Photocatalytic Activity: Experimental Features to Report in Heterogeneous Photocatalysis

Heterogeneous photocatalysis is a prominent area of research with major applications in solar energy conversion, air pollution mitigation, and removal of contaminants from water. A large number of scientific papers related to the photocatalysis field and its environmental applications are published in different journals specializing in materials and nanomaterials. However, many problems exist in the conception of papers by authors unfamiliar with standard characterization methods of photocatalysts as well as with the procedures needed to determine photocatalytic activities based on the determination of “apparent quantum efficiencies” within a wavelength interval or “apparent quantum yields” in the case of using monochromatic light. In this regard, an astonishing number of recent research articles include claims of highly efficient (photo)catalysts or similar terms about materials with superior or enhanced efficiency for a given reaction without proper experimental support. Consequently, the comparison of the efficiencies of photocatalysts may result as being meaningless, especially when reports are only based on expressions determining (1) a reaction rate per weight of catalyst or its surface area, (2) quantum efficiencies or quantum yields, and (3) turnover frequencies or turnover numbers. Herein, we summarize the standards needed for reporting valuable data in photocatalysis and highlight some common discrepancies found in the literature. This work should inform researchers interested in reporting photocatalysis projects about the correct procedures for collecting experimental data and properly characterizing the materials by providing examples and key supporting literature

Knowing the price of everything? Exploring the impact of increased procurement professional involvement on management consultancy purchasing

Much of the estimated $554 billion annual expenditure on management consultancy services is accounted for by projects with a direct link to client profitability. As such, it is critical for clients (and arguably the wider economy) that the purchase process for such services is managed effectively. For many within the management consultancy literature, this requires close, bilateral buy-side service end-user / supplier engagement. In recent years, however, this bilateral engagement has been modified by a significant increase in procurement professional involvement. This has caused concern within the management consultancy literature as it is believed it will inevitably lead to a cost-focused approach that disrupts close end-user / supplier engagement and causes sub-standard service outcomes. In this paper, we explore, via qualitative research, whether this concern is justified. In the event, the analysis suggested partial justification. However, examples of positive procurement involvement were also reported, suggesting that existing models and assumptions within the management consultancy literature regarding the impact of increased procurement involvement require modification

LCSA Framework for Assessing Sustainability of Alternative Fuels for Transport Sector

Consideration of alternative transport fuels, produced from feedstocks and renewable resources, is inevitable to enhance energy security and alleviate environmental burdens. Whilst these fuels are apparently considered to be clean, they may not be entirely sustainable from economic, environmental and social perspectives. A Life Cycle Sustainability Assessment (LCSA) framework that integrates all three components of the Triple Bottom Line (TBL) sustainability can potentially be used to evaluate the sustainability performance of fuels from well to wheel. This paper presents an LCSA framework consisting of Environmental Life Cycle Assessment (ELCA), Life Cycle Cost (LCC) and Social Life Cycle Assessment (SLCA) tools to assess the environmental, economic and social performance of alternative fuels. The framework is aimed at identifying the areas that require improvements for overall sustainability performance. The proposed framework provides a comprehensive basis that considers the region-specific variations in the life cycle data pertaining to alternative fuels. The added feature of the framework is its robustness to accommodate variations in natural resources, and other regional issues, such as socio-economic and demographic changes. The framework has been tested using a hypothetical example of canola-based biodiesel

Anisotropic nonlinear elasticity in a spherical bead pack: influence of the fabric anisotropy

