed that the intensive system performed well, which is attributable to the greater depth of soil media. Treated greywater effluent from the green roofs met the local standards for recycled wastewater-based irrigation for a number of parameters (pH, electrical conductivity, salinity, and total dissolved solids), but exceeded the maximum allowable limits for turbidity, COD, and sodium ions (Na+), which may be because of the short retention time of the experiment. Both the intensive and the extensive systems were inefficient in reducing the total bacterial count of the greywater

Quadratic optimal functional quantization of stochastic processes and numerical applications

In this paper, we present an overview of the recent developments of functional quantization of stochastic processes, with an emphasis on the quadratic case. Functional quantization is a way to approximate a process, viewed as a Hilbert-valued random variable, using a nearest neighbour projection on a finite codebook. A special emphasis is made on the computational aspects and the numerical applications, in particular the pricing of some path-dependent European options.Comment: 41 page

Greywater quality changes in laboratory scale vegetative biofiltration prototypes

Greywater recycling and reuse is becoming a popular choice in many water-scarce regions. Greywater is the largest component of domestic indoor wastewater. However, in many arid regions, including the United Arab Emirates (UAE), this unconventional resource is under-utilized. Although, traditionally, a biofiltration system operates using stormwater, findings have shown that the operation of biofiltration systems in arid regions can be successful using greywater. This research endeavors to assess how the quality of the effluent from a biofiltration system changes with different vegetation, both native and introduced to the arid region (UAE). The prototype biofilters, planted with twelve ornamental plant species, were irrigated daily with an equal amount of synthetic greywater and the water quality parameters were monitored on a weekly basis. Analysis of variance (ANOVA) was performed in order to statistically evaluate the consistency of results between the three replicates of each of the twelve species and, subsequently, the variation of treatment effectiveness among the twelve species with respect to eight water quality parameters. Most of the plants show a high degree of consistency between replicates; however, significant differences were observed across the selected plant species. The species Ficus nitida and Canna indica performed well in reducing pH. Except in the earlier stages of the experiment, all the systems were found to reduce turbidity by almost 100%. Overall, it was observed that Ficus nitida, Canna indica and Pennisetum setaceum performed well to improve greywater quality in the biofiltration columns

Floods and health in Gambella region, Ethiopia: a qualitative assessment of the strengths and weaknesses of coping mechanisms

BACKGROUND: Floods are the most frequent and devastating type of natural disaster worldwide, causing unprecedented deaths, diseases, and destruction of property and crops. Flooding has a greater impact in developing countries due to lack of sufficient disaster management structures and a lack of economic resources. OBJECTIVE: This study was conducted with the aim of contributing to the knowledge base of development strategies that reduce flood-related health risks in developing countries. The study focused particularly on assessing the flood risks and health-related issues in the Gambella region of Ethiopia; with the intent of producing relevant information to assist with the improvements in the efficacy of the current flood coping strategies in the region. METHODS: Data were gathered through interviews with 14 officers from different government and non-governmental organizations and a questionnaire survey given to 35 flood victims in Itang woreda. A qualitative approach was applied and the data were analyzed using content analysis. RESULTS: It was found that flooding is a common problem in Gambella region. The findings also indicate that the flood frequency and magnitude has increased rapidly during the last decade. The increase in floods was driven mainly by climate change and changes in land use, specifically deforestation. The reported main impacts of flooding on human health in Gambella region were deaths, injuries, and diseases such as malaria and diarrhea. Another notable consequence of flooding was crop destruction and subsequent malnutrition. CONCLUSIONS: Three weaknesses that were identified in the current coping strategies for flood-related health impacts in Gambella region were a lack of flood-specific policy, absence of risk assessment, and weak institutional capacity. This study recommends new policy approaches that will increase the effectiveness of the current flood coping strategies to sustainably address the impact of flooding on human health