Stress-strain measurements and ultrasound propagation experiments in glass bead packs have been simultaneously conducted to characterize the stress-induced anisotropy under uniaxial loading. These measurements, realized respectively with finite and incremental deformations of the granular assembly, are analyzed within the framework of the effective medium theory based on the Hertz-Mindlin contact theory. Our work shows that both compressional and shear wave velocities and consequently the incremental elastic moduli agree fairly well with the effective medium model by Johnson et al. [J. Appl. Mech. 65, 380 (1998)], but the anisotropic stress ratio resulting from finite deformation does not at all. As indicated by numerical simulations, the discrepancy may arise from the fact that the model doesn't properly allow the grains to relax from the affine motion approximation. Here we find that the interaction nature at the grain contact could also play a crucial role for the relevant prediction by the model; indeed, such discrepancy can be significantly reduced if the frictional resistance between grains is removed. Another main experimental finding is the influence of the inherent anisotropy of granular packs, realized by different protocols of the sample preparation. Our results reveal that compressional waves are more sensitive to the stress-induced anisotropy, whereas the shear waves are more sensitive to the fabric anisotropy, not being accounted in analytical effective medium models.Comment: 9 pages, 8 figure

Uterine arteriovenous malformation: a rare cause of abnormal uterine bleeding

Uterine arteriovenous malformation (AVM) is a rare gynecological entity that usually presents with vaginal bleeding of variable spectrum. High level of suspicion aided by color Doppler ultrasound is needed to confirm the diagnosis. This case report describes a 52-year-old woman G7P6A1 who presented with irregular pervaginal bleeding for 5 years. Her symptom was recurrent, on and off and refractory to hormone therapy. She was diagnosed with uterine AVM on pelvic color Doppler ultrasound that revealed a dilated and hypervascular cystic mass of 6.2×4.1 cm located at right uterine wall where blood flow was bidirectional. As a definitive treatment, open abdominal hysterectomy was performed successfully. This report reminds gynecologists to consider uterine AVM as a rare differential diagnosis of abnormal uterine bleeding (AUB)

Long-Term Genomic and Epigenomic Dysregulation as a Consequence of Prenatal Alcohol Exposure: A Model for Fetal Alcohol Spectrum Disorders

There is abundant evidence that prenatal alcohol exposure leads to a range of behavioral and cognitive impairments, categorized under the term fetal alcohol spectrum disorders (FASDs). These disorders are pervasive in Western cultures and represent the most common preventable source of neurodevelopmental disabilities. The genetic and epigenetic etiology of these phenotypes, including those factors that may maintain these phenotypes throughout the lifetime of an affected individual, has become a recent topic of investigation. This review integrates recent data that has progressed our understanding FASD as a continuum of molecular events, beginning with cellular stress response and ending with a long-term footprint of epigenetic dysregulation across the genome. It reports on data from multiple ethanol-treatment paradigms in mouse models that identify changes in gene expression that occur with respect to neurodevelopmental timing of exposure and ethanol dose. These studies have identified patterns of genomic alteration that are dependent on the biological processes occurring at the time of ethanol exposure. This review also adds to evidence that epigenetic processes such as DNA methylation, histone modifications, and non-coding RNA regulation may underlie long-term changes to gene expression patterns. These may be initiated by ethanol-induced alterations to DNA and histone methylation, particularly in imprinted regions of the genome, affecting transcription which is further fine-tuned by altered microRNA expression. These processes are likely complex, genome-wide, and interrelated. The proposed model suggests a potential for intervention, given that epigenetic changes are malleable and may be altered by postnatal environment. This review accentuates the value of mouse models in deciphering the molecular etiology of FASD, including those processes that may provide a target for the ammelioration of this common yet entirely preventable disorder

Access to safe drining water and availability of environmental sanitation facilities among Dukem town households in Ethiopia

The objective of this study was to assess the accessibility of water and environmental sanitation amongst households of Dukem town in Ethiopia. This was a cross-sectional study conducted among 391 households. Almost all the households had access to improved sources of drinking water. Majority of the households had access to water within a distance of up to 200 metres or less and had access to water within a time of 30 minutes or less. More than two-thirds of households had improved toilets (flush/pour-flush toilet, ventilated improved pit (VIP) latrine and traditional pit latrine). It is important to make water available by supplying with private or yard tap connections for underserved population and improved basic sanitation by promoting Total Sanitation Approach which aims to achieve universal access and use of toilets and the elimination of open defecation in the communities.NoneHealth Studie