Mechanisms of Hearing Loss after Blast Injury to the Ear

Given the frequent use of improvised explosive devices (IEDs) around the world, the study of traumatic blast injuries is of increasing interest. The ear is the most common organ affected by blast injury because it is the bodyﾒs most sensitive pressure transducer. We fabricated a blast chamber to re-create blast profiles similar to that of IEDs and used it to develop a reproducible mouse model to study blast-induced hearing loss. The tympanic membrane was perforated in all mice after blast exposure and found to heal spontaneously. Micro-computed tomography demonstrated no evidence for middle ear or otic capsule injuries; however, the healed tympanic membrane was thickened. Auditory brainstem response and distortion product otoacoustic emission threshold shifts were found to be correlated with blast intensity. As well, these threshold shifts were larger than those found in control mice that underwent surgical perforation of their tympanic membranes, indicating cochlear trauma. Histological studies one week and three months after the blast demonstrated no disruption or damage to the intra-cochlear membranes. However, there was loss of outer hair cells (OHCs) within the basal turn of the cochlea and decreased spiral ganglion neurons (SGNs) and afferent nerve synapses. Using our mouse model that recapitulates human IED exposure, our results identify that the mechanisms underlying blast-induced hearing loss does not include gross membranous rupture as is commonly believed. Instead, there is both OHC and SGN loss that produce auditory dysfunction

Auditory cortex activation to natural speech and simulated cochlear implant speech measured with functional near-infrared spectroscopy

The primary goal of most cochlear implant procedures is to improve a patient’s ability to discriminate speech. To accomplish this, cochlear implants are programmed so as to maximize speech understanding. However, programming a cochlear implant can be an iterative, labor-intensive process that takes place over months. In this study, we sought to determine whether functional near-infrared spectroscopy (fNIRS), a non-invasive neuroimaging method which is safe to use repeatedly and for extended periods of time, can provide an objective measure of whether a subject is hearing normal speech or distorted speech. We used a 140 channel fNIRS system to measure activation within the auditory cortex in 19 normal hearing subjects while they listed to speech with different levels of intelligibility. Custom software was developed to analyze the data and compute topographic maps from the measured changes in oxyhemoglobin and deoxyhemoglobin concentration. Normal speech reliably evoked the strongest responses within the auditory cortex. Distorted speech produced less region-specific cortical activation. Environmental sounds were used as a control, and they produced the least cortical activation. These data collected using fNIRS are consistent with the fMRI literature and thus demonstrate the feasibility of using this technique to objectively detect differences in cortical responses to speech of different intelligibility

Contentment among religious individuals: An exploratory factor analysis

This present study aimed to explore the experience of contentment among religious priests and nuns. An exploratory factor analysis (EFA) was conducted on the responses of 358 religious individuals on a 100-item questionnaire, developed from interviews conducted with 29 religious individuals on how they experience contentment in their lives. Results suggest that a four-factor structure– characterized by pursuing purpose, accepting and actualizing self, belonging in the community, and receiving affirmation from others– describe the experience and components of contentment among religious. Limitations of the study and suggestions for future directions are also discussed

Removal of Heavy Metals in Vegetative Graywater Biofiltration Columns

This study investigates the performance of laboratory-scale vegetative biofiltration systems in reducing five heavy metals [cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn)] from synthetic graywater. Thirty-six biofiltration columns of the same design were constructed, and twelve species of ornamental plants were planted, with three specimens from each species being planted in a single column. The study was conducted for six months in an arid climate. The overall removal efficiency for Zn and Cu was found to be about 98% and 75%, respectively. It was observed that soil Zn and Cu concentrations increased from 11.24 to 26.13 mg/L and from 11.09 to 12.12 mg/L, respectively, after irrigation with graywater. Zn and Cu were mainly removed by soil accumulation and plant uptake, respectively. Both Pb and Cr increased in effluent (about 29% and 6.5%, respectively) and in soil (about 12% and 63%, respectively) after irrigation with graywater, whereas Cd increased in effluent (about 7.6%) but decreased in soil (about 46%). Finally, the plants were ranked and recommended for application based on their performance consistency and effectiveness. The species Alternanthera ficondea topped the ranking, followed by the species Ixora coccinaea, Vitex agnus, Rhoeo discolor, and Jasmine sambac